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Sample records for acid glycine histidine

  1. Histidyl-histidine catalysis of glycine condensation in fluctuating clay environments

    NASA Technical Reports Server (NTRS)

    White, D. H.; Erickson, J. C.

    1981-01-01

    Histidyl-histidine is a remarkably effective catalyst of peptide bond formation in the reaction of glycine in a fluctuating (hot-dry, cold-wet) clay environment. It has shown turnover numbers (molecules of glycine incorporated in oligoglycines per molecule of catalyst) as high as 18 in a single cycle and as high as 52 overall. A number of other dipeptides were tested, as well as monomeric histidine, N-acetyl histidine, and imidazole, none of which showed turnover numbers greater than one. Histidyl-histidine is a model for a prebiotic protoenzyme, and implications for the development of a simple translation mechanism are discussed.

  2. Standard thermodynamic functions of Co2+ complexation with glycine and L-histidine in aqueous solution

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.

    2016-02-01

    The enthalpies of the reactions between solutions of Co(NO3)2 and solutions of glycine (Gly) and L-histidine (His) are determined via direct calorimetry at different pH values and metal: ligand ratios using KNO3 as a background electrolyte ( T = 298.15 K, I = 0.2-1.0). The enthalpy changes upon the formation of cobalt glycinate complexes and Co2+ mixed-ligand complex, viz., glycine-L-histidine, were calculated. The standard thermodynamic parameters (Δr H°, Δr G°, Δr S°) of complexation are determined. The CoGlyHis complex is shown to be stable toward decomposition into homogeneous complexes.

  3. Standard thermodynamic functions of complexation between copper(II) and glycine and L-histidine in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.

    2016-09-01

    The Cu2+-glycine-L-histidine system is studied calorimetrically at 298.15 K and an ionic strength of 0.2, 0.5, and 1.0 in aqueous solutions containing potassium nitrate. The standard thermodynamic parameters (Δr H°, Δr G°, Δr S°) of complexation processes are determined.

  4. 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. PMID:17440630

  5. Thermodynamics of the formation of the Ni2+-glycine-L-histidine complex in aqueous solutions at 298.15 K

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.; Bychkova, S. A.

    2015-05-01

    The Ni2+-glycine-L-histidine system in aqueous solution at 298.15 K and ionic strengths of 0.2, 0.5, and 1.0 with potassium nitrate as the supporting electrolyte has been investigated calorimetrically. Standard thermodynamic characteristics (Δr H°, Δr G°, Δr S°) of complexation have been determined. The NiLY complex is highly stable with respect to decomposition into homoligand complexes.

  6. Enhanced trophic factor secretion by mesenchymal stem/stromal cells with Glycine-Histidine-Lysine (GHK)-modified alginate hydrogels

    PubMed Central

    Jose, Soumia; Hughbanks, Marissa L.; Binder, Bernard Y.K.; Ingavle, Ganesh C.; Leach, J. Kent

    2014-01-01

    Recombinant proteins and cytokines are under broad preclinical and clinical investigation to promote angiogenesis, but their success is limited by ineffective delivery, lack of long-term stability, and excessive cost. Mesenchymal stem/stromal cells (MSC) secrete bioactive trophic factors, and thus, may provide an effective alternative to address these challenges. Glycine-Histidine-Lysine (GHK) is a peptide fragment of osteonectin (SPARC), a matricellular protein with reported proangiogenic potential. We examined the capacity of GHK to upregulate secretion of proangiogenic factors from human MSC in culture and when covalently coupled to alginate hydrogels. GHK had no apparent cytotoxic effects on MSC in culture over a wide range of concentrations. We detected a dose-dependent increase in vascular endothelial growth factor (VEGF) concentration in media conditioned by GHK-treated MSC, which increased endothelial cell proliferation, migration, and tubule formation. We covalently coupled GHK to alginate using carbodiimide chemistry, and human MSC were entrapped in alginate hydrogels to assess VEGF secretion. Similar to monolayer culture, MSC responded to GHK-modified gels by secreting increased concentrations of VEGF and basic fibroblast growth factor (bFGF) compared to unmodified gels. The pre-treatment of MSC with antibodies to α6 and β1 integrins prior to entrapment in GHK-modified gels abrogated VEGF secretion, suggesting that the proangiogenic response of MSC was integrin-mediated. These data demonstrate that the proangiogenic potential of MSC can be significantly increased by the presentation of GHK with a biodegradable carrier, therefore increasing their clinical potential when used for tissue repair. PMID:24468583

  7. Nitrate and amino acid availability affects glycine betaine and mycosporine-2-glycine in response to changes of salinity in a halotolerant cyanobacterium Aphanothece halophytica.

    PubMed

    Waditee-Sirisattha, Rungaroon; Kageyama, Hakuto; Fukaya, Minoru; Rai, Vandna; Takabe, Teruhiro

    2015-12-01

    A halotolerant cyanobacterium Aphanothece halophytica thrives in extreme salinity with accumulation of a potent osmoprotectant glycine betaine. Recently, this cyanobacterium was shown to accumulate sunscreen molecule mycosporine-2-glycine significantly at high salinity. In this study, we investigated effects of nitrate and amino acid provision on the accumulation of glycine betaine and mycosporine-2-glycine. With elevated nitrate concentrations at high salinity, intracellular levels of both metabolites were enhanced. Six-fold high nitrate concentration increased the relative amounts of glycine betaine and mycosporine-2-glycine to be 1.5 and 2.0 folds compared with control condition : Increased levels were time- and dose-dependent manner. Exogenous supply of glycine/serine at high salinity resulted in the similar trends as observed in excess nitrate experiment. Intracellular level of glycine betaine increased ∼1.6 folds with glycine/serine supplementation. These supplementations also caused the increased level of mycosporine-2-glycine, namely 1.4 and 2 folds by glycine and serine, respectively. The transcription of glycine betaine and mycosporine-2-glycine biosynthetic genes was strongly induced under high-nitrate-salt condition. These results suggest the dependence of glycine betaine and mycosporine-2-glycine productions on substrate availability, and the effect of nitrate was possibly associated with stimulation of osmoprotectant increment in this extremophile. PMID:26474598

  8. Nitrate and amino acid availability affects glycine betaine and mycosporine-2-glycine in response to changes of salinity in a halotolerant cyanobacterium Aphanothece halophytica.

    PubMed

    Waditee-Sirisattha, Rungaroon; Kageyama, Hakuto; Fukaya, Minoru; Rai, Vandna; Takabe, Teruhiro

    2015-12-01

    A halotolerant cyanobacterium Aphanothece halophytica thrives in extreme salinity with accumulation of a potent osmoprotectant glycine betaine. Recently, this cyanobacterium was shown to accumulate sunscreen molecule mycosporine-2-glycine significantly at high salinity. In this study, we investigated effects of nitrate and amino acid provision on the accumulation of glycine betaine and mycosporine-2-glycine. With elevated nitrate concentrations at high salinity, intracellular levels of both metabolites were enhanced. Six-fold high nitrate concentration increased the relative amounts of glycine betaine and mycosporine-2-glycine to be 1.5 and 2.0 folds compared with control condition : Increased levels were time- and dose-dependent manner. Exogenous supply of glycine/serine at high salinity resulted in the similar trends as observed in excess nitrate experiment. Intracellular level of glycine betaine increased ∼1.6 folds with glycine/serine supplementation. These supplementations also caused the increased level of mycosporine-2-glycine, namely 1.4 and 2 folds by glycine and serine, respectively. The transcription of glycine betaine and mycosporine-2-glycine biosynthetic genes was strongly induced under high-nitrate-salt condition. These results suggest the dependence of glycine betaine and mycosporine-2-glycine productions on substrate availability, and the effect of nitrate was possibly associated with stimulation of osmoprotectant increment in this extremophile.

  9. Gas-phase structures and thermochemistry of neutral histidine and its conjugated acid and base.

    PubMed

    Riffet, Vanessa; Bouchoux, Guy

    2013-04-28

    Extensive exploration of the conformational space of neutral, protonated and deprotonated histidine has been conducted at the G4MP2 level. Theoretical protonation and deprotonation thermochemistry as well as heats of formation of gaseous histidine and its ionized forms have been calculated at the G4 level considering either the most stable conformers or an equilibrium population of conformers at 298 K. These theoretical results were compared to evaluated experimental determinations. Recommended proton affinity and protonation entropy deduced from these comparisons are PA(His) = 980 kJ mol(-1) and ΔpS(His) ∼ 0 J mol(-1) K(-1), thus leading to a gas-phase basicity value of GB(His) = 947.5 kJ mol(-1). Similarly, gas phase acidity parameters are ΔacidH(o)(His) = 1373 kJ mol(-1), ΔacidS(His) ∼ 10 J mol(-1) K(-1) and ΔacidG(o)(His) = 1343 kJ mol(-1). Computed G4 heats of formation values are equal to -290, 265 and -451 kJ mol(-1) for gaseous neutral histidine and its protonated and deprotonated forms, respectively. The present computational data correct, and complete, previous thermochemical parameter estimates proposed for gas-phase histidine and its acido-basic properties.

  10. Glycine-Linked Nucleoside-β-Amino Acids: Polyamide Analogues of Nucleic Acids.

    PubMed

    Banerjee, Anjan; Bagmare, Seema; Varada, Manojkumar; Kumar, Vaijayanti A

    2015-08-19

    3'-5'-Deoxyribose-sugar-phoshate backbone in DNA is completely replaced by 2'-deoxyribonucleoside-based β-amino acids interlinked by glycine to create uncharged polyamide DNA with 3'-5'-directionality. These oligomers as conjugates of α-amino acids and nucleoside-β-amino acids bind strongly and sequence-specifically only to the antiparallel complementary RNA and DNA.

  11. Analysis of histidine and urocanic acid isomers by reversed-phase high-performance liquid chromatography.

    PubMed

    Hermann, K; Abeck, D

    2001-01-01

    The qualitative separation performance of a C18, C8 and C4 reversed-phase column was investigated for the separation of histidine and its metabolites histamine, 1-methyihistamine and trans- and cis-urocanic acid. Trans- and cis-urocanic acid were baseline separated from their precursor histidine on all three columns using isocratic elution with a mobile phase composed of 0.01 M aqueous TEAP pH 3.0 and acetonitrile at a ratio of 98:2 (v/v). However, histidine was not separated from histamine and 1-methyihistamine. Selecting the C8 column and introducing 0.005 M of the ion pairing reagent 1-octanesulfonic acid sodium salt into the aqueous solution and acetonitrile at a ratio of 90:10 (v/v), significantly improved the separation. The separation was also followed by a change in the retention times and the order of elution. The sequence of elution was histidine, cis-urocanic acid, trans-urocanic acid, histamine and 1-methylhistamine with retention times of 5.58 +/- 0.07, 7.03 +/- 0.15, 7.92 +/- 0.18, 18.77 +/- 0.24 and 20.79 +/- 0.21 min (mean +/- SD; n=5). The separation on the C8 column in the presence of the ion-pairing reagent was further improved with gradient elution that resulted in a reduction in the retention times and elution volumes of histamine and 1-methylhistamine. The detection limits of histidine and trans-urocanic acid at a wavelength of 210 nm and an injection volume of 0.05 ml were 5 x 10(-8) mol l(-1) (n=3). The kinetic of the in-vitro conversion of trans- into the cis-isomer after UV irradiation was depending on the time of exposure and the energy of the light source. UVB light induced a significantly faster conversion than UVA light. TUCA and cUCA samples kept at -25 degrees C were stable for up to 50 weeks. Samples, eluted from human skin showed various concentrations of histidine and trans- and cis-urocanic acid with an average of 1.69 +/- 0.33 x 10(-5) mol l(-1), 1.17 +/- 0.43 x 10(-5) mol l(-1) and 1.67 +/- 0.33 x 10(-5) mol l(-1), respectively

  12. Active transport of. gamma. -aminobutyric acid and glycine into synaptic vesicles

    SciTech Connect

    Kish, P.E.; Fischer-Bovenkerk, C.; Ueda, T. )

    1989-05-01

    Although {gamma}-aminobutyric acid (GABA) and glycine are recognized as major amino acid inhibitory neurotransmitters in the central nervous system, their storage is poorly understood. In this study the authors have characterized vesicular GABA and glycine uptakes in the cerebrum and spinal cord, respectively. They present evidence that GABA and glycine are each taken up into isolated synaptic vesicles in an ATP-dependent manner and that the uptake is driven by an electrochemical proton gradient. Uptake for both amino acids exhibited kinetics with low affinity similar to a vesicular glutamate uptake. The ATP-dependent GABA uptake was not inhibited by the putative amino acid neurotransmitters glycine, taurine, glutamate, or aspartate or by GABA analogs, agonists, and antagonists. Similarly, ATP-dependent glycine uptake was hardly affected by GABA, taurine, glutamate, or aspartate or by glycine analogs or antagonists. The GABA uptake was not affected by chloride, which is in contrast to the uptake of the excitatory neurotransmitter glutamate, whereas the glycine uptake was slightly stimulated by low concentrations of chloride. Tissue distribution studies indicate that the vesicular uptake systems for GABA, glycine, and glutamate are distributed in different proportions in the cerebrum and spinal cord. These results suggest that the vesicular uptake systems for GABA, glycine, and glutamate are distinct from each other.

  13. Crystallization of a newly discovered histidine acid phosphatase from Francisella tularensis

    SciTech Connect

    Felts, Richard L.; Reilly, Thomas J.; Calcutt, Michael J.; Tanner, John J.

    2006-01-01

    A histidine acid phosphatase from the CDC Category A pathogen F. tularensis has been crystallized in space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 61.96, c = 210.78 Å. A 1.75 Å resolution data set was collected at Advanced Light Source beamline 4.2.2. Francisella tularensis is a highly infectious bacterial pathogen that is considered by the Centers for Disease Control and Prevention to be a potential bioterrorism weapon. Here, the crystallization of a 37.2 kDa phosphatase encoded by the genome of F. tularensis subsp. holarctica live vaccine strain is reported. This enzyme shares 41% amino-acid sequence identity with Legionella pneumophila major acid phosphatase and contains the RHGXRXP motif that is characteristic of the histidine acid phosphatase family. Large diffraction-quality crystals were grown in the presence of Tacsimate, HEPES and PEG 3350. The crystals belong to space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 61.96, c = 210.78 Å. The asymmetric unit is predicted to contain one protein molecule, with a solvent content of 53%. A 1.75 Å resolution native data set was recorded at beamline 4.2.2 of the Lawrence Berkeley National Laboratory Advanced Light Source. Molecular-replacement trials using the human prostatic acid phosphatase structure as the search model (28% amino-acid sequence identity) did not produce a satisfactory solution. Therefore, the structure of F. tularensis histidine acid phosphatase will be determined by multiwavelength anomalous dispersion phasing using a selenomethionyl derivative.

  14. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SERVICES (CONTINUED) FOOD ADDITIVES Specific Administrative Rulings and Decisions § 170.50 Glycine...) Shall bring such products into compliance with an authorizing food additive regulation. A food additive... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Glycine (aminoacetic acid) in food for...

  15. trans-cis Configuration regulated supramolecular polymer gels and chirality transfer based on a bolaamphiphilic histidine and dicarboxylic acids.

    PubMed

    Chen, Chunfeng; Wang, Tianyu; Fu, Yunzhi; Liu, Minghua

    2016-01-25

    Supramolecular polymer gels based on the co-assembly of bolaamphiphilic l-histidine(BolaHis) and dicarboxylic acids are dependent on the molar ratios, flexibility and cis-trans configuration of acid molecules. Thus, oligomerized rigid cis-maleic acid or flexible trans-cyclohexane dicarboxylic acid can form chiral supramolecular polymer gels with l-BolaHis. PMID:26617194

  16. Crystal Structures of the Histidine Acid Phosphatase from Francisella tularensis Provide Insight into Substrate Recognition

    SciTech Connect

    Singh, Harkewal; Felts, Richard L.; Schuermann, Jonathan P.; Reilly, Thomas J.; Tanner, John J.

    2009-12-01

    Histidine acid phosphatases catalyze the transfer of a phosphoryl group from phosphomonoesters to water at acidic pH using an active-site histidine. The histidine acid phosphatase from the category A pathogen Francisella tularensis (FtHAP) has been implicated in intramacrophage survival and virulence, motivating interest in understanding the structure and mechanism of this enzyme. Here, we report a structure-based study of ligand recognition by FtHAP. The 1.70-{angstrom}-resolution structure of FtHAP complexed with the competitive inhibitor L(+)-tartrate was solved using single-wavelength anomalous diffraction phasing. Structures of the ligand-free enzyme and the complex with inorganic phosphate were determined at resolutions of 1.85 and 1.70 {angstrom}, respectively. The structure of the Asp261Ala mutant enzyme complexed with the substrate 3'-AMP was determined at 1.50 {angstrom} resolution to gain insight into substrate recognition. FtHAP exhibits a two-domain fold similar to that of human prostatic acid phosphatase, consisting of an {alpha}/{beta} core domain and a smaller domain that caps the core domain. The structures show that the core domain supplies the phosphoryl binding site, catalytic histidine (His17), and an aspartic acid residue (Asp261) that protonates the leaving group, while the cap domain contributes residues that enforce substrate preference. FtHAP and human prostatic acid phosphatase differ in the orientation of the crucial first helix of the cap domain, implying differences in the substrate preferences of the two enzymes. 3'-AMP binds in one end of a 15-{angstrom}-long tunnel, with the adenine clamped between Phe23 and Tyr135, and the ribose 2'-hydroxyl interacting with Gln132. The importance of the clamp is confirmed with site-directed mutagenesis; mutation of Phe23 and Tyr135 individually to Ala increases K{sub m} by factors of 7 and 10, respectively. The structural data are consistent with a role for FtHAP in scavenging phosphate from small

  17. Zinc-Mediated Binding of Nucleic Acids to Amyloid-β Aggregates: Role of Histidine Residues.

    PubMed

    Khmeleva, Svetlana A; Radko, Sergey P; Kozin, Sergey A; Kiseleva, Yana Y; Mezentsev, Yuri V; Mitkevich, Vladimir A; Kurbatov, Leonid K; Ivanov, Alexis S; Makarov, Alexander A

    2016-09-01

    Amyloid-β peptide (Aβ) plays a central role in Alzheimer's disease (AD) pathogenesis. Besides extracellular Aβ, intraneuronal Aβ (iAβ) has been suggested to contribute to AD onset and development. Based on reported in vitro Aβ-DNA interactions and nuclear localization of iAβ, the interference of iAβ with the normal DNA expression has recently been proposed as a plausible pathway by which Aβ can exert neurotoxicity. Employing the sedimentation assay, thioflavin T fluorescence, and dynamic light scattering we have studied effects of zinc ions on binding of RNA and single- and double-stranded DNA molecules to Aβ42 aggregates. It has been found that zinc ions significantly enhance the binding of RNA and DNA molecules to pre-formed β-sheet rich Aβ42 aggregates. Another type of Aβ42 aggregates, the zinc-induced amorphous aggregates, was demonstrated to also bind all types of nucleic acids tested. To evaluate the role of the Aβ metal-binding domain's histidine residues in Aβ-nucleic acid interactions mediated by zinc, Aβ16 mutants with substitutions H6R and H6A-H13A and rat Aβ16 lacking histidine residue 13 were used. The zinc-induced interaction of Aβ16 with DNA was shown to critically depend on histidine residues 6 and 13. However, the inclusion of H6R mutation in Aβ42 peptide did not affect DNA binding to Aβ42 aggregates. Since oxidative and/or nitrosative stresses implicated in AD pathogenesis are known to release zinc ions from metallothioneins in cytoplasm and cell nuclei, our findings suggest that intracellular zinc can be an important player in iAβ-nucleic acid interactions. PMID:27567853

  18. Crystal structure and tartrate inhibition of Legionella pneumophila histidine acid phosphatase.

    PubMed

    Dhatwalia, Richa; Singh, Harkewal; Reilly, Thomas J; Tanner, John J

    2015-11-01

    Histidine acid phosphatases (HAPs) utilize a nucleophilic histidine residue to catalyze the transfer of a phosphoryl group from phosphomonoesters to water. HAPs function as protein phosphatases and pain suppressors in mammals, are essential for Giardia lamblia excystation, and contribute to virulence of the category A pathogen Francisella tularensis. Herein we report the first crystal structure and steady-state kinetics measurements of the HAP from Legionella pneumophila (LpHAP), also known as Legionella major acid phosphatase. The structure of LpHAP complexed with the inhibitor l(+)-tartrate was determined at 2.0 Å resolution. Kinetics assays show that l(+)-tartrate is a 50-fold more potent inhibitor of LpHAP than of other HAPs. Electrostatic potential calculations provide insight into the basis for the enhanced tartrate potency: the tartrate pocket of LpHAP is more positive than other HAPs because of the absence of an ion pair partner for the second Arg of the conserved RHGXRXP HAP signature sequence. The structure also reveals that LpHAP has an atypically expansive active site entrance and lacks the nucleotide substrate base clamp found in other HAPs. These features imply that nucleoside monophosphates may not be preferred substrates. Kinetics measurements confirm that AMP is a relatively inefficient in vitro substrate of LpHAP. PMID:26380880

  19. Lipoic acid synthetase deficiency causes neonatal-onset epilepsy, defective mitochondrial energy metabolism, and glycine elevation.

    PubMed

    Mayr, Johannes A; Zimmermann, Franz A; Fauth, Christine; Bergheim, Christa; Meierhofer, David; Radmayr, Doris; Zschocke, Johannes; Koch, Johannes; Sperl, Wolfgang

    2011-12-01

    Lipoic acid is an essential prosthetic group of four mitochondrial enzymes involved in the oxidative decarboxylation of pyruvate, α-ketoglutarate, and branched chain amino acids and in the glycine cleavage. Lipoic acid is synthesized stepwise within mitochondria through a process that includes lipoic acid synthetase. We identified the homozygous mutation c.746G>A (p.Arg249His) in LIAS in an individual with neonatal-onset epilepsy, muscular hypotonia, lactic acidosis, and elevated glycine concentration in plasma and urine. Investigation of the mitochondrial energy metabolism showed reduced oxidation of pyruvate and decreased pyruvate dehydrogenase complex activity. A pronounced reduction of the prosthetic group lipoamide was found in lipoylated proteins.

  20. Hypercondensation of an amino acid: synthesis and characterization of a black glycine polymer.

    PubMed

    Fox, Stefan; Dalai, Punam; Lambert, Jean-François; Strasdeit, Henry

    2015-06-01

    A granular material was obtained by thermal polymerization of glycine at 200 °C. It has been named "thermomelanoid" because of its strikingly deep-black color. The polymerization process is mainly a dehydration condensation leading to conventional amide bonds, and also CC double bonds that are formed from CO and CH2 groups ("hypercondensation"). Spectroscopic data, in particular from (13) C and (15) N solid-state cross-polarization magic angle spinning (CP-MAS) NMR spectra, suggest that the black color is due to (cross-)conjugated CC, CO, and NH groups. Small glycine peptides, especially triglycine, appear to be key intermediates in the formation of the thermomelanoid. This has been concluded by comparing the thermal behavior of glyn homopeptides (n=2-6) and glycine. The glycine polymerization was accompanied by the formation of small amounts of byproducts. Notably, a few percent of alanine and aspartic acid could be detected in the polymer. By using (13) C-labeled glycine, it was shown that these two amino acids formed through a common pathway, namely CαCα bond formation between glycine molecules. The thermomelanoid is hydrolyzed by strong acids and bases at room temperature, forming brown solutions. PMID:25933438

  1. Hydrogels formed by enantioselective self-assembly of histidine-derived amphiphiles with tartaric acid.

    PubMed

    Zhang, Fanjun; Xu, Zhenghu; Dong, Shuli; Feng, Lei; Song, Aixin; Tung, Chen-Ho; Hao, Jingcheng

    2014-07-21

    Two chiral enantiomers of histidine-derived amphiphilic gelators, (4R,6S)-UIPCA and (4S,6R)-UIPCA, were synthesized through Pictet-Spengler reaction and their gelation behaviors with different organic acids were investigated. Interestingly, the chiral enantiomers of UIPCA showed smart enantioselectivity for gelating tartaric acid enantiomers to form hydrogels with excellent mechanical strength. The TEM and SEM images demonstrated that the hydrogels were composed of networks by physical entanglement of nanofibers with high aspect ratios. The formation of nanofibers was considered to be driven by the interplay of hydrogen bonding, electrostatic attraction, and hydrophobic interaction, which was supported by XRD and FT-IR spectra. The hydrogels exhibited sensitive response to a series of external stimuli, such as temperature, metal ions, and host-guest interactions, to realize the reversible gel-sol transition. The property of the gelation was elaborated and the gelators were expected to find their applications in chiral discrimination. PMID:24865976

  2. Dietary histidine increases mouse skin urocanic acid levels and enhances UVB-induced immune suppression of contact hypersensitivity.

    PubMed

    Reilly, S K; De Fabo, E C

    1991-04-01

    Urocanic Acid (UCA) exists in mammalian skin primarily as the trans isomer and is photoisomerized to cis UCA upon UVB absorption. Our previous studies indicated that the photoisomerization of UCA is the initiating event in UBV-induced suppression of cell-mediated immunity (tUCA----cUCA----immune suppression). The purpose of this study was to verify the role of UCA in UV-induced immune suppression of contact hypersensitivity (CHS) in BALB/c mice. Since UCA is a metabolite of the amino acid L-histidine, we reasoned that increased dietary levels of histidine should raise skin tUCA levels. If skin tUCA is the UVB photoreceptor for immune suppression, this increase should enhance UV-induced suppression of CHS. HPLC analysis of skin from BALB/c mice given a histidine-rich diet (10%) showed that the total amount of UCA is significantly higher in these animals than in mice fed a normal diet. Further, levels of suppression of CHS of 3% and 49% in control fed mice, induced by 4.8 and 7.2 kJ/m2 UVB were significantly increased to 21% and 71% respectively in histidine-fed animals at these same UVB doses. These findings provide additional support for the UCA model for immune suppression, and provide the first evidence that UV-induced immune suppression can be enhanced by a dietary component, L-histidine. PMID:1857737

  3. Determination of histidine and urocanic acid isomers in the human skin by high-performance capillary electrophoresis.

    PubMed

    Hermann, K; Abeck, D

    2000-11-10

    Histidine was baseline separated from histamine, 1-methylhistamine and cis- and trans-urocanic acid using high-performance capillary electrophoresis (HPCE) on a fused-silica column (50 cm x 75 microm) with 0.05 M NaH2PO4 buffer, pH 5.0, and 12 kV. The detection limit of histidine, trans- and cis-urocanic acid was 10(-6) M at a wavelength of 214 nm. The detection limit of the urocanic acid isomers was slightly enhanced to 5 x 10(-7) M at 267 nm. The transformation of the trans-urocanic acid standard in vitro into the cis-isomer was dependent on the time of exposure and the energy of the light source. UVB light induced a significantly faster conversion than UVA light. The HPCE method was used for the characterization and measurement of histidine and urocanic acid in human skin eluates. The concentrations of histidine, trans- or cis-urocanic acid in ethanol washes from the skin of healthy, non-allergic volunteers were 2.22+/-0.40 x 10(-5) 0.96+/-0.26 x 10(-5) and 1.04+/-0.30 x 10(-5) M, respectively, (mean+/-SEM, n=8). The results obtained by HPCE correlated well with data obtained by HPLC. Correlation coefficients of r2=0.981, r2=0.814 and r2=0.956 were found for histidine, trans- and cis-urocanic acid, respectively.

  4. Iminodiacetic acid functionalized porous hydroxyapatite nanoparticles for capturing histidine-tagged proteins.

    PubMed

    Yao, Shasha; Huang, Yanqin; Zhao, Yanbao; Zhang, Yu; Zou, Xueyan; Song, Chunpeng

    2014-06-01

    A simple strategy has been developed to synthesize hydroxyapatite (HAP) nanoparticles (NPs) in a simulated body fluid (SBF). The HAP NPs have an average diameter of 50nm and present porous structure. By taking advantage of surface hydroxyl groups, the HAP NPs are further modified with iminodiacetic acid (IDA), followed by chelating Ni(2+) ions. The HAP/IDA-Ni(2+) NPs as novel adsorbent can capture directly histidine-tagged (His-tagged) proteins from the mixture of lysed cells without sample pretreatment. Results indicated that the HAP/IDA-Ni(2+) NPs present negligible nonspecific adsorption and high protein binding ability, and their specificity and affinity toward His-tagged proteins can remain after 5 times of recycling. The HAP/IDA-Ni(2+) NPs are especially suitable for purification of His-tagged proteins with low molecule weight. PMID:24863189

  5. Formation routes of interstellar glycine involving carboxylic acids: possible favoritism between gas and solid phase.

    PubMed

    Pilling, Sergio; Baptista, Leonardo; Boechat-Roberty, Heloisa M; Andrade, Diana P P

    2011-11-01

    Despite the extensive search for glycine (NH₂CH₂COOH) and other amino acids in molecular clouds associated with star-forming regions, only upper limits have been derived from radio observations. Nevertheless, two of glycine's precursors, formic acid and acetic acid, have been abundantly detected. Although both precursors may lead to glycine formation, the efficiency of reaction depends on their abundance and survival in the presence of a radiation field. These facts could promote some favoritism in the reaction pathways in the gas phase and solid phase (ice). Glycine and these two simplest carboxylic acids are found in many meteorites. Recently, glycine was also observed in cometary samples returned by the Stardust space probe. The goal of this work was to perform theoretical calculations for several interstellar reactions involving the simplest carboxylic acids as well as the carboxyl radical (COOH) in both gas and solid (ice) phase to understand which reactions could be the most favorable to produce glycine in interstellar regions fully illuminated by soft X-rays and UV, such as star-forming regions. The calculations were performed at four different levels for the gas phase (B3LYP/6-31G*, B3LYP/6-31++G**, MP2/6-31G*, and MP2/6-31++G**) and at MP2/6-31++G** level for the solid phase (ice). The current two-body reactions (thermochemical calculation) were combined with previous experimental data on the photodissociation of carboxylic acids to promote possible favoritism for glycine formation in the scenario involving formic and acetic acid in both gas and solid phase. Given that formic acid is destroyed more in the gas phase by soft X-rays than acetic acid is, we suggest that in the gas phase the most favorable reactions are acetic acid with NH or NH₂OH. Another possible reaction involves NH₂CH₂ and COOH, one of the most-produced radicals from the photodissociation of acetic acid. In the solid phase, we suggest that the reactions of formic acid with NH

  6. The Infrared Spectrum of Matrix Isolated Aminoacetonitrile: A Precursor to the Amino Acid Glycine

    NASA Technical Reports Server (NTRS)

    Bernstein, Max P.; Bauschlicher, Charles W., Jr.; Sandford, Scott A.

    2003-01-01

    We present infrared (IR) spectral data from matrix isolation experiments and density functional theory calculations on the pre-biologically interesting molecule aminoacetonitrile, a precursor to glycine. We find that this nitrile has an unusually weak nitrile (C=N) stretch in the infrared, in contrast to expectations based on measurements and models of other nitriles under astrophysical conditions. The absence of an observable nitrile absorption feature in the infrared will make the IR search for this molecule considerably more difficult, and will raise estimates of upper limits on nitriles in interstellar and outer Solar System ices. This is also of relevance to assessing the formation routes of the amino acid glycine, since aminoacetonitrile is the putative precursor to glycine via the Strecker synthesis, the mechanism postulated to have produced the amino acids in meteorites.

  7. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Glycine (aminoacetic acid) in food for human consumption. 170.50 Section 170.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES Specific Administrative...

  8. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Glycine (aminoacetic acid) in food for human consumption. 170.50 Section 170.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES Specific Administrative...

  9. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... consumption. 170.50 Section 170.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES Specific Administrative Rulings and Decisions § 170.50 Glycine (aminoacetic acid) in food for human consumption. (a) Heretofore,...

  10. Genetic identification of ACC-RESISTANT2 reveals involvement of LYSINE HISTIDINE TRANSPORTER1 in the uptake of 1-aminocyclopropane-1-carboxylic acid in Arabidopsis thaliana.

    PubMed

    Shin, Kihye; Lee, Sumin; Song, Won-Yong; Lee, Rin-A; Lee, Inhye; Ha, Kyungsun; Koo, Ja-Choon; Park, Soon-Ki; Nam, Hong-Gil; Lee, Youngsook; Soh, Moon-Soo

    2015-03-01

    1-Aminocyclopropane-1-carboxylic acid (ACC) is a biosynthetic precursor of ethylene, a gaseous plant hormone which controls a myriad of aspects of development and stress adaptation in higher plants. Here, we identified a mutant in Arabidopsis thaliana, designated as ACC-resistant2 (are2), displaying a dose-dependent resistance to exogenously applied ACC. Physiological analyses revealed that mutation of are2 impaired various aspects of exogenous ACC-induced ethylene responses, while not affecting sensitivity to other plant hormones during seedling development. Interestingly, the are2 mutant was normally sensitive to gaseous ethylene, compared with the wild type. Double mutant analysis showed that the ethylene-overproducing mutations, eto1 or eto3, and the constitutive ethylene signaling mutation, ctr1 were epistatic to the are2 mutation. These results suggest that the are2 mutant is not defective in ethylene biosynthesis or ethylene signaling per se. Map-based cloning of ARE2 demonstrated that LYSINE HISTIDINE TRANSPORTER1 (LHT1), encoding an amino acid transporter, is the gene responsible. An uptake experiment with radiolabeled ACC indicated that mutations of LHT1 reduced, albeit not completely, uptake of ACC. Further, we performed an amino acid competition assay and found that two amino acids, alanine and glycine, known as substrates of LHT1, could suppress the ACC-induced triple response in a LHT1-dependent way. Taken together, these results provide the first molecular genetic evidence supporting that a class of amino acid transporters including LHT1 takes part in transport of ACC, thereby influencing exogenous ACC-induced ethylene responses in A. thaliana. PMID:25520403

  11. Hog1p activation by marasmic acid through inhibition of the histidine kinase Sln1p

    PubMed Central

    Schüffler, Anja

    2016-01-01

    Abstract BACKGROUND The histidine kinase (HK) MoHik1p within the high‐osmolarity glycerol (HOG) pathway is known to be the target of the fungicide fludioxonil. Treatment of the fungus with fludioxonil causes an uncontrolled hyperactivation of the pathway and cell death. In this study, we used a target‐based in vivo test system with mutant strains of the rice blast fungus Magnaporthe oryzae to search for new fungicidal compounds having various target locations within the HOG pathway. Mutants with inactivated HOG signalling are resistant to fungicides having the target located in the HOG pathway. RESULTS The HK MoSln1p was identified as being involved in the new antifungal mode of action of marasmic acid, as single inactivation of the genes MoSLN1, MoSSK1, MoSSK2, MoPBS2 and MoHOG1 resulted in mutant strains resistant against the sesquiterpenoid, whereas the wild‐type strain and the ΔMohik1 mutant were susceptible. Western blot analysis of phosphorylated MoHog1p confirmed the hypothesis that marasmic acid interferes with the HOG pathway, as a strong phosphorylation of MoHog1p was detectable after sesquiterpenoid treatment in the wild‐type strain but not in the ΔMosln1 mutant. CONCLUSION This study provides evidence for marasmic acid activating the HOG pathway via the HK MoSln1p, and we propose that the sesquiterpenoid has a new mode of action in M. oryzae that differs from that of known HOG inhibitors, e.g. fludioxonil. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:26888741

  12. Histidine-Based Lipopeptides Enhance Cleavage of Nucleic Acids: Interactions with DNA and Hydrolytic Properties.

    PubMed

    Bélières, M; Déjugnat, C; Chouini-Lalanne, N

    2015-12-16

    Interaction studies and cleavage activity experiments were carried out between plasmid DNA and a series of histidine-based lipopeptides. Specific fluorescent probes (ethidium bromide, Hoechst 33342, and pyrene) were used to monitor intercalation, minor groove binding, and self-assembly of lipopeptides, respectively. Association between DNA and lipopeptides was thus evidenced, highlighting the importance of both histidine and hydrophobic tail in the interaction process. DNA cleavage in the presence of lipopeptides was then detected by gel electrophoresis and quantified, showing the importance of histidine and the involvement of its side-chain imidazole in the hydrolysis mechanism. These systems could then be developed as synthetic nucleases while raising concern of introducing histidine in the design of lipopeptide-based transfection vectors.

  13. Histidine and other amino acids in blood and urine after administration of Bretschneider solution (HTK) for cardioplegic arrest in patients: effects on N-metabolism.

    PubMed

    Teloh, Johanna K; Dohle, Daniel-Sebastian; Petersen, Miriam; Verhaegh, Rabea; Waack, Indra N; Roehrborn, Friederike; Jakob, Heinz; de Groot, Herbert

    2016-06-01

    Bretschneider (histidine-tryptophan-ketoglutarate, HTK) solution employed for induction of cardioplegic arrest possesses a high histidine concentration (198 mM). Due to the large volume administered, massive amounts of histidine are incorporated. The aim of the study was to evaluate alterations in amino acid and nitrogen metabolism originating from histidine degradation. Between 07/2014 and 10/2014, a total of 29 consecutive patients scheduled for elective isolated coronary artery bypass grafting with cardiopulmonary bypass (CPB) were enrolled in this prospective observational study. The patients received 1.6 L cardioplegic Bretschneider solution on average. Blood gas and urine samples obtained were analyzed for amino acid as well as urea and ammonium concentrations. After CPB initiation, plasma histidine concentration greatly increased to 21,000 µM to reach 8000 µM at the end. Within the operative period, plasma concentrations of aspartate, glutamate, asparagine, alanine, and glutamine increased variable in magnitude. During the same time, urinary analysis revealed histidine excretion of 19,500 µmol in total and marked elevations in glutamate and glutamine excretion. The absolute amounts of urea and ammonium excreted additionally were 3 mmol and 8 mmol, respectively. Already during CPB, distinct amounts of the histidine administered are metabolized, mainly to other amino acids, but only small amounts to urea and ammonia. Thus, the impact of the histidine incorporated on acid-base status in the intraoperative phase is minor. On the other hand, intraoperative provision of several amino acids arising from histidine metabolism might mitigate postaggression syndrome. PMID:26922473

  14. AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS : II. TITRATION OF SULFANILIC ACID-GLYCINE MIXTURES.

    PubMed

    Stearn, A E

    1926-11-20

    Electrometric titrations of glycine, sulfanilic acid, and various mixtures of the two have been made. These mixtures are shown to give a curve which, between their respective isoelectric points, is different from that of either substance. These mixtures have a maximum buffering power at a pH which can be theoretically calculated, and which has the characteristics of an "isoelectric point of the system." Other pairs of ampholytes are shown to act in an analogous manner.

  15. Glycine intake decreases plasma free fatty acids, adipose cell size, and blood pressure in sucrose-fed rats.

    PubMed

    El Hafidi, Mohammed; Pérez, Israel; Zamora, Jose; Soto, Virgilia; Carvajal-Sandoval, Guillermo; Baños, Guadalupe

    2004-12-01

    The study investigated the mechanism by which glycine protects against increased circulating nonesterified fatty acids (NEFA), fat cell size, intra-abdominal fat accumulation, and blood pressure (BP) induced in male Wistar rats by sucrose ingestion. The addition of 1% glycine to the drinking water containing 30% sucrose, for 4 wk, markedly reduced high BP in sucrose-fed rats (SFR) (122.3 +/- 5.6 vs. 147.6 +/- 5.4 mmHg in SFR without glycine, P < 0.001). Decreases in plasma triglyceride (TG) levels (0.9 +/- 0.3 vs. 1.4 +/- 0.3 mM, P < 0.001), intra-abdominal fat (6.8 +/- 2.16 vs. 14.8 +/- 4.0 g, P < 0.01), and adipose cell size were observed in SFR treated with glycine compared with SFR without treatment. Total NEFA concentration in the plasma of SFR was significantly decreased by glycine intake (0.64 +/- 0.08 vs. 1.11 +/- 0.09 mM in SFR without glycine, P < 0.001). In control animals, glycine decreased glucose, TGs, and total NEFA but without reaching significance. In SFR treated with glycine, mitochondrial respiration, as an indicator of the rate of fat oxidation, showed an increase in the state IV oxidation rate of the beta-oxidation substrates octanoic acid and palmitoyl carnitine. This suggests an enhancement of hepatic fatty acid metabolism, i.e., in their transport, activation, or beta-oxidation. These findings imply that the protection by glycine against elevated BP might be attributed to its effect in increasing fatty acid oxidation, reducing intra-abdominal fat accumulation and circulating NEFA, which have been proposed as links between obesity and hypertension.

  16. Tip-induced domain structures and polarization switching in ferroelectric amino acid glycine

    NASA Astrophysics Data System (ADS)

    Seyedhosseini, E.; Bdikin, I.; Ivanov, M.; Vasileva, D.; Kudryavtsev, A.; Rodriguez, B. J.; Kholkin, A. L.

    2015-08-01

    Bioorganic ferroelectrics and piezoelectrics are becoming increasingly important in view of their intrinsic compatibility with biological environment and biofunctionality combined with strong piezoelectric effect and a switchable polarization at room temperature. Here, we study tip-induced domain structures and polarization switching in the smallest amino acid β-glycine, representing a broad class of non-centrosymmetric amino acids. We show that β-glycine is indeed a room-temperature ferroelectric and polarization can be switched by applying a bias to non-polar cuts via a conducting tip of atomic force microscope (AFM). Dynamics of these in-plane domains is studied as a function of an applied voltage and pulse duration. The domain shape is dictated by polarization screening at the domain boundaries and mediated by growth defects. Thermodynamic theory is applied to explain the domain propagation induced by the AFM tip. Our findings suggest that the properties of β-glycine are controlled by the charged domain walls which in turn can be manipulated by an external bias.

  17. Tip-induced domain structures and polarization switching in ferroelectric amino acid glycine

    SciTech Connect

    Seyedhosseini, E. Ivanov, M.; Bdikin, I.; Vasileva, D.; Kudryavtsev, A.; Rodriguez, B. J.; Kholkin, A. L.

    2015-08-21

    Bioorganic ferroelectrics and piezoelectrics are becoming increasingly important in view of their intrinsic compatibility with biological environment and biofunctionality combined with strong piezoelectric effect and a switchable polarization at room temperature. Here, we study tip-induced domain structures and polarization switching in the smallest amino acid β-glycine, representing a broad class of non-centrosymmetric amino acids. We show that β-glycine is indeed a room-temperature ferroelectric and polarization can be switched by applying a bias to non-polar cuts via a conducting tip of atomic force microscope (AFM). Dynamics of these in-plane domains is studied as a function of an applied voltage and pulse duration. The domain shape is dictated by polarization screening at the domain boundaries and mediated by growth defects. Thermodynamic theory is applied to explain the domain propagation induced by the AFM tip. Our findings suggest that the properties of β-glycine are controlled by the charged domain walls which in turn can be manipulated by an external bias.

  18. Electron attachment to amino acid clusters in helium nanodroplets: Glycine, alanine, and serine

    NASA Astrophysics Data System (ADS)

    Ferreira da Silva, F.; Denifl, S.; Märk, T. D.; Ellis, A. M.; Scheier, P.

    2010-06-01

    The first detailed study of electron attachment to amino acid clusters is reported. The amino acids chosen for investigation were glycine, alanine, and serine. Clusters of these amino acids were formed inside helium nanodroplets, which provide a convenient low temperature (0.37 K) environment for growing noncovalent clusters. When subjected to low energy (2 eV) electron impact the chemistry for glycine and alanine clusters was found to be similar. In both cases, parent cluster anions were the major products, which contrasts with the corresponding monomers in the gas phase, where the dehydrogenated products ([AAn-H]-, where AA=amino acid monomer) dominate. Serine clusters are different, with the major product being the parent anion minus an OH group, an outcome presumably conferred by the facile loss of an OH group from the β carbon of serine. In addition to the bare parent anions and various fragment anions, helium atoms are also observed attached to both the parent anion clusters and the dehydrogenated parent anion clusters. Finally, we present the first anion yield spectra of amino acid clusters from doped helium nanodroplets as a function of incident electron energy.

  19. Theoretical study of the adsorption of histidine amino acid on graphene

    NASA Astrophysics Data System (ADS)

    Rodríguez, S. J.; Makinistian, L.; Albanesi, E.

    2016-04-01

    Previous studies have demonstrated how the interactions between biomolecules and graphene play a crucial role in the characterization and functionalization of biosensors. In this paper we present a theoretical study of the adsorption of histidine on graphene using density functional theory (DFT). In order to evaluate the relevance of including the carboxyl (-COOH) and amino (-NH2) groups in the calculations, we considered i) the histidine complete (i.e., with its carboxyl and its amino groups included), and ii) the histidine’s imidazole ring alone. We calculated the density of states for the two systems before and after adsorption. Furthermore, we compared the results of three approximations of the exchange and correlation interactions: local density (LDA), the generalized gradients by Perdew, Burke and Ernzerhof (GGA-PBE), and one including van der Waals forces (DFT-D2). We found that the adsorption energy calculated by DFT-D2 is higher than the other two: Eads-DFT-D2 >E ads-LDA >E ads-GGA . We report the existence of charge transfer from graphene to the molecule when the adsorption occurs; this charge transfer turns up to be greater for the complete histidine than for the imidazole ring alone. Our results revealed that including the carboxyl and amino groups generates a shift in the states of imidazole ring towards EF .

  20. Effect of folic acid and glycine supplementation on embryo development and folate metabolism during early pregnancy in pigs.

    PubMed

    Guay, F; Matte, J J; Girard, C L; Palin, M F; Giguère, A; Laforest, J P

    2002-08-01

    The present work aimed to determine if different levels of prolificacy either by parity or by genetic origin are linked to folate metabolism. Nulliparous Yorkshire-Landrace (YL) and multiparous YL, and multiparous Meishan-Landrace (ML) sows were randomly assigned to two treatments: 0 ppm or 15 ppm folic acid+0.6% glycine. Supplements were given from the estrus before mating until slaughter on d 25 of gestation. At slaughter, embryo and endometrial tissues were collected to determine concentrations of DNA, protein, and homocysteine. Allantoic fluid samples were also collected to determine concentrations of folates, vitamin B12 and amino acids. Blood samples were taken at first estrus, at mating, and on d 8, 16, and 25 of gestation to determine serum concentrations of folates, vitamin B12, and relative total folate binding capacity (TFBC). Over the entire experiment, multiparous YL sows had higher average serum concentrations of folates than nulliparous YL sows (P < 0.05) but had similar serum concentrations of relative TFBC. Concentrations of folates and relative TFBC averaged higher in ML measured over the entire experiment than in multiparous YL sows (P < 0.05). Concentrations of serum vitamin B12 were higher in multiparous YL than in ML sows or YL nulliparous sows (P < 0.05) over the entire experiment. In allantoic fluid, folates, vitamin B12, and essential amino acids contents were significantly lower in ML than in YL multiparous sows (P < 0.05). The folic acid+glycine supplement increased concentrations of serum folates, but the increase was more marked in nulliparous YL sows (nulliparous x folic acid+glycine, P < 0.05). The folic acid+glycine supplement had no effect on litter size and embryo survival, but it tended to increase embryo DNA in multiparous YL sows (P = 0.06) but not in ML and nulliparous YL sows. Homocysteine was decreased by folic acid+glycine supplement in embryos from all sows, but in endometrium, the folic acid+glycine effect was dependent on

  1. Tautomerism in neutral histidine.

    PubMed

    Bermúdez, Celina; Mata, Santiago; Cabezas, Carlos; Alonso, José L

    2014-10-01

    Histidine is an important natural amino acid, involved in many relevant biological processes, which, because of its physical properties, proved difficult to characterize experimentally in its neutral form. In this work, neutral histidine has been generated in the gas phase by laser ablation of solid samples and its N(ε)H tautomeric form unraveled through its rotational spectrum. The quadrupole hyperfine structure, arising from the existing three (14)N nuclei, constituted a site-specifically probe for revealing the tautomeric form as well as the side chain configuration of this proteogenic amino acid.

  2. First report for voltammetric determination of methyldopa in the presence of folic acid and glycine.

    PubMed

    Molaakbari, Elahe; Mostafavi, Ali; Beitollahi, Hadi

    2014-03-01

    In this study, a carbon paste electrode modified with TiO2 nanoparticles and ferrocene monocarboxylic acid (FM) was used to prepare a novel electrochemical sensor. The objective of this novel electrode modification was to seek new electrochemical performances for the detection of methyldopa in the presence of folic acid and glycine. The peak potentials recorded in a phosphate buffer solution (PBS) of pH7.0 were 325, 750 and 880 mV vs. Ag/AgCl/KCl (3.0M) for methyldopa, folic acid and glycine, respectively. Under the optimum pH of 7.0, the oxidation of methyldopa occurred at a potential about 160 mV less positive than that of the unmodified carbon paste electrode (CPE). The response of catalytic current with methyldopa concentration showed a linear relation in the range from 2.0×10(-7) to 1.0×10(-4)M with a detection limit of 8.0 (± 0.2)×10(-8)M.

  3. FORMATION OF GLYCINE ON ULTRAVIOLET-IRRADIATED INTERSTELLAR ICE-ANALOG FILMS AND IMPLICATIONS FOR INTERSTELLAR AMINO ACIDS

    SciTech Connect

    Lee, Chang-Woo; Kim, Joon-Ki; Moon, Eui-Seong; Kang, Heon; Minh, Y. C.

    2009-05-20

    We report the synthesis of glycine on interstellar ice-analog films composed of water, methylamine (MA), and carbon dioxide under irradiation of ultraviolet (UV) photons. Analysis of the UV-irradiated ice films by in situ mass spectrometric methods revealed glycine and other isomers as photochemical products. Deuterium-labeling experiments were conducted to determine the structures of the photoproducts and to examine their formation pathways. The reactions occur via photocleavages of C-H and N-H bonds in MA, followed by subsequent reactions of the nascent H atom with CO{sub 2}, leading to the formation of HOCO and then to glycine and carbamic acid. The photochemical synthesis of glycine occurs efficiently at the ice surfaces, and the competing photosynthesis and photodestruction processes can reach a steady-state kinetic balance at an extended UV exposure, maintaining a substantial population level of glycine. The observation suggests that interstellar amino acids can be created on ice grains, and that they can also be stored in the ices by maintaining a kinetic balance under interstellar UV irradiation. As such, the transport of amino acids in interstellar space may be possible without depleting the net abundance of amino acids in the ices but rather increasing the structural diversity of the molecules.

  4. Genetics Home Reference: glycine encephalopathy

    MedlinePlus

    ... a molecule called glycine. This molecule is an amino acid , which is a building block of proteins. Glycine ... Additional Information & Resources MedlinePlus (3 links) Health Topic: Amino Acid Metabolism Disorders Health Topic: Genetic Brain Disorders Health ...

  5. 21 CFR 172.320 - Amino acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-Cysteine L-Cystine L-Glutamic acid L-Glutamine Aminoacetic acid (glycine) L-Histidine L-Isoleucine L... following: L-Alanine L-Arginine L-Arginine Monohydrochloride L-Cysteine Monohydrochloride L-Cystine... (including L-asparagine) 7.0 L-Cystine (including L-cysteine) 2.3 L-Glutamic acid (including L-glutamine)...

  6. Chemical vectors for gene delivery: a current review on polymers, peptides and lipids containing histidine or imidazole as nucleic acids carriers

    PubMed Central

    Midoux, Patrick; Pichon, Chantal; Yaouanc, Jean-Jacques; Jaffrès, Paul-Alain

    2009-01-01

    DNA/cationic lipid (lipoplexes), DNA/cationic polymer (polyplexes) and DNA/cationic polymer/cationic lipid (lipopolyplexes) electrostatic complexes are proposed as non-viral nucleic acids delivery systems. These DNA-nanoparticles are taken up by the cells through endocytosis processes, but the low capacity of DNA to escape from endosomes is regarded as the major limitations of their transfection efficiency. Here, we present a current report on a particular class of carriers including the polymers, peptides and lipids, which is based on the exploitation of the imidazole ring as an endosome destabilization device to favour the nucleic acids delivery in the cytosol. The imidazole ring of histidine is a weak base that has the ability to acquire a cationic charge when the pH of the environment drops bellow 6. As it has been demonstrated for poly(histidine), this phenomena can induce membrane fusion and/or membrane permeation in an acidic medium. Moreover, the accumulation of histidine residues inside acidic vesicles can induce a proton sponge effect, which increases their osmolarity and their swelling. The proof of concept has been shown with polylysine partially substituted with histidine residues that has caused a dramatic increase by 3–4.5 orders of magnitude of the transfection efficiency of DNA/polylysine polyplexes. Then, several histidine-rich polymers and peptides as well as lipids with imidazole, imidazolinium or imidazolium polar head have been reported to be efficient carriers to deliver nucleic acids including genes, mRNA or SiRNA in vitro and in vivo. More remarkable, histidylated carriers are often weakly cytotoxic, making them promising chemical vectors for nucleic acids delivery. This article is part of a themed section on Vector Design and Drug Delivery. For a list of all articles in this section see the end of this paper, or visit: http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2009 PMID:19459843

  7. Diamond nanowires modified with poly[3-(pyrrolyl)carboxylic acid] for the immobilization of histidine-tagged peptides.

    PubMed

    Subramanian, Palaniappan; Mazurenko, Ievgen; Zaitsev, Vladimir; Coffinier, Yannick; Boukherroub, Rabah; Szunerits, Sabine

    2014-09-01

    Coating boron-doped diamond nanowires (BDD NWs) with a conducting polymer, poly[3-(pyrrolyl)carboxylic acid], has been reported. Polymer coating was achieved through electropolymerization of 3-(pyrrolyl)carboxylic acid at the electrode interface by amperometrically biasing the BDD NWs interface until a predefined charge has passed. The poly[3-(pyrrolyl)carboxylic acid] modified BDD NWs (PPA-BDD NWs) were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Using a deposition charge of 11 mC cm(-2) resulted in a thin polymer film deposition. The availability of the carboxylic groups of the polymer coated BDD NWs electrode was demonstrated through copper ion (Cu(2+)) chelation. The resulting complex was successfully used for the site-specific immobilization of histidine-tagged peptides. The binding process was followed by electrochemical impedance spectroscopy (EIS). The Cu(2+)-chelated PPA-BDD NWs interface showed peptide loading capability comparable to those of commercially available interfaces and can be easily regenerated several times using ethylenediaminetetraacetic acid (EDTA).

  8. Diamond nanowires modified with poly[3-(pyrrolyl)carboxylic acid] for the immobilization of histidine-tagged peptides.

    PubMed

    Subramanian, Palaniappan; Mazurenko, Ievgen; Zaitsev, Vladimir; Coffinier, Yannick; Boukherroub, Rabah; Szunerits, Sabine

    2014-09-01

    Coating boron-doped diamond nanowires (BDD NWs) with a conducting polymer, poly[3-(pyrrolyl)carboxylic acid], has been reported. Polymer coating was achieved through electropolymerization of 3-(pyrrolyl)carboxylic acid at the electrode interface by amperometrically biasing the BDD NWs interface until a predefined charge has passed. The poly[3-(pyrrolyl)carboxylic acid] modified BDD NWs (PPA-BDD NWs) were characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). Using a deposition charge of 11 mC cm(-2) resulted in a thin polymer film deposition. The availability of the carboxylic groups of the polymer coated BDD NWs electrode was demonstrated through copper ion (Cu(2+)) chelation. The resulting complex was successfully used for the site-specific immobilization of histidine-tagged peptides. The binding process was followed by electrochemical impedance spectroscopy (EIS). The Cu(2+)-chelated PPA-BDD NWs interface showed peptide loading capability comparable to those of commercially available interfaces and can be easily regenerated several times using ethylenediaminetetraacetic acid (EDTA). PMID:25009833

  9. A theoretical study of medium effects on the structure of the glycine analogue aminomethylphosphonic acid.

    PubMed

    Benbrahim, Nasséra; Rahmouni, Ali; Ruiz-López, Manuel F

    2008-09-28

    alpha-Aminophosphonic acids are analogues of natural alpha-aminoacids and very promising agents for use in various pharmaceutical applications. However, in contrast to the numerous theoretical investigations on the structure of natural alpha-aminoacids, only very few studies on alpha-aminophosphonic acids have been performed. In the present work, we report a detailed investigation of the simplest compound, the glycine analogue aminomethylphosphonic acid (AMPA), by means of quantum mechanical calculations at the B3LYP/6-311++G(3df,2p)//B3LYP/6-31+G(d,p) and MP2/6-311++G(3df,2p)//B3LYP/6-31+G(d,p) levels. We focus on the structure of the neutral species looking at the evolution of non-ionized and ionized forms from gas phase to non-polar solvents and aqueous media. Continuum and discrete-continuum solvent models have been employed to account for the effects of the environment. The discussion is centered on: (1) the geometry and relative stability of possible conformers in gas phase and aqueous solution, (2) the free energy of tautomerization in different media, (3) the role of hydrogen bonds in liquid water, and (4) the free energy of transfer from water to a hydrophobic solvent such as cyclohexane. Systematic comparison between AMPA and Gly is performed. Though both systems exhibit many similarities, some important differences have also been found that may be explained, at least in part, by the higher acidity of phosphonic acids compared to carboxylic acids. In particular, in solvents lacking hydrogen-bond formation capability, Gly derivatives should mainly exist as non-ionized molecules while the equivalent AMPA derivatives should adopt a zwitterionic structure in media with dielectric constant above 10. This might have significant environmental or biological consequences that will need to be addressed.

  10. Altered Glycine Decarboxylation Inhibition in Isonicotinic Acid Hydrazide-Resistant Mutant Callus Lines and in Regenerated Plants and Seed Progeny

    PubMed Central

    Zelitch, Israel; Berlyn, Mary B.

    1982-01-01

    Isonicotinic acid hydrazide (INH), an inhibitor of the photorespiratory pathway blocking the conversion of glycine to serine and CO2, has been used as a selective agent to obtain INH-resistant tobacco (Nicotiana tabacum) callus cells. Of 22 cell lines that were INH-resistant, none were different from wild-type cells in their ability to take up [3H]INH or to oxidize INH to isonicotinic acid. In 7 of the 22 cell lines, INH resistance was associated with decreased inhibition of NAD-dependent glycine decarboxylation activity in isolated mitochondrial preparations. In the cell line that was most extensively investigated (I 24), this biochemical phenotype (exhibiting a 3-fold higher Ki with INH) was observed in leaf mitochondria of regenerated plants and of plants produced from them by self-fertilization. After crosses between resistant and sensitive plants, the decreased inhibition of glycine decarboxylation was observed among F2 and backcross progeny only in those plants previously identified as INH-resistant by callus growth tests. In contrast, in siblings identified as INH-sensitive, glycine decarboxylation was inhibited by INH at the wild-type level. This demonstration of the transfer of an altered enzyme property from callus to regenerated plants and through seed progeny fulfills an important requirement for the use of somatic cell genetics to produce biochemical mutants of higher plants. PMID:16662158

  11. Vanadate inhibition of fungal phyA and bacterial appA2 histidine acid phosphatases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal PhyA protein, which was first identified as an acid optimum phosphomonoesterase (EC 3.1.3.8), could also serve as a vanadate haloperoxidase (EC 1.11.1.10) provided the acid phosphatase activity is shutdown by vanadate. To understand how vanadate inhibits both phytate and pNPP degrading ac...

  12. Assessing the Indirect Photochemical Transformation of Dissolved Combined Amino Acids through the Use of Systematically Designed Histidine-Containing Oligopeptides.

    PubMed

    Chu, Chiheng; Lundeen, Rachel A; Sander, Michael; McNeill, Kristopher

    2015-11-01

    Photooxidation is an important abiotic transformation pathway for amino acids (AAs) in sunlit waters. Although dissolved free AAs are well studied, the photooxidation of dissolved combined AAs (DCAAs) remains poorly investigated. This study is a systematic investigation of the effect of neighboring photostable AA residues (i.e., aliphatic, cationic, anionic, or aromatic residues) on the environmental indirect photochemical transformation of histidine (His) in His-containing oligopeptides. The pKa values of His residues in the studied oligopeptides were found to be between 4.3 and 8.1. Accordingly, the phototransformation rate constants of the His-containing oligopeptides were highly pH-dependent in an environmentally relevant pH range with higher reactivity for neutral His than for the protonated species. The photostable AA residues significantly modulated the photoreactivity of oligopeptides either through altering the accessibility of His to photochemically produced oxidants or through shifting the pKa values of His residues. In addition, the influence of neighboring photostable AA residues on the sorption-enhanced phototransformation of oligopeptides in solutions containing chromophoric dissolved organic matter (CDOM) was assessed. The constituent photostable AA residues promoted sorption of His-containing oligopeptides to CDOM macromolecules through electrostatic attraction, hydrophobic effects, and/or low-barrier hydrogen bonds, and subsequently increased the apparent phototransformation rate constants by up to 2 orders of magnitude.

  13. Predicting Three-Dimensional Conformations of Peptides Constructed of Only Glycine, Alanine, Aspartic Acid, and Valine

    NASA Astrophysics Data System (ADS)

    Oda, Akifumi; Fukuyoshi, Shuichi

    2015-06-01

    The GADV hypothesis is a form of the protein world hypothesis, which suggests that life originated from proteins (Lacey et al. 1999; Ikehara 2002; Andras 2006). In the GADV hypothesis, life is thought to have originated from primitive proteins constructed of only glycine, alanine, aspartic acid, and valine ([GADV]-proteins). In this study, the three-dimensional (3D) conformations of randomly generated short [GADV]-peptides were computationally investigated using replica-exchange molecular dynamics (REMD) simulations (Sugita and Okamoto 1999). Because the peptides used in this study consisted of only 20 residues each, they could not form certain 3D structures. However, the conformational tendencies of the peptides were elucidated by analyzing the conformational ensembles generated by REMD simulations. The results indicate that secondary structures can be formed in several randomly generated [GADV]-peptides. A long helical structure was found in one of the hydrophobic peptides, supporting the conjecture of the GADV hypothesis that many peptides aggregated to form peptide multimers with enzymatic activity in the primordial soup. In addition, these results indicate that REMD simulations can be used for the structural investigation of short peptides.

  14. DL-β-Aminobutyric Acid-Induced Resistance in Soybean against Aphis glycines Matsumura (Hemiptera: Aphididae)

    PubMed Central

    Zhong, Yunpeng; Wang, Biao; Yan, Junhui; Cheng, Linjing; Yao, Luming; Xiao, Liang; Wu, Tianlong

    2014-01-01

    Priming can improve plant innate capability to deal with the stresses caused by both biotic and abiotic factors. In this study, the effect of DL-β-amino-n-butyric acid (BABA) against Aphis glycines Matsumura, the soybean aphid (SA) was evaluated. We found that 25 mM BABA as a root drench had minimal adverse impact on plant growth and also efficiently protected soybean from SA infestation. In both choice and non-choice tests, SA number was significantly decreased to a low level in soybean seedlings drenched with 25 mM BABA compared to the control counterparts. BABA treatment resulted in a significant increase in the activities of several defense enzymes, such as phenylalanine ammonia-lyase (PAL), peroxidase (POX), polyphenol oxidase (PPO), chitinase (CHI), and β-1, 3-glucanase (GLU) in soybean seedlings attacked by aphid. Meanwhile, the induction of 15 defense-related genes by aphid, such as AOS, CHS, MMP2, NPR1-1, NPR1-2, and PR genes, were significantly augmented in BABA-treated soybean seedlings. Our study suggest that BABA application is a promising way to enhance soybean resistance against SA. PMID:24454805

  15. Predicting three-dimensional conformations of peptides constructed of only glycine, alanine, aspartic acid, and valine.

    PubMed

    Oda, Akifumi; Fukuyoshi, Shuichi

    2015-06-01

    The GADV hypothesis is a form of the protein world hypothesis, which suggests that life originated from proteins (Lacey et al. 1999; Ikehara 2002; Andras 2006). In the GADV hypothesis, life is thought to have originated from primitive proteins constructed of only glycine, alanine, aspartic acid, and valine ([GADV]-proteins). In this study, the three-dimensional (3D) conformations of randomly generated short [GADV]-peptides were computationally investigated using replica-exchange molecular dynamics (REMD) simulations (Sugita and Okamoto 1999). Because the peptides used in this study consisted of only 20 residues each, they could not form certain 3D structures. However, the conformational tendencies of the peptides were elucidated by analyzing the conformational ensembles generated by REMD simulations. The results indicate that secondary structures can be formed in several randomly generated [GADV]-peptides. A long helical structure was found in one of the hydrophobic peptides, supporting the conjecture of the GADV hypothesis that many peptides aggregated to form peptide multimers with enzymatic activity in the primordial soup. In addition, these results indicate that REMD simulations can be used for the structural investigation of short peptides.

  16. Energy compensation mechanism for charge-separated protonation states in aspartate-histidine amino acid residue pairs.

    PubMed

    Kamiya, Katsumasa; Boero, Mauro; Shiraishi, Kenji; Oshiyama, Atsushi; Shigeta, Yasuteru

    2010-05-20

    The initial stage of proton propagation in the D-path channel of bovine cytochrome c oxidase, consisting of the approach of an H(+) to the entrance of this specific pathway, is inspected via first-principles calculations. Our model, extracted from the X-ray crystallographic structure, includes the amino acid residue pair aspartate (Asp91) and histidine (His503) as protonatable sites. Our calculations show that an additional proton, corresponding to the H(+) uptake by the enzyme from the inner bulk water, is transferred to either Asp91 or His503, leading to the formation of a neutral or a charge-separated protonation state. The relative stability between the two states amounts to a total energy difference of about 5 kcal/mol; this indicates that both Asp91 and His503 are involved in the proton supply to the D-path, playing the role of proton acceptors. The hydrogen-bond environment around Asp91 and His503 has an important influence on both the energetics and the electronic structure of the system; for instance, it compensates the Coulomb-energy cost in the charge-separated protonation state. An energy partitioning analysis shows that the compensatory effect is mainly due to local electrostatic interactions among the charged Asp91 and His503 side chains and the surrounding polar residues. The energy compensation mechanism we found in this work balances the energetics of Asp-His pairs, hence permitting an efficient and selective regulation of the protonatable amino acid residues, where several protonation states are accessible within energy differences of the order of a few H-bonds. PMID:20411975

  17. Substitution of a single amino acid (aspartic acid for histidine) converts the functional activity of human complement C4B to C4A

    SciTech Connect

    Carroll, M.C.; Fathallah, D.M.; Bergamaschini, L.; Alicot, E.M. ); Isenman, D.E. )

    1990-09-01

    The C4B isotype of the fourth component of human complement (C4) displays 3- to 4-fold greater hemolytic activity than does its other isotype C4A. This correlates with differences in their covalent binding efficiencies to erythrocytes coated with antibody and complement C1. C4A binds to a greater extent when C1 is on IgG immune aggregates. The differences in covalent binding properties correlate only with amino acid changes between residues 1101 and 1106 (pro-C4 numbering)-namely, Pro-1101, Cys-1102, Leu-1105, and Asp-1106 in C4A and Leu-1101, Ser-1102, Ile-1105, and His-1106 in C4B, which are located in the C4d region of the {alpha} chain. To more precisely identify the residues that are important for the functional differences, C4A-C4B hybrid proteins were constructed by using recombinant DNA techniques. Comparison of these by hemolytic assay and binding to IgG aggregates showed that the single substitution of aspartic acid for histidine at position 1106 largely accounted for the change in functional activity and nature of the chemical bond formed. Surprisingly, substitution of a neutral residue, alanine, for histidine at position 1106 resulted in an increase in binding to immune aggregates without subsequent reduction in the hemolytic activity. This result strongly suggests that position 1106 is not catalytic as previously proposed but interacts sterically/electrostatically with potential acceptor sites and serves to select binding sites on potential acceptor molecules.

  18. A Non-Invasive NMR Method Based on Histidine Imidazoles to Analyze the pH-Modulation of Protein-Nucleic Acid Interfaces.

    PubMed

    Cruz-Gallardo, Isabel; Del Conte, Rebecca; Velázquez-Campoy, Adrián; García-Mauriño, Sofía M; Díaz-Moreno, Irene

    2015-05-11

    A useful (2) J(N-H) coupling-based NMR spectroscopic approach is proposed to unveil, at the molecular level, the contribution of the imidazole groups of histidines from RNA/DNA-binding proteins on the modulation of binding to nucleic acids by pH. Such protonation/deprotonation events have been monitored on the single His96 located at the second RNA/DNA recognition motif (RRM2) of T-cell intracellular antigen-1 (TIA-1) protein. The pKa values of the His96 ionizable groups were substantially higher in the complexes with short U-rich RNA and T-rich DNA oligonucleotides than those of the isolated TIA-1 RRM2. Herein, the methodology applied to determine changes in pKa of histidine side chains upon DNA/RNA binding, gives valuable information to understand the pH effect on multidomain DNA/RNA-binding proteins that shuttle among different cellular compartments.

  19. Variable clinical manifestations of a glycine to glutamic acid substitution of the COL3A1 gene at residue 736

    SciTech Connect

    Pope, F.M.; Narcisi, P.; Richards, A.J.

    1994-09-01

    Glycine substitutions at the 3{prime} end of the COL3A1 gene generally produce a characteristic clinical phenotype including acrogeria and severe vascular fragility. Here we report a three generation British family in which the propositus presented with aneurysms of the groins. He, his mother, sister and elder daughter all had the external clinical phenotype of vascular EDS IV whilst another daughter and nephew were clinically normal. Cultured skin fibroblasts from the propositus and his clinically affected relatives poorly secreted normal and overmodified collagen III species. Normal components of secreted proteins predominated whilst overmodified molecules were prominent in intracellular material. Surprisingly the normal children also secreted less collagen type III than expected (though more than their clinically abnormal relatives). cDNA from bases 2671 to 3714 were amplified as four overlapping PCR fragments and analysed by DGGE. The region between 2671 and 3015 was heterozygous. Sequencing showed a mutation of glycine to glutamic acid at residue 736. This mutation created an extra Apa 1 restriction site which was suitable for family studies. These showed inheritance of the mutant gene by both vascular and non-vascular clinical phenotypes. This family therefore illustrates that replacement of glycine to glutamic acid at position 736 produces variable clinical and biochemical phenotypes ranging from easily recognizable vascular EDS IV with very poor collagen secretion to an EDS III-like picture and with less severe protein disturbance. The reasons for these differences are at present unexplained.

  20. Engineered protein A ligands, derived from a histidine-scanning library, facilitate the affinity purification of IgG under mild acidic conditions

    PubMed Central

    2014-01-01

    Background In antibody purification processes, the acidic buffer commonly used to elute the bound antibodies during conventional affinity chromatograph, can damage the antibody. Herein we describe the development of several types of affinity ligands which enable the purification of antibodies under much milder conditions. Results Staphylococcal protein A variants were engineered by using both structure-based design and combinatorial screening methods. The frequency of amino acid residue substitutions was statistically analyzed using the sequences isolated from a histidine-scanning library screening. The positions where the frequency of occurrence of a histidine residue was more than 70% were thought to be effective histidine-mutation sites. Consequently, we identified PAB variants with a D36H mutation whose binding of IgG was highly sensitive to pH change. Conclusion The affinity column elution chromatograms demonstrated that antibodies could be eluted at a higher pH (∆pH**≧2.0) than ever reported (∆pH = 1.4) when the Staphylococcal protein A variants developed in this study were used as affinity ligands. The interactions between Staphylococcal protein A and IgG-Fab were shown to be important for the behavior of IgG bound on a SpA affinity column, and alterations in the affinity of the ligands for IgG-Fab clearly affected the conditions for eluting the bound IgG. Thus, a histidine-scanning library combined with a structure-based design was shown to be effective in engineering novel pH-sensitive proteins. PMID:25057290

  1. Prebiotic synthesis of histidyl-histidine

    NASA Technical Reports Server (NTRS)

    Shen, C.; Mills, T.; Oro, J.

    1990-01-01

    Histidyl-histidine (His-His) has been synthesized in a yield of up to 14.4% under plausible prebiotic conditions using histidine (His), cyanamide, and 4-amino-5-imidazole carboxamide. A trace amount of His trimer was also detected. Because the imidazole group of His is involved in a number of important enzymatic reactions, and His-His has been shown to catalyze the prebiotic synthesis of glycyl-glycine, we expect this work will stimulate further studies on the catalytic activities of simple His-containing peptides in prebiotic reactions.

  2. Association of amino acids embedded in helium droplets detected by mass spectrometry

    NASA Astrophysics Data System (ADS)

    Lalanne, Matthieu R.; Achazi, Georg; Reichwald, Sebastian; Lindinger, Albrecht

    2015-12-01

    Amino acids were embedded in helium droplets. The electron impact ionization allows for detecting positively charged glycine, valine, histidine, tryptophan and their principal fragments. Monomers and polymers with up to four amino acids are reported. Heterodimers of tryptophan and valine or histidine are observed as well as heterodimers of included fragments. The ability of these associations of molecules to form complexes with water is examined.

  3. 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.

  4. The DNA replication inhibitor microcin B17 is a forty-three-amino-acid protein containing sixty percent glycine.

    PubMed

    Davagnino, J; Herrero, M; Furlong, D; Moreno, F; Kolter, R

    1986-11-01

    Microcin B17 is a low-molecular-weight protein that inhibits DNA replication in a number of enteric bacteria. It is produced by bacterial strains which harbor a 70-kilobase plasmid called pMccB17. Four plasmid genes (named mcbABCD) are required for its production. The product of the mcbA gene was identified by labelling minicells. The mcbA gene product was slightly larger when a mutation in any of the other three production genes was present. This indicates that these genes are involved in processing the primary mcbA product to yield the active molecule. The mcbA gene product predicted from the nucleotide sequence has 69 amino acids including 28 glycine residues. Microcin B17 was extracted from the cells by boiling in 100 mM acetic acid, 1 mM EDTA, and purified to homogeneity in a single step by high-performance liquid chromatography through a C18 column. The N-terminal amino acid sequence and amino acid composition demonstrated that mcbA is the structural gene for microcin B17. The active molecule is a processed product lacking the first 26 N-terminal residues. The 43 remaining residues include 26 glycines. While microcin B17 is an exported protein, the cleaved N-terminal peptide does not have the characteristic properties of a "signal sequence", which suggests that it is secreted by a mechanism different from that used by most secreted proteins of E. coli.

