Sample records for acids lysine arginine

  1. Arginine and Lysine Transporters Are Essential for Trypanosoma brucei.

    PubMed

    Mathieu, Christoph; Macêdo, Juan P; Hürlimann, Daniel; Wirdnam, Corina; Haindrich, Alexander C; Suter Grotemeyer, Marianne; González-Salgado, Amaia; Schmidt, Remo S; Inbar, Ehud; Mäser, Pascal; Bütikofer, Peter; Zilberstein, Dan; Rentsch, Doris

    2017-01-01

    For Trypanosoma brucei arginine and lysine are essential amino acids and therefore have to be imported from the host. Heterologous expression in Saccharomyces cerevisiae mutants identified cationic amino acid transporters among members of the T. brucei AAAP (amino acid/auxin permease) family. TbAAT5-3 showed high affinity arginine uptake (Km 3.6 ± 0.4 μM) and high selectivity for L-arginine. L-arginine transport was reduced by a 10-times excess of L-arginine, homo-arginine, canavanine or arginine-β-naphthylamide, while lysine was inhibitory only at 100-times excess, and histidine or ornithine did not reduce arginine uptake rates significantly. TbAAT16-1 is a high affinity (Km 4.3 ± 0.5 μM) and highly selective L-lysine transporter and of the compounds tested, only L-lysine and thialysine were competing for L-lysine uptake. TbAAT5-3 and TbAAT16-1 are expressed in both procyclic and bloodstream form T. brucei and cMyc-tagged proteins indicate localization at the plasma membrane. RNAi-mediated down-regulation of TbAAT5 and TbAAT16 in bloodstream form trypanosomes resulted in growth arrest, demonstrating that TbAAT5-mediated arginine and TbAAT16-mediated lysine transport are essential for T. brucei. Growth of induced RNAi lines could partially be rescued by supplementing a surplus of arginine or lysine, respectively, while addition of both amino acids was less efficient. Single and double RNAi lines indicate that additional low affinity uptake systems for arginine and lysine are present in T. brucei.

  2. Arginine and Lysine Transporters Are Essential for Trypanosoma brucei

    PubMed Central

    Hürlimann, Daniel; Wirdnam, Corina; Haindrich, Alexander C.; Suter Grotemeyer, Marianne; González-Salgado, Amaia; Schmidt, Remo S.; Inbar, Ehud; Mäser, Pascal; Bütikofer, Peter; Zilberstein, Dan; Rentsch, Doris

    2017-01-01

    For Trypanosoma brucei arginine and lysine are essential amino acids and therefore have to be imported from the host. Heterologous expression in Saccharomyces cerevisiae mutants identified cationic amino acid transporters among members of the T. brucei AAAP (amino acid/auxin permease) family. TbAAT5-3 showed high affinity arginine uptake (Km 3.6 ± 0.4 μM) and high selectivity for L-arginine. L-arginine transport was reduced by a 10-times excess of L-arginine, homo-arginine, canavanine or arginine-β-naphthylamide, while lysine was inhibitory only at 100-times excess, and histidine or ornithine did not reduce arginine uptake rates significantly. TbAAT16-1 is a high affinity (Km 4.3 ± 0.5 μM) and highly selective L-lysine transporter and of the compounds tested, only L-lysine and thialysine were competing for L-lysine uptake. TbAAT5-3 and TbAAT16-1 are expressed in both procyclic and bloodstream form T. brucei and cMyc-tagged proteins indicate localization at the plasma membrane. RNAi-mediated down-regulation of TbAAT5 and TbAAT16 in bloodstream form trypanosomes resulted in growth arrest, demonstrating that TbAAT5-mediated arginine and TbAAT16-mediated lysine transport are essential for T. brucei. Growth of induced RNAi lines could partially be rescued by supplementing a surplus of arginine or lysine, respectively, while addition of both amino acids was less efficient. Single and double RNAi lines indicate that additional low affinity uptake systems for arginine and lysine are present in T. brucei. PMID:28045943

  3. Study on mutual interactions and electronic structures of hyaluronan with Lysine, 6-Aminocaproic acid and Arginine.

    PubMed

    Chytil, Martin; Trojan, Martin; Kovalenko, Alexander

    2016-05-20

    Interactions between polyelectrolytes and oppositely charged surfactants have been in a great interest for several decades, yet the conventional surfactants may cause a problem in medical applications. Interactivity between polysaccharide hyaluronan (HA) and amino acids Lysine, 6-Aminocaproic acid (6-AcA), and Arginine as an alternative system is reported. The interactions were investigated by means of rheology and electric conductance and the electronic structures were explored by the density functional theory (DFT). Lysine exhibits the strongest interaction of all, which was manifested, e.g. by nearly 6-time drop of the initial viscosity comparing with only 1.3-time lower value in the case of 6-AcA. Arginine interaction with HA was surprisingly weaker in terms of viscosity than that of Lysine due to a lower and delocalized charge density on its guanidine group. According to the DFT calculations, the binding of Lysine to HA was found to be more flexible, while Arginine creates more rigid structure with HA. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Complementary dietary treatment using lysine-free, arginine-fortified amino acid supplements in glutaric aciduria type I - A decade of experience.

    PubMed

    Kölker, Stefan; Boy, S P Nikolas; Heringer, Jana; Müller, Edith; Maier, Esther M; Ensenauer, Regina; Mühlhausen, Chris; Schlune, Andrea; Greenberg, Cheryl R; Koeller, David M; Hoffmann, Georg F; Haege, Gisela; Burgard, Peter

    2012-09-01

    The cerebral formation and entrapment of neurotoxic dicarboxylic metabolites (glutaryl-CoA, glutaric and 3-hydroxyglutaric acid) are considered to be important pathomechanisms of striatal injury in glutaric aciduria type I (GA-I). The quantitatively most important precursor of these metabolites is lysine. Recommended therapeutic interventions aim to reduce lysine oxidation (low lysine diet, emergency treatment to minimize catabolism) and to enhance physiologic detoxification of glutaryl-CoA via formation of glutarylcarnitine (carnitine supplementation). It has been recently shown in Gcdh(-/-) mice that cerebral lysine influx and oxidation can be modulated by arginine which competes with lysine for transport at the blood-brain barrier and the inner mitochondrial membrane [Sauer et al., Brain 134 (2011) 157-170]. Furthermore, short-term outcome of 12 children receiving arginine-fortified diet showed very promising results [Strauss et al., Mol. Genet. Metab. 104 (2011) 93-106]. Since lysine-free, arginine-fortified amino acid supplements (AAS) are commercially available and used in Germany for more than a decade, we evaluated the effect of arginine supplementation in a cohort of 34 neonatally diagnosed GA-I patients (median age, 7.43 years; cumulative follow-up period, 221.6 patient years) who received metabolic treatment according to a published guideline [Kölker et al., J. Inherit. Metab. Dis. 30 (2007) 5-22]. Patients used one of two AAS product lines during the first year of life, resulting in differences in arginine consumption [group 1 (Milupa Metabolics): mean=111 mg arginine/kg; group 2 (Nutricia): mean=145 mg arginine/kg; p<0.001]. However, in both groups the daily arginine intake was increased (mean, 137 mg/kg body weight) and the dietary lysine-to-arginine ratio was decreased (mean, 0.7) compared to infants receiving human milk and other natural foods only. All other dietary parameters were in the same range. Despite significantly different arginine intake

  5. A comparison of DNA compaction by arginine and lysine peptides: A physical basis for arginine rich protamines

    PubMed Central

    DeRouchey, Jason; Hoover, Brandon

    2013-01-01

    Protamines are small, highly positively charged peptides used to package DNA to very high densities in sperm nuclei. Tight DNA packing is considered essential to minimize DNA damage by mutagens and reactive oxidizing species. A striking and general feature of protamines is the almost exclusive use of arginine over lysine for the positive charge to neutralize DNA. We have investigated whether this preference for arginine might arise from a difference in DNA condensation by arginine and lysine peptides. The forces underlying DNA compaction by arginine, lysine, and ornithine peptides are measured using the osmotic stress technique coupled with x-ray scattering. The equilibrium spacings between DNA helices condensed by lysine and ornithine peptides are significantly larger than the interhelical distances with comparable arginine peptides. The DNA surface-to-surface separation, for example, is some 50% larger with poly-lysine compared to poly-arginine. DNA packing by lysine rich peptides in sperm nuclei would allow much greater accessibility to small molecules that could damage DNA. The larger spacing with lysine peptides is due to both a weaker attraction and a stronger short ranged repulsion relative to the arginine peptides. A previously proposed model for poly-arginine and protamine binding to DNA provides a convenient framework for understanding the differences between the ability of lysine and arginine peptides to assemble DNA. PMID:23540557

  6. Tracking the behavior of Maillard browning in lysine/arginine-sugar model systems under high hydrostatic pressure.

    PubMed

    Ma, Xiao-Juan; Gao, Jin-Yan; Tong, Ping; Li, Xin; Chen, Hong-Bing

    2017-12-01

    High-pressure processing is gaining popularity in the food industry. However, its effect on the Maillard reaction during high-pressure-assisted pasteurization and sterilization is not well documented. This study aimed to investigate the effects of high hydrostatic pressure on the Maillard reaction during these processes using amino acid (lysine or arginine)-sugar (glucose or fructose) solution models. High pressure retarded the intermediate and final stages of the Maillard reaction in the lysine-sugar model. For the lysine-glucose model, the degradation rate of Amadori compounds was decelerated, while acceleration was observed in the arginine-sugar model. Increased temperature not only accelerated the Maillard reaction over time but also formed fluorescent compounds with different emission wavelengths. Lysine reacted with the sugars more readily than arginine under the same conditions. In addition, it was easier for lysine to react with glucose, whereas arginine reacted more readily with fructose under high pressure. High pressure exerts different effects on lysine-sugar and arginine-sugar models. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Synthesis and characterization of arginine-glycine-aspartic peptides conjugated poly(lactic acid-co-L-lysine) diblock copolymer.

    PubMed

    Yu, Hui; Guo, Xiaojuan; Qi, Xueliang; Liu, Peifeng; Shen, Xinyuan; Duan, Yourong

    2008-03-01

    A biodegradable Copolymer of poly(lactic acid-co-lysine)(PLA-PLL) was synthesized by a modified method and novel Arginine-Glycine-Aspartic (RGD) peptides were chemical conjugated to the primary epsilon-amine groups of lysine components in four steps: I to prepare the monomer of 3-(Nepsilon-benzoxycarbonyl-L-lysine)-6-L-methyl-2,5-morpholinedione; II to prepare diblock copolymer poly(lactic acid-co-(Z)-L-lysine) (PLA-PLL(Z)) by ring-opening polymerization of monomer and L,L-lactide with stannous octoate as initiator; III to prepare diblock copolymer PLA-PLL by deprotected the copolymer PLA-PLL(Z) in HBr/HoAc solution; IV the reaction between RGD and the primary epsilon-amine groups of the PLA-PLL. The structure of PLA-PLL-RGD and its precursors were conformed by FTIR-Raman and 1H NMR. Low weight average molecular weight (9,200 g/mol) of the PLA-PLL was obtained and its PDI is 1.33 determined by GPC. The PLA-PLL contained 2.1 mol% lysine groups as determined by 1H NMR using the lysine protecting group's phenyl protons. Therefore, the novel RGD-grafted diblock copolymer is expected to find application in drug carriers for tumor therapy or non-viral DNA carriers for gene therapy.

  8. Interaction of arginine, lysine, and guanidine with surface residues of lysozyme: implication to protein stability.

    PubMed

    Shah, Dhawal; Shaikh, Abdul Rajjak

    2016-01-01

    Additives are widely used to suppress aggregation of therapeutic proteins. However, the molecular mechanisms of effect of additives to stabilize proteins are still unclear. To understand this, we herein perform molecular dynamics simulations of lysozyme in the presence of three commonly used additives: arginine, lysine, and guanidine. These additives have different effects on stability of proteins and have different structures with some similarities; arginine and lysine have aliphatic side chain, while arginine has a guanidinium group. We analyze atomic contact frequencies to study the interactions of the additives with individual residues of lysozyme. Contact coefficient, quantified from contact frequencies, is helpful in analyzing the interactions with the guanidine groups as well as aliphatic side chains of arginine and lysine. Strong preference for contacts to the additives (over water) is seen for the acidic followed by polar and the aromatic residues. Further analysis suggests that the hydration layer around the protein surface is depleted more in the presence of arginine, followed by lysine and guanidine. Molecular dynamics simulations also reveal that the internal dynamics of protein, as indicated by the lifetimes of the hydrogen bonds within the protein, changes depending on the additives. Particularly, we note that the side-chain hydrogen-bonding patterns within the protein differ with the additives, with several side-chain hydrogen bonds missing in the presence of guanidine. These results collectively indicate that the aliphatic chain of arginine and lysine plays a critical role in the stabilization of the protein.

  9. Polydiacetylenyl β-cyclodextrin based smart vesicles for colorimetric assay of arginine and lysine

    NASA Astrophysics Data System (ADS)

    Cho, Eunae; Kim, Hwanhee; Choi, Youngjin; Paik, Seung R.; Jung, Seunho

    2016-08-01

    Selective visualization of arginine and lysine has been explored among 20 amino acids using the hybrid conjugate of β-cyclodextrin (β-CD) and polydiacetylene (PDA). The mono pentacosa-10,12-diynyl aminomethyl group was successfully coupled to either the primary or the secondary face of β-CD, where mono-6-amino-6-deoxy-β-CD or mono-3-amino-3-deoxy-β-CD reacted with the N-hydroxysuccinimide ester of 10,12-pentacosadiynoic acid. In this combinatorial system, the cylindrical β-cyclodextrin functions as a channel for the introduction of the cationic amino acids to the artificial membrane. The membrane perturbation and aggregation by the target amino acids could be exclusively visualized as a blue to red color change based on the responsive polydiacetylene domain. These interesting findings demonstrated that the developed β-CD conjugated PDA system may offer a new method of cell-penetrating mechanism, a promising vector system, as well as impact the production industry of arginine or lysine.

  10. A Study on the Effect of Surface Lysine to Arginine Mutagenesis on Protein Stability and Structure Using Green Fluorescent Protein

    PubMed Central

    Sokalingam, Sriram; Raghunathan, Govindan; Soundrarajan, Nagasundarapandian; Lee, Sun-Gu

    2012-01-01

    Two positively charged basic amino acids, arginine and lysine, are mostly exposed to protein surface, and play important roles in protein stability by forming electrostatic interactions. In particular, the guanidinium group of arginine allows interactions in three possible directions, which enables arginine to form a larger number of electrostatic interactions compared to lysine. The higher pKa of the basic residue in arginine may also generate more stable ionic interactions than lysine. This paper reports an investigation whether the advantageous properties of arginine over lysine can be utilized to enhance protein stability. A variant of green fluorescent protein (GFP) was created by mutating the maximum possible number of lysine residues on the surface to arginines while retaining the activity. When the stability of the variant was examined under a range of denaturing conditions, the variant was relatively more stable compared to control GFP in the presence of chemical denaturants such as urea, alkaline pH and ionic detergents, but the thermal stability of the protein was not changed. The modeled structure of the variant indicated putative new salt bridges and hydrogen bond interactions that help improve the rigidity of the protein against different chemical denaturants. Structural analyses of the electrostatic interactions also confirmed that the geometric properties of the guanidinium group in arginine had such effects. On the other hand, the altered electrostatic interactions induced by the mutagenesis of surface lysines to arginines adversely affected protein folding, which decreased the productivity of the functional form of the variant. These results suggest that the surface lysine mutagenesis to arginines can be considered one of the parameters in protein stability engineering. PMID:22792305

  11. Neurohypophyseal hormones as evolutionary tracers: identification of oxytocin, lysine vasopressin, and arginine vasopressin in two South American opossums (Didelphis marsupialis and Philander opossum).

    PubMed

    Chauvet, J; Hurpet, D; Colne, T; Michel, G; Chauvet, M T; Acher, R

    1985-02-01

    The neurohypophyseal hormones of two South American opossums (Didelphis marsupialis and Philander opossum) were isolated by molecular sieving and preparative high-pressure liquid chromatography (HPLC). One oxytocin-like and two vasopressin-like peptides were found in each species. These peptides have been identified by their amino acid composition and by their retention time in HPLC. Oxytocin, lysine vasopressin, and arginine vasopressin have been characterized in both species. Lysine vasopressin is roughly as abundant as arginine vasopressin. Comparison is made with Australian marsupials Macropodidae and Phalangeridae, and possible evolutionary mechanisms are discussed.

  12. Quantitative microspectral evaluation of the ratio of arginine-rich to lysine-rich histones in neurons and neuroglial cells.

    PubMed

    Pevzner, L Z; Raygorodskaya, T G; Agroskin, L S

    1978-09-01

    Staining of nervous tissue sections with ammoniacal silver according to Black et al. has been confirmed to be a reliable histochemical colour reaction for quantitative evaluation of arginine-rich and lysine-rich histones in cell structures on the basis of determinations of the position of spectral curve maximum. Neurons of several brain nuclei which differed in predominating neurotransmitter did not differ in the ratio of arginine-rich to lysine-rich histones while some differences in this ratio were found out in the glial satelite cells adjacent to the corresponding neurons of these nuclei. Moderate circadian fluctuations were observed in the arginine-rich to lysine-rich histone ratio, these fluctuations being rather similar in the neurons studied and in the cells of perineuronal neuroglia.

  13. Selection of tRNA(Asp) amber suppressor mutants having alanine, arginine, glutamine, and lysine identity.

    PubMed Central

    Martin, F; Reinbolt, J; Dirheimer, G; Gangloff, J; Eriani, G

    1996-01-01

    Elements that confer identity to a tRNA in the cellular environment, where all aminoacyl-tRNA synthetases are competing for substrates, may be delineated by in vivo experiments using suppressor tRNAs. Here we describe the selection of active Escherichia coli tRNAAsp amber mutants and analyze their identity. Starting from a library containing randomly mutated tRNA(CUA)Asp genes, we isolated four amber suppressors presenting either lysine, alanine, or glutamine activity. Two of them, presenting mainly alanine or lysine activity, were further submitted to a second round of mutagenesis selection in order to improve their efficiency of suppression. Eleven suppressors were isolated, each containing two or three mutations. Ten presented identities of the two parental mutants, whereas one had switched from lysine to arginine identity. Analysis of the different mutants revealed (or confirmed for some nucleotides) their role as positive and/or negative determinants in AlaRS, LysRS, and ArgRS recognition. More generally, it appears that tRNAAsp presents identity characteristics closely related to those of tRNALys, as well as a structural basis for acquiring alanine or arginine identity upon moderate mutational changes; these consist of addition or suppression of the corresponding positive or negative determinants, as well as tertiary interactions. Failure to isolate aspartic acid-inserting suppressors is probably due to elimination of the important G34 identity element and its replacement by an antideterminant when changing the anticodon of the tRNAAsp to the CUA triplet. PMID:8809018

  14. HDAC inhibitors induce global changes in histone lysine and arginine methylation and alter expression of lysine demethylases.

    PubMed

    Lillico, Ryan; Sobral, Marina Gomez; Stesco, Nicholas; Lakowski, Ted M

    2016-02-05

    Histone deacetylase (HDAC) inhibitors are cancer treatments that inhibit the removal of the epigenetic modification acetyllysine on histones, resulting in altered gene expression. Such changes in expression may influence other histone epigenetic modifications. We describe a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify lysine acetylation and methylation and arginine methylation on histones extracted from cultured cells treated with HDAC inhibitors. The HDAC inhibitors vorinostat, mocetinostat and entinostat induced 400-600% hyperacetylation in HEK 293 and K562 cells. All HDAC inhibitors decreased histone methylarginines in HEK 293 cells but entinostat produced dose dependent reductions in asymmetric dimethylarginine, not observed in K562 cells. Vorinostat produced increases in histone lysine methylation and decreased expression of some lysine demethylases (KDM), measured by quantitative PCR. Entinostat had variable effects on lysine methylation and decreased expression of some KDM while increasing expression of others. Mocetinostat produced dose dependent increases in histone lysine methylation by LC-MS/MS. This was corroborated with a multiplex colorimetric assay showing increases in histone H3 lysine 4, 9, 27, 36 and 79 methylation. Increases in lysine methylation were correlated with dose dependent decreases in the expression of seven KDM. Mocetinostat functions as an HDAC inhibitor and a de facto KDM inhibitor. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Optimum dietary arginine:lysine ratio for broiler chickens is altered during heat stress in association with changes in intestinal uptake and dietary sodium chloride.

    PubMed

    Brake, J; Balnave, D; Dibner, J J

    1998-12-01

    1. The effects of varying the dietary arginine:lysine (Arg:Lys) ratio for broiler chickens at thermoneutral and high temperatures was studied in a series of 5 experiments which measured intestinal epithelial transport or evaluated growth and food efficiency with practical diets or diets supplemented with L-arginine free base. 2. The growth studies showed that increasing the Arg:Lys ratio at high temperatures produced consistent improvements in food conversion without any loss in growth. 3. Increasing dietary sodium chloride concentration reduced the Arg:Lys ratio necessary for optimum food conversion. 4. Food conversion responses were improved whether L-arginine free base was used as a dietary supplement in place of an inert filler or practical diets with differing ingredients were used to vary the Arg:Lys ratio. 5. In the presence of an equimolar concentration of lysine the uptake of arginine by the intestinal epithelium of heat-stressed broilers was reduced significantly compared with that of broilers at thermoneutral temperatures. 6. The results indicate that the ideal amino acid balance for broilers varies with ambient temperature.

  16. Arginine side chain interactions and the role of arginine as a gating charge carrier in voltage sensitive ion channels

    PubMed Central

    Armstrong, Craig T.; Mason, Philip E.; Anderson, J. L. Ross; Dempsey, Christopher E.

    2016-01-01

    Gating charges in voltage-sensing domains (VSD) of voltage-sensitive ion channels and enzymes are carried on arginine side chains rather than lysine. This arginine preference may result from the unique hydration properties of the side chain guanidinium group which facilitates its movement through a hydrophobic plug that seals the center of the VSD, as suggested by molecular dynamics simulations. To test for side chain interactions implicit in this model we inspected interactions of the side chains of arginine and lysine with each of the 19 non-glycine amino acids in proteins in the protein data bank. The arginine guanidinium interacts with non-polar aromatic and aliphatic side chains above and below the guanidinium plane while hydrogen bonding with polar side chains is restricted to in-plane positions. In contrast, non-polar side chains interact largely with the aliphatic part of the lysine side chain. The hydration properties of arginine and lysine are strongly reflected in their respective interactions with non-polar and polar side chains as observed in protein structures and in molecular dynamics simulations, and likely underlie the preference for arginine as a mobile charge carrier in VSD. PMID:26899474

  17. Arginine side chain interactions and the role of arginine as a gating charge carrier in voltage sensitive ion channels

    NASA Astrophysics Data System (ADS)

    Armstrong, Craig T.; Mason, Philip E.; Anderson, J. L. Ross; Dempsey, Christopher E.

    2016-02-01

    Gating charges in voltage-sensing domains (VSD) of voltage-sensitive ion channels and enzymes are carried on arginine side chains rather than lysine. This arginine preference may result from the unique hydration properties of the side chain guanidinium group which facilitates its movement through a hydrophobic plug that seals the center of the VSD, as suggested by molecular dynamics simulations. To test for side chain interactions implicit in this model we inspected interactions of the side chains of arginine and lysine with each of the 19 non-glycine amino acids in proteins in the protein data bank. The arginine guanidinium interacts with non-polar aromatic and aliphatic side chains above and below the guanidinium plane while hydrogen bonding with polar side chains is restricted to in-plane positions. In contrast, non-polar side chains interact largely with the aliphatic part of the lysine side chain. The hydration properties of arginine and lysine are strongly reflected in their respective interactions with non-polar and polar side chains as observed in protein structures and in molecular dynamics simulations, and likely underlie the preference for arginine as a mobile charge carrier in VSD.

  18. Mammalian Protein Arginine Methyltransferase 7 (PRMT7) Specifically Targets RXR Sites in Lysine- and Arginine-rich Regions*

    PubMed Central

    Feng, You; Maity, Ranjan; Whitelegge, Julian P.; Hadjikyriacou, Andrea; Li, Ziwei; Zurita-Lopez, Cecilia; Al-Hadid, Qais; Clark, Amander T.; Bedford, Mark T.; Masson, Jean-Yves; Clarke, Steven G.

    2013-01-01

    The mammalian protein arginine methyltransferase 7 (PRMT7) has been implicated in roles of transcriptional regulation, DNA damage repair, RNA splicing, cell differentiation, and metastasis. However, the type of reaction that it catalyzes and its substrate specificity remain controversial. In this study, we purified a recombinant mouse PRMT7 expressed in insect cells that demonstrates a robust methyltransferase activity. Using a variety of substrates, we demonstrate that the enzyme only catalyzes the formation of ω-monomethylarginine residues, and we confirm its activity as the prototype type III protein arginine methyltransferase. This enzyme is active on all recombinant human core histones, but histone H2B is a highly preferred substrate. Analysis of the specific methylation sites within intact histone H2B and within H2B and H4 peptides revealed novel post-translational modification sites and a unique specificity of PRMT7 for methylating arginine residues in lysine- and arginine-rich regions. We demonstrate that a prominent substrate recognition motif consists of a pair of arginine residues separated by one residue (RXR motif). These findings will significantly accelerate substrate profile analysis, biological function study, and inhibitor discovery for PRMT7. PMID:24247247

  19. Mammalian protein arginine methyltransferase 7 (PRMT7) specifically targets RXR sites in lysine- and arginine-rich regions.

    PubMed

    Feng, You; Maity, Ranjan; Whitelegge, Julian P; Hadjikyriacou, Andrea; Li, Ziwei; Zurita-Lopez, Cecilia; Al-Hadid, Qais; Clark, Amander T; Bedford, Mark T; Masson, Jean-Yves; Clarke, Steven G

    2013-12-27

    The mammalian protein arginine methyltransferase 7 (PRMT7) has been implicated in roles of transcriptional regulation, DNA damage repair, RNA splicing, cell differentiation, and metastasis. However, the type of reaction that it catalyzes and its substrate specificity remain controversial. In this study, we purified a recombinant mouse PRMT7 expressed in insect cells that demonstrates a robust methyltransferase activity. Using a variety of substrates, we demonstrate that the enzyme only catalyzes the formation of ω-monomethylarginine residues, and we confirm its activity as the prototype type III protein arginine methyltransferase. This enzyme is active on all recombinant human core histones, but histone H2B is a highly preferred substrate. Analysis of the specific methylation sites within intact histone H2B and within H2B and H4 peptides revealed novel post-translational modification sites and a unique specificity of PRMT7 for methylating arginine residues in lysine- and arginine-rich regions. We demonstrate that a prominent substrate recognition motif consists of a pair of arginine residues separated by one residue (RXR motif). These findings will significantly accelerate substrate profile analysis, biological function study, and inhibitor discovery for PRMT7.

  20. Potential of single cationic amino acid molecule "Arginine" for stimulating oral absorption of insulin.

    PubMed

    Kamei, Noriyasu; Khafagy, El-Sayed; Hirose, Jun; Takeda-Morishita, Mariko

    2017-04-15

    We have reported that cell-penetrating peptides, such as oligoarginine, act as powerful absorption enhancers for the development of oral insulin delivery systems. However, the minimal essential sequence of oligoarginine that stimulates intestinal insulin absorption remains unclear. Therefore, the present study was conducted to clarify this minimum sequence of oligoarginine and to examine the effect of single cationic amino acid arginine on the intestinal and oral absorption of insulin. The results demonstrated that a remarkable enhancement of intestinal insulin absorption was observed after coadministration of insulin with l-arginine. The efficacy of d-forms of oligoarginine/arginine tended to decrease with a decreasing number of amino acid residues, whereas the effect of l-arginine was the strongest of any of the l-forms of oligoarginine/arginine. Interestingly, the effect of l-arginine was stronger than that of d-arginine at various concentrations, and the effect of other cationic amino acids such as lysine and histidine was relatively lower than that of arginine. In addition, no leakage of lactate dehydrogenase from the intestinal epithelium and no change in the transepithelial electrical resistance of a Caco-2 cell monolayer were detected after administration of l-arginine as the single amino acid, which suggests that there were no undesirable effects of arginine on the integrity of cell membranes and paracellular tight junctions. Oral administration study in mice demonstrated that the stronger hypoglycemic effects were observed after coadministration of insulin with l-arginine. In this study, we found that arginine is a key cationic amino acid for delivering insulin across intestinal epithelial barriers and hopefully accelerating the clinical development of oral insulin delivery systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Mechanisms for Improved Hygroscopicity of L-Arginine Valproate Revealed by X-Ray Single Crystal Structure Analysis.

    PubMed

    Ito, Masataka; Nambu, Kaori; Sakon, Aya; Uekusa, Hidehiro; Yonemochi, Etsuo; Noguchi, Shuji; Terada, Katsuhide

    2017-03-01

    Valproic acid is widely used as an antiepileptic agent. Valproic acid is in liquid phase while sodium valproate is in solid phase at room temperature. Sodium valproate is hard to manufacture because of its hygroscopic and deliquescent properties. To improve these, cocrystal and salt screening for valproic acid was employed in this study. Two solid salt forms, l-arginine valproate and l-lysine valproate, were obtained and characterized. By using dynamic vapor sorption method, the critical relative humidity of sodium valproate, l-arginine valproate, and l-lysine valproate were measured. Critical relative humidity of sodium valproate was 40%, of l-lysine valproate was 60%, and of l-arginine valproate was 70%. Single-crystal X-ray structure determination of l-arginine valproate was employed. l-Lysine valproate was of low diffraction quality, and l-arginine valproate formed a 1:1 salt. Crystal l-arginine valproate has a disorder in the methylene carbon chain that creates 2 conformations. The carboxylate group of valproic acid is connected to the amino group of l-arginine. Crystalline morphologies were calculated from its crystal structure. Adsorption of water molecules to crystal facets was simulated by Material Studio. When comparing adsorption energy per site of these salts, sodium valproate is more capable of adsorption of water molecule than l-arginine valproate. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  2. Occurrence, Functions and Biological Significance of Arginine-Rich Proteins.

    PubMed

    Chandana, Thimmegowda; Venkatesh, Yeldur P

    2016-01-01

    Arginine, the most basic among the 20 amino acids, occurs less frequently than lysine in proteins despite being coded by six codons. Only a few important proteins of biological significance have been found to be abundant in arginine. It has been established that these arginine-rich proteins have been assigned important roles in the biological systems. Arginine-rich cationic proteins are known to stabilize macromolecular structures by establishing appropriate interactions (salt bridges, hydrogen bonds and cation-π interactions). These proteins are also known to be the key members of many regulatory pathways such as gene expression, chromatin stability, expurgation of introns from naïve mRNA, mRNA splicing, membrane-penetrating activity and pathogenesis-related defense, to name a few. Further, arginine occurs in various combinations with other amino acids (serine, lysine, proline, tryptophan, valine, glycine and glutamic acid) which diversify the potential functions of arginine-rich proteins. Arginine-rich proteins known till date from dietary sources have been described in terms of their structure and functional properties. A variety of activities such as bactericidal, membrane-penetrating, antimicrobial, anti-hypertensive, pro-angiogenic and others have been reported for arginine-rich proteins. This review attempts to collate the occurrence, functions and the biological significance of this unique class of proteins rich in arginine.

  3. Poly-arginine and arginine-rich peptides are neuroprotective in stroke models

    PubMed Central

    Meloni, Bruno P; Brookes, Laura M; Clark, Vince W; Cross, Jane L; Edwards, Adam B; Anderton, Ryan S; Hopkins, Richard M; Hoffmann, Katrin; Knuckey, Neville W

    2015-01-01

    Using cortical neuronal cultures and glutamic acid excitotoxicity and oxygen-glucose deprivation (OGD) stroke models, we demonstrated that poly-arginine and arginine-rich cell-penetrating peptides (CPPs), are highly neuroprotective, with efficacy increasing with increasing arginine content, have the capacity to reduce glutamic acid-induced neuronal calcium influx and require heparan sulfate preotoglycan-mediated endocytosis to induce a neuroprotective effect. Furthermore, neuroprotection could be induced with immediate peptide treatment or treatment up to 2 to 4 hours before glutamic acid excitotoxicity or OGD, and with poly-arginine-9 (R9) when administered intravenously after stroke onset in a rat model. In contrast, the JNKI-1 peptide when fused to the (non-arginine) kFGF CPP, which does not rely on endocytosis for uptake, was not neuroprotective in the glutamic acid model; the kFGF peptide was also ineffective. Similarly, positively charged poly-lysine-10 (K10) and R9 fused to the negatively charged poly-glutamic acid-9 (E9) peptide (R9/E9) displayed minimal neuroprotection after excitotoxicity. These results indicate that peptide positive charge and arginine residues are critical for neuroprotection, and have led us to hypothesize that peptide-induced endocytic internalization of ion channels is a potential mechanism of action. The findings also question the mode of action of different neuroprotective peptides fused to arginine-rich CPPs. PMID:25669902

  4. Computational prediction of methylation types of covalently modified lysine and arginine residues in proteins.

    PubMed

    Deng, Wankun; Wang, Yongbo; Ma, Lili; Zhang, Ying; Ullah, Shahid; Xue, Yu

    2017-07-01

    Protein methylation is an essential posttranslational modification (PTM) mostly occurs at lysine and arginine residues, and regulates a variety of cellular processes. Owing to the rapid progresses in the large-scale identification of methylation sites, the available data set was dramatically expanded, and more attention has been paid on the identification of specific methylation types of modification residues. Here, we briefly summarized the current progresses in computational prediction of methylation sites, which provided an accurate, rapid and efficient approach in contrast with labor-intensive experiments. We collected 5421 methyllysines and methylarginines in 2592 proteins from the literature, and classified most of the sites into different types. Data analyses demonstrated that different types of methylated proteins were preferentially involved in different biological processes and pathways, whereas a unique sequence preference was observed for each type of methylation sites. Thus, we developed a predictor of GPS-MSP, which can predict mono-, di- and tri-methylation types for specific lysines, and mono-, symmetric di- and asymmetrical di-methylation types for specific arginines. We critically evaluated the performance of GPS-MSP, and compared it with other existing tools. The satisfying results exhibited that the classification of methylation sites into different types for training can considerably improve the prediction accuracy. Taken together, we anticipate that our study provides a new lead for future computational analysis of protein methylation, and the prediction of methylation types of covalently modified lysine and arginine residues can generate more useful information for further experimental manipulation. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Novel therapy for pyridoxine dependent epilepsy due to ALDH7A1 genetic defect: L-arginine supplementation alternative to lysine-restricted diet.

    PubMed

    Mercimek-Mahmutoglu, Saadet; Cordeiro, Dawn; Cruz, Vivian; Hyland, Keith; Struys, Eduard A; Kyriakopoulou, Lianna; Mamak, Eva

    2014-11-01

    Pyridoxine dependent epilepsy (PDE) due to mutations in the ALDH7A1 gene (PDE-ALDH7A1) is caused by α-aminoadipic-semialdehyde-dehydrogenase enzyme deficiency in the lysine pathway resulting in the accumulation of α-aminoadipic acid semialdehyde (α-AASA). Classical presentation is neonatal intractable seizures with a dramatic response to pyridoxine. Pyridoxine therapy does not prevent developmental delays in the majority of the patients. We hypothesized that L-arginine supplementation will decrease accumulation of α-AASA by competitive inhibition of lysine transport into the central nervous system and improve neurodevelopmental and neurocognitive functions in PDE-ALDH7A1. A 12-year-old male with PDE-ALDH7A1 was treated with l-arginine supplementation as an innovative therapy. Treatment outcome was monitored by cerebral-spinal-fluid (CSF) α-AASA measurements at baseline, 6th and 12th months of therapy. Neuropsychological assessments were performed at baseline and 12th months of therapy. L-arginine therapy was well tolerated without side effects. CSF α-AASA was decreased 57% at 12th months of therapy. Neuropsychological assessments revealed improvements in general abilities index from 108 to 116 and improvements in verbal and motor functioning at 12th months of therapy. The short-term treatment outcome of this novel L-arginine supplementation therapy for PDE-ALDH7A1 was successful for biochemical and neurocognitive improvements. Copyright © 2014 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  6. Lysine Methylation of Nuclear Co-repressor Receptor Interacting Protein 140

    PubMed Central

    Huq, MD Mostaqul; Ha, Sung Gil; Barcelona, Helene; Wei, Li-Na

    2009-01-01

    Receptor interacting protein 140 (RIP140) undergoes extensive posttranslational modifications (PTMs), including phosphorylation, acetylation, arginine methylation, and pyridoxylation. PTMs affect its sub-cellular distribution, protein-protein interaction, and biological activity in adipocyte differentiation. Arginine methylation on Arg240, Arg650, and Arg948 suppresses the repressive activity of RIP140. Here we find that endogenous RIP140 in differentiated 3T3-L1 cells is also modified by lysine methylation. Three lysine residues, Lys591, Lys653, and Lys757 are mapped as potential methylation sites by mass spectrometry. Site-directed mutagenesis study shows that lysine methylation enhances its gene repressive activity. Mutation of lysine methylation sites enhances arginine methylation, while mutation on arginine methylation sites has little effect on its lysine methylation, suggesting a relationship between lysine methylation and arginine methylation. Kinetic analysis of PTMs of endogenous RIP140 in differentiated 3T3-L1 cells demonstrates sequential modifications on RIP140, initiated from constitutive lysine methylation, followed by increased arginine methylation later in differentiation. This study reveals a potential hierarchy of modifications, at least for lysine and arginine methylation, which bi-directionally regulate the functionality of a non-histone protein. PMID:19216533

  7. The effect of aspartate-lysine-isoleucine and aspartate-arginine-tyrosine mutations on the expression and activity of vasopressin V2 receptor gene.

    PubMed

    Najafzadeh, Hossein; Safaeian, Leila; Mirmohammad Sadeghi, Hamid; Rabbani, Mohammad; Jafarian, Abbas

    2010-01-01

    Vasopressin type 2 receptor (V2R) plays an important role in the water reabsorption in the kidney collecting ducts. V2R is a G protein coupled receptor (GPCR) and the triplet of amino acids aspartate-arginine-histidine (DRH) in this receptor might significantly influence its activity similar to other GPCR. However, the role of this motif has not been fully confirmed. Therefore, the present study attempted to shed some more light on the role of DRH motif in G protein coupling and V2R function with the use of site-directed mutagenesis. Nested PCR using specific primers was used to produce DNA fragments containing aspartate-lysine-isoleucine and aspartate-arginine-tyrosine mutations with replacements of the arginine to lysine and histidine to tyrosine, respectively. After digestion, these inserts were ligated into the pcDNA3 vector and transformation into E. coli HB101 was performed using heat shock method. The obtained colonies were analyzed for the presence and orientation of the inserts using proper restriction enzymes. After transient transfection of COS-7 cells using diethylaminoethyl-dextran method, the adenylyl cyclase activity assay was performed for functional study. The cell surface expression was analyzed by indirect ELISA method. The functional assay indicated that none of these mutations significantly altered cAMP production and cell surface expression of V2R in these cells. Since some substitutions in arginine residue have shown to lead to the inactive V2 receptor, further studies are required to define the role of this residue more precisely. However, it seems that the role of the histidine residue is not critical in the V2 receptor function.

  8. Dietary L-lysine prevents arterial calcification in adenine-induced uremic rats.

    PubMed

    Shimomura, Akihiro; Matsui, Isao; Hamano, Takayuki; Ishimoto, Takuya; Katou, Yumiko; Takehana, Kenji; Inoue, Kazunori; Kusunoki, Yasuo; Mori, Daisuke; Nakano, Chikako; Obi, Yoshitsugu; Fujii, Naohiko; Takabatake, Yoshitsugu; Nakano, Takayoshi; Tsubakihara, Yoshiharu; Isaka, Yoshitaka; Rakugi, Hiromi

    2014-09-01

    Vascular calcification (VC) is a life-threatening complication of CKD. Severe protein restriction causes a shortage of essential amino acids, and exacerbates VC in rats. Therefore, we investigated the effects of dietary l-lysine, the first-limiting amino acid of cereal grains, on VC. Male Sprague-Dawley rats at age 13 weeks were divided randomly into four groups: low-protein (LP) diet (group LP), LP diet+adenine (group Ade), LP diet+adenine+glycine (group Gly) as a control amino acid group, and LP diet+adenine+l-lysine·HCl (group Lys). At age 18 weeks, group LP had no VC, whereas groups Ade and Gly had comparable levels of severe VC. l-Lysine supplementation almost completely ameliorated VC. Physical parameters and serum creatinine, urea nitrogen, and phosphate did not differ among groups Ade, Gly, and Lys. Notably, serum calcium in group Lys was slightly but significantly higher than in groups Ade and Gly. Dietary l-lysine strongly suppressed plasma intact parathyroid hormone in adenine rats and supported a proper bone-vascular axis. The conserved orientation of the femoral apatite in group Lys also evidenced the bone-protective effects of l-lysine. Dietary l-lysine elevated plasma alanine, proline, arginine, and homoarginine but not lysine. Analyses in vitro demonstrated that alanine and proline inhibit apoptosis of cultured vascular smooth muscle cells, and that arginine and homoarginine attenuate mineral precipitations in a supersaturated calcium/phosphate solution. In conclusion, dietary supplementation of l-lysine ameliorated VC by modifying key pathways that exacerbate VC. Copyright © 2014 by the American Society of Nephrology.

  9. Dietary l-Lysine Prevents Arterial Calcification in Adenine-Induced Uremic Rats

    PubMed Central

    Shimomura, Akihiro; Matsui, Isao; Hamano, Takayuki; Ishimoto, Takuya; Katou, Yumiko; Takehana, Kenji; Inoue, Kazunori; Kusunoki, Yasuo; Mori, Daisuke; Nakano, Chikako; Obi, Yoshitsugu; Fujii, Naohiko; Takabatake, Yoshitsugu; Nakano, Takayoshi; Tsubakihara, Yoshiharu; Rakugi, Hiromi

    2014-01-01

    Vascular calcification (VC) is a life-threatening complication of CKD. Severe protein restriction causes a shortage of essential amino acids, and exacerbates VC in rats. Therefore, we investigated the effects of dietary l-lysine, the first-limiting amino acid of cereal grains, on VC. Male Sprague-Dawley rats at age 13 weeks were divided randomly into four groups: low-protein (LP) diet (group LP), LP diet+adenine (group Ade), LP diet+adenine+glycine (group Gly) as a control amino acid group, and LP diet+adenine+l-lysine·HCl (group Lys). At age 18 weeks, group LP had no VC, whereas groups Ade and Gly had comparable levels of severe VC. l-Lysine supplementation almost completely ameliorated VC. Physical parameters and serum creatinine, urea nitrogen, and phosphate did not differ among groups Ade, Gly, and Lys. Notably, serum calcium in group Lys was slightly but significantly higher than in groups Ade and Gly. Dietary l-lysine strongly suppressed plasma intact parathyroid hormone in adenine rats and supported a proper bone-vascular axis. The conserved orientation of the femoral apatite in group Lys also evidenced the bone-protective effects of l-lysine. Dietary l-lysine elevated plasma alanine, proline, arginine, and homoarginine but not lysine. Analyses in vitro demonstrated that alanine and proline inhibit apoptosis of cultured vascular smooth muscle cells, and that arginine and homoarginine attenuate mineral precipitations in a supersaturated calcium/phosphate solution. In conclusion, dietary supplementation of l-lysine ameliorated VC by modifying key pathways that exacerbate VC. PMID:24652795

  10. Intricate Effects of α-Amino and Lysine Modifications on Arginine Methylation of the N-Terminal Tail of Histone H4.

    PubMed

    Fulton, Melody D; Zhang, Jing; He, Maomao; Ho, Meng-Chiao; Zheng, Y George

    2017-07-18

    Chemical modifications of the DNA and nucleosomal histones tightly control the gene transcription program in eukaryotic cells. The "histone code" hypothesis proposes that the frequency, combination, and location of post-translational modifications (PTMs) of the core histones compose a complex network of epigenetic regulation. Currently, there are at least 23 different types and >450 histone PTMs that have been discovered, and the PTMs of lysine and arginine residues account for a crucial part of the histone code. Although significant progress has been achieved in recent years, the molecular basis for the histone code is far from being fully understood. In this study, we investigated how naturally occurring N-terminal acetylation and PTMs of histone H4 lysine-5 (H4K5) affect arginine-3 methylation catalyzed by both type I and type II PRMTs at the biochemical level. Our studies found that acylations of H4K5 resulted in decreased levels of arginine methylation by PRMT1, PRMT3, and PRMT8. In contrast, PRMT5 exhibits an increased rate of arginine methylation upon H4K5 acetylation, propionylation, and crotonylation, but not upon H4K5 methylation, butyrylation, or 2-hydroxyisobutyrylation. Methylation of H4K5 did not affect arginine methylation by PRMT1 or PRMT5. There was a small increase in the rate of arginine methylation by PRMT8. Strikingly, a marked increase in the rate of arginine methylation was observed for PRMT3. Finally, N-terminal acetylation reduced the rate of arginine methylation by PRMT3 but had little influence on PRMT1, -5, and -8 activity. These results together highlight the underlying mechanistic differences in substrate recognition among different PRMTs and pave the way for the elucidation of the complex interplay of histone modifications.

  11. Cationic amino acid transporter 1-mediated L-arginine transport at the inner blood-retinal barrier.

    PubMed

    Tomi, Masatoshi; Kitade, Naohisa; Hirose, Shirou; Yokota, Noriko; Akanuma, Shin-Ichi; Tachikawa, Masanori; Hosoya, Ken-ichi

    2009-11-01

    The purpose of this study was to identify the transporter mediating l-arginine transport at the inner blood-retinal barrier (BRB). The apparent uptake clearance of [(3)H]L-arginine into the rat retina was found to be 118 microL/(min.g retina), supporting a carrier-mediated influx transport of L-arginine at the BRB. [(3)H]L-arginine uptake by a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB2 cells), used as an in vitro model of the inner BRB, was primarily an Na(+)-independent and saturable process with Michaelis-Menten constants of 11.2 microM and 530 microM. This process was inhibited by rat cationic amino acid transporter (CAT) 1-specific small interfering RNA as well as substrates of CATs, L-arginine, L-lysine, and L-ornithine. The expression of cationic amino acid transporter (CAT) 1 mRNA was 25.9- and 796-fold greater than that of CAT3 in TR-iBRB2 and magnetically isolated rat retinal vascular endothelial cells, respectively. The expression of CAT1 protein was detected in TR-iBRB2 cells and immunostaining of CAT1 was observed along the rat retinal capillaries. In conclusion, CAT1 is localized in retinal capillary endothelial cells and at least in part mediates L-arginine transport at the inner BRB. This process seems to be closely involved in visual functions by supplying precursors of biologically important molecules like nitric oxide in the neural retina.

  12. Protein arginine methylation: a prominent modification and its demethylation.

    PubMed

    Wesche, Juste; Kühn, Sarah; Kessler, Benedikt M; Salton, Maayan; Wolf, Alexander

    2017-09-01

    Arginine methylation of histones is one mechanism of epigenetic regulation in eukaryotic cells. Methylarginines can also be found in non-histone proteins involved in various different processes in a cell. An enzyme family of nine protein arginine methyltransferases catalyses the addition of methyl groups on arginines of histone and non-histone proteins, resulting in either mono- or dimethylated-arginine residues. The reversibility of histone modifications is an essential feature of epigenetic regulation to respond to changes in environmental factors, signalling events, or metabolic alterations. Prominent histone modifications like lysine acetylation and lysine methylation are reversible. Enzyme family pairs have been identified, with each pair of lysine acetyltransferases/deacetylases and lysine methyltransferases/demethylases operating complementarily to generate or erase lysine modifications. Several analyses also indicate a reversible nature of arginine methylation, but the enzymes facilitating direct removal of methyl moieties from arginine residues in proteins have been discussed controversially. Differing reports have been seen for initially characterized putative candidates, like peptidyl arginine deiminase 4 or Jumonji-domain containing protein 6. Here, we review the most recent cellular, biochemical, and mass spectrometry work on arginine methylation and its reversible nature with a special focus on putative arginine demethylases, including the enzyme superfamily of Fe(II) and 2-oxoglutarate-dependent oxygenases.

  13. Lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats: a systematic review.

    PubMed

    Bol, Sebastiaan; Bunnik, Evelien M

    2015-11-16

    Feline herpesvirus 1 is a highly contagious virus that affects many cats. Virus infection presents with flu-like signs and irritation of ocular and nasal regions. While cats can recover from active infections without medical treatment, examination by a veterinarian is recommended. Lysine supplementation appears to be a popular intervention (recommended by > 90 % of veterinarians in cat hospitals). We investigated the scientific merit of lysine supplementation by systematically reviewing all relevant literature. NCBI's PubMed database was used to search for published work on lysine and feline herpesvirus 1, as well as lysine and human herpesvirus 1. Seven studies on lysine and feline herpesvirus 1 (two in vitro studies and 5 studies with cats), and 10 publications on lysine and human herpesvirus 1 (three in vitro studies and 7 clinical trials) were included for qualitative analysis. There is evidence at multiple levels that lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats. Lysine does not have any antiviral properties, but is believed to act by lowering arginine levels. However, lysine does not antagonize arginine in cats, and evidence that low intracellular arginine concentrations would inhibit viral replication is lacking. Furthermore, lowering arginine levels is highly undesirable since cats cannot synthesize this amino acid themselves. Arginine deficiency will result in hyperammonemia, which may be fatal. In vitro studies with feline herpesvirus 1 showed that lysine has no effect on the replication kinetics of the virus. Finally, and most importantly, several clinical studies with cats have shown that lysine is not effective for the prevention or the treatment of feline herpesvirus 1 infection, and some even reported increased infection frequency and disease severity in cats receiving lysine supplementation. We recommend an immediate stop of lysine supplementation because of the complete lack of

  14. Arginine and lysine reduce the high viscosity of serum albumin solutions for pharmaceutical injection.

    PubMed

    Inoue, Naoto; Takai, Eisuke; Arakawa, Tsutomu; Shiraki, Kentaro

    2014-05-01

    Therapeutic protein solutions for subcutaneous injection must be very highly concentrated, which increases their viscosity through protein-protein interactions. However, maintaining a solution viscosity below 50 cP is important for the preparation and injection of therapeutic protein solutions. In this study, we examined the effect of various amino acids on the solution viscosity of very highly concentrated bovine serum albumin (BSA) and human serum albumin (HSA) at a physiological pH. Among the amino acids tested, l-arginine hydrochloride (ArgHCl) and l-lysine hydrochloride (LysHCl) (50-200 mM) successfully reduced the viscosity of both BSA and HSA solutions; guanidine hydrochloride (GdnHCl), NaCl, and other sodium salts were equally as effective, indicating the electrostatic shielding effect of these additives. Fourier transform infrared spectroscopy showed that BSA is in its native state even in the presence of ArgHCl, LysHCl, and NaCl at high protein concentrations. These results indicate that weakened protein-protein interactions play a key role in reducing solution viscosity. ArgHCl and LysHCl, which are also non-toxic compounds, will be used as additives to reduce the solution viscosity of concentrated therapeutic proteins. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Histone arginine methylations: their roles in chromatin dynamics and transcriptional regulation

    PubMed Central

    LITT, Michael; QIU, Yi; HUANG, Suming

    2017-01-01

    Synopsis PRMTs (protein arginine N-methyltransferases) specifically modify the arginine residues of key cellular and nuclear proteins as well as histone substrates. Like lysine methylation, transcriptional repression or activation is dependent upon the site and type of arginine methylation on histone tails. Recent discoveries imply that histone arginine methylation is an important modulator of dynamic chromatin regulation and transcriptional controls. However, under the shadow of lysine methylation, the roles of histone arginine methylation have been under-explored. The present review focuses on the roles of histone arginine methylation in the regulation of gene expression, and the interplays between histone arginine methylation, histone acetylation, lysine methylation and chromatin remodelling factors. In addition, we discuss the dynamic regulation of arginine methylation by arginine demethylases, and how dysregulation of PRMTs and their activities are linked to human diseases such as cancer. PMID:19220199

  16. Kinetics and molecular characteristics of arginine transport by Leishmania donovani promastigotes.

    PubMed

    Kandpal, M; Fouce, R B; Pal, A; Guru, P Y; Tekwani, B L

    1995-05-01

    Characteristics of transport of L-arginine were studied in Leishmania donovani promastigotes grown in vitro in a defined medium. The promastigotes exhibited a time-dependent, temperature-sensitive, pH-dependent and saturable uptake of arginine. Metabolic inhibitors caused 81-92% inhibition, indicating that arginine influx in promastigotes is an energy requiring process. The presence of Na+ ions was necessary for full activity. Considerable inhibition was also noticed with valinomycin, gramicidin and amiloride. The transporter seems to involve an -SH group at the active site. The most distinctive feature of the leishmanial transporter was that lysine and ornithine did not show significant competition with arginine transport. Other neutral and acidic amino acids, as well as polyamines were also ineffective. The arginine analogues, viz., nitro-L-arginine methyl ester, N-nitro-L-arginine, aminoguanidine, agmatine and D-arginine were not recognised by the transporter, while N-methyl-L-arginine acetate and phospho-L-arginine showed competition, indicating stereo-specificity of the transporter and recognition of both the guanidino group, as well as the arginine side chain by the transporter. No exchange of intracellular [14C]arginine taken up by the promastigotes was noticed during incubation with 2 or 5 mM arginine in the extracellular medium. Eighty percent of the arginine taken up remained in the trichloroacetic acid-soluble fraction. Pentamidine caused competitive inhibition of arginine transport, exhibiting an IC50 value of 40 microM. Results indicate the presence of a novel distinct arginine transporter in Leishmania promastigotes.

  17. A lysine-to-arginine mutation on NEDD8 markedly reduces the activity of cullin RING E3 ligase through the impairment of neddylation cascades

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sui, Yiyan; Liu, Yaobin; Xu, Guoqiang, E-mail: gux2002@suda.edu.cn

    2015-06-12

    Neural-precursor-cell-expressed developmentally down-regulated 8 (NEDD8) is a ubiquitin-like modifier, which forms covalent conjugates on lysines of its substrates. This post-translational modification, neddylation, plays important roles in tumor cell proliferation and viability. Ubiquitin can form diverse polyubiquitin chains, on its seven lysines, which play important functions in various biological processes. However, the roles of lysines in NEDD8 have not been explored. Here, we generated nine NEDD8 point mutants, each with one lysine replaced by an arginine, to study the putative function of lysines in NEDD8. Our experiments discover that Lys27 in NEDD8 is a critical residue for protein neddylation. Replacement ofmore » this residue with arginine almost completely eliminates the conjugation of NEDD8 to its substrates. Furthermore, we find that the K27R mutant impairs NEDD8 conjugation to the E2 enzyme, which normally forms thioester bonds for further transferring NEDD8 to its ligases and substrates. Therefore, this mutation completely inhibits global protein neddylation, including neddylation of cullin family proteins, resulting in decreased activity of cullin-RING E3 ligases. This work sheds new light on the roles of NEDD8 lysines on neddylation cascades and provides a dominant negative mutant for the study of neddylation and its biological functions. - Highlights: • Lys27 in NEDD8 is critical for protein neddylation. • NEDD8 K27R mutant impairs the NEDD8 conjugation. • NEDD8 K27R mutant significantly reduces the activity of cullin-RING E3 ligases.« less

  18. Effects of L-arginine on solubilization and purification of plant membrane proteins.

    PubMed

    Arakawa, Junji; Uegaki, Masamichi; Ishimizu, Takeshi

    2011-11-01

    Biochemical analysis of membrane proteins is problematic at the level of solubilization and/or purification because of their hydrophobic nature. Here, we developed methods for efficient solubilization and purification of membrane proteins using L-arginine. The addition of 100 mM of basic amino acids (L-arginine, L-lysine, and L-ornithine) to a detergent-containing solubilization buffer enhanced solubilization (by 2.6-4.3 fold) of a model membrane protein-polygalacturonic acid synthase. Of all the amino acids, arginine was the most effective additive for solubilization of this membrane protein. Arginine addition also resulted in the best solubilization of other plant membrane proteins. Next, we examined the effects of arginine on purification of a model membrane protein. In anion-exchange chromatography, the addition of arginine to the loading and elution buffers resulted in a greater recovery of a membrane protein. In ultrafiltration, the addition of arginine to a protein solution significantly improved the recovery of a membrane protein. These results were thought to be due to the properties of arginine that prevent aggregation of hydrophobic proteins. Taken together, the results of our study showed that arginine is useful for solubilization and purification of aggregate-prone membrane proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Arginine-lysine positional swap of the LL-37 peptides reveals evolutional advantages of the native sequence and leads to bacterial probes.

    PubMed

    Wang, Xiuqing; Junior, José Carlos Bozelli; Mishra, Biswajit; Lushnikova, Tamara; Epand, Richard M; Wang, Guangshun

    2017-08-01

    Antimicrobial peptides are essential components of the innate immune system of multicellular organisms. Although cationic and hydrophobic amino acids are known determinants of these amphipathic molecules for bacterial killing, it is not clear how lysine-arginine (K-R) positional swaps influence peptide structure and activity. This study addresses this question by investigating two groups of peptides (GF-17 and 17BIPHE2) derived from human cathelicidin LL-37. K-R positional swap showed little effect on minimal inhibitory concentrations of the peptides. However, there are clear differences in bacterial killing kinetics. The membrane permeation patterns vary with peptide and bacterial types, but not changes in fluorescent dyes, salts or pH. In general, the original peptide is more efficient in bacterial killing, but less toxic to human cells, than the K-R swapped peptides, revealing the evolutionary significance of the native sequence for host defense. The characteristic membrane permeation patterns for different bacteria suggest a possible application of these K-R positional-swapped peptides as molecular probes for the type of bacteria. Such differences are related to bacterial membrane compositions: minimal for Gram-positive Staphylococcus aureus with essentially all anionic lipids (cardiolipin and phosphatidylglycerol), but evident for Gram-negative Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli with a mixture of phosphatidylethanolamine and phosphatidylglycerol. Biophysical characterization found similar structures and binding affinities for these peptides in vesicle systems mimicking E. coli and S. aureus. It seems that interfacial arginines of GF-17 are preferred over lysines in bacterial membrane permeation. Our study sheds new light on the design of cationic amphipathic peptides. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. 6th Amino Acid Assessment Workshop

    USDA-ARS?s Scientific Manuscript database

    The focus of the 6th workshop is on lysine, arginine, and related amino acids. Functions, metabolic pathways, clinical uses, and upper tolerance intakes are emphasized in the articles that follow. Lysine is arguably the most deficient amino acid in the food supply of countries where poverty exists, ...

  1. Acquired Amino Acid Deficiencies: A Focus on Arginine and Glutamine.

    PubMed

    Morris, Claudia R; Hamilton-Reeves, Jill; Martindale, Robert G; Sarav, Menaka; Ochoa Gautier, Juan B

    2017-04-01

    Nonessential amino acids are synthesized de novo and therefore not diet dependent. In contrast, essential amino acids must be obtained through nutrition since they cannot be synthesized internally. Several nonessential amino acids may become essential under conditions of stress and catabolic states when the capacity of endogenous amino acid synthesis is exceeded. Arginine and glutamine are 2 such conditionally essential amino acids and are the focus of this review. Low arginine bioavailability plays a pivotal role in the pathogenesis of a growing number of varied diseases, including sickle cell disease, thalassemia, malaria, acute asthma, cystic fibrosis, pulmonary hypertension, cardiovascular disease, certain cancers, and trauma, among others. Catabolism of arginine by arginase enzymes is the most common cause of an acquired arginine deficiency syndrome, frequently contributing to endothelial dysfunction and/or T-cell dysfunction, depending on the clinical scenario and disease state. Glutamine, an arginine precursor, is one of the most abundant amino acids in the body and, like arginine, becomes deficient in several conditions of stress, including critical illness, trauma, infection, cancer, and gastrointestinal disorders. At-risk populations are discussed together with therapeutic options that target these specific acquired amino acid deficiencies.

  2. Reducing renal uptake of 111In-DOTATOC: a comparison among various basic amino acids.

    PubMed

    Lin, Yung-Chang; Hung, Guang-Uei; Luo, Tsai-Yueh; Tsai, Shih-Chuan; Sun, Shung-Shung; Hsia, Chien-Chung; Chen, Shu-Ling; Lin, Wan-Yu

    2007-01-01

    Several studies have reported significant renal toxicity after the use of a high dose of 90Y-DOTATOC. Thus, renal protection is necessary in treatments with 90Y-DOTA Tyr3-octreotide (DOTATOC). The infusion of certain positively charged amino acids has been shown to effectively reduce renal uptake of DOTATOC. In this study, we compared the effectiveness of three kinds of amino acids, D-lysine (lysine), L-arginine (arginine) and histidine, on renal protection in healthy rats and tried to determine which one was the most effective. Twenty SD healthy male rats were divided into 4 groups: lysine, histidine, arginine, and control. The rats were injected with a dose of 400 mg/kg of amino acid or 2 ml of phosphate-buffered saline (PBS) (as control) intraperitoneally. All rats were sacrificed at 4 hrs after the injection of 1 MBq 111In-DOTATOC. Samples of the kidney were taken and weighed carefully. The counts of radioactivity were measured by a gamma counter and renal concentrations were calculated and expressed as percent injected dose per gram (% ID/g). The renal uptake of 111In-DOTATOC was significantly lower for all three kinds of amino acids when compared to the control group. The renal uptake of 111In-DOTATOC in the lysine group was significantly lower than those in the histidine and arginine groups. The renal uptake of 111In-DOTATOC in the histidine group was lower than that in the arginine group, but no statistical difference was noted. Among these three amino acids, lysine had the best reduction rate of renal uptake of DOTATOC. Histidine was more effective than arginine but no statistical difference was noted.

  3. Interfacial electrostatics of poly(vinylamine hydrochloride), poly(diallyldimethylammonium chloride), poly-l-lysine, and poly-l-arginine interacting with lipid bilayers.

    PubMed

    McGeachy, A C; Dalchand, N; Caudill, E R; Li, T; Doğangün, M; Olenick, L L; Chang, H; Pedersen, J A; Geiger, F M

    2018-04-25

    Charge densities of cationic polymers adsorbed to lipid bilayers are estimated from second harmonic generation (SHG) spectroscopy and quartz crystal microbalance with dissipation monitoring (QCM-D) measurements. The systems surveyed included poly(vinylamine hydrochloride) (PVAm), poly(diallyldimethylammonium chloride) (PDADMAC), poly-l-lysine (PLL), and poly-l-arginine (PLR), as well as polyalcohol controls. Upon accounting for the number of positive charges associated with each polyelectrolyte, the binding constants and apparent free energies of adsorption as estimated from SHG data are comparable despite differences in molecular masses and molecular structure, with ΔGads values of -61 ± 2, -58 ± 2, -57 ± 1, -52 ± 2, -52 ± 1 kJ mol-1 for PDADMAC400, PDADMAC100, PVAm, PLL, and PLR, respectively. Moreover, we find charge densities for polymer adlayers of approximately 0.3 C m-2 for poly(diallyldimethylammonium chloride) while those of poly(vinylamine) hydrochloride, poly-l-lysine, and poly-l-arginine are approximately 0.2 C m-2. Time-dependent studies indicate that polycation adsorption to supported lipid bilayers is only partially reversible for most of the polymers explored. Poly(diallyldimethylammonium chloride) does not demonstrate reversible binding even over long timescales (>8 hours).

  4. Parkinsonism-associated Protein DJ-1/Park7 Is a Major Protein Deglycase That Repairs Methylglyoxal- and Glyoxal-glycated Cysteine, Arginine, and Lysine Residues

    PubMed Central

    Richarme, Gilbert; Mihoub, Mouadh; Dairou, Julien; Bui, Linh Chi; Leger, Thibaut; Lamouri, Aazdine

    2015-01-01

    Glycation is an inevitable nonenzymatic covalent reaction between proteins and endogenous reducing sugars or dicarbonyls (methylglyoxal, glyoxal) that results in protein inactivation. DJ-1 was reported to be a multifunctional oxidative stress response protein with poorly defined function. Here, we show that human DJ-1 is a protein deglycase that repairs methylglyoxal- and glyoxal-glycated amino acids and proteins by acting on early glycation intermediates and releases repaired proteins and lactate or glycolate, respectively. DJ-1 deglycates cysteines, arginines, and lysines (the three major glycated amino acids) of serum albumin, glyceraldehyde-3-phosphate dehydrogenase, aldolase, and aspartate aminotransferase and thus reactivates these proteins. DJ-1 prevented protein glycation in an Escherichia coli mutant deficient in the DJ-1 homolog YajL and restored cell viability in glucose-containing media. These results suggest that DJ-1-associated Parkinsonism results from excessive protein glycation and establishes DJ-1 as a major anti-glycation and anti-aging protein. PMID:25416785

  5. Therapeutic modulation of cerebral L-lysine metabolism in a mouse model for glutaric aciduria type I.

    PubMed

    Sauer, Sven W; Opp, Silvana; Hoffmann, Georg F; Koeller, David M; Okun, Jürgen G; Kölker, Stefan

    2011-01-01

    Glutaric aciduria type I, an inherited deficiency of glutaryl-coenzyme A dehydrogenase localized in the final common catabolic pathway of L-lysine, L-hydroxylysine and L-tryptophan, leads to accumulation of neurotoxic glutaric and 3-hydroxyglutaric acid, as well as non-toxic glutarylcarnitine. Most untreated patients develop irreversible brain damage during infancy that can be prevented in the majority of cases if metabolic treatment with a low L-lysine diet and L-carnitine supplementation is started in the newborn period. The biochemical effect of this treatment remains uncertain, since cerebral concentrations of neurotoxic metabolites can only be determined by invasive techniques. Therefore, we studied the biochemical effect and mechanism of metabolic treatment in glutaryl-coenzyme A dehydrogenase-deficient mice, an animal model with complete loss of glutaryl-coenzyme A dehydrogenase activity, focusing on the tissue-specific changes of neurotoxic metabolites and key enzymes of L-lysine metabolism. Here, we demonstrate that low L-lysine diet, but not L-carnitine supplementation, lowered the concentration of glutaric acid in brain, liver, kidney and serum. L-carnitine supplementation restored the free L-carnitine pool and enhanced the formation of glutarylcarnitine. The effect of low L-lysine diet was amplified by add-on therapy with L-arginine, which we propose to result from competition with L-lysine at system y(+) of the blood-brain barrier and the mitochondrial L-ornithine carriers. L-lysine can be catabolized in the mitochondrial saccharopine or the peroxisomal pipecolate pathway. We detected high activity of mitochondrial 2-aminoadipate semialdehyde synthase, the rate-limiting enzyme of the saccharopine pathway, in the liver, whereas it was absent in the brain. Since we found activity of the subsequent enzymes of L-lysine oxidation, 2-aminoadipate semialdehyde dehydrogenase, 2-aminoadipate aminotransferase and 2-oxoglutarate dehydrogenase complex as well as

  6. Arginine-Dependent Acid Resistance in Salmonella enterica Serovar Typhimurium

    PubMed Central

    Kieboom, Jasper; Abee, Tjakko

    2006-01-01

    Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid resistance (AR) provided the cells are grown under anoxic conditions and not under the microaerobic conditions used for assessment of AR in E. coli. The role of the arginine decarboxylase pathway in Salmonella AR was shown by the loss of AR in mutants lacking adiA, which encodes arginine decarboxylase; adiC, which encodes the arginine-agmatine antiporter; or adiY, which encodes an AraC-like regulator. Transcription of adiA and adiC was found to be dependent on AdiY, anaerobiosis, and acidic pH. PMID:16855258

  7. A Candida guilliermondii lysine hyperproducer capable of elevated citric acid production.

    PubMed

    West, Thomas P

    2016-05-01

    A mutant of the yeast Candida guilliermondii ATCC 9058 exhibiting elevated citric acid production was isolated based upon its ability to overproduce lysine. This method involved the use of a solid medium containing a combination of lysine analogues to identify a mutant that produced a several-fold higher lysine level compared to its parent strain using glucose or glycerol as a carbon source. The mutant strain was also capable of producing more than a fivefold higher citric acid level on glycerol as a carbon source compared to its parent strain. It was concluded that the screening of yeast lysine hyperproducer strains could provide a rapid approach to isolate yeast citric acid hyperproducer strains.

  8. Efficiency of cardioplegic solutions containing L-arginine and L-aspartic acid.

    PubMed

    Pisarenko, O I; Shul'zhenko, V S; Studneva, I M

    2006-04-01

    In experiments on rats we studied the effects of cardioplegic solutions with L-aspartic acid or L-arginine on functional recovery and metabolism of isolated working heart after 40-min normothermal global ischemia and 30-min reperfusion. After reperfusion of the hearts preventively protected with cardioplegic solution containing L-aspartic acid or L-arginine, coronary flow decreased in comparison with the initial values. As a component of cardioplegic solution, L-arginine was less efficient in recovery of contractility and cardiac output of the hearts in comparison with L-aspartic acid. In hearts protected with L-aspartic acid, the postischemic levels of ATP and phosphocreatine were significantly higher, and the level of lactate was significantly lower than in hearts protected with L-arginine. In comparison with L-arginine, L-aspartic acid is a more efficient component of cardioplegic solution in protection of the heart from metabolic and functional damages caused by global ischemia and reperfusion.

  9. The Crucial Role of Early Mitochondrial Injury in L-Lysine-Induced Acute Pancreatitis

    PubMed Central

    Biczó, György; Hegyi, Péter; Dósa, Sándor; Shalbuyeva, Natalia; Berczi, Sándor; Sinervirta, Riitta; Hracskó, Zsuzsanna; Siska, Andrea; Kukor, Zoltán; Jármay, Katalin; Venglovecz, Viktória; Varga, Ilona S.; Iványi, Béla; Alhonen, Leena; Wittmann, Tibor; Gukovskaya, Anna; Takács, Tamás

    2011-01-01

    Abstract Aims Large doses of intraperitoneally injected basic amino acids, L-arginine, or L-ornithine, induce acute pancreatitis in rodents, although the mechanisms mediating pancreatic toxicity remain unknown. Another basic amino acid, L-lysine, was also shown to cause pancreatic acinar cell injury. The aim of the study was to get insight into the mechanisms through which L-lysine damages the rat exocrine pancreas, in particular to characterize the kinetics of L-lysine-induced mitochondrial injury, as well as the pathologic responses (including alteration of antioxidant systems) characteristic of acute pancreatitis. Results We showed that intraperitoneal administration of 2 g/kg L-lysine induced severe acute necrotizing pancreatitis. L-lysine administration caused early pancreatic mitochondrial damage that preceded the activation of trypsinogen and the proinflammatory transcription factor nuclear factor-κB (NF-κB), which are commonly thought to play an important role in the development of acute pancreatitis. Our data demonstrate that L-lysine impairs adenosine triphosphate synthase activity of isolated pancreatic, but not liver, mitochondria. Innovation and Conclusion Taken together, early mitochondrial injury caused by large doses of L-lysine may lead to the development of acute pancreatitis independently of pancreatic trypsinogen and NF-κB activation. PMID:21644850

  10. Arginine-based cationic liposomes for efficient in vitro plasmid DNA delivery with low cytotoxicity.

    PubMed

    Sarker, Satya Ranjan; Aoshima, Yumiko; Hokama, Ryosuke; Inoue, Takafumi; Sou, Keitaro; Takeoka, Shinji

    2013-01-01

    Currently available gene delivery vehicles have many limitations such as low gene delivery efficiency and high cytotoxicity. To overcome these drawbacks, we designed and synthesized two cationic lipids comprised of n-tetradecyl alcohol as the hydrophobic moiety, 3-hydrocarbon chain as the spacer, and different counterions (eg, hydrogen chloride [HCl] salt or trifluoroacetic acid [TFA] salt) in the arginine head group. Cationic lipids were hydrated in 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer to prepare cationic liposomes and characterized in terms of their size, zeta potential, phase transition temperature, and morphology. Lipoplexes were then prepared and characterized in terms of their size and zeta potential in the absence or presence of serum. The morphology of the lipoplexes was determined using transmission electron microscopy and atomic force microscopy. The gene delivery efficiency was evaluated in neuronal cells and HeLa cells and compared with that of lysine-based cationic assemblies and Lipofectamine™ 2000. The cytotoxicity level of the cationic lipids was investigated and compared with that of Lipofectamine™ 2000. We synthesized arginine-based cationic lipids having different counterions (ie, HCl-salt or TFA-salt) that formed cationic liposomes of around 100 nm in size. In the absence of serum, lipoplexes prepared from the arginine-based cationic liposomes and plasmid (p) DNA formed large aggregates and attained a positive zeta potential. However, in the presence of serum, the lipoplexes were smaller in size and negative in zeta potential. The morphology of the lipoplexes was vesicular. Arginine-based cationic liposomes with HCl-salt showed the highest transfection efficiency in PC-12 cells. However, arginine-based cationic liposomes with TFA salt showed the highest transfection efficiency in HeLa cells, regardless of the presence of serum, with very low associated cytotoxicity. The gene delivery efficiency of amino acid

  11. Arginine-based cationic liposomes for efficient in vitro plasmid DNA delivery with low cytotoxicity

    PubMed Central

    Sarker, Satya Ranjan; Aoshima, Yumiko; Hokama, Ryosuke; Inoue, Takafumi; Sou, Keitaro; Takeoka, Shinji

    2013-01-01

    Background Currently available gene delivery vehicles have many limitations such as low gene delivery efficiency and high cytotoxicity. To overcome these drawbacks, we designed and synthesized two cationic lipids comprised of n-tetradecyl alcohol as the hydrophobic moiety, 3-hydrocarbon chain as the spacer, and different counterions (eg, hydrogen chloride [HCl] salt or trifluoroacetic acid [TFA] salt) in the arginine head group. Methods Cationic lipids were hydrated in 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer to prepare cationic liposomes and characterized in terms of their size, zeta potential, phase transition temperature, and morphology. Lipoplexes were then prepared and characterized in terms of their size and zeta potential in the absence or presence of serum. The morphology of the lipoplexes was determined using transmission electron microscopy and atomic force microscopy. The gene delivery efficiency was evaluated in neuronal cells and HeLa cells and compared with that of lysine-based cationic assemblies and Lipofectamine™ 2000. The cytotoxicity level of the cationic lipids was investigated and compared with that of Lipofectamine™ 2000. Results We synthesized arginine-based cationic lipids having different counterions (ie, HCl-salt or TFA-salt) that formed cationic liposomes of around 100 nm in size. In the absence of serum, lipoplexes prepared from the arginine-based cationic liposomes and plasmid (p) DNA formed large aggregates and attained a positive zeta potential. However, in the presence of serum, the lipoplexes were smaller in size and negative in zeta potential. The morphology of the lipoplexes was vesicular. Arginine-based cationic liposomes with HCl-salt showed the highest transfection efficiency in PC-12 cells. However, arginine-based cationic liposomes with TFA salt showed the highest transfection efficiency in HeLa cells, regardless of the presence of serum, with very low associated cytotoxicity. Conclusion The gene

  12. Mechanism of arginine sensing by CASTOR1 upstream of mTORC1

    PubMed Central

    Saxton, Robert A.; Chantranupong, Lynne; Knockenhauer, Kevin E.; Schwartz, Thomas U.; Sabatini, David M.

    2016-01-01

    Summary The mechanistic Target of Rapamycin Complex 1 (mTORC1) is a major regulator of eukaryotic growth that coordinates anabolic and catabolic cellular processes with inputs such as growth factors and nutrients, including amino acids1–3. In mammals, arginine is particularly important and promotes diverse physiological effects including immune cell activation, insulin secretion, and muscle growth, largely through activation of mTORC14–7. Arginine activates mTORC1 upstream of the Rag GTPases8, through either the lysosomal amino acid transporter SLC38A9 or the GATOR2-interacting CASTOR1 (Cellular Arginine Sensor for mTORC1)9–12. However, the mechanism by which the mTORC1 pathway detects and transmits the arginine signal has been elusive. Here, we present the 1.8 Å crystal structure of arginine-bound CASTOR1. Homodimeric CASTOR1 binds arginine at the interface of two ACT domains, enabling allosteric control of the adjacent GATOR2-binding site to trigger dissociation from GATOR2 and the downstream activation of mTORC1. Our data reveal that CASTOR1 shares substantial structural homology with the lysine-binding regulatory domain of prokaryotic aspartate kinases, suggesting that the mTORC1 pathway exploited an ancient amino-acid-dependent allosteric mechanism to acquire arginine sensitivity. Together, these results establish a structural basis for arginine sensing by the mTORC1 pathway and provide insights into the evolution of a mammalian nutrient sensor. PMID:27487210

  13. Escherichia coli tatC mutations that suppress defective twin-arginine transporter signal peptides.

    PubMed

    Strauch, Eva-Maria; Georgiou, George

    2007-11-23

    In vitro studies have suggested that the TatBC complex serves as the receptor for signal peptides targeted for export via the twin-arginine translocation (Tat) pathway. Substitution of the hallmark twin-arginine dipeptide with two lysines abrogates export of physiological substrates in all organisms. We report the isolation and characterization of suppressor mutations that allow export of an ssTor(KK)-GFP-SsrA tripartite fusion. We identified two amino acid suppressor mutations in the first cytoplasmic loop of TatC. In addition, two other amino acids in the first cytoplasmic loop exhibit epistatic suppression. Surprisingly, we also identified a suppressor mutation predicted to lie within the second periplasmic loop of TatC, a region that is not expected to interact directly with the signal peptide. The suppressor mutations allowed export of the native Esherichia coli Tat substrate trimethylamine N-oxide reductase with a twin-lysine substitution in its signal sequence. The cytoplasmic suppressor mutations conferred SDS sensitivity and partial filamentation, indicating that Tat export of authentic substrates was impaired.

  14. Non-enzymatic interactions of glyoxylate with lysine, arginine, and glucosamine: a study of advanced non-enzymatic glycation like compounds.

    PubMed

    Dutta, Udayan; Cohenford, Menashi A; Guha, Madhumita; Dain, Joel A

    2007-02-01

    Glyoxylate is a 2 carbon aldo acid that is formed in hepatic tissue from glycolate. Once formed, the molecule can be converted to glycine by alanine-glyoxylate aminotransferase (AGAT). In defects of AGAT, glyoxylate is transformed to oxalate, resulting in high levels of oxalate in the body. The objective of this study was 2-fold. First, it was to determine, if akin to D-glucose, D-fructose or DL-glyceraldehyde, glyoxylate was susceptible to non-enzymatic attack by amino containing molecules such as lysine, arginine or glucosamine. Second, if by virtue of its molecular structure and size, glyoxylate was as reactive a reagent in non-enzymatic reactions as DL-glyceraldehyde; i.e., a glycose that we previously demonstrated to be a more effective glycating agent than D-glucose or D-fructose. Using capillary electrophoresis (CE), high performance liquid chromatography and UV and fluorescence spectroscopy, glyoxylate was found to be a highly reactive precursor of advanced glycation like end products (AGLEs) and a more effective promoter of non-enzymatic end products than D-glucose, D-fructose or DL-glyceraldehyde.

  15. Investigation and kinetic evaluation of the reactions of hydroxymethylfurfural with amino and thiol groups of amino acids.

    PubMed

    Hamzalıoğlu, Aytül; Gökmen, Vural

    2018-02-01

    In this study, reactions of hydroxymethylfurfural (HMF) with selected amino acids (arginine, cysteine and lysine) were investigated in HMF-amino acid (high moisture) and Coffee-amino acid (low moisture) model systems at 5, 25 and 50°C. The results revealed that HMF reacted efficiently and effectively with amino acids in both high and low moisture model systems. High-resolution mass spectrometry (HRMS) analyses of the reaction mixtures confirmed the formations of Michael adduct and Schiff base of HMF with amino acids. Calculated pseudo-first order reaction rate constants were in the following order; k Cysteine >k Arginine >k Lysine for high moisture model systems. Comparing to these rate constants, the k Cysteine decreased whereas, k Arginine and k Lysine increased under the low moisture conditions of Coffee-amino acid model systems. The temperature dependence of the rate constants was found to obey the Arrhenius law in a temperature range of 5-50°C under both low and high moisture conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Opposite Associations of Plasma Homoarginine and Ornithine with Arginine in Healthy Children and Adolescents

    PubMed Central

    JaŸwińska-Kozuba, Aleksandra; Martens-Lobenhoffer, Jens; Kruszelnicka, Olga; Rycaj, Jarosław; Chyrchel, Bernadeta; Surdacki, Andrzej; Bode-Böger, Stefanie M.

    2013-01-01

    Homoarginine, a non-proteinogenic amino acid, is formed when lysine replaces ornithine in reactions catalyzed by hepatic urea cycle enzymes or lysine substitutes for glycine as a substrate of renal arginine:glycine amidinotransferase. Decreased circulating homoarginine and elevated ornithine, a downstream product of arginase, predict adverse cardiovascular outcome. Our aim was to investigate correlates of plasma homoarginine and ornithine and their relations with carotid vascular structure in 40 healthy children and adolescents aged 3–18 years without coexistent diseases or subclinical carotid atherosclerosis. Homoarginine, ornithine, arginine, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) were measured by liquid chromatography-tandem mass spectrometry with stable isotope-labeled internal standards. Intima-media thickness (IMT) and extra-medial thickness (EMT) of common carotid arteries were estimated by B-mode ultrasound. Homoarginine correlated with arginine (r = 0.43, p = 0.005), age (r = 0.42, p = 0.007) and, weakly, with an increased arginine-to-ornithine ratio, a putative measure of lower arginase activity (r = 0.31, p = 0.048). Ornithine correlated inversely with arginine (r = −0.64, p < 0.001). IMT, EMT or their sum were unrelated to any of the biochemical parameters (p > 0.12). Thus, opposite associations of plasma homoarginine and ornithine with arginine may partially result from possible involvement of arginase, an enzyme controlling homoarginine degradation and ornithine synthesis from arginine. Age-dependency of homoarginine levels can reflect developmental changes in homoarginine metabolism. However, neither homoarginine nor ornithine appears to be associated with carotid vascular structure in healthy children and adolescents. PMID:24192823

  17. Roles of export genes cgmA and lysE for the production of L-arginine and L-citrulline by Corynebacterium glutamicum.

    PubMed

    Lubitz, Dorit; Jorge, João M P; Pérez-García, Fernando; Taniguchi, Hironori; Wendisch, Volker F

    2016-10-01

    L-arginine is a semi-essential amino acid with application in cosmetic, pharmaceutical, and food industries. Metabolic engineering strategies have been applied for overproduction of L-arginine by Corynebacterium glutamicum. LysE was the only known L-arginine exporter of this bacterium. However, an L-arginine-producing strain carrying a deletion of lysE still accumulated about 10 mM L-arginine in the growth medium. Overexpression of the putative putrescine and cadaverine export permease gene cgmA was shown to compensate for the lack of lysE with regard to L-arginine export. Moreover, plasmid-borne overexpression of cgmA rescued the toxic effect caused by feeding of the dipeptide Arg-Ala to lysE-deficient C. glutamicum and argO-deficient Escherichia coli strains. Deletion of the repressor gene cgmR improved L-arginine titers by 5 %. Production of L-lysine and L-citrulline was not affected by cgmA overexpression. Taken together, CgmA may function as an export system not only for the diamine putrescine and cadaverine but also for L-arginine. The major export system for L-lysine and L-arginine LysE may also play a role in L-citrulline export since production of L-citrulline was reduced when lysE was deleted and improved by 45 % when lysE was overproduced.

  18. Conformational dynamics of L-lysine, L-arginine, L-ornithine binding protein reveals ligand-dependent plasticity.

    PubMed

    Silva, Daniel-Adriano; Domínguez-Ramírez, Lenin; Rojo-Domínguez, Arturo; Sosa-Peinado, Alejandro

    2011-07-01

    The molecular basis of multiple ligand binding affinity for amino acids in periplasmic binding proteins (PBPs) and in the homologous domain for class C G-protein coupled receptors is an unsolved question. Here, using unrestrained molecular dynamic simulations, we studied the ligand binding mechanism present in the L-lysine, L-arginine, L-ornithine binding protein. We developed an analysis based on dihedral angles for the description of the conformational changes upon ligand binding. This analysis has an excellent correlation with each of the two main movements described by principal component analysis (PCA) and it's more convenient than RMSD measurements to describe the differences in the conformational ensembles observed. Furthermore, an analysis of hydrogen bonds showed specific interactions for each ligand studied as well as the ligand interaction with the aromatic residues Tyr-14 and Phe-52. Using uncharged histidine tautomers, these interactions are not observed. On the basis of these results, we propose a model in which hydrogen bond interactions place the ligand in the correct orientation to induce a cation-π interaction with Tyr-14 and Phe-52 thereby stabilizing the closed state. Our results also show that this protein adopts slightly different closed conformations to make available specific hydrogen bond interactions for each ligand thus, allowing a single mechanism to attain multiple ligand specificity. These results shed light on the experimental evidence for ligand-dependent conformational plasticity not explained by the previous crystallographic data. Copyright © 2011 Wiley-Liss, Inc.

  19. Complexation des acides aminés basiques arginine, histidine et lysine avec l'ADN plasmidique en solution aqueuse : participation à la capture de radicaux sous irradiation X à 1,5 keV

    NASA Astrophysics Data System (ADS)

    Tariq Khalil, Talat; Taillefumier, Baptiste; Boulanouar, Omar; Mavon, Christophe; Fromm, Michel

    2016-09-01

    L'environnement chimique de l'ADN en situation biologique est complexe notam-ment en raison de la présence d'histones, protéines nucléaires, associées en quantité approximativement égales à l'ADN pour former la chromatine. Les histones possèdent de nombreux radicaux basiques arginine et lysine chargés positivement et dont la majorité se trouve sur les chaînes émergentes, l'ADN présente quant à lui des charges négatives sur ses groupements phosphates localisés tout au long de la double hélice. Dans cette étude, la complexité de la structure de la chromatine nucléaire est dans un premier temps mimée en solution aqueuse par la formation de complexes entre un ADN plasmidique sonde et les trois acides aminés basiques, Arg, His, Lys, qui, mis à part His, sont protonés au pH physiologique. Ces acides aminés libres en solution sont réputés être des capteurs efficaces de radicaux libres, notamment pour le radical hydroxyle, conférant ainsi un pouvoir protecteur vis-à-vis des effets indirects sur l'ADN en situation d'exposition aux rayonnements ionisants. A concentration fixée, les capacités de capture des acides aminés libres, σ, pour le radical hydroxyle sont typiquement les suivantes σHis ≈σArg > σLys (σLys ≈ 0,1 × σArg). Nous avons mesuré les taux de cassures simple brin par plasmide et par Gray (χ) lors d'expositions de solutions aqueuses de complexes [acide aminé - ADN plasmidique] aux rayons X ultra-mous (1,5 keV). A concentrations égales, les trois acides aminés complexés et présents en large excès ne manifestent pas une capacité de protection de l'ADN proportionnelle à leur capacité de capture libre et en solution ; on trouve en effet des taux de cassures dans l'ordre suivant χHis > χArg > χLys (χLys ≈ 0,01 χArg). Après avoir détaillé le mode opératoire de ces mesures, nous analyserons sur des bases bibliographiques, les modes spécifiques d'interaction des acides aminés basiques avec l'ADN. La sp

  20. Structural Basis for Recognition of L-lysine, L-ornithine, and L-2,4-diamino Butyric Acid by Lysine Cyclodeaminase.

    PubMed

    Min, Kyungjin; Yoon, Hye-Jin; Matsuura, Atsushi; Kim, Yong Hwan; Lee, Hyung Ho

    2018-04-30

    L-pipecolic acid is a non-protein amino acid commonly found in plants, animals, and microorganisms. It is a well-known precursor to numerous microbial secondary metabolites and pharmaceuticals, including anticancer agents, immunosuppressants, and several antibiotics. Lysine cyclodeaminase (LCD) catalyzes β-deamination of L-lysine into L-pipecolic acid using β-nicotinamide adenine dinucleotide as a cofactor. Expression of a human homolog of LCD, μ-crystallin, is elevated in prostate cancer patients. To understand the structural features and catalytic mechanisms of LCD, we determined the crystal structures of Streptomyces pristinaespiralis LCD (SpLCD) in (i) a binary complex with NAD + , (ii) a ternary complex with NAD + and L-pipecolic acid, (iii) a ternary complex with NAD + and L-proline, and (iv) a ternary complex with NAD + and L-2,4-diamino butyric acid. The overall structure of SpLCD was similar to that of ornithine cyclodeaminase from Pseudomonas putida . In addition, SpLCD recognized L-lysine, L-ornithine, and L-2,4-diamino butyric acid despite differences in the active site, including differences in hydrogen bonding by Asp236, which corresponds with Asp228 from Pseudomonas putida ornithine cyclodeaminase. The substrate binding pocket of SpLCD allowed substrates smaller than lysine to bind, thus enabling binding to ornithine and L-2,4-diamino butyric acid. Our structural and biochemical data facilitate a detailed understanding of substrate and product recognition, thus providing evidence for a reaction mechanism for SpLCD. The proposed mechanism is unusual in that NAD + is initially converted into NADH and then reverted back into NAD + at a late stage of the reaction.

