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Sample records for alanine glycine lysine

  1. NQR in Alanine and Lysine Iodates

    NASA Astrophysics Data System (ADS)

    Petrosyan, A. M.; Burbelo, V. M.; Tamazyan, R. A.; Karapetyan, H. A.; Sukiasyan, R. P.

    2000-02-01

    The structure o f iodates of α- and β-alanine ( Ala) (2(β-Ala • HIO3) • H2O , β-Ala-2HIO3 , D L-Ala• HIO3 • 2H2O, L-Ala • HIO3) and L-lysine (L-Lys) (L-Lys • HIO3, L-Lys • 2HIO3,L-Lys • 3HIO3, L-Lys • 6HIO3) have been investigated by means of iodine-127 NQR, IR spectroscopy and X-ray diffraction

  2. 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.

  3. Beta-alanine and taurine as endogenous agonists at glycine receptors in rat hippocampus in vitro.

    PubMed

    Mori, Masahiro; Gähwiler, Beat H; Gerber, Urs

    2002-02-15

    Electrophysiological and pharmacological properties of glycine receptors were characterized in hippocampal organotypic slice cultures. In the presence of ionotropic glutamate and GABA(B) receptor antagonists, pressure-application of glycine onto CA3 pyramidal cells induced a current associated with increased chloride conductance, which was inhibited by strychnine. Similar chloride currents could also be induced with beta-alanine or taurine. Whole-cell glycine responses were significantly greater in CA3 pyramidal cells than in CA1 pyramidal cells and dentate granule cells, while responses to GABA were similar among these three cell types. Although these results demonstrate the presence of functional glycine receptors in the hippocampus, no evidence for their activation during synaptic stimulation was found. Gabazine, a selective GABA(A) receptor antagonist, totally blocked evoked IPSCs in CA3 pyramidal cells. Glycine receptor activation is not dependent on transporter-controlled levels of extracellular glycine, as no chloride current was observed in response to sarcosine, an inhibitor of glycine transporters. In contrast, application of guanidinoethanesulfonic acid, an uptake inhibitor of beta-alanine and taurine, induced strychnine-sensitive chloride current in the presence of gabazine. These data indicate that modulation of transporters for the endogenous amino acids, beta-alanine and taurine, can regulate tonic activation of glycine receptors, which may function in maintenance of inhibitory tone in the hippocampus.

  4. Positron and electron scattering by glycine and alanine: Shape resonances and methylation effect

    NASA Astrophysics Data System (ADS)

    Nunes, Fernanda B.; Bettega, Márcio H. F.; Sanchez, Sergio d'Almeida

    2016-12-01

    We report integral cross sections (ICSs) for both positron and electron scattering by glycine and alanine amino acids. These molecules differ only by a methyl group. We computed the scattering cross sections using the Schwinger multichannel method for both glycine and alanine in different levels of approximation for both projectiles. The alanine ICSs are greater in magnitude than the glycine ICSs for both positron and electron scattering, probably due to the larger size of the molecule. In electron scattering calculations, we found two resonances for each molecule. Glycine presents one at 1.8 eV, and another centered at around 8.5 eV, in the static-exchange plus polarization (SEP) approximation. The ICS for alanine shows one resonance at 2.5 eV and another at around 9.5 eV, also in SEP approximation. The results are in good agreement with most of the data present in the literature. The comparison of the electron scattering ICSs for both molecules indicates that the methylation of glycine destabilizes the resonances, shifting them to higher energies.

  5. Influence of lysine content and pH on the stability of alanine-based copolypeptides.

    PubMed

    Vila, J A; Ripoll, D R; Scheraga, H A

    2001-03-01

    To account for the relative contributions of lysine and alanine residues to the stability of alpha-helices of copolymers of these two residues, conformational energy calculations were carried out for several hexadecapeptides at several pHs. All the calculations considered explicitly the coupling between the conformation of the molecule and the ionization equilibria as a function of pH. The total free energy function used in these calculations included terms that account for the solvation free energy and free energy of ionization. These terms were evaluated by means of a fast multigrid boundary element method. Reasonable agreement with experimental values was obtained for the helix contents and vicinal coupling constants ((3)J(HNalpha)). The helix contents were found to depend strongly on the lysine content, in agreement with recent experimental results of Williams et al. (Journal of the American Chemical Society, 1998, Vol. 120, pp. 11033-11043) In the lowest energy conformation computed for a hexadecapeptide containing 3 lysine residues at pH 6, the lysine side chains are preferentially hydrated; this decreases the hydration of the backbone CO and NH groups, thereby forcing the latter to form hydrogen bonds with each other in the helical conformation. The lowest energy conformation computed for a hexadecapeptide containing 6 lysine residues at pH 6 shows a close proximity between the NH3(+) groups of the lysine side chains, a feature that was previously observed in calculations of short alanine-based oligopeptides. The calculation on a blocked 16-mer of alanine shows a 7% helix content based on the Boltzmann averaged vicinal coupling constants computed from the dihedral angles phi, consistent with previous experimental evidence on triblock copolymers containing a central block of alanines, and with earlier theoretical calculations.

  6. GABA, β-alanine and glycine in the digestive juice of privet-specialist insects: convergent adaptive traits against plant iridoids.

    PubMed

    Konno, Kotaro; Hirayama, Chikara; Yasui, Hiroe; Okada, Sachiko; Sugimura, Masahiro; Yukuhiro, Fumiko; Tamura, Yasumori; Hattori, Makoto; Shinbo, Hiroshi; Nakamura, Masatoshi

    2010-09-01

    The privet tree, Ligustrum obtusifolium (Oleaceae), defends its leaves against insects with a strong lysine-decreasing activity that make proteins non-nutritive. This is caused by oleuropein, an iridoid glycoside. We previously found that some privet-specialist caterpillars adapt by secreting glycine in the digestive juice as a neutralizer that prevents the loss of lysine. Here, we extended the survey into 42 lepidopteran and hymenopteran species. The average concentration of glycine in digestive juice for 11 privet-feeding species (40.396 mM) was higher than that for 32 non-privet-feeding species (2.198 mM). The glycine concentrations exceeded 10 mM in 7 out of 11 privet-feeding species. In Macrophya timida (Hymenoptera), it reached 164.8 mM. Three out of the four remaining privet-feeding species had other amino acids instead. Larvae of a privet-specialist butterfly, Artopoetes pryeri (Lycaenidae), had a high concentration (60.812 mM) of GABA. In two other specialists, β-alanine was found. GABA, β-alanine, and glycine as well as alanine, amines, and ammonium ion inhibited the lysine decrease, indicating that amino residues are responsible for the inhibition. However, the three amino acids found in the specialists were far more effective (20 mM showed 80% inhibition) than the rest (>140 mM was required for 80% inhibition). Our results show a clear and rare case of the apparent convergent evolution of herbivores' molecular adaptations of feeding on a plant with a chemical defense in a manner that minimizes the cost of adaptation. The novel role of GABA in plant-herbivore interactions shown here is probably the first reported non-neuronal role of animal-derived GABA.

  7. Formation of homochiral glycine/Cu(111) quantum corral array realized using alanine nuclei

    NASA Astrophysics Data System (ADS)

    Nakamura, Miki; Huang, Hui; Kanazawa, Ken; Taninaka, Atsushi; Yoshida, Shoji; Takeuchi, Osamu; Shigekawa, Hidemi

    2015-08-01

    Glycine has enantiomeric isomers on a Cu(111) surface through the dissociation of hydrogen from the carboxyl group and forms an array of quantum corrals of ∼1.3 nm diameter. Stable homo-chiral glycinate trimers are formed in the first step, which subsequently form a network with a hexagonal arrangement. However, domains with R- or S-chirality coexist with the same probability. On the other hand, α-alanine has D- and L-chirality in nature and forms a similar quantum corral array on Cu(111) with R- and S-chirality, respectively. Here, by using α-alanine molecules as nuclei, the chirality of glycine molecules was controlled and a homochiral quantum corral array was successfully formed, which indicates the possibility that the optical isomers can be separated through a method such as preferential crystallization.

  8. Structure-function relationship in the antifreeze activity of synthetic alanine-lysine antifreeze polypeptides.

    PubMed

    Wierzbicki, A; Knight, C A; Rutland, T J; Muccio, D D; Pybus, B S; Sikes, C S

    2000-01-01

    Recently antifreeze proteins (AFP) have been the subject of many structure-function relationship studies regarding their antifreeze activity. Attempts have been made to elucidate the structure-function relationship by various amino acid substitutions, but to our knowledge there has been no successful from first principles design of a polypeptide that would bind to designated ice planes along a specific direction. In this paper we show the results of our first attempt on an entirely de novo design of an alanine-lysine-rich antifreeze polypeptide. This 43 residue alanine-lysine peptide exhibits characteristic nonequilibrium freezing point depression and binds to the designated (210) planes of ice along the [122] vector. The structural and thermodynamic properties of this polypeptide were determined using circular dichroism spectroscopy and its nonequilibrium antifreeze properties were investigated using an ice-etching method and nanoliter osmometry.

  9. 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.

  10. Effects of glycine, beta-alanine and diazepam upon morphine-tolerant-dependent mice.

    PubMed

    Contreras, E; Tamayo, L

    1980-05-01

    The effects in mice of glycine, beta-alanine and diazepam on the analgesic response to morphine, on the intensity of tolerance and on the physical dependence on the analgesic have been examined. The two amino acids increased the analgesic response to morphine in a dose-related manner. However, both compounds were ineffective in the analgesic test (hot plate) when administered without morphine. Diazepam was ineffective in the analgesic test and it did not alter morphine analgesia, except when administered in a high dose which decreased and analgesic response. Glycine, either in single or repeated doses, did not modify tolerance to morphine, whereas beta-alanine induced a dose-related partial antagonism, which promptly reached a plateau. Diazepam induced a small decrease in the intensity of tolerance to the analgesic. The abstinence syndrome to morphine, induced by naloxone administration to primed mice, was reduced by single doses of glycine or beta-alanine. Diazepam behaved as a weak inhibitor of the abstinence syndrome when administered at a high dose. The potentiation of morphine analgesia and the antagonism of the abstinence syndrome induced by the amino acids may be related to their hyperpolarizing action in the c.n. system. The effects of beta-alanine on morphine tolerance cannot be explained by the same mechanism.