  5. Experimental and theoretical enthalpies of formation of glycine-based sulfate/bisulfate amino acid ionic liquids.

    PubMed

    Zhu, Jing-Fang; He, Ling; Zhang, Lei; Huang, Ming; Tao, Guo-Hong

    2012-01-12

    The experimental and theoretical enthalpies of formation of several structural-similar glycine-based sulfate/bisulfate amino acid ionic liquids including glycine sulfate (Gly(2)SO(4), 1), glycine bisulfate (GlyHSO(4), 2), N,N-dimethylglycine sulfate ([DMGly](2)SO(4), 3), N,N-dimethylglycine bisulfate ([DMGly]HSO(4), 4), N,N-dimethylglycine methyl ester sulfate ([DMGlyC(1)](2)SO(4), 5), N,N-dimethylglycine methyl ester bisulfate ([DMGlyC(1)]HSO(4), 6), N,N,N-trimethylglycine methyl ester sulfate ([TMGlyC(1)](2)SO(4), 7), and N,N,N-trimethylglycine methyl ester bisulfate ([TMGlyC(1)]HSO(4), 8) were studied. Their experimental enthalpies of formation were obtained from the corresponding energies of combustion determined by the bomb calorimetry method. The enthalpies of formation of these amino acid ionic liquids are in the range from -1406 kJ mol(-1) to -1128 kJ mol(-1). Systematic theoretical study on these amino acid ionic liquids were performed by quantum chemistry calculation using the Gaussian03 suite of programs. The geometric optimization and the frequency analyses are carried out using the B3LYP method with the 6-31+G** basis set. Their calculated enthalpies of formation were derived from the single point energies carried out with the HF/6-31+G**, B3LYP/6-31+G**, B3LYP/6-311++G**, and MP2/6-311++G** level of theory, respectively. The relevance of experimental and calculated enthalpies of formation was studied. The calculated enthalpies of formation are in good agreement with their experimental data in less than 3% error. PMID:22148242

  6. Characterization of a factor IX variant with a glycine207 to glutamic acid mutation.

    PubMed

    Lin, S W; Lin, C N; Hamaguchi, N; Smith, K J; Shen, M C

    1994-09-15

    Factor IXTaipei9 is a factor IX variant from a hemophilia B patient with reduced levels of circulating protein molecules (cross-reacting material reduced, CRM). This variant contained a glycine (Gly) to glutamic acid (Glu) substitution at the 207th codon of mature factor IX. The functional consequences of the Gly-->Glu mutation in factor IXTaipei9 (IXG207E) were characterized in this study. Plasma-derived IXG207E exhibited a mobility similar to that of normal factor IX on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its specific activity was estimated to be 3.5% that of the purified normal factor IX in a one-stage partial thromboplastin time assay (aPTT). Cleavage of factor IXG207E by factor XIa or factor VIIa-tissue factor complex appeared to be normal. When the calcium-dependent conformational change was examined by monitoring quenching of intrinsic fluorescence, both normal factor IX and IXG207E exhibited equivalent intrinsic fluorescence quenching. Activated factor IXG207E (IXaG207E) also binds antithrombin III equally as well as normal factor IXa. However, aberrant binding of the active site probe p-aminobenzamidine was observed for factor XIa-activated factor IXG207E, indicating that the active site pocket of the heavy chain of factor IXaG207E was abnormal. Moreover, the rate of activation of factor X by factor IXaG207E, as measured in a purified system using chromogenic substrates, was estimated to be 1/40 of that of normal factor IXa. A computer-modeled heavy-chain structure of factor IXa predicts a hydrophobic environment surrounding Gly-207 and this Gly forms a hydrogen bound to the active site serine-365. The molecular mechanism of the Gly-->Glu mutation in factor IXTaipei9 might result in the alteration of the microenvironment of the active site pocket which renders the active site serine-365 inaccessible to its substrate. PMID:7915915

  7. Glassin, a histidine-rich protein from the siliceous skeletal system of the marine sponge Euplectella, directs silica polycondensation.

    PubMed

    Shimizu, Katsuhiko; Amano, Taro; Bari, Md Rezaul; Weaver, James C; Arima, Jiro; Mori, Nobuhiro

    2015-09-15

    The hexactinellids are a diverse group of predominantly deep sea sponges that synthesize elaborate fibrous skeletal systems of amorphous hydrated silica. As a representative example, members of the genus Euplectella have proved to be useful model systems for investigating structure-function relationships in these hierarchically ordered siliceous network-like composites. Despite recent advances in understanding the mechanistic origins of damage tolerance in these complex skeletal systems, the details of their synthesis have remained largely unexplored. Here, we describe a previously unidentified protein, named "glassin," the main constituent in the water-soluble fraction of the demineralized skeletal elements of Euplectella. When combined with silicic acid solutions, glassin rapidly accelerates silica polycondensation over a pH range of 6-8. Glassin is characterized by high histidine content, and cDNA sequence analysis reveals that glassin shares no significant similarity with any other known proteins. The deduced amino acid sequence reveals that glassin consists of two similar histidine-rich domains and a connecting domain. Each of the histidine-rich domains is composed of three segments: an amino-terminal histidine and aspartic acid-rich sequence, a proline-rich sequence in the middle, and a histidine and threonine-rich sequence at the carboxyl terminus. Histidine always forms HX or HHX repeats, in which most of X positions are occupied by glycine, aspartic acid, or threonine. Recombinant glassin reproduces the silica precipitation activity observed in the native proteins. The highly modular composition of glassin, composed of imidazole, acidic, and hydroxyl residues, favors silica polycondensation and provides insights into the molecular mechanisms of skeletal formation in hexactinellid sponges.

  8. Glassin, a histidine-rich protein from the siliceous skeletal system of the marine sponge Euplectella, directs silica polycondensation

    PubMed Central

    Shimizu, Katsuhiko; Amano, Taro; Bari, Md. Rezaul; Weaver, James C.; Arima, Jiro; Mori, Nobuhiro

    2015-01-01

    The hexactinellids are a diverse group of predominantly deep sea sponges that synthesize elaborate fibrous skeletal systems of amorphous hydrated silica. As a representative example, members of the genus Euplectella have proved to be useful model systems for investigating structure–function relationships in these hierarchically ordered siliceous network-like composites. Despite recent advances in understanding the mechanistic origins of damage tolerance in these complex skeletal systems, the details of their synthesis have remained largely unexplored. Here, we describe a previously unidentified protein, named “glassin,” the main constituent in the water-soluble fraction of the demineralized skeletal elements of Euplectella. When combined with silicic acid solutions, glassin rapidly accelerates silica polycondensation over a pH range of 6–8. Glassin is characterized by high histidine content, and cDNA sequence analysis reveals that glassin shares no significant similarity with any other known proteins. The deduced amino acid sequence reveals that glassin consists of two similar histidine-rich domains and a connecting domain. Each of the histidine-rich domains is composed of three segments: an amino-terminal histidine and aspartic acid-rich sequence, a proline-rich sequence in the middle, and a histidine and threonine-rich sequence at the carboxyl terminus. Histidine always forms HX or HHX repeats, in which most of X positions are occupied by glycine, aspartic acid, or threonine. Recombinant glassin reproduces the silica precipitation activity observed in the native proteins. The highly modular composition of glassin, composed of imidazole, acidic, and hydroxyl residues, favors silica polycondensation and provides insights into the molecular mechanisms of skeletal formation in hexactinellid sponges. PMID:26261346

  9. Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Free Amino Acid Pools during Germination 1

    PubMed Central

    Duke, Stanley H.; Schrader, Larry E.; Miller, Marna Geyer; Niece, Ronald L.

    1978-01-01

    The free amino acid concentrations in cotyledons and axes of soybean (Glycine max [L.] Merr. cv. Wells) seedlings were determined by automated single column analysis after germination at 10 and 23 C. After 5 days germination at 10 C, glutamate and aspartate were in high concentration in both cotyledons and axes (38 and 24% of total free amino acids recovered, respectively), whereas the concentrations of their amide derivatives, asparagine and glutamine, were low in cotyledons (4.4%) and high in axes (21%). In contrast, after 5 days germination at 23 C, asparagine and glutamine accounted for 22 and 45% of total free amino acids in cotyledons and axes respectively, and aspartate and glutamate concentrations were low. The activities of glutamine synthetase and asparagine synthetase were considerably lower in tissues from the 10 C treatment than those from the 23 C treatment. Aspartate and glutamate concentrations were nearly equal in all but one sample. Both glutamate oxaloacetate transaminase and glutamate dehydrogenase activities were much higher in axis tissues at 23 C as compared to 10 C. Arrhenius plots of axis glutamate oxaloacetate transaminase and glutamate dehydrogenase activities were biphasic and triphasic, respectively, with energies of activation for both increasing with low temperature. Energies of activation were identical for glutamate oxaloacetate transaminase from 10 and 23 C treatments but much higher for glutamate dehydrogenase from 23 C-treated axes. This indicates a difference in enzyme complement for glutamate dehydrogenase with the two treatments. Hydrolysis of free amino acid sample (basic fraction) aliquots showed large quantities of peptides in 23 C-treated axes at 2 days, while few or no peptides were found in the 10 C treatment. Amino acid residues most prevalent in peptides were aspartate, threonine, serine, glutamate, and glycine. PMID:16660575

  10. The importance of glutamate, glycine, and {gamma}-aminobutyric acid transport and regulation in manganese, mercury and lead neurotoxicity

    SciTech Connect

    Fitsanakis, Vanessa A.; Aschner, Michael . E-mail: michael.aschner@vanderbilt.edu

    2005-05-01

    Historically, amino acids were studied in the context of their importance in protein synthesis. In the 1950s, the focus of research shifted as amino acids were recognized as putative neurotransmitters. Today, many amino acids are considered important neurochemicals. Although many amino acids play a role in neurotransmission, glutamate (Glu), glycine (Gly), and {gamma}-aminobutyric acid (GABA) are among the more prevalent and better understood. Glu, the major excitatory neurotransmitter, and Gly and GABA, the major inhibitory neurotransmitters, in the central nervous system, are known to be tightly regulated. Prolonged exposure to environmental toxicants, such as manganese (Mn), mercury (Hg), or lead (Pb), however, can lead to dysregulation of these neurochemicals and subsequent neurotoxicity. While the ability of these metals to disrupt the regulation of Glu, Gly and GABA have been studied, few articles have examined the collective role of these amino acids in the respective metal's mechanism of toxicity. For each of the neurotransmitters above, we will provide a brief synopsis of their regulatory function, including the importance of transport and re-uptake in maintaining their optimal function. Additionally, the review will address the hypothesis that aberrant homeostasis of any of these amino acids, or a combination of the three, plays a role in the neurotoxicity of Mn, Hg, or Pb.

  11. Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

    PubMed

    Kumar, Sandeep; Kayastha, Arvind M

    2010-10-01

    Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

  12. New force field parameters for metalloproteins I: Divalent copper ion centers including three histidine residues and an oxygen-ligated amino acid residue.

    PubMed

    Wise, Olivia; Coskuner, Orkid

    2014-06-30

    Transition metal ion complexation with proteins is ubiquitous across such diverse fields as neurodegenerative and cardiovascular diseases and cancer. In this study, the structures of divalent copper ion centers including three histidine and one oxygen-ligated amino acid residues and the relative binding affinities of the oxygen-ligated amino acid residues with these metal ion centers, which are debated in the literature, are presented. Furthermore, new force field parameters, which are currently lacking for the full-length metal-ligand moieties, are developed for metalloproteins that have these centers. These new force field parameters enable investigations of metalloproteins possessing these binding sites using molecular simulations. In addition, the impact of using the atom equivalence and inequivalence atomic partial charge calculation procedures on the simulated structures of these metallopeptides, including hydration properties, is described.

  13. Effect of acidity on the glycine-nitrate combustion synthesis of nanocrystalline alumina powder

    SciTech Connect

    Peng Tianyou . E-mail: typeng@whu.edu.cn; Liu Xun; Dai Ke; Xiao Jiangrong; Song Haibo

    2006-09-14

    Nanocrystalline alumina powders were prepared by combustion synthesis using glycine as fuel and nitrate as an oxidizer. The effect of the pH values in the precursor solutions on crystallite sizes, surface areas and morphologies of the synthesized alumina powder has been investigated by X-ray diffractometry, thermal analysis, nitrogen adsorption-desorption, and transmission electron microscopy. With decreasing the pH values in the precursor solutions, the obtained materials could be modified from segregated nanoparticles (pH 10.5) to aggregates of nanoparticles (pH 6.0), and finally to a flaky morphology (pH 2.5). The rates of decomposition, the interaction of coordination as well as the hydrogen bonding of the glycine and the Al-hydroxides species at different pH values were found to be responsible for the generation of flake and/or segregated nanoparticles during auto-ignition reactions. The as-prepared combustion ashes were converted into pure nanocrystalline alumina after calcination at elevated temperatures. The specific surface areas of the products calcined at 800 deg. C ranged from 96 to 39 m{sup 2}/g with the pH decreased from 10.5 to 2.5.

  14. Prebiotic synthesis of histidine

    NASA Technical Reports Server (NTRS)

    Shen, C.; Yang, L.; Miller, S. L.; Oro, J.

    1990-01-01

    The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

  15. A Non-Invasive NMR Method Based on Histidine Imidazoles to Analyze the pH-Modulation of Protein-Nucleic Acid Interfaces.

    PubMed

    Cruz-Gallardo, Isabel; Del Conte, Rebecca; Velázquez-Campoy, Adrián; García-Mauriño, Sofía M; Díaz-Moreno, Irene

    2015-05-11

    A useful (2) J(N-H) coupling-based NMR spectroscopic approach is proposed to unveil, at the molecular level, the contribution of the imidazole groups of histidines from RNA/DNA-binding proteins on the modulation of binding to nucleic acids by pH. Such protonation/deprotonation events have been monitored on the single His96 located at the second RNA/DNA recognition motif (RRM2) of T-cell intracellular antigen-1 (TIA-1) protein. The pKa values of the His96 ionizable groups were substantially higher in the complexes with short U-rich RNA and T-rich DNA oligonucleotides than those of the isolated TIA-1 RRM2. Herein, the methodology applied to determine changes in pKa of histidine side chains upon DNA/RNA binding, gives valuable information to understand the pH effect on multidomain DNA/RNA-binding proteins that shuttle among different cellular compartments. PMID:25846236

  16. Calcium Binding to Amino Acids and Small Glycine Peptides in Aqueous Solution: Toward Peptide Design for Better Calcium Bioavailability.

    PubMed

    Tang, Ning; Skibsted, Leif H

    2016-06-01

    Deprotonation of amino acids as occurs during transfer from stomach to intestines during food digestion was found by comparison of complex formation constants as determined electrochemically for increasing pH to increase calcium binding (i) by a factor of around 6 for the neutral amino acids, (ii) by a factor of around 4 for anions of the acidic amino acids aspartic and glutamic acid, and (iii) by a factor of around 5.5 for basic amino acids. Optimized structures of the 1:1 complexes and ΔHbinding for calcium binding as calculated by density functional theory (DFT) confirmed in all complexes a stronger calcium binding and shorter calcium-oxygen bond length in the deprotonated form. In addition, the stronger calcium binding was also accompanied by a binding site shift from carboxylate binding to chelation by α-amino group and carboxylate oxygen for leucine, aspartate, glutamate, alanine, and asparagine. For binary amino acid mixtures, the calcium-binding constant was close to the predicted geometric mean of the individual amino acid binding constants indicating separate binding of calcium to two amino acids when present together in solution. At high pH, corresponding to conditions for calcium absorption, the binding affinity increased in the order Lys < Arg < Cys < Gln < Gly ∼ Ala < Asn < His < Leu < Glu< Asp. In a series of glycine peptides, calcium-binding affinity was found to increase in the order Gly-Leu ∼ Gly-Gly < Ala-Gly < Gly-His ∼ Gly-Lys-Gly < Glu-Cys-Gly < Gly-Glu, an ordering confirmed by DFT calculations for the dipeptides and which also accounted for large synergistic effects in calcium binding for up to 6 kJ/mol when compared to the corresponding amino acid mixtures.

  17. Histidine-41 of the cytochrome b5 domain of the borage delta6 fatty acid desaturase is essential for enzyme activity.

    PubMed

    Sayanova, O; Shewry, P R; Napier, J A

    1999-10-01

    Unlike most other plant microsomal desaturases, the Delta6-fatty acid desaturase from borage (Borago officinalis) contains an N-terminal extension that shows homology to the small hemoprotein cytochrome (Cyt) b5. To determine if this domain serves as a functional electron donor for the Delta6-fatty acid desaturase, mutagenesis and functional analysis by expression in transgenic Arabidopsis was carried out. Although expression of the wild-type borage Delta6-fatty acid desaturase resulted in the synthesis and accumulation of Delta6-unsaturated fatty acids, this was not observed in plants transformed with N-terminally deleted forms of the desaturase. Site-directed mutagenesis was used to disrupt one of the axial heme-binding residues (histidine-41) of the Cyt b5 domain; expression of this mutant form of the Delta6-desaturase in transgenic plants failed to produce Delta6-unsaturated fatty acids. These data indicate that the Cyt b5 domain of the borage Delta6-fatty acid desaturase is essential for enzymatic activity.

  18. Histidine-41 of the Cytochrome b5 Domain of the Borage Δ6 Fatty Acid Desaturase Is Essential for Enzyme Activity1

    PubMed Central

    Sayanova, Olga; Shewry, Peter R.; Napier, Johnathan A.

    1999-01-01

    Unlike most other plant microsomal desaturases, the Δ6-fatty acid desaturase from borage (Borago officinalis) contains an N-terminal extension that shows homology to the small hemoprotein cytochrome (Cyt) b5. To determine if this domain serves as a functional electron donor for the Δ6-fatty acid desaturase, mutagenesis and functional analysis by expression in transgenic Arabidopsis was carried out. Although expression of the wild-type borage Δ6-fatty acid desaturase resulted in the synthesis and accumulation of Δ6-unsaturated fatty acids, this was not observed in plants transformed with N-terminally deleted forms of the desaturase. Site-directed mutagenesis was used to disrupt one of the axial heme-binding residues (histidine-41) of the Cyt b5 domain; expression of this mutant form of the Δ6-desaturase in transgenic plants failed to produce Δ6-unsaturated fatty acids. These data indicate that the Cyt b5 domain of the borage Δ6-fatty acid desaturase is essential for enzymatic activity. PMID:10517856

  19. Growth, Optical, Dielectric and Ferroelectric Properties of Non-Linear Optical Single Crystal: Glycine-Phthalic Acid

    NASA Astrophysics Data System (ADS)

    Suresh, Sagadevan

    2016-07-01

    Single crystals of glycine-phthalic acid (GPA) were grown by slow evaporation process using aqueous solution. X-ray diffraction analysis was used to examine its cell structure and it was found that the GPA crystal corresponded to the orthorhombic system. To identify absorption range and cut-off wavelength for the GPA crystal, UV-visible spectrum was recorded. UV-visible spectroscopy was used to study the optical constants such as the refractive index, the extinction coefficient, electrical susceptibility, and optical conductivity. As a function of different frequencies and temperatures, the dielectric constant and the dielectric loss were examined. The electrical properties like plasma energy, Penn gap, Fermi energy, and polarizability were determined for the analysis of the second harmonic generation (SHG). Using the Kurtz powder technique, the SHG of the GPA crystal was studied. Investigations relating to hysteresis were carried out to ascertain the ferroelectric nature of the material.

  20. Growth, Optical, Dielectric and Ferroelectric Properties of Non-Linear Optical Single Crystal: Glycine-Phthalic Acid

    NASA Astrophysics Data System (ADS)

    Suresh, Sagadevan

    2016-11-01

    Single crystals of glycine-phthalic acid (GPA) were grown by slow evaporation process using aqueous solution. X-ray diffraction analysis was used to examine its cell structure and it was found that the GPA crystal corresponded to the orthorhombic system. To identify absorption range and cut-off wavelength for the GPA crystal, UV-visible spectrum was recorded. UV-visible spectroscopy was used to study the optical constants such as the refractive index, the extinction coefficient, electrical susceptibility, and optical conductivity. As a function of different frequencies and temperatures, the dielectric constant and the dielectric loss were examined. The electrical properties like plasma energy, Penn gap, Fermi energy, and polarizability were determined for the analysis of the second harmonic generation (SHG). Using the Kurtz powder technique, the SHG of the GPA crystal was studied. Investigations relating to hysteresis were carried out to ascertain the ferroelectric nature of the material.

  1. Okadaic acid-induced, naringin-sensitive phosphorylation of glycine N-methyltransferase in isolated rat hepatocytes.

    PubMed Central

    Møller, Michael T N; Samari, Hamid R; Fengsrud, Monica; Strømhaug, Per E; øStvold, Anne C; Seglen, Per O

    2003-01-01

    Glycine N-methyltransferase (GNMT) is an abundant cytosolic enzyme that catalyses the methylation of glycine into sarcosine, coupled with conversion of the methyl donor, S -adenosylmethionine (AdoMet), into S -adenosylhomocysteine (AdoHcy). GNMT is believed to play a role in monitoring the AdoMet/AdoHcy ratio, and hence the cellular methylation capacity, but regulation of the enzyme itself is not well understood. In the present study, treatment of isolated rat hepatocytes with the protein phosphatase inhibitor okadaic acid, was found to induce an overphosphorylation of GNMT, as shown by proteomic analysis. The analysis comprised two-dimensional gel electrophoretic separation of (32)P-labelled phosphoproteins and identification of individual protein spots by matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry. The identity of GNMT was verified by N-terminal Edman sequencing of tryptic peptides. Chromatographic separation of proteolytic peptides and (32)P-labelled amino acids suggested that GNMT was phosphorylated within a limited region, and only at serine residues. GNMT phosphorylation could be suppressed by naringin, an okadaic acid-antagonistic flavonoid. To assess the possible functional role of GNMT phosphorylation, the effect of okadaic acid on hepatocytic AdoMet and AdoHcy levels was examined, using HPLC separation for metabolite analysis. Surprisingly, okadaic acid was found to have no effect on the basal levels of AdoMet or AdoHcy. An accelerated AdoMet-AdoHcy flux, induced by the addition of methionine (1 mM), was likewise unaffected by okadaic acid. 5-Aminoimidazole-4-carboxamide riboside, an activator of the hepatocytic AMP-activated protein kinase, similarly induced GNMT phosphorylation without affecting AdoMet and AdoHcy levels. Activation of cAMP-dependent protein kinase by dibutyryl-cAMP, reported to cause GNMT phosphorylation under cell-free conditions, also had little effect on hepatocytic AdoMet and AdoHcy levels

  2. Effect of folic acid plus glycine supplement on uterine prostaglandin and endometrial granulocyte-macrophage colony-stimulating factor expression during early pregnancy in pigs.

    PubMed

    Guay, Frédéric; Matte, J Jacques; Girard, Christiane L; Palin, Marie-France; Giguère, Alain; Laforest, Jean-Paul

    2004-01-15

    The objective was to determine the effects of folic acid+glycine supplement on uterine metabolism of prostaglandin and mRNA expression of endometrial granulocyte-macrophage colony-stimulating factor (GM-CSF) in nulliparous (NYL) and multiparous Yorkshire-Landrace (YL) sows, and in multiparous Meishan-Landrace sows (ML). In each of these three groups, sows were randomly assigned to two treatments: 15 ppm folic acid+0.6% glycine or no supplement. The dietary supplement was given from the estrus before mating to slaughter on Day 25 of pregnancy. At slaughter, endometrial tissue was collected to determine endometrial expression levels of GM-CSF mRNA, cyclooxygenase-1 (COX1) and -2 (COX2) and to evaluate in vitro endometrial secretion of prostaglandin E2 (PGE2) secretion. Allantoic fluid samples were also collected to determine the concentration of PGE2, prostaglandin F2alpha (PGF2alpha), estradiol-17beta (E2), progesterone (P4), and transforming-growth factor-beta2 (TGF-beta2). The allantoic contents of PGF2alpha, E2 and P4, and endometrial in vitro secretion of PGE2 were not significantly influenced by the folic acid+glycine supplement. The folic acid+glycine supplement tended (P<0.07) to increase allantoic content of PGE2 and TGF-beta2 in all sows and increased (P<0.05) endometrial expression of COX2, especially in NYL sows. The endometrial expression of COX1 was decreased (P<0.05) by folic acid+glycine supplement, especially in multiparous YL sows. The allantoic contents of PGE2 and PGF2alpha were not significantly affected by sow type. However, NYL sows had higher (P<0.05) endometrial in vitro secretion of PGE2 and allantoic content of P4 than multiparous YL and ML sows. The allantoic content of E2 was also higher (P<0.05) in NYL sows than in multiparous ML sows only. The allantoic content of TGF-beta2 was lower (P<0.05) in multiparous ML than in multiparous YL only sows. Finally, in YL and NYL sows, folic acid+glycine supplement decreased (P<0.05) the endometrial

  3. Oxidation of the His-52 --> Leu mutant of cytochrome c peroxidase by p-nitroperoxybenzoic acid: role of the distal histidine in hydroperoxide activation.

    PubMed

    Palamakumbura, A H; Vitello, L B; Erman, J E

    1999-11-23

    Both cytochrome c peroxidase (CcP) and a mutant cytochrome c peroxidase in which the distal histidine has been replaced by leucine, CcP(H52L), are converted to hydroxy-ligated derivatives at alkaline pH. In CcP, the hydroxy-ligated derivative is subsequently converted to a bis-imidazole species prior to protein denaturation while the initial hydroxy-ligated CcP(H52L) is converted to a second, spectroscopically distinct hydroxy-ligated species prior to denaturation. The spectra of the alkaline forms of CcP and CcP(H52L) have been determined between 310 and 700 nm. The pH dependence of the rate of reaction between CcP(H52L) and hydrogen peroxide has been extended to pH 10. The hydroxy-ligated form of CcP(H52L) reacts with hydrogen peroxide 4 times more rapidly than the pentacoordinate, high-spin form of CcP(H52L) that exists at neutral pH. The rate of the reaction between p-nitroperoxybenzoic acid and CcP(H52L) has been measured between pH 4 and pH 8. Neutral p-nitroperoxybenzoic acid reacts with CcP(H52L) 10(5) times more slowly than with CcP while the negatively charged p-nitroperoxybenzoate reacts with CcP(H52L) 10(3) times more slowly than with CcP. These data indicate that the role of the distal histidine during the initial formation of the peroxy anion/heme iron complex is not simply base catalysis. PMID:10569951

  4. Dual Mode Fluorophore-Doped Nickel Nitrilotriacetic Acid-Modified Silica Nanoparticles Combine Histidine-Tagged Protein Purification with Site-Specific Fluorophore Labeling

    PubMed Central

    Kim, Sung Hoon; Jeyakumar, M.; Katzenellenbogen, John A.

    2008-01-01

    We present the first example of a fluorophore-doped nickel chelate surface- modified silica nanoparticle that functions in a dual mode, combining histidine-tagged protein purification with site-specific fluorophore labeling. Tetramethylrhodamine (TMR)-doped silica nanoparticles, estimated to contain 700–900 TMRs per ca. 23-nm particle, were surface modified with nitrilotriacetic acid (NTA), producing TMR-SiO2-NTA-Ni+2. Silica-embedded TMR retains very high quantum yield, is resistant to quenching by buffer components and is modestly quenched and only to a certain depth (ca. 2 nm) by surface-attached Ni+2. When exposed to a bacterial lysate containing estrogen receptor α ligand binding domain (ERα) as a minor component, these beads showed very high specificity binding, enabling protein purification in one step. The capacity and specificity of these beads for binding a his-tagged protein were characterized by electrophoresis, radiometric counting, and MALDI-TOF MS. ERα, bound to TMR-SiO2-NTA-Ni++ beads in a site-specific manner, exhibited good activity for ligand binding and for ligand-induced binding to coactivators in solution FRET experiments and protein microarray fluorometric and FRET assays. This dual-mode type TMR-SiO2-NTA-Ni++ system represents a powerful combination of one-step histidine-tagged protein purification and site-specific labeling with multiple fluorophore species. BRIEFS Tetramethylrhodamine-doped silica nanoparticles surface modified with nitrilotriacetic acid are dual-mode agents that can be used to purify and site-specifically fluorophore label his-tagged proteins in one step for fluorometric and FRET experiments. PMID:17910454

  5. Nitrosation of aspartic acid, aspartame, and glycine ethylester. Alkylation of 4-(p-nitrobenzyl)pyridine (NBP) in vitro and binding to DNA in the rat.

    PubMed

    Meier, I; Shephard, S E; Lutz, W K

    1990-05-01

    In a colorimetric assay using 4-(p-nitrobenzyl)pyridine (NBP) as a nucleophilic scavenger of alkylating agents, the nitrosation and alkylation reactions were investigated for a number of amino acids and derivatives. The alkylating activity increased with the square of the nitrite concentration. The nitrosation rate constants for aspartic acid, aspartame, and glycine ethylester (= precursors C) were 0.08, 1.4 and less than or equal to 0.2, respectively, expressed in terms of the pH-dependent k2 rate constant of the equation dNOC/dt = k2.[C].[nitrite]2. The rates correlated inversely with the basicity of the amino group. The stability of the alkylating activity was astonishingly high, both in acid and at neutral pH. Half-lives of 500, 200, and 30 min were determined for aspartic acid (pH 3.5), aspartame (pH 2.5), and glycine ethylester (pH 2.5). Values of 60, 15, and 2 min, respectively, were found at pH 7. It is concluded that rearrangement of the primary N-nitroso product to the ultimate alkylating agent could be rate-limiting. The potential of nitrosated alpha-amino acids to bind to DNA in vivo was investigated by oral gavage of radiolabelled glycine ethylester to rats, followed immediately by sodium nitrite. DNA was isolated from stomach and liver and analysed for radioactivity and modified nucleotides. No indication of DNA adduct formation was obtained. Based on an estimation of the dose fraction converted from glycine ethylester to the nitroso product under the given experimental conditions, the maximum possible DNA-binding potency of nitroso glycine ethylester is about one order of magnitude below the methylating potency of N-nitrosomethylurea in rat stomach. The apparent discrepancy to the in vitro data could be due to efficient detoxification processes in mammalian cells.

  6. Inoculation with Bradyrhizobium japonicum enhances the organic and fatty acids content of soybean (Glycine max (L.) Merrill) seeds.

    PubMed

    Silva, Luís R; Pereira, Maria J; Azevedo, Jessica; Mulas, Rebeca; Velazquez, Encarna; González-Andrés, Fernando; Valentão, Patrícia; Andrade, Paula B

    2013-12-15

    Soybean (Glycine max (L.) Merrill) is one of the most important food crops for human and animal consumption, providing oil and protein at relatively low cost. The least expensive source of nitrogen for soybean is the biological fixation of atmospheric nitrogen by the symbiotic association with soil bacteria, belonging mainly to the genus Bradyrhizobium. This study was conducted to assess the effect of the inoculation of G. max with Bradyrhizobium japonicum on the metabolite profile and antioxidant potential of its seeds. Phenolic compounds, sterols, triterpenes, organic acids, fatty acids and volatiles profiles were characterised by different chromatographic techniques. The antioxidant activity was evaluated against DPPH, superoxide and nitric oxide radicals. Inoculation with B. japonicum induced changes in the profiles of primary and secondary metabolites of G. max seeds, without affecting their antioxidant capacity. The increase of organic and fatty acids and volatiles suggest a positive effect of the inoculation process. These findings indicate that the inoculation with nodulating B. japonicum is a beneficial agricultural practice, increasing the content of bioactive metabolites in G. max seeds owing to the establishment of symbiosis between plant and microorganism, with direct effects on seed quality.

  7. LeProT1, a transporter for proline, glycine betaine, and gamma-amino butyric acid in tomato pollen.

    PubMed Central

    Schwacke, R; Grallath, S; Breitkreuz, K E; Stransky, E; Stransky, H; Frommer, W B; Rentsch, D

    1999-01-01

    During maturation, pollen undergoes a period of dehydration accompanied by the accumulation of compatible solutes. Solute import across the pollen plasma membrane, which occurs via proteinaceous transporters, is required to support pollen development and also for subsequent germination and pollen tube growth. Analysis of the free amino acid composition of various tissues in tomato revealed that the proline content in flowers was 60 times higher than in any other organ analyzed. Within the floral organs, proline was confined predominantly to pollen, where it represented >70% of total free amino acids. Uptake experiments demonstrated that mature as well as germinated pollen rapidly take up proline. To identify proline transporters in tomato pollen, we isolated genes homologous to Arabidopsis proline transporters. LeProT1 was specifically expressed both in mature and germinating pollen, as demonstrated by RNA in situ hybridization. Expression in a yeast mutant demonstrated that LeProT1 transports proline and gamma-amino butyric acid with low affinity and glycine betaine with high affinity. Direct uptake and competition studies demonstrate that LeProT1 constitutes a general transporter for compatible solutes. PMID:10072398

  8. Water deficit-induced changes in abscisic acid, growth polysomes, and translatable RNA in soybean hypocotyls. [Glycine max L

    SciTech Connect

    Bensen, R.J.; Boyer, J.S.; Mullet, J.E. )

    1988-01-01

    Soybean seedlings (Glycine max L.) were germinated and dark-grown in water-saturated vermiculite for 48 hours, then transferred either to water-saturated vermiculite or to low water potential vermiculite. A decrease in growth rate was detectable within 0.8 hour post-transfer to low water potential vermiculite. A fourfold increase in the abscisic acid content of the elongating region was observed within 0.5 hour. At 24 hours post-transfer, hypocotyl elongation was severely arrested and abscisic acid reached its highest measured level. A comparison of the polyA{sup +} RNA populations isolated at 24 hours post-transfer from the elongating region of water-saturated and low water potential vermiculite-grown seedlings was made by two-dimensional polyacrylamide gel analysis of in vitro translation products. It revealed both increases and decreases in the relative amounts of a number of translation products. Rewatering seedlings grown in low water potential vermiculite at 24 hours post-transfer led to a total recovery in growth rate within 0.5 hour, while abscisic acid in the elongating hypocotyl region required 1 to 2 hours to return to uninduced levels. Application of 1.0 millimolar {+-} abscisic acid to well-watered seedlings resulted in a 48% reduction in hypocotyl growth rate during the first 2 hours after treatment. Plants treated with abscisic acid for 24 hours had a lower polysome content than control plants. However, hypocotyl growth inhibition in abscisic acid-treated seedlings preceded the decline in polysome content.

  9. Syn-Selective Synthesis of β-Branched α-Amino Acids by Alkylation of Glycine-Derived Imines with Secondary Sulfonates.

    PubMed

    Lou, Sha; McKenna, Grace M; Tymonko, Steven A; Ramirez, Antonio; Benkovics, Tamas; Conlon, David A; González-Bobes, Francisco

    2015-10-16

    A syn-selective synthesis of β-branched α-amino acids has been developed based on the alkylation of glycine imine esters with secondary sulfonates. The potassium counterion for the enolate, the solvent, and the leaving group on the electrophile were key levers to maximize the diasteroselectivity of the alkylation. The optimized conditions enabled a straightforward preparation of a number of β-branched α-amino acids that can be challenging to obtain.

  10. Structure and synthesis of histopine, a histidine derivative produced by crown gall tumors

    SciTech Connect

    Bates, H.A.; Kaushal, A.; Deng, P.N.; Sciaky, D.

    1984-07-03

    Histopine, an unusual amino acid derivative of histidine isolated from crown gall tumors of sunflowers (Helianthus annus) inoculated with Agrobacterium tumefaciens strain B/sub 6/, was previously assigned the gross structure N-(1-carboxyethyl)histidine. A diastereomeric mixture containing histopine was readily prepared by reductive alkylation of (S)-histidine with pyruvic acid and sodium cyanoborohydride. The individual diastereomers were prepared by reaction of (S)-histidine with (R)- and (S)-2-bromopropionic acid. (R)-N-(1-Carboxyethyl)-(S)-histidine supports the growth of A. tumefaciens whereas (S)-N-(1-carboxyethyl)-(S)-histidine is inactive.

  11. Transporter-associated currents in the gamma-aminobutyric acid transporter GAT-1 are conditionally impaired by mutations of a conserved glycine residue.

    PubMed

    Zhou, Yonggang; Kanner, Baruch I

    2005-05-27

    To determine whether glycine residues play a role in the conformational changes during neurotransmitter transport, we have analyzed site-directed mutants of the gamma-aminobutyric acid (GABA) transporter GAT-1 in a domain containing three consecutive glycines conserved throughout the sodium- and chloride-dependent neurotransmitter transporter family. Only cysteine replacement of glycine 80 resulted in the complete loss of [(3)H]GABA uptake, but oocytes expressing this mutant exhibited the sodium-dependent transient currents thought to reflect a charge-moving conformational change. When sodium was removed and subsequently added back, the transients by G80C did not recover, as opposed to wild type, where recovery was almost complete. Remarkably, the transients by G80C could be restored after exposure of the oocytes to either GABA or a depolarizing pre-pulse. These treatments also resulted in a full recovery of the transients by the wild type. Whereas in wild type lithium leak currents are observed after prior sodium depletion, this was not the case for the glycine 80 mutants unless GABA was added or the oocytes were subjected to a depolarizing pre-pulse. Thus, glycine 80 appears essential for conformational transitions in GAT-1. When this residue is mutated, removal of sodium results in "freezing" the transporter in one conformation from which it can only exit by compensatory changes induced by GABA or depolarization. Our results can be explained by a model invoking two outward-facing states of the empty transporter and a defective transition between these states in the glycine 80 mutants.

  12. Genome-Wide Identification, Classification, and Expression Analysis of Amino Acid Transporter Gene Family in Glycine Max.

    PubMed

    Cheng, Lin; Yuan, Hong-Yu; Ren, Ren; Zhao, Shi-Qi; Han, Ya-Peng; Zhou, Qi-Ying; Ke, Dan-Xia; Wang, Ying-Xiang; Wang, Lei

    2016-01-01

    Amino acid transporters (AATs) play important roles in transporting amino acid across cellular membranes and are essential for plant growth and development. To date, the AAT gene family in soybean (Glycine max L.) has not been characterized. In this study, we identified 189 AAT genes from the entire soybean genomic sequence, and classified them into 12 distinct subfamilies based upon their sequence composition and phylogenetic positions. To further investigate the functions of these genes, we analyzed the chromosome distributions, gene structures, duplication patterns, phylogenetic tree, tissue expression patterns of the 189 AAT genes in soybean. We found that a large number of AAT genes in soybean were expanded via gene duplication, 46 and 36 GmAAT genes were WGD/segmental and tandemly duplicated, respectively. Further comprehensive analyses of the expression profiles of GmAAT genes in various stages of vegetative and reproductive development showed that soybean AAT genes exhibited preferential or distinct expression patterns among different tissues. Overall, our study provides a framework for further analysis of the biological functions of AAT genes in either soybean or other crops.

  13. Genome-Wide Identification, Classification, and Expression Analysis of Amino Acid Transporter Gene Family in Glycine Max

    PubMed Central

    Cheng, Lin; Yuan, Hong-Yu; Ren, Ren; Zhao, Shi-Qi; Han, Ya-Peng; Zhou, Qi-Ying; Ke, Dan-Xia; Wang, Ying-Xiang; Wang, Lei

    2016-01-01

    Amino acid transporters (AATs) play important roles in transporting amino acid across cellular membranes and are essential for plant growth and development. To date, the AAT gene family in soybean (Glycine max L.) has not been characterized. In this study, we identified 189 AAT genes from the entire soybean genomic sequence, and classified them into 12 distinct subfamilies based upon their sequence composition and phylogenetic positions. To further investigate the functions of these genes, we analyzed the chromosome distributions, gene structures, duplication patterns, phylogenetic tree, tissue expression patterns of the 189 AAT genes in soybean. We found that a large number of AAT genes in soybean were expanded via gene duplication, 46 and 36 GmAAT genes were WGD/segmental and tandemly duplicated, respectively. Further comprehensive analyses of the expression profiles of GmAAT genes in various stages of vegetative and reproductive development showed that soybean AAT genes exhibited preferential or distinct expression patterns among different tissues. Overall, our study provides a framework for further analysis of the biological functions of AAT genes in either soybean or other crops. PMID:27148336

  14. The glycine deportation system and its pharmacological consequences☆

    PubMed Central

    Beyoğlu, Diren; Idle, Jeffrey R.

    2013-01-01

    The glycine deportation system is an essential component of glycine catabolism in man whereby 400 to 800 mg glycine per day are deported into urine as hippuric acid. The molecular escort for this deportation is benzoic acid, which derives from the diet and from gut microbiota metabolism of dietary precursors. Three components of this system, involving hepatic and renal metabolism, and renal active tubular secretion help regulate systemic and central nervous system levels of glycine. When glycine levels are pathologically high, as in congenital nonketotic hyperglycinemia, the glycine deportation system can be upregulated with pharmacological doses of benzoic acid to assist in normalization of glycine homeostasis. In congenital urea cycle enzymopathies, similar activation of the glycine deportation system with benzoic acid is useful for the excretion of excess nitrogen in the form of glycine. Drugs which can substitute for benzoic acid as substrates for the glycine deportation system have adverse reactions that may involve perturbations of glycine homeostasis. The cancer chemotherapeutic agent ifosfamide has an unacceptably high incidence of encephalopathy. This would appear to arise as a result of the production of toxic aldehyde metabolites which deplete ATP production and sequester NADH in the mitochondrial matrix, thereby inhibiting the glycine deportation system and causing de novo glycine synthesis by the glycine cleavage system. We hypothesize that this would result in hyperglycinemia and encephalopathy. This understanding may lead to novel prophylactic strategies for ifosfamide encephalopathy. Thus, the glycine deportation system plays multiple key roles in physiological and neurotoxicological processes involving glycine. PMID:22584143

  15. Growth performance of 20- to 50-kilogram pigs fed low-crude-protein diets supplemented with histidine, cystine, glycine, glutamic acid, or arginine.

    PubMed

    Powell, S; Bidner, T D; Payne, R L; Southern, L L

    2011-11-01

    The purpose of this investigation was to compare the growth performance of grower pigs fed low-CP, corn-soybean meal (C-SBM) AA-supplemented diets with that of pigs fed a positive control (PC) C-SBM diet with no supplemental Lys. Five experiments were conducted with Yorkshire crossbred pigs, blocked by BW (average initial and final BW were 21 and 41 kg, respectively) and assigned within block to treatment. Each treatment was replicated 4 to 6 times with 4 or 5 pigs per replicate pen. Each experiment lasted 28 d and plasma urea N was determined at the start and end of each experiment. All diets were formulated to contain 0.83% standardized ileal digestible Lys. All the experiments contained PC and negative control (NC) diets. The PC diet contained 18% CP and was supplemented with only DL-Met. The NC diet contained 13% CP and was supplemented with L-Lys, DL-Met, L-Thr, and L-Trp. The NC + Ile + Val diet was supplemented with 0.10% Val + 0.06% Ile. The NC + Ile + Val diet was supplemented with either His (Exp. 1), Cys (Exp. 2), Gly (Exp. 2, 3, and 4), Glu (Exp. 3), Arg (Exp. 4), or combinations of Gly + Arg (Exp. 4 and 5) or Gly + Glu (Exp. 5). Treatment differences were considered significant at P < 0.10. In 3 of the 4 experiments that had PC and NC diets, pigs fed the NC diet had decreased ADG and G:F compared with pigs fed the PC diet. The supplementation of Ile + Val to the NC diet restored ADG in 4 out of 5 experiments. However, G:F was less than in pigs fed the PC diet in 1 experiment and was intermediate between the NC and PC diets in 3 experiments. Pigs fed supplemental Ile + Val + His had decreased G:F compared with pigs fed the PC. Pigs fed supplemental Cys to achieve 50:50 Met:Cys had decreased G:F compared with pigs fed the PC. Pigs fed Ile + Val + 0.224% supplemental Gly had similar ADG, greater ADFI, and decreased G:F compared with pigs fed the PC. Pigs fed Ile + Val + 0.52% supplemental Gly had ADG and G:F similar to that of pigs fed the PC. Pigs fed supplemental Glu had decreased G:F compared with pigs fed the PC. Pigs fed Ile + Val + 0.48% supplemental Arg had decreased G:F compared with pigs fed the PC. Pigs fed the diet supplemented with Gly + Arg had ADG and G:F similar to pigs fed the PC. Pigs fed the low-CP diets had reduced plasma urea N compared with pigs fed PC. The results of these experiments indicate that supplementing Gly or Gly + Arg to a low-CP C-SBM diet with 0.34% Lys, Met, Thr, Trp, Ile, and Val restores growth performance to be similar to that of pigs fed a PC diet with no Lys supplementation.

  16. Modification of photosynthetic electron transport and amino acid levels by overexpression of a circadian-related histidine kinase hik8 in Synechocystis sp. PCC 6803

    PubMed Central

    Kuwahara, Ayuko; Arisaka, Satomi; Takeya, Masahiro; Iijima, Hiroko; Hirai, Masami Yokota; Osanai, Takashi

    2015-01-01

    Cyanobacteria perform oxygenic photosynthesis, and the maintenance of photosynthetic electron transport chains is indispensable to their survival in various environmental conditions. Photosynthetic electron transport in cyanobacteria can be studied through genetic analysis because of the natural competence of cyanobacteria. We here show that a strain overexpressing hik8, a histidine kinase gene related to the circadian clock, exhibits an altered photosynthetic electron transport chain in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Respiratory activity was down-regulated under nitrogen-replete conditions. Photosynthetic activity was slightly lower in the hik8-overexpressing strain than in the wild-type after nitrogen depletion, and the values of photosynthetic parameters were altered by hik8 overexpression under nitrogen-replete and nitrogen-depleted conditions. Transcripts of genes encoding Photosystem I and II were increased by hik8 overexpression under nitrogen-replete conditions. Nitrogen starvation triggers increase in amino acids but the magnitude of the increase in several amino acids was diminished by hik8 overexpression. These genetic data indicate that Hik8 regulates the photosynthetic electron transport, which in turn alters primary metabolism during nitrogen starvation in this cyanobacterium. PMID:26539179

  17. Propofol differentially inhibits the release of glutamate, γ-aminobutyric acid and glycine in the spinal dorsal horn of rats

    PubMed Central

    Yang, Jing; Wang, Wei; Yong, Zheng; Mi, Weidong; Zhang, Hong

    2015-01-01

    Objective(s): Propofol (2, 6-diisopropylphenol) is an intravenous anesthetic that is commonly used for the general anesthesia. It is well known that the spinal cord is one of the working targets of general anesthesia including propofol. However, there is a lack of investigation of the effects of propofol on spinal dorsal horn which is important for the sensory transmission of nociceptive signals. The objective of this study was to investigate the effects of increasing dosage of propofol on the release of glutamate (Glu), γ-aminobutyric acid (GABA) and glycine (Gly) in the spinal dorsal horn. Materials and Methods: The efflux of Glu, GABA or Gly in the spinal dorsal horn of rats was detected using transverse spinal microdialysis under an awake condition and various depths of propofol anesthesia. The infusion rates of propofol were, in order, 400 µg/(kg·min), 600 µg/(kg·min) and 800 µg/(kg·min), with a 20 min infusion period being maintained at each infusion rate. Results: Propofol decreased the glutamate efflux within spinal dorsal horn in a dose-dependent manner, and the maximum decrease was 56.8 ± 6.0% at high-dose propofol infusion producing immobility. The inhibitory GABA and Gly efflux was also decreased about 15–20% at low-dose propofol infusion only producing sedation, but did not continue to drop with higher doses of propofol. Conclusion: Propofol decreased both excitatory and inhibitory amino acids efflux in spinal dorsal horn, and the preferential suppression of the excitatory amino acid might be associated with the analgesic effect of propofol. PMID:26557972

  18. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 3: Michael addition reactions and miscellaneous transformations.

    PubMed

    Aceña, José Luis; Sorochinsky, Alexander E; Soloshonok, Vadim

    2014-09-01

    The major goal of this review is a critical discussion of the literature data on asymmetric synthesis of α-amino acids via Michael addition reactions involving Ni(II)-complexes of amino acids. The material covered is divided into two conceptually different groups dealing with applications of: (a) Ni(II)-complexes of glycine as C-nucleophiles and (b) Ni(II)-complexes of dehydroalanine as Michael acceptors. The first group is significantly larger and consequently subdivided into four chapters based on the source of stereocontrolling element. Thus, a chiral auxiliary can be used as a part of nucleophilic glycine Ni(II) complex, Michael acceptor or both, leading to the conditions of matching vs. mismatching stereochemical preferences. The particular focus of the review is made on the practical aspects of the methodology under discussion and mechanistic considerations.

  19. Incorporation of glycine-2-C-14 in acid-insoluble proteins of rat bones and teeth during hypokinesia and administration of thyrocalcitonine

    NASA Technical Reports Server (NTRS)

    Volozhin, A. I.; Stekolnikov, L. I.; Uglova, N. N.; Potkin, V. Y.

    1979-01-01

    A forced limitation of the motor activity in rats (from 5 to 60 days) results in reduced incorporation of glycine 2-C14 in the total acid insoluble proteins of limb bones and its increase in the teeth and mandibular-maxillary bones. Daily administration of five micrograms of thyrocalcitonine together with polyvinylpyrrolidone normalizes the protein metabolism in the bone tissues during the 40 days of experimentation.

  20. Combination of cathodic reduction with adsorption for accelerated removal of Cr(VI) through reticulated vitreous carbon electrodes modified with sulfuric acid-glycine co-doped polyaniline.

    PubMed

    Mo, Xi; Yang, Zhao-hui; Xu, Hai-yin; Zeng, Guang-ming; Huang, Jing; Yang, Xia; Song, Pei-pei; Wang, Li-ke

    2015-04-01

    Improving the reduction kinetics is crucial in the electroreduction process of Cr(VI). In this study, we developed a novel adsorption-electroreduction system for accelerated removal of Cr(VI) by employing reticulated vitreous carbon electrode modified with sulfuric acid-glycine co-doped polyaniline (RVC/PANI-SA-GLY). Firstly, response surface methodology confirmed the optimum polymerization condition of co-doped polyaniline for modifying electrodes (Aniline, sulfuric acid and glycine, respectively, of 0.2 mol/L, 0.85 mol/L, 0.93 mol/L) when untraditional dopant glycine was added. Subsequently, RVC/PANI-SA-GLY showed higher Cr(VI) removal percentages in electroreduction experiments over RVC electrode modified with sulfuric acid doped polyaniline (RVC/PANI-SA) and bare RVC electrode. In contrast to RVC/PANI-SA, the improvement by RVC/PANI-SA-GLY was more significant and especially obvious at more negative potential, lower initial Cr(VI) concentration, relatively less acidic solution and higher current densities, best achieving 7.84% higher removal efficiency with entire Cr(VI) eliminated after 900 s. Current efficiencies were likewise enhanced by RVC/PANI-SA-GLY under quite negative potentials. Fourier transform infrared (FTIR) and energy dispersive spectrometer (EDS) analysis revealed a possible adsorption-reduction mechanism of RVC/PANI-SA-GLY, which greatly contributed to the faster reduction kinetics and was probably relative to the absorption between protonated amine groups of glycine and HCrO4(-). Eventually, the stability of RVC/PANI-SA-GLY was proven relatively satisfactory.

  1. Identification of a highly conserved valine-glycine-phenylalanine amino acid triplet required for HIV-1 Nef function

    PubMed Central

    2012-01-01

    Background The Nef protein of HIV facilitates virus replication and disease progression in infected patients. This role as pathogenesis factor depends on several genetically separable Nef functions that are mediated by interactions of highly conserved protein-protein interaction motifs with different host cell proteins. By studying the functionality of a series of nef alleles from clinical isolates, we identified a dysfunctional HIV group O Nef in which a highly conserved valine-glycine-phenylalanine (VGF) region, which links a preceding acidic cluster with the following proline-rich motif into an amphipathic surface was deleted. In this study, we aimed to study the functional importance of this VGF region. Results The dysfunctional HIV group O8 nef allele was restored to the consensus sequence, and mutants of canonical (NL4.3, NA-7, SF2) and non-canonical (B2 and C1422) HIV-1 group M nef alleles were generated in which the amino acids of the VGF region were changed into alanines (VGF→AAA) and tested for their capacity to interfere with surface receptor trafficking, signal transduction and enhancement of viral replication and infectivity. We found the VGF motif, and each individual amino acid of this motif, to be critical for downregulation of MHC-I and CXCR4. Moreover, Nef’s association with the cellular p21-activated kinase 2 (PAK2), the resulting deregulation of cofilin and inhibition of host cell actin remodeling, and targeting of Lck kinase to the trans-golgi-network (TGN) were affected as well. Of particular interest, VGF integrity was essential for Nef-mediated enhancement of HIV virion infectivity and HIV replication in peripheral blood lymphocytes. For targeting of Lck kinase to the TGN and viral infectivity, especially the phenylalanine of the triplet was essential. At the molecular level, the VGF motif was required for the physical interaction of the adjacent proline-rich motif with Hck. Conclusion Based on these findings, we propose that this highly

  2. N-Acetylglucosaminidases from CAZy Family GH3 Are Really Glycoside Phosphorylases, Thereby Explaining Their Use of Histidine as an Acid/Base Catalyst in Place of Glutamic Acid*

    PubMed Central

    Macdonald, Spencer S.; Blaukopf, Markus; Withers, Stephen G.

    2015-01-01

    CAZy glycoside hydrolase family GH3 consists primarily of stereochemistry-retaining β-glucosidases but also contains a subfamily of β-N-acetylglucosaminidases. Enzymes from this subfamily were recently shown to use a histidine residue within a His-Asp dyad contained in a signature sequence as their catalytic acid/base residue. Reasons for their use of His rather than the Glu or Asp found in other glycosidases were not apparent. Through studies on a representative member, the Nag3 β-N-acetylglucosaminidase from Cellulomonas fimi, we now show that these enzymes act preferentially as glycoside phosphorylases. Their need to accommodate an anionic nucleophile within the enzyme active site explains why histidine is used as an acid/base catalyst in place of the anionic glutamate seen in other GH3 family members. Kinetic and mechanistic studies reveal that these enzymes also employ a double-displacement mechanism involving a covalent glycosyl-enzyme intermediate, which was directly detected by mass spectrometry. Phosphate has no effect on the rates of formation of the glycosyl-enzyme intermediate, but it accelerates turnover of the N-acetylglucosaminyl-enzyme intermediate ∼3-fold, while accelerating turnover of the glucosyl-enzyme intermediate several hundredfold. These represent the first reported examples of retaining β-glycoside phosphorylases, and the first instance of free β-GlcNAc-1-phosphate in a biological context. PMID:25533455

  3. N-acetylglucosaminidases from CAZy family GH3 are really glycoside phosphorylases, thereby explaining their use of histidine as an acid/base catalyst in place of glutamic acid.

    PubMed

    Macdonald, Spencer S; Blaukopf, Markus; Withers, Stephen G

    2015-02-20

    CAZy glycoside hydrolase family GH3 consists primarily of stereochemistry-retaining β-glucosidases but also contains a subfamily of β-N-acetylglucosaminidases. Enzymes from this subfamily were recently shown to use a histidine residue within a His-Asp dyad contained in a signature sequence as their catalytic acid/base residue. Reasons for their use of His rather than the Glu or Asp found in other glycosidases were not apparent. Through studies on a representative member, the Nag3 β-N-acetylglucosaminidase from Cellulomonas fimi, we now show that these enzymes act preferentially as glycoside phosphorylases. Their need to accommodate an anionic nucleophile within the enzyme active site explains why histidine is used as an acid/base catalyst in place of the anionic glutamate seen in other GH3 family members. Kinetic and mechanistic studies reveal that these enzymes also employ a double-displacement mechanism involving a covalent glycosyl-enzyme intermediate, which was directly detected by mass spectrometry. Phosphate has no effect on the rates of formation of the glycosyl-enzyme intermediate, but it accelerates turnover of the N-acetylglucosaminyl-enzyme intermediate ∼3-fold, while accelerating turnover of the glucosyl-enzyme intermediate several hundredfold. These represent the first reported examples of retaining β-glycoside phosphorylases, and the first instance of free β-GlcNAc-1-phosphate in a biological context.

  4. Acidic pH retards the fibrillization of human islet amyloid polypeptide due to electrostatic repulsion of histidines

    NASA Astrophysics Data System (ADS)

    Li, Yang; Xu, Weixin; Mu, Yuguang; Zhang, John Z. H.

    2013-08-01

    The human Islet Amyloid Polypeptide (hIAPP) is the major constituent of amyloid deposits in pancreatic islets of type-II diabetes. IAPP is secreted together with insulin from the acidic secretory granules at a low pH of approximately 5.5 to the extracellular environment at a neutral pH. The increased accumulation of extracellular hIAPP in diabetes indicates that changes in pH may promote amyloid formation. To gain insights and underlying mechanisms of the pH effect on hIAPP fibrillogenesis, all-atom molecular dynamics simulations in explicit solvent model were performed to study the structural properties of five hIAPP protofibrillar oligomers, under acidic and neutral pH, respectively. In consistent with experimental findings, simulation results show that acidic pH is not conducive to the structural stability of these oligomers. This provides a direct evidence for a recent experiment [L. Khemtemourian, E. Domenech, J. P. F. Doux, M. C. Koorengevel, and J. A. Killian, J. Am. Chem. Soc. 133, 15598 (2011)], 10.1021/ja205007j, which suggests that acidic pH inhibits the fibril formation of hIAPP. In addition, a complementary coarse-grained simulation shows the repulsive electrostatic interactions among charged His18 residues slow down the dimerization process of hIAPP by twofold. Besides, our all-atom simulations reveal acidic pH mainly affects the local structure around residue His18 by destroying the surrounding hydrogen-bonding network, due to the repulsive interactions between protonated interchain His18 residues at acidic pH. It is also disclosed that the local interactions nearby His18 operating between adjacent β-strands trigger the structural transition, which gives hints to the experimental findings that the rate of hIAPP fibril formation and the morphologies of the fibrillar structures are strongly pH-dependent.

  5. The interaction of salicylic acid and Ca(2+) alleviates aluminum toxicity in soybean (Glycine max L.).

    PubMed

    Lan, Tu; You, Jiangfeng; Kong, Lingnan; Yu, Miao; Liu, Minghui; Yang, Zhenming

    2016-01-01

    Both calcium ion (Ca(2+)) and salicylic acid (SA) influence various stress responses in plants. In acidic soils, aluminum (Al) toxicity adversely affects crop yield. In this study, we determined the influences of Ca(2+) and SA on root elongation, Al accumulation, and citrate secretion in soybean plant. We also investigated the activity of antioxidative enzymes in Al-exposed soybean roots. Root elongation was severally inhibited when the roots were exposed to 30 μM Al. The Al-induced inhibition of root elongation was ameliorated by Ca(2+) and SA but aggravated by Ca(2+) channel inhibitor (VP), CaM antagonists (TFP), Ca(2+) chelator (EGTA), and SA biosynthesis inhibitor (PAC). Furthermore, 1.0 mM CaCl2 and 10 μM SA reduced the accumulation of Al in roots, but their inhibitors stimulated the accumulation of Al in roots. Citrate secretion from these roots increased with the addition of either 1.0 mM CaCl2 or 10 μM SA but did not increase significantly when treated with higher Ca(2+) concentration. Enzymatic analysis showed that Ca(2+) and SA stimulated the activities of superoxidase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in Al-treated roots. In addition, SA restored the inhibition of Ca(2+) inhibitors on root elongation and Al content. Thus, both Ca(2+) and SA contribute to Al tolerance in soybean. Furthermore, Ca(2+) supplements rapidly increased Al-induced accumulation of free-SA or conjugated SA (SAG), while Ca(2+) inhibitors delayed the accumulation of SA for more than 8 h. Within 4 h of treatment, SA increased cytosolic Ca(2+) concentration in Al-treated roots, and upregulated the expression of four genes that possibly encode calmodulin-like (CML) proteins. These findings indicate that SA is involved in Ca(2+)-mediated signal transduction pathways in Al tolerance.

  6. Catalysis of peptide bond formation by histidyl-histidine in a fluctuating clay environment

    NASA Technical Reports Server (NTRS)

    White, D. H.; Erickson, J. C.

    1980-01-01

    The condensation of glycine to form oligoglycines during wet-dry fluctuations on clay surfaces was enhanced up to threefold or greater by small amounts of histidyl-histidine. In addition, higher relative yields of the longer oligomers were produced. Other specific dipeptides tested gave no enhancement, and imidazole, histidine, and N-acetylhistidine gave only slight enhancements. Histidyl-histidine apparently acts as a true catalyst (in the sense of repeatedly catalyzing the reaction), since up to 52 nmol of additional glycine were incorporated into oligoglycine for each nmol of catalyst added. This is the first known instance of a peptide or similar molecule demonstrating a catalytic turnover number greater than unity in a prebiotic oligomer synthesis reaction, and suggests that histidyl-histidine is a model for a primitive prebiotic proto-enzyme. Catalysis of peptide bond synthesis by a molecule which is itself a peptide implies that related systems may be capable of exhibiting autocatalytic growth.

  7. Jasmonic Acid Modulates the Physio-Biochemical Attributes, Antioxidant Enzyme Activity, and Gene Expression in Glycine max under Nickel Toxicity.

    PubMed

    Sirhindi, Geetika; Mir, Mudaser Ahmad; Abd-Allah, Elsayed Fathi; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    In present study, we evaluated the effects of Jasmonic acid (JA) on physio-biochemical attributes, antioxidant enzyme activity, and gene expression in soybean (Glycine max L.) plants subjected to nickel (Ni) stress. Ni stress decreases the shoot and root length and chlorophyll content by 37.23, 38.31, and 39.21%, respectively, over the control. However, application of JA was found to improve the chlorophyll content and length of shoot and root of Ni-fed seedlings. Plants supplemented with JA restores the chlorophyll fluorescence, which was disturbed by Ni stress. The present study demonstrated increase in proline, glycinebetaine, total protein, and total soluble sugar (TSS) by 33.09, 51.26, 22.58, and 49.15%, respectively, under Ni toxicity over the control. Addition of JA to Ni stressed plants further enhanced the above parameters. Ni stress increases hydrogen peroxide (H2O2) by 68.49%, lipid peroxidation (MDA) by 50.57% and NADPH oxidase by 50.92% over the control. Supplementation of JA minimizes the accumulation of H2O2, MDA, and NADPH oxidase, which helps in stabilization of biomolecules. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) increases by 40.04, 28.22, 48.53, and 56.79%, respectively, over the control in Ni treated seedlings and further enhancement in the antioxidant activity was observed by the application of JA. Ni treated soybean seedlings showed increase in expression of Fe-SOD by 77.62, CAT by 15.25, POD by 58.33, and APX by 80.58% over the control. Nevertheless, application of JA further enhanced the expression of the above genes in the present study. Our results signified that Ni stress caused negative impacts on soybean seedlings, but, co-application of JA facilitate the seedlings to combat the detrimental effects of Ni through enhanced osmolytes, activity of antioxidant enzymes and gene expression.

  8. Asparagine and glycine metabolism in rat liver mitochondria and in mouse L5178Y lymphoma cells resistant or sensitive to the anticancer drug L-asparaginase

    SciTech Connect

    Keefer, J.F. Jr.

    1986-01-01

    Rat liver mitochondrial asparagine was found to be degraded via an aminotransferase and omega-amidase. Evidence includes oxaloacetate production from asparagine only when glyoxylate was added and production of radiolabeled ..cap alpha..-ketosuccinamate via metabolism of (U-/sup 14/C)asparagine. In the cytosol, asparagine is degraded primarily via asparaginase and subsequent transamination. A new HPLC technique for separation of citric acid cycle intermediates was developed using: ion pairing with 20 mM each to tetrabutylammonium hydroxide and Na/sub 2/SO/sub 4/; pH 7.0; isocratic elution; and detection at 210 nm. Amino acid content of mouse lymphoma cells either sensitive (L5178Y) or resistant (L5178Y/L-ASE) to the anticancer drug L-asparaginase was studied. The concentration of asparagine was 1.5 times higher and the concentrations of the essential amino acids histidine, methionine, valine and phenylalanine were two times higher in asparaginase-resistant than sensitive cells. In vivo but not in vitro studies indicated that glucine decreases in sensitive but not resistant cells upon asparaginase treatment. Asparagine and glycine metabolism was further studied using /sup 14/C radiolabel conversion of asparagine, glyoxylate, glycine and serine. Glycine metabolism is especially important in lymphomas and leukemias because these cells contain higher concentrations of glycine that other cancer and normal cells. Therefore, glycine levels were studied and were found to decrease in sensitive but not resistant cells upon asparaginase administration.

  9. Biochemical effect of a histidine phosphatase acid (phytase) of Aspergillus japonicus var. Saito on performance and bony characteristics of broiler.

    PubMed

    Maller, Alexandre; de Quadros, Thays Cristina Oliveira; Junqueira, Otto M; Graña, Alfredo Lora; de Lima Montaldi, Ana Paula; Alarcon, Ricardo Fernandes; Jorge, João Atílio; de Lourdes T M Polizeli, Maria

    2016-01-01

    Phytases are enzymes that hydrolyze the ester linkage of phytic acid, releasing inositol and inorganic phosphate. The phytic acid (phytate) is a major form of phosphorus in plant foods. Knowing that diet for animal of production has the cereal base (corn and soybean), primarily, broilers need for an alternative to use of the phosphate present in these ingredients, since it does not naturally produce the enzyme phytase, which makes it available. The aims of this work was studding the safe supplementation of Aspergillus japonicus var. Saito crude phytase in feeding broilers and check the biochemical effect on performance and bones of these animals. The enzymatic extract did not have aflatoxins B1, B2, G2 and G1 and zearalenone and ochratoxin, and low concentrations of this extract did not have cytotoxic effects on cells derived from lung tissue. The in vivo experiments showed that the phytase supplied the available phosphate reduction in the broiler feed formulation, with a live weight, weight gain, feed intake, feed conversion, viability, productive efficiency index and carcass yield similar to the control test. Furthermore, the phytase supplementation favored the formation of bone structure and performance of the broilers. The results show the high biotechnological potential of A. japonicus phytase on broiler food supplementation to reduce phosphorus addition in the food formulation. So, this enzyme could be used as a commercial alternative to animal diet supplementation.

  10. Biochemical effect of a histidine phosphatase acid (phytase) of Aspergillus japonicus var. Saito on performance and bony characteristics of broiler.

    PubMed

    Maller, Alexandre; de Quadros, Thays Cristina Oliveira; Junqueira, Otto M; Graña, Alfredo Lora; de Lima Montaldi, Ana Paula; Alarcon, Ricardo Fernandes; Jorge, João Atílio; de Lourdes T M Polizeli, Maria

    2016-01-01

    Phytases are enzymes that hydrolyze the ester linkage of phytic acid, releasing inositol and inorganic phosphate. The phytic acid (phytate) is a major form of phosphorus in plant foods. Knowing that diet for animal of production has the cereal base (corn and soybean), primarily, broilers need for an alternative to use of the phosphate present in these ingredients, since it does not naturally produce the enzyme phytase, which makes it available. The aims of this work was studding the safe supplementation of Aspergillus japonicus var. Saito crude phytase in feeding broilers and check the biochemical effect on performance and bones of these animals. The enzymatic extract did not have aflatoxins B1, B2, G2 and G1 and zearalenone and ochratoxin, and low concentrations of this extract did not have cytotoxic effects on cells derived from lung tissue. The in vivo experiments showed that the phytase supplied the available phosphate reduction in the broiler feed formulation, with a live weight, weight gain, feed intake, feed conversion, viability, productive efficiency index and carcass yield similar to the control test. Furthermore, the phytase supplementation favored the formation of bone structure and performance of the broilers. The results show the high biotechnological potential of A. japonicus phytase on broiler food supplementation to reduce phosphorus addition in the food formulation. So, this enzyme could be used as a commercial alternative to animal diet supplementation. PMID:27625972

  11. Synthetic Cyclolipopeptides Selective against Microbial, Plant and Animal Cell Targets by Incorporation of D-Amino Acids or Histidine

    PubMed Central

    Vilà, Sílvia; Badosa, Esther; Montesinos, Emilio; Planas, Marta; Feliu, Lidia

    2016-01-01

    Cyclolipopeptides derived from the antimicrobial peptide c(Lys-Lys-Leu-Lys-Lys-Phe-Lys-Lys-Leu-Gln) (BPC194) were prepared on solid-phase and screened against four plant pathogens. The incorporation at Lys5 of fatty acids of 4 to 9 carbon atoms led to active cyclolipopeptides. The influence on the antimicrobial activity of the Lys residue that is derivatized was also evaluated. In general, acylation of Lys1, Lys2 or Lys5 rendered the sequences with the highest activity. Incorporation of a D-amino acid maintained the antimicrobial activity while significantly reduced the hemolysis. Replacement of Phe with a His also yielded cyclolipopeptides with low hemolytic activity. Derivatives exhibiting low phytotoxicity in tobacco leaves were also found. Interestingly, sequences with or without significant activity against phytopathogenic bacteria and fungi, but with differential hemolysis and phytotoxicity were identified. Therefore, this study represents an approach to the development of bioactive peptides with selective activity against microbial, plant and animal cell targets. These selective cyclolipopeptides are candidates useful not only to combat plant pathogens but also to be applied in other fields. PMID:27008420

  12. Histidine-40 of ribonuclease T1 acts as base catalyst when the true catalytic base, glutamic acid-58, is replaced by alanine.

    PubMed

    Steyaert, J; Hallenga, K; Wyns, L; Stanssens, P

    1990-09-25

    Mechanisms for the ribonuclease T1 (RNase T1; EC 3.1.27.3) catalyzed transesterification reaction generally include the proposal that Glu58 and His92 provide general base and general acid assistance, respectively [Heinemann, U., & Saenger, W. (1982) Nature (London) 299, 27-31]. This view was recently challenged by the observation that mutants substituted at position 58 retain high residual activity; a revised mechanism was proposed in which His40, and not Glu58, is engaged in catalysis as general base [Nishikawa, S., Morioka, H., Kim, H., Fuchimura, K., Tanaka, T., Uesugi, S., Hakoshima, T., Tomita, K., Ohtsuka, E., & Ikehara, M. (1987) Biochemistry 26, 8620-8624]. To clarify the functional roles of His40, Glu58, and His92, we analyzed the consequences of several amino acid substitutions (His40Ala, His40Lys, His40Asp, Glu58Ala, Glu58Gln, and His92Gln) on the kinetics of GpC transesterification. The dominant effect of all mutations is on Kcat, implicating His40, Glu58, and His92 in catalysis rather than in substrate binding. Plots of log (Kcat/Km) vs pH for wild-type, His40Lys, and Glu58Ala RNase T1, together with the NMR-determined pKa values of the histidines of these enzymes, strongly support the view that Glu58-His92 acts as the base-acid couple. The curves also show that His40 is required in its protonated form for optimal activity of wild-type enzyme. We propose that the charged His40 participates in electrostatic stabilization of the transition state; the magnitude of the catalytic defect (a factor of 2000) from the His40 to Ala replacement suggests that electrostatic catalysis contributes considerably to the overall rate acceleration. For Glu58Ala RNase T1, the pH dependence of the catalytic parameters suggests an altered mechanism in which His40 and His92 act as base and acid catalyst, respectively. The ability of His40 to adopt the function of general base must account for the significant activity remaining in Glu58-mutated enzymes.

  13. Laboratory simulation of ultraviolet irradiation from the Sun on amino acids. III. irradiation of glycine-tyrosine

    NASA Astrophysics Data System (ADS)

    Scappini, F.; Capobianco, M. L.; Casadei, F.; Zamboni, R.

    2009-04-01

    The effects of near ultraviolet (UV) radiation on water solutions of tyrosine and glycine-tyrosine are investigated using a broadband xenon lamp in the region 200-800 nm. These experiments form a contribution in the laboratory simulation of the solar irradiation on the building blocks of life with regard to the origin of life. Results are presented showing the photodecomposition of tyrosine and glycine-tyrosine, at different concentrations, against UV doses. The analysis of the irradiated solutions is carried out by spectroscopic and analytical techniques. The findings of our laboratory simulations are used to constrain the early stages of the life emerging process.

  14. Histidine-functionalized water-soluble nanoparticles for biomimetic nucleophilic/general-base catalysis under acidic conditions.

    PubMed

    Chadha, Geetika; Zhao, Yan

    2013-10-21

    Cross-linking the micelles of 4-dodecyloxybenzyltripropargylammonium bromide by 1,4-diazidobutane-2,3-diol in the presence of azide-functionalized imidazole derivatives yielded surface-cross-linked micelles (SCMs) with imidazole groups on the surface. The resulting water-soluble nanoparticles were found, by fluorescence spectroscopy, to contain hydrophobic binding sites. The imidazole groups promoted the photo-deprotonation of 2-naphthol at pH 6 and catalyzed the hydrolysis of p-nitrophenylacetate (PNPA) in aqueous solution at pH ≥ 4. Although the overall hydrolysis rate slowed down with decreasing solution pH, the catalytic effect of the imidazole became stronger because the reactions catalyzed by unfunctionalized SCMs slowed down much more. The unusual ability of the imidazole–SCMs to catalyze the hydrolysis of PNPA under acidic conditions was attributed to the local hydrophobicity and the positive nature of the SCMs.

  15. Impact of combined resistance and aerobic exercise training on branched-chain amino acid turnover, glycine metabolism and insulin sensitivity in overweight humans

    PubMed Central

    Glynn, Erin L.; Piner, Lucy W.; Huffman, Kim M.; Slentz, Cris A.; Elliot-Penry, Lorraine; AbouAssi, Hiba; White, Phillip J.; Bain, James R.; Muehlbauer, Michael J.; Ilkayeva, Olga R.; Stevens, Robert D.; Porter Starr, Kathryn N.; Bales, Connie W.; Volpi, Elena; Brosnan, M. Julia; Trimmer, Jeff K.; Rolph, Timothy P.

    2016-01-01

    Aims/hypotheses Obesity is associated with decreased insulin sensitivity (IS) and elevated plasma branched-chain amino acids (BCAAs). The purpose of this study was to investigate the relationship between BCAA metabolism and IS in overweight (OW) individuals during exercise intervention. Methods Whole-body leucine turnover, IS by hyperinsulinaemic–euglycaemic clamp, and circulating and skeletal muscle amino acids, branched-chain α-keto acids and acylcarnitines were measured in ten healthy controls (Control) and nine OW, untrained, insulin-resistant individuals (OW-Untrained). OW-Untrained then underwent a 6 month aerobic and resistance exercise programme and repeated testing (OW-Trained). Results IS was higher in Control vs OW-Untrained and increased significantly following exercise. IS was lower in OW-Trained vs Control expressed relative to body mass, but was not different from Control when normalised to fat-free mass (FFM). Plasma BCAAs and leucine turnover (relative to FFM) were higher in OW-Untrained vs Control, but did not change on average with exercise. Despite this, within individuals, the decrease in molar sum of circulating BCAAs was the best metabolic predictor of improvement in IS. Circulating glycine levels were higher in Control and OW-Trained vs OW-Untrained, and urinary metabolic profiling suggests that exercise induces more efficient elimination of excess acyl groups derived from BCAA and aromatic amino acid (AA) metabolism via formation of urinary glycine adducts. Conclusions/interpretation A mechanism involving more efficient elimination of excess acyl groups derived from BCAA and aromatic AA metabolism via glycine conjugation in the liver, rather than increased BCAA disposal through oxidation and turnover, may mediate interactions between exercise, BCAA metabolism and IS. Trial registration Clinicaltrials.gov NCT01786941 PMID:26254576

  16. Acid-base properties and copper(II) complexes of dipeptides containing histidine and additional chelating bis(imidazol-2-yl) residues.

    PubMed

    Osz, Katalin; Várnagy, Katalin; Süli-Vargha, Helga; Csámpay, Antal; Sanna, Daniele; Micera, Giovanni; Sóvágó, Imre

    2004-01-01

    Copper(II) complexes of dipeptides of histidine containing additional chelating bis(imidazol-2-yl) agent at the C-termini (PheHis-BIMA [N-phenylalanyl-histidyl-bis(imidazol-2-yl)methylamine] and HisPhe-BIMA [N-histidyl-phenylalanyl-bis(imidazol-2-yl)methylamine]) were studied by potentiometric, UV-Visible and Electron Paramagnetic Resonance (EPR) techniques. The imidazole nitrogen donor atoms of the bis(imidazol-2-yl)methyl group are described as the primary metal binding sites forming stable mono- and bis(ligand) complexes at acidic pH. The formation of a ligand-bridged dinuclear complex [Cu2L2]4+ is detected in equimolar solutions of copper(II) and HisPhe-BIMA. The coordination isomers of the dinuclear complex are described via the metal binding of the bis(imidazol-2-yl)methyl, amino-carbonyl and amino-imidazole(His) functions. In the case of the copper(II)-PheHis-BIMA system the [NH2, N-(amide), N(Im)] tridentate coordination of the ligand is favoured and results in the formation of di- and trinuclear complexes [Cu2H(-1)L]3+ and [Cu3H(-2)L2]4+ in equimolar solutions. The presence of these coordination modes shifts the formation of "tripeptide-like" ([NH2, N-, N-, N(Im)]-coordinated) [CuH(-2)L] complexes into alkaline pH range as compared to other dipeptide derivatives of bis(imidazol-2-yl) ligands. Although there are different types of imidazoles in these ligands, the deprotonation and coordination of the pyrrole-type N(1)H groups does not occur below pH 10. PMID:14659629

  17. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases; Part 1: alkyl halide alkylations.