  1. Lactic acid bacteria isolated from apples are able to catabolise arginine.

    PubMed

    Savino, María J; Sánchez, Leandro A; Saguir, Fabiana M; de Nadra, María C Manca

    2012-03-01

    We investigated the potentiality of lactic acid bacteria (LAB) isolated from two apples variety to utilize arginine at different initial pH values. Apples surface contained average levels of bacteria ranging from log 2.49 ± 0.53 to log 3.73 ± 0.48 cfu/ml for Red Delicious and Golden Delicious varieties, respectively. Thirty-one strains able to develop in presence of arginine at low pH were phenotypically and genotipically identified as belonging to Lactobacillus, Pediococcus and Leuconostoc genera. In general, they did not produce ammonia from arginine when cultivated in basal medium with arginine (BMA) at pH 4.5 or 5.2. When this metabolite was quantified only six strains belonging to Leuconostoc dextranicum, Lactobacillus brevis and Lactobacillus plantarum species formed higher ammonia amounts in BMA as compared to control. This was correlated with arginine utilization and it was more pronounced at pH 4.5 than 5.2. Analysis of citrulline production confirmed the arginine utilization in these bacteria by the arginine deiminase (ADI) pathway. Maxima citrulline production was observed for Lactobacillus brevis M15 at the two pH values. In this strain ammonia was formed at higher rate than citrulline, which was detected in concentration lower than 1 mM. Thus, main LAB species found on apple surfaces with abilities to degrade arginine by the ADI pathway under different conditions were reported here at the first time. The results suggested that the ADI pathway in apples LAB might not be mainly relevant for their survival in the acid natural environmental, despite leading to the ammonia formation, which may contribute to the increase in pH, coping the acid stress.

  2. Histidine-lysine peptides as carriers of nucleic acids.

    PubMed

    Leng, Qixin; Goldgeier, Lisa; Zhu, Jingsong; Cambell, Patricia; Ambulos, Nicholas; Mixson, A James

    2007-03-01

    With their biodegradability and diversity of permutations, peptides have significant potential as carriers of nucleic acids. This review will focus on the sequence and branching patterns of peptide carriers composed primarily of histidines and lysines. While lysines within peptides are important for binding to the negatively charged phosphates, histidines are critical for endosomal lysis enabling nucleic acids to reach the cytosol. Histidine-lysine (HK) polymers by either covalent or ionic bonds with liposomes augment transfection compared to liposome carriers alone. More recently, we have examined peptides as sole carriers of nucleic acids because of their intrinsic advantages compared to the bipartite HK/liposome carriers. With a protocol change and addition of a histidine-rich tail, HK peptides as sole carriers were more effective than liposomes alone in several cell lines. While four-branched polymers with a primary repeating sequence pattern of -HHK- were more effective as carriers of plasmids, eight-branched polymers with a sequence pattern of -HHHK- were more effective as carriers of siRNA. Compared to polyethylenimine, HK carriers of siRNA and plasmids had reduced toxicity. When injected intravenously, HK polymers in complex with plasmids encoding antiangiogenic proteins significantly decreased tumor growth. Furthermore, modification of HK polymers with polyethylene glycol and vascular-specific ligands increased specificity of the polyplex to the tumor by more than 40-fold. Together with further development and insight on the structure of HK polyplexes, HK peptides may prove to be useful as carriers of different forms of nucleic acids both in vitro and in vivo.

  3. Escherichia coli twin arginine (Tat) mutant translocases possessing relaxed signal peptide recognition specificities.

    PubMed

    Kreutzenbeck, Peter; Kröger, Carsten; Lausberg, Frank; Blaudeck, Natascha; Sprenger, Georg A; Freudl, Roland

    2007-03-16

    The twin arginine (Tat) secretion pathway allows the translocation of folded proteins across the cytoplasmic membrane of bacteria. Tat-specific signal peptides contain a characteristic amino acid motif ((S/T)RRXFLK) including two highly conserved consecutive arginine residues that are thought to be involved in the recognition of the signal peptides by the Tat translocase. Here, we have analyzed the specificity of Tat signal peptide recognition by using a genetic approach. Replacement of the two arginine residues in a Tat-specific precursor protein by lysine-glutamine resulted in an export-defective mutant precursor that was no longer accepted by the wild-type translocase. Selection for restored export allowed for the isolation of Tat translocases possessing single mutations in either the amino-terminal domain of TatB or the first cytosolic domain of TatC. The mutant Tat translocases still efficiently accepted the unaltered precursor protein, indicating that the substrate specificity of the translocases was not strictly changed; rather, the translocases showed an increased tolerance toward variations of the amino acids occupying the positions of the twin arginine residues in the consensus motif of a Tat signal peptide.

  4. Voluntary wheel running is beneficial to the amino acid profile of lysine-deficient rats.

    PubMed

    Nagao, Kenji; Bannai, Makoto; Seki, Shinobu; Kawai, Nobuhiro; Mori, Masato; Takahashi, Michio

    2010-06-01

    Rats voluntarily run up to a dozen kilometers per night when their cages are equipped with a running wheel. Daily voluntary running is generally thought to enhance protein turnover. Thus, we sought to determine whether running worsens or improves protein degradation caused by a lysine-deficient diet and whether it changes the utilization of free amino acids released by proteolysis. Rats were fed a lysine-deficient diet and were given free access to a running wheel or remained sedentary (control) for 4 wk. Amino acid levels in plasma, muscle, and liver were measured together with plasma insulin levels and tissue weight. The lysine-deficient diet induced anorexia, skeletal muscle loss, and serine and threonine aminoacidemia, and it depleted plasma insulin and essential amino acids in skeletal muscle. Allowing rats to run voluntarily improved these symptoms; thus, voluntary wheel running made the rats less susceptible to dietary lysine deficiency. Amelioration of the declines in muscular leucine and plasma insulin observed in running rats could contribute to protein synthesis together with the enhanced availability of lysine and other essential amino acids in skeletal muscle. These results indicate that voluntary wheel running under lysine-deficient conditions does not enhance protein catabolism; on the contrary, it accelerates protein synthesis and contributes to the maintenance of muscle mass. The intense nocturnal voluntary running that characterizes rodents might be an adaptation of lysine-deficient grain eaters that allows them to maximize opportunities for food acquisition.

  5. Expanding lysine industry: industrial biomanufacturing of lysine and its derivatives.

    PubMed

    Cheng, Jie; Chen, Peng; Song, Andong; Wang, Dan; Wang, Qinhong

    2018-04-13

    L-Lysine is widely used as a nutrition supplement in feed, food, and beverage industries as well as a chemical intermediate. At present, great efforts are made to further decrease the cost of lysine to make it more competitive in the markets. Furthermore, lysine also shows potential as a feedstock to produce other high-value chemicals for active pharmaceutical ingredients, drugs, or materials. In this review, the current biomanufacturing of lysine is first presented. Second, the production of novel derivatives from lysine is discussed. Some chemicals like L-pipecolic acid, cadaverine, and 5-aminovalerate already have been obtained at a lab scale. Others like 6-aminocaproic acid, valerolactam, and caprolactam could be produced through a biological and chemical coupling pathway or be synthesized by a hypothetical pathway. This review demonstrates an active and expansive lysine industry, and these green biomanufacturing strategies could also be applied to enhance the competitiveness of other amino acid industry.

  6. Protein arginine methylation/demethylation and cancer

    PubMed Central

    Poulard, Coralie; Corbo, Laura; Le Romancer, Muriel

    2016-01-01

    Protein arginine methylation is a common post-translational modification involved in numerous cellular processes including transcription, DNA repair, mRNA splicing and signal transduction. Currently, there are nine known members of the protein arginine methyltransferase (PRMT) family, but only one arginine demethylase has been identified, namely the Jumonji domain-containing 6 (JMJD6). Although its demethylase activity was initially challenged, its dual activity as an arginine demethylase and a lysine hydroxylase is now recognized. Interestingly, a growing number of substrates for arginine methylation and demethylation play key roles in tumorigenesis. Though alterations in the sequence of these enzymes have not been identified in cancer, their overexpression is associated with various cancers, suggesting that they could constitute targets for therapeutic strategies. In this review, we present the recent knowledge of the involvement of PRMTs and JMJD6 in tumorigenesis. PMID:27556302

  7. Arginine- and lysine-specific polymers for protein recognition and immobilization.

    PubMed

    Renner, Christian; Piehler, Jacob; Schrader, Thomas

    2006-01-18

    Free radical polymerization of methacrylamide-based bisphosphonates turns weak arginine binders into powerful polymeric protein receptors. Dansyl-labeled homo- and copolymers with excellent water solubility are accessible through a simple copolymerization protocol. Modeling studies point to a striking structural difference between the stiff rodlike densely packed homopolymer 1 and the flexible copolymer 2 with spatially separated bisphosphonate units. Fluorescence titrations in buffered aqueous solution (pH = 7.0) confirm the superior affinity of the homopolymer toward oligoarginine peptides reaching nanomolar K(D) values for the Tat peptide. Basic proteins are bound almost equally well by 1 and 2 with micromolar affinities, with the latter producing much more soluble complexes. The Arg selectivity of the monomer is transferred to the polymer, which binds Arg-rich proteins 1 order of magnitude tighter than lysine-rich pendants of comparable pI, size, and (Arg/Lys vs Glu/Asp) ratio. Noncovalent deposition of both polymers on glass substrates via polyethyleneimine layers results in new materials suitable for peptide and protein immobilization. RIfS measurements allow calculation of association constants K(a) as well as dissociation kinetics k(D). They generally confirm the trends already found in free solution. Close inspection of electrostatic potential surfaces suggest that basic domains favor protein binding on the flat surface. The high specificity of the bisphosphonate polymers toward basic proteins is demonstrated by comparison with polyvinyl sulfate, which has almost no effect in RIfS experiments. Thus, copolymerization of few different comonomer units without cross-linking enables surface recognition of basic proteins in free solution as well as their effective immobilization on surfaces.

  8. Synthesis and cytotoxicity of azo nano-materials as new biosensors for L-Arginine determination.

    PubMed

    Shang, Xuefang; Luo, Leiming; Ren, Kui; Wei, Xiaofang; Feng, Yaqian; Li, Xin; Xu, Xiufang

    2015-06-01

    Inspired from biological counterparts, chemical modification of azo derivatives with function groups may provide a highly efficient method to detect amino acid. Herein, we have designed and prepared a series of azo nano-materials involving -NO2, -COOH, -SO3H and naphthyl group, which showed high response for Arginine (Arg) among normal twenty kinds of (Alanine, Valine, Leucine, Isoleucine, Methionine, Aspartic acid, Glutamic acid, Arginine, Glycine, Serine, Threonine, Asparagine, Phenylalanine, Histidine, Tryptophan, Proline, Lysine, Glutamine, Tyrosine and Cysteine). Furthermore, theoretical investigation further illustrated the possible binding mode in the host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. In addition, nano-material 3 exhibited high binding ability for Arg and low cytotoxicity to KYSE450 cells over a concentration range of 5-50μmol·L(-1) which may be used a biosensor for the Arg detection in vivo. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Arginine Catabolism by Sourdough Lactic Acid Bacteria: Purification and Characterization of the Arginine Deiminase Pathway Enzymes from Lactobacillus sanfranciscensis CB1

    PubMed Central

    De Angelis, Maria; Mariotti, Liberato; Rossi, Jone; Servili, Maurizio; Fox, Patrick F.; Rollán, Graciela; Gobbetti, Marco

    2002-01-01

    The cytoplasmic extracts of 70 strains of the most frequently isolated sourdough lactic acid bacteria were screened initially for arginine deiminase (ADI), ornithine transcarbamoylase (OTC), and carbamate kinase (CK) activities, which comprise the ADI (or arginine dihydrolase) pathway. Only obligately heterofermentative strains such as Lactobacillus sanfranciscensis CB1; Lactobacillus brevis AM1, AM8, and 10A; Lactobacillus hilgardii 51B; and Lactobacillus fructivorans DD3 and DA106 showed all three enzyme activities. Lactobacillus plantarum B14 did not show CK activity. L. sanfranciscensis CB1 showed the highest activities, and the three enzymes were purified from this microorganism to homogeneity by several chromatographic steps. ADI, OTC, and CK had apparent molecular masses of ca. 46, 39, and 37 kDa, respectively, and the pIs were in the range of 5.07 to 5.2. The OTCs, CKs, and especially ADIs were well adapted to pH (acidic, pH 3.5 to 4.5) and temperature (30 to 37°C) conditions which are usually found during sourdough fermentation. Internal peptide sequences of the three enzymes had the highest level of homology with ADI, OTC, and CK of Lactobacillus sakei. L. sanfranciscensis CB1 expressed the ADI pathway either on MAM broth containing 17 mM arginine or during sourdough fermentation with 1 to 43 mM added arginine. Two-dimensional electrophoresis showed that ADI, OTC, and CK were induced by factors of ca. 10, 4, and 2 in the whole-cell extract of cells grown in MAM broth containing 17 mM arginine compared to cells cultivated without arginine. Arginine catabolism in L. sanfranciscensis CB1 depended on the presence of a carbon source and arginine; glucose at up to ca. 54 mM did not exert an inhibitory effect, and the pH was not relevant for induction. The pH of sourdoughs fermented by L. sanfranciscensis CB1 was dependent on the amount of arginine added to the dough. A low supply of arginine (6 mM) during sourdough fermentation by L. sanfranciscensis CB1

  10. A molecular rotor based ratiometric sensor for basic amino acids

    NASA Astrophysics Data System (ADS)

    Pettiwala, Aafrin M.; Singh, Prabhat K.

    2018-01-01

    The inevitable importance of basic amino acids, arginine and lysine, in human health and metabolism demands construction of efficient sensor systems for them. However, there are only limited reports on the 'ratiometric' detection of basic amino acids which is further restricted by the use of chemically complex sensor molecules, which impedes their prospect for practical applications. Herein, we report a ratiometric sensor system build on simple mechanism of disassociation of novel emissive Thioflavin-T H-aggregates from heparin surface, when subjected to interaction with basic amino acids. The strong and selective electrostatic and hydrogen bonding interaction of basic amino acids with heparin leads to large alteration in photophysical attributes of heparin bound Thioflavin-T, which forms a highly sensitive sensor platform for detection of basic amino acids in aqueous solution. These selective interactions between basic amino acids and heparin allow our sensor system to discriminate arginine and lysine from other amino acids. This unique mechanism of dissociation of Thioflavin-T aggregates from heparin surface provides ratiometric response on both fluorimetric and colorimetric outputs for detection of arginine and lysine, and thus it holds a significant advantage over other developed sensor systems which are restricted to single wavelength detection. Apart from the sensitivity and selectivity, our system also provides the advantage of simplicity, dual mode of sensing, and more importantly, it employs an inexpensive commercially available probe molecule, which is a significant advantage over other developed sensor systems that uses tedious synthesis protocol for the employed probe in the detection scheme, an impediment for practical applications. Additionally, our sensor system also shows response in complex biological media of serum samples.

  11. A molecular rotor based ratiometric sensor for basic amino acids.

    PubMed

    Pettiwala, Aafrin M; Singh, Prabhat K

    2018-01-05

    The inevitable importance of basic amino acids, arginine and lysine, in human health and metabolism demands construction of efficient sensor systems for them. However, there are only limited reports on the 'ratiometric' detection of basic amino acids which is further restricted by the use of chemically complex sensor molecules, which impedes their prospect for practical applications. Herein, we report a ratiometric sensor system build on simple mechanism of disassociation of novel emissive Thioflavin-T H-aggregates from heparin surface, when subjected to interaction with basic amino acids. The strong and selective electrostatic and hydrogen bonding interaction of basic amino acids with heparin leads to large alteration in photophysical attributes of heparin bound Thioflavin-T, which forms a highly sensitive sensor platform for detection of basic amino acids in aqueous solution. These selective interactions between basic amino acids and heparin allow our sensor system to discriminate arginine and lysine from other amino acids. This unique mechanism of dissociation of Thioflavin-T aggregates from heparin surface provides ratiometric response on both fluorimetric and colorimetric outputs for detection of arginine and lysine, and thus it holds a significant advantage over other developed sensor systems which are restricted to single wavelength detection. Apart from the sensitivity and selectivity, our system also provides the advantage of simplicity, dual mode of sensing, and more importantly, it employs an inexpensive commercially available probe molecule, which is a significant advantage over other developed sensor systems that uses tedious synthesis protocol for the employed probe in the detection scheme, an impediment for practical applications. Additionally, our sensor system also shows response in complex biological media of serum samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Transport of aspartic acid, arginine, and tyrosine by the opportunistic protist Pneumocystis carinii.

    PubMed

    Basselin, M; Lipscomb, K J; Qiu, Y H; Kaneshiro, E S

    2001-04-02

    In order to improve culture media and to discover potential drug targets, uptake of an acidic, a basic, and an aromatic amino acid were investigated. Current culture systems, axenic or co-cultivation with mammalian cells, do not provide either the quantity or quality of cells needed for biochemical studies of this organism. Insight into nutrient acquisition can be expected to lead to improved culture media and improved culture growth. Aspartic acid uptake was directly related to substrate concentration, Q(10) was 1.10 at pH 7.4. Hence the organism acquired this acidic amino acid by simple diffusion. Uptake of the basic amino acid arginine and the aromatic amino acid tyrosine exhibited saturation kinetics consistent with carrier-mediated mechanisms. Kinetic parameters indicated two carriers (K(m)=22.8+/-2.5 microM and K(m)=3.6+/-0.3 mM) for arginine and a single carrier for tyrosine (K(m)=284+/-23 microM). The effects of other L-amino acids showed that the tyrosine carrier was distinct from the arginine carriers. Tyrosine and arginine transport were independent of sodium and potassium ions, and did not appear to require energy from ATP or a proton motive force. Thus facilitated diffusion was identified as the mechanism of uptake. After 30 min of incubation, these amino acids were incorporated into total lipids and the sedimentable material following lipid extraction; more than 90% was in the cellular soluble fraction.

  13. Selective control of toxic Microcystis water blooms using lysine and malonic acid: an enclosure experiment.

    PubMed

    Kaya, Kunimitsu; Liu, Yong-Ding; Shen, Yin-Wu; Xiao, Bang-Ding; Sano, Tomoharu

    2005-04-01

    Three enclosures (10 x 10 x 1.5-1.3 m in depth) were set beside Dianch Lake, Kunming, People's Republic of China, for the period from July 28 to August 26, 2002. The enclosures were filled with cyanobacterial (Microcystis aeruginosa) water bloom-containing lake water. Lake sediment that contained macrophytes and water chestnut seeds was spread over the entire bottom of each enclosure. Initially, 10 g/m(2) of lysine was sprayed in Enclosure B, and 10 g/m(2) each of lysine and malonic acid were sprayed together in Enclosure C. Enclosure A remained untreated and was used as a control. The concentrations of lysine, malonic acid, chlorophyll a, and microcystin as well as the cell numbers of phytoplankton such as cyanobacteria, diatom, and euglena were monitored. On day 1 of the treatment, formation of cyanobacterial blooms almost ceased in Enclosures B and C, although Microcystis cells in the control still formed blooms. On day 7 Microcystis cells in Enclosure B that had been treated with lysine started growing again, whereas growth was not observed in Microcystis cells in Enclosure C, which had been treated with lysine and malonic acid. On day 28 the surface of Enclosure B was covered with water chestnut (Trapa spp.) and the Microcystis blooms again increased. In contrast, growth of macrophytes (Myriophllum spicatum and Potamogeton crispus) was observed in Enclosure C; however, no cyanobacterial blooms were observed. Lysine and malonic acid had completely decomposed. The microcystin concentration on day 28 decreased to 25% of the initial value, and the pH shifted from the initial value of 9.2 to 7.8. We concluded that combined treatment with lysine and malonic acid selectively controlled toxic Microcystis water blooms and induced the growth of macrophytes.

  14. Influence of phenolic compounds on the growth and arginine deiminase system in a wine lactic acid bacterium

    PubMed Central

    Alberto, María R.; de Nadra, María C. Manca; Arena, Mario E.

    2012-01-01

    The influence of seven phenolic compounds, normally present in wine, on the growth and arginine deiminase system (ADI) of Lactobacillus hilgardii X1B, a wine lactic acid bacterium, was established. This system provides energy for bacterial growth and produces citrulline that reacts with ethanol forming the carcinogen ethyl carbamate (EC), found in some wines. The influence of phenolic compounds on bacterial growth was compound dependent. Growth and final pH values increased in presence of arginine. Arginine consumption decreased in presence of protocatechuic and gallic acids (31 and 17%, respectively) and increased in presence of quercetin, rutin, catechin and the caffeic and vanillic phenolic acids (between 10 and 13%, respectively). ADI enzyme activities varied in presence of phenolic compounds. Rutin, quercetin and caffeic and vanillic acids stimulated the enzyme arginine deiminase about 37–40%. Amounts of 200 mg/L gallic and protocatechuic acids inhibited the arginine deiminase enzyme between 53 and 100%, respectively. Ornithine transcarbamylase activity was not modified at all concentrations of phenolic compounds. As gallic and protocatechuic acids inhibited the arginine deiminase enzyme that produces citrulline, precursor of EC, these results are important considering the formation of toxic compounds. PMID:24031815

  15. Detection of non-protein amino acids in the presence of protein amino acids. II.

    NASA Technical Reports Server (NTRS)

    Shapshak, P.; Okaji, M.

    1972-01-01

    Studies conducted with the JEOL 5AH amino acid analyzer are described. This instrument makes possible the programming of the chromatographic process. Data are presented showing the separations of seventeen non-protein amino acids in the presence of eighteen protein amino acids. It is pointed out that distinct separations could be obtained in the case of a number of chemically similar compounds, such as ornithine and lysine, N-amidino alanine and arginine, and iminodiacetic acid and S-carboxymethyl cysteine and aspartic acid.

  16. Mimicking of Arginine by Functionalized N(ω)-Carbamoylated Arginine As a New Broadly Applicable Approach to Labeled Bioactive Peptides: High Affinity Angiotensin, Neuropeptide Y, Neuropeptide FF, and Neurotensin Receptor Ligands As Examples.

    PubMed

    Keller, Max; Kuhn, Kilian K; Einsiedel, Jürgen; Hübner, Harald; Biselli, Sabrina; Mollereau, Catherine; Wifling, David; Svobodová, Jaroslava; Bernhardt, Günther; Cabrele, Chiara; Vanderheyden, Patrick M L; Gmeiner, Peter; Buschauer, Armin

    2016-03-10

    Derivatization of biologically active peptides by conjugation with fluorophores or radionuclide-bearing moieties is an effective and commonly used approach to prepare molecular tools and diagnostic agents. Whereas lysine, cysteine, and N-terminal amino acids have been mostly used for peptide conjugation, we describe a new, widely applicable approach to peptide conjugation based on the nonclassical bioisosteric replacement of the guanidine group in arginine by a functionalized carbamoylguanidine moiety. Four arginine-containing peptide receptor ligands (angiotensin II, neurotensin(8-13), an analogue of the C-terminal pentapeptide of neuropeptide Y, and a neuropeptide FF analogue) were subject of this proof-of-concept study. The N(ω)-carbamoylated arginines, bearing spacers with a terminal amino group, were incorporated into the peptides by standard Fmoc solid phase peptide synthesis. The synthesized chemically stable peptide derivatives showed high receptor affinities with Ki values in the low nanomolar range, even when bulky fluorophores had been attached. Two new tritiated tracers for angiotensin and neurotensin receptors are described.

  17. Enhanced antibacterial activity of amino acids-functionalized multi walled carbon nanotubes by a simple method.

    PubMed

    Zardini, Hadi Zare; Amiri, Ahmad; Shanbedi, Mehdi; Maghrebi, Morteza; Baniadam, Majid

    2012-04-01

    Multi-walled carbon nanotubes (MWCNTs) were first functionalized by arginine and lysine under microwave radiation. Surface functionalization was confirmed by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and transmission electron microscopy (TEM). After the MWCNTs were functionalized by arginine and lysine, the antibacterial activity of all treated samples was increased significantly against all bacteria that were tested. Based on the observed minimum inhibitory concentration and radial diffusion assay, the sequence of antibacterial activity was MWCNTs-arginine>MWCNTs-lysine>pristine MWCNTs. The functionalized MWCNTs were especially effective against gram-negative bacteria (e.g., Escherichia coli and Salmonella typhimurium). Interestingly, the MWCNT samples were effective against the resistant strain Staphylococcos aureus. The enhanced antibacterial activity was attributed to electrostatic adsorption of bacteria membrane due to positive charges of the functional groups on MWCNTs surface. Since MWCNTs have lower cytotoxicity than single-walled carbon nanotubes, their functionalization with cationic amino acids could be a beneficial approach in the disinfection industry. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

    PubMed

    Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

    2014-09-01

    Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar. © 2014 Scandinavian Plant Physiology Society.

  19. Dose- and Glucose-Dependent Effects of Amino Acids on Insulin Secretion from Isolated Mouse Islets and Clonal INS-1E Beta-Cells

    PubMed Central

    Liu, Zhenping; Jeppesen, Per B.; Gregersen, Søren; Chen, Xiaoping; Hermansen, Kjeld

    2008-01-01

    BACKGROUND: The influence of glucose and fatty acids on beta-cell function is well established whereas little is known about the role of amino acids (AAs). METHODS: Islets isolated from NMRI mice were incubated overnight. After preincubation, isolated islets as well as clonal INS-1E beta-cells were incubated for 60 min in a modified Krebs Ringer buffer containing glucose and AAs. RESULTS: At 16.7 mmol/l (mM) glucose, L-arginine, L-lysine, L-alanine, L-proline, L-leucine, and L-glutamine potentiated glucose-stimulated insulin secretion dose-dependently, while DL-homocysteine inhibited insulin secretion. Maximal insulin stimulation was obtained at 20 mM L-proline, L-lysine, L-alanine, L-arginine (islets: 2.5 to 6.7 fold increase; INS-1E cells: 1.6 to 2.2 fold increase). L-glutamine and L-leucine only increased glucose-stimulated (16.7 mM) insulin secretion (INS-1E cells: 1.5 and 1.3 fold, respectively) at an AA concentration of 20 mM. Homocysteine inhibited insulin secretion both at 5.6 mM and 16.7 mM glucose. At glucose levels ranging from 1.1 to 25 mM, the equimolar concentration of 10 mM, L-proline, L-lysine, L-arginine increased insulin secretion from mouse islets and INS-1E cells at all glucose levels applied, with a maximal effect obtained at 25 mM glucose. At a concentration of 10 mM, L-arginine and L-lysine had the highest insulinotropic potency among the AAs investigated. CONCLUSION: L-arginine, L-lysine, L-alanine, L-proline, L-leucine and L-glutamine acutely stimulate insulin secretion from mouse islets and INS-1E cells in a dose- and glucose-dependent manner, whereas DL-homocysteine inhibits insulin release. PMID:19290384

  20. Lysine and glutamate transport in the erythrocytes of common brushtail possum, Tammar Wallaby and eastern grey, kangaroo.

    PubMed

    Ogawa, E; Kuchel, P W; Agar, N S

    1998-04-01

    It was recently coincidentally discovered, using 1H NMR spectroscopy, that the erythrocytes of two species of Australian marsupials, Tammar Wallaby (Macropus eugenii) and Bettong (Bettongia penicillata), contain relatively high concentrations of the essential amino acid lysine (Agar NS, Rae CD, Chapman BE, Kuchel PW. Comp Biochem Physiol 1991;99B:575-97). Hence, in the present work the rates of transport of lysine into the erythrocytes from the Common Brushtail Possum (Dactylopsilia trivirgata) and Eastern Grey Kangaroo (Macropus giganteus) (which both have low lysine concentrations), and Tammar Wallaby were studied, to explore the mechanistic basis of this finding. The concentration-dependence of the uptake was studied with lysine alone and in the presence of arginine, which may be a competitor of the transport in some species. In relation to GSH metabolism, glutamate uptake was determined in the presence and absence of Na+. The data was analysed to yield estimates of the maximal velocity (Vmax) and the Km in each of the species. Erythrocytes from Tammar Wallaby lacked saturable lysine transport in contrast to the other two species. The glutamate uptake was normal in all three animals for adequate GSH biosynthesis.

  1. Insight into the collagen assembly in the presence of lysine and glutamic acid: An in vitro study.

    PubMed

    Liu, Xinhua; Dan, Nianhua; Dan, Weihua

    2017-01-01

    The aim of this study is to evaluate the effects of two different charged amino acids in collagen chains, lysine and glutamic acid, on the fibrillogenesis process of collagen molecules. The turbidity, zeta potential, and fiber diameter analysis suggest that introducing the positively charged lysine into collagen might improve the sizes or amounts of the self-assembled collagen fibrils significantly. Conversely, the negatively charged glutamic acid might restrict the self-assembly of collagen building blocks into a higher order structure. Meanwhile, the optimal fibrillogenesis condition is achieved when the concentration of lysine reaches to 1mM. Both scanning electron microscopy (SEM) and atomic force microscope (AFM) analysis indicates that compared to pure collagen fibrils, the reconstructed collagen-lysine co-fibrils exhibit a higher degree of inter-fiber entanglements with more straight and longer fibrils. Noted that the specific D-period patterns of the reconstructed collagen fibrils could be clearly discernible and the width of D-banding increases steadily after introducing lysine. Besides, the kinetic and thermodynamic collagen self-assembly analysis confirms that the rate constants of both the first and second assembly phase decrease after introducing lysine, and lysine could promote the process of collagen fibrillogenesis obeying the laws of thermodynamics. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Loss of the arginine methyltranserase PRMT7 causes syndromic intellectual disability with microcephaly and brachydactyly.

    PubMed

    Kernohan, K D; McBride, A; Xi, Y; Martin, N; Schwartzentruber, J; Dyment, D A; Majewski, J; Blaser, S; Boycott, K M; Chitayat, D

    2017-05-01

    Post-translational protein modifications exponentially expand the functional complement of proteins encoded by the human genome. One such modification is the covalent addition of a methyl group to arginine or lysine residues, which is used to regulate a substantial proportion of the proteome. Arginine and lysine methylation are catalyzed by protein arginine methyltransferase (PRMTs) and protein lysine methyltransferase proteins (PKMTs), respectively; each methyltransferase has a specific set of target substrates. Here, we report a male with severe intellectual disability, facial dysmorphism, microcephaly, short stature, brachydactyly, cryptorchidism and seizures who was found to have a homozygous 15,309 bp deletion encompassing the transcription start site of PRMT7, which we confirmed is functionally a null allele. We show that the patient's cells have decreased levels of protein arginine methylation, and that affected proteins include the essential histones, H2B and H4. Finally, we demonstrate that patient cells have altered Wnt signaling, which may have contributed to the skeletal abnormalities. Our findings confirm the recent disease association of PRMT7, expand the phenotypic manifestations of this disorder and provide insight into the molecular pathogenesis of this new condition. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Amino acid nutrition beyond methionine and lysine for milk protein

    USDA-ARS?s Scientific Manuscript database

    Amino acids are involved in many important physiological processes affecting the production, health, and reproduction of high-producing dairy cows. Most research and recommendations for lactating dairy cows has focused on methionine and lysine for increasing milk protein yield. This is because these...

  4. L-arginine availability and arginase activity: Characterization of amino acid permease 3 in Leishmania amazonensis.

    PubMed

    Aoki, Juliana Ide; Muxel, Sandra Marcia; Zampieri, Ricardo Andrade; Acuña, Stephanie Maia; Fernandes, Juliane Cristina Ribeiro; Vanderlinde, Rubia Heloisa; Sales, Maria Carmen Oliveira de Pinho; Floeter-Winter, Lucile Maria

    2017-10-01

    Leishmania uses the amino acid L-arginine as a substrate for arginase, enzyme that produces urea and ornithine, last precursor of polyamine pathway. This pathway is used by the parasite to replicate and it is essential to establish the infection in the mammalian host. L-arginine is not synthesized by the parasite, so its uptake occurs through the amino acid permease 3 (AAP3). AAP3 is codified by two copies genes (5.1 and 4.7 copies), organized in tandem in the parasite genome. One copy presents the expression regulated by L-arginine availability. RNA-seq data revealed 14 amino acid transporters differentially expressed in the comparison of La-WT vs. La-arg- promastigotes and axenic amastigotes. The 5.1 and 4.7 aap3 transcripts were down-regulated in La-WT promastigotes vs. axenic amastigotes, and in La-WT vs. La-arg- promastigotes. In contrast, transcripts of other transporters were up-regulated in the same comparisons. The amount of 5.1 and 4.7 aap3 mRNA of intracellular amastigotes was also determined in sample preparations from macrophages, obtained from BALB/c and C57BL/6 mice and the human THP-1 lineage infected with La-WT or La-arg-, revealing that the genetic host background is also important. We also determined the aap3 mRNA and AAP3 protein amounts of promastigotes and axenic amastigotes in different environmental growth conditions, varying pH, temperature and L-arginine availability. Interestingly, the increase of temperature increased the AAP3 level in plasma membrane and consequently the L-arginine uptake, independently of pH and L-arginine availability. In addition, we demonstrated that besides the plasma membrane localization, AAP3 was also localized in the glycosome of L. amazonensis promastigotes and axenic amastigotes. In this report, we described the differential transcriptional profiling of amino acids transporters from La-WT and La-arg- promastigotes and axenic amastigotes. We also showed the increased AAP3 levels under amino acid starvation or

  5. Piezoelectric and pyroelectric properties of DL-alanine and L-lysine amino-acid polymer nanofibres

    NASA Astrophysics Data System (ADS)

    de Matos Gomes, Etelvina; Viseu, Teresa; Belsley, Michael; Almeida, Bernardo; Costa, Maria Margarida R.; Rodrigues, Vitor H.; Isakov, Dmitry

    2018-04-01

    The piezoelectric and pyroelectric properties of electrospun polyethylene oxide nanofibres embedded with polar amino acids DL-alanine and L-lysine hemihydrate are reported. A high pyroelectric coefficient of 150 μC m‑2 K‑1 was measured for L-lysine hemihydrate and piezoelectric current densities up to 7 μA m‑2 were obtained for the nanofibres. The study reveals a potential for polymer amino-acid nanofibres to be used as biocompatible energy harvesters for autonomous circuit applications like in implantable electronics.

  6. Protein Arginine Methylation in Mammals: Who, What, and Why

    PubMed Central

    Bedford, Mark T.; Clarke, Steven G.

    2012-01-01

    The covalent marking of proteins by methyl group addition to arginine residues can promote their recognition by binding partners or can modulate their biological activity. A small family of gene products that catalyze such methylation reactions in eukaryotes (PRMTs) work in conjunction with a changing cast of associated subunits to recognize distinct cellular substrates. These reactions display many of the attributes of reversible covalent modifications such as protein phosphorylation or protein lysine methylation; however, it is unclear to what extent protein arginine demethylation occurs. Physiological roles for protein arginine methylation have been established in signal transduction, mRNA splicing, transcriptional control, DNA repair, and protein translocation. PMID:19150423

  7. Development and cytotoxicity of Schiff base derivative as a fluorescence probe for the detection of L-Arginine

    NASA Astrophysics Data System (ADS)

    Shang, Xuefang; Li, Jie; Guo, Kerong; Ti, Tongyu; Wang, Tianyun; Zhang, Jinlian

    2017-04-01

    Inspired from biological counter parts, chemical modification of Schiff base derivatives with function groups may provide a highly efficient method to detect amino acids. Therefore, a fluorescent probe involving Schiff base and hydroxyl group has been designed and prepared, which showed high response and specificity for Arginine (Arg) among normal eighteen standard kinds of amino acids (Alanine, Valine, Leucine, Isoleucine, Methionine, Asparticacid, Glutamicacid, Arginine, Glycine, Serine, Threonine, Asparagine, Phenylalanine, Histidine, Tryptophan, Proline, Lysine, Glutamine, Tyrosine and Cysteine). Furthermore, theoretical investigation further illustrated the possible binding mode in the host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. In addition, the synthesized fluorescent probe exhibited high binding ability for Arg and low cytotoxicity to MCF-7 cells over a concentration range of 0-200 μg mL-1 which can be also used as a biosensor for the Arg detection in vivo.

  8. Lysine and Glutamic Acids as the End Products of Multi-response of Optimized Fermented Medium by Mucor mucedo KP736529.

    PubMed

    El-Hersh, Mohammed S; Saber, WesamEldin I A; El-Fadaly, Husain A; Mahmoud, Mohammed K

    Amino acids are important for living organisms, they acting as crucial for metabolic activities and energy generation, wherein the deficiency in these amino acids cause various physiological defects. The aim of this study is to investigate the effect of some nutritional factors on the amino acids production by Mucor mucedo KP736529 during fermentation intervals. Mucor mucedo KP736529 was selected according to proteolytic activity. Corn steep liquor and olive cake were used in the fermented medium during Placket-Burman and central composite design to maximize the production of lysine and glutamic acids. During the screening by Plackett-Burman design, olive cake and Corn Steep Liquor (CSL) had potential importance for the higher production of amino acids. The individual fractionation of total amino acids showed both lysine and glutamic as the major amino acids associated with the fermentation process. Moreover, the Central Composite Design (CCD) has been adopted to explain the interaction between olive cake and CSL on the production of lysine and glutamic acids. The model recorded significant F-value, with high values of R 2, adjusted R 2 and predicted R 2 for both lysine and glutamic, indicating the validity of the data. Solving equation for maximum production of lysine recorded theoretical levels of olive cake and CSL, being 2.58 and 1.83 g L -1, respectively, with predicting value of lysine at 1.470 μg mL -1, whereas the predicting value of glutamic acid reached 0.805 mg mL -1 at levels of 2.49 and 1.93 g L -1 from olive cake and CSL, respectively. The desirability function (D) showed the actual responses being 1.473±0.009 and 0.801±0.004 μg mL -1 for lysine and glutamic acids, respectively. The model showed adequate validity to be applied in a large-scale production of both lysine and glutamic acids.

  9. Molecular control mechanisms of lysine and threonine biosynthesis in amino acid-producing corynebacteria: redirecting carbon flow.

    PubMed

    Malumbres, M; Martín, J F

    1996-10-01

    Threonine and lysine are two of the economically most important essential amino acids. They are produced industrially by species of the genera Corynebacterium and Brevibacterium. The branched biosynthetic pathway of these amino acids in corynebacteria is unusual in gene organization and in the control of key enzymatic steps with respect to other microorganisms. This article reviews the molecular control mechanisms of the biosynthetic pathways leading to threonine and lysine in corynebacteria, and their implications in the production of these amino acids. Carbon flux can be redirected at branch points by gene disruption of the competing pathways for lysine or threonine. Removal of bottlenecks has been achieved by amplification of genes which encode feedback resistant aspartokinase and homoserine dehydrogenase (obtained by in vitro directed mutagenesis).

  10. Effect of lysine to arginine mutagenesis in the V3 loop of HIV-1 gp120 on viral entry efficiency and neutralization.

    PubMed

    Schwalbe, Birco; Schreiber, Michael

    2015-01-01

    HIV-1 infection is characterized by an ongoing replication leading to T-lymphocyte decline which is paralleled by the switch from CCR5 to CXCR4 coreceptor usage. To predict coreceptor usage, several computer algorithms using gp120 V3 loop sequence data have been developed. In these algorithms an occupation of the V3 positions 11 and 25, by one of the amino acids lysine (K) or arginine (R), is an indicator for CXCR4 usage. Amino acids R and K dominate at these two positions, but can also be identified at positions 9 and 10. Generally, CXCR4-viruses possess V3 sequences, with an overall positive charge higher than the V3 sequences of R5-viruses. The net charge is calculated by subtracting the number of negatively charged amino acids (D, aspartic acid and E, glutamic acid) from the number of positively charged ones (K and R). In contrast to D and E, which are very similar in their polar and acidic properties, the characteristics of the R guanidinium group differ significantly from the K ammonium group. However, in coreceptor predictive computer algorithms R and K are both equally rated. The study was conducted to analyze differences in infectivity and coreceptor usage because of R-to-K mutations at the V3 positions 9, 10 and 11. V3 loop mutants with all possible RRR-to-KKK triplets were constructed and analyzed for coreceptor usage, infectivity and neutralization by SDF-1α and RANTES. Virus mutants R9R10R11 showed the highest infectivity rates, and were inhibited more efficiently in contrast to the K9K10K11 viruses. They also showed higher efficiency in a virus-gp120 paired infection assay. Especially V3 loop position 9 was relevant for a switch to higher infectivity when occupied by R. Thus, K-to-R exchanges play a role for enhanced viral entry efficiency and should therefore be considered when the viral phenotype is predicted based on V3 sequence data.

  11. Effect of Lysine to Arginine Mutagenesis in the V3 Loop of HIV-1 gp120 on Viral Entry Efficiency and Neutralization

    PubMed Central

    Schwalbe, Birco; Schreiber, Michael

    2015-01-01

    HIV-1 infection is characterized by an ongoing replication leading to T-lymphocyte decline which is paralleled by the switch from CCR5 to CXCR4 coreceptor usage. To predict coreceptor usage, several computer algorithms using gp120 V3 loop sequence data have been developed. In these algorithms an occupation of the V3 positions 11 and 25, by one of the amino acids lysine (K) or arginine (R), is an indicator for CXCR4 usage. Amino acids R and K dominate at these two positions, but can also be identified at positions 9 and 10. Generally, CXCR4-viruses possess V3 sequences, with an overall positive charge higher than the V3 sequences of R5-viruses. The net charge is calculated by subtracting the number of negatively charged amino acids (D, aspartic acid and E, glutamic acid) from the number of positively charged ones (K and R). In contrast to D and E, which are very similar in their polar and acidic properties, the characteristics of the R guanidinium group differ significantly from the K ammonium group. However, in coreceptor predictive computer algorithms R and K are both equally rated. The study was conducted to analyze differences in infectivity and coreceptor usage because of R-to-K mutations at the V3 positions 9, 10 and 11. V3 loop mutants with all possible RRR-to-KKK triplets were constructed and analyzed for coreceptor usage, infectivity and neutralization by SDF-1α and RANTES. Virus mutants R9R10R11 showed the highest infectivity rates, and were inhibited more efficiently in contrast to the K9K10K11 viruses. They also showed higher efficiency in a virus-gp120 paired infection assay. Especially V3 loop position 9 was relevant for a switch to higher infectivity when occupied by R. Thus, K-to-R exchanges play a role for enhanced viral entry efficiency and should therefore be considered when the viral phenotype is predicted based on V3 sequence data. PMID:25785610

  12. Effect of Maillard browning reaction on protein utilization and plasma amino acid response by rainbow trout (Salmo gairdneri).

    PubMed

    Plakas, S M; Lee, T C; Wolke, R E; Meade, T L

    1985-12-01

    The effect of the Maillard browning reaction in the diet of rainbow trout (Salmo gairdneri) on growth and amino acid availability was investigated. Chemical and enzymatic hydrolysis methods were applied for the detection of the losses of amino acids in a model protein browning system. Arginine and lysine exhibited the greatest losses in the mixture of fish protein isolate and glucose stored for 40 d at 37 degrees C. The apparent digestibility and absorption of individual amino acids, particularly lysine, was lower in trout fed browned protein than in those fed the control protein. Plasma lysine levels were significantly depressed, while the plasma levels of glucose and most other amino acids were elevated in relation to the loss in nutritive value of dietary protein after browning. The early Maillard reaction derivative of lysine, epsilon-deoxy-fructosyl-lysine, was recovered from browned protein (by using the in vitro enzymatic hydrolysis procedure) and from the plasma of trout fed browned protein. Analysis of plasma free amino acids provided an indication of lysine bioavailability and identified lysine as the first-limiting amino acid in the diets containing browned protein.

  13. Use of amino acids as counterions improves the solubility of the BCS II model drug, indomethacin.

    PubMed

    ElShaer, Amr; Khan, Sheraz; Perumal, Dhaya; Hanson, Peter; Mohammed, Afzal R

    2011-07-01

    The number of new chemical entities (NCE) is increasing every day after the introduction of combinatorial chemistry and high throughput screening to the drug discovery cycle. One third of these new compounds have aqueous solubility less than 20µg/mL [1]. Therefore, a great deal of interest has been forwarded to the salt formation technique to overcome solubility limitations. This study aims to improve the drug solubility of a Biopharmaceutical Classification System class II (BCS II) model drug (Indomethacin; IND) using basic amino acids (L-arginine, L-lysine and L-histidine) as counterions. Three new salts were prepared using freeze drying method and characterised by FT-IR spectroscopy, proton nuclear magnetic resonance ((1)HNMR), Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA). The effect of pH on IND solubility was also investigated using pH-solubility profile. Both arginine and lysine formed novel salts with IND, while histidine failed to dissociate the free acid and in turn no salt was formed. Arginine and lysine increased IND solubility by 10,000 and 2296 fold, respectively. An increase in dissolution rate was also observed for the novel salts. Since these new salts have improved IND solubility to that similar to BCS class I drugs, IND salts could be considered for possible waivers of bioequivalence.

  14. Transcriptomic and biochemical evidence for the role of lysine biosynthesis against linoleic acid hydroperoxide-induced stress in Saccharomyces cerevisiae.

    PubMed

    O'Doherty, P J; Lyons, V; Tun, N M; Rogers, P J; Bailey, T D; Wu, M J

    2014-12-01

    Amino acid biosynthesis forms part of an integrated stress response against oxidants in Saccharomyces cerevisiae and higher eukaryotes. Here we show an essential protective role of the l-lysine biosynthesis pathway in response to the oxidative stress condition induced by the lipid oxidant-linoleic acid hydroperoxide (LoaOOH), by means of transcriptomic profiling and phenotypic analysis, and using the deletion mutant dal80∆ and lysine auxotroph lys1∆. A comprehensive up-regulation of lysine biosynthetic genes (LYS1, LYS2, LYS4, LYS9, LYS12, LYS20 and LYS21) was revealed in dal80Δ following the oxidant challenge. The lysine auxotroph (lys1∆) exhibited a significant decrease in growth compared with that of BY4743 upon exposure to LoaOOH, albeit with the sufficient provision of lysine in the medium. Furthermore, the growth of wild type BY4743 exposed to LoaOOH was also greatly reduced in lysine-deficient conditions, despite a full complement of lysine biosynthetic genes. Amino acid analysis of LoaOOH-treated yeast showed that the level of cellular lysine remained unchanged throughout oxidant challenge, suggesting that the induced lysine biosynthesis leads to a steady-state metabolism as compared to the untreated yeast cells. Together, these findings demonstrate that lysine availability and its biosynthesis pathway play an important role in protecting the cell from lipid peroxide-induced oxidative stress, which is directly related to understanding environmental stress and industrial yeast management in brewing, wine making and baking.

  15. L-arginine availability and arginase activity: Characterization of amino acid permease 3 in Leishmania amazonensis

    PubMed Central

    Aoki, Juliana Ide; Muxel, Sandra Marcia; Zampieri, Ricardo Andrade; Acuña, Stephanie Maia; Fernandes, Juliane Cristina Ribeiro; Vanderlinde, Rubia Heloisa; Sales, Maria Carmen Oliveira de Pinho

    2017-01-01

    Background Leishmania uses the amino acid L-arginine as a substrate for arginase, enzyme that produces urea and ornithine, last precursor of polyamine pathway. This pathway is used by the parasite to replicate and it is essential to establish the infection in the mammalian host. L-arginine is not synthesized by the parasite, so its uptake occurs through the amino acid permease 3 (AAP3). AAP3 is codified by two copies genes (5.1 and 4.7 copies), organized in tandem in the parasite genome. One copy presents the expression regulated by L-arginine availability. Methodology/Principal findings RNA-seq data revealed 14 amino acid transporters differentially expressed in the comparison of La-WT vs. La-arg- promastigotes and axenic amastigotes. The 5.1 and 4.7 aap3 transcripts were down-regulated in La-WT promastigotes vs. axenic amastigotes, and in La-WT vs. La-arg- promastigotes. In contrast, transcripts of other transporters were up-regulated in the same comparisons. The amount of 5.1 and 4.7 aap3 mRNA of intracellular amastigotes was also determined in sample preparations from macrophages, obtained from BALB/c and C57BL/6 mice and the human THP-1 lineage infected with La-WT or La-arg-, revealing that the genetic host background is also important. We also determined the aap3 mRNA and AAP3 protein amounts of promastigotes and axenic amastigotes in different environmental growth conditions, varying pH, temperature and L-arginine availability. Interestingly, the increase of temperature increased the AAP3 level in plasma membrane and consequently the L-arginine uptake, independently of pH and L-arginine availability. In addition, we demonstrated that besides the plasma membrane localization, AAP3 was also localized in the glycosome of L. amazonensis promastigotes and axenic amastigotes. Conclusions/Significance In this report, we described the differential transcriptional profiling of amino acids transporters from La-WT and La-arg- promastigotes and axenic amastigotes. We

  16. Biofortification of rice with the essential amino acid lysine: molecular characterization, nutritional evaluation, and field performance

    PubMed Central

    Yang, Qing-qing; Zhang, Chang-quan; Chan, Man-ling; Zhao, Dong-sheng; Chen, Jin-zhu; Wang, Qing; Li, Qian-feng; Yu, Heng-xiu; Gu, Ming-hong; Sun, Samuel Sai-ming; Liu, Qiao-quan

    2016-01-01

    Rice (Oryza sativa L.), a major staple crop worldwide, has limited levels of the essential amino acid lysine. We previously produced engineered rice with increased lysine content by expressing bacterial aspartate kinase and dihydrodipicolinate synthase and inhibiting rice lysine ketoglutarate reductase/saccharopine dehydrogenase activity. However, the grain quality, field performance, and integration patterns of the transgenes in these lysine-enriched lines remain unclear. In the present study, we selected several elite transgenic lines with endosperm-specific or constitutive regulation of the above key enzymes but lacking the selectable marker gene. All target transgenes were integrated into the intragenic region in the rice genome. Two pyramid transgenic lines (High Free Lysine; HFL1 and HFL2) with free lysine levels in seeds up to 25-fold that of wild type were obtained via a combination of the above two transgenic events. We observed a dramatic increase in total free amino acids and a slight increase in total protein content in both pyramid lines. Moreover, the general physicochemical properties were improved in pyramid transgenic rice, but the starch composition was not affected. Field trials indicated that the growth of HFL transgenic rice was normal, except for a slight difference in plant height and grain colour. Taken together, these findings will be useful for the potential commercialization of high-lysine transgenic rice. PMID:27252467

  17. Acetylome Profiling Reveals Extensive Lysine Acetylation of the Fatty Acid Metabolism Pathway in the Diatom Phaeodactylum tricornutum.

    PubMed

    Chen, Zhuo; Luo, Ling; Chen, Runfa; Hu, Hanhua; Pan, Yufang; Jiang, Haibo; Wan, Xia; Jin, Hu; Gong, Yangmin

    2018-03-01

    N ε -lysine acetylation represents a highly dynamic and reversibly regulated post-translational modification widespread in almost all organisms, and plays important roles for regulation of protein function in diverse metabolic pathways. However, little is known about the role of lysine acetylation in photosynthetic eukaryotic microalgae. We integrated proteomic approaches to comprehensively characterize the lysine acetylome in the model diatom Phaeodactylum tricornutum In total, 2324 acetylation sites from 1220 acetylated proteins were identified, representing the largest data set of the lysine acetylome in plants to date. Almost all enzymes involved in fatty acid synthesis were found to be lysine acetylated. Six putative lysine acetylation sites were identified in a plastid-localized long-chain acyl-CoA synthetase. Site-directed mutagenesis and site-specific incorporation of N-acetyllysine in acyl-CoA synthetase show that acetylation at K407 and K425 increases its enzyme activity. Moreover, the nonenzymatically catalyzed overall hyperacetylation of acyl-CoA synthetase by acetyl-phosphate can be effectively deacetylated and reversed by a sirtuin-type NAD + -dependent deacetylase with subcellular localization of both the plastid and nucleus in Phaeodactylum This work indicates the regulation of acyl-CoA synthetase activity by site-specific lysine acetylation and highlights the potential regulation of fatty acid metabolism by lysine actetylation in the plastid of the diatom Phaeodactylum . © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Arginine supplementation induces myoblast fusion via augmentation of nitric oxide production.

    PubMed

    Long, Jodi H D; Lira, Vitor A; Soltow, Quinlyn A; Betters, Jenna L; Sellman, Jeff E; Criswell, David S

    2006-01-01

    The semi-essential amino acid, L-arginine (L-Arg), is the substrate for endogenous synthesis of nitric oxide, a molecule that is involved in myoblast proliferation and fusion. Since L-Arg supply may limit nitric oxide synthase (NOS) activity in endothelial cells, we examined L-Arg supplementation in differentiating mouse myoblasts and tested the hypothesis that L-Arg exerts direct effects on myoblast fusion via augmentation of endogenous nitric oxide production. C(2)C(12) myoblasts in differentiation media received one of the following treatments for 120 h: 1 mM L-Arg, 0.1 mM N-nitro-L-arginine methyl ester (L-NAME), L-Arg + L-NAME, 10 mM L-Lysine, or no supplement (Control). Cultures were fixed and stained with hematoxylin and eosin for microphotometric image analysis of myotube density, nuclear density, and fusion index (% of total nuclei in myotubes). Endogenous production of nitric oxide during the treatment period peaked between 24 and 48 h. L-Arg amplified nitric oxide production between 0 and 24 h and increased myotube density, total nuclei number, and nuclear fusion index. These L-Arg effects were prevented by the NOS inhibitor, L-NAME. Further, L-Lysine, a competitive inhibitor of L-Arg uptake, repressed nitric oxide production and reduced myotube density and fusion index. In summary, L-Arg augments myotube formation and increases nitric oxide production in a process limited by cellular L-Arg uptake.

  19. Global Analysis of Protein Lysine Succinylation Profiles and Their Overlap with Lysine Acetylation in the Marine Bacterium Vibrio parahemolyticus.

    PubMed

    Pan, Jianyi; Chen, Ran; Li, Chuchu; Li, Weiyan; Ye, Zhicang

    2015-10-02

    Protein lysine acylation, including acetylation and succinylation, has been found to be a major post-translational modification (PTM) and is associated with the regulation of cellular processes that are widespread in bacteria. Vibrio parahemolyticus is a model marine bacterium that causes seafood-borne illness in humans worldwide. The lysine acetylation of V. parahemolyticus has been extensively characterized in our previous work, and here, we report the first global analysis of lysine succinylation and the overlap between the two types of acylation in this bacterium. Using high-accuracy nano liquid chromatography-tandem mass spectrometry combined with affinity purification, we identified 1931 lysine succinylated peptides matched on 642 proteins, with the quantity of the succinyl-proteins accounting for 13.3% of the total proteins in cells. Bioinformatics analysis results showed that these succinylated proteins are involved in almost every cellular process, particularly in protein biosynthesis and metabolism, and are distributed in diverse subcellular compartments. Moreover, several sequence motifs were identified, including succinyl-lysine flanked by a lysine or arginine residue at the -8, -7, or +7 position and without these residues at the -1 or +2 position, and these motifs differ from those found in other bacteria and eukaryotic cells. Furthermore, a total of 517 succinyl-lysine sites (26.7%) on 288 proteins (44.9%) were also found to be acetylated, suggesting extensive overlap between succinylation and acetylation in this bacterium. This systematic analysis provides a promising starting point for further investigations of the physiologic and pathogenic roles of lysine succinylation and acetylation in V. parahemolyticus.

  20. In vitro study of the effect of a dentifrice containing 8% arginine, calcium carbonate, and sodium monofluorophosphate on acid-softened enamel.

    PubMed

    Rege, Aarti; Heu, Rod; Stranick, Michael; Sullivan, Richard J

    2014-01-01

    To investigate the possible mode of action of a dentifrice containing 8% arginine and calcium carbonate (Pro-Argin Technology), and sodium monofluorophosphate in delivering the benefits of preventing acid erosion and rehardening acid-softened enamel. The surfaces of acid-softened bovine enamel specimens were evaluated after application of a dentifrice containing 8% arginine, calcium carbonate, and sodium monofluorophosphate in vitro. Scanning Electron Microscopy (SEM), Electronic Spectrometry for Chemical Analysis (ESCA), and Secondary Ion Mass Spectrometry (SIMS) were used to characterize the enamel surfaces. Exposure of pristine enamel surfaces to citric acid resulted in clear roughening of the surface. Multiple applications of a dentifrice containing 8% arginine, calcium carbonate, and sodium monofluorophosphate to the surface of the enamel resulted in the disappearance of the microscopic voids observed by SEM as a function of treatment applications. The ESCA analysis demonstrated that both the nitrogen and carbonate levels increased as the number of treatments increased, which provides evidence that arginine and calcium carbonate were bound to the surface. Observance of arginine's signature mass fragmentation pattern by SIMS analysis confirmed the identity of arginine on the enamel surface. A series of in vitro experiments has demonstrated a possible mode of action by which a dentifrice containing 8% arginine, calcium carbonate, and sodium monofluorophosphate delivers the benefits of preventing acid erosion and rehardening acid-softened enamel. The combination of arginine and calcium carbonate adheres to the enamel surface and helps to fill the microscopic gaps created by acid, which in turn helps repair the enamel and provides a protective coating against future acid attacks.

  1. Vba2p, a vacuolar membrane protein involved in basic amino acid transport in Schizosaccharomyces pombe.

    PubMed

    Sugimoto, Naoko; Iwaki, Tomoko; Chardwiriyapreecha, Soracom; Shimazu, Masamitsu; Sekito, Takayuki; Takegawa, Kaoru; Kakinuma, Yoshimi

    2010-01-01

    A recent study filling the gap in the genome sequence in the left arm of chromosome 2 of Schizosaccharomyces pombe revealed a homolog of budding yeast Vba2p, a vacuolar transporter of basic amino acids. GFP-tagged Vba2p in fission yeast was localized to the vacuolar membrane. Upon disruption of vba2, the uptake of several amino acids, including lysine, histidine, and arginine, was impaired. A transient increase in lysine uptake under nitrogen starvation was lowered by this mutation. These findings suggest that Vba2p is involved in basic amino acid transport in S. pombe under diverse conditions.

  2. The primary structure of aspartate aminotransferase from pig heart muscle. Digestion with a proteinase having specificity for lysine residues.

    PubMed Central

    Doonan, S; Doonan, H J; Hanford, R; Vernon, C A; Walker, J M; da Airold, L P; Bossa, F; Barra, D; Carloni, M; Fasella, P; Riva, F

    1975-01-01

    Carboxymethylated aspartate aminotransferase was digested with a proteinase claimed to be specific for lysine residues. Complete cleavage occurred at 12 of the 19 lysine residues in the protein, but at the remaining seven residues cleavage was either restricted or absent. In addition, cleavage was observed at three of the 26 arginine residues. These results are discussed with reference to the amino acid residues adjacent to points of complete or restricted cleavage. The complete primary structure of aspartate aminotransferase, based on these and other studies, is given. Evidence for the assignment of some acid and amide side chains has been deposited as Supplementary Publication SUP 50050 (11 pp.) at the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1975) 145, 5. The evidence for the assignment of residue 366 was less conclusive than for the other acid and amide side chains and is, therefore, given in the main paper. PMID:1239277

  3. Functional relationship between cationic amino acid transporters and beta-defensins: implications for dry skin diseases and the dry eye.

    PubMed

    Jäger, Kristin; Garreis, Fabian; Posa, Andreas; Dunse, Matthias; Paulsen, Friedrich P

    2010-04-20

    The ocular surface, constantly exposed to environmental pathogens, is particularly vulnerable to infection. Hence an advanced immune defence system is essential to protect the eye from microbial attack. Antimicrobial peptides, such as beta-defensins, are essential components of the innate immune system and are the first line of defence against invaders of the eye. High concentrations of L-arginine and L-lysine are necessary for the expression of beta-defensins. These are supplied by epithelial cells in inflammatory processes. The limiting factor for initiation of beta-defensin production is the transport of L-arginine and L-lysine into the cell. This transport is performed to 80% by only one transporter system in the human, the y(+)-transporter. This group of proteins exclusively transports the cationic amino acids L-arginine, L-lysine and L-ornithine and is also known under the term cationic amino acid transporter proteins (CAT-proteins). Various infections associated with L-arginine deficiency (for example psoriasis, keratoconjuctivitis sicca) are also associated with an increase in beta-defensin production. For the first time, preliminary work has shown the expression of human CATs in ocular surface epithelia and tissues of the lacrimal apparatus indicating their relevance for diseases of the ocular surface. In this review, we summarize current knowledge on the human CATs that appear to be integrated in causal regulation cascades of beta-defensins, thereby offering novel concepts for therapeutic perspectives. Copyright 2010 Elsevier GmbH. All rights reserved.

  4. Arginine supplementation modulates pig plasma lipids, but not hepatic fatty acids, depending on dietary protein level with or without leucine.

    PubMed

    Madeira, Marta Sofia Morgado Dos Santos; Rolo, Eva Sofia Alves; Pires, Virgínia Maria Rico; Alfaia, Cristina Maria Riscado Pereira Mateus; Coelho, Diogo Francisco Maurício; Lopes, Paula Alexandra Antunes Brás; Martins, Susana Isabel Vargas; Pinto, Rui Manuel Amaro; Prates, José António Mestre

    2017-05-30

    In the present study, the effect of arginine and leucine supplementation, and dietary protein level, were investigated in commercial crossbred pigs to clarify their individual or combined impact on plasma metabolites, hepatic fatty acid composition and mRNA levels of lipid sensitive factors. The experiment was conducted on fifty-four entire male pigs (Duroc × Pietrain × Large White × Landrace crossbred) from 59 to 92 kg of live weight. Each pig was randomly assigned to one of six experimental treatments (n = 9). The treatments followed a 2 × 3 factorial arrangement, providing two levels of arginine supplementation (0 vs. 1%) and three levels of basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet with 2% of leucine, RPDL). Significant interactions between arginine supplementation and protein level were observed across plasma lipids. While dietary arginine increased total lipids, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol and triacylglycerols in NPD, the inverse effect was observed in RPD. Overall, dietary treatments had a minor impact on hepatic fatty acid composition. RPD increased 18:1c9 fatty acid while the combination of leucine and RPD reduced 18:0 fatty acid. Arginine supplementation increased the gene expression of FABP1, which contributes for triacylglycerols synthesis without affecting hepatic fatty acids content. RPD, with or without leucine addition, upregulated the lipogenic gene CEBPA but downregulated the fat oxidation gene LPIN1. Arginine supplementation was responsible for a modulated effect on plasma lipids, which is dependent on dietary protein level. It consistently increased lipaemia in NPD, while reducing the correspondent metabolites in RPD. In contrast, arginine had no major impact, neither on hepatic fatty acids content nor on fatty acid composition. Likewise, leucine supplementation of RPD, regardless the presence of arginine, promoted no changes on total fatty acids in

  5. Supplemental citrulline is more efficient than arginine to increase systemic arginine availability in mice

    USDA-ARS?s Scientific Manuscript database

    Arginine is considered an essential amino acid in various (patho)physiological conditions of high demand. However, dietary arginine supplementation (ARG) suffers various drawbacks, including extensive first-pass extraction. Citrulline supplementation (CIT) may be a better alternative than arginine, ...

  6. Lysine Fermentation: History and Genome Breeding.

    PubMed

    Ikeda, Masato

    Lysine fermentation by Corynebacterium glutamicum was developed in 1958 by Kyowa Hakko Kogyo Co. Ltd. (current Kyowa Hakko Bio Co. Ltd.) and is the second oldest amino acid fermentation process after glutamate fermentation. The fundamental mechanism of lysine production, discovered in the early stages of the process's history, gave birth to the concept known as "metabolic regulatory fermentation," which is now widely applied to metabolite production. After the development of rational metabolic engineering, research on lysine production first highlighted the need for engineering of the central metabolism from the viewpoints of precursor supply and NADPH regeneration. Furthermore, the existence of active export systems for amino acids was first demonstrated for lysine in C. glutamicum, and this discovery has resulted in the current recognition of such exporters as an important consideration in metabolite production. Lysine fermentation is also notable as the first process to which genomics was successfully applied to improve amino acid production. The first global "genome breeding" strategy was developed using a lysine producer as a model; this has since led to new lysine producers that are more efficient than classical industrial producers. These advances in strain development technology, combined with recent systems-level approaches, have almost achieved the optimization of entire cellular systems as cell factories for lysine production. In parallel, the continuous improvement of the process has resulted not only in fermentation processes with reduced load on downstream processing but also in commercialization of various product forms according to their intended uses. Nowadays lysine fermentation underpins a giant lysine demand of more than 2 million metric tons per year.

  7. Effect of a new injectable male contraceptive on the seminal plasma amino acids studied by proton NMR spectroscopy.

    PubMed

    Chaudhury, Koel; Sharma, Uma; Jagannathan, N R; Guha, Sujoy K

    2002-09-01

    Effect of RISUG, a newly developed male contraceptive, on various amino acids of seminal plasma ejaculates was studied by proton magnetic resonance spectroscopy at 400 MHz. Levels of amino acids were compared with the seminal plasma of obstructive azoospermia and controls. Glutamic acid, glutamine, and arginine were found to be high in concentration in human seminal plasma. The concentration of aromatic amino acids such as tyrosine, histidine, and phenylalanine in RISUG-injected subjects showed no significant difference compared to controls (p > 0.1); however, there was a statistically significant decrease in the concentration of these amino acids in obstructive azoospermia. The concentration of some prominent amino acids that showed overlapping resonances, such as isoleucine+leucine+valine (p < 0.01), alanine+isoleucine+lysine (p < 0.01), arginine+lysine+leucine (p < 0.01), and glutamic acid+glutamine (p < 0.01), showed a statistically significant decrease in RISUG-injected subjects compared to controls. Overlap of these amino acid resonances were noticed even at 600 MHz. In general, the total amino acids concentration in RISUG-injected subjects was found to be higher than in azoospermic subjects, confirming the occurrence of 'partial' obstructive azoospermia in subjects injected with this contraceptive.

  8. Injectable supramolecular hydrogel formed from α-cyclodextrin and PEGylated arginine-functionalized poly(l-lysine) dendron for sustained MMP-9 shRNA plasmid delivery.

    PubMed

    Lin, Qianming; Yang, Yumeng; Hu, Qian; Guo, Zhong; Liu, Tao; Xu, Jiake; Wu, Jianping; Kirk, Thomas Brett; Ma, Dong; Xue, Wei

    2017-02-01

    Hydrogels have attracted much attention in cancer therapy and tissue engineering due to their sustained gene delivery ability. To obtain an injectable and high-efficiency gene delivery hydrogel, methoxypolyethylene glycol (MPEG) was used to conjugate with the arginine-functionalized poly(l-lysine) dendron (PLLD-Arg) by click reaction, and then the synthesized MPEG-PLLD-Arg interacted with α-cyclodextrin (α-CD) to form the supramolecular hydrogel by the host-guest interaction. The gelation dynamics, hydrogel strength and shear viscosity could be modulated by α-CD content in the hydrogel. MPEG-PLLD-Arg was confirmed to bind and deliver gene effectively, and its gene transfection efficiency was significantly higher than PEI-25k under its optimized condition. After gelation, MMP-9 shRNA plasmid (pMMP-9) could be encapsulated into the hydrogel matrix in situ and be released from the hydrogels sustainedly, as the release rate was dependent on α-CD content. The released MPEG-PLLD-Arg/pMMP-9 complex still showed better transfection efficiency than PEI-25k and induced sustained tumor cell apoptosis. Also, in vivo assays indicated that this pMMP-9-loaded supramolecular hydrogel could result in the sustained tumor growth inhibition meanwhile showed good biocompatibility. As an injectable, sustained and high-efficiency gene delivery system, this supramolecular hydrogel is a promising candidate for long-term gene therapy. To realize the sustained gene delivery for gene therapy, a supramolecular hydrogel with high-efficiency gene delivery ability was prepared through the host-guest interaction between α-cyclodextrin and PEGylated arginine-functionalized poly(l-lysine) dendron. The obtained hydrogel was injectable and biocompatible with adjustable physicochemical property. More importantly, the hydrogel showed the high-efficiency and sustained gene transfection to our used cells, better than PEI-25k. The supramolecular hydrogel resulted in the sustained tumor growth

  9. Protein recycling in growing rabbits: contribution of microbial lysine to amino acid metabolism.

    PubMed

    Belenguer, Alvaro; Balcells, Joaquim; Guada, Jose A; Decoux, Marc; Milne, Eric

    2005-11-01

    To study the absorption of microbial lysine in growing rabbits, a labelled diet (supplemented with (15)NH4Cl) was administered to six animals (group ISOT); a control group (CTRL, four rabbits) received a similar, but unlabelled, diet. Diets were administered for 30 d. An additional group of six animals were fed the unlabelled diet for 20 d and then the labelled diet for 10 d while wearing a neck collar to avoid caecotrophy (group COLL), in order to discriminate it from direct intestinal absorption. At day 30 animals were slaughtered and caecal bacteria and liver samples taken. The (15)N enrichment in amino acids of caecal bacteria and liver were determined by GC-combustion/isotope ratio MS. Lysine showed a higher enrichment in caecal microflora (0.925 atom% excess, APE) than liver (0.215 APE) in group ISOT animals, confirming the double origin of body lysine: microbial and dietary. The COLL group showed a much lower enrichment in tissue lysine (0.007 (se 0.0029) APE for liver). Any enrichment in the latter animals was due to direct absorption of microbial lysine along the digestive tract, since recycling of microbial protein (caecotrophy) was avoided. In such conditions liver enrichment was low, indicating a small direct intestinal absorption. From the ratio of [(15)N]lysine enrichment between liver and bacteria the contribution of microbes to body lysine was estimated at 23 %, with 97 % of this arising through caecotrophy. Absorption of microbial lysine through caecotrophy was 119 (se 4.0) mg/d, compared with 406 (se 1.8) mg/d available from the diet. This study confirms the importance of caecotrophy in rabbit nutrition (15 % of total protein intake).

  10. Activation of l-arginine transport by protein kinase C in rabbit, rat and mouse alveolar macrophages

    PubMed Central

    Racké, Kurt; Hey, Claudia; Mössner, Jutta; Hammermann, Rainer; Stichnote, Christina; Wessler, Ignaz

    1998-01-01

    The role of protein kinase C in controlling L-arginine transport in alveolar macrophages was investigated. L-[3H]Arginine uptake in rabbit alveolar macrophages declined by 80 % after 20 h in culture. 4β-Phorbol 12-myristate 13-acetate (PMA), but not 4α-phorbol 12-myristate 13-acetate (α-PMA), present during 20 h culture, enhanced L-[3H]arginine uptake more than 10-fold. Staurosporine and chelerythrine opposed this effect. L-[3H]Arginine uptake was saturable and blockable by L-lysine. After PMA treatment Vmax was increased more than 5-fold and Km was reduced from 0.65 to 0.32 mM. Time course experiments showed that PMA increased L-[3H]arginine uptake almost maximally within 2 h. This short-term effect was not affected by cycloheximide or actinomycin D. L-[3H]Arginine uptake and its stimulation by PMA was also observed in sodium-free medium. L-Leucine (0.1 mM) inhibited L-[3H]arginine uptake by 50 % in sodium-containing medium, but not in sodium-free medium. At 1 mM, L-leucine caused significant inhibition in sodium-free medium also. L-Leucine showed similar effects on PMA-treated cells. N-Ethylmaleimide (200 μm, 10 min) reduced L-[3H]arginine uptake by 70 % in control cells, but had no effect on PMA-treated (20 or 2 h) cells. In alveolar macrophages, multiple transport systems are involved in L-arginine uptake, which is markedly stimulated by protein kinase C, probably by modulation of the activity of already expressed cationic amino acid transporters. PMID:9714862

  11. Nitrogen fertilizer factory effects on the amino acid and nitrogen content in the needles of Scots pine.

    PubMed

    Kupsinskiene, E

    2001-12-04

    The aim of the research was to evaluate the content of amino acids in the needles of Pinus sylvestris growing in the area affected by a nitrogen fertilizer factory and to compare them with other parameters of needles, trees, and sites. Three young-age stands of Scots pine were selected at a distance of 0.5 km, 5 km, and 17 km from the factory. Examination of the current-year needles in winter of the year 2000 revealed significant (p < 0.05) differences between the site at a 0.5-km distance from the factory and the site at a 17-km distance from the factory--with the site closest to the factory showing the highest concentrations of protein (119%), total arginine (166%), total other amino acids (depending on amino acid, the effect ranged between 119 and 149%), free arginine (771%), other free amino acids (glutamic acid, threonine, serine, lysine--depending on amino acid, the effect ranged between 162 and 234%), also the longest needles, widest diameter, largest surface area, and heaviest dry weight (respectively, 133, 110, 136, and 169%). The gradient of nitrogen concentration in the needles was assessed on the selected plots over the period of 1995-2000, with the highest concentration (depending on year, 119 to 153%) documented in the site located 0.5 km from the factory. Significant correlations were determined between the total amino acid contents (r = 0.448 -0.939, p < 0.05), some free amino acid (arginine, aspartic acid, glutamic acid, lysine, threonine, and serine) contents (r = 0.418 - 0.975, p < 0.05), and air pollutant concentration at the sites, the distance between the sites and the factory, and characteristics of the needles. No correlation was found between free or total arginine content and defoliation or retention of the needles. In conclusion, it was revealed that elevated mean monthly concentration of ammonia (26 microg m(-3)) near the nitrogen fertilizer factory caused changes in nitrogen metabolism, especially increasing (nearly eight times

  12. The Effect of Carbohydrates and Arginine on Arginine Metabolism by Excised Bean Leaves in the Dark

    PubMed Central

    Stewart, Cecil R.

    1975-01-01

    The effect of carbohydrate on arginine utilization by excised bean (Phaseolus vulgaris L. var. Tendergreen) leaves in the dark was studied by adding arginine to leaves differing in carbohydrate levels, and measuring the arginine content of the leaves at intervals. In nonstarved leaves, the arginine content decreased steadily after vacuum infiltration of 10 mm arginine and was essentially completely utilized by 36 hours after infiltration. In starved leaves, the arginine content did not decrease except for a brief period of about 4 hours after infiltration. The distribution of 14C after adding 14C-arginine to starved and nonstarved leaves indicated that the presence of carbohydrates in the leaves stimulates the utilization of arginine for protein synthesis and conversion to other amino acids, organic acids, and CO2 (catabolism). Adding sucrose along with arginine to starved leaves stimulated this utilization of arginine for both protein synthesis and catabolism. This effect of sugar on catabolism is different than results of similar studies done previously with proline. Increasing the concentration of added arginine greatly increased arginine catabolism but had a relatively small effect on utilization of arginine for protein synthesis. This result is the same as similar results from adding different concentrations of proline to excised leaves. PMID:16659159

  13. Metabolic Availability of the Limiting Amino Acids Lysine and Tryptophan in Cooked White African Cornmeal Assessed in Healthy Young Men Using the Indicator Amino Acid Oxidation Technique.

    PubMed

    Rafii, Mahroukh; Elango, Rajavel; Ball, Ronald O; Pencharz, Paul B; Courtney-Martin, Glenda

    2018-06-01

    Maize is a staple food in many regions of the world, particularly in Africa and Latin America. However, maize protein is limiting in the indispensable amino acids lysine and tryptophan, making its protein of poor quality. The main objective of this study was to determine the protein quality of white African cornmeal by determining the metabolic availability (MA) of lysine and tryptophan. To determine the MA of lysine, 4 amounts of l-lysine (10, 13, 16, and 18 mg · kg-1 · d-1 totaling 28.6%, 37.1%, 45.7%, and 51.4% of the mean lysine requirement of 35 mg · kg-1 · d-1, respectively) were studied in 6 healthy young men in a repeated-measures design. To determine the MA of tryptophan, 4 amounts of l-tryptophan (0.5, 1, 1.5, and 2 mg · kg-1 · d-1 totaling 12.5%, 25.0%, 37.5%, and 50.0% of the mean tryptophan requirement of 4 mg · kg-1 · d-1, respectively) were studied in 7 healthy young men in a repeated-measures design. The MAs of lysine and tryptophan were estimated by comparing the indicator amino acid oxidation (IAAO) response with varying intakes of lysine and tryptophan in cooked white cornmeal compared with the IAAO response to l-lysine and l-tryptophan intakes in the reference protein (crystalline amino acid mixture patterned after egg protein) with the use of the slope ratio method. The MAs of lysine and tryptophan from African cooked white cornmeal were 71% and 80%, respectively. Our study provides a robust estimate of the availability of lysine and tryptophan in African white maize to healthy young men. This estimate provides a basis for postproduction fortification or supplementation of maize-based diets. This trial was registered at www.clinicaltrials.gov as NCT02402179.

  14. Differential cystine and dibasic amino acid handling after loss of function of the amino acid transporter b0,+AT (Slc7a9) in mice.

    PubMed

    Di Giacopo, Andrea; Rubio-Aliaga, Isabel; Cantone, Alessandra; Artunc, Ferruh; Rexhepaj, Rexhep; Frey-Wagner, Isabelle; Font-Llitjós, Mariona; Gehring, Nicole; Stange, Gerti; Jaenecke, Isabel; Mohebbi, Nilufar; Closs, Ellen I; Palacín, Manuel; Nunes, Virginia; Daniel, Hannelore; Lang, Florian; Capasso, Giovambattista; Wagner, Carsten A

    2013-12-15

    Cystinuria is an autosomal recessive disease caused by mutations in SLC3A1 (rBAT) and SLC7A9 (b(0,+)AT). Gene targeting of the catalytic subunit (Slc7a9) in mice leads to excessive excretion of cystine, lysine, arginine, and ornithine. Here, we studied this non-type I cystinuria mouse model using gene expression analysis, Western blotting, clearance, and brush-border membrane vesicle (BBMV) uptake experiments to further characterize the renal and intestinal consequences of losing Slc7a9 function. The electrogenic and BBMV flux studies in the intestine suggested that arginine and ornithine are transported via other routes apart from system b(0,+). No remarkable gene expression changes were observed in other amino acid transporters and the peptide transporters in the intestine and kidney. Furthermore, the glomerular filtration rate (GFR) was reduced by 30% in knockout animals compared with wild-type animals. The fractional excretion of arginine was increased as expected (∼100%), but fractional excretions of lysine (∼35%), ornithine (∼16%), and cystine (∼11%) were less affected. Loss of function of b(0,+)AT reduced transport of cystine and arginine in renal BBMVs and completely abolished the exchanger activity of dibasic amino acids with neutral amino acids. In conclusion, loss of Slc7a9 function decreases the GFR and increases the excretion of several amino acids to a lesser extent than expected with no clear regulation at the mRNA and protein level of alternative transporters and no increased renal epithelial uptake. These observations indicate that transporters located in distal segments of the kidney and/or metabolic pathways may partially compensate for Slc7a9 loss of function.

  15. Solubility of the Proteinogenic α-Amino Acids in Water, Ethanol, and Ethanol–Water Mixtures

    PubMed Central

    2018-01-01

    The addition of organic solvents to α-amino acids in aqueous solution could be an effective method in crystallization. We reviewed the available data on the solubility of α-amino acids in water, water–ethanol mixtures, and ethanol at 298.15 K and 0.1 MPa. The solubility of l-alanine, l-proline, l-arginine, l-cysteine, and l-lysine in water and ethanol mixtures and the solubility of l-alanine, l-proline, l-arginine, l-cysteine, l-lysine, l-asparagine, l-glutamine, l-histidine, and l-leucine in pure ethanol systems were measured and are published here for the first time. The impact on the solubility of amino acids that can convert in solution, l-glutamic acid and l-cysteine, was studied. At lower concentrations, only the ninhydrin method and the ultraperfomance liquid chromatography (UPLC) method yield reliable results. In the case of α-amino acids that convert in solution, only the UPLC method was able to discern between the different α-amino acids and yields reliable results. Our results demonstrate that α-amino acids with similar physical structures have similar changes in solubility in mixed water/ethanol mixtures. The solubility of l-tryptophan increased at moderate ethanol concentrations. PMID:29545650

  16. Sirtuin 3 (SIRT3) Protein Regulates Long-chain Acyl-CoA Dehydrogenase by Deacetylating Conserved Lysines Near the Active Site

    PubMed Central

    Bharathi, Sivakama S.; Zhang, Yuxun; Mohsen, Al-Walid; Uppala, Radha; Balasubramani, Manimalha; Schreiber, Emanuel; Uechi, Guy; Beck, Megan E.; Rardin, Matthew J.; Vockley, Jerry; Verdin, Eric; Gibson, Bradford W.; Hirschey, Matthew D.; Goetzman, Eric S.

    2013-01-01

    Long-chain acyl-CoA dehydrogenase (LCAD) is a key mitochondrial fatty acid oxidation enzyme. We previously demonstrated increased LCAD lysine acetylation in SIRT3 knockout mice concomitant with reduced LCAD activity and reduced fatty acid oxidation. To study the effects of acetylation on LCAD and determine sirtuin 3 (SIRT3) target sites, we chemically acetylated recombinant LCAD. Acetylation impeded substrate binding and reduced catalytic efficiency. Deacetylation with recombinant SIRT3 partially restored activity. Residues Lys-318 and Lys-322 were identified as SIRT3-targeted lysines. Arginine substitutions at Lys-318 and Lys-322 prevented the acetylation-induced activity loss. Lys-318 and Lys-322 flank residues Arg-317 and Phe-320, which are conserved among all acyl-CoA dehydrogenases and coordinate the enzyme-bound FAD cofactor in the active site. We propose that acetylation at Lys-318/Lys-322 causes a conformational change which reduces hydride transfer from substrate to FAD. Medium-chain acyl-CoA dehydrogenase and acyl-CoA dehydrogenase 9, two related enzymes with lysines at positions equivalent to Lys-318/Lys-322, were also efficiently deacetylated by SIRT3 following chemical acetylation. These results suggest that acetylation/deacetylation at Lys-318/Lys-322 is a mode of regulating fatty acid oxidation. The same mechanism may regulate other acyl-CoA dehydrogenases. PMID:24121500

  17. KSHV encoded ORF59 modulates histone arginine methylation of the viral genome to promote viral reactivation

    PubMed Central

    McDowell-Sargent, Maria; Uppal, Timsy; Purushothaman, Pravinkumar

    2017-01-01

    Kaposi’s sarcoma associated herpesvirus (KSHV) persists in a highly-ordered chromatin structure inside latently infected cells with the majority of the viral genome having repressive marks. However, upon reactivation the viral chromatin landscape changes into ‘open’ chromatin through the involvement of lysine demethylases and methyltransferases. Besides methylation of lysine residues of histone H3, arginine methylation of histone H4 plays an important role in controlling the compactness of the chromatin. Symmetric methylation of histone H4 at arginine 3 (H4R3me2s) negatively affects the methylation of histone H3 at lysine 4 (H3K4me3), an active epigenetic mark deposited on the viral chromatin during reactivation. We identified a novel binding partner to KSHV viral DNA processivity factor, ORF59-a protein arginine methyl transferase 5 (PRMT5). PRMT5 is an arginine methyltransferase that dimethylates arginine 3 (R3) of histone H4 in a symmetric manner, one hallmark of condensed chromatin. Our ChIP-seq data of symmetrically methylated H4 arginine 3 showed a significant decrease in H4R3me2s on the viral genome of reactivated cells as compared to the latent cells. Reduction in arginine methylation correlated with the binding of ORF59 on the viral chromatin and disruption of PRMT5 from its adapter protein, COPR5 (cooperator of PRMT5). Binding of PRMT5 through COPR5 is important for symmetric methylation of H4R3 and the expression of ORF59 competitively reduces the association of PRMT5 with COPR5, leading to a reduction in PRMT5 mediated arginine methylation. This ultimately resulted in a reduced level of symmetrically methylated H4R3 and increased levels of H3K4me3 marks, contributing to the formation of an open chromatin for transcription and DNA replication. Depletion of PRMT5 levels led to a decrease in symmetric methylation and increase in viral gene transcription confirming the role of PRMT5 in viral reactivation. In conclusion, ORF59 modulates histone

  18. KSHV encoded ORF59 modulates histone arginine methylation of the viral genome to promote viral reactivation.

    PubMed

    Strahan, Roxanne C; McDowell-Sargent, Maria; Uppal, Timsy; Purushothaman, Pravinkumar; Verma, Subhash C

    2017-07-01

    Kaposi's sarcoma associated herpesvirus (KSHV) persists in a highly-ordered chromatin structure inside latently infected cells with the majority of the viral genome having repressive marks. However, upon reactivation the viral chromatin landscape changes into 'open' chromatin through the involvement of lysine demethylases and methyltransferases. Besides methylation of lysine residues of histone H3, arginine methylation of histone H4 plays an important role in controlling the compactness of the chromatin. Symmetric methylation of histone H4 at arginine 3 (H4R3me2s) negatively affects the methylation of histone H3 at lysine 4 (H3K4me3), an active epigenetic mark deposited on the viral chromatin during reactivation. We identified a novel binding partner to KSHV viral DNA processivity factor, ORF59-a protein arginine methyl transferase 5 (PRMT5). PRMT5 is an arginine methyltransferase that dimethylates arginine 3 (R3) of histone H4 in a symmetric manner, one hallmark of condensed chromatin. Our ChIP-seq data of symmetrically methylated H4 arginine 3 showed a significant decrease in H4R3me2s on the viral genome of reactivated cells as compared to the latent cells. Reduction in arginine methylation correlated with the binding of ORF59 on the viral chromatin and disruption of PRMT5 from its adapter protein, COPR5 (cooperator of PRMT5). Binding of PRMT5 through COPR5 is important for symmetric methylation of H4R3 and the expression of ORF59 competitively reduces the association of PRMT5 with COPR5, leading to a reduction in PRMT5 mediated arginine methylation. This ultimately resulted in a reduced level of symmetrically methylated H4R3 and increased levels of H3K4me3 marks, contributing to the formation of an open chromatin for transcription and DNA replication. Depletion of PRMT5 levels led to a decrease in symmetric methylation and increase in viral gene transcription confirming the role of PRMT5 in viral reactivation. In conclusion, ORF59 modulates histone

  19. The effect of amino acids on the intestinal absorption of immunoglobulins in the neonatal rat

    PubMed Central

    Bamford, D. R.; Donnelly, H.

    1974-01-01

    An in vitro preparation of 10-day-old rat intestine was used to examine the absorption of a number of amino acids and immunoglobulins. Evidence was obtained for the active absorption of alanine, leucine, methionine, histidine and lysine, but not for aspartic acid. A selective absorption of the homologous molecule was found in experiments where 131I-labelled rat and bovine IgG were presented to the ileum in 10-minute incubations. The greater uptake of rat IgG was unrelated to the relative rates of catabolism of the two molecules. Although the uptake of rat IgG was unaffected by 100 mM concentrations of neutral and acidic amino acids, the basic amino acids arginine and lysine significantly stimulated uptake. PMID:4854740

  20. Effect of l-lysine-assisted surface grafting for nano-hydroxyapatite on mechanical properties and in vitro bioactivity of poly(lactic acid-co-glycolic acid).