  11. Mutation of glycine receptor subunit creates beta-alanine receptor responsive to GABA.

    PubMed

    Schmieden, V; Kuhse, J; Betz, H

    1993-10-08

    The amino acid at position 160 of the ligand-binding subunit, alpha 1, is an important determinant of agonist and antagonist binding to the glycine receptor. Exchange of the neighboring residues, phenylalanine at position 159 and tyrosine at position 161, increased the efficacy of amino acid agonists. Whereas wild-type alpha 1 channels expressed in Xenopus oocytes required 0.7 millimolar beta-alanine for a half-maximal response, the doubly mutated (F159Y,Y161F) alpha 1 subunit had an affinity for beta-alanine (which was more potent than glycine) that was 110-fold that of the wild type. Also, gamma-aminobutyric acid and D-serine, amino acids that do not activate wild-type alpha 1 receptors, efficiently gated the mutant channel. Thus, aromatic hydroxyl groups are crucial for ligand discrimination at inhibitory amino acid receptors.

  12. Stabilization of helices in glycine and alanine dipeptides in a reaction field model of solvent

    SciTech Connect

    Shang, H.S. Lawrence Berkeley Lab., CA ); Head-Gordon, T. )

    1994-02-23

    We present molecular orbital calculations of the full conformational space of blocked glycine and alanine dipeptide in the presence of a reaction field representation of water. Secondary structures of right- and left-handed helices are found, in contrast to recent gas-phase results, indicating that the origin of helical stabilization in dipeptides is strictly due to environment. Limitations of the reaction field model and the various implications of stabilization due to environment are discussed. 43 refs., 2 figs., 3 tabs.

  13. An overlooked effect of glycine betaine on fermentation: prevents caramelization and increases the L-lysine production.

    PubMed

    Xu, Jianzhong; Xia, Xiuhua; Zhang, Junlan; Guo, Yanfeng; Zhang, Weiguo

    2014-10-01

    This article focuses on the effects of glycine betaine on preventing caramelization, and increasing DCW and L-lysine production. The additional glycine betaine not only decreased the browning intensity (decreased 4 times), and the concentrations of 5-hydroxymethylfurfural (decreased 7.8 times) and furfural (decreased 12 times), but also increased the availability of glucose (increased 17.5%) for L-lysine production. The DCW and L-lysine production were increased by adding no more than 20 mM glycine betaine, whereas the DCW and L-lysine production were decreased with the reduction of pH values, although pH had a better response to prevent caramelization than did glycine betaine. For L-lysine production, the highest increase (40%) was observed on the media with 20 mM glycine betaine. The crucial enzymes in glycolysis and L-lysine biosynthesis pathway were investigated. The results indicated that additional glycine betaine increases the activity of enzymes in glycolysis, in contrast to the effect of pH. All the results indicated that glycine betaine can be used to prevent caramelization and increase the L-lysine production. By applying this strategy, glucose would not be have to be separated from the culture media during autoclaving so that factories can save production costs and shorten the fermentation period.

  14. Effect of lysine to alanine mutations on the phosphate activation and BPTES inhibition of glutaminase.

    PubMed

    McDonald, Charles J; Acheff, Eric; Kennedy, Ryan; Taylor, Lynn; Curthoys, Norman P

    2015-09-01

    The GLS1 gene encodes a mitochondrial glutaminase that is highly expressed in brain, kidney, small intestine and many transformed cells. Recent studies have identified multiple lysine residues in glutaminase that are sites of N-acetylation. Interestingly, these sites are located within either a loop segment that regulates access of glutamine to the active site or the dimer:dimer interface that participates in the phosphate-dependent oligomerization and activation of the enzyme. These two segments also contain the binding sites for bis-2[5-phenylacetamido-1,2,4-thiadiazol-2-yl]ethylsulfide (BPTES), a highly specific and potent uncompetitive inhibitor of this glutaminase. BPTES is also the lead compound for development of novel cancer chemotherapeutic agents. To provide a preliminary assessment of the potential effects of N-acetylation, the corresponding lysine to alanine mutations were constructed in the hGACΔ1 plasmid. The wild type and mutated proteins were purified by Ni(+)-affinity chromatography and their phosphate activation and BPTES inhibition profiles were analyzed. Two of the alanine substitutions in the loop segment (K311A and K328A) and the one in the dimer:dimer interface (K396A) form enzymes that require greater concentrations of phosphate to produce half-maximal activation and exhibit greater sensitivity to BPTES inhibition. By contrast, the K320A mutation results in a glutaminase that exhibits near maximal activity in the absence of phosphate and is not inhibited by BPTES. Thus, lysine N-acetylation may contribute to the acute regulation of glutaminase activity in various tissues and alter the efficacy of BPTES-type inhibitors.

  15. The role of metal ions in chemical evolution - Polymerization of alanine and glycine in a cation-exchanged clay environment

    NASA Technical Reports Server (NTRS)

    Lawless, J. G.; Levi, N.

    1979-01-01

    The effect of the exchangeable cation on the condensation of glycine and alanine was investigated using a series of homoionic bentonites. A cycling procedure of drying, warming and wetting was employed. Peptide bond formation was observed, and the effectiveness of metal ions to catalyze the condensation was Cu(2+) greater than Ni(2) approximately equals Zn(2+) greater than Na(+). Glycine showed 6% of the monomer incorporated into oligomers with the largest detected being the pentamer. Alanine showed less peptide bond formation (a maximum of 2%) and only the dimer was observed.

  16. Exploiting the right side of the Ramachandran plot: substitution of glycines by D-alanine can significantly increase protein stability.

    PubMed

    Anil, Burcu; Song, Benben; Tang, Yuefeng; Raleigh, Daniel P

    2004-10-20

    A major goal of protein engineering is the enhancement of protein stability. Here we demonstrate a rational method for enhancing the stability of globular proteins by targeting glycine residues which adopt conformations with Phi > 0. Replacement of such a glycine by d-alanine can lead to a significant increase in stability. The approach is tested at three sites in two model proteins. NMR and CD indicated that the substitutions do not alter the structure. Replacement of glycine-24 of the N-terminal domain of L9 (NTL9) with d-Ala results in an increase in stability of 1.3 kcal mol-1, while replacement of glycine-34 of NTL9 leads to an increase of 1.9 kcal mol-1. Replacement of glycine-331 of the UBA domain with d-Ala leads to an increase in stability of 0.6 kcal mol-1.

  17. A single glycine-alanine exchange directs ligand specificity of the elephant progestin receptor.

    PubMed

    Wierer, Michael; Schrey, Anna K; Kühne, Ronald; Ulbrich, Susanne E; Meyer, Heinrich H D

    2012-01-01

    The primary gestagen of elephants is 5α-dihydroprogesterone (DHP), which is unlike all other mammals studied until now. The level of DHP in elephants equals that of progesterone in other mammals, and elephants are able to bind DHP with similar affinity to progesterone indicating a unique ligand-binding specificity of the elephant progestin receptor (PR). Using site-directed mutagenesis in combination with in vitro binding studies we here report that this change in specificity is due to a single glycine to alanine exchange at position 722 (G722A) of PR, which specifically increases DHP affinity while not affecting binding of progesterone. By conducting molecular dynamics simulations comparing human and elephant PR ligand-binding domains (LBD), we observed that the alanine methyl group at position 722 is able to push the DHP A-ring into a position similar to progesterone. In the human PR, the DHP A-ring position is twisted towards helix 3 of PR thereby disturbing the hydrogen bond pattern around the C3-keto group, resulting in a lower binding affinity. Furthermore, we observed that the elephant PR ligand-binding pocket is more rigid than the human analogue, which probably explains the higher affinity towards both progesterone and DHP. Interestingly, the G722A substitution is not elephant-specific, rather it is also present in five independent lineages of mammalian evolution, suggesting a special role of the substitution for the development of distinct mammalian gestagen systems.

  18. Analysis of dihedral angle preferences for alanine and glycine residues in alpha and beta transmembrane regions.

    PubMed

    Saravanan, K M; Krishnaswamy, S

    2015-01-01

    For the past 50 years, the Ramachandran map has been used effectively to study the protein structure and folding. However, though extensive analysis has been done on dihedral angle preferences of residues in globular proteins, related studies and reports of membrane proteins are limited. It is of interest to explore the conformational preferences of residues in transmembrane regions of membrane proteins which are involved in several important and diverse biological processes. Hence, in the present work, a systematic comparative computational analysis has been made on dihedral angle preferences of alanine and glycine in alpha and beta transmembrane regions (the two major classes of transmembrane proteins) with the aid of the Ramachandran map. Further, the conformational preferences of residues in transmembrane regions were compared with the non-transmembrane regions. We have extracted cation-pi interacting residues present in transmembrane regions and explored the dihedral angle preferences. From our observations, we reveal the higher percentage of occurrences of glycine in alpha and beta transmembrane regions than other hydrophobic residues. Further, we noted a clear shift in ψ-angle preferences of glycine residues from negative bins in alpha transmembrane regions to positive bins in beta transmembrane regions. Also, cation-pi interacting residues in beta transmembrane regions avoid preferring ψ-angles in the range of -59° to -30°. In this article, we insist that the studies on preferences of dihedral angles in transmembrane regions, thorough understanding of structure and folding of transmembrane proteins, can lead to modeling of novel transmembrane regions towards designing membrane proteins.