    PubMed

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim A

    2013-10-01

    Alkylations of chiral or achiral Ni(II) complexes of glycine Schiff bases constitute a landmark in the development of practical methodology for asymmetric synthesis of α-amino acids. Straightforward, easy preparation as well as high reactivity of these Ni(II) complexes render them ready available and inexpensive glycine equivalents for preparing a wide variety of α-amino acids, in particular on a relatively large scale. In the case of Ni(II) complexes containing benzylproline moiety as a chiral auxiliary, their alkylation proceeds with high thermodynamically controlled diastereoselectivity. Similar type of Ni(II) complexes derived from alanine can also be used for alkylation providing convenient access to quaternary, α,α-disubstituted α-amino acids. Achiral type of Ni(II) complexes can be prepared from picolinic acid or via recently developed modular approach using simple secondary or primary amines. These Ni(II) complexes can be easily mono/bis-alkylated under homogeneous or phase-transfer catalysis conditions. Origin of diastereo-/enantioselectivity in the alkylations reactions, aspects of practicality, generality and limitations of this methodology is critically discussed.

  18. Biological functions of histidine-dipeptides and metabolic syndrome.

    PubMed

    Song, Byeng Chun; Joo, Nam-Seok; Aldini, Giancarlo; Yeum, Kyung-Jin

    2014-02-01

    The rapid increase in the prevalence of metabolic syndrome, which is associated with a state of elevated systemic oxidative stress and inflammation, is expected to cause future increases in the prevalence of diabetes and cardiovascular diseases. Oxidation of polyunsaturated fatty acids and sugars produces reactive carbonyl species, which, due to their electrophilic nature, react with the nucleophilic sites of certain amino acids. This leads to formation of protein adducts such as advanced glycoxidation/lipoxidation end products (AGEs/ALEs), resulting in cellular dysfunction. Therefore, an effective reactive carbonyl species and AGEs/ALEs sequestering agent may be able to prevent such cellular dysfunction. There is accumulating evidence that histidine containing dipeptides such as carnosine (β-alanyl-L-histidine) and anserine (β-alanyl-methyl-L-histidine) detoxify cytotoxic reactive carbonyls by forming unreactive adducts and are able to reverse glycated protein. In this review, 1) reaction mechanism of oxidative stress and certain chronic diseases, 2) interrelation between oxidative stress and inflammation, 3) effective reactive carbonyl species and AGEs/ALEs sequestering actions of histidine-dipeptides and their metabolism, 4) effects of carnosinase encoding gene on the effectiveness of histidine-dipeptides, and 5) protective effects of histidine-dipeptides against progression of metabolic syndrome are discussed. Overall, this review highlights the potential beneficial effects of histidine-dipeptides against metabolic syndrome. Randomized controlled human studies may provide essential information regarding whether histidine-dipeptides attenuate metabolic syndrome in humans. PMID:24611099

  19. Jasmonic Acid Modulates the Physio-Biochemical Attributes, Antioxidant Enzyme Activity, and Gene Expression in Glycine max under Nickel Toxicity

    PubMed Central

    Sirhindi, Geetika; Mir, Mudaser Ahmad; Abd-Allah, Elsayed Fathi; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    In present study, we evaluated the effects of Jasmonic acid (JA) on physio-biochemical attributes, antioxidant enzyme activity, and gene expression in soybean (Glycine max L.) plants subjected to nickel (Ni) stress. Ni stress decreases the shoot and root length and chlorophyll content by 37.23, 38.31, and 39.21%, respectively, over the control. However, application of JA was found to improve the chlorophyll content and length of shoot and root of Ni-fed seedlings. Plants supplemented with JA restores the chlorophyll fluorescence, which was disturbed by Ni stress. The present study demonstrated increase in proline, glycinebetaine, total protein, and total soluble sugar (TSS) by 33.09, 51.26, 22.58, and 49.15%, respectively, under Ni toxicity over the control. Addition of JA to Ni stressed plants further enhanced the above parameters. Ni stress increases hydrogen peroxide (H2O2) by 68.49%, lipid peroxidation (MDA) by 50.57% and NADPH oxidase by 50.92% over the control. Supplementation of JA minimizes the accumulation of H2O2, MDA, and NADPH oxidase, which helps in stabilization of biomolecules. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) increases by 40.04, 28.22, 48.53, and 56.79%, respectively, over the control in Ni treated seedlings and further enhancement in the antioxidant activity was observed by the application of JA. Ni treated soybean seedlings showed increase in expression of Fe-SOD by 77.62, CAT by 15.25, POD by 58.33, and APX by 80.58% over the control. Nevertheless, application of JA further enhanced the expression of the above genes in the present study. Our results signified that Ni stress caused negative impacts on soybean seedlings, but, co-application of JA facilitate the seedlings to combat the detrimental effects of Ni through enhanced osmolytes, activity of antioxidant enzymes and gene expression. PMID:27242811

  20. Jasmonic Acid Modulates the Physio-Biochemical Attributes, Antioxidant Enzyme Activity, and Gene Expression in Glycine max under Nickel Toxicity.

    PubMed

    Sirhindi, Geetika; Mir, Mudaser Ahmad; Abd-Allah, Elsayed Fathi; Ahmad, Parvaiz; Gucel, Salih

    2016-01-01

    In present study, we evaluated the effects of Jasmonic acid (JA) on physio-biochemical attributes, antioxidant enzyme activity, and gene expression in soybean (Glycine max L.) plants subjected to nickel (Ni) stress. Ni stress decreases the shoot and root length and chlorophyll content by 37.23, 38.31, and 39.21%, respectively, over the control. However, application of JA was found to improve the chlorophyll content and length of shoot and root of Ni-fed seedlings. Plants supplemented with JA restores the chlorophyll fluorescence, which was disturbed by Ni stress. The present study demonstrated increase in proline, glycinebetaine, total protein, and total soluble sugar (TSS) by 33.09, 51.26, 22.58, and 49.15%, respectively, under Ni toxicity over the control. Addition of JA to Ni stressed plants further enhanced the above parameters. Ni stress increases hydrogen peroxide (H2O2) by 68.49%, lipid peroxidation (MDA) by 50.57% and NADPH oxidase by 50.92% over the control. Supplementation of JA minimizes the accumulation of H2O2, MDA, and NADPH oxidase, which helps in stabilization of biomolecules. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) increases by 40.04, 28.22, 48.53, and 56.79%, respectively, over the control in Ni treated seedlings and further enhancement in the antioxidant activity was observed by the application of JA. Ni treated soybean seedlings showed increase in expression of Fe-SOD by 77.62, CAT by 15.25, POD by 58.33, and APX by 80.58% over the control. Nevertheless, application of JA further enhanced the expression of the above genes in the present study. Our results signified that Ni stress caused negative impacts on soybean seedlings, but, co-application of JA facilitate the seedlings to combat the detrimental effects of Ni through enhanced osmolytes, activity of antioxidant enzymes and gene expression. PMID:27242811

  1. Visualizing autophosphorylation in histidine kinases.

    PubMed

    Casino, Patricia; Miguel-Romero, Laura; Marina, Alberto

    2014-01-01

    Reversible protein phosphorylation is the most widespread regulatory mechanism in signal transduction. Autophosphorylation in a dimeric sensor histidine kinase is the first step in two-component signalling, the predominant signal-transduction device in bacteria. Despite being the most abundant sensor kinases in nature, the molecular bases of the histidine kinase autophosphorylation mechanism are still unknown. Furthermore, it has been demonstrated that autophosphorylation can occur in two directions, cis (intrasubunit) or trans (intersubunit) within the dimeric histidine kinase. Here, we present the crystal structure of the complete catalytic machinery of a chimeric histidine kinase. The structure shows an asymmetric histidine kinase dimer where one subunit is caught performing the autophosphorylation reaction. A structure-guided functional analysis on HK853 and EnvZ, two prototypical cis- and trans-phosphorylating histidine kinases, has allowed us to decipher the catalytic mechanism of histidine kinase autophosphorylation, which seems to be common independently of the reaction directionality.

  2. Cyanobacteria produce N-(2-aminoethyl)glycine, a backbone for peptide nucleic acids which may have been the first genetic molecules for life on Earth.

    PubMed

    Banack, Sandra Anne; Metcalf, James S; Jiang, Liying; Craighead, Derek; Ilag, Leopold L; Cox, Paul Alan

    2012-01-01

    Prior to the evolution of DNA-based organisms on earth over 3.5 billion years ago it is hypothesized that RNA was the primary genetic molecule. Before RNA-based organisms arose, peptide nucleic acids may have been used to transmit genetic information by the earliest forms of life on earth. We discovered that cyanobacteria produce N-(2-aminoethyl)glycine (AEG), a backbone for peptide nucleic acids. We detected AEG in axenic strains of cyanobacteria with an average concentration of 1 µg/g. We also detected AEG in environmental samples of cyanobacteria as both a free or weakly bound molecule and a tightly bound form released by acid hydrolysis, at concentrations ranging from not detected to 34 µg/g. The production of AEG by diverse taxa of cyanobacteria suggests that AEG may be a primitive feature which arose early in the evolution of life on earth.

  3. Cyanobacteria Produce N-(2-Aminoethyl)Glycine, a Backbone for Peptide Nucleic Acids Which May Have Been the First Genetic Molecules for Life on Earth

    PubMed Central

    Banack, Sandra Anne; Metcalf, James S.; Jiang, Liying; Craighead, Derek; Ilag, Leopold L.; Cox, Paul Alan

    2012-01-01

    Prior to the evolution of DNA-based organisms on earth over 3.5 billion years ago it is hypothesized that RNA was the primary genetic molecule. Before RNA-based organisms arose, peptide nucleic acids may have been used to transmit genetic information by the earliest forms of life on earth. We discovered that cyanobacteria produce N-(2-aminoethyl)glycine (AEG), a backbone for peptide nucleic acids. We detected AEG in axenic strains of cyanobacteria with an average concentration of 1 µg/g. We also detected AEG in environmental samples of cyanobacteria as both a free or weakly bound molecule and a tightly bound form released by acid hydrolysis, at concentrations ranging from not detected to 34 µg/g. The production of AEG by diverse taxa of cyanobacteria suggests that AEG may be a primitive feature which arose early in the evolution of life on earth. PMID:23145061

  4. Evidence that three histidine residues of a base non-specific and adenylic acid preferential ribonuclease from Rhizopus niveus are involved in the catalytic function.

    PubMed

    Ohgi, K; Horiuchi, H; Watanabe, H; Iwama, M; Takagi, M; Irie, M

    1992-07-01

    In order to study the structure-function relationship of an RNase T2 family enzyme, RNase Rh, from Rhizopus niveus, we investigated the roles of three histidine residues by means of site-specific mutagenesis. One of the three histidine residues of RNase RNAP Rh produced in Saccharomyces cerevisiae by recombinant DNA technology was substituted to a phenylalanine or alanine residue. A Phe or Ala mutant enzyme at His46 or His109 showed less than 0.03%, but a mutant enzyme at His104 showed 0.54% of the enzymatic activity of the wild-type enzyme with RNA as a substrate. Similar results were obtained, when ApU was used as a substrate. The binding constant of a Phe mutant enzyme at His46 or His109 towards 2'-AMP decreased twofold, but that at His104 decreased more markedly. Therefore, we assumed that these three histidine residues are components of the active site of RNase Rh, that His104 contributes to some extent to the binding and less to the catalysis, and that the other two histidine residues and one carboxyl group not yet identified are probably involved in the catalysis. We assigned the C-2 proton resonances of His46, His104, and His109 by comparison of the 1H-NMR spectra of the three mutant enzymes containing Phe in place of His with that of the native enzyme, and also determined the individual pKa values for His46 and His104 to be 6.70 and 5.94. His109 was not titrated in a regular way, but the apparent pKa value was estimated to be around 6.3. The fact that addition of 2'-AMP caused a greater effect on the chemical shift of His104 in the 1NMR spectra as compared with those of the other histidine residues, may support the idea described above on the role of His104.

  5. Conformational Structure of Tyrosine, Tyrosyl-Glycine, and Tyrosyl-Glycyl-Glycine by Double Resonance Spectroscopy

    NASA Technical Reports Server (NTRS)

    Abo-Riziq, Ali; Grace, Louis; Crews, Bridgit; Callahan, Michael P,; van Mourik, Tanja; de Vries, Mattanjah S,

    2011-01-01

    We investigated the variation in conformation for the amino acid tyrosine (Y), alone and in the small peptides tyrosine-glycine (YC) and tyrosine-glycine-glycine (YGG), in the gas phase by using UV-UV and IR-UV double resonance spectroscopy and density functional theory calculations. For tyrosine we found seven different conformations, for YG we found four different conformations, and for YGG we found three different conformations. As the peptides get larger, we observe fewer stable conformers, despite the increasing complexity and number of degrees of freedom. We find structural trends similar to those in phenylalanine-glycine glycine (FGG) and tryptophan-glycine-glycine (WGG)j however) the effect of dispersive forces in FGG for stabilizing a folded structure is replaced by that of hydrogen bonding in YGG.

  6. Plane wave density functional theory studies of the structural and the electronic properties of amino acids attached to graphene oxide via peptide bonding

    NASA Astrophysics Data System (ADS)

    Min, Byeong June; Jeong, Hae Kyung; Lee, ChangWoo

    2015-08-01

    We studied via plane wave pseudopotential total-energy calculations within the local spin density approximation (LSDA) the electronic and the structural properties of amino acids (alanine, glycine, and histidine) attached to graphene oxide (GO) by peptide bonding. The HOMO-LUMO gap, the Hirshfeld charges, and the equilibrium geometrical structures exhibit distinctive variations that depend on the species of the attached amino acid. The GO-amino acid system appears to be a good candidate for a biosensor.

  7. Identification in pituitary tissue of a peptide alpha-amidation activity that acts on glycine-extended peptides and requires molecular oxygen, copper, and ascorbic acid.

    PubMed

    Eipper, B A; Mains, R E; Glembotski, C C

    1983-08-01

    An enzymatic activity capable of producing an alpha-amidated peptide product from its glycine-extended precursor has been identified in secretory granules of rat anterior, intermediate, and neural pituitary and bovine intermediate pituitary. High levels of endogenous inhibitors of this alpha-amidation activity have also been found in tissue homogenates. The alpha-amidation activity is totally inhibited by addition of divalent metal ion chelators such as diethyldithiocarbamate, o-phenanthroline, and EDTA; alpha-amidation activity is restored to above control levels upon addition of copper. The alpha-amidation reaction requires the presence of molecular oxygen. Of the various cofactors tested, ascorbic acid was the most potent stimulator of alpha-amidation. The alpha-amidation activity has a neutral pH optimum and is primarily soluble following several cycles of freezing and thawing. Kinetic studies with the bovine intermediate pituitary granule-associated activity demonstrated a linear Lineweaver-Burk plot when D-Tyr-Val-Gly was the varied substrate; the apparent Km and Vmax varied with the concentration of ascorbic acid. The substrate specificity of the alpha-amidation activity appears to be quite broad; the conversion of D-Tyr-Val-Gly into D-Tyr-Val-NH2 is inhibited by the addition of a variety of glycine-extended peptides.

  8. Low-temperature phase transition in glycine-glutaric acid co-crystals studied by single-crystal X-ray diffraction, Raman spectroscopy and differential scanning calorimetry.

    PubMed

    Zakharov, Boris A; Losev, Evgeniy A; Kolesov, Boris A; Drebushchak, Valeri A; Boldyreva, Elena V

    2012-06-01

    The occurrence of a first-order reversible phase transition in glycine-glutaric acid co-crystals at 220-230 K has been confirmed by three different techniques - single-crystal X-ray diffraction, polarized Raman spectroscopy and differential scanning calorimetry. The most interesting feature of this phase transition is that every second glutaric acid molecule changes its conformation, and this fact results in the space-group symmetry change from P2(1)/c to P1. The topology of the hydrogen-bonded motifs remains almost the same and hydrogen bonds do not switch to other atoms, although the hydrogen bond lengths do change and some of the bonds become inequivalent.

  9. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  10. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  11. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  12. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  13. Carboplatin binding to histidine

    SciTech Connect

    Tanley, Simon W. M.; Diederichs, Kay; Kroon-Batenburg, Loes M. J.; Levy, Colin; Schreurs, Antoine M. M.; Helliwell, John R.

    2014-08-29

    An X-ray crystal structure showing the binding of purely carboplatin to histidine in a model protein has finally been obtained. This required extensive crystallization trials and various novel crystal structure analyses. Carboplatin is a second-generation platinum anticancer agent used for the treatment of a variety of cancers. Previous X-ray crystallographic studies of carboplatin binding to histidine (in hen egg-white lysozyme; HEWL) showed the partial conversion of carboplatin to cisplatin owing to the high NaCl concentration used in the crystallization conditions. HEWL co-crystallizations with carboplatin in NaBr conditions have now been carried out to confirm whether carboplatin converts to the bromine form and whether this takes place in a similar way to the partial conversion of carboplatin to cisplatin observed previously in NaCl conditions. Here, it is reported that a partial chemical transformation takes place but to a transplatin form. Thus, to attempt to resolve purely carboplatin binding at histidine, this study utilized co-crystallization of HEWL with carboplatin without NaCl to eliminate the partial chemical conversion of carboplatin. Tetragonal HEWL crystals co-crystallized with carboplatin were successfully obtained in four different conditions, each at a different pH value. The structural results obtained show carboplatin bound to either one or both of the N atoms of His15 of HEWL, and this particular variation was dependent on the concentration of anions in the crystallization mixture and the elapsed time, as well as the pH used. The structural details of the bound carboplatin molecule also differed between them. Overall, the most detailed crystal structure showed the majority of the carboplatin atoms bound to the platinum centre; however, the four-carbon ring structure of the cyclobutanedicarboxylate moiety (CBDC) remained elusive. The potential impact of the results for the administration of carboplatin as an anticancer agent are described.

  14. Glycine fluxes in squid giant axons.

    PubMed

    Caldwell, P C; Lea, T J

    1978-05-01

    1. The influx of a number of amino acids into squid giant axons has been studied. Particular emphasis has been placed on glycine and to a lesser extent glutamate. 2. To facilitate the study of the uptake of 14C-labelled amino acids a technique was devised in which the 14C taken up was measured directly in the intact axon with a glass scintillator fibre. This technique gave results similar to the usual technique in which the axoplasm was extruded for the assay of radioactivity. 3. The changes in glycine influx with extracellular glycine concentration suggests that two saturating components are present, one with high affinity and one with low affinity. 4. The glycine influx does not seem normally to be sensitive to the removal of extracellular sodium by replacement with choline. A Na-sensitive component appeared, however, after a period of immersion in artificial sea water. There was also some depression of glycine influx if Na were replaced by Li. 5. Glutamate uptake was greatly reduced by removal of extracellular Na in confirmation of work by Baker & Potashner (1973). Orthophosphate uptake was also greatly reduced by removal of extracellular Na. 6. CN reversibly inhibited glycine uptake after a delay, indicating that part of the uptake mechanism may require ATP. 7. 14C-labelled glycine injected into squid axons was found not to exchange to any serious extent with other compounds over periods of a few hours. The glycine efflux could therefore be studied. This was found to be markedly increased by extracellular glycine and by certain other neutral amino acids applied extracellularly in the artificial sea water. 8. The enhanced glycine efflux in extracellular glycine was not affected by ouabain and CN. 9. It is suggested that glycine uptake in squid axons involves two components. One is sensitive to CN and ouabain and probably derives energy from ATP break-down. The other is probably an ATP independent exchange diffusion system in which other amino acids as well as

  15. Inhibition of copper absorption by zinc. Effect of histidine.

    PubMed

    Wapnir, R A; Balkman, C

    1991-06-01

    Copper and zinc interact at the intestinal mucosal level, affecting copper absorption. Amino acids, such as histidine, may affect the absorption of these two elements by chelating these cations. The two mechanisms could have additive potential. This possibility was investigated using a duodenal-jejunal single-pass perfusion procedure in anesthetized rats. Copper absorption and tissue retention from solutions containing 0.1 mM copper were determined in the presence of either no zinc or equimolar zinc, or at a zinc/copper ratio of 10/1, either without histidine or with histidine at a 10/1 or 20/1 ratio to copper. Copper removal from the intestinal lumen was decreased by zinc, and further reduced by increasing concentrations of histidine. There was a greater accumulation of copper in the small intestine, reaching a maximum with a 10-fold excess of histidine. With zinc at a 10/1 ratio to copper, the addition of a 10- or 20-fold molar excess of histidine further decreased the net uptake of copper from the perfusate while greater copper accumulation in the tissue occurred. Histidine thus enhances the inhibitory effects of zinc on copper absorption, suggesting the application of convergent mechanisms for diminishing copper uptake. This could be relevant for the treatment of Wilson's disease.

  16. Elimination of amino acids in acute renal failure.

    PubMed

    Druml, W; Bürger, U; Kleinberger, G; Lenz, K; Laggner, A

    1986-01-01

    Plasma amino acid concentrations and the elimination of parenterally administered amino acids were investigated in 12 patients with nonhypercatabolic acute renal failure. A distinctive plasma amino acid pattern could be observed: plasma concentrations of phenylalanine and methionine were increased, those of valine and leucine decreased. Of the nonessential amino acids, cystine, taurine und tyrosine had elevated but none of them reduced plasma concentrations. The elimination of amino acids was evaluated in a monocompartment model after bolus injection of an amino acid solution containing essential and nonessential amino acids. Pharmacokinetic parameters of 17 amino acids were calculated. The mean elimination half-time was raised by 25%. The elimination half-time of phenylalanine, methionine, glutamic acid, proline and ornithine was increased. Histidine was the only amino acid with--however insignificantly--accelerated elimination from the intravascular compartment. The total clearance rate and total transfer rate was not altered (107 and 97% of normal, respectively). The clearance of threonine, lysine, serine, glycine and histidine was increased, of valine, phenylalanine, glutamic acid and to a minor degree of methionine was decreased. The transfer rate of methionine, lysine, glycine was elevated, of valine, aspartic acid, glutamic acid and ornithine reduced. The demonstration of these pronounced alterations of amino acid elimination in acute renal failure may have major consequences in parenteral amino acid therapy.

  17. GAS-PHASE SYNTHESIS OF PRECURSORS OF INTERSTELLAR GLYCINE: A COMPUTATIONAL STUDY OF THE REACTIONS OF ACETIC ACID WITH HYDROXYLAMINE AND ITS IONIZED AND PROTONATED DERIVATIVES

    SciTech Connect

    Barrientos, Carmen; Redondo, Pilar; Largo, Laura; Rayon, Victor M.; Largo, Antonio

    2012-04-01

    A computational study of the reactions of hydroxylamine and its ionized and protonated derivatives with acetic acid is provided. The reaction of neutral hydroxylamine with acetic acid, despite being clearly exothermic, involves a very large energy barrier. The reaction of ionized hydroxylamine with acetic acid is also clearly exothermic, but again a significant energy barrier is found (around 24 kcal mol{sup -1} at the CCSD(T) level). The reaction of the most stable protonated isomer of hydroxylamine, NH{sub 3}OH{sup +}, with acetic acid also involves a high barrier (more than 27 kcal mol{sup -1} at the CCSD(T) level). Only the higher energy isomer, NH{sub 2}OH{sup +}{sub 2}, leads to a sensibly lower energy barrier (about 2.3 kcal mol{sup -1} at the CCSD(T) level). Nevertheless, an estimate of the reaction coefficient at low temperatures such as those reigning in the interstellar medium gives very low values. Therefore, it seems that precursors of interstellar glycine could not be efficiently produced from the reactions of hydroxylamine-derived ions with acetic acid.

  18. N-Glycosylation Improves the Pepsin Resistance of Histidine Acid Phosphatase Phytases by Enhancing Their Stability at Acidic pHs and Reducing Pepsin's Accessibility to Its Cleavage Sites.

    PubMed

    Niu, Canfang; Luo, Huiying; Shi, Pengjun; Huang, Huoqing; Wang, Yaru; Yang, Peilong; Yao, Bin

    2015-12-04

    N-Glycosylation can modulate enzyme structure and function. In this study, we identified two pepsin-resistant histidine acid phosphatase (HAP) phytases from Yersinia kristensenii (YkAPPA) and Yersinia rohdei (YrAPPA), each having an N-glycosylation motif, and one pepsin-sensitive HAP phytase from Yersinia enterocolitica (YeAPPA) that lacked an N-glycosylation site. Site-directed mutagenesis was employed to construct mutants by altering the N-glycosylation status of each enzyme, and the mutant and wild-type enzymes were expressed in Pichia pastoris for biochemical characterization. Compared with those of the N-glycosylation site deletion mutants and N-deglycosylated enzymes, all N-glycosylated counterparts exhibited enhanced pepsin resistance. Introduction of the N-glycosylation site into YeAPPA as YkAPPA and YrAPPA conferred pepsin resistance, shifted the pH optimum (0.5 and 1.5 pH units downward, respectively) and improved stability at acidic pH (83.2 and 98.8% residual activities at pH 2.0 for 1 h). Replacing the pepsin cleavage sites L197 and L396 in the immediate vicinity of the N-glycosylation motifs of YkAPPA and YrAPPA with V promoted their resistance to pepsin digestion when produced in Escherichia coli but had no effect on the pepsin resistance of N-glycosylated enzymes produced in P. pastoris. Thus, N-glycosylation may improve pepsin resistance by enhancing the stability at acidic pH and reducing pepsin's accessibility to peptic cleavage sites. This study provides a strategy, namely, the manipulation of N-glycosylation, for improvement of phytase properties for use in animal feed.

  19. N-Glycosylation Improves the Pepsin Resistance of Histidine Acid Phosphatase Phytases by Enhancing Their Stability at Acidic pHs and Reducing Pepsin's Accessibility to Its Cleavage Sites

    PubMed Central

    Niu, Canfang; Luo, Huiying; Shi, Pengjun; Huang, Huoqing; Wang, Yaru; Yang, Peilong

    2015-01-01

    N-Glycosylation can modulate enzyme structure and function. In this study, we identified two pepsin-resistant histidine acid phosphatase (HAP) phytases from Yersinia kristensenii (YkAPPA) and Yersinia rohdei (YrAPPA), each having an N-glycosylation motif, and one pepsin-sensitive HAP phytase from Yersinia enterocolitica (YeAPPA) that lacked an N-glycosylation site. Site-directed mutagenesis was employed to construct mutants by altering the N-glycosylation status of each enzyme, and the mutant and wild-type enzymes were expressed in Pichia pastoris for biochemical characterization. Compared with those of the N-glycosylation site deletion mutants and N-deglycosylated enzymes, all N-glycosylated counterparts exhibited enhanced pepsin resistance. Introduction of the N-glycosylation site into YeAPPA as YkAPPA and YrAPPA conferred pepsin resistance, shifted the pH optimum (0.5 and 1.5 pH units downward, respectively) and improved stability at acidic pH (83.2 and 98.8% residual activities at pH 2.0 for 1 h). Replacing the pepsin cleavage sites L197 and L396 in the immediate vicinity of the N-glycosylation motifs of YkAPPA and YrAPPA with V promoted their resistance to pepsin digestion when produced in Escherichia coli but had no effect on the pepsin resistance of N-glycosylated enzymes produced in P. pastoris. Thus, N-glycosylation may improve pepsin resistance by enhancing the stability at acidic pH and reducing pepsin's accessibility to peptic cleavage sites. This study provides a strategy, namely, the manipulation of N-glycosylation, for improvement of phytase properties for use in animal feed. PMID:26637601

  20. Arginine-glycine-aspartic acid-polyethylene glycol-polyamidoamine dendrimer conjugate improves liver-cell aggregation and function in 3-D spheroid culture.

    PubMed

    Chen, Zhanfei; Lian, Fen; Wang, Xiaoqian; Chen, Yanling; Tang, Nanhong

    2016-01-01

    The polyamidoamine (PAMAM) dendrimer, a type of macromolecule material, has been used in spheroidal cell culture and drug delivery in recent years. However, PAMAM is not involved in the study of hepatic cell-spheroid culture or its biological activity, particularly in detoxification function. Here, we constructed a PAMAM-dendrimer conjugate decorated by an integrin ligand: arginine-glycine-aspartic acid (RGD) peptide. Our studies demonstrate that RGD-polyethylene glycol (PEG)-PAMAM conjugates can promote singly floating hepatic cells to aggregate together in a sphere-like growth with a weak reactive oxygen species. Moreover, RGD-PEG-PAMAM conjugates can activate the AKT-MAPK pathway in hepatic cells to promote cell proliferation and improve basic function and ammonia metabolism. Together, our data support the hepatocyte sphere treated by RGD-PEG-PAMAM conjugates as a potential source of hepatic cells for a biological artificial liver system. PMID:27621619

  1. Facilitation of cell adhesion by immobilized dengue viral nonstructural protein 1 (NS1): arginine-glycine-aspartic acid structural mimicry within the dengue viral NS1 antigen.

    PubMed

    Chang, Hsin-Hou; Shyu, Huey-Fen; Wang, Yo-Ming; Sun, Der-Shan; Shyu, Rong-Hwa; Tang, Shiao-Shek; Huang, Yao-Shine

    2002-09-15

    Dengue virus infection causes life-threatening hemorrhagic fever. Increasing evidence implies that dengue viral nonstructural protein 1 (NS1) exhibits a tendency to elicit potentially hazardous autoantibodies, which show a wide spectrum of specificity against extracellular matrix and platelet antigens. How NS1 elicits autoantibodies remains unclear. To address the hypothesis that NS1 and matrix proteins may have structural and functional similarity, cell-matrix and cell-NS1 interactions were evaluated using a cell-adhesion assay. The present study showed that dengue NS1 immobilized on coverslips resulted in more cell adhesion than did the control proteins. This cell adhesion was inhibited by peptides containing arginine-glycine-aspartic acid (RGD), a motif important for integrin-mediated cell adhesion. In addition, anti-NS1 antibodies blocked RGD-mediated cell adhesion. Although there is no RGD motif in the NS1 protein sequence, these data indicate that RGD structural mimicry exists within the NS1 antigen.

  2. Interactions between the histidine stimulation of cadmium and zinc influx into human erythrocytes.

    PubMed Central

    Horn, N M; Thomas, A L

    1996-01-01

    1. Histidine (2-40 mM) stimulated cadmium uptake into human erythrocytes incubated in the presence of 1% bovine serum albumin to ensure that the free, ionic cadmium concentration was low. 2. The histidine-stimulated cadmium uptake correlated with the calculated concentration of the cadmium-bis-histidine complex rather than the cadmium-mono-histidine complex or free ionic cadmium. 3. The histidine stimulation of cadmium uptake was saturable and stereospecific. D-Histidine (10 mM) had no effect. 4. Cadmium and zinc were both able to inhibit 65Zn2+ uptake into erythrocytes incubated in the presence of 40 mM L-histidine. The relationships between the percentage inhibition of 65Zn2+ uptake and the calculated concentrations of cadmium-bis-histidine and zinc-bis-histidine were very similar, which suggests that the metal histidine complexes compete for a common transport mechanism. 5. Pretreatment of the erythrocytes with N-ethylmaleimide using a protocol which is known to inhibit the system y+ amino acid transport mechanism had no effect on the histidine stimulation of metal transport. PMID:8930838

  3. Protective effect of Mn(III)-desferrioxamine B upon oxidative stress caused by ozone and acid rain in the Brazilian soybean cultivar Glycine max "Sambaiba".

    PubMed

    Esposito, Jéssica Bordotti Nobre; Esposito, Breno Pannia; Azevedo, Ricardo Antunes; Cruz, Luciano Soares; da Silva, Luzimar Campos; de Souza, Silvia Ribeiro

    2015-04-01

    This study aimed to investigate the effects of the Mn complex (Mn(III)-desferrioxamine B (MnDFB)) on oxidative stress in the Brazilian soybean cultivar Glycine max "Sambaiba" following exposure to ozone and acid rain. We determined the suitable dose of MnDFB to apply to G. max seedlings using a dose-response curve. The highest superoxide dismutase (SOD) activity and Mn content in leaves were found upon the application of 8 μM MnDFB. Thus, G. max seedlings pretreated with 8 μM MnDFB were individually exposed to ozone and acid rain simulated. Pretreatment with MnDFB reduced lipid peroxidation upon ozone exposure and increased SOD activity in leaves; it did not alter the metal content in any part of the plant. Conversely, following acid rain exposure, neither the metal content in leaves nor SOD enzyme activity were directly affected by MnDFB, unlike pH. Our findings demonstrated that exogenous MnDFB application before ozone exposure may modulate the MnSOD, Cu/ZnSOD, and FeSOD activities to combat the ROS excess in the cell. Here, we demonstrated that the applied dose of MnDFB enhances antioxidative defenses in soybean following exposure to acid rain and especially to ozone.

  4. The effect of an arginine-glycine-aspartic acid peptide and hyaluronate synthetic matrix on epithelialization of meshed skin graft interstices.

    PubMed

    Cooper, M L; Hansbrough, J F; Polarek, J W

    1996-01-01

    Keratinocytes and fibroblasts interact with proteins of the extracellular matrix such as fibronectin and vitronectin through RGD (arginine-glycine-aspartic acid) cell-attachment sequences. This study evaluated the ability of a provisional synthetic matrix composed of an RGD peptide and hyaluronic acid to accelerate the epithelialization of the interstices of meshed, human, split-thickness skin when placed on full-thickness wounds of athymic mice. Full-thickness skin defects, sparing the panniculus carnosus, were created on athymic mice and 3:1 meshed, human skin was placed on them. The grafts had four central, isolated interstices, which epithelialized by migration of human keratinocytes. Conditions were either the addition to the wound of the synthetic matrix or a matrix of hyaluronic acid alone. The time to closure of the graft interstices was decreased (p < 0.02) in the wounds treated with the RGD peptide-hyaluronic acid provisional matrix. The resultant epithelium of the closed interstices was significantly thicker 8 days after surgery for the RGD-treated wounds. Basement membrane proteins (laminin and type IV collagen) were also found to be present at the dermoepidermal junction earlier in the RGD-treated wounds. These results imply that use of the RGD peptide conjugate to effect cell-matrix interactions may have clinical significance in the field of wound healing.

  5. Protective effect of Mn(III)-desferrioxamine B upon oxidative stress caused by ozone and acid rain in the Brazilian soybean cultivar Glycine max "Sambaiba".

    PubMed

    Esposito, Jéssica Bordotti Nobre; Esposito, Breno Pannia; Azevedo, Ricardo Antunes; Cruz, Luciano Soares; da Silva, Luzimar Campos; de Souza, Silvia Ribeiro

    2015-04-01

    This study aimed to investigate the effects of the Mn complex (Mn(III)-desferrioxamine B (MnDFB)) on oxidative stress in the Brazilian soybean cultivar Glycine max "Sambaiba" following exposure to ozone and acid rain. We determined the suitable dose of MnDFB to apply to G. max seedlings using a dose-response curve. The highest superoxide dismutase (SOD) activity and Mn content in leaves were found upon the application of 8 μM MnDFB. Thus, G. max seedlings pretreated with 8 μM MnDFB were individually exposed to ozone and acid rain simulated. Pretreatment with MnDFB reduced lipid peroxidation upon ozone exposure and increased SOD activity in leaves; it did not alter the metal content in any part of the plant. Conversely, following acid rain exposure, neither the metal content in leaves nor SOD enzyme activity were directly affected by MnDFB, unlike pH. Our findings demonstrated that exogenous MnDFB application before ozone exposure may modulate the MnSOD, Cu/ZnSOD, and FeSOD activities to combat the ROS excess in the cell. Here, we demonstrated that the applied dose of MnDFB enhances antioxidative defenses in soybean following exposure to acid rain and especially to ozone. PMID:25510614

  6. Carboplatin binding to histidine.

    PubMed

    Tanley, Simon W M; Diederichs, Kay; Kroon-Batenburg, Loes M J; Levy, Colin; Schreurs, Antoine M M; Helliwell, John R

    2014-09-01

    Carboplatin is a second-generation platinum anticancer agent used for the treatment of a variety of cancers. Previous X-ray crystallographic studies of carboplatin binding to histidine (in hen egg-white lysozyme; HEWL) showed the partial conversion of carboplatin to cisplatin owing to the high NaCl concentration used in the crystallization conditions. HEWL co-crystallizations with carboplatin in NaBr conditions have now been carried out to confirm whether carboplatin converts to the bromine form and whether this takes place in a similar way to the partial conversion of carboplatin to cisplatin observed previously in NaCl conditions. Here, it is reported that a partial chemical transformation takes place but to a transplatin form. Thus, to attempt to resolve purely carboplatin binding at histidine, this study utilized co-crystallization of HEWL with carboplatin without NaCl to eliminate the partial chemical conversion of carboplatin. Tetragonal HEWL crystals co-crystallized with carboplatin were successfully obtained in four different conditions, each at a different pH value. The structural results obtained show carboplatin bound to either one or both of the N atoms of His15 of HEWL, and this particular variation was dependent on the concentration of anions in the crystallization mixture and the elapsed time, as well as the pH used. The structural details of the bound carboplatin molecule also differed between them. Overall, the most detailed crystal structure showed the majority of the carboplatin atoms bound to the platinum centre; however, the four-carbon ring structure of the cyclobutanedicarboxylate moiety (CBDC) remained elusive. The potential impact of the results for the administration of carboplatin as an anticancer agent are described.

  7. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 2: aldol, Mannich addition reactions, deracemization and (S) to (R) interconversion of α-amino acids.

    PubMed

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim

    2013-11-01

    This review provides a comprehensive treatment of literature data dealing with asymmetric synthesis of α-amino-β-hydroxy and α,β-diamino acids via homologation of chiral Ni(II) complexes of glycine Schiff bases using aldol and Mannich-type reactions. These reactions proceed with synthetically useful chemical yields and thermodynamically controlled stereoselectivity and allow direct introduction of two stereogenic centers in a single operation with predictable stereochemical outcome. Furthermore, new application of Ni(II) complexes of α-amino acids Schiff bases for deracemization of racemic α-amino acids and (S) to (R) interconversion providing additional synthetic opportunities for preparation of enantiomerically pure α-amino acids, is also reviewed. Origin of observed diastereo-/enantioselectivity in the aldol, Mannich-type and deracemization reactions, generality and limitations of these methodologies are critically discussed.

  8. Synthesis, structural characterization, in vitro antimicrobial and anticancer activity studies of ternary metal complexes containing glycine amino acid and the anti-inflammatory drug lornoxicam

    NASA Astrophysics Data System (ADS)

    Mahmoud, Walaa H.; Mohamed, Gehad G.; El-Dessouky, Maher M. I.

    2015-02-01

    Mixed ligand complexes were synthesized using lornoxicam (LOR) as the primary ligand and glycine amino acid (HGly) as the secondary ligand. They were characterized by FT-IR, UV-Vis, mass, 1H NMR, ESR spectral studies, TG-DTG, X-ray powder diffraction and physical analytical studies. From the molar conductance, magnetic moment and electronic spectral data of the synthesized complexes, general formulae of [M(LOR)2(Gly)]·Xn·yH2O where M = Cr(III) (X = Cl, n = 2, y = 3), Mn(II) (X = Cl, n = 1, y = 1), Co(II) (X = BF4, n = 1, y = 0), Ni(II) (X = Cl, n = 1, y = 0), Cu(II) (X = BF4, n = 1, y = 2) and Zn(II) (X = BF4, n = 1, y = 2) and (M = Fe(II) (X = BF4, n = 1, y = 1) and Fe(III) (X = Cl, n = 2, y = 1) with an octahedral structure were proposed. Thermal analyses show that the complexes lose water molecules of hydration initially and subsequently expel anionic parts and organic ligands in continuous steps. The kinetic parameters namely E, ΔH∗, ΔS∗ and ΔG∗ illustrate the spontaneous association of the metal and ligands in the formation of the complexes. The antimicrobial efficiency of the LOR and HGly ligands and the ternary complexes were examined by in vitro method against various pathogenic bacterial and fungal strains. The metal complexes were found to possess efficient antimicrobial properties compared to lornoxicam and most of these complexes could turn out to be excellent models for the design of effective antibiotic drug substances. Also, the two ligands, in comparison to ternary metal complexes are screened for their anticancer activity against breastic cancer cell line. The results showed that the metal complexes be more active than the parent LOR and glycine free ligands except Cr(III) ternary complex which was found to be inactive.

  9. Growth, structural, optical and mechanical studies on acid mixed glycine metal salt (GABN) crystal as potential NLO material

    NASA Astrophysics Data System (ADS)

    Khandpekar, Mahendra M.; Dongare, Shailesh S.; Patil, Shirish B.; Pati, Shankar P.

    2012-03-01

    Transparent crystals of α-glycine with ammonium nitrate and barium nitrate (GABN) have been grown from aqueous solution by slow evaporation technique at room temperature. Crystals of size 11 × 7 × 4 mm 3 have been obtained in about 3-4 weeks time. The solubility of GABN has been determined in water. The grown crystal belongs to orthorhombic system with cell parameters a = 7.317 A.U, b = 12.154 A.U and c = 5.468 A.U with a unit cell volume 486.35 (A.U) 3. The presence of chemical components/groups has been identified by CHN, EDAX and NMR analysis. Comparative IR and Raman studies indicate a molecule with a lack of centre of symmetry. A wide transparency window useful for optoelectronic applications is indicated by the UV Studies. Using a Nd-YAG laser (1064 nm), the optical second harmonic generation (SHG) conversion efficiency of GABN is found to be 1.406 times of that of standard KDP. On exposure to light the GABN crystals are found to exhibit negative photoconductivity. I-V characteristics, SEM studies, dielectrics studies, and Vickers micro hardness measurement have been carried out.

  10. Mutation of asparagine 52 to glycine promotes the alkaline form of iso-1-cytochrome c and causes loss of cooperativity in acid unfolding.

    PubMed

    Baddam, Saritha; Bowler, Bruce E

    2006-04-11

    The kinetics and thermodynamics of the alkaline and acid conformational transitions of a Lys 79 --> Ala/Asn 52 --> Gly (A79G52) variant of iso-1-cytochrome c are studied. The Lys 79 --> Ala mutation is designed to limit heme ligation in the alkaline conformer to Lys 73. The Asn 52 --> Gly mutation is intended to shift the population of the alkaline conformer to physiological pH based on the hierarchical nature of the cooperative substructures of this protein. The midpoint pH for formation of the alkaline conformer is approximately 7.45. The kinetics for the alkaline conformational transition of the A79G52 variant are consistent with the ionization constant, pK(H), for the trigger group controlling formation of the alkaline conformer being approximately 9.5. This pK(H) is low for alkaline conformers involving lysine-heme ligation but is consistent with the pK(a) of the highest of three ionizable groups which modulate formation of the histidine-heme alkaline conformer of a His 73 variant of iso-1-cytochrome c [Martinez, R. E., and Bowler, B. E. (2004) J. Am. Chem. Soc. 126, 6751-6758]. The acid transition of the A79G52 variant is split into two phases. Both the Lys 79 --> Ala and Asn 52 --> Gly mutations are expected to affect the buried hydrogen bond network of cytochrome c, suggesting that this network is an important modulator of the acid unfolding of cytochrome c. PMID:16584196

  11. Additivity of the Stabilization Effect of Single Amino Acid Substitutions in Triple Mutants of Recombinant Formate Dehydrogenase from the Soybean Glycine max.

    PubMed

    Alekseeva, A A; Kargov, I S; Kleimenov, S Yu; Savin, S S; Tishkov, V I

    2015-01-01

    Recently, we demonstrated that the amino acid substitutions Ala267Met and Ala267Met/Ile272Val (Alekseeva et al., Biochemistry, 2012), Phe290Asp, Phe290Asn and Phe290Ser (Alekseeva et al., Prot. Eng. Des. Select, 2012) in recombinant formate dehydrogenase from soya Glycine max (SoyFDH) lead to a significant (up to 30-100 times) increase in the thermal stability of the enzyme. The substitutions Phe290Asp, Phe290Asn and Phe290Ser were introduced into double mutant SoyFDH Ala267Met/Ile272Val by site-directed mutagenesis. Combinations of three substitutions did not lead to a noticeable change in the catalytic properties of the mutant enzymes. The stability of the resultant triple mutants was studied through thermal inactivation kinetics and differential scanning calorimetry. The thermal stability of the new mutant SoyFDHs was shown to be much higher than that of their precursors. The stability of the best mutant SoyFDH Ala267Met/Ile272Val/Phe290Asp turned out to be comparable to that of the most stable wild-type formate dehydrogenases from other sources. The results obtained with both methods indicate a great synergistic contribution of individual amino acid substitutions to the common stabilization effect.

  12. Amino acids

    MedlinePlus

    ... amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan , and valine. Nonessential amino acids "Nonessential" means that our bodies produce an amino ...

  13. Effects of glycine-arginine-α-ketoisocaproic acid supplementation in college-age trained females during multi-bouts of resistance exercise.

    PubMed

    Wax, Benjamin; Hilton, Laura; Vickers, Brad; Gilliland, Katherine; Conrad, Mandy

    2013-03-01

    Glycine-arginine-α-ketoisocaproic acid (GAKIC) has been proposed to increase anaerobic high-intensity exercise performance in male subjects. However, the effects of GAKIC ingestion in female subjects have not been studied. Therefore, the purpose of this study was to investigate the effects of GAKIC supplementation on total load volume (i.e., mass lifted) and metabolic parameters during repeated bouts of submaximal leg extensions in college-age females. Nine resistance-trained females participated in a randomized, counterbalanced, double blind study. Subjects were randomly assigned to placebo or GAKIC (10.2 g) and performed six sets of 50% of one repetition maximum leg extensions (two legs simultaneously) to failure. One week later, subjects ingested the other supplement and performed the same exercise protocol. Furthermore, blood lactic acid, blood glucose, and heart rate were also measured preexercise and 5 s after the completion of the exercise protocol (postexercise). GAKIC supplementation significantly increased leg extension total load volume (GAKIC = 1721.7 ± 479.9 kg; placebo = 1479.1 ± 396.8 kg, p < .01). Heart rate and blood lactic acid were significantly increased (p < .01 for both measures) postexercise compared to preexercise, but were not significantly different between GAKIC and placebo (p = .40 for heart rate; p = .88 for lactic acid). Blood glucose was significantly decreased (p = .03) postexercise compared to preexercise, but was not significantly different (p = .78) between GAKIC and placebo. Collectively, these findings suggest that GAKIC increased lower body resistance performance in trained college-age females; however, these findings are not necessarily generalizable.

  14. Spectroscopic investigations of humic-like acids formed via polycondensation reactions between glycine, catechol and glucose in the presence of natural zeolites

    NASA Astrophysics Data System (ADS)

    Fukuchi, Shigeki; Miura, Akitaka; Okabe, Ryo; Fukushima, Masami; Sasaki, Masahide; Sato, Tsutomu

    2010-10-01

    Polycondensation reactions between low-molecular-weight compounds, such as amino acids, sugars and phenols, are crucially important processes in the formation of humic substances, and clay minerals have the ability to catalyze these reactions. In the present study, catechol (CT), glycine (Gly) and glucose (Gl) were used as representative phenols, amino acids and sugars, respectively, and the effects of the catalytic activities of natural zeolites on polycondensation reactions between these compounds were investigated. The extent of polycondensation was evaluated by measuring the specific absorbance at 600 nm ( E600) as an index of the degree of darkening. After a 3-week incubation period, the E600 values for solutions that contained zeolite samples were 4-10 times greater than those measured in the absence of zeolite, suggesting that the zeolite had, in fact, catalyzed the polycondensation reaction. The humic-like acids (HLAs) produced in the reactions were isolated, and their elemental composition and molecular weights determined. When formed in the presence of a zeolite, the nitrogen contents and molecular weights for the HLAs were significantly higher, compared to the HLA sample formed in the absence of zeolite. In addition, solid-state CP-MAS 13C NMR spectra and carboxylic group analyses of the HLA samples indicated that the concentration of carbonyl carbon species for quinones and ketones produced in the presence of zeolite were higher than the corresponding values for samples produced in the absence of a zeolite. Carbonyl carbons in quinones and ketones indicate the nucleophilic characteristics of the samples. Therefore, a nitrogen atom in Gly, which serves as nucleophile, is incorporated into quinones and ketones in CT and Gl. The differences in the catalytic activities of the zeolite samples can be attributed to differences in their transition metal content (Fe, Mn and Ti), which function as Lewis acids.

  15. Effect of Cooking on Isoflavones, Phenolic Acids, and Antioxidant Activity in Sprouts of Prosoy Soybean (Glycine max).

    PubMed

    Kumari, Shweta; Chang, Sam K C

    2016-07-01

    Soy sprouts possess health benefits and is required to be cooked before consumption. The effects of cooking on the phenolic components and antioxidant properties of soy sprouts with different germination days were investigated. A food-grade cultivar Prosoy with a high protein content was germinated for 1, 2, 3, 5, and 7 d and cooked till palatable for 20, 20, 5, 5, and 7 min, respectively. Total phenolic content (TPC), total flavonoids content (TFC), condensed tannins content (CTC), individual phenolic acids, isoflavones, DPPH, ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) of raw and cooked sprouts were measured. Cooking caused significant losses in phenolic content and antioxidant activities, and maximum loss was on day 3 > 5 > 7, including TPC (32%, 23%, and 15%), TFC (50%, 44%, and 20%), CTC (73%, 47%, and 12%), DPPH (31%, 15%, and 5%), FRAP (34%, 25%, and 1%), and ORAC (34%, 22%, 32%), respectively. Cooking caused significant losses in most individual phenolic acid, benzoic group, cinnamic group, total phenolic composition, individual isoflavones, and total isoflavones. The losses of phenolic acids such as gallic, protocatechuic, hydroxybenzoic, syringic, chlorogenic, or sinapic acids during cooking were not compensated by the increases in trihydroxybenzoic, vanillic or coumaric acids on certain days of germination. Cooking caused minimal changes in phenolic acid composition of day 1 and 2 sprouts compared to 3, 5, and 7 d sprouts. PMID:27258930

  16. Evidence of histidine phosphorylation in isocitrate lyase from Escherichia coli

    SciTech Connect

    Roberston, E.F.; Hoyt, J.C.; Reeves, H.C.

    1987-05-01

    Escherichia coli isocitrate lyase can be phosphorylated in vitro in an ATP-dependent reaction. Partially purified extracts were incubated with ..gamma..-/sup 32/P-ATP and analyzed by two-dimensional polyacrylamide gel electrophoresis followed by a Western blot and autoradiography. Radioactivity was associated with the lyase only when blotting was performed under alkaline conditions. This suggests that phosphate groups are attached to the lyase via an acid-labile P-N bond rather than a more stable P-O bond. Treatment of the lyase with diethyl pyrocarbonate, a histidine modifying agent, blocks incorporation of /sup 32/P-phosphate. Treatment with phosphoramidate, a histidine phosphorylating agent, alters the isoelectric point of the lyase suggesting that the enzyme can be phosphorylated at histidine residues. Loss of catalytic activity after treatment with potato acid phosphatase indicates that isocitrate lyase activity may be modulated by phosphorylation.

  17. [Analysis of roots of soybean (Glycine max Merrill) treated with exogenous citric acid plus short-time aluminum stress by direct determination of FTIR spectrum].

    PubMed

    Jin, Ting-Ting; Liu, Peng; Zhang, Zhi-Xiang; Xu, Gen-Di; Zhao, Li-Li

    2009-02-01

    In the present study, 19 soybean (Glycine max L.) cultivars were analyzed and found to differ considerably in aluminum (Al) resistance. The cultivars Zhechun No. 2 (Al-resistant) and Zhechun No. 3 (Al-sensitive) were selected for further analysis. Experiments were performed with plants grown in full nutrient solution for 30 days. Fourier transform infrared spectrometry (FTIR) with OMNI-sampler was applied to the direct determination of different varieties of soybean root tissues, treated with aluminum in a dose-and time-dependent manner plus exogenous citric acid. Then the characteristic absorption peaks of spectra were analyzed and some differences in the FTIR spectra among samples were found from the comparison of the spectra. Results showed that the intensity and the shape of absorption peaks of their FTIR spectra exhibited some differences between different kinds of soybean and different treatment, especially around 1 057, 1 602, 2 927 and 3 292 cm(-1), which mainly reflected the content variety of protein, glucide, nucleic acid and so on. Thus it could be concluded that the effect of aluminum stress and existence of exogenous citric acid did not change the component of chemical substance in soybean roots, although the content of certain substance varied. The two dimensional discriminates analysis chart was drawn by the ratio of area at 2 927 cm(-1) to that at 3297 cm(-1) as the abscissa vs the ratio of area at 1 057 cm(-1) to that at 1 602 cm(-1) as the vertical, to discover the difference between the treatment of aluminum plus exogenous citric acid and that of single aluminum. Result indicates that the difference in the shape of absorption peaks of FTIR spectra became smaller and that presumed the content variety with different treatment was not remarkable under the condition of exogenous citric acid, especially in Zhechun No 3. From all mentioned above it is made clear that exogenous citric acid could really ameliorate distinctly the effect of aluminum on

  18. Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils.

    PubMed

    Schimmelmann, Arndt; Qi, Haiping; Coplen, Tyler B; Brand, Willi A; Fong, Jon; Meier-Augenstein, Wolfram; Kemp, Helen F; Toman, Blaza; Ackermann, Annika; Assonov, Sergey; Aerts-Bijma, Anita T; Brejcha, Ramona; Chikaraishi, Yoshito; Darwish, Tamim; Elsner, Martin; Gehre, Matthias; Geilmann, Heike; Gröning, Manfred; Hélie, Jean-François; Herrero-Martín, Sara; Meijer, Harro A J; Sauer, Peter E; Sessions, Alex L; Werner, Roland A

    2016-04-19

    An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.8 to +397.0 mUr or ‰, for δ(13)C(VPDB-LSVEC) from -40.81 to +0.49 mUr and for δ(15)N(Air) from -5.21 to +61.53 mUr. Many of the new RMs are amenable to gas and liquid chromatography. The RMs include triads of isotopically contrasting caffeines, C16 n-alkanes, n-C20-fatty acid methyl esters (FAMEs), glycines, and l-valines, together with polyethylene powder and string, one n-C17-FAME, a vacuum oil (NBS 22a) to replace NBS 22 oil, and a (2)H-enriched vacuum oil. A total of 11 laboratories from 7 countries used multiple analytical approaches and instrumentation for 2-point isotopic normalization against international primary measurement standards. The use of reference waters in silver tubes allowed direct normalization of δ(2)H values of organic materials against isotopic reference waters following the principle of identical treatment. Bayesian statistical analysis yielded the mean values reported here. New RMs are numbered from USGS61 through USGS78, in addition to NBS 22a. Because of exchangeable hydrogen, amino acid RMs currently are recommended only for carbon- and nitrogen-isotope measurements. Some amino acids contain (13)C and carbon-bound organic (2)H-enrichments at different molecular sites to provide RMs for potential site-specific isotopic analysis in future studies. PMID:26974360

  19. Differential neuroprotective effects of the NMDA receptor-associated glycine site partial agonists 1-aminocyclopropanecarboxylic acid (ACPC) and D-cycloserine in lithium-pilocarpine status epilepticus.

    PubMed

    Peterson, Steven L; Purvis, Rebecca S; Griffith, James W

    2004-09-01

    The status epilepticus (SE) induced in rats by lithium-pilocarpine (Li-pilo) shares many common features with soman-induced SE including a glutamatergic phase that is inhibited by NMDA antagonists. The present study determined whether 1-aminocyclopropanecarboxylic acid (ACPC) or D-cycloserine (DCS), both partial agonists of the strychnine-insensitive glycine site on the NMDA receptor ionophore complex, exerted anticonvulsant or neuroprotectant activity in Li-pilo SE. ACPC or DCS were administered either immediately following pilocarpine (exposure treatment) or 5 min after the onset of SE as determined by ECoG activity. SE was allowed to proceed for 3 h before termination with propofol. The rats were sacrificed 24 h following pilocarpine administration. Neither drug had an effect on the latency to seizure onset or the duration of seizure activity. ACPC administered 5 min after SE onset produced significant neuroprotection in cortical regions, amygdala and CA1 of the hippocampus. In contrast, when administered as exposure treatment ACPC enhanced the neural damage in the thalamus and CA3 of the hippocampus suggesting the neuropathology in those regions is mediated by a different subset of NMDA receptors. DCS had no neuroprotectant activity in Li-pilo SE but exacerbated neuronal damage in the thalamus. Neither drug affected the cholinergic convulsions but both had differential effects on neural damage. This suggests that the SE-induced seizure activity and subsequent neuronal damage involve independent mechanisms.

  20. Improving impurities clearance by amino acids addition to buffer solutions for chromatographic purifications of monoclonal antibodies.

    PubMed

    Ishihara, Takashi; Hosono, Mareto

    2015-07-15

    The performance of amino acids in Protein A affinity chromatography, anion exchange chromatography and cation exchange chromatography for monoclonal antibody purification was investigated. Glycine, threonine, arginine, glutamate, and histidine were used as buffer components in the equilibration, washing, and elution steps of these chromatographies. Improved clearance of impurity, high molecular weight species (HMW) and host cell proteins (HCP) was observed in the purification processes when using the amino acids as base-buffer constituents, additives or eluents compared with that of buffers without these amino acids. In addition, we designed a buffer system in which the mobile phases were composed of only a single amino acid, histidine, and applied it to the above three chromatographies. Effective HMW and HCP clearance was also obtained in this manner. These results suggest that amino acids may enhance impurity clearance during the purification of monoclonal antibodies. PMID:26057847

  1. Modulatory role of jasmonic acid on photosynthetic pigments, antioxidants and stress markers of Glycine max L. under nickel stress.

    PubMed

    Sirhindi, Geetika; Mir, Mudaser Ahmad; Sharma, Poonam; Gill, Sarvajeet Singh; Kaur, Harpreet; Mushtaq, Ruquia

    2015-10-01

    Jasmonic acid (JA) is a very young candidate of plant growth regulators which is being explored for various antistress properties. Present study deals with the hypothesis that JA can modulate antioxidant mechanism of higher plants with tight regulation of biomembrane peroxidation, making plants tolerant to toxic Ni(2+). 2 mM NiCl2 as a source of Ni(2+) appeared as sub lethal dose for the growth of 15 days old Glycine max seedlings. Exogenous application of 1 μM and 1 nM JA prior to NiCl2 exposure, made seedlings of Glycine max more tolerant to Ni(2+)stress as compared to control untreated seedlings. Regulatory inhibition of MDA and H2O2 production by JA with or without Ni(2+) treatment made plants more resistant to Ni(2+) stress which may be associated with ameliorative activity of antioxidant enzymes system composed of SOD, POD, CAT and APOX. Ascorbate, a secondary metabolite synthesized from D-glucose act as an antioxidant in plant cells. Many fold enhancements in AsA content of Ni(2+) treated seedlings supplemented with different concentrations of JA was observed. Significant improvement in AsA levels by JA with or without Ni(2+) stress may involve two aspects, either denovo synthesis level regulation of AsA or recycling of AsA from an oxidized form. Improvement in total protein content showed the uplift modulation of transcriptional machinery by JA which was also maintained under Ni(2+) stress. Photosynthetic pigments as total chl, chl a and b showed inhibition in presence of Ni(2+) stress which was not found much effective under JA supplementation as compared to control. Present findings revealed that although JA was not helpful for protection of photosynthetic pigments but it modulates the other machinery of plants significantly including various antioxidants positively, while tightly inhibiting stress related processes responsible for lipid peroxidation to make plants tolerant to Ni(2+) stress.

  2. Modulatory role of jasmonic acid on photosynthetic pigments, antioxidants and stress markers of Glycine max L. under nickel stress.

    PubMed

    Sirhindi, Geetika; Mir, Mudaser Ahmad; Sharma, Poonam; Gill, Sarvajeet Singh; Kaur, Harpreet; Mushtaq, Ruquia

    2015-10-01

    Jasmonic acid (JA) is a very young candidate of plant growth regulators which is being explored for various antistress properties. Present study deals with the hypothesis that JA can modulate antioxidant mechanism of higher plants with tight regulation of biomembrane peroxidation, making plants tolerant to toxic Ni(2+). 2 mM NiCl2 as a source of Ni(2+) appeared as sub lethal dose for the growth of 15 days old Glycine max seedlings. Exogenous application of 1 μM and 1 nM JA prior to NiCl2 exposure, made seedlings of Glycine max more tolerant to Ni(2+)stress as compared to control untreated seedlings. Regulatory inhibition of MDA and H2O2 production by JA with or without Ni(2+) treatment made plants more resistant to Ni(2+) stress which may be associated with ameliorative activity of antioxidant enzymes system composed of SOD, POD, CAT and APOX. Ascorbate, a secondary metabolite synthesized from D-glucose act as an antioxidant in plant cells. Many fold enhancements in AsA content of Ni(2+) treated seedlings supplemented with different concentrations of JA was observed. Significant improvement in AsA levels by JA with or without Ni(2+) stress may involve two aspects, either denovo synthesis level regulation of AsA or recycling of AsA from an oxidized form. Improvement in total protein content showed the uplift modulation of transcriptional machinery by JA which was also maintained under Ni(2+) stress. Photosynthetic pigments as total chl, chl a and b showed inhibition in presence of Ni(2+) stress which was not found much effective under JA supplementation as compared to control. Present findings revealed that although JA was not helpful for protection of photosynthetic pigments but it modulates the other machinery of plants significantly including various antioxidants positively, while tightly inhibiting stress related processes responsible for lipid peroxidation to make plants tolerant to Ni(2+) stress. PMID:26600682

  3. Differentiation of Malassezia furfur and Malassezia sympodialis by glycine utilization.

    PubMed

    Murai, T; Nakamura, Y; Kano, R; Watanabe, S; Hasegawa, A

    2002-06-01

    The genus Malassezia has been revised to include six lipophilic species and one nonlipophilic species. These Malassezia species have been investigated to differentiate their morphological and physiological characteristics. However, assimilation of amino acids as a nitrogen source by these species was not well elucidated. In the present study, isolates of Malassezia species were examined with a glycine medium (containing 7-266 mmol glycine, 7.4 mmol KH(2)PO(4), 4.1 mmol MgSO(4)7H(2)O, 29.6 mmol thiamine, 0.5% Tween-80 and 2% agar) and a modified Dixon glycine medium (0.6% peptone, 3.6% malt extract, 2% ox-bile, 1% Tween-40, 0.2% glycerol, 0.2% oleic acid, 7 mmol glycine and 2% agar). All M. furfur isolates developed on the glycine medium, assimilating glycine at concentrations of at least 7 mmol l(-1). However, the other six Malassezia species were unable to grow on the glycine medium. Also, many colonies of M. furfur grew rapidly, within 2-3 days on the modified Dixon glycine medium, although the other six species showed slow and poor development. From these results, it was suggested that M. furfur might be able to utilize glycine as a single nitrogen source, which the other Malassezia species could not. Therefore, glycine medium was recommended for the differentiation of M. furfur from other species of Malassezia.

  4. Effects of two low phytic acid mutations on seed quality and nutritional traits in soybean (Glycine max L. Merr).

    PubMed

    Yuan, Feng-Jie; Zhu, Dan-Hua; Deng, Bo; Fu, Xu-Jun; Dong, De-Kun; Zhu, Shen-Long; Li, Bai-Quan; Shu, Qing-Yao

    2009-05-13

    Reduction of phytic acid in soybean seeds has the potential to improve the nutritional value of soybean meal and lessen phosphorus pollution in large scale animal farming. The objective of this study was to assess the effect of two new low phytic acid (LPA) mutations on seed quality and nutritional traits. Multilocation/season comparative analyses showed that the two mutations did not affect the concentration of crude protein, any of the individual amino acids, crude oil, and individual saturated fatty acids. Among other traits, Gm-lpa-TW75-1 had consistently higher sucrose contents (+47.4-86.1%) and lower raffinose contents (-74.2 to -84.3%) than those of wild type (WT) parent Taiwan 75; Gm-lpa-ZC-2 had higher total isoflavone contents (3038.8-4305.4 microg/g) than its parent Zhechun # 3 (1583.6-2644.9 microg/g) in all environments. Further tests of homozygous F(3) progenies of the cross Gm-lpa-ZC-2 x Wuxing # 4 (WT variety) showed that LPA lines had a mean content of total isoflavone significantly higher than WT lines. This study demonstrated that two LPA mutant genes have no negative effects on seed quality and nutritional traits; they instead have the potential to improve a few other properties. Therefore, these two mutant genes are valuable genetic resources for breeding high quality soybean varieties.

  5. Effects of two low phytic acid mutations on seed quality and nutritional traits in soybean (Glycine max L. Merr).

    PubMed

    Yuan, Feng-Jie; Zhu, Dan-Hua; Deng, Bo; Fu, Xu-Jun; Dong, De-Kun; Zhu, Shen-Long; Li, Bai-Quan; Shu, Qing-Yao

    2009-05-13

    Reduction of phytic acid in soybean seeds has the potential to improve the nutritional value of soybean meal and lessen phosphorus pollution in large scale animal farming. The objective of this study was to assess the effect of two new low phytic acid (LPA) mutations on seed quality and nutritional traits. Multilocation/season comparative analyses showed that the two mutations did not affect the concentration of crude protein, any of the individual amino acids, crude oil, and individual saturated fatty acids. Among other traits, Gm-lpa-TW75-1 had consistently higher sucrose contents (+47.4-86.1%) and lower raffinose contents (-74.2 to -84.3%) than those of wild type (WT) parent Taiwan 75; Gm-lpa-ZC-2 had higher total isoflavone contents (3038.8-4305.4 microg/g) than its parent Zhechun # 3 (1583.6-2644.9 microg/g) in all environments. Further tests of homozygous F(3) progenies of the cross Gm-lpa-ZC-2 x Wuxing # 4 (WT variety) showed that LPA lines had a mean content of total isoflavone significantly higher than WT lines. This study demonstrated that two LPA mutant genes have no negative effects on seed quality and nutritional traits; they instead have the potential to improve a few other properties. Therefore, these two mutant genes are valuable genetic resources for breeding high quality soybean varieties. PMID:19323582

  6. 21 CFR 520.550 - Dextrose/glycine/electrolyte.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ingredients: sodium chloride 8.82 grams, potassium phosphate 4.20 grams, citric acid anhydrous 0.5 gram, potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and dextrose 44.0 grams. (b)...

  7. Safety, absorption, and antioxidant effects of chromium histidine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Supplemental chromium has been shown to be involved in the alleviation of the metabolic syndrome, glucose intolerance, polycystic ovary syndrome, depression, excess body fat, and gestational, steroid-induced, and type 2 diabetes. Chromium amino acid complexes that contained histidine displayed cons...

  8. Synthesis and carbonic anhydrase inhibitory properties of amino acid - coumarin/quinolinone conjugates incorporating glycine, alanine and phenylalanine moieties.

    PubMed

    Küçükbay, F Zehra; Küçükbay, Hasan; Tanc, Muhammet; Supuran, Claudiu T

    2016-12-01

    N-Protected amino acids (Gly, Ala and Phe) were reacted with amino substituted coumarin and quinolinone derivatives, leading to the corresponding N-protected amino acid-coumarin/quinolinone conjugates. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was assessed against various human (h) isoforms, such as hCA I, hCA II, hCA IV and hCA XII. The quinolinone conjugates were inactive as enzyme inhibitors, whereas the coumarins were ineffective hCA I/II inhibitors (KIs > 50 μM) but were submicromolar hCA IV and XII inhibitors, with inhibition constants ranging between 92 nM and 1.19 μM for hCA IV, and between 0.11 and 0.79 μM for hCA XII. These coumarin derivatives, as many others reported earlier, thus show an interesting selective inhibitory profile for the membrane-bound over the cytosolic CA isoforms.

  9. Measurement and modeling of acid dissociation constants of tri-peptides containing Glu, Gly, and His using potentiometry and generalized multiplicative analysis of variance.

    PubMed

    Khoury, Rima Raffoul; Sutton, Gordon J; Hibbert, D Brynn; Ebrahimi, Diako

    2013-02-28

    We report pK(a) values with measurement uncertainties for all labile protons of the 27 tri-peptides prepared from the amino acids glutamic acid (E), glycine (G) and histidine (H). Each tri-peptide (GGG, GGE, GGH, …, HHH) was subjected to alkali titration and pK(a) values were calculated from triplicate potentiometric titrations data using HyperQuad 2008 software. A generalized multiplicative analysis of variance (GEMANOVA) of pK(a) values for the most acidic proton gave the optimum model having two terms, an interaction between the end amino acids plus an isolated main effect of the central amino acid.

  10. Measurement and modeling of acid dissociation constants of tri-peptides containing Glu, Gly, and His using potentiometry and generalized multiplicative analysis of variance.

    PubMed

    Khoury, Rima Raffoul; Sutton, Gordon J; Hibbert, D Brynn; Ebrahimi, Diako

    2013-02-28

    We report pK(a) values with measurement uncertainties for all labile protons of the 27 tri-peptides prepared from the amino acids glutamic acid (E), glycine (G) and histidine (H). Each tri-peptide (GGG, GGE, GGH, …, HHH) was subjected to alkali titration and pK(a) values were calculated from triplicate potentiometric titrations data using HyperQuad 2008 software. A generalized multiplicative analysis of variance (GEMANOVA) of pK(a) values for the most acidic proton gave the optimum model having two terms, an interaction between the end amino acids plus an isolated main effect of the central amino acid. PMID:23247603

  11. Molecular dynamics simulations of glycine crystal-solution interface

    NASA Astrophysics Data System (ADS)

    Banerjee, Soumik; Briesen, Heiko

    2009-11-01

    Glycine is an amino acid that has several applications in the pharmaceutical industry. Hence, growth of α-glycine crystals through solution crystallization is an important process. To gain a fundamental understanding of the seeded growth of α-glycine from aqueous solution, the (110) face of α-glycine crystal in contact with a solution of glycine in water has been simulated with molecular dynamics. The temporal change in the location of the interface of the α-glycine crystal seed has been characterized by detecting a density gradient. It is found that the α-glycine crystal dissolves with time at a progressively decreasing rate. Diffusion coefficients of glycine adjacent to (110) face of α-glycine crystal have been calculated at various temperatures (280, 285, 290, 295, and 300 K) and concentrations (3.6, 4.5, and 6.0 mol/l) and compared to that in the bulk solution. In order to gain a fundamental insight into the nature of variation in such properties at the interface and the bulk, the formation of hydrogen bonds at various temperatures and concentrations has been investigated. It is found that the nature of interaction between various atoms of glycine molecules, as characterized by radial distribution functions, can provide interesting insight into the formation of hydrogen bonds that in turn affect the diffusion coefficients at the interface.

  12. Potential environmental influence of amino acids on the behavior of ZnO nanoparticles.

    PubMed

    Molina, Rodrigo; Al-Salama, Yasser; Jurkschat, Kerstin; Dobson, Peter J; Thompson, Ian P

    2011-04-01

    The fate of nanomaterials when they enter the environment is an issue of increasing concern and thus it is important to know how they interact with natural organic molecules since this may have a significant impact on the particles' behavior. Because of our poor knowledge in this regard, the interaction of ZnO nanoparticles with amino acids of contrasting surface charge, including Histidine (HIS), Glycine (GLY), Aspartic acid (ASP) and Glutamic acid (GLU) which occur commonly in natural habitats, such as the plant root zone, was investigated over a range of pH conditions and concentrations. The addition of the individual amino acid led to significant changes in nanoparticle colloidal zeta potential stability, particle size distribution and the extent of agglomeration. Variations in pH resulted in considerable changes in nanoparticle surface charge and hydrodynamic size. In general, the particle size distribution decreased as the amino acid concentration increased, with more acidic conditions exacerbating this effect. In addition, increased concentrations of amino acids resulted in more stable nanoparticles in aqueous suspensions. Histidine had the greatest effect on colloidal stability, followed by Glycine, Aspartic acid and finally Glutamic acid. This study illustrates how nanoparticle behavior may change in the presence of naturally occurring amino acids, an important consideration when assessing the fate of nanoparticles in the environment. Additionally, utilization of amino acids in industrial processes could reduce particle agglomeration and it could lead to a way of employing more sustainable reagents. PMID:21220148

  13. Amino acid abundances and stereochemistry in hydrothermally altered sediments from the Juan de Fuca Ridge, northeastern Pacific Ocean.

    PubMed

    Andersson, E; Simoneit, B R; Holm, N G

    2000-09-01

    The Juan de Fuca Ridge is a hydrothermally active, sediment covered, spreading ridge situated a few hundred kilometres off the west coast of North America in the northeastern Pacific Ocean. Sediments from seven sites drilled during the Ocean Drilling Program (ODP) Legs 139 and 168 were analyzed for total hydrolyzable amino acids (THAA), individual amino acid distributions, total organic C (TOC) and total N (TN) contents. The aim was to evaluate the effects of hydrothermal stress on the decomposition and transformation of sedimentary amino acids. Hydrolyzable amino acids account for up to 3.3% of the total organic C content and up to 12% of the total N content of the upper sediments. The total amounts of amino acids decrease significantly with depth in all drilled holes. This trend is particularly pronounced in holes with a thermal gradient of around 0.6 degrees C/m or higher. The most abundant amino acids in shallow sediments are glycine, alanine, lysine, glutamic acid, valine and histidine. The changes in amino acid distributions in low temperature holes are characterized by increased relative abundances of non-protein beta-alanine and gamma-aminobutyric acid. In high temperature holes the amino acid compositions are characterized by high abundances of glycine, alanine, serine, ornithine and histidine at depth. D/L ratios of samples with amino acid distributions similar to those found in acid hydrolysates of kerogen, indicate that racemization rates of amino acids bound by condensation reactions may be diminished.

  14. Structural Basis of Cooperative Ligand Binding by the Glycine Riboswitch

    SciTech Connect

    E Butler; J Wang; Y Xiong; S Strobel

    2011-12-31

    The glycine riboswitch regulates gene expression through the cooperative recognition of its amino acid ligand by a tandem pair of aptamers. A 3.6 {angstrom} crystal structure of the tandem riboswitch from the glycine permease operon of Fusobacterium nucleatum reveals the glycine binding sites and an extensive network of interactions, largely mediated by asymmetric A-minor contacts, that serve to communicate ligand binding status between the aptamers. These interactions provide a structural basis for how the glycine riboswitch cooperatively regulates gene expression.

  15. Influence of amino acid specificities on the molecular and supramolecular organization of glycine-rich elastin-like polypeptides in water.

    PubMed

    Salvi, Anna M; Moscarelli, Pasquale; Satriano, Giuseppina; Bochicchio, Brigida; Castle, James E

    2011-10-01

    Elastin-like polypeptides adopt complex supramolecular structures, showing either a hydrophobic or a hydrophilic surface, depending on their surrounding environment and the supporting substrate. The preferred organization is important in many situations ranging from biocompatibility to bio-function. Here we compare the n-repeat pentamer LeuGlyGlyValGly (n = 7) with the analogue ValGlyGlyValGly (n = 5), as water suspensions and as deposits on silicon substrates. These sequences contain the repeat XxxGlyGlyZzzGly (Xxx, Zzz = Val, Leu) motif belonging to the hydrophobic glycine-rich domain of elastin and represent a simplified model from which to obtain information on molecular interactions functional to elastin itself. The compounds studied differ only by the presence of the -CH(2)- spacer in the Leu moiety and thus the work was aimed at revealing the influence of this spacer element on self assembly. Both polypeptides were studied under identical conditions, using combined techniques, to identify differences in their conformational states both at molecular (CD, FTIR) and supramolecular (XPS, AFM) levels. By these means, together with a Congo Red spectroscopic assay of β-sheet formation in water, a clear correlation between amino acid sequences (sequence specificity) and their kinetics and ordering of aggregation has emerged. The novel outcomes of this work are from the supplementary measurements, made to augment the AFM and XPS studies, showing that the significant step in the self assembly of both polypeptides takes place in the liquid phase and from the finding that the substitution of Val by Leu in the first position of the pentapeptide effectively inhibits the formation of amyloidal fibers. PMID:21509743

  16. 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

  17. Glycine Ablation during Comet/Meteoroid Impact

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Dateo, Christopher E.; Mckay, Christopher P.; Borucki, William J.