    PubMed

    Liuyun, Jiang; Lixin, Jiang; Chengdong, Xiong; Lijuan, Xu; Ye, Li

    2016-01-01

    It is promising and challenging to study surface modification for nano-hydroxyapatite to improve the dispersion and enhance the mechanical properties and bioactivity of poly(lactic acid-co-glycolic acid). In this paper, we designed an effective new surface grafting with the assist of l-lysine for nano-hydroxyapatite, and the nano-hydroxyapatite surface grafted with the assist of l-lysine (g-nano-hydroxyapatite) was incorporated into poly(lactic acid-co-glycolic acid) to develop a series of g-nano-hydroxyapatite/poly(lactic acid-co-glycolic acid) nano-composites. The surface modification reaction for nano-hydroxyapatite, the mechanical properties, and in vitro human osteoblast-like cell (MG-63) response were characterized and investigated by Fourier transformation infrared, thermal gravimetric analysis, dispersion test, electromechanical universal tester, differential scanning calorimeter measurements, and in vitro cells culture experiment. The results showed that the grafting amount on the surface of nano-hydroxyapatite was enhanced with the increase of l-lysine, and the dispersion of nano-hydroxyapatite was improved more, so that it brought about better promotion crystallization and more excellent mechanical enhancement effect for poly(lactic acid-co-glycolic acid), comparing with the unmodified nano-hydroxyapatite. Moreover, the cells' attachment and proliferation results confirmed that the incorporation of the g-nano-hydroxyapatite into poly(lactic acid-co-glycolic acid) exhibited better biocompatibility than poly(lactic acid-co-glycolic acid). The above results indicated that the new surface grafting with the assist of l-lysine for nano-hydroxyapatite was an ideal novel surface modification method, which brought about better mechanical enhancement effect and in vitro bioactivity for poly(lactic acid-co-glycolic acid) with adding higher g-nano-hydroxyapatite content, suggesting it had a great potential to be used as bone fracture internal fixation materials

  1. Jugular-infused methionine, lysine and branched-chain amino acids does not improve milk production in Holstein cows experiencing heat stress.

    PubMed

    Kassube, K R; Kaufman, J D; Pohler, K G; McFadden, J W; Ríus, A G

    2017-12-01

    Poor utilization of amino acids contributes to losses of milk protein yield in dairy cows exposed to heat stress (HS). Our objective was to test the effect of essential amino acids on milk production in lactating dairy cows exposed to short-term HS conditions. To achieve this objective, 12 multiparous, lactating Holstein cows were assigned to two environments (thermoneutral (THN) or HS) from days 1 to 14 in a split-plot type cross-over design. All cows received 0 g/day of essential amino acids from days 1 to 7 (negative control (NC)) followed by an intravenous infusion of l-methionine (12 g/day), l-lysine (21 g/day), l-leucine (35 g/day), l-isoleucine (15 g/day) and l-valine (15 g/day, methionine, lysine and branched-chain amino acids (ML+BCAA)) from days 8 to 14. The basal diet was composed of ryegrass silage and hay, and a concentrate mix. This diet supplied 44 g of methionine, 125 g of lysine, 167 g of leucine, 98 g of isoleucine and 109 g of valine per day to the small intestine of THN cows. Temperature-humidity index was maintained below 66 for the THN environment, whereas the index was maintained above 68, peaking at 76, for 14 continuous h/day for the HS environment. Heat stress conditioning increased the udder temperature from 37.0°C to 39.6°C. Cows that received the ML+BCAA treatment had greater p.m. rectal and vaginal temperatures (0.50°C and 0.40°C, respectively), and respiration rate (8 breaths/min) compared with those on the NC treatment and exposed to a HS environment. However, neither NC nor ML+BCAA affected rectal or vaginal temperatures and respiration rates in the THN environment. Compared with THN, the HS environment reduced dry matter intake (1.48 kg/day), milk yield (2.82 kg/day) and milk protein yield (0.11 kg/day). However, compared with NC, the ML+BCAA treatment increased milk protein percent by 0.07 points. For the THN environment, the ML+BCAA treatment increased concentrations of milk urea nitrogen. For the HS environment, the ML

  2. Systematic analysis of the lysine acetylome in Vibrio parahemolyticus.

    PubMed

    Pan, Jianyi; Ye, Zhicang; Cheng, Zhongyi; Peng, Xiaojun; Wen, Liangyou; Zhao, Fukun

    2014-07-03

    Lysine acetylation of proteins is a major post-translational modification that plays an important regulatory role in almost every aspect of cells, both eukaryotes and prokaryotes. Vibrio parahemolyticus, a model marine bacterium, is a worldwide cause of bacterial seafood-borne illness. Here, we conducted the first lysine acetylome in this bacterium through a combination of highly sensitive immune-affinity purification and high-resolution LC-MS/MS. Overall, we identified 1413 lysine acetylation sites in 656 proteins, which account for 13.6% of the total proteins in the cells; this is the highest ratio of acetyl proteins that has so far been identified in bacteria. The bioinformatics analysis of the acetylome showed that the acetylated proteins are involved in a wide range of cellular functions and exhibit diverse subcellular localizations. More specifically, proteins related to protein biosynthesis and carbon metabolism are the preferential targets of lysine acetylation. Moreover, two types of acetylation motifs, a lysine or arginine at the +4/+5 positions and a tyrosine, histidine, or phenylalanine at the +1/+2 positions, were revealed from the analysis of the acetylome. Additionally, protein interaction network analysis demonstrates that a wide range of interactions are modulated by protein acetylation. This study provides a significant beginning for the in-depth exploration of the physiological role of lysine acetylation in V. parahemolyticus.

  3. Effects of single oral doses of lysine clonixinate and acetylsalicylic acid on platelet functions in man.

    PubMed

    Pallapies, D; Muhs, A; Bertram, L; Rohleder, G; Nagyiványi, P; Peskar, B A

    1996-01-01

    Lysine clonixinate is an analgesic drug with a so far unknown mechanism of action. We have determined its effect on platelet cyclooxygenase in man. Biosynthesis of thromboxane (TX)B2 and prostaglandin (PG)F2 alpha in clotting whole blood ex vivo as well as collagen-induced platelet aggregation measured before and at various time points after oral administration of 125 mg lysine clonixinate were compared to results obtained with 500 mg acetylsalicylic acid (ASA). While biosynthesis of both TXB2 and PGF2 alpha measured radioimmunologically was inhibited significantly 2.5 h, but not 6 h, after administration of lysine clonixinate, inhibition by ASA was much greater and still highly significant after 48 h. Similarly, collagen-induced aggregation of platelet-rich plasma was inhibited for a longer period and to a greater extent after administration of ASA than after lysine clonixinate. Our results indicate that lysine clonixinate is a cyclooxygenase inhibitor of moderate potency. It remains to be investigated whether mechanisms other than inhibition of cyclooxygenase contribute to the analgesic activity of lysine clonixinate.

  4. The structure, vibrational spectra and nonlinear optical properties of the L-lysine × tartaric acid complex—Theoretical studies

    NASA Astrophysics Data System (ADS)

    Drozd, M.; Marchewka, M. K.

    2006-05-01

    The room temperature X-ray studies of L-lysine × tartaric acid complex are not unambiguous. The disorder of three atoms of carbon in L-lysine molecule is observed. These X-ray studies are ambiguous. The theoretical geometry study performed by DFT methods explain the most doubts which are connected with crystallographic measurements. The theoretical vibrational frequencies and potential energy distribution (PED) of L-lysine × tartaric acid were calculated by B3LYP method. The calculated frequencies were compared with experimental measured IR spectra. The complete assignment of the bands has been made on the basis of the calculated PED. The restricted Hartee-Fock (RHF) methods were used for calculation of the hyperpolarizability for investigated compound. The theoretical results are compared with experimental value of β.

  5. Short peptides containing L-lysine and epsilon-aminocaproic acid as potential plasmin inhibitors.

    PubMed

    Purwin, M; Bruzgo, I; Markowska, A; Midura-Nowaczek, K

    2009-11-01

    Eight short peptides containing L-lysine and epsilon-aminocaproic acid were obtained and their effect on the amidolytic activities of plasmin, thrombin and trypsin was examined. Tripeptide amide Boc-EACA-L-Lys-EACA-NH2 was the most effective and specific plasmin inhibitor.

  6. Simple physics-based analytical formulas for the potentials of mean force of the interaction of amino-acid side chains in water. V. Like-charged side chains.

    PubMed

    Makowski, Mariusz; Liwo, Adam; Sobolewski, Emil; Scheraga, Harold A

    2011-05-19

    A new model of side-chain-side-chain interactions for charged side-chains of amino acids, to be used in the UNRES force-field, has been developed, in which a side chain consists of a nonpolar and a charged site. The interaction energy between the nonpolar sites is composed of a Gay-Berne and a cavity term; the interaction energy between the charged sites consists of a Lennard-Jones term, a Coulombic term, a generalized-Born term, and a cavity term, while the interaction energy between the nonpolar and charged sites is composed of a Gay-Berne and a polarization term. We parametrized the energy function for the models of all six pairs of natural like-charged amino-acid side chains, namely propionate-propionate (for the aspartic acid-aspartic acid pair), butyrate-butyrate (for the glutamic acid-glutamic acid pair), propionate-butyrate (for the aspartic acid-glutamic acid pair), pentylamine cation-pentylamine cation (for the lysine-lysine pair), 1-butylguanidine cation-1-butylguanidine cation (for the arginine-arginine pair), and pentylamine cation-1-butylguanidine cation (for the lysine-arginine pair). By using umbrella-sampling molecular dynamics simulations in explicit TIP3P water, we determined the potentials of mean force of the above-mentioned pairs as functions of distance and orientation and fitted analytical expressions to them. The positions and depths of the contact minima and the positions and heights of the desolvation maxima, including their dependence on the orientation of the molecules were well represented by analytical expressions for all systems. The values of the parameters of all the energy components are physically reasonable, which justifies use of such potentials in coarse-grain protein-folding simulations. © 2011 American Chemical Society

  7. The effect of amino acid lysine and methionine addition on feed toward the growth and retention on mud crab (Scylla serrata)

    NASA Astrophysics Data System (ADS)

    Alissianto, Y. R.; Sandriani, Z. A.; Rahardja, B. S.; Agustono; Rozi

    2018-04-01

    High market demand of mud crab (Scylla serrata) encourages farmers to increase the production of mud crab. However, mud crab can not synthesize essential amino acids, so it is necessary to supply essential amino acids such as lysine and methionine in the diet. This study aims to determine the effect of lysine and methionine on feeds to increase growth and retention of mud crabs (Scylla serrata). In this study the amount of lysine amino acid and methionine added to the trash fish diet were: P0 (0: 0%); P1 (0.75: 0.75%); P2 (1: 1%); P3 (1.25: 1.25%); P4 (1.5: 1.5%) with the ratio of lysine and methionine 1: 1. The parameters observed in this study were Survival Rate (SR), Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Efficiency Feed (EF), protein retention and energy retention. The results of the 35-day maintenance study showed significant differences (P <0.05) against Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Efficiency Feed (EF), protein retention and no significant effect (P> 0.05) on energy retention and Survival Rate (SR) on mud crab. The best results in this study were found in P4 treatment with addition of lysine amino acids and methionine (1.5: 1.5%).

  8. Prolonged incubation time in sheep with prion protein containing lysine at position 171

    USDA-ARS?s Scientific Manuscript database

    Sheep scrapie susceptibility or resistance is a function of genotype with polymorphisms at codon 171 in the sheep prion gene playing a major role. Glutamine (Q) at 171 contributes to scrapie susceptibility while arginine (R) is associated with resistance. In some breeds, lysine (K) occurs at codon 1...

  9. Guanidinium/ammonium competition and proton transfer in the interaction of the amino acid arginine with the tetracarboxylic 18-crown-6 ionophore.

    PubMed

    Avilés-Moreno, Juan Ramón; Berden, Giel; Oomens, Jos; Martínez-Haya, Bruno

    2018-02-07

    The recognition of arginine plays a central role in modern proteomics and genomics. Arginine is unique among natural amino acids due to the high basicity of its guanidinium side chain, which sustains specific interactions and proton exchange biochemical processes. The search for suitable macrocyclic ionophores constitutes a promising route towards the development of arginine receptors. This study evaluates the conformational features involved in the binding of free arginine by the polyether macrocycle (18-crown-6)-tetracarboxylic acid. Infrared action vibrational spectroscopy and quantum-chemical computations are combined to characterize the complexes with net charges +1 and +2. The spectrum of the +1 complex can be explained in terms of a configuration predominantly stabilized by a robust bidentate coordination of guanidinium with a carboxylate group formed from the deprotonation of one side group of the crown ether. The released proton is transferred to the amino terminus of arginine, which then coordinates with the crown ether ring. In an alternative type of conformation, partly consistent with experiment, the amino terminus is neutral and the guanidinium group inserts into the crown ether cavity. In the +2 complexes, arginine is always doubly protonated and the most stable conformations are characterized by a tripodal coordination of the ammonium -NH 3 + group of arginine with the oxygen atoms of the macrocycle ring, while the interactions of the amino acid with the side carboxylic acid groups of the crown ether acquire a remarkable lesser role.

  10. An economically and environmentally acceptable synthesis of chiral drug intermediate L-pipecolic acid from biomass-derived lysine via artificially engineered microbes.

    PubMed

    Cheng, Jie; Huang, Yuding; Mi, Le; Chen, Wujiu; Wang, Dan; Wang, Qinhong

    2018-05-10

    Deficiency in petroleum resources and increasing environmental concerns have pushed a bio-based economy to be built, employing a highly reproducible, metal contaminant free, sustainable and green biomanufacturing method. Here, a chiral drug intermediate L-pipecolic acid has been synthesized from biomass-derived lysine. This artificial bioconversion system involves the coexpression of four functional genes, which encode L-lysine α-oxidase from Scomber japonicus, glucose dehydrogenase from Bacillus subtilis, Δ 1 -piperideine-2-carboxylase reductase from Pseudomonas putida, and lysine permease from Escherichia coli. Besides, a lysine degradation enzyme has been knocked out to strengthen the process in this microbe. The overexpression of LysP improved the L-pipecolic acid titer about 1.6-folds compared to the control. This engineered microbial factory showed the highest L-pipecolic acid production of 46.7 g/L reported to date and a higher productivity of 2.41 g/L h and a yield of 0.89 g/g. This biotechnological L-pipecolic acid production is a simple, economic, and green technology to replace the presently used chemical synthesis.

  11. Changes in N-acetylglutamate are involved in regulating urea synthesis in rats given a low gluten diet supplemented with L-lysine, L-methinone and L-threonine.

    PubMed

    Tujioka, Kazuyo; Tuchiya, Tamami; Shi, Xianglan; Ohsumi, Miho; Hayase, Kazutoshi; Yokogoshi, Hidehiko

    2009-01-01

    We have shown that urinary urea excretion decreased in rats fed a low gluten diet supplemented with dietary limiting amino acids. The purpose of present study was to determine whether the addition of dietary limiting amino acids to a low gluten diet affected the synthesis and degradation of N-acetylglutamate and regulated urea synthesis. Experiments were done on two groups of rats, given diets containing 10% gluten or 10% gluten+0.5% L-lysine, 0.2% L-threonine and 0.2% L-methionine for 10 d. The urinary excretion of urea, and the liver concentration of N-acetylglutamate, and the liver activity of N-acetylglutamate synthetase decreased with the addition of dietary L-lysine, L-threonine and L-methionine. N-Acetylglutamate concentration in the liver was closely correlated with the N-acetylglutamate synthetase activity in the liver and excretion of urea. The greater degradation of N-acetylglutamate was observed in the group fed the 10% gluten+L-lysine, L-threonine and L-methionine. The hepatic concentration of glutamate and plasma concentration of arginine were not related to the N-acetylglutamate concentration in the liver. These results suggest that the addition of limiting amino acids to the low gluten diet controls the synthesis and degradation of N-acetylglutamate in the liver and lowers urea synthesis.

  12. Arginine inactivates human herpesvirus 2 and inhibits genital herpesvirus infection.

    PubMed

    Ikeda, Keiko; Yamasaki, Hisashi; Minami, Sawako; Suzuki, Yukiko; Tsujimoto, Kazuko; Sekino, Yoshihisa; Irie, Hiroshi; Arakawa, Tsutomu; Koyama, A Hajime

    2012-12-01

    Arginine, among the amino acids, has demonstrated unique properties, including suppression of protein-protein interactions and virus inactivation. We investigated the effects of arginine on the infectivity of human herpesvirus 2 (HHV-2) and the potential application of arginine as a chemotherapeutic agent against genital herpes. Arginine directly inactivated HHV-2 and characterization of the inactivation demonstrated that 1 M arginine at pH 4.3 inactivated the virus more efficiently compared to 0.1 M citrate or 1 M sodium chloride, indicating that neither acidic pH nor ionic strength alone is sufficient for virus inactivation. The effect of arginine was rapid and concentration-dependent. Although virus inactivation was efficient at an acidic pH, arginine inactivated the virus even at a neutral pH, provided that a higher arginine concentration and prolonged incubation time were used. In addition, arginine suppressed the multiplication of HHV-2 under the conditions at which its effect on cell viability was insignificant. Pilot mouse model studies revealed a marked suppression of death by arginine when the mice were infected with HHV-2 through the vaginal route, followed by an intermittent application of acidic arginine by vaginal instillation.

  13. Novel α-Oxoamide Advanced-Glycation Endproducts within the N6-Carboxymethyl Lysine and N6-Carboxyethyl Lysine Reaction Cascades.

    PubMed

    Baldensperger, Tim; Jost, Tobias; Zipprich, Alexander; Glomb, Marcus A

    2018-02-28

    The highly reactive α-dicarbonyl compounds glyoxal and methylglyoxal are major precursors of posttranslational protein modifications in vivo. Model incubations of N 2 -t-Boc-lysine and either glyoxal or methylglyoxal were used to further elucidate the underlying mechanisms of the N 6 -carboxymethyl lysine and N 6 -carboxyethyl lysine reaction cascades. After independent synthesis of the authentic reference standards, we were able to detect N 6 -glyoxylyl lysine and N 6 -pyruvoyl lysine for the first time by HPLC-MS 2 analyses. These two novel amide advanced-glycation endproducts were exclusively formed under aerated conditions, suggesting that they were potent markers for oxidative stress. Analogous to the well-known Strecker degradation pathway, leading from amino acids to Strecker acids, the oxidation of an enaminol intermediate is suggested to be the key mechanistic step. A highly sensitive workup for the determination of AGEs in tissues was developed. In support of our hypothesis, the levels of N 6 -glyoxylyl lysine and N 6 -pyruvoyl lysine in rat livers indeed correlated with liver cirrhosis and aging.

  14. A periplasmic, pyridoxal-5'-phosphate-dependent amino acid racemase in Pseudomonas taetrolens.

    PubMed

    Matsui, Daisuke; Oikawa, Tadao; Arakawa, Noriaki; Osumi, Shintaro; Lausberg, Frank; Stäbler, Norma; Freudl, Roland; Eggeling, Lothar

    2009-07-01

    The pyridoxal-5'-phosphate (PLP)-dependent amino acid racemases occur in almost every bacterium but may differ considerably with respect to substrate specificity. We here isolated the cloned broad substrate specificity racemase ArgR of Pseudomonas taetrolens from Escherichia coli by classical procedures. The racemase was biochemically characterized and amongst other aspects it was confirmed that it is mostly active with lysine, arginine and ornithine, but merely weakly active with alanine, whereas the alanine racemase of the same organism studied in comparison acts on alanine only. Unexpectedly, sequencing the amino-terminal end of ArgR revealed processing of the protein, with a signal peptide cleaved off. Subsequent localization studies demonstrated that in both P. taetrolens and E. coli ArgR activity was almost exclusively present in the periplasm, a feature so far unknown for any amino acid racemase. An ArgR-derivative carrying a carboxy-terminal His-tag was made and this was demonstrated to localize even in an E. coli mutant devoid of the twin-arginine translocation (Tat) pathway in the periplasm. These data indicate that ArgR is synthesized as a prepeptide and translocated in a Tat-independent manner. We therefore propose that ArgR translocation depends on the Sec system and a post-translocational insertion of PLP occurs. As further experiments showed, ArgR is necessary for the catabolism of D: -arginine and D: -lysine by P. taetrolens.

  15. Polymerization on the rocks: beta-amino acids and arginine

    NASA Technical Reports Server (NTRS)

    Liu, R.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1998-01-01

    We have studied the accumulation of long oligomers of beta-amino acids on the surface of minerals using the 'polymerization on the rocks' protocol. We find that long oligopeptides of beta-glutamic acid which cannot be formed in homogeneous aqueous solution are accumulated efficiently on the surface of hydroxylapatite using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as condensing agent. The EDAC-induced oligomerization of aspartic acid on hydroxylapatite proceeds even more efficiently. Hydroxylapatite can also facilitate the ligation of the tripeptide (glu)3. The 'polymerization on the rocks' scenario is not restricted to negatively-charged amino acids. Oligoarginines are accumulated on the surface of illite using carbonyldiimidizole (CDI) as condensing agent. We find that FeS2 catalyzes the CDI-induced oligomerization of arginine, although it does not adsorb oligoarginines. These results are relevant to the formation of polypeptides on the primitive earth.

  16. Boosting Anaplerotic Reactions by Pyruvate Kinase Gene Deletion and Phosphoenolpyruvate Carboxylase Desensitization for Glutamic Acid and Lysine Production in Corynebacterium glutamicum.

    PubMed

    Yokota, Atsushi; Sawada, Kazunori; Wada, Masaru

    In the 1980s, Shiio and coworkers demonstrated using random mutagenesis that the following three phenotypes were effective for boosting lysine production by Corynebacterium glutamicum: (1) low-activity-level citrate synthase (CS L ), (2) phosphoenolpyruvate carboxylase (PEPC) resistant to feedback inhibition by aspartic acid (PEPC R ), and (3) pyruvate kinase (PYK) deficiency. Here, we reevaluated these phenotypes and their interrelationship in lysine production using recombinant DNA techniques.The pyk deletion and PEPC R (D299N in ppc) independently showed marginal effects on lysine production, but both phenotypes synergistically increased lysine yield, demonstrating the importance of PEPC as an anaplerotic enzyme in lysine production. Similar effects were also found for glutamic acid production. CS L (S252C in gltA) further increased lysine yield. Thus, using molecular techniques, the combination of these three phenotypes was reconfirmed to be effective for lysine production. However, a simple CS L mutant showed instabilities in growth and lysine yield.Surprisingly, the pyk deletion was found to increase biomass production in wild-type C. glutamicum ATCC13032 under biotin-sufficient conditions. The mutant showed a 37% increase in growth (based on OD 660 ) compared with the ATCC13032 strain in a complex medium containing 100 g/L glucose. Metabolome analysis revealed the intracellular accumulation of excess precursor metabolites. Thus, their conversion into biomass was considered to relieve the metabolic distortion in the pyk-deleted mutant. Detailed physiological studies of various pyk-deleted mutants also suggested that malate:quinone oxidoreductase (MQO) is important to control both the intracellular oxaloacetic acid (OAA) level and respiration rate. These findings may facilitate the rational use of C. glutamicum in fermentation industries.

  17. Topological dispositions of lysine. alpha. 380 and lysine. gamma. 486 in the acetylcholine receptor from Torpedo californica

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dwyer, B.P.

    1991-04-23

    The locations have been determined, with respect to the plasma membrane, of lysine {alpha}380 and lysine {gamma}486 in the {alpha} subunit and the {gamma} subunit, respectively, of the nicotinic acetylcholine receptor from Torpedo californica. Immunoadsorbents were constructed that recognize the carboxy terminus of the peptide GVKYIAE released by proteolytic digestion from positions 378-384 in the amino acid sequence of the {alpha} subunit of the acetylcholine receptor and the carboxy terminus of the peptide KYVP released by proteolytic digestion from positions 486-489 in the amino acid sequence of the {gamma} subunit. They were used to isolate these peptides from proteolytic digestsmore » of polypeptides from the acetylcholine receptor. Sealed vesicles containing the native acetylcholine receptor were labeled with pyridoxal phosphate and sodium ({sup 3}H)-borohydride. The effect of saponin on the incorporation of pyridoxamine phosphate into lysine {alpha}380 and lysine {gamma}486 from the acetylcholine receptor in these vesicles was assessed with the immunoadsorbents. The conclusions that follow from these results are that lysine {alpha}380 is on the inside surface of a vesicle and lysine {gamma}486 is on the outside surface. Because a majority (85%) of the total binding sites for {alpha}-bungarotoxin bind the toxin in the absence of saponin, the majority of the vesicles are right side out with the inside of the vesicle corresponding to the cytoplasmic surface and the outside of the vesicle corresponding to the extracytoplasmic, synaptic surface. Because lysine {alpha}380 and lysine {gamma}486 lie on opposite sides of the membrane, a membrane-spanning segment must be located between the two positions occupied by these two amino acids in the common sequence of a polypeptide of the acetylcholine receptor.« less

  18. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice

    USDA-ARS?s Scientific Manuscript database

    Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depl...

  19. Evaluating Force Fields for the Computational Prediction of Ionized Arginine and Lysine Side-Chains Partitioning into Lipid Bilayers and Octanol.

    PubMed

    Sun, Delin; Forsman, Jan; Woodward, Clifford E

    2015-04-14

    Abundant peptides and proteins containing arginine (Arg) and lysine (Lys) amino acids can apparently permeate cell membranes with ease. However, the mechanisms by which these peptides and proteins succeed in traversing the free energy barrier imposed by cell membranes remain largely unestablished. Precise thermodynamic studies (both theoretical and experimental) on the interactions of Arg and Lys residues with model lipid bilayers can provide valuable clues to the efficacy of these cationic peptides and proteins. We have carried out molecular dynamics simulations to calculate the interactions of ionized Arg and Lys side-chains with the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayer for 10 widely used lipid/protein force fields: CHARMM36/CHARMM36, SLIPID/AMBER99SB-ILDN, OPLS-AA/OPLS-AA, Berger/OPLS-AA, Berger/GROMOS87, Berger/GROMOS53A6, GROMOS53A6/GROMOS53A6, nonpolarizable MARTINI, polarizable MARTINI, and BMW MARTINI. We performed umbrella sampling simulations to obtain the potential of mean force for Arg and Lys side-chains partitioning from water to the bilayer interior. We found significant differences between the force fields, both for the interactions between side-chains and bilayer surface, as well as the free energy cost for placing the side-chain at the center of the bilayer. These simulation results were compared with the Wimley-White interfacial scale. We also calculated the free energy cost for transferring ionized Arg and Lys side-chains from water to both dry and wet octanol. Our simulations reveal rapid diffusion of water molecules into octanol whereby the equilibrium mole fraction of water in the wet octanol phase was ∼25%. Surprisingly, our free energy calculations found that the high water content in wet octanol lowered the water-to-octanol partitioning free energies for cationic residues by only 0.6 to 0.7 kcal/mol.

  20. Year-long changes in protein metabolism in elderly men and women supplemented with a nutrition cocktail of beta-hydroxy-beta-methylbutyrate (HMB), L-arginine, and L-lysine.

    PubMed

    Baier, Shawn; Johannsen, Darcy; Abumrad, Naji; Rathmacher, John A; Nissen, Steven; Flakoll, Paul

    2009-01-01

    A major contributing factor to the loss of mobility in elderly people is the gradual and continuous loss of lean body mass. To determine whether supplementation of an amino acid cocktail daily for 1 year could improve the age-associated changes in protein turnover and lean body mass in elderly people. Elderly (76+/-1.6 years) women (n=39) and men (n=38) were recruited for a double-blinded controlled study. Study participants were randomly assigned to either an isonitrogenous control-supplement (n=37) or a treatment-supplement (HMB/Arg/Lys) consisting of beta-hydroxy-beta-methylbutyrate, L-arginine, and L-lysine (n=40) for the 1-year study. Lean tissue mass was measured using both bioelectrical-impedance analysis (BIA) and dual energy x-ray absorptiometry (DXA). Rates of whole-body protein turnover were estimated using primed/intermittent oral doses of 15N-glycine. In subjects taking the HMB/Arg/Lys supplement, lean tissue increased over the year of study while in the control group, lean tissue did not change. Compared with control, HMB/Arg/Lys increased body cell mass (BIA) by 1.6% (P=.002) and lean mass (DXA) by 1.2% (P=.05). The rates of protein turnover were significantly increased 8% and 12% in the HMB/Arg/Lys-supplemented group while rates of protein turnover decreased 11% and 9% in the control-supplemented subjects (P<.01), at 3 and 12 months, respectively. Consumption of a simple amino acid-related cocktail increased protein turnover and lean tissue in elderly individuals in a year-long study.

  1. Characterisation of neuroprotective efficacy of modified poly-arginine-9 (R9) peptides using a neuronal glutamic acid excitotoxicity model.

    PubMed

    Edwards, Adam B; Anderton, Ryan S; Knuckey, Neville W; Meloni, Bruno P

    2017-02-01

    In a recent study, we highlighted the importance of cationic charge and arginine residues for the neuroprotective properties of poly-arginine and arginine-rich peptides. In this study, using cortical neuronal cultures and an in vitro glutamic acid excitotoxicity model, we examined the neuroprotective efficacy of different modifications to the poly-arginine-9 peptide (R9). We compared an unmodified R9 peptide with R9 peptides containing the following modifications: (i) C-terminal amidation (R9-NH2); (ii) N-terminal acetylation (Ac-R9); (iii) C-terminal amidation with N-terminal acetylation (Ac-R9-NH2); and (iv) C-terminal amidation with D-amino acids (R9D-NH2). The three C-terminal amidated peptides (R9-NH2, Ac-R9-NH2, and R9D-NH2) displayed neuroprotective effects greater than the unmodified R9 peptide, while the N-terminal acetylated peptide (Ac-R9) had reduced efficacy. Using the R9-NH2 peptide, neuroprotection could be induced with a 10 min peptide pre-treatment, 1-6 h before glutamic acid insult, or when added to neuronal cultures up to 45 min post-insult. In addition, all peptides were capable of reducing glutamic acid-mediated neuronal intracellular calcium influx, in a manner that reflected their neuroprotective efficacy. This study further highlights the neuroprotective properties of poly-arginine peptides and provides insight into peptide modifications that affect efficacy.

  2. X-ray studies on crystalline complexes involving amino acids and peptides. XXXII. Effect of chirality on ionisation state, stoichiometry and aggregation in the complexes of oxalic acid with DL- and L-lysine.

    PubMed

    Venkatraman, J; Prabu, M M; Vijayan, M

    1997-08-01

    Crystals of the oxalic acid complex of DL-lysine (triclinic P1; a = 5.540(1), b = 10.764(2), c = 12.056(2) A, alpha = 77.8(1), beta = 80.6(1), gamma = 75.6(1).; R = 4.7% for 2023 observed reflections) contain lysine and semioxalate ions in the 1:1 ratio, whereas the ratio of lysine and semioxalate/oxalate ions is 2:3 in the crystals of the L-lysine complex (monoclinic P2(1); alpha = 4.906(1), b = 20.145(4), c = 12.455(1) A, beta = 92.5(1).; R = 4.4% for 1494 observed reflections). The amino acid molecule in the L-lysine complex has an unusual ionisation state with positively charged alpha- and side-chain amino groups and a neutral carboxyl group. The unlike molecules aggregate into separate alternating layers in the DL-lysine complex in a manner similar to that observed in several of the amino acid complexes. The L-lysine complex exhibits a new aggregation pattern which cannot be easily explained in terms of planar features, thus emphasizing the fundamental dependence of aggregation on molecular characteristics. Despite the differences in stoichiometry, ionisation state and long-range aggregation patterns, the basic element of aggregation in the two complexes exhibits considerable similarity.

  3. N-nitrosations of basic amino acid residues in polypeptide.

    PubMed

    Kuo, Wu-Nan; Ivy, Dynisha; Guruvadoo, Luvina; White, Atavia; Graham, Latia

    2004-09-01

    Changes in the electrophoretic pattern were noted in the products of polypeptides of identical basic amino acids preincubated with reactive or degraded PN, suggesting the occurrence of N-nitrosation of the epsilon-amino group of lysine, the guanido group of arginine and the imidazole group of histidine. Additionally, increase in the N-nitroso immunoreactivity of preincubated histones H2A and H2B was detected by Western blot analysis.

  4. PubMed Central

    Carbonneau, Roch; Demers, Jean-Marie

    1965-01-01

    The object of this experiment was to study the influence of essential amino acids on the growth, fatty infiltration of liver and cholesterol level of the serum in ducklings. A 11 per cent protein basal diet, deficient in many essential amino acids, given to ducklings, resulted in poor growth, fatty infiltration of liver and high cholesterol level of the serum. In our experimental design, three amino acids, lysine, methionine and threonine were promoting growth whereas lysine and threonine were preventing fatty infiltration of liver but methionine failed to do so. Rather than a deficiency in lysine alone, simultaneous deficiencies in valine, arginine and lysine resulted in better growth for ducklings. This protective effect of deficiency in valine and arginine together with one in lysine was not effective against fatty infiltration of liver. The cholesterolemia found for the ducklings given basal diet or diets with deficiency in many essential amino acids was higher than that found for the ducklings given diets without essential amino acids deficiency. PMID:4220644

  5. The effect of antioxidants on quantitative changes of lysine and methionine in linoleic acid emulsions at different pH conditions.

    PubMed

    Hęś, Marzanna; Gliszczyńska-Świgło, Anna; Gramza-Michałowska, Anna

    2017-01-01

    Plants are an important source of phenolic compounds. The antioxidant capacities of green tea, thyme and rosemary extracts that contain these compounds have been reported earlier. However, there is a lack of accessible information about their activity against lipid oxidation in emulsions and inhibit the interaction of lipid oxidation products with amino acids. Therefore, the influence of green tea, thyme and rosemary extracts and BHT (butylated hydroxytoluene) on quantitative changes in lysine and methionine in linoleic acid emulsions at a pH of isoelectric point and a pH lower than the isoelectric point of amino acids was investigated. Total phenolic contents in plant extracts were determined spectrophotometrically by using Folin-Ciocalteu's reagent, and individual phenols by using HPLC. The level of oxidation of emulsion was determined using the measurement of peroxides and TBARS (thiobarbituric acid reactive substances). Methionine and lysine in the system were reacted with sodium nitroprusside and trinitrobenzenesulphonic acid respectively, and the absorbance of the complexes was measured. Extract of green tea had the highest total polyphenol content. The system containing antioxidants and amino acid protected linoleic acid more efficiently than by the addition of antioxidants only. Lysine and methionine losses in samples without the addition of antioxidants were lower in their isoelectric points than below these points. Antioxidants decrease the loss of amino acids. The protective properties of antioxidants towards methionine were higher in a pH of isoelectric point whereas towards lysine in pH below this point. Green tea, thyme and rosemary extracts exhibit antioxidant activity in linoleic acid emulsions. Moreover, they can be utilized to inhibit quantitative changes in amino acids in lipid emulsions. However, the antioxidant efficiency of these extracts seems to depend on pH conditions. Further investigations should be carried out to clarify this issue.

  6. Effects of fortified lysine on the amino acid profile and sensory qualities of deep-fried and dried noodles.

    PubMed

    Polpuech, C; Chavasit, V; Srichakwal, P; Paniangvait, P

    2011-08-01

    Lysine fortification of wheat flour has been used toward reducing protein energy malnutrition in developing countries. The feasibility of fortifying instant noodles with lysine was evaluated based on sensory qualities and the residual lysine content. Fifty grams of deep-fried and dried instant noodles were fortified with 0.23 and 0.21 g lysine, respectively. The production temperatures used for deep-frying were 165-175 degrees C and for drying, 80-105 degrees C; these are the temperatures used in the industrial production of both kinds of noodles. Lysine fortification was then performed at the local factories using the commercial production lines and packaging for both types of instant noodles. Both fortified and unfortified deep-fried and dried instant noodles were stored at 50 degrees C under fluorescent light for 2 and 4 months, respectively. The fortified products were tested for residual lysine content and sensory qualities as compared with unfortified noodles. The results show fortified products from the tested processing temperatures were all accepted. After storage, significant losses of lysine were not found in both types of noodles analysed. The lysine-fortified noodles had amino acid scores of 102% and 122%, respectively. After 2 months, the sensory quality of fortified deep-fried noodles was still acceptable; however, the dried noodles turned to an unacceptable dark colour. This study shows that it is feasible to fortify deep-fried instant noodles with lysine, though lysine fortification exhibited an undesirable colour in the dried instant noodles after storage.

  7. Structural characterization of arginine-vasopressin and lysine-vasopressin by Fourier- transform ion cyclotron resonance mass spectrometry and infrared multiphoton dissociation.

    PubMed

    Bianco, Giuliana; Battista, Fabio; Buchicchio, Alessandro; Amarena, Concetta G; Schmitt-Kopplin, Philippe; Guerrieri, Antonio

    2015-01-01

    Arginine-vasopressin (AVP) and lysine-vasopressin (LVP) were analyzed by reversed-phase liquid chromatography/mass spectrometry (LC-MS) using Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) electrospray ionization (ESI) in the positive ion mode. LVP and AVP exhibited the protonated adduct [M+H](+) as the predominant ion at m/z 1056.43965 and at m/z 1084.44561, respectively. Infrared multiphoton dissociation (IRMPD), using a CO(2) laser source at a wavelength of 10.6 μm, was applied to protonated vasopressin molecules. The IRMPD mass spectra presented abundant mass fragments essential for a complete structural information. Several fragment ions, shared between two target molecules, are discussed in detail. Some previously unpublished fragments were identified unambiguously utilizing the high resolution and accurate mass information provided by the FT-ICR mass spectrometer. The opening of the disulfide loop and the cleavage of the peptide bonds within the ring were observed even under low-energy fragmentation conditions. Coupling the high-performance FT-ICR mass spectrometer with IRMPD as a contemporary fragmentation technique proved to be very promising for the structural characterization of vasopressin.

  8. Lysine 206 in Arabidopsis phytochrome A is the major site for ubiquitin-dependent protein degradation.

    PubMed

    Rattanapisit, Kaewta; Cho, Man-Ho; Bhoo, Seong Hee

    2016-02-01

    Phytochrome A (phyA) is a light labile phytochrome that mediates plant development under red/far-red light condition. Degradation of phyA is initiated by red light-induced phyA-ubiquitin conjugation through the 26S proteasome pathway. The N-terminal of phyA is known to be important in phyA degradation. To determine the specific lysine residues in the N-terminal domain of phyA involved in light-induced ubiquitination and protein degradation, we aligned the amino acid sequence of the N-terminal domain of Arabidopsis phyA with those of phyA from other plant species. Based on the alignment results, phytochrome over-expressing Arabidopsis plants were generated. In particular, wild-type and mutant (substitutions of conserved lysines by arginines) phytochromes fused with GFP were expressed in phyA(-)211 Arabidopsis plants. Degradation kinetics of over-expressed phyA proteins revealed that degradation of the K206R phyA mutant protein was delayed. Delayed phyA degradation of the K206R phyA mutant protein resulted in reduction of red-light-induced phyA-ubiquitin conjugation. Furthermore, seedlings expressing the K206R phyA mutant protein showed an enhanced phyA response under far-red light, resulting in inhibition of hypocotyl elongation as well as cotyledon opening. Together, these results suggest that lysine 206 is the main lysine for rapid ubiquitination and protein degradation of Arabidopsis phytochrome A. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  9. Acid Evolution of Escherichia coli K-12 Eliminates Amino Acid Decarboxylases and Reregulates Catabolism.

    PubMed

    He, Amanda; Penix, Stephanie R; Basting, Preston J; Griffith, Jessie M; Creamer, Kaitlin E; Camperchioli, Dominic; Clark, Michelle W; Gonzales, Alexandra S; Chávez Erazo, Jorge Sebastian; George, Nadja S; Bhagwat, Arvind A; Slonczewski, Joan L

    2017-06-15

    Acid-adapted strains of Escherichia coli K-12 W3110 were obtained by serial culture in medium buffered at pH 4.6 (M. M. Harden, A. He, K. Creamer, M. W. Clark, I. Hamdallah, K. A. Martinez, R. L. Kresslein, S. P. Bush, and J. L. Slonczewski, Appl Environ Microbiol 81:1932-1941, 2015, https://doi.org/10.1128/AEM.03494-14). Revised genomic analysis of these strains revealed insertion sequence (IS)-driven insertions and deletions that knocked out regulators CadC (acid induction of lysine decarboxylase), GadX (acid induction of glutamate decarboxylase), and FNR (anaerobic regulator). Each acid-evolved strain showed loss of one or more amino acid decarboxylase systems, which normally help neutralize external acid (pH 5 to 6) and increase survival in extreme acid (pH 2). Strains from populations B11, H9, and F11 had an IS 5 insertion or IS-mediated deletion in cadC , while population B11 had a point mutation affecting the arginine activator adiY The cadC and adiY mutants failed to neutralize acid in the presence of exogenous lysine or arginine. In strain B11-1, reversion of an rpoC (RNA polymerase) mutation partly restored arginine-dependent neutralization. All eight strains showed deletion or downregulation of the Gad acid fitness island. Strains with the Gad deletion lost the ability to produce GABA (gamma-aminobutyric acid) and failed to survive extreme acid. Transcriptome sequencing (RNA-seq) of strain B11-1 showed upregulated genes for catabolism of diverse substrates but downregulated acid stress genes (the biofilm regulator ariR , yhiM , and Gad). Other strains showed downregulation of H 2 consumption mediated by hydrogenases ( hya and hyb ) which release acid. Strains F9-2 and F9-3 had a deletion of fnr and showed downregulation of FNR-dependent genes ( dmsABC , frdABCD , hybABO , nikABCDE , and nrfAC ). Overall, strains that had evolved in buffered acid showed loss or downregulation of systems that neutralize unbuffered acid and showed altered regulation of

  10. Modulatory effects of arginine, glutamine and branched-chain amino acids on heat shock proteins, immunity and antioxidant response in exercised rats.

    PubMed

    Moura, Carolina Soares; Lollo, Pablo Christiano Barboza; Morato, Priscila Neder; Risso, Eder Muller; Amaya-Farfan, Jaime

    2017-09-20

    Heat shock proteins (HSPs) are endogenous proteins whose function is to maintain the cell's tolerance to insult, and glutamine supplementation is known to increase HSP expression during intense exercise. Since few studies have addressed the possibility that supplementation with other amino acids could have similar effects to that of glutamine, our objective was to evaluate the effects of leucine, valine, isoleucine and arginine as potential stimulators of HSPs 25, 60, 70 and 90 in rats subjected to acute exercise as a stressing factor. The immune markers, antioxidant system, blood parameters, glycogen and amino acid profile responses were also assessed. Male Wistar rats were divided into seven groups: control (rest, without gavage), vehicle (water), l-leucine, l-isoleucine, l-valine, l-arginine and l-glutamine. Except for the control, all animals were exercised and received every amino acid by oral gavage. Arginine supplementation up-regulated muscle HSP70 and HSP90 and serum HSP70, however, none of the amino acids affected the HSP25. All amino acids increased exercise-induced HSP60 expression, except for valine. Antioxidant enzymes were reduced by exercise, but both glutamine and arginine restored glutathione peroxidase, while isoleucine and valine restored superoxide dismutase. Exercise reduced monocyte, platelet, lymphocyte and erythrocyte levels, while leucine stimulated immune response, preserved the levels of the lymphocytes and increased leukocytes and maintained platelets at control levels. Plasma and muscle amino acid profiles showed specific metabolic features. The data suggest that the tissue-protecting effects of arginine could proceed by enhancing specific HSPs in the body.

  11. Characterization and biocompatibility studies of new degradable poly(urea)urethanes prepared with arginine, glycine or aspartic acid as chain extenders.

    PubMed

    Chan-Chan, L H; Tkaczyk, C; Vargas-Coronado, R F; Cervantes-Uc, J M; Tabrizian, M; Cauich-Rodriguez, J V

    2013-07-01

    Polyurethanes are very often used in the cardiovascular field due to their tunable physicochemical properties and acceptable hemocompatibility although they suffer from poor endothelialization. With this in mind, we proposed the synthesis of a family of degradable segmented poly(urea)urethanes (SPUUs) using amino acids (L-arginine, glycine and L-aspartic acid) as chain extenders. These polymers degraded slowly in PBS (pH 7.4) after 24 weeks via a gradual decrease in molecular weight. In contrast, accelerated degradation showed higher mass loss under acidic, alkaline and oxidative media. MTT tests on polyurethanes with L-arginine as chain extenders showed no adverse effect on the metabolism of human umbilical vein endothelial cells (HUVECs) indicating the leachables did not provoke any toxic responses. In addition, SPUUs containing L-arginine promoted higher levels of HUVECs adhesion, spreading and viability after 7 days compared to the commonly used Tecoflex(®) polyurethane. The biodegradability and HUVEC proliferation on L-arginine-based SPUUs suggests that they can be used in the design of vascular grafts for tissue engineering.

  12. Effects of three permeases on arginine utilization in Saccharomyces cerevisiae

    PubMed Central

    Zhang, Peng; Du, Guocheng; Zou, Huijun; Chen, Jian; Xie, Guangfa; Shi, Zhongping; Zhou, Jingwen

    2016-01-01

    Arginine plays an important role in cellular function and metabolism. Arginine uptake mainly occurs through three amino acid permeases, Alp1p, Gap1p and Can1p, which act as both transporters and receptors for amino acid utilization. In this study, seven mutants were constructed with different combinations of permease deficiencies that inhibit arginine utilization. Their effects on arginine metabolism were measured. The three amino acid permeases were also individually overexpressed in wild-type (WT), Δalp1Δgap1Δcan1 and Δnpr1 strains. The growth and arginine utilization of Δcan1, Δgap1Δcan1 and Δalp1Δgap1Δcan1 mutants were suppressed in YNB medium when arginine was the sole nitrogen source. Meanwhile, overexpression of Alp1p and Can1p enhanced growth and arginine utilization in WT, Δalp1Δgap1Δcan1 and Δnpr1. Besides, overexpression of Can1p caused a 26.7% increase in OD600 and 29.3% increase in arginine utilization compared to that of Alp1p in Δalp1Δgap1Δcan1. Transcription analysis showed that the effects of three amino acid permeases on the arginine utilization and the regulation of related genes, were tightly related to their individual characteristics. However, their overall effects were different for different combinations of mutants. The results presented here suggest some possible synergistic effects of different amino acid permeases on regulation of amino acid utilization and metabolism. PMID:26865023

  13. Arginine methylation of HSP70 regulates retinoid acid-mediated RARβ2 gene activation

    PubMed Central

    Gao, Wei-wei; Xiao, Rong-quan; Peng, Bing-ling; Xu, Huan-teng; Shen, Hai-feng; Huang, Ming-feng; Shi, Tao-tao; Yi, Jia; Zhang, Wen-juan; Wu, Xiao-nan; Gao, Xiang; Lin, Xiang-zhi; Dorrestein, Pieter C.; Rosenfeld, Michael G.; Liu, Wen

    2015-01-01

    Although “histone” methyltransferases and demethylases are well established to regulate transcriptional programs and to use nonhistone proteins as substrates, their possible roles in regulation of heat-shock proteins in the nucleus have not been investigated. Here, we report that a highly conserved arginine residue, R469, in HSP70 (heat-shock protein of 70 kDa) proteins, an evolutionarily conserved protein family of ATP-dependent molecular chaperone, was monomethylated (me1), at least partially, by coactivator-associated arginine methyltransferase 1/protein arginine methyltransferase 4 (CARM1/PRMT4) and demethylated by jumonji-domain–containing 6 (JMJD6), both in vitro and in cultured cells. Functional studies revealed that HSP70 could directly regulate retinoid acid (RA)-induced retinoid acid receptor β2 (RARβ2) gene transcription through its binding to chromatin, with R469me1 being essential in this process. HSP70’s function in gene transcriptional regulation appears to be distinct from its protein chaperon activity. R469me1 was shown to mediate the interaction between HSP70 and TFIIH, which involves in RNA polymerase II phosphorylation and thus transcriptional initiation. Our findings expand the repertoire of nonhistone substrates targeted by PRMT4 and JMJD6, and reveal a new function of HSP70 proteins in gene transcription at the chromatin level aside from its classic role in protein folding and quality control. PMID:26080448

  14. Removal of acidic or basic α-amino acids in water by poorly water soluble scandium complexes.

    PubMed

    Hayashi, Nobuyuki; Jin, Shigeki; Ujihara, Tomomi

    2012-11-02

    To recognize α-amino acids with highly polar side chains in water, poorly water soluble scandium complexes with both Lewis acidic and basic portions were synthesized as artificial receptors. A suspension of some of these receptor molecules in an α-amino acid solution could remove acidic and basic α-amino acids from the solution. The compound most efficient at preferentially removing basic α-amino acids (arginine, histidine, and lysine) was the receptor with 7,7'-[1,3-phenylenebis(carbonylimino)]bis(2-naphthalenesulfonate) as the ligand. The neutral α-amino acids were barely removed by these receptors. Removal experiments using a mixed amino acid solution generally gave results similar to those obtained using solutions containing a single amino acid. The results demonstrated that the scandium complex receptors were useful for binding acidic and basic α-amino acids.

  15. Differential distribution of amino acids in plants.

    PubMed

    Kumar, Vinod; Sharma, Anket; Kaur, Ravdeep; Thukral, Ashwani Kumar; Bhardwaj, Renu; Ahmad, Parvaiz

    2017-05-01

    Plants are a rich source of amino acids and their individual abundance in plants is of great significance especially in terms of food. Therefore, it is of utmost necessity to create a database of the relative amino acid contents in plants as reported in literature. Since in most of the cases complete analysis of profiles of amino acids in plants was not reported, the units used and the methods applied and the plant parts used were different, amino acid contents were converted into relative units with respect to lysine for statistical analysis. The most abundant amino acids in plants are glutamic acid and aspartic acid. Pearson's correlation analysis among different amino acids showed that there were no negative correlations between the amino acids. Cluster analysis (CA) applied to relative amino acid contents of different families. Alismataceae, Cyperaceae, Capparaceae and Cactaceae families had close proximity with each other on the basis of their relative amino acid contents. First three components of principal component analysis (PCA) explained 79.5% of the total variance. Factor analysis (FA) explained four main underlying factors for amino acid analysis. Factor-1 accounted for 29.4% of the total variance and had maximum loadings on glycine, isoleucine, leucine, threonine and valine. Factor-2 explained 25.8% of the total variance and had maximum loadings on alanine, aspartic acid, serine and tyrosine. 14.2% of the total variance was explained by factor-3 and had maximum loadings on arginine and histidine. Factor-4 accounted 8.3% of the total variance and had maximum loading on the proline amino acid. The relative content of different amino acids presented in this paper is alanine (1.4), arginine (1.8), asparagine (0.7), aspartic acid (2.4), cysteine (0.5), glutamic acid (2.8), glutamine (0.6), glycine (1.0), histidine (0.5), isoleucine (0.9), leucine (1.7), lysine (1.0), methionine (0.4), phenylalanine (0.9), proline (1.1), serine (1.0), threonine (1

  16. Evaluation of Drosophila metabolic labeling strategies for in vivo quantitative proteomic analyses with applications to early pupa formation and amino acid starvation.

    PubMed

    Chang, Ying-Che; Tang, Hong-Wen; Liang, Suh-Yuen; Pu, Tsung-Hsien; Meng, Tzu-Ching; Khoo, Kay-Hooi; Chen, Guang-Chao

    2013-05-03

    Although stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomics was first developed as a cell culture-based technique, stable isotope-labeled amino acids have since been successfully introduced in vivo into select multicellular model organisms by manipulating the feeding diets. An earlier study by others has demonstrated that heavy lysine labeled Drosophila melanogaster can be derived by feeding with an exclusive heavy lysine labeled yeast diet. In this work, we have further evaluated the use of heavy lysine and/or arginine for metabolic labeling of fruit flies, with an aim to determine its respective quantification accuracy and versatility. In vivo conversion of heavy lysine and/or heavy arginine to several nonessential amino acids was observed in labeled flies, leading to distorted isotope pattern and underestimated heavy to light ratio. These quantification defects can nonetheless be rectified at protein level using the normalization function. The only caveat is that such a normalization strategy may not be suitable for every biological application, particularly when modified peptides need to be individually quantified at peptide level. In such cases, we showed that peptide ratios calculated from the summed intensities of all isotope peaks are less affected by the heavy amino acid conversion and therefore less sequence-dependent and more reliable. Applying either the single Lys8 or double Lys6/Arg10 metabolic labeling strategy to flies, we quantitatively mapped the proteomic changes during the onset of metamorphosis and upon amino acid deprivation. The expression of a number of steroid hormone 20-hydroxyecdysone regulated proteins was found to be changed significantly during larval-pupa transition, while several subunits of the V-ATPase complex and components regulating actomyosin were up-regulated under starvation-induced autophagy conditions.

  17. Effects of dietary valine:lysine ratio on the performance, amino acid composition of tissues and mRNA expression of genes involved in branched-chain amino acid metabolism of weaned piglets

    PubMed Central

    Xu, Ye Tong; Ma, Xiao Kang; Wang, Chun Lin; Yuan, Ming Feng; Piao, Xiang Shu

    2018-01-01

    Objective The goal of this study was to investigate the effects of dietary standard ileal digestible (SID) valine:lysine ratios on performance, intestinal morphology, amino acids of liver and muscle, plasma indices and mRNA expression of branched-chain amino acid (BCAA) metabolism enzymes. Methods A total of 144 crossbred pigs (Duroc×Landrace×Large White) weaned at 28±4 days of age (8.79±0.02 kg body weight) were randomly allotted to 1 of 4 diets formulated to provide SID valine:lysine ratios of 50%, 60%, 70%, or 80%. Each diet was fed to 6 pens of pigs with 6 pigs per pen (3 gilts and 3 barrows) for 28 days. Results Average daily gain increased quadratically (p<0.05), the villous height of the duodenum, jejunum and ileum increased linearly (p<0.05) as the SID valine:lysine ratio increased. The concentrations of plasma α-keto isovaleric and valine increased linearly (p<0.05), plasma aspartate, asparagine and cysteine decreased (p<0.05) as the SID valine:lysine ratio increased. An increase in SID lysine:valine levels increased mRNA expression levels of mitochondrial BCAA transaminase and branched-chain α-keto acid dehydrogenase in the longissimus dorsi muscle (p<0.05). Conclusion Using a quadratic model, a SID valine:lysine ratio of 68% was shown to maximize the growth of weaned pigs which is slightly higher than the level recommended by the National Research Council [6]. PMID:28728397

  18. Supplemental Citrulline Is More Efficient Than Arginine in Increasing Systemic Arginine Availability in Mice.

    PubMed

    Agarwal, Umang; Didelija, Inka C; Yuan, Yang; Wang, Xiaoying; Marini, Juan C

    2017-04-01

    Background: Arginine is considered to be an essential amino acid in various (patho)physiologic conditions of high demand. However, dietary arginine supplementation suffers from various drawbacks, including extensive first-pass extraction. Citrulline supplementation may be a better alternative than arginine, because its only fate in vivo is conversion into arginine. Objective: The goal of the present research was to determine the relative efficiency of arginine and citrulline supplementation to improve arginine availability. Methods: Six-week-old C57BL/6J male mice fitted with gastric catheters were adapted to 1 of 7 experimental diets for 2 wk. The basal diet contained 2.5 g l-arginine/kg, whereas the supplemented diets contained an additional 2.5, 7.5, and 12.5 g/kg diet of either l-arginine or l-citrulline. On the final day, after a 3-h food deprivation, mice were continuously infused intragastrically with an elemental diet similar to the dietary treatment, along with l-[ 13 C 6 ]arginine, to determine the splanchnic first-pass metabolism (FPM) of arginine. In addition, tracers were continuously infused intravenously to determine the fluxes and interconversions between citrulline and arginine. Linear regression slopes were compared to determine the relative efficiency of each supplement. Results: Whereas all the supplemented citrulline (105% ± 7% SEM) appeared in plasma and resulted in a marginal increase of 86% in arginine flux, supplemental arginine underwent an ∼70% FPM, indicating that only 30% of the supplemental arginine entered the peripheral circulation. However, supplemental arginine did not increase arginine flux. Both supplements linearly increased ( P < 0.01) plasma arginine concentration from 109 μmol/L for the basal diet to 159 and 214 μmol/L for the highest arginine and citrulline supplementation levels, respectively. However, supplemental citrulline increased arginine concentrations to a greater extent (35%, P < 0.01). Conclusions: Citrulline

  19. Role of L-lysine-alpha-ketoglutarate aminotransferase in catabolism of lysine as a nitrogen source for Rhodotorula glutinis.

    PubMed Central

    Kinzel, J J; Winston, M K; Bhattacharjee, J K

    1983-01-01

    Wild-type and saccharopine dehydrogenaseless mutant strains of Rhodotorula glutinis grew in minimal medium containing lysine as the sole nitrogen source and simultaneously accumulated, in the culture supernatant, large amounts of a product identified as alpha-aminoadipic-delta-semialdehyde. The saccharopine dehydrogenase and pipecolic acid oxidase levels remained unchanged in wild-type cells grown in the presence of ammonium or lysine as the nitrogen source. Lysine-alpha-ketoglutarate aminotransferase activity was demonstrated in ammonium-grown cells. This activity was depressed in cells grown in the presence of lysine as the sole source of nitrogen. PMID:6408065

  20. The Human Gene SLC25A29, of Solute Carrier Family 25, Encodes a Mitochondrial Transporter of Basic Amino Acids*

    PubMed Central

    Porcelli, Vito; Fiermonte, Giuseppe; Longo, Antonella; Palmieri, Ferdinando

    2014-01-01

    The human genome encodes 53 members of the solute carrier family 25 (SLC25), also called the mitochondrial carrier family, many of which have been shown to transport carboxylates, amino acids, nucleotides, and cofactors across the inner mitochondrial membrane, thereby connecting cytosolic and matrix functions. In this work, a member of this family, SLC25A29, previously reported to be a mitochondrial carnitine/acylcarnitine- or ornithine-like carrier, has been thoroughly characterized biochemically. The SLC25A29 gene was overexpressed in Escherichia coli, and the gene product was purified and reconstituted in phospholipid vesicles. Its transport properties and kinetic parameters demonstrate that SLC25A29 transports arginine, lysine, homoarginine, methylarginine and, to a much lesser extent, ornithine and histidine. Carnitine and acylcarnitines were not transported by SLC25A29. This carrier catalyzed substantial uniport besides a counter-exchange transport, exhibited a high transport affinity for arginine and lysine, and was saturable and inhibited by mercurial compounds and other inhibitors of mitochondrial carriers to various degrees. The main physiological role of SLC25A29 is to import basic amino acids into mitochondria for mitochondrial protein synthesis and amino acid degradation. PMID:24652292

  1. The human gene SLC25A29, of solute carrier family 25, encodes a mitochondrial transporter of basic amino acids.

    PubMed

    Porcelli, Vito; Fiermonte, Giuseppe; Longo, Antonella; Palmieri, Ferdinando

    2014-05-09

    The human genome encodes 53 members of the solute carrier family 25 (SLC25), also called the mitochondrial carrier family, many of which have been shown to transport carboxylates, amino acids, nucleotides, and cofactors across the inner mitochondrial membrane, thereby connecting cytosolic and matrix functions. In this work, a member of this family, SLC25A29, previously reported to be a mitochondrial carnitine/acylcarnitine- or ornithine-like carrier, has been thoroughly characterized biochemically. The SLC25A29 gene was overexpressed in Escherichia coli, and the gene product was purified and reconstituted in phospholipid vesicles. Its transport properties and kinetic parameters demonstrate that SLC25A29 transports arginine, lysine, homoarginine, methylarginine and, to a much lesser extent, ornithine and histidine. Carnitine and acylcarnitines were not transported by SLC25A29. This carrier catalyzed substantial uniport besides a counter-exchange transport, exhibited a high transport affinity for arginine and lysine, and was saturable and inhibited by mercurial compounds and other inhibitors of mitochondrial carriers to various degrees. The main physiological role of SLC25A29 is to import basic amino acids into mitochondria for mitochondrial protein synthesis and amino acid degradation.

  2. Ablation of arginase II spares arginine and abolishes the arginine requirement for growth in male mice

    USDA-ARS?s Scientific Manuscript database

    Arginine is considered a semi-essential amino acid in many species, including humans, because under certain conditions its demand exceeds endogenous production. Arginine availability, however, is not only determined by its production, but also by its disposal. Manipulation of disposal pathways has t...

  3. Plasma membrane transporters for arginine.

    PubMed

    Closs, Ellen I; Simon, Alexandra; Vékony, Nicole; Rotmann, Alexander

    2004-10-01

    The supply of arginine may become rate limiting for enzymatic reactions that use this semiessential amino acid as a substrate (e.g., nitric oxide, agmatine, creatine, and urea synthesis), particularly under conditions of high demand such as growth, sepsis, or wound healing. In addition, arginine acts as a signaling molecule that regulates essential cellular functions such as protein synthesis, apoptosis, and growth. In the past decade, a number of carrier proteins for amino acids have been identified on the molecular level. They belong to different gene families, exhibit overlapping but distinctive substrate specificities, and can further be distinguished by their requirement for the cotransport or countertransport of inorganic ions. A number of these transporters function as exchangers rather than uniporters. Uptake of amino acids by these transporters therefore depends largely on the intracellular substrate composition. Hence, there is a complex crosstalk between transporters for cationic and neutral amino acids as well as for peptides. This article briefly reviews current knowledge regarding mammalian plasma membrane transporters that accept arginine as a substrate.

  4. Diminished L-arginine bioavailability in hypertension.

    PubMed

    Moss, Monique B; Brunini, Tatiana M C; Soares De Moura, Roberto; Novaes Malagris, Lúcia E; Roberts, Norman B; Ellory, J Clive; Mann, Giovanni E; Mendes Ribeiro, Antônio C

    2004-10-01

    L-Arginine is the precursor of NO (nitric oxide), a key endogenous mediator involved in endothelium-dependent vascular relaxation and platelet function. Although the concentration of intracellular L-arginine is well above the Km for NO synthesis, in many cells and pathological conditions the transport of L-arginine is essential for NO production (L-arginine paradox). The present study was designed to investigate the modulation of L-arginine/NO pathway in systemic arterial hypertension. Transport of L-arginine into RBCs (red blood cells) and platelets, NOS (NO synthase) activity and amino acid profiles in plasma were analysed in hypertensive patients and in an animal model of hypertension. Influx of L-arginine into RBCs was mediated by the cationic amino acid transport systems y+ and y+L, whereas, in platelets, influx was mediated only via system y+L. Chromatographic analyses revealed higher plasma levels of L-arginine in hypertensive patients (175+/-19 micromol/l) compared with control subjects (137+/-8 micromol/l). L-Arginine transport via system y+L, but not y+, was significantly reduced in RBCs from hypertensive patients (60+/-7 micromol.l(-1).cells(-1).h(-1); n=16) compared with controls (90+/-17 micromol.l(-1).cells(-1).h(-1); n=18). In human platelets, the Vmax for L-arginine transport via system y+L was 86+/-17 pmol.10(9) cells(-1).min(-1) in controls compared with 36+/-9 pmol.10(9) cells(-1).min(-1) in hypertensive patients (n=10; P<0.05). Basal NOS activity was decreased in platelets from hypertensive patients (0.12+/-0.02 pmol/10(8) cells; n=8) compared with controls (0.22+/-0.01 pmol/10(8) cells; n=8; P<0.05). Studies with spontaneously hypertensive rats demonstrated that transport of L-arginine via system y+L was also inhibited in RBCs. Our findings provide the first evidence that hypertension is associated with an inhibition of L-arginine transport via system y+L in both humans and animals, with reduced availability of L-arginine limiting NO synthesis

  5. Vba5p, a novel plasma membrane protein involved in amino acid uptake and drug sensitivity in Saccharomyces cerevisiae.

    PubMed

    Shimazu, Masamitsu; Itaya, Teruhiro; Pongcharoen, Pongsanat; Sekito, Takayuki; Kawano-Kawada, Miyuki; Kakinuma, Yoshimi

    2012-01-01

    Vba5p is closest to Vba3p in the vacuolar transporter for basic amino acids (VBA) family of Saccharomyces cerevisiae. We found that green fluorescence protein (GFP)-tagged Vba5p localized exclusively to the plasma membrane. The uptake of lysine and arginine by whole cells was little affected by deletion of the VBA5 gene, but was stimulated by overexpression of the VBA5 gene. The inhibitory effect of 4-nitroquinoline N-oxide on cell growth was accelerated by expression of the VBA5 gene, and was lessened by the addition of arginine. These results suggest that Vba5p is a plasma membrane protein involved in amino acid uptake and drug sensitivity.

  6. Role of activator protein-1 on the effect of arginine-glycine-aspartic acid containing peptides on transforming growth factor-beta1 promoter activity.

    PubMed

    Ruiz-Torres, M P; Perez-Rivero, G; Diez-Marques, M L; Griera, M; Ortega, R; Rodriguez-Puyol, M; Rodríguez-Puyol, D

    2007-01-01

    While arginine-glycine-aspartic acid-based peptidomimetics have been employed for the treatment of cardiovascular disorders and cancer, their use in other contexts remains to be explored. Arginine-glycine-aspartic acid-serine induces Transforming growth factor-beta1 transcription in human mesangial cells, but the molecular mechanisms involved have not been studied extensively. We explored whether this effect could be due to Activator protein-1 activation and studied the potential pathways involved. Addition of arginine-glycine-aspartic acid-serine promoted Activator protein-1 binding to its cognate sequence within the Transforming growth factor-beta1 promoter as well as c-jun and c-fos protein abundance. Moreover, this effect was suppressed by curcumin, a c-Jun N terminal kinase inhibitor, and was absent when the Activator protein-1 cis-regulatory element was deleted. Activator protein-1 binding was dependent on the activity of integrin linked kinase, as transfection with a dominant negative mutant suppressed both Activator protein-1 binding and c-jun and c-fos protein increment. Integrin linked kinase was, in turn, dependent on Phosphoinositol-3 kinase activity. Arginine-glycine-aspartic acid-serine stimulated Phosphoinositol-3 kinase activity, and Transforming growth factor-beta1 promoter activation was abrogated by the use of Phosphoinositol-3 kinase specific inhibitors. In summary, we propose that arginine-glycine-aspartic acid-serine activates Integrin linked kinase via the Phosphoinositol-3 kinase pathway and this leads to activation of c-jun and c-fos and increased Activator protein-1 binding and Transforming growth factor-beta1 promoter activity. These data may contribute to understand the molecular mechanisms involved in the cellular actions of arginine-glycine-aspartic acid-related peptides and enhance their relevance as these products evolve into clinical therapeutic use.

  7. Supplemental Citrulline Is More Efficient Than Arginine in Increasing Systemic Arginine Availability in Mice123

    PubMed Central

    Agarwal, Umang; Didelija, Inka C; Yuan, Yang; Wang, Xiaoying; Marini, Juan C

    2017-01-01

    Background: Arginine is considered to be an essential amino acid in various (patho)physiologic conditions of high demand. However, dietary arginine supplementation suffers from various drawbacks, including extensive first-pass extraction. Citrulline supplementation may be a better alternative than arginine, because its only fate in vivo is conversion into arginine. Objective: The goal of the present research was to determine the relative efficiency of arginine and citrulline supplementation to improve arginine availability. Methods: Six-week-old C57BL/6J male mice fitted with gastric catheters were adapted to 1 of 7 experimental diets for 2 wk. The basal diet contained 2.5 g l-arginine/kg, whereas the supplemented diets contained an additional 2.5, 7.5, and 12.5 g/kg diet of either l-arginine or l-citrulline. On the final day, after a 3-h food deprivation, mice were continuously infused intragastrically with an elemental diet similar to the dietary treatment, along with l-[13C6]arginine, to determine the splanchnic first-pass metabolism (FPM) of arginine. In addition, tracers were continuously infused intravenously to determine the fluxes and interconversions between citrulline and arginine. Linear regression slopes were compared to determine the relative efficiency of each supplement. Results: Whereas all the supplemented citrulline (105% ± 7% SEM) appeared in plasma and resulted in a marginal increase of 86% in arginine flux, supplemental arginine underwent an ∼70% FPM, indicating that only 30% of the supplemental arginine entered the peripheral circulation. However, supplemental arginine did not increase arginine flux. Both supplements linearly increased (P < 0.01) plasma arginine concentration from 109 μmol/L for the basal diet to 159 and 214 μmol/L for the highest arginine and citrulline supplementation levels, respectively. However, supplemental citrulline increased arginine concentrations to a greater extent (35%, P < 0.01). Conclusions: Citrulline

  8. Citrulline protects Streptococcus pyogenes from acid stress using the arginine deiminase pathway and the F1Fo-ATPase.

    PubMed

    Cusumano, Zachary T; Caparon, Michael G

    2015-04-01

    A common stress encountered by both pathogenic and environmental bacteria is exposure to a low-pH environment, which can inhibit cell growth and lead to cell death. One major defense mechanism against this stress is the arginine deiminase (ADI) pathway, which catabolizes arginine to generate two ammonia molecules and one molecule of ATP. While this pathway typically relies on the utilization of arginine, citrulline has also been shown to enter into the pathway and contribute to protection against acid stress. In the pathogenic bacterium Streptococcus pyogenes, the utilization of citrulline has been demonstrated to contribute to pathogenesis in a murine model of soft tissue infection, although the mechanism underlying its role in infection is unknown. To gain insight into this question, we analyzed a panel of mutants defective in different steps in the ADI pathway to dissect how arginine and citrulline protect S. pyogenes in a low-pH environment. While protection provided by arginine utilization occurred through the buffering of the extracellular environment, citrulline catabolism protection was pH independent, requiring the generation of ATP via the ADI pathway and a functional F1Fo-ATP synthase. This work demonstrates that arginine and citrulline catabolism protect against acid stress through distinct mechanisms and have unique contributions to virulence during an infection. An important aspect of bacterial pathogenesis is the utilization of host-derived nutrients during an infection for growth and virulence. Previously published work from our lab identified a unique role for citrulline catabolism in Streptococcus pyogenes during a soft tissue infection. The present article probes the role of citrulline utilization during this infection and its contribution to protection against acid stress. This work reveals a unique and concerted action between the catabolism of citrulline and the F1Fo-ATPase that function together to provide protection for bacteria in a low

  9. Avt5p is required for vacuolar uptake of amino acids in the fission yeast Schizosaccharomyces pombe.

    PubMed

    Chardwiriyapreecha, Soracom; Mukaiyama, Hiroyuki; Sekito, Takayuki; Iwaki, Tomoko; Takegawa, Kaoru; Kakinuma, Yoshimi

    2010-06-03

    We identified SPBC1685.07c of Schizosaccharomyces pombe as a novel vacuolar protein, Avt5p, with similarity to vacuolar amino acid transporters Avt5p from Saccharomyces cerevisiae. Avt5p localizes to the vacuolar membrane and upon disruption of avt5, uptake of histidine, glutamate, tyrosine, arginine, lysine or serine was impaired. During nitrogen starvation, the transient increase of vacuolar lysine transport observed for wild-type cells still occurred in the mutant cells, however, uptake of glutamate did not significantly increase in response to nitrogen starvation. Our results show that under diverse growth conditions Avt5p is involved in vacuolar transport of a selective set of amino acids. Copyright 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  10. Sensing and adaptation to low pH mediated by inducible amino acid decarboxylases in Salmonella.

    PubMed

    Viala, Julie P M; Méresse, Stéphane; Pocachard, Bérengère; Guilhon, Aude-Agnès; Aussel, Laurent; Barras, Frédéric

    2011-01-01

    During the course of infection, Salmonella enterica serovar Typhimurium must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments. Three low pH inducible amino acid decarboxylases were annotated in the genome of S. Typhimurium, AdiA, CadA and SpeF, which are specific for arginine, lysine and ornithine, respectively. In this study, we characterized and compared the contributions of those enzymes in response to acidic challenges. Individual mutants as well as a strain deleted for the three genes were tested for their ability (i) to survive an extreme acid shock, (ii) to grow at mild acidic pH and (iii) to infect the mouse animal model. We showed that the lysine decarboxylase CadA had the broadest range of activity since it both had the capacity to promote survival at pH 2.3 and growth at pH 4.5. The arginine decarboxylase AdiA was the most performant in protecting S. Typhimurium from a shock at pH 2.3 and the ornithine decarboxylase SpeF conferred the best growth advantage under anaerobiosis conditions at pH 4.5. We developed a GFP-based gene reporter to monitor the pH of the environment as perceived by S. Typhimurium. Results showed that activities of the lysine and ornithine decarboxylases at mild acidic pH did modify the local surrounding of S. Typhimurium both in culture medium and in macrophages. Finally, we tested the contribution of decarboxylases to virulence and found that these enzymes were dispensable for S. Typhimurium virulence during systemic infection. In the light of this result, we examined the genomes of Salmonella spp. normally responsible of systemic infection and observed that the genes encoding these enzymes were not well conserved, supporting the idea that these enzymes may be not required during systemic infection.

  11. Vacuolar transporter Avt4 is involved in excretion of basic amino acids from the vacuoles of Saccharomyces cerevisiae.

    PubMed

    Sekito, Takayuki; Chardwiriyapreecha, Soracom; Sugimoto, Naoko; Ishimoto, Masaya; Kawano-Kawada, Miyuki; Kakinuma, Yoshimi

    2014-01-01

    Basic amino acids (lysine, histidine and arginine) accumulated in Saccharomyces cerevisiae vacuoles should be mobilized to cytosolic nitrogen metabolism under starvation. We found that the decrease of vacuolar basic amino acids in response to nitrogen starvation was impaired by the deletion of AVT4 gene encoding a vacuolar transporter. In addition, overexpression of AVT4 reduced the accumulation of basic amino acids in vacuoles under nutrient-rich condition. In contrast to AVT4, the deletion and overexpression of AVT3, which encodes the closest homologue of Avt4p, did not affect the contents of vacuolar basic amino acids. Consistent with these, arginine uptake into vacuolar membrane vesicles was decreased by Avt4p-, but not by Avt3p-overproduction, whereas various neutral amino acids were excreted from vacuolar membrane vesicles in a manner dependent on either Avt4p or Avt3p. These results suggest that Avt4p is a vacuolar amino acid exporter involving in the recycling of basic amino acids.

  12. Synthesis of pro-prodrugs L-lysine based for 5-aminosalicylic acid and 6-mercaptopurine colon specific release.

    PubMed

    Trombino, Sonia; Cassano, Roberta; Cilea, Alessia; Ferrarelli, Teresa; Muzzalupo, Rita; Picci, Nevio

    2011-11-28

    The aim of this work is to design, prepare and characterize L-lysine based prodrugs capable of targeting 6-mercaptopurine to the colon, an anti-tumor and immunosuppressant drug, and 5-aminosalicylic acid (5-ASA), drug of choice for inflammatory bowel disease (IBD). More specifically, Nɛ-feruloyl-S-(6-purinyl)-L-lysine and Nɛ-acryloyl-S-(6-purinyl)-L-lysine were synthesized and then characterized by FT-IR, (1)H-NMR and GC/MS spectroscopies. The ability of feruloyl derivative in inhibiting lipid peroxidation in rat liver microsomal membranes, induced in vitro by tert-butyl hydroperoxide as source of free radicals, was evaluated. Moreover, Nɛ-acryloyl-S-(6-purinyl)-L-lysine, polymerizable prodrug, was used to microspheres realization for 5-ASA release. These lasts, obtained by emulsion inverse technique, were characterized by light scattering and scanning electron microscopy (SEM) analysis. The microspheres equilibrium swelling degree was evaluated and showed good swelling behaviour in simulating colonic fluids. Results confirm the possibility that the application range of L-lysine prodrug can be extended to the treatment of intestinal diseases whose conventional therapy envisages medications with serious side effects that, thanks to this new strategy, can be minimized in an optimal way. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Synthesis of peptides from amino acids and ATP with lysine-rich proteinoid

    NASA Technical Reports Server (NTRS)

    Nakashima, T.; Fox, S. W.

    1980-01-01

    The paper examines the synthesis of peptides from aminoacids and ATP with a lysine-rich protenoid. The latter in aqueous solution catalyzes the formation of peptides from free amino acids and ATP; this catalytic activity is not found in acidic protenoids, even though the latter contain a basic aminoacid. The pH optimum for the synthesis is about 11, but it is appreciable below 8 and above 13. Temperature data indicate an optimum at 20 C or above, with little increase in rate up to 60 C. Pyrophosphate can be used instead of ATP, but the yields are lower. The ATP-aided syntheses of peptides in aqueous solution occur with several types of proteinous aminoacids.

  14. L-Arginine in the treatment of valproate overdose - five clinical cases.

    PubMed

    Schrettl, Verena; Felgenhauer, Norbert; Rabe, Christian; Fernando, Malkanthi; Eyer, Florian

    2017-04-01

    Valproic acid and its metabolites - particularly valproyl-CoA - are inhibitors of the enzyme N-acetylglutamate synthetase. The amino acid l-arginine can stimulate N-acetylglutamate synthetase activity and could be potentially used therapeutically to correct hyperammonemia caused by valproate therapy or overdose. Severely valproic-acid-poisoned patients are usually treated with l-carnitine or hemodialysis in order to decrease hyperammonemia. We herein report of five cases, in which l-arginine was administered. Observational study on five cases. Patients with hyperammonemia (i.e., ammonia 80 > μg/dL) and symptoms consistent with valproate overdose (i.e., drowsiness, coma) were selected for treatment with l-arginine. Data was collected retrospectively. l-Arginine decreased ammonia levels in a close temporal relation (case I ammonia in EDTA-plasma [μg/dL] decreased from 381 to 39; case II from 281 to 50; case III from 669 to 74; case IV from 447 to 56; case V from 202 to 60). In cases I and II, hemodialysis was performed and l-carnitine was given before the administration of l-arginine. In case III, hemodialysis was performed after the administration of l-arginine was already started. In cases IV and V, treatment with l-arginine was the sole measure to decrease ammonia levels in plasma. The results suggest that l-arginine may be beneficial in selected cases of valproate overdose complicated by hyperammonemia. l-Arginine could extend our conventional treatment options for valproic acid overdose.

  15. The role of arginine and arginine-metabolizing enzymes during Giardia – host cell interactions in vitro

    PubMed Central

    2013-01-01

    Background Arginine is a conditionally essential amino acid important in growing individuals and under non-homeostatic conditions/disease. Many pathogens interfere with arginine-utilization in host cells, especially nitric oxide (NO) production, by changing the expression of host enzymes involved in arginine metabolism. Here we used human intestinal epithelial cells (IEC) and three different isolates of the protozoan parasite Giardia intestinalis to investigate the role of arginine and arginine-metabolizing enzymes during intestinal protozoan infections. Results RNA expression analyses of major arginine-metabolizing enzymes revealed the arginine-utilizing pathways in human IECs (differentiated Caco-2 cells) grown in vitro. Most genes were constant or down-regulated (e.g. arginase 1 and 2) upon interaction with Giardia, whereas inducible NO synthase (iNOS) and ornithine decarboxylase (ODC) were up-regulated within 6 h of infection. Giardia was shown to suppress cytokine-induced iNOS expression, thus the parasite has both iNOS inducing and suppressive activities. Giardial arginine consumption suppresses NO production and the NO-degrading parasite protein flavohemoglobin is up-regulated in response to host NO. In addition, the secreted, arginine-consuming giardial enzyme arginine deiminase (GiADI) actively reduces T-cell proliferation in vitro. Interestingly, the effects on NO production and T cell proliferation could be reversed by addition of external arginine or citrulline. Conclusions Giardia affects the host’s arginine metabolism on many different levels. Many of the effects can be reversed by addition of arginine or citrulline, which could be a beneficial supplement in oral rehydration therapy. PMID:24228819

  16. Free amino acids hydroxyproline, lysine, and glycine promote differentiation of retinal pericytes to adipocytes: A protective role against proliferative diabetic retinopathy.

    PubMed

    Vidhya, S; Ramya, R; Coral, K; Sulochana, K N; Bharathidevi, S R

    2018-05-10

    This study was conducted to estimate the aminoacid levels in the vitreous of patients with proliferative diabetic retinopathy, and to correlate it with the adiponectin levels. Secondly to test if these amino acids can alter or induce adiponectin levels and its related factors in retinal cells like pericyte as an in vitro model. All human studies were done as per declaration of Helsinki with institutional approval and after obtaining consent from participating individuals. The vitreous amino acids were estimated in PDR (Proliferative diabetic retinopathy) and MH (Macular Hole) as disease control using HPLC. Bovine retinal pericytes (BRP) were cultured in DMEM/F12 medium and treated with 0.5 mM of any one of the individual amino acids (proline, hydroxyproline, phenylalanine, alanine, serine, glycine, lysine, isoleucine or valine) along with 100 nM insulin for 14 days in high glucose (25 mM) condition. The mRNA expression profile of adipogenic markers (such as Pref1, APN, ZAG and PPARγ), angiogenic markers (VEGF, MMP-2 and MMP-9, TGF-β) and antioxidant markers (Nrf2 and UCP-2) were evaluated by qPCR. Adipogenesis was further confirmed by adipogenesis assay, secretion of adiponectin in medium and triglyceride accumulation by Oil red O staining in Bovine retinal pericytes. Amino acids valine (p < 0.004), isoleucine (p < 0.0007), leucine (p < 0.022), serine (p < 0.0007), glycine (p < 0.001), alanine (p < 0.017), phenylalanine (p < 0.013), and lysine (p < 0.001) were significantly elevated in the vitreous of PDR group (n = 30) when compared to macular hole (n = 20). There was a significant positive correlation between serine (p < 0.021), alanine (p < 0.00016), phenylalanine (p < 0.04), isoleucine (p < 0.023), leucine (p < 0.043), and lysine (p < 0.026) with adiponectin level in the vitreous. The amino acids hydroxyproline, proline, lysine, glycine and alanine induced the triglyceride accumulation and

  17. Unexpected Crosslinking and Diglycation as Advanced Glycation End-Products from Glyoxal

    NASA Astrophysics Data System (ADS)

    Lopez-Clavijo, Andrea F.; Duque-Daza, Carlos A.; Soulby, Andrew; Canelon, Isolda Romero; Barrow, Mark; O'Connor, Peter B.

    2014-12-01

    Glyoxal-derived advanced glycation end-products (AGEs) are formed in physiological systems affecting protein/peptide function and structure. These AGEs are generated during aging and chronic diseases such as diabetes and are considered arginine glycating agents. Thus, the study of glyoxal-derived AGEs in lysine residues and amino acid competition is addressed here using acetylated and non-acetylated undecapeptides, with one arginine and one lysine residue available for glycation. Tandem mass spectrometry results from a Fourier transform ion cyclotron resonance mass spectrometer showed glycated species at both the arginine and lysine residues. One species with the mass addition of 116.01096 Da is formed at the arginine residue. A possible structure is proposed to explain this finding (Nδ-[2-(dihydroxymethyl)-2H,3aH,4H,6aH-[1, 3]dioxolo[5,6-d]imidazolin-5-yl]-L-ornithine-derived AGE). The second species corresponded to intramolecular crosslink involving the lysine residue and its presence is checked with ion-mobility mass spectrometry.

  18. Differential effects of arginine methylation on diastolic dysfunction and disease progression in patients with chronic systolic heart failure

    PubMed Central

    Wilson Tang, Wai Hong; Tong, Wilson; Shrestha, Kevin; Wang, Zeneng; Levison, Bruce S.; Delfraino, Brian; Hu, Bo; Troughton, Richard W.; Klein, Allan L.; Hazen, Stanley L.

    2008-01-01

    Aims To investigate the association of arginine methylation with myocardial function and prognosis in chronic systolic heart failure patients. Methods and results Asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), as well as N-mono-methylarginine (MMA) and methyl-lysine, were simultaneously measured by tandem mass spectrometry in 132 patients with chronic systolic heart failure with echocardiographic evaluation and follow-up. Increasing ADMA and SDMA levels were associated with elevated natriuretic peptide levels (both P < 0.001), and increasing SDMA levels were associated with worsening renal function (P < 0.001). Higher plasma levels of methylated arginine metabolites (but not methyl-lysine) were associated with the presence of left ventricular (LV) diastolic dysfunction (E/septal E′, Spearman's r = 0.31–0.36, P < 0.001). Patients taking beta-blockers had lower ADMA levels than those not taking beta-blockers [0.42 (0.33, 0.50) vs. 0.51 (0.40, 0.58), P < 0.001]. Only increasing ADMA levels were associated with advanced right ventricular (RV) systolic dysfunction. Elevated ADMA levels remained a consistent independent predictor of adverse clinical events (hazard ratio = 1.64, 95% CI: 1.20–2.22, P = 0.002). Conclusion In chronic systolic heart failure, accumulation of methylated arginine metabolites is associated with the presence of LV diastolic dysfunction. Among the methylated derivatives of arginine, ADMA provides the strongest independent prediction of disease progression and adverse long-term outcomes. PMID:18687662

  19. l-lysine production by Bacillus methanolicus: Genome-based mutational analysis and l-lysine secretion engineering.

    PubMed

    Nærdal, Ingemar; Netzer, Roman; Irla, Marta; Krog, Anne; Heggeset, Tonje Marita Bjerkan; Wendisch, Volker F; Brautaset, Trygve

    2017-02-20

    Bacillus methanolicus is a methylotrophic bacterium with an increasing interest in academic research and for biotechnological applications. This bacterium was previously applied for methanol-based production of l-glutamate, l-lysine and the five-carbon diamine cadaverine by wild type, classical mutant and recombinant strains. The genomes of two different l-lysine secreting B. methanolicus classical mutant strains, NOA2#13A52-8A66 and M168-20, were sequenced. We focused on mutational mapping in genes present in l-lysine and other relevant amino acid biosynthetic pathways, as well as in the primary cell metabolism important for precursor supply. In addition to mutations in the aspartate pathway genes dapG, lysA and hom-1, new mutational target genes like alr, proA, proB1, leuC, odhA and pdhD were identified. Surprisingly, no mutations were found in the putative l-lysine transporter gene lysE MGA3 . Inspection of the wild type B. methanolicus strain PB1 genome sequence identified two homologous putative l-lysine transporter genes, lysE PB1 and lysE2 PB1 . The biological role of these putative l-lysine transporter genes, together with the heterologous l-lysine exporter gene lysE Cg from Corynebacterium glutamicum, were therefore investigated. Our results demonstrated that the titer of secreted l-lysine in B. methanolicus was significantly increased by overexpression of lysE Cg while overexpression of lysE MGA3 , lysE PB1 and lysE2 PB1 had no measurable effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Reengineering of a Corynebacterium glutamicum L-arginine and L-citrulline producer.