  19. Oligomerization of Glycine and Alanine Catalyzed by Iron Oxides: Implications for Prebiotic Chemistry

    NASA Astrophysics Data System (ADS)

    Shanker, Uma; Bhushan, Brij; Bhattacharjee, G.; Kamaluddin

    2012-02-01

    Iron oxide minerals are probable constituents of the sediments present in geothermal regions of the primitive earth. They might have adsorbed different organic monomers (amino acids, nucleotides etc.) and catalyzed polymerization processes leading to the formation of the first living cell. In the present work we tested the catalytic activity of three forms of iron oxides (Goethite, Akaganeite and Hematite) in the intermolecular condensation of each of the amino acids glycine and L-alanine. The effect of zinc oxide and titanium dioxide on the oligomerization has also been studied. Oligomerization studies were performed for 35 days at three different temperatures 50, 90 and 120°C without applying drying/wetting cycling. The products formed were characterized by HPLC and ESI-MS techniques. All three forms of iron oxides catalyzed peptide bond formation (23.2% of gly2 and 10.65% of ala2). The reaction was monitored every 7 days. Formation of peptides was observed to start after 7 days at 50°C. Maximum yield of peptides was found after 35 days at 90°C. Reaction at 120°C favors formation of diketopiperazine derivatives. It is also important to note that after 35 days of reaction, goethite produced dimer and trimer with the highest yield among the oxides tested. We suggest that the activity of goethite could probably be due to its high surface area and surface acidity.

  20. 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.

  1. 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.

  2. Molecular dynamics of glycine ions in alanine doped TGS single crystal as probed by polarized laser raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Bajpai, P. K.; Verma, A. L.

    2012-10-01

    Polarized Raman spectra of pure and alanine doped tri-glycine sulfate (TGS) single crystals at 12 K in different scattering geometries are analyzed. Sub species modes due to three crystallographically distinguishable glycine ions G (I), G (II) and G (III) are assigned. It is observed that alanine doping does not change the crystalline field and acts as local perturbation only. The major changes due to doping are observed in the relative intensities of different modes; most of the modes associated with G (I) and SO42- ions show reversal behavior in relative intensity at high doping concentration. The observed spectral changes are analyzed in terms of reorientation of G (I) ions with sub species modes of G (II)/ G (III) following the reorientation due to complex hydrogen bonding network.

  3. Molecular dynamics of glycine ions in alanine doped TGS single crystal as probed by polarized laser Raman spectroscopy.

    PubMed

    Bajpai, P K; Verma, A L

    2012-10-01

    Polarized Raman spectra of pure and alanine doped tri-glycine sulfate (TGS) single crystals at 12 K in different scattering geometries are analyzed. Sub species modes due to three crystallographically distinguishable glycine ions G (I), G (II) and G (III) are assigned. It is observed that alanine doping does not change the crystalline field and acts as local perturbation only. The major changes due to doping are observed in the relative intensities of different modes; most of the modes associated with G (I) and SO(4)(2-) ions show reversal behavior in relative intensity at high doping concentration. The observed spectral changes are analyzed in terms of reorientation of G (I) ions with sub species modes of G (II)/ G (III) following the reorientation due to complex hydrogen bonding network.

  4. Oligomerization of glycine and alanine on metal(II) octacynaomolybdate(IV): role of double metal cyanides in prebiotic chemistry.

    PubMed

    Kumar, Anand; Kamaluddin

    2012-12-01

    Condensation reactions of amino acid (glycine and alanine) on the surface of metal(II) octacyanomolybdate(IV) (MOCMo) complexes are investigated using high-performance liquid chromatography (HPLC) and electron spray ionizations-mass spectroscopy (ESI-MS). The series of MOCMo have been synthesized and the effect of outer sphere metal ions present in the MOCMo on the oligomerization of glycine and alanine at different temperature and time found out. Formation of peptides was observed to start after 7 days at 60 °C. Maximum yield of peptides was found after 35 days at 90 °C. It has been found that zinc(II) octacyanomolybdate(IV) and cobalt(II) were the most effective metal cations present in outer sphere of the MOCMo for the production of high yield of oligomerized products. Surface area of MOCMo seems to play dominating parameter for the oligomerization of alanine and glycine. The results of the present study reveal the role of MOCMo in chemical evolution for the oligomerization of biomolecules.

  5. Taurine and beta-alanine act on both GABA and glycine receptors in Xenopus oocyte injected with mouse brain messenger RNA.

    PubMed

    Horikoshi, T; Asanuma, A; Yanagisawa, K; Anzai, K; Goto, S

    1988-09-01

    The responding pathway (process from agonist binding to channel opening) of taurine and beta-alanine was investigated in Xenopus oocytes injected with mouse brain poly(A)+ RNA. Responses to gamma-aminobutyric acid (GABA), glycine, taurine and beta-alanine were induced in oocytes injected with poly(A)+ RNA extracted from 3 regions, cerebrum, cerebellum and brainstem of the mouse brain. From comparison, responses to these 4 inhibitory amino acids in each regional poly(A)+ RNA-injected oocytes were categorized into at least 3 groups: (1) GABA, (2) glycine, and (3) taurine and beta-alanine. No cross-desensitization was observed between GABA response and glycine response, but taurine and beta-alanine responses cross-desensitized both the GABA and glycine responses. Taurine and beta-alanine responses were partially inhibited by the GABA antagonist, bicuculline, and also by the glycine antagonist, strychnine. The results suggest that the taurine or the beta-alanine response in the brain is caused through both the GABA receptor and the glycine receptor.

  6. Functional characterization of a member of alanine or glycine: cation symporter family in halotolerant cyanobacterium Aphanothece halophytica.

    PubMed

    Bualuang, Aporn; Kageyama, Hakuto; Tanaka, Yoshito; Incharoensakdi, Aran; Takabe, Teruhiro

    2015-01-01

    Membrane proteins of amino acid-polyamine-organocation (APC) superfamily transport amino acids and amines across membranes and play important roles in the regulation of cellular processes. The alanine or glycine: cation symporter (AGCS) family belongs to APC superfamily and is found in prokaryotes, but its substrate specificity remains to be clarified. In this study, we found that a halotolerant cyanobacterium, Aphanothece halophytica has two putative ApagcS genes. The deduced amino acid sequence of one of genes, ApagcS1, exhibited high homology to Pseudomonas AgcS. The ApagcS1 gene was expressed in Escherichia coli JW4166 which is deficient in glycine uptake. Kinetics studies in JW4166 revealed that ApAgcS1 is a sodium-dependent glycine transporter. Competition experiments showed the significant inhibition by glutamine, asparagine, and glycine. The level of mRNA for ApagcS1 was induced by NaCl and nitrogen-deficient stresses. Uptake of glutamine by ApAgcS1 was also observed. Based on these data, the physiological role of ApAgcS1 was discussed.

  7. Solvation and hydrogen bonding in alanine- and glycine-containing dipeptides probed using solution- and solid-state NMR spectroscopy.

    PubMed

    Bhate, Manasi P; Woodard, Jaie C; Mehta, Manish A

    2009-07-15

    The NMR chemical shift is a sensitive reporter of peptide secondary structure and its solvation environment, and it is potentially rich with information about both backbone dihedral angles and hydrogen bonding. We report results from solution- and solid-state (13)C and (15)N NMR studies of four zwitterionic model dipeptides, L-alanyl-L-alanine, L-alanyl-glycine, glycyl-L-alanine, and glycyl-glycine, in which we attempt to isolate structural and environmental contributions to the chemical shift. We have mapped hydrogen-bonding patterns in the crystalline states of these dipeptides using the published crystal structures and correlated them with (13)C and (15)N magic angle spinning chemical shift data. To aid in the interpretation of the solvated chemical shifts, we performed ab initio quantum chemical calculations to determine the low-energy conformers and their chemical shifts. Assuming low energy barriers to interconversion between thermally accessible conformers, we compare the Boltzmann-averaged chemical shifts with the experimentally determined solvated-state shifts. The results allow us to correlate the observed differences in chemical shifts between the crystalline and solvated states to changes in conformation and hydrogen bonding that occur upon solvation.

  8. N- Trichloro- and dichloroacetyl amino acids and compounds of amino acids with halogeno acetic acids: 35Cl nuclear quadrupole resonance spectroscopy; crystal structure of N- trichloroacetyl- glycine, - DL-alanine, and - L-alanine

    NASA Astrophysics Data System (ADS)

    Dou, Shi-qi; Kehrer, Armin; Ofial, Armin R.; Weiss, Alarich

    1995-02-01

    The crystal structures of N- trichloroacetyl- glycine ( N- TCA- G), N-trichloroacetyl-dl-alanine ( N-TCA- dl-A ), and N-trichloroacetyl- l-alanine ( N-TCA- l-A ) were determined. In addition, the 35Cl NQR spectra of these N-trichloroacetyl amino acids, of N-trichloroacetyl- l-valine ( N-TCA- l-V ), and of N- dichloroacetyl- glycine and - L-alanine were measured, mostly as a function of temperature. Compounds of glycine and L-alanine with chlorodifluoroacetic acid, of glycine and L-leucine with monochloroacetic acid, of glycine and L-leucine with dichloroacetic acid, and of glycine and L-leucine with trichloroacetic acid were also studied using 35Cl NQR. The structures (in picometres and degrees) were found to be as follows. N- TCA- G: Pna2 1, Z = 8, a = 1641, b = 1002, c = 1018. N-TCA- dl-A : {C2}/{c}, Z = 8, a = 3280, b = 556, c = 1031, β = 96.68. N-TCA- l-A: P1 , Z = 2, a = 967, b = 949, c = 619, α = 74.97, β = 74.20, γ = 61.20. The 35Cl NQR frequencies (ν) were observed in the range 35-41 MHz, and decrease with increasing temperature. Some of the resonances bleach out at a temperature ( Tb) far below the melting temperature; this provides information about the crystal structures at 77 K. No phase transitions were observed by differential thermal analysis between 77 and 295 K. The crystal structures are discussed in connection with the NQR results, and conclusions are drawn about the structures of the compounds for which only 35Cl NQR data are available.