    2004-01-01

    Amino acids and other organic compounds important to the chemistry of life are thought to have been delivered to early Earth by asteroids and comets. The survivability of such compounds upon high speed entry is not well understood. If molecular processing occurs during entry, the nature of the new molecules produced by such processing is also an open question. To address this question, we have initiated a study of the ablation of glycine, the simplest amino acid, upon the high speed entry of a comet or meteoroid into an atmosphere. The study assumes glycine is distributed on the surface of the comet/meteoroid. The high speed impact creates electrons, ions, and radicals in the atmosphere that react with the surface and either desorb glycine or break it up. The ablation process is studied as a function of entry speed and atmospheric composition. The AURORA code from the commercially available software package CHEMKIN is used in the study.

  18. Thermophysical properties of carboxylic and amino acid buffers at subzero temperatures: relevance to frozen state stabilization.

    PubMed

    Sundaramurthi, Prakash; Suryanarayanan, Raj

    2011-06-01

    Macromolecules and other thermolabile biologicals are often buffered and stored in frozen or dried (freeze-dried) state. Crystallization of buffer components in frozen aqueous solutions and the consequent pH shifts were studied in carboxylic (succinic, malic, citric, tartaric acid) and amino acid (glycine, histidine) buffers. Aqueous buffer solutions were cooled from room temperature (RT) to -25 °C and the pH of the solution was measured as a function of temperature. The thermal behavior of frozen solutions was investigated by differential scanning calorimetry (DSC), and the crystallized phases were identified by X-ray diffractometry (XRD). Based on the solubility of the neutral species of each buffer system over a range of temperatures, it was possible to estimate its degree of supersaturation at the subambient temperature of interest. This enabled us to predict its crystallization propensity in frozen systems. The experimental and the predicted rank orderings were in excellent agreement. The malate buffer system was robust with no evidence of buffer component crystallization and hence negligible pH shift. In the citrate and tartrate systems, at initial pH < pK(a)(2), only the most acidic buffer component (neutral form) crystallized on cooling, causing an increase in the freeze-concentrate pH. In glycine buffer solutions, when the initial pH was ∼3 units < isoelectric pH (pI = 5.9), β-glycine crystallization caused a small decrease in pH, while a similar effect but in the opposite direction was observed when the initial pH was ∼3 units > pI. In the histidine buffer system, depending on the initial pH, either histidine or histidine HCl crystallized.

  19. New crystals of L-histidine maleates

    NASA Astrophysics Data System (ADS)

    Fleck, M.; Ghazaryan, V. V.; Bezhanova, L. S.; Atanesyan, A. K.; Petrosyan, A. M.

    2013-03-01

    Two new crystals were obtained in the system L-histidine (L-His) + maleic acid + H2O: L-His+·maleate-·H2O (I) and L-His2+·2maleate- (II) in addition to two previously known species: L-His+·maleate- (III) and 2L-His+·2maleate-·3H2O (IV). Crystal structures and vibrational spectra of (I) and (II) are determined and compared with structures of (III) and (IV). L-His+·maleate-·H2O is monoclinic (space group P21, Z = 2), L-His2+·2maleate- is triclinic (space group P1, Z = 2). The conformation of the histidine molecules in (I) is closed - as it was found in (III) - whereas in (II) all molecules are in open conformation. Moreover, it is shown that in the structure published for (IV), extremely short Csbnd H⋯O type hydrogen bonds are included, which along with several other data indicate that in this structure N and C atoms in imidazole group of one L-His+ cation have been confused.

  20. Optimum ratio of histidine in the piglet ideal protein model and its effects on body metabolism. I. Basal diet formulation based on digestible amino acids according to the ideal protein model for 10 to 20 kg piglets.

    PubMed

    Zhang, J H; Li, D F; Gong, L M; Zhang, Y C; Zhang, D F

    2002-04-01

    A 4 x 4 Latin square design was used to determine ileal apparent digestibility of amino acids (AAs) in corn, soybean meal, feather meal and dried whey in young pigs. The data were then to be used in formulating a basal diet for studies on AA metabolism in young pigs. Eight castrates T-cannulated at terminal ileum (average initial body weight 12.5 +/- 0.62 kg) were divided into 4 groups on the basis of body weight and transferred to individual metabolism crates. They were then fed four experimental diets containing the four feedstuffs to be tested (corn, soybean meal, feather meal and dried whey). The trial lasted 20 days, which included 4 five-day periods for ileal digesta collection. It was found that the digestibility of the AAs was similar to that reported in literature. Based on the findings a basal diet for this research was formulated according to an ideal protein model for the 10 to 20 kg piglet, on the basis of digestible AAs and containing 14.13 MJ/kg digestible energy, 18.22% crude protein, 1.04% digestible lysine and 0.23% digestible histidine.

  1. Purine and glycine metabolism by purinolytic clostridia.

    PubMed Central

    Dürre, P; Andreesen, J R

    1983-01-01

    Cell extracts of Clostridium acidiurici, C. cylindrosporum, and C. purinolyticum converted purine, hypoxanthine, 2-hydroxypurine, 6,8-dihydroxypurine, and uric acid into xanthine by the shortest possible route. Adenine was transformed to xanthine only by C. purinolyticum, whereas the other two species formed 6-amino-8-hydroxypurine, which was neither deaminated nor hydroxylated further. 8-Hydroxypurine was formed from purine by all three species. Xanthine dehydrogenase activity was constitutively expressed by C. purinolyticum. Due to the lability of the enzyme activity, comparative studies could not be done with a purified preparation. All enzymes reported to be involved in formiminoglycine metabolism of C. acidiurici and C. cylindrosporum were present in C. purinolyticum. However, glycine was reduced directly to acetate in all three species, as indicated by radiochemical data and by the detection of glycine reductase in cell extracts of C. cylindrosporum and C. purinolyticum. The expression of glycine reductase and the high ratio of glycine fermented to uric acid present points to an energetic advantage for the glycine reductase system, which is expressed when selenium compounds are added to the growth media. PMID:6833177

  2. Genomic organization, structure and possible function of histidine-rich proteins of malaria parasites.

    PubMed

    Sharma, Y D

    1988-01-01

    The current status of histidine-rich proteins in malaria parasites with regard to their genomic organization, protein structure and function is discussed, one of such protein present in an avian malaria parasite Plasmodium lophurae contains about 73% histidine and called as HRP (histidine-rich protein). Among human malaria parasites, in Plasmodium falciparum, only three such proteins have been described, namely knob protein also known as knob associated histidine-rich protein (KP or KAHRP), soluble histidine-alanine rich protein (soluble HARP or PfHRP II) and small histidine-alanine rich protein (SHARP) containing 8, 35 and 30% histidine contents respectively. With rapid emergence of powerful tools in molecular biology the genes of all these histidine-rich proteins have been cloned and sequenced within a short period of time. The genomic organizations of all these proteins are very much similar to each other, in each case the gene contains a signal peptide coding sequence (exon 1) followed by an intron. This intron is followed by the main coding region (exon 2) which has no further intervening sequences. In the main coding region of each gene, the histidine-rich sequences start after 25-30 amino acids from N-terminal end (75-90 nucleotides from 5' in exon 2). All the three histidine-rich proteins of P. falciparum share some homology with the HRP of P. lophurae; they all cross react with anti HRP and incorporate higher amount of exogenous histidine. The relationship between KP and HRP resides in the repeated polyhistidine sequences, (His) 6-9, from the core of the multiple tandem repeats of HRP, whereas, the peptide Ala-His-His is commonly shared by HRP and two other proteins of P. falciparum (soluble HARP and SHARP).(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Ectopic expression of Arabidopsis genes encoding salicylic acid- and jasmonic acid-related proteins confers partial resistance to soybean cyst nematode (Heterodera glycines) in transgenic soybean roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background. Extensive studies using the model system Arabidopsis thaliana to elucidate plant defense signaling and pathway networks indicate that salicylic acid (SA) is the key hormone triggering the plant defense response against biotrophic and hemi-biotrophic pathogens, while jasmonic acid (JA) an...

  4. Agglutination of human erythrocytes by the interaction of Zn(2+)ion with histidine-651 on the extracellular domain of band 3.

    PubMed

    Kiyotake, Kento; Ochiai, Hideharu; Yamaguchi, Takeo

    2016-05-01

    Clustering of band 3, chloride/bicarbonate exchanger, has been reported in Zn(2+)-treated human erythrocytes. However, the agglutination of human erythrocytes is also induced by the interaction of Zn(2+)ion with histidine on band 3. Identification of histidine that interacts with Zn(2+)ion remains to be determined. The Zn(2+)-induced agglutination of human erythrocytes was unaffected by chymotrypsin cleavage of the small loop region containing His-547 in the extracellular domain of band 3. On the other hand, papain digestion of the large loop region containing His-651 in band 3 inhibited such Zn(2+)-induced agglutination. Moreover, Zn(2+)-induced erythrocyte agglutination was inhibited by the peptide (ARGWVIHPLG) containing His-651, but not by the peptide such as ARGWVIRPLG, which His-651 was substituted by arginine. Among 10 kinds of animal erythrocytes tested, interestingly, no agglutination by Zn(2+)ions was observed in cow cells only that the forth amino acid in the upstream from His-669 on the large loop of cow band 3 is aspartate (Asp-665) instead of glycine. As expected, the agglutination of human erythrocytes by Zn(2+) ions was inhibited in the presence of aspartate. These data indicate that the interaction of Zn(2+) ion with His-651 residue of band 3 plays an important role in the Zn(2+)-induced agglutination of human erythrocytes.

  5. Free amino acid composition in hemolymph and muscle of the ghost crab, Ocypode platytarsis.

    PubMed

    Sankar, R Siva; Yogamoorthi, A

    2012-05-15

    Free amino acid plays an important role in physiological functions. The ghost crab, Ocypode platytarsis caught off the Puducherry sandy beaches, south east coast of India were investigated for the pattern of distribution of free amino acids. The hemolymph and muscle were sampled from male and female crabs and then subjected to free amino acid analysis quantitatively by HPLC. Fourteen free amino acids have been determined in hemolymph and muscle of both sexes in Ocypode platytarsis. The essential amino acids were leucine, lysine, methionine, phenylalanine, threonine, valine and histidine and non-essential amino acids were alanine, arginine, glutamic acid, glycine, serine and tyrosine. The total concentration of free amino acid found in the male and female hemolymph was lower than that in the muscle. Glutamic acid is of higher concentration in the hemolymph whereas histidine found was higher in the muscle of both sexes. The male crab contains a strikingly higher concentration of histidine of about eight times than that of female in muscles. The study revealed that distribution pattern of free amino acids differ in relation to hemolymph and muscle of male and female crabs.

  6. Glycine decarboxylase in Rhodopseudomonas spheroides and in rat liver mitochondria

    PubMed Central

    Tait, G. H.

    1970-01-01

    1. Glycine decarboxylase and glycine–bicarbonate exchange activities were detected in extracts of Rhodopseudomonas spheroides and in rat liver mitochondria and their properties were studied. 2. The glycine decarboxylase activity from both sources is stimulated when glyoxylate is added to the assay system. 3. Several proteins participate in these reactions and a heat-stable low-molecular-weight protein was purified from both sources. 4. These enzyme activities increase markedly when R. spheroides is grown in the presence of glycine, glyoxylate, glycollate, oxalate or serine. 5. All the enzymes required to catalyse the conversion of glycine into acetyl-CoA via serine and pyruvate were detected in extracts of R. spheroides; of these glycine decarboxylase has the lowest activity. 6. The increase in the activity of glycine decarboxylase on illumination of R. spheroides in a medium containing glycine, and the greater increase when ATP is also present in the medium, probably accounts for the increased incorporation of the methylene carbon atom of glycine into fatty acids found previously under these conditions (Gajdos, Gajdos-Török, Gorchein, Neuberger & Tait, 1968). 7. The results are compared with those obtained by other workers on the glycine decarboxylase and glycine–bicarbonate exchange activities in other systems. PMID:5476725

  7. Preparation and pH stability of ferrous glycinate liposomes.

    PubMed

    Ding, Baomiao; Xia, Shuqin; Hayat, Khizar; Zhang, Xiaoming

    2009-04-01

    Ferrous glycinate liposomes were prepared by reverse phase evaporation method. The effects of cholesterol, Tween 80, ferrous glycinate concentration, hydrating medium, pH of hydrating medium, and sonication strength on the encapsulation efficiency of liposomes were investigated. Encapsulation efficiency was significantly influenced by the different technique parameters. Ferrous glycinate liposomes might be obtained with high encapsulation efficiency of 84.80% under the conditions of optimized technique parameters. The zeta potential and average particle size of liposomes in the hydrating medium of pH 7.0 were 9.6 mV and 559.2 nm, respectively. The release property of ferrous glycinate liposomes in vitro was investigated in simulated gastrointestinal juice. A small amount of ferrous glycinate was released from liposomes in the first 4 h in simulated gastrointestinal juice. The mean diameters of liposomes increased from 559.2 to 692.9, 677.8, and 599.3 nm after incubation in simulated gastrointestinal juice of pH 1.3, 7.5, and 7.5 in the presence of bile salts, respectively. Results showed that the stability of ferrous glycinate in strong acid environment was greatly improved by encapsulation in liposomes, which protected ferrous glycinate from disrupting the extracapsular environment by lipid bilayer. The bioavailability of ferrous glycinate, as the iron source for biological activity including hemoglobin formation, may be increased. The ferrous glycinate liposomes may be a kind of promising iron fortifier. PMID:19253959

  8. Un-catalyzed peptide bond formation between two monomers of glycine, alanine, serine, threonine, and aspartic acid in gas phase: a density functional theory study

    NASA Astrophysics Data System (ADS)

    Bhunia, Snehasis; Singh, Ajeet; Ojha, Animesh K.

    2016-05-01

    In the present report, un-catalyzed peptide bond formation between two monomers of glycine (Gly), alanine (Ala), serine (Ser), threonine (Thr), and aspartic acid (Asp) has been investigated in gas phase via two steps reaction mechanism and concerted mechanism at B3LYP/6-31G(d,p) and M062X/6-31G(d,p) level of theories. The peptide bond is formed through a nucleophilic reaction via transition states, TS1 and TS2 in stepwise mechanism. The TS1 reveals formation of a new C-N bond while TS2 illustrate the formation of C=O bond. In case of concerted mechanism, C-N bond is formed by a single four-centre transition state (TS3). The energy barrier is used to explain the involvement of energy at each step of the reaction. The energy barrier (20-48 kcal/mol) is required for the transformation of reactant state R1 to TS1 state and intermediate state I1 to TS2 state. The large value of energy barrier is explained in terms of distortion and interaction energies for stepwise mechanism. The energy barrier of TS3 in concerted mechanism is very close to the energy barrier of the first transition state (TS1) of the stepwise mechanism for the formation of Gly-Gly and Ala-Ala di- peptide. However, in case of Ser-Ser, Thr-Thr and Asp-Asp di-peptide, the energy barrier of TS3 is relatively high than that of the energy barrier of TS1 calculated at B3LYP/6-31G(d,p) and M062X/6-31G(d,p) level of theories. In both the mechanisms, the value of energy barrier calculated at B3LYP/6-31G(d,p) level of theory is greater than that of the value calculated at M062X/6-31G(d,p) level of theory.

  9. High-affinity labeling and tracking of individual histidine-tagged proteins in live cells using Ni2+ tris-nitrilotriacetic acid quantum dot conjugates.

    PubMed

    Roullier, Victor; Clarke, Samuel; You, Changjiang; Pinaud, Fabien; Gouzer, G Géraldine; Schaible, Dirk; Marchi-Artzner, Valérie; Piehler, Jacob; Dahan, Maxime

    2009-03-01

    Investigation of many cellular processes using fluorescent quantum dots (QDs) is hindered by the nontrivial requirements for QD surface functionalization and targeting. To address these challenges, we designed, characterized and applied QD-trisNTA, which integrates tris-nitrilotriacetic acid, a small and high-affinity recognition unit for the ubiquitous polyhistidine protein tag. Using QD-trisNTA, we demonstrate two-color QD tracking of the type-1 interferon receptor subunits in live cells, potentially enabling direct visualization of protein-protein interactions at the single molecule level. PMID:19216518

  10. Sequencing, characterization, and gene expression analysis of the histidine decarboxylase gene cluster of Morganella morganii.

    PubMed

    Ferrario, Chiara; Borgo, Francesca; de Las Rivas, Blanca; Muñoz, Rosario; Ricci, Giovanni; Fortina, Maria Grazia

    2014-03-01

    The histidine decarboxylase gene cluster of Morganella morganii DSM30146(T) was sequenced, and four open reading frames, named hdcT1, hdc, hdcT2, and hisRS were identified. Two putative histidine/histamine antiporters (hdcT1 and hdcT2) were located upstream and downstream the hdc gene, codifying a pyridoxal-P dependent histidine decarboxylase, and followed by hisRS gene encoding a histidyl-tRNA synthetase. This organization was comparable with the gene cluster of other known Gram negative bacteria, particularly with that of Klebsiella oxytoca. Recombinant Escherichia coli strains harboring plasmids carrying the M. morganii hdc gene were shown to overproduce histidine decarboxylase, after IPTG induction at 37 °C for 4 h. Quantitative RT-PCR experiments revealed the hdc and hisRS genes were highly induced under acidic and histidine-rich conditions. This work represents the first description and identification of the hdc-related genes in M. morganii. Results support the hypothesis that the histidine decarboxylation reaction in this prolific histamine producing species may play a role in acid survival. The knowledge of the role and the regulation of genes involved in histidine decarboxylation should improve the design of rational strategies to avoid toxic histamine production in foods.

  11. Relative utilization of serine and glycine by chicks.

    PubMed

    Featherston, W R

    1975-01-01

    Studies were conducted on the relative utilizaiton of glycine and serine by chicks fed basal crystalline amino acid diets devoid of these amino acids. The crystalline amino acid mixture was fed at one and three times the requirement levels, thereby stimulating uric acid synthesis at differing rates. In addition, 5 per cent L-glutamine replaced L-glutamic acid on an isonitrogenous basis in three diets containing normal levels of amino acids in the second study. Chicks fed diets devoid of glycine and serine grew less rapidly and less efficiently than chicks fed diets containing either serine or glycine plus serine. These decreases were roughly the same whether the diet contained normal or high levels of amino acids. Serine was as efficient as glycine in supporting chick growth and feed efficiency regardless of whether diets containing normal or high levels of amino acids were fed. Chicks fed diets containing high levels of amino acids grew approximately 81 per cent as rapidly, but 24 per cent more efficiently, than chicks fed normal levels of amino acids, and excreted approximately twice the amount of uric acid per gram of nitrogen consumed. In spite of increased uric acid excretion by chicks fed the high amino acid diets, the dietary void in glycine and serine was no more detrimental to chick growth or feed efficiency than that noted when normal levels of amino acids were fed. Feeding 5 per cent L-glutamine rather than L-glutamic acid in the diet containing normal levels of amino acids had little effect on weight gain, feed efficiency or uric acid excretion. The absence of cystine from the amino acid mixture used in the third study did not have a marked influence on the relative utilization of glycine and serine by the chick. PMID:1169769

  12. Impact of histidine residue on chelating ability of 2'-deoxyriboadenosine.

    PubMed

    Lodyga-Chruścińska, Elżbieta; Ołdziej, Stanisław; Sochacka, Elżbieta; Korzycka, Karolina; Chruściński, Longin; Micera, Giovanni; Sanna, Daniele; Turek, Monika; Pawlak, Justyna

    2011-09-01

    Copper(II) complexes with a new chelator-type nucleoside-histidine modified 2'-deoxyriboadenosine (N-[(9-β-D-2'-deoxyribofuranosylpurin-6-yl)-carbamoyl]histidine) were studied by potentiometric and spectroscopic (UV-visible, CD, EPR) techniques, in conjunction with computer modeling optimization. The ligand can act as bidentate or tridentate depending on pH range. In acidic pH a very stable dimeric complex Cu(2)L(2) predominates with coordination spheres of both metal ions composed of oxygen atoms from carboxylic groups, one oxygen atom from ureido group and two nitrogen atoms derived from purine base and histidine ring. Above pH 5, deprotonation of carbamoyl nitrogens leads to the formation of CuL(2), Cu(2)L(2)H(-1) and Cu(2)L(2)H(-2) species. The CuL(2)H(-1) and CuL(2)H(-2) complexes with three or four nitrogens in Cu(II) coordination sphere have been detected in alkaline medium. Our findings suggest that N-[(9-beta-D-2'-deoxyribofuranosylpurin-6-yl)-carbamoyl]histidine chelates copper(II) ions very efficiently. The resulting complex might be used as an alternative base-pairing mode in which hydrogen-bonded base pairs present in natural DNA are replaced by metal-mediated ones. PMID:21723807

  13. Impact of histidine residue on chelating ability of 2'-deoxyriboadenosine.

    PubMed

    Lodyga-Chruścińska, Elżbieta; Ołdziej, Stanisław; Sochacka, Elżbieta; Korzycka, Karolina; Chruściński, Longin; Micera, Giovanni; Sanna, Daniele; Turek, Monika; Pawlak, Justyna

    2011-09-01

    Copper(II) complexes with a new chelator-type nucleoside-histidine modified 2'-deoxyriboadenosine (N-[(9-β-D-2'-deoxyribofuranosylpurin-6-yl)-carbamoyl]histidine) were studied by potentiometric and spectroscopic (UV-visible, CD, EPR) techniques, in conjunction with computer modeling optimization. The ligand can act as bidentate or tridentate depending on pH range. In acidic pH a very stable dimeric complex Cu(2)L(2) predominates with coordination spheres of both metal ions composed of oxygen atoms from carboxylic groups, one oxygen atom from ureido group and two nitrogen atoms derived from purine base and histidine ring. Above pH 5, deprotonation of carbamoyl nitrogens leads to the formation of CuL(2), Cu(2)L(2)H(-1) and Cu(2)L(2)H(-2) species. The CuL(2)H(-1) and CuL(2)H(-2) complexes with three or four nitrogens in Cu(II) coordination sphere have been detected in alkaline medium. Our findings suggest that N-[(9-beta-D-2'-deoxyribofuranosylpurin-6-yl)-carbamoyl]histidine chelates copper(II) ions very efficiently. The resulting complex might be used as an alternative base-pairing mode in which hydrogen-bonded base pairs present in natural DNA are replaced by metal-mediated ones.

  14. Evidence in support of lysine 77 and histidine 96 as acid-base catalytic residues in saccharopine dehydrogenase from Saccharomyces cerevisiae.

    PubMed

    Kumar, Vidya Prasanna; Thomas, Leonard M; Bobyk, Kostyantyn D; Andi, Babak; Cook, Paul F; West, Ann H

    2012-01-31

    Saccharopine dehydrogenase (SDH) catalyzes the final reaction in the α-aminoadipate pathway, the conversion of l-saccharopine to l-lysine (Lys) and α-ketoglutarate (α-kg) using NAD⁺ as an oxidant. The enzyme utilizes a general acid-base mechanism to conduct its reaction with a base proposed to accept a proton from the secondary amine of saccharopine in the oxidation step and a group proposed to activate water to hydrolyze the resulting imine. Crystal structures of an open apo form and a closed form of the enzyme with saccharopine and NADH bound have been determined at 2.0 and 2.2 Å resolution, respectively. In the ternary complex, a significant movement of domain I relative to domain II that closes the active site cleft between the two domains and brings H96 and K77 into the proximity of the substrate binding site is observed. The hydride transfer distance is 3.6 Å, and the side chains of H96 and K77 are properly positioned to act as acid-base catalysts. Preparation of the K77M and H96Q single-mutant and K77M/H96Q double-mutant enzymes provides data consistent with their role as the general acid-base catalysts in the SDH reaction. The side chain of K77 initially accepts a proton from the ε-amine of the substrate Lys and eventually donates it to the imino nitrogen as it is reduced to a secondary amine in the hydride transfer step, and H96 protonates the carbonyl oxygen as the carbinolamine is formed. The K77M, H976Q, and K77M/H96Q mutant enzymes give 145-, 28-, and 700-fold decreases in V/E(t) and >10³-fold increases in V₂/K(Lys)E(t) and V₂/K(α-kg)E(t) (the double mutation gives >10⁵-fold decreases in the second-order rate constants). In addition, the K77M mutant enzyme exhibits a primary deuterium kinetic isotope effect of 2.0 and an inverse solvent deuterium isotope effect of 0.77 on V₂/K(Lys). A value of 2.0 was also observed for (D)(V₂/K(Lys))(D₂O) when the primary deuterium kinetic isotope effect was repeated in D₂O, consistent with a

  15. Evidence in support of lysine 77 and histidine 96 as acid-base catalytic residues in saccharopine dehydrogenase from Saccharomyces cerevisiae.

    PubMed

    Kumar, Vidya Prasanna; Thomas, Leonard M; Bobyk, Kostyantyn D; Andi, Babak; Cook, Paul F; West, Ann H

    2012-01-31

    Saccharopine dehydrogenase (SDH) catalyzes the final reaction in the α-aminoadipate pathway, the conversion of l-saccharopine to l-lysine (Lys) and α-ketoglutarate (α-kg) using NAD⁺ as an oxidant. The enzyme utilizes a general acid-base mechanism to conduct its reaction with a base proposed to accept a proton from the secondary amine of saccharopine in the oxidation step and a group proposed to activate water to hydrolyze the resulting imine. Crystal structures of an open apo form and a closed form of the enzyme with saccharopine and NADH bound have been determined at 2.0 and 2.2 Å resolution, respectively. In the ternary complex, a significant movement of domain I relative to domain II that closes the active site cleft between the two domains and brings H96 and K77 into the proximity of the substrate binding site is observed. The hydride transfer distance is 3.6 Å, and the side chains of H96 and K77 are properly positioned to act as acid-base catalysts. Preparation of the K77M and H96Q single-mutant and K77M/H96Q double-mutant enzymes provides data consistent with their role as the general acid-base catalysts in the SDH reaction. The side chain of K77 initially accepts a proton from the ε-amine of the substrate Lys and eventually donates it to the imino nitrogen as it is reduced to a secondary amine in the hydride transfer step, and H96 protonates the carbonyl oxygen as the carbinolamine is formed. The K77M, H976Q, and K77M/H96Q mutant enzymes give 145-, 28-, and 700-fold decreases in V/E(t) and >10³-fold increases in V₂/K(Lys)E(t) and V₂/K(α-kg)E(t) (the double mutation gives >10⁵-fold decreases in the second-order rate constants). In addition, the K77M mutant enzyme exhibits a primary deuterium kinetic isotope effect of 2.0 and an inverse solvent deuterium isotope effect of 0.77 on V₂/K(Lys). A value of 2.0 was also observed for (D)(V₂/K(Lys))(D₂O) when the primary deuterium kinetic isotope effect was repeated in D₂O, consistent with a

  16. Molecular analysis and physicochemical properties of electrophoretic variants of wild soybean Glycine soja storage proteins.

    PubMed

    Fukuda, Takako; Maruyama, Nobuyuki; Kanazawa, Akira; Abe, Jun; Shimamoto, Yoshiya; Hiemori, Miki; Tsuji, Hideaki; Tanisaka, Takatoshi; Utsumi, Shigeru

    2005-05-01

    Cultivated soybeans (Glycine max) are derived from wild soybeans (Glycine soja) and can be crossed with them to produce fertile offspring. The latter exhibit greater genetic variation than the former, suggesting a possibility that wild soybeans contain storage proteins with properties different from and better than those of cultivated soybeans. To identify a wild soybean suitable for breeding a new soybean cultivar, we analyzed seed proteins from 390 lines of wild soybeans by electrophoresis. We found some lines containing electrophoretic variants of glycinin and beta-conglycinin subunits: one line containing a small alpha' subunit of beta-conglycinin and two and five lines containing small A3 and large A4 polypeptides of glycinin, respectively. Beta-Conglycinin and glycinin containing such variant subunits exhibited solubility and emulsifying ability similar to those of the predominant types of wild and cultivated soybeans. Glycinins containing small A3 and large A4 gave a shoulder derived from the start of denaturation at a temperature 4 degrees C lower than that of glycinin from the predominant types of wild and cultivated soybeans, although their thermal denaturation midpoint temperatures were very similar to each other. Cloning and sequencing of the predominant and variant subunit cDNAs revealed that the small alpha' and the small A3 lacked 24 amino acid residues in the extension region and four amino acid residues in the hypervariable region, respectively, and that the large A4 did not have an insert corresponding to the difference in the electrophoretic mobility but Arg279 and Gln305 were replaced by glutamine and histidine, respectively, in the hypervariable region. These suggest that small differences even in the hypervariable region can affect the thermal stability, as well as the electrophoretic mobilities, of the proteins.

  17. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  18. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China

    PubMed Central

    Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3−-N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  19. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  20. Reversible Major Histocompatibility Complex I-Peptide Multimers Containing Ni2+-Nitrilotriacetic Acid Peptides and Histidine Tags Improve Analysis and Sorting of CD8+ T Cells*

    PubMed Central

    Schmidt, Julien; Guillaume, Philippe; Irving, Melita; Baumgaertner, Petra; Speiser, Daniel; Luescher, Immanuel F.

    2011-01-01

    MHC-peptide multimers containing biotinylated MHC-peptide complexes bound to phycoerythrin (PE) streptavidin (SA) are widely used for analyzing and sorting antigen-specific T cells. Here we describe alternative T cell-staining reagents that are superior to conventional reagents. They are built on reversible chelate complexes of Ni2+-nitrilotriacetic acid (NTA) with oligohistidines. We synthesized biotinylated linear mono-, di-, and tetra-NTA compounds using conventional solid phase peptide chemistry and studied their interaction with HLA-A*0201-peptide complexes containing a His6, His12, or 2×His6 tag by surface plasmon resonance on SA-coated sensor chips and equilibrium dialysis. The binding avidity increased in the order His6 < His12 < 2×His6 and NTA1 < NTA2 < NTA4, respectively, depending on the configuration of the NTA moieties and increased to picomolar KD for the combination of a 2×His6 tag and a 2×Ni2+-NTA2. We demonstrate that HLA-A2–2×His6-peptide multimers containing either Ni2+-NTA4-biotin and PE-SA- or PE-NTA4-stained influenza and Melan A-specific CD8+ T cells equal or better than conventional multimers. Although these complexes were highly stable, they very rapidly dissociated in the presence of imidazole, which allowed sorting of bona fide antigen-specific CD8+ T cells without inducing T cell death as well as assessment of HLA-A2-peptide monomer dissociation kinetics on CD8+ T cells. PMID:21990358

  1. Allosteric modulation of glycine receptors

    PubMed Central

    Yevenes, Gonzalo E; Zeilhofer, Hanns Ulrich

    2011-01-01

    Inhibitory (or strychnine sensitive) glycine receptors (GlyRs) are anion-selective transmitter-gated ion channels of the cys-loop superfamily, which includes among others also the inhibitory γ-aminobutyric acid receptors (GABAA receptors). While GABA mediates fast inhibitory neurotransmission throughout the CNS, the action of glycine as a fast inhibitory neurotransmitter is more restricted. This probably explains why GABAA receptors constitute a group of extremely successful drug targets in the treatment of a wide variety of CNS diseases, including anxiety, sleep disorders and epilepsy, while drugs specifically targeting GlyRs are virtually lacking. However, the spatially more restricted distribution of glycinergic inhibition may be advantageous in situations when a more localized enhancement of inhibition is sought. Inhibitory GlyRs are particularly relevant for the control of excitability in the mammalian spinal cord, brain stem and a few selected brain areas, such as the cerebellum and the retina. At these sites, GlyRs regulate important physiological functions, including respiratory rhythms, motor control, muscle tone and sensory as well as pain processing. In the hippocampus, RNA-edited high affinity extrasynaptic GlyRs may contribute to the pathology of temporal lobe epilepsy. Although specific modulators have not yet been identified, GlyRs still possess sites for allosteric modulation by a number of structurally diverse molecules, including alcohols, neurosteroids, cannabinoids, tropeines, general anaesthetics, certain neurotransmitters and cations. This review summarizes the present knowledge about this modulation and the molecular bases of the interactions involved. PMID:21557733

  2. Comparative 4f-4f absorption spectral study for the interactions of Nd(III) with some amino acids: Preliminary thermodynamics and kinetic studies of interaction of Nd(III):glycine with Ca(II)

    NASA Astrophysics Data System (ADS)

    Moaienla, T.; Bendangsenla, N.; David Singh, Th.; Sumitra, Ch.; Rajmuhon Singh, N.; Indira Devi, M.

    2012-02-01

    Spectral analysis of Nd(III) complexes with some amino acids viz.; glycine, L-alanine, L-phenylalanine and L-aspartic acid in the presence and absence of Ca 2+ was carried out in some organic solvents; CH 3OH, CH 3CN, DMF and dioxane using comparative absorption spectra of 4f-4f transitions. The study was carried out by evaluating various energy interaction parameters like Slator-Condon ( Fk), Lande factor ( ξ4f), nephelauxetic ratio ( β), bonding parameter ( b1/2), percent-covalency ( δ) by applying partial and multiple regression analysis. The values of oscillator strength ( Pobs) and Judd-Ofelt electric dipole intensity parameter Tλ ( λ = 2, 4, 6) for different 4f-4f transitions have been calculated. On analysis of the variation of the various energy interaction parameters as well as the changes in the oscillator strength ( Pobs) and Tλ values, reveal the mode of binding with the different ligands. Kinetic studies for the complexation of Nd(III):glycine:Ca(II) have also been discussed at different temperatures in DMF medium and from it the values of activation energy ( Ea) and thermodynamic parameters like Δ H°, Δ S° and Δ G° for the complexation are evaluated.

  3. Proton transfer in histidine-tryptophan heterodimers embedded in helium droplets

    SciTech Connect

    Bellina, Bruno; Merthe, Daniel J.; Kresin, Vitaly V.

    2015-03-21

    We used cold helium droplets as nano-scale reactors to form and ionize, by electron bombardment and charge transfer, aromatic amino acid heterodimers of histidine with tryptophan, methyl-tryptophan, and indole. The molecular interaction occurring through an N–H ⋅ ⋅ ⋅ N hydrogen bond leads to a proton transfer from the indole group of tryptophan to the imidazole group of histidine in a radical cationic environment.

  4. Proton transfer in histidine-tryptophan heterodimers embedded in helium droplets.

    PubMed

    Bellina, Bruno; Merthe, Daniel J; Kresin, Vitaly V

    2015-03-21

    We used cold helium droplets as nano-scale reactors to form and ionize, by electron bombardment and charge transfer, aromatic amino acid heterodimers of histidine with tryptophan, methyl-tryptophan, and indole. The molecular interaction occurring through an N-H···N hydrogen bond leads to a proton transfer from the indole group of tryptophan to the imidazole group of histidine in a radical cationic environment.

  5. Glycine receptors are functionally expressed on bullfrog retinal cone photoreceptors.

    PubMed

    Ge, L-H; Lee, S-C; Liu, J; Yang, X-L

    2007-04-25

    Using immunocytochemical and whole cell recording techniques, we examined expression of glycine receptors on bullfrog retinal cone photoreceptors. Immunofluorescence double labeling experiments conducted on retinal sections and isolated cell preparations showed that terminals and inner segments of cones were immunoreactive to both alpha1 and beta subunits of glycine receptors. Moreover, application of glycine induced a sustained inward current from isolated cones, which increased in amplitude in a dose-dependent manner, with an EC50 (concentration of glycine producing half-maximal response) of 67.3+/-4.9 microM, and the current was blocked by the glycine receptor antagonist strychnine, but not 5,7-dichlorokynurenic acid (DCKA) of 200 microM, a blocker of the glycine recognition site at the N-methyl-D-aspartate (NMDA) receptor. The glycine-induced current reversed in polarity at a potential close to the calculated chloride equilibrium potential, and the reversal potential was changed as a function of the extracellular chloride concentration. These results suggest that strychnine-sensitive glycine receptors are functionally expressed in bullfrog cones, which may mediate signal feedback from glycinergic interplexiform cells to cones in the outer retina. PMID:17346892

  6. Photorespiratory Glycine Metabolism in Corn Leaf Discs 1

    PubMed Central

    Marek, Laura F.; Stewart, Cecil R.

    1983-01-01

    The total glycine pool in Zea mays L. Mo17×B73 leaf discs was measured after steady state photosynthesis in 50%, 21% and 1% O2. The glycine pool was a function of O2 concentration; it was largest in 50% O2 and smallest in 1% O2. Incubation of discs with methyl hydroxybutynoic acid in 21% O2 in the light caused an accumulation of carbon in glycolate. This accumulation was O2 sensitive, as subsequent photosynthetic periods in 50%, 21%, and 1% O2 resulted in the largest glycolate pool in 50% O2 and the smallest in 1% O2. At the same time, the O2-dependent increase in the glycine pool was eliminated. After untreated leaf discs reached steady state photosynthesis in 21% O2, measurements made subsequently in darkness, or in 1% O2 in the light, showed that the glycine pool decreased. On the basis of these results, we conclude that a major portion of the total glycine pool in corn is an intermediate in the photorespiratory glycolate pathway. Considering both the rate of decay of the glycine pool in the dark and the rate of decay of the glycine pool after changing from 21% to 1% O2, we conclude that this glycine pool is turning over slowly. PMID:16663158

  7. L-histidine inhibits biofilm formation and FLO11-associated phenotypes in Saccharomyces cerevisiae flor yeasts.

    PubMed

    Bou Zeidan, Marc; Zara, Giacomo; Viti, Carlo; Decorosi, Francesca; Mannazzu, Ilaria; Budroni, Marilena; Giovannetti, Luciana; Zara, Severino

    2014-01-01

    Flor yeasts of Saccharomyces cerevisiae have an innate diversity of Flo11p which codes for a highly hydrophobic and anionic cell-wall glycoprotein with a fundamental role in biofilm formation. In this study, 380 nitrogen compounds were administered to three S. cerevisiae flor strains handling Flo11p alleles with different expression levels. S. cerevisiae strain S288c was used as the reference strain as it cannot produce Flo11p. The flor strains generally metabolized amino acids and dipeptides as the sole nitrogen source, although with some exceptions regarding L-histidine and histidine containing dipeptides. L-histidine completely inhibited growth and its effect on viability was inversely related to Flo11p expression. Accordingly, L-histidine did not affect the viability of the Δflo11 and S288c strains. Also, L-histidine dramatically decreased air-liquid biofilm formation and adhesion to polystyrene of the flor yeasts with no effect on the transcription level of the Flo11p gene. Moreover, L-histidine modified the chitin and glycans content on the cell-wall of flor yeasts. These findings reveal a novel biological activity of L-histidine in controlling the multicellular behavior of yeasts [corrected]. PMID:25369456

  8. L-Histidine Inhibits Biofilm Formation and FLO11-Associated Phenotypes in Saccharomyces cerevisiae Flor Yeasts

    PubMed Central

    Bou Zeidan, Marc; Zara, Giacomo; Viti, Carlo; Decorosi, Francesca; Mannazzu, Ilaria; Budroni, Marilena; Giovannetti, Luciana; Zara, Severino

    2014-01-01

    Flor yeasts of Saccharomyces cerevisiae have an innate diversity of FLO11 which codes for a highly hydrophobic and anionic cell-wall glycoprotein with a fundamental role in biofilm formation. In this study, 380 nitrogen compounds were administered to three S. cerevisiae flor strains handling FLO11 alleles with different expression levels. S. cerevisiae strain S288c was used as the reference strain as it cannot produce FLO11p. The flor strains generally metabolized amino acids and dipeptides as the sole nitrogen source, although with some exceptions regarding L-histidine and histidine containing dipeptides. L-histidine completely inhibited growth and its effect on viability was inversely related to FLO11 expression. Accordingly, L-histidine did not affect the viability of the Δflo11 and S288c strains. Also, L-histidine dramatically decreased air–liquid biofilm formation and adhesion to polystyrene of the flor yeasts with no effect on the transcription level of the FLO11 gene. Moreover, L-histidine modified the chitin and glycans content on the cell-wall of flor yeasts. These findings reveal a novel biological activity of L-histidine in controlling the multicellular behavior of yeasts. PMID:25369456

  9. 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

  10. Catalysis of Dialanine Formation by Glycine in the Salt-Induced Peptide Formation Reaction.

    NASA Astrophysics Data System (ADS)

    Suwannachot, Yuttana; Rode, Bernd M.

    1998-02-01

    Mutual catalysis of amino acids in the salt-induced peptide formation (SIPF) reaction is demonstrated for the case of glycine/alanine. The presence of glycine enhances dialanine formation by a factor up to 50 and enables dialanine formation at much lower alanine concentrations. The actual amounts of glycine play an important role for this catalytic effect, the optimal glycine concentration is 1/8 of the alanine concentration. The mechanism appears to be based on the formation of the intermediate Gly-Ala-Ala tripeptide, connected to one coordination site of copper(II) ion, and subsequent hydrolysis to dialanine and glycine.

  11. Na sup + -glycine cotransport in canalicular liver plasma membrane vesicles

    SciTech Connect

    Moseley, R.H.; Ballatori, N.; Murphy, S.M. Yale Univ. School of Medicine, New Haven, CT Univ. of Rochester School of Medicine and Dentistry, NY )

    1988-08-01

    By use of purified rat canalicular liver plasma membrane (cLPM) vesicles, the present study determined the driving forces for glycine transport across this membrane domain. Initial rates of ({sup 3}H)glycine uptake in cLPM vesicles were stimulated by an inwardly directed Na{sup +} gradient but not by a K{sup +} gradient. Na{sup +} gradient-dependent uptake of glycine demonstrated cation specificity for Na{sup +}, dependence on extravesicular Cl{sup {minus}}, stimulation by an intravesicular-negative membrane potential, and inhibition by dissipation of the Na{sup +} gradient with gramicidin D. Na{sup +} gradient-dependent glycine cotransport also demonstrated greater sensitivity to inhibition by sarcosine than 2-(methylamino)-isobutyric acid. Accelerated exchange diffusion of ({sup 3}H)glycine was demonstrated in the presence of Na{sup +} when cLPM vesicles were preloaded with glycine but not with L-alanine or L-proline. Substrate velocity analysis of net Na{sup +}-dependent ({sup 3}H)glycine uptake over the range of amino acid concentrations from 5 {mu}M to 5 mM demonstrated two saturable transport systems, one of high capacity and low affinity and one of low capacity and comparatively high affinity. These results indicate that, in addition to previously described neutral and anionic amino acid transport systems, Na{sup +} gradient-dependent glycine transport mechanisms are present on the canalicular domain of the liver plasma membrane. These canalicular reabsorptive mechanisms may serve to reclaim some of the glycine generated within the canalicular lumen from the intrabiliary hydrolysis of glutathione.

  12. Accurate determination of the amino acid content of selected feedstuffs.

    PubMed

    Rutherfurd, Shane M

    2009-01-01

    The accurate determination of the amino acid content is important. In the present study, a least-squares non-linear regression model of the amino acid content determined over multiple hydrolysis times was used to accurately determine the content of amino acids in five different feedstuffs. These values were compared with 24-h hydrolysis values determined for the same feedstuffs. Overall, approximately two-thirds of the amino acids determined in this study (aspartic acid, threonine, glutamic acid, proline, glycine, alanine, leucine, tyrosine, phenylalanine and arginine) using 24-h hydrolysis were in good agreement (<3% difference). When examined across feedstuffs, the concentration of serine was underestimated by the 24-h hydrolysis method by 4.8%, while the concentrations of histidine and lysine were overestimated by 3.9% and 3.1%, respectively.

  13. Glycine and Glycine Receptor Signalling in Non-Neuronal Cells

    PubMed Central

    den Eynden, Jimmy Van; Ali, Sheen Saheb; Horwood, Nikki; Carmans, Sofie; Brône, Bert; Hellings, Niels; Steels, Paul; Harvey, Robert J.; Rigo, Jean-Michel

    2009-01-01

    Glycine is an inhibitory neurotransmitter acting mainly in the caudal part of the central nervous system. Besides this neurotransmitter function, glycine has cytoprotective and modulatory effects in different non-neuronal cell types. Modulatory effects were mainly described in immune cells, endothelial cells and macroglial cells, where glycine modulates proliferation, differentiation, migration and cytokine production. Activation of glycine receptors (GlyRs) causes membrane potential changes that in turn modulate calcium flux and downstream effects in these cells. Cytoprotective effects were mainly described in renal cells, hepatocytes and endothelial cells, where glycine protects cells from ischemic cell death. In these cell types, glycine has been suggested to stabilize porous defects that develop in the plasma membranes of ischemic cells, leading to leakage of macromolecules and subsequent cell death. Although there is some evidence linking these effects to the activation of GlyRs, they seem to operate in an entirely different mode from classical neuronal subtypes. PMID:19738917

  14. Detection of histidine oxidation in a monoclonal immunoglobulin gamma (IgG) 1 antibody.

    PubMed

    Amano, Masato; Kobayashi, Naoki; Yabuta, Masayuki; Uchiyama, Susumu; Fukui, Kiichi

    2014-08-01

    Although oxidation of methionine and tryptophan are known as popular chemical modifications that occur in monoclonal antibody (mAb) molecules, oxidation of other amino acids in mAbs has not been reported to date. In this study, oxidation of the histidine residue in a human immunoglobulin gamma (IgG) 1 molecule was discovered for the first time by mass spectrometry. The oxidation of a specific histidine located at the CH2 domain of IgG1 occurred under light stress, but it was not observed under heat stress. With the forced degradation study using several reactive oxygen species, the singlet oxygen was attributed to a reactive source of the histidine oxidation. The reaction mechanism of the histidine oxidation was proposed on the basis of the mass spectrometric analysis of IgG1 oxidized in deuterium oxide and hydrogen heavy oxide. PMID:24940720

  15. 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.

  16. Glycine enhanced separation of Co(II) and Ni(II) with bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) by liquid-liquid extraction and supported liquid membranes

    SciTech Connect

    Reichley-Yinger, L.; Danesi, P.R.

    1985-01-01

    The extraction behavior of Co and Ni ions from aqueous nitrate solution containing glycine, and their separation by liquid-liquid extraction and supported liquid membranes (SLMs) has been studied. The separation factor between the two metals is greatly enhanced by the presence of glycine. The enhancement is due to the preferential complexation of the Ni ions by glycine. The conditional equilibrium constants of the extraction reactions and the SLM permeability coefficients have been measured. The results indicate that metal glycinate complexes are not extracted and that in presence of glycine very clean Co-Ni separation can be obtained in a single SLM pass.

  17. cDNA cloning and deduced amino acid sequence of a major, glycine-rich cuticular protein from the coleopteran Tenebrio molitor. Temporal and spatial distribution of the transcript during metamorphosis.

    PubMed

    Charles, J P; Bouhin, H; Quennedey, B; Courrent, A; Delachambre, J

    1992-06-15

    In Coleoptera, the elytra (forewings), with a very hard and thick cuticle, protect the membranous and delicate hindwings against mechanical stress. We have isolated and characterized a cDNA encoding a major cuticle protein in Tenebrio molitor, named ACP-20. The deduced amino acid sequence is roughly tripartite, with two terminal glycine-rich domains and a central region showing pronounced similarities with some other hard cuticle proteins. Northern blot and in situ hybridization analyses reveal that ACP-20 gene expression is developmentally regulated since transcript accumulation occurs only in epidermal regions synthesizing hard cuticle and is restricted to the period of preecdysial adult cuticle deposition. Moreover, application of a juvenile hormone analogue prevents the appearance of the transcript, indicating that juvenile hormone, a key molecule involved in the control of insect metamorphosis, negatively regulates the expression of the ACP-20 gene.

  18. Glycine lithium nitrate crystals

    NASA Astrophysics Data System (ADS)

    González-Valenzuela, R.; Hernández-Paredes, J.; Medrano-Pesqueira, T.; Esparza-Ponce, H. E.; Jesús-Castillo, S.; Rodriguez-Mijangos, R.; Terpugov, V. S.; Alvarez-Ramos, M. E.; Duarte-Möller, A.

    Crystals of glycine lithium nitrate with non-linear optical properties have been grown in a solution by slow evaporation at room temperature. The crystal shows a good thermal stability from room temperature to 175 °C where the crystal begins to degrade. This property is desirable for future technological applications. Also, a good performance on the second harmonic generation was found, characterizing the emitted dominant wavelength by a customized indirect procedure using luminance and chromaticity measured data based on the CIE-1931 standard. Additionally, the 532 nm signal was detected by using a variant to the Kurtz and Perry method.

  19. The effect of histidine on mental fatigue and cognitive performance in subjects with high fatigue and sleep disruption scores.

    PubMed

    Sasahara, Ikuko; Fujimura, Naoko; Nozawa, Yoshizu; Furuhata, Yasufumi; Sato, Hitoshi

    2015-08-01

    Our previous study reported that a dried bonito broth known in Japan as 'dashi' improved or ameliorated mood states, including fatigue, during the daily lives of human subjects. Histidine is an amino acid that is present in dried bonito broth, and we sought to evaluate whether histidine would affect feelings of fatigue in humans. We investigated the effects of histidine intake on the feeling of fatigue, mood states and mental task performance by performing a placebo-controlled, double-blind crossover trial. Twenty subjects with high fatigue and sleep disruption scores were asked to ingest histidine or a placebo every day for two weeks. The subjects' mood states were evaluated using the Profile of Mood States (POMS) scale and a visual analog scale (VAS) for eight feelings (fatigue, depression, carelessness, drowsiness, clear thinking, motivation, attentiveness and concentration). We also measured subjects' cognitive performance using the CogHealth test battery. The fatigue T-scores on the POMS test decreased significantly following histidine ingestion compared to placebo ingestion (p<0.05). After two weeks of histidine ingestion, the reaction time for the working memory task in the CogHealth test battery was significantly shorten compared to placebo ingestion. The VAS scores for clear thinking and for attentiveness were increased significantly following histidine ingestion compared to placebo ingestion (p<0.05). These results suggest that daily ingestion of histidine may ameliorate feelings of fatigue, increase performance during working memory tasks, and improve the clear thinking and attentiveness. PMID:25921948

  20. The effect of histidine on mental fatigue and cognitive performance in subjects with high fatigue and sleep disruption scores.

    PubMed

    Sasahara, Ikuko; Fujimura, Naoko; Nozawa, Yoshizu; Furuhata, Yasufumi; Sato, Hitoshi

    2015-08-01

    Our previous study reported that a dried bonito broth known in Japan as 'dashi' improved or ameliorated mood states, including fatigue, during the daily lives of human subjects. Histidine is an amino acid that is present in dried bonito broth, and we sought to evaluate whether histidine would affect feelings of fatigue in humans. We investigated the effects of histidine intake on the feeling of fatigue, mood states and mental task performance by performing a placebo-controlled, double-blind crossover trial. Twenty subjects with high fatigue and sleep disruption scores were asked to ingest histidine or a placebo every day for two weeks. The subjects' mood states were evaluated using the Profile of Mood States (POMS) scale and a visual analog scale (VAS) for eight feelings (fatigue, depression, carelessness, drowsiness, clear thinking, motivation, attentiveness and concentration). We also measured subjects' cognitive performance using the CogHealth test battery. The fatigue T-scores on the POMS test decreased significantly following histidine ingestion compared to placebo ingestion (p<0.05). After two weeks of histidine ingestion, the reaction time for the working memory task in the CogHealth test battery was significantly shorten compared to placebo ingestion. The VAS scores for clear thinking and for attentiveness were increased significantly following histidine ingestion compared to placebo ingestion (p<0.05). These results suggest that daily ingestion of histidine may ameliorate feelings of fatigue, increase performance during working memory tasks, and improve the clear thinking and attentiveness.

  1. Cometary Glycine Detected in Samples Returned by Stardust

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

    2009-01-01

    Our previous analysis of cometary samples returned to Earth by NASA's Stardust spacecraft showed several amines and amino acids, but the or igin of these compounds could not be firmly established. Here, we pre sent the stable carbon isotopic ratios of glycine and E-amino-n-caproic acid (EACA), the two most abundant amino acids identified in Stardu st-returned foil samples measured by gas chromatography-mass spectrom etry coupled with isotope ratio mass spectrometry. The Delta C-13 value for glycine of +29 +/- ? 6%: strongly suggests an extraterrestrial origin For glycine, while the Delta C-13 value for EACA of -25 +/-2 % indicates terrestrial contamination by Nylon-6 during curation. This represents the first detection of a cometary amino acid.

  2. Glycine and Folate Ameliorate Models of Congenital Sideroblastic Anemia

    PubMed Central

    Dufay, J. Noelia; Steele, Shelby L.; Gaston, Daniel; Nasrallah, Gheyath K.; Coombs, Andrew J.; Liwski, Robert S.; Fernandez, Conrad V.; Berman, Jason N.; McMaster, Christopher R.

    2016-01-01

    Sideroblastic anemias are acquired or inherited anemias that result in a decreased ability to synthesize hemoglobin in red blood cells and result in the presence of iron deposits in the mitochondria of red blood cell precursors. A common subtype of congenital sideroblastic anemia is due to autosomal recessive mutations in the SLC25A38 gene. The current treatment for SLC25A38 congenital sideroblastic anemia is chronic blood transfusion coupled with iron chelation. The function of SLC25A38 is not known. Here we report that the SLC25A38 protein, and its yeast homolog Hem25, are mitochondrial glycine transporters required for the initiation of heme synthesis. To do so, we took advantage of the fact that mitochondrial glycine has several roles beyond the synthesis of heme, including the synthesis of folate derivatives through the glycine cleavage system. The data were consistent with Hem25 not being the sole mitochondrial glycine importer, and we identify a second SLC25 family member Ymc1, as a potential secondary mitochondrial glycine importer. Based on these findings, we observed that high levels of exogenous glycine, or 5-aminolevulinic acid (5-Ala) a metabolite downstream of Hem25 in heme biosynthetic pathway, were able to restore heme levels to normal in yeast cells lacking Hem25 function. While neither glycine nor 5-Ala could ameliorate SLC25A38 congenital sideroblastic anemia in a zebrafish model, we determined that the addition of folate with glycine was able to restore hemoglobin levels. This difference is likely due to the fact that yeast can synthesize folate, whereas in zebrafish folate is an essential vitamin that must be obtained exogenously. Given the tolerability of glycine and folate in humans, this study points to a potential novel treatment for SLC25A38 congenital sideroblastic anemia. PMID:26821380

  3. Glycine and Folate Ameliorate Models of Congenital Sideroblastic Anemia.

    PubMed

    Fernández-Murray, J Pedro; Prykhozhij, Sergey V; Dufay, J Noelia; Steele, Shelby L; Gaston, Daniel; Nasrallah, Gheyath K; Coombs, Andrew J; Liwski, Robert S; Fernandez, Conrad V; Berman, Jason N; McMaster, Christopher R

    2016-01-01

    Sideroblastic anemias are acquired or inherited anemias that result in a decreased ability to synthesize hemoglobin in red blood cells and result in the presence of iron deposits in the mitochondria of red blood cell precursors. A common subtype of congenital sideroblastic anemia is due to autosomal recessive mutations in the SLC25A38 gene. The current treatment for SLC25A38 congenital sideroblastic anemia is chronic blood transfusion coupled with iron chelation. The function of SLC25A38 is not known. Here we report that the SLC25A38 protein, and its yeast homolog Hem25, are mitochondrial glycine transporters required for the initiation of heme synthesis. To do so, we took advantage of the fact that mitochondrial glycine has several roles beyond the synthesis of heme, including the synthesis of folate derivatives through the glycine cleavage system. The data were consistent with Hem25 not being the sole mitochondrial glycine importer, and we identify a second SLC25 family member Ymc1, as a potential secondary mitochondrial glycine importer. Based on these findings, we observed that high levels of exogenous glycine, or 5-aminolevulinic acid (5-Ala) a metabolite downstream of Hem25 in heme biosynthetic pathway, were able to restore heme levels to normal in yeast cells lacking Hem25 function. While neither glycine nor 5-Ala could ameliorate SLC25A38 congenital sideroblastic anemia in a zebrafish model, we determined that the addition of folate with glycine was able to restore hemoglobin levels. This difference is likely due to the fact that yeast can synthesize folate, whereas in zebrafish folate is an essential vitamin that must be obtained exogenously. Given the tolerability of glycine and folate in humans, this study points to a potential novel treatment for SLC25A38 congenital sideroblastic anemia.

  4. DETECTABILITY OF GLYCINE IN SOLAR-TYPE SYSTEM PRECURSORS

    SciTech Connect

    Jiménez-Serra, Izaskun; Testi, Leonardo; Caselli, Paola; Viti, Serena E-mail: ltesti@eso.org E-mail: sv@star.ucl.ac.uk

    2014-06-01

    Glycine (NH{sub 2}CH{sub 2}COOH) is the simplest amino acid relevant to life. Its detection in the interstellar medium is key to understanding the formation mechanisms of pre-biotic molecules and their subsequent delivery onto planetary systems. Glycine has been extensively searched for toward hot molecular cores, although these studies did not yield any firm detection. In contrast to hot cores, low-mass star forming regions, in particular their earliest stages represented by cold pre-stellar cores, may be better suited for the detection of glycine as well as more relevant to the study of pre-biotic chemistry in young solar system analogs. We present one-dimensional spherically symmetric radiative transfer calculations of the glycine emission expected to arise from the low-mass pre-stellar core L1544. Water vapor has recently been reported toward this core, indicating that a small fraction of the grain mantles in L1544 (∼0.5%) has been injected into the gas phase. Assuming that glycine is photo-desorbed together with water in L1544, and considering a solid abundance of glycine on ices of ∼10{sup –4} with respect to water, our calculations reveal that several glycine lines between 67 GHz and 80 GHz have peak intensities larger than 10 mK. These results show for the first time that glycine could reach detectable levels in cold objects such as L1544. This opens up the possibility of detecting glycine, and other pre-biotic species, at the coldest and earliest stages in the formation of solar-type systems with near-future instrumentation such as the Band 2 receivers of ALMA.

  5. Influence of the morphology and impurities of Ni(OH) 2 on the synthesis of neutral Ni(II)-amino acid complexes

    NASA Astrophysics Data System (ADS)

    Rodríguez-González, Vicente; Marceau, Eric; Che, Michel; Pepe, Claude

    2007-12-01

    Synthesis of neutral complexes of Ni 2+ with amino acids has often been reported on a qualitative basis, with a lack of information on the parameters involved in the dissolution of the nickel-containing solid precursor. This paper reports on a systematic study of the reactivity of Ni(OH) 2 toward glycine in aqueous solution. The crystallinity and size of hydroxide particles are found to be key parameters in the rapid glycine-promoted dissolution of the hydroxide and synthesis of [Ni(glycinate) 2(H 2O) 2]. These parameters derive from the nature of the salt used to prepare the hydroxide. Ni(II) chloride leads to the most reactive solid precursor, because of the presence of defects in the Ni(OH) 2 sheets arrangements, assigned to the substitution of Cl - ions to OH - ions at the edges of the particles. The reaction between this hydroxide and glycine at 80 °C is quantitative after 7 min and similar rates of dissolution are obtained with other amino acids, alanine or histidine, the reaction with serine being slower. When the hydroxide contains nitrate or carbonate ions, a glycinato complex with composition similar to [Ni(glycinate) 2(H 2O) 2], but with a different crystal structure, is also formed. Spectroscopic results may suggest a structure involving bridging ligands.

  6. Compositions containing poly ([gamma]glutamylcysteinyl)glycines

    DOEpatents

    Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.

    1992-02-18

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting the removal, and the apparatus used in effecting the removal are described. One or more of the polypeptides, poly ([gamma]glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ([gamma]glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form. 1 figs.

  7. A DFT study of adsorption of glycine onto the surface of BC2N nanotube

    NASA Astrophysics Data System (ADS)

    Soltani, Alireza; Azmoodeh, Zivar; Javan, Masoud Bezi; Lemeski, E. Tazikeh; Karami, Leila

    2016-10-01

    A theoretical study of structure and the energy interaction of amino acid glycine (NH2CH2COOH) with BC2N nanotube is crucial for apperception behavior occurring at the nanobiointerface. Herein, we studied the adsorption of glycine in their radical and zwitterionic forms upon the surface of BC2N nanotube using M06 functional and 6-311G** standard basis set. We also considered the different orientations of the glycine amino acid on the surface of adsorbent. Further, we found out that the stability of glycine from its carbonyl group is higher than hydroxyl and amine groups. Our results also indicated that the electronic structure of BC2N nanotube on the adsorption of glycine from its amine group is more altered than the other groups. Our study exhibits that opto-electronic property of adsorbent is changed after the glycine adsorption.

  8. Glycine Transporters and Their Inhibitors

    NASA Astrophysics Data System (ADS)

    Gilfillan, Robert; Kerr, Jennifer; Walker, Glenn; Wishart, Grant

    Glycine plays a ubiquitous role in many biological processes. In the central nervous system it serves as an important neurotransmitter acting as an agonist at strychnine-sensitive glycine receptors and as an essential co-agonist with glutamate at the NMDA receptor complex. Control of glycine concentrations in the vicinity of these receptors is mediated by the specific glycine transporters, GlyT1 and GlyT2. Inhibition of these transporters has been postulated to be of potential benefit in several therapeutic indications including schizophrenia and pain. In this review we discuss our current knowledge of glycine transporters and focus on recent advances in the medicinal chemistry of GlyT1 and GlyT2 inhibitors.

  9. Baicalin Activates Glycine and γ-Aminobutyric Acid Receptors on Substantia Gelatinosa Neurons of the Trigeminal Subsnucleus Caudalis in Juvenile Mice.

    PubMed

    Yin, Hua; Bhattarai, Janardhan Prasad; Oh, Sun Mi; Park, Soo Joung; Ahn, Dong Kuk; Han, Seong Kyu

    2016-01-01

    The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) receives nociceptive afferent inputs from thin-myelinated A[Formula: see text] fibers and unmyelinated C fibers and has been shown to be involved in the processing of orofacial nociceptive information. Scutellaria baicalensis Georgi (Huang-Qin, SbG), one of the 50 fundamental herbs of Chinese herbology, has been used historically as anti-inflammatory and antineoplastic medicine. Baicalin, one of the major compounds of SbG, has been reported to have neuroprotective, anti-inflammatory and analgesic effects. However, the receptor type activated by baicalin and its precise action mechanism on the SG neurons of Vc have not yet been studied. The whole-cell patch clamp technique was performed to examine the ion channels activated by baicalin on the SG neurons of Vc. In high Cl[Formula: see text] pipette solution, the baicalin (300[Formula: see text][Formula: see text]M) induced repeatable inward currents ([Formula: see text][Formula: see text]pA, [Formula: see text]) without desensitization on all the SG neurons tested. Further, the inward currents showed a concentration (0.1-3[Formula: see text]mM) dependent pattern. The inward current was sustained in the presence of tetrodotoxin (0.5[Formula: see text][Formula: see text]M), a voltage sensitive Na[Formula: see text] channel blocker. In addition, baicalin-induced inward currents were reduced in the presence of picrotoxin (50[Formula: see text][Formula: see text]M), a GABAA receptor antagonist, flumazenil (100[Formula: see text][Formula: see text]M), a benzodiazepine-sensitive GABAA receptor antagonist, and strychnine (2[Formula: see text][Formula: see text]M), a glycine receptor antagonist, respectively. These results indicate that baicalin has inhibitory effects on the SG neurons of the Vc, which are due to the activation of GABAA and/or the glycine receptor. Our results suggest that baicalin may be a potential target for orofacial pain modulation

  10. Ionization constants of aqueous amino acids at temperatures up to 250°C using hydrothermal pH indicators and UV-visible spectroscopy: Glycine, α-alanine, and proline

    NASA Astrophysics Data System (ADS)

    Clarke, Rodney G. F.; Collins, Christopher M.; Roberts, Jenene C.; Trevani, Liliana N.; Bartholomew, Richard J.; Tremaine, Peter R.

    2005-06-01

    Ionization constants for several simple amino acids have been measured for the first time under hydrothermal conditions, using visible spectroscopy with a high-temperature, high-pressure flow cell and thermally stable colorimetric pH indicators. This method minimizes amino acid decomposition at high temperatures because the data can be collected rapidly with short equilibration times. The first ionization constant for proline and α-alanine, K a,COOH, and the first and second ionization constants for glycine, K a,COOH and K a,NH4+, have been determined at temperatures as high as 250°C. Values for the standard partial molar heat capacity of ionization, Δ rC po, COOH and Δ rC po, NH4+, have been determined from the temperature dependence of ln (K a,COOH) and ln (K a,NH4+). The methodology has been validated by measuring the ionization constant of acetic acid up to 250°C, with results that agree with literature values obtained by potentiometric measurements to within the combined experimental uncertainty. We dedicate this paper to the memory of Dr. Donald Irish (1932-2002) of the University of Waterloo—friend and former supervisor of two of the authors (R.J.B. and P.R.T.).

  11. Antimicrobial Activity of Metal & Metal Oxide Nanoparticles Interfaced With Ligand Complexes Of 8-Hydroxyquinoline And α-Amino Acids

    NASA Astrophysics Data System (ADS)

    Bhanjana, Gaurav; Kumar, Neeraj; Thakur, Rajesh; Dilbaghi, Neeraj; Kumar, Sandeep

    2011-12-01

    Antimicrobial nanotechnology is a recent addition to the fight against disease causing organisms, replacing heavy metals and toxins. In the present work, mixed ligand complexes of metals like zinc, silver etc. and metal oxide have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and N-and/O-donor amino acids such as L-serine, L-alanine, glycine, cysteine and histidine as secondary ligands. These complexes were characterized using different spectroscopic techniques. The complexes were tested for antifungal and antibacterial activity by using agar well diffusion bioassay.

  12. 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.

  13. Conformationally Constrained Histidines in the Design of Peptidomimetics: Strategies for the χ-Space Control

    PubMed Central

    Stefanucci, Azzurra; Pinnen, Francesco; Feliciani, Federica; Cacciatore, Ivana; Lucente, Gino; Mollica, Adriano

    2011-01-01

    A successful design of peptidomimetics must come to terms with χ-space control. The incorporation of χ-space constrained amino acids into bioactive peptides renders the χ1 and χ2 torsional angles of pharmacophore amino acids critical for activity and selectivity as with other relevant structural features of the template. This review describes histidine analogues characterized by replacement of native α and/or β-hydrogen atoms with alkyl substituents as well as analogues with α, β-didehydro unsaturation or Cα-Cβ cyclopropane insertion (ACC derivatives). Attention is also dedicated to the relevant field of β-aminoacid chemistry by describing the synthesis of β2- and β3-models (β-hHis). Structural modifications leading to cyclic imino derivatives such as spinacine, aza-histidine and analogues with shortening or elongation of the native side chain (nor-histidine and homo-histidine, respectively) are also described. Examples of the use of the described analogues to replace native histidine in bioactive peptides are also given. PMID:21686155

  14. Reaction behaviors of glycine under super- and subcritical water conditions.

    PubMed

    Alargov, Dimitar K; Deguchi, Shigeru; Tsujii, Kaoru; Horikoshi, Koki

    2002-02-01

    The influence of temperature and pressure on the dimerization and decomposition of glycine under simulated hydrothermal system conditions was studied by injecting a glycine solution into water in the sub- and supercritical state. The experiments at five different temperatures of supplied water--250, 300, 350, 374, and 400 degrees C--were performed at 22.2 and 40.0 MPa. At 350 degrees C, experiments under 15.0-40.0 MPa were conducted. Diglycine, triglycine (trace), diketopiperazine, and an unidentified product with a high molecular mass (433 Da) were the main products of oligomerization. The results show that temperature and pressure influence the extent of dimerization and decomposition of glycine. The maximum of dimers formation was observed at 350 and 375 degrees C at 22.2 and 40.0 MPa, respectively, and coincided with a high rate of glycine decomposition. Glycine, alanine, aspartic acid, as well as other amino acids, were obtained by injecting a mixture of formaldehyde and ammonia. The results support the oligomerization and synthesis of amino acids in a submarine hydrothermal system. PMID:11889913

  15. Reaction Behaviors of Glycine under Super- and Subcritical Water Conditions

    NASA Astrophysics Data System (ADS)

    Alargov, Dimitar K.; Deguchi, Shigeru; Tsujii, Kaoru; Horikoshi, Koki

    2002-02-01

    The influence of temperature and pressure on the dimerization and decomposition of glycine under simulated hydrothermal system conditions was studied by injecting a glycine solution into water in the sub- and supercritical state. The experiments at five different temperatures of supplied water - 250, 300, 350, 374, and 400 °C - were performed at 22.2 and 40.0 MPa. At 350 °C, experiments under 15.0-40.0 MPa were conducted. Diglycine, triglycine (trace), diketopiperazine, and an unidentified product with a high molecular mass (433 Da) were the main products of oligomerization. The results show that temperature and pressure influence the extent of dimerization and decomposition of glycine. The maximum of dimers formation was observed at 350 and 375 °C at 22.2 and 40.0 MPa, respectively, and coincided with a high rate of glycine decomposition. Glycine, alanine, aspartic acid, as well as other amino acids, were obtained by injecting a mixture of formaldehyde and ammonia. The results support the oligomerization and synthesis of amino acids in a submarine hydrothermal system.

  16. Alpha-amylase from germinating soybean (Glycine max) seeds--purification, characterization and sequential similarity of conserved and catalytic amino acid residues.

    PubMed

    Kumari, Arpana; Singh, Vinay Kumar; Fitter, Jörg; Polen, Tino; Kayastha, Arvind M

    2010-10-01

    Starch hydrolyzing amylase from germinated soybeans seeds (Glycine max) has been purified 400-fold to electrophoretic homogeneity with a final specific activity of 384 units/mg. SDS-PAGE of the final preparation revealed a single protein band of 100 kDa, whereas molecular mass was determined to be 84 kDa by MALDI-TOF and gel filtration on Superdex-200 (FPLC). The enzyme exhibited maximum activity at pH 5.5 and a pI value of 4.85. The energy of activation was determined to be 6.09 kcal/mol in the temperature range 25-85 degrees C. Apparent Michaelis constant (K(m)((app))) for starch was 0.71 mg/mL and turnover number (k(cat)) was 280 s(-1) in 50 mM sodium acetate buffer, pH 5.5. Thermal inactivation studies at 85 degrees C showed first-order kinetics with rate constant (k) equal to 0.0063 min(-1). Soybean alpha-amylase showed high specificity for its primary substrate starch. High similarity of soybean alpha-amylase with known amylases suggests that this alpha-amylase belongs to glycosyl hydrolase family 13. Cereal alpha-amylases have gained importance due to their compatibility for biotechnological applications. Wide availability and easy purification protocol make soybean as an attractive alternative for plant alpha-amylase. Soybean can be used as commercially viable source of alpha-amylase for various industrial applications. PMID:20655076

  17. Amino Acid Residues Critical for the Specificity for Betaine Aldehyde of the Plant ALDH10 Isoenzyme Involved in the Synthesis of Glycine Betaine1[W][OA

    PubMed Central

    Díaz-Sánchez, Ángel G.; González-Segura, Lilian; Mújica-Jiménez, Carlos; Rudiño-Piñera, Enrique; Montiel, Carmina; Martínez-Castilla, León P.; Muñoz-Clares, Rosario A.

    2012-01-01

    Plant Aldehyde Dehydrogenase10 (ALDH10) enzymes catalyze the oxidation of ω-primary or ω-quaternary aminoaldehydes, but, intriguingly, only some of them, such as the spinach (Spinacia oleracea) betaine aldehyde dehydrogenase (SoBADH), efficiently oxidize betaine aldehyde (BAL) forming the osmoprotectant glycine betaine (GB), which confers tolerance to osmotic stress. The crystal structure of SoBADH reported here shows tyrosine (Tyr)-160, tryptophan (Trp)-167, Trp-285, and Trp-456 in an arrangement suitable for cation-π interactions with the trimethylammonium group of BAL. Mutation of these residues to alanine (Ala) resulted in significant Km(BAL) increases and Vmax/Km(BAL) decreases, particularly in the Y160A mutant. Tyr-160 and Trp-456, strictly conserved in plant ALDH10s, form a pocket where the bulky trimethylammonium group binds. This space is reduced in ALDH10s with low BADH activity, because an isoleucine (Ile) pushes the Trp against the Tyr. Those with high BADH activity instead have Ala (Ala-441 in SoBADH) or cysteine, which allow enough room for binding of BAL. Accordingly, the mutation A441I decreased the Vmax/Km(BAL) of SoBADH approximately 200 times, while the mutation A441C had no effect. The kinetics with other ω-aminoaldehydes were not affected in the A441I or A441C mutant, demonstrating that the existence of an Ile in the second sphere of interaction of the aldehyde is critical for discriminating against BAL in some plant ALDH10s. A survey of the known sequences indicates that plants have two ALDH10 isoenzymes: those known to be GB accumulators have a high-BAL-affinity isoenzyme with Ala or cysteine in this critical position, while non GB accumulators have low-BAL-affinity isoenzymes containing Ile. Therefore, BADH activity appears to restrict GB synthesis in non-GB-accumulator plants. PMID:22345508

  18. [Effects of low molecular organic acids on nitrogen accumulation, nodulation, and nitrogen fixation of soybean (Glycine max L.) under phosphorus deficiency stress].

    PubMed

    Wang, Shu-Qi; Han, Xiao-Zeng; Qiao, Yun-Fa; Yan, Jun; Li, Xiao-Hui

    2009-05-01

    A greenhouse sand culture experiment was conducted to study the effects of citric acid, oxalic acid, malic acid, and their mixture on the nitrogen accumulation, nodulation, and nitrogen fixation of soybean. After the application of test low molecular weight organic acids, the nitrogen accumulation in the aboveground part of soybean decreased by 17.6%-44.9% at seedling stage, 29.8%-88.4% at flowering stage, 9.18%-69.6% at podding stage, and 2.21%-41.7% at maturing stage). In the meanwhile, the nodule number, nitrogenase activity, and leghemoglobin content decreased by 11.4%-59.6%, 80.5%-91.7%, and 11.9%-59.9%, respectively, resulting in a significant decrease (9.71%-64.5%) of nitrogen fixation of soybean, compared with the control. The inhibitory effect of test low molecular weight organic acids increased with their increasing concentration. Oxalic acid had a higher inhibitory effect than citric acid and malic acid, and the mixture of the three organic acids had an enhanced inhibitory effect.

  19. Growth medium-dependent glycine incorporation into the peptidoglycan of Caulobacter crescentus.

    PubMed

    Takacs, Constantin N; Hocking, Jason; Cabeen, Matthew T; Bui, Nhat Khai; Poggio, Sebastian; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2013-01-01

    The peptidoglycan (PG) is a macromolecular component of the bacterial cell wall that maintains the shape and integrity of the cell. The PG of Caulobacter crescentus, unlike that of many other Gram-negative bacteria, has repeatedly been shown to contain significant amounts of glycine. This compositional peculiarity has been deemed an intrinsic characteristic of this species. By performing a comprehensive qualitative and quantitative analysis of the C. crescentus PG by high-performance liquid chromatography (HPLC) and mass spectrometry (MS), we show here that glycine incorporation into the C. crescentus PG depends on the presence of exogenous glycine in the growth medium. High levels of glycine were detected at the fifth position of the peptide side chains of PG isolated from C. crescentus cells grown in the complex laboratory medium PYE or in defined medium (M2G) supplemented with casamino acids or glycine alone. In contrast, glycine incorporation was undetectable when cells were grown in M2G medium lacking glycine. Remarkably, glycine incorporation into C. crescentus peptidoglycan occurred even in the presence of low millimolar to sub-millimolar concentrations of free glycine. High glycine content in the PG had no obvious effects on growth rates, mode of PG incorporation or cell morphology. Hence, the C. crescentus PG is able to retain its physiological functions in cell growth and morphogenesis despite significant alterations in its composition, in what we deem to be unprecedented plasticity.