    PubMed

    Ikeda, Masato; Mitsuhashi, Satoshi; Tanaka, Kenji; Hayashi, Mikiro

    2009-03-01

    Toward the creation of a robust and efficient producer of L-arginine and L-citrulline (arginine/citrulline), we have performed reengineering of a Corynebacterium glutamicum strain by using genetic information of three classical producers. Sequence analysis of their arg operons identified three point mutations (argR123, argG92(up), and argG45) in one producer and one point mutation (argB26 or argB31) in each of the other two producers. Reconstitution of the former three mutations or of each argB mutation on a wild-type genome led to no production. Combined introduction of argB26 or argB31 with argR123 into a wild type gave rise to arginine/citrulline production. When argR123 was replaced by an argR-deleted mutation (Delta argR), the production was further increased. The best mutation set, Delta argR and argB26, was used to screen for the highest productivity in the backgrounds of different wild-type strains of C. glutamicum. This yielded a robust producer, RB, but the production was still one-third of that of the best classical producer. Transcriptome analysis revealed that the arg operon of the classical producer was much more highly upregulated than that of strain RB. Introduction of leuC456, a mutation derived from a classical L-lysine producer and provoking global induction of the amino acid biosynthesis genes, including the arg operon, into strain RB led to increased production but incurred retarded fermentation. On the other hand, replacement of the chromosomal argB by heterologous Escherichia coli argB, natively insensitive to arginine, caused a threefold-increased production without retardation, revealing that the limitation in strain RB was the activity of the argB product. To overcome this, in addition to argB26, the argB31 mutation was introduced into strain RB, which caused higher deregulation of the enzyme and resulted in dramatically increased production, like the strain with E. coli argB. This reconstructed strain displayed an enhanced performance

  1. EFFECT OF TETRACYCLINES ON THE INTRACELLULAR AMINO ACIDS OF MOLDS

    PubMed Central

    Freeman, Bob A.; Circo, Richard

    1963-01-01

    Freeman, Bob A. (University of Chicago, Chicago, Ill.) and Richard Circo. Effect of tetracyclines on the intracellular amino acids of molds. J. Bacteriol. 86:38–44. 1963.—The tetracycline antibiotics were shown to alter the amino acid metabolism of molds whose growth is not markedly affected. Eight molds were grown in the presence of these antiobiotics; four exhibited a general reduction in the concentration of the intracellular amino acids, except for glutamic acid and alanine. In most of these four cultures, the tetracyclines also caused the complete disappearance of arginine, lysine, proline, phenylalanine, and tyrosine from the intracellular amino acid pool. The significance of these observations and the usefulness of the method in the study of the mechanisms of antibiotic action are discussed. PMID:14051820

  2. Serum Amino Acids Profile and the Beneficial Effects of L-Arginine or L-Glutamine Supplementation in Dextran Sulfate Sodium Colitis

    PubMed Central

    Wu, Miaomiao; Liu, Gang; Yang, Guan; Xion, Yan; Su, Dingding; Wu, Li; Li, Tiejun; Chen, Shuai; Duan, Jielin; Yin, Yulong; Wu, Guoyao

    2014-01-01

    This study was conducted to investigate serum amino acids profile in dextran sulfate sodium (DSS)-induced colitis, and impacts of graded dose of arginine or glutamine supplementation on the colitis. Using DSS-induced colitis model, which is similar to human ulcerative colitis, we determined serum profile of amino acids at day 3, 7, 10 and 12 (5 days post DSS treatment). Meanwhile, effects of graded dose of arginine (0.4%, 0.8%, and 1.5%) or glutamine (0.5%, 1.0% and 2.0%) supplementation on clinical parameters, serum amino acids, colonic tight junction proteins, colonic anti-oxidative indicators [catalase, total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px)], colonic pro-inflammatory cytokines [interleukin-1 beta (IL-1β), IL-6, IL-17 and tumor necrosis factor alpha (TNF-α)] in DSS-induced colitis were fully analyzed at day 7 and 12. Additionally, the activation of signal transduction pathways, including nuclear factor kappa B (NF-κB), mitogen-activated protein kinases (MAPK), phosphoinositide-3-kinases (PI3K)/PI3K-protein kinase B (Akt), and myosin light chain kinase (MLCK)- myosin light chain (MLC20), were analyzed using immunoblotting. Serum amino acids analysis showed that DSS treatment changed the serum contents of amino acids, such as Trp, Glu, and Gln (P<0.05). Dietary arginine or glutamine supplementation had significant (P<0.05) influence on the clinical and biochemical parameters (T-SOD, IL-17 and TNF-α) in colitis model. These results were associated with colonic NF-κB, PI3K-Akt and MLCK signaling pathways. In conclusion, arginine or glutamine could be a potential therapy for intestinal inflammatory diseases. PMID:24505477

  3. Serum amino acids profile and the beneficial effects of L-arginine or L-glutamine supplementation in dextran sulfate sodium colitis.

    PubMed

    Ren, Wenkai; Yin, Jie; Wu, Miaomiao; Liu, Gang; Yang, Guan; Xion, Yan; Su, Dingding; Wu, Li; Li, Tiejun; Chen, Shuai; Duan, Jielin; Yin, Yulong; Wu, Guoyao

    2014-01-01

    This study was conducted to investigate serum amino acids profile in dextran sulfate sodium (DSS)-induced colitis, and impacts of graded dose of arginine or glutamine supplementation on the colitis. Using DSS-induced colitis model, which is similar to human ulcerative colitis, we determined serum profile of amino acids at day 3, 7, 10 and 12 (5 days post DSS treatment). Meanwhile, effects of graded dose of arginine (0.4%, 0.8%, and 1.5%) or glutamine (0.5%, 1.0% and 2.0%) supplementation on clinical parameters, serum amino acids, colonic tight junction proteins, colonic anti-oxidative indicators [catalase, total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px)], colonic pro-inflammatory cytokines [interleukin-1 beta (IL-1β), IL-6, IL-17 and tumor necrosis factor alpha (TNF-α)] in DSS-induced colitis were fully analyzed at day 7 and 12. Additionally, the activation of signal transduction pathways, including nuclear factor kappa B (NF-κB), mitogen-activated protein kinases (MAPK), phosphoinositide-3-kinases (PI3K)/PI3K-protein kinase B (Akt), and myosin light chain kinase (MLCK)-myosin light chain (MLC20), were analyzed using immunoblotting. Serum amino acids analysis showed that DSS treatment changed the serum contents of amino acids, such as Trp, Glu, and Gln (P<0.05). Dietary arginine or glutamine supplementation had significant (P<0.05) influence on the clinical and biochemical parameters (T-SOD, IL-17 and TNF-α) in colitis model. These results were associated with colonic NF-κB, PI3K-Akt and MLCK signaling pathways. In conclusion, arginine or glutamine could be a potential therapy for intestinal inflammatory diseases.

  4. Pharmacokinetic investigations in adult humans after parenteral administration of the lysine salt of acetyl-salicylic acid.

    PubMed

    von Voss, H; Göbel, U; Petrich, C; Pütter, J

    1978-11-15

    The lysine salt of acetylsalicylic acid was administered intravenously to four volunteers and intramuscularly to three of them. The drug was tolerated without any observed side effects. Immediately after intravenous application most of the plasma salicylate was acetylsalicylic acid. The highest concentration of acetylsalicylic acid was found after 2 minutes, highest levels of salicylic acid after 60 minutes. Elimination of acetylsalicylic acid was relatively quick within the first period after intravenous administration according to a half-life of 8 minutes. Half-life of salicylic acid was determined to be 3 hours. Intramuscular application results in a constant blood level for a longer period. Bioavailability of acetylsalicylic acid was slightly lower after intramuscular application than after intravenous administration.

  5. Intestinal absorption of an arginine-containing peptide in cystinuria

    PubMed Central

    Asatoor, A. M.; Harrison, B. D. W.; Milne, M. D.; Prosser, D. I.

    1972-01-01

    Separate tolerance tests involving oral intake of the dipeptide, L-arginyl-L-aspartate, and of a corresponding free amino acid mixture, were carried out in a single type 2 cystinuric patient. Absorption of aspartate was within normal limits, whilst that of arginine was normal after the peptide but considerably reduced after the amino acid mixture. The results are compared with the increments of serum arginine found in eight normal subjects after the oral intake of the free amino acid mixture. Analyses of urinary pyrrolidine and of tetramethylenediamine in urine samples obtained after the two tolerance tests in the patient support the view that arginine absorption was subnormal after the amino acid mixture but within normal limits after the dipeptide. PMID:5045711

  6. Ablation of Arginase II Spares Arginine and Abolishes the Arginine Requirement for Growth in Male Mice.

    PubMed

    Didelija, Inka C; Mohammad, Mahmoud A; Marini, Juan C

    2017-08-01

    Background: Arginine is considered a semiessential amino acid in many species, including humans, because under certain conditions its demand exceeds endogenous production. Arginine availability, however, is determined not only by its production but also by its disposal. Manipulation of disposal pathways has the potential to increase availability and thus abolish the requirement for arginine. Objective: The objective of the study was to test the hypothesis that arginase II ablation increases arginine availability for growth. Methods: In a completely randomized design with a factorial arrangement of treatments, postweaning growth was determined for 3 wk in male and female wild-type (WT) mice and arginase II knockout mice (ARGII) on a C57BL/6J background fed arginine-sufficient [Arg(+); 8 g arginine/kg] or arginine-free [Arg(-)] diets. Tracers were used to determine citrulline and arginine kinetics. Results: A sex dimorphism in arginine metabolism was detected; female mice had a greater citrulline flux (∼30%, P < 0.001), which translated to greater de novo synthesis of arginine (∼31%, P < 0.001). Female mice also had greater arginine fluxes ( P < 0.015) and plasma arginine concentrations ( P < 0.01), but a reduced arginine clearance rate ( P < 0.001). Ablation of arginase II increased plasma arginine concentrations in both sexes (∼27%, P < 0.01) but increased arginine flux only in males ( P < 0.01). The absence of arginine in the diet limited the growth of male WT mice ( P < 0.01), but had no effect on male ARGII mice ( P = 0.12). In contrast, WT females on the Arg(-) diet grew at the same rate and achieved final weight similar to that of female WT mice fed the Arg(+) diet ( P = 0.47). Conclusion: The ablation of arginase II in male mice spares arginine that can then be used for growth and to meet other metabolic functions, thus abolishing arginine requirements. © 2017 American Society for Nutrition.

  7. Crystallization of dicalcium phosphate dihydrate with presence of glutamic acid and arginine at 37 °C.

    PubMed

    Li, Chengfeng; Ge, Xiaolu; Li, Guochang; Bai, Jiahai; Ding, Rui

    2014-08-01

    The formations of non-metabolic stones, bones and teeth were seriously related to the morphology, size and surface reactivity of dicalcium phosphate dihydrate (DCPD). Herein, a facile biomimetic mineralization method with presence of glutamic acid and arginine was employed to fabricate DCPD with well-defined morphology and adjustable crystallite size. In reaction solution containing more arginine, crystallization of DCPD occurred with faster rate of nucleation and higher density of stacked layers due to the generation of more OH(-) ions after hydrolysis of arginine at 37 °C. With addition of fluorescein or acetone, the consumption of OH(-) ions or desolvation reaction of Ca(2+) ions was modulated, which resulted in the fabrication of DCPD with adjustable crystallite sizes and densities of stacked layers. In comparison with fluorescein-loading DCPD, dicalcium phosphate anhydrate was prepared with enhanced photoluminescence properties due to the reduction of self-quenching effect and regular arrangement of encapsulated fluorescein molecules. With addition of more acetone, DCPD was prepared with smaller crystallite size via antisolvent crystallization. The simulated process with addition of amino acids under 37 °C would shed light on the dynamic process of biomineralization for calcium phosphate compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Guanidinium Group Remains Protonated in a Strongly Basic Arginine Solution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, Bo; Jacobs, Michael I.; Kostko, Oleg

    Knowledge of the acid dissociation constant of an amino acid has very important ramifications in the biochemistry of proteins and lipid bilayers in aqueous environments because charge and proton transfer depend on its value. The acid dissociation constant for the guanidinium group in arginine has historically been posited as 12.5, but there is substantial variation in published values over the years. Recent experiments suggest that the dissociation constant for arginine is much higher than 12.5, which explains why the arginine guanidinium group retains its positive charge under all physiological conditions. Here, we use X-ray photoelectron spectroscopy to study unsupported, aqueousmore » arginine nanoparticles. By varying the pH of the constituent solution, we provide evidence that the guanidinium group is protonated even in a very basic solution. By analyzing the energy shifts in the C and N X-ray photoelectron spectra, we establish a molecular level picture of how charge and proton transport in aqueous solutions of arginine occur.« less

  9. Guanidinium Group Remains Protonated in a Strongly Basic Arginine Solution

    DOE PAGES

    Xu, Bo; Jacobs, Michael I.; Kostko, Oleg; ...

    2017-05-16

    Knowledge of the acid dissociation constant of an amino acid has very important ramifications in the biochemistry of proteins and lipid bilayers in aqueous environments because charge and proton transfer depend on its value. The acid dissociation constant for the guanidinium group in arginine has historically been posited as 12.5, but there is substantial variation in published values over the years. Recent experiments suggest that the dissociation constant for arginine is much higher than 12.5, which explains why the arginine guanidinium group retains its positive charge under all physiological conditions. Here, we use X-ray photoelectron spectroscopy to study unsupported, aqueousmore » arginine nanoparticles. By varying the pH of the constituent solution, we provide evidence that the guanidinium group is protonated even in a very basic solution. By analyzing the energy shifts in the C and N X-ray photoelectron spectra, we establish a molecular level picture of how charge and proton transport in aqueous solutions of arginine occur.« less

  10. Studies on the biochemical composition, energetics and essential amino acids of three mudskippers in Xiamen Harbour

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Su, Yong-Quan

    1995-12-01

    Measurements were made on the contents of protein, lipid, glycogen (PLG) and water, and on caloric values and amino acids, in muscle of three mudskippers Periophthalmus cantonensis, Scarteiaos viridis and Boleophthalmus pectinirostris collected from Haicang, Xiamen. The essential amino acids (EAA) for these fishes were also studied with radioisotopic trace method. The results showed: (1) The content of each component in tested fish muscles differed slightly, and protein was the most important component making up from 6.685% to 9.891% of the wet weight (about 44.21% 50.45% of dry weight); (2) Energy calculated from the sum of protein, lipid and glycogen in wet muscle was low (<4.3kJ/g) in these fishes, especially in B. pectinirostris (<3.1 kJ/g); the ratios of energy to protein content ( E/P) also were low (<39.873 45.535kJ/g); (3) Seventeen amino acids were determined in these three fishes. The content of the same amino acid (among the seventeen) tested in different species and sexes varied slightly. The amounts of methionine, phenylalanine lysine, arginine, histidine, threonine isoleucine and leucine which are indispensable for the needs of human beings and animals were relatively high, accounting for 47.35% 48.06% of the total amino acid content. (4) Leucine, isoleucine, arginine, lysine, phenylalanine, tryptophan, methionine, histidine, threonine, and valine, are essential in the diet of the three mudskippers as the radioisotopic trace method using D-[U-14C]-glucose showed little or no radioactivity was incorporated into these ten amino acids.

  11. Studies on the biochemical composition, energetics and essential amino acids of three mudskippers in Xiamen Harbour

    NASA Astrophysics Data System (ADS)

    Jun, Wang; Yong-Quan, Su

    1995-12-01

    Measurements were made on the contents of protein, lipid, glycogen (PLG) and water, and on caloric values and amino acids, in muscle of three mudskippers Periophthalmus cantonensis, Scarteiaos viridis and Boleophthalmus pectinirostris collected from Haicang, Xiamen. The essential amino acids (EAA) for these fishes were also studied with radioisotopic trace method. The results showed: (1) The content of each component in tested fish muscles differed slightly, and protein was the most important component making up from 6.685% to 9.891% of the wet weight (about 44.21%-50.45% of dry weight); (2) Energy calculated from the sum of protein, lipid and glycogen in wet muscle was low (<4.3kJ/g) in these fishes, especially in B. pectinirostris (<3.1 kJ/g); the ratios of energy to protein content ( E/P) also were low (<39.873-45.535kJ/g); (3) Seventeen amino acids were determined in these three fishes. The content of the same amino acid (among the seventeen) tested in different species and sexes varied slightly. The amounts of methionine, phenylalanine lysine, arginine, histidine, threonine isoleucine and leucine which are indispensable for the needs of human beings and animals were relatively high, accounting for 47.35%-48.06% of the total amino acid content. (4) Leucine, isoleucine, arginine, lysine, phenylalanine, tryptophan, methionine, histidine, threonine, and valine, are essential in the diet of the three mudskippers as the radioisotopic trace method using D-[U-14C]-glucose showed little or no radioactivity was incorporated into these ten amino acids.

  12. Determination of N epsilon-(carboxymethyl)lysine in foods and related systems.

    PubMed

    Ames, Jennifer M

    2008-04-01

    The sensitive and specific determination of advanced glycation end products (AGEs) is of considerable interest because these compounds have been associated with pro-oxidative and proinflammatory effects in vivo. AGEs form when carbonyl compounds, such as glucose and its oxidation products, glyoxal and methylglyoxal, react with the epsilon-amino group of lysine and the guanidino group of arginine to give structures including N epsilon-(carboxymethyl)lysine (CML), N epsilon-(carboxyethyl)lysine, and hydroimidazolones. CML is frequently used as a marker for AGEs in general. It exists in both the free or peptide-bound forms. Analysis of CML involves its extraction from the food (including protein hydrolysis to release any peptide-bound adduct) and determination by immunochemical or instrumental means. Various factors must be considered at each step of the analysis. Extraction, hydrolysis, and sample clean-up are all less straight forward for food samples, compared to plasma and tissue. The immunochemical and instrumental methods all have their advantages and disadvantages, and no perfect method exists. Currently, different procedures are being used in different laboratories, and there is an urgent need to compare, improve, and validate methods.

  13. Arginine homopeptides for plasmid DNA purification using monolithic supports.

    PubMed

    Cardoso, Sara; Sousa, Ângela; Queiroz, João A; Azzoni, Adriano R; Sousa, Fani

    2018-06-15

    Purification of plasmid DNA targeting therapeutic applications still presents many challenges, namely on supports and specific ligand development. Monolithic supports have emerged as interesting approaches for purifying pDNA due to its excellent mass transfer properties and higher binding capacity values. Moreover, arginine ligands were already described to establish specific and preferential interactions with pDNA. Additionally, some studies revealed the ability of arginine based cationic peptides to condense plasmid DNA, which increased lengthening can result in strongest interactions with higher binding capacities for chromatographic purposes of large molecules such as pDNA. In this work, arginine homopeptides were immobilized in monolithic supports and their performance was evaluated and compared with a single arginine monolithic column regarding supercoiled (sc) plasmid DNA purification. Specific interactions of arginine based peptides with several nucleic acids present in a clarified Escherichia coli lysate sample showed potential for the sc pDNA purification. Effectively, the immobilization of the arginine homopeptides became more functional compared with the single arginine amino acid, showing higher binding capacities, which was also reflected in the intensity of the interactions. The combination of structural versatilities of monoliths with the specificity of arginine peptides raised as a promising strategy for sc pDNA purification. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Atg22p, a vacuolar membrane protein involved in the amino acid compartmentalization of Schizosaccharomyces pombe.

    PubMed

    Sugimoto, Naoko; Iwaki, Tomoko; Chardwiriyapreecha, Soracom; Shimazu, Masamitsu; Kawano, Miyuki; Sekito, Takayuki; Takegawa, Kaoru; Kakinuma, Yoshimi

    2011-01-01

    The fission yeast Schizosaccharomyces pombe has a homolog of the budding yeast Atg22p, which is involved in spore formation (Mukaiyama H. et al., Microbiology, 155, 3816-3826 (2009)). GFP-tagged Atg22p in the fission yeast was localized to the vacuolar membrane. Upon disruption of atg22, the amino acid levels of the cellular fraction as well as the vacuolar fraction decreased. The uptake of several amino acids, such as lysine, histidine, and arginine, was impaired in atg22Δ cells. S. pombe Atg22p plays an important role in the compartmentalization of amino acids.

  15. Quantum Computational Calculations of the Ionization Energies of Acidic and Basic Amino Acids: Aspartate, Glutamate, Arginine, Lysine, and Histidine

    NASA Astrophysics Data System (ADS)

    de Guzman, C. P.; Andrianarijaona, M.; Lee, Y. S.; Andrianarijaona, V.

    An extensive knowledge of the ionization energies of amino acids can provide vital information on protein sequencing, structure, and function. Acidic and basic amino acids are unique because they have three ionizable groups: the C-terminus, the N-terminus, and the side chain. The effects of multiple ionizable groups can be seen in how Aspartate's ionizable side chain heavily influences its preferred conformation (J Phys Chem A. 2011 April 7; 115(13): 2900-2912). Theoretical and experimental data on the ionization energies of many of these molecules is sparse. Considering each atom of the amino acid as a potential departing site for the electron gives insight on how the three ionizable groups affect the ionization process of the molecule and the dynamic coupling between the vibrational modes. In the following study, we optimized the structure of each acidic and basic amino acid then exported the three dimensional coordinates of the amino acids. We used ORCA to calculate single point energies for a region near the optimized coordinates and systematically went through the x, y, and z coordinates of each atom in the neutral and ionized forms of the amino acid. With the calculations, we were able to graph energy potential curves to better understand the quantum dynamic properties of the amino acids. The authors thank Pacific Union College Student Association for providing funds.

  16. Global Profiling of Protein Lysine Malonylation in Escherichia coli Reveals Its Role in Energy Metabolism.

    PubMed

    Qian, Lili; Nie, Litong; Chen, Ming; Liu, Ping; Zhu, Jun; Zhai, Linhui; Tao, Sheng-Ce; Cheng, Zhongyi; Zhao, Yingming; Tan, Minjia

    2016-06-03

    Protein lysine malonylation is a recently identified post-translational modification (PTM), which is evolutionarily conserved from bacteria to mammals. Although analysis of lysine malonylome in mammalians suggested that this modification was related to energy metabolism, the substrates and biological roles of malonylation in prokaryotes are still poorly understood. In this study, we performed qualitative and quantitative analyses to globally identify lysine malonylation substrates in Escherichia coli. We identified 1745 malonylation sites in 594 proteins in E. coli, representing the first and largest malonylome data set in prokaryotes up to date. Bioinformatic analyses showed that lysine malonylation was significantly enriched in protein translation, energy metabolism pathways and fatty acid biosynthesis, implying the potential roles of protein malonylation in bacterial physiology. Quantitative proteomics by fatty acid synthase inhibition in both auxotrophic and prototrophic E. coli strains revealed that lysine malonylation is closely associated with E. coli fatty acid metabolism. Protein structural analysis and mutagenesis experiment suggested malonylation could impact enzymatic activity of citrate synthase, a key enzyme in citric acid (TCA) cycle. Further comparative analysis among lysine malonylome, succinylome and acetylome data showed that these three modifications could participate in some similar enriched metabolism pathways, but they could also possibly play distinct roles such as in fatty acid synthesis. These data expanded our knowledge of lysine malonylation in prokaryotes, providing a resource for functional study of lysine malonylation in bacteria.

  17. AMINO ACID COMPOSITION OF HIGHLY PURIFIED VIRAL PARTICLES OF INFLUENZA A AND B

    PubMed Central

    Knight, C. A.

    1947-01-01

    Microbiological assays for amino acids were made on hydrolysates of four to five highly purified preparations each of influenza A virus (PR8 strain) and influenza B virus (Lee strain). The results of the assays indicated that these strains of influenza virus contain approximately the same amounts of alanine, aspartic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, and valine. However, significant differences were found in the values for arginine, glutamic acid, lysine, tryptophane, and tyrosine. It is believed that these differences may provide, at least in part, a chemical explanation for some of the differing properties of the PR8 and Lee strains of influenza viruses. PMID:19871660

  18. Auto-assembly of nanometer thick, water soluble layers of plasmid DNA complexed with diamines and basic amino acids on graphite: Greatest DNA protection is obtained with arginine.

    PubMed

    Khalil, T T; Boulanouar, O; Heintz, O; Fromm, M

    2017-02-01

    We have investigated the ability of diamines as well as basic amino acids to condense DNA onto highly ordered pyrolytic graphite with minimum damage after re-dissolution in water. Based on a bibliographic survey we briefly summarize DNA binding properties with diamines as compared to basic amino acids. Thus, solutions of DNA complexed with these linkers were drop-cast in order to deposit ultra-thin layers on the surface of HOPG in the absence or presence of Tris buffer. Atomic Force Microscopy analyses showed that, at a fixed ligand-DNA mixing ratio of 16, the mean thickness of the layers can be statistically predicted to lie in the range 0-50nm with a maximum standard deviation ±6nm, using a simple linear law depending on the DNA concentration. The morphology of the layers appears to be ligand-dependent. While the layers containing diamines present holes, those formed in the presence of basic amino acids, except for lysine, are much more compact and dense. X-ray Photoelectron Spectroscopy measurements provide compositional information indicating that, compared to the maximum number of DNA sites to which the ligands may bind, the basic amino acids Arg and His are present in large excess. Conservation of the supercoiled topology of the DNA plasmids was studied after recovery of the complex layers in water. Remarkably, arginine has the best protection capabilities whether Tris was present or not in the initial solution. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion

    PubMed Central

    Strasser, Rona; Zeituni-Molad, Michal; Bendelak, Keren; Rentsch, Doris; Ephros, Moshe; Wiese, Martin; Jardim, Armando; Myler, Peter J.; Zilberstein, Dan

    2016-01-01

    Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines) that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3), as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade. PMID:27043018

  20. Solubility of xenon in amino-acid solutions. II. Nine less-soluble amino acids

    NASA Astrophysics Data System (ADS)

    Kennan, Richard P.; Himm, Jeffrey F.; Pollack, Gerald L.

    1988-05-01

    Ostwald solubility (L) of xenon gas, as the radioisotope 133Xe, has been measured as a function of solute concentration, at 25.0 °C, in aqueous solutions of nine amino acids. The amino-acid concentrations investigated covered much of their solubility ranges in water, viz., asparagine monohydrate (0-0.19 M), cysteine (0-1.16 M), glutamine (0-0.22 M), histidine (0-0.26 M), isoleucine (0-0.19 M), methionine (0-0.22 M), serine (0-0.38 M), threonine (0-1.4 M), and valine (0-0.34 M). We have previously reported solubility results for aqueous solutions of six other, generally more soluble, amino acids (alanine, arginine, glycine, hydroxyproline, lysine, and proline), of sucrose and sodium chloride. In general, L decreases approximately linearly with increasing solute concentration in these solutions. If we postulate that the observed decreases in gas solubility are due to hydration, the results under some assumptions can be used to calculate hydration numbers (H), i.e., the number of H2O molecules associated with each amino-acid solute molecule. The average values of hydration number (H¯) obtained at 25.0 °C are 15.3±1.5 for asparagine, 6.8±0.3 for cysteine, 11.5±1.1 for glutamine, 7.3±0.7 for histidine, 5.9±0.4 for isoleucine, 10.6±0.8 for methionine, 11.2±1.3 for serine, 7.7± 1.0 for threonine, and 6.6±0.6 for valine. We have also measured the temperature dependence of solubility L(T) from 5-40 °C for arginine, glycine, and proline, and obtained hydration numbers H¯(T) in this range. Between 25-40 °C, arginine has an H¯ near zero. This may be evidence for an attractive interaction between xenon and arginine molecules in aqueous solution.

  1. Orally administered L-arginine and glycine are highly effective against acid reflux esophagitis in rats

    PubMed Central

    Nagahama, Kenji; Nishio, Hikaru; Yamato, Masanori; Takeuchi, Koji

    2012-01-01

    Summary Background Reflux esophagitis is caused mainly by excessive exposure of the mucosa to gastric contents. In the present study, we examined the effect of several amino acids on acid reflux esophagitis in rats. Material/Methods After 18 h of fasting, acid reflux esophagitis was induced by ligating both the pylorus and the transitional region between the forestomach and the corpus under ether anesthesia, and the animals were killed 4 h later. The severity of esophagitis was reduced by the oral administration of omeprazole, a proton pump inhibitor, or pepstatin, a specific pepsin inhibitor. Results The development of esophageal lesions was dose-dependently prevented by L-arginine and glycine, given intragastrically (i.g.) after the ligation, with complete inhibition obtained at 250 mg/kg and 750 mg/kg, respectively, and these effects were not influenced by the prior s.c. administration of indomethacin or L-NAME. By contrast, both L-alanine and L-glutamine given i.g. after the ligation aggravated these lesions in a dose-dependent manner. These amino acids had no effect on acid secretion but increased the pH of the gastric contents to 1.8~2.3 due to their buffering action. Conclusions The results confirmed an essential role for acid and pepsin in the pathogenesis of acid reflux esophagitis in the rat model and further suggested that various amino acids affect the severity of esophagitis in different ways, due to yet unidentified mechanisms; L-alanine and L-glutamine exert a deleterious effect on the esophagitis, while L-arginine and glycine are highly protective, independent of endogenous prostaglandins and nitric oxide. PMID:22207112

  2. The growth of ZnO nanostructures using Arginine

    NASA Astrophysics Data System (ADS)

    Singh, Baljinder; Moudgil, Lovika; Singh, Gurinder; Kaura, Aman

    2018-05-01

    The growth mechanism of Zinc oxide (ZnO) nanomaterial with amino acid (Arginine) is explained at different shapes. The present study of ZnO nanostructures (NSs) in the presence of Arginine has enabled us to not only determine the growth mechanism of ZnO NSs but also to determine the effect of Arginine at different temperature of reactants. The synthesized samples are characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Results reveal that Arginine is responsible for formation of NSs. Based on these results, a plausible mechanism is explained.

  3. The Glycoprotein B Cytoplasmic Domain Lysine Cluster Is Critical for Varicella-Zoster Virus Cell-Cell Fusion Regulation and Infection

    PubMed Central

    Arvin, Ann M.; Oliver, Stefan L.

    2016-01-01

    ABSTRACT The conserved glycoproteins gB and gH-gL are essential for herpesvirus entry and cell-cell fusion induced syncytium formation, a characteristic of varicella-zoster virus (VZV) pathology in skin and sensory ganglia. VZV syncytium formation, which has been implicated in the painful condition of postherpetic neuralgia, is regulated by the cytoplasmic domains of gB (gBcyt) via an immunoreceptor tyrosine-based inhibition motif (ITIM) and gH (gHcyt). A lysine cluster (K894, K897, K898, and K900) in the VZV gBcyt was identified by sequence alignment to be conserved among alphaherpesviruses, suggesting a functional role. Alanine and arginine substitutions were used to determine if the positive charge and susceptibility to posttranslational modifications of these lysines contributed to gB/gH-gL cell-cell fusion. Critically, the positive charge of the lysine residues was necessary for fusion regulation, as alanine substitutions induced a 440% increase in fusion compared to that of the wild-type gBcyt while arginine substitutions had wild-type-like fusion levels in an in vitro gB/gH-gL cell fusion assay. Consistent with these results, the alanine substitutions in the viral genome caused exaggerated syncytium formation, reduced VZV titers (−1.5 log10), and smaller plaques than with the parental Oka (pOka) strain. In contrast, arginine substitutions resulted in syncytia with only 2-fold more nuclei, a −0.5-log10 reduction in titers, and pOka-like plaques. VZV mutants with both an ITIM mutation and either alanine or arginine substitutions had reduced titers and small plaques but differed in syncytium morphology. Thus, effective VZV propagation is dependent on cell-cell fusion regulation by the conserved gBcyt lysine cluster, in addition to the gBcyt ITIM and the gHcyt. IMPORTANCE Varicella-zoster virus (VZV) is a ubiquitous pathogen that causes chickenpox and shingles. Individuals afflicted with shingles risk developing the painful condition of postherpetic

  4. Lysine-Grafted MCM-41 Silica as an Antibacterial Biomaterial.

    PubMed

    Villegas, María F; Garcia-Uriostegui, Lorena; Rodríguez, Ofelia; Izquierdo-Barba, Isabel; Salinas, Antonio J; Toriz, Guillermo; Vallet-Regí, María; Delgado, Ezequiel

    2017-09-26

    This paper proposes a facile strategy for the zwitterionization of bioceramics that is based on the direct incorporation of l-lysine amino acid via the ε-amino group onto mesoporous MCM-41 materials. Fourier transform infrared (FTIR) studies of lysine-grafted MCM-41 (MCM-LYS) simultaneously showed bands at 3080 and 1540 cm -1 and bands at 1625 and 1415 cm -1 corresponding to -NH 3+ /COO - pairs, which demonstrate the incorporation of the amino acid on the material surface keeping its zwitterionic character. Both elemental and thermogravimetric analyses showed that the amount of grafted lysine was 8 wt. % based on the bioceramic total weight. Moreover, MCM-LYS exhibited a reduction of adhesion of S. aureus and E. coli bacteria in 33% and 50%, respectively at physiological pH, as compared with pristine MCM-41. Biofilm studies onto surfaces showed that lysine functionalization elicited a reduction of the area covered by S. aureus biofilm from 42% to only 5% (88%). This research shows a simple and effective approach to chemically modify bioceramics using single amino acids that provides zwitterionic functionality, which is useful to develop new biomaterials that are able to resist bacterial adhesion.

  5. Lysine-Grafted MCM-41 Silica as an Antibacterial Biomaterial

    PubMed Central

    Villegas, María F.; Garcia-Uriostegui, Lorena; Rodríguez, Ofelia; Izquierdo-Barba, Isabel; Salinas, Antonio J.; Toriz, Guillermo; Vallet-Regí, María; Delgado, Ezequiel

    2017-01-01

    This paper proposes a facile strategy for the zwitterionization of bioceramics that is based on the direct incorporation of l-lysine amino acid via the ε-amino group onto mesoporous MCM-41 materials. Fourier transform infrared (FTIR) studies of lysine-grafted MCM-41 (MCM-LYS) simultaneously showed bands at 3080 and 1540 cm−1 and bands at 1625 and 1415 cm−1 corresponding to -NH3+/COO− pairs, which demonstrate the incorporation of the amino acid on the material surface keeping its zwitterionic character. Both elemental and thermogravimetric analyses showed that the amount of grafted lysine was 8 wt. % based on the bioceramic total weight. Moreover, MCM-LYS exhibited a reduction of adhesion of S. aureus and E. coli bacteria in 33% and 50%, respectively at physiological pH, as compared with pristine MCM-41. Biofilm studies onto surfaces showed that lysine functionalization elicited a reduction of the area covered by S. aureus biofilm from 42% to only 5% (88%). This research shows a simple and effective approach to chemically modify bioceramics using single amino acids that provides zwitterionic functionality, which is useful to develop new biomaterials that are able to resist bacterial adhesion. PMID:28952559

  6. Genetics Home Reference: lysinuric protein intolerance

    MedlinePlus

    ... abnormally large amount of these amino acids in urine. A shortage of lysine, arginine, and ornithine disrupts many vital functions. Arginine and ornithine are involved in a cellular process called the urea cycle, which processes excess nitrogen (in the form ...

  7. Optimal content and ratio of lysine to arginine in the diet of Pacific white shrimp, Litopenaeus vannamei

    NASA Astrophysics Data System (ADS)

    Feng, Zhengfu; Dong, Chaohua; Wang, Linlin; Hu, Yanjiang; Zhu, Wei

    2013-07-01

    The optimal quantity of dietary lysine (Lys) and arginine (Arg), and the optimal ratio of dietary Lys to Arg for Pacific white shrimp Litopenaeus vannamei were investigated. Coated Lys and Arg were added to a basal diet (37.99% crude protein and 7.28% crude lipid) to provide graded levels of Lys and Arg. The experimental diets contained three Lys levels (2.51%, 2.11%, and 1.70% of total diet), and three Arg levels (1.41%, 1.80%, and 2.21% of total diet) and all combinations of these levels were tested. Pacific white shrimp, with a mean weight of 3.62±0.1 g, were randomly distributed in 36 fiberglass tanks with 30 shrimp per tank and reared on the experimental diets for 50 days. After the feeding trial, the growth performance, survival, feed conversion rate (FCR), body composition and protease and lipase activities in the hepatopancreases of the experimental shrimps were determined. The results show that weight gain (WG), specific growth rate (SGR), FCR, body protein, body Lys and Arg content were significantly affected by dietary Lys and Arg ( P <0.05) and improved when dietary Lys and Arg levels were 2.11% ˜ 2.51% and 1.80%˜2.21%, respectively. Protease and lipase activities in the hepatopancreases of the shrimps appeared higher when dietary Lys and Arg quantities were 2.11% ˜2.51% and 1.80%˜2.21%, although the difference was not statistically significant ( P >0.05). Therefore, according to our results, the optimal Lys and Arg quantities in the diet of Pacific white shrimp, L. vannamei, were considered to be 2.11%-2.51% and 1.80%-2.21%, respectively, and the optimal ratio to be 1:0.88-1:1.05.

  8. Application of PCDA/SPH/CHO/Lysine vesicles to detect pathogenic bacteria in chicken.

    PubMed

    de Oliveira, Taíla V; Soares, Nilda de F F; de Andrade, Nélio J; Silva, Deusanilde J; Medeiros, Eber Antônio A; Badaró, Amanda T

    2015-04-01

    During the course of infection, Salmonella must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments, as lysine decarboxylation to cadaverine. The idea of Salmonella defenses responses could be employed in systems as polydiacetylene (PDA) to detect this pathogen so important to public health system. Beside that PDA is an important substance because of the unique optical property; that undergoes a colorimetric transitions by various external stimuli. Therefore 10,12-pentacosadyinoic acid (PCDA)/Sphingomyelin(SPH)/Cholesterol(CHO)/Lysine system was tested to determine the colorimetric response induced by Salmonella choleraesuis. PCDA/SPH/CHO/Lysine vesicles showed a colour change even in low S. choleraesuis concentration present in laboratory conditions and in chicken meat. Thus, this work showed a PCDA/SPH/CHO/Lysine vesicle application to simplify routine analyses in food industry, as chicken meat industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Plasma growth hormone (GH), insulin and amino acid responses to arginine with or without aspartic acid in pigs. Effect of the dose.

    PubMed

    Cochard, A; Guilhermet, R; Bonneau, M

    1998-01-01

    The aim of the present study was to examine, for the first time in pigs, the dose-dependent effect of arginine (ARG) on growth hormone (GH) and insulin release and the effect of the combined ARG and aspartic acid (ASP) treatment on GH and insulin release. ARG (0.5 or 1 g/kg body weight) with or without an equimolar supplement of ASP (0.38 or 0.76 g/kg, respectively) was administered in piglets via the duodenum. ARG increased plasma arginine, ornithine, urea, proline and branched chain amino acid concentrations. ASP increased specifically plasma aspartic acid, glutamic acid, alanine and citrulline concentrations. Plasma insulin increased with no apparent difference between treatments. Maximum GH level and the area under the GH curve (AUC) were increased in a dose-dependent manner in response to ARG treatment. GH response to the combined ARG and ASP treatment (ARGASP) was delayed compared to ARG alone and was not dose-dependent. AUC for GH after ARGASP treatments were intermediate between those observed after the two ARG doses. Our data suggest that high ASP doses transiently inhibit and delay ARG-induced GH release in pigs and that an equimolar supplement of ASP stimulates or inhibits ARG-induced GH release depending on the dose used.

  10. Free amino acid profiling in the giant puffball mushroom (Calvatia gigantea) using UPLC-MS/MS.

    PubMed

    Kıvrak, İbrahim; Kıvrak, Şeyda; Harmandar, Mansur

    2014-09-01

    Wild edible and medicinal mushroom, Calvatia gigantea, was quantitatively analyzed for the determination of its free amino acids using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The concentrations of total free amino acids, essential and non-essential amino acids were 199.65 mg/100 g, 113.69 mg/100 g, and 85.96 mg/100 g in C. gigantea, respectively. This study showed that C. gigantea, so called a giant puffball mushroom, has free amino acids content. The essential amino acids: tryptophan, isoleucine, valine, phenylalanine, leucine, threonine, lysine, histidine, methionine, and the non-essential amino acids: tyrosine, 4-hyrdroxy proline, arginine, proline, glycine, serine, alanine, glutamine, glutamic acid, aspargine, aspartic acid were detected. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Dietary arginine supplementation affects microvascular development in the small intestine of early-weaned pigs.

    PubMed

    Zhan, Zhenfeng; Ou, Deyuan; Piao, Xiangshu; Kim, Sung Woo; Liu, Yanhong; Wang, Junjun

    2008-07-01

    This study was conducted to evaluate the effects of dietary arginine levels on microvascular development of the small intestine in early-weaned pigs. Twenty-four crossbred pigs (5.0 +/- 0.3 kg body weight) were individually housed and randomly allotted to 1 of 3 diets supplemented with 0, 0.7, and 1.2% L-arginine (8 pigs per group). Pigs consumed the diets ad libitum for 10 d. We collected blood samples on d 3, 6, and 10. On d 10, 6 pigs from each group were randomly selected and killed for tissue sample collection. Compared with control pigs, dietary supplementation with 0.7% L-arginine increased (P < 0.05) jejunal concentrations of nitrite and nitrate (stable oxidation products of nitric oxide), intestinal villus height, as well as plasma proline and arginine concentrations on d 6 and 10. Dietary supplementation with 0.7% L-arginine also increased (P < 0.05) immunoreactive expression of CD34 in duodenal submucosa, ileal mucosa and submucosa, and expression of vascular endothelial growth factor (VEGF) in duodenal submucosa, jejunal mucosa and submucosa, and ileal mucosa compared with the control and 1.2% L-arginine supplementation. Dietary supplementation with 1.2% L-arginine increased (P < 0.05) the concentration of jejunal endothelin-1 compared with the control pigs. Immunoexpression of VEGF in duodenal mucosa and plasma lysine concentrations on d 6 and 10 were lower (P < 0.05) in pigs supplemented with 1.2% L-arginine than in unsupplemented pigs. Collectively, these findings indicate that the effects of L-arginine on microvascular development are beneficial at lower levels but have adverse effects at higher intakes. Dietary supplementation with 0.7% L-arginine may be a useful method to improve microvascular development in the small intestine of early-weaned pigs.

  12. Synthesis of stereoarray isotope labeled (SAIL) lysine via the "head-to-tail" conversion of SAIL glutamic acid.

    PubMed

    Terauchi, Tsutomu; Kamikawai, Tomoe; Vinogradov, Maxim G; Starodubtseva, Eugenia V; Takeda, Mitsuhiro; Kainosho, Masatsune

    2011-01-07

    A stereoarray isotope labeled (SAIL) lysine, (2S,3R,4R,5S,6R)-[3,4,5,6-(2)H(4);1,2,3,4,5,6-(13)C(6);2,6-(15)N(2)]lysine, was synthesized by the "head-to-tail" conversion of SAIL-Glu, (2S,3S,4R)-[3,4-(2)H(2);1,2,3,4,5-(13)C(5);2-(15)N]glutamic acid, with high stereospecificities for all five chiral centers. With the SAIL-Lys in hand, the unambiguous simultaneous stereospecific assignments were able to be established for each of the prochiral protons within the four methylene groups of the Lys side chains in proteins.

  13. Arginine, scurvy and Cartier's "tree of life"

    PubMed Central

    Durzan, Don J

    2009-01-01

    Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compounds were also probably present in decoctions prepared in the severe winter. The semi-essential arginine, proline and all the essential amino acids, would have provided additional nutritional benefits for the rapid recovery from scurvy by vitamin C when food supply was limited. The value of arginine, especially in the recovery of the critically ill sailors, is postulated as a source of nitric oxide, and the arginine-derived guanidino compounds as controlling factors for the activities of different nitric oxide synthases. This review provides further insights into the use of the candidate "trees of life" by indigenous peoples in eastern Canada. It raises hypotheses on the nutritional and synergistic roles of arginine, its metabolites, and other biofactors complementing the role of vitamin C especially in treating Cartier's critically ill sailors. PMID:19187550

  14. Phase equilibria in a system of aqueous arginine with an octane solution of sulfonic acid

    NASA Astrophysics Data System (ADS)

    Kuvaeva, Z. I.; Koval'chuk, I. V.; Vodop'yanova, L. A.; Soldatov, V. S.

    2013-05-01

    The extraction of arginine (Arg) from aqueous salt (0.1 M NaCl) solutions with a sulfo extractant in a wide range of pH values and amino acid concentrations was studied. The 0.1 M solution of dinonylnaphthalenesulfonic acid (HD) in octane was used as an extractant. The degree of extraction was found to be high at pH 0.8-9.0. This can be explained by the effect of additional intermolecular interactions in the extractant phase involving the guanidine group of Arg.

  15. Arginine and Citrulline and the Immune Response in Sepsis

    PubMed Central

    Wijnands, Karolina A.P.; Castermans, Tessy M.R.; Hommen, Merel P.J.; Meesters, Dennis M.; Poeze, Martijn

    2015-01-01

    Arginine, a semi-essential amino acid is an important initiator of the immune response. Arginine serves as a precursor in several metabolic pathways in different organs. In the immune response, arginine metabolism and availability is determined by the nitric oxide synthases and the arginase enzymes, which convert arginine into nitric oxide (NO) and ornithine, respectively. Limitations in arginine availability during inflammatory conditions regulate macrophages and T-lymfocyte activation. Furthermore, over the past years more evidence has been gathered which showed that arginine and citrulline deficiencies may underlie the detrimental outcome of inflammatory conditions, such as sepsis and endotoxemia. Not only does the immune response contribute to the arginine deficiency, also the impaired arginine de novo synthesis in the kidney has a key role in the eventual observed arginine deficiency. The complex interplay between the immune response and the arginine-NO metabolism is further underscored by recent data of our group. In this review we give an overview of physiological arginine and citrulline metabolism and we address the experimental and clinical studies in which the arginine-citrulline NO pathway plays an essential role in the immune response, as initiator and therapeutic target. PMID:25699985

  16. Arginine mimetic structures in biologically active antagonists and inhibitors.

    PubMed

    Masic, Lucija Peterlin

    2006-01-01

    Peptidomimetics have found wide application as bioavailable, biostable, and potent mimetics of naturally occurring biologically active peptides. L-Arginine is a guanidino group-containing basic amino acid, which is positively charged at neutral pH and is involved in many important physiological and pathophysiological processes. Many enzymes display a preference for the arginine residue that is found in many natural substrates and in synthetic inhibitors of many trypsin-like serine proteases, e.g. thrombin, factor Xa, factor VIIa, trypsin, and in integrin receptor antagonists, used to treat many blood-coagulation disorders. Nitric oxide (NO), which is produced by oxidation of L-arginine in an NADPH- and O(2)-dependent process catalyzed by isoforms of nitric oxide synthase (NOS), exhibits diverse roles in both normal and pathological physiologies and has been postulated to be a contributor to the etiology of various diseases. Development of NOS inhibitors as well as analogs and mimetics of the natural substrate L-arginine, is desirable for potential therapeutic use and for a better understanding of their conformation when bound in the arginine binding site. The guanidino residue of arginine in many substrates, inhibitors, and antagonists forms strong ionic interactions with the carboxylate of an aspartic acid moiety, which provides specificity for the basic amino acid residue in the active side. However, a highly basic guanidino moiety incorporated in enzyme inhibitors or receptor antagonists is often associated with low selectivity and poor bioavailability after peroral application. Thus, significant effort is focused on the design and preparation of arginine mimetics that can confer selective inhibition for specific trypsin-like serine proteases and NOS inhibitors as well as integrin receptor antagonists and possess reduced basicity for enhanced oral bioavailability. This review will describe the survey of arginine mimetics designed to mimic the function of the

  17. L-arginine: a new opportunity in the management of clinical derangements in dialysis patients.

    PubMed

    Bellinghieri, Guido; Santoro, Domenico; Mallamace, Agostino; Di Giorgio, Rosa Maria; De Luca, Grazia; Savica, Vincenzo

    2006-07-01

    L-Arginine is an essential amino acid for infants and growing children, as well as for pregnant women. This amino acid is a substrate for at least 5 enzymes identified in mammals, including arginase, arginine-glycine transaminase, kyotorphine synthase, nitric oxide synthase, and arginine decarboxylase. L-arginine is essential for the synthesis of creatine, urea, polyamines, nitric oxide, and agmatine. Arginine may be considered an essential amino acid in sepsis, and its supplementation could be beneficial in this clinical setting by improving microcirculation and protein anabolism. Rats receiving arginine-supplemented parenteral nutrition showed an increased ability to synthesize acute phase proteins when challenged with sepsis. Finally, L-arginine exerts antihypertensive and antiproliferative effects on vascular smooth muscles. It has been shown to reduce systemic blood pressure in some forms of experimental hypertension. Endothelial dysfunction and reduced nitric oxide bioactivity are associated with increased incidence of cardiovascular diseases. A beneficial effect of acute and chronic L-arginine supplementation on endothelial derived nitric oxide production and endothelial function has been shown. In end-stage renal disease patients, the rate of de novo arginine synthesis seemed to be preserved. Our preliminary data on a group of dialysis patients showed that predialysis arginine levels were stable in a normal range during the dialysis session and that hypertensive patients had lower arginine-citrulline ratio than normotensive patients.

  18. Light-activated amino acid transport in Halobacterium halobium envelope vesicles

    NASA Technical Reports Server (NTRS)

    Macdonald, R. E.; Lanyi, J. K.

    1977-01-01

    Vesicles prepared from Halobacterium halobium cell envelopes accumulate amino acids in response to light-induced electrical and chemical gradients. Nineteen of 20 commonly occurring amino acids have been shown to be actively accumulated by these vesicles in response to illumination or in response to an artificially created Na+ gradient. On the basis of shared common carriers the transport systems can be divided into eight classes, each responsible for the transport of one or several amino acids: arginine, lysine, histidine; asparagine, glutamine; alanine, glycine, threonine, serine; leucine, valine, isoleucine, methionine; phenylalanine, tyrosine, tryptophan; aspartate; glutamate; proline. Available evidence suggests that these carriers are symmetrical in that amino acids can be transported equally well in both directions across the vesicle membranes. A tentative working model to account for these observations is presented.

  19. Solubilization of aromatic and hydrophobic moieties by arginine in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Li, Jianguo; Garg, Manju; Shah, Dhawal; Rajagopalan, Raj

    2010-08-01

    Experiments hold intriguing, circumstantial clues to the mechanisms behind arginine-mediated solubilization of small organic drugs and suppression of protein aggregation driven by hydrophobic or aromatic associations, but how exactly arginine's molecular structure and interactions contribute to its function remains unclear since attention has focused so far on the thermodynamics of the preferential exclusion or binding of arginine. Here, we examine, through molecular dynamics simulations, how arginine solubilizes nanoscale particles with hydrophobic surfaces or aromatic-ring-type surface interactions. We show that preferential, hydrophobic, and dispersion interactions of arginine's guanidinium group with the particles lead to a surfactant-like behavior of arginine around the particles and to a solvation layer with a protective polar mask creating a hydrophilic shell. Additionally, arginine-arginine association around the solvation layer further prevents aggregative contacts. The results shed some light on the mechanistic basis of arginine's function as a suppressant of protein aggregation, although the complex energy landscapes and kinetic pathways of aggregation are protein-dependent and pose formidable challenges to developing comprehensive mechanistic pictures. Our results suggest arginine's mode of interaction with hydrophobic patches and aromatic residues could reduce aggregation-prone intermediate states of proteins and shield protein-protein aggregative contacts. The approach used here offers a systematic way of exploring implications of other amino acid/excipient interactions by studying interactions of the excipient with particles grafted with amino acids.

  20. Amine oxidation by d-arginine dehydrogenase in Pseudomonas aeruginosa.

    PubMed

    Ouedraogo, Daniel; Ball, Jacob; Iyer, Archana; Reis, Renata A G; Vodovoz, Maria; Gadda, Giovanni

    2017-10-15

    d-Arginine dehydrogenase from Pseudomonas aeruginosa (PaDADH) is a flavin-dependent oxidoreductase, which is part of a novel two-enzyme racemization system that functions to convert d-arginine to l-arginine. PaDADH contains a noncovalently linked FAD that shows the highest activity with d-arginine. The enzyme exhibits broad substrate specificity towards d-amino acids, particularly with cationic and hydrophobic d-amino acids. Biochemical studies have established the structure and the mechanistic properties of the enzyme. The enzyme is a true dehydrogenase because it displays no reactivity towards molecular oxygen. As established through solvent and multiple kinetic isotope studies, PaDADH catalyzes an asynchronous CH and NH bond cleavage via a hydride transfer mechanism. Steady-state kinetic studies with d-arginine and d-histidine are consistent with the enzyme following a ping-pong bi-bi mechanism. As shown by a combination of crystallography, kinetic and computational data, the shape and flexibility of loop L1 in the active site of PaDADH are important for substrate capture and broad substrate specificity. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Cation–π interactions in protein–ligand binding: theory and data-mining reveal different roles for lysine and arginine† †Electronic supplementary information (ESI) available: DLPNO-CCSD(T)/aug-cc-pVnZ benchmarks; PLIP geometric criteria; polycyclic aromatic ring visualizations; van der Waals surfaces of model complexes; absolute energies from DLPNO-CCSD(T)/aug-cc-pVTZ and SAPT2+3/aug-cc-pVDZ calculations; Cartesian coordinates; Table of PDB IDs and corresponding cation–π interactions identified (.xls). See DOI: 10.1039/c7sc04905f

    PubMed Central

    Kumar, Kiran; Woo, Shin M.; Siu, Thomas; Cortopassi, Wilian A.

    2018-01-01

    We have studied the cation–π interactions of neutral aromatic ligands with the cationic amino acid residues arginine, histidine and lysine using ab initio calculations, symmetry adapted perturbation theory (SAPT), and a systematic meta-analysis of all available Protein Data Bank (PDB) X-ray structures. Quantum chemical potential energy surfaces (PES) for these interactions were obtained at the DLPNO-CCSD(T) level of theory and compared against the empirical distribution of 2012 unique protein–ligand cation–π interactions found in X-ray crystal structures. We created a workflow to extract these structures from the PDB, filtering by interaction type and residue pKa. The gas phase cation–π interaction of lysine is the strongest by more than 10 kcal mol–1, but the empirical distribution of 582 X-ray structures lies away from the minimum on the interaction PES. In contrast, 1381 structures involving arginine match the underlying calculated PES with good agreement. SAPT analysis revealed that underlying differences in the balance of electrostatic and dispersion contributions are responsible for this behavior in the context of the protein environment. The lysine–arene interaction, dominated by electrostatics, is greatly weakened by a surrounding dielectric medium and causes it to become essentially negligible in strength and without a well-defined equilibrium separation. The arginine–arene interaction involves a near equal mix of dispersion and electrostatic attraction, which is weakened to a much smaller degree by the surrounding medium. Our results account for the paucity of cation–π interactions involving lysine, even though this is a more common residue than arginine. Aromatic ligands are most likely to interact with cationic arginine residues as this interaction is stronger than for lysine in higher polarity surroundings. PMID:29719674

  2. Coacervate-like microspheres from lysine-rich proteinoid

    NASA Technical Reports Server (NTRS)

    Rohlfing, D. L.

    1975-01-01

    Microspheres form isothermally from lysine-rich proteinoid when the ionic strength of the solution is increased with NaCl or other salts. Studies with different monovalent anions and with polymers of different amino acid composition indicate that charge neutralization and hydrophobic bonding contribute to microsphere formation. The particles also form in sea water, especially if heated or made slightly alkaline. The microspheres differ from those made from acidic proteinoid but resemble coacervate droplets in some ways (isothermal formation, limited stability, stabilization by quinone, uptake of dyes). Because the constituent lysine-rich proteinoid is of simulated prebiotic origin, the study is interpreted to add emphasis to and suggest an evolutionary continuity for coacervation phenomena.

  3. l-Arginine Uptake by Cationic Amino Acid Transporter Promotes Intra-Macrophage Survival of Leishmania donovani by Enhancing Arginase-Mediated Polyamine Synthesis

    PubMed Central

    Mandal, Abhishek; Das, Sushmita; Kumar, Ajay; Roy, Saptarshi; Verma, Sudha; Ghosh, Ayan Kumar; Singh, Ruby; Abhishek, Kumar; Saini, Savita; Sardar, Abul Hasan; Purkait, Bidyut; Kumar, Ashish; Mandal, Chitra; Das, Pradeep

    2017-01-01

    The survival of intracellular protozoan parasite, Leishmania donovani, the causative agent of Indian visceral leishmaniasis (VL), depends on the activation status of macrophages. l-Arginine, a semi-essential amino acid plays a crucial regulatory role for activation of macrophages. However, the role of l-arginine transport in VL still remains elusive. In this study, we demonstrated that intra-macrophage survival of L. donovani depends on the availability of extracellular l-arginine. Infection of THP-1-derived macrophage/human monocyte-derived macrophage (hMDM) with Leishmania, resulted in upregulation of l-arginine transport. While investigating the involvement of the transporters, we observed that Leishmania survival was greatly impaired when the transporters were blocked either using inhibitor or siRNA-mediated downregulation. CAT-2 was found to be the main isoform associated with l-arginine transport in L. donovani-infected macrophages. l-arginine availability and its transport regulated the host arginase in Leishmania infection. Arginase and inducible nitric oxide synthase (iNOS) expression were reciprocally regulated when assayed using specific inhibitors and siRNA-mediated downregulation. Interestingly, induction of iNOS expression and nitric oxide production were observed in case of inhibition of arginase in infected macrophages. Furthermore, inhibition of l-arginine transport as well as arginase resulted in decreased polyamine production, limiting parasite survival inside macrophages. l-arginine availability and transport regulated Th1/Th2 cytokine levels in case of Leishmania infection. Upregulation of l-arginine transport, induction of host arginase, and enhanced polyamine production were correlated with increased level of IL-10 and decreased level of IL-12 and TNF-α in L. donovani-infected macrophages. Our findings provide clear evidence for targeting the metabolism of l-arginine and l-arginine-metabolizing enzymes as an important therapeutic and

  4. Reversible Lysine Acetylation Regulates Activity of Human Glycine N-Acyltransferase-like 2 (hGLYATL2)

    PubMed Central

    Waluk, Dominik P.; Sucharski, Filip; Sipos, Laszlo; Silberring, Jerzy; Hunt, Mary C.

    2012-01-01

    Lysine acetylation is a major post-translational modification of proteins and regulates many physiological processes such as metabolism, cell migration, aging, and inflammation. Proteomic studies have identified numerous lysine-acetylated proteins in human and mouse models (Kim, S. C., Sprung, R., Chen, Y., Xu, Y., Ball, H., Pei, J., Cheng, T., Kho, Y., Xiao, H., Xiao, L., Grishin, N. V., White, M., Yang, X. J., and Zhao, Y. (2006) Mol. Cell 23, 607–618). One family of proteins identified in this study was the murine glycine N-acyltransferase (GLYAT) enzymes, which are acetylated on lysine 19. Lysine 19 is a conserved residue in human glycine N-acyltransferase-like 2 (hGLYATL2) and in several other species, showing that this residue may be important for enzyme function. Mutation of lysine 19 in recombinant hGLYATL2 to glutamine (K19Q) and arginine (K19R) resulted in a 50–80% lower production of N-oleoyl glycine and N-arachidonoylglycine, indicating that lysine 19 is important for enzyme function. LC/MS/MS confirmed that Lys-19 is not acetylated in wild-type hGLYATL2, indicating that Lys-19 requires to be deacetylated for full activity. The hGLYATL2 enzyme conjugates medium- and long-chain saturated and unsaturated acyl-CoA esters to glycine, resulting in the production of N-oleoyl glycine and also N-arachidonoyl glycine. N-Oleoyl glycine and N-arachidonoyl glycine are structurally and functionally related to endocannabinoids and have been identified as signaling molecules that regulate functions like the perception of pain and body temperature and also have anti-inflammatory properties. In conclusion, acetylation of lysine(s) in hGLYATL2 regulates the enzyme activity, thus linking post-translational modification of proteins with the production of biological signaling molecules, the N-acyl glycines. PMID:22408254

  5. Arginine-based poly(ester amide) nanoparticle platform: From structure-property relationship to nucleic acid delivery.

    PubMed

    You, Xinru; Gu, Zhipeng; Huang, Jun; Kang, Yang; Chu, Chih-Chang; Wu, Jun

    2018-05-25

    Many different types of polycations have been vigorously studied for nucleic acid delivery, but a systematical investigation of the structure-property relationships of polycations for nucleic acid delivery is still lacking. In this study, a new library of biodegradable and biocompatible arginine-based poly(ester amide) (Arg-PEA) biomaterials was designed and synthesized with a tunable structure for such a comprehensive structure-property research. Nanoparticle (NP) complexes were formed through the electrostatic interactions between the polycationic Arg-PEAs and anionic nucleic acids. The following structure effects of the Arg-PEAs on the transfection efficiency of nucleic acids were investigated: 1) the linker/spacer length (length effect and odd-even effect); 2) salt type of arginine; 3) the side chain; 4) chain stiffness; 5) molecular weight (MW). The data obtained revealed that a slight change in the Arg-PEA structure could finely tune its physicochemical property such as hydrophobicity, and this could subsequently affect the nanoparticle size and zeta potential, which, in turn, regulate the transfection efficiency and silencing outcomes. A further study of the Arg-PEA/CpG oligodeoxynucleotide NP complexes indicated that the polymer structure could precisily regulate the immune response of CpG, thus providing a new potential nano-immunotherapy strategy. The in vitro data have further confirmed that the Arg-PEA NPs showed a satisfactory delivery performance for a variety of nucleic acids. Therefore, the data from the current study provide comprehensive information about the Arg-PEA structure-transfection property relationship; the tunable property of the library of Arg-PEA biomaterials can be one of the promising candidates for nucleic acid delivery and other biomedical applications. Polycations have being intensive utilized for nucleic acid delivery. However, there has not been elucidated about the relationship between polycation's structure and the

  6. Variability in arginine content and yield components in Valencia peanut germplasm

    USDA-ARS?s Scientific Manuscript database

    Peanut seeds are rich in arginine, an amino acid that has several positive effects on human health. Establishing the genetic variability of arginine content in peanut will be useful for breeding programs that have high arginine as one of their goals. The objective of this study was to evaluate the...

  7. Quantitative detection of crystalline lysine supplementation in poultry feeds using a rapid bacterial bioluminescence assay.

    PubMed

    Zabala Díaz, I B; Ricke, S C

    2003-08-01

    Lysine is an essential amino acid for both humans and animals; and it is usually the first or second limiting amino acid in most formulated diets. In order to estimate the lysine content in feeds and feed sources, rapid amino acid bioassays have been developed. The objective of this work is to assess a rapid assay for lysine supplementation in chicken feeds, using a luminescent Escherichia coli lysine-auxotrophic strain, to avoid prior thermal sterilization. An E. coli lysine auxotroph carrying a plasmid with lux genes was used as the test organism. The lysine assay was conducted using depleted auxotrophic cells in lysine samples. Luminescence was measured with a Dynex MLX luminometer after addition of the aldehyde substrate. Growth response (monitored as optical density at 600 nm) and light emission response of the assay E. coli strain were monitored to generate standard curves. Bioluminescent analysis of feed samples indicated that the method works well in the presence of a complex feed matrix. Comparison of both optical density and luminescent-based methods indicated that, when the assay takes place under optimal conditions, both methodologies correlated well ( r(2)=0.99). Except for the 0.64% lysine-supplemented feed, estimates for lysine based on the bacterial assay were over 80% (82-97%) of the theoretical values. Animal data showed that the bacterial bioluminescent method correlated well with the chick bioassay when diets with different levels of lysine supplementation were assayed for lysine bioavailability ( r(2)=0.97). Luminescent methodology coupled with a bacterial growth assay is a promising technique to assess lysine availability in supplemented animal feeds.

  8. Metabolic engineering of Corynebacterium glutamicum for L-arginine production.

    PubMed

    Park, Seok Hyun; Kim, Hyun Uk; Kim, Tae Yong; Park, Jun Seok; Kim, Suok-Su; Lee, Sang Yup

    2014-08-05

    L-arginine is an important amino acid for diverse industrial and health product applications. Here we report the development of metabolically engineered Corynebacterium glutamicum ATCC 21831 for the production of L-arginine. Random mutagenesis is first performed to increase the tolerance of C. glutamicum to L-arginine analogues, followed by systems metabolic engineering for further strain improvement, involving removal of regulatory repressors of arginine operon, optimization of NADPH level, disruption of L-glutamate exporter to increase L-arginine precursor and flux optimization of rate-limiting L-arginine biosynthetic reactions. Fed-batch fermentation of the final strain in 5 l and large-scale 1,500 l bioreactors allows production of 92.5 and 81.2 g l(-1) of L-arginine with the yields of 0.40 and 0.35 g L-arginine per gram carbon source (glucose plus sucrose), respectively. The systems metabolic engineering strategy described here will be useful for engineering Corynebacteria strains for the industrial production of L-arginine and related products.

  9. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice.

    PubMed

    Marini, Juan C; Didelija, Inka Cajo

    2015-01-01

    Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20) on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (<1 μmol/L), and increased citrulline concentration more than tenfold. Body weight and body composition, however, were not affected by ADI-PEG 20. Despite the depletion of arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas) were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight.

  10. Biological and Structural Characterization of a Host-Adapting Amino Acid in Influenza Virus

    PubMed Central

    Yamada, Shinya; Hatta, Masato; Staker, Bart L.; Watanabe, Shinji; Imai, Masaki; Shinya, Kyoko; Sakai-Tagawa, Yuko; Ito, Mutsumi; Ozawa, Makoto; Watanabe, Tokiko; Sakabe, Saori; Li, Chengjun; Kim, Jin Hyun; Myler, Peter J.; Phan, Isabelle; Raymond, Amy; Smith, Eric; Stacy, Robin; Nidom, Chairul A.; Lank, Simon M.; Wiseman, Roger W.; Bimber, Benjamin N.; O'Connor, David H.; Neumann, Gabriele; Stewart, Lance J.; Kawaoka, Yoshihiro

    2010-01-01

    Two amino acids (lysine at position 627 or asparagine at position 701) in the polymerase subunit PB2 protein are considered critical for the adaptation of avian influenza A viruses to mammals. However, the recently emerged pandemic H1N1 viruses lack these amino acids. Here, we report that a basic amino acid at position 591 of PB2 can compensate for the lack of lysine at position 627 and confers efficient viral replication to pandemic H1N1 viruses in mammals. Moreover, a basic amino acid at position 591 of PB2 substantially increased the lethality of an avian H5N1 virus in mice. We also present the X-ray crystallographic structure of the C-terminus of a pandemic H1N1 virus PB2 protein. Arginine at position 591 fills the cleft found in H5N1 PB2 proteins in this area, resulting in differences in surface shape and charge for H1N1 PB2 proteins. These differences may affect the protein's interaction with viral and/or cellular factors, and hence its ability to support virus replication in mammals. PMID:20700447

  11. Metabolism of arginine by aging and 7 day old pumpkin seedlings.

    PubMed

    Splittstoesser, W E

    1969-03-01

    The metabolism of arginine by etiolated pumpkin (Cucurbita moschata) seedlings was studied over various time and age intervals by injecting arginine-U-(14)C into the cotyledons. At most, 25% of the (14)C was transported from the cotyledon to the axis tissue and the amount of this transport decreased with increasing age of the seedlings. The cotyledons of 25 day old plants contained 60% of the administered (14)C as unmetabolized arginine. Little (14)C was in sugars and it appeared that arginine was the primary translocation product. Time course studies showed that arginine was extensively metabolized and the labeling patterns suggest that different pathways were in operation in the axis and cotyledons. The amount of arginine incorporated into cotyledonary protein show that synthesis and turnover were occurring at rapid rate. Only 25% of the label incorporated into protein by 1.5 hr remained after 96 hr. The label in protein was stable in the axis tissue. By 96 hr 50% of the administered label occurred as (14)CO(2) and it appeared that arginine was metabolized, through glutamate, by the citrio acid cycle in the cotyledons. The experiments showed that an extensive conversion of arginine carbon into other amino acids did not occur.

  12. Hepatic Adaptation Compensates Inactivation of Intestinal Arginine Biosynthesis in Suckling Mice

    PubMed Central

    Marion, Vincent; Sankaranarayanan, Selvakumari; de Theije, Chiel; van Dijk, Paul; Hakvoort, Theo B. M.; Lamers, Wouter H.; Köhler, Eleonore S.

    2013-01-01

    Suckling mammals, including mice, differ from adults in the abundant expression of enzymes that synthesize arginine from citrulline in their enterocytes. To investigate the importance of the small-intestinal arginine synthesis for whole-body arginine production in suckling mice, we floxed exon 13 of the argininosuccinate synthetase (Ass) gene, which codes for a key enzyme in arginine biosynthesis, and specifically and completely ablated Ass in enterocytes by crossing Ass fl and Villin-Cre mice. Unexpectedly, Ass fl/fl /VilCre tg/- mice showed no developmental impairments. Amino-acid fluxes across the intestine, liver, and kidneys were calculated after determining the blood flow in the portal vein, and hepatic and renal arteries (86%, 14%, and 33%, respectively, of the transhepatic blood flow in 14-day-old mice). Relative to control mice, citrulline production in the splanchnic region of Ass fl/fl /VilCre tg/- mice doubled, while arginine production was abolished. Furthermore, the net production of arginine and most other amino acids in the liver of suckling control mice declined to naught or even changed to consumption in Ass fl/fl /VilCre tg/- mice, and had, thus, become remarkably similar to that of post-weaning wild-type mice, which no longer express arginine-biosynthesizing enzymes in their small intestine. The adaptive changes in liver function were accompanied by an increased expression of genes involved in arginine metabolism (Asl, Got1, Gpt2, Glud1, Arg1, and Arg2) and transport (Slc25a13, Slc25a15, and Slc3a2), whereas no such changes were found in the intestine. Our findings suggest that the genetic premature deletion of arginine synthesis in enterocytes causes a premature induction of the post-weaning pattern of amino-acid metabolism in the liver. PMID:23785515

  13. PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN.

    PubMed

    Robscheit-Robbins, F S; Miller, L L; Whipple, G H

    1947-02-28

    Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive

  14. Inhibition of Protein Aggregation: Supramolecular Assemblies of Arginine Hold the Key

    PubMed Central

    Das, Utpal; Hariprasad, Gururao; Ethayathulla, Abdul S.; Manral, Pallavi; Das, Taposh K.; Pasha, Santosh; Mann, Anita; Ganguli, Munia; Verma, Amit K.; Bhat, Rajiv; Chandrayan, Sanjeev Kumar; Ahmed, Shubbir; Sharma, Sujata; Kaur, Punit; Singh, Tej P.; Srinivasan, Alagiri

    2007-01-01

    Background Aggregation of unfolded proteins occurs mainly through the exposed hydrophobic surfaces. Any mechanism of inhibition of this aggregation should explain the prevention of these hydrophobic interactions. Though arginine is prevalently used as an aggregation suppressor, its mechanism of action is not clearly understood. We propose a mechanism based on the hydrophobic interactions of arginine. Methodology We have analyzed arginine solution for its hydrotropic effect by pyrene solubility and the presence of hydrophobic environment by 1-anilino-8-naphthalene sulfonic acid fluorescence. Mass spectroscopic analyses show that arginine forms molecular clusters in the gas phase and the cluster composition is dependent on the solution conditions. Light scattering studies indicate that arginine exists as clusters in solution. In the presence of arginine, the reverse phase chromatographic elution profile of Alzheimer's amyloid beta 1-42 (Aβ1-42) peptide is modified. Changes in the hydrodynamic volume of Aβ1-42 in the presence of arginine measured by size exclusion chromatography show that arginine binds to Aβ1-42. Arginine increases the solubility of Aβ1-42 peptide in aqueous medium. It decreases the aggregation of Aβ1-42 as observed by atomic force microscopy. Conclusions Based on our experimental results we propose that molecular clusters of arginine in aqueous solutions display a hydrophobic surface by the alignment of its three methylene groups. The hydrophobic surfaces present on the proteins interact with the hydrophobic surface presented by the arginine clusters. The masking of hydrophobic surface inhibits protein-protein aggregation. This mechanism is also responsible for the hydrotropic effect of arginine on various compounds. It is also explained why other amino acids fail to inhibit the protein aggregation. PMID:18000547

  15. Structural Insight into Amino Group-carrier Protein-mediated Lysine Biosynthesis

    PubMed Central

    Yoshida, Ayako; Tomita, Takeo; Fujimura, Tsutomu; Nishiyama, Chiharu; Kuzuyama, Tomohisa; Nishiyama, Makoto

    2015-01-01

    In the biosynthesis of lysine by Thermus thermophilus, the metabolite α-ketoglutarate is converted to the intermediate α-aminoadipate (AAA), which is protected by the 54-amino acid acidic protein LysW. In this study, we determined the crystal structure of LysZ from T. thermophilus (TtLysZ), an amino acid kinase that catalyzes the second step in the AAA to lysine conversion, which was in a complex with LysW at a resolution of 1.85 Å. A crystal analysis coupled with isothermal titration calorimetry of the TtLysZ mutants for TtLysW revealed tight interactions between LysZ and the globular and C-terminal extension domains of the LysW protein, which were mainly attributed to electrostatic forces. These results provided structural evidence for LysW acting as a protecting molecule for the α-amino group of AAA and also as a carrier protein to guarantee better recognition by biosynthetic enzymes for the efficient biosynthesis of lysine. PMID:25392000

  16. Altered brain arginine metabolism in schizophrenia

    PubMed Central

    Liu, P; Jing, Y; Collie, N D; Dean, B; Bilkey, D K; Zhang, H

    2016-01-01

    Previous research implicates altered metabolism of l-arginine, a versatile amino acid with a number of bioactive metabolites, in the pathogenesis of schizophrenia. The present study, for we believe the first time, systematically compared the metabolic profile of l-arginine in the frontal cortex (Brodmann's area 8) obtained post-mortem from schizophrenic individuals and age- and gender-matched non-psychiatric controls (n=20 per group). The enzyme assays revealed no change in total nitric oxide synthase (NOS) activity, but significantly increased arginase activity in the schizophrenia group. Western blot showed reduced endothelial NOS protein expression and increased arginase II protein level in the disease group. High-performance liquid chromatography and liquid chromatography/mass spectrometric assays confirmed significantly reduced levels of γ-aminobutyric acid (GABA), but increased agmatine concentration and glutamate/GABA ratio in the schizophrenia cases. Regression analysis indicated positive correlations between arginase activity and the age of disease onset and between l-ornithine level and the duration of illness. Moreover, cluster analyses revealed that l-arginine and its main metabolites l-citrulline, l-ornithine and agmatine formed distinct groups, which were altered in the schizophrenia group. The present study provides further evidence of altered brain arginine metabolism in schizophrenia, which enhances our understanding of the pathogenesis of schizophrenia and may lead to the future development of novel preventions and/or therapeutics for the disease. PMID:27529679

  17. Altered brain arginine metabolism in schizophrenia.

    PubMed

    Liu, P; Jing, Y; Collie, N D; Dean, B; Bilkey, D K; Zhang, H

    2016-08-16

    Previous research implicates altered metabolism of l-arginine, a versatile amino acid with a number of bioactive metabolites, in the pathogenesis of schizophrenia. The present study, for we believe the first time, systematically compared the metabolic profile of l-arginine in the frontal cortex (Brodmann's area 8) obtained post-mortem from schizophrenic individuals and age- and gender-matched non-psychiatric controls (n=20 per group). The enzyme assays revealed no change in total nitric oxide synthase (NOS) activity, but significantly increased arginase activity in the schizophrenia group. Western blot showed reduced endothelial NOS protein expression and increased arginase II protein level in the disease group. High-performance liquid chromatography and liquid chromatography/mass spectrometric assays confirmed significantly reduced levels of γ-aminobutyric acid (GABA), but increased agmatine concentration and glutamate/GABA ratio in the schizophrenia cases. Regression analysis indicated positive correlations between arginase activity and the age of disease onset and between l-ornithine level and the duration of illness. Moreover, cluster analyses revealed that l-arginine and its main metabolites l-citrulline, l-ornithine and agmatine formed distinct groups, which were altered in the schizophrenia group. The present study provides further evidence of altered brain arginine metabolism in schizophrenia, which enhances our understanding of the pathogenesis of schizophrenia and may lead to the future development of novel preventions and/or therapeutics for the disease.

  18. PRMT5: A novel regulator of Hepatitis B virus replication and an arginine methylase of HBV core

    PubMed Central

    Lubyova, Barbora; Hodek, Jan; Zabransky, Ales; Prouzova, Hana; Hubalek, Martin; Hirsch, Ivan

    2017-01-01

    In mammals, protein arginine methyltransferase 5, PRMT5, is the main type II enzyme responsible for the majority of symmetric dimethylarginine formation in polypeptides. Recent study reported that PRMT5 restricts Hepatitis B virus (HBV) replication through epigenetic repression of HBV DNA transcription and interference with encapsidation of pregenomic RNA. Here we demonstrate that PRMT5 interacts with the HBV core (HBc) protein and dimethylates arginine residues within the arginine-rich domain (ARD) of the carboxyl-terminus. ARD consists of four arginine rich subdomains, ARDI, ARDII, ARDIII and ARDIV. Mutation analysis of ARDs revealed that arginine methylation of HBc required the wild-type status of both ARDI and ARDII. Mass spectrometry analysis of HBc identified multiple potential ubiquitination, methylation and phosphorylation sites, out of which lysine K7 and arginines R150 (within ARDI) and R156 (outside ARDs) were shown to be modified by ubiquitination and methylation, respectively. The HBc symmetric dimethylation appeared to be linked to serine phosphorylation and nuclear import of HBc protein. Conversely, the monomethylated HBc retained in the cytoplasm. Thus, overexpression of PRMT5 led to increased nuclear accumulation of HBc, and vice versa, down-regulation of PRMT5 resulted in reduced levels of HBc in nuclei of transfected cells. In summary, we identified PRMT5 as a potent controller of HBc cell trafficking and function and described two novel types of HBc post-translational modifications (PTMs), arginine methylation and ubiquitination. PMID:29065155

  19. Reasons for the occurrence of the twenty coded protein amino acids

    NASA Technical Reports Server (NTRS)

    Weber, A. L.; Miller, S. L.

    1981-01-01

    Factors involved in the selection of the 20 protein L-alpha-amino acids during chemical evolution and the early stages of Darwinian evolution are discussed. The selection is considered on the basis of the availability in the primitive ocean, function in proteins, the stability of the amino acid and its peptides, stability to racemization, and stability on the transfer RNA. It is concluded that aspartic acid, glutamic acid, arginine, lysine, serine and possibly threonine are the best choices for acidic, basic and hydroxy amino acids. The hydrophobic amino acids are reasonable choices, except for the puzzling absences of alpha-amino-n-butyric acid, norvaline and norleucine. The choices of the sulfur and aromatic amino acids seem reasonable, but are not compelling. Asparagine and glutamine are apparently not primitive. If life were to arise on another planet, it would be expected that the catalysts would be poly-alpha-amino acids and that about 75% of the amino acids would be the same as on the earth.

  20. Association of plasma free amino acids with hyperuricemia in relation to diabetes mellitus, dyslipidemia, hypertension and metabolic syndrome.

    PubMed

    Mahbub, M H; Yamaguchi, Natsu; Takahashi, Hidekazu; Hase, Ryosuke; Ishimaru, Yasutaka; Sunagawa, Hiroshi; Amano, Hiroki; Kobayashi-Miura, Mikiko; Kanda, Hideyuki; Fujita, Yasuyuki; Yamamoto, Hiroshi; Yamamoto, Mai; Kikuchi, Shinya; Ikeda, Atsuko; Kageyama, Naoko; Nakamura, Mina; Tanabe, Tsuyoshi

    2017-12-15

    Previous studies demonstrated independent contributions of plasma free amino acids (PFAAs) and high uric acid (UA) concentrations to increased risks of lifestyle-related diseases (LSRDs), but the important associations between these factors and LSRDs remain unknown. We quantified PFAAs and UA amongst Japanese subjects without LSRDs (no-LSRD, n = 2805), and with diabetes mellitus (DM, n = 415), dyslipidemia (n = 3207), hypertension (n = 2736) and metabolic syndrome (MetS, n = 717). The concentrations of most amino acids differed significantly between the subjects with and without hyperuricemia (HU) and also between the no-LSRD and LSRD groups (p < 0.05 to 0.001). After adjustment, the logistic regression analyses revealed that lysine in DM, alanine, proline and tyrosine in dyslipidemia, histidine, lysine and ornithine in hypertension, and lysine and tyrosine in MetS demonstrated significant positive associations with HU among the patients with LSRDs only (p < 0.05 to 0.005). By contrast, arginine, asparagine and threonine showed significant inverse associations with HU in the no-LSRD group only (p < 0.05 to 0.01). For the first time, we provide evidence for distinct patterns of association between PFAAs and HU in LSRDs, and postulate the possibility of interplay between PFAAs and UA in their pathophysiology.

  1. Asymmetric arginine dimethylation of heterogeneous nuclear ribonucleoprotein K by protein-arginine methyltransferase 1 inhibits its interaction with c-Src.

    PubMed

    Ostareck-Lederer, Antje; Ostareck, Dirk H; Rucknagel, Karl P; Schierhorn, Angelika; Moritz, Bodo; Huttelmaier, Stefan; Flach, Nadine; Handoko, Lusy; Wahle, Elmar

    2006-04-21

    Arginine methylation is a post-translational modification found in many RNA-binding proteins. Heterogeneous nuclear ribonucleoprotein K (hnRNP K) from HeLa cells was shown, by mass spectrometry and Edman degradation, to contain asymmetric N(G),N(G)-dimethylarginine at five positions in its amino acid sequence (Arg256, Arg258, Arg268, Arg296, and Arg299). Whereas these five residues were quantitatively modified, Arg303 was asymmetrically dimethylated in <33% of hnRNP K and Arg287 was monomethylated in <10% of the protein. All other arginine residues were unmethylated. Protein-arginine methyltransferase 1 was identified as the only enzyme methylating hnRNP K in vitro and in vivo. An hnRNP K variant in which the five quantitatively modified arginine residues had been substituted was not methylated. Methylation of arginine residues by protein-arginine methyltransferase 1 did not influence the RNA-binding activity, the translation inhibitory function, or the cellular localization of hnRNP K but reduced the interaction of hnRNP K with the tyrosine kinase c-Src. This led to an inhibition of c-Src activation and hnRNP K phosphorylation. These findings support the role of arginine methylation in the regulation of protein-protein interactions.

  2. Lysine methylation modulates the protein-protein interactions of yeast cytochrome C Cyc1p.

    PubMed

    Winter, Daniel L; Abeygunawardena, Dhanushi; Hart-Smith, Gene; Erce, Melissa A; Wilkins, Marc R

    2015-07-01

    In recent years, protein methylation has been established as a major intracellular PTM. It has also been proposed to modulate protein-protein interactions (PPIs) in the interactome. To investigate the effect of PTMs on PPIs, we recently developed the conditional two-hybrid (C2H) system. With this, we demonstrated that arginine methylation can modulate PPIs in the yeast interactome. Here, we used the C2H system to investigate the effect of lysine methylation. Specifically, we asked whether Ctm1p-mediated trimethylation of yeast cytochrome c Cyc1p, on lysine 78, modulates its interactions with Erv1p, Ccp1p, Cyc2p and Cyc3p. We show that the interactions between Cyc1p and Erv1p, and between Cyc1p and Cyc3p, are significantly increased upon trimethylation of lysine 78. This increase of interaction helps explain the reported facilitation of Cyc1p import into the mitochondrial intermembrane space upon methylation. This first application of the C2H system to the study of methyllysine-modulated interactions further confirms its robustness and flexibility. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Aminocella lysinolytica gen. nov., sp. nov., a L-lysine-degrading, strictly anaerobic bacterium in the class Clostridia isolated from a methanogenic reactor of cattle farms.

    PubMed

    Ueki, Atsuko; Shibuya, Toru; Kaku, Nobuo; Ueki, Katsuji

    2015-01-01

    A strictly anaerobic bacterial strain (WN037(T)) was isolated from a methanogenic reactor. Cells were Gram-positive rods. Strain WN037(T) was asaccharolytic. The strain fermented L-lysine in the presence of B-vitamin mixture or vitamin B12 and produced acetate and butyrate. L-arginine and casamino acids poorly supported the growth. Strain WN037(T) used neither other amino acids nor organic acids examined. The strain had C18:1 ω7c, C16:0 and C18:1 ω7c DMA as the predominant cellular fatty acids. The genomic DNA G + C content was 44.2 mol %. Phylogenetic analysis based on the 16S rRNA gene sequence placed strain WN037(T) in the family Eubacteriaceae in the class Clostridia. The closest relative was Eubacterium pyruvativorans (sequence similarity, 92.8 %). Based on the comprehensive analyses, the novel genus and species, Aminocella lysinolytica gen. nov., sp. nov. was proposed to accommodate the strain. The type strain is WN037(T) (= JCM 19863(T) = DSM 28287(T)).

  4. Global profiling of lysine reactivity and ligandability in the human proteome

    NASA Astrophysics Data System (ADS)

    Hacker, Stephan M.; Backus, Keriann M.; Lazear, Michael R.; Forli, Stefano; Correia, Bruno E.; Cravatt, Benjamin F.

    2017-12-01

    Nucleophilic amino acids make important contributions to protein function, including performing key roles in catalysis and serving as sites for post-translational modification. Electrophilic groups that target amino-acid nucleophiles have been used to create covalent ligands and drugs, but have, so far, been mainly limited to cysteine and serine. Here, we report a chemical proteomic platform for the global and quantitative analysis of lysine residues in native biological systems. We have quantified, in total, more than 9,000 lysines in human cell proteomes and have identified several hundred residues with heightened reactivity that are enriched at protein functional sites and can frequently be targeted by electrophilic small molecules. We have also discovered lysine-reactive fragment electrophiles that inhibit enzymes by active site and allosteric mechanisms, as well as disrupt protein-protein interactions in transcriptional regulatory complexes, emphasizing the broad potential and diverse functional consequences of liganding lysine residues throughout the human proteome.

  5. Global profiling of lysine reactivity and ligandability in the human proteome.

    PubMed

    Hacker, Stephan M; Backus, Keriann M; Lazear, Michael R; Forli, Stefano; Correia, Bruno E; Cravatt, Benjamin F

    2017-12-01

    Nucleophilic amino acids make important contributions to protein function, including performing key roles in catalysis and serving as sites for post-translational modification. Electrophilic groups that target amino-acid nucleophiles have been used to create covalent ligands and drugs, but have, so far, been mainly limited to cysteine and serine. Here, we report a chemical proteomic platform for the global and quantitative analysis of lysine residues in native biological systems. We have quantified, in total, more than 9,000 lysines in human cell proteomes and have identified several hundred residues with heightened reactivity that are enriched at protein functional sites and can frequently be targeted by electrophilic small molecules. We have also discovered lysine-reactive fragment electrophiles that inhibit enzymes by active site and allosteric mechanisms, as well as disrupt protein-protein interactions in transcriptional regulatory complexes, emphasizing the broad potential and diverse functional consequences of liganding lysine residues throughout the human proteome.

  6. Poly (ethylenimine)-grafted-poly [(aspartic acid)-co-lysine], a potential non-viral vector for DNA delivery.

    PubMed

    Tang, Gu Ping; Yang, Zhi; Zhou, Jun

    2006-01-01

    A potential non-viral gene-transfer vector, poly(ethylenimine)-grafted-poly[(aspartic acid)-co-lysine] (PSL), has been developed by thermal polycondensation of aspartic acid and lysine under reduced pressure. Low-molecular-mass branch poly(ethylenimine) (PEI600) was conjugated to the backbone. The chemical structure of the resulting co-polymer was identified by 1H-NMR, FT-IR, TGA and X-ray diffraction. The results of the MTT assay showed that at concentration up to 4000 nmol/l of the vector cell viability was over 80% and showed low toxicity. Electrophoretic retardation and ethidum bromide assay showed that at N/P ratios 12-15 (w/w) the DNA could be condensed and neutralized. Using the zeta potential assay we discovered that it had a high positive charge on its surface of the particle (over 30 mV). The particle sizes of the co-polymer/DNA complexes were 150-170 nm, as measured by DLS and AFM. Compared with PEI600, co-polymer/DNA complexes showed a significant enhancement of transfection activity in the absence and presence of serum in NT2 and COS7 cell lines. This means that the PEI600-PSL co-polymer is a promising candidate for gene delivery.

  7. Protective effect of chlorogenic acid on the inflammatory damage of pancreas and lung in mice with l-arginine-induced pancreatitis.

    PubMed

    Ohkawara, Tatsuya; Takeda, Hiroshi; Nishihira, Jun

    2017-12-01

    Pancreatitis is characterized by inflammatory disease with severe tissue injury in pancreas, and the incidence of pancreatitis has been recently increasing. Although several treatments of acute pancreatitis have been developed, some patients have been resistant to current therapy. Chlorogenic acid (CGA) is one of the polyphenols, and is known to have an anti-inflammatory effect. In this study, we investigated the effects of CGA on experimental pancreatitis in mice. Pancreatitis was induced by twice injection of l-arginine (5g/kg body weight). Mice were intraperitoneally injected with CGA (20mg/kg or 40mg/kg) 1h before administration of l-arginine. Administration of 40mg/kg of CGA decreased the histological severity of pancreatitis and pancreatitis-associated lung injury. Moreover, administration of CGA inhibited the levels of pancreatic enzyme activity. Interestingly, CGA reduced the serum and pancreatic levels of macrophage migration inhibitory factor (MIF) in mice with l-arginine-induced pancreatitis. Our results suggest that CGA has an anti-inflammatory effect on l-arginine-induced pancreatitis and pancreatitis-associated lung injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Supplementing a low-protein diet with dibasic amino acids increases urinary calcium excretion in young women.