  9. Assembly Properties of an Alanine-Rich, Lysine-Containing Peptide and the Formation of Peptide/Polymer Hybrid Hydrogels

    PubMed Central

    Grieshaber, Sarah E.; Nie, Ting; Yan, Congqi; Zhong, Sheng; Teller, Sean S.; Clifton, Rodney J.; Pochan, Darrin J.

    2010-01-01

    We are interested in developing peptide/polymer hybrid hydrogels that are chemically diverse and structurally complex. Towards this end, an alanine-based peptide doped with charged lysines with a sequence of (AKA3KA)2 (AK2) was selected from the crosslinking regions of the natural elastin. Pluronic® F127, known to self-assemble into defined micellar structures, was employed as the synthetic building blocks. Fundamental investigations on the environmental effects on the secondary structure and assembly properties of AK2 peptide were carried out with or without the F-127 micelles. At a relatively low peptide concentration (~0.5 mg/mL), the F127 micelles are capable of not only increasing the peptide helicity but also stabilizing it against thermal denaturation. At a higher peptide concentration in basic media, the AK2 peptide developed a substantial amount of β-sheet structure that is conducive to the formation of nanofibrils. The fibril formation was confirmed collectively by atomic force microscopy (AFM), small angle neutron scattering (SANS) and transmission electron microscopy (TEM). The assembly kinetics is strongly dependent on solution temperature and pH; an increased temperature and a more basic environment led to faster fibril assembly. The self-assembled nanoscale structures were covalently interlocked via the Michael-type addition reaction between vinyl sulfone-decorated F127 micelles and the lysine amines exposed at the surface of the nanofibers. The crosslinked hybrid hydrogels were viscoelastic, exhibiting an elastic modulus of approximately 17 kPa and a loss tangent of 0.2. PMID:21359141

  10. Production of Alanine by Fusarium moniliforme

    PubMed Central

    Carito, Sebastian L.; Pisano, Michael A.

    1966-01-01

    Fusarium moniliforme grown in a chemically defined medium in submerged culture accumulated amino acids extracellularly. Alanine and glutamic acid were present in greatest amounts, with traces of glycine, lysine, threonine, and valine detectable. Increasing the glucose and urea concentrations of the medium increased yields of alanine. Further increases in alanine production occurred with elevated levels of mineral salts in the medium, whereas the addition of a vitamin mixture proved to be inhibitory. Chemical changes resulting from the growth of F. moniliforme in the final fermentation medium disclosed maximal alanine production, mycelial weight, and glucose consumption after 72 hr of incubation at 28.5 C. Total soluble nitrogen, by contrast, was minimal at the same time period. The pH remained in the alkaline range throughout the fermentation. PMID:5914495

  11. Effect of substituting arginine and lysine with alanine on antimicrobial activity and the mechanism of action of a cationic dodecapeptide (CL(14-25)), a partial sequence of cyanate lyase from rice.

    PubMed

    Taniguchi, Masayuki; Takahashi, Nobuteru; Takayanagi, Tomohiro; Ikeda, Atsuo; Ishiyama, Yohei; Saitoh, Eiichi; Kato, Tetsuo; Ochiai, Akihito; Tanaka, Takaaki

    2014-01-01

    The antimicrobial activity of analogs obtained by substituting arginine and lysine in CL(14-25), a cationic α-helical dodecapeptide, with alanine against Porphyromonas gingivalis, a periodontal pathogen, varied significantly depending on the number and position of cationic amino acids. The alanine-substituted analogs had no hemolytic activity, even at a concentration of 1 mM. The antimicrobial activities of CL(K20A) and CL(K20A, K25A) were 3.8-fold and 9.1-fold higher, respectively, than that of CL(14-25). The antimicrobial activity of CL(R15A) was slightly lower than that of CL(14-25), suggesting that arginine at position 15 is not essential but is important for the antimicrobial activity. The experiments in which the alanine-substituted analogs bearing the replacement of arginine at position 24 and/or lysine at position 25 were used showed that arginine at position 24 was crucial for the antimicrobial activity whenever lysine at position 25 was substituted with alanine. Helical wheel projections of the alanine-substituted analogs indicate that the hydrophobicity in the vicinity of leucine at position 16 and alanines at positions 18 and/or 21 increased by substituting lysine at positions 20 and 25 with alanine, respectively. The degrees of diSC3 -5 release from P. gingivalis cells and disruption of GUVs induced by the alanine-substituted analogs with different positive charges were not closely related to their antimicrobial activities. The enhanced antimicrobial activities of the alanine-substituted analogs appear to be mainly attributable to the changes in properties such as hydrophobicity and amphipathic propensity due to alanine substitution and not to their extents of positive charge (cationicity).

  12. FT-IR and Raman spectroscopic and DFT studies of anti-cancer active molecule N-{(meta-ferrocenyl) Benzoyl} - L-Alanine - Glycine ethyl ester

    NASA Astrophysics Data System (ADS)

    Xavier, T. S.; Kenny, Peter T. M.; Manimaran, D.; Joe, I. Hubert

    2015-06-01

    FT-Raman and FT-IR spectra of N-{(meta-ferrocenyl) Benzoyl} - L-alanine - glycine ethyl ester were recorded in solid phase. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and the Raman scattering intensities were calculated by using density functional method(B3LYP) with 6-31G(d, p) basis set. Vibrational assignment of the molecule was done by using potential energy distribution analysis. Natural bond orbital analysis, Mulliken charge analysis and HOMO-LUMO energy were used to elucidate the reasons for intra molecular charge transfer. Docking studies were conducted to predict its anticancer activity.

  13. Genome-enabled determination of amino acid biosynthesis in Xanthomonas campestris pv. campestris and identification of biosynthetic pathways for alanine, glycine, and isoleucine by 13C-isotopologue profiling.

    PubMed

    Schatschneider, Sarah; Vorhölter, Frank-Jörg; Rückert, Christian; Becker, Anke; Eisenreich, Wolfgang; Pühler, Alfred; Niehaus, Karsten

    2011-10-01

    To elucidate the biosynthetic pathways for all proteinogenic amino acids in Xanthomonas campestris pv. campestris, this study combines results obtained by in silico genome analysis and by (13)C-NMR-based isotopologue profiling to provide a panoramic view on a substantial section of bacterial metabolism. Initially, biosynthesis pathways were reconstructed from an improved annotation of the complete genome of X. campestris pv. campestris B100. This metabolic reconstruction resulted in the unequivocal identification of biosynthesis routes for 17 amino acids in total: arginine, asparagine, aspartate, cysteine, glutamate, glutamine, histidine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. Ambiguous pathways were reconstructed from the genome data for alanine, glycine, and isoleucine biosynthesis. (13)C-NMR analyses supported the identification of the metabolically active pathways. The biosynthetic routes for these amino acids were derived from the precursor molecules pyruvate, serine, and pyruvate, respectively. By combining genome analysis and isotopologue profiling, a comprehensive set of biosynthetic pathways covering all proteinogenic amino acids was unraveled for this plant pathogenic bacterium, which plays an important role in biotechnology as a producer of the exopolysaccharide xanthan. The data obtained lay ground for subsequent functional analyses in post-genomics and biotechnology, while the innovative combination of in silico and wet lab technology described here is promising as a general approach to elucidate metabolic pathways.

  14. Beneficial effects of cod protein on inflammatory cell accumulation in rat skeletal muscle after injury are driven by its high levels of arginine, glycine, taurine and lysine.

    PubMed

    Dort, Junio; Leblanc, Nadine; Maltais-Giguère, Julie; Liaset, Bjørn; Côté, Claude H; Jacques, Hélène

    2013-01-01

    We have shown that feeding cod protein, which is rich in anti-inflammatory arginine, glycine, and taurine, may beneficially modulate the inflammatory response during recovery following skeletal muscle injury; however it is unknown if these amino acids are responsible for this effect. This study was designed to assess whether supplementing casein with an amino acid mixture composed of arginine, glycine, taurine and lysine, matching their respective levels in cod protein, may account for the anti-inflammatory effect of cod protein. Male Wistar rats were fed isoenergetic diets containing either casein, cod protein, or casein supplemented with L-arginine (0.45%), glycine (0.43%), L-taurine (0.17%) and L-lysine (0.44%) (casein+). After 21 days of ad libitum feeding, one tibialis anterior muscle was injured with 200 µl bupivacaine while the saline-injected contra-lateral tibialis anterior was served as sham. Cod protein and casein+ similarly modulated the inflammation as they decreased COX-2 level at day 2 post-injury (cod protein, p=0.014; casein+, p=0.029) and ED1(+) macrophage density at days 2 (cod protein, p=0.012; casein+, p<0.0001), 5 (cod protein, p=0.001; casein+, p<0.0001) and 14 (cod protein, p<0.0001; casein+, p<0.0001) post-injury, and increased ED2(+) macrophage density at days 5 (cod protein, p<0.0001; casein+, p=0.006), 14 (cod protein, p=0.001; casein+, p<0.002) and 28 (cod protein, p<0.009; casein+, p<0.005) post-injury compared with casein. Furthermore, cod protein up-regulated (p=0.037) whereas casein+ tended to up-regulate (p=0.062) myogenin expression at day 5 post-injury compared with casein. In the cod protein-fed group, these changes resulted in greater muscle mass at days 14 (p=0.002), and 28 (p=0.001) post-injury and larger myofiber cross-sectional area at day 28 post-injury compared with casein (p=0.012). No such effects were observed with casein+. These data indicate that anti-inflammatory actions of cod protein, contrary to its effect on