  20. Mode of Action of Glycine on the Biosynthesis of Peptidoglycan

    PubMed Central

    Hammes, W.; Schleifer, K. H.; Kandler, O.

    1973-01-01

    The mechanism of glycine action in growth inhibition was studied on eight different species of bacteria of various genera representing the four most common peptidoglycan types. To inhibit the growth of the different organisms to 80%, glycine concentrations from 0.05 to 1.33 M had to be applied. The inhibited cells showed morphological aberrations. It has been demonstrated that glycine is incorporated into the nucleotide-activated peptidoglycan precursors. The amount of incorporated glycine was equivalent to the decrease in the amount of alanine. With one exception glycine is also incorporated into the peptidoglycan. Studies on the primary structure of both the peptidoglycan precursors and the corresponding peptidoglycan have revealed that glycine can replace l-alanine in position 1 and d-alanine residues in positions 4 and 5 of the peptide subunit. Replacement of l-alanine in position 1 of the peptide subunit together with an accumulation of uridine diphosphate-muramic acid (UDP-MurNAc), indicating an inhibition of the UDP-MurNAc:l-Ala ligase, has been found in three bacteria (Staphylococcus aureus, Lactobacillus cellobiosus and L. plantarum). However, discrimination against precursors with glycine in position 1 in peptidoglycan synthesis has been observed only in S. aureus. Replacement of d-alanine residues was most common. It occurred in the peptidoglycan with one exception in all strains studied. In Corynebacterium sp., C. callunae, L. plantarum, and L. cellobiosus most of the d-alanine replacing glycine occurs C-terminal in position 4, and in C. insidiosum and S. aureus glycine is found C-terminal in position 5. It is suggested that the modified peptidoglycan precursors are accumulated by being poor substrates for some of the enzymes involved in peptidoglycan synthesis. Two mechanisms leading to a more loosely cross-linked peptidoglycan and to morphological changes of the cells are considered. First, the accumulation of glycine-containing precursors may lead to

  1. Determination of β-N-methylamino-L-alanine, N-(2-aminoethyl)glycine, and 2,4-diaminobutyric acid in Food Products Containing Cyanobacteria by Ultra-Performance Liquid Chromatography and Tandem Mass Spectrometry: Single-Laboratory Validation.

    PubMed

    Glover, W Broc; Baker, Teesha C; Murch, Susan J; Brown, Paula N

    2015-01-01

    A single-laboratory validation study was completed for the determination of β-N-methylamino-L-alanine (BMAA), N-(2-aminoethyl)glycine (AEG), and 2,4-diaminobutyric acid (DAB) in bulk natural health product supplements purchased from a health food store in Canada. BMAA and its isomers were extracted with acid hydrolysis to free analytes from protein association. Acid was removed with the residue evaporated to dryness and reconstituted with derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AccQ-Fluor). Chromatographic separation and detection were achieved using RP ultra-performance LC coupled to a tandem mass spectrometer operated in multiple reaction monitoring mode. Data from biological samples were evaluated for precision and accuracy across different days to ensure repeatability. Accuracy was assessed by spike recovery of biological samples using varying amino acid concentrations, with an average recovery across all samples of 108.6%. The analytical range was found to be 764-0.746 ng/mL prior to derivatization, thereby providing a linear range compatible with potentially widely varying analyte concentrations in commercial health food products. Both the U. S. Food and Drug Administration (FDA) and U. S. Pharmacopeia definitions were evaluated for determining method limits, with the FDA approach found to be most suitable having an LOD of 0.187 ng/mL and LLOQ of 0.746 ng/mL. BMAA in the collected specimens was detected at concentrations lower than 1 μg/g, while AEG and DAB were found at concentrations as high as 100 μg/g. Finding these analytes, even at low concentrations, has potential public health significance and suggests a need to screen such products prior to distribution. The method described provides a rapid, accurate, and precise method to facilitate that screening process. PMID:26651568

  2. Modulation of N-methyl-d-aspartate receptor function by glycine transport

    PubMed Central

    Bergeron, Richard; Meyer, Torsten M.; Coyle, Joseph T.; Greene, Robert W.

    1998-01-01

    The recent discovery of glycine transporters in both the central nervous system and the periphery suggests that glycine transport may be critical to N-methyl-d-aspartate receptor (NMDAR) function by controlling glycine concentration at the NMDAR modulatory glycine site. Data obtained from whole-cell patch–clamp recordings of hippocampal pyramidal neurons, in vitro, demonstrated that exogenous glycine and glycine transporter type 1 (GLYT1) antagonist selectively enhanced the amplitude of the NMDA component of a glutamatergic excitatory postsynaptic current. The effect was blocked by 2-amino-5-phosphonovaleric acid and 7-chloro-kynurenic acid but not by strychnine. Thus, the glycine-binding site was not saturated under the control conditions. Furthermore, GLYT1 antagonist enhanced NMDAR function during perfusion with medium containing 10 μM glycine, a concentration similar to that in the cerebrospinal fluid in vivo, thereby supporting the hypothesis that the GLYT1 maintains subsaturating concentration of glycine at synaptically activated NMDAR. The enhancement of NMDAR function by specific GLYT1 antagonism may be a feasible target for therapeutic agents directed toward diseases related to hypofunction of NMDAR. PMID:9861038

  3. Synthesis of water soluble glycine capped silver nanoparticles and their surface selective interaction

    SciTech Connect

    Agasti, Nityananda; Singh, Vinay K.; Kaushik, N.K.

    2015-04-15

    Highlights: • Synthesis of water soluble silver nanoparticles at ambient reaction conditions. • Glycine as stabilizing agent for silver nanoparticles. • Surface selective interaction of glycine with silver nanoparticles. • Glycine concentration influences crystalinity and optical property of silver nanoparticles. - Abstract: Synthesis of biocompatible metal nanoparticles has been an area of significant interest because of their wide range of applications. In the present study, we have successfully synthesized water soluble silver nanoparticles assisted by small amino acid glycine. The method is primarily based on reduction of AgNO{sub 3} with NaBH{sub 4} in aqueous solution under atmospheric air in the presence of glycine. UV–vis spectroscopy, transmission electron microscopy (TEM), X–ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG) and differential thermal analysis (DTA) techniques used for characterization of resulting silver nanoparticles demonstrated that, glycine is an effective capping agent to stabilize silver nanoparticles. Surface selective interaction of glycine on (1 1 1) face of silver nanoparticles has been investigated. The optical property and crystalline behavior of silver nanoparticles were found to be sensitive to concentration of glycine. X–ray diffraction studies ascertained the phase specific interaction of glycine on silver nanoparticles. Silver nanoparticles synthesized were of diameter 60 nm. We thus demonstrated an efficient synthetic method for synthesis of water soluble silver nanoparticles capped by amino acid under mild reaction conditions with excellent reproducibility.

  4. l-Histidine Induces Resistance in Plants to the Bacterial Pathogen Ralstonia solanacearum Partially Through the Activation of Ethylene Signaling.

    PubMed

    Seo, Shigemi; Nakaho, Kazuhiro; Hong, Si Won; Takahashi, Hideki; Shigemori, Hideyuki; Mitsuhara, Ichiro

    2016-09-01

    Wilt disease in plants, which is caused by the soil-borne bacterial pathogen Ralstonia solanacearum, is one of the most devastating plant diseases. We previously detected bacterial wilt disease-inhibiting activity in an extract from yeast cells. In the present study, we purified this activity and identified one of the substances responsible for the activity as the amino acid histidine. The exogenous application of l-histidine, but not d-histidine, inhibited wilt disease in tomato and Arabidopsis plants without exhibiting any antibacterial activity. l-Histidine induced the expression of genes related to ethylene (ET) biosynthesis and signaling as well as the production of ET in tomato and Arabidopsis plants. l-Histidine-induced resistance to R. solanacearum was partially abolished in ein3-1, an ET-insensitive Arabidopsis mutant line. Resistance to the fungal pathogen Botrytis cinerea, which is known to require ET biosynthesis or signaling, was also induced by exogenously applied l-histidine. These results suggest that l-histidine induces resistance to R. solanacearum and B. cinerea partially through the activation of ET signaling in plants. PMID:27335353

  5. l-Histidine Induces Resistance in Plants to the Bacterial Pathogen Ralstonia solanacearum Partially Through the Activation of Ethylene Signaling.

    PubMed

    Seo, Shigemi; Nakaho, Kazuhiro; Hong, Si Won; Takahashi, Hideki; Shigemori, Hideyuki; Mitsuhara, Ichiro

    2016-09-01

    Wilt disease in plants, which is caused by the soil-borne bacterial pathogen Ralstonia solanacearum, is one of the most devastating plant diseases. We previously detected bacterial wilt disease-inhibiting activity in an extract from yeast cells. In the present study, we purified this activity and identified one of the substances responsible for the activity as the amino acid histidine. The exogenous application of l-histidine, but not d-histidine, inhibited wilt disease in tomato and Arabidopsis plants without exhibiting any antibacterial activity. l-Histidine induced the expression of genes related to ethylene (ET) biosynthesis and signaling as well as the production of ET in tomato and Arabidopsis plants. l-Histidine-induced resistance to R. solanacearum was partially abolished in ein3-1, an ET-insensitive Arabidopsis mutant line. Resistance to the fungal pathogen Botrytis cinerea, which is known to require ET biosynthesis or signaling, was also induced by exogenously applied l-histidine. These results suggest that l-histidine induces resistance to R. solanacearum and B. cinerea partially through the activation of ET signaling in plants.

  6. Analytical continuation in coupling constant method; application to the calculation of resonance energies and widths for organic molecules: Glycine, alanine and valine and dimer of formic acid

    NASA Astrophysics Data System (ADS)

    Papp, P.; Matejčík, Š.; Mach, P.; Urban, J.; Paidarová, I.; Horáček, J.

    2013-06-01

    The method of analytic continuation in the coupling constant (ACCC) in combination with use of the statistical Padé approximation is applied to the determination of resonance energy and width of some amino acids and formic acid dimer. Standard quantum chemistry codes provide accurate data which can be used for analytic continuation in the coupling constant to obtain the resonance energy and width of organic molecules with a good accuracy. The obtained results are compared with the existing experimental ones.

  7. Neighbor-directed histidine N (τ)-alkylation: A route to imidazolium-containing phosphopeptide macrocycles.

    PubMed

    Qian, Wen-Jian; Park, Jung-Eun; Grant, Robert; Lai, Christopher C; Kelley, James A; Yaffe, Michael B; Lee, Kyung S; Burke, Terrence R

    2015-11-01

    Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. Interestingly, these cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.

  8. Neighbor-directed histidine N(τ) alkylation. A route to imidazolium-containing phosphopeptide macrocycles

    SciTech Connect

    Qian, Wen-Jian; Park, Jung-Eun; Grant, Robert; Lai, Christopher C.; Kelley, James A.; Yaffe, Michael B.; Lee, Kyung S.; Burke, Terrence R.

    2015-07-07

    Our recently discovered, selective, on-resin route to N(τ)-alkylated imidazolium-containing histidine residues affords new strategies for peptide mimetic design. In this, we demonstrate the use of this chemistry to prepare a series of macrocyclic phosphopeptides, in which imidazolium groups serve as ring-forming junctions. These cationic moieties subsequently serve to charge-mask the phosphoamino acid group that directed their formation. Furthermore, neighbor-directed histidine N(τ)-alkylation opens the door to new families of phosphopeptidomimetics for use in a range of chemical biology contexts.

  9. Glycine reduces cadmium-induced teratogenic damage in mice.

    PubMed

    Paniagua-Castro, Norma; Escalona-Cardoso, Gerardo; Chamorro-Cevallos, Germán

    2007-01-01

    The effect of glycine in preventing cadmium (Cd) teratogenicity in mice was studied. Cadmium chloride (CdCl2) was administered subcutaneously at 1, 2 or 4 mg/kg doses on gestation days (GD) 7, 8 and 9. Glycine was given ad libitum (in the drinking water) from GD0 through GD18 (the day when animals were killed), as a 1% and 2% drinking water solution. Cd and nucleic acid concentrations in embryos were determined. The most common finding seen after CdCl2 4 mg/kg exposure was exencephaly. The incidence of this malformation was significantly reduced in mice receiving 2% glycine while fetal Cd significantly decreased as compared to cadmium-treated positive control animals. Increased nucleic acid levels were seen in the same embryos. In glycine non-supplemented mice given CdCl2 4 mg/kg, embryonic lipid peroxidation proved to be increased. In conclusion, lipid peroxidation was associated with cadmium-induced teratogenicity, and glycine inhibited the cadmium-induced effect by inhibiting placental transport of cadmium. However, further detailed studies are needed to establish the mechanism(s) of action.

  10. Stabilisation of proteins via mixtures of amino acids during spray drying.

    PubMed

    Ajmera, Ankur; Scherließ, Regina

    2014-03-10

    Biologicals are often formulated as solids in an effort to preserve stability which generally requires stabilising excipients for proper drying. The purpose of this study was to screen amino acids and their combinations for their stabilising effect on proteins during spray drying. Catalase, as model protein, was spray dried in 1+1 or 1+2 ratios with amino acids. Some amino acids namely arginine, glycine and histidine showed good retention of catalase functionality after spray drying and subsequent storage stress. A 1+1 combination of arginine and glycine in a 1+2 ratio with catalase resulted in a tremendously good stabilising effect. Storage at high temperature/humidity also showed beneficial effects of this combination. To evaluate whether this was a general principle, these findings were transferred to an antigenic protein of comparable size and supramolecular structure (haemagglutinin) as well as to a smaller enzyme (lysozyme). Upon spray drying with the combination of amino acids it could be shown that both proteins remain more stable especially after storage compared to the unprotected protein. The combination of arginine and glycine is tailored to the needs of protein stabilisation during spray drying and may hence be utilised in dry powder formulation of biomolecules with superior stability characteristics. PMID:24412336

  11. Photolysis of copper(II)-amino acid complexes in water

    SciTech Connect

    Hayase, K.; Zepp, R.G. )

    1991-07-01

    Kinetics of the photolysis of Cu{sup 2+}-amino acid complexes were investigated under sunlight or monochromatic radiation. Under sunlight (latitude 40{degree}N) in the absence of dioxygen, the mean half-lives estimated for the photoreduction of the bis-Cu{sup 2+} complexes (CuL{sub 2}) at pH 8.0 and 25C were 0.55, 1.6, 8.6, 8.8, 45. and 71 days for L = tris(hydroxymethyl)aminomethane (Tris), {beta}-alanine, L-aspartic acid, L-glutamic acid, glycine, and histidine, respectively. Under monochromatic UV irradiation (310 nm) with dioxygen absent, quantum yields for the photoproduction of Cu(I) from CuL{sub 2} were found to be 0.071, 0.098, 0.063, 0.066, 0.025, and 0.0011 for L = Tris, {beta}-alanine, L-aspartic acid, L-glutamic acid, glycine, and L-histidine, respectively. The effects of pH on the quantum yields were determined for Cu{sup 2+}-{beta}-alanine and Cu{sup 2+}-Tris complexes. Decreases in quantum yields observed with increasing acidity were attributed to changes in speciation from predominantly CuL{sub 2} to less photoreactive complexes, mainly CuL and Cu{sup 2+}. In air-saturated solutions, rates and quantum yields for Cu(I) formation were sharply reduced and hydrogen peroxide was formed. Results of the study suggest that photoreactions of Cu{sup 2+} coordination complexes may contribute to its toxicity to aquatic biota.

  12. Assessment of Fatty Acid Profile and Seed Mineral Nutrients of Two Soybean (Glycine max L.) Cultivars Under Elevated Ultraviolet-B: Role of ROS, Pigments and Antioxidants.

    PubMed

    Choudhary, Krishna Kumar; Agrawal, Shashi Bhushan

    2016-01-01

    Current scenarios under global climate change envisage a considerable increase in ultraviolet B (UV-B) radiation in near future which may affect the productivity and yield quality of major agricultural crops. Present investigation was conducted to examine various defense strategies adopted against elevated UV-B (ambient + 7.2 kJ m-(2) day-(1) ) and their impact on seed nutrients, content and quality of oil including fatty acid profile of two soybean cultivars (JS-335 and PS-1042). Elevated UV-B (eUV-B) exposure leads toward higher unsaturation of fatty acids and changes in other oil quality parameters (acid, iodine and saponification value) indicated that eUV-B favored the synthesis of long-chain fatty acids with fewer carboxylic acid groups, making the oil rancid, with undesirable flavor and low nutritional value. The effect was more severe in JS-335 as compared to PS-1042. Negative effects were also seen on nutrients of soybean seeds. Adverse effects resulted due to insufficient quenching of ROS (superoxide radical and hydrogen peroxide) by the defense system and thus unable to overcome the imposed oxidative stress. Credit of better performance by PS-1042 against eUV-B may be given to the adoption of efficient defense strategies like higher wax deposition, increase in lignin and flavonoids (quercetin and kaempferol) contents. PMID:26489397

  13. Targeting the histidine pathway in Mycobacterium tuberculosis.

    PubMed

    Lunardi, Juleane; Nunes, José Eduardo S; Bizarro, Cristiano V; Basso, Luiz Augusto; Santos, Diógenes Santiago; Machado, Pablo

    2013-01-01

    Worldwide, tuberculosis is the leading cause of morbidity and mortality due to a single bacterial pathogen, Mycobacterium tuberculosis (Mtb). The increasing prevalence of this disease, the emergence of multi-, extensively, and totally drug-resistant strains, complicated by co-infection with the human immunodeficiency virus, and the length of tuberculosis chemotherapy have led to an urgent and continued need for the development of new and more effective antitubercular drugs. Within this context, the L-histidine biosynthetic pathway, which converts 5-phosphoribosyl 1-pyrophosphate to L-histidine in ten enzymatic steps, has been reported as a promising target of antimicrobial agents. This pathway is found in bacteria, archaebacteria, lower eukaryotes, and plants but is absent in mammals, making these enzymes highly attractive targets for the drug design of new antimycobacterial compounds with selective toxicity. Moreover, the biosynthesis of L-histidine has been described as essential for Mtb growth in vitro. Accordingly, a comprehensive overview of Mycobacterium tuberculosis histidine pathway enzymes as attractive targets for the development of new antimycobacterial agents is provided, mainly summarizing the previously reported inhibition data for Mtb or orthologous proteins. PMID:24111909

  14. 21 CFR 582.5361 - Histidine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Histidine. 582.5361 Section 582.5361 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  15. 21 CFR 582.5361 - Histidine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Histidine. 582.5361 Section 582.5361 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  16. 21 CFR 582.5361 - Histidine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Histidine. 582.5361 Section 582.5361 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  17. 21 CFR 582.5361 - Histidine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Histidine. 582.5361 Section 582.5361 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  18. 21 CFR 582.5361 - Histidine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Histidine. 582.5361 Section 582.5361 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary...

  19. Growth enhancing effect of exogenous glycine and characterization of its uptake in halotolerant cyanobacterium Aphanothece halophytica.

    PubMed

    Bualuang, Aporn; Incharoensakdi, Aran

    2015-02-01

    Alkaliphilic halotolerant cyanobacterium Aphanothece halophytica showed optimal growth in the medium containing 0.5 M NaCl. The increase of exogenously added glycine to the medium up to 10 mM significantly promoted cell growth under both normal (0.5 M NaCl) and salt stress (2.0 M NaCl) conditions. Salt stress imposed by either 2.0 or 3.0 M NaCl retarded cell growth; however, exogenously added glycine at 10 mM concentration to salt-stress medium resulted in the reduction of growth inhibition particularly under 3.0 M NaCl condition. The uptake of glycine by intact A. halophytica was shown to exhibit saturation kinetics with an apparent K s of 160 μM and V max of 3.9 nmol/min/mg protein. The optimal pH for glycine uptake was at pH 8.0. The uptake activity was decreased in the presence of high concentration of NaCl. Both metabolic inhibitors and ionophores decreased glycine uptake in A. halophytica suggesting an energy-dependent glycine uptake. Several neutral amino acids showed considerable inhibition of glycine uptake with higher than 50 % inhibition observed with serine, cysteine and alanine whereas acidic, basic and aromatic amino acids showed only slight inhibition of glycine uptake.

  20. Integrin αvβ3 as a Promising Target to Image Neoangiogenesis Using In-House Generator-Produced Positron Emitter (68)Ga-Labeled DOTA-Arginine-Glycine-Aspartic Acid (RGD) Ligand.

    PubMed

    Vatsa, Rakhee; Bhusari, Priya; Kumar, Sunil; Chakraborty, Sudipta; Dash, Ashutosh; Singh, Gurpreet; Dhawan, Devinder Kumar; Shukla, Jaya; Mittal, Bhagwant Rai

    2015-06-01

    For the growth and spread of a tumor beyond 2 mm, angiogenesis plays a crucial role, and association of various integrins with angiogenesis is evidential. The aim of the study was radiolabeling of DOTA-chelated RGD (arginine-glycine-aspartic acid) peptide with (68)Ga for PET imaging in locally advanced breast carcinoma. DOTA-RGD was incubated with (68)GaCl3, eluted in 0.05 m HCl. Elution volume, peptide amount, and reaction pH were studied. Radio-ITLC, gas chromatography, endotoxin, and sterility testing were performed. Serial (n=3) and whole-body (n=2) PET/CT imaging was done on patients post i.v. injection of 111-185 MBq of (68)Ga-DOTA-RGD. Maximum radiolabeling yield was achieved with 3 mL elution volume of 15-20 μg peptide at pH 3.5-4.0 with 10 minutes of incubation at 95°C. Product samples were sterile having 99.5% radiochemical purity with residual ethanol content and endotoxins in injectable limits. Intense radiotracer uptake was noticed in the tumor with SUVmax 15.3 at 45 minutes in serial images. Physiological radiotracer uptake was seen in the liver, spleen, ventricles, and thyroid with excretion through the kidneys. The authors concluded that (68)Ga-DOTA-RGD has the potential for imaging α,vβ3 integrin-expressing tumors. PMID:26083951

  1. Integrin αvβ3 as a Promising Target to Image Neoangiogenesis Using In-House Generator-Produced Positron Emitter (68)Ga-Labeled DOTA-Arginine-Glycine-Aspartic Acid (RGD) Ligand.

    PubMed

    Vatsa, Rakhee; Bhusari, Priya; Kumar, Sunil; Chakraborty, Sudipta; Dash, Ashutosh; Singh, Gurpreet; Dhawan, Devinder Kumar; Shukla, Jaya; Mittal, Bhagwant Rai

    2015-06-01

    For the growth and spread of a tumor beyond 2 mm, angiogenesis plays a crucial role, and association of various integrins with angiogenesis is evidential. The aim of the study was radiolabeling of DOTA-chelated RGD (arginine-glycine-aspartic acid) peptide with (68)Ga for PET imaging in locally advanced breast carcinoma. DOTA-RGD was incubated with (68)GaCl3, eluted in 0.05 m HCl. Elution volume, peptide amount, and reaction pH were studied. Radio-ITLC, gas chromatography, endotoxin, and sterility testing were performed. Serial (n=3) and whole-body (n=2) PET/CT imaging was done on patients post i.v. injection of 111-185 MBq of (68)Ga-DOTA-RGD. Maximum radiolabeling yield was achieved with 3 mL elution volume of 15-20 μg peptide at pH 3.5-4.0 with 10 minutes of incubation at 95°C. Product samples were sterile having 99.5% radiochemical purity with residual ethanol content and endotoxins in injectable limits. Intense radiotracer uptake was noticed in the tumor with SUVmax 15.3 at 45 minutes in serial images. Physiological radiotracer uptake was seen in the liver, spleen, ventricles, and thyroid with excretion through the kidneys. The authors concluded that (68)Ga-DOTA-RGD has the potential for imaging α,vβ3 integrin-expressing tumors.

  2. Liquid chromatography/electrospray ionization/isotopic dilution mass spectrometry analysis of n-(phosphonomethyl) glycine and mass spectrometry analysis of aminomethyl phosphonic acid in environmental water and vegetation matrixes.

    PubMed

    Grey, L; Nguyen, B; Yang, P

    2001-01-01

    A liquid chromatography/electrospray/mass spectrometry (LC/ES/MS) method was developed for the analysis of glyphosate (n-phosphonomethyl glycine) and its metabolite, aminomethyl phosphonic acid (AMPA) using isotope-labelled glyphosate as a method surrogate. Optimized parameters were achieved to derivatize glyphosate and AMPA using 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer prior to a reversed-phase LC analysis. Method spike recovery data obtained using laboratory and real world sample matrixes indicated an excellent correlation between the recovery of the native and isotope-labelled glyphosate. Hence, the first performance-based, isotope dilution MS method with superior precision, accuracy, and data quality was developed for the analysis of glyphosate. There was, however, no observable correlation between the isotope-labelled glyphosate and AMPA. Thus, the use of this procedure for the accurate analysis of AMPA was not supported. Method detection limits established using standard U.S. Environmental Protection Agency protocol were 0.06 and 0.30 microg/L, respectively, for glyphosate and AMPA in water matrixes and 0.11 and 0.53 microg/g, respectively, in vegetation matrixes. Problems, solutions, and the method performance data related to the analysis of chlorine-treated drinking water samples are discussed. Applying this method to other environmental matrixes, e.g., soil, with minimum modifications is possible, assuring accurate, multimedia studies of glyphosate concentration in the environment and the delivery of useful multimedia information for regulatory applications.

  3. Functional characterization of two members of histidine phosphatase superfamily in Mycobacterium tuberculosis

    PubMed Central

    2013-01-01

    Background Functional characterization of genes in important pathogenic bacteria such as Mycobacterium tuberculosis is imperative. Rv2135c, which was originally annotated as conserved hypothetical, has been found to be associated with membrane protein fractions of H37Rv strain. The gene appears to contain histidine phosphatase motif common to both cofactor-dependent phosphoglycerate mutases and acid phosphatases in the histidine phosphatase superfamily. The functions of many of the members of this superfamily are annotated based only on similarity to known proteins using automatic annotation systems, which can be erroneous. In addition, the motif at the N-terminal of Rv2135c is ‘RHA’ unlike ‘RHG’ found in most members of histidine phosphatase superfamily. These necessitate the need for its experimental characterization. The crystal structure of Rv0489, another member of the histidine phosphatase superfamily in M. tuberculosis, has been previously reported. However, its biochemical characteristics remain unknown. In this study, Rv2135c and Rv0489 from M. tuberculosis were cloned and expressed in Escherichia coli with 6 histidine residues tagged at the C terminal. Results Characterization of the purified recombinant proteins revealed that Rv0489 possesses phosphoglycerate mutase activity while Rv2135c does not. However Rv2135c has an acid phosphatase activity with optimal pH of 5.8. Kinetic parameters of Rv2135c and Rv0489 are studied, confirming that Rv0489 is a cofactor dependent phosphoglycerate mutase of M. tuberculosis. Additional characterization showed that Rv2135c exists as a tetramer while Rv0489 as a dimer in solution. Conclusion Most of the proteins orthologous to Rv2135c in other bacteria are annotated as phosphoglycerate mutases or hypothetical proteins. It is possible that they are actually phosphatases. Experimental characterization of a sufficiently large number of bacterial histidine phosphatases will increase the accuracy of the automatic

  4. Primary structure and subcellular localization of the knob-associated histidine-rich protein of Plasmodium falciparum.

    PubMed Central

    Pologe, L G; Pavlovec, A; Shio, H; Ravetch, J V

    1987-01-01

    Plasmodium falciparum-infected erythrocytes bind to venular endothelial cells by means of electron-dense deformations (knobs) on the parasitized erythrocyte surface. The primary structure of a parasite-derived histidine-rich protein associated with the knob structure was deduced from cDNA sequence analysis. The 634 amino acid sequence is rich in lysine and histidine and contains three distinct, tandemly repeated domains. Indirect immunofluorescence, using affinity-purified monospecific antibodies directed against recombinant protein synthesized in Escherichia coli, localized the knob-associated histidine-rich protein to the membrane of knobby infected erythrocytes. Immunoelectron microscopy established that the protein is clustered on the cytoplasmic side of the erythrocyte membrane and is associated with the electron-dense knobs. A role for this histidine-rich protein in knob structure and cytoadherence is suggested based upon these data. Images PMID:3313387

  5. Activation of synaptic and extrasynaptic glycine receptors by taurine in preoptic hypothalamic neurons.

    PubMed

    Bhattarai, Janardhan Prasad; Park, Soo Joung; Chun, Sang Woo; Cho, Dong Hyu; Han, Seong Kyu

    2015-11-01

    Taurine is an essential amino-sulfonic acid having a fundamental function in the brain, participating in both cell volume regulation and neurotransmission. Using a whole cell voltage patch clamp technique, the taurine-activated neurotransmitter receptors in the preoptic hypothalamic area (PHA) neurons were investigated. In the first set of experiments, different concentrations of taurine were applied on PHA neurons. Taurine-induced responses were concentration-dependent. Taurine-induced currents were action potential-independent and sensitive to strychnine, suggesting the involvement of glycine receptors. In addition, taurine activated not only α-homomeric, but also αβ-heteromeric glycine receptors in PHA neurons. Interestingly, a low concentration of taurine (0.5mM) activated glycine receptors, whereas a higher concentration (3mM) activated both glycine and gamma-aminobutyric acid A (GABAA) receptors in PHA neurons. These results suggest that PHA neurons are influenced by taurine and respond via glycine and GABAA receptors.

  6. How the Glycine and GABA Receptors Were Purified

    PubMed Central

    2012-01-01

    Purification by Affinity Chromatography of the Glycine Receptor of Rat Spinal Cord (Pfeiffer, F., Graham, D., and Betz, H. (1982) J. Biol. Chem. 257, 9389–9393) A γ-Aminobutyric Acid/Benzodiazepine Receptor Complex of Bovine Cerebral Cortex (Sigel, E., Stephenson, F. A., Mamalaki, C., and Barnard, E. A. (1983) J. Biol. Chem. 258, 6965–6971) PMID:23180805

  7. Glycine Polymerization on Oxide Minerals

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio; Oonishi, Hiroyuki; Umemoto, Koichiro; Usui, Tomohiro; Fukushi, Keisuke; Nakashima, Satoru

    2016-07-01

    It has long been suggested that mineral surfaces played an important role in peptide bond formation on the primitive Earth. However, it remains unclear which mineral species was key to the prebiotic processes. This is because great discrepancies exist among the reported catalytic efficiencies of minerals for amino acid polymerizations, owing to mutually different experimental conditions. This study examined polymerization of glycine (Gly) on nine oxide minerals (amorphous silica, quartz, α-alumina and γ-alumina, anatase, rutile, hematite, magnetite, and forsterite) using identical preparation, heating, and analytical procedures. Results showed that a rutile surface is the most effective site for Gly polymerization in terms of both amounts and lengths of Gly polymers synthesized. The catalytic efficiency decreased as rutile > anatase > γ-alumina > forsterite > α- alumina > magnetite > hematite > quartz > amorphous silica. Based on reported molecular-level information for adsorption of Gly on these minerals, polymerization activation was inferred to have arisen from deprotonation of the NH3 + group of adsorbed Gly to the nucleophilic NH2 group, and from withdrawal of electron density from the carboxyl carbon to the surface metal ions. The orientation of adsorbed Gly on minerals is also a factor influencing the Gly reactivity. The examination of Gly-mineral interactions under identical experimental conditions has enabled the direct comparison of various minerals' catalytic efficiencies and has made discussion of polymerization mechanisms and their relative influences possible Further systematic investigations using the approach reported herein (which are expected to be fruitful) combined with future microscopic surface analyses will elucidate the role of minerals in the process of abiotic peptide bond formation.

  8. Influence of high glycine diets on the activity of glycine-catabolizing enzymes and on glycine catabolism in rats

    SciTech Connect

    Petzke, K.J.; Albrecht, V.; Przybilski, H.

    1986-05-01

    Male albino rats were adapted to isocaloric purified diets that differed mainly in their glycine and casein contents. Controls received a 30% casein diet. In experimental diets gelatin or gelatin hydrolysate was substituted for half of the 30% casein. An additional group was fed a glycine-supplemented diet, which corresponded in glycine level to the gelatin diet but in which the protein level was nearly the same as that of the casein control diet. Another group received a 15% casein diet. Rat liver glycine cleavage system, serine hydroxymethyltransferase and serine dehydratase activities were measured. /sup 14/CO/sub 2/ production from the catabolism of /sup 14/C-labeled glycine was measured in vivo and in vitro (from isolated hepatocytes). Serine dehydratase and glycine cleavage system activities were higher in animals fed 30% casein diets than in those fed 15% casein diets. Serine hydroxymethyltransferase activity of the cytosolic and mitochondrial fractions was highest when a high glycine diet (glycine administered as pure, protein bound in gelatin or peptide bound in gelatin hydrolysate) was fed. /sup 14/CO/sub 2/ formation from (1-/sup 14/C)- and (2-/sup 14/C)glycine both in vivo and in isolated hepatocytes was higher when a high glycine diet was fed than when a casein diet was fed. These results suggest that glycine catabolism is dependent on and adaptable to the glycine content of the diet. Serine hydroxymethyltransferase appears to play a major role in the regulation of glycine degradation via serine and pyruvate.

  9. 75 FR 66352 - Glycine From the People's Republic of China: Initiation of Antidumping Anti-circumvention Inquiry

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... sweetener/taste enhancer, a buffering agent, re-absorbable amino acid, chemical intermediate, and a metal... and Chiyuen International Trading Ltd., a manufacturer in the PRC of amino acetic acid (i.e., glycine... China (PRC). See Antidumping Duty Order: Glycine from People's Republic of China, 60 FR 16116 (March...

  10. Amino acids assisted hydrothermal synthesis of hierarchically structured ZnO with enhanced photocatalytic activities

    NASA Astrophysics Data System (ADS)

    Guo, Yanxia; Lin, Siwen; Li, Xuan; Liu, Yuping

    2016-10-01

    Novel hierarchically structured ZnO, including rose-like, dandelion-like and flower-like, have been synthesized through a simple hydrothermal process using different amino acids (glutamine, histidine and glycine) as structure-directing agents and urea as deposition agent, followed by subsequent calcination. Amino acids played a crucial role in the formation of hierarchically structured ZnO, and different amino acids could induce different exquisite shapes and assembly ways, as well as more oxygen defects. The prepared hierarchically structured ZnO exhibited excellent photocatalytic activities for the photodegradation of Rhodamine B, which was associated with their special hierarchical structures, large BET surface area and the existence of more oxygen defects. Amino acid-assisted growth mechanism of hierarchically structured ZnO was also discussed.

  11. 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.

  12. Formation of RNA phosphodiester bond by histidine-containing dipeptides.

    PubMed

    Wieczorek, Rafał; Dörr, Mark; Chotera, Agata; Luisi, Pier Luigi; Monnard, Pierre-Alain

    2013-01-21

    A new scenario for prebiotic formation of nucleic acid oligomers is presented. Peptide catalysis is applied to achieve condensation of activated RNA monomers into short RNA chains. As catalysts, L-dipeptides containing a histidine residue, primarily Ser-His, were used. Reactions were carried out in self-organised environment, a water-ice eutectic phase, with low concentrations of reactants. Incubation periods up to 30 days resulted in the formation of short oligomers of RNA. During the oligomerisation, an active intermediate (dipeptide-mononucleotide) is produced, which is the reactive species. Details of the mechanism and kinetics, which were elucidated with a set of control experiments, further establish that the imidazole side chain of a histidine at the carboxyl end of the dipeptide plays a crucial role in the catalysis. These results suggest that this oligomerisation catalysis occurs by a transamination mechanism. Because peptides are much more likely products of spontaneous condensation than nucleotide chains, their potential as catalysts for the formation of RNA is interesting from the origin-of-life perspective. Finally, the formation of the dipeptide-mononucleotide intermediate and its significance for catalysis might also be viewed as the tell-tale signs of a new example of organocatalysis. PMID:23255284

  13. 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.

  14. Quest for Cells Responsible for Age-related Increase of Salivary Glycine and Proline.

    PubMed

    Hino, Shunsuke; Nishiyama, Akira; Matsuta, Tomohiko; Horie, Norio; Shimoyama, Tetsuo; Tanaka, Shoji; Sakagami, Hiroshi

    2016-01-01

    We have previously reported that salivary glycine and proline levels are increased to nearly butanoate level in elderly people. In order to identify the source of glycine and proline, we performed high-performance liquid chromatography analysis of amino acid production to a total of seven oral cells before and after stimulation with inflammation inducers. We found that production of amino acids (per a given number of cells) by normal oral mesenchymal cells (gingival fibroblast, pulp cell, periodontal ligament fibroblast) was approximately three-fold that of oral squamous cell carcinoma cell lines (HSC-2, HSC-3, HSC-4, Ca9-22), and that production of glycine and especially proline by all these seven cells was much lower than that of glutamine and glutamic acid. Treatment of three oral mesenchymal cells with interleukin (IL)-1β or lipopoly-saccharide (LPS) reproducibly increased the production of glutamic acid and glutamine, but not that of glycine and proline. Glycine and proline only marginally stimulated the IL-8 production by IL-1β-stimulated gingival fibroblast, whereas glycine dose-dependently inhibited the nitric oxide production by lipopolysaccharide-stimulated mouse macrophage-like RAW264.7 cells. These data demonstrated that normal oral mesenchymal cells are not the major source of glycine and proline that accumulates in the saliva of aged people, suggesting the involvement of the deregulation of collagen metabolism during aging. PMID:26912818

  15. Ion chromatographic analysis of selected free amino acids and cations to investigate the change of nitrogen metabolism by herbicide stress in soybean (glycine max).

    PubMed

    Jia, M; Keutgen, N; Matsuhashi, S; Mitzuniwa, C; Ito, T; Fujimura, T; Hashimoto, S

    2001-01-01

    A simple and reliable method for the determination of NH4+, K+, Na+, aspartic acid, asparagine, glutamine, and alanine by ion chromatography has been developed. It is suitable for monitoring changes of nitrogen metabolism in soybean because it can accurately measure concentrations o asparagine and NH4+, two key substances for nitrogen storage and transport in this plant species Analysis of asparagine distribution in soybean indicated that higher levels (up to 18.4 micromol g(-1) of fresh mass) occur in stems and lower levels in roots (2.0 micromol g(-1) of fresh mass) and leaves (1.6 micromol g(-1) of fresh mass). When the herbicide metsulfuron-methyl (0.5, 5, and 50 ppb) was applied via the nutrient solution to the root system, asparagine concentrations increased 3-6 times in stems roots, and leaves. Metsulfuron-methyl is known to impair the synthesis of branched amino acids and, in consequence, protein synthesis. Thus, nitrogen consumption was limited, leading to ar accumulation of asparagine. The possible use of this physiological response in agricultural practice to identify herbicide stress in soybean and to detect low-level residues of sulfonylurea herbicides ir the soil is discussed.

  16. Photosensitizers form in histidine buffer and mediate the photodegradation of a monoclonal antibody.

    PubMed

    Stroop, Steven D; Conca, David M; Lundgard, Robert P; Renz, Mark E; Peabody, Lynn M; Leigh, Scott D

    2011-12-01

    Fluorescent light (FL) photodegradation of a monoclonal antibody (mAb) formulated in histidine buffer is mediated by histidine-derived photosensitizers that accumulate and greatly increase with light exposure. Histidine-derived photosensitizers are the primary mediators of Trp photooxidation. FL-photodegradation requires light exposure and is pH dependent. It is significantly reduced or eliminated by buffer exchanges, by oxygen depletion, or at pH values greater than 7. Antibody-fragment MS ion counts reveal that oxidation of a single light chain Trp in CDR1 correlates with binding loss. Multiple heavy chain methionines oxidize, but poorly correlate with binding loss. Photosensitizers extracted from photo-aged histidine buffer are potent mediators of FL-photodegradation including oxidation and, to a lesser degree, fragmentation and aggregation of the mAb. These photosensitizers absorb visible light and have neutral mass of 187.1- 386.1 Da. They are also fluorescent with ex/em at 360/450 nm. When spiked into histidine or MES buffered mAb formulations they produce a concentration dependent and pronounced increase in FL-photodegradation; however, no oxidation or loss of antibody function occurs in the dark and hydrogen peroxide does not oxidize Trp. The major component is consistent with histidine oxidation to 6a-hydroxy-2-oxo-octahydro-pyrollo[2,3-d]imidazole-5-carboxylic acid. Photosensitizer levels measured in the formulation prior to light exposure, are linearly related to the FL-photodegradation observed and can predict degradation in photostability testing.

  17. Mechanism of regulation of receptor histidine kinases.

    PubMed

    Ferris, Hedda U; Dunin-Horkawicz, Stanislaw; Hornig, Nora; Hulko, Michael; Martin, Jörg; Schultz, Joachim E; Zeth, Kornelius; Lupas, Andrei N; Coles, Murray

    2012-01-11

    Bacterial transmembrane receptors regulate an intracellular catalytic output in response to extracellular sensory input. To investigate the conformational changes that relay the regulatory signal, we have studied the HAMP domain, a ubiquitous intracellular module connecting input to output domains. HAMP forms a parallel, dimeric, four-helical coiled coil, and rational substitutions in our model domain (Af1503 HAMP) induce a transition in its interhelical packing, characterized by axial rotation of all four helices (the gearbox signaling model). We now illustrate how these conformational changes are propagated to a downstream domain by fusing Af1503 HAMP variants to the DHp domain of EnvZ, a bacterial histidine kinase. Structures of wild-type and mutant constructs are correlated with ligand response in vivo, clearly associating them with distinct signaling states. We propose that altered recognition of the catalytic domain by DHp, rather than a shift in position of the phospho-accepting histidine, forms the basis for regulation of kinase activity.

  18. Role of polymeric endosomolytic agents in gene transfection: a comparative study of poly(L-lysine) grafted with monomeric L-histidine analogue and poly(L-histidine).

    PubMed

    Hwang, Hee Sook; Hu, Jun; Na, Kun; Bae, You Han

    2014-10-13

    Endosomal entrapment is one of the main barriers that must be overcome for efficient gene expression along with cell internalization, DNA release, and nuclear import. Introducing pH-sensitive ionizable groups into the polycationic polymers to increase gene transfer efficiency has proven to be a useful method; however, a comparative study of introducing equal numbers of ionizable groups in both polymer and monomer forms, has not been reported. In this study, we prepared two types of histidine-grafted poly(L-lysine) (PLL), a stacking form of poly(L-histidine) (PLL-g-PHis) and a mono-L-histidine (PLL-g-mHis) with the same number of imidazole groups. These two types of histidine-grafted PLL, PLL-g-PHis and PLL-g-mHis, showed profound differences in hemolytic activity, cellular uptake, internalization, and transfection efficiency. Cy3-labeled PLL-g-PHis showed strong fluorescence in the nucleus after internalization, and high hemolytic activity upon pH changes was also observed from PLL-g-PHis. The arrangement of imidazole groups from PHis also provided higher gene expression than mHis due to its ability to escape the endosome. mHis or PHis grafting reduced the cytotoxicity of PLL and changed the rate of cellular uptake by changing the quantity of free ε-amines available for gene condensation. The subcellular localization of PLL-g-PHis/pDNA measured by YOYO1-pDNA intensity was highest inside the nucleus, while the lysotracker, which stains the acidic compartments was lowest among these polymers. Thus, the polymeric histidine arrangement demonstrate the ability to escape the endosome and trigger rapid release of polyplexes into the cytosol, resulting in a greater amount of pDNA available for translocation to the nucleus and enhanced gene expression.

  19. N-H···N Hydrogen Bonds Involving Histidine Imidazole Nitrogen Atoms: A New Structural Role for Histidine Residues in Proteins.

    PubMed

    Krishna Deepak, R N V; Sankararamakrishnan, Ramasubbu

    2016-07-12

    The amino acid histidine can play a significant role in the structure and function of proteins. Its various functions include enzyme catalysis, metal binding activity, and involvement in cation-π, π-π, salt-bridge, and other types of noncovalent interactions. Although histidine's imidazole nitrogens (Nδ and Nε) are known to participate in hydrogen bond (HB) interactions as an acceptor or a donor, a systematic study of N-H···N HBs with the Nδ/Nε atom as the acceptor has not been conducted. In this study, we have examined two data sets of ultra-high-resolution (data set I) and very high-resolution (data set II) protein structures and identified 28 and 4017 examples of HBs of the N-H···Nδ/Nε type from both data sets involving histidine imidazole nitrogen as the acceptor. In nearly 70% of them, the main-chain N-H bond is the HB donor, and a majority of the examples are from the N-H group separated by two residues (Ni+2-Hi+2) from histidine. Quantum chemical calculations using model compounds were performed with imidazole and N-methylacetamide, and they assumed conformations from 19 examples from data set I with N-H···Nδ/Nε HBs. Basis set superposition error-corrected interaction energies varied from -5.0 to -6.78 kcal/mol. We also found that the imidazole nitrogen of 9% of histidine residues forming N-H···Nδ/Nε interactions in data set II participate in bifurcated HBs. Natural bond orbital analyses of model compounds indicate that the strength of each HB is mutually influenced by the other. Histidine residues involved in Ni+2-Hi+2···Nδi/Nεi HBs are frequently observed in a specific N-terminal capping position giving rise to a novel helix-capping motif. Along with their predominant occurrence in loop segments, we propose a new structural role for histidines in protein structures. PMID:27305350

  20. NMR contour maps as a new parameter of carboxyl's OH groups in amino acids recognition: A reason of tRNA-amino acid conjugation

    NASA Astrophysics Data System (ADS)

    Monajjemi, Majid; Wayne, Robert; Boggs, James E.

    2014-03-01

    In this work, we have applied a statistical method by computing statistical nucleus-independent chemical shifts (SNICS) in point of probes motions within a spatial shielding and de-shielding spaces around the OH groups of some amino acids. NMR contour maps as a new parameter have been created for amino-acyl-tRNA conjugation, by using a computational method to identify this model theoretically, it is critical to understand the reasons for tRNA-amino acid conjugation. DFT, NMR, 3D Gaussian distribution and Monte Carlo methods have been applied for Methionine, Serine, Histidine, Glycine and Glutamine to investigate the structural stability in the active parts of the amino acid-tRNA linkage by chemical shielding effects.

  1. The nature of electronic excitations at the metal-bioorganic interface illustrated on histidine-silver hybrids.

    PubMed

    Sanader, Željka; Mitrić, Roland; Bonačić-Koutecký, Vlasta; Bellina, Bruno; Antoine, Rodolphe; Dugourd, Philippe

    2014-01-21

    We present a joint theoretical and experimental study of the structure selective optical properties of cationic and anionic histidine-silver complexes with Ag and Ag3 which were prepared in the gas phase using mass spectroscopy coupled to electrospray ion source. Our TDDFT calculations provide general insight into the nature of electronic excitations at the metal-bioorganic interface that involve π-π* excitation within bioorganic subunits, charge transfer between two subunits and intrametallic excitations. The binding of silver to histidine, one of the most important amino acids, induces red shift in the optical absorption of protonated histidine particularly for anionic species. The presence of the smallest metallic subunit Ag3 increases the intensity of low energy transitions of histidine illustrating a metal cluster-induced enhancement of absorption of biomolecules in hybrid systems. Comparison of calculated absorption spectra with experimental photofragmentation yield provides structural assignment of the measured spectroscopic patterns. Our findings may serve to establish silver-labeling as the tool for the detection of histidine or histidine-tagged proteins.

  2. Urinary Amino Acid Alterations in 3-Year-Old Children with Neurodevelopmental Effects due to Perinatal Dioxin Exposure in Vietnam: A Nested Case-Control Study for Neurobiomarker Discovery

    PubMed Central

    Nishijo, Muneko; Tai, Pham The; Anh, Nguyen Thi Nguyet; Nghi, Tran Ngoc; Nakagawa, Hideaki; Van Luong, Hoang; Anh, Tran Hai; Morikawa, Yuko; Waseda, Tomoo; Kido, Teruhiko; Nishijo, Hisao

    2015-01-01

    In our previous study of 3-year-old children in a dioxin contamination hot spot in Vietnam, the high total dioxin toxic equivalent (TEQ-PCDDs/Fs)-exposed group during the perinatal period displayed lower Bayley III neurodevelopmental scores, whereas the high 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-exposed group displayed increased autistic traits. In autistic children, urinary amino acid profiles have revealed metabolic alterations in the amino acids that serve as neurotransmitters in the developing brain. Therefore, our present study aimed to investigate the use of alterations in urinary amino acid excretion as biomarkers of dioxin exposure-induced neurodevelopmental deficits in highly exposed 3-year-old children in Vietnam. A nested case-control study of urinary analyses was performed for 26 children who were selected from 111 3-year-old children whose perinatal dioxin exposure levels and neurodevelopmental status were examined in follow-up surveys conducted in a dioxin contaminated hot spot. We compared urinary amino acid levels between the following 4 groups: (1) a high TEQ-PCDDs/Fs and high TCDD-exposed group; (2) a high TEQ-PCDDs/Fs but low TCDD-exposed group; (3) a low TEQ-PCDDs/Fs exposed and poorly developed group; and (4) a low TEQ-PCDDs/Fs exposed and well-developed group. Urinary levels of histidine and tryptophan were significantly decreased in the high TEQ-PCDDs/Fs and high TCDD group, as well as in the high TEQ-PCDDs/Fs but low TCDD group, compared with the low TEQ-PCDDs/Fs and well-developed group. However, the ratio of histidine to glycine was significantly lower only in the high TEQ-PCDDs/Fs and high TCDD group. Furthermore, urinary histidine levels and the ratio of histidine to glycine were significantly correlated with neurodevelopmental scores, particularly for language and fine motor skills. These results indicate that urinary histidine is specifically associated with dioxin exposure-induced neurodevelopmental deficits, suggesting that

  3. Intravenous infusion of L-isomers of phenylalanine and tryptophan stimulate gastric acid secretion at physiologic plasma concentrations in normal subjects and after parietal cell vagotomy.

    PubMed Central

    McArthur, K E; Isenberg, J I; Hogan, D L; Dreier, S J

    1983-01-01

    To determine whether intravenous infusion of individual amino acids stimulated gastric acid secretion in man, graded doses of phenylalanine, tryptophan, glycine, alanine, histidine, and NaCl control were infused on separate days in nine healthy subjects. Intravenous infusion of phenylalanine and tryptophan significantly stimulated gastric acid secretion to 50 and 52%, respectively, of the acid secretory response to intragastric peptone. Intravenous alanine and histidine were without effect, whereas glycine produced a slight response. Serum gastrin concentrations did not significantly change during intravenous amino acid infusion, except in response to 0.1 M phenylalanine. However, the increase in serum gastrin occurred 2 h after acid secretion had significantly increased in response to the 0.025 M phenylalanine infusion. Plasma amino acid concentrations were measured during intravenous amino acid infusion and in response to a steak meal in five of the subjects. At a time when acid secretion was significantly increased during intravenous infusion of phenylalanine and tryptophan, plasma amino acids were similar to, or less than, that observed after the steak meal, suggesting that circulating levels of these three amino acids have a physiologic effect on gastric secretion in man. Intravenous infusion of a combination of graded doses of phenylalanine plus a continuous infusion of 0.01 M tryptophan shifted the dose-response curve to the left and resulted in a significantly greater response than to either amino acid alone. In five subjects with parietal cell vagotomy, intravenous phenylalanine and tryptophan stimulated acid secretion, whereas histidine was without effect, similar to normal subjects. These studies indicate that intravenous infusion of small amounts of phenylalanine (0.025 M, 3.1 mmol/h) and tryptophan (0.01 M, 1.25 mmol/h) stimulated gastric acid secretion at plasma concentrations similar to those observed after a steak meal, suggesting a physiologic role

  4. Glycine modulates membrane potential, cell volume, and phagocytosis in murine microglia.

    PubMed

    Komm, Barbara; Beyreis, Marlena; Kittl, Michael; Jakab, Martin; Ritter, Markus; Kerschbaum, Hubert H

    2014-08-01

    Phagocytes form engulfment pseudopodia at the contact area with their target particle by a process resembling cell volume (CV) regulatory mechanisms. We evaluated whether the osmoregulatory active neutral amino acid glycine, which contributes to CV regulation via activation of sodium-dependent neutral amino acid transporters (SNATs) improves phagocytosis in isotonic and hypertonic conditions in the murine microglial cell line BV-2 and primary microglial cells (pMG). In BV-2 cells and pMG, RT-PCR analysis revealed expression of SNATs (Slc38a1, Slc38a2), but not of GlyRs (Glra1-4). In BV-2 cells, glycine (5 mM) led to a rapid Na(+)-dependent depolarization of membrane potential (V mem). Furthermore, glycine increased CV by about 9%. Visualizing of phagocytosis of polystyrene microspheres by scanning electron microscopy revealed that glycine (1 mM) increased the number of BV-2 cells containing at least one microsphere by about 13%. Glycine-dependent increase in phagocytosis was suppressed by the SNAT inhibitor α-(methylamino)isobutyric acid (MeAIB), by replacing extracellular Na(+) with choline, and under hypertonic conditions, but not by the GlyR antagonist strychnine or the GlyR agonist taurine. Interestingly, hypertonicity-induced suppression of phagocytosis was rescued by glycine. These findings demonstrate that glycine increases phagocytosis in iso- and hypertonic conditions by activation of SNATs.

  5. 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.

  6. Mutual Amino Acid Catalysis in Salt-Induced Peptide Formation Supports this Mechanism's Role in Prebiotic Peptide Evolution

    NASA Astrophysics Data System (ADS)

    Suwannachot, Yuttana; Rode, Bernd M.

    1999-10-01

    The presence of some amino acids and dipeptides under the conditions of the salt-induced peptide formation reaction (aqueous solution at 85 °C, Cu(II) and NaCl) has been found to catalyze the formation of homopeptides of other amino acids, which are otherwise produced only in traces or not at all by this reaction. The condensation of Val, Leu and Lys to form their homodipeptides can occur to a considerable extent due to catalytic effects of other amino acids and related compounds, among which glycine, histidine, diglycine and diketopiperazine exhibit the most remarkable activity. These findings also lead to a modification of the table of amino acid sequences preferentially formed by the salt-induced peptide formation (SIPF) reaction, previously used for a comparison with the sequence preferences in membrane proteins of primitive organisms

  7. 1-Aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC synthase expression in soybean roots, root tips, and soybean cyst nematode (Heterodera glycines)-infected roots.

    PubMed

    Tucker, Mark L; Xue, Ping; Yang, Ronghui

    2010-01-01

    Colonization of plant roots by root knot and cyst nematodes requires a functional ethylene response pathway. However, ethylene plays many roles in root development and whether its role in nematode colonization is direct or indirect, for example lateral root initiation or root hair growth, is not known. The temporal requirement for ethylene and localized synthesis of ethylene during the life span of soybean cyst nematode (SCN) on soybean roots was further investigated. Although a significant increase in ethylene evolution was not detected from SCN-colonized roots, the concentration of the immediate precursor to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), was higher in SCN-colonized root pieces and root tips than in other parts of the root. Moreover, expression analysis of 17 ACC synthase (ACS) genes indicated that a select set of ACS genes is expressed in SCN-colonized root pieces that is clearly different from the set of genes expressed in non-colonized roots or root tips. Semi-quantitative real-time PCR indicated that ACS transcript accumulation correlates with the high concentration of ACC in root tips. In addition, an ACS-like sequence was found in the public SCN nucleotide database. Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS. Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested.

  8. A THREE-PHASE CHEMICAL MODEL OF HOT CORES: THE FORMATION OF GLYCINE

    SciTech Connect

    Garrod, Robin T.

    2013-03-01

    A new chemical model is presented that simulates fully coupled gas-phase, grain-surface, and bulk-ice chemistry in hot cores. Glycine (NH{sub 2}CH{sub 2}COOH), the simplest amino acid, and related molecules such as glycinal, propionic acid, and propanal, are included in the chemical network. Glycine is found to form in moderate abundance within and upon dust-grain ices via three radical-addition mechanisms, with no single mechanism strongly dominant. Glycine production in the ice occurs over temperatures {approx}40-120 K. Peak gas-phase glycine fractional abundances lie in the range 8 Multiplication-Sign 10{sup -11}-8 Multiplication-Sign 10{sup -9}, occurring at {approx}200 K, the evaporation temperature of glycine. A gas-phase mechanism for glycine production is tested and found insignificant, even under optimal conditions. A new spectroscopic radiative-transfer model is used, allowing the translation and comparison of the chemical-model results with observations of specific sources. Comparison with the nearby hot-core source NGC 6334 IRS1 shows excellent agreement with integrated line intensities of observed species, including methyl formate. The results for glycine are consistent with the current lack of a detection of this molecule toward other sources; the high evaporation temperature of glycine renders the emission region extremely compact. Glycine detection with ALMA is predicted to be highly plausible, for bright, nearby sources with narrow emission lines. Photodissociation of water and subsequent hydrogen abstraction from organic molecules by OH, and NH{sub 2}, are crucial to the buildup of complex organic species in the ice. The inclusion of alternative branches within the network of radical-addition reactions appears important to the abundances of hot-core molecules; less favorable branching ratios may remedy the anomalously high abundance of glycolaldehyde predicted by this and previous models.

  9. Antioxidant status of turkey breast meat and blood after feeding a diet enriched with histidine.

    PubMed

    Kopec, W; Wiliczkiewicz, A; Jamroz, D; Biazik, E; Pudlo, A; Hikawczuk, T; Skiba, T; Korzeniowska, M

    2016-01-01

    The objective of this study was to investigate the effects of 1) spray dried blood cells rich in histidine and 2) pure histidine added to feed on the antioxidant status and concentration of carnosine related components in the blood and breast meat of female turkeys. The experiment was performed on 168 Big7 turkey females randomly assigned to 3 dietary treatments: control; control with the addition of 0.18% L-histidine (His); and control with the addition of spray dried blood cells (SDBC). Birds were raised for 103 d on a floor with sawdust litter, with drinking water and feed ad libitum. The antioxidant status of blood plasma and breast muscle was analyzed by ferric reducing ability (FRAP) and by 2,2-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging ability. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was analyzed in the blood and breast meat, with the content of carnosine and anserine quantified by HPLC. Proximate analysis as well as amino acid profiling were carried out for the feed and breast muscles. Growth performance parameters also were calculated. Histidine supplementation of the turkey diet resulted in increased DPPH radical scavenging capacity in the breast muscles and blood, but did not result in higher histidine dipeptide concentrations. The enzymatic antioxidant system of turkey blood was affected by the diet with SDBC. In the plasma, the SDBC addition increased both SOD and GPx activity, and decreased GPx activity in the erythrocytes. Feeding turkeys with an SDBC containing diet increased BW and the content of isoleucine and valine in breast muscles.

  10. Antioxidant status of turkey breast meat and blood after feeding a diet enriched with histidine.

    PubMed

    Kopec, W; Wiliczkiewicz, A; Jamroz, D; Biazik, E; Pudlo, A; Hikawczuk, T; Skiba, T; Korzeniowska, M

    2016-01-01

    The objective of this study was to investigate the effects of 1) spray dried blood cells rich in histidine and 2) pure histidine added to feed on the antioxidant status and concentration of carnosine related components in the blood and breast meat of female turkeys. The experiment was performed on 168 Big7 turkey females randomly assigned to 3 dietary treatments: control; control with the addition of 0.18% L-histidine (His); and control with the addition of spray dried blood cells (SDBC). Birds were raised for 103 d on a floor with sawdust litter, with drinking water and feed ad libitum. The antioxidant status of blood plasma and breast muscle was analyzed by ferric reducing ability (FRAP) and by 2,2-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging ability. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was analyzed in the blood and breast meat, with the content of carnosine and anserine quantified by HPLC. Proximate analysis as well as amino acid profiling were carried out for the feed and breast muscles. Growth performance parameters also were calculated. Histidine supplementation of the turkey diet resulted in increased DPPH radical scavenging capacity in the breast muscles and blood, but did not result in higher histidine dipeptide concentrations. The enzymatic antioxidant system of turkey blood was affected by the diet with SDBC. In the plasma, the SDBC addition increased both SOD and GPx activity, and decreased GPx activity in the erythrocytes. Feeding turkeys with an SDBC containing diet increased BW and the content of isoleucine and valine in breast muscles. PMID:26574038

  11. Substitution of aspartic acid for glycine at position 310 in type II collagen produces achondrogenesis II, and substitution of serine at position 805 produces hypochondrogenesis: analysis of genotype-phenotype relationships.

    PubMed Central

    Bonaventure, J; Cohen-Solal, L; Ritvaniemi, P; Van Maldergem, L; Kadhom, N; Delezoide, A L; Maroteaux, P; Prockop, D J; Ala-Kokko, L

    1995-01-01

    Two different mutations were found in two unrelated probands with lethal chondrodysplasias, one with achondrogenesis type II and the other with the less severe phenotype of hypochondrogenesis. The mutations in the COL2A1 gene were identified by denaturing gradient gel electrophoresis analysis of genomic DNA followed by dideoxynucleotide sequencing and restriction site analysis. The proband with achondrogenesis type II had a heterozygous single-base mutation that substituted aspartate for glycine at position 310 of the alpha 1(II) chain of type II procollagen. The proband with hypochondrogenesis had a heterozygous single-base mutation that substituted serine for glycine at position 805. Type II collagen extracted from cartilage from the probands demonstrated the presence of type I collagen and a delayed electrophoretic mobility, indicating post-translational overmodifications. Analysis of CNBr peptides showed that, in proband 1, the entire peptides were overmodified. Examination of chondrocytes cultured in agarose or alginate indicated that there was a delayed secretion of type II procollagen. In addition, type II collagen synthesized by cartilage fragments from the probands demonstrated a decreased thermal stability. The melting temperature of the type II collagen containing the aspartate-for-glycine substitution was reduced by 4 degrees C, and that of the collagen containing the serine-for-glycine substitution was reduced by 2 degrees C. Electron microscopy of the extracellular matrix from the chondrocyte cultures showed a decreased density of matrix and the presence of unusually short and thin fibrils. Our results indicate that glycine substitutions in the N-terminal region of the type II collagen molecule can produce more severe phenotypes than mutations in the C-terminal region. The aspartate-for-glycine substitution at position 310, which was associated with defective secretion and a probable increased degradation of collagen, is the most destabilizing

  12. Substitution of aspartic acid for glycine at position 310 in type II collagen produces achondrogenesis II, and substitution of serine at position 805 produces hypochondrogenesis: analysis of genotype-phenotype relationships.

    PubMed

    Bonaventure, J; Cohen-Solal, L; Ritvaniemi, P; Van Maldergem, L; Kadhom, N; Delezoide, A L; Maroteaux, P; Prockop, D J; Ala-Kokko, L

    1995-05-01

    Two different mutations were found in two unrelated probands with lethal chondrodysplasias, one with achondrogenesis type II and the other with the less severe phenotype of hypochondrogenesis. The mutations in the COL2A1 gene were identified by denaturing gradient gel electrophoresis analysis of genomic DNA followed by dideoxynucleotide sequencing and restriction site analysis. The proband with achondrogenesis type II had a heterozygous single-base mutation that substituted aspartate for glycine at position 310 of the alpha 1(II) chain of type II procollagen. The proband with hypochondrogenesis had a heterozygous single-base mutation that substituted serine for glycine at position 805. Type II collagen extracted from cartilage from the probands demonstrated the presence of type I collagen and a delayed electrophoretic mobility, indicating post-translational overmodifications. Analysis of CNBr peptides showed that, in proband 1, the entire peptides were overmodified. Examination of chondrocytes cultured in agarose or alginate indicated that there was a delayed secretion of type II procollagen. In addition, type II collagen synthesized by cartilage fragments from the probands demonstrated a decreased thermal stability. The melting temperature of the type II collagen containing the aspartate-for-glycine substitution was reduced by 4 degrees C, and that of the collagen containing the serine-for-glycine substitution was reduced by 2 degrees C. Electron microscopy of the extracellular matrix from the chondrocyte cultures showed a decreased density of matrix and the presence of unusually short and thin fibrils. Our results indicate that glycine substitutions in the N-terminal region of the type II collagen molecule can produce more severe phenotypes than mutations in the C-terminal region. The aspartate-for-glycine substitution at position 310, which was associated with defective secretion and a probable increased degradation of collagen, is the most destabilizing

  13. Understanding the Role of Histidine in the GHSxG Acyltransferase Active Site Motif: Evidence for Histidine Stabilization of the Malonyl-Enzyme Intermediate

    PubMed Central

    Poust, Sean; Yoon, Isu; Adams, Paul D.; Katz, Leonard; Petzold, Christopher J.; Keasling, Jay D.

    2014-01-01

    Acyltransferases determine which extender units are incorporated into polyketide and fatty acid products. The ping-pong acyltransferase mechanism utilizes a serine in a conserved GHSxG motif. However, the role of the conserved histidine in this motif is poorly understood. We observed that a histidine to alanine mutation (H640A) in the GHSxG motif of the malonyl-CoA specific yersiniabactin acyltransferase results in an approximately seven-fold higher hydrolysis rate over the wildtype enzyme, while retaining transacylation activity. We propose two possibilities for the reduction in hydrolysis rate: either H640 structurally stabilizes the protein by hydrogen bonding with a conserved asparagine in the ferredoxin-like subdomain of the protein, or a water-mediated hydrogen bond between H640 and the malonyl moiety stabilizes the malonyl-O-AT ester intermediate. PMID:25286165

  14. Understanding the role of histidine in the GHSxG acyltransferase active site motif: Evidence for histidine stabilization of the malonyl-enzyme intermediate

    SciTech Connect

    Poust, Sean; Yoon, Isu; Adams, Paul D.; Katz, Leonard; Petzold, Christopher J.; Keasling, Jay D.

    2014-10-06

    Acyltransferases determine which extender units are incorporated into polyketide and fatty acid products. Thus, the ping-pong acyltransferase mechanism utilizes a serine in a conserved GHSxG motif. However, the role of the conserved histidine in this motif is poorly understood. We observed that a histidine to alanine mutation (H640A) in the GHSxG motif of the malonyl-CoA specific yersiniabactin acyltransferase results in an approximately seven-fold higher hydrolysis rate over the wildtype enzyme, while retaining transacylation activity. We propose two possibilities for the reduction in hydrolysis rate: either H640 structurally stabilizes the protein by hydrogen bonding with a conserved asparagine in the ferredoxin-like subdomain of the protein, or a water-mediated hydrogen bond between H640 and the malonyl moiety stabilizes the malonyl-O-AT ester intermediate.

  15. Understanding the role of histidine in the GHSxG acyltransferase active site motif: Evidence for histidine stabilization of the malonyl-enzyme intermediate

    DOE PAGES

    Poust, Sean; Yoon, Isu; Adams, Paul D.; Katz, Leonard; Petzold, Christopher J.; Keasling, Jay D.

    2014-10-06

    Acyltransferases determine which extender units are incorporated into polyketide and fatty acid products. Thus, the ping-pong acyltransferase mechanism utilizes a serine in a conserved GHSxG motif. However, the role of the conserved histidine in this motif is poorly understood. We observed that a histidine to alanine mutation (H640A) in the GHSxG motif of the malonyl-CoA specific yersiniabactin acyltransferase results in an approximately seven-fold higher hydrolysis rate over the wildtype enzyme, while retaining transacylation activity. We propose two possibilities for the reduction in hydrolysis rate: either H640 structurally stabilizes the protein by hydrogen bonding with a conserved asparagine in the ferredoxin-likemore » subdomain of the protein, or a water-mediated hydrogen bond between H640 and the malonyl moiety stabilizes the malonyl-O-AT ester intermediate.« less

  16. [Resorption and incorporation of radioactive labeled amino acids during administration of various protein carriers in rats. 1. Resorption of 14C leucine and 3H glycine after intragastric administration].

    PubMed

    Zimmer, M; Bergner, H; Simon, O

    1975-07-01

    Male Albino rats (90-100 g) were fed ad libitum (with limited periods of feeding) for 14 days. The diets were adjusted to a crude protein content of 10%. Powdered whole egg, fish meal, yeast and gelatine were used as protein sources. Additionally, one group of rats was fed a protein-free diet. On the 15th day of experiment the rats were fed a test diet at a level of 2 g per 100 g of body weight. 2 hrs after that the rats received 25 muCi of 3H glycine and 5 muCi of 14C-L-Leucine per 100 g of body weight administered by way of intragastric infusion. It was found that a large proportion of the radioactive amino acids were absorbed as early as after 0.5 hr. The highest rate of absorption was observed in animals fed dietary proteins of poor quality or a protein free diet, so that in animals receiving a gelatine diet or a protein-free diet only 68.4% or 56.4% of the administered amount of 14C activity were detected inside the gastro intestinal tract after 0.5 hr. Analogous data for the 3H activity were 52.4% and 25.3%. Maximum absorption occurred after 3-7 hrs. Following this the level of radioactivity in the intestinal contents again increased reaching a peak value after 14-24 hrs; in the case of 14C activity this peak value amounted to 25.4% of the administered dose in animals fed the gelatine diet and 32.8% in the group receiving the protein-free diet. It was established that the major proportion of the resecreted amount of 14C activity was present in leucine. Until 72 hrs after the intake of 14C activity the level of radioactivity was again found to decline, a processes which was induced by processes occurring in the large intestines. Moreover, evidence was obtained in confirmation of previous findings, indicating that the composition of faecal amino acids was constant and unaffected by dietary proteins.

  17. Promoter- and attenuator-related metabolic regulation of the Salmonella typhimurium histidine operon.

    PubMed Central

    Winkler, M E; Roth, D J; Hartman, P E

    1978-01-01

    Expression of the histidine (his) operon in Salmonella typhimurium was found to be positively correlated with the intracellular level of guanosine tetraphosphate (ppGpp). Limitation for amino acids other than histidine elicited a histidine-independent metabolic regulation of the operon. In bacteria grown at decreased growth rates, his operon expression was metabolically regulated up to a point, after which further decreases in growth rate no longer resulted in further enhancement of operon expression. Studies using strains carrying various regulatory and deletion mutations indicated that metabolic regulation is achieved predominantly by increased RNA chain initiations at the primary (P1) and internal (P2) promoters. Metabolic regulation ordinarly did not involve changes in RNA chain terminations at the attenuator site of the his operon. A model is proposed that involves ppGpp-induced changes in RNA polymerase initiation specificity at particular promoters. A second, special form of metabolic regulation may operate which also is histidine independent, but does involve relief of attenuation. PMID:342509

  18. protonation behavior of histidine during HSF1 activation by physiological acidification.

    PubMed

    Lu, Ming; Park, Jang-Su

    2015-06-01

    The expression of eukaryotic molecular chaperones (heat shock proteins, HSPs) is triggered in response to a wide range of environmental stresses, including: heat shock, hydrogen peroxide, heavy metal, low-pH, or virus infection. Biochemical and genetic studies have clearly shown the fundamental roles of heat shock factor 1 (HSF1) in stress-inducible HSP gene expression, resistance to stress-induced cell death, carcinogenesis, and other biological phenomena. Previous studies show that acidic pH changes within the physiological range directly activate the HSF1 function in vitro. However, the detailed mechanism is unclear. Though computational pKa-predications of the amino acid side-chain, acidic-pH induced protonation of a histidine residue was found to be most-likely involved in this process. The histidine 83 (His83) residue, which could be protonated by mild decrease in pH, causes mild acidic-induced HSF1 activation (including in-vitro trimerization, DNA binding, in-vivo nuclear accumulation, and HSPs expression). His83, which is located in the loop region of the HSF1 DNA binding domain, was suggested to enhance the intermolecular force with Arginine 79, which helps HSF1 form a DNA-binding competent. Therefore, low-pH-induced activation of HSF1 by the protonation of histidine can help us better to understand the HSF1 mechanism and develop more therapeutic applications (particularly in cancer therapy). J. Cell. Biochem. 116: 977-984, 2015. © 2015 Wiley Periodicals, Inc.

  19. AMINO ACIDS AND HEMOGLOBIN PRODUCTION IN ANEMIA

    PubMed Central

    Whipple, G. H.; Robscheit-Robbins, F. S.

    1940-01-01

    Certain individual amino acids when given to standard anemic dogs cause an increase in new hemoglobin production. Occasional negative experiments are recorded. Glycine, glutamic acid, aspartic acid, cystine, histidine, phenylalanine, and proline when given in 1 gm. doses daily for 2 weeks, increase hemoglobin output on the average 23 to 25 gm. above the control level. This reaction amounts to 25 to 30 per cent of the new hemoglobin produced by the feeding of 300 gm. liver daily for 2 weeks—a standard liver test. Alanine, valine, isoleucine, and arginine in the same dosage increase the hemoglobin output on the average 13 to 17 gm. per 2 weeks over the control level. Leucine, methionine, lysine, tryptophane, and tyrosine fall in a middle group with hemoglobin output of about 20 gm. Isovaleric acid, β-hydroxybutyric acid, glutaric acid, and asparagine have shown positive effects and the butyrate is unusually potent for hemoglobin production (Table 2). The isomeric and dl-synthetic forms of the amino acids are as effectively utilized in this reaction as are the natural forms. PMID:19870982

  20. ESR Spectroscopy Provides Direct Evidence of Cu^2+ Coordination by Three Histidine Residues in Aβ1-16

    NASA Astrophysics Data System (ADS)

    Shin, Byong-Kyu; Saxena, Sunil

    2009-03-01

    We provide direct evidence that all three histidine residues in amyloid-β1-16 (Aβ1-16) coordinate to Cu^2+. In our approach, we generate three Aβ1-16 analogues, in each of which a selected histidine residue is isotopically enriched with ^15N. Pulsed electron spin resonance (ESR) experiments such as electron spin echo envelope modulation (ESEEM) and hyperfine sublevel correlation (HYSCORE) clearly show that each of the three histidine imidazole rings at position 6, 13, and 14 in Aβ1-16 binds to Cu^2+ as each of the three Cu^2+--^15N-labeled Aβ1-16 complexes displays ESEEM and HYSCORE spectra which are distinctively different from those of the Cu^2+--nonlabeled Aβ1-16 complex. The method employed here does not require either chemical side-chain modification or amino acid residue replacement, each of which is traditionally used to determine whether an amino acid residue in a protein binds to a metal ion. We also find that the histidine coordination in Aβ1-16 is independent of the Cu^2+-to-peptide ratio, which is in contrast to the case of Aβ1-40. The ESR results suggest tight binding between the histidine residues and the Cu^2+ ion, which is likely the reason of the high binding affinity of Aβ peptide to Cu^2+.