    PubMed

    Bihuniak, Jessica D; Sullivan, Rebecca R; Simpson, Christine A; Caseria, Donna M; Huedo-Medina, Tania B; O'Brien, Kimberly O; Kerstetter, Jane E; Insogna, Karl L

    2014-03-01

    Increasing dietary protein within a physiologic range stimulates intestinal calcium absorption, but it is not known if specific amino acids or dietary protein as a whole are responsible for this effect. Therefore, we selectively supplemented a low-protein (0.7 g/kg) diet with either the calcium-sensing receptor-activating amino acids (CaSR-AAAs) L-tryptophan, L-phenylalanine, and L-histidine, or the dibasic amino acids (DAAs) L-arginine and L-lysine, to achieve intakes comparable to the content of a high-protein diet (2.1 g/kg) and measured intestinal calcium absorption. Fourteen young women took part in a placebo-controlled, double-blind, crossover feeding trial in which each participant ingested a 6-d low-protein diet supplemented with CaSR-AAAs, DAAs, or methylcellulose capsules (control) after an 11-d adjustment period. All participants ingested all 3 diets in random order. Intestinal calcium absorption was measured between days 5 and 6 using dual-stable calcium isotopes ((42)Ca, (43)Ca, and (44)Ca). There was no difference in calcium absorption between the diet supplemented with CaSR-AAAs (22.9 ± 2.0%) and the control diet (22.3 ± 1.4%) (P = 0.64). However, calcium absorption tended to be greater during the DAA supplementation period (25.2 ± 1.4%) compared with the control diet period (22.3 ± 1.4%) (P < 0.10). Larger and longer clinical trials are needed to clarify the possible benefit of arginine and lysine on calcium absorption.

  9. Lysine-functionalized nanodiamonds: synthesis, physiochemical characterization, and nucleic acid binding studies

    PubMed Central

    Kaur, Randeep; Chitanda, Jackson M; Michel, Deborah; Maley, Jason; Borondics, Ferenc; Yang, Peng; Verrall, Ronald E; Badea, Ildiko

    2012-01-01

    Purpose: Detonation nanodiamonds (NDs) are carbon-based nanomaterials that, because of their size (4–5 nm), stable inert core, alterable surface chemistry, fluorescence, and biocompatibility, are emerging as bioimaging agents and promising tools for the delivery of biochemical molecules into cellular systems. However, diamond particles possess a strong propensity to aggregate in liquid formulation media, restricting their applicability in biomedical sciences. Here, the authors describe the covalent functionalization of NDs with lysine in an attempt to develop nanoparticles able to act as suitable nonviral vectors for transferring genetic materials across cellular membranes. Methods: NDs were oxidized and functionalized by binding lysine moieties attached to a three-carbon-length linker (1,3-diaminopropane) to their surfaces through amide bonds. Raman and Fourier transform infrared spectroscopy, zeta potential measurement, dynamic light scattering, atomic force microscopic imaging, and thermogravimetric analysis were used to characterize the lysine-functionalized NDs. Finally, the ability of the functionalized diamonds to bind plasmid DNA and small interfering RNA was investigated by gel electrophoresis assay and through size and zeta potential measurements. Results: NDs were successfully functionalized with the lysine linker, producing surface loading of 1.7 mmol g−1 of ND. These modified NDs formed highly stable aqueous dispersions with a zeta potential of 49 mV and particle size of approximately 20 nm. The functionalized NDs were found to be able to bind plasmid DNA and small interfering RNA by forming nanosized “diamoplexes”. Conclusion: The lysine-substituted ND particles generated in this study exhibit stable aqueous formulations and show potential for use as carriers for genetic materials. PMID:22904623

  10. Long-term enteral arginine supplementation in rats with intestinal ischemia and reperfusion.

    PubMed

    Lee, Chien-Hsing; Hsiao, Chien-Chou; Hung, Ching-Yi; Chang, Yu-Jun; Lo, Hui-Chen

    2012-06-01

    The effects of short-term enteral arginine supplementation on intestinal ischemia-reperfusion (IR) injury have been widely studied, especially the ischemic preconditioning supplementation. The aim of this study was to investigate the effects of long-term intra-duodenal supplementation of arginine on intestinal morphology, arginine-associated amino acid metabolism, and inflammatory responses in rats with intestinal IR. Male Wistar rats with or without three hours of ileal ischemia underwent duodenal cannulation for continuous infusion of formula with 2% arginine or commercial protein powder for 7 d. The serological examinations, plasma amino acid and cytokine profiles, and intestinal morphology were assessed. Intestinal IR injury had significant impacts on the decreases in circulating red blood cells, hemoglobin, ileum mass, and villus height and crypt depth of the distal jejunum. In addition, arginine supplementation decreased serum cholesterol and increased plasma arginine concentrations. In rats with intestinal IR injury, arginine supplementation significantly decreased serum nitric oxide, plasma citrulline and ornithine, and the mucosal protein content of the ileum. These results suggest that long-term intra-duodenal arginine administration may not have observable benefits on intestinal morphology or inflammatory response in rats with intestinal ischemia and reperfusion injury. Therefore, the necessity of long-term arginine supplementation for patients with intestinal ischemia and reperfusion injury remains questionable and requires further investigation. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Betaine and arginine supplementation of low protein diets improves plasma lipids but does not affect hepatic fatty acid composition and related gene expression profiling in pigs.

    PubMed

    Madeira, Marta S; Rolo, Eva A; Lopes, Paula A; Ramos, Denis A; Alfaia, Cristina M; Pires, Virgínia Mr; Martins, Susana V; Pinto, Rui Ma; Prates, José Am

    2018-01-01

    The individual and combined effects of betaine and arginine supplemented to reduced protein diets were investigated on plasma metabolites, hepatic fatty acid composition and mRNA levels of lipid-sensitive factors in commercial pigs. Betaine has previously been shown to reduce carcass fat deposition and arginine improves meat quality of finishing pigs. Forty male crossbred pigs were randomly assigned to one of five diets (n = 8): 160 g kg -1 of crude protein (NPD), 130 g kg -1 of crude protein (RPD), RPD with 3.3 g kg -1 of betaine, RPD with 15 g kg -1 of arginine, and RPD with 3.3 g kg -1 of betaine and 15 g kg -1 of arginine. The restriction of dietary protein increased total lipids (P < 0.001), total cholesterol (P < 0.001), high-density lipoprotein-cholesterol (P < 0.001) and low-density lipoprotein cholesterol (P < 0.001). Betaine and arginine, individually or combined, reduced the majority of plasma lipids (P < 0.05) without affecting total fatty acids in the liver and the overall gene expression pattern. These findings suggest a positive effect of betaine and arginine, singly or combined, by reversing plasma lipids increase promoted by dietary protein restriction. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Antioxidative Categorization of Twenty Amino Acids Based on Experimental Evaluation.

    PubMed

    Xu, Naijin; Chen, Guanqun; Liu, Hui

    2017-11-27

    In view of the great importance bestowed on amino acids as antioxidants in oxidation resistance, we attempted two common redox titration methods in this report, including micro-potassium permanganate titration and iodometric titration, to measure the antioxidative capacity of 20 amino acids, which are the construction units of proteins in living organisms. Based on the relative intensities of the antioxidative capacity, we further conducted a quantitative comparison and found out that the product of experimental values obtained from the two methods was proven to be a better indicator for evaluating the relative antioxidative capacity of amino acids. The experimental results were largely in accordance with structural analysis made on amino acids. On the whole, the 20 amino acids concerned could be divided into two categories according to their antioxidative capacity. Seven amino acids, including tryptophan, methionine, histidine, lysine, cysteine, arginine and tyrosine, were greater in total antioxidative capacity compared with the other 13 amino acids.

  13. Combined effects of dietary arginine, leucine and protein levels on fatty acid composition and gene expression in the muscle and subcutaneous adipose tissue of crossbred pigs.

    PubMed

    Madeira, Marta S; Pires, Virgínia M R; Alfaia, Cristina M; Luxton, Richard; Doran, Olena; Bessa, Rui J B; Prates, José A M

    2014-05-01

    The cumulative effects of dietary arginine, leucine and protein levels on fat content, fatty acid composition and mRNA levels of genes controlling lipid metabolism in pig longissimus lumborum muscle and subcutaneous adipose tissue (SAT) were investigated. The experiment was performed on fifty-four intact male pigs (Duroc × Pietrain × Large White × Landrace crossbred), with a live weight ranging from 59 to 92 kg. The pigs were randomly assigned to one of six experimental treatments (n 9). The treatments followed a 2 × 3 factorial arrangement, with two levels of arginine supplementation (0 v. 1 %) and three levels of a basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet to achieve 2 % of leucine, RPDL). The results showed that dietary arginine supplementation did not affect the intramuscular fat (IMF) content and back fat thickness, but increased the total fat in SAT. This effect was associated with an increase in fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD) mRNA levels in SAT, which suggests that arginine might be involved in the differential regulation of some key lipogenic genes in pig muscle and SAT. The increase in IMF content under the RPD, with or without leucine supplementation, was accompanied by increased FASN and SCD mRNA levels. Arginine supplementation did not influence the percentage of main fatty acids, while the RPD had a significant effect on fatty acid composition in both tissues. Leucine supplementation of RPD did not change IMF, total fat of SAT and back fat thickness, but increased 16 : 0 and 18 : 1cis-9 and decreased 18 : 2n-6 in muscle.

  14. Altering dietary lysine:arginine ratio has little effect on cardiovascular risk factors and vascular reactivity in moderately hypercholesterolemic adults

    PubMed Central

    Vega-López, Sonia; Matthan, Nirupa R.; Ausman, Lynne M.; Harding, Scott V.; Rideout, Todd C.; Ai, Masumi; Otokozawa, Seiko; Freed, Alicia; Kuvin, Jeffrey T; Jones, Peter J; Schaefer, Ernst J; Lichtenstein, Alice H.

    2010-01-01

    Background Information is scarce regarding the effect of dietary protein type, with specific focus on the lysine to arginine (Lys:Arg) ratio, on cardiovascular risk factors and vascular reactivity in humans. Objective Determine effect of dietary Lys:Arg ratio on cardiovascular risk factors and vascular reactivity in moderately hypercholesterolemic adults. Design Randomized cross-over design of two 35-day diet phases; thirty adults (21 females and 9 males, ≥50 y, LDL cholesterol ≥120 mg/dL). Diets had 20% energy (E) protein, 30%E fat, 50%E carbohydrate and were designed to have low (0.7) or high (1.4) Lys:Arg ratio. Measures included fasting and postprandial lipid, lipoprotein, apolipoprotein concentrations; fasting high sensitivity C-reactive protein (hsCRP), small dense LDL (sdLDL)-cholesterol, remnant lipoprotein cholesterol (RemLC), glycated albumin, adiponectin and immunoreactive insulin concentrations, endogenous cholesteryl ester transfer protein (CETP) and lecithin:cholesterol acyl transferase (LCAT) activities; cholesterol fractional synthesis rate (FSR); and flow mediated dilation (FMD) and peripheral artery tonometry (PAT). Results No differences were observed in fasting and/or postprandial total, LDL, HDL and sdLDL cholesterol, RemLC, Lp(a) or apo B concentrations, LCAT and CETP activities, FSR, glycated albumin, immunoreactive insulin, FMD or PAT. The low, relative to the high, Lys:Arg ratio diet resulted in lower postprandial VLDL cholesterol (−24%, P=0.001) and triglycerides (−23%, P=0.001), and small but significant differences in fasting (−3%, P=0.003) and postprandial (−3%, P=0.018) apo AI, and fasting adiponectin concentrations (+7%, P=0.035). Fasting and postprandial hsCRP concentrations were 23% lower after the low Lys:Arg ratio diet (P=0.020 for both). Conclusions Diets differing in Lys:Arg ratios had no or small effects on cardiovascular risk factors and vascular reactivity. PMID:20042191

  15. Amino acid catabolism and generation of volatiles by lactic acid bacteria.

    PubMed

    Tavaria, F K; Dahl, S; Carballo, F J; Malcata, F X

    2002-10-01

    Twelve isolates of lactic acid bacteria, belonging to the Lactobacillus, Lactococcus, Leuconostoc, and Enterococcus genera, were previously isolated from 180-d-old Serra da Estrela cheese, a traditional Portuguese cheese manufactured from raw milk and coagulated with a plant rennet. These isolates were subsequently tested for their ability to catabolize free amino acids, when incubated independently with each amino acid in free form or with a mixture thereof. Attempts were made in both situations to correlate the rates of free amino acid uptake with the numbers of viable cells. When incubated individually, leucine, valine, glycine, aspartic acid, serine, threonine, lysine, glutamic acid, and alanine were degraded by all strains considered; arginine tended to build up, probably because of transamination of other amino acids. When incubated together, the degradation of free amino acids by each strain was dependent on pH (with an optimum pH around 6.0). The volatiles detected in ripened Serra da Estrela cheese originated mainly from leucine, phenylalanine, alanine, and valine, whereas in vitro they originated mainly from valine, phenylalanine, serine, leucine, alanine, and threonine. The wild strains tested offer a great potential for flavor generation, which might justify their inclusion in a tentative starter/nonstarter culture for that and similar cheeses.

  16. Elevated glutaric acid levels in Dhtkd1-/Gcdh- double knockout mice challenge our current understanding of lysine metabolism.

    PubMed

    Biagosch, Caroline; Ediga, Raga Deepthi; Hensler, Svenja-Viola; Faerberboeck, Michael; Kuehn, Ralf; Wurst, Wolfgang; Meitinger, Thomas; Kölker, Stefan; Sauer, Sven; Prokisch, Holger

    2017-09-01

    Glutaric aciduria type I (GA-I) is a rare organic aciduria caused by the autosomal recessive inherited deficiency of glutaryl-CoA dehydrogenase (GCDH). GCDH deficiency leads to disruption of l-lysine degradation with characteristic accumulation of glutarylcarnitine and neurotoxic glutaric acid (GA), glutaryl-CoA, 3-hydroxyglutaric acid (3-OHGA). DHTKD1 acts upstream of GCDH, and its deficiency leads to none or often mild clinical phenotype in humans, 2-aminoadipic 2-oxoadipic aciduria. We hypothesized that inhibition of DHTKD1 may prevent the accumulation of neurotoxic dicarboxylic metabolites suggesting DHTKD1 inhibition as a possible treatment strategy for GA-I. In order to validate this hypothesis we took advantage of an existing GA-I (Gcdh -/- ) mouse model and established a Dhtkd1 deficient mouse model. Both models reproduced the biochemical and clinical phenotype observed in patients. Under challenging conditions of a high lysine diet, only Gcdh -/- mice but not Dhtkd1 -/- mice developed clinical symptoms such as lethargic behaviour and weight loss. However, the genetic Dhtkd1 inhibition in Dhtkd1 -/- /Gcdh -/- mice could not rescue the GA-I phenotype. Biochemical results confirm this finding with double knockout mice showing similar metabolite accumulations as Gcdh -/- mice with high GA in brain and liver. This suggests that DHTKD1 inhibition alone is not sufficient to treat GA-I, but instead a more complex strategy is needed. Our data highlights the many unresolved questions within the l-lysine degradation pathway and provides evidence for a so far unknown mechanism leading to glutaryl-CoA. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Possible Evidence of Amide Bond Formation Between Sinapinic Acid and Lysine-Containing Bacterial Proteins by Matrix-Assisted Laser Desorption/Ionization (MALDI) at 355 nm

    NASA Astrophysics Data System (ADS)

    Fagerquist, Clifton K.; Sultan, Omar; Carter, Michelle Q.

    2012-12-01

    We previously reported the apparent formation of matrix adducts of 3,5-dimethoxy-4-hydroxy-cinnamic acid (sinapinic acid or SA) via covalent attachment to disulfide bond-containing proteins (HdeA, Hde, and YbgS) from bacterial cell lysates ionized by matrix-assisted laser desorption/ionization (MALDI) time-of-flight-time-of-flight tandem mass spectrometry (TOF-TOF-MS/MS) and post-source decay (PSD). We also reported the absence of adduct formation when using α-cyano-4-hydroxycinnamic acid (CHCA) matrix. Further mass spectrometric analysis of disulfide-intact and disulfide-reduced over-expressed HdeA and HdeB proteins from lysates of gene-inserted E. coli plasmids suggests covalent attachment of SA occurs not at cysteine residues but at lysine residues. In this revised hypothesis, the attachment of SA is preceded by formation of a solid phase ammonium carboxylate salt between SA and accessible lysine residues of the protein during sample preparation under acidic conditions. Laser irradiation at 355 nm of the dried sample spot results in equilibrium retrogradation followed by nucleophilic attack by the amine group of lysine at the carbonyl group of SA and subsequent amide bond formation and loss of water. The absence of CHCA adducts suggests that the electron-withdrawing effect of the α-cyano group of this matrix may inhibit salt formation and/or amide bond formation. This revised hypothesis is supported by dissociative loss of SA (-224 Da) and the amide-bound SA (-206 Da) from SA-adducted HdeA and HdeB ions by MS/MS (PSD). It is proposed that cleavage of the amide-bound SA from the lysine side-chain occurs via rearrangement involving a pentacyclic transition state followed by hydrogen abstraction/migration and loss of 3-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-ynal (-206 Da).

  18. Influence of Amino Acids in Dairy Products on Glucose Homeostasis: The Clinical Evidence.

    PubMed

    Chartrand, Dominic; Da Silva, Marine S; Julien, Pierre; Rudkowska, Iwona

    2017-06-01

    Dairy products have been hypothesized to protect against type 2 diabetes because of their high content of whey proteins, rich in branched-chain amino acids (BCAAs) - leucine, isoleucine and valine - and lysine, which may decrease postprandial glucose responses and stimulate insulin secretion. Paradoxically, epidemiologic studies also show that higher levels of plasma BCAAs have been linked to insulin resistance and type 2 diabetes. Therefore, the objective was to review the recent clinical evidence concerning the intake of amino acids found in dairy proteins so as to determine their impact on glucose homeostasis in healthy persons and in those with prediabetes and type 2 diabetes. Clinical studies have reported that the major dairy amino acids, namely, leucine, isoleucine, glutamine, phenylalanine, proline and lysine, have beneficial effects on glucose homeostasis. Yet the reported doses of amino acids investigated are too elevated to be reached through adequate dairy product intake. The minor dairy amino acids, arginine and glycine, may improve glucose homeostasis by improving other risk factors for type 2 diabetes. Further, the combination of amino acids may also improve glucose-related outcomes, suggesting additive or synergistic effects. Nevertheless, additional long-term studies in individuals with prediabetes and type 2 diabetes are needed to ascertain the benefits for glucose homeostasis of amino acids found in dairy foods. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  19. Effects of arginine on heat-induced aggregation of concentrated protein solutions.

    PubMed

    Shah, Dhawal; Shaikh, Abdul Rajjak; Peng, Xinxia; Rajagopalan, Raj

    2011-01-01

    Arginine is one of the commonly used additives to enhance refolding yield of proteins, to suppress aggregation of proteins, and to increase solubility of proteins, and yet the molecular interactions that contribute to the role of arginine are unclear. Here, we present experiments, using bovine serum albumin (BSA), lysozyme (LYZ), and β-lactoglobulin (BLG) as model proteins, to show that arginine can enhance heat-induced aggregation of concentrated protein solutions, contrary to the conventional belief that arginine is a universal suppressor of aggregation. Results show that the enhancement in aggregation is caused only for BSA and BLG, but not for LYZ, indicating that arginine's preferential interactions with certain residues over others could determine the effect of the additive on aggregation. We use this previously unrecognized behavior of arginine, in combination with density functional theory calculations, to identify the molecular-level interactions of arginine with various residues that determine arginine's role as an enhancer or suppressor of aggregation of proteins. The experimental and computational results suggest that the guanidinium group of arginine promotes aggregation through the hydrogen-bond-based bridging interactions with the acidic residues of a protein, whereas the binding of the guanidinium group to aromatic residues (aggregation-prone) contributes to the stability and solubilization of the proteins. The approach, we describe here, can be used to select suitable additives to stabilize a protein solution at high concentrations based on an analysis of the amino acid content of the protein. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  20. HU participates in expression of a specific set of genes required for growth and survival at acidic pH in Escherichia coli.

    PubMed

    Bi, Hongkai; Sun, Lianle; Fukamachi, Toshihiko; Saito, Hiromi; Kobayashi, Hiroshi

    2009-05-01

    The major histone-like Escherichia coli protein, HU, is composed of alpha and beta subunits respectively encoded by hupA and hupB in Escherichia coli. A mutant deficient in both hupA and hupB grew at a slightly slower rate than the wild type at pH 7.5. Growth of the mutant diminished with a decrease in pH, and no growth was observed at pH 4.6. Mutants of either hupA or hupB grew at all pH levels tested. The arginine-dependent survival at pH 2.5 was diminished approximately 60-fold by the deletion of both hupA and hupB, whereas the survival was slightly affected by the deletion of either hupA or hupB. The mRNA levels of adiA and adiC, which respectively encode arginine decarboxylase and arginine/agmatine antiporter, were low in the mutant deficient in both hupA and hupB. The deletion of both hupA and hupB had little effect on survival at pH 2.5 in the presence of glutamate or lysine, and expression of the genes for glutamate and lysine decarboxylases was not impaired by the deletion of the HU genes. These results suggest that HU regulates expression of the specific set of genes required for growth and survival in acidic environments.

  1. On the possible origin and evolution of the genetic code

    NASA Technical Reports Server (NTRS)

    Jukes, T. H.

    1974-01-01

    The genetic code is examined for indications of possible preceding codes that existed during early evolution. Eight of the 20 amino acids are coded by 'quartets' of codons with fourfold degeneracy, and 16 such quartets can exist, so that an earlier code could have provided for 15 or 16 amino acids, rather than 20. If twofold degeneracy is postulated for the first position of the codon, there could have been ten amino acids in the code. It is speculated that these may have been phenylalanine, valine, proline, alanine, histidine, glutamine, glutanic acid, aspartic acid, cysteine and glycine. There is a notable deficiency of arginine in proteins, despite the fact that it has six codons. Simultaneously, there is more lysine in proteins than would be expected from its two codons, if the four bases in mRNA are equiprobable and are arranged randomly. It is speculated that arginine is an 'intruder' into the genetic code, and that it may have displayed another amino acid such as ornithine, or may even have displayed lysine from some of its previous codon assignments. As a result, natural selection has favored lysine against the fact that it has only two codons.

  2. Compartmentalization of amino acids in surfactant aggregates - Partitioning between water and aqueous micellar sodium dodecanoate and between hexane and dodecylammonium propionate trapped water in hexane

    NASA Technical Reports Server (NTRS)

    Fendler, J. H.; Nome, F.; Nagyvary, J.

    1975-01-01

    The partitioning of amino acids (glycine, alanine, leucine, phenylalanine, histidine, aspartic acid, glutamic acid, lysine, isoleucine, threonine, serine, valine, proline, arginine) in aqueous and nonaqueous micellar systems was studied experimentally. Partitioning from neat hexane into dodecylammonium propionate trapped water in hexane was found to be dependent on both electrostatic and hydrophobic interactions, which implies that the interior of dodecylammonium propionate aggregates is negatively charged and is capable of hydrogen bonding in addition to providing a hydrophobic environment. Unitary free energies of transfer of amino acid side chains from hexane to water were determined and solubilities of amino acids in neat hexane substantiated the amino acid hydrophobicity scale. The relevance of the experiments to prebiotic chemistry was examined.

  3. Arginine prevents thermal aggregation of hen egg white proteins.

    PubMed

    Hong, Taehun; Iwashita, Kazuki; Handa, Akihiro; Shiraki, Kentaro

    2017-07-01

    The control of aggregation and solubilization of hen egg white protein (HEWP) is an important issue for industrial applications of one of the most familiar food protein sources. Here, we investigated the effects of edible amino acids on heat-induced aggregation of HEWP. The addition of 0.6M arginine (Arg) completely suppressed the formation of insoluble aggregates of 1mgmL -1 HEWP following heat treatment, even at 90°C for 20min. In contrast, lysine (Lys), glycine (Gly), and sodium chloride (NaCl) did little to suppress the aggregation of HEWP under the same conditions. SDS-PAGE indicated that Arg suppresses the thermal aggregation of almost all types of HEWP at 1mgmL -1 . However, Arg did not suppress the thermal aggregation of HEWP at concentrations ≥10mgmL -1 and prompted the formation of aggregates. Transmission electron micrographs revealed a high-density structure of unfolded proteins in the presence of Arg. These results indicate that Arg exerts a greater suppressive effect on a protein mixture, such as HEWP, than on a single model protein. These observations may propose Arg as a safe and reasonable additive to HEWP for the elimination of microorganisms by allowing an increase in sterilization temperature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Functional interactions between arginine-133 and aspartate-88 in the human reduced folate carrier: evidence for a charge-pair association.

    PubMed Central

    Liu, X Y; Matherly, L H

    2001-01-01

    The human reduced folate carrier (hRFC) is an integral membrane protein that mediates cellular uptake of reduced folates and antifolates. hRFC contains several highly conserved charged residues predicted to lie in the transmembrane domains (TMDs). To explore the possible roles of the conserved arginine-133, located in TMD 4, in hRFC structure and function, this residue was systematically mutagenized to histidine, leucine, lysine and glutamate. When transfected into transport-impaired K562 cells, the mutant hRFC constructs were expressed at high levels; however, only lysine-133 hRFC was able to transport methotrexate and (6S)-5-formyl tetrahydrofolate. Substitution of aspartate-453 (in hRFC TMD 12) by valine largely preserved transport activity for both substrates. Although mutagenesis of aspartate-88 (in TMD 2) to leucine completely abolished transport activity in transfected cells, substitution with a glutamate preserved low levels ( approximately 12%) of transport. To assess the possibility that arginine-133 and aspartate-88 may form a charge-pair to stabilize hRFC tertiary structure, both charges were neutralized (by substituting leucine and valine, respectively) in the same construct. In contrast to the singly mutated hRFCs, the double mutant exhibited high levels of transport with both methotrexate and 5-formyl tetrahydrofolate. These results strongly suggest that arginine-133 and aspartate-88 form a charge-pair and that TMD 4 lies next to TMD 2 in the hRFC tertiary structure. PMID:11513752

  5. Accumulation of Citrulline by Microbial Arginine Metabolism during Alcoholic Fermentation of Soy Sauce.

    PubMed

    Fang, Fang; Zhang, Jiran; Zhou, Jingwen; Zhou, Zhaohui; Li, Tieqiao; Lu, Liling; Zeng, Weizhu; Du, Guocheng; Chen, Jian

    2018-03-07

    Citrulline, the major precursor of ethyl carbamate in soy sauce, is an intermediate catabolite of arginine produced by bacteria present in soy sauce moromi mash. Pediococcus acidilactici is responsible for the formation of citrulline during the lactic acid fermentation process of soy sauce. However, citrulline accumulation during the alcoholic fermentation process and the corresponding bacteria involved have not been identified. Salt-tolerant, arginine-utilizing bacteria were isolated from moromi mash during the alcoholic fermentation process. Under normal cultivation conditions, arginine utilization by these strains did not contribute to citrulline accumulation. However, the conversion of arginine to citrulline by these bacteria increased when cultivated during the alcoholic fermentation process. Additionally, the ethanol-enhanced solubility of free fatty acids in moromi mash stimulated the accumulation of citrulline. Staphylococcus exhibited the highest capability in the conversion of arginine to citrulline.

  6. Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.

    ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCEPost-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

  7. Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.

    ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCE Post-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

  8. Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

    DOE PAGES

    Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.; ...

    2017-11-28

    ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCE Post-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

  9. Arginine dependence of tumor cells: targeting a chink in cancer’s armor

    PubMed Central

    Patil, MD; Bhaumik, J; Babykutty, S; Banerjee, UC; Fukumura, D

    2017-01-01

    Arginine, one among the 20 most common natural amino acids, has a pivotal role in cellular physiology as it is being involved in numerous cellular metabolic and signaling pathways. Dependence on arginine is diverse for both tumor and normal cells. Because of decreased expression of argininosuccinate synthetase and/or ornithine transcarbamoylase, several types of tumor are auxotrophic for arginine. Deprivation of arginine exploits a significant vulnerability of these tumor cells and leads to their rapid demise. Hence, enzyme-mediated arginine depletion is a potential strategy for the selective destruction of tumor cells. Arginase, arginine deiminase and arginine decarboxylase are potential enzymes that may be used for arginine deprivation therapy. These arginine catabolizing enzymes not only reduce tumor growth but also make them susceptible to concomitantly administered anti-cancer therapeutics. Most of these enzymes are currently under clinical investigations and if successful will potentially be advanced as anti-cancer modalities. PMID:27109103

  10. A Proteomic Approach to Analyze the Aspirin-mediated Lysine Acetylome*

    PubMed Central

    Tatham, Michael H.; Cole, Christian; Scullion, Paul; Wilkie, Ross; Westwood, Nicholas J.; Stark, Lesley A.; Hay, Ronald T.

    2017-01-01

    Aspirin, or acetylsalicylic acid is widely used to control pain, inflammation and fever. Important to this function is its ability to irreversibly acetylate cyclooxygenases at active site serines. Aspirin has the potential to acetylate other amino acid side-chains, leading to the possibility that aspirin-mediated lysine acetylation could explain some of its as-yet unexplained drug actions or side-effects. Using isotopically labeled aspirin-d3, in combination with acetylated lysine purification and LC-MS/MS, we identified over 12000 sites of lysine acetylation from cultured human cells. Although aspirin amplifies endogenous acetylation signals at the majority of detectable endogenous sites, cells tolerate aspirin mediated acetylation very well unless cellular deacetylases are inhibited. Although most endogenous acetylations are amplified by orders of magnitude, lysine acetylation site occupancies remain very low even after high doses of aspirin. This work shows that while aspirin has enormous potential to alter protein function, in the majority of cases aspirin-mediated acetylations do not accumulate to levels likely to elicit biological effects. These findings are consistent with an emerging model for cellular acetylation whereby stoichiometry correlates with biological relevance, and deacetylases act to minimize the biological consequences of nonspecific chemical acetylations. PMID:27913581

  11. Variability of arginine content and yield components in Valencia peanut germplasm.

    PubMed

    Aninbon, Chorkaew; Jogloy, Sanun; Vorasoot, Nimitr; Nuchadomrong, Suporn; Holbrook, C Corley; Kvien, Craig; Puppala, Naveen; Patanothai, Aran

    2017-06-01

    Peanut seeds are rich in arginine, an amino acid that has several positive effects on human health. Establishing the genetic variability of arginine content in peanut will be useful for breeding programs that have high arginine as one of their goals. The objective of this study was to evaluate the variation of arginine content, pods/plant, seeds/pod, seed weight, and yield in Valencia peanut germplasm. One hundred and thirty peanut genotypes were grown under field condition for two years. A randomized complete block design with three replications was used for this study. Arginine content was analyzed in peanut seeds at harvest using spectrophotometry. Yield and yield components were recorded for each genotype. Significant differences in arginine content and yield components were found in the tested Valencia peanut germplasm. Arginine content ranged from 8.68-23.35 μg/g seed. Kremena was the best overall genotype of high arginine content, number of pods/plant, 100 seed weight and pod yield.

  12. Intestinal trophic effect of enteral arginine is independent of blood flow in neonatal piglets

    USDA-ARS?s Scientific Manuscript database

    Arginine is an indispensable amino acid in neonates. Arginine is synthesized by gut epithelial cells and may have a protective role in preventing necrotizing enterocolitis. We hypothesized our method included that enteral arginine is a stimulus for intestinal blood flow and subsequent mucosal growth...

  13. Amino acid sensing in hypothalamic tanycytes via umami taste receptors.

    PubMed

    Lazutkaite, Greta; Soldà, Alice; Lossow, Kristina; Meyerhof, Wolfgang; Dale, Nicholas

    2017-11-01

    Hypothalamic tanycytes are glial cells that line the wall of the third ventricle and contact the cerebrospinal fluid (CSF). While they are known to detect glucose in the CSF we now show that tanycytes also detect amino acids, important nutrients that signal satiety. Ca 2+ imaging and ATP biosensing were used to detect tanycyte responses to l-amino acids. The downstream pathway of the responses was determined using ATP receptor antagonists and channel blockers. The receptors were characterized using mice lacking the Tas1r1 gene, as well as an mGluR4 receptor antagonist. Amino acids such as Arg, Lys, and Ala evoke Ca 2+ signals in tanycytes and evoke the release of ATP via pannexin 1 and CalHM1, which amplifies the signal via a P2 receptor dependent mechanism. Tanycytes from mice lacking the Tas1r1 gene had diminished responses to lysine and arginine but not alanine. Antagonists of mGluR4 greatly reduced the responses to alanine and lysine. Two receptors previously implicated in taste cells, the Tas1r1/Tas1r3 heterodimer and mGluR4, contribute to the detection of a range of amino acids by tanycytes in CSF. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  14. Arginine: Its pKa value revisited

    PubMed Central

    Fitch, Carolyn A; Platzer, Gerald; Okon, Mark; Garcia-Moreno E, Bertrand; McIntosh, Lawrence P

    2015-01-01

    Using complementary approaches of potentiometry and NMR spectroscopy, we have determined that the equilibrium acid dissociation constant (pKa value) of the arginine guanidinium group is 13.8 ± 0.1. This is substantially higher than that of ∼12 often used in structure-based electrostatics calculations and cited in biochemistry textbooks. The revised intrinsic pKa value helps explains why arginine side chains in proteins are always predominantly charged, even at pH values as great as 10. The high pKa value also reinforces the observation that arginine side chains are invariably protonated under physiological conditions of near neutral pH. This occurs even when the guanidinium moiety is buried in a hydrophobic micro-environment, such as that inside a protein or a lipid membrane, thought to be incompatible with the presence of a charged group. PMID:25808204

  15. Proteomic and Biochemical Studies of Lysine Malonylation Suggest Its Malonic Aciduria-associated Regulatory Role in Mitochondrial Function and Fatty Acid Oxidation*

    PubMed Central

    Colak, Gozde; Pougovkina, Olga; Dai, Lunzhi; Tan, Minjia; te Brinke, Heleen; Huang, He; Cheng, Zhongyi; Park, Jeongsoon; Wan, Xuelian; Liu, Xiaojing; Yue, Wyatt W.; Wanders, Ronald J. A.; Locasale, Jason W.; Lombard, David B.; de Boer, Vincent C. J.; Zhao, Yingming

    2015-01-01

    The protein substrates of sirtuin 5-regulated lysine malonylation (Kmal) remain unknown, hindering its functional analysis. In this study, we carried out proteomic screening, which identified 4042 Kmal sites on 1426 proteins in mouse liver and 4943 Kmal sites on 1822 proteins in human fibroblasts. Increased malonyl-CoA levels in malonyl-CoA decarboxylase (MCD)-deficient cells induces Kmal levels in substrate proteins. We identified 461 Kmal sites showing more than a 2-fold increase in response to MCD deficiency as well as 1452 Kmal sites detected only in MCD−/− fibroblast but not MCD+/+ cells, suggesting a pathogenic role of Kmal in MCD deficiency. Cells with increased lysine malonylation displayed impaired mitochondrial function and fatty acid oxidation, suggesting that lysine malonylation plays a role in pathophysiology of malonic aciduria. Our study establishes an association between Kmal and a genetic disease and offers a rich resource for elucidating the contribution of the Kmal pathway and malonyl-CoA to cellular physiology and human diseases. PMID:26320211

  16. Characterization of the Drosophila protein arginine methyltransferases DART1 and DART4.

    PubMed

    Boulanger, Marie-Chloé; Miranda, Tina Branscombe; Clarke, Steven; Di Fruscio, Marco; Suter, Beat; Lasko, Paul; Richard, Stéphane

    2004-04-15

    The role of arginine methylation in Drosophila melanogaster is unknown. We identified a family of nine PRMTs (protein arginine methyltransferases) by sequence homology with mammalian arginine methyltransferases, which we have named DART1 to DART9 ( Drosophila arginine methyltransferases 1-9). In keeping with the mammalian PRMT nomenclature, DART1, DART4, DART5 and DART7 are the putative homologues of PRMT1, PRMT4, PRMT5 and PRMT7. Other DART family members have a closer resemblance to PRMT1, but do not have identifiable homologues. All nine genes are expressed in Drosophila at various developmental stages. DART1 and DART4 have arginine methyltransferase activity towards substrates, including histones and RNA-binding proteins. Amino acid analysis of the methylated arginine residues confirmed that both DART1 and DART4 catalyse the formation of asymmetrical dimethylated arginine residues and they are type I arginine methyltransferases. The presence of PRMTs in D. melanogaster suggest that flies are a suitable genetic system to study arginine methylation.

  17. Kinetic characterization of arginine deiminase and carbamate kinase from Streptococcus pyogenes M49.

    PubMed

    Hering, Silvio; Sieg, Antje; Kreikemeyer, Bernd; Fiedler, Tomas

    2013-09-01

    Streptococcus pyogenes (group A Streptococcus, GAS) is an important human pathogen causing mild superficial infections of skin and mucous membranes, but also life-threatening systemic diseases. S. pyogenes and other prokaryotic organisms use the arginine deiminase system (ADS) for survival in acidic environments. In this study, the arginine deiminase (AD), and carbamate kinase (CK) from S. pyogenes M49 strain 591 were heterologously expressed in Escherichia coli DH5α, purified, and kinetically characterized. AD and CK from S. pyogenes M49 share high amino acid sequence similarity with the respective enzymes from Lactococcus lactis subsp. lactis IL1403 (45.6% and 53.5% identical amino acids) and Enterococcus faecalis V583 (66.8% and 66.8% identical amino acids). We found that the arginine deiminase of S. pyogenes is not allosterically regulated by the intermediates and products of the arginine degradation (e.g., ATP, citrulline, carbamoyl phosphate). The Km and Vmax values for arginine were 1.13±0.12mM (mean±SD) and 1.51±0.07μmol/min/mg protein. The carbamate kinase is inhibited by ATP but unaffected by arginine and citrulline. The Km and Vmax values for ADP were 0.72±0.08mM and 1.10±0.10μmol/min/mg protein and the Km for carbamoyl phosphate was 0.65±0.07mM. The optimum pH and temperature for both enzymes were 6.5 and 37°C, respectively. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Lysines 72, 80 and 213 and aspartic acid 210 of the Lactococcus lactis LacR repressor are involved in the response to the inducer tagatose-6-phosphate leading to induction of lac operon expression.

    PubMed

    van Rooijen, R J; Dechering, K J; Niek, C; Wilmink, J; de Vos, W M

    1993-02-01

    Site-directed mutagenesis of the Lactococcus lactis lacR gene was performed to identify residues in the LacR repressor that are involved in the induction of lacABCDFEGX operon expression by tagatose-6-phosphate. A putative inducer binding domain located near the C-terminus was previously postulated based on homology studies with the Escherichia coli DeoR family of repressors, which all have a phosphorylated sugar as inducer. Residues within this domain and lysine residues that are charge conserved in the DeoR family were changed into alanine or arginine. The production of the LacR mutants K72A, K80A, K80R, D210A, K213A and K213R in the LacR-deficient L.lactis strain NZ3015 resulted in repressed phospho-beta-galactosidase (LacG) activities and decreased growth rates on lactose. Gel mobility shift assays showed that the complex between a DNA fragment carrying the lac operators and LacR mutants K72A, K80A, K213A and D210A did not dissociate in the presence of tagatose-6-phosphate, in contrast to wild type LacR. Other mutations (K62A/K63A, K72R, K73A, K73R, T212A, F214R, R216R and R216K) exhibited no gross effects on inducer response. The results strongly suggest that the lysines at positions 72, 80 and 213 and aspartic acid at position 210 are involved in the induction of lac operon expression by tagatose-6-phosphate.

  19. Electron beam-induced graft polymerization of acrylic acid and immobilization of arginine-glycine-aspartic acid-containing peptide onto nanopatterned polycaprolactone.

    PubMed

    Sun, Hui; Wirsén, Anders; Albertsson, Ann-Christine

    2004-01-01

    Electron beam- (EB-) induced graft polymerization of acrylic acid and the subsequent immobilization of arginine-glycine-aspartic acid (RGD) peptide onto nanopatterned polycaprolactone with parallel grooves is reported. A high concentration of carboxylic groups was introduced onto the polymer substrate by EB-induced polymerization of acrylic acid. In the coupling of the RGD peptide to the carboxylated polymer surface, a three-step peptide immobilization process was used. This process included the activation of surface carboxylic acid into an active ester intermediate by use of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), the introduction of disulfide groups by use of 2-(2-pyridinyldithio)ethanamine hydrochloride (PDEA), and final immobilization of the peptide via a thiol-disulfide exchange reaction. The extent of coupling was measured by UV spectroscopy. A preliminary study of the in vitro behavior of keratinocytes (NCTC 2544) cultured on the acrylic acid-grafted and RGD peptide-coupled surface showed that most cells grown on the coupled samples had a spread-rounded appearance, while the majority of cells tended to be elongated along the grooves on uncoupled substrates.

  20. Control of TSC2-Rheb signaling axis by arginine regulates mTORC1 activity

    PubMed Central

    Carroll, Bernadette; Maetzel, Dorothea; Maddocks, Oliver DK; Otten, Gisela; Ratcliff, Matthew; Smith, Graham R; Dunlop, Elaine A; Passos, João F; Davies, Owen R; Jaenisch, Rudolf; Tee, Andrew R; Sarkar, Sovan; Korolchuk, Viktor I

    2016-01-01

    The mammalian target of rapamycin complex 1 (mTORC1) is the key signaling hub that regulates cellular protein homeostasis, growth, and proliferation in health and disease. As a prerequisite for activation of mTORC1 by hormones and mitogens, there first has to be an available pool of intracellular amino acids. Arginine, an amino acid essential during mammalian embryogenesis and early development is one of the key activators of mTORC1. Herein, we demonstrate that arginine acts independently of its metabolism to allow maximal activation of mTORC1 by growth factors via a mechanism that does not involve regulation of mTORC1 localization to lysosomes. Instead, arginine specifically suppresses lysosomal localization of the TSC complex and interaction with its target small GTPase protein, Rheb. By interfering with TSC-Rheb complex, arginine relieves allosteric inhibition of Rheb by TSC. Arginine cooperates with growth factor signaling which further promotes dissociation of TSC2 from lysosomes and activation of mTORC1. Arginine is the main amino acid sensed by the mTORC1 pathway in several cell types including human embryonic stem cells (hESCs). Dependence on arginine is maintained once hESCs are differentiated to fibroblasts, neurons, and hepatocytes, highlighting the fundamental importance of arginine-sensing to mTORC1 signaling. Together, our data provide evidence that different growth promoting cues cooperate to a greater extent than previously recognized to achieve tight spatial and temporal regulation of mTORC1 signaling. DOI: http://dx.doi.org/10.7554/eLife.11058.001 PMID:26742086

  1. Effects of glucose and oxygen on arginine metabolism by coagulase-negative staphylococci.

    PubMed

    Sánchez Mainar, María; Matheuse, Fréderick; De Vuyst, Luc; Leroy, Frédéric

    2017-08-01

    Coagulase-negative staphylococci (CNS) are not only part of the desirable microbiota of fermented meat products but also commonly inhabit skin and flesh wounds. Their proliferation depends on the versatility to use energy sources and the adaptation to fluctuating environmental parameters. In this study, the conversion of the amino acid arginine by two strains with arginine deiminase (ADI) activity (Staphylococcus carnosus 833 and S. pasteuri αs3-13) and a strain with nitric oxide synthase (NOS) activity (S. haemolyticus G110) was modelled as a function of glucose and oxygen availability. Both factors moderately inhibited the ADI-based conversion kinetics, never leading to full repression. However, for NOS-driven conversion of arginine by S. haemolyticus G110, oxygen was an absolute requirement. When changing from microaerobic conditions to aerobiosis, a switch from homolactic fermentation to a combined formation of lactic acid, acetic acid, and acetoin was found in all cases, after which lactic acid and acetic acid were used as substrates. The kinetic model proposed provided a suitable description of the data of glucose and arginine co-metabolism as a function of oxygen levels and may serve as a tool to further analyse the behaviour of staphylococci in different ecosystems or when applying specific food processing conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Cloacibacillus evryensis gen. nov., sp. nov., a novel asaccharolytic, mesophilic, amino-acid-degrading bacterium within the phylum 'Synergistetes', isolated from an anaerobic sludge digester.

    PubMed

    Ganesan, Akila; Chaussonnerie, Sébastien; Tarrade, Anne; Dauga, Catherine; Bouchez, Théodore; Pelletier, Eric; Le Paslier, Denis; Sghir, Abdelghani

    2008-09-01

    A novel anaerobic, mesophilic, amino-acid-utilizing bacterium, strain 158T, was isolated from an anaerobic digester of a wastewater treatment plant. Cells of strain 158T were non-motile, rod-shaped (2.0-3.0 x 0.8-1.0 microm) and stained Gram-negative. Optimal growth occurred at 37 degrees C and pH 7.0 in an anaerobic basal medium containing 1 % Casamino acids. Strain 158T fermented arginine, histidine, lysine and serine and showed growth on yeast extract, brain-heart infusion (BHI) medium and tryptone, but not on carbohydrates, organic acids or alcohols. The end products of degradation were: acetate, butyrate, H2 and CO2 from arginine; acetate, propionate, butyrate, H2 and CO2 from lysine; and acetate, propionate, butyrate, valerate, H2 and CO2 from histidine, serine, BHI medium, Casamino acids and tryptone. The DNA G+C content was 55.8 mol%. The 16S rRNA gene sequence of strain 158T showed only 92.6 % sequence similarity with that of Synergistes jonesii, the only described species of the 'Synergistes' group. The major cellular fatty acids were iso-C(15:0) (16.63 %), iso-C(15:0) 3-OH (12.41 %) and C(17:1)omega6c (9.46 %) and the polar fatty acids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylamine; these fatty acid profiles did not resemble those of any recognized bacterial species. Due to the considerable differences in genotypic, phenotypic and phylogenetic characteristics between strain 158T and those of its nearest relative, it is proposed that strain 158T represents a novel species in a new genus, Cloacibacillus evryensis gen. nov., sp. nov., in the phylum 'Synergistetes'. The type strain is 158T (=DSM 19522T=JCM 14828T).

  3. The role of the arginine metabolome in pain: implications for sickle cell disease.

    PubMed

    Bakshi, Nitya; Morris, Claudia R

    2016-01-01

    Sickle cell disease (SCD) is the most common hemoglobinopathy in the US, affecting approximately 100,000 individuals in the US and millions worldwide. Pain is the hallmark of SCD, and a subset of patients experience pain virtually all of the time. Of interest, the arginine metabolome is associated with several pain mechanisms highlighted in this review. Since SCD is an arginine deficiency syndrome, the contribution of the arginine metabolome to acute and chronic pain in SCD is a topic in need of further attention. Normal arginine metabolism is impaired in SCD through various mechanisms that contribute to endothelial dysfunction, vaso-occlusion, pulmonary complications, risk of leg ulcers, and early mortality. Arginine is a semiessential amino acid that serves as a substrate for protein synthesis and is the precursor to nitric oxide (NO), polyamines, proline, glutamate, creatine, and agmatine. Since arginine is involved in multiple metabolic processes, a deficiency of this amino acid has the potential to disrupt many cellular and organ functions. NO is a potent vasodilator that is depleted in SCD and may contribute to vaso-occlusive pain. As the obligate substrate for NO production, arginine also plays a mechanistic role in SCD-related pain, although its contribution to pain pathways likely extends beyond NO. Low global arginine bioavailability is associated with pain severity in both adults and children with SCD as well as other non-SCD pain syndromes. Preliminary clinical studies of arginine therapy in SCD demonstrate efficacy in treating acute vaso-occlusive pain, as well as leg ulcers and pulmonary hypertension. Restoration of arginine bioavailability through exogenous supplementation of arginine is, therefore, a promising therapeutic target. Phase II clinical trials of arginine therapy for sickle-related pain are underway and a Phase III randomized controlled trial is anticipated in the near future.

  4. The Topology of the l-Arginine Exporter ArgO Conforms to an Nin-Cout Configuration in Escherichia coli: Requirement for the Cytoplasmic N-Terminal Domain, Functional Helical Interactions, and an Aspartate Pair for ArgO Function.

    PubMed

    Pathania, Amit; Gupta, Arvind Kumar; Dubey, Swati; Gopal, Balasubramanian; Sardesai, Abhijit A

    2016-12-01

    ArgO and LysE are members of the LysE family of exporter proteins and ordinarily mediate the export of l-arginine (Arg) in Escherichia coli and l-lysine (Lys) and Arg in Corynebacterium glutamicum, respectively. Under certain conditions, ArgO also mediates Lys export. To delineate the arrangement of ArgO in the cytoplasmic membrane of E. coli, we have employed a combination of cysteine accessibility in situ, alkaline phosphatase fusion reporters, and protein modeling to arrive at a topological model of ArgO. Our studies indicate that ArgO assumes an N in -C out configuration, potentially forming a five-transmembrane helix bundle flanked by a cytoplasmic N-terminal domain (NTD) comprising roughly its first 38 to 43 amino acyl residues and a short periplasmic C-terminal region (CTR). Mutagenesis studies indicate that the CTR, but not the NTD, is dispensable for ArgO function in vivo and that a pair of conserved aspartate residues, located near the opposing edges of the cytoplasmic membrane, may play a pivotal role in facilitating transmembrane Arg flux. Additional studies on amino acid substitutions that impair ArgO function in vivo and their derivatives bearing compensatory amino acid alterations indicate a role for intramolecular interactions in the Arg export mechanism, and some interactions are corroborated by normal-mode analyses. Lastly, our studies suggest that ArgO may exist as a monomer in vivo, thus highlighting the requirement for intramolecular interactions in ArgO, as opposed to interactions across multiple ArgO monomers, in the formation of an Arg-translocating conduit. The orthologous proteins LysE of C. glutamicum and ArgO of E. coli function as exporters of the basic amino acids l-arginine and l-lysine and the basic amino acid l-arginine, respectively, and LysE can functionally substitute for ArgO when expressed in E. coli Notwithstanding this functional equivalence, studies reported here show that ArgO possesses a membrane topology that is distinct

  5. The Topology of the l-Arginine Exporter ArgO Conforms to an Nin-Cout Configuration in Escherichia coli: Requirement for the Cytoplasmic N-Terminal Domain, Functional Helical Interactions, and an Aspartate Pair for ArgO Function

    PubMed Central

    Pathania, Amit; Gupta, Arvind Kumar; Dubey, Swati; Gopal, Balasubramanian

    2016-01-01

    ABSTRACT ArgO and LysE are members of the LysE family of exporter proteins and ordinarily mediate the export of l-arginine (Arg) in Escherichia coli and l-lysine (Lys) and Arg in Corynebacterium glutamicum, respectively. Under certain conditions, ArgO also mediates Lys export. To delineate the arrangement of ArgO in the cytoplasmic membrane of E. coli, we have employed a combination of cysteine accessibility in situ, alkaline phosphatase fusion reporters, and protein modeling to arrive at a topological model of ArgO. Our studies indicate that ArgO assumes an Nin-Cout configuration, potentially forming a five-transmembrane helix bundle flanked by a cytoplasmic N-terminal domain (NTD) comprising roughly its first 38 to 43 amino acyl residues and a short periplasmic C-terminal region (CTR). Mutagenesis studies indicate that the CTR, but not the NTD, is dispensable for ArgO function in vivo and that a pair of conserved aspartate residues, located near the opposing edges of the cytoplasmic membrane, may play a pivotal role in facilitating transmembrane Arg flux. Additional studies on amino acid substitutions that impair ArgO function in vivo and their derivatives bearing compensatory amino acid alterations indicate a role for intramolecular interactions in the Arg export mechanism, and some interactions are corroborated by normal-mode analyses. Lastly, our studies suggest that ArgO may exist as a monomer in vivo, thus highlighting the requirement for intramolecular interactions in ArgO, as opposed to interactions across multiple ArgO monomers, in the formation of an Arg-translocating conduit. IMPORTANCE The orthologous proteins LysE of C. glutamicum and ArgO of E. coli function as exporters of the basic amino acids l-arginine and l-lysine and the basic amino acid l-arginine, respectively, and LysE can functionally substitute for ArgO when expressed in E. coli. Notwithstanding this functional equivalence, studies reported here show that ArgO possesses a membrane topology

  6. Identification of candidate amino acids involved in the formation of blue pigments in crushed garlic cloves (Allium sativum L.).

    PubMed

    Cho, Jungeun; Lee, Eun Jin; Yoo, Kil Sun; Lee, Seung Koo; Patil, Bhimanagouda S

    2009-01-01

    The color-forming ability of amino acids with thiosulfinate in crushed garlic was investigated. We developed reaction systems for generating pure blue pigments using extracted thiosulfinate from crushed garlic and onion and all 22 amino acids. Each amino acid was reacted with thiosulfinate solution and was then incubated at 60 degrees C for 3 h to generate pigments. Unknown blue pigments, responsible for discoloration in crushed garlic cloves (Allium sativum L.), were separated and tentatively characterized using high-performance liquid chromatography (HPLC) and a diode array detector ranging between 200 and 700 nm. Blue pigment solutions exhibited 2 maximal absorbance peaks at 440 nm and 580 nm, corresponding to yellow and blue, respectively, with different retention times. Our findings indicated that green discoloration is created by the combination of yellow and blue pigments. Eight naturally occurring blue pigments were separated from discolored garlic extracts using HPLC at 580 nm. This suggests that garlic discoloration is not caused by only 1 blue pigment, as reported earlier, but by as many as 8 pigments. Overall, free amino acids that formed blue pigment when reacted with thiosulfinate were glycine, arginine, lysine, serine, alanine, aspartic acid, asparagine, glutamic acid, and tyrosine. Arginine, asparagine, and glutamine had spectra that were more similar to naturally greened garlic extract.

  7. Arginine-Ornithine Antiporter ArcD Controls Arginine Metabolism and Interspecies Biofilm Development of Streptococcus gordonii*♦

    PubMed Central

    Sakanaka, Akito; Kuboniwa, Masae; Takeuchi, Hiroki; Hashino, Ei; Amano, Atsuo

    2015-01-01

    Arginine is utilized by the oral inhabitant Streptococcus gordonii as a substrate of the arginine deiminase system (ADS), eventually producing ATP and NH3, the latter of which is responsible for microbial resistance to pH stress. S. gordonii expresses a putative arginine-ornithine antiporter (ArcD) whose function has not been investigated despite relevance to the ADS and potential influence on inter-bacterial communication with periodontal pathogens that utilize amino acids as a main energy source. Here, we generated an S. gordonii ΔarcD mutant to explore the role of ArcD in physiological homeostasis and bacterial cross-feeding. First, we confirmed that S. gordonii ArcD plays crucial roles for mediating arginine uptake and promoting bacterial growth, particularly under arginine-limited conditions. Next, metabolomic profiling and transcriptional analysis of the ΔarcD mutant revealed that deletion of this gene caused intracellular accumulation of ornithine leading to malfunction of the ADS and suppression of de novo arginine biosynthesis. The mutant strain also showed increased susceptibility to low pH stress due to reduced production of ammonia. Finally, accumulation of Fusobacterium nucleatum was found to be significantly decreased in biofilm formed by the ΔarcD mutant as compared with the wild-type strain, although ornithine supplementation restored fusobacterium biovolume in dual-species biofilms with the ΔarcD mutant and also enhanced single species biofilm development by F. nucleatum. Our results are the first direct evidence showing that S. gordonii ArcD modulates not only alkali and energy production but also interspecies interaction with F. nucleatum, thus initiating a middle stage of periodontopathic biofilm formation, by metabolic cross-feeding. PMID:26085091

  8. The synthesis and cell interaction of statistical L-arginine - glycine - L-aspartic acid terpolypeptides.

    PubMed

    Mbizana, Siyasanga; Hlalele, Lebohang; Pfukwa, Rueben; du Toit, Andre; Lumkwana, Dumisile; Loos, Benjamin; Klumperman, Bert

    2018-05-01

    Copolymerizations and terpolymerizations of N-carboxyanhydrides (NCAs) of glycine (Gly), Nδ-carbobenzyloxy-L-ornithine ((Z)-Orn) and β-benzyl-L-aspartate ((Bz)-Asp) were investigated. In situ 1H NMR spectroscopy was used to monitor individual comonomer consumptions during binary and ternary copolymerizations. The six relevant reactivity ratios were determined from copolymerizations of the NCAs of amino acids via nonlinear least squares curve fitting. The reactivity ratios were subsequently used to maximize the occurrence of the Asp-Gly-Orn (DGR') sequence in the terpolymers. Terpolymers with variable probability of occurrence of DGR' were prepared in the lab. Subsequently, the ornithine residues on the terpolymers were converted to L-arginine (R) residues via guanidination reaction after removal of the protecting groups. The resulting DGR terpolymers translate to traditional peptides and proteins with variable RGD content, due to the convention in nomenclature that peptides are depicted from N- to C-terminus, whereas the NCA ring-opening polymerization is conducted from C- to N-terminus. The L-arginine containing terpolymers were evaluated for cell interaction, where it was found that neuronal cells display enhanced adhesion and process formation when plated in the presence of statistical DGR terpolymers.

  9. Antidepressant-like effect of folic acid: Involvement of NMDA receptors and L-arginine-nitric oxide-cyclic guanosine monophosphate pathway.

    PubMed

    Brocardo, Patrícia de Souza; Budni, Josiane; Lobato, Kelly Ribas; Kaster, Manuella Pinto; Rodrigues, Ana Lúcia S

    2008-11-19

    Antidepressant-like activity of folic acid in forced swimming test and in the tail suspension test was demonstrated previously by our group. In this study we investigated the involvement of N-methyl-d-aspartate (NMDA) receptors and l-arginine-nitric oxide (NO)-cyclic guanosine monophosphate pathway in its antidepressant-like effect in the forced swimming test in mice. The antidepressant-like effect of folic acid (10 nmol/site, i.c.v.) was prevented by the pretreatment of mice with NMDA (0.1 pmol/site, i.c.v.), l-arginine (750 mg/kg, i.p., substrate for nitric oxide synthase), S-nitroso-N-acetyl-penicillamine (SNAP, 25 microg/site, i.c.v, a NO donor) or sildenafil (5 mg/kg, i.p., phosphodiesterase 5 inhibitor). The administration of 7-nitroindazole (25 and 50 mg/kg, i.p., a specific neuronal nitric oxide synthase (nNOS) inhibitor) or methylene blue (20 mg/kg, i.p., direct inhibitor of both nitric oxide synthase and soluble guanylate cyclase) in combination with a sub-effective dose of folic acid (1 nmol/site, i.c.v.) reduced the immobility time in the FST as compared with either drug alone. Together the results suggest that the antidepressant-like effect of folic acid in the forced swimming test is dependent on an inhibition of either NMDA receptors or NO and cGMP synthesis.

  10. N6-Trimethyl-lysine metabolism. 3-Hydroxy-N6-trimethyl-lysine and carnitine biosynthesis.

    PubMed Central

    Hoppel, C L; Cox, R A; Novak, R F

    1980-01-01

    Rats injected with N6-[Me-3H]trimethyl-lysine excrete in the urine five radioactively labelled metabolites. Two of these identified metabolites are carnitine and 4-trimethylammoniobutyrate. A third metabolite, identified as 5-trimethylammoniopentanoate, is not an intermediate in the biosynthesis of carnitine; the fourth and major metabolite, N2-acetyl-N6-trimethyl-lysine, is not a precursor of carnitine. The remaining metabolite (3-hydroxy-N6-trimethyl-lysine) is converted into trimethylammoniobutyrate and carnitine by rat liver slices and into trimethylammoniobutyrate by rat kidney slices. In rat liver and kidney-slice experiments, radioactivity from DL-N6-trimethyl-[1-14C]lysine and DL-N6-trimethyl-[2-14C]lysine was incorporated into N2-acetyl-N6-trimethyl-lysine and 3-hydroxy-N6-trimethyl-lysine, but not into trimethylammoniobutyrate or carnitine. A procedure was devised to purify milligram quantities of 3-hydroxy-N6-trimethyl-lysine from the urine of rats injected chronically with N6-trimethyl-lysine (100 mg/kg body wt. per day). The structure of 3-hydroxy-N6-trimethyl-lysine was confirmed chemically and by nuclear-magnetic-resonance spectrometry [Novak, Swift & Hoppel (1980) Biochem. J. 188, 521--527]. The sequence for carnitine biosynthesis in liver is: N6-trimethyl-lysine leads to 3-hydryxy-N6-trimethyl-lysine leads to leads to 4-trimethylammoniobutyrate leads to carnitine. PMID:6772168

  11. Effects of Mutations and Ligands on the Thermostability of the l-Arginine/Agmatine Antiporter AdiC and Deduced Insights into Ligand-Binding of Human l-Type Amino Acid Transporters

    PubMed Central

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Colas, Claire; Ucurum, Zöhre; Schlessinger, Avner; Fotiadis, Dimitrios

    2018-01-01

    The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures (Tms) of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg), agmatine, l-arginine methyl ester, and l-arginine amide. The resulting Tms indicated stabilization of AdiC variants upon ligand binding, in which Tms and ligand binding affinities correlated positively. Considering results from this and previous studies, we revisited the role of AdiC residue S26 in Arg binding and proposed interactions of the α-carboxylate group of Arg exclusively with amide groups of the AdiC backbone. In the context of substrate binding in the human SLC7 family member l-type amino acid transporter-1 (LAT1; SLC7A5), an analogous role of S66 in LAT1 to S26 in AdiC is discussed based on homology modeling and amino acid sequence analysis. Finally, we propose a binding mechanism for l-amino acid substrates to LATs from the SLC7 family. PMID:29558430

  12. The CASTOR proteins are arginine sensors for the mTORC1 pathway

    PubMed Central

    Chantranupong, Lynne; Scaria, Sonia M.; Saxton, Robert A.; Gygi, Melanie P.; Shen, Kuang; Wyant, Gregory A.; Wang, Tim; Harper, J. Wade; Gygi, Steven P.; Sabatini, David M.

    2016-01-01

    Amino acids signal to the mTOR complex I (mTORC1) growth pathway through the Rag GTPases. Multiple distinct complexes regulate the Rags, including GATOR1, a GTPase activating protein (GAP), and GATOR2, a positive regulator of unknown molecular function. Arginine stimulation of cells activates mTORC1, but how it is sensed is not well understood. Recently, SLC38A9 was identified as a putative lysosomal arginine sensor required for arginine to activate mTORC1 but how arginine deprivation represses mTORC1 is unknown. Here, we show that CASTOR1, a previously uncharacterized protein, interacts with GATOR2 and is required for arginine deprivation to inhibit mTORC1. CASTOR1 homodimerizes and can also heterodimerize with the related protein, CASTOR2. Arginine disrupts the CASTOR1-GATOR2 complex by binding to CASTOR1 with a dissociation constant of ~30 μM, and its arginine-binding capacity is required for arginine to activate mTORC1 in cells. Collectively, these results establish CASTOR1 as an arginine sensor for the mTORC1 pathway. PMID:26972053

  13. Characterization of the Drosophila protein arginine methyltransferases DART1 and DART4.

    PubMed Central

    Boulanger, Marie-Chloé; Miranda, Tina Branscombe; Clarke, Steven; Di Fruscio, Marco; Suter, Beat; Lasko, Paul; Richard, Stéphane

    2004-01-01

    The role of arginine methylation in Drosophila melanogaster is unknown. We identified a family of nine PRMTs (protein arginine methyltransferases) by sequence homology with mammalian arginine methyltransferases, which we have named DART1 to DART9 ( Drosophila arginine methyltransferases 1-9). In keeping with the mammalian PRMT nomenclature, DART1, DART4, DART5 and DART7 are the putative homologues of PRMT1, PRMT4, PRMT5 and PRMT7. Other DART family members have a closer resemblance to PRMT1, but do not have identifiable homologues. All nine genes are expressed in Drosophila at various developmental stages. DART1 and DART4 have arginine methyltransferase activity towards substrates, including histones and RNA-binding proteins. Amino acid analysis of the methylated arginine residues confirmed that both DART1 and DART4 catalyse the formation of asymmetrical dimethylated arginine residues and they are type I arginine methyltransferases. The presence of PRMTs in D. melanogaster suggest that flies are a suitable genetic system to study arginine methylation. PMID:14705965

  14. Effect of betaine and arginine in lysine-deficient diets on growth, carcass traits, and pork quality.

    PubMed

    Madeira, M S; Alfaia, C M; Costa, P; Lopes, P A; Martins, S V; Lemos, J P C; Moreira, O; Santos-Silva, J; Bessa, R J B; Prates, J A M

    2015-10-01

    Forty entire male pigs from a commercial crossbreed (Duroc × Large White × Landrace) were used to investigate the individual or combined effects of betaine and Arg supplementation in Lys-deficient diets on growth performance, carcass traits, and pork quality. Pigs with 59.9 ± 1.65 kg BW were randomly assigned to 1 of 5 dietary treatments ( = 8). The 5 dietary treatments were normal Lys and CP diet (0.51% Lys and 16% CP; control), reduced Lys and CP diet (0.35% Lys and 13% CP), reduced Lys and CP diet with betaine supplementation (0.33%), reduced Lys and CP diet with Arg supplementation (1.5%), and reduced Lys and CP diet with betaine and Arg supplementation (0.33% betaine and 1.5% Arg). Pigs were slaughtered at 92.7 ± 2.54 kg BW. The Lys-deficient diets (-35% Lys) increased intramuscular fat (IMF) content by 25% ( = 0.041) and meat juiciness by 12% ( = 0.041) but had a negative effect on growth performance ( < 0.05) of pigs. In addition, Lys-deficient diets increased L* ( = 0.005) and b* ( = 0.010) muscle color parameters and perirenal fat deposition ( < 0.001) and decreased both HCW ( = 0.015) and loin weight ( = 0.023). Betaine and Arg supplementation of Lys-deficient diets had no effect on IMF content but increased ( < 0.05) overall pork acceptability. Arginine supplementation also increased ( = 0.003) meat tenderness. Differences in fatty acid composition of pork were not detected among dietary treatment groups. However, oleic acid was positively correlated ( < 0.05) with IMF content, juiciness, flavor, and overall acceptability of meat. Data confirm that dietary CP reduction enhances pork eating quality but negatively affects pigs' growth performance. Moreover, it is suggested that betaine and Arg supplementation of Lys-deficient diets does not further increase IMF content but improves some pork sensory traits, including overall acceptability.

  15. Loss of RUNX1/AML1 arginine-methylation impairs in peripheral T cell homeostasis

    PubMed Central

    Mizutani, Shinsuke; Yoshida, Tatsushi; Zhao, Xinyang; Nimer, Stephen D.; Taniwaki, Masafumi; Okuda, Tsukasa

    2016-01-01

    Summary RUNX1 (previously termed AML1) is a frequent target of human leukaemia-associated gene aberrations, and it encodes the DNA-binding subunit of the Core-Binding Factor transcription factor complex. RUNX1 expression is essential for the initiation of definitive haematopoiesis, for steady-state thrombopoiesis, and for normal lymphocytes development. Recent studies revealed that protein arginine methyltransferase 1 (PRMT1), which accounts for the majority of the type I PRMT activity in cells, methylates two arginine residues in RUNX1 (R206 and R210), and these modifications inhibit corepressor-binding to RUNX1 thereby enhancing its transcriptional activity. In order to elucidate the biological significance of these methylations, we established novel knock-in mouse lines with non-methylable, double arginine-to-lysine (RTAMR-to-KTAMK) mutations in RUNX1. Homozygous Runx1KTAMK/KTAMK mice are born alive and appear normal during adulthood. However, Runx1KTAMK/KTAMK mice showed a reduction in CD3+ T lymphoid cells and a decrease in CD4+ T cells in peripheral lymphoid organs, in comparison to their wild-type littermates, leading to a reduction in the CD4+ to CD8+ T-cell ratio. These findings suggest that arginine-methylation of RUNX1 in the RTAMR-motif is dispensable for the development of definitive haematopoiesis and for steady-state platelet production, however this modification affects the role of RUNX1 in the maintenance of the peripheral CD4+ T-cell population. PMID:26010396

  16. Identification of amino acids that promote specific and rigid TAR RNA-tat protein complex formation.

    PubMed

    Edwards, Thomas E; Robinson, Bruce H; Sigurdsson, Snorri Th

    2005-03-01

    The Tat protein and the transactivation responsive (TAR) RNA form an essential complex in the HIV lifecycle, and mutations in the basic region of the Tat protein alter this RNA-protein molecular recognition. Here, EPR spectroscopy was used to identify amino acids, flanking an essential arginine of the Tat protein, which contribute to specific and rigid TAR-Tat complex formation by monitoring changes in the mobility of nitroxide spin-labeled TAR RNA nucleotides upon binding. Arginine to lysine N-terminal mutations did not affect TAR RNA interfacial dynamics. In contrast, C-terminal point mutations, R56 in particular, affected the mobility of nucleotides U23 and U38, which are involved in a base-triple interaction in the complex. This report highlights the role of dynamics in specific molecular complex formation and demonstrates the ability of EPR spectroscopy to study interfacial dynamics of macromolecular complexes.

  17. Chemical rescue of the post-translationally carboxylated lysine mutant of allantoinase and dihydroorotase by metal ions and short-chain carboxylic acids.

    PubMed

    Ho, Ya-Yeh; Huang, Yen-Hua; Huang, Cheng-Yang

    2013-04-01

    Bacterial allantoinase (ALLase) and dihydroorotase (DHOase) are members of the cyclic amidohydrolase family. ALLase and DHOase possess similar binuclear metal centers in the active site in which two metals are bridged by a post-translationally carboxylated lysine. In this study, we determined the effects of carboxylated lysine and metal binding on the activities of ALLase and DHOase. Although DHOase is a metalloenzyme, purified DHOase showed high activity without additional metal supplementation in a reaction mixture or bacterial culture. However, unlike DHOase, ALLase had no activity unless some specific metal ions were added to the reaction mixture or culture. Substituting the metal binding sites H59, H61, K146, H186, H242, or D315 with alanine completely abolished the activity of ALLase. However, the K146C, K146D and K146E mutants of ALLase were still active with about 1-6% activity of the wild-type enzyme. These ALLase K146 mutants were found to have 1.4-1.7 mol metal per mole enzyme subunit, which may indicate that they still contained the binuclear metal center in the active site. The activity of the K146A mutant of the ALLase and the K103A mutant of DHOase can be chemically rescued by short-chain carboxylic acids, such as acetic, propionic, and butyric acids, but not by ethanol, propan-1-ol, and imidazole, in the presence of Co2+ or Mn2+ ions. However, the activity was still ~10-fold less than that of wild-type ALLase. Overall, these results indicated that the 20 natural basic amino acid residues were not sufficiently able to play the role of lysine. Accordingly, we proposed that during evolution, the post-translational modification of carboxylated lysine in the cyclic amidohydrolase family was selected for promoting binuclear metal center self-assembly and increasing the nucleophilicity of the hydroxide at the active site for enzyme catalysis. This kind of chemical rescue combined with site-directed mutagenesis may also be used to identify a binuclear metal

  18. Arginine for gestating sows and foetal development: A systematic review.

    PubMed

    Palencia, J Y P; Lemes, M A G; Garbossa, C A P; Abreu, M L T; Pereira, L J; Zangeronimo, M G

    2018-02-01

    The use of functional amino acids during pregnancy has been linked to improved reproduction in mammals. In this context, arginine is a precursor in the synthesis of numerous molecules, such as nitric oxide and polyamines, which play an important role during reproduction. However, contradictory studies are found in the literature, particularly regarding the amount of supplementation and the period of pregnancy in which it is used. The objective of this study was to evaluate the effects of dietary arginine supplementation for pregnant sows on foetal development via a systematic review. The search for papers was performed during the month of December 2015, in the databases ISI Web of Science, Science Direct, Scopus, and SciELO. From a total of 5675 returned studies, only 13 papers were selected after applying selection criteria. Most (47%) of the studies that evaluated the effects of dietary arginine supplementation on foetal development in pigs used 1% arginine. Supplementation was initiated in the first third of pregnancy in 47% of tests, including in both primiparous and multiparous sows. These studies showed positive results for embryo survival and foetal development, evidenced by the increase in placental weight and the number and weight of piglets born alive. Of all evaluated studies, 53% showed benefits on foetal development. It is concluded that supplementing dietary arginine in gestating sows can benefit embryo survival and foetal development. However, to establish a supplementation plan with this amino acid, aspects related to the period of pregnancy, supplementation levels, and source of arginine must be well defined. © 2017 Blackwell Verlag GmbH.

  19. Characterization of Agronomy, Grain Physicochemical Quality, and Nutritional Property of High-Lysine 35R Transgenic Rice with Simultaneous Modification of Lysine Biosynthesis and Catabolism.

    PubMed

    Yang, Qingqing; Wu, Hongyu; Li, Qianfeng; Duan, Ruxu; Zhang, Changquan; Sun, Samuel Saiming; Liu, Qiaoquan

    2017-05-31

    Lysine is the first limiting essential amino acid in rice. We previously constructed a series of transgenic rice lines to enhance lysine biosynthesis (35S), down-regulate its catabolism (Ri), or simultaneously achieve both metabolic effects (35R). In this study, nine transgenic lines, three from each group, were selected for both field and animal feeding trials. The results showed that the transgene(s) caused no obvious effects on field performance and main agronomic traits. Mature seeds of transgenic line 35R-17 contained 48-60-fold more free lysine than in wild type and had slightly lower apparent amylose content and softer gel consistency. Moreover, a 35-day feeding experiment showed that the body weight gain, food efficiency, and protein efficiency ratio of rats fed the 35R-17 transgenic rice diet were improved when compared with those fed wild-type rice diet. These data will be useful for further evaluation and potential commercialization of 35R high-lysine transgenic rice.

  20. Sensitive arginine sensing based on inner filter effect of Au nanoparticles on the fluorescence of CdTe quantum dots

    NASA Astrophysics Data System (ADS)

    Liu, Haijian; Li, Ming; Jiang, Linye; Shen, Feng; Hu, Yufeng; Ren, Xueqin

    2017-02-01

    Arginine plays an important role in many biological functions, whose detection is very significant. Herein, a sensitive, simple and cost-effective fluorescent method for the detection of arginine has been developed based on the inner filter effect (IFE) of citrate-stabilized gold nanoparticles (AuNPs) on the fluorescence of thioglycolic acid-capped CdTe quantum dots (QDs). When citrate-stabilized AuNPs were mixed with thioglycolic acid-capped CdTe QDs, the fluorescence of CdTe QDs was significantly quenched by AuNPs via the IFE. With the presence of arginine, arginine could induce the aggregation and corresponding absorption spectra change of AuNPs, which then IFE-decreased fluorescence could gradually recover with increasing amounts of arginine, achieving fluorescence ;turn on; sensing for arginine. The detection mechanism is clearly illustrated and various experimental conditions were also optimized. Under the optimum conditions, a decent linear relationship was obtained in the range from 16 to 121 μg L- 1 and the limit of detection was 5.6 μg L- 1. And satisfactory results were achieved in arginine analysis using arginine injection, compound amino acid injection, even blood plasma as samples. Therefore, the present assay showed various merits, such as simplicity, low cost, high sensitivity and selectivity, making it promising for sensing arginine in biological samples.

  1. Stability and resilience of oral microcosms toward acidification and Candida outgrowth by arginine supplementation.

    PubMed

    Koopman, Jessica E; Röling, Wilfred F M; Buijs, Mark J; Sissons, Christopher H; ten Cate, Jacob M; Keijser, Bart J F; Crielaard, Wim; Zaura, Egija

    2015-02-01

    Dysbiosis induced by low pH in the oral ecosystem can lead to caries, a prevalent bacterial disease in humans. The amino acid arginine is one of the pH-elevating agents in the oral cavity. To obtain insights into the effect of arginine on oral microbial ecology, a multi-plaque "artificial mouth" (MAM) biofilm model was inoculated with saliva from a healthy volunteer and microcosms were grown for 4 weeks with 1.6 % (w/v) arginine supplement (Arginine) or without (Control), samples were taken at several time-points. A cariogenic environment was mimicked by sucrose pulsing. The bacterial composition was determined by 16S rRNA gene amplicon sequencing, the presence and amount of Candida and arginine deiminase system genes arcA and sagP by qPCR. Additionally, ammonium and short-chain fatty acid concentrations were determined. The Arginine microcosms were dominated by Streptococcus, Veillonella, and Neisseria and remained stable in time, while the composition of the Control microcosms diverged significantly in time, partially due to the presence of Megasphaera. The percentage of Candida increased 100-fold in the Control microcosms compared to the Arginine microcosms. The pH-raising effect of arginine was confirmed by the pH and ammonium results. The abundances of sagP and arcA were highest in the Arginine microcosms, while the concentration of butyrate was higher in the Control microcosms. We demonstrate that supplementation with arginine serves a health-promoting function; it enhances microcosm resilience toward acidification and suppresses outgrowth of the opportunistic pathogen Candida. Arginine facilitates stability of oral microbial communities and prevents them from becoming cariogenic.

  2. A role for PPARα in the regulation of arginine metabolism and nitric oxide synthesis.

    PubMed

    Guelzim, Najoua; Mariotti, François; Martin, Pascal G P; Lasserre, Frédéric; Pineau, Thierry; Hermier, Dominique

    2011-10-01

    The pleiotropic effects of PPARα may include the regulation of amino acid metabolism. Nitric oxide (NO) is a key player in vascular homeostasis. NO synthesis may be jeopardized by a differential channeling of arginine toward urea (via arginase) versus NO (via NO synthase, NOS). This was studied in wild-type (WT) and PPARα-null (KO) mice fed diets containing either saturated fatty acids (COCO diet) or 18:3 n-3 (LIN diet). Metabolic markers of arginine metabolism were assayed in urine and plasma. mRNA levels of arginases and NOS were determined in liver. Whole-body NO synthesis and the conversion of systemic arginine into urea were assessed by using (15)N(2)-guanido-arginine and measuring urinary (15)NO(3) and [(15)N]-urea. PPARα deficiency resulted in a markedly lower whole-body NO synthesis, whereas the conversion of systemic arginine into urea remained unaffected. PPARα deficiency also increased plasma arginine and decreased citrulline concentration in plasma. These changes could not be ascribed to a direct effect on hepatic target genes, since NOS mRNA levels were unaffected, and arginase mRNA levels decreased in KO mice. Despite the low level in the diet, the nature of the fatty acids modulated some effects of PPARα deficiency, including plasma arginine and urea, which increased more in KO mice fed the LIN diet than in those fed the COCO diet. In conclusion, PPARα is largely involved in normal whole-body NO synthesis. This warrants further study on the potential of PPARα activation to maintain NO synthesis in the initiation of the metabolic syndrome.

  3. Effect of counter ions of arginine as an additive for the solubilization of protein and aromatic compounds.

    PubMed

    Yoshizawa, Shunsuke; Arakawa, Tsutomu; Shiraki, Kentaro

    2016-10-01

    Arginine is widely used in biotechnological application, but mostly with chloride counter ion. Here, we examined the effects of various anions on solubilization of aromatic compounds and reduced lysozyme and on refolding of the lysozyme. All arginine salts tested increased the solubility of propyl gallate with acetate much more effectively than chloride. The effects of arginine salts were compared with those of sodium or guanidine salts, indicating that the ability of anions to modulate the propyl gallate solubility is independent of the cation. Comparison of transfer free energy of propyl gallate between sodium and arginine salts indicates that the interaction of propyl gallate is more favorable with arginine than sodium. On the contrary, the solubility of aromatic amino acids is only slightly modulated by anions, implying that there is specific interaction between acetic acid and propyl gallate. Unlike their effects on the solubility of small aromatic compounds, the solubility of reduced lysozyme was much higher in arginine chloride than in arginine acetate or sulfate. Consistent with high solubility, refolding of reduced lysozyme was most effective in arginine chloride. These results suggest potential broader applications of arginine modulated by different anions. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Contribution of the net charge to the regulatory effects of amino acids and epsilon-poly(L-lysine) on the gelatinization behavior of potato starch granules.

    PubMed

    Ito, Azusa; Hattori, Makoto; Yoshida, Tadashi; Takahashi, Koji

    2006-01-01

    The effects of lysine (Lys), monosodium glutamate (GluNa), glycine, alanine and epsilon-poly(L-lysine) (PL) with different degrees of polymerization on the gelatinization behavior of potato starch granules were investigated by DSC, viscosity and swelling measurements, microscopic observation, and measurement of the retained amino acid amount to clarify the contribution of the net charge to their regulatory effects on the gelatinization behavior. The amino acids and PL each contributed to an increase in the gelatinization temperature, and a decrease in the peak viscosity and swelling. These effects strongly depended on the absolute value of their net charge. The disappearance of a negative or positive net charge by adjusting the pH value weakened the contribution. The swelling index and size of the potato starch granules changed according to replacement of the swelling medium. The amino acids and PL were easily retained by the swollen potato starch granules according to replacement of the outer solution of the starch granules.

  5. Dietary supplementation with arginine and glutamic acid enhances key lipogenic gene expression in growing pigs.

    PubMed

    Hu, C J; Jiang, Q Y; Zhang, T; Yin, Y L; Li, F N; Su, J Y; Wu, G Y; Kong, X F

    2017-12-01

    Our previous study showed dietary supplementation with Arg and Glu increased intramuscular fat deposition and decreased back fat thickness in pigs, suggesting that the genes involved in lipid metabolism might be regulated differently in muscle and s.c. adipose (SA) tissues. Sixty Duroc × Large White × Landrace pigs with an average initial BW of 77.1 ± 1.3 kg were randomly assigned to 1 of 5 treatment groups (castrated male to female ratio = 1:1). Pigs in the control group were fed a basic diet, and those in experimental groups were fed the basic diet supplemented with 2.05% alanine (isonitrogenous group), 1.00% arginine (Arg group), 1.00% glutamic acid + 1.44% alanine (Glu group), or 1.00% arginine + 1.00% glutamic acid (Arg+Glu group). Fatty acid percentages and mRNA expression levels of the genes involved in lipid metabolism in muscle and SA tissues were examined. The percentages of C14:0 and C16:0 in the SA tissue of Glu group pigs and C14:0 in the longissimus dorsi (LD) muscle of Glu and Arg+Glu groups decreased ( < 0.05) compared to the basic diet group. The Arg+Glu group showed the highest ( < 0.05) hormone-sensitive lipase expression level in SA tissue and higher ( < 0.05) mRNA levels of in the LD muscle than the basic diet and isonitrogenous groups. Additionally, the mRNA level of fatty acid synthase in the Arg+Glu group was more upregulated ( < 0.05) than that of the Arg group. An increase in the mRNA level of in the biceps femoris muscle was also observed in the Arg+Glu group ( < 0.05) compared with the basic diet and isonitrogenous groups. Collectively, these findings suggest that dietary supplementation with Arg and Glu upregulates the expression of genes involved in adipogenesis in muscle tissues and lipolysis in SA tissues.

  6. The reaction of iodobenzene-p-sulphonyl chloride (pipsyl chloride) with certain amino acids and peptides, and with insulin

    PubMed Central

    Fletcher, J. C.

    1967-01-01

    1. A system of separation using buffered Celite columns is described that enables the pipsyl derivatives of most of the common amino acids to be separated. 2. The reaction of pipsyl chloride with several amino acids not included in previous studies has been investigated. In particular, knowledge of the acid-soluble pipsyl derivatives of arginine, histidine, lysine, tyrosine and cysteic acid has been extended. 3. Reproducible factors have been obtained that enable corrections to be applied for the breakdown of pipsylamino acids on acid hydrolysis. 4. The reaction of pipsyl chloride with peptides has been studied under various conditions. 5. The extent of the reaction between pipsyl chloride and insulin depends on the nature of the solvent–buffer system, and under the best conditions so far found is about 75% complete. 6. In an Appendix, the separation of pipsylamino acids by thin-layer chromatography is described. PMID:16742498

  7. Ornithine is a novel amino acid and a marker of arginine damage by oxoaldehydes in senescent proteins.

    PubMed

    Sell, David R; Monnier, Vincent M

    2005-06-01

    Long-lived proteins undergo age-related postsynthetic modifications by glycation and advanced glycation end products (AGEs), which destabilize them by altering their conformation and charge. It was accidentally discovered that ornithine (orn) increased with age in acid hydrolyzates of human skin collagen and lens crystallins which led us to investigate the source of orn. Here, we detected such modifications of orn in these proteins. Acid hydrolysis of arginine (arg)-base AGE standards produced orn at different yields. The data provide unequivocal evidence for the in vivo formation of orn and its own AGEs in aging proteins, and suggest that arg-based AGEs serve as precursors of orn.

  8. Quantification of malondialdehyde and 4-hydroxynonenal adducts to lysine residues in native and oxidized human low-density lipoprotein.

    PubMed Central

    Requena, J R; Fu, M X; Ahmed, M U; Jenkins, A J; Lyons, T J; Baynes, J W; Thorpe, S R

    1997-01-01

    Malondialdehyde (MDA) and 4-hydroxynonenal (HNE) are major end-products of oxidation of polyunsaturated fatty acids, and are frequently measured as indicators of lipid peroxidation and oxidative stress in vivo. MDA forms Schiff-base adducts with lysine residues and cross-links proteins in vitro; HNE also reacts with lysines, primarily via a Michael addition reaction. We have developed methods using NaBH4 reduction to stabilize these adducts to conditions used for acid hydrolysis of protein, and have prepared reduced forms of lysine-MDA [3-(N epsilon-lysino)propan-1-ol (LM)], the lysine-MDA-lysine iminopropene cross-link [1,3-di(N epsilon-lysino)propane (LML)] and lysine-HNE [3-(N epsilon-lysino)-4-hydroxynonan-l-ol (LHNE)]. Gas chromatography/MS assays have been developed for quantification of the reduced compounds in protein. RNase incubated with MDA or HNE was used as a model for quantification of the adducts by gas chromatography/MS. There was excellent agreement between measurement of MDA bound to RNase as LM and LML, and as thiobarbituric acid-MDA adducts measured by HPLC; these adducts accounted for 70-80% of total lysine loss during the reaction with MDA. LM and LML (0.002-0.12 mmol/ mol of lysine) were also found in freshly isolated low-density lipoprotein (LDL) from healthy subjects. LHNE was measured in RNase treated with HNE, but was not detectable in native LDL. LM, LML and LHNE increased in concert with the formation of conjugated dienes during the copper-catalysed oxidation of LDL, but accounted for modification of < 1% of lysine residues in oxidized LDL. These results are the first report of direct chemical measurement of MDA and HNE adducts to lysine residues in LDL. LM, LML and LHNE should be useful as biomarkers of lipid peroxidative modification of protein and of oxidative stress in vitro and in vivo. PMID:9078279

  9. Effects of Mutations and Ligands on the Thermostability of the l-Arginine/Agmatine Antiporter AdiC and Deduced Insights into Ligand-Binding of Human l-Type Amino Acid Transporters.

    PubMed

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Colas, Claire; Ucurum, Zöhre; Schlessinger, Avner; Fotiadis, Dimitrios

    2018-03-20

    The l-arginine/agmatine transporter AdiC is a prokaryotic member of the SLC7 family, which enables pathogenic enterobacteria to survive the extremely acidic gastric environment. Wild-type AdiC from Escherichia coli, as well as its previously reported point mutants N22A and S26A, were overexpressed homologously and purified to homogeneity. A size-exclusion chromatography-based thermostability assay was used to determine the melting temperatures ( T m s) of the purified AdiC variants in the absence and presence of the selected ligands l-arginine (Arg), agmatine, l-arginine methyl ester, and l-arginine amide. The resulting T m s indicated stabilization of AdiC variants upon ligand binding, in which T m s and ligand binding affinities correlated positively. Considering results from this and previous studies, we revisited the role of AdiC residue S26 in Arg binding and proposed interactions of the α-carboxylate group of Arg exclusively with amide groups of the AdiC backbone. In the context of substrate binding in the human SLC7 family member l-type amino acid transporter-1 (LAT1; SLC7A5), an analogous role of S66 in LAT1 to S26 in AdiC is discussed based on homology modeling and amino acid sequence analysis. Finally, we propose a binding mechanism for l-amino acid substrates to LATs from the SLC7 family.

  10. Investigation of Lysine-Functionalized Dendrimers as Dichlorvos Detoxification Agents.

    PubMed

    Durán-Lara, Esteban F; Marple, Jennifer L; Giesen, Joseph A; Fang, Yunlan; Jordan, Jacobs H; Godbey, W Terrence; Marican, Adolfo; Santos, Leonardo S; Grayson, Scott M

    2015-11-09

    Lysine-containing polymers have seen broad application due to their amines' inherent ability to bind to a range of biologically relevant molecules. The synthesis of multiple generations of polyester dendrimers bearing lysine groups on their periphery is described in this report. Their hydrolytic stabilities with respect to pH and time, their toxicity to a range of cell lines, and their possible application as nano-detoxification agents of organophosphate compounds are all investigated. These zeroth-, first-, and second-generation water-soluble dendrimers have been designed to bear exactly 4, 8, and 16 lysine groups, respectively, on their dendritic periphery. Such monodisperse bioactive polymers show potential for a range of applications including drug delivery, gene delivery, heavy metal binding, and the sequestration of organic toxins. These monodisperse bioactive dendrimers were synthesized using an aliphatic ester dendritic core (prepared from pentaerythritol) and protected amino acid moieties. This library of lysine-conjugated dendrimers showed the ability to efficiently capture the pesticide dichlorvos, confirming the potential of dendrimer-based antidotes to maintain acetylcholinesterase activity in response to poisoning events.