  15. Structures of two bacterial resistance factors mediating tRNA-dependent aminoacylation of phosphatidylglycerol with lysine or alanine

    PubMed Central

    Hebecker, Stefanie; Krausze, Joern; Hasenkampf, Tatjana; Schneider, Julia; Groenewold, Maike; Reichelt, Joachim; Jahn, Dieter; Heinz, Dirk W.; Moser, Jürgen

    2015-01-01

    The cytoplasmic membrane is probably the most important physical barrier between microbes and the surrounding habitat. Aminoacylation of the polar head group of the phospholipid phosphatidylglycerol (PG) catalyzed by Ala-tRNAAla–dependent alanyl-phosphatidylglycerol synthase (A-PGS) or by Lys-tRNALys–dependent lysyl-phosphatidylglycerol synthase (L-PGS) enables bacteria to cope with cationic peptides that are harmful to the integrity of the cell membrane. Accordingly, these synthases also have been designated as multiple peptide resistance factors (MprF). They consist of a separable C-terminal catalytic domain and an N-terminal transmembrane flippase domain. Here we present the X-ray crystallographic structure of the catalytic domain of A-PGS from the opportunistic human pathogen Pseudomonas aeruginosa. In parallel, the structure of the related lysyl-phosphatidylglycerol–specific L-PGS domain from Bacillus licheniformis in complex with the substrate analog L-lysine amide is presented. Both proteins reveal a continuous tunnel that allows the hydrophobic lipid substrate PG and the polar aminoacyl-tRNA substrate to access the catalytic site from opposite directions. Substrate recognition of A-PGS versus L-PGS was investigated using misacylated tRNA variants. The structural work presented here in combination with biochemical experiments using artificial tRNA or artificial lipid substrates reveals the tRNA acceptor stem, the aminoacyl moiety, and the polar head group of PG as the main determinants for substrate recognition. A mutagenesis approach yielded the complementary amino acid determinants of tRNA interaction. These results have broad implications for the design of L-PGS and A-PGS inhibitors that could render microbial pathogens more susceptible to antimicrobial compounds. PMID:26261323

  16. Pore Diameter Dependence and Segmental Dynamics of Poly-Z-L-lysine and Poly-L-alanine Confined in 1D Nanocylindrical Geometry

    NASA Astrophysics Data System (ADS)

    Tuncel, Eylul; Suzuki, Yasuhito; Iossifidis, Agathaggelos; Steinhart, Martin; Butt, Hans-Jurgen; Floudas, George; Duran, Hatice

    Structure formation, thermodynamic stability, phase and dynamic behaviors of polypeptides are strongly affected by confinement. Since understanding the changes in these behaviors will allow their rational design as functional devices with tunable properties, herein we investigated Poly-Z-L-lysine (PZLL) and Poly-L-alanine (PAla) homopolypeptides confined in nanoporous alumina containing aligned cylindrical nanopores as a function of pore size by differential scanning calorimetry (DSC), Fourier Transform Infrared Spectroscopy, Solid-state NMR, X-ray diffraction, Dielectric spectroscopy(DS). Bulk PZLL exhibits a glass transition temperature (Tg) at about 301K while PZLL nanorods showed slightly lower Tg (294K). The dynamic investigation by DS also revealed a decrease (4K) in Tg between bulk and PZLL nanorods. DS is a very sensitive probe of the local and global secondary structure relaxation through the large dipole to study effect of confinement. The results revealed that the local segmental dynamics, associated with broken hydrogen bonds, and segmental dynamics speed-up on confinement.

  17. Vibrational 13C-cross-polarization/magic angle spinning NMR spectroscopic and thermal characterization of poly(alanine-glycine) as model for silk I Bombyx mori fibroin.

    PubMed

    Monti, Patrizia; Taddei, Paola; Freddi, Giuliano; Ohgo, Kosuke; Asakura, Tetsuo

    2003-01-01

    This study focuses on the conformational characterization of poly(alanine-glycine) II (pAG II) as a model for a Bombyx mori fibroin silk I structure. Raman, IR, and 13C-cross-polarization/magic angle spinning NMR spectra of pAG II are discussed in comparison with those of the crystalline fraction of B. mori silk fibroin (chymotryptic precipitate, Cp) with a silk I (silk I-Cp) structure. The spectral data give evidence that silk I-Cp and the synthetic copolypeptide pAG II have similar conformations. Moreover, the spectral findings reveal that silk I-Cp is more crystalline than pAG II; consequently, the latter contains a larger amount of the random coil conformation. Differential scanning calorimetry measurements confirm this result. N-Deuteration experiments on pAG II allow us to attribute the Raman component at 1320 cm(-1) to the amide III mode of a beta-turn type II conformation, thus confirming the results of those who propose a repeated beta-turn type II structure for silk I. The analysis of the Raman spectra in the nuNH region confirms that the silk I structure is characterized by the presence of different types of H-bonding arrangements, in agreement with the above model.

  18. Limiting values of diffusion coefficients of glycine, alanine, [Formula: see text]-amino butyric acid, norvaline and norleucine in a relevant physiological aqueous medium.

    PubMed

    Rodriguez, Diana M; Verissimo, Luis M P; Barros, Marisa C F; Rodrigues, Daniela F S L; Rodrigo, Maria Melia; Esteso, Miguel A; Romero, Carmen M; Ribeiro, Ana C F

    2017-02-01

    The side chain effect on transport in ionic aqueous salt solutions was investigated for [Formula: see text]-amino acids glycine, alanine, [Formula: see text]-amino butyric acid, norvaline, and norleucine --that together define a chemical homologous series based on the length of the characteristic side chain which increases from zero to four carbons, respectively. Binary mutual diffusion coefficients at infinitesimal concentration in aqueous solutions of NaCl (0.15 mol kg (-1)) are measured by means of Taylor dispersion technique for this series and significant differences were found against previous published results for identical systems in pure water. In this way, NaCl effect on the transport of each amino acid is thus assessed and discussed in terms of salting-out effects. Also, solvated Stokes hydrodynamic radii were computed for the series showing comparable results in water and NaCl solution. The new information should prove useful in the design and characterization of transport-controlled systems in physiological and pharmacological studies.

  19. Multiple sclerosis: the elevated antibody response to Epstein-Barr virus primarily targets, but is not confined to, the glycine-alanine repeat of Epstein-Barr nuclear antigen-1.

    PubMed

    Ruprecht, Klemens; Wunderlich, Benjamin; Gieß, René; Meyer, Petra; Loebel, Madlen; Lenz, Klaus; Hofmann, Jörg; Rosche, Berit; Wengert, Oliver; Paul, Friedemann; Reimer, Ulf; Scheibenbogen, Carmen

    2014-07-15

    Patients with multiple sclerosis (MS) have elevated antibodies against Epstein-Barr virus (EBV), but data on the epitope-resolved specificity of these antibodies are scarce. Using a peptide microarray containing 1465 peptides representing 8 full-length EBV proteins, we identified higher (p<0.001) antibody reactivities to 39 EBV-peptides in MS patients (n=29) compared to healthy controls (n=22). Seventeen of the 39 peptides were from EBNA-1 and 13 located within the glycine-alanine repeat of EBNA-1. Further reactivities were directed against EBNA-3, EBNA-4, EBNA-6, VP26, and LMP1. Thus, antibodies against EBV in MS patients primarily target, but are not confined to, the glycine-alanine repeat of EBNA-1.

  20. 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.

  1. Effects of basic site proximity on deprotonation and hydrogen/deuterium exchange reactions for model dodecapeptide ions containing lysine and glycine

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Ewing, Nigel P.; Cassady, Carolyn J.

    1998-05-01

    The effects of basic site proximity on gas-phase deprotonation and hydrogen/deuterium (H/D) exchange reactions were investigated for three model dodecapeptide ions in a Fourier transform ion cyclotron resonance mass spectrometer. Each peptide contained four high basicity lysine (K) residues and eight low basicity glycine (G) residues; however, the ordering of the residues differed. In the deprotonation studies, `fully protonated' peptide ions, [M + 4H]4+, where M = (KGG)4, (K2G4)2, and K4G8, were reacted with reference compounds of known basicities. Reaction efficiencies were in the order: [K4G8 + 4H]4+ > [(K2G4)2 + 4H]4+ ~ [(KGG)4 + 4H]4+. The facile reaction of [K4G8 + 4H]4+ is consistent with this ion having the highest Coulomb energy. For gas-phase H/D exchange reactions with d4-methanol, [K4G8 + 4H]4+ has the fastest exchange rate and undergoes the largest number of exchanges; 22 of the 26 labile hydrogens exchanged within the timescale studied. In contrast, [(KGG)4 + 4H]4+ and [(K2G4)2 + 4H]4+ reacted more slowly, but at similar rates, with a maximum of 14 observed exchanges for both ions. Molecular dynamics calculations were conducted to gain insights into conformations. In the lowest energy structures for [(KGG)4 + 4H]4+ and [(K2G4)2 + 4H]4+, the lysine n-butylamino chains stretch out to minimize Coulomb energy; there is little or no intramolecular hydrogen bonding involving the protonated amino groups. In contrast, for [K4G8 + 4H]4+, the proximity of the basicity residues makes minimization of the Coulomb energy difficult; instead, the structure becomes more compact with stabilization of the protonated amino groups by extensive intramolecular hydrogen bonding to heteroatoms in the peptide backbone. The calculated structures suggest that, in the H/D exchange reactions, the compact conformation of [K4G8 + 4H]4+ allows stabilization of the methanolpeptide intermediate by hydrogen bonding, thus lowering the barrier to proton transfer within the complex. The

  2. Characterization of recombinant biosynthetic precursors of the cysteine tryptophylquinone cofactors of l-lysine-epsilon-oxidase and glycine oxidase from Marinomonas mediterranea.