  1. Dual-histidine kinases in basidiomycete fungi.

    PubMed

    Lavín, José L; Sarasola-Puente, Vanessa; Ramírez, Lucía; Pisabarro, Antonio G; Oguiza, José A

    2014-02-01

    Dual-histidine kinases (HKs) are complex hybrid HKs containing in a single polypeptide two HK transmitter modules (T) and two-response regulator received domains (R) that are combined in a TRTR geometry. In fungi, this protein family is limited to some particular species of the phylum Basidiomycota and absent in the other phyla. This study extends the investigation of dual-HKs to 80 fully sequenced genomes of basidiomycetes, analyzing their distribution, domain architecture and phylogenetic relationships. Moreover, similarly to dual-HKs of basidiomycetes, several species of bacteria were found that contain hybrid HKs with a TRTR domain architecture encoded in a single gene. PMID:24581805

  2. Environmental stress causes oxidative damage to plant mitochondria leading to inhibition of glycine decarboxylase.

    PubMed

    Taylor, Nicolas L; Day, David A; Millar, A Harvey

    2002-11-01

    A cytotoxic product of lipid peroxidation, 4-hydroxy-2-nonenal (HNE), rapidly inhibited glycine, malate/pyruvate, and 2-oxoglutarate-dependent O2 consumption by pea leaf mitochondria. Dose- and time-dependence of inhibition showed that glycine oxidation was the most severely affected with a K(0.5) of 30 microm. Several mitochondrial proteins containing lipoic acid moieties differentially lost their reactivity to a lipoic acid antibody following HNE treatment. The most dramatic loss of antigenicity was seen with the 17-kDa glycine decarboxylase complex (GDC) H-protein, which was correlated with the loss of glycine-dependent O2 consumption. Paraquat treatment of pea seedlings induced lipid peroxidation, which resulted in the rapid loss of glycine-dependent respiration and loss of H-protein reactivity with lipoic acid antibodies. Pea plants exposed to chilling and water deficit responded similarly. In contrast, the damage to other lipoic acid-containing mitochondrial enzymes was minor under these conditions. The implication of the acute sensitivity of glycine decarboxylase complex H-protein to lipid peroxidation products is discussed in the context of photorespiration and potential repair mechanisms in plant mitochondria.

  3. Developmental stability of taurine's activation on glycine receptors in cultured neurons of rat auditory cortex.

    PubMed

    Tang, Zheng-Quan; Lu, Yun-Gang; Chen, Lin

    2008-01-01

    Taurine is an endogenous amino acid that can activate glycine and/or gamma-aminobutyric acid type A (GABA(A)) receptors in the central nervous system. During natural development, taurine's receptor target undergoes a shift from glycine receptors to GABA(A) receptors in cortical neurons. Here, we demonstrate that taurine's receptor target in cortical neurons remains stable during in vitro development. With whole-cell patch-clamp recordings, we found that taurine always activated glycine receptors, rather than GABA(A) receptors, in neurons of rat auditory cortex cultured for 5-22 days. Our results suggest that the functional sensitivity of glycine and GABA(A) receptors to taurine is critically regulated by their developmental environments.

  4. Effects of Rhizobacteria on Soybean Cyst Nematode, Heterodera glycines

    PubMed Central

    Tian, Honglin; Riggs, Robert D.

    2000-01-01

    Rhizobacteria were isolated from the rhizoplane and rhizosphere of soybean plants from fields in Arkansas and tested for their effect on numbers of soybean cyst nematode (Heterodera glycines). In initial greenhouse tests in heat-treated silt loam soil, 138 of the 201 bacterial isolates tested had no influence on numbers of cysts and eggs + second-stage juveniles (J2) of H. glycines, 36 reduced (suppressive isolates) and 27 increased (enhancing isolates) numbers of cysts and (or) eggs + J2 when compared to the controls (P ≤ 0.05). When 20 suppressive and five enhancing isolates were retested in the same soil, the results were highly variable and inconclusive. The 25 isolates were then evaluated in vitro for their effects on eggs and J2 of H. glycines. No clear relationship was detected between the inhibition of egg hatch or immobilization of J2 in vitro and antagonistic activity toward nematodes in vivo. Amendment of the soil with 0.1% (w/w) peptone or casein hydrolysate did not improve the effects of suppressive isolates on numbers of H. glycines. Nineteen of the 25 isolates were identified based on analysis of fatty acid methyl esters, and they are in 11 different genera. PMID:19270992

  5. Biosynthesis of glyoxylate from glycine in Saccharomyces cerevisiae.

    PubMed

    Villas-Bôas, Silas Granato; Kesson, Mats; Nielsen, Jens

    2005-05-01

    Glyoxylate biosynthesis in Saccharomyces cerevisiae is traditionally mainly ascribed to the reaction catalyzed by isocitrate lyase (Icl), which converts isocitrate to glyoxylate and succinate. However, Icl is generally reported to be repressed by glucose and yet glyoxylate is detected at high levels in S. cerevisiae extracts during cultivation on glucose. In bacteria there is an alternative pathway for glyoxylate biosynthesis that involves a direct oxidation of glycine. Therefore, we investigated the glycine metabolism in S. cerevisiae coupling metabolomics data and (13)C-isotope-labeling analysis of two reference strains and a mutant with a deletion in a gene encoding an alanine:glyoxylate aminotransferase. The strains were cultivated on minimal medium containing glucose or galactose, and (13)C-glycine as sole nitrogen source. Glyoxylate presented (13)C-labeling in all cultivation conditions. Furthermore, glyoxylate seemed to be converted to 2-oxovalerate, an unusual metabolite in S. cerevisiae. 2-Oxovalerate can possibly be converted to 2-oxoisovalerate, a key precursor in the biosynthesis of branched-chain amino acids. Hence, we propose a new pathway for glycine catabolism and glyoxylate biosynthesis in S. cerevisiae that seems not to be repressed by glucose and is active under both aerobic and anaerobic conditions. This work demonstrates the great potential of coupling metabolomics data and isotope-labeling analysis for pathway reconstructions.

  6. Β-alanine and l-histidine transport across the inner blood-retinal barrier: potential involvement in L-carnosine supply.

    PubMed

    Usui, Takuya; Kubo, Yoshiyuki; Akanuma, Shin-Ichi; Hosoya, Ken-Ichi

    2013-08-01

    The supply of L-carnosine, a bioactive dipeptide of β-alanine and l-histidine, to the retina across the blood-retinal barrier (BRB) was studied. The in vivo and in vitro studies revealed low uptake activities for [(3)H]Gly-Sar, a representative dipeptide, suggesting that l-carnosine transport plays only a minor role at the BRB. The in vivo study using rats showed approximately 18- and 23-fold greater retinal uptake indexes (RUI) for [(3)H]β-alanine and [(3)H]l-histidine compared with that of a paracellular marker, respectively. The RUI of [(3)H]β-alanine was taurine- and γ-aminobutyric acid-sensitive, and the in vitro uptake by TR-iBRB2 cells showed time- concentration- and temperature-dependent [(3)H]β-alanine uptake, suggesting that a carrier-mediated process was involved in β-alanine transport across the inner BRB. [(3)H]β-Alanine uptake was inhibited by taurine and β-guanidinopropionic acid, suggesting that taurine transporter (TAUT/SLC6A6) is responsible for the influx transport of β-alanine across the inner BRB. Regarding l-histidine, the l-leucine-sensitive RUI of [(3)H]l-histidine was identified, and the in vitro [(3)H]l-histidine uptake by TR-iBRB2 cells suggested that a carrier-mediated process was involved in l-histidine transport across the inner BRB. The inhibition profile suggested that L-type amino acid transporter (LAT1/SLC7A5) is responsible for the influx transport of l-histidine across the inner BRB. These results show that the influx transports of β-alanine and l-histidine across the inner BRB is carried out by TAUT and LAT1, respectively, suggesting that the retinal l-carnosine is supplied by enzymatic synthesis from two kinds of amino acids transported across the inner BRB.

  7. Soft x-ray ionization induced fragmentation of glycine

    SciTech Connect

    Itälä, E.; Kooser, K.; Rachlew, E.; Huels, M. A.; Kukk, E.

    2014-06-21

    X-ray absorption commonly involves dissociative core ionization producing not only momentum correlated charged fragments but also low- and high-energy electrons capable of inducing damage in living tissue. This gives a natural motivation for studying the core ionization induced fragmentation processes in biologically important molecules such as amino acids. Here the fragmentation of amino acid glycine following carbon 1s core ionization has been studied. Using photoelectron-photoion-photoion coincidence technique, a detailed analysis on fragmentation of the sample molecule into pairs of momentum correlated cations has been carried out. The main characteristics of core ionization induced fragmentation of glycine were found to be the rupture of the C–C{sub α} bond and the presence of the CNH{sub 2}{sup +} fragment.

  8. Enhanced silencing and stabilization of siRNA polyplexes by histidine-mediated hydrogen bonds

    PubMed Central

    Chou, Szu-Ting; Hom, Kellie; Zhang, Daoning; Leng, Qixin; Tricoli, Lucas J.; Hustedt, Jason M.; Lee, Amy; Shapiro, Michael J.; Seog, Joonil; Kahn, Jason D.; Mixson, A. James

    2013-01-01

    Branched peptides containing histidines and lysines (HK) have been shown to be effective carriers for DNA and siRNA. We anticipate that elucidation of the binding mechanism of HK with siRNA will provide greater insight into the self-assembly and delivery of the HK:siRNA polyplex. Non-covalent bonds between histidine residues and nucleic acids may enhance the stability of siRNA polyplexes. We first compared the polyplex biophysical properties of a branched HK with those of branched asparagines-lysine peptide (NK). Consistent with siRNA silencing experiments, gel electrophoresis demonstrated that the HK siRNA polyplex maintained its integrity with prolonged incubation in serum, whereas siRNA in complex with NK was degraded in a time-dependent manner. Isothermal titration calorimetry of various peptides binding to siRNA at pH 7.3 showed that branched polylysine, interacted with siRNA was initially endothermic, whereas branched HK exhibited an exothermic reaction at initial binding. The exothermic interaction indicates formation of non-ionic bonds between histidines and siRNA; purely electrostatic interaction is entropy-driven and endothermic. To investigate the type of non-ionic bond, we studied the protonation state of imidazole rings of a selectively 15N labeled branched HK by heteronuclear single quantum coherence NMR. The peak of Nδ1-H tautomers of imidazole shifted downfield (in the direction of deprotonation) by 0.5 to 1.0 ppm with addition of siRNA, providing direct evidence that histidines formed hydrogen bonds with siRNA at physiological pH. These results establish that histidine-rich peptides form hydrogen bonds with siRNA, thereby enhancing the stability and biological activity of the polyplex in vitro and in vivo. PMID:24161165

  9. Cometary Glycine Detected in Stardust-Returned Samples

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie E.; Glavin, D. P.; Dworkin, J. P.

    2010-01-01

    In January 2006, NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth. The Stardust cometary collector consisted of aerogel cells lined with aluminum foils designed to capture impacting particles and facilitate removal of the aerogel. Preliminary examinations of these comet-exposed materials revealed a suite of organic compounds, including several amines and amino acids which were later examined in more detail. Methylamine (NH2CH3) and ethylamine (NH2C2H5) were detected in the exposed aerogel at concentrations greatly exceeding those found in control samples, while the amino acid glycine (NH2CH2COOH) was detected in several foil samples as well as in the comet-exposed aerogel. None of these three compounds had been previously detected in comets, although methylamine had been observed in the interstellar medium. Although comparison with control samples suggested that the detected glycine was cometary. the previous work was not able to conclusively identify its origin. Here, we present the results of compound-specific carbon isotopic analysis of glycine in Stardust cometary collector foils. Several foils from the interstellar side of the Stardust collector were also analyzed for amino acid abundance, but concentrations were too low to perform isotopic ana!ysis.

  10. Electrogeneration of a poly(pyrrole)-NTA chelator film for a reversible oriented immobilization of histidine-tagged proteins.

    PubMed

    Haddour, Naoufel; Cosnier, Serge; Gondran, Chantal

    2005-04-27

    This contribution reports, for the first time, the synthesis and electropolymerization of a pyrrole N-substituted by a nitrilotriacetic acid acting as a chelating center of Cu2+. A step-by-step approach for protein immobilization was developed via the successive coordination of Cu2+ and histidine-tagged proteins. The self-assembly of histidine-tagged glucose oxidase led to the formation of a close-packed enzyme monolayer at the poly(pyrrole) surface, and the reversibility and reproducibility of this affinity process were demonstrated.

  11. Glycine and L-carnitine therapy in 3-methylcrotonyl-CoA carboxylase deficiency.

    PubMed

    Rutledge, S L; Berry, G T; Stanley, C A; van Hove, J L; Millington, D

    1995-01-01

    Genetic deficiency of 3-methylcrotonyl-CoA carboxylase (3-MCC) is a rare inborn error of leucine metabolism producing an organic acidaemia. With accumulation of 3-methylcrotonyl-CoA, there is increased production of 3-hydroxyisovaleric acid, the glycine conjugate (3-methylcrotonylglycine), and the carnitine conjugate (3-hydroxyisovalerylcarnitine). The conjugates represent endogenous detoxification products. We studied excretion rates of these conjugates at baseline and with glycine and carnitine therapy in an 8-year-old girl with 3-MCC deficiency. Her preadmission diet was continued. Plasma and urine samples were obtained after 24 h of each of the following: L-carnitine 100 mg/kg per day and glycine 100, 175 and 250 mg/kg per day. Plasma and urinary carnitine levels were reduced by 80% and 50%, respectively with abnormal urinary excretion patterns. These normalized with carnitine therapy. Acylcarnitine excretion increased with carnitine therapy. The glycine conjugate, 3-methylcrotonylglycine (3-MCG), was the major metabolite excreted at all times and its excretion increased with glycine therapy. Clearly, in 3-MCC deficiency the available glycine and carnitine pools are not sufficient to meet the potential for conjugation of accumulated metabolites, suggesting a possible therapeutic role for glycine and carnitine therapy in this disorder.

  12. Activation-induced structural change in the GluN1/GluN3A excitatory glycine receptor

    SciTech Connect

    Balasuriya, Dilshan; Takahashi, Hirohide; Srivats, Shyam; Edwardson, J. Michael

    2014-08-08

    Highlights: • We studied the response of the GluN1/GluN3A excitatory glycine receptor to activation. • GluN1 and GluN3A subunits interacted within transfected cells. • The GluN1/GluN3A receptor was functionally active. • Glycine or D-serine caused a ∼1 nm height reduction in bilayer-integrated receptors. • This height reduction was abolished by the glycine antagonist DCKA. - Abstract: Unlike GluN2-containing N-methyl-D-aspartate (NMDA) receptors, which require both glycine and glutamate for activation, receptors composed of GluN1 and GluN3 subunits are activated by glycine alone. Here, we used atomic force microscopy (AFM) imaging to examine the response to activation of the GluN1/GluN3A excitatory glycine receptor. GluN1 and GluN3A subunits were shown to interact intimately within transfected tsA 201 cells. Isolated GluN1/GluN3A receptors integrated into lipid bilayers responded to addition of either glycine or D-serine, but not glutamate, with a ∼1 nm reduction in height of the extracellular domain. The height reduction in response to glycine was abolished by the glycine antagonist 5,7-dichlorokynurenic acid. Our results represent the first demonstration of the effect of activation on the conformation of this receptor.

  13. About the detectability of glycine in the interstellar medium

    NASA Astrophysics Data System (ADS)

    Lattelais, M.; Pauzat, F.; Pilmé, J.; Ellinger, Y.; Ceccarelli, C.

    2011-08-01

    Context. Glycine, the simplest of aminoacids, has been found in several carbonaceous meteorites. It remains unclear, however, wether glycine is formed in the interstellar medium (ISM) and therefore available everywhere in the Universe. For this reason, radioastronomers have searched for many years unsuccessfully to detect glycine in the ISM. Aims: We provide possible guidelines to optimize the return of these searches. Since, for most of the species observed so far in the ISM, the most abundant isomer of a given generic chemical formula is the most stable one (minimum energy principle (MEP)), we assess whether neutral glycine is the best molecule to search for or whether one of its isomers/conformers or ionic, protonated, or zwitterionic derivatives would have a higher probability of being detected. Methods: The question of the relative stability of these different species is addressed by means of quantum density functional theory (DFT) simulations within the hybrid B3LYP formalism. Each fully optimized structure is verified as a stationary point by means of a vibrational analysis. A comprehensive screening of 32 isomers/conformers of the C2H5O2N chemical formula (neutral, negative, and positive ions together with the corresponding protonated species and the possible zwitterionic structures) is carried out. In the sensitive case of the neutral compounds, more accurate relative energies were obtained by means of high level post Hartree-Fock coupled cluster calculations with large basis sets (CCSD(T)/cc-pVQZ). Results: We find that neutral glycine is not the most stable isomer and, therefore, probably not the most abundant one, which might explain why it has escaped detection so far. We find instead that N-methyl carbamic acid and methyl carbamate are the two most stable isomers and, therefore, probably the two most abundant ones. Among the non-neutral forms, we found that glycine is the most stable isomer only if protonated or zwitterionic if present in interstellar

  14. A Sensitive VLA Search for Small-Scale Glycine Emission Toward OMC-1

    NASA Technical Reports Server (NTRS)

    Hollis, J. M.; Pedelty, J. A.; Snyder, L. E.; Jewell, P. R.; Lovas, F. J.; Palmer, Patrick; Liu, S.-Y.

    2002-01-01

    We have conducted a deep Q-band (lambda-7 mm) search with the Very Large Array (VLA) toward OMC-1 for the lowest energy conformation (conformer I) of glycine (NH2CH2COOH) in four rotational transitions: the 6(sub 15)- 5(sub 14), 6(sub 24)-5(sub 23), 7(sub 17- 6(sub 16), and 7(sub 07)-6(sub 06). Our VLA observations sample the smallest-scale structures to date in the search for glycine toward OMC-1. No glycine emission features were detected. Thus if glycine exists in OMC-1, either it is below our detection limit, or it is more spatially extended than other large molecules in this source, or it is primarily in its high energy form (conformer II). Our VLA glycine fractional abundance limits in OMC-1 are comparable to those determined from previous IRAM 30m measurements -- somewhat better or worse depending on the specific source model -- and the entire approximately 1 foot primary beam of the VLA was searched while sensitive to an areal spatial scale approximately 150 times smaller than the 24 inch beam of the IRAM single-element telescope. In the course of this work, we detected and imaged the 4(sub 14)-3(sub 13) A and E transitions of methyl formate (HCOOCH3) and also the 2(sub 02) - 1(sub 01) transition of formic acid (HCOOH). Since formic acid is a possible precursor to glycine, our glycine limits and formic acid results provide a constraint on this potential formation chemistry route for glycine in OMC-1.

  15. pH-Sensitive Poly(histidine methacrylamide).

    PubMed

    Wang, Huifeng; Wu, Haiyan; Lee, Chen-Jung; Lei, Xia; Zhe, Jiang; Xu, Fujian; Cheng, Fang; Cheng, Gang

    2016-06-28

    This research reports a synthetic amino acid based zwitterionic poly(histidine methacrylamide) (PHisMA), which possesses switchability among zwitterionic, anionic, and cationic states, pH-dependent antifouling properties, and chelation capability to multivalent metal ions. The PHisMA polymer brush surface shows good antifouling properties to resist protein adsorption and bacterial attachment in its zwitterionic state at pH 5. This study also demonstrates that the solution acidity significantly affects the mechanical properties of PHisMA hydrogels. PHisMA hydrogels show higher viscoelastic properties and lower swelling ratios in the zwitterionic state at pH 4 and pH 5, compared to higher or lower pH conditions. It was discovered that PHisMA can chelate multivalent metal ions, such as Ca(2+), Mg(2+), Cu(2+), Ni(2+) and Fe(3+). This study provides us a better understanding of structure-property relationships of switchable zwitterionic polymers. PHisMA can potentially be adapted for a broad range of applications including wound care, water treatment, bioseparation, coating, drug and gene delivery carriers, etc. PMID:27310924

  16. Histidine kinase activity in nuclei of Physarum polycephalum

    SciTech Connect

    Matthews, H.R.; Pesis, K. Wei, Y.

    1987-05-01

    Nuclei of the true slime mold Physarum polycephalum, contain a kinase that specifically phosphorylates the 1-nitrogen of histidine-75 of histone H4, in vitro. Phosphohistidine is alkali stable and acid labile. Similar alkali stable phosphorylation has been observed with beef heart extracts and S-100 extracts from S. cerevisiae. The activity may be similar to that previously reported by R.A. Smith and his colleagues in several mammalian tissues. They have begun a search for nuclear proteins that contain phosphohistidine. Cultures of Physarum were grown in the presence of /sup 32/P-phosphate using several different labeling protocols. Labeled nuclear proteins were fractionated on a Superose-12 column. Alkali stable phosphate label eluted close to the position of histone H1, although it was not on H1 itself. No alkali stable phosphate eluted at the position of histone H4, which was obtained in high yield by this procedure. The absence of alkali-stable phosphorylation of histone H4 was confirmed by gel electrophoresis of the crude nuclear proteins. The fraction containing alkali-stable phosphate was shown to contain phosphohistidine by amino acid analysis of a total alkaline hydrolysate. They conclude that Physarum nuclei possess at least one protein that contains phosphohistidine in vivo and that histone H4 does not contain phosphohistidine in this system.

  17. Modulation of brain opioid receptors by zinc and histidine

    SciTech Connect

    Hanissian, S.H.

    1988-01-01

    The effect of zinc and several trace elements was studied on the binding of the opioid receptor antagonist ({sup 3}H)-naloxone and the agonists ({sup 3}H)-DAGO, ({sup 3}H)-DSTLE, and ({sup 3}H)-EKC, specific for the mu, delta and kappa receptors, respectively, in several areas of the rat brain. Physiological concentrations of zinc were inhibitory to the binding of naloxone, DAGO, and EKC, whereas delta receptors were insensitive to this inhibition. Copper, cadmium, and mercury also inhibited the binding of all the ligands studied to their receptors. Histidine was most effective in preventing the inhibitory effects of zinc and copper, whereas it was less effective on cadmium, and without any effect on the inhibit was less effective on cadmium, and without any effect on the inhibition caused by mercury. Its metabolites histamine and imidazoleacetic acid, and also citrate were ineffective. Magnesium and manganese were stimulatory to opioid receptor binding, whereas cobalt and nickel had dual effects. Concentrations of zinc less that its IC{sub 50} totally prevented the stimulatory effects of magnesium and manganese on the mu and delta receptors on which zinc alone had no effects. The reducing reagents dithiothreitol and B-mercaptoethanol partially protected against zinc inhibition, and the oxidizing reagent dithiobisnitrobenzoic acid even potentiated the inhibitory effects of zinc on DSTLE and DAGO binding, although to different extents.

  18. Determination of glycine in biofluid by hydrophilic interaction chromatography coupled with tandem mass spectrometry and its application to the quantification of glycine released by embryonal carcinoma stem cells.

    PubMed

    Tang, Ya-Bin; Teng, Lin; Sun, Fan; Wang, Xiao-Lin; Peng, Liang; Cui, Yong-Yao; Hu, Jin-Jia; Luan, Xin; Zhu, Liang; Chen, Hong-Zhuan

    2012-09-15

    Because glycine plays a prominent role in living creatures, an accurate and precise quantitative analysis method for the compound is needed. Herein, a new approach to analyze glycine by hydrophilic interaction chromatography (HILIC) coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) was developed. This method avoids the use of derivatization and/or ion-pairing reagents. N-methyl-D-aspartate (NMDA) is used as the internal standard (IS). The mobile phase for the isocratic elution consisted of 10 mM ammonium formate in acetonitrile-water (70:30, v/v, adjusted to pH 2.8 with formic acid), and a flow rate of 250 μL/min was used. Two microliters of sample was injected for analysis. The signal was monitored in the positive multiple reaction monitoring (MRM) mode. The total run time was 5 min. The dynamic range was 40-2000 ng/mL for glycine in the biological matrix. The LLOQ (lower limit of quantification) of this method was 40 ng/mL (80 pg on column). The validated method was applied to determine the dynamic release of glycine from P19 embryonal carcinoma stem cells (ECSCs). Glycine spontaneously released from the ECSCs into the intercellular space gradually increased from 331.02±60.36 ng/mL at 2 min in the beginning to 963.52±283.80 ng/mL at 60 min and 948.27±235.09 ng/mL at 120 min, finally reaching a plateau, indicating that ECSCs consecutively release glycine until achieving equilibration between the release and the reuptake of the compound; on the contrary, the negative control NIH/3T3 embryonic fibroblast cells did not release glycine. This finding will help to improve our understanding of the novel effects of neurotransmitters, including glycine, on non-neural systems. PMID:22906796

  19. Effects of Protonation State on a Tyrosine-Histidine Bioinspired Redox Mediator

    SciTech Connect

    Moore, Gary F.; Hambourger, Michael; Kodis, Gerdenis; Michl, Weston; Gust, Devens; Moore, Thomas A.; Moore, Ana L.

    2010-11-18

    The conversion of tyrosine to the corresponding tyrosyl radical in photosytem II (PSII) is an example of proton-coupled electron transfer. Although the tyrosine moiety (TyrZ) is known to function as a redox mediator between the photo-oxidized primary donor (P680 •+) and the Mn-containing oxygen-evolving complex, the protonation states involved in the course of the reaction remain an active area of investigation. Herein, we report on the optical, structural, and electrochemical properties of tyrosine-histidine constructs, which model the function of their naturally occurring counterparts in PSII. Electrochemical studies show that the phenoxyl/phenol couple of the model is chemically reversible and thermodynamically capable of water oxidation. Studies under acidic and basic conditions provide clear evidence that an ionizable proton controls the electrochemical potential of the tyrosine-histidine mimic and that an exogenous base or acid can be used to generate a low-potential or high-potential mediator, respectively. The phenoxyl/phenoxide couple associated with the low-potential mediator is thermodynamically incapable of water oxidation, whereas the relay associated with the high-potential mediator is thermodynamically incapable of reducing an attached photoexcited porphyrin. These studies provide insight regarding the mechanistic role of the tyrosine-histidine complex in water oxidation and strategies for making use of hydrogen bonds to affect the coupling between proton and electron transfer in artificial photosynthetic systems.

  20. Synthesis of novel chitosan resin possessing histidine moiety and its application to the determination of trace silver by ICP-AES coupled with triplet automated-pretreatment system.

    PubMed

    Hosoba, Minako; Oshita, Koji; Katarina, Rosi K; Takayanagi, Toshio; Oshima, Mitsuko; Motomizu, Shoji

    2009-04-20

    A novel chitosan resin, cross-linked chitosan functionalized with histidine moiety (histidine-type chitosan resin), was synthesized for the collection and concentration of trace silver in aquatic samples. A triplet automated-pretreatment system (Triplet Auto-Pret System) installed mini-columns packed with the synthesized histidine-type chitosan resin was coupled with an inductively coupled plasma-atomic emission spectrometry (ICP-AES) for a rapid and sensitive analysis. Adsorption behavior of 50 elements on the histidine-type chitosan resin was examined. A trace amount of Ag(I) was shown a good adsorption in wide pH regions (pH 5-9), and Ag(I) adsorbed was readily recovered with 1 M nitric acid solution. The limit of detection (3sigma) for silver was 0.03 microg L(-1). The system was successfully applied to river water and dipped water in silver coated container.

  1. Phytoremediation of mixed-contaminated soil using the hyperaccumulator plant Alyssum lesbiacum: evidence of histidine as a measure of phytoextractable nickel.

    PubMed

    Singer, Andrew C; Bell, Thomas; Heywood, Chloe A; Smith, J A C; Thompson, Ian P

    2007-05-01

    In this study we examine the effects of polycyclic aromatic hydrocarbons (PAHs) on the ability of the hyperaccumulator plant Alyssum lesbiacum to phytoextract nickel from co-contaminated soil. Planted and unplanted mesocosms containing the contaminated soils were repeatedly amended with sorbitan trioleate, salicylic acid and histidine in various combinations to enhance the degradation of two PAHs (phenanthrene and chrysene) and increase nickel phytoextraction. Plant growth was negatively affected by PAHs; however, there was no significant effect on the phytoextraction of Ni per unit biomass of shoot. Exogenous histidine did not increase nickel phytoextraction, but the histidine-extractable fraction of soil nickel showed a high correlation with phytoextractable nickel. These results indicate that Alyssum lesbiacum might be effective in phytoextracting nickel from marginally PAH-contaminated soils. In addition, we provide evidence for the broader applicability of histidine for quantifying and predicting Ni phytoavailability in soils. PMID:17084494

  2. Insufficient intake of L-histidine reduces brain histamine and causes anxiety-like behaviors in male mice.

    PubMed

    Yoshikawa, Takeo; Nakamura, Tadaho; Shibakusa, Tetsuro; Sugita, Mayu; Naganuma, Fumito; Iida, Tomomitsu; Miura, Yamato; Mohsen, Attayeb; Harada, Ryuichi; Yanai, Kazuhiko

    2014-10-01

    L-histidine is one of the essential amino acids for humans, and it plays a critical role as a component of proteins. L-histidine is also important as a precursor of histamine. Brain histamine is synthesized from L-histidine in the presence of histidine decarboxylase, which is expressed in histamine neurons. In the present study, we aimed to elucidate the importance of dietary L-histidine as a precursor of brain histamine and the histaminergic nervous system. C57BL/6J male mice at 8 wk of age were assigned to 2 different diets for at least 2 wk: the control (Con) diet (5.08 g L-histidine/kg diet) or the low L-histidine diet (LHD) (1.28 g L-histidine/kg diet). We measured the histamine concentration in the brain areas of Con diet-fed mice (Con group) and LHD-fed mice (LHD group). The histamine concentration was significantly lower in the LHD group [Con group vs. LHD group: histamine in cortex (means ± SEs): 13.9 ± 1.25 vs. 9.36 ± 0.549 ng/g tissue; P = 0.002]. Our in vivo microdialysis assays revealed that histamine release stimulated by high K(+) from the hypothalamus in the LHD group was 60% of that in the Con group (P = 0.012). However, the concentrations of other monoamines and their metabolites were not changed by the LHD. The open-field tests showed that the LHD group spent a shorter amount of time in the central zone (87.6 ± 14.1 vs. 50.0 ± 6.03 s/10 min; P = 0.019), and the light/dark box tests demonstrated that the LHD group spent a shorter amount of time in the light box (198 ± 8.19 vs. 162 ± 14.1 s/10 min; P = 0.048), suggesting that the LHD induced anxiety-like behaviors. However, locomotor activity, memory functions, and social interaction did not differ between the 2 groups. The results of the present study demonstrated that insufficient intake of histidine reduced the brain histamine content, leading to anxiety-like behaviors in the mice.

  3. Glycine transporter 1 is a target for the treatment of epilepsy.

    PubMed

    Shen, Hai-Ying; van Vliet, Erwin A; Bright, Kerry-Ann; Hanthorn, Marissa; Lytle, Nikki K; Gorter, Jan; Aronica, Eleonora; Boison, Detlev

    2015-12-01

    Glycine is the major inhibitory neurotransmitter in brainstem and spinal cord, whereas in hippocampus glycine exerts dual modulatory roles on strychnine-sensitive glycine receptors and on the strychnine-insensitive glycineB site of the N-methyl-D-aspartate receptor (NMDAR). In hippocampus, the synaptic availability of glycine is largely under control of glycine transporter 1 (GlyT1). Since epilepsy is a disorder of disrupted network homeostasis affecting the equilibrium of various neurotransmitters and neuromodulators, we hypothesized that changes in hippocampal GlyT1 expression and resulting disruption of glycine homeostasis might be implicated in the pathophysiology of epilepsy. Using two different rodent models of temporal lobe epilepsy (TLE)--the intrahippocampal kainic acid model of TLE in mice, and the rat model of tetanic stimulation-induced TLE--we first demonstrated robust overexpression of GlyT1 in the hippocampal formation, suggesting dysfunctional glycine signaling in epilepsy. Overexpression of GlyT1 in the hippocampal formation was corroborated in human TLE samples by quantitative real time PCR. In support of a role of dysfunctional glycine signaling in the pathophysiology of epilepsy, both the genetic deletion of GlyT1 in hippocampus and the GlyT1 inhibitor LY2365109 increased seizure thresholds in mice. Importantly, chronic seizures in the mouse model of TLE were robustly suppressed by systemic administration of the GlyT1 inhibitor LY2365109. We conclude that GlyT1 overexpression in the epileptic brain constitutes a new target for therapeutic intervention, and that GlyT1 inhibitors constitute a new class of antiictogenic drugs. These findings are of translational value since GlyT1 inhibitors are already in clinical development to treat cognitive symptoms in schizophrenia.

  4. Glycine transporter 1 is a target for the treatment of epilepsy.

    PubMed

    Shen, Hai-Ying; van Vliet, Erwin A; Bright, Kerry-Ann; Hanthorn, Marissa; Lytle, Nikki K; Gorter, Jan; Aronica, Eleonora; Boison, Detlev

    2015-12-01

    Glycine is the major inhibitory neurotransmitter in brainstem and spinal cord, whereas in hippocampus glycine exerts dual modulatory roles on strychnine-sensitive glycine receptors and on the strychnine-insensitive glycineB site of the N-methyl-D-aspartate receptor (NMDAR). In hippocampus, the synaptic availability of glycine is largely under control of glycine transporter 1 (GlyT1). Since epilepsy is a disorder of disrupted network homeostasis affecting the equilibrium of various neurotransmitters and neuromodulators, we hypothesized that changes in hippocampal GlyT1 expression and resulting disruption of glycine homeostasis might be implicated in the pathophysiology of epilepsy. Using two different rodent models of temporal lobe epilepsy (TLE)--the intrahippocampal kainic acid model of TLE in mice, and the rat model of tetanic stimulation-induced TLE--we first demonstrated robust overexpression of GlyT1 in the hippocampal formation, suggesting dysfunctional glycine signaling in epilepsy. Overexpression of GlyT1 in the hippocampal formation was corroborated in human TLE samples by quantitative real time PCR. In support of a role of dysfunctional glycine signaling in the pathophysiology of epilepsy, both the genetic deletion of GlyT1 in hippocampus and the GlyT1 inhibitor LY2365109 increased seizure thresholds in mice. Importantly, chronic seizures in the mouse model of TLE were robustly suppressed by systemic administration of the GlyT1 inhibitor LY2365109. We conclude that GlyT1 overexpression in the epileptic brain constitutes a new target for therapeutic intervention, and that GlyT1 inhibitors constitute a new class of antiictogenic drugs. These findings are of translational value since GlyT1 inhibitors are already in clinical development to treat cognitive symptoms in schizophrenia. PMID:26302655

  5. Influence of the morphology and impurities of Ni(OH){sub 2} on the synthesis of neutral Ni(II)-amino acid complexes

    SciTech Connect

    Rodriguez-Gonzalez, Vicente; Marceau, Eric Che, Michel; Pepe, Claude

    2007-12-15

    Synthesis of neutral complexes of Ni{sup 2+} with amino acids has often been reported on a qualitative basis, with a lack of information on the parameters involved in the dissolution of the nickel-containing solid precursor. This paper reports on a systematic study of the reactivity of Ni(OH){sub 2} toward glycine in aqueous solution. The crystallinity and size of hydroxide particles are found to be key parameters in the rapid glycine-promoted dissolution of the hydroxide and synthesis of [Ni(glycinate){sub 2}(H{sub 2}O){sub 2}]. These parameters derive from the nature of the salt used to prepare the hydroxide. Ni(II) chloride leads to the most reactive solid precursor, because of the presence of defects in the Ni(OH){sub 2} sheets arrangements, assigned to the substitution of Cl{sup -} ions to OH{sup -} ions at the edges of the particles. The reaction between this hydroxide and glycine at 80 deg. C is quantitative after 7 min and similar rates of dissolution are obtained with other amino acids, alanine or histidine, the reaction with serine being slower. When the hydroxide contains nitrate or carbonate ions, a glycinato complex with composition similar to [Ni(glycinate){sub 2}(H{sub 2}O){sub 2}], but with a different crystal structure, is also formed. Spectroscopic results may suggest a structure involving bridging ligands. - Graphical abstract: Ni(OH){sub 2} solid precursors can be readily selected on the basis of their defects, themselves stemming from the nickel salt chosen for precipitation, to rapidly synthesize neutral Ni(II)-aminoacid complexes by ligand-promoted dissolution.

  6. Implication of citrate, malate and histidine in the accumulation and transport of nickel in Mesembryanthemum crystallinum and Brassica juncea.

    PubMed

    Amari, Taoufik; Lutts, Stanley; Taamali, Manel; Lucchini, Giorgio; Sacchi, Gian Attilio; Abdelly, Chedly; Ghnaya, Tahar

    2016-04-01

    Citrate, malate and histidine have been involved in many processes including metal tolerance and accumulation in plants. These molecules have been frequently reported to be the potential nickel chelators, which most likely facilitate metal transport through xylem. In this context, we assess here, the relationship between organics acids and histidine content and nickel accumulation in Mesembryanthemum crystallinum and Brassica juncea grown in hydroponic media added with 25, 50 and 100 µM NiCl2. Results showed that M. crystallinum is relatively more tolerant to Ni toxicity than B. juncea. For both species, xylem transport rate of Ni increased with increasing Ni supply. A positive correlation was established between nickel and citrate concentrations in the xylem sap. In the shoot of B. juncea, citric and malic acids concentrations were significantly higher than in the shoot of M. crystallinum. Also, the shoots and roots of B. juncea accumulated much more histidine. In contrast, a higher root citrate concentration was observed in M. crystallinum. These findings suggest a specific involvement of malic and citric acid in Ni translocation and accumulation in M. crystallinum and B. juncea. The high citrate and histidine accumulation especially at 100µM NiCl2, in the roots of M. crystallinum might be among the important factors associated with the tolerance of this halophyte to toxic Ni levels.

  7. Implication of citrate, malate and histidine in the accumulation and transport of nickel in Mesembryanthemum crystallinum and Brassica juncea.

    PubMed

    Amari, Taoufik; Lutts, Stanley; Taamali, Manel; Lucchini, Giorgio; Sacchi, Gian Attilio; Abdelly, Chedly; Ghnaya, Tahar

    2016-04-01

    Citrate, malate and histidine have been involved in many processes including metal tolerance and accumulation in plants. These molecules have been frequently reported to be the potential nickel chelators, which most likely facilitate metal transport through xylem. In this context, we assess here, the relationship between organics acids and histidine content and nickel accumulation in Mesembryanthemum crystallinum and Brassica juncea grown in hydroponic media added with 25, 50 and 100 µM NiCl2. Results showed that M. crystallinum is relatively more tolerant to Ni toxicity than B. juncea. For both species, xylem transport rate of Ni increased with increasing Ni supply. A positive correlation was established between nickel and citrate concentrations in the xylem sap. In the shoot of B. juncea, citric and malic acids concentrations were significantly higher than in the shoot of M. crystallinum. Also, the shoots and roots of B. juncea accumulated much more histidine. In contrast, a higher root citrate concentration was observed in M. crystallinum. These findings suggest a specific involvement of malic and citric acid in Ni translocation and accumulation in M. crystallinum and B. juncea. The high citrate and histidine accumulation especially at 100µM NiCl2, in the roots of M. crystallinum might be among the important factors associated with the tolerance of this halophyte to toxic Ni levels. PMID:26745003

  8. Graphdiyne as a promising material for detecting amino acids

    PubMed Central

    Chen, Xi; Gao, Pengfei; Guo, Lei; Zhang, Shengli

    2015-01-01

    The adsorption of glycine, glutamic acid, histidine and phenylalanine on single-layer graphdiyne/ graphene is investigated by ab initio calculations. The results show that for each amino acid molecule, the adsorption energy on graphdiyne is larger than the adsorption energy on graphene and dispersion interactions predominate in the adsorption. Molecular dynamics simulations reveal that at room temperature the amino acid molecules keep migrating and rotating on graphdiyne surface and induce fluctuation in graphdiyne bandgap. Additionally, the photon absorption spectra of graphdiyne-amino-acid systems are investigated. We uncover that the presence of amino acid molecules makes the photon absorption peaks of graphdiyne significantly depressed and shifted. Finally, quantum electronic transport properties of graphdiyne-amino-acid systems are compared with the transport properties of pure graphdiyne. We reveal that the amino acid molecules induce distinct changes in the electronic conductivity of graphdiyne. The results in this paper reveal that graphdiyne is a promising two-dimensional material for sensitively detecting amino acids and may potentially be used in biosensors. PMID:26568200

  9. Graphdiyne as a promising material for detecting amino acids

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Gao, Pengfei; Guo, Lei; Zhang, Shengli

    2015-11-01

    The adsorption of glycine, glutamic acid, histidine and phenylalanine on single-layer graphdiyne/ graphene is investigated by ab initio calculations. The results show that for each amino acid molecule, the adsorption energy on graphdiyne is larger than the adsorption energy on graphene and dispersion interactions predominate in the adsorption. Molecular dynamics simulations reveal that at room temperature the amino acid molecules keep migrating and rotating on graphdiyne surface and induce fluctuation in graphdiyne bandgap. Additionally, the photon absorption spectra of graphdiyne-amino-acid systems are investigated. We uncover that the presence of amino acid molecules makes the photon absorption peaks of graphdiyne significantly depressed and shifted. Finally, quantum electronic transport properties of graphdiyne-amino-acid systems are compared with the transport properties of pure graphdiyne. We reveal that the amino acid molecules induce distinct changes in the electronic conductivity of graphdiyne. The results in this paper reveal that graphdiyne is a promising two-dimensional material for sensitively detecting amino acids and may potentially be used in biosensors.

  10. Plant-Induced Hatching of Eggs of the Soybean Cyst Nematode Heterodera glycines.

    PubMed

    Tefft, P M; Bone, L W

    1985-07-01

    Root diffusate from soybean plants caused greater hatching of Heterodera glycines eggs during vegetative growth of the host, but the activity declined with plant senescence. Chelation of the root diffusate with ethylenediamine tetraacetic acid (EDTA) significantly increased hatching activity for H. glycines eggs. Diffusate from leafless plants caused little hatching, whereas treatment of intact plants with the growth regulators gibberellin and kinetin had no effect on the hatching activity of root diffusate. Treating H. glycines eggs with zinc chloride and root diffusate reduced egg hatching from zinc chloride alone. Levels of zinc in the root diffusate were insufficient to induce egg hatch, based on analysis by atomic absorption spectrophotometry. The enzymatic activity of leucine aminopeptidase in H. glycines eggs was not altered by treatment with chelated or nonchelated root diffusate.

  11. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The...

  12. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The...

  13. 75 FR 62141 - Glycine From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... glycine from China (60 FR 16116). Following first five-year reviews by Commerce and the Commission... from China (65 FR 45752). Following second five-year reviews by Commerce and the Commission, effective... glycine from China (70 FR 69316). The Commission is now conducting a third review to determine...

  14. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions

    PubMed Central

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard

    2015-01-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. 13C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using 3H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  15. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions.

    PubMed

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard; Nielsen, Per Halkjær

    2015-07-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. (13)C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using (3)H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  16. Solubility calculations of branched and linear amino acids using lattice cluster theory

    NASA Astrophysics Data System (ADS)

    Fischlschweiger, Michael; Enders, Sabine; Zeiner, Tim

    2014-09-01

    In this work, the activity coefficients and the solubility of amino acids in water were calculated using the lattice cluster theory (LCT) combined with the extended chemical association lattice model allowing self-association as well as cross-association. This permits the study of the influence of the amino acids structure on the thermodynamic properties for the first time. By the used model, the activity coefficient and solubilities of the investigated fourteen amino acids (glycine, alanine, γ-aminobutyric acid, dl-valine, dl-threonine, dl-methionine, l-leucine, l-glutamic acid, l-proline, hydroxyproline, histidine, l-arginine, α-amino valeric acid) could be described in good accordance with experimental data. In the case of different α-amino acids, but different hydrocarbon chains, the same interaction energy parameter can be used within the LCT. All studied amino acids could be modelled using the same parameter for the description of the amino acid association properties. The formed cross-associates contain more amino acids than expressed by the overall mole fraction of the solution. Moreover, the composition of the cross-associates depends on temperature, where the amount of amino acids increases with increasing temperature.

  17. 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.

  18. Contribution of flavin covalent linkage with histidine 99 to the reaction catalyzed by choline oxidase.

    PubMed

    Quaye, Osbourne; Cowins, Sharonda; Gadda, Giovanni

    2009-06-19

    The FAD-dependent choline oxidase has a flavin cofactor covalently attached to the protein via histidine 99 through an 8alpha-N(3)-histidyl linkage. The enzyme catalyzes the four-electron oxidation of choline to glycine betaine, forming betaine aldehyde as an enzyme-bound intermediate. The variant form of choline oxidase in which the histidine residue has been replaced with asparagine was used to investigate the contribution of the 8alpha-N(3)-histidyl linkage of FAD to the protein toward the reaction catalyzed by the enzyme. Decreases of 10-fold and 30-fold in the k(cat)/K(m) and k(cat) values were observed as compared with wild-type choline oxidase at pH 10 and 25 degrees C, with no significant effect on k(cat)/K(O) using choline as substrate. Both the k(cat)/K(m) and k(cat) values increased with increasing pH to limiting values at high pH consistent with the participation of an unprotonated group in the reductive half-reaction and the overall turnover of the enzyme. The pH independence of both (D)(k(cat)/K(m)) and (D)k(cat), with average values of 9.2 +/- 3.3 and 7.4 +/- 0.5, respectively, is consistent with absence of external forward and reverse commitments to catalysis, and the chemical step of CH bond cleavage being rate-limiting for both the reductive half-reaction and the overall enzyme turnover. The temperature dependence of the (D)k(red) values suggests disruption of the preorganization in the asparagine variant enzyme. Altogether, the data presented in this study are consistent with the FAD-histidyl covalent linkage being important for the optimal positioning of the hydride ion donor and acceptor in the tunneling reaction catalyzed by choline oxidase.

  19. Hormone-fuel concentrations in anephric subjects. Effect of hemodialysis (with special reference to amino acids).

    PubMed Central

    Ganda, O P; Aoki, T T; Soeldner, J S; Morrison, R S; Cahill, G F

    1976-01-01

    Arterial blood concentrations of insulin, glucagon, and various substrates were determined in six anephric subjects in the postabsorptive state and immediately after hemodialysis. Plasma glucose and serum insulin concentrations were normal, and declined during dialysis. Plasma glucagon was elevated and remained unchanged. There was moderate hypertriglyceridemia before dialysis, but this decreased significantly after administration of heparin just before the start of dialysis, and at the end of dialysis was lowered further into the normal range. Comparison of postabsorptive whole blood concentrations of amino acids with those in normal, healthy adults revealed striking differences. Glutamine, proline, citrulline, glycine and both 1- and 3-methyl-histidines were increased, while serine, glutamate, tyrosine, lysine, and branched-chain amino acids were decreased. The glycine/serine ratio was elevated to 300% and tyrosine/phenylalanine ratio was lowered to 60% of normal. To investigate the potential role of blood cells in amino acid transport, the distribution of individual amino acids in plasma and blood cell compartments was studied. Despite a markedly diminished blood cell mass (mean hematocrit, 20.6 +/- 1.4%), there was no significant decrease in the fraction of most amino acids present in the cell compartment, and this was explained by increases of several amino acids in cellular water. None were decreased. Furthermore, during dialysis, whole blood and plasma amino acids declined by approximately 30% and 40%, respectively, whereas no significant change was observed in the cell compartment. Alanine was the only amino acid whose concentration declined in the cells as well as in plasma. The results indicate (a) significant alterations in the concentrations of hormones and substrates in patients on chronic, intermittent hemodialysis; (b) removal of amino acids during hemodialysis, predominantly from the plasma compartment, with no significant change in cell content

  20. Chemical composition and amino acid profiles of goose muscles from native Polish breeds.

    PubMed

    Okruszek, A; Woloszyn, J; Haraf, G; Orkusz, A; Werenska, M

    2013-04-01

    The aim of the study was to compare the chemical and amino acid composition of breast (pectoralis major) and thigh (biceps femoris) muscles in 17-wk-old geese from 2 Polish conservative flocks: Rypińska (Ry, n = 20) and Garbonosa (Ga, n = 20). The geese were fed ad libitum during the experimental period on the same complete feed. Genotypes affected the moisture and fat content of breast and thigh meat. The Ga geese were characterized by higher moisture as well as lower fat lipid content compared with the Ry breast and thigh muscles. The amino acid proportions of meat proteins depended on the goose flock and type of muscles, where significant differences were found. The proteins of Ga breast muscles contained more glutamic acid, glycine, lysine, tryptophan, histidine, and methionine, and less aspartic acid, proline, serine, leucine, valine, phenyloalanine, tyrosine, and threonine than the Ry geese (P ≤ 0.05). The proteins of Ry thigh muscles were characterized by higher content of proline, serine, and essential amino acids (without lysine and methionine) and lower glutamic and asparagine acid, alanine, and glycine compared with the Ga flock. According to the Food and Agriculture Organization of the United Nations/World Health Organization (1991) standard, tryptophan was the amino acid limiting the nutritional value of meat proteins of Ry breast muscles (amino acid score for tryptophan = 90%). Except for tryptophan, the meat proteins of the investigated raw materials contained more essential amino acids than the standard. The total content of essential amino acids for all investigated muscles was also higher (52.51 to 55.54%) than the standard (33.90%). It is evident that muscle protein from both flocks of geese have been characterized by high nutritional value. The values of the essential amino acid index of breast muscle proteins were similar in both flocks.

  1. Rapid and efficient purification of native histidine-tagged protein expressed by recombinant vaccinia virus.

    PubMed Central

    Janknecht, R; de Martynoff, G; Lou, J; Hipskind, R A; Nordheim, A; Stunnenberg, H G

    1991-01-01

    Vaccinia virus has been used as a vector to express foreign genes for the production of functional and posttranslationally modified proteins. A procedure is described here that allows the rapid native purification of vaccinia-expressed proteins fused to an amino-terminal tag of six histidines. Extracts from cells infected with recombinant vaccinia virus are loaded onto Ni2+.nitrilotriacetic acid (Ni2+.NTA)-agarose and histidine-tagged proteins are selectively eluted with imidazole-containing buffers. In the case of the human serum response factor (SRF), a transcription factor involved in the regulation of the c-fos protooncogene, the vaccinia-expressed histidine-tagged SRF (SRF-6His) could be purified solely by this step to greater than 95% purity. SRF-6His was shown to resemble authentic SRF by functional criteria: it was transported to the nucleus, bound specifically the c-fos serum response element, interacted with the p62TCF protein to form a ternary complex, and stimulated in vitro transcription from the serum response element. Thus, the combination of vaccinia virus expression and affinity purification by Ni2+.NTA chromatography promises to be useful for the production of proteins in a functional and posttranslationally modified form. Images PMID:1924358

  2. Computational study of enantioselective interaction between C60 fullerene and its derivatives with L-histidine.

    PubMed

    Lal, Bhajan

    2007-04-01

    The mechanism of the enantioselective binding of L-histidine with C(60) fullerene and its derivatives, (1,2-methanofullerene C(60))-61-carboxylic acid, diethyl (1,2-methanofullerene C(60))-61-61-dicarboxylate and tert-butyl (1,2-methanofullerene C(60))-61-carboxylate based chiral selectors was studied by quantum chemical calculations. All the molecules were fully optimized at RHF/6-31G* basis set. Relative energies between the different complexes were subsequently estimated with single-point electronic energies computed using Møller-Plesset perturbation theory (MP2). Stability and feasibility of all the generated structures were supported by their respective energy minima and fundamental frequencies. It was observed that interaction of fullerene derivatives with L-histidine is due to the existence of hydrogen bonding forces during the complex formation. The intermolecular forces, flow of atomic charges, binding energy, hardness, dipole moment and localization of electrostatic potential are in agreement with enantioselective interaction of L-histidine with C(60) fullerene and its derivatives. It is found that theoretical evaluation to be consistent with the experimental data.

  3. A rapid and ultrasensitive SERRS assay for histidine and tyrosine based on azo coupling.

    PubMed

    Sui, Huimin; Wang, Yue; Yu, Zhi; Cong, Qian; Han, Xiao Xia; Zhao, Bing

    2016-10-01

    A simple and highly sensitive surface-enhanced resonance Raman scattering (SERRS)-based approach coupled with azo coupling reaction has been put forward for quantitative analysis of histidine and tyrosine. The SERRS-based assay is simple and rapid by mixing the azo reaction products with silver nanoparticles (AgNPs) for measurements within 2min. The limits of detection (LODs) of the method are as low as 4.33×10(-11) and 8.80×10(-11)M for histidine and tyrosine, respectively. Moreover, the SERRS fingerprint information specific to corresponding amino acids guarantees the selective detection for the target histidine and tyrosine. The results from serum indicated the potential application of the proposed approach into biological samples. Compared with the methods ever reported, the main advantages of this methodology are simpleness, rapidity without time-consuming separation or pretreatment steps, high sensitivity, selectivity and the potential for determination of other molecules containing imidazole or phenol groups. PMID:27474300

  4. Hybrid histidine kinases in pathogenic fungi.

    PubMed

    Defosse, Tatiana A; Sharma, Anupam; Mondal, Alok K; Dugé de Bernonville, Thomas; Latgé, Jean-Paul; Calderone, Richard; Giglioli-Guivarc'h, Nathalie; Courdavault, Vincent; Clastre, Marc; Papon, Nicolas

    2015-03-01

    Histidine kinases (HK) sense and transduce via phosphorylation events many intra- and extracellular signals in bacteria, archaea, slime moulds and plants. HK are also widespread in the fungal kingdom, but their precise roles in the regulation of physiological processes remain largely obscure. Expanding genomic resources have recently given the opportunity to identify uncharacterised HK family members in yeasts and moulds and now allow proposing a complex classification of Basidiomycota, Ascomycota and lower fungi HK. A growing number of genetic approaches have progressively provided new insight into the role of several groups of HK in prominent fungal pathogens. In particular, a series of studies have revealed that members of group III HK, which occur in the highest number of fungal species and contain a unique N-terminus region consisting of multiple HAMP domain repeats, regulate morphogenesis and virulence in various human, plant and insect pathogenic fungi. This research field is further supported by recent shape-function studies providing clear correlation between structural properties and signalling states in group III HK. Since HK are absent in mammals, these represent interesting fungal target for the discovery of new antifungal drugs.

  5. Hybrid histidine kinases in pathogenic fungi.

    PubMed

    Defosse, Tatiana A; Sharma, Anupam; Mondal, Alok K; Dugé de Bernonville, Thomas; Latgé, Jean-Paul; Calderone, Richard; Giglioli-Guivarc'h, Nathalie; Courdavault, Vincent; Clastre, Marc; Papon, Nicolas

    2015-03-01

    Histidine kinases (HK) sense and transduce via phosphorylation events many intra- and extracellular signals in bacteria, archaea, slime moulds and plants. HK are also widespread in the fungal kingdom, but their precise roles in the regulation of physiological processes remain largely obscure. Expanding genomic resources have recently given the opportunity to identify uncharacterised HK family members in yeasts and moulds and now allow proposing a complex classification of Basidiomycota, Ascomycota and lower fungi HK. A growing number of genetic approaches have progressively provided new insight into the role of several groups of HK in prominent fungal pathogens. In particular, a series of studies have revealed that members of group III HK, which occur in the highest number of fungal species and contain a unique N-terminus region consisting of multiple HAMP domain repeats, regulate morphogenesis and virulence in various human, plant and insect pathogenic fungi. This research field is further supported by recent shape-function studies providing clear correlation between structural properties and signalling states in group III HK. Since HK are absent in mammals, these represent interesting fungal target for the discovery of new antifungal drugs. PMID:25560420

  6. Comparison of histidine recognition in human and trypanosomatid histidyl-tRNA synthetases

    PubMed Central

    Koh, Cho Yeow; Wetzel, Allan B; de van der Schueren, Will J.; Hol, Wim G. J.

    2014-01-01

    As part of a project aimed at obtaining selective inhibitors and drug-like compounds targeting tRNA synthetases from trypanosomatids, we have elucidated the crystal structure of human cytosolic histidyl-tRNA synthetase (Hs-cHisRS) in complex with histidine in order to be able to compare human and parasite enzymes. The resultant structure of Hs-cHisRS·His represents the substrate-bound state (H-state) of the enzyme. It provides an interesting opportunity to compare with ligand-free and imidazole-bound structures Hs-cHisRS published recently, both of which represent the ligand-free state (F-state) of the enzyme. The H-state Hs-cHisRS undergoes conformational changes in active site residues and several conserved motif of HisRS, compared to F-state structures. The histidine forms eight hydrogen bonds with HisRS of which six engage the amino and carboxylate groups of this amino acid. The availability of published imidazole-bound structure provides a unique opportunity to dissect the structural roles of individual chemical groups of histidine. Remarkably, the analysis revealed the importance of the amino and carboxylate groups, of the histidine in leading to these dramatic conformational changes of the H-state. Further, comparison with previously published trypanosomatid HisRS structures reveals a pocket in the F-state of the parasite enzyme that may provide opportunities for developing specific inhibitors of Trypanosoma brucei HisRS. PMID:25151410

  7. Stimulation of glycolysis by histidine buffers in mammalian liver during cold hypoxia.

    PubMed

    Churchill, T A; Green, C J; Fuller, B J

    1995-06-20

    This study was designed to address the reasons why glycolysis in mammalian liver is unable to function more efficiently during periods of cold hypoxia. Our hypothesis was that control of intracellular pH, by use of amino acid buffers with high pKa values, would allow prolonged flux through glycolysis and better maintenance of liver high-energy adenine nucleotide pool. The effects of two concentrations of histidine (90 and 180 mM) and one of carnosine (90 mM), a histidyl dipeptide, on energy metabolism and levels of glycolytic substrate (glucose) and anaerobic endproduct (lactate) were investigated during cold hypoxia using rat livers to model the mammalian system. The transition to anaerobic metabolism was apparent by an immediate rise in lactate levels upon entry into cold hypoxia. By 10-14 h hypoxia, contents of the endproduct had increased by 10, 13.5, and 14.5 mumol/g in buffers containing 90 and 180 mM histidine and 90 mM carnosine, respectively. As well, ATP, total adenylate contents, and "energy charge" ratios exhibited a rapid decline from initial values of 2.3-3.3 mumol/g, 4.3-5.5 mumol/g, and 0.64-0.75, respectively, over the first 2-4 h of cold hypoxia. With respect to efficacy, the 180 mM histidine buffer exhibited the most positive maintenance of adenylate levels, followed closely by 90 mM carnosine, and finally 90 mM histidine as the least effective of the three buffers. Nevertheless, all three buffers examined in this study showed positive effects compared to similarly treated livers stored in a solution of minor buffering capacity (a citrate-based solution) over the same time period. The data support the hypothesis that glycolytic flux and cellular energetics can be maintained by the inclusion of efficient buffering agents during periods of cold hypoxia.

  8. Hemoglobin istanbul: substitution of glutamine for histidine in a proximal histidine (F8(92)β)

    PubMed Central

    Aksoy, M.; Erdem, S.; Efremov, G. D.; Wilson, J. B.; Huisman, T. H. J.; Schroeder, W. A.; Shelton, J. R.; Shelton, J. B.; Ulitin, O. N.; Müftüoğlu, A.

    1972-01-01

    A presumably spontaneous mutation has resulted in the formation of Hemoglobin (Hb) Istanbul in which glutamine is substituted for histidine in the proximal position of the β-chain (F8(92)). The anemia and other physiological effects that occur in the presence of Hb Istanbul were much ameliorated by splenectomy. Hb Istanbul is a relatively unstable molecule which produces a rather moderate case of “unstable hemoglobin hemolytic anemia.” In the determination of structure, a method of preferential cleavage of an aspartyl-proline bond at residues 99-100 of the β-chain was used. Images PMID:4639022

  9. Recyclable decoration of amine-functionalized magnetic nanoparticles with Ni(2+) for determination of histidine by photochemical vapor generation atomic spectrometry.

    PubMed

    Hu, Yuan; Wang, Qi; Zheng, Chengbin; Wu, Li; Hou, Xiandeng; Lv, Yi

    2014-01-01

    It is critically important to accurately determine histidine since it is an indicator for many diseases when at an abnormal level. Here, an inexpensive and simple method using an amine-functionalized magnetic nanoparticle-based Ni(2+)-histidine affinity pair system was developed for highly sensitive and selective detection of histidine in human urine by photochemical vapor generation atomic spectrometry. Ni(2+) was first bound to the amine groups of the amine-functionalized magnetic nanoparticles and then liberated to solution via the highly specific interaction between the histidine and Ni(2+) in the presence of histidine. The liberated histidine-Ni(2+) complex was exposed to UV irradiation in the presence of formic acid to form gaseous nickel tetracarbonyl, which was separated from the sample matrix and determined by atomic absorption/fluorescence spectrometry. Compared to other methods, this approach promises high sensitivity, simplicity in design, and convenient operation. The need for organic solvents, enzymatic reactions, separation processes, chemical modification, expensive instrumentations, and sophisticated and complicated pretreatment is minimized with this strategy. A limit of detection of 1 nM was obtained and provided tens-to-hundreds of fold improvements over that achieved with conventional methods. The protocol was evaluated by analysis of several urine samples with good recoveries and showed great potential for practical application. PMID:24286112

  10. Relative hydrophobicity between the phases and partition of cytochrome-c in glycine ionic liquids aqueous two-phase systems.

    PubMed

    Wu, Changzeng; Wang, Jianji; Li, Zhiyong; Jing, Jun; Wang, Huiyong

    2013-08-30

    In this work, glycine ionic liquids tetramethylammonium glycine ([N1111][Gly]), tetraethylammonium glycine ([N2222][Gly]), tetra-n-butylammonium glycine ([N4444][Gly]), tetra-n-butylphosphonium glycine ([P4444][Gly]) and tetra-n-pentylammonium glycine ([N5555][Gly]) were synthesized and used to prepare aqueous two-phase systems (ATPSs) in the presence of K2HPO4. Binodal curves of such ATPSs and partition coefficients of a series of dinitrophenylated (DNP) amino acids in these ATPSs were determined at 298.15K to understand the effect of cationic structure of the ionic liquids on the phase-forming ability of glycine ionic liquids, relative hydrophobicity between the phases in the ionic liquids ATPSs, and polarity of the ionic liquids-rich phases. With the attempt to correlate the relative hydrophobicity of the phases in the ATPSs with their extraction capability for proteins, partition coefficients of cytochrome-c in the ATPSs were also determined. It was shown that partition coefficients of cytochrome-c were in the range from 2.83 to 20.7 under the studied pH conditions. Then, hydrophobic interactions between cytochrome-c and the ionic liquid are suggested to be the main driving force for the preferential partition of cytochrome-c in the glycine ionic liquid-rich phases of the ATPSs. Result derived from polarity of the ionic liquids-rich phases supports this mechanism.

  11. Characterisation of L-alanine and glycine absorption across the gut of an ancient vertebrate.

    PubMed

    Glover, Chris N; Bucking, Carol; Wood, Chris M

    2011-08-01

    This study utilised an in vitro technique to characterise absorption of two amino acids across the intestinal epithelium of Pacific hagfish, Eptatretus stoutii. Uptake of L-alanine and glycine conformed to Michaelis-Menten kinetics. An uptake affinity (K(m); substrate concentration required to attain a 50% uptake saturation) of 7.0 mM and an uptake capacity (J (max)) of 83 nmol cm(-2) h(-1) were described for L-alanine. The K(m) and J(max) for glycine were 2.2 mM and 11.9 nmol cm(-2) h(-1), respectively. Evidence suggested that the pathways of L-alanine and glycine absorption were shared, and sodium dependent. Further analysis indicated that glycine uptake was independent of luminal pH and proline, but a component of uptake was significantly impaired by 100-fold excesses of threonine or asparagine. The presence of a short-term (24 h) exposure to waterborne glycine, similar in nature to that which may be expected to occur when feeding inside an animal carcass, had no significant impact on gastrointestinal glycine uptake. This may indicate a lack of cross talk between absorptive epithelia. These results are the first published data to describe gastrointestinal uptake of an organic nutrient in the oldest extant vertebrate and may provide potential insight into the evolution of nutrient transport systems.

  12. Microbial Community Responses to Glycine Addition in Kansas Prairie Soils

    NASA Astrophysics Data System (ADS)

    Bottos, E.; Roy Chowdhury, T.; White, R. A., III; Brislawn, C.; Fansler, S.; Kim, Y. M.; Metz, T. O.; McCue, L. A.; Jansson, J.

    2015-12-01

    Advances in sequencing technologies are rapidly expanding our abilities to unravel aspects of microbial community structure and function in complex systems like soil; however, characterizing the highly diverse communities is problematic, due primarily to challenges in data analysis. To tackle this problem, we aimed to constrain the microbial diversity in a soil by enriching for particular functional groups within a community through addition of "trigger substrates". Such trigger substrates, characterized by low molecular weight, readily soluble and diffusible in soil solution, representative of soil organic matter derivatives, would also be rapidly degradable. A relatively small energy investment to maintain the cell in a state of metabolic alertness for such substrates would be a better evolutionary strategy and presumably select for a cohort of microorganisms with the energetics and cellular machinery for utilization and growth. We chose glycine, a free amino acid (AA) known to have short turnover times (in the range of hours) in soil. As such, AAs are a good source of nitrogen and easily degradable, and can serve as building blocks for microbial proteins and other biomass components. We hypothesized that the addition of glycine as a trigger substrate will decrease microbial diversity and evenness, as taxa capable of metabolizing it are enriched in relation to those that are not. We tested this hypothesis by incubating three Kansas native prairie soils with glycine for 24 hours at 21 degree Celsius, and measured community level responses by 16S rRNA gene sequencing, metagenomics, and metatranscriptomics. Preliminary evaluation of 16S rRNA gene sequences revealed minor changes in bacterial community composition in response to glycine addition. We will also present data on functional gene abundance and expression. The results of these analyses will be useful in designing sequencing strategies aimed at dissecting and deciphering complex microbial communities.

  13. Child Stunting is Associated with Low Circulating Essential Amino Acids

    PubMed Central

    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.

    2016-01-01

    Background 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. Methods 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 12–59 months, from rural Malawi. Children underwent anthropometry. Findings 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. Interpretation 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. PMID:27211567

  14. Can an Imidazole Be Formed from an Alanyl-Seryl-Glycine Tripeptide under Possible Prebiotic Conditions?

    NASA Astrophysics Data System (ADS)

    Vázquez-Salazar, Alberto; Tan, George; Stockton, Amanda; Fani, Renato; Becerra, Arturo; Lazcano, Antonio

    2016-10-01

    The five-membered heterocyclic imidazole group, which is an essential component of purines, histidine and many cofactors, has been abiotically synthesized in different model experiments that attempt to simulate the prebiotic environment. The evolutionary significance of imidazoles is highlighted not only by its presence in nucleic acid components and in histidine, but also by experimental reports of its ability to restore the catalytic activity of ribozymes. However, as of today there are no reports of histidine in carbonaceous chondrites, and although the abiotic synthesis of His reported by Shen et al. (1987, 1990a) proceeds via an Amadori rearrangement, like in the biosynthesis of histidine, neither the reactants nor the conditions are truly prebiotic. Based on the autocatalytic biosynthesis of 4-methylidene-imidazole-one (MIO), a cofactor of some members of the amino acid aromatic ammonia-lyases and aminomutases, which occur via the self-condensation of a simple Ala-Ser-Gly motif within the sequence of the enzymes, we propose a possible prebiotic synthesis of an imidazolide.

  15. Temporal alteration of spreading depression by the glycine transporter type-1 inhibitors NFPS and Org-24461 in chicken retina.

    PubMed

    Kertesz, Szabolcs; Szabo, Geza; Udvari, Szabolcs; Levay, Gyorgy; Matyus, Peter; Harsing, Laszlo G

    2013-01-25

    We used isolated chicken retina to induce spreading depression by the glutamate receptor agonist N-methyl-d-aspartate. The N-methyl-d-aspartate-induced latency time of spreading depression was extended by the glycine(B) binding site competitive antagonist 7-chlorokynurenic acid. Addition of the glycine transporter type-1 inhibitors NFPS and Org-24461 reversed the inhibitory effect of 7-chlorokynurenic acid on N-methyl-d-aspartate-evoked spreading depression. The glycine uptake inhibitory activity of Org-24461, NFPS, and some newly synthesized analogs of NFPS was determined in CHO cells stably expressing human glycine transporter type-1b isoform. Compounds, which failed to inhibit glycine transporter type-1, also did not have effect on retinal spreading depression. These experiments indicate that the spreading depression model in chicken retina is a useful in vitro test to determine activity of glycine transporter type-1 inhibitors. In addition, our data serve further evidence for the role of glycine transporter type-1 in retinal neurotransmission and light processing.

  16. GABA and glycine in the developing brain.

    PubMed

    Ito, Susumu

    2016-09-01

    GABA and glycine are major inhibitory neurotransmitters in the CNS and act on receptors coupled to chloride channels. During early developmental periods, both GABA and glycine depolarize membrane potentials due to the relatively high intracellular Cl(-) concentration. Therefore, they can act as excitatory neurotransmitters. GABA and glycine are involved in spontaneous neural network activities in the immature CNS such as giant depolarizing potentials (GDPs) in neonatal hippocampal neurons, which are generated by the synchronous activity of GABAergic interneurons and glutamatergic principal neurons. GDPs and GDP-like activities in the developing brains are thought to be important for the activity-dependent functiogenesis through Ca(2+) influx and/or other intracellular signaling pathways activated by depolarization or stimulation of metabotropic receptors. However, if GABA and glycine do not shift from excitatory to inhibitory neurotransmitters at the birth and in maturation, it may result in neural disorders including autism spectrum disorders. PMID:26951057

  17. A Didactic Experience of Statistical Analysis for the Determination of Glycine in a Nonaqueous Medium Using ANOVA and a Computer Program

    ERIC Educational Resources Information Center

    Santos-Delgado, M. J.; Larrea-Tarruella, L.

    2004-01-01

    The back-titration methods are compared statistically to establish glycine in a nonaqueous medium of acetic acid. Important variations in the mean values of glycine are observed due to the interaction effects between the analysis of variance (ANOVA) technique and a statistical study through a computer software.

  18. Ampholytes as background electrolytes in capillary zone electrophoresis: sense or nonsense? Histidine as a model ampholyte.

    PubMed

    Beckers, Jozef L

    2003-01-01

    A lot of phenomena, occuring in capillary zone electrophoresis (CZE), are linked with the ionic concentration of the background electrolyte (BGE). If weak bases and acids are used as BGEs in CZE, at a pH where they are scarcely ionized, the ionic concentration of the BGE is very low and this brings a strong peak broadening, limited sample stacking and low sample load. Because the electromigration dispersion increases extremely, moreover, the existence of low-conductivity BGEs in CZE is a contradiction in terms. The behavior of ampholytes as BGE in CZE is examined, by means of histidine as a model ampholyte. For BGEs consisting of histidine, important parameters, including the ionic concentrations, buffer capacity, transfer ratio, and the indicator for electromigration dispersion E(1)m(1)/E(2)m(2), are calculated at various pH. Although the transfer ratio is fairly constant over the whole pH traject, the ionic concentration and buffer capacity decrease whereas the electromigration dispersion strongly increases near the pI of histidine. I.e., that ampholytes can be applied as BGEs in CZE, however, just not at pH near their pI value, except as the difference between the pK values of the basic and acidic group, the deltapK value, is very small. For ampholytes with a low deltapK value or at high concentrations, all the before-mentioned effects are less fatal, but in that case we can not speak of a real low-conductivity BGE. If ampholytes are used at pH near their pK values, the use of ampholytes as BGE is not advantageously compared with simple weak bases and acids. This has been confirmed by calculations and experiments. PMID:12569544

  19. Standard thermodynamic functions of complex formation between Cu2+ and glycine in aqueous solution

    NASA Astrophysics Data System (ADS)

    Gorboletova, G. G.; Metlin, A. A.

    2013-05-01

    Heat effects of the interaction of copper(II) solutions with aminoacetic acid (glycine) are measured by the direct calorimetry at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 against a background of potassium nitrate. Standard enthalpy values for reactions of the formation of aminoacetic acid copper complexes in aqueous solutions are obtained using an equation with a single individual parameter by extrapolating it to zero ionic strength. The standard thermodynamic characteristics of complex formation in the Cu2+-glycine system are calculated. It is shown that glycine-like coordination is most likely in Cu(II) complexes with L-asparagine, L-glutamine, and L-valine.

  20. Glycine-Glomus-Rhizobium Symbiosis

    PubMed Central

    Bethlenfalvay, Gabor J.; Brown, Milford S.; Mihara, Keiko L.; Stafford, Alan E.

    1987-01-01

    Soybean (Glycine max [L.] Merr.) plants were nodulated (Bradyrhizobium japonicum) and either inoculated with the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus mosseae (Nicol. & Gerd.) Gerd. and Trappe or left uncolonized. All plants were grown unstressed for 21 days initially. After this period, some VAM and non-VAM plants were exposed to four 8-day drought cycles while others were kept well watered. Drought cycles were terminated by rewatering when soil moisture potentials reached −1.2 megapascal. Nodule development and activity, transpiration, leaf conductance, leaf and root parameters including fresh and dry weight, and N and P nutrition of VAM plants and of non-VAM, P-fed plants grown under the same controlled conditions were compared. All parameters, except N content, were greater in VAM plants than in P-fed, non-VAM plants when under stress. The opposite was generally true in the unstressed comparisons. Transpiration and leaf conductance were significantly greater in stressed VAM than in non-VAM plants during the first half of the final stress cycle. Values for both VAM and non-VAM plants decreased linearly with time during the cycle and converged at a high level of stress (−1.2 megapascal). Effects of VAM fungi on the consequences of drought stress relative to P nutrition and leaf gas exchange are discussed in the light of these findings and those reported in the literature. PMID:16665641

  1. 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.

  2. Glycine exists mainly as monomers, not dimers, in supersaturated aqueous solutions: implications for understanding its crystallization and polymorphism.

    PubMed

    Huang, Jun; Stringfellow, Thomas C; Yu, Lian

    2008-10-22

    Glycine, the simplest amino acid, is described as existing as hydrogen-bonded cyclic dimers in supersaturated aqueous solutions and, as a result, crystallizing in a centrosymmetric polymorph (polymorph alpha) for which the dimer can be viewed as the building unit, in favor of other polymorphs of polar structures. In exhibiting this relation between polymorphic selectivity and self-association in solution, glycine is thought to illustrate a general principle. We measured the freezing-point depression of glycine-water up to 30% supersaturation and found that glycine exists mainly as monomers, not dimers, and that the dimer stability constant K D is smaller than 0.1 kg of H 2O/mol if the observed osmotic abnormality is attributed to dimerization. We also revisited a report cited as evidence for glycine dimerization: the slowdown of glycine diffusion with solution age. Pulsed gradient spin-echo NMR spectroscopy was used in place of the previous method of Gouy interferometry to avoid perturbations to sloution structure caused by the interdiffusion between two solutions of different concentrations. No aging effect was observed on glycine diffusion up to 24% supersaturation after five days. The solute size calculated from diffusivity, viscosity, and the Stokes-Einstein relation showed no increase with concentration or solution age. We conclude that glycine exists in supersaturated aqueous solutions mainly as monomers, not dimers, and remains so upon aging. This result does not invalidate the theories of how pH and additives affect glycine's polymorphic preference, because they begin with the assumption that alpha glycine is the preferred polymorph under normal conditions, but requires a new explanation for that assumption itself. PMID:18816054

  3. Structural perspective on the direct inhibition mechanism of EGCG on mammalian histidine decarboxylase and DOPA decarboxylase.