  11. Antioxidant Activity of Syringic Acid Prevents Oxidative Stress in l-arginine-Induced Acute Pancreatitis: An Experimental Study on Rats.

    PubMed

    Cikman, Oztekin; Soylemez, Omer; Ozkan, Omer Faruk; Kiraz, Hasan Ali; Sayar, Ilyas; Ademoglu, Serkan; Taysi, Seyithan; Karaayvaz, Muammer

    2015-05-01

    The aim of this study was to investigate the possible protective role of antioxidant treatment with syringic acid (SA) on l-arginine-induced acute pancreatitis (AP) using biochemical and histopathologic approaches. A total of 30 rats were divided into 3 groups. The control group received normal saline intraperitoneally. The AP group was induced by 3.2 g/kg body weight l-arginine intraperitoneally, administered twice with an interval of 1 hour between administrations. The AP plus SA group, after having AP induced by 3.2 g/kg body weight l-arginine, was given SA (50 mg kg(-1)) in 2 parts within 24 hours. The rats were killed, and pancreatic tissue was removed and used in biochemical and histopathologic examinations. Compared with the control group, the mean pancreatic tissue total oxidant status level, oxidative stress index, and lipid hydroperoxide levels were significantly increased in the AP group, being 30.97 ± 7.13 (P < 0.05), 1.76 ± 0.34 (P < 0.0001), and 19.18 ± 4.91 (P < 0.01), respectively. However, mean total antioxidant status and sulfhydryl group levels were significantly decreased in the AP group compared with the control group, being 1.765 ± 0.21 (P < 0.0001) and 0.21 ± 0.04 (P < 0.0001), respectively. SA reduces oxidative stress markers and has antioxidant effects. It also augments antioxidant capacity in l-arginine-induced acute toxicity of pancreas in rats.

  12. Arginine depletion increases susceptibility to serious infections in preterm newborns

    PubMed Central

    Badurdeen, Shiraz; Mulongo, Musa; Berkley, James A.

    2015-01-01

    Preterm newborns are highly susceptible to bacterial infections. This susceptibility is regarded as being due to immaturity of multiple pathways of the immune system. However, it is unclear whether a mechanism that unifies these different, suppressed pathways exists. Here, we argue that the immune vulnerability of the preterm neonate is critically related to arginine depletion. Arginine, a “conditionally essential” amino acid, is depleted in acute catabolic states, including sepsis. Its metabolism is highly compartmentalized and regulated, including by arginase-mediated hydrolysis. Recent data suggest that arginase II-mediated arginine depletion is essential for the innate immune suppression that occurs in newborn models of bacterial challenge, impairing pathways critical for the immune response. Evidence that arginine depletion mediates protection from immune activation during first gut colonization suggests a regulatory role in controlling gut-derived pathogens. Clinical studies show that plasma arginine is depleted during sepsis. In keeping with animal studies, small clinical trials of L-arginine supplementation have shown benefit in reducing necrotizing enterocolitis in premature neonates. We propose a novel, broader hypothesis that arginine depletion during bacterial challenge is a key factor limiting the neonate's ability to mount an adequate immune response, contributing to the increased susceptibility to infections, particularly with respect to gut-derived sepsis. PMID:25360828

  13. Development of high-lysine rice via endosperm-specific expression of a foreign LYSINE RICH PROTEIN gene.

    PubMed

    Liu, Xin; Zhang, Cuicui; Wang, Xiurong; Liu, Qiaoquan; Yuan, Dingyang; Pan, Gang; Sun, Samuel S M; Tu, Jumin

    2016-06-29

    Lysine (Lys) is considered to be the first limiting essential amino acid in rice. Although there have been extensive efforts to improve the Lys content of rice through traditional breeding and genetic engineering, no satisfactory products have been achieved to date. We expressed a LYSINE-RICH PROTEIN gene (LRP) from Psophocarpus tetragonolobus (L.) DC using an endosperm-specific GLUTELIN1 promoter (GT1) in Peiai64S (PA64S), an elite photoperiod-thermo sensitive male sterility (PTSMS) line. The expression of the foreign LRP protein was confirmed by Western blot analysis. The Lys level in the transgenic rice seeds increased more than 30 %, the total amount of other amino acids also increased compared to wild-type. Persistent investigation of amino acids in 3 generations showed that the Lys content was significantly increased in seeds of transgenic rice. Furthermore, Lys content in the hybrid of the transgenic plants also had an approximate 20 % increase compared to hybrid control. At the grain-filling stage, we monitored the transcript abundance of many genes encoding key enzymes involved in amino acid metabolism, and the results suggested that reduced amino acid catabolism led to the accumulation of amino acids in the transgenic plants. The genetically engineered rice showed unfavorable grain phenotypes compared to wild-type, however, its hybrid displayed little negative effects on grain. Endosperm-specific expression of foreign LRP significantly increased the Lys content in the seeds of transgenic plant, and the the Lys increase was stably heritable with 3 generation investigation. The hybrid of the transgenic plants also showed significant increases of Lys content in the seeds. These results indicated that expression of LRP in rice seeds may have promising applications in improving Lys levels in rice.

  14. Role of L-arginine in the pathogenesis and treatment of renal disease.

    PubMed

    Cherla, Gautam; Jaimes, Edgar A

    2004-10-01

    L-arginine is a semi essential amino acid and also a substrate for the synthesis of nitric oxide (NO), polyamines, and agmatine. These L-arginine metabolites may participate in the pathogenesis of renal disease and constitute the rationale for manipulating L-arginine metabolism as a strategy to ameliorate kidney disease. Modification of dietary L-arginine intake in experimental models of kidney diseases has been shown to have both beneficial as well as deleterious effects depending on the specific model studied. L-arginine supplementation in animal models of glomerulonephritis has been shown to be detrimental, probably by increasing the production of NO from increased local expression of inducible NO synthase (iNOS). L-arginine supplementation does not modify the course of renal disease in humans with chronic glomerular diseases. However, beneficial effects of L-arginine supplementation have been reported in several models of chronic kidney disease including renal ablation, ureteral obstruction, nephropathy secondary to diabetes, and salt-sensitive hypertension. L-arginine is reduced in preeclampsia and recent experimental studies indicate that L-arginine supplementation may be beneficial in attenuating the symptoms of preeclampsia. Administration of exogenous L-arginine has been shown to be protective in ischemic acute renal failure. In summary, the role of L-arginine in the pathogenesis and treatment of renal disease is not completely understood and remains to be established.

  15. Antioxidant activity of amino acids in soybean oil at frying temperature: Structural effects and synergism with tocopherols.

    PubMed

    Hwang, Hong-Sik; Winkler-Moser, Jill K

    2017-04-15

    The purpose of this study was to evaluate amino acids as natural antioxidants for frying. Twenty amino acids were added to soybean oil heated to 180°C, and the effects of amino acid structure on the antioxidant activity were investigated. Amino acids containing a thiol, a thioether, or an extra amine group such as arginine, cysteine, lysine, methionine, and tryptophan had the strongest antioxidant activities. At 5.5mM, these amino acids had stronger antioxidant activities than 0.02% (1.1mM) tert-butylhydroquinone (TBHQ). A functional group such as an amide, carboxylic acid, imidazole, or phenol appeared to negatively affect amino acid antioxidant activity. Synergism between amino acids and tocopherols was demonstrated, and we found that this synergistic interaction may be mostly responsible for the antioxidant activity that was observed. In a frying study with potato cubes, 5.5mM l-methionine had significantly stronger antioxidant activity than 0.02% TBHQ. Published by Elsevier Ltd.

  16. Synthesis of Lysine Methyltransferase Inhibitors

    NASA Astrophysics Data System (ADS)

    Ye, Tao; Hui, Chunngai

    2015-07-01

    Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  17. Safety of long-term dietary supplementation with L-arginine in pigs.

    PubMed

    Hu, Shengdi; Li, Xilong; Rezaei, Reza; Meininger, Cynthia J; McNeal, Catherine J; Wu, Guoyao

    2015-05-01

    This study was conducted with a swine model to determine the safety of long-term dietary supplementation with L-arginine-HCl or L-arginine free base. Beginning at 30 days of age, pigs were fed a corn- and soybean meal-based diet (31.5 g/kg body weight/day) supplemented with 0, 1.21, 1.81 or 2.42 % L-arginine-HCl (Experiment 1) or with 0, 1, 1.5 or 2 % L-arginine (Experiment 2). The supplemental doses of 0, 1, 1.5, and 2 % L-arginine provided pigs with 0, 315, 473, and 630 mg L-arginine/kg body weight/day, respectively, which were equivalent to 0, 286, 430, and 573 mg L-arginine/kg body weight/day, respectively, in humans. At 121 days of age (91 days after initiation of supplementation), blood samples were obtained from the jugular vein of pigs at 1 and 4 h after feeding for hematological and clinical chemistry tests. Dietary supplementation with L-arginine increased plasma concentrations of arginine, ornithine, proline, albumin and reticulocytes, while reducing plasma concentrations of ammonia, free fatty acids, triglyceride, cholesterol, and neutrophils. L-Arginine supplementation enhanced protein gain and reduced white-fat deposition in the body. Other variables in standard hematology and clinical chemistry tests, serum concentrations of insulin, growth hormone and insulin-like growth factor-I did not differ among all the groups of pigs. These results indicate that dietary supplementation with L-arginine (up to 630 mg/kg body weight/day) is safe in pigs for at least 91 days. Our findings help guide clinical studies to determine the safety of long-term oral administration of L-arginine to humans.

  18. The phosphatidic acid-binding, polybasic domain is responsible for the differences in the phosphoregulation of lipins 1 and 3.

    PubMed

    Boroda, Salome; Takkellapati, Sankeerth; Lawrence, Robert T; Entwisle, Samuel W; Pearson, Jennifer M; Granade, Mitchell E; Mullins, Garrett R; Eaton, James M; Villén, Judit; Harris, Thurl E

    2017-12-15

    Lipins 1, 2, and 3 are Mg 2+ -dependent phosphatidic acid phosphatases and catalyze the penultimate step of triacylglycerol synthesis. We have previously investigated the biochemistry of lipins 1 and 2 and shown that di-anionic phosphatidic acid (PA) augments their activity and lipid binding and that lipin 1 activity is negatively regulated by phosphorylation. In the present study, we show that phosphorylation does not affect the catalytic activity of lipin 3 or its ability to associate with PA in vitro The lipin proteins each contain a conserved polybasic domain (PBD) composed of nine lysine and arginine residues located between the conserved N- and C-terminal domains. In lipin 1, the PBD is the site of PA binding and sensing of the PA electrostatic charge. The specific arrangement and number of the lysines and arginines of the PBD vary among the lipins. We show that the different PBDs of lipins 1 and 3 are responsible for the presence of phosphoregulation on the former but not the latter enzyme. To do so, we generated lipin 1 that contained the PBD of lipin 3 and vice versa. The lipin 1 enzyme with the lipin 3 PBD lost its ability to be regulated by phosphorylation but remained downstream of phosphorylation by mammalian target of rapamycin. Conversely, the presence of the lipin 1 PBD in lipin 3 subjected the enzyme to negative intramolecular control by phosphorylation. These results indicate a mechanism for the observed differences in lipin phosphoregulation in vitro . © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Raman spectra of amino acids and their aqueous solutions

    NASA Astrophysics Data System (ADS)

    Zhu, Guangyong; Zhu, Xian; Fan, Qi; Wan, Xueliang

    2011-03-01

    Amino acids are the basic "building blocks" that combine to form proteins and play an important physiological role in all life-forms. Amino acids can be used as models for the examination of the importance of intermolecular bonding in life processes. Raman spectra serve to obtain information regarding molecular conformation, giving valuable insights into the topology of more complex molecules (peptides and proteins). In this paper, amino acids and their aqueous solution have been studied by Raman spectroscopy. Comparisons of certain values for these frequencies in amino acids and their aqueous solutions are given. Spectra of solids when compared to those of the solute in solution are invariably much more complex and almost always sharper. We present a collection of Raman spectra of 18 kinds of amino acids ( L-alanine, L-arginine, L-aspartic acid, cystine, L-glutamic acid, L-glycine, L-histidine, L-isoluecine, L-leucine, L-lysine, L-phenylalanine, L-methionone, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, L-valine) and their aqueous solutions that can serve as references for the interpretation of Raman spectra of proteins and biological materials.

  20. Dietary supplementation with arginine and glutamic acid modifies growth performance, carcass traits, and meat quality in growing-finishing pigs.

    PubMed

    Hu, C J; Jiang, Q Y; Zhang, T; Yin, Y L; Li, F N; Deng, J P; Wu, G Y; Kong, X F

    2017-06-01

    Sixty Duroc × Large White × Landrace pigs with an average initial BW of 77.1 ± 1.3 kg were used to investigate the effects of dietary supplementation with arginine and glutamic acid on growth performance, carcass traits, and meat quality in growing-finishing pigs. The animals were randomly assigned to 1 of 5 treatment groups (12 pigs/group, male:female ratio 1:1). The pigs in the control group were fed a basal diet (basal diet group), and those in the experimental groups were fed the basal diet supplemented with 2.05% -alanine (isonitrogenous group), 1.0% -arginine (Arg group), 1% glutamic acid + 1.44% -alanine (Glu group), or 1.0% -arginine + 1.0% glutamic acid (Arg+Glu group). After a 60-d period of supplementation, growth performance, carcass traits, and meat quality were evaluated. The results showed no significant differences ( > 0.05) in growth performance and carcass traits of the pigs in the Arg group relative to the basal diet group; however, the longissimus dorsi (LD) muscle and back fat showed a decrease ( < 0.05) in the percentage of SFA. In the Glu group, the final BW, phase 1 (d 1 to 30) and phase 2 (d 31 to 60) ADFI, and average back fat thickness of the pigs decreased ( < 0.05) by 7.14%, 23.43%, 8.03%, and 33.88%, respectively, when compared with the basal diet group. Dietary Arg+Glu supplementation had no effect ( > 0.05) on the final BW, phase 2 ADFI, and average daily weight gain in pigs but decreased ( < 0.05) their phase 1 ADFI, average back fat thickness, and percentage of SFA in the LD muscle and back fat, and increased ( < 0.05) the i.m. fat (IMF) content of the LD and biceps femoris muscles when compared with the basal diet group. Furthermore, a 16% decrease in yellowness (b* value; < 0.05) was observed in the Arg+Glu group pigs when compared with the isonitrogenous group. These findings suggest that dietary supplementation with both Arg and Glu beneficially increases the IMF deposition and improves the meat color and fatty acid

  1. Streptococcus pyogenes Arginine and Citrulline Catabolism Promotes Infection and Modulates Innate Immunity

    PubMed Central

    Cusumano, Zachary T.; Watson, Michael E.

    2014-01-01

    A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (ΔArcA) or citrulline (ΔArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ΔArcA mutant was attenuated but the ΔArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS−/−) were infected with the ΔArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient. PMID:24144727

  2. Elevated levels of branched-chain amino acids have little effect on pancreatic islet cells, but L-arginine impairs function through activation of the endoplasmic reticulum stress response.

    PubMed

    Mullooly, Niamh; Vernon, Wendy; Smith, David M; Newsholme, Philip

    2014-03-01

    Recent metabolic profiling studies have identified a correlation between branched-chain amino acid levels, insulin resistance associated with prediabetes and susceptibility to type 2 diabetes. Glucose and lipids in chronic excess have been reported to induce toxic effects in pancreatic β-cells, but the effect of elevated amino acid concentrations on primary islet cell function has not been investigated to date. The aim of this study was to investigate the effect of chronic exposure to various amino acids on islet cell function in vitro. Isolated rat islets were incubated over periods of 48 h with a range of concentrations of individual amino acids (0.1 μm to 10 mm). After 48 h, islets were assessed for glucose-dependent insulin secretion capacity, proliferation or islet cell apoptosis. We report that elevated levels of branched-chain amino acids have little effect on pancreatic islet cell function or viability; however, increased levels of the amino acid l-arginine were found to be β-cell toxic, causing a dose-dependent decrease in insulin secretion accompanied by a decrease in islet cell proliferation and an increase in islet cell apoptosis. These effects were not due to l-arginine-dependent increases in production of nitric oxide but arose through elicitation of the islet cell endoplasmic reticulum stress response. This novel finding indicates, for the first time, that the l-arginine concentration in vitro may impact negatively on islet cell function, thus indicating further complexity in relationship to in vivo susceptibility of β-cells to nutrient-induced dysfunction.

  3. Standardized ileal digestibility of proteins and amino acids in sesame expeller and soya bean meal in weaning piglets.

    PubMed

    Aguilera, A; Reis de Souza, T C; Mariscal-Landín, G; Escobar, K; Montaño, S; Bernal, M G

    2015-08-01

    Apparent ileal digestibility (AID) of diets containing sesame expeller (SE) and soya bean meal (SBM) was determined using 15 piglets (Genetiporc(®)), weaned at 17 ± 0.4 days with average body weight of 6.4 ± 0.7 kg (Fertilis 20 × G Performance, Genetiporc(®), PIC México, Querétaro, México). Piglets were randomly assigned to three treatments: (i) a reference diet with casein as the sole protein source; (ii) a mixed diet of casein-SE; and (iii) a mixed diet of casein-SBM. The chemical composition of SE and SBM was determined, and AID and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AAs) were determined for each protein source. SE contained greater quantities of ether extract, neutral detergent fibre, phytic acid, methionine and arginine than SBM. Lysine and proline contents and trypsin inhibitor activity were higher in SBM than in SE. The AID and SID of CP and AA (except for lysine and proline) were similar in SE and SBM. The AID of lysine and proline was higher in SBM than in SE (p < 0.05), and the SID of proline was higher in SE than in SBM (p < 0.05). These findings indicate that SE is an appropriate alternative protein source for early weaned pigs. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  4. Arginine kinase in Phytomonas, a trypanosomatid parasite of plants.

    PubMed

    Canepa, Gaspar E; Carrillo, Carolina; Miranda, Mariana R; Sayé, Melisa; Pereira, Claudio A

    2011-09-01

    Phytomonas are trypanosomatid plant parasites closely related to parasites that cause several human diseases. Little is known about the biology of these organisms including aspects of their metabolism. Arginine kinase (E.C. 2.7.3.3) is a phosphotransferase which catalyzes the interconversion between the phosphagen phosphoarginine and ATP. This enzyme is present in some invertebrates and is a homolog of another widely distributed phosphosphagen kinase, creatine kinase. In this work, a single canonical arginine kinase isoform was detected in Phytomonas Jma by enzymatic activity assays, PCR, and Western Blot. This arginine kinase is very similar to the canonical isoforms found in T. cruzi and T. brucei, presenting about 70% of amino acid sequence identity and a very similar molecular weight (40kDa). The Phytomonas phosphagen system seems to be very similar to T. cruzi, which has only one isoform, or T. brucei (three isoforms); establishing a difference with other trypanosomatids, such as Leishmania, which completely lacks phosphagen kinases, probably by the presence of the arginine-consuming enzyme, arginase. Finally, phylogenetic analysis suggests that Kinetoplastids' arginine kinase was acquired, during evolution, from the arthropod vectors by horizontal gene transfer. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Differential Contributions of Ubiquitin-Modified APOBEC3G Lysine Residues to HIV-1 Vif-Induced Degradation.

    PubMed

    Turner, Tiffany; Shao, Qiujia; Wang, Weiran; Wang, Yudi; Wang, Chenliang; Kinlock, Ballington; Liu, Bindong

    2016-08-28

    Apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (A3G) is a host restriction factor that impedes HIV-1 replication. Viral integrity is salvaged by HIV-1 virion infectivity factor (Vif), which mediates A3G polyubiquitination and subsequent cellular depletion. Previous studies have implied that A3G polyubiquitination is essential for Vif-induced degradation. However, the contribution of polyubiquitination to the rate of A3G degradation remains unclear. Here, we show that A3G polyubiquitination is essential for degradation. Inhibition of ubiquitin-activating enzyme E1 by PYR-41 or blocking the formation of ubiquitin chains by over-expressing the lysine to arginine mutation of ubiquitin K48 (K48R) inhibited A3G degradation. Our A3G mutagenesis study showed that lysine residues 297, 301, 303, and 334 were not sufficient to render lysine-free A3G sensitive to Vif-mediated degradation. Our data also confirm that Vif could induce ubiquitin chain formation on lysine residues interspersed throughout A3G. Notably, A3G degradation relied on the lysine residues involved in polyubiquitination. Although A3G and the A3G C-terminal mutant interacted with Vif and were modified by ubiquitin chains, the latter remained more resistant to Vif-induced degradation. Furthermore, the A3G C-terminal mutant, but not the N-terminal mutant, maintained potent antiviral activity in the presence of Vif. Taken together, our results suggest that the location of A3G ubiquitin modification is a determinant for Vif-mediated degradation, implying that in addition to polyubiquitination, other factors may play a key role in the rate of A3G degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Influence of aspartic acid and lysine on the uptake of gold nanoparticles in rice.

    PubMed

    Ye, Xinxin; Li, Hongying; Wang, Qingyun; Chai, Rushan; Ma, Chao; Gao, Hongjian; Mao, Jingdong

    2018-02-01

    The interactions between plants and nanomaterials (NMs) can shed light on the environmental consequences of nanotechnology. We used the major crop plant rice (Oryza sativa L.) to investigate the uptake of gold nanoparticles (GNPs) coated with either negatively or positively charged ligands, over a 5-day period, in the absence or presence of one of two amino acids, aspartic acid (Asp) or lysine (Lys), acting as components of rice root exudates. The presence of Asp or Lys influenced the uptake and distribution of GNPs in rice, which depended on the electrical interaction between the coated GNPs and each amino acid. When the electrical charge of the amino acid was the same as that of the surface ligand coated onto the GNPs, the GNPs could disperse well in nutrient solution, resulting in increased uptake of GNPs into rice tissue. The opposite was true where the charge on the surface ligand was different from that on the amino acid, resulting in agglomeration and reduced Au uptake into rice tissue. The behavior of GNPs in the hydroponic nutrient solution was monitored in terms of agglomeration, particle size distribution, and surface charge in the presence and absence of Asp or Lys, which depended strongly on the electrostatic interaction. Results from this study indicated that the species of root exudates must be taken into account in assessing the bioavailability of nanomaterials to plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Evolution of Substrate Specificity within a Diverse Family of [beta/alpha]-Barrel-fold Basic Amino Acid Decarboxylases X-ray Structure Determination of Enzymes with Specificity for L-Arginine and Carboxynorspermidine

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Deng, Xiaoyi; Lee, Jeongmi; Michael, Anthony J.

    2010-08-26

    Pyridoxal 5{prime}-phosphate (PLP)-dependent basic amino acid decarboxylases from the {beta}/{alpha}-barrel-fold class (group IV) exist in most organisms and catalyze the decarboxylation of diverse substrates, essential for polyamine and lysine biosynthesis. Herein we describe the first x-ray structure determination of bacterial biosynthetic arginine decarboxylase (ADC) and carboxynorspermidine decarboxylase (CANSDC) to 2.3- and 2.0-{angstrom} resolution, solved as product complexes with agmatine and norspermidine. Despite low overall sequence identity, the monomeric and dimeric structures are similar to other enzymes in the family, with the active sites formed between the {beta}/{alpha}-barrel domain of one subunit and the {beta}-barrel of the other. ADC contains bothmore » a unique interdomain insertion (4-helical bundle) and a C-terminal extension (3-helical bundle) and it packs as a tetramer in the asymmetric unit with the insertions forming part of the dimer and tetramer interfaces. Analytical ultracentrifugation studies confirmed that the ADC solution structure is a tetramer. Specificity for different basic amino acids appears to arise primarily from changes in the position of, and amino acid replacements in, a helix in the {beta}-barrel domain we refer to as the 'specificity helix.' Additionally, in CANSDC a key acidic residue that interacts with the distal amino group of other substrates is replaced by Leu{sup 314}, which interacts with the aliphatic portion of norspermidine. Neither product, agmatine in ADC nor norspermidine in CANSDC, form a Schiff base to pyridoxal 5{prime}-phosphate, suggesting that the product complexes may promote product release by slowing the back reaction. These studies provide insight into the structural basis for the evolution of novel function within a common structural-fold.« less

  8. Study of an Unusual Advanced Glycation End-Product (AGE) Derived from Glyoxal Using Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Lopez-Clavijo, Andrea F.; Duque-Daza, Carlos A.; Romero Canelon, Isolda; Barrow, Mark P.; Kilgour, David; Rabbani, Naila; Thornalley, Paul J.; O'Connor, Peter B.

    2014-04-01

    Glycation is a post-translational modification (PTM) that affects the physiological properties of peptides and proteins. In particular, during hyperglycaemia, glycation by α-dicarbonyl compounds generate α-dicarbonyl-derived glycation products also called α-dicarbonyl-derived advanced glycation end products. Glycation by the α-dicarbonyl compound known as glyoxal was studied in model peptides by MS/MS using a Fourier transform ion cyclotron resonance mass spectrometer. An unusual type of glyoxal-derived AGE with a mass addition of 21.98436 Da is reported in peptides containing combinations of two arginine-two lysine, and one arginine-three lysine amino acid residues. Electron capture dissociation and collisionally activated dissociation results supported that the unusual glyoxal-derived AGE is formed at the guanidino group of arginine, and a possible structure is proposed to illustrate the 21.9843 Da mass addition.

  9. Maternal Dietary L-Arginine and Adverse Birth Outcomes in Dar es Salaam, Tanzania.

    PubMed

    Darling, Anne Marie; McDonald, Chloe R; Urassa, Willy S; Kain, Kevin C; Mwiru, Ramadhani S; Fawzi, Wafaie W

    2017-09-01

    The amino acid arginine is a physiological precursor to nitric oxide, which is a key mediator of embryonic survival, fetal growth, and pregnancy maintenance. We evaluated the association between consumption of the amino acid arginine and the rate of adverse birth outcomes using data from a double-blind, randomized, placebo-controlled micronutrient supplementation trial among pregnant women in Dar es Salaam, Tanzania (2001-2004). Dietary intakes of arginine were assessed using repeated 24-hour recalls that were administered throughout pregnancy. Participants (n = 7,591) were monitored by research midwives throughout follow-up to assess pregnancy outcomes. Cubic-restricted splines and multivariable log-Poisson regression with empirical standard errors were used to estimate the continuous and categorical associations between arginine intake and adverse birth outcomes. Compared with women within the lowest quintile of arginine intake, those within the highest quintile had 0.79 times the risk of preterm birth before 37 weeks (95% confidence interval: 0.63, 1.00; P = 0.03). The continuous associations of arginine intake with preterm birth before 37 weeks and with preterm birth before 34 weeks were characterized by an initial rapid decrease in risk with increasing intake (P for nonlinearity < 0.01). Arginine intake was not associated with fetal loss or giving birth to infants who were born small for their gestational ages. This data suggest that the association between dietary arginine intake and preterm birth warrants further investigation. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Influence of betaine and arginine supplementation of reduced protein diets on fatty acid composition and gene expression in the muscle and subcutaneous adipose tissue of cross-bred pigs.

    PubMed

    Madeira, Marta S; Rolo, Eva S; Alfaia, Cristina M; Pires, Virgínia R; Luxton, Richard; Doran, Olena; Bessa, Rui J B; Prates, José A M

    2016-03-28

    The isolated or combined effects of betaine and arginine supplementation of reduced protein diets (RPD) on fat content, fatty acid composition and mRNA levels of genes controlling lipid metabolism in pig m. longissimus lumborum and subcutaneous adipose tissue (SAT) were assessed. The experiment was performed on forty intact male pigs (Duroc×Large White×Landrace cross-breed) with initial and final live weights of 60 and 93 kg, respectively. Pigs were randomly assigned to one of the following five diets (n 8): 16·0 % of crude protein (control), 13·0 % of crude protein (RPD), RPD supplemented with 0·33 % of betaine, RPD supplemented with 1·5 % of arginine and RPD supplemented with 0·33 % of betaine and 1·5 % of arginine. Data confirmed that RPD increase intramuscular fat (IMF) content and total fat content in SAT. The increased total fat content in SAT was accompanied by higher GLUT type 4, lipoprotein lipase and stearoyl-CoA desaturase mRNA expression levels. In addition, the supplementation of RPD with betaine and/or arginine did not affect either IMF or total fat in SAT. However, dietary betaine supplementation slightly affected fatty acid composition in both muscle and SAT. This effect was associated with an increase of carnitine O-acetyltransferase mRNA levels in SAT but not in muscle, which suggests that betaine might be involved in the differential regulation of some key genes of lipid metabolism in pig muscle and SAT. Although the arginine-supplemented diet decreased the mRNA expression level of PPARG in muscle and SAT, it did not influence fat content or fatty acid composition in any of these pig tissues.

  11. Amino acid metabolism during exercise in trained rats: the potential role of carnitine in the metabolic fate of branched-chain amino acids.

    PubMed

    Ji, L L; Miller, R H; Nagle, F J; Lardy, H A; Stratman, F W

    1987-08-01

    The influence of endurance training and an acute bout of exercise on plasma concentrations of free amino acids and the intermediates of branched-chain amino acid (BCAA) metabolism were investigated in the rat. Training did not affect the plasma amino acid levels in the resting state. Plasma concentrations of alanine (Ala), aspartic acid (Asp), asparagine (Asn), arginine (Arg), histidine (His), isoleucine (Ile), leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), and valine (Val) were significantly lower, whereas glutamate (Glu), glycine (Gly), ornithine (Orn), tryptophan (Trp), tyrosine (Tyr), creatinine, urea, and ammonia levels were unchanged, after one hour of treadmill running in the trained rats. Plasma concentration of glutamine (Glu), the branched-chain keto acids (BCKA) and short-chain acyl carnitines were elevated with exercise. Ratios of plasma BCAA/BCKA were dramatically lowered by exercise in the trained rats. A decrease in plasma-free carnitine levels was also observed. These data suggest that amino acid metabolism is enhanced by exercise even in the trained state. BCAA may only be partially metabolized within muscle and some of their carbon skeletons are released into the circulation in forms of BCKA and short-chain acyl carnitines.

  12. Sided functions of an arginine-agmatine antiporter oriented in liposomes.

    PubMed

    Tsai, Ming-Feng; Fang, Yiling; Miller, Christopher

    2012-02-28

    The arginine-dependent extreme acid resistance system helps enteric bacteria survive the harsh gastric environment. At the center of this multiprotein system is an arginine-agmatine antiporter, AdiC. To maintain cytoplasmic pH, AdiC imports arginine and exports its decarboxylated product, agmatine, resulting in a net extrusion of one "virtual proton" in each turnover. The random orientation of AdiC in reconstituted liposomes throws up an obstacle to quantifying its transport mechanism. To overcome this problem, we introduced a mutation, S26C, near the substrate-binding site. This mutant exhibits substrate recognition and pH-dependent activity similar to those of the wild-type protein but loses function completely upon reaction with thiol reagents. The membrane-impermeant MTSES reagent can then be used as a cleanly sided inhibitor to silence those S26C-AdiC proteins whose extracellular portion projects from the external side of the liposome. Alternatively, the membrane-permeant MTSEA and membrane-impermeant reducing reagent, TCEP, can be used together to inhibit proteins in the opposite orientation. This approach allows steady-state kinetic analysis of AdiC in a sided fashion. Arginine and agmatine have similar Michaelis-Menten parameters for both sides of the protein, while the extracellular side selects arginine over argininamide, a mimic of the carboxylate-protonated form of arginine, more effectively than does the cytoplasmic side. Moreover, the two sides of AdiC have different pH sensitivities. AdiC activity increases to a plateau at pH 4 as the extracellular side is acidified, while the cytoplasmic side shows an optimal pH of 5.5, with further acidification inhibiting transport. This oriented system allows more precise analysis of AdiC-mediated substrate transport than has been previously available and permits comparison to the situation experienced by the bacterial membrane under acid stress.

  13. Hyperexcretion of homocitrulline in a Malaysian patient with lysinuric protein intolerance.

    PubMed

    Habib, Anasufiza; Md Yunus, Zabedah; Azize, Nor Azimah; Ch'ng, Gaik-Siew; Ong, Winnie Peitee; Chen, Bee-Chin; Hsu, Ho-Torng; Wong, Ke-Juin; Pitt, James; Ngu, Lock-Hock

    2013-09-01

    Lysinuric protein intolerance (LPI; MIM 222700) is an inherited aminoaciduria with an autosomal recessive mode of inheritance. Biochemically, affected patients present with increased excretion of the cationic amino acids: lysine, arginine, and ornithine. We report the first case of LPI diagnosed in Malaysia presented with excessive excretion of homocitrulline. The patient was a 4-year-old male who presented with delayed milestones, recurrent diarrhea, and severe failure to thrive. He developed hyperammonemic coma following a forced protein-rich diet. Plasma amino acid analysis showed increased glutamine, alanine, and citrulline but decreased lysine, arginine and ornithine. Urine amino acids showed a marked excretion of lysine and ornithine together with a large peak of unknown metabolite which was subsequently identified as homocitrulline by tandem mass spectrometry. Molecular analysis confirmed a previously unreported homozygous mutation at exon 1 (235 G > A, p.Gly79Arg) in the SLC7A7 gene. This report demonstrates a novel mutation in the SLC7A7 gene in this rare inborn error of diamino acid metabolism. It also highlights the importance of early and efficient treatment of infections and dehydration in these patients. The diagnosis of LPI is usually not suspected by clinical findings alone, and specific laboratory investigations and molecular analysis are important to get a definitive diagnosis.

  14. Quantification of nitrogen in the liquid fraction and in vitro assessment of lysine bioavailability in the solid fraction of soybean meal hydrolysates.

    PubMed

    Luján-Rhenals, D; Morawicki, R; Shi, Z; Ricke, S C

    2018-01-02

    Soybean meal (SBM) is a product generated from the manufacture of soybean oil and has the potential for use as a source of fermentable sugars for ethanol production or as a protein source for animal feeds. Knowing the levels of nitrogen available from ammonium is a necessary element of the ethanolic fermentation process while identifying the levels of essential amino acids such as lysine is important in determining usage as a feed source. As such the purpose of this study was to quantify total nitrogen and ammonium in the liquid fraction of hydrolyzed SBM and to evaluate total and bioavailable lysine in the solid fraction of the hydrolyzed SBM. The effects of acid concentration, cellulase and β-glucosidase on total and ammonium nitrogen were studied with analysis indicating that higher acid concentrations increased nitrogen compounds with ammonium concentrations ranging from 0.20 to 1.24 g L -1 while enzymatic treatments did not significantly increase nitrogen levels. Total and bioavailable lysine was quantified by use of an auxotrophic gfpmut3 E.coli whole-cell bioassay organism incapable of lysine biosynthesis. Acid and enzymatic treatments were applied with lysine bioavailability increasing from a base of 82% for untreated SBM to up to 97%. Our results demonstrated that SBM has the potential to serve in ethanolic fermentation and as an optimal source essential amino acid lysine.

  15. Arginine Improves pH Homeostasis via Metabolism and Microbiome Modulation.

    PubMed

    Agnello, M; Cen, L; Tran, N C; Shi, W; McLean, J S; He, X

    2017-07-01

    Dental caries can be described as a dysbiosis of the oral microbial community, in which acidogenic, aciduric, and acid-adapted bacterial species promote a pathogenic environment, leading to demineralization. Alkali generation by oral microbes, specifically via arginine catabolic pathways, is an essential factor in maintaining plaque pH homeostasis. There is evidence that the use of arginine in dentifrices helps protect against caries. The aim of the current study was to investigate the mechanistic and ecological effect of arginine treatment on the oral microbiome and its regulation of pH dynamics, using an in vitro multispecies oral biofilm model that was previously shown to be highly reflective of the in vivo oral microbiome. Pooled saliva from 6 healthy subjects was used to generate overnight biofilms, reflecting early stages of biofilm maturation. First, we investigated the uptake of arginine by the cells of the biofilm as well as the metabolites generated. We next explored the effect of arginine on pH dynamics by pretreating biofilms with 75 mM arginine, followed by the addition of sucrose (15 mM) after 0, 6, 20, or 48 h. pH was measured at each time point and biofilms were collected for 16S sequencing and targeted arginine quantification, and supernatants were prepared for metabolomic analysis. Treatment with only sucrose led to a sustained pH drop from 7 to 4.5, while biofilms treated with sucrose after 6, 20, or 48 h of preincubation with arginine exhibited a recovery to higher pH. Arginine was detected within the cells of the biofilms, indicating active uptake, and arginine catabolites citrulline, ornithine, and putrescine were detected in supernatants, indicating active metabolism. Sequencing analysis revealed a shift in the microbial community structure in arginine-treated biofilms as well as increased species diversity. Overall, we show that arginine improved pH homeostasis through a remodeling of the oral microbial community.

  16. Fatty Acid Comprising Lysine Conjugates: Anti-MRSA Agents That Display In Vivo Efficacy by Disrupting Biofilms with No Resistance Development.

    PubMed

    Konai, Mohini M; Haldar, Jayanta

    2017-04-19

    Methicillin-resistant Staphylococcus aureus (MRSA) has developed resistance to antibiotics of last resort such as vancomycin, linezolid, and daptomycin. Additionally, their biofilm forming capability has set an alarming situation in the treatment of bacterial infections. Herein we report the potency of fatty acid comprising lysine conjugates as novel anti-MRSA agents, which were not only capable of killing growing planktonic MRSA at low concentration (MIC = 3.1-6.3 μg/mL), but also displayed potent activity against nondividing stationary phase cells. Furthermore, the conjugates eradicated established biofilms of MRSA. The bactericidal activity of d-lysine conjugated tetradecanoyl analogue (D-LANA-14) is attributed to its membrane disruption against these metabolically distinct cells. In a mouse model of superficial skin infection, D-LANA-14 displayed potent in vivo anti-MRSA activity (2.7 and 3.9 Log reduction at 20 mg/kg and 40 mg/kg, respectively) without showing any skin toxicity even at 200 mg/kg of the compound exposure. Additionally, MRSA could not develop resistance against D-LANA-14 even after 18 subsequent passages, whereas the topical anti-MRSA antibiotic fusidic acid succumbed to rapid resistance development. Collectively, the results suggested that this new class of membrane targeting conjugates bear immense potential to treat MRSA infections over conventional antibiotic therapy.

  17. Influence of arginine-glycine-aspartic acid (RGD), integrins (alphaV and alpha5) and osteopontin on bovine sperm-egg binding, and fertilization in vitro.

    PubMed

    Gonçalves, R F; Wolinetz, C D; Killian, G J

    2007-02-01

    Osteopontin (OPN), a phosphoprotein containing an arginine-glycine-aspartic acid (RGD) sequence, has been identified in cow oviduct epithelium and fluid. To investigate the potential role OPN in fertilization, we evaluated the ability of RGD peptide (arginine-glycine-aspartic), RGE peptide (arginine-glycine-glutamic acid), integrins alphaV and alpha5 antibodies and OPN antibody to influence bovine in vitro sperm-egg binding and fertilization. Treatment of sperm or oocytes with the RGD peptide prior fertilization significantly decreased in vitro sperm-egg binding and fertilization compared to the non-treated controls or those treated with RGE peptide. Binding and fertilization were also significantly decreased when in vitro matured bovine oocytes or sperm were pre-incubated with integrins alphaV and alpha5 antibodies at concentration ranging from 5 to 20 microg/mL. Addition of a rabbit polyclonal IgG antibody against purified bovine milk OPN with sperm or/and oocytes decreased (P<0.05) fertilization compared to the in vitro-fertilized control. These data provided evidence that integrin ligands existed on bovine oocytes and spermatozoa that contained RGD recognition sequences, and that antibody to OPN, a protein that contains that RGD sequence, was capable of reducing sperm-egg binding and fertilization in vitro.

  18. Feed intake and brain neuropeptide Y (NPY) and cholecystokinin (CCK) gene expression in juvenile cobia fed plant-based protein diets with different lysine to arginine ratios.

    PubMed

    Nguyen, Minh Van; Jordal, Ann-Elise Olderbakk; Espe, Marit; Buttle, Louise; Lai, Hung Van; Rønnestad, Ivar

    2013-07-01

    Cobia (Rachycentron canadum, Actinopterygii, Perciformes;10.5±0.1g) were fed to satiation with three plant-based protein test diets with different lysine (L) to arginine (A) ratios (LL/A, 0.8; BL/A, 1.1; and HL/A, 1.8), using a commercial diet as control for six weeks. The test diets contained 730 g kg(-1) plant ingredients with 505-529 g protein, 90.2-93.9 g lipid kg(-1) dry matter; control diet contained 550 g protein and 95 g lipid kg(-1) dry matter. Periprandial expression of brain NPY and CCK (npy and cck) was measured twice (weeks 1 and 6). At week one, npy levels were higher in pre-feeding than postfeeding cobia for all diets, except LL/A. At week six, npy levels in pre-feeding were higher than in postfeeding cobia for all diets. cck in pre-feeding cobia did not differ from that in postfeeding for all diets, at either time point. Cobia fed LL/A had lower feed intake (FI) than cobia fed BL/A and control diet, but no clear correlations between dietary L/A ratio and FI, growth and expression of npy and cck were detected. The data suggest that NPY serves as an orexigenic factor, but further studies are necessary to describe links between dietary L/A and regulation of appetite and FI in cobia. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. The development and amino acid binding ability of nano-materials based on azo derivatives: theory and experiment.

    PubMed

    Shang, Xuefang; Du, Jinge; Yang, Wancai; Liu, Yun; Fu, Zhiyuan; Wei, Xiaofang; Yan, Ruifang; Yao, Ningcong; Guo, Yaping; Zhang, Jinlian; Xu, Xiufang

    2014-05-01

    Two nano-material-containing azo groups have been designed and developed, and the binding ability of nano-materials with various amino acids has been characterized by UV-vis and fluorescence titrations. Results indicated that two nano-materials showed the strongest binding ability for homocysteine among twenty normal kinds of amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, threonine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, tyrosine and homocysteine). The reason for the high sensitivity for homocysteine was that two nano-materials containing an aldehyde group reacted with SH in homocysteine and afforded very stable thiazolidine derivatives. Theoretical investigation further illustrated the possible binding mode in host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. Thus, the two nano-materials can be used as optical sensors for the detection of homocysteine. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Arginine Metabolism in Bacterial Pathogenesis and Cancer Therapy

    PubMed Central

    Xiong, Lifeng; Teng, Jade L. L.; Botelho, Michael G.; Lo, Regina C.; Lau, Susanna K. P.; Woo, Patrick C. Y.

    2016-01-01

    Antibacterial resistance to infectious diseases is a significant global concern for health care organizations; along with aging populations and increasing cancer rates, it represents a great burden for government healthcare systems. Therefore, the development of therapies against bacterial infection and cancer is an important strategy for healthcare research. Pathogenic bacteria and cancer have developed a broad range of sophisticated strategies to survive or propagate inside a host and cause infection or spread disease. Bacteria can employ their own metabolism pathways to obtain nutrients from the host cells in order to survive. Similarly, cancer cells can dysregulate normal human cell metabolic pathways so that they can grow and spread. One common feature of the adaption and disruption of metabolic pathways observed in bacterial and cancer cell growth is amino acid pathways; these have recently been targeted as a novel approach to manage bacterial infections and cancer therapy. In particular, arginine metabolism has been illustrated to be important not only for bacterial pathogenesis but also for cancer therapy. Therefore, greater insights into arginine metabolism of pathogenic bacteria and cancer cells would provide possible targets for controlling of bacterial infection and cancer treatment. This review will summarize the recent progress on the relationship of arginine metabolism with bacterial pathogenesis and cancer therapy, with a particular focus on arginase and arginine deiminase pathways of arginine catabolism. PMID:26978353

  1. Atomic-Resolution Structure of an N(5) Flavin Adduct in D-Arginine Dehydrogenase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fu, Guoxing; Yuan, Hongling; Wang, Siming

    2011-09-06

    D-Arginine dehydrogenase (DADH) catalyzes the flavin-dependent oxidative deamination of D-arginine and other D-amino acids to the corresponding imino acids. The 1.07 {angstrom} atomic-resolution structure of DADH crystallized with D-leucine unexpectedly revealed a covalent N(5) flavin adduct, instead of the expected iminoleucine product in the active site. This acyl adduct has been successfully reproduced by photoreduction of DADH in the presence of 4-methyl-2-oxopentanoic acid (ketoleucine). The iminoleucine may be released readily because of weak interactions in the binding site, in contrast to iminoarginine, converted to ketoleucine, which reacts with activated FAD to form the covalently linked acyl adduct.

  2. Histone Arginine Methylation

    PubMed Central

    Lorenzo, Alessandra Di; Bedford, Mark T.

    2012-01-01

    Arginine methylation is a common posttranslational modification (PTM). This type of PTM occurs on both nuclear and cytoplasmic proteins, and is particularly abundant on shuttling proteins. In this review, we will focus on one aspect of this PTM: the diverse roles that arginine methylation of the core histone tails play in regulating chromatin function. A family of nine protein arginine methyltransferases (PRMTs) catalyze methylation reactions, and a subset target histones. Importantly, arginine methylation of histone tails can promote or prevent the docking of key transcriptional effector molecules, thus playing a central role in the orchestration of the histone code. PMID:21074527

  3. Substrate specificity of human protein arginine methyltransferase 7 (PRMT7): the importance of acidic residues in the double E loop.

    PubMed

    Feng, You; Hadjikyriacou, Andrea; Clarke, Steven G

    2014-11-21

    Protein arginine methyltransferase 7 (PRMT7) methylates arginine residues on various protein substrates and is involved in DNA transcription, RNA splicing, DNA repair, cell differentiation, and metastasis. The substrate sequences it recognizes in vivo and the enzymatic mechanism behind it, however, remain to be explored. Here we characterize methylation catalyzed by a bacterially expressed GST-tagged human PRMT7 fusion protein with a broad range of peptide and protein substrates. After confirming its type III activity generating only ω-N(G)-monomethylarginine and its distinct substrate specificity for RXR motifs surrounded by basic residues, we performed site-directed mutagenesis studies on this enzyme, revealing that two acidic residues within the double E loop, Asp-147 and Glu-149, modulate the substrate preference. Furthermore, altering a single acidic residue, Glu-478, on the C-terminal domain to glutamine nearly abolished the activity of the enzyme. Additionally, we demonstrate that PRMT7 has unusual temperature dependence and salt tolerance. These results provide a biochemical foundation to understanding the broad biological functions of PRMT7 in health and disease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Lysine acetylation sites prediction using an ensemble of support vector machine classifiers.

    PubMed

    Xu, Yan; Wang, Xiao-Bo; Ding, Jun; Wu, Ling-Yun; Deng, Nai-Yang

    2010-05-07

    Lysine acetylation is an essentially reversible and high regulated post-translational modification which regulates diverse protein properties. Experimental identification of acetylation sites is laborious and expensive. Hence, there is significant interest in the development of computational methods for reliable prediction of acetylation sites from amino acid sequences. In this paper we use an ensemble of support vector machine classifiers to perform this work. The experimentally determined acetylation lysine sites are extracted from Swiss-Prot database and scientific literatures. Experiment results show that an ensemble of support vector machine classifiers outperforms single support vector machine classifier and other computational methods such as PAIL and LysAcet on the problem of predicting acetylation lysine sites. The resulting method has been implemented in EnsemblePail, a web server for lysine acetylation sites prediction available at http://www.aporc.org/EnsemblePail/. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  5. Multifactorial modulation of susceptibility to l-lysine in an animal model of glutaric aciduria type I.

    PubMed

    Sauer, Sven W; Opp, Silvana; Komatsuzaki, Shoko; Blank, Anna-Eva; Mittelbronn, Michel; Burgard, Peter; Koeller, D M; Okun, Jürgen G; Kölker, Stefan

    2015-05-01

    Glutaric aciduria type I is an inherited defect in L-lysine, L-hydroxylysine and L-tryptophan degradation caused by deficiency of glutaryl-CoA dehydrogenase (GCDH). The majority of untreated patients presents with accumulation of neurotoxic metabolites - glutaric acid (GA) and 3-hydroxyglutaric acid (3-OHGA) - and striatal injury. Gcdh(-/-) mice display elevated levels of GA and 3-OH-GA but do not spontaneously develop striatal lesions. L-lysine-enriched diets (appr. 235 mg/d) were suggested to induce a neurological phenotype similar to affected patients. In our hands 93% of mice stressed according to the published protocol remained asymptomatic. To understand the underlying mechanism, we modified their genetic background (F1 C57BL6/Jx129/SvCrl) and increased the daily oral L-lysine supply (235-433 mg). We identified three modulating factors, (1) gender, (2) genetic background, and (3) amount of L-lysine. Male mice displayed higher vulnerability and inbreeding for more than two generations as well as elevating L-lysine supply increased the diet-induced mortality rate (up to 89%). Onset of first symptoms leads to strongly reduced intake of food and, thus, L-lysine suggesting a threshold for toxic metabolite production to induce neurological disease. GA and 3-OH-GA tissue concentrations did not correlate with dietary L-lysine supply but differed between symptomatic and asymptomatic mice. Cerebral activities of glyceraldehyde 3-phosphate dehydrogenase, 2-oxoglutarate dehydrogenase complex, and aconitase were decreased. Symptomatic mice did not develop striatal lesions or intracerebral hemorrhages. We found severe spongiosis in the hippocampus of Gcdh(-/-) mice which was independent of dietary L-lysine supply. In conclusion, the L-lysine-induced pathology in Gcdh(-/-) mice depends on genetic and dietary parameters. Copyright © 2014. Published by Elsevier B.V.

  6. Characterization and crystal structure of lysine insensitive Corynebacterium glutamicum dihydrodipicolinate synthase (cDHDPS) protein

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rice, E.A.; Bannon, G.A.; Glenn, K.C.

    2008-11-21

    The lysine insensitive Corynebacterium glutamicum dihydrodipicolinate synthase enzyme (cDHDPS) was recently successfully introduced into maize plants to enhance the level of lysine in the grain. To better understand lysine insensitivity of the cDHDPS, we expressed, purified, kinetically characterized the protein, and solved its X-ray crystal structure. The cDHDPS enzyme has a fold and overall structure that is highly similar to other DHDPS proteins. A noteworthy feature of the active site is the evidence that the catalytic lysine residue forms a Schiff base adduct with pyruvate. Analyses of the cDHDPS structure in the vicinity of the putative binding site for S-lysinemore » revealed that the allosteric binding site in the Escherichia coli DHDPS protein does not exist in cDHDPS due to three non-conservative amino acids substitutions, and this is likely why cDHDPS is not feedback inhibited by lysine.« less

  7. Changes in conformational dynamics of basic side chains upon protein-DNA association.

    PubMed

    Esadze, Alexandre; Chen, Chuanying; Zandarashvili, Levani; Roy, Sourav; Pettitt, B Montgometry; Iwahara, Junji

    2016-08-19

    Basic side chains play major roles in recognition of nucleic acids by proteins. However, dynamic properties of these positively charged side chains are not well understood. In this work, we studied changes in conformational dynamics of basic side chains upon protein-DNA association for the zinc-finger protein Egr-1. By nuclear magnetic resonance (NMR) spectroscopy, we characterized the dynamics of all side-chain cationic groups in the free protein and in the complex with target DNA. Our NMR order parameters indicate that the arginine guanidino groups interacting with DNA bases are strongly immobilized, forming rigid interfaces. Despite the strong short-range electrostatic interactions, the majority of the basic side chains interacting with the DNA phosphates exhibited high mobility, forming dynamic interfaces. In particular, the lysine side-chain amino groups exhibited only small changes in the order parameters upon DNA-binding. We found a similar trend in the molecular dynamics (MD) simulations for the free Egr-1 and the Egr-1-DNA complex. Using the MD trajectories, we also analyzed side-chain conformational entropy. The interfacial arginine side chains exhibited substantial entropic loss upon binding to DNA, whereas the interfacial lysine side chains showed relatively small changes in conformational entropy. These data illustrate different dynamic characteristics of the interfacial arginine and lysine side chains. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Preventive effect of a high fluoride toothpaste and arginine-carbonate toothpaste on dentinal tubules exposure followed by acid challenge: a dentine permeability evaluation

    PubMed Central

    2014-01-01

    Background Considering the current high use of high fluoride toothpastes, the aim of the study was to quantify alterations in the root dentine permeability submitted to treatment with a high fluoride toothpaste and 8% arginine, calcium carbonate, sodium monofluorophosphate toothpaste as a preventive treatment for dentinal tubules exposure followed by acid challenge. Methods Thirty-third molars were sectioned below the cementoenamel. The root segments were connected to a hydraulic pressure apparatus to measure dentine permeability after the following sequential steps (n = 10 per group): I) Baseline; II) treatment with phosphoric acid for 30 s (maximum permeability); III) Toothbrushing (1 min) according to the experimental groups (G1- control; G2- 5000 ppm fluoride toothpaste; G3- 8% arginine-calcium carbonate toothpaste); IV) acid challenge for 5 min (orange juice). The data were converted into percentage, considering stage II as 100%. Results The results have shown a statistically significant decreasing on dentine permeability after treatment with toothpaste (Friedman test and Dunn’s post hoc test). Comparison among groups demonstrated a high increasing on dentine permeability when acid challenge was performed after toothbrushing with distilled water (control group) (Kruskal-Wallis and Dunn’s post hoc test). Conclusion The toothpaste treatment may provide sufficient resistance on dentine surface, preventing dentinal tubules exposure after acid challenge. PMID:24958423

  9. Immunoaffinity Enrichment and Mass Spectrometry Analysis of Protein Methylation

    PubMed Central

    Guo, Ailan; Gu, Hongbo; Zhou, Jing; Mulhern, Daniel; Wang, Yi; Lee, Kimberly A.; Yang, Vicky; Aguiar, Mike; Kornhauser, Jon; Jia, Xiaoying; Ren, Jianmin; Beausoleil, Sean A.; Silva, Jeffrey C.; Vemulapalli, Vidyasiri; Bedford, Mark T.; Comb, Michael J.

    2014-01-01

    Protein methylation is a common posttranslational modification that mostly occurs on arginine and lysine residues. Arginine methylation has been reported to regulate RNA processing, gene transcription, DNA damage repair, protein translocation, and signal transduction. Lysine methylation is best known to regulate histone function and is involved in epigenetic regulation of gene transcription. To better study protein methylation, we have developed highly specific antibodies against monomethyl arginine; asymmetric dimethyl arginine; and monomethyl, dimethyl, and trimethyl lysine motifs. These antibodies were used to perform immunoaffinity purification of methyl peptides followed by LC-MS/MS analysis to identify and quantify arginine and lysine methylation sites in several model studies. Overall, we identified over 1000 arginine methylation sites in human cell line and mouse tissues, and ∼160 lysine methylation sites in human cell line HCT116. The number of methylation sites identified in this study exceeds those found in the literature to date. Detailed analysis of arginine-methylated proteins observed in mouse brain compared with those found in mouse embryo shows a tissue-specific distribution of arginine methylation, and extends the types of proteins that are known to be arginine methylated to include many new protein types. Many arginine-methylated proteins that we identified from the brain, including receptors, ion channels, transporters, and vesicle proteins, are involved in synaptic transmission, whereas the most abundant methylated proteins identified from mouse embryo are transcriptional regulators and RNA processing proteins. PMID:24129315

  10. Arginine in the salt-induced peptide formation reaction: enantioselectivity facilitated by glycine, L- and D-histidine.

    PubMed

    Li, Feng; Fitz, Daniel; Fraser, Donald G; Rode, Bernd M

    2010-07-01

    The salt-induced peptide formation reaction has been proposed as a conceivable preliminary to the prebiotic evolution of peptides. In the present paper, the behaviour of arginine is reported for this reaction together with a discussion of the catalytic effects of glycine, and L- and D-histidine. Importantly, the behaviour of the two histidine enantiomers is different. Both histidine enantiomers perform better than glycine in enhancing the yields of arginine dipeptide with L-histidine being more effective than D-histidine. Yields in the presence of histidine are up to 70 times greater than for arginine solutions alone. This compares with 4.2 times higher in the presence of glycine. This difference is most pronounced in the most concentrated (containing 80 mM arginine) reaction solution where arginine has the lowest reactivity. A distinct preference for dimerisation of L-arginine also appears in the 80 mM cases for catalyses of other amino acids. This phenomenon is different from the behaviour of aliphatic amino acids, which display obvious inherent enantioselectivity for the L-stereomers in the SIPF reaction on their own rather than when catalysed by glycine or histidine.

  11. Dietary arginine and linear growth: the Copenhagen School Child Intervention Study.

    PubMed

    van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W; Froberg, Karsten; Andersen, Lars B; El-Naaman, Bianca; Bugge, Anna; Nielsen, Birgit M; Heitman, Berit L

    2013-03-28

    The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.

  12. Quantification of Nε-(2-Furoylmethyl)-L-lysine (furosine), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL) and total lysine through stable isotope dilution assay and tandem mass spectrometry.

    PubMed

    Troise, Antonio Dario; Fiore, Alberto; Wiltafsky, Markus; Fogliano, Vincenzo

    2015-12-01

    The control of Maillard reaction (MR) is a key point to ensure processed foods quality. Due to the presence of a primary amino group on its side chain, lysine is particularly prone to chemical modifications with the formation of Amadori products (AP), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL). A new analytical strategy was proposed which allowed to simultaneously quantify lysine, CML, CEL and the Nε-(2-Furoylmethyl)-L-lysine (furosine), the indirect marker of AP. The procedure is based on stable isotope dilution assay followed by liquid chromatography tandem mass spectrometry. It showed high sensitivity and good reproducibility and repeatability in different foods. The limit of detection and the RSD% were lower than 5 ppb and below 8%, respectively. Results obtained with the new procedure not only improved the knowledge about the reliability of thermal treatment markers, but also defined new insights in the relationship between Maillard reaction products and their precursors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Reverse Transcriptase-Containing Particles Induced in Rous Sarcoma Virus-Transformed Rat Cells by Arginine Deprivation

    PubMed Central

    Kotler, Moshe; Weinberg, Eynat; Haspel, Osnat; Becker, Yechiel

    1972-01-01

    Incubation of rat cells transformed by Rous sarcoma virus (RSV) in an arginine-deficient medium resulted in accumulation of particles in the culture medium. Such particles did not appear when the transformed rat cells were incubated in a complete medium nor in the medium of primary rat cells which were incubated either in arginine-deficient or complete media. The particles which were released from the arginine-deprived transformed rat cells resemble C-type particles in their properties. These particles band in sucrose gradients at a density of 1.16 g/ml and contain 35S ribonucleic acid (RNA) molecules and a reverse transcriptase activity. Analysis of the cytoplasm of transformed and primary rat cells, deprived and undeprived of arginine, revealed the presence of reverse transcriptase-containing particles which banded in sucrose gradients at a density of 1.14 g/ml. These particles differed from the particles released into the medium by the arginine-deprived RSV-transformed rat cells. The deoxyribonucleic acid (DNA) molecules synthesized in vitro by the reverse transcriptase present in the particles isolated from the medium of arginine-deprived cells hybridized to RSV RNA, whereas the DNA synthesized by the cell-bound enzyme had no homology to RSV RNA. PMID:4116137

  14. Role of aspartate 400, arginine 262, and arginine 401 in the catalytic mechanism of human coproporphyrinogen oxidase

    PubMed Central

    Stephenson, Jason R.; Stacey, Julie A.; Morgenthaler, Justin B.; Friesen, Jon A.; Lash, Timothy D.; Jones, Marjorie A.

    2007-01-01

    Coproporphyrinogen oxidase (CPO) is the sixth enzyme in the heme biosynthetic pathway, catalyzing two sequential oxidative decarboxylations of propionate moieties on coproporphyrinogen-III forming protoporphyrinogen-IX through a monovinyl intermediate, harderoporphyrinogen. Site-directed mutagenesis studies were carried out on three invariant amino acids, aspartate 400, arginine 262, and arginine 401, to determine residue contribution to substrate binding and/or catalysis by human recombinant CPO. Kinetic analyses were performed on mutant enzymes incubated with three substrates, coproporphyrinogen-III, harderoporphyrinogen, or mesoporphyrinogen-VI, in order to determine catalytic ability to perform the first and/or second oxidative decarboxylation. When Asp400 was mutated to alanine no divinyl product was detected, but the production of a small amount of monovinyl product suggested the Km value for coproporphyrinogen-III did not change significantly compared to the wild-type enzyme. Upon mutation of Arg262 to alanine, CPO was again a poor catalyst for the production of a divinyl product, with a catalytic efficiency <0.01% compared to wild-type, including a 15-fold higher Km for coproporphyrinogen-III. The efficiency of divinyl product formation for mutant enzyme Arg401Ala was ∼3% compared to wild-type CPO, with a threefold increase in the Km value for coproporphyrinogen-III. These data suggest Asp400, Arg262, and Arg401 are active site amino acids critical for substrate binding and/or catalysis. Possible roles for arginine 262 and 401 include coordination of carboxylate groups of coproporphyrinogen-III, while aspartate 400 may initiate deprotonation of substrate, resulting in an oxidative decarboxylation. PMID:17242372

  15. Role of aspartate 400, arginine 262, and arginine 401 in the catalytic mechanism of human coproporphyrinogen oxidase.

    PubMed

    Stephenson, Jason R; Stacey, Julie A; Morgenthaler, Justin B; Friesen, Jon A; Lash, Timothy D; Jones, Marjorie A

    2007-03-01

    Coproporphyrinogen oxidase (CPO) is the sixth enzyme in the heme biosynthetic pathway, catalyzing two sequential oxidative decarboxylations of propionate moieties on coproporphyrinogen-III forming protoporphyrinogen-IX through a monovinyl intermediate, harderoporphyrinogen. Site-directed mutagenesis studies were carried out on three invariant amino acids, aspartate 400, arginine 262, and arginine 401, to determine residue contribution to substrate binding and/or catalysis by human recombinant CPO. Kinetic analyses were performed on mutant enzymes incubated with three substrates, coproporphyrinogen-III, harderoporphyrinogen, or mesoporphyrinogen-VI, in order to determine catalytic ability to perform the first and/or second oxidative decarboxylation. When Asp400 was mutated to alanine no divinyl product was detected, but the production of a small amount of monovinyl product suggested the K(m) value for coproporphyrinogen-III did not change significantly compared to the wild-type enzyme. Upon mutation of Arg262 to alanine, CPO was again a poor catalyst for the production of a divinyl product, with a catalytic efficiency <0.01% compared to wild-type, including a 15-fold higher K(m) for coproporphyrinogen-III. The efficiency of divinyl product formation for mutant enzyme Arg401Ala was approximately 3% compared to wild-type CPO, with a threefold increase in the K(m) value for coproporphyrinogen-III. These data suggest Asp400, Arg262, and Arg401 are active site amino acids critical for substrate binding and/or catalysis. Possible roles for arginine 262 and 401 include coordination of carboxylate groups of coproporphyrinogen-III, while aspartate 400 may initiate deprotonation of substrate, resulting in an oxidative decarboxylation.

  16. Expression of arginine kinase enzymatic activity and mRNA in gills of the euryhaline crabs Carcinus maenas and Callinectes sapidus.

    PubMed

    Kotlyar, S; Weihrauch, D; Paulsen, R S; Towle, D W

    2000-08-01

    Phosphagen kinases catalyze the reversible dephosphorylation of guanidino phosphagens such as phosphocreatine and phosphoarginine, contributing to the restoration of adenosine triphosphate concentrations in cells experiencing high and variable demands on their reserves of high-energy phosphates. The major invertebrate phosphagen kinase, arginine kinase, is expressed in the gills of two species of euryhaline crabs, the blue crab Callinectes sapidus and the shore crab Carcinus maenas, in which energy-requiring functions include monovalent ion transport, acid-base balance, nitrogen excretion and gas exchange. The enzymatic activity of arginine kinase approximately doubles in the ion-transporting gills of C. sapidus, a strong osmoregulator, when the crabs are transferred from high to low salinity, but does not change in C. maenas, a more modest osmoregulator. Amplification and sequencing of arginine kinase cDNA from both species, accomplished by reverse transcription of gill mRNA and the polymerase chain reaction, revealed an open reading frame coding for a 357-amino-acid protein. The predicted amino acid sequences showed a minimum of 75 % identity with arginine kinase sequences of other arthropods. Ten of the 11 amino acid residues believed to participate in arginine binding are completely conserved among the arthropod sequences analyzed. An estimation of arginine kinase mRNA abundance indicated that acclimation salinity has no effect on arginine kinase gene transcription. Thus, the observed enhancement of enzyme activity in C. sapidus probably results from altered translation rates or direct activation of pre-existing enzyme protein.

  17. L-Arginine

    MedlinePlus

    ... SAFE when taken by mouth appropriately for a short-term during pregnancy. Not enough is known about using L-arginine long-term in pregnancy or during breast-feeding. Stay on the safe side and avoid use. Children: L-arginine is POSSIBLY SAFE when used by ...

  18. Distance restraints from crosslinking mass spectrometry: mining a molecular dynamics simulation database to evaluate lysine-lysine distances.

    PubMed

    Merkley, Eric D; Rysavy, Steven; Kahraman, Abdullah; Hafen, Ryan P; Daggett, Valerie; Adkins, Joshua N

    2014-06-01

    Integrative structural biology attempts to model the structures of protein complexes that are challenging or intractable by classical structural methods (due to size, dynamics, or heterogeneity) by combining computational structural modeling with data from experimental methods. One such experimental method is chemical crosslinking mass spectrometry (XL-MS), in which protein complexes are crosslinked and characterized using liquid chromatography-mass spectrometry to pinpoint specific amino acid residues in close structural proximity. The commonly used lysine-reactive N-hydroxysuccinimide ester reagents disuccinimidylsuberate (DSS) and bis(sulfosuccinimidyl)suberate (BS(3) ) have a linker arm that is 11.4 Å long when fully extended, allowing Cα (alpha carbon of protein backbone) atoms of crosslinked lysine residues to be up to ∼24 Å apart. However, XL-MS studies on proteins of known structure frequently report crosslinks that exceed this distance. Typically, a tolerance of ∼3 Å is added to the theoretical maximum to account for this observation, with limited justification for the chosen value. We used the Dynameomics database, a repository of high-quality molecular dynamics simulations of 807 proteins representative of diverse protein folds, to investigate the relationship between lysine-lysine distances in experimental starting structures and in simulation ensembles. We conclude that for DSS/BS(3), a distance constraint of 26-30 Å between Cα atoms is appropriate. This analysis provides a theoretical basis for the widespread practice of adding a tolerance to the crosslinker length when comparing XL-MS results to structures or in modeling. We also discuss the comparison of XL-MS results to MD simulations and known structures as a means to test and validate experimental XL-MS methods. © 2014 The Protein Society.

  19. Association of plasma arginine with breast cancer molecular subtypes in women of Liaoning province.

    PubMed

    Hu, Lu; Gao, Yu; Cao, Yunfeng; Zhang, Yinxu; Xu, Minghao; Wang, Yuanyuan; Jing, Yu; Guo, Shengnan; Jing, Fangyu; Hu, Xiaodan; Zhu, Zhitu

    2016-12-01

    Arginine is one of the human nonessential amino acids critical for the growth of human cancers. The aim of this study is to investigate the variation of arginine between breast cancer (BC) patients and benign mammary gland disease (control) patients to determine its value in predicting the risk of BC. We also explore the associations between arginine levels and breast cancer subtypes. Preoperative blood samples were obtained from 267 patients (102 BC and 165 controls) in 2015. Plasma arginine values were determined for all preoperative blood samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to analyse differences in arginine levels between BC patients and control patients and the correlations between arginine and clinicopathologic parameters in BC. The arginine levels of BC patients were significantly lower than those of control patients (5.96 [3.76-12.47] vs. 12.54 [7.14-24.94], P = 0.000). The area under the curve (AUC) for arginine was 0.721 (95% CI, 0.660-0.782, P < 0.0001). The concentration of arginine was significantly different among different molecular BC subtypes (P = 0.030). Our results suggested that plasma arginine was associated with breast cancer molecular subtypes. © 2016 IUBMB Life, 68(12):980-984, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

  20. A diurnal component to the variation in sieve tube amino acid content in wheat.

    PubMed

    Gattolin, Stefano; Newbury, H John; Bale, Jeffrey S; Tseng, Hua-Ming; Barrett, David A; Pritchard, Jeremy

    2008-06-01

    We have used high-sensitivity capillary electrophoresis coupled to a laser-induced fluorescence detection method to quantify 16 amino acids in wheat (Triticum aestivum) sieve tube (ST) samples as small as 2 nL collected by severing the stylets of feeding aphids. The sensitivity of the method was sufficient to determine a quantitative amino acid profile of individual STs without the need to bulk samples to produce larger volumes for analysis. This allowed the observation of the full range of variation that exists in individual STs. Some of the total concentrations of amino acids recorded are higher than those reported previously. The results obtained show variation in the concentrations of phenylalanine (Phe), histidine/valine (His/Val), leucine/isoleucine (Leu/Ile), arginine, asparagine, glutamine, tyrosine (Tyr), and lysine (Lys) across the ST samples. These could not be explained by plant-to-plant variation. Statistical analyses revealed five analytes (Tyr, Lys, Phe, His/Val, and Leu/Ile) that showed striking covariation in their concentrations across ST samples. A regression analysis revealed a significant relationship between the concentrations of Tyr, Lys, Phe, Leu/Ile, His/Val, asparagine, arginine, and proline and the time of collection of ST samples, with these amino acids increasing in concentration during the afternoon. This increase was confirmed to occur in individual STs by analyzing samples obtained from stylet bundles exuding for many hours. Finally, an apparent relationship between the exudation rate of ST sap and its total amino acid concentration was observed: samples containing higher total amino acid concentrations were observed to exude from the severed stylet bundles more slowly.

  1. Adaptation to a long term (4 weeks) arginine- and precursor (glutamate, proline and aspartate)-free diet.

    PubMed

    Tharakan, John F; Yu, Yong M; Zurakowski, David; Roth, Rachel M; Young, Vernon R; Castillo, Leticia

    2008-08-01

    It is not known whether arginine homeostasis is negatively affected by a "long term" dietary restriction of arginine and its major precursors in healthy adults. To assess the effects of a 4-week arginine- and precursor-free dietary intake on the regulatory mechanisms of arginine homeostasis in healthy subjects. Ten healthy adults received a complete amino acid diet for 1 week (control diet) and following a break period, six subjects received a 4-week arginine, proline, glutamate and aspartate-free diet (APF diet). The other four subjects continued for 4 weeks with the complete diet. On days 4 and 7 of the first week and days 25 and 28 of the 4-week period, the subjects received 24-h infusions of arginine, citrulline, leucine and urea tracers. During the 4-week APF, plasma arginine fluxes for the fed state, were significantly reduced. There were no significant differences for citrulline, leucine or urea fluxes. Arginine de novo synthesis was not affected by the APF intake. However, arginine oxidation was significantly decreased. In healthy adults, homeostasis of arginine under a long term arginine- and precursor-free intake is achieved by decreasing catabolic rates, while de novo arginine synthesis is maintained.

  2. Adsorption of Lysine on Na-Montmorillonite and Competition with Ca(2+): A Combined XRD and ATR-FTIR Study.

    PubMed

    Yang, Yanli; Wang, Shengrui; Liu, Jingyang; Xu, Yisheng; Zhou, Xiaoyun

    2016-05-17

    Lysine adsorption at clay/aqueous interfaces plays an important role in the mobility, bioavailability, and degradation of amino acids in the environment. Knowledge of these interfacial interactions facilitates our full understanding of the fate and transport of amino acids. Here, X-ray diffraction (XRD) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) measurements were used to explore the dynamic process of lysine adsorption on montmorillonite and the competition with Ca(2+) at the molecular level. Density functional theory (DFT) calculations were employed to determine the peak assignments of dissolved lysine in the solution phase. Three surface complexes, including dicationic, cationic, and zwitterionic structures, were observed to attach to the clay edge sites and penetrate the interlayer space. The increased surface coverage and Ca(2+) competition did not affect the interfacial lysine structures at a certain pH, whereas an elevated lysine concentration contributed to zwitterionic-type coordination at pH 10. Moreover, clay dissolution at pH 4 could be inhibited at a higher surface coverage with 5 and 10 mM lysine, whereas the inhibition effect was inconspicuous or undetected at pH 7 and 10. The presence of Ca(2+) not only could remove a part of the adsorbed lysine but also could facilitate the readsorption of dissolved Si(4+) and Al(3+) and surface protonation. Our results provide new insights into the process of lysine adsorption and its effects on montmorillonite surface sites.

  3. The role of lysine(100) in the binding of acetylcoenzyme A to human arylamine N-acetyltransferase 1: implications for other acetyltransferases.

    PubMed

    Minchin, Rodney F; Butcher, Neville J

    2015-04-01

    The arylamine N-acetyltransferases (NATs) catalyze the acetylation of aromatic and heterocyclic amines as well as hydrazines. All proteins in this family of enzymes utilize acetyl coenzyme A (AcCoA) as an acetyl donor, which initially binds to the enzyme and transfers an acetyl group to an active site cysteine. Here, we have investigated the role of a highly conserved amino acid (Lys(100)) in the enzymatic activity of human NAT1. Mutation of Lys(100) to either a glutamine or a leucine significantly increased the Ka for AcCoA without changing the Kb for the acetyl acceptor p-aminobenzoic acid. In addition, substrate inhibition was more marked with the mutant enzymes. Steady state kinetic analyzes suggested that mutation of Lys(100) to either leucine or glutamine resulted in a less stable enzyme-cofactor complex, which was not seen with a positively charged arginine at this position. When p-nitrophenylacetate was used as acetyl donor, no differences were seen between the wild-type and mutant enzymes because p-nitrophenylacetate is too small to interact with Lys(100) when bound to the active site. Using 3'-dephospho-AcCoA as the acetyl donor, kinetic data confirmed that Ly(100) interacts with the 3'-phosphoanion to stabilize the enzyme-cofactor complex. Mutation of Lys(100) decreases the affinity of AcCoA for the protein and increases the rate of CoA release. Crystal structures of several other unrelated acetyltransferases show a lysine or arginine residue within 3Å of the 3'-phosphoanion of AcCoA, suggesting that this mechanism for stabilizing the complex by the formation of a salt bridge may be widely applicable in nature. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Formation and reduction of 5-hydroxymethylfurfural at frying temperature in model system as a function of amino acid and sugar composition.

    PubMed

    Kavousi, Parviz; Mirhosseini, Hamed; Ghazali, Hasanah; Ariffin, Abdul Azis

    2015-09-01

    5-Hydroxymethylfurfural (HMF) is formed during heat treatment of carbohydrate-containing foods, especially in a deep-fat frying process. This study aimed to investigate the effect of amino acids on the formation and reduction of HMF from glucose, fructose and sucrose at frying temperature in model systems containing binary mixtures of an amino acid and a sugar in equal concentrations (0.3M). The results revealed that the formation of HMF from sugars accelerated in the presence of acidic amino acids (i.e. glutamic and aspartic acids). Conversely, the presence of basic amino acids (i.e. lysine, arginine and histidine) led to reduced concentrations of HMF to non-detectable levels in model systems. The results showed that both pH and heating time significantly affected the formation of HMF from fructose in the presence of glutamic acid. In this regard, a higher amount of HMF was formed at lower pH. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Dietary arginine requirements for growth are dependent on the rate of citrulline production in mice

    USDA-ARS?s Scientific Manuscript database

    In many species, including humans, arginine is considered a semiessential amino acid because under certain conditions endogenous synthesis cannot meet its demand. The requirements of arginine for growth in mice are ill defined and seem to vary depending on the genetic background of the mice. The obj...

  6. Neutralization of a single arginine residue gates open a two-pore domain, alkali-activated K+ channel

    PubMed Central

    Niemeyer, María Isabel; González-Nilo, Fernando D.; Zúñiga, Leandro; González, Wendy; Cid, L. Pablo; Sepúlveda, Francisco V.

    2007-01-01

    Potassium channels share a common selectivity filter that determines the conduction characteristics of the pore. Diversity in K+ channels is given by how they are gated open. TASK-2, TALK-1, and TALK-2 are two-pore region (2P) KCNK K+ channels gated open by extracellular alkalinization. We have explored the mechanism for this alkalinization-dependent gating using molecular simulation and site-directed mutagenesis followed by functional assay. We show that the side chain of a single arginine residue (R224) near the pore senses pH in TASK-2 with an unusual pKa of 8.0, a shift likely due to its hydrophobic environment. R224 would block the channel through an electrostatic effect on the pore, a situation relieved by its deprotonation by alkalinization. A lysine residue in TALK-2 fulfills the same role but with a largely unchanged pKa, which correlates with an environment that stabilizes its positive charge. In addition to suggesting unified alkaline pH-gating mechanisms within the TALK subfamily of channels, our results illustrate in a physiological context the principle that hydrophobic environment can drastically modulate the pKa of charged amino acids within a protein. PMID:17197424

  7. Lysine Succinylation Contributes to Aflatoxin Production and Pathogenicity in Aspergillus flavus*

    PubMed Central

    Ren, Silin; Yang, Mingkun; Yue, Yuewei; Ge, Feng; Li, Yu; Guo, Xiaodong; Zhang, Jia; Zhang, Feng; Nie, Xinyi; Wang, Shihua

    2018-01-01

    Aspergillus flavus (A. flavus) is a ubiquitous saprophytic and pathogenic fungus that produces the aflatoxin carcinogen, and A. flavus can have tremendous economic and health impacts worldwide. Increasing evidence demonstrates that lysine succinylation plays an important regulatory role in metabolic processes in both bacterial and human cells. However, little is known about the extent and function of lysine succinylation in A. flavus. Here, we performed a global succinylome analysis of A. flavus using high accuracy nano-LC-MS/MS in combination with the enrichment of succinylated peptides from digested cell lysates and subsequent peptide identification. In total, 985 succinylation sites on 349 succinylated proteins were identified in this pathogen. Bioinformatics analysis revealed that the succinylated proteins were involved in various biological processes and were particularly enriched in the aflatoxin biosynthesis process. Site-specific mutagenesis and biochemical studies showed that lysine succinylation on the norsolorinic acid reductase NorA (AflE), a key enzyme in aflatoxins biosynthesis, can affect the production of sclerotia and aflatoxins biosynthesis in A. flavus. Together, our findings reveal widespread roles for lysine succinylation in regulating metabolism and aflatoxins biosynthesis in A. flavus. Our data provide a rich resource for functional analyses of lysine succinylation and facilitate the dissection of metabolic networks in this pathogen. PMID:29298838

  8. Photochemical reaction of 2-(3-benzoylphenyl)propionic acid (ketoprofen) with basic amino acids and dipeptides.

    PubMed

    Suzuki, Tadashi; Shinoda, Mio; Osanai, Yohei; Isozaki, Tasuku

    2013-08-22

    Photoreaction of 2-(3-benzoylphenyl)propionic acid (ketoprofen, KP) with basic amino acids (histidine, lysine, and arginine) and dipeptides (carnosine and anserine) including a histidine moiety in phosphate buffer solution (pH 7.4) has been investigated with transient absorption spectroscopy. With UV irradiation KP(-) gave rise to a carbanion through a decarboxylation reaction, and the carbanion easily abstracted a proton from the surrounding molecule to yield a 3-ethylbenzophenone ketyl biradical (EBPH). The dipeptides as well as the basic amino acids were found to accelerate the proton transfer reaction whereas alanine and glycine had no effect on the reaction, revealing that these amino acids having a protonated side chain act as a proton donor. The formation quantum yield of EBPH was estimated to be fairly large by means of an actinometrical method with benzophenone, and the bimolecular reaction rate constant for the proton transfer between the carbanion and the protonated basic amino acids or the protonated dipeptides was successfully determined. It has become apparent that the bimolecular reaction rate constant for the proton transfer depended on the acid dissociation constant for the side chain of the amino acids for the first time. This reaction mechanism was interpreted by difference of the heat of reaction for each basic amino acid based on the thermodynamical consideration. These results strongly suggest that the side chain of the basic amino acid residue in protein should play an important role for photochemistry of KP in vivo.

  9. Plasma Amino Acid Responses After Consumption of Beverages with Varying Protein Type

    DTIC Science & Technology

    2009-07-01

    lysine 0.92 1.32 0.91 methionine 0.31 0.28 OJI phenylalanine 0.58 0.46 0.61 threonine 0.49 0.60 0.52 tryptophan 0.18 0.29 0.13 valine 0.69 0.64 0.68...threonine. serine. glutamine. proline. glycine, alanine, valine. isoleucine. leucine. tyrosine, phenylalanine . lysine, histidine, and arginine (Terrlink. van...with peak concentration in parentheses, were 2 ± 2 (45ŕ" ± 34%), 4 ± 3 (50% ± 32%). and 3 ± 3 mg/ dl (79% ± 37%). respectively. Postexercise, WP. CAS

  10. The microbiome, intestinal function, and arginine metabolism of healthy Indian women are different from those of American and Jamaican women

    USDA-ARS?s Scientific Manuscript database

    Indian women have slower arginine flux during pregnancy compared with American and Jamaican women. Arginine is a semi-essential amino acid that becomes essential during periods of rapid lean tissue deposition. It is synthesized only from citrulline, a nondietary amino acid produced mainly in the gut...

  11. Tannic acid and chromic chloride-induced binding of protein to red cells: a preliminary study of possible binding sites and reaction mechanisms.

    PubMed

    Hunt, A F; Reed, M I

    1990-07-01

    The binding mechanisms and binding sites involved in the tannic acid and chromic chloride-induced binding of protein to red cells were investigated using the binding of IgA paraprotein to red cells as model systems. Inhibition studies of these model systems using amino acid homopolymers and compounds (common as red cell membrane constituents) suggest that the mechanisms involved are similar to those proposed for the conversion of hide or skin collagen to leather, as in commercial tanning. These studies also suggest that tannic acid-induced binding of IgA paraprotein to red cells involves the amino acid residues of L-arginine, L-lysine, L-histidine, and L-proline analogous to tanning with phenolic plant extracts. The amino acid residues of L-aspartate, L-glutamate and L-asparagine are involved in a similar manner in chronic chloride-induced binding of protein to red cells.

  12. Electrostatically driven immobilization of peptides onto (Maleic anhydride-alt-methyl vinyl ether) copolymers in aqueous media.

    PubMed

    Ladavière, C; Lorenzo, C; Elaïssari, A; Mandrand, B; Delair, T

    2000-01-01

    The covalent immobilization of a model peptide onto the MAMVE copolymer, via the formation of amide bonds, occurred in moderate yields in aqueous conditions. The improvement of the grafting reaction was achieved by adding at the amino terminus of the model peptide a sequence (tag) of three positively charged amino acids, lysine or arginine, and by taking profit of electrostatic attractive interactions between the negatively charged copolymer and the tagged peptides. The arginine tag was more efficient than the lysine tag for enhancing the immobilization reaction, proving that the effect was due to an electrostic driving force. On the basis of these results, a tentative mechanism is discussed, and Scatchard plots pointed out two regimes of binding. With the first, at low polymer load (up to 50% of saturation for a lysine tag and 60-70% for an arginine tag), the binding occurred with a positive cooperative effect, the already bound peptide participating to the binding of others. A second one for higher coverages, for which the binding occurred with a negative cooperativity, and saturation was reached in the presence of a large excess of peptide.

  13. Lysine and novel hydroxylysine lipids in soil bacteria: amino acid membrane lipid response to temperature and pH in Pseudopedobacter saltans

    PubMed Central

    Moore, Eli K.; Hopmans, Ellen C.; Rijpstra, W. Irene C.; Sánchez-Andrea, Irene; Villanueva, Laura; Wienk, Hans; Schoutsen, Frans; Stams, Alfons J. M.; Sinninghe Damsté, Jaap S.

    2015-01-01

    Microbial decomposition of organic matter is an essential process in the global carbon cycle. The soil bacteria Pseudopedobacter saltans and Flavobacterium johnsoniae are both able to degrade complex organic molecules, but it is not fully known how their membrane structures are adapted to their environmental niche. The membrane lipids of these species were extracted and analyzed using high performance liquid chromatography-electrospray ionization/ion trap/mass spectrometry (HPLC-ESI/IT/MS) and high resolution accurate mass/mass spectrometry (HRAM/MS). Abundant unknown intact polar lipids (IPLs) from P. saltans were isolated and further characterized using amino acid analysis and two dimensional nuclear magnetic resonance (NMR) spectroscopy. Ornithine IPLs (OLs) with variable (hydroxy) fatty acid composition were observed in both bacterial species. Lysine-containing IPLs (LLs) were also detected in both species and were characterized here for the first time using HPLC-MS. Novel LLs containing hydroxy fatty acids and novel hydroxylysine lipids with variable (hydroxy) fatty acid composition were identified in P. saltans. The confirmation of OL and LL formation in F. johnsoniae and P. saltans and the presence of OlsF putative homologs in P. saltans suggest the OlsF gene coding protein is possibly involved in OL and LL biosynthesis in both species, however, potential pathways of OL and LL hydroxylation in P. saltans are still undetermined. Triplicate cultures of P. saltans were grown at three temperature/pH combinations: 30°C/pH 7, 15°C/pH 7, and 15°C/pH 9. The fractional abundance of total amino acid containing IPLs containing hydroxylated fatty acids was significantly higher at higher temperature, and the fractional abundance of lysine-containing IPLs was significantly higher at lower temperature and higher pH. These results suggest that these amino acid-containing IPLs, including the novel hydroxylysine lipids, could be involved in temperature and pH stress

  14. Amino and fatty acid dynamics of octopus (Octopus vulgaris) early life stages under ocean warming.

    PubMed

    Lopes, Vanessa M; Faleiro, Filipa; Baptista, Miguel; Pimentel, Marta S; Paula, José R; Couto, Ana; Bandarra, Narcisa; Anacleto, Patrícia; Marques, António; Rosa, Rui

    2016-01-01

    The oceans are becoming warmer, and the higher temperatures are expected to have a major impact on marine life at different levels of biological organization, especially at the most vulnerable early life stages. Thus, we hypothesize that the future warmer scenarios (here +3 °C) will affect the biochemical composition (amino acid - AA, and fatty acid-FA) of octopod (Octopus vulgaris) embryos and recently-hatched pelagic paralarvae. The main essential amino acids found in octopus embryos were arginine, leucine and lysine; while aspartic and glutamic acids, and taurine were the main non-essential amino acids. Palmitic, eicosapentaenoic and docosahexaenoic acids were the main FAs found in octopus tissues. Relevant ontogenetic changes were observed, namely a steep decrease in the content of many AAs, and a selective retention of FAs, thus evidencing the protein-based metabolism of these cephalopods. Temperature per si did not elicit significant changes in the overall FA composition, but was responsible for a significant decrease in the content of several AAs, indicating increased embryonic consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Role of L-arginine in the biological effects of blue light

    NASA Astrophysics Data System (ADS)

    Makela, Anu M.

    2005-11-01

    Arginine, a semi-essential amino acid, and metabolites of arginine exert multiple biological effects. It has been known that arginine causes the release of various hormones such as insulin, glucagon, growth hormone, prolactin, and adrenal catecholamines. Arginine infusion also produces vasodilation, and in the kidney increased plasma flow accompanied by increases in glomerular filtration rate (GFR). Recent studies have showed that blue and red light irradiation in vitro and in vivo can increase production of nitric oxide (NO), superoxide anion, and related reactive oxygen species (ROS). These then can modulate the production and secretion of several cytokines and other mediators and play an important role as regulatory mediators in signaling processes which can then modulate the production, mobilization and homing of stem cells. It is proposed that some of the therapeutic effects of light can be considered to be due to the changes in the metabolism of L-arginine. The regulation of L-arginine turnover by the use of light at blue wavelengths between 400nm and 510nm can be the explanation for some of the observed effects of blue light: lowering of blood pressure, pain killing effect, regulating insulin production, anti-inflammatory action, and possible effects on the release and homing of stem cells.