    PubMed

    Chacón-Verdú, María Dolores; Campillo-Brocal, Jonatan C; Lucas-Elío, Patricia; Davidson, Victor L; Sánchez-Amat, Antonio

    2015-09-01

    The lysine-ε-oxidase, LodA, and glycine oxidase, GoxA, from Marinomonas mediteranea each possesses a cysteine tryptophylquinone (CTQ) cofactor. This cofactor is derived from posttranslational modifications which are covalent crosslinking of tryptophan and cysteine residues and incorporation of two oxygen atoms into the indole ring of Trp. In this manuscript, it is shown that the recombinant synthesis of LodA and GoxA containing a fully synthesized CTQ cofactor requires coexpression of a partner flavoprotein, LodB for LodA and GoxB for GoxA, which are not interchangeable. An inactive precursor of LodA or GoxA which contained a monohydroxylated Trp residue and no crosslink to the Cys was isolated from the soluble fraction when they were expressed alone. The structure of LodA revealed an Asp residue close to the cofactor which is conserved in quinohemoprotein amine dehydrogenase (QHNDH), containing CTQ, and methylamine dehydrogenase (MADH) containing tryptophan tryptophylquinone (TTQ) as cofactor. To study the role of this residue in the synthesis of the LodA precursor, Asp-512 was mutated to Ala. When the mutant protein was coexpressed with LodB an inactive protein was isolated which was soluble and contained no modifications at all, suggesting a role for this Asp in the initial LodB-independent hydroxylation of Trp. A similar role had been proposed for this conserved Asp residue in MADH. It is noteworthy that the formation of TTQ in MADH from the precursor also requires an accessory enzyme for its biosynthesis but it is a diheme enzyme MauG and not a flavoprotein. The results presented reveal novel mechanisms of post-translational modification involved in the generation of protein-derived cofactors. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.

  3. Arachnoid cyst and chronic subdural haematoma in a child with osteogenesis imperfecta type III resulting from the substitution of glycine 1006 by alanine in the pro alpha 2(I) chain of type I procollagen.

    PubMed Central

    Cole, W G; Lam, T P

    1996-01-01

    The features of a child with osteogenesis imperfecta type III (OI III) resulting from the heterozygous substitution of glycine 1006 by alanine in the pro alpha 2(I) chain of type I procollagen were studied. He was born at term with the clinical features of severe OI, including deep grey-blue sclerae. He had severe osteopenia and all long bones were smaller than normal with cortical thinning, metaphyseal expansion, poor metaphyseal modelling, and multiple fractures. However, the vertebrae, pelvis, and shoulder girdle were of normal shape and there were few rib fractures. Histological examination of the calvarium and tibial shaft showed woven bone without lamellar bone or Haversian systems. The shafts of the long bones were widened owing to repeated fractures. Progressive enlargement of the calvarium occurred between 3 and 4.5 months of age owing to bilateral chronic subdural haematomata and a large arachnoid cyst in the Sylvian fissure. The cyst was probably developmental in origin while the subdural collections were probably the result of perinatal skull trauma. The cyst and the subdural collections resolved following drainage but ventricular dilatation with normal cerebrospinal fluid pressure followed. The proband is the first reported case of OI with a glycine substitution by alanine in the pro alpha 2(I) chain of type I procollagen. Images PMID:8728690

  4. Analysis of alanine aminotransferase in various organs of soybean (Glycine max) and in dependence of different nitrogen fertilisers during hypoxic stress.

    PubMed

    Rocha, Marcio; Sodek, Ladaslav; Licausi, Francesco; Hameed, Muhammad Waqar; Dornelas, Marcelo Carnier; van Dongen, Joost T

    2010-10-01

    Alanine aminotransferase (AlaAT) catalyses the reversible conversion of pyruvate and glutamate into alanine and oxoglutarate. In soybean, two subclasses were identified, each represented by two highly similar members. To investigate the role of AlaAT during hypoxic stress in soybean, changes in transcript level of both subclasses were analysed together with the enzyme activity and alanine content of the tissue. Moreover, the dependency of AlaAT activity and gene expression was investigated in relation to the source of nitrogen supplied to the plants. Using semi-quantitative PCR, GmAlaAT genes were determined to be highest expressed in roots and nodules. Under normal growth conditions, enzyme activity of AlaAT was detected in all organs tested, with lowest activity in the roots. Upon waterlogging-induced hypoxia, AlaAT activity increased strongly. Concomitantly, alanine accumulated. During re-oxygenation, AlaAT activity remained high, but the transcript level and the alanine content decreased. Our results show a role for AlaAT in the catabolism of alanine during the initial period of re-oxygenation following hypoxia. GmAlaAT also responded to nitrogen availability in the solution during waterlogging. Ammonium as nitrogen source induced both gene expression and enzyme activity of AlaAT more than when nitrate was supplied in the nutrient solution. The work presented here indicates that AlaAT might not only be important during hypoxia, but also during the recovery phase after waterlogging, when oxygen is available to the tissue again.

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

    PubMed

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

    2014-09-01

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

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

    PubMed Central

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

    2014-01-01

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

  7. THE EFFECT OF THE HYDROGEN ION CONCENTRATION ON THE RATE OF HYDROLYSIS OF GLYCYL GLYCINE, GLYCYL LEUCINE, GLYCYL ALANINE, GLYCYL ASPARAGINE, GLYCYL ASPARTIC ACID, AND BIURET BASE BY EREPSIN.

    PubMed

    Northrop, J H; Simms, H S

    1928-11-20

    1. The rate of hydrolysis at different pH values of glycyl glycine, glycyl leucine, glycyl alanine, glycyl asparagine, glycyl aspartic acid and biuret base has been determined. 2. The pH-activity curves obtained in this way differ for the different substrates. 3. The curves can be satisfactorily predicted by the assumption that erepsin is a weak acid or base with a dissociation constant of 10(-7.6) and that the reaction takes place between a particular ionic species of the enzyme and of the substrate. There are several possible arrangements which will predict the experimental results. 4. The rate of inactivation of erepsin at various pH values has been determined and found to agree with the assumption used above, that the enzyme is a weak acid or base with a dissociation constant of about 10(-7.6). 5. It is pointed out that if the mechanism assumed is correct, the determination of a significant value for the relative rate of hydrolysis of various peptides is a very uncertain procedure.

  8. Halotolerance in methanosarcina spp.: Role of N{sup {epsilon}}-acetyl-{beta}-lysine, {alpha}-glutamate, glycine betaine, and K{sup +} as compatible solutes for osmotic adaptation

    SciTech Connect

    Sowers, K.R.; Gunsalus, R.P.

    1995-12-01

    The methanogenic Archaea, like the Bacteria and Eucarya, possess several osmoregulatory strategies that enable them to adapt to osmotic changes in their environment. The physiological responses of Methanosarcina species to different osmotic pressures were studied in extracellular osmolalities ranging from 0.3 to 2.0 osmol/kg. Regardless of the isolation source, the maximum rate of growth for species from freshwater, sewage, and marine sources occurred in extracellular osmolalities between 0.62 and 1.0 osmol/kg and decreased to minimal detectable growth as the solute concentration approached 2.0 osmol/kg. The distribution and concentration of compatible solutes in eight strains representing five Methanosarcina spp. were similar to those found in M. thermophila grown in extracellular osmolalities of 0.3 and 2.0 osmol/kg. Results of this study demonstrate that the mechanism of halotolerance in Methanosarcina spp. involves the regulation of K{sup +}, {alpha}-glutamate, N{sup {epsilon}}-acetyl-{beta}-lysine, and glycine betaine accumulation in response to the osmotic effects of extracellular solute.

  9. Inhibitors of alanine racemase enzyme: a review.

    PubMed

    Azam, Mohammed Afzal; Jayaram, Unni

    2016-08-01

    Alanine racemase is a fold type III PLP-dependent amino acid racemase enzyme catalysing the conversion of l-alanine to d-alanine utilised by bacterial cell wall for peptidoglycan synthesis. As there are no known homologs in humans, it is considered as an excellent antibacterial drug target. The standard inhibitors of this enzyme include O-carbamyl-d-serine, d-cycloserine, chlorovinyl glycine, alaphosphin, etc. d-Cycloserine is indicated for pulmonary and extra pulmonary tuberculosis but therapeutic use of drug is limited due to its severe toxic effects. Toxic effects due to off-target affinities of cycloserine and other substrate analogs have prompted new research efforts to identify alanine racemase inhibitors that are not substrate analogs. In this review, an updated status of known inhibitors of alanine racemase enzyme has been provided which will serve as a rich source of structural information and will be helpful in generating selective and potent inhibitor of alanine racemase.

  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. Lysine Transport across Isolated Rabbit Ileum

    PubMed Central

    Munck, B. G.; Schultz, Stanley G.

    1969-01-01

    Lysine transport by in vitro distal rabbit ileum has been investigated by determining (a) transmural fluxes across short-circuited segments of the tissue; (b) accumulation by mucosal strips; and (c) influx from the mucosal solution across the brush border into the epithelium. Net transmural flux of lysine is considerably smaller than that of alanine. However, lysine influx across the brush border and lysine accumulation by mucosal strips are quantitatively comparable to alanine influx and accumulation. Evidence is presented that the "low transport capacity" of rabbit ileum for lysine is due to: (a) a carrier-mediated process responsible for efflux of lysine out of the cell across the serosal and/or lateral membranes that is characterized by a low maximal velocity; and (b) a high "backflux" of lysine out of the cell across the mucosal membrane. A possible explanation for the latter observation is discussed with reference to the relatively low Na dependence of lysine transport across the intestinal brush border. PMID:5764744

  12. Contribution of the net charge to the regulatory effects of amino acids and epsilon-poly(L-lysine) on the gelatinization behavior of potato starch granules.