    PubMed

    Ruiz-Pérez, M Victoria; Pino-Ángeles, Almudena; Medina, Miguel A; Sánchez-Jiménez, Francisca; Moya-García, Aurelio A

    2012-01-23

    Histidine decarboxylase (HDC) and l-aromatic amino acid decarboxylase (DDC) are homologous enzymes that are responsible for the synthesis of important neuroactive amines related to inflammatory, neurodegenerative, and neoplastic diseases. Epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, has been shown to target histamine-producing cells and to promote anti-inflammatory, antitumor, and antiangiogenic effects. Previous experimental work has demonstrated that EGCG has a direct inhibitory effect on both HDC and DDC. In this study, we investigated the binding modes of EGCG to HDC and DDC as a first step for designing new polyphenol-based HDC/DDC-specific inhibitors. PMID:22107329

  4. N-[[(Mercaptoacetyl)amino]benzoyl]glycines as mucolytic agents.

    PubMed

    Martin, T A; Comer, W T

    1985-07-01

    m- and p-aminobenzoic acids were converted to the title compounds by sequential use of ClCH2COCl, SOCl2, glycine methyl or ethyl ester, AcSK, and hydrolysis. The title compounds and a number of salts were compared for mucolytic activity, toxicity, stability, and hygroscopicity. When compared to N-acetyl-L-cysteine (NAC), the compounds exhibit several times the in vitro mucolytic activity of NAC on a molar basis. The most promising candidate appears to be the sodium salt 3.5H2O 2 of the meta series. PMID:4009614

  5. N-[[(Mercaptoacetyl)amino]benzoyl]glycines as mucolytic agents.

    PubMed

    Martin, T A; Comer, W T

    1985-07-01

    m- and p-aminobenzoic acids were converted to the title compounds by sequential use of ClCH2COCl, SOCl2, glycine methyl or ethyl ester, AcSK, and hydrolysis. The title compounds and a number of salts were compared for mucolytic activity, toxicity, stability, and hygroscopicity. When compared to N-acetyl-L-cysteine (NAC), the compounds exhibit several times the in vitro mucolytic activity of NAC on a molar basis. The most promising candidate appears to be the sodium salt 3.5H2O 2 of the meta series.

  6. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

    PubMed

    Umeda, Yuhei; Fukunaga, Nao; Sekine, Toshimori; Furukawa, Yoshihiro; Kakegawa, Takeshi; Kobayashi, Takamichi; Nakazawa, Hiromoto

    2016-01-01

    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well. PMID:26369758

  7. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

    PubMed

    Umeda, Yuhei; Fukunaga, Nao; Sekine, Toshimori; Furukawa, Yoshihiro; Kakegawa, Takeshi; Kobayashi, Takamichi; Nakazawa, Hiromoto

    2016-01-01

    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

  8. Poly(L-histidine) based copolymers: Effect of the chemically substituted L-histidine on the physio-chemical properties of the micelles and in vivo biodistribution.

    PubMed

    Zhang, Xiaojun; Chen, Dawei; Ba, Shuang; Chang, Jing; Zhou, Jiaying; Zhao, Haixia; Zhu, Jia; Zhao, Xiuli; Hu, Haiyang; Qiao, Mingxi

    2016-04-01

    Even though the Poly(l-histidine) (PHis) based copolymers have been well studied, the effect of the chemically substituted l-histidine on the physio-chemical and biological properties of the micelles has never been elucidated to date. To address this issue, triblock copolymer of poly(ethylene glycol)-poly(D,L-lactide)-poly(2,4-dinitrophenol-L-histidine)(mPEG-b-PLA-b-DNP-PHis) with DNP group substituted to the saturated nitrogen of l-histidine were synthesized. The pH sensitive properties of the copolymer micelles were characterized using an acid-base titration method, fluorescene probe technique, DLS observation, in vitro drug release and cytotoxicity against MCF-7 cells under different pH conditions, respectively. The results suggest that mPEG-b-PLA-b-DNP-PHis copolymers showed similar micellar stability for DOX loaded micelles, increased particle size, and similar pH responsive properties with mPEG-b-PLA-b-PHis copolymers. The subcellular distribution observation demonstrated that mPEG-b-PLA-b-DNP-PHis micelles showed a slightly compromised endo-lysosmal escape of doxorubicin as compared to mPEG-b-PLA-b-PHis micelles. The mPEG-b-PLA-b-DNP-PHis micelles showed higher cellular uptake by MCF-7 cells than mPEG-b-PLA-b-PHis micelles due to the different uptake pathways. Effect of DNP substitution on the in vivo distribution of the copolymer micelles was studied using non-invasive near-infrared fluorescence (NIRF) imaging with mPEG-b-PLA-b-PHis micelles as control. The results indicate that the mPEG-b-PLA-b-DNP-PHis micelles showed a reduced passive targeting to the tumor due to the larger particle size. These results suggest that saturated nitrogen of PHis may serve as a valuable site for chemical modification of the PHis based copolymers because of the little effect on the pH responsive properties. However, selection of the substitution group needs to be considered due to the possible increase of micellar particle size of the micelles, leading to compromised passive

  9. Nickel deficiency disrupts metabolism of ureides, amino acids, and organic acids of young pecan foliage.

    PubMed

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2006-02-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan. PMID:16415214

  10. Amino Acid compositions of 27 food fishes and their importance in clinical nutrition.

    PubMed

    Mohanty, Bimal; Mahanty, Arabinda; Ganguly, Satabdi; Sankar, T V; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md; Debnath, Dipesh; Vijayagopal, P; Sridhar, N; Akhtar, M S; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Paria, Prasenjit; Das, Debajeet; Das, Pushpita; Vijayan, K K; Laxmanan, P T; Sharma, A P

    2014-01-01

    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs.

  11. Changes in tissue free amino acid pools in growing chickens fed thermally treated vetch diets.

    PubMed

    Fernández-Fígares, I; Nieto, R; Aguilera, J F; Lachica, M

    2014-04-01

    A three-day assay was developed to evaluate the effect of autoclaving on protein quality of vetch as an alternative to classical growth methods. Male chickens (n = 10/diet) were given approximately isonitrogenous diets based on raw or autoclaved vetch for 3 days. Samples of plasma, muscle and liver were obtained for free amino acid analysis. Heating vetch depressed growth (11.9 vs. 23.2 g/d; p < 0.05). Plasma methionine and histidine increased (0.05 < p < 0.06), while gluconeogenic amino acids tended to decrease (p < 0.10) after heating. Muscle free amino acids did not change except for a trend to increased methionine (p = 0.06) in birds fed autoclaved vetch. In liver, most essential amino acids, glycine, proline and tyrosine increased markedly with heated vetch diet. Correlations between plasma and muscle free amino acids were poor compared with those between plasma and liver free amino acids. Liver free amino acid pool was more sensitive than muscle or plasma pool to amino acid inflow modifications after vetch heating.

  12. Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition

    PubMed Central

    Mahanty, Arabinda; Sankar, T. V.; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md.; Debnath, Dipesh; Vijayagopal, P.; Sridhar, N.; Akhtar, M. S.; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Das, Debajeet; Das, Pushpita; Vijayan, K. K.; Laxmanan, P. T.; Sharma, A. P.

    2014-01-01

    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs. PMID:25379285

  13. Organic foliar Milstop shows efficacy against soybean aphid (Aphis glycines) on soybean (Glycine max)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max (L.) Merr.) has been produced in the United States since 1765. Soybean aphids (Aphis glycines Matsumura) were first detected on soybean in the United States in 2000 and now cause an estimated yield loss of up to US$4.9 billion annually. Organic soybean producers have few insecti...

  14. Infrared Spectroscopy of Hydrogen-Bonded Clusters of Protonated Histidine

    NASA Astrophysics Data System (ADS)

    Kondo, Makoto; Kasahara, Yasutoshi; Ishikawa, Haruki

    2015-06-01

    Histidine(His), one of the essential amino acids, is involved in active sites in many enzyme proteins, and known to play fundamental roles in human body. Thus, to gain detailed information about intermolecular interactions of His as well as its structure is very important. In the present study, we have recorded IR spectra of hydrogen-bonded clusters of protonated His (HisH^+) in the gas phase to discuss the relation between the molecular structure and intermolecular interaction of HisH^+. Clusters of HisH^+-(MeOH)_n (n = 1, 2) were generated by an electrospray ionization of the MeOH solution of L-His hydrochloride monohydrate. IR photodissociation spectra of HisH^+-(MeOH)1,2 were recorded. By comparing with the results of the DFT calculations, we determined the structures of these clusters. In the case of n = 1 cluster, MeOH is bonded to the imidazole ring as a proton acceptor. The most of vibrational bands observed were well explained by this isomer. However, a free NH stretch band of the imidazole ring was also observed in the spectrum. This indicates an existence of an isomer in which MeOH is bounded to the carboxyl group of HisH^+. Furthermore, it is found that a protonated position of His is influenced by a hydrogen bonding position of MeOH. In the case of n = 2 cluster, one MeOH molecule is bonded to the amino group, while the other MeOH molecule is separately bonded to the carboxyl group in the most stable isomer. However, there is a possibility that other conformers also exist in our experimental condition. The details of the experimental and theoretical results will be presented in the paper.

  15. A cis/trans Test of the Effect of the First Enzyme for Histidine Biosynthesis on Regulation of the Histidine Operon

    PubMed Central

    Kovach, John S.; Ballesteros, Antonio O.; Meyers, Marilyn; Soria, Marco; Goldberger, Robert F.

    1973-01-01

    Previous studies showed that when triazolalanine was added to a derepressed culture of a histidine auxotroph, repression of the histidine operon occurred as though histidine had been added (6). However, when triazolalanine was added to a derepressed culture of a strain with a mutation in the first gene of the histidine operon which rendered the first enzyme for histidine biosynthesis resistant to inhibition by histidine, repression did not occur. The studies reported here represent a cis/trans test of this effect of mutations to feedback resistance. Using specially constructed merodiploid strains, we were able to show that the wild-type allele is dominant to the mutant (feedback resistant) allele and that the effect operates in trans. We conclude that the enzyme encoded by the first gene of the histidine operon exerts its regulatory effect on the operon not by acting locally at its site of synthesis, but by acting as a freely diffusible protein. PMID:4572718

  16. Comparative metabolomics in Glycine max and Glycine soja under salt stress to reveal the phenotypes of their offspring.

    PubMed

    Lu, Yonghai; Lam, Honming; Pi, Erxu; Zhan, Qinglei; Tsai, Sauna; Wang, Chunmei; Kwan, Yiuwa; Ngai, Saiming

    2013-09-11

    Metabolomics is developing as an important functional genomics tool for understanding plant systems' response to genetic and environmental changes. Here, we characterized the metabolic changes of cultivated soybean C08 (Glycine max L. Merr) and wild soybean W05 (Glycine soja Sieb.et Zucc.) under salt stress using MS-based metabolomics, in order to reveal the phenotypes of their eight hybrid offspring (9H0086, 9H0124, 9H0391, 9H0736, 9H0380, 9H0400, 9H0434, and 9H0590). Total small molecule extracts of soybean seedling leaves were profiled by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-Fourier transform mass spectrometry (LC-FT/MS). We found that wild soybean contained higher amounts of disaccharides, sugar alcohols, and acetylated amino acids than cultivated soybean, but with lower amounts of monosaccharides, carboxylic acids, and unsaturated fatty acids. Further investigations demonstrated that the ability of soybean to tolerate salt was mainly based on synthesis of compatible solutes, induction of reactive oxygen species (ROS) scavengers, cell membrane modifications, and induction of plant hormones. On the basis of metabolic phenotype, the salt-tolerance abilities of 9H0086, 9H0124, 9H0391, 9H0736, 9H0380, 9H0400, 9H0434, and 9H0590 were discriminated. Our results demonstrated that MS-based metabolomics provides a fast and powerful approach to discriminate the salt-tolerance characteristics of soybeans.

  17. Glycine receptor antibodies in PERM and related syndromes: characteristics, clinical features and outcomes

    PubMed Central

    Carvajal-González, Alexander; Leite, M. Isabel; Waters, Patrick; Woodhall, Mark; Coutinho, Ester; Balint, Bettina; Lang, Bethan; Pettingill, Philippa; Carr, Aisling; Sheerin, Una-Marie; Press, Raomand; Lunn, Michael P.; Lim, Ming; Maddison, Paul; Meinck, H.-M.; Vandenberghe, Wim

    2014-01-01

    The clinical associations of glycine receptor antibodies have not yet been described fully. We identified prospectively 52 antibody-positive patients and collated their clinical features, investigations and immunotherapy responses. Serum glycine receptor antibody endpoint titres ranged from 1:20 to 1:60 000. In 11 paired samples, serum levels were higher than (n = 10) or equal to (n = 1) cerebrospinal fluid levels; there was intrathecal synthesis of glycine receptor antibodies in each of the six pairs available for detailed study. Four patients also had high glutamic acid decarboxylase antibodies (>1000 U/ml), and one had high voltage-gated potassium channel-complex antibody (2442 pM). Seven patients with very low titres (<1:50) and unknown or alternative diagnoses were excluded from further study. Three of the remaining 45 patients had newly-identified thymomas and one had a lymphoma. Thirty-three patients were classified as progressive encephalomyelitis with rigidity and myoclonus, and two as stiff person syndrome; five had a limbic encephalitis or epileptic encephalopathy, two had brainstem features mainly, two had demyelinating optic neuropathies and one had an unclear diagnosis. Four patients (9%) died during the acute disease, but most showed marked improvement with immunotherapies. At most recent follow-up, (2–7 years, median 3 years, since first antibody detection), the median modified Rankin scale scores (excluding the four deaths) decreased from 5 at maximal severity to 1 (P < 0.0001), but relapses have occurred in five patients and a proportion are on reducing steroids or other maintenance immunotherapies as well as symptomatic treatments. The glycine receptor antibodies activated complement on glycine receptor-transfected human embryonic kidney cells at room temperature, and caused internalization and lysosomal degradation of the glycine receptors at 37°C. Immunoglobulin G antibodies bound to rodent spinal cord and brainstem co-localizing with

  18. Mutagenesis and heterologous expression in yeast of a plant Delta6-fatty acid desaturase.

    PubMed

    Sayanova, O; Beaudoin, F; Libisch, B; Castel, A; Shewry, P R; Napier, J A

    2001-07-01

    Membrane-bound microsomal fatty acid desaturases are known to have three conserved histidine boxes, comprising a total of up to eight histidine residues. Recently, a number of deviations from this consensus have been reported, with the substitution of a glutamine for the first histidine residue of the third histidine box being present in the so called 'front end' desaturases. These enzymes are also characterized by the presence of a cytochrome b5 domain at the protein N-terminus. Site-directed mutagenesis has been used to probe the functional importance of a number of amino acid residues which comprise the third histidine box of a 'front end' desaturase, the borage Delta6-fatty acid desaturase. This showed that the variant glutamine in the third histidine box is essential for enzyme activity and that histidine is not able to substitute for this residue. PMID:11457919

  19. Nazarov cyclization of dienylaziridines: synthesis of cyclopentadienyl/hydrinedienyl/indenyl glycines.

    PubMed

    Sudhakar, Gangarajula; Reddy, Karla Janardhan; Nanubolu, Jagadesh Babu

    2015-09-01

    Cyclopentadienyl, hydrinedienyl, and indenyl glycines were synthesized using dienylaziridines as Nazarov cyclization precursors for the first time. Several substrates were synthesized to demonstrate the compatibility of this reaction. Asymmetric synthesis of these amino acids was also developed to show the additional scope of this method. PMID:26203635

  20. 77 FR 73426 - Glycine From the People's Republic of China: Final Partial Affirmative Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... of purity and is used as a sweetener/taste enhancer, a buffering agent, reabsorbable amino acid... Antidumping Duty Order: Glycine From the People's Republic of China, 60 FR 16116 (March 29, 1995) (Order... Order and Initiation of Scope Inquiry, 77 FR 21532 (April 10, 2012) (Preliminary Determination)....

  1. 76 FR 57951 - Glycine From the People's Republic of China: Continuation of Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ... and is used as a sweetener/taste enhancer, a buffering agent, reabsorbable amino acid, chemical... Antidumping Duty Order: Glycine From the People's Republic of China, 60 FR 16116 (March 29, 1995). On October... of Five-Year (``Sunset'') Review, 75 FR 60731 (October 1, 2010). As a result of this sunset...

  2. 77 FR 21532 - Glycine From the People's Republic of China: Preliminary Partial Affirmative Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... of purity and is used as a sweetener/taste enhancer, a buffering agent, reabsorbable amino acid...: Glycine From the People's Republic of China, 60 FR 16116 (March 29, 1995) (Order). DATES: Effective Date... FR 16640 (March 28, 2008) (Indian Investigation) and accompanying Issues and Decision Memorandum...

  3. Ir-Spectroscopy of Glycine and its Complexes with Water in Helium Nanodroplets

    NASA Astrophysics Data System (ADS)

    Letzner, M.; Grün, S. A.; Schwaab, G.; Havenith, M.

    2011-06-01

    Glycine is the smallest amino acid, and therefore it is of special interest as a model and starting point for theoretical and experimental studies. Whereas the crystalline form of glycine consists of zwitterions NH_3+-CH_2-COO-, gas phase glycine is known to exist in the nonionized form NH_2-CH_2-COOH. The interaction between glycine and water has been widely studied using a large variety of theoretical methods. Depending on the theoretical level used, a stabilisation of the zwitterionic form is predicted for complexes containing from 2 to 7 water molecules. In low-temperature Ar matrices a set of characteristic IR absorption bands for the zwitterionic form has been observed. The higher stoichiometry complexes (glycine)\\cdots(H_2O)_n with n larger than 3 are demonstrated to be zwitterionic H-bonded complexes. The multitude of conformations expected for these glycine-water complexes makes a combination of low temperature and high resolution spectroscopy essential. We want to use the advantages of our experiment to investigate glycine and its complexes with water in helium-nanodroplets at ultracold temperatures in the range from 3000-3800 Cm-1. Our measurements were carried out using a high power IR-OPO (cw: 2.7 W) as radiation source and a helium nanodroplet spectrometer. Helium-nanodroplets are formed by expansion of helium at 55 bar through a 5 μm nozzle which is kept at a temperature of 16 K. The status of the project is presented. P.-G. Jönsson et al., Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 28, 1827 (1972) G. Junk et al., J. Am. Chem. Soc. 85, 839 (1963) R. Ramaekers et al., J. Chem. Phys., 120 (2004)

  4. Kinetic study of carbon dioxide absorption into glycine promoted diethanolamine (DEA)

    NASA Astrophysics Data System (ADS)

    Pudjiastuti, Lily; Susianto, Altway, Ali; IC, Maria Hestia; Arsi, Kartika

    2015-12-01

    In industry, especially petrochemical, oil and natural gas industry, required separation process of CO2 gas which is a corrosive gas (acid gas). This characteristic can damage the plant utility and piping systems as well as reducing the caloric value of natural gas. Corrosive characteristic of CO2 will appear in areas where there is a decrease in temperature and pressure, such as at the elbow pipe, tubing, cooler and injector turbine. From disadvantages as described above, then it is important to do separation process in the CO2 gas stream, one of the method for remove CO2 from the gas stream is reactive absorption using alkanolamine based solution with promotor. Therefore, this study is done to determine the kinetics constant of CO2 absorption in diethanolamine (DEA) solution using a glycine promoter. Glycine is chosen as a promoter because glycine is a primary amine compound which is reactive, moreover, glycine has resistance to high temperatures so it will not easy to degradable and suitable for application in industry. The method used in this study is absorption using laboratory scale wetted wall column equipment at atmospheric of pressure. This study will to provide the reaction kinetics data information in order to optimize the separation process of CO2 in the industrialized world. The experimental results show that rising temperatures from 303,15 - 328,15 K and the increase of concentration of glycine from 1% - 3% weight will increase the absorption rate of carbon dioxide in DEA promoted with glycine by 24,2% and 59,764% respectively, also the reaction kinetic constant is 1.419 × 1012 exp (-3634/T) (m3/kmol.s). This result show that the addition of glycine as a promoter can increase absorption rate of carbon dioxide in diethanolamine solution and cover the weaknesses of diethanolamine solution.

  5. Uptake of nitrate, ammonium and glycine by plants of Tasmanian wet eucalypt forests.

    PubMed

    Warren, C R; Adams, P R

    2007-03-01

    A central assumption of ecosystem N cycling has been that organic N must be converted to inorganic N to be available for plant uptake, but this has been questioned by recent studies. We examined uptake of nitrate, ammonium and the amino acid glycine in three species from Eucalyptus obliqua L'Her. wet forest in Tasmania, south-eastern Australia, to test the hypothesis that all three species can take up glycine, and to compare rates of glycine uptake with rates of uptake of nitrate and ammonium uptake. The alternative hypothesis that species vary in their preference for nitrate, ammonium and glycine ("niche differentiation") was also examined. Measurements were made on the canopy dominant Eucalyptus obliqua, and two rain forest tree species found in the understory or as sub-dominants of the canopy, Nothofagus cunninghamii (Hook.) Oerst. and Phyllocladus aspleniifolius (Labill.) Hook.f. Nitrogen uptake was examined in situ with attached roots placed in uptake solutions containing equimolar concentrations (100 micromol l(-1)) of (15)N-nitrate, (15)N-ammonium and 2-(13)C(2) (15)N-glycine. Species did not differ in their preference for different forms of N (species x N form interaction, P > 0.05), and thus there was no evidence of niche differentiation. In all species, rates of uptake were highest for ammonium (11 +/- 5 micromol g(DM) (-1) h(-1); mean +/- SD, n = 108), uptake of glycine occurred at less than half this rate (4.4 +/- 2.6 micromol g(DM) (-1) h(-1)), whereas uptake of nitrate occurred at one-tenth of this rate (0.9 +/- 1.2 micromol g(DM) (-1) h(-1)). The strong positive relationship between (15)N and (13)C uptake indicated that at least 72% of glycine-N was taken up intact. These findings indicate the potential for considerable uptake of organic N in the field.

  6. Determination of pKa values of the histidine side chains of phosphatidylinositol-specific phospholipase C from Bacillus cereus by NMR spectroscopy and site-directed mutagenesis.

    PubMed Central

    Liu, T.; Ryan, M.; Dahlquist, F. W.; Griffith, O. H.

    1997-01-01

    Two active site histidine residues have been implicated in the catalysis of phosphatidylinositol-specific phospholipase C (PI-PLC). In this report, we present the first study of the pKa values of histidines of a PI-PLC. All six histidines of Bacillus cereus PI-PLC were studied by 2D NMR spectroscopy and site-directed mutagenesis. The protein was selectively labeled with 13C epsilon 1-histidine. A series of 1H-13C HSQC NMR spectra were acquired over a pH range of 4.0-9.0. Five of the six histidines have been individually substituted with alanine to aid the resonance assignments in the NMR spectra. Overall, the remaining histidines in the mutants show little chemical shift changes in the 1H-13C HSQC spectra, indicating that the alanine substitution has no effect on the tertiary structure of the protein. H32A and H82A mutants are inactive enzymes, while H92A and H61A are fully active, and H81A retains about 15% of the wild-type activity. The active site histidines, His32 and His82, display pKa values of 7.6 and 6.9, respectively. His92 and His227 exhibit pKa values of 5.4 and 6.9. His61 and His81 do not titrate over the pH range studied. These values are consistent with the crystal structure data, which shows that His92 and His227 are on the surface of the protein, whereas His61 and His81 are buried. The pKa value of 6.9 corroborates the hypothesis of His82 acting as a general acid in the catalysis. His32 is essential to enzyme activity, but its putative role as the general base is in question due to its relatively high pKa. PMID:9300493

  7. A Rigorous Attempt to Verify Interstellar Glycine

    NASA Technical Reports Server (NTRS)

    Snyder, L. E.; Lovas, F. J.; Hollis, J. M.; Friedel, D. N.; Jewell, P. R.; Remijan, A.; Ilyushin, V. V.; Alekseev, E. A.; Dyubko, S. F.

    2004-01-01

    In 2003, Kuan, Charnley, and co-workers reported the detection of interstellar glycine (NH2CH2COOH) based on observations of 27 lines in 19 different spectral bands in one or more of the sources Sgr BP(N-LMH), Orion KL, and W51 e1/e2. They supported their detection report with rotational temperature diagrams for all three sources. In this paper, we present essential criteria which can be used in a straightforward analysis technique to confirm the identity of an interstellar asymmetric rotor such as glycine. We use new laboratory measurements of glycine as a basis for applying this analysis technique, both to our previously unpublished 12 m telescope data and to the previously published SEST data of Nummelin and colleagues. We conclude that key lines necessary for an interstellar glycine identification have not yet been found. We identify several common molecular candidates that should be examined further as more likely carriers of the lines reported as glycine. Finally, we illustrate that rotational temperature diagrams used without the support of correct spectroscopic assignments are not a reliable tool for the identification of interstellar molecules. Subject headings: ISM: abundances - ISM: clouds - ISM: individual (Sagittarius B2[N-

  8. The effects of short intensive exercise on plasma free amino acids in standardbred trotters.

    PubMed

    Hackl, S; van den Hoven, R; Zickl, M; Spona, J; Zentek, J

    2009-04-01

    The aim of this study was to investigate the effect of short intense exercise on plasma amino acid concentrations in trotters and to test the repeatability of plasma amino acids concentration in samples obtained on two independent days under field conditions. Plasma amino acid concentrations were analysed in blood samples of 36 standardbred trotters before and after intense exercise over a distance of 2000 m. Sampling was repeated in 20 horses after 35 days. Exercise intensity was estimated from post-exercise lactate levels. Horses were divided in two groups according to a cut-off lactate concentration at 15 mmol/l. The plasma concentrations of alanine, aspartate, glutamate, isoleucine, leucine, lysine and taurine increased and arginine, asparagine, citrulline, glutamine, glycine, histidine, methionine, serine, tryptophan and 3-methylhistidine decreased after exercise. Ornithine, threonine, tyrosine, phenylalanine and valine concentrations remained constant. Higher intensity of exercise significantly decreased tryptophan and increased taurine concentrations. Sampling day had a significant effect on the absolute pre- and post-exercise amino acid concentrations. Exercise had a significant influence on the concentrations of most plasma amino acids in trotters. These changes could reflect shifts between the free amino acid compartments, but there were also some indications for muscle catabolism. The amino acid supply of sporting horses could be of specific significance for maintaining muscle integrity and for the improvement of post-exercise recovery of competition horses. PMID:19320929

  9. Transgenic manipulation of a single polyamine in poplar cells affects the accumulation of all amino acids.

    PubMed

    Mohapatra, Sridev; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash C

    2010-04-01

    The polyamine metabolic pathway is intricately connected to metabolism of several amino acids. While ornithine and arginine are direct precursors of putrescine, they themselves are synthesized from glutamate in multiple steps involving several enzymes. Additionally, glutamate is an amino group donor for several other amino acids and acts as a substrate for biosynthesis of proline and gamma-aminobutyric acid, metabolites that play important roles in plant development and stress response. Suspension cultures of poplar (Populus nigra x maximowiczii), transformed with a constitutively expressing mouse ornithine decarboxylase gene, were used to study the effect of up-regulation of putrescine biosynthesis (and concomitantly its enhanced catabolism) on cellular contents of various protein and non-protein amino acids. It was observed that up-regulation of putrescine metabolism affected the steady state concentrations of most amino acids in the cells. While there was a decrease in the cellular contents of glutamine, glutamate, ornithine, arginine, histidine, serine, glycine, cysteine, phenylalanine, tryptophan, aspartate, lysine, leucine and methionine, an increase was seen in the contents of alanine, threonine, valine, isoleucine and gamma-aminobutyric acid. An overall increase in percent cellular nitrogen and carbon content was also observed in high putrescine metabolizing cells compared to control cells. It is concluded that genetic manipulation of putrescine biosynthesis affecting ornithine consumption caused a major change in the entire ornithine biosynthetic pathway and had pleiotropic effects on other amino acids and total cellular carbon and nitrogen, as well. We suggest that ornithine plays a key role in regulating this pathway.

  10. Decreased Plasma Histidine Level Predicts Risk of Relapse in Patients with Ulcerative Colitis in Remission

    PubMed Central

    Hisamatsu, Tadakazu; Ono, Nobukazu; Imaizumi, Akira; Mori, Maiko; Suzuki, Hiroaki; Uo, Michihide; Hashimoto, Masaki; Naganuma, Makoto; Matsuoka, Katsuyoshi; Mizuno, Shinta; Kitazume, Mina T.; Yajima, Tomoharu; Ogata, Haruhiko; Iwao, Yasushi; Hibi, Toshifumi; Kanai, Takanori

    2015-01-01

    Ulcerative colitis (UC) is characterized by chronic intestinal inflammation. Patients with UC have repeated remission and relapse. Clinical biomarkers that can predict relapse in UC patients in remission have not been identified. To facilitate the prediction of relapse of UC, we investigated the potential of novel multivariate indexes using statistical modeling of plasma free amino acid (PFAA) concentrations. We measured fasting PFAA concentrations in 369 UC patients in clinical remission, and 355 were observed prospectively for up to 1 year. Relapse rate within 1 year was 23% (82 of 355 patients). The age- and gender-adjusted hazard ratio for the lowest quartile compared with the highest quartile of plasma histidine concentration was 2.55 (95% confidence interval: 1.41–4.62; p = 0.0020 (log-rank), p for trend = 0.0005). We demonstrated that plasma amino acid profiles in UC patients in clinical remission can predict the risk of relapse within 1 year. Decreased histidine level in PFAAs was associated with increased risk of relapse. Metabolomics could be promising for the establishment of a non-invasive predictive marker in inflammatory bowel disease. PMID:26474176

  11. Development of 2′-substituted (2S,1′R,2′S)-2-(carboxycyclopropyl)glycine analogues as potent N-methyl-d-aspartic acid receptor agonists

    PubMed Central

    Risgaard, Rune; Nielsen, Simon D.; Hansen, Kasper B.; Jensen, Christina M.; Nielsen, Birgitte; Traynelis, Stephen F.; Clausen, Rasmus P.

    2013-01-01

    A series of 2′-substituted analogues of the selective NMDA receptor ligand (2S,1′R,2′S)-2-(carboxycyclopropyl)glycine ((S)-CCG-IV) have been designed, synthesized and pharmacologically characterized. The design was based on a docking study hypothesizing that substituents in the 2′-position would protrude into a region where differences among the NMDA receptor GluN2 subunits exist. Various synthetic routes were explored, and two different routes provided a series of alkyl-substituted analogues. Pharmacological characterization revealed that these compounds are NMDA receptor agonists and that potency decreases with increasing size of the alkyl groups. Variations in agonist activity are observed at the different recombinant NMDA receptor subtypes. This study demonstrates that it is possible to introduce substituents in the 2′-position of (S)-CCG-IV while maintaining agonist activity and that variation among NMDA receptor subtypes may be achieved by probing this region of the receptor. PMID:23614571

  12. Biosynthesis of prodigiosin by non-proliferating wild-type Serratia marcescens and mutants deficient in catabolism of alanine, histidine, and proline.

    PubMed

    Lim, D V; Qadri, S M; Nichols, C; Williams, R P

    1977-01-01

    Mutants of Serratia marcescens Nima, designated as Aut, Hut, or Put, did not utilize L-alanine, L-histidine, or L-proline, respectively, as a sole carbon source but did utilize other amino acids or glycerol as carbon sources. The bacteria were permeable to alanine, histidine, and proline but lacked the enzymes responsible for degradation of these amino acids. The Aut mutant contained no L-alanine dehydrogenase activity, whereas the Hut and Put mutants contained only 7 and 4% of the histidase and proline oxidase activities, respectively, found in the wild-type strain. Rates of oxygen uptake and protein synthesis were significantly lower when the mutants were incubated in the presence of amino acids they could not degrade. Studies of L-[14C]alanine, L-[14C]histidine, and L-[14C]proline incorporation into prodigiosin synthesized by these mutants and the wild-type strain revealed that proline was incorporated intact, whereas all of alanine except the carboxyl group was incorporated into the pigment molecule. Histidine did not enter prodigiosin directly. These data suggested that the presence of unique biosynthetic pathways, independent of primary metabolism, leads to formation of prodigiosin from specific amino acids.

  13. Antidepressants modulate glycine action in rat hippocampus

    PubMed Central

    Chang, Hyun-Kyung; Kim, Khae Hawn; Kang, Ki-Woon; Kang, Yoo-Jin; Kim, Tae-Wook; Park, Hun-Kyung; Kim, Sung-Eun; Kim, Chang-Ju

    2015-01-01

    Antidepressants are drugs that relieve symptoms of depressive disorders. Fluoxetine, tianeptine, and milnacipran are different types of antidepressants, and they have widely been used for relieving of depression symptoms. In the present study, the effects of fluoxetine, tianeptine, and milnacipran on the glycine-induced ion current by nystatin-perforated patch clamp and on the amplitude of field potential in the hippocampal CA1 region by multichannel extracellular recording, MED64, system, were studied. In the present results, fluoxetine, tianeptine, and milnacipran reduced glycine-induced ion current in the hippocampal CA1 neurons in nystatin-perforated patch clamp method. These drugs enhanced the amplitude of the field potential in the hippocampal CA1 region in MED64 system. These results suggest that antidepressants may increase neuronal activity by enhancing field potential through inhibition on glycine-induced ion current. PMID:26730381

  14. Glycine decarboxylase controls photosynthesis and plant growth.

    PubMed

    Timm, Stefan; Florian, Alexandra; Arrivault, Stephanie; Stitt, Mark; Fernie, Alisdair R; Bauwe, Hermann

    2012-10-19

    Photorespiration makes oxygenic photosynthesis possible by scavenging 2-phosphoglycolate. Hence, compromising photorespiration impairs photosynthesis. We examined whether facilitating photorespiratory carbon flow in turn accelerates photosynthesis and found that overexpression of the H-protein of glycine decarboxylase indeed considerably enhanced net-photosynthesis and growth of Arabidopsis thaliana. At the molecular level, lower glycine levels confirmed elevated GDC activity in vivo, and lower levels of the CO(2) acceptor ribulose 1,5-bisphosphate indicated higher drain from CO(2) fixation. Thus, the photorespiratory enzyme glycine decarboxylase appears as an important feed-back signaller that contributes to the control of the Calvin-Benson cycle and hence carbon flow through both photosynthesis and photorespiration.

  15. Antidepressants modulate glycine action in rat hippocampus.

    PubMed

    Chang, Hyun-Kyung; Kim, Khae Hawn; Kang, Ki-Woon; Kang, Yoo-Jin; Kim, Tae-Wook; Park, Hun-Kyung; Kim, Sung-Eun; Kim, Chang-Ju

    2015-12-01

    Antidepressants are drugs that relieve symptoms of depressive disorders. Fluoxetine, tianeptine, and milnacipran are different types of antidepressants, and they have widely been used for relieving of depression symptoms. In the present study, the effects of fluoxetine, tianeptine, and milnacipran on the glycine-induced ion current by nystatin-perforated patch clamp and on the amplitude of field potential in the hippocampal CA1 region by multichannel extracellular recording, MED64, system, were studied. In the present results, fluoxetine, tianeptine, and milnacipran reduced glycine-induced ion current in the hippocampal CA1 neurons in nystatin-perforated patch clamp method. These drugs enhanced the amplitude of the field potential in the hippocampal CA1 region in MED64 system. These results suggest that antidepressants may increase neuronal activity by enhancing field potential through inhibition on glycine-induced ion current. PMID:26730381

  16. Glycine as a regulator of tryptophan-dependent pigment synthesis in Malassezia furfur.

    PubMed

    Barchmann, Thorsten; Hort, Wiebke; Krämer, Hans-Joachim; Mayser, Peter

    2011-01-01

    The effects of the addition of different amino nitrogens on growth, morphology and secondary metabolism of Malassezia furfur were investigated. After primary culture on Dixon agar, M. furfur CBS 1878 was transferred into a fluid medium together with the nitrogen sources, glycine (Gly) or tryptophan (Trp), or a combination of both. Growth was measured by means of a direct cell counting method and pigment synthesis was photometrically assessed. Addition of glycine resulted in an exponential increase in biomass, but not in pigment production. Tryptophan as the sole nitrogen source caused distinct brown staining of the medium, without increasing biomass. Simultaneous equimolar addition of both amino acids resulted in an initial increase in biomass as a sign of preferential metabolism of glycine, followed by a growth plateau and pigment production which, caused by higher biomass, occurred more rapidly than after addition of tryptophan alone. The yeast-cell morphology changed from round to oval. Addition of glycine to the tryptophan-containing liquid culture stopped pigment formation with simultaneous growth induction. These in vitro on-off phenomena depending on the nitrogen source might be significant in the pathogenesis of pityriasis versicolor: hyperhidrosis followed by preferential consumption of individual nitrogen sources such as glycine with exponential growth and thereafter transamination of tryptophan and TRP-dependent pigment synthesis. PMID:19702622

  17. Oligo-Glycine Synthesis in an Aqueous Solution of Glycine Under Oxidative Conditions

    NASA Astrophysics Data System (ADS)

    Yamagata, Yukio; Yamashita, Atsunori; Inomata, Katsuhiko

    1980-03-01

    Di-and tri-glycine were synthesized in 1M aqueous solution of glycine by bubbling for 90 hr with oxygen discharged in the path from an oxygen cylinder. The peptides were also produced by an incubation at 37°C of 2M glycine solution prepared with 75% hydrogen peroxide, and the yields were traced for 200 days. The final yields were about 0.25% and 0.01% for di-and tri-glycine, respectively. The solution at 166 days of incubation was applied to a Sephadex G 10 column, and the fractions around the top of the chromatogram were found to increase the intensity of ninhydrin color about 4˜5 times after hydrolysis, indicating an existence of oligo-glycine. The solutions of 1M glycine and 0.5M diglycine prepared with 30% hydrogen peroxide were incubated at 37°C for 38 days, and di-and tetra-glycine were detected in the yields of 0.12% and 0.33%, respectively.

  18. NMR Structures of the Histidine-Rich Peptide LAH4 in Micellar Environments: Membrane Insertion, pH-Dependent Mode of Antimicrobial Action, and DNA Transfection

    PubMed Central

    Georgescu, Julia; Munhoz, Victor H.O.; Bechinger, Burkhard

    2010-01-01

    The LAH4 family of histidine-rich peptides exhibits potent antimicrobial and DNA transfection activities, both of which require interactions with cellular membranes. The bilayer association of the peptides has been shown to be strongly pH-dependent, with in-planar alignments under acidic conditions and transmembrane orientations when the histidines are discharged. Therefore, we investigated the pH- and temperature-dependent conformations of LAH4 in DPC micellar solutions and in a TFE/PBS solvent mixture. In the presence of detergent and at pH 4.1, LAH4 adopts helical conformations between residues 9 and 24 concomitantly with a high hydrophobic moment. At pH 6.1, a helix-loop-helix structure forms with a hinge encompassing residues His10–Ala13. The data suggest that the high density of histidine residues and the resulting electrostatic repulsion lead to both a decrease in the pK values of the histidines and a less stable α-helical conformation of this region. The hinged structure at pH 6.1 facilitates membrane anchoring and insertion. At pH 7.8, the histidines are uncharged and an extended helical conformation including residues 4–21 is again obtained. LAH4 thus exhibits a high degree of conformational plasticity. The structures provide a stroboscopic view of the conformational changes that occur during membrane insertion, and are discussed in the context of antimicrobial activity and DNA transfection. PMID:20959091

  19. Extraterrestrial material analysis: loss of amino acids during liquid-phase acid hydrolysis

    NASA Astrophysics Data System (ADS)

    Buch, Arnaud; Brault, Amaury; Szopa, Cyril; Freissinet, Caroline

    2015-04-01

    Searching for building blocks of life in extraterrestrial material is a way to learn more about how life could have appeared on Earth. With this aim, liquid-phase acid hydrolysis has been used, since at least 1970 , in order to extract amino acids and other organic molecules from extraterrestrial materials (e.g. meteorites, lunar fines) or Earth analogues (e.g. Atacama desert soil). This procedure involves drastic conditions such as heating samples in 6N HCl for 24 h, either under inert atmosphere/vacuum, or air. Analysis of the hydrolyzed part of the sample should give its total (free plus bound) amino acid content. The present work deals with the influence of the 6N HCl hydrolysis on amino acid degradation. Our experiments have been performed on a standard solution of 17 amino acids. After liquid-phase acid hydrolysis (6N HCl) under argon atmosphere (24 h at 100°C), the liquid phase was evaporated and the dry residue was derivatized with N-Methyl-N-(t-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and dimethylformamide (DMF), followed by gas chromatography-mass spectrometry analysis. After comparison with derivatized amino acids from the standard solution, a significant reduction of the chromatographic peak areas was observed for most of the amino acids after liquid-phase acid hydrolysis. Furthermore, the same loss pattern was observed when the amino acids were exposed to cold 6N HCl for a short amount of time. The least affected amino acid, i.e. glycine, was found to be 73,93% percent less abundant compared to the non-hydrolyzed standard, while the most affected, i.e. histidine, was not found in the chromatograms after hydrolysis. Our experiments thereby indicate that liquid-phase acid hydrolysis, even under inert atmosphere, leads to a partial or total loss of all of the 17 amino acids present in the standard solution, and that a quick cold contact with 6N HCl is sufficient to lead to a loss of amino acids. Therefore, in the literature, the reported increase

  20. Metabolomic analysis reveals decreased skeletal muscle amino acid content and altered fatty acid handling in obese humans

    PubMed Central

    Koves, Timothy R.; Ilkayeva, Olga R.; Muoio, Deborah M.; Houmard, Joseph A.; Friedman, Jacob E.

    2015-01-01

    Objective Investigate the effects of obesity and high fat diet (HFD) exposure on fatty acid oxidation and TCA cycle intermediates and amino acids in skeletal muscle to better characterize energy metabolism. Design and Methods Plasma and skeletal muscle metabolomic profiles were measured from lean and obese males before and after a 5 day HFD in the 4h post-prandial condition. Results At both time points, plasma short-chain acylcarnitine species (SCAC) were higher in the obese subjects, while the amino acids glycine, histidine, methionine, and citrulline were lower in skeletal muscle of obese subjects. Skeletal muscle medium-chain acylcarnitines (MCAC) C6, C8, C10:2, C10:1, C10, and C12:1 increased in obese subjects, but decreased in lean subjects, from Pre- to Post-HFD. Plasma content of C10:1 was also decreased in lean, but increased in the obese subjects from Pre- to Post-HFD. CD36 increased from Pre- to Post-HFD in obese but not lean subjects. Conclusions Lower skeletal muscle amino acid content and accumulation of plasma SCAC in obese subjects could reflect increased anaplerosis for TCA cycle intermediates, while accumulation of MCAC suggests limitations in β-oxidation. These measures may be important markers of or contributors to dysregulated metabolism observed in skeletal muscle of obese humans. PMID:25864501

  1. 21 CFR 862.1375 - Histidine test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Histidine test system. 862.1375 Section 862.1375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  2. Biomimetic synthesis of highly biocompatible gold nanoparticles with amino acid-dithiocarbamate as a precursor for SERS imaging

    NASA Astrophysics Data System (ADS)

    Li, Li; Liu, Jianbo; Yang, Xiaohai; Huang, Jin; He, Dinggeng; Guo, Xi; Wan, Lan; He, Xiaoxiao; Wang, Kemin

    2016-03-01

    Amino acid-dithiocarbamate (amino acid-DTC) was developed as both the reductant and ligand stabilizer for biomimetic synthesis of gold nanoparticles (AuNPs), which served as an excellent surface-enhanced Raman scattering (SERS) contrast nanoprobe for cell imaging. Glycine (Gly), glutamic acid (Glu), and histidine (His) with different isoelectric points were chosen as representative amino acid candidates to synthesize corresponding amino acid-DTC compounds through mixing with carbon disulfide (CS2), respectively. The pyrogenic decomposition of amino acid-DTC initiated the reduction synthesis of AuNPs, and the strong coordinating dithiocarbamate group of amino acid-DTC served as a stabilizer that grafted onto the surface of the AuNPs, which rendered the as-prepared nanoparticles a negative surface charge and high colloidal stability. MTT cell viability assay demonstrated that the biomimetic AuNPs possessed neglectful toxicity to the human hepatoma cell, which guaranteed them good biocompatibility for biomedical application. Meanwhile, the biomimetic AuNPs showed a strong SERS effect with an enhancement factor of 9.8 × 105 for the sensing of Rhodamine 6G, and two distinct Raman peaks located at 1363 and 1509 cm-1 could be clearly observed in the cell-imaging experiments. Therefore, biomimetic AuNPs can be explored as an excellent SERS contrast nanoprobe for biomedical imaging, and the amino acid-DTC mediated synthesis of the AuNPs has a great potential in bio-engineering and biomedical imaging applications.

  3. Changes in urinary amino acids excretion in relationship with muscle activity markers over a professional cycling stage race: in search of fatigue markers.

    PubMed

    Corsetti, Roberto; Barassi, Alessandra; Perego, Silvia; Sansoni, Veronica; Rossi, Alessandra; Damele, Clara Anna Linda; Melzi D'Eril, Gianlodovico; Banfi, Giuseppe; Lombardi, Giovanni

    2016-01-01

    The aim of this study was to identify the relationship between metabolic effort, muscular damage/activity indices, and urinary amino acids profile over the course of a strenuous prolonged endurance activity, as a cycling stage race is, in order to identify possible fatigue markers. Nine professional cyclists belonging to a single team, competing in the Giro d'Italia cycling stage race, were anthropometrically characterized and sampled for blood and urine the day before the race started, and on days 12 and 23 of the race. Diet was kept the same over the race, and power output and energy expenditure were recorded. Sera were assayed for muscle markers (lactate dehydrogenase, aspartate aminotransferase, and creatine kinase activities, and blood urea nitrogen), and creatinine, all corrected for plasma volume changes. Urines were profiled for amino acid concentrations, normalized on creatinine excretion. Renal function, in terms of glomerular filtration rate, was monitored by MDRD equation corrected on body surface area. Creatine kinase activity and blood urea were increased during the race as did serum creatinine while kidney function remained stable. Among the amino acids, taurine, glycine, cysteine, leucine, carnosine, 1-methyl histidine, and 3-methyl histidine showed a net decreased, while homocysteine was increased. Taurine and the dipeptide carnosine (β-alanyl-L-histidine) were significantly correlated with the muscle activity markers and the indices of effort. In conclusion, the metabolic profile is modified strikingly due to the effort. Urinary taurine and carnosine seem useful tools to evaluate the muscle damage and possibly the fatigue status on a long-term basis. PMID:26306846

  4. Changes in urinary amino acids excretion in relationship with muscle activity markers over a professional cycling stage race: in search of fatigue markers.

    PubMed

    Corsetti, Roberto; Barassi, Alessandra; Perego, Silvia; Sansoni, Veronica; Rossi, Alessandra; Damele, Clara Anna Linda; Melzi D'Eril, Gianlodovico; Banfi, Giuseppe; Lombardi, Giovanni

    2016-01-01

    The aim of this study was to identify the relationship between metabolic effort, muscular damage/activity indices, and urinary amino acids profile over the course of a strenuous prolonged endurance activity, as a cycling stage race is, in order to identify possible fatigue markers. Nine professional cyclists belonging to a single team, competing in the Giro d'Italia cycling stage race, were anthropometrically characterized and sampled for blood and urine the day before the race started, and on days 12 and 23 of the race. Diet was kept the same over the race, and power output and energy expenditure were recorded. Sera were assayed for muscle markers (lactate dehydrogenase, aspartate aminotransferase, and creatine kinase activities, and blood urea nitrogen), and creatinine, all corrected for plasma volume changes. Urines were profiled for amino acid concentrations, normalized on creatinine excretion. Renal function, in terms of glomerular filtration rate, was monitored by MDRD equation corrected on body surface area. Creatine kinase activity and blood urea were increased during the race as did serum creatinine while kidney function remained stable. Among the amino acids, taurine, glycine, cysteine, leucine, carnosine, 1-methyl histidine, and 3-methyl histidine showed a net decreased, while homocysteine was increased. Taurine and the dipeptide carnosine (β-alanyl-L-histidine) were significantly correlated with the muscle activity markers and the indices of effort. In conclusion, the metabolic profile is modified strikingly due to the effort. Urinary taurine and carnosine seem useful tools to evaluate the muscle damage and possibly the fatigue status on a long-term basis.

  5. Influence of different histidine sources and zinc supplementation of broiler diets on dipeptide content and antioxidant status of blood and meat.

    PubMed

    Kopeć, W; Jamroz, D; Wiliczkiewicz, A; Biazik, E; Pudlo, A; Hikawczuk, T; Skiba, T; Korzeniowska, M

    2013-01-01

    1. The objective of this study was to investigate how a diet containing spray-dried blood cells (SDBC) (4%) with or without zinc (Zn) would affect the concentration of two histidine heterodipeptides and the antioxidant status of broiler blood and breast muscles. 2. The study was carried out on 920 male Flex chickens randomly assigned to 4 dietary treatments: I - control, II - diet I with SDBC, III - diet I with SDBC and supplemented with Zn and IV - diet I supplemented with L-histidine. Birds were raised on floor littered with wood shavings, given free access to water and fed ad libitum. Performance indices were measured on d 1, 21 and 42. 3. The activity of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase was analysed in plasma, erythrocytes and muscle tissue. The total antioxidant capacity of plasma and breast muscles was measured by 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, as well as by ferric reducing antioxidant power (FRAP). Carnosine/anserine content of meat and plasma were determined using HPLC. Diets and breast muscles were analysed for amino acid profile and selected microelement content. 4. Histidine supplementation of the diet increased glutathione peroxidase activity in plasma and superoxide dismutase activity in erythrocytes. Moreover, the addition of SDBC or pure histidine in the diet increased histidine dipeptide content and activated enzymatic and non-enzymatic antioxidant systems in chicken blood and muscles. However, it led to lower growth performance indices. 5. The enrichment of broiler diets with Zn increased the antioxidant potential and the activity of superoxide dismutase in plasma, which was independent of the histidine dipeptide concentration. Zn supplementation combined with SDBC in a broiler diet led to the increase of superoxide dismutase and glutathione peroxidase activity, but it did not affect the radical

  6. Glycine restores the anabolic response to leucine in a mouse model of acute inflammation.

    PubMed

    Ham, Daniel J; Caldow, Marissa K; Chhen, Victoria; Chee, Annabel; Wang, Xuemin; Proud, Christopher G; Lynch, Gordon S; Koopman, René

    2016-06-01

    Amino acids, especially leucine, potently stimulate protein synthesis and reduce protein breakdown in healthy skeletal muscle and as a result have received considerable attention as potential treatments for muscle wasting. However, the normal anabolic response to amino acids is impaired during muscle-wasting conditions. Although the exact mechanisms of this anabolic resistance are unclear, inflammation and ROS are believed to play a central role. The nonessential amino acid glycine has anti-inflammatory and antioxidant properties and preserves muscle mass in calorie-restricted and tumor-bearing mice. We hypothesized that glycine would restore the normal muscle anabolic response to amino acids under inflammatory conditions. Relative rates of basal and leucine-stimulated protein synthesis were measured using SUnSET methodology 4 h after an injection of 1 mg/kg lipopolysaccharide (LPS). Whereas leucine failed to stimulate muscle protein synthesis in LPS-treated mice pretreated with l-alanine (isonitrogenous control), leucine robustly stimulated protein synthesis (+51%) in mice pretreated with 1 g/kg glycine. The improvement in leucine-stimulated protein synthesis was accompanied by a higher phosphorylation status of mTOR, S6, and 4E-BP1 compared with l-alanine-treated controls. Despite its known anti-inflammatory action in inflammatory cells, glycine did not alter the skeletal muscle inflammatory response to LPS in vivo or in vitro but markedly reduced DHE staining intensity, a marker of oxidative stress, in muscle cross-sections and attenuated LPS-induced wasting in C2C12 myotubes. Our observations in male C57BL/6 mice suggest that glycine may represent a promising nutritional intervention for the attenuation of skeletal muscle wasting.

  7. GcsR, a TyrR-Like Enhancer-Binding Protein, Regulates Expression of the Glycine Cleavage System in Pseudomonas aeruginosa PAO1

    PubMed Central

    Sarwar, Zaara; Lundgren, Benjamin R.; Grassa, Michael T.; Wang, Michael X.; Gribble, Megan; Moffat, Jennifer F.

    2016-01-01

    ABSTRACT Glycine serves as a major source of single carbon units for biochemical reactions within bacterial cells. Utilization of glycine is tightly regulated and revolves around a key group of proteins known as the glycine cleavage system (GCS). Our lab previously identified the transcriptional regulator GcsR (PA2449) as being required for catabolism of glycine in the opportunistic pathogen Pseudomonas aeruginosa PAO1. In an effort to clarify and have an overall better understanding of the role of GcsR in glycine metabolism, a combination of transcriptome sequencing and electrophoretic mobility shift assays was used to identify target genes of this transcriptional regulator. It was found that GcsR binds to an 18-bp consensus sequence (TGTAACG-N4-CGTTCCG) upstream of the gcs2 operon, consisting of the gcvH2, gcvP2, glyA2, sdaA, and gcvT2 genes. The proteins encoded by these genes, namely, the GCS (GcvH2-GcvP2-GcvT2), serine hydroxymethyltransferase (GlyA2), and serine dehydratase (SdaA), form a metabolic pathway for the conversion of glycine into pyruvate, which can enter the central metabolism. GcsR activates transcription of the gcs2 operon in response to glycine. Interestingly, GcsR belongs to a family of transcriptional regulators known as TyrR-like enhancer-binding proteins (EBPs). Until this study, TyrR-like EBPs were only known to function in regulating aromatic amino acid metabolism. GcsR is the founding member of a new class of TyrR-like EBPs that function in the regulation of glycine metabolism. Indeed, homologs of GcsR and its target genes are present in almost all sequenced genomes of the Pseudomonadales order, suggesting that this genetic regulatory mechanism is a common theme for pseudomonads. IMPORTANCE Glycine is required for various cellular functions, including cell wall synthesis, protein synthesis, and the biosynthesis of several important metabolites. Regulating levels of glycine metabolism allows P. aeruginosa to maintain the metabolic flux

  8. A rare case of glycine encephalopathy unveiled by valproate therapy.

    PubMed

    Subramanian, Velusamy; Kadiyala, Pramila; Hariharan, Praveen; Neeraj, E

    2015-01-01

    Glycine encephalopathy (GE) or nonketotic hyperglycinemia is an autosomal recessive disorder due to a primary defect in glycine cleavage enzyme system. It is characterized by elevated levels of glycine in plasma and cerebrospinal fluid usually presenting with seizures, hypotonia, and developmental delay. In our case, paradoxical increase in seizure frequency on starting sodium valproate led us to diagnose GE. PMID:26167219

  9. Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin

    NASA Astrophysics Data System (ADS)

    Kliber, Marta; Broda, Małgorzata A.; Nackiewicz, Joanna

    2016-02-01

    Effect of selected amino acids (glycine, L-histidine, L-cysteine, L-serine, L-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366 nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC: amino acids complexes in the gas phase and in water environment as well as the BSSE corrected interaction energies indicates that the more likely is the formation of equatorial complexes in which H-bonds are formed between the COOH groups of the phthalocyanine and carboxyl or amino groups of amino acids. UV-Vis spectra calculated by employing time dependent density functional theory (TD-DFT) are also consistent with this conclusion.

  10. Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin.

    PubMed

    Kliber, Marta; Broda, Małgorzata A; Nackiewicz, Joanna

    2016-02-15

    Effect of selected amino acids (glycine, l-histidine, l-cysteine, l-serine, l-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC: amino acids complexes in the gas phase and in water environment as well as the BSSE corrected interaction energies indicates that the more likely is the formation of equatorial complexes in which H-bonds are formed between the COOH groups of the phthalocyanine and carboxyl or amino groups of amino acids. UV-Vis spectra calculated by employing time dependent density functional theory (TD-DFT) are also consistent with this conclusion.

  11. DNA damage induced by phorbol ester-stimulated neutrophils is augmented by extracellular cofactors. Role of histidine and metals.

    PubMed

    Shacter, E; Lopez, R L; Beecham, E J; Janz, S

    1990-04-25

    Activated neutrophils cause extensive DNA damage in neighboring nonphagocytic cells. To determine whether compounds in the extracellular milieu participate in the DNA damage process, murine neutrophils were cocultivated with target tumor cells in media of varying composition. Using the alkaline elution assay, it was found that the level of strand breaks induced was significantly higher (2.8-fold) in complex cell culture media than in minimal phosphate-buffered saline. Addition of amino acids in general and of histidine in particular increased the level of damage nearly to that observed in complete media (2.7- and 2.1-fold, respectively). The histidine stimulation was concentration-dependent and reached a maximum at 100-400 microM. The mechanism whereby this occurred is not proven but probably derived from chelation of metals and participation in a site-specific Fenton reaction. Addition of the cell-impermeable chelator EDTA dramatically inhibited induction of strand breaks by neutrophils in complete media and prevented the enhancement of damage induced by histidine in phosphate-buffered saline. None of the effects on neutrophil-induced damage could be attributed to modulation of the oxidative burst activity of the cells (O2- and H2O2 production). Histidine also enhanced induction of strand breaks by reagent H2O2. However, EDTA had no effect or actually increased the level of damage induced by both a bolus of H2O2 and a flux of H2O2 generated by glucose oxidase. The cell-permeable chelator o-phenanthroline inhibited both neutrophil- and H2O2-induced damage. The results indicate that secondary reactions involving extracellular amino acids and metals contribute significantly to neutrophil-induced DNA damage to neighboring cells. Moreover, the data show that the mechanism whereby neutrophils induce this damage cannot be attributed solely to secretion of H2O2.

  12. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN...

  13. Engineering and characterization of fluorogenic glycine riboswitches

    PubMed Central

    Ketterer, Simon; Gladis, Lukas; Kozica, Adnan; Meier, Matthias

    2016-01-01

    A set of 12 fluorogenic glycine riboswitches with different thermodynamic and kinetic response properties was engineered. For the design of functional riboswitches, a three-part RNA approach was applied based on the idea of linking a RNA sensor, transmitter and actuator part together. For the RNA sensor and actuator part, we used the tandem glycine aptamer structure from Bacillus subtillis, and fluorogenic aptamer Spinach, respectively. To achieve optimal signal transduction from the sensor to the actuator, a riboswitch library with variable transmitter was screened with a microfluidic large-scale integration chip. This allowed us to establish the complete thermodynamic binding profiles of the riboswitch library. Glycine dissociation constants of the 12 strong fluorescence response riboswitches varied between 99.7 and 570 μM. Furthermore, the kinetic glycine binding (kon), and dissociation (koff) rates, and corresponding energy barriers of the 10 strongest fluorescence response riboswitches were determined with the same chip platform. kon and koff were in the order of 10−3s−1 and 10−2s−1, respectively. Conclusively, we demonstrate that systematic screening of synthetic and natural linked RNA parts with microfluidic chip technology is an effective approach to rapidly generate fluorogenic metabolite riboswitches with a broad range of biophysical response properties. PMID:27220466

  14. Identification of Rotylenchulus reniformis resistant Glycine lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identification of resistance to reniform nematode (Rotylenchulus reniformis) is the first step in developing resistant soybean (Glycine max) cultivars that will benefit growers in the Mid South. This study was conducted to identify soybean (G. max and G. soja) lines with resistance to this pathogen....

  15. Rapid crystallization of glycine using metal-assisted and microwave-accelerated evaporative crystallization: the effect of engineered surfaces and sample volume.

    PubMed

    Grell, Tsehai A J; Pinard, Melissa A; Pettis, Danielle; Aslan, Kadir

    2012-01-01

    Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC), is a new approach to crystallization of drug compounds, amino acids, DNA and proteins. In this work, we report our additional findings on the effect of engineered surfaces and sample volume on the rapid crystallization of glycine. With the use of hydrophilic functionalized surfaces and the MA-MAEC technique, glycine crystals ~1 mm in size were grown in 35 seconds with 100% selectivity for the α-form.The use of moderately hydrophobic surfaces resulted in the growth of glycine crystals only at room temperature. An increase in volume of initial glycine solution (5-100 μL) resulted in an increase in crystal size without a significant increase in total crystallization time. Raman spectroscopy and powder X-ray diffraction results demonstrated that the glycine crystals grown on engineered surfaces were structurally identical to those grown using conventional evaporative crystallization.

  16. Molecular insight in the purification of immunoglobulin by pseudobiospecific ligand l-histidine and histidyl moieties in histidine ligand affinity chromatography (HLAC) by molecular docking.

    PubMed

    Savane, Tushar S; Kumar, Sanjit; Janakiraman, Vignesh Narasimhan; Kamalanathan, Agamudi S; Vijayalakshmi, Mookambeswaran A

    2016-05-15

    Pseudobiospecific ligand l-histidine is an inexpensive, highly stable, non-toxic ligand explored successfully over the last twenty years for the purification of immunoglobulins in immobilised histidine ligand affinity chromatography. It is of great interest to know the molecular recognition sites of IgG to immobilized l-histidine. Here, we have used an in silico approach to explore the molecular recognition of l-histidine by IgG. We have assessed the feasible binding modes of histidine and its moieties at different sites of IgG and considered only those binding conformations which are exhibited via the imidazole ring NH group or any other OH donating group apart from the ones which are terminally conjugated with the support matrix. We categorised binding site into two categories; category I: inner binding groove and category II: surface binding groove and observed that the hinge region of IgG has most favourable binding pocket for l-histidine and histidyl moieties. Ser and Tyr residues on the hinge region make several significant interactions with l-histidine and histidyl moieties. In case of Fc region of IgG, l-histidine and histidyl moieties closely resemble the binding modes of Protein A, biomimetic ligand 22/8 and B domain of SpA to IgG. In addition to these we have also observed a significant binding site for l-histidine and histidyl moieties at Fab region of IgG. PMID:26476866

  17. Crystal Structure of a Histidine Kinase Sensor Domain with Similarity to Periplasmic Binding Proteins

    SciTech Connect

    Cheung, J.; Le-Khac, M; Hendrickson, W

    2009-01-01

    Histidine kinase receptors are elements of the two-component signal transduction systems commonly found in bacteria and lower eukaryotes, where they are crucial for environmental adaption through the coupling of extracellular changes to intracellular responses. The typical two-component system consists of a membrane-spanning histidine kinase sensor and a cytoplasmic response regulator. In the calssic system, extracellular signals such as small molecule ligands and ions are detected by the periplasmic sensor domain of the histidine kinase receptor, which modulates the catalytic activity of the cytoplasmic histidine kinase domain and promotes ATP-dependent autophosphorylation of a conserved histidine residue. G. sulfurreducens genomic DNA was used.

  18. A Novel Glycinate-based Body Wash

    PubMed Central

    Regan, Jamie; Ananthapadmanabhan, K.P.

    2013-01-01

    Objective: To assess the properties of a novel body wash containing the mild surfactant glycinate. Design: Biochemical and clinical assays. Setting: Research laboratories and clinical sites in the United States and Canada. Participants: Women 18 to 65 years of age (cleansing efficacy); male and female subjects 26 to 63 years of age with mild or moderate dryness and erythema (leg-controlled application test); subjects 5 to 65 years of age with mild-to-moderate eczema (eczema compatibility); and women 18 to 64 years of age (home use). Measurements: Assessments across studies included colorimetric dye exclusion to assess skin damage potential (corneosurfametry), efficacy of cosmetic product removal from skin, change from baseline in visual dryness, change from baseline in Eczema Area and Severity Index, and self-perceived eczema attributes and self-reported product preference. Results: The glycinate-based cleanser demonstrated mildness to skin components when evaluated in a corneosurfametry assay. Short-term use under exaggerated wash conditions in subjects with dryness scores <3 and erythema scores <2 (both on a 0-6 scale) indicated an initial reduction in visual dryness. In subjects with eczema, normal use resulted in significant improvements (p<0.05) at Week 4 compared with baseline in skin dryness (change from baseline = −0.73), rash (−0.56), itch (−0.927), tightness (−0.585), and all eczema (−0.756). The glycinate-based body wash removed 56 percent of a long-lasting cosmetic foundation from skin compared with less than 30 percent removed by two competitive products tested. The glycinate-based body wash was preferred over a competitive mild cleansing product overall. Conclusion: The patented glycinate-containing body wash demonstrated better product mildness and patient-preferred attributes and clinical benefits. PMID:23882306

  19. Amino acid metabolism during total parenteral nutrition in healthy volunteers: evaluation of a new amino acid solution.

    PubMed

    Berard, M P; Hankard, R; Cynober, L

    2001-10-01

    The aim of this study was to determine the metabolism and the tolerance of a new amino acid (AA) solution administered under conditions mimicking cyclical parenteral nutrition (PN) in humans. Eight healthy volunteers received peripheral PN for 10 h providing 10.5 mg N x kg(-1) x h(-1) and 2.0 kcal x kg(-1) x h(-1) (glucose-to-lipids ratio: 70/30%). For adaptation, a non-protein energy intake was increased progressively for 90 min; thereafter, AA infusion was started and maintained at a constant rate for 10 h. Plasma and urine concentrations of all the AAs were measured before, during and after the PN. For each given AA, the relation between plasma variations at the steady-state and infusion rate, plasma clearance (Cl), renal clearance (Clr), re-absorption rate (Reab) and, retention rate (Reten) were determined. The nitrogen balance (DeltaN) was calculated during the PN period. The results are presented as means+/-sem. All plasma AA concentrations decreased during the starting period of non-protein energy intake. The plasma AA concentrations reached a steady-state within 3 h upon AA infusion, except for glycine and lysine (6 h). At the steady state, the plasma concentrations of the infused AAs were closely correlated to their infusion rate (y= -18.3+1.5x, r(2)=0.92). The plasma glutamine concentration was maintained during the PN, which indicates that the solution might stimulate the de novo synthesis of this AA. When the PN was stopped, plasma levels of the AAs decreased, most of them returning to their basal levels, or significantly below for lysine (P<0.05), alanine (P<0.05), proline (P<0.01) and glutamine (P<0.05). No volunteer showed any adverse effect during the infusion period. DeltaN was: 0.8+/-0.5 gN/10 h. Metabolic characteristics for essential AAs were: Cl<0.5 l min(-1), Clr <1.5 ml x min(-1) Reab >or= 99%, Reten >or=99% and for non-essential AAs: Cl <0.6 l x min(-1) except aspartate (2.8+/-0.3 l x min(-1)), Clr < 3 ml x min(-1) except glycine (6

  20. Comparative mapping of the wild perennial Glycine latifolia and soybean (G. max) reveals extensive chromosome rearrangements in the genus Glycine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max L. Mer.), like many cultivated crops, has a relatively narrow genetic base and lacks diversity for some economically important traits. Glycine latifolia (Benth.) Newell & Hymowitz, a perennial wild relative of soybean in the subgenus Glycine Willd., shows high levels of resistan...

  1. Preparation of silica coated cobalt ferrite magnetic nanoparticles for the purification of histidine-tagged proteins

    NASA Astrophysics Data System (ADS)

    Aygar, Gülfem; Kaya, Murat; Özkan, Necati; Kocabıyık, Semra; Volkan, Mürvet

    2015-12-01

    Surface modified cobalt ferrite (CoFe2O4) nanoparticles containing Ni-NTA affinity group were synthesized and used for the separation of histidine tag proteins from the complex matrices through the use of imidazole side chains of histidine molecules. Firstly, CoFe2O4 nanoparticles with a narrow size distribution were prepared in an aqueous solution using the controlled co-precipitation method. In order to obtain small CoFe2O4 agglomerates, oleic acid and sodium chloride were used as dispersants. The CoFe2O4 particles were coated with silica and subsequently the surface of these silica coated particles (SiO2-CoFe2O4) was modified by amine (NH2) groups in order to add further functional groups on the silica shell. Then, carboxyl (-COOH) functional groups were added to the SiO2-CoFe2O4 magnetic nanoparticles through the NH2 groups. After that Nα,Nα-Bis(carboxymethyl)-L-lysine hydrate (NTA) was attached to carboxyl ends of the structure. Finally, the surface modified nanoparticles were labeled with nickel (Ni) (II) ions. Furthermore, the modified SiO2-CoFe2O4 magnetic nanoparticles were utilized as a new system that allows purification of the N-terminal His-tagged recombinant small heat shock protein, Tpv-sHSP 14.3.

  2. Formation and Operation of the Histidine-degrading Pathway in Pseudomonas aeruginosa

    PubMed Central

    Lessie, Thomas G.; Neidhardt, Frederick C.

    1967-01-01

    Histidine ammonia lyase (histidase), urocanase, and the capacity to degrade formiminoglutamate, which are respectively involved in steps I, II, and IV in the catabolism of histidine, were induced during growth of Pseudomonas aeruginosa on histidine or urocanate, and were formed gratuitously in the presence of dihydro-urocanate. Urocanase-deficient bacteria formed enzymes I and IV constitutively; presumably they accumulate enough urocanate from the breakdown of endogenous histidine to induce formation of the pathway. Urocanate did not satisfy the histidine requirement of a histidine auxotroph, indicating that it probably acted as an inducer without being converted to histidine. The results imply that urocanate is the physiological inducer of the histidine-degrading enzymes in P. aeruginosa. Enzymes of the pathway were extremely sensitive to catabolite repression; enzymes I and II, but not IV, were coordinately repressed. Our results suggest a specific involvement of nitrogenous metabolites in the repression. Mutant bacteria with altered sensitivity to repression were obtained. The molecular weight of partially purified histidase was estimated at 210,000 by sucrose gradient centrifugation. Its Km for histidine was 2 × 10−3 m in tris(hydroxymethyl)aminomethane chloride buffer. Sigmoid saturation curves were obtained in pyrophosphate buffer, indicating that the enzyme might have multiple binding sites for histidine. Under certain conditions, histidase appeared to be partially inactive in vivo. These findings suggest that some sort of allosteric interaction involving histidase may play a role in governing the operation of the pathway of histidine catabolism. PMID:4290562

  3. A novel phytase with sequence similarity to purple acid phosphatases is expressed in cotyledons of germinating soybean seedlings.

    PubMed

    Hegeman, C E; Grabau, E A

    2001-08-01

    Phytic acid (myo-inositol hexakisphosphate) is the major storage form of phosphorus in plant seeds. During germination, stored reserves are used as a source of nutrients by the plant seedling. Phytic acid is degraded by the activity of phytases to yield inositol and free phosphate. Due to the lack of phytases in the non-ruminant digestive tract, monogastric animals cannot utilize dietary phytic acid and it is excreted into manure. High phytic acid content in manure results in elevated phosphorus levels in soil and water and accompanying environmental concerns. The use of phytases to degrade seed phytic acid has potential for reducing the negative environmental impact of livestock production. A phytase was purified to electrophoretic homogeneity from cotyledons of germinated soybeans (Glycine max L. Merr.). Peptide sequence data generated from the purified enzyme facilitated the cloning of the phytase sequence (GmPhy) employing a polymerase chain reaction strategy. The introduction of GmPhy into soybean tissue culture resulted in increased phytase activity in transformed cells, which confirmed the identity of the phytase gene. It is surprising that the soybean phytase was unrelated to previously characterized microbial or maize (Zea mays) phytases, which were classified as histidine acid phosphatases. The soybean phytase sequence exhibited a high degree of similarity to purple acid phosphatases, a class of metallophosphoesterases.

  4. Removal of brownish-black tarnish on silver-copper alloy objects with sodium glycinate

    NASA Astrophysics Data System (ADS)

    de Figueiredo, João Cura D.'Ars; Asevedo, Samara Santos; Barbosa, João Henrique Ribeiro

    2014-10-01

    This article has the principal aim of presenting a new method of chemical cleaning of tarnished silver-copper alloy objects. The chemical cleaning must be harmless to the health, selective to tarnish removal, and easy to use. Sodium glycinate was selected for the study. The reactions of sodium glycinate with tarnish and the silver-copper alloy were evaluated. Products of the reaction, the lixiviated material, and the esthetics of silver-copper alloy coins (used as prototypes) were studied to evaluate if the proposed method can be applied to the cleaning of silver objects. Silver-copper alloys can be deteriorated through a uniform and superficial corrosion process that produces brownish-black tarnish. This tarnish alters the esthetic of the object. The cleaning of artistic and archeological objects requires more caution than regular cleaning, and it must take into account the procedures for the conservation and restoration of cultural heritage. There are different methods for cleaning silver-copper alloy objects, chemical cleaning is one of them. We studied two chemical cleaning methods that use sodium glycinate and sodium acetylglycinate solutions. Silver-copper alloy coins were artificially corroded in a basic thiourea solution and immersed in solutions of sodium glycinate and sodium acetylglycinate. After immersion, optical microscopy and scanning electron microscopy of the surfaces were studied. The sodium glycinate solution was shown to be very efficient in removing the brownish-black tarnish. Absorption spectroscopy measured the percentage of silver and copper lixiviated in immersion baths, and very small quantities of these metals were detected. Infrared absorption spectroscopy and X-ray fluorescence characterized the obtained products. The greater efficiency of the sodium glycinate solution compared to the sodium acetylglycinate solution was explained by chelation and Hard-Soft Acid-Base Theory with the aid of quantum chemical calculations.

  5. Differential distribution of glycine transporters in Müller cells and neurons in amphibian retinas.

    PubMed

    Jiang, Zheng; Li, Baoqin; Jursky, Frantisek; Shen, Wen

    2007-01-01

    Amphibian retinas are commonly used for electrophysiological studies on neural function and transduction because they share the same general properties as higher vertebrate retinas. Glycinergic synapses have been well described in amphibian retinas. However, the role of glycine transporters in the synapses is largely unknown. We studied the distribution and function of glycine transporters in the retinas from tiger salamanders, mudpuppies, and leopard frogs by immunofluorescence labeling and whole-cell recording methods. Our results indicated that GlyT1- and GlyT2-like transporters were present in Müller cells and neurons, respectively. GlyT1 labeling was present in Müller glial cells and co-localized with Glial fibrillary acidic protein (GFAP), a Müller cell marker, whereas the GlyT2 immunoreactivity was present in the somas of amacrine cells (ACs) and processes in the inner plexiform layer (IPL) and the outer plexiform layer (OPL). Because the axon processes of glycinergic interplexiform cells (IPCs) are the only source of glycine input in the OPL, GlyT2 staining revealed a spatial pattern of the axon processes of IPCs in the OPL. The function of GlyT2 in the IPCs was studied in tiger salamander retinal horizontal cells (HCs) by whole-cell gramicidin perforated recording. The results demonstrated that inhibition of GlyT2 by a specific inhibitor, amoxapine, increased a tonic glycine input to HCs. Thus, the GlyT2 transporter is responsible for uptake of synaptic glycine in the outer retina. We also compared the distribution of glycine transporters in other amphibian species: salamander, mudpuppy, and frog. The results are consistent with the general pattern that GlyT1-like transporters are present in Müller cells and GlyT2-like transporters in neurons in amphibian retinas. PMID:17640406

  6. Thermal formation of methylammonium methylcarbamate in interstellar ice analogs: a glycine salt precursor under VUV irradiation

    NASA Astrophysics Data System (ADS)

    Duvernay, Fabrice; Borget, Fabien; Bossa, Jean-Baptiste; Theule, Patrice; Dhendecourt, Louis; Chiavassa, Thierry

    Dust grains in the interstellar medium (ISM) play an important role in dense molecular clouds chemistry of providing a surface (catalyst) upon which atoms and molecules can freeze out, forming icy mantles. Dense molecular clouds are characterized by low temperature (10 -50 K) and represent the birth sites of stars. After a gravitationnal breakdown, a part of the dense molecular cloud collapses toward the formation of star and subsequently a protoplanetary disk from which planets, asteroids and comets will appear. During this evolution, interstellar or-ganic material inside ices undergoes different range of chemical alterations (thermal cycling process, ultraviolet photons, electron scattering and cosmic rays irradiation) hence increasing the molecular complexity before their incorporation inside precometary ices. To date, it is supposed that comets could have delivered to the early Earth the organic materials essential to a prebiotic chemistry, one of the prerequisites toward the origin of living systems. The for-mation of prebiotical molecules such as the simplest amino acids (glycine) is proposed in this current study mainly based on laboratory experiments simulating the chemistry occuring on ices within protostellar environments. Infrared spectroscopy and mass spectroscopy are used to monitor the thermal formation of glycine isomer form: the methylammonium methylcarbamate [CH3NH3+][CH3NHCOO-] in interstellar ice analogs made up of two astrophysical relevant molecules: carbon dioxide (CO2) and methylamine (CH3NH2). Using infrared spectroscopy, we study the photochemical behaviour of a pure sample of methylammonium methylcarbamate under vacuum ultraviolet (VUV) field. We show that a glycine isomer salt could readily enter into the composition of ices in colder region of protostellar environments. Upon ultraviolet irra-diation, this latter can undergo an isomerization process induced by photons yielding a glycine salt: the methylammonium glycinate [CH3NH3+][NH2CH2

  7. Characterization of storage proteins in wild (Glycine soja) and cultivated (Glycine max) soybean seeds using proteomic analysis.