  16. Ex-vivo absorption study of lysine R-lipoate salt, a new pharmaceutical form of R-ALA.

    PubMed

    Amenta, Francesco; Buccioni, Michela; Ben, Diego Dal; Lambertucci, Catia; Navia, Aleix Martí; Ngouadjeu Ngnintedem, Michael A; Ricciutelli, Massimo; Spinaci, Andrea; Volpini, Rosaria; Marucci, Gabriella

    2018-06-15

    Alpha-lipoic acid (ALA) oral supplements were used in many pathologies associated with increased oxidative stress. Although only R-ALA is considered the biologically active form, R,S-ALA is used in therapeutic applications even showing poor water solubility. The aim of this work was to study the absorption and transport mechanism across the intestinal barrier of new R-ALA stable and water soluble form, consisting in the lysine R-ALA salt, in presence and absence of specific inhibitors of Na + /multivitamin (SMVT) and monocarboxylic acids (MCT). The absorption of a new ALA form was investigated at rat everted sacs in comparison with R-ALA, S-ALA, and R,S-ALA. Results showed that duodenum is the best portion of intestine for ALA forms absorption. The absorption percentage of R-ALA, S-ALA, R,S-ALA, and lysine R-ALA salt was 66%, 43%, 55%, and 70%, respectively. The modest effect of the SMVT inhibitor biotin demonstrated that this transporter system is not principally involved in the absorption of lysine R-lipoate salt across the rat intestinal barrier. On the contrary, the MCT inhibitor octanoic acid significantly reduced the transport of this salt, whit an absorption decrease of R-ALA and lysine R-lipoate salt of 28% and 24%, respectively. Since the highest concentration of these inhibitors did not completely inhibit the absorption of lysine R-lipoate salt, other transport mechanisms probably operate for its intracellular delivery. The new form of ALA, lysine R-lipoate salt, was the most absorbed respect to the other ALA forms demonstrating that this compound is more suitable for oral administration. This new salt could represent a promising candidate for ALA oral supplementation. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Effect of doping of KDP crystal with amino acid L-arginine on the strength properties and character of laser damage

    NASA Astrophysics Data System (ADS)

    Dolzhenkova, E. F.; Kostenyukova, E. I.; Bezkrovnaya, O. N.; Pritula, I. M.

    2017-11-01

    Studied were the strength characteristics of KDP crystals doped with L-arginine under a concentrated load and irradiation of the first harmonic YAG:Nd3+ laser. The crystals were obtained by means of the temperature reduction method on a point seed, the content of L-arginine in the aqueous solution being 0.3, 0.4, 1.0 and 1.4 wt%. The character of the dependence of KDP microhardness versus the concentration of amino acid in the crystal was investigated. The regularities of brittle damage of the doped KDP crystal at mechanical testing and laser irradiation were shown to be similar. As confirmed in the study, the planes of easy crack extension in the crystal are {2 2 1}, (1 0 0), and (0 0 1) planes, the cracks mainly propagate parallel to {2 2 1} planes. The mechanical and laser strength values of doped KDP crystals were evaluated.

  18. Adaptation to a long term (4 weeks) arginine- and precursor (glutamate, proline and aspartate)-free diet☆

    PubMed Central

    Tharakan, John F.; Yu, Yong M.; Zurakowski, David; Roth, Rachel M.; Young, Vernon R.; Castillo, Leticia

    2008-01-01

    Summary Background & aims It is not known whether arginine homeostasis is negatively affected by a “long term” dietary restriction of arginine and its major precursors in healthy adults. To assess the effects of a 4-week arginine- and precursor-free dietary intake on the regulatory mechanisms of arginine homeostasis in healthy subjects. Methods Ten healthy adults received a complete amino acid diet for 1 week (control diet) and following a break period, six subjects received a 4-week arginine, proline, glutamate and aspartate-free diet (APF diet). The other four subjects continued for 4 weeks with the complete diet. On days 4 and 7 of the first week and days 25 and 28 of the 4-week period, the subjects received 24-h infusions of arginine, citrulline, leucine and urea tracers. Results During the 4-week APF, plasma arginine fluxes for the fed state, were significantly reduced. There were no significant differences for citrulline, leucine or urea fluxes. Arginine de novo synthesis was not affected by the APF intake. However, arginine oxidation was significantly decreased. Conclusions In healthy adults, homeostasis of arginine under a long term arginine- and precursor-free intake is achieved by decreasing catabolic rates, while de novo arginine synthesis is maintained. PMID:18590940

  19. Stimulated Nitric Oxide Production and Arginine Deficiency in Cystic Fibrosis Children with Nutritional Failure

    PubMed Central

    Engelen, Mariëlle PKJ; Com, Gulnur; Luiking, Yvette C; Deutz, Nicolaas EP

    2013-01-01

    Objective Reduced nitric oxide (NO) concentrations are found in the airways of many patients with cystic fibrosis (CF) and are associated with increased airflow obstruction. We determined whether upregulated whole body de novo arginine synthesis and protein breakdown are present as a compensatory mechanism to meet the increased demand for arginine and nitric oxide production in pediatric patients with CF and nutritional failure. Study design In 16 children with CF, studied at the end of antibiotic treatment for a pulmonary exacerbation, and 17 healthy controls, whole body arginine, citrulline, and protein turnover were assessed by stable isotope methodology and de novo arginine synthesis, arginine clearance, NO synthesis, protein synthesis and breakdown, and net protein balance were calculated. The plasma isotopic enrichments and amino acid concentrations were measured by LC-MS/MS. Results Increased arginine clearance was found in patients with CF (p<0.001) whereas whole body NO production rate and plasma arginine levels were not different. Whole body arginine production (P<0.001), de novo arginine synthesis, and protein breakdown and synthesis (P<0.05) were increased in patients with CF, but net protein balance was comparable. Patients with CF with nutritional failure (n=7) had significantly higher NO production (P<0.05), de novo arginine synthesis, citrulline production (P<0.001), and plasma citrulline concentration (P<0.05) and lower plasma arginine concentration (P<0.05) than those without nutritional failure (n=9). Conclusions Nutritional failure in CF is associated with increased NO production. However, upregulation of de novo arginine synthesis and citrulline production was not sufficient to meet the increased arginine needs leading to arginine deficiency. PMID:23419590

  20. Dietary arginine depletion reduces depressive-like responses in male, but not female, mice.

    PubMed

    Workman, Joanna L; Weber, Michael D; Nelson, Randy J

    2011-09-30

    Previous behavioral studies have manipulated nitric oxide (NO) production either by pharmacological inhibition of its synthetic enzyme, nitric oxide synthase (NOS), or by deletion of the genes that code for NOS. However manipulation of dietary intake of the NO precursor, L-arginine, has been understudied in regard to behavioral regulation. L-Arginine is a common amino acid present in many mammalian diets and is essential during development. In the brain L-arginine is converted into NO and citrulline by the enzyme, neuronal NOS (nNOS). In Experiment 1, paired mice were fed a diet comprised either of an L-arginine-depleted, L-arginine-supplemented, or standard level of L-arginine during pregnancy. Offspring were continuously fed the same diets and were tested in adulthood in elevated plus maze, forced swim, and resident-intruder aggression tests. L-Arginine depletion reduced depressive-like responses in male, but not female, mice and failed to significantly alter anxiety-like or aggressive behaviors. Arginine depletion throughout life reduced body mass overall and eliminated the sex difference in body mass. Additionally, arginine depletion significantly increased corticosterone concentrations, which negatively correlated with time spent floating. In Experiment 2, adult mice were fed arginine-defined diets two weeks prior to and during behavioral testing, and again tested in the aforementioned tests. Arginine depletion reduced depressive-like responses in the forced swim test, but did not alter behavior in the elevated plus maze or the resident intruder aggression test. Corticosterone concentrations were not altered by arginine diet manipulation in adulthood. These results indicate that arginine depletion throughout development, as well as during a discrete period during adulthood ameliorates depressive-like responses. These results may yield new insights into the etiology and sex differences of depression. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. "One-pot" preparation of basic amino acid-silica hybrid monolithic column for capillary electrochromatography.

    PubMed

    Xu, Hongrui; Xu, Zhendong; Yang, Limin; Wang, Qiuquan

    2011-08-01

    A novel "one-pot" strategy was developed for the preparation of amino acid (AA)-silica hybrid monolithic column. The basic AA (L-Arginine, L-Lysine and L-Histidine) was covalently incorporated into the silica hybrid skeleton via the epoxy ring-opening reaction between the amine group and the glycidyl moiety in γ-glycidoxypropyltrimethoxysilane (GPTMS), which was confirmed by elemental analysis and FT-IR studies, while the basic AA was also found to catalyze the polycondensation of tetramethoxysilane and GPTMS. The average mesopore and macropore sizes of the prepared basic AA-silica hybrid monolithic columns were 3.86 nm and 1.71 μm for the L-Lysine-silica hybrid monolith, 5.38 nm and 4.24 μm for the L-Arginine-silica hybrid monolith, and 6.38 nm and 1.24 μm for the L-Histidine-silica hybrid monolith. The hybrid monolith afforded a zwitterionic stationary phase for CEC, the direction and magnitude of EOF can be controlled by the pH of the mobile phase used. Besides an electrophoretic mechanism, the monoliths behave in a typical hydrophilic interaction with the analytes when ACN percentage in the mobile phase is over 40%. Four polar compounds (toluene, DMF, formamide and thiourea) were tested on the three AA-silica hybrid monolithic columns, and the best separation efficiency was observed in the L-Lysine-silica hybrid monolithic column, its theoretical plate height was down to 5.7 μm for thiourea when 20 mM HCOOH-HCOONH4 containing 20% ACN (pH 4.1) was used as a running buffer. The corresponding theoretical plate number for toluene, DMF, formamide and thiourea were 123,385, 103,620, 121,845 and 105,345 plates/m, respectively. Effective separation of phenols and peptides on the L-Lysine-silica hybrid monolithic column was achieved using CEC. We believe that this strategy paves a way for the easy preparation of various functional silica hybrid monolithic columns, aiming at different separation purposes. Copyright © 2011 WILEY-VCH Verlag Gmb

  2. Stimulated nitric oxide production and arginine deficiency in children with cystic fibrosis with nutritional failure.

    PubMed

    Engelen, Mariëlle P K J; Com, Gulnur; Luiking, Yvette C; Deutz, Nicolaas E P

    2013-08-01

    To determine whether upregulated whole body de novo arginine synthesis and protein breakdown are present as a compensatory mechanism to meet the increased demand for arginine and nitric oxide (NO) production in pediatric patients with cystic fibrosis (CF) and nutritional failure. In 16 children with CF, studied at the end of antibiotic treatment for a pulmonary exacerbation, and 17 healthy controls, whole body arginine, citrulline (Cit), and protein turnover were assessed by stable isotope methodology and de novo arginine synthesis, arginine clearance, NO synthesis, protein synthesis and breakdown, and net protein balance were calculated. The plasma isotopic enrichments and amino acid concentrations were measured by liquid chromatography-tandem mass spectrometry. Increased arginine clearance was found in patients with CF (P < .001), whereas whole body NO production rate and plasma arginine levels were not different. Whole body arginine production (P < .001), de novo arginine synthesis, and protein breakdown and synthesis (P < .05) were increased in patients with CF, but net protein balance was comparable. Patients with CF with nutritional failure (n = 7) had significantly higher NO production (P < .05), de novo arginine synthesis, Cit production (P < .001), and plasma Cit concentration (P < .05) and lower plasma arginine concentration (P < .05) than those without nutritional failure (n = 9). Nutritional failure in CF is associated with increased NO production. However, up-regulation of de novo arginine synthesis and Cit production was not sufficient to meet the increased arginine needs leading to arginine deficiency. Copyright © 2013 Mosby, Inc. All rights reserved.

  3. N-alpha-Cocoyl-L-arginine ethyl ester, DL-pyroglutamic acid salt, as an inactivator of hepatitis B surface antigen.

    PubMed Central

    Sugimoto, Y; Toyoshima, S

    1979-01-01

    N-alpha-Cocoyl-L-arginine ethyl ester, DL-pyroglutamic acid salt (CAE), exhibited a strong inactivating effect on hepatitis B surface antigen. Concentrations of CAE required for 50 and 100% inactivation of the antigen were 0.01 to 0.025% and 0.025 to 0.05% respectively. CAE completely inactivated hepatitis B surface antigen at the lowest concentration compared with various compounds including about 500 amino acid derivatives, sodium hypochlorite, 2,4,4'-trichloro-2'-hydroxydiphenyl ether, and some detergents. Furthermore, CAE inactivated vaccinia virus, herpes simplex virus, and influenza virus, whereas poliovirus was not inactivated at all. The results suggest that the inactivating effects of CAE are related to interaction with lipid-containing viral envelopes. PMID:228595

  4. L-arginine enhances cell proliferation and reduces apoptosis in human endometrial RL95-2 cells

    USDA-ARS?s Scientific Manuscript database

    L-arginine is considered to be one of the most versatile amino acids due to the fact that it serves as a precursor for many important molecules in cellular physiology. When supplemented in the diet, L-arginine can increase the number of implantation sites in mice and rats, suggesting an effect at th...

  5. L-Arginine Modulates Glucose and Lipid Metabolism in Obesity and Diabetes.

    PubMed

    Hu, Shengdi; Han, Meng; Rezaei, Arash; Li, Defa; Wu, Guoyao; Ma, Xi

    2017-01-01

    Type 2 diabetes has become a global public health problem affecting approximately 380 million people throughout the world. It can cause many complications and lead to greater mortality. At present, there is no available medicine for effectively preventing diabetes. L-arginine, a functional amino acid, the precursor of nitric oxide, plays a crucial role in maintenance, reproduction, growth, anti-aging and immunity for animals. Growing clinical evidence indicates that dietary L-arginine supplementation can reduce obesity, decrease arterial blood pressure, resist oxidation and normalize endothelial dysfunction to bring about remission of type 2 diabetes. The potential molecular mechanism may play a role in modulating glucose homeostasis, promoting lipolysis, maintaining hormone levels, ameliorating insulin resistance, and fetal programing in early stages. The possible signaling pathway of the beneficial effects of L-arginine likely involves L-arginine-nitric oxide pathway through which cell signal protein can be activated. Accumulating studies have indicated that L-arginine may have potential to prevent and/or relieve type 2 diabetes via restoring insulin sensitivity in vivo. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  6. Apple snack enriched with L-arginine using vacuum impregnation/ohmic heating technology.

    PubMed

    Moreno, Jorge; Echeverria, Julian; Silva, Andrea; Escudero, Andrea; Petzold, Guillermo; Mella, Karla; Escudero, Carlos

    2017-07-01

    Modern life has created a high demand for functional food, and in this context, emerging technologies such as vacuum impregnation and ohmic heating have been applied to generate functional foods. The aim of this research was to enrich the content of the semi-essential amino acid L-arginine in apple cubes using vacuum impregnation, conventional heating, and ohmic heating. Additionally, combined vacuum impregnation/conventional heating and vacuum impregnation/ohmic heating treatments were evaluated. The above treatments were applied at 30, 40 and 50  ℃ and combined with air-drying at 40 ℃ in order to obtain an apple snack rich in L-arginine. Both the impregnation kinetics of L-arginine and sample color were evaluated. The impregnated samples created using vacuum impregnation/ohmic heating at 50 ℃ presented a high content of L-arginine, an effect attributed primarily to electropermeabilization. Overall, vacuum impregnation/ohmic heating treatment at 50 ℃, followed by drying at 40 ℃, was the best process for obtaining an apple snack rich in L-arginine.

  7. Malate and Aspartate Increase L-Arginine and Nitric Oxide and Attenuate Hypertension.

    PubMed

    Hou, Entai; Sun, Na; Zhang, Fuchang; Zhao, Chenyang; Usa, Kristie; Liang, Mingyu; Tian, Zhongmin

    2017-05-23

    Fumarase catalyzes the interconversion of fumarate and L-malate in the tricarboxylic acid cycle. The Dahl salt-sensitive (SS) rat, a model of salt-sensitive hypertension, exhibits fumarase insufficiencies. To investigate the mechanism mediating the effect of fumarase-related metabolites on hypertension, we considered the pathway in which L-malate can be converted to oxaloacetate, aspartate, argininosuccinate, and L-arginine, the substrate of nitric oxide (NO) synthase. The levels of aspartate, citrulline, L-arginine, and NO were significantly decreased in the kidneys of SS rats compared to salt-insensitive consomic SS.13 BN rats. Knockdown of fumarase in human kidney cells and vascular endothelial cells resulted in decreased levels of malate, aspartate, L-arginine, and NO. Supplementation of aspartate or malate increased renal levels of L-arginine and NO and attenuated hypertension in SS rats. These findings reveal a multi-step metabolic pathway important for hypertension in which malate and aspartate may modulate blood pressure by altering levels of L-arginine and NO. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Biotechnological production of polyamines by bacteria: recent achievements and future perspectives.

    PubMed

    Schneider, Jens; Wendisch, Volker F

    2011-07-01

    In Bacteria, the pathways of polyamine biosynthesis start with the amino acids L-lysine, L-ornithine, L-arginine, or L-aspartic acid. Some of these polyamines are of special interest due to their use in the production of engineering plastics (e.g., polyamides) or as curing agents in polymer applications. At present, the polyamines for industrial use are mainly synthesized on chemical routes. However, since a commercial market for polyamines as well as an industry for the fermentative production of amino acid exist, and since bacterial strains overproducing the polyamine precursors L-lysine, L-ornithine, and L-arginine are known, it was envisioned to engineer these amino acid-producing strains for polyamine production. Only recently, researchers have investigated the potential of amino acid-producing strains of Corynebacterium glutamicum and Escherichia coli for polyamine production. This mini-review illustrates the current knowledge of polyamine metabolism in Bacteria, including anabolism, catabolism, uptake, and excretion. The recent advances in engineering the industrial model bacteria C. glutamicum and E. coli for efficient production of the most promising polyamines, putrescine (1,4-diaminobutane), and cadaverine (1,5-diaminopentane), are discussed in more detail.

  9. Studies on the advent of ureotelism. Factors that render the hepatic arginase of the Mexican axolotl able to hydrolyse endogenous arginine

    PubMed Central

    Palacios, R.; Tarrab, Rebeca; Soberón, G.

    1968-01-01

    1. A study was undertaken of the conditions that might operate in the synthesis and hydrolysis of arginine by axolotl liver homogenate to test a previous postulate that liver arginase of the non-metamorphosed Mexican axolotl is not able to hydrolyse arginine formed from citrulline and aspartic acid, though it can split exogenous arginine, and also that an enhanced capacity to hydrolyse endogenous arginine plays a major role in the advent of ureotelism observed during the metamorphosis of the axolotl. 2. It was found that the arginase from axolotl liver is very unstable under the conditions followed, contrary to what is observed in rat liver. 3. Axolotl arginase is able to hydrolyse endogenous arginine if preserved. 4. Mn2+ protects the enzyme and renders it able to split endogenous arginine. 5. It is suggested that the metal ion produces a change of conformation of the enzyme that, being stable, is capable of hydrolysing the amino acid, or that the new conformation is appropriate for interaction with the sites of arginine synthesis. PMID:5701670

  10. Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells

    PubMed Central

    Stadelmann, Britta; Merino, María C.; Persson, Lo; Svärd, Staffan G.

    2012-01-01

    In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the host´s production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI). Reduced intestinal epithelial cell (IEC) proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful and that

  11. Specificity determinants for lysine incorporation in Staphylococcus aureus peptidoglycan as revealed by the structure of a MurE enzyme ternary complex.

    PubMed

    Ruane, Karen M; Lloyd, Adrian J; Fülöp, Vilmos; Dowson, Christopher G; Barreteau, Hélène; Boniface, Audrey; Dementin, Sébastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Gobec, Stanislav; Dessen, Andréa; Roper, David I

    2013-11-15

    Formation of the peptidoglycan stem pentapeptide requires the insertion of both L and D amino acids by the ATP-dependent ligase enzymes MurC, -D, -E, and -F. The stereochemical control of the third position amino acid in the pentapeptide is crucial to maintain the fidelity of later biosynthetic steps contributing to cell morphology, antibiotic resistance, and pathogenesis. Here we determined the x-ray crystal structure of Staphylococcus aureus MurE UDP-N-acetylmuramoyl-L-alanyl-D-glutamate:meso-2,6-diaminopimelate ligase (MurE) (E.C. 6.3.2.7) at 1.8 Å resolution in the presence of ADP and the reaction product, UDP-MurNAc-L-Ala-γ-D-Glu-L-Lys. This structure provides for the first time a molecular understanding of how this Gram-positive enzyme discriminates between L-lysine and D,L-diaminopimelic acid, the predominant amino acid that replaces L-lysine in Gram-negative peptidoglycan. Despite the presence of a consensus sequence previously implicated in the selection of the third position residue in the stem pentapeptide in S. aureus MurE, the structure shows that only part of this sequence is involved in the selection of L-lysine. Instead, other parts of the protein contribute substrate-selecting residues, resulting in a lysine-binding pocket based on charge characteristics. Despite the absolute specificity for L-lysine, S. aureus MurE binds this substrate relatively poorly. In vivo analysis and metabolomic data reveal that this is compensated for by high cytoplasmic L-lysine concentrations. Therefore, both metabolic and structural constraints maintain the structural integrity of the staphylococcal peptidoglycan. This study provides a novel focus for S. aureus-directed antimicrobials based on dual targeting of essential amino acid biogenesis and its linkage to cell wall assembly.

  12. Specificity Determinants for Lysine Incorporation in Staphylococcus aureus Peptidoglycan as Revealed by the Structure of a MurE Enzyme Ternary Complex*

    PubMed Central

    Ruane, Karen M.; Lloyd, Adrian J.; Fülöp, Vilmos; Dowson, Christopher G.; Barreteau, Hélène; Boniface, Audrey; Dementin, Sébastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Gobec, Stanislav; Dessen, Andréa; Roper, David I.

    2013-01-01

    Formation of the peptidoglycan stem pentapeptide requires the insertion of both l and d amino acids by the ATP-dependent ligase enzymes MurC, -D, -E, and -F. The stereochemical control of the third position amino acid in the pentapeptide is crucial to maintain the fidelity of later biosynthetic steps contributing to cell morphology, antibiotic resistance, and pathogenesis. Here we determined the x-ray crystal structure of Staphylococcus aureus MurE UDP-N-acetylmuramoyl-l-alanyl-d-glutamate:meso-2,6-diaminopimelate ligase (MurE) (E.C. 6.3.2.7) at 1.8 Å resolution in the presence of ADP and the reaction product, UDP-MurNAc-l-Ala-γ-d-Glu-l-Lys. This structure provides for the first time a molecular understanding of how this Gram-positive enzyme discriminates between l-lysine and d,l-diaminopimelic acid, the predominant amino acid that replaces l-lysine in Gram-negative peptidoglycan. Despite the presence of a consensus sequence previously implicated in the selection of the third position residue in the stem pentapeptide in S. aureus MurE, the structure shows that only part of this sequence is involved in the selection of l-lysine. Instead, other parts of the protein contribute substrate-selecting residues, resulting in a lysine-binding pocket based on charge characteristics. Despite the absolute specificity for l-lysine, S. aureus MurE binds this substrate relatively poorly. In vivo analysis and metabolomic data reveal that this is compensated for by high cytoplasmic l-lysine concentrations. Therefore, both metabolic and structural constraints maintain the structural integrity of the staphylococcal peptidoglycan. This study provides a novel focus for S. aureus-directed antimicrobials based on dual targeting of essential amino acid biogenesis and its linkage to cell wall assembly. PMID:24064214

  13. Inhibitory Effects of Lysine Analogues on t-PA Induced Whole Blood Clot Lysis

    DTIC Science & Technology

    1994-01-01

    aminocaproic acid (EACA) and trans-4-amino- methyl cyclohexane carboxylic acid (AMCA) are used to prevent excessive bleeding in patients with... aminocaproic acid (EACA) and the others have lower affinity binding sites (K&=5 mM) (5). The lysine analogues EACA and trans-4-aniinomethyl...JL, Wissler FC. Quantitative determination of the binding of epsilon- aminocaproic acid to native plasminogen. J Biol Chem 253, 727-732, 1978. 6

  14. Investigating on the fermentation behavior of six lactic acid bacteria strains in barley malt wort reveals limitation in key amino acids and buffer capacity.

    PubMed

    Nsogning, Sorelle Dongmo; Fischer, Susann; Becker, Thomas

    2018-08-01

    Understanding lactic acid bacteria (LAB) fermentation behavior in malt wort is a milestone towards flavor improvement of lactic acid fermented malt beverages. Therefore, this study aims to outline deficiencies that may exist in malt wort fermentation. First, based on six LAB strains, cell viability and vitality were evaluated. Second, sugars, organic acids, amino acids, pH value and buffering capacity (BC) were monitored. Finally, the implication of key amino acids, fructose and wort BC on LAB growth was determined. Short growth phase coupled with prompt cell death and a decrease in metabolic activity was observed. Low wort BC caused rapid pH drop with lactic acid accumulation, which conversely increased the BC leading to less pH change at late-stage fermentation. Lactic acid content (≤3.9 g/L) was higher than the reported inhibitory concentration (1.8 g/L). Furthermore, sugars were still available but fructose and key amino acids lysine, arginine and glutamic acid were considerably exhausted (≤98%). Wort supplementations improved cell growth and viability leading to conclude that key amino acid depletion coupled with low BC limits LAB growth in malt wort. Then, a further increase in organic acid reduces LAB viability. This knowledge opens doors for LAB fermentation process optimization in malt wort. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Effect of lysine clonixinate on the pharmacokinetics and anticoagulant activity of phenprocoumon.

    PubMed

    Russmann, S; Dilger, K; Trenk, D; Nagyivanyi, P; Jähnchen, E

    2001-11-01

    The effect of the non-steroidal anti-inflammatory drug lysine clonixinate ([2-(3-chloro-o-toluidino)nicotinic acid]-L-lysinate, CAS 55837-30-4) on the pharmacokinetics and anticoagulant activity of phenprocoumon (4-hydroxy-3-(1-phenylpropyl)-coumarin, CAS 435-97-2) was investigated in an open, randomised, two-fold, cross-over study in 12 healthy male volunteers. These subjects received a single dose of 18 mg phenprocoumon without or with concomitant treatment with lysine clonixinate (125 mg five times a day for 3 days before and 13 days after ingestion of a single dose of phenprocoumon). Pharmacokinetic parameters of phenprocoumon following oral administration were: CL/f: 0.779 +/- 0.157 ml/min, half-life of elimination: 147.2 +/- 19.9 h; free fraction in serum: 0.51 +/- 0.20%. These parameters were not significantly altered by concomitant treatment with lysine clonixinate. Prothrombin time increased from 13.3 +/- 1.3 s (at time 0) to 17.7 +/- 2.7 s following phenprocoumon and from 13.3 +/- 1.2 s to 18.0 +/- 2.2 s following combined administration. Prothrombin time returned to the pretreatment values 240 h after administration of phenprocoumon. The integrated effect (AUEC0-288 h) was identical following both treatments (4.303 +/- 461 and 4.303 +/- 312 s x h for phenprocoumon alone and phenprocoumon with lysine clonixinate, respectively). Thus, lysine clonixinate administered in therapeutic doses does not affect the pharmacokinetics and anticoagulant activity of phenproxoumon.

  16. Lysine Requirements of Healthy Pregnant Women are Higher During Late Stages of Gestation Compared to Early Gestation.

    PubMed

    Payne, Magdalene; Stephens, Trina; Lim, Kenneth; Ball, Ronald O; Pencharz, Paul B; Elango, Rajavel

    2018-01-01

    Lysine is the first limiting amino acid in cereal proteins and is found mainly in animal-derived products. Current Dietary Reference Intake (DRI) recommendations extrapolate lysine requirements during pregnancy from nonpregnant adult data, and may underestimate true requirements. Our objective is to define a quantitative lysine requirement in healthy pregnant women and to determine whether requirements vary between 2 phases of gestation. Fourteen pregnant women in early (12-19 wk) and 19 women in late (33-39 wk) gestation were studied using the indicator amino acid oxidation technique. Individual lysine intakes (6-84 mg · kg-1 · d-1, deficient to excess) were tested on each study day as a crystalline amino acid mixture based on egg protein composition. Isonitrogenous diets maintained protein intake at 1.5 g · kg-1 · d-1 and calorie intake at 1.7 times resting energy expenditure during each study day. Phenylalanine and tyrosine intakes were held constant across all lysine intakes. Breath and urine samples were collected at baseline and isotopic steady state. Lysine requirements were determined by measuring the oxidation of L-[1-13C]-phenylalanine to 13CO2 (F13CO2). Biphase linear regression crossover analysis was used to determine a breakpoint (which represents the estimated average requirement, EAR) in F13CO2. The EAR for lysine during early gestation was determined to be 36.6 mg · kg-1 · d-1 (R2 = 0.484, upper 95% CI = 46.2 mg · kg-1 · d-1), similar to an earlier adult requirement of 36 mg · kg-1 · d-1. The EAR for lysine during late gestation was determined to be 50.3 mg · kg-1 · d-1 (R2 = 0.664, upper 95% CI = 60.4 mg · kg-1 · d-1), 23% higher than the current pregnancy DRI EAR recommendation of 41 mg · kg-1 · d-1. Our results suggest that lysine requirements are higher during late gestation compared to early gestation, and that current dietary lysine recommendations during late

  17. Diminished Global Arginine Bioavailability and Increased Arginine Catabolism as Metabolic Profile of Increased Cardiovascular Risk

    PubMed Central

    Tang, W. H. Wilson; Wang, Zeneng; Cho, Leslie; Brennan, Danielle M.; Hazen, Stanley L.

    2009-01-01

    Objective We hypothesized that an integrated assessment of arginine with its catabolic products may better predict cardiovascular risks than arginine levels alone. Background Arginine is the sole nitrogen source for nitric oxide (NO) synthesis. The major catabolic products of arginine are ornithine and citrulline. Methods Plasma levels of free arginine, ornithine, citrulline and the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) were measured using LC/MS/MS. We examined the relationship of global arginine bioavailability ratio (GABR, defined as arginine/[ornithine+citrulline]) vs. arginine and its catabolic metabolites to prevalence of coronary artery disease (CAD) and incidence of major adverse cardiovascular events (MACE = death, myocardial infarction, stroke) over a 3-year follow-up in 1,010 subjects undergoing elective cardiac catheterization. Results Patients with CAD had significantly lower GABR [median(IQR); 1.06(0.75, 1.31) versus 1.27(0.96, 1.73), p<0.001] and arginine levels [mean: 68 ±20 μM versus 74 ±24 μM, p<0.001) than those without CAD. After adjusting for Framingham risk score, C-reactive protein, and renal function, lower GABR (but not arginine levels) and higher citrulline levels remained significantly associated with both prevalence of CAD [adjusted odds-ratio (OR) 3.93, p<0.001 and 5.98, p<0.001, respectively] and 3-year risk for incidence of MACE [adjusted Hazard ratio (HR) 1.98, p=0.025 and 2.40, p=0.01, respectively], and remained significant after adjusting for ADMA. Conclusions GABR may serve as a more comprehensive concept of reduced NO synthetic capacity compared to systemic arginine levels. Diminished GABR and high citrulline levels are associated with both development of atherosclerotic CAD and heightened long-term risk for major adverse cardiac events. PMID:19477356

  18. Arginine-rich proteins in spherical inclusions of human locus coeruleus neurons demonstrated by benzil modification.

    PubMed

    Panayotacopoulou, M T; Issidorides, M R

    1984-11-01

    Previous studies have shown that aminergic neurons in the normal human brain contain acidophilic cytoplasmic inclusions--called protein bodies (PBs)--that are reduced or absent in parkinsonism and disrupted in depression. The purpose of the present study was to elucidate the constitution of PBs in five formalin-fixed normal human brains using histochemical methods specific for histones, protamines, and the amino acid arginine. PBs were revealed with alkaline fast green and bromphenol blue, exhibiting a high content in histones and in protamines. They developed blue metachromasia with phosphotungstic acid-hematoxylin and green fluorescence with phenanthrenequinone, which established the presence of arginyl residues. Using benzil, which selectively modifies the guanido group of arginine, staining was blocked for each of the above two methods. The application of Mallory's trichrome procedure after benzil differentiated the PBs into an unstained core and a still fuchsinophilic rim. Since the fuchsinophilia of the rim was shown to persist after acetylation as well, we suggest that this rim probably contains acidic macromolecules that attach to the basic charges of the amphoteric acid fuchsin. We conclude that the PB are complex structures consisting of a core segregating arginine-rich proteins and a rim which probably contains macromolecules of an acidic nature.

  19. Clinical Outcome And Arginine Serum of Acute Ischemic Stroke Patients Supplemented by Snakehead Fish Extract

    NASA Astrophysics Data System (ADS)

    Pudjonarko, Dwi; Retnaningsih; Abidin, Zainal

    2018-02-01

    Background: Levels of arginine associated with clinical outcome in acute ischemic stroke (AIS). Arginine is a protein needed to synthesis nitric oxide (NO), a potential vasodilator and antioxidant. Snakehead fish is a source of protein which has antioxidant activity. Snakehead fish contains mineral, vitamin, and amino acids. One of the amino acids that were found quite high in snakehead fish extract is arginine. The aim of this study was done to determine the effect of snakehead fish extracts (SFE) on serum arginin levels and clinical outcome of AIS patients. Methods: It was double-blind randomized pretest-posttest control group design, with. AIS patients were divided into two groups i.e. snakehead fish extracts (SFE) and control. SFE group were administered 15 grams SFE for 7 days . Arginine serum levels and clinical outcome (measured by National Institute of Health Stroke Scale = NIHSS) were measured before and after treatment, other related factors were also analyzed in Logistic regression. Results: A total of 42 subjects who were performed random allocation as SFE or control group. There was no differences in subject characteristics between the two groups. There was a differences Δ arginine serum levels between SFE and control (33.6±19.95 μmol/L 0.3±2.51 μmol/L p<0.001). Change in NIHSS score in SFE improved significantly compared to the control group (4.14 ± 2.03; 2.52 ± 1.81;p=0.009 ). Logistic regression analysis showed only female gender factor that affected on improvement of NIHSS (OR=7; p=0,01). Conclusion: There is Clinical outcome improvement and enhancement of arginine serum levels in AIS patient with snakehead fish extract supplementation.

  20. Supplemental dietary arginine accelerates intestinal mucosal regeneration and enhances bacterial clearance following radiation enteritis in rats.

    PubMed

    Gurbuz, A T; Kunzelman, J; Ratzer, E E

    1998-02-01

    Arginine is a dibasic amino acid with significant metabolic and immunologic, effects especially in trauma and stress situations. Arginine supplementation has been shown to promote wound healing and improve immune system. We designed a study to evaluate the effects of supplemental dietary arginine on intestinal mucosal recovery and bacterial translocation and bacterial clearance after induction of radiation injury in rats. Twenty-one male Sprague-Dawley rats were subjected to a single dose of 1100 rads of abdominal X radiation. Rats were divided into three groups; the first group received diet enriched with 2% arginine, the second group with 4% arginine, and the third group with isonitrogenous 4% glycine. Rats were sacrificed 7 days after the radiation. Blood was drawn for arginine levels and mesenteric lymph nodes were harvested for quantitative aerobic and anaerobic cultures. Segments of ileum and jejunum were evaluated for villous height, number of villi per centimeter of intestine, and the number of mucous cells per villous. Arginine is absorbed reliably from the gut following oral administration. Dietary 4% arginine supplementation enhanced bacterial clearance from mesenteric lymph nodes compared to 2% arginine and 4% glycine supplemented diet following radiation enteritis in rats. Four percent arginine resulted in clear improvement in intestinal mucosal recovery when compared to 2% arginine and 4% glycine after abdominal irradiation in rats.

  1. Conformational profile of a proline-arginine hybrid

    PubMed Central

    Revilla-López, Guillermo; Jiménez, Ana I.; Cativiela, Carlos; Nussinov, Ruth; Alemán, Carlos; Zanuy, David

    2010-01-01

    The intrinsic conformational preferences of a new non-proteinogenic amino acid have been explored by computational methods. This tailored molecule, named (βPro)Arg, is conceived as a replacement for arginine in bioactive peptides when the stabilization of folded turn-like conformations is required. The new residue features a proline skeleton that bears the guanidilated side chain of arginine at the Cβ position of the five-membered pyrrolidine ring, either in a cis or a trans orientation with respect to the carboxylic acid. The conformational profile of the N-acetyl-N'-methylamide derivatives of the cis and trans isomers of (βPro)Arg has been examined in the gas phase and in solution by B3LYP/6–31+G(d,p) calculations and molecular dynamics simulations. The main conformational features of both isomers represent a balance between geometric restrictions imposed by the five-membered pyrrolidine ring and the ability of the guanidilated side chain to interact with the backbone through hydrogen-bonds. Thus, both cis and trans (βPro)Arg exhibit a preference for the αL conformation as a consequence of the interactions established between the guanidinium moiety and the main-chain amide groups. PMID:20886854

  2. Conformational profile of a proline-arginine hybrid.

    PubMed

    Revilla-López, Guillermo; Jiménez, Ana I; Cativiela, Carlos; Nussinov, Ruth; Alemán, Carlos; Zanuy, David

    2010-10-25

    The intrinsic conformational preferences of a new nonproteinogenic amino acid have been explored by computational methods. This tailored molecule, named ((β)Pro)Arg, is conceived as a replacement for arginine in bioactive peptides when the stabilization of folded turn-like conformations is required. The new residue features a proline skeleton that bears the guanidilated side chain of arginine at the C(β) position of the five-membered pyrrolidine ring, in either a cis or a trans orientation with respect to the carboxylic acid. The conformational profiles of the N-acetyl-N'-methylamide derivatives of the cis and trans isomers of ((β)Pro)Arg have been examined in the gas phase and in solution by B3LYP/6-31+G(d,p) calculations and molecular dynamics simulations. The main conformational features of both isomers represent a balance between geometric restrictions imposed by the five-membered pyrrolidine ring and the ability of the guanidilated side chain to interact with the backbone through hydrogen bonds. Thus, both cis- and trans-((β)Pro)Arg exhibit a preference for the α(L) conformation as a consequence of the interactions established between the guanidinium moiety and the main-chain amide groups.

  3. A defined medium for Leishmania culture allows definition of essential amino acids.

    PubMed

    Nayak, Archana; Akpunarlieva, Snezhana; Barrett, Michael; Burchmore, Richard

    2018-02-01

    Axenic culture of Leishmania is generally performed in rich, serum-supplemented media which sustain robust growth over multiple passages. The use of such undefined media, however, obscures proteomic analyses and confounds the study of metabolism. We have established a simple, defined culture medium that supports the sustained growth of promastigotes over multiple passages and which yields parasites that have similar infectivity to macrophages to parasites grown in a conventional semi-defined medium. We have exploited this medium to investigate the amino acid requirements of promastigotes in culture and have found that phenylalanine, tryptophan, arginine, leucine, lysine and valine are essential for viability in culture. Most of the 20 proteogenic amino acids promote growth of Leishmania promastigotes, with the exception of alanine, asparagine, and glycine. This defined medium will be useful for further studies of promastigote substrate requirements, and will facilitate future proteomic and metabolomic analyses. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Child Stunting is Associated with Low Circulating Essential Amino Acids.

    PubMed

    Semba, Richard D; Shardell, Michelle; Sakr Ashour, Fayrouz A; Moaddel, Ruin; Trehan, Indi; Maleta, Kenneth M; Ordiz, M Isabel; Kraemer, Klaus; Khadeer, Mohammed A; Ferrucci, Luigi; Manary, Mark J

    2016-04-01

    Stunting affects about one-quarter of children under five worldwide. The pathogenesis of stunting is poorly understood. Nutritional interventions have had only modest effects in reducing stunting. We hypothesized that insufficiency in essential amino acids may be limiting the linear growth of children. We used a targeted metabolomics approach to measure serum amino acids, glycerophospholipids, sphingolipids, and other metabolites using liquid chromatography-tandem mass spectrometry in 313 children, aged 12-59months, from rural Malawi. Children underwent anthropometry. Sixty-two percent of the children were stunted. Children with stunting had lower serum concentrations of all nine essential amino acids (tryptophan, isoleucine, leucine, valine, methionine, threonine, histidine, phenylalanine, lysine) compared with nonstunted children (p<0.01). In addition, stunted children had significantly lower serum concentrations of conditionally essential amino acids (arginine, glycine, glutamine), non-essential amino acids (asparagine, glutamate, serine), and six different sphingolipids compared with nonstunted children. Stunting was also associated with alterations in serum glycerophospholipid concentrations. Our findings support the idea that children with a high risk of stunting may not be receiving an adequate dietary intake of essential amino acids and choline, an essential nutrient for the synthesis of sphingolipids and glycerophospholipids. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  5. The Preventive Effect of L-Lysine on Lysozyme Glycation in Type 2 Diabetes.

    PubMed

    Mirmiranpour, Hossein; Khaghani, Shahnaz; Bathaie, S Zahra; Nakhjavani, Manouchehr; Kebriaeezadeh, Abbas; Ebadi, Maryam; Gerayesh-Nejad, Siavash; Zangooei, Mohammad

    2016-01-01

    Lysozyme is a bactericidal enzyme whose structure and functions change in diabetes. Chemical chaperones are small molecules including polyamines (e.g. spermine), amino acids (e.g. L-lysine) and polyols (e.g. glycerol). They can improve protein conformation in several stressful conditions such as glycation. In this study, the authors aimed to observe the effect of L-lysine as a chemical chaperone on structure and function of glycated lysozyme. In this study, in vitro and in vivo effects of L-lysine on lysozyme glycation were investigated. Lysozyme was incubated with glucose and/or L-lysine, followed by an investigation of its structure by electrophoresis, fluorescence spectroscopy, and circular dichroism spectroscopy and also assessment of its bactericidal activity against M. lysodeikticus. In the clinical trial, patients with type 2 diabetes mellitus (T2DM) were randomly divided into two groups of 25 (test and control). All patients received metformin and glibenclamide for a three months period. The test group was supplemented with 3 g/day of L-lysine. The quantity and activity of lysozyme and other parameters were then measured. Among the test group, L-lysine was found to reduce the advanced glycation end products (AGEs) in the sera of patients with T2DM and in vitro condition. This chemical chaperone reversed the alteration in lysozyme structure and function due to glycation and resulted in increased lysozyme activity. Structure and function of glycated lysozyme are significantly improved by l-lysine; therefore it can be considered an effective therapeutic supplementation in T2DM, decreasing the risk of infection in these patients.

  6. The effects on plasma L-arginine levels of combined oral L-citrulline and L-arginine supplementation in healthy males.

    PubMed

    Suzuki, Takashi; Morita, Masahiko; Hayashi, Toshio; Kamimura, Ayako

    2017-02-01

    We investigated the effects of combining 1 g of l-citrulline and 1 g of l-arginine as oral supplementation on plasma l-arginine levels in healthy males. Oral l-citrulline plus l-arginine supplementation more efficiently increased plasma l-arginine levels than 2 g of l-citrulline or l-arginine, suggesting that oral l-citrulline and l-arginine increase plasma l-arginine levels more effectively in humans when combined.

  7. Insights into the molecular basis for substrate binding and specificity of the wild-type L-arginine/agmatine antiporter AdiC.

    PubMed

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Gapsys, Vytautas; Ucurum, Zöhre; de Groot, Bert L; Fotiadis, Dimitrios

    2016-09-13

    Pathogenic enterobacteria need to survive the extreme acidity of the stomach to successfully colonize the human gut. Enteric bacteria circumvent the gastric acid barrier by activating extreme acid-resistance responses, such as the arginine-dependent acid resistance system. In this response, l-arginine is decarboxylated to agmatine, thereby consuming one proton from the cytoplasm. In Escherichia coli, the l-arginine/agmatine antiporter AdiC facilitates the export of agmatine in exchange of l-arginine, thus providing substrates for further removal of protons from the cytoplasm and balancing the intracellular pH. We have solved the crystal structures of wild-type AdiC in the presence and absence of the substrate agmatine at 2.6-Å and 2.2-Å resolution, respectively. The high-resolution structures made possible the identification of crucial water molecules in the substrate-binding sites, unveiling their functional roles for agmatine release and structure stabilization, which was further corroborated by molecular dynamics simulations. Structural analysis combined with site-directed mutagenesis and the scintillation proximity radioligand binding assay improved our understanding of substrate binding and specificity of the wild-type l-arginine/agmatine antiporter AdiC. Finally, we present a potential mechanism for conformational changes of the AdiC transport cycle involved in the release of agmatine into the periplasmic space of E. coli.

  8. Anaerobic degradation of amino acids generated from the hydrolysis of sewage sludge.

    PubMed

    Park, Junghoon; Park, Seyong; Kim, Moonil

    2014-01-01

    The anaerobic degradation of each amino acid that could be generated through the hydrolysis of sewage sludge was evaluated. Stickland reaction as an intermediate reaction between two kinds of amino acids was restricted in order to evaluate each amino acid. Changes in the chemical oxygen demand (COD), T-N, NH4(+)-N, biogas, and CH4 were analysed for the anaerobic digestion process. The initial nitrogen concentration of all amino acids is adjusted as 1000 mg/L. The degradation rate of the amino acids was determined based on the ammonia form of nitrogen, which is generated by the deamination of amino acids. Among all amino acids, such as alpha-alanine, beta-alanine, lysine, arginine, glycine, histidine, cysteine, methionine, and leucine, deamination rates of cysteine, leucine, and methionine were just 61.55%, 54.59%, and 46.61%, respectively, and they had low removal rates of organic matter and showed very low methane production rates of 13.55, 71.04, and 80.77 mL CH4/g CODin, respectively. Especially for cysteine, the methane content was maintained at approximately 7% during the experiment. If wastewater contains high levels of cysteine, leucine, and methionine and Stickland reaction is not prepared, these amino acids may reduce the efficiency of the anaerobic digestion.

  9. Inhibition of lytic infection of pseudorabies virus by arginine depletion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, H.-C.; Kao, Y.-C.; Chang, T-J.

    2005-08-26

    Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzingmore » the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression.« less

  10. Inhibition of nitric oxide synthase abrogates lipopolysaccharides-induced up-regulation of L-arginine uptake in rat alveolar macrophages

    PubMed Central

    Hammermann, Rainer; Stichnote, Christina; Closs, Ellen Ildicho; Nawrath, Hermann; Racké, Kurt

    2001-01-01

    It was tested whether the inducible nitric oxide synthase (iNOS) pathway might be involved in lipopolysaccharides-(LPS)-induced up-regulation of L-arginine transport in rat alveolar macrophages (AMΦ). AMΦ were cultured in absence or presence of LPS. Nitrite accumulation was determined in culture media and cells were used to study [3H]-L-arginine uptake or to isolate RNA for RT – PCR. Culture in presence of LPS (1 μg ml−1, 20 h) caused 11 fold increase of nitrite accumulation and 2.5 fold increase of [3H]-L-arginine uptake. The inducible NO synthase (iNOS) inhibitor 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) present alone during culture had only marginal effects on [3H]-L-arginine uptake. However, AMT present during culture additionally to LPS, suppressed LPS-induced nitrite accumulation and LPS-stimulated [3H]-L-arginine uptake in the same concentration-dependent manner. AMT present only for the last 30 min of the culture period had similar effects on [3H]-L-arginine uptake. AMT present only during the uptake period also inhibited LPS-stimulated [3H]-L-arginine uptake, but with lower potency. The inhibitory effect of AMT could not be opposed by the NO releasing compound DETA NONOate. LPS caused an up-regulation of the mRNA for the cationic amino acid transporter CAT-2B, and this effect was not affected by AMT. AMT (100 μM) did not affect L-arginine transport studied by electrophysiological techniques in Xenopus laevis oocytes expressing either the human cationic amino acid transporter hCAT-1 or hCAT-2B. In conclusion, iNOS inhibition in rat AMΦ abolished LPS-activated L-arginine uptake. This effect appears to be caused by reduced flow of L-arginine through the iNOS pathway. PMID:11375254

  11. Global Proteomics Analysis of Protein Lysine Methylation.

    PubMed

    Cao, Xing-Jun; Garcia, Benjamin A

    2016-11-01

    Lysine methylation is a common protein post-translational modification dynamically mediated by protein lysine methyltransferases (PKMTs) and protein lysine demethylases (PKDMs). Beyond histone proteins, lysine methylation on non-histone proteins plays a substantial role in a variety of functions in cells and is closely associated with diseases such as cancer. A large body of evidence indicates that the dysregulation of some PKMTs leads to tumorigenesis via their non-histone substrates. However, most studies on other PKMTs have made slow progress owing to the lack of approaches for extensive screening of lysine methylation sites. However, recently, there has been a series of publications to perform large-scale analysis of protein lysine methylation. In this unit, we introduce a protocol for the global analysis of protein lysine methylation in cells by means of immunoaffinity enrichment and mass spectrometry. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  12. Lysine Malonylation Is Elevated in Type 2 Diabetic Mouse Models and Enriched in Metabolic Associated Proteins*

    PubMed Central

    Du, Yipeng; Cai, Tanxi; Li, Tingting; Xue, Peng; Zhou, Bo; He, Xiaolong; Wei, Peng; Liu, Pingsheng; Yang, Fuquan; Wei, Taotao

    2015-01-01

    Protein lysine malonylation, a newly identified protein post-translational modification (PTM), has been proved to be evolutionarily conserved and is present in both eukaryotic and prokaryotic cells. However, its potential roles associated with human diseases remain largely unknown. In the present study, we observed an elevated lysine malonylation in a screening of seven lysine acylations in liver tissues of db/db mice, which is a typical model of type 2 diabetes. We also detected an elevated lysine malonylation in ob/ob mice, which is another model of type 2 diabetes. We then performed affinity enrichment coupled with proteomic analysis on liver tissues of both wild-type (wt) and db/db mice and identified a total of 573 malonylated lysine sites from 268 proteins. There were more malonylated lysine sites and proteins in db/db than in wt mice. Five proteins with elevated malonylation were verified by immunoprecipitation coupled with Western blot analysis. Bioinformatic analysis of the proteomic results revealed the enrichment of malonylated proteins in metabolic pathways, especially those involved in glucose and fatty acid metabolism. In addition, the biological role of lysine malonylation was validated in an enzyme of the glycolysis pathway. Together, our findings support a potential role of protein lysine malonylation in type 2 diabetes with possible implications for its therapy in the future. PMID:25418362

  13. Role of Protein and Amino Acids in Infant and Young Child Nutrition: Protein and Amino Acid Needs and Relationship with Child Growth.

    PubMed

    Uauy, Ricardo; Kurpad, Anura; Tano-Debrah, Kwaku; Otoo, Gloria E; Aaron, Grant A; Toride, Yasuhiko; Ghosh, Shibani

    2015-01-01

    Over a third of all deaths of children under the age of five are linked to undernutrition. At a 90% coverage level, a core group of ten interventions inclusive of infant and young child nutrition could save one million lives of children under 5 y of age (15% of all deaths) (Lancet 2013). The infant and young child nutrition package alone could save over 220,000 lives in children under 5 y of age. High quality proteins (e.g. milk) in complementary, supplementary and rehabilitation food products have been found to be effective for good growth. Individual amino acids such as lysine and arginine have been found to be factors linked to growth hormone release in young children via the somatotropic axis and high intakes are inversely associated with fat mass index in pre-pubertal lean girls. Protein intake in early life is positively associated with height and weight at 10 y of age. This paper will focus on examining the role of protein and amino acids in infant and young child nutrition by examining protein and amino acid needs in early life and the subsequent relationship with stunting.

  14. [Influence of intestinal microflora on the amino acid composition of lamb feces].

    PubMed

    Combe, E

    1976-01-01

    6 conventional and 5 germfree male lambs were fed ad libitum a UHT sterilized cow milk. Body weight and food intake were recorded. Whole feces were collected for 5 consecutive days. Growth rate reached 259 g/d for the germfree. Daily fecal excretion of dry matter and nitrogenous compounds are not found different in the two groups of animals. The influence of intestinal microflora appears on the biochemical composition of the feces. As compared to the conventional fecal proteins from germfree lambs are very high in threonine and serine and low in lysine. Moreover the difference of amino acid composition between these two groups come not only from the histidine alanine and arginine composition of bacteries; it also involves the high levels of threonine serine cystine and tyrosine of the endogenous digestive proteins.

  15. Glutamine and arginine improve permeability and tight junction protein expression in methotrexate-treated Caco-2 cells.

    PubMed

    Beutheu, Stéphanie; Ghouzali, Ibtissem; Galas, Ludovic; Déchelotte, Pierre; Coëffier, Moïse

    2013-10-01

    Chemotherapy induces an increase of intestinal permeability that is partially related to an alteration of tight junction proteins, occludin and zonula occludens-1 (ZO-1). Protective effects of glutamine on intestinal barrier function have been previously shown but the effects of other amino acids remained poorly documented. Thus, we aimed to evaluate the effects of nine amino acids on intestinal permeability during methotrexate (MTX) treatment in Caco-2 cells. Caco-2 cells were incubated in culture medium supplemented with glutamine, arginine, glutamate, leucine, taurine, citrulline, glycine, histidine or cysteine during 24 h and then treated with MTX (100 ng/ml). The dose of each amino acid was 16.6 fold the physiological plasma concentrations. Barrier function was assessed by transepithelial electrical resistance (TEER), FITC-dextran paracellular flux, occludin and ZO-1 expression and localization. Signaling pathways were also studied. Only glutamine, glutamate, arginine and leucine reversed the decrease of TEER observed after MTX treatment (P < 0.05). Interestingly, the addition of 6-diazo-5-oxo-1-norleucine, an inhibitor of glutaminase, blunted the effect of glutamine on MTX-treated cells (P < 0.05). Glutamine and arginine combination restored TEER and FITC-dextran flux to a similar extent than glutamine alone. In addition, pretreatment of Caco-2 cells with glutamine and arginine, alone or combined, differently limited the decrease of ZO-1 and occludin expression (P < 0.05) and the alteration of their cellular distribution, through c-Jun N-terminal kinase (JNK), Extracellular signal-regulated kinase (ERK) and nuclear factor kappa B (NF-κB) pathways. Glutamine prevented MTX-induced barrier disruption in Caco-2 cells. Arginine also had protective effects but in a lesser extent. The effect of glutamine and arginine should be evaluated in vivo. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  16. Molecular mechanics calculations on deaminooxytocin and on deamino-arginine-vasopressin and its analogues

    NASA Astrophysics Data System (ADS)

    Liwo, A.; Tempczyk, A.; Grzonka, Z.

    1989-01-01

    The backbone conformations of the cyclic moieties of 1-[ β-mercaptopropionic acid]-oxytocin ([Mpa1]-OT), [1- β-mercaptopropionic acid]-arginine-vasopressin ([Mpa1]-AVP), [1-( β'-mercapto- β,β-cyclopentamethylene)propionic acid]-arginine-vasopressin ([Cpp1]-AVP), and [1-thiosalicylic acid]-arginine-vasopressin ([Ths1]-AVP) have been analyzed by means of molecular mechanics. In these calculations, the side chains were simulated by pseudoatoms. For the three last compounds, the calculations were also performed on the whole molecules, in order to shed light on the differences in their biological activity. Their starting conformations were obtained by attaching the acyclic tail and side chains to the lowest energy conformations of the cyclic parts. In the case of [Ths1]-AVP, however, other starting conformations were also examined, which were obtained by attaching the planar benzene ring to the lowest energy conformations of [Mpa1]-AVP. In the calculations, all the degrees of freedom were relaxed and Weiner's force field was used, the parameters required for the benzene parts of [Ths1]-AVP being determined from the experimental data available, as well as from the results of molecular dynamics calculations on the model compounds. The lowest energy conformations of [Mpa1]-AVP and [Cpp1]-AVP are similar, while [Ths1]-AVP differs from them near the disulphide region, due to the presence of a planar benzene ring. Interactions involving the charged guanidine group of arginine make, in each case, an important contribution to the conformational energy. A model description of the shapes of the oxytocin and vasopressin ring has been proposed, which is based on the cyclohexane geometry. This description is in good correlation with the energetics of the conformations corresponding to different shapes.

  17. Free energy of solvated salt bridges: a simulation and experimental study.

    PubMed

    White, Andrew D; Keefe, Andrew J; Ella-Menye, Jean-Rene; Nowinski, Ann K; Shao, Qing; Pfaendtner, Jim; Jiang, Shaoyi

    2013-06-20

    Charged amino acids are the most common on surfaces of proteins and understanding the interactions between these charged amino acids, salt bridging, is crucial for understanding protein-protein interactions. Previous simulations have been limited to implicit solvent or fixed binding geometry due to the sampling required for converged free energies. Using well-tempered metadynamics, we have calculated salt bridge free energy surfaces in water and confirmed the results with NMR experiments. The simulations give binding free energies, quantitative ranking of salt bridging strength, and insights into the hydration of the salt bridges. The arginine-aspartate salt bridge was found to be the weakest and arginine-glutamate the strongest, showing that arginine can discriminate between aspartate and glutamate, whereas the salt bridges with lysine are indistinguishable in their free energy. The salt bridging hydration is found to be complementary to salt bridge orientation with arginine having specific orientations.

  18. Design and Application of Synthetic Receptors for Recognition of Methylated Lysine and Supramolecular Affinity Labeling

    NASA Astrophysics Data System (ADS)

    Gober, Isaiah Nathaniel

    possible ways for detecting PTMs and may find use in the development of new assays for enzymes that lack robust methods for measuring their activity. The third section explores the development of new small molecule receptors capable of selectively binding hydrophilic guests in water, such as the lower methylation states of lysine. We identified a receptor, A2I, that has improved binding affinity and selectivity for dimethyllysine (Kme2). The receptor was discovered and synthesized by using dynamic combinatorial chemistry (DCC) to redesign a small molecule receptor (A2B ) that preferentially binds trimethyllysine (Kme3). Incorporating a biphenyl monomer with ortho-di-substituted carboxylates into the receptor lead to the formation of a salt bridge interaction with Kme2. These favorable electrostatic and hydrogen bonding interactions produced a receptor with 32-fold tighter binding to Kme2, which is the highest affinity synthetic receptor for Kme2 in the context of a peptide that has been reported. This work provides insight into effective strategies for binding hydrophilic, cationic guests in water and is an encouraging result toward a synthetic receptor that selectively binds Kme2 over other methylation states of lysine. In the final section, a small molecule receptor for Kme3 (A 2B) was redesigned using DCC to incorporate either aromatic or acidic amino acids into the receptor. We proposed that the incorporation of amino acids could introduce additional non-covalent interactions (such as cation-pi, electrostatic, and hydrogen bonding) with a guest bound inside the pocket of the receptor. However, selective non-covalent interactions between the amino acid side chain on the modified receptor and the bound methylated lysine guest could not be achieved. This is most likely due to the conformational flexibility of the amino acid-functionalized receptors. Furthermore, attaching amino acids to the receptor seemed to increase non-specific electrostatic interactions, resulting in

  19. Enteral arginine does not increase superior mesenteric arterial blood flow and but induces mucosal growth in neonatal pigs

    USDA-ARS?s Scientific Manuscript database

    Arginine is an essential amino acid in neonates synthesized by gut epithelial cells and a precursor for nitric oxide (NO) that regulates vasodilatation and blood flow. Arginine supplementation has been shown to improve intestinal integrity in ischemia-reperfusion models and low plasma levels are ass...

  20. Characterization of pea (Pisum sativum) seed protein fractions.

    PubMed

    Rubio, Luis A; Pérez, Alicia; Ruiz, Raquel; Guzmán, M Ángeles; Aranda-Olmedo, Isabel; Clemente, Alfonso

    2014-01-30

    Legume seed proteins have to be chemically characterized in order to properly link their nutritional effects with their chemical structure. Vicilin and albumin fractions devoid of cross-contamination, as assessed by mass peptide fingerprinting analysis, were obtained from defatted pea (Pisum sativum cv. Bilbo) meal. The extracted protein fractions contained 56.7-67.7 g non-starch polysaccharides kg⁻¹. The vicilin fraction was higher than legumins in arginine, isoleucine, leucine, phenylalanine and lysine. The most abundant amino acids in the albumin fraction were aspartic acid, glutamic acid, lysine and arginine, and the amounts of methionine were more than double than those in legumins and vicilins. The pea albumin fraction showed a clear enrichment of protease inhibitory activity when compared with the seed meal. In vitro digestibility values for pea proteins were 0.63 ±  0.04, 0.88 ±  0.04 and 0.41 ±  0.23 for legumins, vicilins and albumins respectively. Vicilin and albumin fractions devoid of cross-contamination with other proteins were obtained from pea seed meal. The vicilin fraction also contained low amounts of soluble non-starch polysaccharides and was enriched in isoleucine, leucine, phenylalanine and lysine. In vitro digestibility values for pea proteins were similar or even numerically higher than those for control proteins. © 2013 Society of Chemical Industry.

  1. Tug of war: adding and removing histone lysine methylation in Arabidopsis.

    PubMed

    Xiao, Jun; Lee, Un-Sa; Wagner, Doris

    2016-12-01

    Histone lysine methylation plays a fundamental role in the epigenetic regulation of gene expression in multicellular eukaryotes, including plants. It shapes plant developmental and growth programs as well as responses to the environment. The methylation status of certain amino-acids, in particular of the histone 3 (H3) lysine tails, is dynamically controlled by opposite acting histone methyltransferase 'writers' and histone demethylase 'erasers'. The methylation status is interpreted by a third set of proteins, the histone modification 'readers', which specifically bind to a methylated amino-acid on the H3 tail. Histone methylation writers, readers, and erasers themselves are regulated by intrinsic or extrinsic stimuli; this forms a feedback loop that contributes to development and environmental adaptation in Arabidopsis and other plants. Recent studies have expanded our knowledge regarding the biological roles and dynamic regulation of histone methylation. In this review, we will discuss recent advances in understanding the regulation and roles of histone methylation in plants and animals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Amino Acid and Vitamin Requirements of Several Bacteroides Strains

    PubMed Central

    Quinto, Grace

    1966-01-01

    Nutritional studies were performed on nine Bacteroides strains, by use of the methodology and media of anaerobic rumen microbiology. Ristella perfoetens CCI required l-arginine hydrochloride, l-tryptophan, l-leucine, l-histidine hydrochloride, l-cysteine hydrochloride, dl-valine, dl-tyrosine, and the vitamin calcium-d-pantothenate, since scant turbidity developed in media without these nutrients. R. perfoetens was stimulated by glycine, dl-lysine hydrochloride, dl-isoleucine, l-proline, l-glutamic acid, dl-alanine, dl-phenylalanine, dl-methionine, and the vitamins nicotinamide and p-aminobenzoic acid, since maximal turbidity developed more slowly in media without these nutrients than in complete medium. Medium A-23, which was devised for R. perfoetens, contained salts, 0.0002% nicotinamide and calcium d-pantothenate, 0.00001% p-aminobenzoic acid, 0.044% l-tryptophan, 0.09% l-glutamic acid, and 0.1% of the other 13 amino acids listed above. Zuberella clostridiformis and seven strains of R. pseudoinsolita did not require vitamins, and showed no absolute requirement for any one amino acid. Various strains produced maximal turbidity more slowly in media deficient in l-proline, glycine, l-glutamic acid, dl-serine, l-histidine hydrochloride, dl-alanine, or l-cysteine hydrochloride, than in complete medium. These eight strains grew optimally in medium A-23 plus 0.1% dl-serine but without vitamins. PMID:16349673

  3. C-terminal amino acid residue loss for deprotonated peptide ions containing glutamic acid, aspartic acid, or serine residues at the C-terminus.

    PubMed

    Li, Zhong; Yalcin, Talat; Cassady, Carolyn J

    2006-07-01

    Deprotonated peptides containing C-terminal glutamic acid, aspartic acid, or serine residues were studied by sustained off-resonance irradiation collision-induced dissociation (SORI-CID) in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer with ion production by electrospray ionization (ESI). Additional studies were performed by post source decay (PSD) in a matrix-assisted laser desorption ionization/time-of-flight (MALDI/TOF) mass spectrometer. This work included both model peptides synthesized in our laboratory and bioactive peptides with more complex sequences. During SORI-CID and PSD, [M - H]- and [M - 2H]2- underwent an unusual cleavage corresponding to the elimination of the C-terminal residue. Two mechanisms are proposed to occur. They involve nucleophilic attack on the carbonyl carbon of the adjacent residue by either the carboxylate group of the C-terminus or the side chain carboxylate group of C-terminal glutamic acid and aspartic acid residues. To confirm the proposed mechanisms, AAAAAD was labelled by 18O specifically on the side chain of the aspartic acid residue. For peptides that contain multiple C-terminal glutamic acid residues, each of these residues can be sequentially eliminated from the deprotonated ions; a driving force may be the formation of a very stable pyroglutamatic acid neutral. For peptides with multiple aspartic acid residues at the C-terminus, aspartic acid residue loss is not sequential. For peptides with multiple serine residues at the C-terminus, C-terminal residue loss is sequential; however, abundant loss of other neutral molecules also occurs. In addition, the presence of basic residues (arginine or lysine) in the sequence has no effect on C-terminal residue elimination in the negative ion mode.

  4. Computational Prediction of Protein Epsilon Lysine Acetylation Sites Based on a Feature Selection Method.

    PubMed

    Gao, JianZhao; Tao, Xue-Wen; Zhao, Jia; Feng, Yuan-Ming; Cai, Yu-Dong; Zhang, Ning

    2017-01-01

    Lysine acetylation, as one type of post-translational modifications (PTM), plays key roles in cellular regulations and can be involved in a variety of human diseases. However, it is often high-cost and time-consuming to use traditional experimental approaches to identify the lysine acetylation sites. Therefore, effective computational methods should be developed to predict the acetylation sites. In this study, we developed a position-specific method for epsilon lysine acetylation site prediction. Sequences of acetylated proteins were retrieved from the UniProt database. Various kinds of features such as position specific scoring matrix (PSSM), amino acid factors (AAF), and disorders were incorporated. A feature selection method based on mRMR (Maximum Relevance Minimum Redundancy) and IFS (Incremental Feature Selection) was employed. Finally, 319 optimal features were selected from total 541 features. Using the 319 optimal features to encode peptides, a predictor was constructed based on dagging. As a result, an accuracy of 69.56% with MCC of 0.2792 was achieved. We analyzed the optimal features, which suggested some important factors determining the lysine acetylation sites. We developed a position-specific method for epsilon lysine acetylation site prediction. A set of optimal features was selected. Analysis of the optimal features provided insights into the mechanism of lysine acetylation sites, providing guidance of experimental validation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Method for one-to-one polishing of silicon nitride and silicon oxide

    NASA Technical Reports Server (NTRS)

    Babu, Suryadevara V. (Inventor); Natarajan, Anita (Inventor)

    2009-01-01

    The present invention provides a method of removing silicon nitride at about the same removal rate as silicon dioxide by CMP. The method utilizes a polishing slurry that includes colloidal silica abrasive particles dispersed in water and additives that modulate the silicon dioxide and silicon nitride removal rates such that they are about the same. In one embodiment of the invention, the additive is lysine or lysine mono hydrochloride in combination with picolinic acid, which is effective at a pH of about 8. In another embodiment of the invention, the additive is arginine in combination with picolinic acid, which is effective at a pH of about 10.

  6. Involvement of arginine 878 together with Ca2+ in mouse aminopeptidase A substrate specificity for N-terminal acidic amino-acid residues

    PubMed Central

    Couvineau, Pierre; de Almeida, Hugo; Maigret, Bernard; Llorens-Cortes, Catherine

    2017-01-01

    Aminopeptidase A (APA) is a membrane-bound zinc metalloprotease cleaving, in the brain, the N-terminal aspartyl residue of angiotensin II to generate angiotensin III, which exerts a tonic stimulatory effect on the control of blood pressure in hypertensive animals. Using a refined APA structure derived from the human APA crystal structure, we docked the specific and selective APA inhibitor, EC33 in the presence of Ca2+. We report the presence in the S1 subsite of Arg-887 (Arg-878 in mouse APA), the guanidinium moiety of which established an interaction with the electronegative sulfonate group of EC33. Mutagenic replacement of Arg-878 with an alanine or a lysine residue decreased the affinity of the recombinant enzymes for the acidic substrate, α-L-glutamyl-β-naphthylamide, with a slight decrease in substrate hydrolysis velocity either with or without Ca2+. In the absence of Ca2+, the mutations modified the substrate specificity of APA for the acidic substrate, the mutated enzymes hydrolyzing more efficiently basic and neutral substrates, although the addition of Ca2+ partially restored the acidic substrate specificity. The analysis of the 3D models of the Arg-878 mutated APAs revealed a change in the volume of the S1 subsite, which may impair the binding and/or the optimal positioning of the substrate in the active site as well as its hydrolysis. These findings demonstrate the key role of Arg-878 together with Ca2 + in APA substrate specificity for N-terminal acidic amino acid residues by ensuring the optimal positioning of acidic substrates during catalysis. PMID:28877217

  7. Structural, kinetic and computational investigation of Vitis vinifera DHDPS reveals new insight into the mechanism of lysine-mediated allosteric inhibition.

    PubMed

    Atkinson, Sarah C; Dogovski, Con; Downton, Matthew T; Czabotar, Peter E; Dobson, Renwick C J; Gerrard, Juliet A; Wagner, John; Perugini, Matthew A

    2013-03-01

    Lysine is one of the most limiting amino acids in plants and its biosynthesis is carefully regulated through inhibition of the first committed step in the pathway catalyzed by dihydrodipicolinate synthase (DHDPS). This is mediated via a feedback mechanism involving the binding of lysine to the allosteric cleft of DHDPS. However, the precise allosteric mechanism is yet to be defined. We present a thorough enzyme kinetic and thermodynamic analysis of lysine inhibition of DHDPS from the common grapevine, Vitis vinifera (Vv). Our studies demonstrate that lysine binding is both tight (relative to bacterial DHDPS orthologs) and cooperative. The crystal structure of the enzyme bound to lysine (2.4 Å) identifies the allosteric binding site and clearly shows a conformational change of several residues within the allosteric and active sites. Molecular dynamics simulations comparing the lysine-bound (PDB ID 4HNN) and lysine free (PDB ID 3TUU) structures show that Tyr132, a key catalytic site residue, undergoes significant rotational motion upon lysine binding. This suggests proton relay through the catalytic triad is attenuated in the presence of lysine. Our study reveals for the first time the structural mechanism for allosteric inhibition of DHDPS from the common grapevine.

  8. Unveiling the Mechanism of Arginine Transport through AdiC with Molecular Dynamics Simulations: The Guiding Role of Aromatic Residues

    PubMed Central

    Krammer, Eva-Maria; Ghaddar, Kassem; André, Bruno

    2016-01-01

    Commensal and pathogenic enteric bacteria have developed several systems to adapt to proton leakage into the cytoplasm resulting from extreme acidic conditions. One such system involves arginine uptake followed by export of the decarboxylated product agmatine, carried out by the arginine/agmatine antiporter (AdiC), which thus works as a virtual proton pump. Here, using classical and targeted molecular dynamics, we investigated at the atomic level the mechanism of arginine transport through AdiC of E. coli. Overall, our MD simulation data clearly demonstrate that global rearrangements of several transmembrane segments are necessary but not sufficient for achieving transitions between structural states along the arginine translocation pathway. In particular, local structural changes, namely rotameric conversions of two aromatic residues, are needed to regulate access to both the outward- and inward-facing states. Our simulations have also enabled identification of a few residues, overwhelmingly aromatic, which are essential to guiding arginine in the course of its translocation. Most of them belong to gating elements whose coordinated motions contribute to the alternating access mechanism. Their conservation in all known E. coli acid resistance antiporters suggests that the transport mechanisms of these systems share common features. Last but not least, knowledge of the functional properties of AdiC can advance our understanding of the members of the amino acid-carbocation-polyamine superfamily, notably in eukaryotic cells. PMID:27482712

  9. Effect of supplementation of crystalline lysine on the performance of WL layers in tropics during summer.

    PubMed

    Kumari, K Naga Raja; Reddy, V Ravinder; Preetham, V Chinni; Kumar, D Srinivas; Sen, Arup Ratan; Rao, S Venkata Rama

    2016-04-01

    A trial was conducted to evaluate the effect of lysine concentration in the diet of WL layers with constant ratio of other essential amino acids to lysine. Pullets (528) aged 25 to 36 weeks were fed with test diet containing two protein levels (13.36 and 15.78%) each with 5% concentration of lysine (0.50, 0.55, 0.60, 0.65, and 0.70) and a control with 17% CP and 0.70%, lysine. Each test diet was fed ad libitum to six replicates of eight birds for a period of 12 weeks. Egg production (EP), egg weight (EW), egg mass (EM), feed efficiency (g/g) (FE), body weight gain (BWG), Haugh unit (HU) and yolk colour (YC) were measured. Increased (P ≤ 0.05) EP, EW, EM, FE and BWG were obtained with increasing lysine concentration in diets. Whereas, feed intake/h/day, feed intake/egg, egg shell defects (ESD), mortality and shell thickness were not affected (P ≥ 0.05) by the concentration of lysine in diet. However, higher (P ≤ 0.05) HU score and YC were noticed at low lysine (0.50 %) concentrations. Based on this, it was concluded that WL layers (25-36 weeks) reared in open-sided houses in the tropics require approximately 0.70 % lysine (597.90 vs. 584.39 mg/h/day) in low (13.36% CP) and high (15.78% CP) protein groups in diets containing approximately 2700 kcal of ME/kg in summer.

  10. Molecular tweezers with varying anions: a comparative study.

    PubMed

    Dutt, Som; Wilch, Constanze; Gersthagen, Thomas; Talbiersky, Peter; Bravo-Rodriguez, Kenny; Hanni, Matti; Sánchez-García, Elsa; Ochsenfeld, Christian; Klärner, Frank-Gerrit; Schrader, Thomas

    2013-07-05

    Selective binding of the phosphate-substituted molecular tweezer 1a to protein lysine residues was suggested to explain the inhibition of certain enzymes and the aberrant aggregation of amyloid petide Aβ42 or α-synuclein, which are assumed to be responsible for Alzheimer's and Parkinson's disease, respectively. In this work we systematically investigated the binding of four water-soluble tweezers 1a-d (substituted by phosphate, methanephosphonate, sulfate, or O-methylenecarboxylate groups) to amino acids and peptides containing lysine or arginine residues by using fluorescence spectroscopy, NMR spectroscopy, and isothermal titration calorimetry (ITC). The comparison of the experimental results with theoretical data obtained by a combination of QM/MM and ab initio(1)H NMR shift calculations provides clear evidence that the tweezers 1a-c bind the amino acid or peptide guest molecules by threading the lysine or arginine side chain through the tweezers' cavity, whereas in the case of 1d the guest molecule is preferentially positioned outside the tweezer's cavity. Attractive ionic, CH-π, and hydrophobic interactions are here the major binding forces. The combination of experiment and theory provides deep insight into the host-guest binding modes, a prerequisite to understanding the exciting influence of these tweezers on the aggregation of proteins and the activity of enzymes.

  11. Druggability of methyl-lysine binding sites

    NASA Astrophysics Data System (ADS)

    Santiago, C.; Nguyen, K.; Schapira, M.

    2011-12-01

    Structural modules that specifically recognize—or read—methylated or acetylated lysine residues on histone peptides are important components of chromatin-mediated signaling and epigenetic regulation of gene expression. Deregulation of epigenetic mechanisms is associated with disease conditions, and antagonists of acetyl-lysine binding bromodomains are efficacious in animal models of cancer and inflammation, but little is known regarding the druggability of methyl-lysine binding modules. We conducted a systematic structural analysis of readers of methyl marks and derived a predictive druggability landscape of methyl-lysine binding modules. We show that these target classes are generally less druggable than bromodomains, but that some proteins stand as notable exceptions.

  12. Overexpression of Wild-Type Aspartokinase Increases l-Lysine Production in the Thermotolerant Methylotrophic Bacterium Bacillus methanolicus▿

    PubMed Central

    Jakobsen, Øyvind M.; Brautaset, Trygve; Degnes, Kristin F.; Heggeset, Tonje M. B.; Balzer, Simone; Flickinger, Michael C.; Valla, Svein; Ellingsen, Trond E.

    2009-01-01

    Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar Vmax values (between 47 and 58 μmol/min/mg protein) and Km values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC50], 0.1 mM) and by l-lysine (IC50, 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC50, 4 mM) and by l-lysine (IC50, 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK. PMID:19060158

  13. Overexpression of wild-type aspartokinase increases L-lysine production in the thermotolerant methylotrophic bacterium Bacillus methanolicus.

    PubMed

    Jakobsen, Oyvind M; Brautaset, Trygve; Degnes, Kristin F; Heggeset, Tonje M B; Balzer, Simone; Flickinger, Michael C; Valla, Svein; Ellingsen, Trond E

    2009-02-01

    Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar V(max) values (between 47 and 58 micromol/min/mg protein) and K(m) values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC(50)], 0.1 mM) and by l-lysine (IC(50), 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC(50), 4 mM) and by l-lysine (IC(50), 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK.

  14. Oral citrulline as arginine precursor may be beneficial in sickle cell disease: early phase two results.

    PubMed Central

    Waugh, W. H.; Daeschner, C. W.; Files, B. A.; McConnell, M. E.; Strandjord, S. E.

    2001-01-01

    L-Arginine may be a conditionally essential amino acid in children and adolescents with sickle cell disease, particularly as required substrate in the arginine-nitric oxide pathway for endogenous nitrovasodilation and vasoprotection. Vasoprotection by arginine is mediated partly by nitric oxide-induced inhibition of endothelial damage and inhibition of adhesion and activation of leukocytes. Activated leukocytes may trigger many of the complications, including vasoocclusive events and intimal hyperplasias. High blood leukocyte counts during steady states in the absence of infection are significant laboratory risk factors for adverse complications. L-Citrulline as precursor amino acid was given orally twice daily in daily doses of approximately 0.1 g/kg in a pilot Phase II clinical trial during steady states in four homozygous sickle cell disease subjects and one sickle cell-hemoglobin C disease patient (ages 10-18). There soon resulted dramatic improvements in symptoms of well-being, raised plasma arginine levels, and reductions in high total leukocyte and high segmented neutrophil counts toward or to within normal limits. Continued L-citrulline supplementation in compliant subjects continued to lessen symptomatology, to maintain plasma arginine concentrations greater than control levels, and to maintain nearly normal total leukocyte and neutrophil counts. Side effects or toxicity from citrulline were not experienced. Oral L-citrulline may portend very useful for palliative therapy in sickle cell disease. Placebo-controlled, long-term trials are now indicated. PMID:11688916

  15. Oral citrulline as arginine precursor may be beneficial in sickle cell disease: early phase two results.

    PubMed

    Waugh, W H; Daeschner, C W; Files, B A; McConnell, M E; Strandjord, S E

    2001-10-01

    L-Arginine may be a conditionally essential amino acid in children and adolescents with sickle cell disease, particularly as required substrate in the arginine-nitric oxide pathway for endogenous nitrovasodilation and vasoprotection. Vasoprotection by arginine is mediated partly by nitric oxide-induced inhibition of endothelial damage and inhibition of adhesion and activation of leukocytes. Activated leukocytes may trigger many of the complications, including vasoocclusive events and intimal hyperplasias. High blood leukocyte counts during steady states in the absence of infection are significant laboratory risk factors for adverse complications. L-Citrulline as precursor amino acid was given orally twice daily in daily doses of approximately 0.1 g/kg in a pilot Phase II clinical trial during steady states in four homozygous sickle cell disease subjects and one sickle cell-hemoglobin C disease patient (ages 10-18). There soon resulted dramatic improvements in symptoms of well-being, raised plasma arginine levels, and reductions in high total leukocyte and high segmented neutrophil counts toward or to within normal limits. Continued L-citrulline supplementation in compliant subjects continued to lessen symptomatology, to maintain plasma arginine concentrations greater than control levels, and to maintain nearly normal total leukocyte and neutrophil counts. Side effects or toxicity from citrulline were not experienced. Oral L-citrulline may portend very useful for palliative therapy in sickle cell disease. Placebo-controlled, long-term trials are now indicated.

  16. Improvement of retinal functions after ischemia with L-arginine and its derivatives.

    PubMed

    Liu, S X; Chiou, G C; Varma, R S

    1995-01-01

    Retinal ischemia was created by occlusion of rat central retinal artery for 30 minutes. The loss of retinal function was indicated by the loss of b-wave of electroretinogram. The recovery of retinal function after reperfusion of central retinal artery was observed with the gradual recovery of b-wave amplitude to approximately 20% of original b-wave amplitude. When L-arginine (RVC-579) was administered at the time of retina ischemia, the b-wave amplitudes recovered up to 64% of original height and were significantly higher than corresponding controls at 120, 180, and 240 min after ischemia. When the derivative of L-arginine, N alpha-benzoyl-L-arginine ethyl ester (RVC-578), was administered, the b-wave recovery was significantly higher than corresponding controls at 90, 120, 180, and 240 min after ischemia; the recovery reached 51% of the original b-wave value. These results indicate that the L-arginine and its lipophilic derivatives could be used for the treatment of ischemic retinopathy. Since L-arginine is a natural amino acid, it is not expected to produce major side effects, if any, and could pave the way for the development of a safer drug to be used in the clinics. Compounds which increase the formation of NO in vivo, dilate blood vessels. Both L-arginine and RVC-578 can be placed in this category. They may improve effects of retinal ischemia by increasing NO production.

  17. Indications and contraindications for infusing specific amino acids (leucine, glutamine, arginine, citrulline, and taurine) in critical illness.

    PubMed

    Ginguay, Antonin; De Bandt, Jean-Pascal; Cynober, Luc

    2016-03-01

    The review assesses the utility of supplementing parenteral or enteral nutrition of ICU patients with each of five specific amino acids that display pharmacological properties. Specifying indications implies also stating contraindications.Combined supplementation of amino acids with ω3-fatty acids and/or trace elements (immune-enhancing diets) will not be considered in this review because these mixtures do not allow the role of amino acids in the effect (positive or negative) of the mixture to be isolated, and so cannot show whether or not supplementation of a given amino acid is indicated. After decades of unbridled use of glutamine (GLN) supplementation in critically ill patients, recent large trials have brought a note of caution, indicating for example that GLN should not be used in patients with multiple organ failure. Yet these large trials do not change the conclusions of recent meta-analyses. Arginine (ARG), as a single dietary supplement, is probably not harmful in critical illness, in particular in a situation of ARG deficiency syndrome with low nitric oxide production. Citrulline supplementation strongly improves microcirculation in animal models with gut injury, but clinical studies are lacking. Taurine has a potent protective effect against ischemic reperfusion injury. Amino acid-based pharmaconutrition has displayed familiar 'big project' stages: enthusiasm (citrulline and taurine), doubt (GLN), hunt for the guilty (ARG), and backpedalling (leucine). Progress in this field is very slow, and sometimes gives way to retreat, as demonstrated by recent large trials on GLN supplementation.

  18. Role of a Helix B Lysine Residue in the Photoactive Site in Channelrhodopsins

    PubMed Central

    Li, Hai; Govorunova, Elena G.; Sineshchekov, Oleg A.; Spudich, John L.

    2014-01-01

    In most studied microbial rhodopsins two conserved carboxylic acid residues (the homologs of Asp-85 and Asp-212 in bacteriorhodopsin) and an arginine residue (the homolog of Arg-82) form a complex counterion to the protonated retinylidene Schiff base, and neutralization of the negatively charged carboxylates causes red shifts of the absorption maximum. In contrast, the corresponding neutralizing mutations in some relatively low-efficiency channelrhodopsins (ChRs) result in blue shifts. These ChRs do not contain a lysine residue in the second helix, conserved in higher efficiency ChRs (Lys-132 in the crystallized ChR chimera). By action spectroscopy of photoinduced channel currents in HEK293 cells and absorption spectroscopy of detergent-purified pigments, we found that in tested ChRs the Lys-132 homolog controls the direction of spectral shifts in the mutants of the photoactive site carboxylic acid residues. Analysis of double mutants shows that red spectral shifts occur when this Lys is present, whether naturally or by mutagenesis, and blue shifts occur when it is replaced with a neutral residue. A neutralizing mutation of the Lys-132 homolog alone caused a red spectral shift in high-efficiency ChRs, whereas its introduction into low-efficiency ChR1 from Chlamydomonas augustae (CaChR1) caused a blue shift. Taking into account that the effective charge of the carboxylic acid residues is a key factor in microbial rhodopsin spectral tuning, these findings suggest that the Lys-132 homolog modulates their pKa values. On the other hand, mutation of the Arg-82 homolog that fulfills this role in bacteriorhodopsin caused minimal spectral changes in the tested ChRs. Titration revealed that the pKa of the Asp-85 homolog in CaChR1 lies in the alkaline region unlike in most studied microbial rhodopsins, but is substantially decreased by introduction of a Lys-132 homolog or neutralizing mutation of the Asp-212 homolog. In the three ChRs tested the Lys-132 homolog also alters

  19. Characterizing Lysine Acetylation of Isocitrate Dehydrogenase in Escherichia coli.

    PubMed

    Venkat, Sumana; Chen, Hao; Stahman, Alleigh; Hudson, Denver; McGuire, Paige; Gan, Qinglei; Fan, Chenguang

    2018-06-22

    The Escherichia coli isocitrate dehydrogenase (ICDH) is one of the tricarboxylic acid cycle enzymes, playing key roles in energy production and carbon flux regulation. E. coli ICDH was the first bacterial enzyme shown to be regulated by reversible phosphorylation. However, the effect of lysine acetylation on E. coli ICDH, which has no sequence similarity with its counterparts in eukaryotes, is still unclear. Based on previous studies of E. coli acetylome and ICDH crystal structures, eight lysine residues were selected for mutational and kinetic analyses. They were replaced with acetyllysine by the genetic code expansion strategy or substituted with glutamine as a classic approach. Although acetylation decreased the overall ICDH activity, its effects were different site by site. Deacetylation tests demonstrated that the CobB deacetylase could deacetylate ICDH both in vivo and in vitro, but CobB was only specific for lysine residues at the protein surface. On the other hand, ICDH could be acetylated by acetyl-phosphate chemically in vitro. And in vivo acetylation tests indicated that the acetylation level of ICDH was correlated with the amounts of intracellular acetyl-phosphate. This study nicely complements previous proteomic studies to provide direct biochemical evidence for ICDH acetylation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Studies of lysine cyclodeaminase from Streptomyces pristinaespiralis: Insights into the complex transition NAD+ state.

    PubMed

    Ying, Hanxiao; Wang, Jing; Shi, Ting; Zhao, Yilei; Wang, Xin; Ouyang, Pingkai; Chen, Kequan

    2018-01-01

    Lysine cyclodeaminase (LCD) catalyzes the piperidine ring formation in macrolide-pipecolate natural products metabolic pathways from a lysine substrate through a combination of cyclization and deamination. This enzyme belongs to a unique enzyme class, which uses NAD + as the catalytic prosthetic group instead of as the co-substrate. To understand the molecular details of NAD + functions in lysine cyclodeaminase, we have determined four ternary crystal structure complexes of LCD-NAD + with pipecolic acid (LCD-PA), lysine (LCD-LYS), and an intermediate (LCD-INT) as ligands at 2.26-, 2.00-, 2.17- and 1.80 Å resolutions, respectively. By combining computational studies, a NAD + -mediated "gate keeper" function involving NAD + /NADH and Arg49 that control the binding and entry of the ligand lysine was revealed, confirming the critical roles of NAD + in the substrate access process. Further, in the gate opening form, a substrate delivery tunnel between ε-carboxyl moiety of Glu264 and the α-carboxyl moiety of Asp236 was observed through a comparison of four structure complexes. The LCD structure details including NAD + -mediated "gate keeper" and substrate tunnel may assist in the exploration the NAD + function in this unique enzyme class, and in regulation of macrolide-pipecolate natural product synthesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. The early mature part of bacterial twin-arginine translocation (Tat) precursor proteins contributes to TatBC receptor binding.