    PubMed

    Ito, Azusa; Hattori, Makoto; Yoshida, Tadashi; Takahashi, Koji

    2006-01-01

    The effects of lysine (Lys), monosodium glutamate (GluNa), glycine, alanine and epsilon-poly(L-lysine) (PL) with different degrees of polymerization on the gelatinization behavior of potato starch granules were investigated by DSC, viscosity and swelling measurements, microscopic observation, and measurement of the retained amino acid amount to clarify the contribution of the net charge to their regulatory effects on the gelatinization behavior. The amino acids and PL each contributed to an increase in the gelatinization temperature, and a decrease in the peak viscosity and swelling. These effects strongly depended on the absolute value of their net charge. The disappearance of a negative or positive net charge by adjusting the pH value weakened the contribution. The swelling index and size of the potato starch granules changed according to replacement of the swelling medium. The amino acids and PL were easily retained by the swollen potato starch granules according to replacement of the outer solution of the starch granules.

  13. Computation of energy interaction parameters as well as electric dipole intensity parameters for the absorption spectral study of the interaction of Pr(III) with L-phenylalanine, L-glycine, L-alanine and L-aspartic acid in the presence and absence of Ca 2+ in organic solvents

    NASA Astrophysics Data System (ADS)

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

    2009-10-01

    Studying the absorption difference and comparative absorption spectra of the interaction of Pr(III) and Nd(III) with L-phenylalanine, L-glycine, L-alanine and L-aspartic acid in the presence and absence of Ca 2+ in organic solvents, various energy interaction parameters like Slater-Condon ( FK), Racah ( Ek), Lande factor ( ξ4f), nephelauxetic ratio ( β), bonding ( b1/2), percentage-covalency ( δ) have been evaluated applying partial and multiple regression analysis. The values of oscillator strength ( P) and Judd-Ofelt electric dipole intensity parameter Tλ ( λ = 2, 4, 6) for different 4f-4f transitions have been computed. On analysis of the variation of the various energy interaction parameters as well as the changes in the oscillator strength ( P) and Tλ values reveal the mode of binding with different ligands.

  14. Pathways of Amino Acid Degradation in Nilaparvata lugens (Stål) with Special Reference to Lysine-Ketoglutarate Reductase/Saccharopine Dehydrogenase (LKR/SDH)

    PubMed Central

    Wan, Pin-Jun; Yuan, San-Yue; Tang, Yao-Hua; Li, Kai-Long; Yang, Lu; Fu, Qiang; Li, Guo-Qing

    2015-01-01

    Nilaparvata lugens harbors yeast-like symbionts (YLSs). In present paper, a genome-wide analysis found 115 genes from Ni. lugens and 90 genes from YLSs that were involved in the metabolic degradation of 20 proteinogenic amino acids. These 205 genes encoded for 77 enzymes. Accordingly, the degradation pathways for the 20 amino acids were manually constructed. It is postulated that Ni. lugens can independently degrade fourteen amino acids (threonine, alanine, glycine, serine, aspartate, asparagine, phenylalanine, tyrosine, glutamate, glutamine, proline, histidine, leucine and lysine). Ni. lugens and YLSs enzymes may work collaboratively to break down tryptophan, cysteine, arginine, isoleucine, methionine and valine. We cloned a lysine-ketoglutarate reductase/saccharopine dehydrogenase gene (Nllkr/sdh) that encoded a bifunctional enzyme catalyzing the first two steps of lysine catabolism. Nllkr/sdh is widely expressed in the first through fifth instar nymphs and adults, and is highly expressed in the fat body, ovary and gut in adults. Ingestion of dsNllkr/sdh by nymphs successfully knocked down the target gene, and caused nymphal/adult mortality, shortened nymphal development stage and reduced adult fresh weight. Moreover, Nllkr/sdh knockdown resulted in three defects: wings were shortened and thickened; cuticles were stretched and thinned; and old nymphal cuticles remained on the tips of legs and abdomen and were not completely shed. These data indicate that impaired lysine degradation negatively affects the survival and development of Ni. lugens. PMID:26000452

  15. Production of D-Alanine by Corynebacterium fascians

    PubMed Central

    Yamada, Shigeki; Maeshima, Haruko; Wada, Mitsuru; Chibata, Ichiro

    1973-01-01

    A strain identified as Corynebacterium fascians was found to accumulate extracellular D-alanine from glycerol. Cultural conditions for the accumulation of D-alanine were investigated and, as a result, a yield of 7 g of D-alanine per liter was obtained after a 96-h incubation in a medium containing 5% glycerol, 4% (NH4)2HPO4, and 0.3% corn steep liquor. Optical purity of D-alanine was dependent upon the concentration of corn steep liquor. At the optimal condition, almost optically pure D-alanine was formed and readily isolated (5 g/liter) from the fermentation broth. The product was not contaminated with any detectable amount of other amino acids, except for glycine which was present at a concentration of less than 1 percent. PMID:4699220

  16. Alanine water complexes.

    PubMed

    Vaquero, Vanesa; Sanz, M Eugenia; Peña, Isabel; Mata, Santiago; Cabezas, Carlos; López, Juan C; Alonso, José L

    2014-04-10

    Two complexes of alanine with water, alanine-(H2O)n (n = 1,2), have been generated by laser ablation of the amino acid in a supersonic jet containing water vapor and characterized using Fourier transform microwave spectroscopy. In the observed complexes, water molecules bind to the carboxylic group of alanine acting as both proton donors and acceptors. In alanine-H2O, the water molecule establishes two intermolecular hydrogen bonds forming a six-membered cycle, while in alanine-(H2O)2 the two water molecules establish three hydrogen bonds forming an eight-membered ring. In both complexes, the amino acid moiety is in its neutral form and shows the conformation observed to be the most stable for the bare molecule. The microsolvation study of alanine-(H2O)n (n = 1,2) can be taken as a first step toward understanding bulk properties at a microscopic level.

  17. Ionized trilysine: a model system for understanding the nonrandom structure of poly-L-lysine and lysine-containing motifs in proteins.

    PubMed

    Verbaro, Daniel J; Mathieu, Daniel; Toal, Siobhan E; Schwalbe, Harald; Schweitzer-Stenner, Reinhard

    2012-07-19

    It is now well-established that different amino acid residues can exhibit different conformational distributions in the unfolded state of peptides and proteins. These conformational propensities can be modulated by nearest neighbors. In the current study, we combined vibrational and NMR spectroscopy to determine the conformational distributions of the central and C-terminal residues in trilysine peptides in aqueous solution. The study was motivated by earlier observations suggesting that interactions between ionized nearest neighbor residues can substantially change conformational propensities. We found that the central lysine residue predominantly adopts conformations that are located at the upper border of the upper left quadrant of the Ramachandran plot and the left border of the polyproline II region. We term this type of conformation deformed polyproline II (pPII(d)). The structures of less populated subensembles of trilysine resemble are comparable with structures at the i + 1 position of type I and type II β-turns. For the C-terminal residue, however, we obtained a mixture of polyproline II, β-strand, and right-handed helical conformations, which is typical for lysine residues in alanine- and glycine-based peptides. Our data thus indicate that the terminal lysines modify and restrict the conformational distribution of the central lysine residue. DFT calculations for ionized trilysine and lysyllysyllysylglycine in vacuo indicate that the pPII(d) is stabilized by a rather strong hydrogen bond between the NH3(+) group of the central lysine and the carbonyl group of the C-terminal peptide. This intramolecular hydrogen bonding induces optical activity in the C-terminal CO stretching vibration, which leads to an unusual and relatively intense positive Cotton band. Additionally, we analyzed the amide I' band profile of ionized triornithine in water. Ornithine is structurally similar to lysine in that its side chain is terminated with an amino group; however, the

  18. Lysis of Escherichia coli by Glycine Is Potentiated by Pyridoxine Starvation

    PubMed Central

    Dempsey, Walter B.

    1973-01-01

    Pyridoxineless mutants of Escherichia coli are lysed in a few hours when starved for pyridoxine in a glucose minimal medium containing glycine at 10 mM. The lysis is prevented equally well by l-alanine and by d-alanine when either is present at 0.1 mM. The lysis is potentiated by 0.5 mM l-methionine. The peculiar susceptibility of E. coli B to glycine-mediated lysis during starvation for pyridoxine suggests that the starvation reduces the availability of some normal antagonist of glycine, presumably alanine. PMID:4583221

  19. Ruthenium-Nitrosyl Complexes with Glycine, l-Alanine, l-Valine, l-Proline, d-Proline, l-Serine, l-Threonine, and l-Tyrosine: Synthesis, X-ray Diffraction Structures, Spectroscopic and Electrochemical Properties, and Antiproliferative Activity

    PubMed Central

    2014-01-01

    The reactions of [Ru(NO)Cl5]2– with glycine (Gly), l-alanine (l-Ala), l-valine (l-Val), l-proline (l-Pro), d-proline (d-Pro), l-serine (l-Ser), l-threonine (l-Thr), and l-tyrosine (l-Tyr) in n-butanol or n-propanol afforded eight new complexes (1–8) of the general formula [RuCl3(AA–H)(NO)]−, where AA = Gly, l-Ala, l-Val, l-Pro, d-Pro, l-Ser, l-Thr, and l-Tyr, respectively. The compounds were characterized by elemental analysis, electrospray ionization mass spectrometry (ESI-MS), 1H NMR, UV–visible and ATR IR spectroscopy, cyclic voltammetry, and X-ray crystallography. X-ray crystallography studies have revealed that in all cases the same isomer type (from three theoretically possible) was isolated, namely mer(Cl),trans(NO,O)-[RuCl3(AA–H)(NO)], as was also recently reported for osmium analogues with Gly, l-Pro, and d-Pro (see Z. Anorg. Allg. Chem.2013, 639, 1590–1597). Compounds 1, 4, 5, and 8 were investigated by ESI-MS with regard to their stability in aqueous solution and reactivity toward sodium ascorbate. In addition, cell culture experiments in three human cancer cell lines, namely, A549 (nonsmall cell lung carcinoma), CH1 (ovarian carcinoma), and SW480 (colon carcinoma), were performed, and the results are discussed in conjunction with the lipophilicity of compounds. PMID:24555845

  20. Murine startle mutant Nmf11 affects the structural stability of the glycine receptor and increases deactivation

    PubMed Central

    Wilkins, Megan E.; Caley, Alex; Gielen, Marc C.; Harvey, Robert J.