    PubMed

    Natarajan, Savithiry S; Xu, Chenping; Bae, Hanhong; Caperna, Thomas J; Garrett, Wesley M

    2006-04-19

    A combined proteomic approach was applied for the separation, identification, and comparison of two major storage proteins, beta-conglycinin and glycinin, in wild (Glycine soja) and cultivated (Glycine max) soybean seeds. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) with three different immobilized pH gradient (IPG) strips was an effective method to separate a large number of abundant and less-abundant storage proteins. Most of the subunits of beta-conglycinin were well-separated in the pH range 3.0-10.0, while acidic and basic glycinin polypeptides were well-separated in pH ranges 4.0-7.0 and 6.0-11.0, respectively. Although the overall distribution pattern of the protein spots was similar in both genotypes using pH 3.0-10.0, variations in number and intensity of protein spots were better resolved using a combination of pH 4.0-7.0 and pH 6.0-11.0. The total number of storage protein spots detected in wild and cultivated genotypes was approximately 44 and 34, respectively. This is the first study reporting the comparison of protein profiles of wild and cultivated genotypes of soybean seeds using proteomic tools.

  8. Activation of glycine receptor phase-shifts the circadian rhythm in neuronal activity in the mouse suprachiasmatic nucleus

    PubMed Central

    Mordel, Jérôme; Karnas, Diana; Inyushkin, Alexey; Challet, Etienne; Pévet, Paul; Meissl, Hilmar

    2011-01-01

    Abstract In mammals, the master clock in the suprachiasmatic nucleus (SCN) of the hypothalamus is composed of numerous synchronized oscillating cells that drive daily behavioural and physiological processes. Several entrainment pathways, afferent inputs to the SCN with their neurotransmitter and neuromodulator systems, can reset the circadian system regularly and also modulate neuronal activity within the SCN. In the present study, we investigated the function of the inhibitory neurotransmitter glycine on neuronal activity in the mouse SCN and on resetting of the circadian clock. The effects of glycine on the electrical activity of SCN cells from C57Bl/6 mice were studied either by patch-clamp recordings from acute brain slices or by long-term recordings from organotypic brain slices using multi-microelectrode arrays (MEA). Voltage-clamp recordings confirmed the existence of glycine-induced, chloride-selective currents in SCN neurons. These currents were reversibly suppressed by strychnine, phenylbenzene ω-phosphono-α-amino acid (PMBA) or ginkgolide B, selective blockers of glycine receptors (GlyRs). Long-term recordings of the spontaneous activity of SCN neurons revealed that glycine application induces a phase advance during the subjective day and a phase delay during the early subjective night. Both effects were suppressed by strychnine or by PMBA. These results suggest that glycine is able to modulate circadian activity by acting directly on its specific receptors in SCN neurons. PMID:21486797

  9. Glycine receptors influence radial migration in the embryonic mouse neocortex.

    PubMed

    Nimmervoll, Birgit; Denter, Denise G; Sava, Irina; Kilb, Werner; Luhmann, Heiko J

    2011-07-13

    To investigate whether glycine receptors influence radial migration in the neocortex, we analyzed the effect of glycine and the glycinergic antagonist strychnine, on the distribution of 5-bromo-2'deoxyuridine-labeled neurons in organotypic slice cultures from embryonic mice cortices. Application of glycine impeded radial migration only in the presence of the glycine-transport blockers, ALX-5407 and ALX-1393. This effect was blocked by the specific glycine receptor antagonist strychnine, whereas application of strychnine in the absence of glycine was without effect. We conclude from these observations that an activation of glycine receptors can impede radial migration, but that the glycinergic system is not directly implicated in the regulation of radial migration in organotypic slice cultures.

  10. Unique amino acid signatures that are evolutionarily conserved distinguish simple-type, epidermal and hair keratins

    PubMed Central

    Strnad, Pavel; Usachov, Valentyn; Debes, Cedric; Gräter, Frauke; Parry, David A. D.; Omary, M. Bishr

    2011-01-01

    Keratins (Ks) consist of central α-helical rod domains that are flanked by non-α-helical head and tail domains. The cellular abundance of keratins, coupled with their selective cell expression patterns, suggests that they diversified to fulfill tissue-specific functions although the primary structure differences between them have not been comprehensively compared. We analyzed keratin sequences from many species: K1, K2, K5, K9, K10, K14 were studied as representatives of epidermal keratins, and compared with K7, K8, K18, K19, K20 and K31, K35, K81, K85, K86, which represent simple-type (single-layered or glandular) epithelial and hair keratins, respectively. We show that keratin domains have striking differences in their amino acids. There are many cysteines in hair keratins but only a small number in epidermal keratins and rare or none in simple-type keratins. The heads and/or tails of epidermal keratins are glycine and phenylalanine rich but alanine poor, whereas parallel domains of hair keratins are abundant in prolines, and those of simple-type epithelial keratins are enriched in acidic and/or basic residues. The observed differences between simple-type, epidermal and hair keratins are highly conserved throughout evolution. Cysteines and histidines, which are infrequent keratin amino acids, are involved in de novo mutations that are markedly overrepresented in keratins. Hence, keratins have evolutionarily conserved and domain-selectively enriched amino acids including glycine and phenylalanine (epidermal), cysteine and proline (hair), and basic and acidic (simple-type epithelial), which reflect unique functions related to structural flexibility, rigidity and solubility, respectively. Our findings also support the importance of human keratin ‘mutation hotspot’ residues and their wild-type counterparts. PMID:22215855

  11. Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine

    NASA Astrophysics Data System (ADS)

    Huang, Rui; Furukawa, Yoshihiro; Otake, Tsubasa; Kakegawa, Takeshi

    2016-09-01

    The abiotic oligomerization of amino acids may have created primordial, protein-like biological catalysts on the early Earth. Previous studies have proposed and evaluated the potential of diagenesis for the amino acid oligomerization, simulating the formation of peptides that include glycine, alanine, and valine, separately. However, whether such conditions can promote the formation of peptides composed of multiple amino acids remains unclear. Furthermore, the chemistry of pore water in sediments should affect the oligomerization and degradation of amino acids and oligomers, but these effects have not been studied extensively. In this study, we investigated the effects of water, ammonia, ammonium bicarbonate, pH, and glycine on the oligomerization and degradation of methionine under high pressure (150 MPa) and high temperature conditions (175 °C) for 96 h. Methionine is more difficult to oligomerize than glycine and methionine dimer was formed in the incubation of dry powder of methionine. Methionine oligomers as long as trimers, as well as methionylglycine and glycylmethionine, were formed under every condition with these additional compounds. Among the compounds tested, the oligomerization reaction rate was accelerated by the presence of water and by an increase in pH. Ammonia also increased the oligomerization rate but consumed methionine by side reactions and resulted in the rapid degradation of methionine and its peptides. Similarly, glycine accelerated the oligomerization rate of methionine and the degradation of methionine, producing water, ammonia, and bicarbonate through its decomposition. With Gly, heterogeneous dimers (methionylglycine and glycylmethionine) were formed in greater amounts than with other additional compounds although smaller amount of these heterogeneous dimers were formed with other additional compounds. These results suggest that accelerated reaction rates induced by water and co-existing reactive compounds promote the oligomerization

  12. Glycine supplementation in vitro enhances porcine preimplantation embryo cell number and decreases apoptosis but does not lead to live births

    PubMed Central

    Redel, Bethany K.; Spate, Lee D.; Lee, Kiho; Mao, Jiude; Whitworth, Kristin M.

    2016-01-01

    SUMMARY Most in vitro culture conditions are less‐than‐optimal for embryo development. Here, we used a transcriptional‐profiling database to identify culture‐induced differences in gene expression in porcine blastocysts compared to in vivo‐produced counterparts. Genes involved in glycine transport (SLC6A9), glycine metabolism (GLDC, GCSH, DLD, and AMT), and serine metabolism (PSAT1, PSPH, and PHGDH) were differentially expressed. Addition of 10 mM glycine to the culture medium (currently containing 0.1 mM) reduced the abundance of SLC6A9 transcript and increased total cell number, primarily in the trophectoderm lineage (P = 0.003); this was likely by decreasing the percentage of apoptotic nuclei. As serine and glycine can be reversibly metabolized by serine hydroxymethyltransferase 2 (SHMT2), we assessed the abundance of SHMT2 transcript as well as its functional role by inhibiting it with aminomethylphosphonic acid (AMPA), a glycine analog, during in vitro culture. Both AMPA supplementation and elevated glycine decreased the mRNA abundance of SHMT2 and tumor protein p53 (TP53), which is activated in response to cellular stress, compared to controls (P ≤ 0.02). On the other hand, mitochondrial activity of blastocysts, mtDNA copy number, and abundance of mitochondria‐related transcripts did not differ between control and 10 mM glycine culture conditions. Despite improvements to these metrics of blastocyst quality, transfer of embryos cultured in 10 mM glycine did not result in pregnancy whereas the transfer of in vitro‐produced embryos cultured in control medium yielded live births. Mol. Reprod. Dev. 83: 246–258, 2016. © 2016 The Authors. PMID:26824641

  13. Glycine supplementation in vitro enhances porcine preimplantation embryo cell number and decreases apoptosis but does not lead to live births.

    PubMed

    Redel, Bethany K; Spate, Lee D; Lee, Kiho; Mao, Jiude; Whitworth, Kristin M; Prather, Randall S

    2016-03-01

    Most in vitro culture conditions are less-than-optimal for embryo development. Here, we used a transcriptional-profiling database to identify culture-induced differences in gene expression in porcine blastocysts compared to in vivo-produced counterparts. Genes involved in glycine transport (SLC6A9), glycine metabolism (GLDC, GCSH, DLD, and AMT), and serine metabolism (PSAT1, PSPH, and PHGDH) were differentially expressed. Addition of 10 mM glycine to the culture medium (currently containing 0.1 mM) reduced the abundance of SLC6A9 transcript and increased total cell number, primarily in the trophectoderm lineage (P = 0.003); this was likely by decreasing the percentage of apoptotic nuclei. As serine and glycine can be reversibly metabolized by serine hydroxymethyltransferase 2 (SHMT2), we assessed the abundance of SHMT2 transcript as well as its functional role by inhibiting it with aminomethylphosphonic acid (AMPA), a glycine analog, during in vitro culture. Both AMPA supplementation and elevated glycine decreased the mRNA abundance of SHMT2 and tumor protein p53 (TP53), which is activated in response to cellular stress, compared to controls (P ≤ 0.02). On the other hand, mitochondrial activity of blastocysts, mtDNA copy number, and abundance of mitochondria-related transcripts did not differ between control and 10 mM glycine culture conditions. Despite improvements to these metrics of blastocyst quality, transfer of embryos cultured in 10 mM glycine did not result in pregnancy whereas the transfer of in vitro-produced embryos cultured in control medium yielded live births. Mol. Reprod. Dev. 83: 246-258, 2016. © 2016 The Authors. PMID:26824641

  14. Signal Transduction in Histidine Kinases: Insights from New Structures

    PubMed Central

    Bhate, Manasi P.; Molnar, Kathleen S.; Goulian, Mark; DeGrado, William F.

    2015-01-01

    Histidine kinases (HKs) are major players in bacterial signaling. There has been an explosion of new HK crystal structures in the last five years. We globally analyze the structures of HKs to yield insights into the mechanisms by which signals are transmitted to and across protein structures in this family. We interpret known enzymological data in the context of new structural data to show how asymmetry across the dimer interface is a key feature of signal transduction in HKs, and discuss how different HK domains undergo asymmetric-to-symmetric transitions during signal transduction and catalysis. A thermodynamic framework for signaling that encompasses these various properties is presented and the consequences of weak thermodynamic coupling are discussed. The synthesis of observations from enzymology, structural biology, protein engineering and thermodynamics paves the way for a deeper molecular understanding of histidine kinase signal transduction. PMID:25982528

  15. Affinity labeling and characterization of the active site histidine of glucosephosphate isomerase

    SciTech Connect

    Gibson, D.R.; Gracy, R.W.; Hartman, F.C.

    1980-10-10

    N-bromoacetylethanolamine phosphate was found to act as a specific affinity label for the active center of glucosephosphate isomerase. The inactivation process followed pseudo-first order kinetics, was irreversible, and exhibited rate saturation kinetics with minimal half-lives of inactivation of 4.5 and 6.3 min for the enzyme isolated from human placenta and rabbit muscle, respectively. The pH dependence of the inactivation process closely paralleled the pH dependence of the overall catalytic process with pK/sub a/ values at pH 6.4 and 9.0. The stoichiometry of labeling of either enzyme, as determined with N-bromo(/sup 14/C/sub 2/)acetylethanolamine phosphate, was 1 eq of the affinity label/subunit of enzyme. After acid hydrolysis and amino acid analysis of the radioactive affinity-labeled human enzyme, only radioactive 3-carboxymethyl histidine was found. In the case of the rabbit enzyme, the only radioactive derivative obtained was 1-carboxymethyl histidine. Active site tryptic peptides were isolated by solvent extraction, thin layer peptide fingerprinting, and ion exchange chromatography before and after removal of the phosphate from the active site peptide. Amino acid analysis of the labeled peptides from the two species were very similar. Using high sensitivity methods for sequence analysis, the primary structure of the active site was established as Val-Leu-His-Ala-Glu-Asn-Val-Asp (Gly,Thr,Ser) Glu-Ile (Thr-Gly-His-Lys-Glx)-Tyr-Phe. Apparent sequence homology between the catalytic center of glucosephosphate isomerase and triosephosphate isomerase suggest that the two enzymes may have evolved from a common ancestral gene.

  16. Multiple active site histidine protonation states in Acetobacter aceti N5-carboxyaminoimidazole ribonucleotide mutase detected by REDOR NMR.

    PubMed

    Schaefer, Jacob; Jiang, Hong; Ransome, Aaron E; Kappock, T Joseph

    2007-08-21

    Class I PurE (N5-carboxyaminoimidazole mutase) catalyzes a chemically unique mutase reaction. A working mechanistic hypothesis involves a histidine (His45 in Escherichia coli PurE) functioning as a general acid, but no evidence for multiple protonation states has been obtained. Solution NMR is a peerless tool for this task but has had limited application to enzymes, most of which are larger than its effective molecular size limit. Solid-state NMR is not subject to this limit. REDOR NMR studies of a 151 kDa complex of uniformly 15N-labeled Acetobacter aceti PurE (AaPurE) and the active site ligand [6-13C]citrate probed a single ionization equilibrium associated with the key histidine (AaPurE His59). In the AaPurE complex, the citrate central carboxylate C6 13C peak moves upfield, indicating diminution of negative charge, and broadens, indicating heterogeneity. Histidine 15N chemical shifts indicate His59 exists in approximately equimolar amounts of an Ndelta-unprotonated (pyridine-like) form and an Ndelta-protonated (pyrrole-like) form, each of which is approximately 4 A from citrate C6. The spectroscopic data are consistent with proton transfers involving His59 Ndelta that are invoked in the class I PurE mechanism.

  17. Histidines, heart of the hydrogen ion channel from influenza A virus: Toward an understanding of conductance and proton selectivity

    NASA Astrophysics Data System (ADS)

    Hu, Jun; Fu, Riqiang; Nishimura, Katsuyuki; Zhang, Li; Zhou, Huan-Xiang; Busath, David D.; Vijayvergiya, Viksita; Cross, Timothy A.

    2006-05-01

    The heart of the H+ conductance mechanism in the homotetrameric M2 H+ channel from influenza A is a set of four histidine side chains. Here, we show that protonation of the third of these imidazoles coincides with acid activation of this transmembrane channel and that, at physiological pH, the channel is closed by two imidazole-imidazolium dimers, each sharing a low-barrier hydrogen bond. This unique construct succeeds in distributing a pair of charges over four rings and many atoms in a low dielectric environment to minimize charge repulsion. These dimers form with identical pKas of 8.2 ± 0.2, suggesting cooperative H+ binding and clearly illustrating high H+ affinity for this channel. The protonation behavior of the histidine side chains has been characterized by using solid-state NMR spectroscopy on the M2 transmembrane domain in fully hydrated lipid bilayers where the tetrameric backbone structure is known. Furthermore, electrophysiological measurements of multichannel and single-channel experiments confirm that these protein constructs are functional. M2 channel | proton channel | solid-state NMR | low-barrier hydrogen bond | histidine ionization constants

  18. Bis-Histidine-Coordinated Hemes in Four-Helix Bundles: How the Geometry of the Bundle Controls the Axial Imidazole Plane Orientations in Transmembrane Cytochromes of Mitochondrial Complexes II and III and Related Proteins

    PubMed Central

    Berry, Edward A.; Walker, F. Ann

    2009-01-01

    Early investigation of the EPR spectra of bis-histidine-coordinated membrane-bound ferriheme proteins led to the description of a spectral signal that had only one resolved feature. These became known as “highly anisotropic low-spin” (HALS) or “large gmax” ferriheme centers. Extensive work with small-molecule model heme complexes showed that this spectroscopic signature occurs in bis-imidazole ferrihemes in which the planes of the imidazole ligands are nearly perpendicular, Δϕ = 57–90°. In the last decade protein crystallographic studies have revealed the atomic structures of a number of examples of bis-histidine heme proteins. A frequent characteristic of these large gmax ferrihemes in membrane-bound proteins is the occurrence of the heme within a four-helix bundle with a left-handed twist. The histidine ligands occur at the same level on two diametrically opposed helices of the bundle. These ligands have the same side chain conformation and ligate heme iron on the bundle axis, resulting in a quasi-2-fold symmetric structure. The two non-ligand-bearing helices also obey this symmetry, and have a conserved small residue, usually glycine, where the edge of the heme ring makes contact with the helix backbones. In many cases this small residue is preceded by a threonine or serine residue whose side chain hydroxyl oxygen acts as a hydrogen-bond acceptor from the Nδ1 atom of the heme-ligating histidine. The Δϕ angle is thus determined by the common histidine side-chain conformation and the crossing angle of the ligand-bearing helices, in some cases constrained by H-bonds to the Ser/Thr residues on the non-ligand-bearing helices. PMID:18418633

  19. [Perissodactyla: the primary structure of hemoglobins from the lowland tapir (Tapirus terrestris): glutamic acid in position 2 of the beta chains].

    PubMed

    Mazur, G; Braunitzer, G

    1984-09-01

    The hemoglobins from a lowland tapir (Tapirus terrestris) were analysed and the complete primary structure is described. The globin chains were separated on CM cellulose column in 8M urea and the amino-acid sequences were determined in the liquid phase sequenator. The results show that globin consists of two alpha chains (alpha I and alpha II) and beta major and beta minor components. The alpha chains differ only at one position: alpha I contains aspartic acid and alpha II glycine. The beta chains are heterogeneous: aspartic and glutamic acid were found at position beta 21 and beta 73 of the beta major components and asparagine and serine at position beta 139. In the beta minor components four positions were found with more than one amino acid, namely beta 2, beta 4, beta 6 and beta 56. The sequences are compared with those of man, horse and rhinoceros. Four residues of horse methemoglobin, which are involved in the alpha 1 beta 1 contacts are substituted in tapir hemoglobins. In the alpha chains: alpha 107(G14)Ser----Val, alpha 111-(G18) Val----Leu, alpha 115(GH3) Asn----Asp or Gly; in the beta chains: beta 116(G18) Arg----Gln. The amino acid at beta 2 of the major components is glutamic acid while glutamine and histidine are found in the minor components. Although glutamic acid, a binding site for ATP, does not interact with 2,3-bisphosphoglycerate, glutamine and histidine in the minor components are responsible for the slight effect of 2,3-bisphosphoglycerate on tapir hemoglobin.

  20. Cell fate regulation governed by a repurposed bacterial histidine kinase

    DOE PAGES

    Childers, W. Seth; Xu, Qingping; Mann, Thomas H.; Mathews, Irimpan I.; Blair, Jimmy A.; Deacon, Ashley M.; Shapiro, Lucy; Stock, Ann M.

    2014-10-28

    One of the simplest organisms to divide asymmetrically is the bacterium Caulobacter crescentus. The DivL pseudo-histidine kinase, positioned at one cell pole, regulates cell-fate by controlling the activation of the global transcription factor CtrA via an interaction with the response regulator (RR) DivK. DivL uniquely contains a tyrosine at the histidine phosphorylation site, and can achieve these regulatory functions in vivo without kinase activity. Determination of the DivL crystal structure and biochemical analysis of wild-type and site-specific DivL mutants revealed that the DivL PAS domains regulate binding specificity for DivK~P over DivK, which is modulated by an allosteric intramolecular interactionmore » between adjacent domains. We discovered that DivL's catalytic domains have been repurposed as a phosphospecific RR input sensor, thereby reversing the flow of information observed in conventional histidine kinase (HK)-RR systems and coupling a complex network of signaling proteins for cell-fate regulation.« less

  1. Cell fate regulation governed by a repurposed bacterial histidine kinase

    SciTech Connect

    Childers, W. Seth; Xu, Qingping; Mann, Thomas H.; Mathews, Irimpan I.; Blair, Jimmy A.; Deacon, Ashley M.; Shapiro, Lucy; Stock, Ann M.

    2014-10-28

    One of the simplest organisms to divide asymmetrically is the bacterium Caulobacter crescentus. The DivL pseudo-histidine kinase, positioned at one cell pole, regulates cell-fate by controlling the activation of the global transcription factor CtrA via an interaction with the response regulator (RR) DivK. DivL uniquely contains a tyrosine at the histidine phosphorylation site, and can achieve these regulatory functions in vivo without kinase activity. Determination of the DivL crystal structure and biochemical analysis of wild-type and site-specific DivL mutants revealed that the DivL PAS domains regulate binding specificity for DivK~P over DivK, which is modulated by an allosteric intramolecular interaction between adjacent domains. We discovered that DivL's catalytic domains have been repurposed as a phosphospecific RR input sensor, thereby reversing the flow of information observed in conventional histidine kinase (HK)-RR systems and coupling a complex network of signaling proteins for cell-fate regulation.

  2. Temperature dependence of histidine ionization constants in myoglobin.

    PubMed Central

    Bhattacharya, S; Lecomte, J T

    1997-01-01

    The standard enthalpy of ionization of six titratable histidines in horse metaquomyoglobin was determined by repeating proton NMR titrations as a function of temperature and using the van't Hoff relationship. It was found that deltaH degrees varies between 16 and 37 kJ mol(-1) in the protein, compared with a value of 29 kJ mol(-1) in free histidine. The standard entropy change was evaluated by combining the enthalpy and free energy changes derived from the pKa values. Although the entropy change could not be precisely and accurately obtained by this method, it could be established that it spans a wide range, from -60 to 0 J K(-1) mol(-1), about the value of -23 J K(-1) mol(-1) for the free histidine. The entropy change was used within the framework of enthalpy-entropy compensation to partition the solvation component from the standard thermodynamic quantities for each of the titrating residues. It was shown that the partitioning of the values in the protein is not readily understood in terms of solvent accessibility or electrostatic interactions. The contribution of solvation effects to the temperature response appeared to be significant only in the case of His-119 and His-48. The standard quantities were also used to explore the energetics of proton binding in the native state at temperatures below the onset of thermal denaturation. Images FIGURE 6 PMID:9414235

  3. Histidine at the active site of Neurospora tyrosinase.

    PubMed

    Pfiffner, E; Lerch, K

    1981-10-13

    The involvement of histidyl residues as potential ligands to the binuclear active-site copper of Neurospora tyrosinase was explored by dye-sensitized photooxidation. The enzymatic activity of the holoenzyme was shown to be unaffected by exposure to light in the presence of methylene blue; however, irradiation of the apoenzyme under the same conditions led to a progressive loss of its ability to be reactivated with Cu2+. This photoinactivation was paralleled by a decrease in the histidine content whereas the number of histidyl residues in the holoenzyme remained constant. Copper measurements of photooxidized, reconstituted apoenzyme demonstrated the loss of binding of one copper atom per mole of enzyme as a consequence of photosensitized oxidation of three out of nine histidine residues. Their sequence positions were determined by a comparison of the relative yields of the histidine containing peptides of photooxidized holo- and apotyrosinases. The data obtained show the preferential modification of histidyl residues 188, 193, and 289 and suggest that they constitute metal ligands to one of the two active-site copper atoms. Substitution of copper by cobalt was found to afford complete protection of the histidyl residues from being modified by dye-sensitized photooxidation. PMID:6458322

  4. Iridium(III) Luminescent Probe for Detection of the Malarial Protein Biomarker Histidine Rich Protein-II.

    PubMed

    Davis, Keersten M; Bitting, Anna L; Markwalter, Christine F; Bauer, Westley S; Wright, David W

    2015-07-07

    This work outlines the synthesis of a non-emissive, cyclometalated Ir(III) complex, Ir(ppy)2(H2O)2(+) (Ir1), which elicits a rapid, long-lived phosphorescent signal when coordinated to a histidine-containing protein immobilized on the surface of a magnetic particle. Synthesis of Ir1, in high yields,is complete O/N and involves splitting of the parent cyclometalated Ir(III) chloro-bridged dimer into two equivalents of the solvated complex. To confirm specificity, several amino acids were probed for coordination activity when added to the synthesized probe, and only histidine elicited a signal response. Using BNT-II, a branched peptide mimic of the malarial biomarker Histidine Rich Protein II (pfHRP-II), the iridium probe was validated as a tool for HRP-II detection. Quenching effects were noted in the BNT-II/Ir1 titration when compared to L-Histidine/Ir1, but these were attributed to steric hindrance and triplet state quenching. Biolayer interferometry was used to determine real-time kinetics of interaction of Ir1 with BNT-II. Once the system was optimized, the limit of detection of rcHRP-II using the probe was found to be 12.8 nM in solution. When this protein was immobilized on the surface of a 50 µm magnetic agarose particle, the limit of detection was 14.5 nM. The robust signal response of this inorganic probe, as well as its flexibility of use in solution or immobilized on a surface, can lend itself toward a variety of applications, from diagnostic use to imaging.

  5. Structural influences on preferential oxazolone versus diketopiperazine b(2+) ion formation for histidine analogue-containing peptides.

    PubMed

    Gucinski, Ashley C; Chamot-Rooke, Julia; Nicol, Edith; Somogyi, Árpád; Wysocki, Vicki H

    2012-05-01

    Studies of peptide fragment ion structures are important to aid in the accurate kinetic modeling and prediction of peptide fragmentation pathways for a given sequence. Peptide b(2)(+) ion structures have been of recent interest. While previously studied b(2)(+) ions that contain only aliphatic or simple aromatic residues are oxazolone structures, the HA b(2)(+) ion consists of both oxazolone and diketopiperazine structures. The structures of a series of histidine-analogue-containing Xxx-Ala b(2)(+) ions were studied by using action infrared multiphoton dissociation (IRMPD) spectroscopy, fragment ion hydrogen-deuterium exchange (HDX), and density functional theory (DFT) calculations to systematically probe the influence of different side chain structural elements on the resulting b(2)(+) ion structures formed. The b(2)(+) ions studied include His-Ala (HA), methylated histidine analogues, including π-methyl-HA and τ-methyl-HA, pyridylalanine (pa) analogues, including 2-(pa)A, 3-(pa)A, and 4-(pa)A, and linear analogues, including diaminobutanoic acid-Ala (DabA) and Lys-Ala (KA). The location and accessibility of the histidine π-nitrogen, or an amino nitrogen on an aliphatic side chain, were seen to be essential for diketopiperazine formation in addition to the more typical oxazolone structure formation, while blocking or removal of the τ-nitrogen did not change the b(2)(+) ion structures formed. Linear histidine analogues, DabA and KA, formed only diketopiperazine structures, suggesting that a steric interaction in the HisAla case may interfere with the complete trans-cis isomerization of the first amide bond that is necessary for diketopiperazine formation.

  6. Helix-Capping Histidines: Diversity of N-H···N Hydrogen Bond Strength Revealed by (2h)JNN Scalar Couplings.

    PubMed

    Preimesberger, Matthew R; Majumdar, Ananya; Rice, Selena L; Que, Lauren; Lecomte, Juliette T J

    2015-11-24

    In addition to its well-known roles as an electrophile and general acid, the side chain of histidine often serves as a hydrogen bond (H-bond) acceptor. These H-bonds provide a convenient pH-dependent switch for local structure and functional motifs. In hundreds of instances, a histidine caps the N-terminus of α- and 310-helices by forming a backbone NH···Nδ1 H-bond. To characterize the resilience and dynamics of the histidine cap, we measured the trans H-bond scalar coupling constant, (2h)JNN, in several forms of Group 1 truncated hemoglobins and cytochrome b5. The set of 19 measured (2h)JNN values were between 4.0 and 5.4 Hz, generally smaller than in nucleic acids (~6-10 Hz) and indicative of longer, weaker bonds in the studied proteins. A positive linear correlation between (2h)JNN and the difference in imidazole ring (15)N chemical shift (Δ(15)N = |δ(15)Nδ1 - δ(15)Nε2|) was found to be consistent with variable H-bond length and variable cap population related to the ionization of histidine in the capping and noncapping states. The relative ease of (2h)JNN detection suggests that this parameter can become part of the standard arsenal for describing histidines in helix caps and other key structural and catalytic elements involving NH···N H-bonds. The combined nucleic acid and protein data extend the utility of (2h)JNN as a sensitive marker of local structural, dynamic, and thermodynamic properties in biomolecules. PMID:26523621

  7. Degradation of glycine and alanine on irradiated quartz.

    PubMed

    Pawlikowski, Maciej; Benko, Aleksandra; Wróbel, Tomasz P

    2013-04-01

    Recent researches suggest participation of minerals in the formation of life under primordial conditions. Among all of the minerals, quartz seems to be one of the most probable to take part in such processes. However, an external source of energy is needed, e.g. electric discharge. A device simulating the proposed conditions was designed and was used to simulate prebiotic conditions. Investigation of processes occurring during the stimulation of quartz with electric discharge was studied by means of Ultraviolet-visible (UV-VIS) spectroscopy, in order to monitor the generation kinetics of free radicals. Additionally, infrared spectroscopy was applied to identify chemical reaction products created in a solution of alanine or glycine, in the presence of quartz treated with electric discharge. Formation of increased amounts of free radicals, compared to experiments performed without quartz and/or amino acid, is reported, along with identification of possible degradation products of alanine. No synthetic reactions were observed.

  8. Co-localization of glycine and gaba immunoreactivity in interneurons in Macaca monkey cerebellar cortex.

    PubMed

    Crook, J; Hendrickson, A; Robinson, F R

    2006-09-15

    of 120 cells/linear mm. Their morphology indicates that they include Golgi and Lugaro cell types with the majority containing both glycine and GABA or glutamic acid decarboxylase. These data are consistent with the proposal that, as in the rat cerebellum, these granular cell layer interneurons corelease glycine and GABA in the primate cerebellum. The patterns of labeling for glycine and GABA within Golgi and Lugaro cells also indicate that there are biochemical sub-types which are morphologically similar. Further, we find that glycine, GABA and glutamic acid decarboxylase identified candelabrum cells adjacent to the Purkinje cells which is the first time that this interneuron has been reported in primate cerebellar cortex. We propose that candelabrum cells, like the majority of Golgi and Lugaro cells, release both glycine and GABA.

  9. Purification and characterization of two forms of cytochrome b5 from an arachidonic acid-producing fungus, Mortierella hygrophila.

    PubMed

    Kouzaki, N; Kawashima, H; Chung, M C; Shimizu, S

    1995-06-01

    Two forms of cytochrome b5 have been purified from the microsomes of an arachidonic acid-producing fungus, Mortierella hygrophila IFO 5941, after detergent solubilization. They have monomeric molecular masses of about 16 kDa and 19 kDa. Their absorption spectra are similar to those of mammalian cytochrome b5s. Their amino acid compositions show some similarity to those of mammalian cytochrome b5s, but the contents of some amino acids (glycine, alanine, aspartic acid + asparagine, glutamic acid + glutamine, arginine, proline, histidine, leucine and lysine) are unique to the cytochrome b5s of M. hygrophila. Some of their internal peptide sequences also show close homology with those of some mammals (approx. 65 to 67%), while some others show no or little homology. The addition of various acyl-CoAs to NADH-reduced microsomes caused an abrupt shiftdown of the steady state reduction level of cytochrome b5. This indicates the increased utilization of electrons for the desaturation process and may suggest that the cytochrome b5s of this fungus actually take part in its microsomal desaturation system for polyunsaturated fatty acid biosynthesis as electron carriers. PMID:7786894

  10. Choline supplementation alters some amino acid concentrations with no change in homocysteine in children with cystic fibrosis and pancreatic insufficiency.

    PubMed

    Alshaikh, Belal; Schall, Joan I; Maqbool, Asim; Mascarenhas, Maria; Bennett, Michael J; Stallings, Virginia A

    2016-05-01

    The present study determined the plasma amino acid status in children with cystic fibrosis (CF) and pancreatic insufficiency (PI) in the modern medical and nutritional care setting and investigated the effect of choline supplementation on amino acid status. A total of 110 children aged 5 to 18 years with CF and PI were randomized to receive choline-enriched structured lipid (LYM-X-SORB) or placebo with similar energy and fat content. Plasma amino acids were measured at baseline and 3 and 12 months. We hypothesized that choline supplementation would result in lower plasma homocysteine concentrations in children with CF. At baseline, dietary protein intake was high and the amino acid profile was within laboratory reference ranges in most participants. Alanine and cysteine were elevated in 24% and 36% of participants, respectively. Children with baseline alanine above reference range had improved weight, body mass index, and fat-free mass. Low homocysteine was found in 62% of children 11 years and older. After 3 and 12 months, there was no effect of choline supplementation on methionine or homocysteine status. Compared with placebo, choline supplementation resulted in increased glycine and decreased threonine, histidine, valine, and total branch chained amino acids at 12 months. In conclusion, daily choline supplementation with LYM-X-SORB did not alter methionine-homocysteine metabolism but did result in alterations in other amino acids in children with CF and PI.

  11. Studies on Dyeing Process Variables for Salt Free Reactive Dyeing of Glycine Modified Cationized Cotton Muslin Fabric

    NASA Astrophysics Data System (ADS)

    Samanta, Ashis Kumar; Kar, Tapas Ranjan; Mukhopadhyay, Asis; Shome, Debashis; Konar, Adwaita

    2015-04-01

    Bleached cotton muslin fabric with or without pre-oxidized with NaIO4 (oxy-cotton) was chemically modified with glycine (amino acid) by pad dry calendar process to investigate the changes in textile properties and its dyeability with reactive dye. This glycine modified cotton incorporates new functional groups producing -NH3 + or -C=NH+ -ion (cationic groups) in acid bath to obtain cationized cotton making it amenable to a newer route of salt free reactive dyeing in acid bath. In the present work the process variables of reactive dyeing in the salt free acid bath for dyeing of amine (glycine) modified cationized cotton were studied and optimized. The present study also includes thorough investigation of changes in important textile related properties and dyeability with reactive dye after such chemical modifications. Between oxidized and unoxidized cotton muslin fabric, unoxidized cotton fabric shows better reactive dye uptake in both conventional alkaline bath dyeing and nonconventional salt free acid bath dyeing particularly for high exhaustion class of reactive dye with acceptable level of colour fastness and overall balance of other textile related properties. Moreover, application of dye fixing agent further improves surface colour depth (K/S) of the glycine treated cotton fabric for HE brand of reactive dyes. Corresponding reaction mechanisms for such modifications were supported by FTIR spectroscopy. Finally unoxidized cotton and pre-oxidized cotton further treated with glycine (amino acid) provide a new route of acid bath salt free reactive dyeing showing much higher dye uptake and higher degree of surface cover with amino acid residue anchored to modified cotton.

  12. Further Characterization of Glycine-Containing Microcystins from the McMurdo Dry Valleys of Antarctica

    PubMed Central

    Puddick, Jonathan; Prinsep, Michèle R.; Wood, Susanna A.; Cary, Stephen Craig; Hamilton, David P.; Holland, Patrick T.

    2015-01-01

    Microcystins are hepatotoxic cyclic peptides produced by several cyanobacterial genera worldwide. In 2008, our research group identified eight new glycine-containing microcystin congeners in two hydro-terrestrial mat samples from the McMurdo Dry Valleys of Eastern Antarctica. During the present study, high-resolution mass spectrometry, amino acid analysis and micro-scale thiol derivatization were used to further elucidate their structures. The Antarctic microcystin congeners contained the rare substitution of the position-1 d-alanine for glycine, as well as the acetyl desmethyl modification of the position-5 Adda moiety (3S-amino-9S-methoxy-2S,6,8S-trimethyl-10-phenyldeca-4E,6E-dienoic acid). Amino acid analysis was used to determine the stereochemistry of several of the amino acids and conclusively demonstrated the presence of glycine in the microcystins. A recently developed thiol derivatization technique showed that each microcystin contained dehydrobutyrine in position-7 instead of the commonly observed N-methyl dehydroalanine. PMID:25675414

  13. Functionalized ZnS quantum dots as luminescent probes for detection of amino acids.

    PubMed

    Mobarraz, Mahsa; Ganjali, Mohammad Reza; Chaichi, Mohammad Javad; Norouzi, Parviz

    2012-10-01

    In this work, L-cysteine capped-ZnS quantum dots were synthesized in aqueous medium, and their interaction with some of the amino acids was studied with fluorescence spectra. The results demonstrated that histidine could effectively quench the Quantum dots emission more than other amino acids. Electron transfer process between the capping ligands and histidine was mainly responsible for the remarkable quenching effect of histidine, because according to the structure of histidine, it is the strongest acceptor among essential amino acids. Under optimum conditions, the quenched fluorescence intensity increased linearly with the concentration of histidine ranging from 1.33×10(-6) to 1.49×10(-4) mol L(-1). The limit of detection for histidine was 0.05×10(-7) mol L(-1). PMID:22925905

  14. Dicationic Surfactants with Glycine Counter Ions for Oligonucleotide Transportation.

    PubMed

    Pietralik, Zuzanna; Skrzypczak, Andrzej; Kozak, Maciej

    2016-08-01

    Gemini surfactants are good candidates to bind, protect, and deliver nucleic acids. Herein, the concept of amino acids (namely glycine) as counter ions of gemini surfactants for gene therapy application was explored. This study was conducted on DNA and RNA oligomers and two quaternary bis-imidazolium salts, having 2,5-dioxahexane and 2,8-dioxanonane spacer groups. The toxicity level of surfactants was assessed by an MTT assay, and their ability to bind nucleic acids was tested through electrophoresis. The nucleic acid conformation was established based on circular dichroism and infrared spectroscopic analyses. The structures of the formed complexes were characterized by small-angle scattering of synchrotron radiation. Both studied surfactants appear to be suitable for gene therapy; however, although they vary by only three methylene groups in the spacer, they differ in binding ability and toxicity. The tested oligonucleotides maintained their native conformations upon surfactant addition and the studied lipoplexes formed a variety of structures. In systems based on a 2,5-dioxahexane spacer, a hexagonal phase was observed for DNA-surfactant complexes and a micellar phase was dominant with RNA. For the surfactant with a 2,8-dioxanonane spacer group, the primitive cubic phase prevailed. PMID:27214208

  15. Resveratrol inhibits glycine receptor-mediated ion currents.

    PubMed

    Lee, Byung-Hwan; Hwang, Sung-Hee; Choi, Sun-Hye; Kim, Hyeon-Joong; Jung, Seok-Won; Kim, Hyun-Sook; Lee, Joon-Hee; Kim, Hyung-Chun; Rhim, Hyewhon; Nah, Seung-Yeol

    2014-01-01

    Resveratrol is found in grapes, red wine, and berries. Resveratrol has been known to have many beneficial health effects, such as anti-cancer, neuroprotective, anti-nociceptive, and life-prolonging effects. However, the single cellular mechanisms by which resveratrol acts are relatively unknown, especially in terms of possible regulation of receptors involved in synaptic transmission. The glycine receptor is an inhibitory ligand-gated ion channel involved in fast synaptic transmission in spinal cord. In the present study, we investigated the effect of resveratrol on human glycine receptor channel activity. Glycine α1 receptors were expressed in Xenopus oocytes and glycine receptor channel activity was measured using a two-electrode voltage clamp technique. Treatment with resveratrol alone had no effect on oocytes injected with H2O or on oocytes injected with glycine α1 receptor cRNA. In the oocytes injected with glycine α1 receptor cRNA, co- or pre-treatment of resveratrol with glycine inhibited the glycine-induced inward peak current (IGly) in a reversible manner. The inhibitory effect of resveratrol on IGly was also concentration dependent, voltage independent, and non-competitive. These results indicate that resveratrol regulates glycine receptor channel activity and that resveratrol-mediated regulation of glycine receptor channel activity is one of several cellular action mechanisms of resveratrol for pain regulation. PMID:24694604

  16. The influence of crystallinity degree on the glycine decomposition induced by 1 MeV proton bombardment in space analog conditions.

    PubMed

    Pilling, Sergio; Mendes, Luiz A V; Bordalo, Vinicius; Guaman, Christian F M; Ponciano, Cássia R; da Silveira, Enio F

    2013-01-01

    Glycine is the simplest proteinaceous amino acid and is present in all life-forms on Earth. In aqueous solutions, it appears mainly as zwitterion glycine (+NH3CH2COO-); however, in solid phase, it may be found in amorphous or crystalline (α, β, and γ) forms. The crystalline forms differ from each other by the packing of zwitterions in the unitary cells and by the number of intermolecular hydrogen bonds. This molecular species has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, glycine is exposed to several radiation fields at different temperatures. We present an experimental study on the destruction of zwitterionic glycine crystals at room temperature by 1 MeV protons, in which the dependence of the destruction rates of the α-glycine and β-glycine crystals on bombardment fluence is investigated. The samples were analyzed in situ by Fourier transform infrared spectrometry at different proton fluences. The experiments occurred under ultrahigh vacuum conditions at the Van de Graaff accelerator lab at the Pontifical Catholic University at Rio de Janeiro (PUC-Rio), Brazil. For low fluences, the dissociation cross section of α-glycine was observed to be 2.5×10(-14) cm2, a value roughly 5 times higher than the dissociation cross section found for β-glycine. The estimated half-lives of α-glycine and β-glycine zwitterionic forms extrapolated to the Earth orbit environment are 9×10(5) and 4×10(6) years, respectively. In the diffuse interstellar medium the estimated values are 1 order of magnitude lower. These results suggest that pristine interstellar β-glycine is the one most likely to survive the hostile environments of space radiation. A small feature around 1650-1700 cm(-1), tentatively attributed to an amide functional group, was observed in the IR spectra of irradiated samples, suggesting that cosmic rays may induce peptide bond synthesis in

  17. The influence of crystallinity degree on the glycine decomposition induced by 1 MeV proton bombardment in space analog conditions.

    PubMed

    Pilling, Sergio; Mendes, Luiz A V; Bordalo, Vinicius; Guaman, Christian F M; Ponciano, Cássia R; da Silveira, Enio F

    2013-01-01

    Glycine is the simplest proteinaceous amino acid and is present in all life-forms on Earth. In aqueous solutions, it appears mainly as zwitterion glycine (+NH3CH2COO-); however, in solid phase, it may be found in amorphous or crystalline (α, β, and γ) forms. The crystalline forms differ from each other by the packing of zwitterions in the unitary cells and by the number of intermolecular hydrogen bonds. This molecular species has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, glycine is exposed to several radiation fields at different temperatures. We present an experimental study on the destruction of zwitterionic glycine crystals at room temperature by 1 MeV protons, in which the dependence of the destruction rates of the α-glycine and β-glycine crystals on bombardment fluence is investigated. The samples were analyzed in situ by Fourier transform infrared spectrometry at different proton fluences. The experiments occurred under ultrahigh vacuum conditions at the Van de Graaff accelerator lab at the Pontifical Catholic University at Rio de Janeiro (PUC-Rio), Brazil. For low fluences, the dissociation cross section of α-glycine was observed to be 2.5×10(-14) cm2, a value roughly 5 times higher than the dissociation cross section found for β-glycine. The estimated half-lives of α-glycine and β-glycine zwitterionic forms extrapolated to the Earth orbit environment are 9×10(5) and 4×10(6) years, respectively. In the diffuse interstellar medium the estimated values are 1 order of magnitude lower. These results suggest that pristine interstellar β-glycine is the one most likely to survive the hostile environments of space radiation. A small feature around 1650-1700 cm(-1), tentatively attributed to an amide functional group, was observed in the IR spectra of irradiated samples, suggesting that cosmic rays may induce peptide bond synthesis in

  18. Detection of O6-carboxymethyl-2'-deoxyguanosine in DNA following reaction of nitric oxide with glycine and in human blood DNA using a quantitative immunoslot blot assay.

    PubMed

    Cupid, Belinda C; Zeng, Zuotao; Singh, Rajinder; Shuker, David E G

    2004-03-01

    Previous research has shown that a range of nitrosated glycine derivatives react with DNA to form O6-carboxymethylguanine and O6-methylguanine DNA adducts [Harrison et al. (1999) Chem. Res. Toxicol. 12, 106-111). Nitrosated glycine derivatives may be formed in the gastrointestinal tract from the reaction of dietary glycine with nitrosating agents. The aim of this study was to further investigate the role of dietary glycine in the formation of O6-guanine adducts at physiologically relevant concentrations. In vitro studies were performed by reacting 10 microM to 50 mM glycine with nitric oxide in the presence of oxygen. An HPLC assay was developed to measure the resulting nitrosated glycine derivative, diazoacetate anion. The amount of nitrosating agent present in the reaction mixture was determined by colorimetric measurement of nitrite, the hydrolysis product of N2O3. Diazoacetate anion formation depended linearly on glycine concentration. Solutions of nitrosated glycine reacted with 2'-deoxyguanosine and calf thymus DNA to give O6-carboxymethyl-2'-deoxyguanosine and, at high concentrations of glycine and nitric oxide, O6-methyl-2'-deoxyguanosine. At physiological concentrations of glycine and nitric oxide, diazoacetate anion was not detectable. Studies with synthetic diazoacetate anion showed that concentrations < 14 microM did not give detectable O6-carboxyethylguanine in DNA, even when a sensitive immunoslot blot assay was used. However, O6-carboxymethylguanine was detected in human blood DNA samples obtained from three volunteers consuming a standardized high meat diet, using the immunoslot blot assay. O6-Carboxymethylguanine levels ranged from 35 to 80 (detection limit = 15) O6-carboxymethylguanine per 10(8) bases. These studies provide further evidence that nitrosated amino acids may be risk factors for gastrointestinal tract cancers.

  19. Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua

    2016-09-01

    Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel hydrothermal system in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature hydrothermal fluids were generated in basalt-hosted hydrothermal vents, where H2 and CO2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent systems. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline hydrothermal vents in origin of life in the early ocean.

  20. Exposure to the Proton Scavenger Glycine under Alkaline Conditions Induces Escherichia coli Viability Loss

    PubMed Central

    Vanhauteghem, Donna; Janssens, Geert Paul Jules; Lauwaerts, Angelo; Sys, Stanislas; Boyen, Filip; Cox, Eric; Meyer, Evelyne

    2013-01-01

    Our previous work described a clear loss of Escherichia coli (E. coli) membrane integrity after incubation with glycine or its N-methylated derivatives N-methylglycine (sarcosine) and N,N-dimethylglycine (DMG), but not N,N,N-trimethylglycine (betaine), under alkaline stress conditions. The current study offers a thorough viability analysis, based on a combination of real-time physiological techniques, of E. coli exposed to glycine and its N-methylated derivatives at alkaline pH. Flow cytometry was applied to assess various physiological parameters such as membrane permeability, esterase activity, respiratory activity and membrane potential. ATP and inorganic phosphate concentrations were also determined. Membrane damage was confirmed through the measurement of nucleic acid leakage. Results further showed no loss of esterase or respiratory activity, while an instant and significant decrease in the ATP concentration occurred upon exposure to either glycine, sarcosine or DMG, but not betaine. There was a clear membrane hyperpolarization as well as a significant increase in cellular inorganic phosphate concentration. Based on these results, we suggest that the inability to sustain an adequate level of ATP combined with a decrease in membrane functionality leads to the loss of bacterial viability when exposed to the proton scavengers glycine, sarcosine and DMG at alkaline pH. PMID:23544135

  1. Glycine: an alternative transmitter candidate of the pallidosubthalamic projection neurons in the rat

    SciTech Connect

    Takada, M.; Hattori, T.

    1987-08-22

    Autoradiographic retrograde tracing techniques with radioactive transmitters were used to analyse the identity of a putative transmitter in the rat pallidosubthalamic (GP-STN) pathway. One to 2 hours after the stereotaxic injection of /sup 3/H-glycine restricted to the STN, a large number of neuronal somata were radiolabeled in the GP. No comparable labeling was observed following the injection of /sup 3/H-gamma-aminobutyric acid (/sup 3/H-GABA) into the same nucleus even with survival times as long as 6 hours. Specifically, no significant somatic labeling was detected either in the GP or in the caudoputamen (CPU). Only when /sup 3/H-GABA was injected into the substantia nigra did CPU and GP neurons become labeled. On the contrary, STN neuronal somata were invariably labeled 6 hours after the intrapallidal injection of /sup 3/H-GABA, whereas no perikaryal labeling was observed in the STN after /sup 3/H-glycine injection into the GP. The perikaryal labeling was prevented in all cases by intraventricular administration of colchicine 1 day before the isotope injections. The observations suggest that /sup 3/H-glycine was preferentially transported retrogradely through the GP-STN pathway, and /sup 3/H-GABA through the STN-GP projection. In view of the recent controversy on the role of GABA as a putative transmitter of the GP-STN projection, we now propose glycine as an alternative transmitter candidate of these critically situated neurons in the basal ganglia.

  2. Synthesis of glycine-containing complexes in impacts of comets on early Earth.

    PubMed

    Goldman, Nir; Reed, Evan J; Fried, Laurence E; William Kuo, I-F; Maiti, Amitesh

    2010-11-01

    Delivery of prebiotic compounds to early Earth from an impacting comet is thought to be an unlikely mechanism for the origins of life because of unfavourable chemical conditions on the planet and the high heat from impact. In contrast, we find that impact-induced shock compression of cometary ices followed by expansion to ambient conditions can produce complexes that resemble the amino acid glycine. Our ab initio molecular dynamics simulations show that shock waves drive the synthesis of transient C-N bonded oligomers at extreme pressures and temperatures. On post impact quenching to lower pressures, the oligomers break apart to form a metastable glycine-containing complex. We show that impact from cometary ice could possibly yield amino acids by a synthetic route independent of the pre-existing atmospheric conditions and materials on the planet.

  3. Replacement of the proximal heme thiolate ligand in chloroperoxidase with a histidine residue

    PubMed Central

    Yi, Xianwen; Mroczko, Mark; Manoj, Kelath M.; Wang, Xiaotang; Hager, Lowell P.

    1999-01-01

    Chloroperoxidase is a versatile heme enzyme which can cross over the catalytic boundaries of other oxidative hemoproteins and perform multiple functions. Chloroperoxidase, in addition to catalyzing classical peroxidative reactions, also acts as a P450 cytochrome and a potent catalase. The multiple functions of chloroperoxidase must be derived from its unique active site structure. Chloroperoxidase possesses a proximal cysteine thiolate heme iron ligand analogous to the P450 cytochromes; however, unlike the P450 enzymes, chloroperoxidase possesses a very polar environment distal to its heme prosthetic group and contains a glutamic acid residue in close proximity to the heme iron. The presence of a thiolate ligand in chloroperoxidase has long been thought to play an essential role in its chlorination and epoxidation activities; however, the research reported in this paper proves that hypothesis to be invalid. To explore the role of Cys-29, the amino acid residue supplying the thiolate ligand in chloroperoxidase, Cys-29 has been replaced with a histidine residue. Mutant clones of the chloroperoxidase genome have been expressed in a Caldariomyces fumago expression system by using gene replacement rather than gene insertion technology. C. fumago produces wild-type chloroperoxidase, thus requiring gene replacement of the wild type by the mutant gene. To the best of our knowledge, this is the first time that gene replacement has been reported for this type of fungus. The recombinant histidine mutants retain most of their chlorination, peroxidation, epoxidation, and catalase activities. These results downplay the importance of a thiolate ligand in chloroperoxidase and suggest that the distal environment of the heme active site plays the major role in maintaining the diverse activities of this enzyme. PMID:10535936

  4. Glycine hydrogen fluoride: Remarkable hydrogen bonding in the dimeric glycine glycinium cation

    NASA Astrophysics Data System (ADS)

    Fleck, M.; Ghazaryan, V. V.; Petrosyan, A. M.

    2010-12-01

    Crystals of glycine hydrogen fluoride (Gly·HF) were prepared from an aqueous solution containing stoichiometric quantities of the components. The crystal structure of Gly·HF was determined, IR and Raman spectra were registered and are discussed. Gly·HF crystallizes in the orthorhombic space group Pbca with Z = 32. The most remarkable feature of the structure is the existence of symmetric dimeric glycine-glycinium cations with short hydrogen bonds (O⋯O distance of 2.446 Å), charge-counterbalanced by hydrogen bifluoride (F sbnd H⋯F) - anions - in addition to the expected glycinium cations and fluoride anions. These results were compared with previously published data on crystals grown in the system glycine-HF-H 2O.

  5. Comparison of electrochemical immunosensors based on gold nano materials and immunoblot techniques for detection of histidine-tagged proteins in culture medium.

    PubMed

    Wasowicz, Michał; Viswanathan, Subramanian; Dvornyk, Anzhela; Grzelak, Krystyna; Kłudkiewicz, Barbara; Radecka, Hanna

    2008-10-15

    In this work, the direct electrochemical determination of poly-histidine tagged proteins using immunosensor based on anti-His (C-term) antibody immobilized on gold electrodes modified with 1,6-hexanedithiol, gold colloid particles or gold nanorods is described. The recombinant histidine-tagged silk proteinase inhibitor protein (rSPI2-His(6)) expressed in Pichia system selected as antigen for this immonosensor. An electrochemical impedance spectroscopy was used as label free detection technique for immune conjugation. The gold nanorods modified electrode layer showed better analytical response than gold nano particles. The linear calibration range was observed between 10 pg/ml and 1 ng/ml with limit of detection 5 pg/ml (S/N=3). Up to four successive assay cycles with retentive sensitivity were achieved for the immunosensors regenerated with 0.2M glycine-HCl buffer, pH 2.8. The performance of this immnosensor were compared with immuoblotting techniques. PMID:18486465

  6. A pre-PEXEL histidine-rich protein II erythrocyte binding peptide as a new way for anti-malarial vaccine development.

    PubMed

    Cifuentes, Gladys; Patarroyo, Manuel Elkin; Reyes, Claudia; Córtes, Jimena; Patarroyo, Manuel Alfonso

    2007-08-17

    The Plasmodium falciparum malaria parasite produces several proteins characterised by an unusually high histidine content in infected red blood cells (iRBC). The histidine-rich protein II (HRP-II) is synthesised throughout the parasite's asexual and gametocyte stages, transported through the parasitophorous vacuole (PV) to iRBC cytosol and membrane and released to the bloodstream via a PEXEL motif. Immunogenicity and protection-inducing studies were begun with an RBC high activity binding peptide (HABP) from this protein named 6800 (preceding the PEXEL motif) in the experimental Aotus monkey model. Modifying critical residues (determined by glycine scanning in this HABP) induced immunogenicity and protection against experimental challenge. Native 6800 did not bind to any HLA-DRbeta(1)(*) molecule, but these modified HABPs acquired the ability to specifically bind to HLA-DRbeta(1)(*)0701. (1)H NMR studies revealed that whilst 6800 had a random structure, modified immunogenic and protection-inducing 24230 displayed very short alpha-helical segments allowing appropriate binding to the MHCII-pep-TCR complex. Modifications in conserved HABPs preceding PEXEL motifs thus open up new avenues for subunit-based, multi-component synthetic anti-malarial vaccine development.

  7. The collagen derived dipeptide hydroxyprolyl-glycine promotes C2C12 myoblast differentiation and myotube hypertrophy.

    PubMed

    Kitakaze, Tomoya; Sakamoto, Tomotaka; Kitano, Takehiro; Inoue, Naoki; Sugihara, Fumihito; Harada, Naoki; Yamaji, Ryoichi

    2016-09-23

    The majority of studies on possible roles for collagen hydrolysates in human health have focused on their effects on bone and skin. Hydroxyprolyl-glycine (Hyp-Gly) was recently identified as a novel collagen hydrolysate-derived dipeptide in human blood. However, any possible health benefits of Hyp-Gly remain unclear. Here, we report the effects of Hyp-Gly on differentiation and hypertrophy of murine skeletal muscle C2C12 cells. Hyp-Gly increased the fusion index, the myotube size, and the expression of the myotube-specific myosin heavy chain (MyHC) and tropomyosin structural proteins. Hyp-Gly increased the phosphorylation of Akt, mTOR, and p70S6K in myoblasts, whereas the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 inhibited their phosphorylation by Hyp-Gly. LY294002 and the mammalian target of rapamycin (mTOR) inhibitor rapamycin repressed the enhancing effects of Hyp-Gly on MyHC and tropomyosin expression. The peptide/histidine transporter 1 (PHT1) was highly expressed in both myoblasts and myotubes, and co-administration of histidine inhibited Hyp-Gly-induced phosphorylation of p70S6K in myoblasts and myotubes. These results indicate that Hyp-Gly can induce myogenic differentiation and myotube hypertrophy and suggest that Hyp-Gly promotes myogenic differentiation by activating the PI3K/Akt/mTOR signaling pathway, perhaps depending on PHT1 for entry into cells.

  8. The collagen derived dipeptide hydroxyprolyl-glycine promotes C2C12 myoblast differentiation and myotube hypertrophy.

    PubMed

    Kitakaze, Tomoya; Sakamoto, Tomotaka; Kitano, Takehiro; Inoue, Naoki; Sugihara, Fumihito; Harada, Naoki; Yamaji, Ryoichi

    2016-09-23

    The majority of studies on possible roles for collagen hydrolysates in human health have focused on their effects on bone and skin. Hydroxyprolyl-glycine (Hyp-Gly) was recently identified as a novel collagen hydrolysate-derived dipeptide in human blood. However, any possible health benefits of Hyp-Gly remain unclear. Here, we report the effects of Hyp-Gly on differentiation and hypertrophy of murine skeletal muscle C2C12 cells. Hyp-Gly increased the fusion index, the myotube size, and the expression of the myotube-specific myosin heavy chain (MyHC) and tropomyosin structural proteins. Hyp-Gly increased the phosphorylation of Akt, mTOR, and p70S6K in myoblasts, whereas the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 inhibited their phosphorylation by Hyp-Gly. LY294002 and the mammalian target of rapamycin (mTOR) inhibitor rapamycin repressed the enhancing effects of Hyp-Gly on MyHC and tropomyosin expression. The peptide/histidine transporter 1 (PHT1) was highly expressed in both myoblasts and myotubes, and co-administration of histidine inhibited Hyp-Gly-induced phosphorylation of p70S6K in myoblasts and myotubes. These results indicate that Hyp-Gly can induce myogenic differentiation and myotube hypertrophy and suggest that Hyp-Gly promotes myogenic differentiation by activating the PI3K/Akt/mTOR signaling pathway, perhaps depending on PHT1 for entry into cells. PMID:27553280

  9. Spectrophotometric Determination of Iron(III)-Glycine Formation Constant in Aqueous Medium Using Competitive Ligand Binding

    ERIC Educational Resources Information Center

    Prasad, Rajendra; Prasad, Surendra

    2009-01-01

    The formation constant of iron(III) complex with glycine (Gly) ligand in aqueous acidic medium (0.2 M HNO[subscript 3], I = 0.2 M at 28 plus or minus 1 degree C) was determined spectrophotometrically in which a competing color reaction between Fe(III) and SCN[superscript -] was used as an indicator reaction. Under the specified conditions Fe(III)…

  10. Functional analyses of carnivorous plant-specific amino acid residues in S-like ribonucleases.

    PubMed

    Arai, Naoki; Nishimura, Emi; Kikuchi, Yo; Ohyama, Takashi

    2015-09-11

    Unlike plants with no carnivory, carnivorous plants seem to use S-like ribonucleases (RNases) as an enzyme for carnivory. Carnivorous plant-specific conserved amino acid residues are present at four positions around the conserved active site (CAS). The roles of these conserved amino acid residues in the enzymatic function were explored in the current study by preparing five recombinant variants of DA-I, the S-like RNase of Drosera adelae. The kcat and kcat/Km values of the enzymes revealed that among the four variants with a single mutation, the serine to glycine mutation at position 111 most negatively influenced the enzymatic activity. The change in the bulkiness of the amino acid residue side-chain seemed to be the major cause of the above effect. Modeling of the three dimensional (3D) structures strongly suggested that the S to G mutation at 111 greatly altered the overall enzyme conformation. The conserved four amino acid residues are likely to function in keeping the two histidine residues, which are essential for the cleavage of RNA strands, and the CAS in the most functional enzymatic conformation.

  11. Alterations in the levels of plasma amino acids in polycystic ovary syndrome- A pilot study

    PubMed Central

    Unni, C. Sumithra N.; Lakshman, Lakshmi R.; Vaidyanathan, Kannan; Subhakumari, K.N.; Menon, N. Leela

    2015-01-01

    Background & objectives: Plasma amino acid levels are known to be altered in conditions like sepsis and burns which are situations of metabolic stress. Polycystic ovary syndrome (PCOS), a condition which affects a woman throughout her life, is said to be associated with metabolic stress. This study was undertaken to assess if there were significant alterations in the levels of plasma amino acids in women with PCOS. Methods: Sixty five women with PCOS along with the similar number of age matched normal controls were included in this study. Levels of 14 amino acids were determined using reverse phase high performance liquid chromatography. Results: The levels of methionine, cystine, isoleucine, phenylalanine, valine, tyrosine, proline, glycine, lysine and histidine were found to be significantly (P<0.001) lower in cases than in controls. Arginine and alanine levels were found to be significantly (P<0.001) higher in cases compared with controls. Interpretation & conclusions: Our findings showed significant derangement in the levels of plasma amino acids in women with PCOS which might be due to the oxidative and metabolic stress associated with it. Further studies need to be done to confirm the findings. PMID:26658589

  12. Functional analyses of carnivorous plant-specific amino acid residues in S-like ribonucleases.

    PubMed

    Arai, Naoki; Nishimura, Emi; Kikuchi, Yo; Ohyama, Takashi

    2015-09-11

    Unlike plants with no carnivory, carnivorous plants seem to use S-like ribonucleases (RNases) as an enzyme for carnivory. Carnivorous plant-specific conserved amino acid residues are present at four positions around the conserved active site (CAS). The roles of these conserved amino acid residues in the enzymatic function were explored in the current study by preparing five recombinant variants of DA-I, the S-like RNase of Drosera adelae. The kcat and kcat/Km values of the enzymes revealed that among the four variants with a single mutation, the serine to glycine mutation at position 111 most negatively influenced the enzymatic activity. The change in the bulkiness of the amino acid residue side-chain seemed to be the major cause of the above effect. Modeling of the three dimensional (3D) structures strongly suggested that the S to G mutation at 111 greatly altered the overall enzyme conformation. The conserved four amino acid residues are likely to function in keeping the two histidine residues, which are essential for the cleavage of RNA strands, and the CAS in the most functional enzymatic conformation. PMID:26235877

  13. The reaction of a platinated methionine motif of CTR1 with cysteine and histidine is dependent upon the type of precursor platinum complex.

    PubMed

    Ma, Guolin; Wu, Qin; Wu, Xuelei; Arnesano, Fabio; Natile, Giovanni; Sletten, Einar; Liu, Yangzhong

    2015-12-01

    The human copper protein (hCTR1) is believed to facilitate the cellular uptake of cisplatin. Cisplatin likely binds to the methionine (Met)-rich motifs located in the N-terminus of hCTR1, and ligand exchange would be essential if cisplatin has to pass through the hCTR1 channel. In this work, we investigated the reaction between platinated adducts of a methionine-rich motif of yeast CTR1 (Mets7) and N-acetyl-cysteine (AcCys) or N-acetyl-histidine (AcHis), mimicking metal-binding residues downstream the CTR1 channel. Platination involved two cis-compounds, cisplatin and oxaliplatin, and one monofunctional complex, cis-diammine(pyridine)chloridoplatinum(II) (cDPCP). The reactions were monitored by HPLC and the products were characterized by ESI-MS. The results indicate different reactivities depending upon the platinum complex. The cisplatin/Mets7 adduct reacts readily with both cysteine and histidine (t1/2<2min). In contrast, the oxaliplatin/Mets7 adduct reacts with cysteine but not with histidine, whereas cDPCP/Mets7 adduct reacts with histidine but not with cysteine. Hence, Mets7 adducts of these platinum complexes exhibit different reactivities towards downstream coordinating amino acids. These results suggest that each platinum complex possesses different reactivities and consequently may lead to differences in their cellular distribution and bioactivity.

  14. Evaluation of mechanical properties of some glycine complexes

    SciTech Connect

    Nagaraju, D.; Raja Shekar, P. V.; Chandra, Ch. Sateesh; Rao, K. Kishan; Krishna, N. Gopi

    2014-04-24

    The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young’s modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

  15. 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.

  16. Claisen-type addition of glycine to pyridoxal in water.

    PubMed

    Toth, Krisztina; Amyes, Tina L; Richard, John P; Malthouse, J Paul G; NíBeilliú, Máire E

    2004-09-01

    The reaction between 5'-deoxypyridoxal and glycine in D2O buffered at pD 7.0 does not result in significant formation of the expected products of pyridoxal-catalyzed transamination or deuterium exchange of the alpha-amino protons of glycine, but rather gives a quantitative yield of the two diastereomeric products of the formal Claisen-type addition of glycine to 5'-deoxypyridoxal. The unexpected extensive formation of these products reflects the extraordinary selectivity of the 5'-deoxypyridoxal-stabilized glycine enolate toward addition to the carbonyl group of 5'-deoxypyridoxal in the protic solvent water.

  17. Effect of amino acids on the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in creatinine/phenylalanine and creatinine/phenylalanine/4-oxo-2-nonenal reaction mixtures.

    PubMed

    Zamora, Rosario; Alcón, Esmeralda; Hidalgo, Francisco J

    2013-12-15

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation in mixtures of creatinine, phenylalanine, amino acids and 4-oxo-2-nonenal was studied, to analyse the role of amino acids on the generation of this heterocyclic aromatic amine. When oxidised lipid was absent, cysteine, serine, aspartic acid, threonine, asparagine, tryptophan, tyrosine, proline, and methionine increased significantly (p < 0.05) the amount of PhIP formed in comparison to the control. When lipid was present, only the addition of methionine, glycine, and serine increased significantly (p < 0.05) the amount of PhIP produced, while histidine, cysteine, lysine, tryptophan, tyrosine, and alanine reduced significantly (p < 0.05) PhIP. These results may be a consequence of the different competitive reactions that occur. Thus, in the absence of lipids, thermal decomposition of the amino acids produced reactive carbonyls that converted phenylalanine into phenylacetaldehyde as a key step in the formation of PhIP. When oxidised lipid was present, amino acids competed with phenylalanine for the lipid, and amino acid degradation products were formed, among which alpha-keto acids seemed to play a role in these reactions. These results suggest that PhIP can be produced by several alternative reaction pathways from all major food components, including amino acids and lipids, in addition to carbohydrates. PMID:23993611

  18. Effect of amino acids on the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in creatinine/phenylalanine and creatinine/phenylalanine/4-oxo-2-nonenal reaction mixtures.

    PubMed

    Zamora, Rosario; Alcón, Esmeralda; Hidalgo, Francisco J

    2013-12-15

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation in mixtures of creatinine, phenylalanine, amino acids and 4-oxo-2-nonenal was studied, to analyse the role of amino acids on the generation of this heterocyclic aromatic amine. When oxidised lipid was absent, cysteine, serine, aspartic acid, threonine, asparagine, tryptophan, tyrosine, proline, and methionine increased significantly (p < 0.05) the amount of PhIP formed in comparison to the control. When lipid was present, only the addition of methionine, glycine, and serine increased significantly (p < 0.05) the amount of PhIP produced, while histidine, cysteine, lysine, tryptophan, tyrosine, and alanine reduced significantly (p < 0.05) PhIP. These results may be a consequence of the different competitive reactions that occur. Thus, in the absence of lipids, thermal decomposition of the amino acids produced reactive carbonyls that converted phenylalanine into phenylacetaldehyde as a key step in the formation of PhIP. When oxidised lipid was present, amino acids competed with phenylalanine for the lipid, and amino acid degradation products were formed, among which alpha-keto acids seemed to play a role in these reactions. These results suggest that PhIP can be produced by several alternative reaction pathways from all major food components, including amino acids and lipids, in addition to carbohydrates.

  19. 21 CFR 176.160 - Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Chromium (Cr III) complex of N-ethyl-N... § 176.160 Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine. The chromium... by weight of the chromium (Cr III) complex of heptadecylfluoro-octane sulfonic acid may be...

  20. Formation of intersubunit disulfide bonds and properties of the single histidine and cysteine residues in each subunit relative to the decameric structure of cyanase.

    PubMed

    Anderson, P M; Korte, J J; Holcomb, T A; Cho, Y G; Son, C M; Sung, Y C

    1994-05-27

    Reaction of the single cysteine residue in each subunit of cyanase with certain SH reagents gives an active decameric derivative that dissociates reversibly to an inactive dimer derivative (Anderson, P. M., Johnson, W. V., Korte, J. J., Xiong, X., Sung, Y.-c., and Fuchs, J. A. (1988) J. Biol. Chem. 263, 5674-5680). Reaction of mixed disulfide dimer derivatives of cyanase with dithiothreitol at 0 degree C results in formation of a disulfide bond between the subunits in the dimer. The disulfide dimer was inactive and did not associate to a decamer; the intersubunit disulfide bond could not be formed when the dimers were associated as a decamer. The two SH groups apparently are in close proximity to each other in the dissociated dimer but not when the dimer is associated to a decamer. Substitution of glycine for the cysteine residue or of tyrosine, asparagine, glycine, valine, or leucine for the single histidine residue in each subunit gave mutant enzymes that were active. However, H113N, H113Y, and C83G were unstable at low temperature and/or ionic strength, dissociating reversibly to an inactive dimer. Efficient reassociation required the presence of bicarbonate or cyanate analog. The results are consistent with a proposed single site per subunit model explaining apparent half-site binding of substrates and the requirement of decameric structure for activity.

  1. Mass spectrometric analysis of catechol-histidine adducts from insect cuticle.

    PubMed

    Kerwin, J L; Turecek, F; Xu, R; Kramer, K J; Hopkins, T L; Gatlin, C L; Yates, J R

    1999-03-15

    Adducts of catechols and histidine, which are produced by reactions of 1,2-quinones and p-quinone methides with histidyl residues in proteins incorporated into the insect exoskeleton, were characterized using electrospray ionization mass spectrometry (ESMS), tandem electrospray mass spectrometry (ESMS-MS, collision-induced dissociation), and ion trap mass spectrometry (ITMS). Compounds examined included adducts obtained from acid hydrolysates of Manduca sexta (tobacco hornworm) pupal cuticle exuviae and products obtained from model reactions under defined conditions. The ESMS and ITMS spectra of 6-(N-3')-histidyldopamine [6-(N-3')-His-DA, pi isomer] isolated from M. sexta cuticle were dominated by a [M + H]+ ion at m/z 308, rather than the expected m/z 307. High-resolution fast atom bombardment MS yielded an empirical formula of C14H18N3O5, which was consistent with this compound being 6-(N-1')-histidyl-2-(3, 4-dihydroxyphenyl)ethanol [6-(N-1')-His-DOPET] instead of a DA adduct. Similar results were obtained when histidyl-catechol compounds linked at C-7 of the catechol were examined; the (N-1') isomer was confirmed as a DA adduct, and the (N-3') isomer identified as an (N-1')-DOPET derivative. Direct MS analysis of unfractionated cuticle hydrolysate revealed intense parent and product ions characteristic of 6- and 7-linked adducts of histidine and DOPET. Mass spectrometric analysis of model adducts synthesized by electrochemical oxidative coupling of N-acetyldopamine (NADA) quinone and N-acetylhistidine (NAcH) identified the point of attachment in the two isomers. A prominent product ion corresponding to loss of CO2 from [M + H]+ of 2-NAcH-NADA confirmed this as being the (N-3') isomer. Loss of (H2O + CO) from 6-NAcH-NADA suggested that this adduct was the (N-1') isomer. The results support the hypothesis that insect cuticle sclerotization involves the formation of C-N cross-links between histidine residues in cuticular proteins, and both ring and side

  2. Prebiotic synthesis of imidazole-4-acetaldehyde and histidine

    NASA Technical Reports Server (NTRS)

    Shen, Chun; Oro, J.; Yang, Lily; Miller, Stanley L.

    1987-01-01

    The prebiotic synthesis of imidazole-4-acetaldehyde and imidazole-4-glycol from erythrose and formamidine has been demonstrated as well as the prebiotic synthesis of imidazole-4-ethanol and imidazole-4-glycol from erythrose, formaldehyde, and ammonia. The maximum yields of imidazole-4-acetaldehyde, imidazole-4-ethanol, and imidazole-4-glycol obtained in these reactions are 1.6, 5.4, and 6.8 percent respectively, based on the erythrose. Imidazole-4-acetaldehyde would have been converted to histidine on the primitive earth by a Strecker synthesis, and several prebiotic reactions would convert imidazole-4-glycol and imidazole-4-ethanol to imidazole-4-acetaldehyde.

  3. Novel Pectate Lyase Genes of Heterodera glycines Play Key Roles in the Early Stage of Parasitism

    PubMed Central

    Peng, Huan; Cui, Jiangkuan; Long, Haibo; Huang, Wenkun; Kong, Lingan; Liu, Shiming; He, Wenting; Hu, Xianqi; Peng, Deliang

    2016-01-01

    Pectate lyases are known to play a key role in pectin degradation by catalyzing the random cleavage of internal polymer linkages (endo-pectinases). In this paper, four novel cDNAs, designated Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7, that encode pectate lyases were cloned and characterized from the soybean cyst nematode, Heterodera glycines. The predicted protein sequences of HG-PEL-3, HG-PEL-4 and HG-PEL-6 differed significantly in both their amino acid sequences and their genomic structures from other pectate lyases of H. glycines (HG-PEL-1, HG-PEL-2 and HG-PEL-7). A phylogenetic study revealed that the pectate lyase proteins of H. glycines are clustered into distinct clades and have distinct numbers and positioning of introns, which suggests that the pectate lyase genes of H. glycines may have evolved from at least two ancestral genes. A Southern blot analysis revealed that multiple Hg-pel-6-like genes were present in the H. glycines genome. In situ hybridization showed that four novel pectate lyases (Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7) were actively transcribed in the subventral esophageal gland cells. A semi-quantitative RT-PCR assay supported the finding that the expression of these genes was strong in the egg, pre-parasitic second-stage juvenile (J2) and early parasitic J2 stages and that it declined in further developmental stages of the nematode. This expression pattern suggests that these proteins play a role in the migratory phase of the nematode life cycle. Knocking down Hg-pel-6 using in vitro RNA interference resulted in a 46.9% reduction of the number of nematodes that invaded the plants and a 61.5% suppression of the development of H. glycines females within roots compared to the GFP-dsRNA control. Plant host-derived RNAi induced the silencing of the Hg-pel-6gene, which significantly reduced the nematode infection levels at 7 Days post inoculation (dpi). Similarly, this procedure reduced the number of female adults at 40 dpi, which suggests