    PubMed

    Ulfig, Agnes; Freudl, Roland

    2018-05-11

    The twin-arginine translocation (Tat) pathway transports folded proteins across bacterial membranes. Tat precursor proteins possess a conserved twin-arginine (RR) motif in their signal peptides that is involved in the binding of the proteins to the membrane-associated TatBC receptor complex. In addition, the hydrophobic region in the Tat signal peptides also contributes to TatBC binding, but whether regions beyond the signal-peptide cleavage site are involved in this process is unknown. Here, we analyzed the contribution of the early mature protein part of the Escherichia coli trimethylamine N -oxide reductase (TorA) to productive TatBC receptor binding. We identified substitutions in the 30 amino acids immediately following the TorA signal peptide (30aa-region) that restored export of a transport-defective TorA[KQ]-30aa-MalE precursor, in which the RR residues had been replaced by a lysine-glutamine pair. Some of these substitutions increased the hydrophobicity of the N-terminal part of the 30aa-region and thereby likely enhanced hydrophobic substrate-receptor interactions within the hydrophobic TatBC substrate-binding cavity. Another class of substitutions increased the positive net charge of the region's C-terminal part, presumably leading to strengthened electrostatic interactions between the mature substrate part and the cytoplasmic TatBC regions. Furthermore, we identified substitutions in the C-terminal domains of TatB following the transmembrane segment that restored transport of various transport-defective TorA-MalE derivatives. Some of these substitutions most likely affected the orientation or conformation of the flexible, carboxy-proximal helices of TatB. Therefore, we propose that a tight accommodation of the folded mature region by TatB contributes to productive binding of Tat substrates to TatBC. © 2018 Ulfig and Freudl.

  2. The scent of danger: arginine as an olfactory cue of reduced predation risk.

    PubMed

    Ferrer, Ryan P; Zimmer, Richard K

    2007-05-01

    Animal perception of chemosensory cues is a function of ecological context. Larvae of the California newt (Taricha torosa), for example, exhibit predator-avoidance behavior in response to a chemical from cannibalistic adults. The poison tetrodotoxin (TTX), well known as an adult chemical defense, stimulates larval escape to refuges. Although they are cannibals, adult newts feed preferentially on worms (Eisenia rosea) over conspecific young. Hence, larval avoidance reactions to TTX are suppressed in the presence of odor from these alternative prey. The free amino acid, arginine, is abundant in fluids emitted by injured worms. Here, we demonstrate that arginine is a natural suppressant of TTX-stimulated larval escape behavior. Compared to a tapwater control, larvae initiated vigorous swimming in response to 10(-7) mol l(-1) TTX. This excitatory response was eliminated when larval nasal cavities were blocked with an inert gel, but not when gel was placed on the forehead (control). In additional trials, a binary mixture of arginine and 10(-7) mol l(-1) TTX failed to induce larval swimming. The inhibitory effect of arginine was, however, dose dependent. An arginine concentration as low as 0.3-times that of TTX was significantly suppressant. Further analysis showed that suppression by arginine of TTX-stimulated behavior was eliminated by altering the positively-charged guanidinium moiety, but not by modifying the carbon chain, carboxyl group, or amine group. These results are best explained by a mechanism of competitive inhibition between arginine and TTX for common, olfactory receptor binding sites. Although arginine alone has no impact on larval behavior, it nevertheless signals active adult predation on alternative prey, and hence, reduced cannibalism risk.

  3. Stabilization of collagen nanofibers with l-lysine improves the ability of carbodiimide cross-linked amniotic membranes to preserve limbal epithelial progenitor cells

    PubMed Central

    Lai, Jui-Yang; Wang, Pei-Ran; Luo, Li-Jyuan; Chen, Si-Tan

    2014-01-01

    To overcome the drawbacks associated with limited cross-linking efficiency of carbodiimide modified amniotic membrane, this study investigated the use of l-lysine as an additional amino acid bridge to enhance the stability of a nanofibrous tissue matrix for a limbal epithelial cell culture platform. Results of ninhydrin assays and zeta potential measurements showed that the amount of positively charged amino acid residues incorporated into the tissue collagen chains is highly correlated with the l-lysine-pretreated concentration. The cross-linked structure and hydrophilicity of amniotic membrane scaffolding materials affected by the lysine molecular bridging effects were determined. With an increase in the l-lysine-pretreated concentration from 1 to 30 mM, the cross-linking density was significantly increased and water content was markedly decreased. The variations in resistance to thermal denaturation and enzymatic degradation were in accordance with the number of cross-links per unit mass of amniotic membrane, indicating l-lysine-modulated stabilization of collagen molecules. It was also noteworthy that the carbodiimide cross-linked tissue samples prepared using a relatively high l-lysine-pretreated concentration (ie, 30 mM) appeared to have decreased light transmittance and biocompatibility, probably due to the influence of a large nanofiber size and a high charge density. The rise in stemness gene and protein expression levels was dependent on improved cross-link formation, suggesting the crucial role of amino acid bridges in constructing suitable scaffolds to preserve limbal progenitor cells. It is concluded that mild to moderate pretreatment conditions (ie, 3–10 mM l-lysine) can provide a useful strategy to assist in the development of carbodiimide cross-linked amniotic membrane as a stable stem cell niche for corneal epithelial tissue engineering. PMID:25395849

  4. Ypq3p-dependent histidine uptake by the vacuolar membrane vesicles of Saccharomyces cerevisiae.

    PubMed

    Manabe, Kunio; Kawano-Kawada, Miyuki; Ikeda, Koichi; Sekito, Takayuki; Kakinuma, Yoshimi

    2016-06-01

    The vacuolar membrane proteins Ypq1p, Ypq2p, and Ypq3p of Saccharomyces cerevisiae are known as the members of the PQ-loop protein family. We found that the ATP-dependent uptake activities of arginine and histidine by the vacuolar membrane vesicles were decreased by ypq2Δ and ypq3Δ mutations, respectively. YPQ1 and AVT1, which are involved in the vacuolar uptake of lysine/arginine and histidine, respectively, were deleted in addition to ypq2Δ and ypq3Δ. The vacuolar membrane vesicles isolated from the resulting quadruple deletion mutant ypq1Δypq2Δypq3Δavt1Δ completely lost the uptake activity of basic amino acids, and that of histidine, but not lysine and arginine, was evidently enhanced by overexpressing YPQ3 in the mutant. These results suggest that Ypq3p is specifically involved in the vacuolar uptake of histidine in S. cerevisiae. The cellular level of Ypq3p-HA(3) was enhanced by depletion of histidine from culture medium, suggesting that it is regulated by the substrate.

  5. [Effect of the lysine guanidination on proteomic analysis].

    PubMed

    Zheng, Hao; Mao, Jiawei; Pan, Yanbo; Liu, Zhongshan; Liu, Zheyi; Ye, Mingliang; Zou, Hanfa

    2014-04-01

    The guanidination of lysine side chain was paid great attention in recent years. It plays an important role in qualitative and quantitative proteomics. In this study, based on the results of separated peptides extracted from HeLa cells before and after the guanidination by liquid chromatography-tandem mass spectrometry (LC-MS/MS), the effect of the guanidination of three different kinds of peptides was systematically analyzed. It was found that the selectivity of the guanidination of the lysine side chain was as high as 96.8%. The ratio of identified peptides with lysine at C-term to all peptides increased from 51.7% to 57.3% and more new peptides were identified, while the ratio of peptides with lysine in the middle or without lysine changed little. Further study on the ratio of b and y ions indicated that there were more y ions of peptides with lysine at C-term after the guanidination. The results proved that the selective conversion of lysine to homoarginine by the guanidination could increase the sensitivity and selectivity of mass spectrum. The increased basicity and ability to sequester proton of lysine produced more y ions fragmentation information, which contributed to more identified peptides. It concluded that the lysine guanidination can improve the coverage of proteomic analysis.

  6. Global analysis of lysine acetylation in strawberry leaves.

    PubMed

    Fang, Xianping; Chen, Wenyue; Zhao, Yun; Ruan, Songlin; Zhang, Hengmu; Yan, Chengqi; Jin, Liang; Cao, Lingling; Zhu, Jun; Ma, Huasheng; Cheng, Zhongyi

    2015-01-01

    Protein lysine acetylation is a reversible and dynamic post-translational modification. It plays an important role in regulating diverse cellular processes including chromatin dynamic, metabolic pathways, and transcription in both prokaryotes and eukaryotes. Although studies of lysine acetylome in plants have been reported, the throughput was not high enough, hindering the deep understanding of lysine acetylation in plant physiology and pathology. In this study, taking advantages of anti-acetyllysine-based enrichment and high-sensitive-mass spectrometer, we applied an integrated proteomic approach to comprehensively investigate lysine acetylome in strawberry. In total, we identified 1392 acetylation sites in 684 proteins, representing the largest dataset of acetylome in plants to date. To reveal the functional impacts of lysine acetylation in strawberry, intensive bioinformatic analysis was performed. The results significantly expanded our current understanding of plant acetylome and demonstrated that lysine acetylation is involved in multiple cellular metabolism and cellular processes. More interestingly, nearly 50% of all acetylated proteins identified in this work were localized in chloroplast and the vital role of lysine acetylation in photosynthesis was also revealed. Taken together, this study not only established the most extensive lysine acetylome in plants to date, but also systematically suggests the significant and unique roles of lysine acetylation in plants.

  7. Altered nitrogen balance and decreased urea excretion in male rats fed cafeteria diet are related to arginine availability.

    PubMed

    Sabater, David; Agnelli, Silvia; Arriarán, Sofía; Fernández-López, José-Antonio; Romero, María del Mar; Alemany, Marià; Remesar, Xavier

    2014-01-01

    Hyperlipidic diets limit glucose oxidation and favor amino acid preservation, hampering the elimination of excess dietary nitrogen and the catabolic utilization of amino acids. We analyzed whether reduced urea excretion was a consequence of higher NO x ; (nitrite, nitrate, and other derivatives) availability caused by increased nitric oxide production in metabolic syndrome. Rats fed a cafeteria diet for 30 days had a higher intake and accumulation of amino acid nitrogen and lower urea excretion. There were no differences in plasma nitrate or nitrite. NO(x) and creatinine excretion accounted for only a small part of total nitrogen excretion. Rats fed a cafeteria diet had higher plasma levels of glutamine, serine, threonine, glycine, and ornithine when compared with controls, whereas arginine was lower. Liver carbamoyl-phosphate synthetase I activity was higher in cafeteria diet-fed rats, but arginase I was lower. The high carbamoyl-phosphate synthetase activity and ornithine levels suggest activation of the urea cycle in cafeteria diet-fed rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  8. Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

    PubMed Central

    Sabater, David; Arriarán, Sofía; Fernández-López, José-Antonio; Romero, María del Mar; Remesar, Xavier

    2014-01-01

    Hyperlipidic diets limit glucose oxidation and favor amino acid preservation, hampering the elimination of excess dietary nitrogen and the catabolic utilization of amino acids. We analyzed whether reduced urea excretion was a consequence of higher NOx; (nitrite, nitrate, and other derivatives) availability caused by increased nitric oxide production in metabolic syndrome. Rats fed a cafeteria diet for 30 days had a higher intake and accumulation of amino acid nitrogen and lower urea excretion. There were no differences in plasma nitrate or nitrite. NOx and creatinine excretion accounted for only a small part of total nitrogen excretion. Rats fed a cafeteria diet had higher plasma levels of glutamine, serine, threonine, glycine, and ornithine when compared with controls, whereas arginine was lower. Liver carbamoyl-phosphate synthetase I activity was higher in cafeteria diet-fed rats, but arginase I was lower. The high carbamoyl-phosphate synthetase activity and ornithine levels suggest activation of the urea cycle in cafeteria diet-fed rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability. PMID:24707502

  9. Immunomodulatory activity of chicken NK-lysin peptides

    USDA-ARS?s Scientific Manuscript database

    Chicken NK-lysin (cNK-lysin), the chicken homologue of human granulysin, is a cationic amphiphilic antimicrobial peptide (AMP) produced by cytotoxic T cells and natural killer cells. We have previously demonstrated that cNK-lysin and cNK-2, which is a synthetic peptide incorporating core alpha-helic...

  10. Increased amino acids levels and the risk of developing of hypertriglyceridemia in a 7-year follow-up.

    PubMed

    Mook-Kanamori, D O; Römisch-Margl, W; Kastenmüller, G; Prehn, C; Petersen, A K; Illig, T; Gieger, C; Wang-Sattler, R; Meisinger, C; Peters, A; Adamski, J; Suhre, K

    2014-04-01

    Recently, five branched-chain and aromatic amino acids were shown to be associated with the risk of developing type 2 diabetes (T2D). We set out to examine whether amino acids are also associated with the development of hypertriglyceridemia. We determined the serum amino acids concentrations of 1,125 individuals of the KORA S4 baseline study, for which follow-up data were available also at the KORA F4 7 years later. After exclusion for hypertriglyceridemia (defined as having a fasting triglyceride level above 1.70 mmol/L) and diabetes at baseline, 755 subjects remained for analyses. Increased levels of leucine, arginine, valine, proline, phenylalanine, isoleucine and lysine were significantly associated with an increased risk of hypertriglyceridemia. These associations remained significant when restricting to those individuals who did not develop T2D in the 7-year follow-up. The increase per standard deviation of amino acid level was between 26 and 40 %. Seven amino acids were associated with an increased risk of developing hypertriglyceridemia after 7 years. Further studies are necessary to elucidate the complex role of these amino acids in the pathogenesis of metabolic disorders.

  11. Hot Melt Extrusion and Spray Drying of Co-amorphous Indomethacin-Arginine With Polymers.

    PubMed

    Lenz, Elisabeth; Löbmann, Korbinian; Rades, Thomas; Knop, Klaus; Kleinebudde, Peter

    2017-01-01

    Co-amorphous drug-amino acid systems have gained growing interest as an alternative to common amorphous formulations which contain polymers as stabilizers. Several preparation methods have recently been investigated, including vibrational ball milling on a laboratory scale or spray drying in a larger scale. In this study, the feasibility of hot melt extrusion for continuous manufacturing of co-amorphous drug-amino acid formulations was examined, challenging the fact that amino acids melt with degradation at high temperatures. Furthermore, the need for an addition of a polymer in this process was evaluated. After a polymer screening via the solvent evaporation method, co-amorphous indomethacin-arginine was prepared by a melting-solvent extrusion process without and with copovidone. The obtained products were characterized with respect to their solid-state properties, non-sink dissolution behavior, and stability. Results were compared to those of spray-dried formulations with the same compositions and to spray-dried indomethacin-copovidone. Overall, stable co-amorphous systems could be prepared by extrusion without or with copovidone, which exhibited comparable molecular interaction properties to the respective spray-dried products, while phase separation was detected by differential scanning calorimetry in several cases. The formulations containing indomethacin in combination with arginine and copovidone showed enhanced dissolution behavior over the formulations with only copovidone or arginine. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. Dietary L-arginine supplementation during mouse gestation enhances reproductive performance and Vegfr2 transcription activity in the fetoplacental unit

    USDA-ARS?s Scientific Manuscript database

    Regarded as one of the most versatile amino acids, arginine serves as a precursor for many molecules and has been reported to improve the reproductive performance of rats and pigs. To this end, we sought to determine if dietary L-arginine alters fetoplacental vascular endothelial growth factor recep...

  13. Collective hydration dynamics in some amino acid solutions: A combined GHz-THz spectroscopic study

    NASA Astrophysics Data System (ADS)

    Samanta, Nirnay; Das Mahanta, Debasish; Choudhury, Samiran; Barman, Anjan; Kumar Mitra, Rajib

    2017-03-01

    A detailed understanding of hydration of amino acids, the building units of protein, is a key step to realize the overall solvation processes in proteins. In the present contribution, we have made a combined GHz (0.2-50) to THz (0.3-2.0) experimental spectroscopic study to investigate the dynamics of water at room temperature in the presence of different amino acids (glycine, L-serine, L-lysine, L-tryptophan, L-arginine, and L-aspartic acid). The THz absorption coefficient, α(ν), of amino acids follows a trend defined by their solvent accessible surface area. The imaginary and real dielectric constants obtained in GHz and THz regions are fitted into multiple Debye model to obtain various relaxation times. The ˜100 ps time scale obtained in the GHz frequency region is attributed to the rotational motion of the amino acids. In the THz region, we obtain ˜8 ps and ˜200 fs time scales which are related to the cooperative dynamics of H-bond network and partial rotation or sudden jump of the under-coordinated water molecules. These time scales are found to be dependent on the amino acid type and the cooperative motion is found to be dependent on both the hydrophobic as well as the hydrophilic residue of amino acids.

  14. l-Arginine administration attenuates airway inflammation by altering l-arginine metabolism in an NC/Nga mouse model of asthma.

    PubMed

    Zhang, Ran; Kubo, Masayuki; Murakami, Ikuo; Setiawan, Heri; Takemoto, Kei; Inoue, Kiyomi; Fujikura, Yoshihisa; Ogino, Keiki

    2015-05-01

    Changes in l-arginine metabolism, including increased arginase levels and decreased nitric oxide production, are involved in the pathophysiology of asthma. In this study, using an intranasal mite-induced NC/Nga mouse model of asthma, we examined whether administration of l-arginine ameliorated airway hyperresponsiveness and inflammation by altering l-arginine metabolism. Experimental asthma was induced in NC/Nga mice via intranasal administration of mite crude extract (50 µg/day) on 5 consecutive days (days 0-4, sensitization) and on day 11 (challenge). Oral administration of l-arginine (250 mg/kg) was performed twice daily on days 5-10 for prevention or on days 11-13 for therapy. On day 14, we evaluated the inflammatory airway response (airway hyperresponsiveness, the number of cells in the bronchoalveolar lavage fluid, and the changes in pathological inflammation of the lung), arginase expression and activity, l-arginine bioavailability, and the concentration of NOx, the end products of nitric oxide. Treatment with l-arginine ameliorated the mite-induced inflammatory airway response. Furthermore, l-arginine administration attenuated the increases in arginase expression and activity and elevated the NOx levels by enhancing l-arginine bioavailability. These findings indicate that l-arginine administration may contribute to the improvement of asthmatic symptoms by altering l-arginine metabolism.

  15. Dissolved Free Amino Acids in Hydrothermal Springs at Yellowstone National Park, U.S.A.

    NASA Astrophysics Data System (ADS)

    Cox, J. S.; Holland, M. E.; Shock, E. L.

    2004-12-01

    Insights into the organic geochemistry of hydrothermal systems, as well as the dynamics of biotic processes in hot spring ecosystems, can be gained by identifying and quantifying dissolved free amino acids (DFAA). Hydrothermal systems form a unique environmental subset relative to other aqueous settings due to their higher temperatures, largely uncharacterized and exotic microbiology, wider pH range, and elevated levels of rare metals, sulfur, and dissolved gases. Previous studies of hot spring and geothermal systems (e.g. Mukhin et al., 1979; Svensson et al., 2004) indicated the presence of micromolar quantities of various amino acids, but the underlying mechanisms controlling amino acid production and disappearance/consumption have continued to remain elusive. DFAA were identified and quantified in five hot springs at Yellowstone National Park that span a range of pH (2 to 8) and temperature (75 to 93° C/boiling). Biotic uptake experiments and enantiomeric analyses on samples from one location were also performed to elucidate biotic pathways. Analyses were performed using high pressure anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), which is able to resolve amino acids as well as certain carbohydrates, oligopeptides, and a variety of related biological molecules. Preliminary data indicate that total DFAA concentrations are quite low (sub-micromolar range) and that amino acids with aliphatic and nitrogen-containing R-groups are predominant in the DFAA fraction. The types and concentrations of amino acids were variable across the sites. Obsidian Pool (pH 5.1, 77.5° C), where multiple microbiological studies have been conducted, was found to have a DFAA fraction consisting primarily of glycine with trace amounts of arginine, lysine, and histidine. In comparison, an acidic spring in the Sylvan Springs area (pH 1.9, 79.7° C) had higher total DFAA concentrations and was found to contain primarily arginine, lysine, and leucine, together

  16. Requirements of juvenile milkfish (Chanos chanos Forsskal) for essential amino acids.

    PubMed

    Borlongan, I G; Coloso, R M

    1993-01-01

    The dietary requirements of juvenile milkfish (Chanos chanos Forsskal) for essential amino acids were determined in a series of experiments. The fish (< or = 8.0 g) were reared in fiber glass tanks provided with flow-through seawater at 28 degrees C and salinity of 32 g/L for 12 wk. In each experiment, a series of amino acid test diets was formulated containing a combination of intact protein sources (casein-gelatin, fish meal-gelatin, fish meal-soybean meal or fish meal-zein) and crystalline amino acids to simulate the levels found in milkfish tissue proteins except for the test amino acid. Each set of isonitrogenous diets contained 40-45% protein and graded levels of the amino acid to be tested. At the end of the feeding experiment, growth, survival and feed efficiency were determined. The requirement level for each essential amino acid was estimated from breakpoint analysis of the growth curve. The dietary essential amino acid requirements (as the percentage of dietary protein) of milkfish juveniles were as follows: arginine, 5.25; histidine, 2.00; isoleucine, 4.00; leucine, 5.11; lysine, 4.00; methionine, 2.50 (cystine, 0.75); phenylalanine, 4.22 (tyrosine, 1.00) or 2.80 (tyrosine, 2.67); threonine, 4.50; tryptophan, 0.60; valine, 3.55. This information is valuable in developing cost-effective practical or commercial feeds and research diets for milkfish juveniles.

  17. Separation and detection of amino acid metabolites of Escherichia coli in microbial fuel cell with CE.

    PubMed

    Wang, Wei; Ma, Lihong; Lin, Ping; Xu, Kaixuan

    2016-07-01

    In this work, CE-LIF was employed to investigate the amino acid metabolites produced by Escherichia coli (E. coli) in microbial fuel cell (MFC). Two peptides, l-carnosine and l-alanyl-glycine, together with six amino acids, cystine, alanine, lysine, methionine, tyrosine, arginine were separated and detected in advance by a CE-LIF system coupled with a homemade spontaneous injection device. The injection device was devised to alleviate the effect of electrical discrimination for analytes during sample injection. All analytes could be completely separated within 8 min with detection limits of 20-300 nmol/L. Then this method was applied to analyze the substrate solution containing amino acid metabolites produced by E. coli. l-carnosine, l-alanyl-glycine, and cystine were used as the carbon, nitrogen, and sulfur source for the E. coli culture in the MFC to investigate the amino acid metabolites during metabolism. Two MFCs were used to compare the activity of metabolism of the bacteria. In the sample collected at the running time 200 h of MFC, the amino acid methionine was discovered as the metabolite with the concentrations 23.3 μg/L. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. N6-Trimethyl-lysine metabolism. Structural identification of the metabolite 3-hydroxy-N6-trimethyl-lysine

    PubMed Central

    Novak, Raymond F.; Swift, Terrence J.; Hoppel, Charles L.

    1980-01-01

    1H and 13C nuclear-magnetic-resonance spectroscopy and functional-group analysis were used to determine the molecular structure of an isolated metabolite (IIb) of trimethyl-lysine as 3-hydroxy-N6-trimethyl-lysine, an important intermediate in the conversion of trimethyl-lysine into trimethylammoniobutyrate and carnitine [Hoppel, Cox & Novak (1980) Biochem. J. 188, 509–519]. Functional-group analysis revealed the presence of a primary amine and reaction of metabolite (IIb) with periodate yielded 4-N-trimethylammoniobutyrate as a product, showing 2,3-substitution on the molecule and suggesting that the 3-substitution on the molecule may be an alcohol ([unk]CH–OH), amine ([unk]CH[unk]–NH2) or carbonyl ([unk]C=O) functional group. 1H integration ratios, 1H and 13C chemical-shift data and 1H and 13C signal multiplicities from the sample (IIb) were used to complete the identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. For example, the proton multiplet at δ 4.2p.p.m. and doublet at δ 4.1p.p.m., positions representative of amine or alcohol substitution on methylene carbon atoms, integration ratios of 1:1:2:9:4 and a positive ninhydrin test suggest 3-hydroxy-N6-trimethyl-lysine as the molecular structure for metabolite (IIb). 13C chemical-shift data obtained from the sample (IIb) and compared with several model compounds (trimethylammoniohexanoate, trimethyl-lysine and 3-hydroxylysine) resulted in generation of the spectrum of the metabolite and allowed independent identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. The 1H spectrum of erythro- and threo-3-hydroxylysine are presented for comparison, and the 1H and 13C n.m.r. spectra of the erythro-isomer support this analysis. PMID:6772169

  19. Purification and Characterization of an Arginine Aminopeptidase from Lactobacillus sakei

    PubMed Central

    Sanz, Yolanda; Toldrá, Fidel

    2002-01-01

    An arginine aminopeptidase (EC 3.4.11.6) that exclusively hydrolyzes basic amino acids from the amino (N) termini of peptide substrates has been purified from Lactobacillus sakei. The purification procedure consisted of ammonium sulfate fractionation and three chromatographic steps, which included hydrophobic interaction, gel filtration, and anion-exchange chromatography. This procedure resulted in a recovery rate of 4.2% and a 500-fold increase in specific activity. The aminopeptidase appeared to be a trimeric enzyme with a molecular mass of 180 kDa. The activity was optimal at pH 5.0 and 37°C. The enzyme was inhibited by sulfhydryl group reagents and several divalent cations (Cu2+, Hg2+, and Zn2+) but was activated by reducing agents, metal-chelating agents, and sodium chloride. The enzyme showed a preference for arginine at the N termini of aminoacyl derivatives and peptides. The Km values for Arg-7-amido-4-methylcoumarin (AMC) and Lys-AMC were 15.9 and 26.0 μM, respectively. The nature of the amino acid residue at the C terminus of dipeptides has an effect on hydrolysis rates. The activity was maximal toward dipeptides with Arg, Lys, or Ala as the C-terminal residue. The properties of the purified enzyme, its potential function in the release of arginine, and its further metabolism are discussed because, as a whole, it could constitute a survival mechanism for L. sakei in the meat environment. PMID:11916721

  20. Correlation between plasma levels of arginine and citrulline in preterm and full-term neonates: Therapeutical implications.

    PubMed

    Contreras, Mike T; Gallardo, Maria J; Betancourt, Luis R; Rada, Pedro V; Ceballos, Gerardo A; Hernandez, Luis E; Hernandez, Luis F

    2017-11-01

    Preterm neonates exhibit several deficiencies that endanger their lives. Understanding those disturbances will provide tools for the management of preterm neonates. The present work focuses on arginine and citrulline which has been flagged among the biochemical landmarks of prematurity. We examined blood samples of preterm newborns as compared with mature neonates to determine the levels of arginine and citrulline by capillary zone electrophoresis with laser induced fluorescence detection (CZE-LIFD). Significantly lower levels of arginine and citrulline were found in preterm neonates than in mature neonates (P<.01). Interestingly there was a highly significant correlation between the two amino acids in mature neonates (P<.0001). Such correlation was present in preterm neonates too (P<.01). Pearson coefficient showed that 60% of the citrulline concentration depends on arginine concentration in mature neonates. Only 20% of the citrulline concentration depends on arginine concentration in preterm neonates. Although the ratio arginine/citrulline was lower in preterm neonates than in mature neonates the difference was not statistically significant. These results suggest that less arginine is converted to citrulline to form nitric oxide in preterm than in full-term neonates. The result is discussed in terms of the immature enzymatic systems in the preterm neonate. © 2017 Wiley Periodicals, Inc.

  1. Green biochemistry approach for synthesis of silver and gold nanoparticles using Ficus racemosa latex and their pH-dependent binding study with different amino acids using UV/Vis absorption spectroscopy.

    PubMed

    Tetgure, Sandesh R; Borse, Amulrao U; Sankapal, Babasaheb R; Garole, Vaman J; Garole, Dipak J

    2015-04-01

    Simple and eco-friendly biosynthesis approach was developed to synthesize silver nanoparticles (SNPs) and gold nanoparticles (GNPs) using Ficus racemosa latex as reducing agent. The presence of sunlight is utilized with latex and achieved the nanoparticles whose average size was in the range of 50-120 nm for SNPs and 20-50 nm for GNPs. The synthesized nanoparticles were characterized by UV/Visible absorption spectroscopy, X-ray diffraction, and field emission-scanning electron microscopy techniques toget understand the obtained nanoparticles. The pH-dependent binding studies of SNPs and GNPs with four amino acids, namely L-lysine, L-arginine, L-glutamine and glycin have been reported.

  2. Reduction of hydrogen peroxide stress derived from fatty acid beta-oxidation improves fatty acid utilization in Escherichia coli.

    PubMed

    Doi, Hidetaka; Hoshino, Yasushi; Nakase, Kentaro; Usuda, Yoshihiro

    2014-01-01

    Fatty acids are a promising raw material for substance production because of their highly reduced and anhydrous nature, which can provide higher fermentation yields than sugars. However, they are insoluble in water and are poorly utilized by microbes in industrial fermentation production. We used fatty acids as raw materials for L-lysine fermentation by emulsification and improved the limited fatty acid-utilization ability of Escherichia coli. We obtained a fatty acid-utilizing mutant strain by laboratory evolution and demonstrated that it expressed lower levels of an oxidative-stress marker than wild type. The intracellular hydrogen peroxide (H₂O₂) concentration of a fatty acid-utilizing wild-type E. coli strain was higher than that of a glucose-utilizing wild-type E. coli strain. The novel mutation rpsA(D210Y) identified in our fatty acid-utilizing mutant strain enabled us to promote cell growth, fatty-acid utilization, and L-lysine production from fatty acid. Introduction of this rpsA(D210Y) mutation into a wild-type strain resulted in lower H₂O₂ concentrations. The overexpression of superoxide dismutase (sodA) increased intracellular H₂O₂ concentrations and inhibited E. coli fatty-acid utilization, whereas overexpression of an oxidative-stress regulator (oxyS) decreased intracellular H₂O₂ concentrations and promoted E. coli fatty acid utilization and L-lysine production. Addition of the reactive oxygen species (ROS) scavenger thiourea promoted L-lysine production from fatty acids and decreased intracellular H₂O₂ concentrations. Among the ROS generated by fatty-acid β-oxidation, H₂O₂ critically affected E. coli growth and L-lysine production. This indicates that the regression of ROS stress promotes fatty acid utilization, which is beneficial for fatty acids used as raw materials in industrial production.

  3. Dietary supplementation with an amino acid blend enhances intestinal function in piglets.

    PubMed

    Yi, Dan; Li, Baocheng; Hou, Yongqing; Wang, Lei; Zhao, Di; Chen, Hongbo; Wu, Tao; Zhou, Ying; Ding, Binying; Wu, Guoyao

    2018-05-16

    The traditionally classified nutritionally non-essential amino acids are now known to be insufficiently synthesized for maximal growth and optimal health in piglets. This study determined the effects of dietary supplementation with an amino acid blend (AAB; glutamate:glutamine:glycine:arginine:N-acetylcysteine = 5:2:2:1:0.5) on piglet growth performance and intestinal functions. Sixteen piglets (24-day-old) were randomly assigned to a corn and soybean meal-based diet supplemented with 0.99% alanine (isonitrogenous control) or 1% AAB. On day 20 of the trial, blood and intestinal tissue samples were obtained from piglets. Compared with the control, AAB supplementation reduced (P < 0.05) diarrhoea incidence; plasma alanine aminotransferase and diamine oxidase activities; intestinal concentrations of hydrogen peroxide, malondialdehyde, and heat shock protein-70, and intestinal mRNA levels for interleukin-1β, interferon-γ, and chemokine (C-X-C motif) ligand-9; and the numbers of Enterobacterium family, Enterococcus genus and Clostridium coccoides in the colon digesta. Furthermore, AAB supplementation enhanced (P < 0.05): the plasma concentrations of serine, aspartate, glutamate, cysteine, tyrosine, phenylalanine, tryptophan, lysine, arginine, citrulline, ornithine, taurine, and γ-aminobutyric acid; intestinal villus height and surface area, villus height/crypt depth ratio, antioxidative enzyme activities, and mRNA levels for porcine β-defensin-1, sodium-independent amino acid transporters (b 0,+ AT and y + LAT1), aquaporin (AQP) 3, AQP8, AQP10, nuclear factor erythroid 2-related factor 2 and glutathione S-transferase omega-2, and protein abundances of AQP3, AQP4, claudin-1, occludin and myxovirus resistance 1; and the numbers of Bifidobacterium genus and Lactobacillus genus in the colon digesta. Collectively, these comprehensive results indicate that dietary AAB supplementation plays an important role in improving piglet growth and intestinal function.

  4. Non-Targeted Metabolomics Analysis of Golden Retriever Muscular Dystrophy-Affected Muscles Reveals Alterations in Arginine and Proline Metabolism, and Elevations in Glutamic and Oleic Acid In Vivo

    PubMed Central

    Abdullah, Muhammad; Kornegay, Joe N.; Honcoop, Aubree; Parry, Traci L.; Balog-Alvarez, Cynthia J.; Muehlbauer, Michael J.; Newgard, Christopher B.; Patterson, Cam

    2017-01-01

    Background: Like Duchenne muscular dystrophy (DMD), the Golden Retriever Muscular Dystrophy (GRMD) dog model of DMD is characterized by muscle necrosis, progressive paralysis, and pseudohypertrophy in specific skeletal muscles. This severe GRMD phenotype includes moderate atrophy of the biceps femoris (BF) as compared to unaffected normal dogs, while the long digital extensor (LDE), which functions to flex the tibiotarsal joint and serves as a digital extensor, undergoes the most pronounced atrophy. A recent microarray analysis of GRMD identified alterations in genes associated with lipid metabolism and energy production. Methods: We, therefore, undertook a non-targeted metabolomics analysis of the milder/earlier stage disease GRMD BF muscle versus the more severe/chronic LDE using GC-MS to identify underlying metabolic defects specific for affected GRMD skeletal muscle. Results: Untargeted metabolomics analysis of moderately-affected GRMD muscle (BF) identified eight significantly altered metabolites, including significantly decreased stearamide (0.23-fold of controls, p = 2.89 × 10−3), carnosine (0.40-fold of controls, p = 1.88 × 10−2), fumaric acid (0.40-fold of controls, p = 7.40 × 10−4), lactamide (0.33-fold of controls, p = 4.84 × 10−2), myoinositol-2-phosphate (0.45-fold of controls, p = 3.66 × 10−2), and significantly increased oleic acid (1.77-fold of controls, p = 9.27 × 10−2), glutamic acid (2.48-fold of controls, p = 2.63 × 10−2), and proline (1.73-fold of controls, p = 3.01 × 10−2). Pathway enrichment analysis identified significant enrichment for arginine/proline metabolism (p = 5.88 × 10−4, FDR 4.7 × 10−2), where alterations in L-glutamic acid, proline, and carnosine were found. Additionally, multiple Krebs cycle intermediates were significantly decreased (e.g., malic acid, fumaric acid, citric/isocitric acid, and succinic acid), suggesting that altered energy metabolism may be underlying the observed GRMD BF muscle

  5. Non-Targeted Metabolomics Analysis of Golden Retriever Muscular Dystrophy-Affected Muscles Reveals Alterations in Arginine and Proline Metabolism, and Elevations in Glutamic and Oleic Acid In Vivo.

    PubMed

    Abdullah, Muhammad; Kornegay, Joe N; Honcoop, Aubree; Parry, Traci L; Balog-Alvarez, Cynthia J; O'Neal, Sara K; Bain, James R; Muehlbauer, Michael J; Newgard, Christopher B; Patterson, Cam; Willis, Monte S

    2017-07-29

    Like Duchenne muscular dystrophy (DMD), the Golden Retriever Muscular Dystrophy (GRMD) dog model of DMD is characterized by muscle necrosis, progressive paralysis, and pseudohypertrophy in specific skeletal muscles. This severe GRMD phenotype includes moderate atrophy of the biceps femoris (BF) as compared to unaffected normal dogs, while the long digital extensor (LDE), which functions to flex the tibiotarsal joint and serves as a digital extensor, undergoes the most pronounced atrophy. A recent microarray analysis of GRMD identified alterations in genes associated with lipid metabolism and energy production. We, therefore, undertook a non-targeted metabolomics analysis of the milder/earlier stage disease GRMD BF muscle versus the more severe/chronic LDE using GC-MS to identify underlying metabolic defects specific for affected GRMD skeletal muscle. Untargeted metabolomics analysis of moderately-affected GRMD muscle (BF) identified eight significantly altered metabolites, including significantly decreased stearamide (0.23-fold of controls, p = 2.89 × 10 -3 ), carnosine (0.40-fold of controls, p = 1.88 × 10 -2 ), fumaric acid (0.40-fold of controls, p = 7.40 × 10 -4 ), lactamide (0.33-fold of controls, p = 4.84 × 10 -2 ), myoinositol-2-phosphate (0.45-fold of controls, p = 3.66 × 10 -2 ), and significantly increased oleic acid (1.77-fold of controls, p = 9.27 × 10 -2 ), glutamic acid (2.48-fold of controls, p = 2.63 × 10 -2 ), and proline (1.73-fold of controls, p = 3.01 × 10 -2 ). Pathway enrichment analysis identified significant enrichment for arginine/proline metabolism (p = 5.88 × 10 -4 , FDR 4.7 × 10 -2 ), where alterations in L-glutamic acid, proline, and carnosine were found. Additionally, multiple Krebs cycle intermediates were significantly decreased (e.g., malic acid, fumaric acid, citric/isocitric acid, and succinic acid), suggesting that altered energy metabolism may be underlying the observed GRMD BF muscle dysfunction. In contrast, two

  6. Comprehensive assessment of the L-lysine production process from fermentation of sugarcane molasses.

    PubMed

    Anaya-Reza, Omar; Lopez-Arenas, Teresa

    2017-07-01

    L-Lysine is an essential amino acid that can be produced by chemical processes from fossil raw materials, as well as by microbial fermentation, the latter being a more efficient and environmentally friendly procedure. In this work, the production process of L-lysine-HCl is studied using a systematic approach based on modeling and simulation, which supports decision making in the early stage of process design. The study considers two analysis stages: first, the dynamic analysis of the fermentation reactor, where the conversion of sugars from sugarcane molasses to L-lysine with a strain of Corynebacterium glutamicum is carried out. In this stage, the operation mode (either batch or fed batch) and operating conditions of the fermentation reactor are defined to reach the maximum technical criteria. Afterwards, the second analysis stage relates to the industrial production process of L-lysine-HCl, where the fermentation reactor, upstream processing, and downstream processing are included. In this stage, the influence of key parameters on the overall process performance is scrutinized through the evaluation of several technical, economic, and environmental criteria, to determine a profitable and sustainable design of the L-lysine production process. The main results show how the operating conditions, process design, and selection of evaluation criteria can influence in the conceptual design. The best plant design shows maximum product yield (0.31 g L-lysine/g glucose) and productivity (1.99 g/L/h), achieving 26.5% return on investment (ROI) with a payback period (PBP) of 3.8 years, decreasing water and energy consumption, and with a low potential environmental impact (PEI) index.

  7. Changes in conformational dynamics of basic side chains upon protein–DNA association

    PubMed Central

    Esadze, Alexandre; Chen, Chuanying; Zandarashvili, Levani; Roy, Sourav; Pettitt, B. Montgometry; Iwahara, Junji

    2016-01-01

    Basic side chains play major roles in recognition of nucleic acids by proteins. However, dynamic properties of these positively charged side chains are not well understood. In this work, we studied changes in conformational dynamics of basic side chains upon protein–DNA association for the zinc-finger protein Egr-1. By nuclear magnetic resonance (NMR) spectroscopy, we characterized the dynamics of all side-chain cationic groups in the free protein and in the complex with target DNA. Our NMR order parameters indicate that the arginine guanidino groups interacting with DNA bases are strongly immobilized, forming rigid interfaces. Despite the strong short-range electrostatic interactions, the majority of the basic side chains interacting with the DNA phosphates exhibited high mobility, forming dynamic interfaces. In particular, the lysine side-chain amino groups exhibited only small changes in the order parameters upon DNA-binding. We found a similar trend in the molecular dynamics (MD) simulations for the free Egr-1 and the Egr-1–DNA complex. Using the MD trajectories, we also analyzed side-chain conformational entropy. The interfacial arginine side chains exhibited substantial entropic loss upon binding to DNA, whereas the interfacial lysine side chains showed relatively small changes in conformational entropy. These data illustrate different dynamic characteristics of the interfacial arginine and lysine side chains. PMID:27288446

  8. The acute effects of a low and high dose of oral L-arginine supplementation in young active males at rest.

    PubMed

    Forbes, Scott C; Bell, Gordon J

    2011-06-01

    L-arginine (2-amino-5-guanidinovaleric acid) is a conditionally essential amino acid. Intravenous (IV) administration of l-arginine invokes a large metabolic (nitrate/nitrite (NO(x))) and hormonal (growth hormone (GH), insulin-like growth factor 1 (IGF-1), and insulin) response; however, research examining oral l-arginine supplementation is conflicting, potentially owing to dose. The purpose of this study was examine a low and high dose of oral l-arginine on blood l-arginine, NO(x), GH, IGF-1, and insulin response. Fourteen physically active males (age: 25 ± 5 years; weight: 78.0 ± 8.5 kg; height: 179.4 ± 4.7 cm) volunteered to be in a randomized, double-blind, repeated-measures study. Following an overnight fast, an IV catheter was placed in a forearm vein and a resting blood sample was drawn at ∼0800 hours. Each subject was then provided 1 of 3 treatment conditions (placebo, low (0.075 g·kg(-1) of body mass), or high (0.15 g·kg(-1) of body mass of l-arginine)). Blood samples were drawn at 30, 60, 90, 120, and 180 min after consumption. l-arginine plasma concentrations significantly increased (p < 0.001) to a similar level at any time point in both the low- and high-dose conditions; there was no change over time in the placebo condition. There was no significant difference between conditions for NO(x), GH, IGF-1, or insulin. Based on these findings, a low dose of l-arginine was just as effective at increasing plasma l-arginine concentrations as a high dose; however, neither dose was able to promote a significant increase in NO(x), GH, IGF-1, or insulin at rest.

  9. Removing a bottleneck in the Bacillus subtilis biotin pathway: bioA utilizes lysine rather than S-adenosylmethionine as the amino donor in the KAPA-to-DAPA reaction.

    PubMed

    Van Arsdell, Scott W; Perkins, John B; Yocum, R Rogers; Luan, Linda; Howitt, C Linda; Chatterjee, Nilu Prasad; Pero, Janice G

    2005-07-05

    In biotin biosynthesis, DAPA aminotransferase encoded by the bioA gene catalyzes the formation of the intermediate 7,8-diaminopelargonic acid (DAPA) from 7-keto-8-aminopelargonic acid (KAPA). DAPA aminotransferases from Escherichia coli, Serratia marcescens, and Bacillus sphaericus use S-adenosylmethionine (SAM) as the amino donor. Our observation that SAM is not an amino donor for B. subtilis DAPA aminotransferase led to a search for an alternative amino donor for this enzyme. Testing of 26 possible amino acids in a cell-free extract assay revealed that only l-lysine was able to dramatically stimulate the in vitro conversion of KAPA to DAPA by the B. subtilis DAPA aminotransferase. The K(m) for lysine and KAPA was estimated to be between 2 and 25 mM, which is significantly higher than the K(m) of purified E. coli BioA for SAM (0.15 mM). This higher requirement for lysine resulted in accumulation of KAPA during fermentation of B. subtilis biotin producing strains. However, this pathway bottleneck could be relieved by either addition of exogenous lysine to the medium or by introduction of lysine deregulated mutations into the production strains.

  10. Antibacterial Activity of a Novel Peptide-Modified Lysin Against Acinetobacter baumannii and Pseudomonas aeruginosa

    PubMed Central

    Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

    2015-01-01

    The global emergence of multidrug-resistant (MDR) bacteria is a growing threat to public health worldwide. Natural bacteriophage lysins are promising alternatives in the treatment of infections caused by Gram-positive pathogens, but not Gram-negative ones, like Acinetobacter baumannii and Pseudomonas aeruginosa, due to the barriers posed by their outer membranes. Recently, modifying a natural lysin with an antimicrobial peptide was found able to break the barriers, and to kill Gram-negative pathogens. Herein, a new peptide-modified lysin (PlyA) was constructed by fusing the cecropin A peptide residues 1–8 (KWKLFKKI) with the OBPgp279 lysin and its antibacterial activity was studied. PlyA showed good and broad antibacterial activities against logarithmic phase A. baumannii and P. aeruginosa, but much reduced activities against the cells in stationary phase. Addition of outer membrane permeabilizers (EDTA and citric acid) could enhance the antibacterial activity of PlyA against stationary phase cells. Finally, no antibacterial activity of PlyA could be observed in some bio-matrices, such as culture media, milk, and sera. In conclusion, we reported here a novel peptide-modified lysin with significant antibacterial activity against both logarithmic (without OMPs) and stationary phase (with OMPs) A. baumannii and P. aeruginosa cells in buffer, but further optimization is needed to achieve broad activity in diverse bio-matrices. PMID:26733995

  11. Substrate Specificity of Human Protein Arginine Methyltransferase 7 (PRMT7)

    PubMed Central

    Feng, You; Hadjikyriacou, Andrea; Clarke, Steven G.

    2014-01-01

    Protein arginine methyltransferase 7 (PRMT7) methylates arginine residues on various protein substrates and is involved in DNA transcription, RNA splicing, DNA repair, cell differentiation, and metastasis. The substrate sequences it recognizes in vivo and the enzymatic mechanism behind it, however, remain to be explored. Here we characterize methylation catalyzed by a bacterially expressed GST-tagged human PRMT7 fusion protein with a broad range of peptide and protein substrates. After confirming its type III activity generating only ω-NG-monomethylarginine and its distinct substrate specificity for RXR motifs surrounded by basic residues, we performed site-directed mutagenesis studies on this enzyme, revealing that two acidic residues within the double E loop, Asp-147 and Glu-149, modulate the substrate preference. Furthermore, altering a single acidic residue, Glu-478, on the C-terminal domain to glutamine nearly abolished the activity of the enzyme. Additionally, we demonstrate that PRMT7 has unusual temperature dependence and salt tolerance. These results provide a biochemical foundation to understanding the broad biological functions of PRMT7 in health and disease. PMID:25294873

  12. Effects of l-arginine pretreatment on nitric oxide metabolism and hepatosplanchnic perfusion during porcine endotoxemia1234

    PubMed Central

    Bruins, Maaike J; Kessels, Fons; Luiking, Yvette C; Lamers, Wouter H; Deutz, Nicolaas EP

    2011-01-01

    Background: Sepsis is accompanied by an increased need for and a decreased supply of arginine, reflecting a condition of arginine deficiency. Objective: The objective was to evaluate the effects of l-arginine pretreatment on arginine–nitric oxide (NO) production and hepatosplanchnic perfusion during subsequent endotoxemia. Design: In a randomized controlled trial, pigs (20–25 kg) received 3 μg ⋅ kg−1 ⋅ min−1 lipopolysaccharide (LPS; 5 endotoxin units/ng) intravenously and saline resuscitation. l-Arginine (n = 8; 5.3 μmol ⋅ kg−1 ⋅ min−1) or saline (n = 8) was infused starting 12 h before LPS infusion and continued for 24 h after the endotoxin infusion ended. Whole-body appearance rates, portal-drained viscera (PDV), and liver fluxes of arginine, citrulline, NO, and arginine de novo synthesis were measured by using stable-isotope infusion of [15N2]arginine and [13C-2H2]citrulline. Hepatosplanchnic perfusion was assessed by using a primed continuous infusion of para-aminohippuric acid and jejunal intramucosal partial pressure of carbon dioxide and was related to systemic hemodynamics. Results: Arginine supplementation before LPS increased whole-body NO production in the PDV but not in the liver. Furthermore, it increased blood flow in the portal vein but not in the aorta and hepatic artery. During endotoxin infusion, arginine pretreatment was associated with an increased whole-body arginine appearance and NO production in the gut. Additional effects included a preserved mean arterial pressure, the prevention of an increase in pulmonary arterial pressure, an attenuated metabolic acidosis, and an attenuated increase in the intramucosal partial pressure of carbon dioxide. Conclusion: Arginine treatment starting before endotoxemia appears to be beneficial because it improves hepatosplanchnic perfusion and oxygenation during prolonged endotoxemia, probably through an enhancement in NO synthesis, without causing deleterious systemic side effects. PMID

  13. Tuning interionic interaction by rationally controlling solution pH for highly selective colorimetric sensing of arginine.

    PubMed

    Qian, Qin; Hao, Jie; Ma, Wenjie; Yu, Ping; Mao, Lanqun

    2016-04-01

    Direct selective sensing of arginine in central nervous systems remains very essential to understanding of the molecular basis of some physiological events. This study presents the first demonstration on a simple yet effective method for arginine sensing with gold nanoparticles (Au-NPs) as the signal readout. The rationale for the method is based on the pH-dependent feature of the interionic interaction between cysteine and arginine. At pH 6.0, cysteine can only interact with arginine through the ion-pair interaction and such interaction can lead to the changes in both the solution color and UV-vis spectrum of the cysteine-protected Au-NPs upon the addition of arginine. These changes are further developed into an analytical strategy for effective sensing of arginine by rationally controlling the pH values of Au-NP dispersions with the ratio of the absorbance at 650 nm (A 650) to that at 520 nm (A 520) (A 650/A 520) as a parameter for analysis. The method is responsive to arginine without the interference from other species in the cerebral system; under the optimized conditions, the A 650/A 520 values are linear with the concentration of arginine within a concentration range from 0.80 to 64 μM, yet remain unchanged with the addition of other kinds of amino acids or the species in the central nervous system into the Au-NPs dispersion containing cysteine. The method demonstrated here is reliable and robust and could thus be used for detection of the increase of arginine in central nervous systems.

  14. Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics

    PubMed Central

    Wu, Xia; Vellaichamy, Adaikkalam; Wang, Dongping; Zamdborg, Leonid; Kelleher, Neil L.; Huber, Steven C.; Zhao, Youfu

    2015-01-01

    Protein lysine acetylation (LysAc) has recently been demonstrated to be widespread in E. coli and Salmonella, and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we first report the lysine acetylome of Erwinia amylovora, an enterobacterium causing serious fire blight disease of apples and pears. Immunoblots using generic anti-lysine acetylation antibodies demonstrated that growth conditions strongly affected the LysAc profiles in E. amylovora. Differential LysAc profiles were also observed for two E. amylovora strains, known to have differential virulence in plants, indicating translational modification of proteins may be important in determining virulence of bacterial strains. Proteomic analysis of LysAc in two E. amylovora strains identified 141 LysAc sites in 96 proteins that function in a wide range of biological pathways. Consistent with previous reports, 44% of the proteins are involved in metabolic processes, including central metabolism, lipopolysaccharide, nucleotide and amino acid metabolism. Interestingly, for the first time, several proteins involved in E. amylovora virulence, including exopolysaccharide amylovoran biosynthesis- and type III secretion-associated proteins, were found to be lysine acetylated, suggesting that LysAc may play a major role in bacterial virulence. Comparative analysis of LysAc sites in E. amylovora and E. coli further revealed the sequence and structural commonality for LysAc in the two organisms. Collectively, these results reinforce the notion that LysAc of proteins is widespread in bacterial metabolism and virulence. PMID:23234799

  15. Understanding cerebral L-lysine metabolism: the role of L-pipecolate metabolism in Gcdh-deficient mice as a model for glutaric aciduria type I.

    PubMed

    Posset, Roland; Opp, Silvana; Struys, Eduard A; Völkl, Alfred; Mohr, Heribert; Hoffmann, Georg F; Kölker, Stefan; Sauer, Sven W; Okun, Jürgen G

    2015-03-01

    Inherited deficiencies of the L-lysine catabolic pathway cause glutaric aciduria type I and pyridoxine-dependent epilepsy. Dietary modulation of cerebral L-lysine metabolism is thought to be an important therapeutic intervention for these diseases. To better understand cerebral L-lysine degradation, we studied in mice the two known catabolic routes -- pipecolate and saccharopine pathways -- using labeled stable L-lysine and brain peroxisomes purified according to a newly established protocol. Experiments with labeled stable L-lysine show that cerebral L-pipecolate is generated along two pathways: i) a minor proportion retrograde after ε-deamination of L-lysine along the saccharopine pathway, and ii) a major proportion anterograde after α-deamination of L-lysine along the pipecolate pathway. In line with these findings, we observed only little production of saccharopine in the murine brain. L-pipecolate oxidation was only detectable in brain peroxisomes, but L-pipecolate oxidase activity was low (7 ± 2μU/mg protein). In conclusion, L-pipecolate is a major degradation product from L-lysine in murine brain generated by α-deamination of this amino acid.

  16. Deprivation of L-Arginine Induces Oxidative Stress Mediated Apoptosis in Leishmania donovani Promastigotes: Contribution of the Polyamine Pathway

    PubMed Central

    Mandal, Abhishek; Das, Sushmita; Roy, Saptarshi; Ghosh, Ayan Kumar; Sardar, Abul Hasan; Verma, Sudha; Saini, Savita; Singh, Ruby; Abhishek, Kumar; Kumar, Ajay; Mandal, Chitra; Das, Pradeep

    2016-01-01

    The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis. PMID:26808657

  17. Replacement of arginine 773 by cysteine or histidine in the human androgen receptor causes complete androgen insensitivity with different receptor phenotypes

    PubMed Central

    Prior, Lynn; Bordet, Sylvie; Trifiro, Mark A.; Mhatre, Anand; Kaufman, Morris; Pinsky, Leonard; Wrogeman, Klaus; Belsham, Denise D.; Pereira, Fred; Greenberg, Cheryl; Trapman, Jan; Brinkman, Albert O.; Chang, Chawnshang; Liao, Shutsung

    1992-01-01

    We have discovered two different point mutations in a single codon of the X-linked androgen-receptor (AR) gene in two pairs of unrelated families who have complete androgen insensitivity (resistance) associated with different AR phenotypes in their genital skin fibroblasts. One mutation is a C-to-T transition at a CpG sequence near the 5' terminus of exon 6; it changes the sense of codon 773 from arginine to cysteine, ablates specific androgen-binding activity at 37°C, and eliminates a unique KpnI site at the intron-exon boundary. The other mutation is a G-to-A transition that changes amino acid 773 to histidine and eliminates an SphI site. This mutant AR has a normal androgen-binding capacity at 37°C but has a reduced affinity for androgens and is thermolabile in their presence. Transient transfection of COS cells with cDNA expression vectors yielded little androgen-binding activity at 37°C from Arg773Cys and abundant activity with abnormal properties from Arg773His, thereby proving the pathogenicity of both sequence alterations. This conclusion coincides with the following facts about evolutionary preservation of the position homologous to Arg773 in the AR: it is occupied by Arg or lysine in the progesterone, glucocorticoid, and mineralocorticoid receptors, and it is within a 14-amino-acid region of their steroid-binding domains that share ∼85% amino acid identity. ImagesFigure 7Figure 2Figure 3Figure 5Figure 6Figure 8 PMID:1609793

  18. 24-Hour protein, arginine and citrulline metabolism in fed critically ill children - A stable isotope tracer study.

    PubMed

    de Betue, Carlijn T I; Garcia Casal, Xiomara C; van Waardenburg, Dick A; Schexnayder, Stephen M; Joosten, Koen F M; Deutz, Nicolaas E P; Engelen, Marielle P K J

    2017-06-01

    The reference method to study protein and arginine metabolism in critically ill children is measuring plasma amino acid appearances with stable isotopes during a short (4-8 h) time period and extrapolate results to 24-h. However, 24-h measurements may be variable due to critical illness related factors and a circadian rhythm could be present. Since only short duration stable isotope studies in critically ill children have been conducted before, the aim of this study was to investigate 24-h appearance of specific amino acids representing protein and arginine metabolism, with stable isotope techniques in continuously fed critically ill children. In eight critically ill children, admitted to the pediatric (n = 4) or cardiovascular (n = 4) intensive care unit, aged 0-10 years, receiving continuous (par)enteral nutrition with protein intake 1.0-3.7 g/kg/day, a 24-h stable isotope tracer protocol was carried out. L-[ring- 2 H 5 ]-phenylalanine, L-[3,3- 2 H 2 ]-tyrosine, L-[5,5,5- 2 H 3 ]-leucine, L-[guanido- 15 N 2 ]-arginine and L-[5- 13 C-3,3,4,4- 2 H 4 ]-citrulline were infused intravenously and L-[ 15 N]-phenylalanine and L-[1- 13 C]leucine enterally. Arterial blood was sampled every hour. Coefficients of variation, representing intra-individual variability, of the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline were high, on average 14-19% for intravenous tracers and 23-26% for enteral tracers. No evident circadian rhythm was present. The pattern and overall 24-h level of whole body protein balance differed per individual. In continuously fed stable critically ill children, the amino acid appearances of phenylalanine, tyrosine, leucine, arginine and citrulline show high variability. This should be kept in mind when performing stable isotope studies in this population. There was no apparent circadian rhythm. NCT01511354 on clinicaltrials.gov. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and

  19. Two Arginine Residues Suppress the Flexibility of Nucleosomal DNA in the Canonical Nucleosome Core

    PubMed Central

    Kono, Hidetoshi; Shirayama, Kazuyoshi; Arimura, Yasuhiro; Tachiwana, Hiroaki; Kurumizaka, Hitoshi

    2015-01-01

    The dynamics of nucleosomes containing either canonical H3 or its centromere-specific variant CENP-A were investigated using molecular dynamics simulations. The simulations showed that the histone cores were structurally stable during simulation periods of 100 ns and 50 ns, while DNA was highly flexible at the entry and exit regions and partially dissociated from the histone core. In particular, approximately 20–25 bp of DNA at the entry and exit regions of the CENP-A nucleosome exhibited larger fluctuations than DNA at the entry and exit regions of the H3 nucleosome. Our detailed analysis clarified that this difference in dynamics was attributable to a difference in two basic amino acids in the αN helix; two arginine (Arg) residues in H3 were substituted by lysine (Lys) residues at the corresponding sites in CENP-A. The difference in the ability to form hydrogen bonds with DNA of these two residues regulated the flexibility of nucleosomal DNA at the entry and exit regions. Our exonuclease III assay consistently revealed that replacement of these two Arg residues in the H3 nucleosome by Lys enhanced endonuclease susceptibility, suggesting that the DNA ends of the CENP-A nucleosome are more flexible than those of the H3 nucleosome. This difference in the dynamics between the two types of nucleosomes may be important for forming higher order structures in different phases. PMID:25786215

  20. New insights into the interplay between the lysine transporter LysP and the pH sensor CadC in Escherichia coli.

    PubMed

    Rauschmeier, Martina; Schüppel, Valentina; Tetsch, Larissa; Jung, Kirsten

    2014-01-09

    The coordination of signal transduction and substrate transport represents a sophisticated way to integrate information on metabolite fluxes into transcriptional regulation. This widely distributed process involves protein-protein interactions between two integral membrane proteins. Here we report new insights into the molecular mechanism of the regulatory interplay between the lysine-specific permease LysP and the membrane-integrated pH sensor CadC, which together induce lysine-dependent adaptation of E. coli under acidic stress. In vivo analyses revealed that, in the absence of either stimulus, the two proteins form a stable association, which is modulated by lysine and low pH. In addition to its transmembrane helix, the periplasmic domain of CadC also participated in the interaction. Site-directed mutagenesis pinpointed Arg265 and Arg268 in CadC as well as Asp275 and Asp278 in LysP as potential periplasmic interaction sites. Moreover, a systematic analysis of 100 LysP variants with single-site replacements indicated that the lysine signal is transduced from co-sensor to sensor via lysine-dependent conformational changes (upon substrate binding and/or transport) of LysP. Our results suggest a scenario in which CadC is inhibited by LysP via intramembrane and periplasmic contacts under non-inducing conditions. Upon induction, lysine-dependent conformational changes in LysP transduce the lysine signal via a direct conformational coupling to CadC without resolving the interaction completely. Moreover, concomitant pH-dependent protonation of periplasmic amino acids in both proteins dissolves their electrostatic connections resulting in further destabilization of the CadC/LysP interaction. © 2013.

  1. Characterization of arginine decarboxylase from Dianthus caryophyllus.

    PubMed

    Ha, Byung Hak; Cho, Ki Joon; Choi, Yu Jin; Park, Ky Young; Kim, Kyung Hyun

    2004-04-01

    Arginine decarboxylase (ADC, EC 4.1.1.9) is a key enzyme in the biosynthesis of polyamines in higher plants, whereas ornithine decarboxylase represents the sole pathway of polyamine biosynthesis in animals. Previously, we characterized a genomic clone from Dianthus caryophyllus, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 78 kDa. In the present study, the ADC gene was subcloned into the pGEX4T1 expression vector in combination with glutathione S-transferase (GST). The fusion protein GST-ADC was water-soluble and thus was purified by sequential GSTrap-arginine affinity chromatography. A thrombin-mediated on-column cleavage reaction was employed to release free ADC from GST. Hiload superdex gel filtration FPLC was then used to obtain a highly purified ADC. The identity of the ADC was confirmed by immunoblot analysis, and its specific activity with respect to (14)C-arginine decarboxylation reaction was determined to be 0.9 CO(2) pkat mg(-1) protein. K(m) and V(max) of the reaction between ADC and the substrate were 0.077 +/- 0.001 mM and 6.0 +/- 0.6 pkat mg(-1) protein, respectively. ADC activity was reduced by 70% in the presence of 0.1 mM Cu(2+) or CO(2+), but was only marginally affected by Mg(2+), or Ca(2+) at the same concentration. Moreover, spermine at 1 mM significantly reduced its activity by 30%.

  2. Effects of aspartic acid and potassium chloride on arginine kinase from shrimp.

    PubMed

    Tang, Hong-min; Yang, Yin-ye; Zhang, Song-fu

    2006-12-15

    The aspartic acid (Asp)-induced unfolding and the salt-induced folding of arginine kinase (AK) were studied in terms of enzyme activity, intrinsic fluorescence emission spectra, 1-anilino-8-naphthalenesulfonate (ANS) fluorescence spectra and far-UV circular dichroism (CD) spectra. The results showed that Asp caused inactivation and unfolding of AK with no aggregation during AK denaturation. The unfolding of the whole molecule and the inactivation of AK in different Asp concentrations were compared. Much lower Asp concentration was required to induce inactivation than to produce significant conformational changes of the enzyme molecule. However, with further addition of Asp, the molar ellipticity at 222 and 208 nm, the wavelength shift and the emission intensity of ANS hardly changed. Asp denatured AK was reactivated by dilution. In addition, potassium chloride (KCl) induced the molten globule state with a compact structure after AK was denatured with 7.5 mM Asp. These results collectively elucidate the osmotic effect of Asp anions for the molten globule formed during unfolding process. They also suggest that the effect of Asp differed from that of other denaturants such as guanidine hydrochloride or urea during AK folding. The molten globule state indicates that intermediates exist during AK folding.

  3. Amino Acid and Peptide Utilization Profiles of the Fluoroacetate-Degrading Bacterium Synergistetes Strain MFA1 Under Varying Conditions.

    PubMed

    Leong, Lex E X; Denman, Stuart E; Hugenholtz, Philip; McSweeney, Christopher S

    2016-02-01

    Synergistetes strain MFA1 is an asaccharolytic ruminal bacterium isolated based on its ability to degrade fluoroacetate, a plant toxin. The amino acid and peptide requirements of the bacterium were investigated under different culturing conditions. The growth of strain MFA1 and its fluoroacetate degradation rate were enhanced by peptide-rich protein hydrolysates (tryptone and yeast extract) compared to casamino acid, an amino acid-rich protein hydrolysate. Complete utilization and preference for arginine, asparagine, glutamate, glycine, and histidine as free amino acids from yeast extract were observed, while the utilization of serine, threonine, and lysine in free form and peptide-bound glutamate was stimulated during growth on fluoroacetate. A predominant peptide in yeast extract preferentially utilized by strain MFA1 was partially characterized by high-liquid performance chromatography-mass spectrometry as a hepta-glutamate oligopeptide. Similar utilization profiles of amino acids were observed between the co-culture of strain MFA1 with Methanobrevibacter smithii without fluoroacetate and pure strain MFA1 culture with fluoroacetate. This suggests that growth of strain MFA1 could be enhanced by a reduction of hydrogen partial pressure as a result of hydrogen removal by a methanogen or reduction of fluoroacetate.

  4. Effects of dietary arginine and glutamine on alleviating the impairment induced by deoxynivalenol stress and immune relevant cytokines in growing pigs.

    PubMed

    Wu, Li; Wang, Wence; Yao, Kang; Zhou, Ting; Yin, Jie; Li, Tiejun; Yang, Lin; He, Liuqin; Yang, Xiaojian; Zhang, Hongfu; Wang, Qi; Huang, Ruilin; Yin, Yulong

    2013-01-01

    Deoxynivalenol (DON) is a mycotoxin that reduces feed intake and animal performance, especially in swine. Arginine and glutamine play important roles in swine nutrition. The objective of this study was to determine the effects of dietary supplementation with arginine and glutamine on both the impairment induced by DON stress and immune relevant cytokines in growing pigs. A total of forty 60-d-old healthy growing pigs with a mean body weight of 16.28±1.54 kg were randomly divided into 5 groups, and assigned to 3 amino acid treatments fed 1.0% arginine (Arg), 1.0% glutamine (Gln) and 0.5% Arg+0.5% Gln, respectively, plus a toxin control and a non-toxin control. Pigs in the 3 amino acid treatments were fed the corresponding amino acids, and those in non-toxin control and toxin control were fed commercial diet with 1.64% Alanine as isonitrogenous control for 7 days. The toxin control and amino acid treatments were then challenged by feeding DON-contaminated diet with a final DON concentration of 6 mg/kg of diet for 21 days. No significant differences were observed between toxin control and the amino acid groups with regard to the average daily gain (ADG), although the values for average daily feed intake (ADFI) in the amino acid groups were significantly higher than that in toxin control (P<0.01). The relative liver weight in toxin control was significantly greater than those in non-toxin control, arginine and Arg+Glu groups (P<0.01), but there were no significant differences in other organs. With regard to serum biochemistry, the values of BUN, ALP, ALT and AST in the amino acid groups were lower than those in toxin control. IGF1, GH and SOD in the amino acid groups were significantly higher than those in toxin control (P<0.01). The IL-2 and TNFα values in the amino acid groups were similar to those in non-toxin control, and significantly lower than those in toxin control (P<0.01). These results showed the effects of dietary supplementation with arginine and

  5. Selective determination of arginine-containing and tyrosine-containing peptides using capillary electrophoresis and laser-induced fluorescence detection.

    PubMed

    Cobb, K A; Novotny, M V

    1992-01-01

    The use of two different amino acid-selective fluorogenic reagents for the derivatization of peptides is investigated. One such scheme utilizes a selective reaction of benzoin with the guanidine moiety to derivatize arginine residues occurring in a peptide. The second scheme involves the formylation of tyrosine, followed by reaction with 4-methoxy-1,2-phenylenediamine. The use of capillary electrophoresis and laser-induced fluorescence detection allows enhanced efficiencies and sensitivities to be obtained for the separations of either arginine- or tyrosine-containing peptides. A helium-cadmium laser (325 nm) is ideally suited for the laser-based detection system due to a close match of the excitation maxima of derivatized peptides from both reactions. A detection limit of 270 amol is achieved for model arginine-containing peptides, while the detection limit for model tyrosine-containing peptides is measured at 390 amol. Both derivatization reactions are found to be useful for high-sensitivity peptide mapping applications in which only the peptides containing the derivatized amino acids are detected.

  6. Supplementation with apple enriched with L-arginine may improve metabolic control and survival rate in alloxan-induced diabetic rats.

    PubMed

    Escudero, Andrea; Petzold, Guillermo; Moreno, Jorge; Gonzalez, Marcelo; Junod, Julio; Aguayo, Claudio; Acurio, Jesenia; Escudero, Carlos

    2013-01-01

    Supplementation with L-arginine or fresh food with high content of this amino acid is associated with favorable effects in the metabolic control of diabetes. We aimed to determine whether supplementation with apples enriched with L-arginine offer additional benefits compared to L-arginine by itself in a preclinical study of diabetes. This study combines food-engineer technologies with in vivo and in vitro analysis. In vitro experiments show that cells derived from non-diabetic animals and exposed to high glucose (25 mM, 12 H) and cells isolated from alloxan-induced diabetic animals exhibited a reduction (∼50%) in the L-arginine uptake. This effect was reverted by L-arginine pretreatment (12 H) in both the normal and diabetes-derived cells. In preclinical studies, normoglycemic (n = 25) and diabetic groups (n = 50) were divided into subgroups that received either L-arginine (375 mg/kg per 10 days) or apple enriched with L-arginine or vehicle (control). In a preliminary analysis, supplementation with L-arginine by itself (50%) or apple enriched with L-arginine (100%) improve survival rate in the diabetic group compared to control (0%) at the end of the follow up (17 days). This phenomenon was associated with a partial but sustained high plasma level of L-arginine, as well as plasma concentration of nitrites and insulin in the L-arginine or apple + L-arginine groups after supplementation. Apple + L-arginine supplementation in diabetic animals induced the highest and longest effects in the level of these three markers among the studied groups. Therefore, apple enriched by L-arginine offers more benefits than L-arginine by itself in this preclinical study. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  7. Molecular dynamics simulations on the Tre1 G protein-coupled receptor: exploring the role of the arginine of the NRY motif in Tre1 structure

    PubMed Central

    2013-01-01

    Background The arginine of the D/E/NRY motif in Rhodopsin family G protein-coupled receptors (GPCRs) is conserved in 96% of these proteins. In some GPCRs, this arginine in transmembrane 3 can form a salt bridge with an aspartic acid or glutamic acid in transmembrane 6. The Drosophila melanogaster GPCR Trapped in endoderm-1 (Tre1) is required for normal primordial germ cell migration. In a mutant form of the protein, Tre1sctt, eight amino acids RYILIACH are missing, resulting in a severe disruption of primordial germ cell development. The impact of the loss of these amino acids on Tre1 structure is unknown. Since the missing amino acids in Tre1sctt include the arginine that is part of the D/E/NRY motif in Tre1, molecular dynamics simulations were performed to explore the hypothesis that these amino acids are involved in salt bridge formation and help maintain Tre1 structure. Results Structural predictions of wild type Tre1 (Tre1+) and Tre1sctt were subjected to over 250 ns of molecular dynamics simulations. The ability of the model systems to form a salt bridge between the arginine of the D/E/NRY motif and an aspartic acid residue in transmembrane 6 was analyzed. The results indicate that a stable salt bridge can form in the Tre1+ systems and a weak salt bridge or no salt bridge, using an alternative arginine, is likely in the Tre1sctt systems. Conclusions The weak salt bridge or lack of a salt bridge in the Tre1sctt systems could be one possible explanation for the disrupted function of Tre1sctt in primordial germ cell migration. These results provide a framework for studying the importance of the arginine of the D/E/NRY motif in the structure and function of other GPCRs that are involved in cell migration, such as CXCR4 in the mouse, zebrafish, and chicken. PMID:24044607

  8. Molecular dynamics simulations on the Tre1 G protein-coupled receptor: exploring the role of the arginine of the NRY motif in Tre1 structure.

    PubMed

    Pruitt, Margaret M; Lamm, Monica H; Coffman, Clark R

    2013-09-18

    The arginine of the D/E/NRY motif in Rhodopsin family G protein-coupled receptors (GPCRs) is conserved in 96% of these proteins. In some GPCRs, this arginine in transmembrane 3 can form a salt bridge with an aspartic acid or glutamic acid in transmembrane 6. The Drosophila melanogaster GPCR Trapped in endoderm-1 (Tre1) is required for normal primordial germ cell migration. In a mutant form of the protein, Tre1sctt, eight amino acids RYILIACH are missing, resulting in a severe disruption of primordial germ cell development. The impact of the loss of these amino acids on Tre1 structure is unknown. Since the missing amino acids in Tre1sctt include the arginine that is part of the D/E/NRY motif in Tre1, molecular dynamics simulations were performed to explore the hypothesis that these amino acids are involved in salt bridge formation and help maintain Tre1 structure. Structural predictions of wild type Tre1 (Tre1+) and Tre1sctt were subjected to over 250 ns of molecular dynamics simulations. The ability of the model systems to form a salt bridge between the arginine of the D/E/NRY motif and an aspartic acid residue in transmembrane 6 was analyzed. The results indicate that a stable salt bridge can form in the Tre1+ systems and a weak salt bridge or no salt bridge, using an alternative arginine, is likely in the Tre1sctt systems. The weak salt bridge or lack of a salt bridge in the Tre1sctt systems could be one possible explanation for the disrupted function of Tre1sctt in primordial germ cell migration. These results provide a framework for studying the importance of the arginine of the D/E/NRY motif in the structure and function of other GPCRs that are involved in cell migration, such as CXCR4 in the mouse, zebrafish, and chicken.

  9. The effect of chaya (Cnidoscolus aconitifolius) leaf meal and of exogenous enzymes on amino acid digestibility in broilers.

    PubMed

    Sarmiento-Franco, L; McNab, J M; Pearson, A; Belmar-Casso, R

    2003-07-01

    1. The apparent ileal nitrogen (N) and amino acid digestibilities in chaya leaf meal (CLM) (Cnidoscolus aconitifolius) with added enzymes, and the same variables in diets containing different amounts of CLM were studied in chickens. 2. In the first experiment pectinase, beta-glucanase, and pectinase + beta-glucanase were added to CLM. In the second experiment, there were three diets based on maize and soybean: 0, 150 and 250 g/kg CLM. 3. Pectinase significantly increased both lysine and overall amino acid digestibilities in CLM. 4. In experiment 2, the amino acid digestibility in birds fed on CLM250 was lower than that from birds fed on either control or CLM150. Only the digestibilities of alanine, arginine and proline were lower in birds fed on CLM150 than in those fed on the control diet. Nitrogen digestibility was lower in birds fed on the CLM250 diet than on either control or CLM150 diets. These findings were attributed to the increasing concentration of fibre with increasing dietary CLM.

  10. Arginine-glycine-aspartic acid-conjugated dendrimer-modified quantum dots for targeting and imaging melanoma.

    PubMed

    Li, Zhiming; Huang, Peng; Lin, Jing; He, Rong; Liu, Bing; Zhang, Xiaomin; Yang, Sen; Xi, Peng; Zhang, Xuejun; Ren, Qiushi; Cui, Daxiang

    2010-08-01

    Angiogenesis is essential for the development of malignant tumors and provides important targets for tumor diagnosis and therapy. Quantum dots have been broadly investigated for their potential application in cancer molecular imaging. In present work, CdSe quantum dots were synthesized, polyamidoamine dendrimers were used to modify surface of quantum dots and improve their solubility in water solution. Then, dendrimer-modified CdSe quantum dots were conjugated with arginine-glycine-aspartic acid (RGD) peptides. These prepared nanoprobes were injected into nude mice loaded with melanoma (A375) tumor xenografts via tail vessels, IVIS imaging system was used to image the targeting and bio-distribution of as-prepared nanoprobes. The dendrimer-modified quantum dots exhibit water-soluble, high quantum yield, and good biocompatibility. RGD-conjugated quantum dots can specifically target human umbilical vein endothelial cells (HUVEC) and A375 melanoma cells, as well as nude mice loaded with A735 melanoma cells. High-performance RGD-conjugated dendrimers modified quantum dot-based nanoprobes have great potential in application such as tumor diagnosis and therapy.

  11. [Dynamics of amino acid and protein metabolism of laying hens after administration of 15N-labeled wheat protein. 5. Incorporation of 15N into the blood fraction and its amino acids].

    PubMed

    Gruhn, K; Zander, R; Kirchner, E

    1987-09-01

    12 colostomized laying hens which received 15N labelled wheat over 4 days were butchered 12 h, 36 h, 60 h and 108 h (3 animals each) after the last 15N application. The intake of 15N excess (15N') from the wheat amounted to 540 mg 15N' during the application period. The 15N' in the blood plasma decreased after the last 15N' application from 0.76 atom-% to 0.55 atom-% after 108 h, the labelling of the corpuscular components at the same measuring points increased from 0.28 to 0.50 atom-% 15N'. 96.6% of the plasma 15N' and 93.8% of that in the corpuscles is precipitable in trichloric acetic acid. The atom-% 15N' of histidine in the total blood remained unchanged in dependence on the butchering time. The 15N amount in lysine and arginine and that in the non-basic amino acids decreased inconsiderably in the period between 12 h and 108 h after the last 15N' wheat feeding.

  12. Effects of Long-Term Protein Restriction on Meat Quality, Muscle Amino Acids, and Amino Acid Transporters in Pigs.

    PubMed

    Yin, Jie; Li, Yuying; Zhu, Xiaotong; Han, Hui; Ren, Wenkai; Chen, Shuai; Bin, Peng; Liu, Gang; Huang, Xingguo; Fang, Rejun; Wang, Bin; Wang, Kai; Sun, Liping; Li, Tiejun; Yin, Yulong

    2017-10-25

    This study aimed to investigate the long-term effects of protein restriction from piglets to finishing pigs for 16 weeks on meat quality, muscle amino acids, and amino acid transporters. Thirty-nine piglets were randomly divided into three groups: a control (20-18-16% crude protein, CP) and two protein restricted groups (17-15-13% CP and 14-12-10% CP). The results showed that severe protein restriction (14-12-10% CP) inhibited feed intake and body weight, while moderate protein restriction (17-15-13% CP) had little effect on growth performance in pigs. Meat quality (i.e., pH, color traits, marbling, water-holding capacity, and shearing force) were tested, and the results exhibited that 14-12-10% CP treatment markedly improved muscle marbling score and increased yellowness (b*). pH value (45 min) was significantly higher in 17-15-13% CP group than that in other groups. In addition, protein restriction reduced muscle histone, arginine, valine, and isoleucine abundances and enhanced glycine and lysine concentrations compared with the control group, while the RT-PCR results showed that protein restriction downregulated amino acids transporters. Mechanistic target of rapamycin (mTOR) signaling pathway was inactivated in the moderate protein restricted group (17-15-13% CP), while severe protein restriction with dietary 14-12-10% CP markedly enhanced mTOR phosphorylation. In conclusion, long-term protein restriction affected meat quality and muscle amino acid metabolism in pigs, which might be associated with mTOR signaling pathway.

  13. Poly(ornithine-co-arginine-co-glycine-co-aspartic Acid): Preparation via NCA Polymerization and its Potential as a Polymeric Tumor-Penetrating Agent.

    PubMed

    Yu, Haiyang; Tang, Zhaohui; Zhang, Dawei; Song, Wantong; Duan, Taicheng; Gu, Jingkai; Chen, Xuesi

    2015-06-01

    A novel random copolypeptide of ornithine, arginine, glycine, and aspartic acid [Poly(ornithine-co-arginine-co-glycine-co-aspartic acid), Poly(O,R,G,D)] has been prepared through ring-opening polymerization of N-δ-carbobenzoxy-l-ornithine N-carboxyanhydride [Orn(Cbz)-NCA)], l-glycine N-carboxyanhydride (Gly-NCA) and β-benzyl l-aspartate N-carboxyanhydride [Asp(Bn)-NCA], following by subsequent deprotection and guanidization. The structure of Poly(O,R,G,D) was confirmed by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Low cytotoxicity of Poly(O,R,G,D) was confirmed from MTT assay. The Poly(O,R,G,D) contain some internal sequences of RXXR (X = O, R, G, or D) that could be proteolytically cleaved to expose the cryptic CendR element and bind to Neuropilin-1. This would lead to vascular and tissue permeabilization. Therefore trypsin-cleaved Poly(O,R,G,D) increase the vascular leakage of Evans blue from dermal microvessels at the injection site in vivo skin permeability assay. The intratumoral injection of the Poly(O,R,G,D) significantly enhanced the concentration of cisplatin-loaded nanoparticles in MCF-7 solid tumors. These results show that Poly(O,R,G,D) could increase the vascular leakage and tissue penetration of nanoparticles in a solid tumor and can be used as a potential polymeric tumor-penetrating agent. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Measurements of radiological data of some amino acids in the energy range 0.122-1.330MeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lokhande, Rajkumar M., E-mail: rajml358@gmail.com; More, Chaitali V.; Surung, Bharat S.

    Radiological parameters such as μ{sub m}, σ{sub t}, σ{sub e}, Z{sub eff} and N{sub eff} of amino acids, namely Lysine (C{sub 6}H{sub 15}N{sub 2}O{sub 2}), Histidine (C{sub 6}H{sub 9}N{sub 3}O{sub 2}) and Arginine (C{sub 6}H{sub 15}N{sub 4}O{sub 2}), were measured using NaI (Tl)-based gamma spectrometry. Radioactive sources used in the study are {sup 57}Co, {sup 133}Ba, {sup 137}Cs, {sup 54}Mn, {sup 60}Co and {sup 22}Na. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against XCOM-based data. The agreement is within 2%.

  15. Mechanism of allosteric inhibition of N-acetyl-L-glutamate synthase by L-arginine.

    PubMed

    Min, Li; Jin, Zhongmin; Caldovic, Ljubica; Morizono, Hiroki; Allewell, Norma M; Tuchman, Mendel; Shi, Dashuang

    2009-02-20

    N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in l-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by l-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with l-arginine bound and in the active R-state complexed with CoA and l-glutamate. Under all of the conditions examined, the enzyme consists of two stacked trimers. Each monomer has two domains: an amino acid kinase (AAK) domain with an AAK-like fold but lacking kinase activity and an N-acetyltransferase (NAT) domain homologous to other GCN5-related transferases. Binding of l-arginine to the AAK domain induces a global conformational change that increases the diameter of the hexamer by approximately 10 A and decreases its height by approximately 20A(.) AAK dimers move 5A outward along their 2-fold axes, and their tilt relative to the plane of the hexamer decreases by approximately 4 degrees . The NAT domains rotate approximately 109 degrees relative to AAK domains enabling new interdomain interactions. Interactions between AAK and NAT domains on different subunits also change. Local motions of several loops at the l-arginine-binding site enable the protein to close around the bound ligand, whereas several loops at the NAT active site become disordered, markedly reducing enzymatic specific activity.

  16. Emerging roles of lysine methylation on non-histone proteins.

    PubMed

    Zhang, Xi; Huang, Yaling; Shi, Xiaobing

    2015-11-01

    Lysine methylation is a common posttranslational modification (PTM) of histones that is important for the epigenetic regulation of transcription and chromatin in eukaryotes. Increasing evidence demonstrates that in addition to histones, lysine methylation also occurs on various non-histone proteins, especially transcription- and chromatin-regulating proteins. In this review, we will briefly describe the histone lysine methyltransferases (KMTs) that have a broad spectrum of non-histone substrates. We will use p53 and nuclear receptors, especially estrogen receptor alpha, as examples to discuss the dynamic nature of non-histone protein lysine methylation, the writers, erasers, and readers of these modifications, and the crosstalk between lysine methylation and other PTMs in regulating the functions of the modified proteins. Understanding the roles of lysine methylation in normal cells and during development will shed light on the complex biology of diseases associated with the dysregulation of lysine methylation on both histones and non-histone proteins.

  17. Terrestrial evolution of polymerization of amino acids - Heat to ATP

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Nakashima, T.

    1981-01-01

    Sets of amino acids containing sufficient trifunctional monomer are thermally polymerized at temperatures such as 65 deg; the amino acids order themselves. Various polymers have diverse catalytic activities. The polymers aggregate, in aqueous solution, to cell-like structures having those activities plus emergent properties, e.g. proliferatability. Polyamino acids containing sufficient lysine catalyze conversion of free amino acids, by ATP, to small peptides and a high molecular weight fraction. The lysine-rich proteinoid is active in solution, within suspensions of cell-like particles, or in other particles composed of lysine-rich proteinoid and homopolyribonucleotide. Selectivities are observed. An archaic polyamino acid prelude to coded protein synthesis is indicated.

  18. Pharmaceutical salts and cocrystals involving amino acids: a brief structural overview of the state-of-art.

    PubMed

    Tilborg, Anaëlle; Norberg, Bernadette; Wouters, Johan

    2014-03-03

    Salification of new drug substances in order to improve physico-chemical or solid-state properties (e.g. dissolution rate or solubility, appropriate workup process, storage for further industrial and marketing development) is a well-accepted procedure. Amino acids, like aspartic acid, lysine or arginine take a great part in this process and are implicated in several different formulations of therapeutic agent families, including antibiotics (amoxicillin from beta lactam class or cephalexin from cephalosporin class), NSAIDs (ketoprofen, ibuprofen and naproxen from profen family, acetylsalicylic acid) or antiarrhythmic agents (e.g. ajmaline). Even if more than a half of known pharmaceutical molecules possess a salifiable moiety, what can be done for new potential drug entity that cannot be improved by transformation into a salt? In this context, after a brief review of pharmaceutical salts on the market and the implication of amino acids in these formulations, we focus on the advantage of using amino acids even when the target compound is not salifiable by exploiting their zwitterionic potentialities for cocrystal edification. We summarize here a series of new examples coming from literature to support the advantages of broadening the application of amino acids in formulation for new drug substances improvement research for non-salifiable molecules. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  19. Pyruvate kinase deletion as an effective phenotype to enhance lysine production in Corynebacterium glutamicum ATCC13032: Redirecting the carbon flow to a precursor metabolite.

    PubMed

    Yanase, Masaki; Aikoh, Tohru; Sawada, Kazunori; Ogura, Kotaro; Hagiwara, Takuya; Imai, Keita; Wada, Masaru; Yokota, Atsushi

    2016-08-01

    Various attempts have been made to enhance lysine production in Corynebacterium glutamicum. Pyruvate kinase (PYK) defect is one of the strategies used to enhance the supply of oxaloacetic acid (OAA), a precursor metabolite for lysine biosynthesis. However, inconsistent effects of this mutation have been reported: positive effects of PYK defect in mutants having phosphoenolpyruvate carboxylase (PEPC) desensitized to feedback inhibition by aspartic acid, while negative effects in simple PYK gene (pyk) knockout mutants. To address these discrepancies, the effects of pyk deletion on lysine yield were investigated with or without the D299N mutation in ppc rendering PEPC desensitization. C. glutamicum ATCC13032 mutant strain P with a feedback inhibition-desensitized aspartokinase was used as the parent strain, producing 9.36 g/L lysine from 100 g/L glucose in a jar fermentor culture. Under these conditions, while the simple mutant D2 with pyk deletion or R2 with the PEPC-desensitization mutation showed marginally increased lysine yield (∼1.1-fold, not significant), the mutant DR2 strain having both mutations showed synergistically increased lysine productivity (1.38-fold, 12.9 g/L). Therefore, the pyk deletion is effective under a PEPC-desensitized background, which ensures enhanced supply of OAA, thus clarifying the discrepancies. A citrate synthase defective mutation (S252C in gltA) further increased the lysine yield in strain DR2 (1.68-fold, 15.7 g/L). Thus, these three mutations coordinately enhanced the lysine yield. Both the malate:quinone oxidoreductase activity and respiration rate were significantly reduced in strains D2 and DR2. Overall, these results provide valuable knowledge for engineering the anaplerotic reaction to increase lysine yield in C. glutamicum. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Biotinylation of lysine method identifies acetylated histone H3 lysine 79 in Saccharomyces cerevisiae as a substrate for Sir2.

    PubMed

    Bheda, Poonam; Swatkoski, Stephen; Fiedler, Katherine L; Boeke, Jef D; Cotter, Robert J; Wolberger, Cynthia

    2012-04-17

    Although the biological roles of many members of the sirtuin family of lysine deacetylases have been well characterized, a broader understanding of their role in biology is limited by the challenges in identifying new substrates. We present here an in vitro method that combines biotinylation and mass spectrometry (MS) to identify substrates deacetylated by sirtuins. The method permits labeling of deacetylated residues with amine-reactive biotin on the ε-nitrogen of lysine. The biotin can be utilized to purify the substrate and identify the deacetylated lysine by MS. The biotinyl-lysine method was used to compare deacetylation of chemically acetylated histones by the yeast sirtuins, Sir2 and Hst2. Intriguingly, Sir2 preferentially deacetylates histone H3 lysine 79 as compared to Hst2. Although acetylation of K79 was not previously reported in Saccharomyces cerevisiae, we demonstrate that a minor population of this residue is indeed acetylated in vivo and show that Sir2, and not Hst2, regulates the acetylation state of H3 lysine 79. The in vitro biotinyl-lysine method combined with chemical acetylation made it possible to identify this previously unknown, low-abundance histone acetyl modification in vivo. This method has further potential to identify novel sirtuin deacetylation substrates in whole cell extracts, enabling large-scale screens for new deacetylase substrates.