    2016-01-01

    Key points Hyperekplexia or startle disease is a serious neurological condition affecting newborn children and usually involves dysfunctional glycinergic neurotransmission.Glycine receptors (GlyRs) are major mediators of inhibition in the spinal cord and brainstem.A missense mutation, replacing asparagine (N) with lysine (K), at position 46 in the GlyR α1 subunit induced hyperekplexia following a reduction in the potency of the transmitter glycine; this resulted from a rapid deactivation of the agonist current at mutant GlyRs.These effects of N46K were rescued by mutating a juxtaposed residue, N61 on binding Loop D, suggesting these two asparagines may interact.Asparagine 46 is considered to be important for the structural stability of the subunit interface and glycine binding site, and its mutation represents a new mechanism by which GlyR dysfunction induces startle disease. Abstract Dysfunctional glycinergic inhibitory transmission underlies the debilitating neurological condition, hyperekplexia, which is characterised by exaggerated startle reflexes, muscle hypertonia and apnoea. Here we investigated the N46K missense mutation in the GlyR α1 subunit gene found in the ethylnitrosourea (ENU) murine mutant, Nmf11, which causes reduced body size, evoked tremor, seizures, muscle stiffness, and morbidity by postnatal day 21. Introducing the N46K mutation into recombinant GlyR α1 homomeric receptors, expressed in HEK cells, reduced the potencies of glycine, β‐alanine and taurine by 9‐, 6‐ and 3‐fold respectively, and that of the competitive antagonist strychnine by 15‐fold. Replacing N46 with hydrophobic, charged or polar residues revealed that the amide moiety of asparagine was crucial for GlyR activation. Co‐mutating N61, located on a neighbouring β loop to N46, rescued the wild‐type phenotype depending on the amino acid charge. Single‐channel recording identified that burst length for the N46K mutant was reduced and fast agonist application

  1. MUTATION OF THE ACTIVE SITE CARBOXY-LYSINE (K70) OF OXA-1 β-LACTAMASE RESULTS IN A DEACYLATION-DEFICIENT ENZYME†

    PubMed Central

    Schneider, Kyle D.; Bethel, Christopher R.; Distler, Anne M.; Hujer, Andrea M.; Bonomo, Robert A.; Leonard, David A.

    2009-01-01

    Class D β-lactamases hydrolyze β-lactam antibiotics by using an active site serine nucleophile to form a covalent acyl-enzyme intermediate, and subsequently employ water to deacylate the β-lactam and release product. Class D β-lactamases are carboxylated on the ε-amino group of an active site lysine, with the resulting carbamate functional group serving as a general base. We discovered that substitutions of the active site serine and lysine in OXA-1 β-lactamase, a monomeric class D enzyme, significantly disrupt catalytic turnover. Substitution of glycine for the nucleophilic serine (S67G) results in an enzyme that can still bind substrate but is unable to form a covalent acyl-enzyme intermediate. Substitution of the carboxylated lysine (K70), on the other hand, results in enzyme that can be acylated by substrate, but is impaired for deacylation. We employed the fluorescent penicillin BOCILLIN FL™ to show that three different substitutions for K70 (alanine, aspartate and glutamate) accumulate significant acyl-enzyme intermediate. Interestingly, BOCILLIN FL™ deacylation rates vary depending on the identity of the substituting residue, from t1/2 ≈ 60 min for K70A to undetectable deacylation for K70D. Tryptophan fluorescence spectroscopy was used to confirm that these results are applicable to natural (i.e. non-fluorescent) substrates. Deacylation by K70A, but not K70D or K70E, can be partially restored by the addition of short-chain carboxylic acid mimetics of the lysine carbamate. In conclusion, we establish the functional role of the carboxylated lysine in OXA-1 and highlight its specific role in acylation and deacylation. PMID:19485421

  2. D-Amino acid dipeptide production utilizing D-alanine-D-alanine ligases with novel substrate specificity.

    PubMed

    Sato, Masaru; Kirimura, Kohtaro; Kino, Kuniki

    2005-06-01

    D-Alanine-D-alanine ligase (Ddl) is an important enzyme in the synthesis of bacterial peptidoglycan. The genes encoding Ddls from Escherichia coli K12 (EcDdlB), Oceanobacillus iheyensis JCM 11309 (OiDdl), Synechocystis sp. PCC 6803 (SsDdl) and Thermotoga maritima ATCC 43589 (TmDdl), the genomic DNA sequences of which have been determined, were cloned and the substrate specificities of these recombinant Ddls were investigated. Although OiDdl had a high substrate specificity for D-alanine; EcDdlB, SsDdl and TmDdl showed broad substrate specificities for D-serine, D-threonine, D-cysteine and glycine, in addition to D-alanine. Four D-amino acid dipeptides were produced using EcDdlB, and D-amino acid homo-dipeptides were successfully produced at high yields except for D-threonyl-D-threonine.

  3. [Alanine solution as enzyme reaction buffer used in A to O blood group conversion].

    PubMed

    Li, Su-Bo; Zhang, Xue; Zhang, Yin-Ze; Tan, Ying-Xia; Bao, Guo-Qiang; Wang, Ying-Li; Ji, Shou-Ping; Gong, Feng; Gao, Hong-Wei

    2014-06-01

    The aim of this study was to investigate the effect of alanine solution as α-N-acetylgalactosaminidase enzyme reaction buffer on the enzymatic activity of A antigen. The binding ability of α-N-acetylgalactosaminidase with RBC in different reaction buffer such as alanine solution, glycine solution, normal saline (0.9% NaCl), PBS, PCS was detected by Western blot. The results showed that the efficiency of A to O conversion in alanine solution was similar to that in glycine solution, and Western blot confirmed that most of enzymes blinded with RBC in glycine or alanine solution, but few enzymes blinded with RBC in PBS, PCS or normal saline. The evidences indicated that binding of enzyme with RBC was a key element for A to O blood group conversion, while the binding ability of α-N-acetylgalactosaminidase with RBC in alanine or glycine solution was similar. It is concluded that alanine solution can be used as enzyme reaction buffer in A to O blood group conversion. In this buffer, the α-N-acetylgalactosaminidase is closely blinded with RBC and α-N-acetylgalactosaminidase plays efficient enzymatic activity of A antigen.

  4. Role of Conserved Glycines in pH Gating of Kir1.1 (ROMK)

    PubMed Central

    Sackin, Henry; Nanazashvili, Mikheil; Palmer, Lawrence G.; Li, Hui

    2006-01-01

    Gating of inward rectifier Kir1.1 potassium channels by internal pH is believed to occur when large hydrophobic leucines, on each of the four subunits, obstruct the permeation path at the cytoplasmic end of the inner transmembrane helices (TM2). In this study, we examined whether closure of the channel at this point involves bending of the inner helix at one or both of two highly conserved glycine residues (corresponding to G134 and G143 in KirBac1.1) that have been proposed as putative “gating hinges” for potassium channels. Replacement of these conserved inner helical glycines by less flexible alanines did not abolish gating but shifted the apparent pKa from 6.6 ± 0.01 (wild-type) to 7.1 ± 0.01 for G157A-Kir1.1b, and to 7.3 ± 0.01 for G148A-Kir1.1b. When both glycines were mutated the effect was additive, shifting the pKa by 1.2 pH units to 7.8 ± 0.04 for the double mutant: G157A+G148A. At this pKa, the double mutant would remain completely closed under physiological conditions. In contrast, when the glycine at G148 was replaced by a proline, the pKa was shifted in the opposite direction from 6.6 ± 0.01 (wild-type) to 5.7 ± 0.01 for G148P. Although conserved glycines at G148 and G157 made it significantly easier to open the channel, they were not an absolute requirement for pH gating in Kir1.1. In addition, none of the glycine mutants produced more than small changes in either the cell-attached or excised single-channel kinetics which, in this channel, argues against changes in the selectivity filter. The putative pH sensor at K61-Kir1.1b, (equivalent to K80-Kir1.1a) was also examined. Mutation of this lysine to an untitratable methionine did not abolish pH gating, but shifted the pKa into an acid range from 6.6 ± 0.01 to 5.4 ± 0.04, similar to pH gating in Kir2.1. Hence K61-Kir1.1b cannot function as the exclusive pH sensor for the channel, although it may act as one of multiple pH sensors, or as a link between a cytoplasmic sensor and the channel

  5. Putative glycine receptors in Hydra: a biochemical and behavioural study.

    PubMed

    Pierobon, P; Minei, R; Porcu, P; Sogliano, C; Tino, A; Marino, G; Biggio, G; Concas, A

    2001-11-01

    Glycine acts as an inhibitory transmitter in the lower brain stem and spinal cord of vertebrate species, while very few data are yet available to support a similar role in invertebrate nervous systems. Here we report the identification and characterization of glycine receptors in the freshwater polyp Hydra vulgaris (Cnidaria, Hydrozoa) by biochemical and behavioural studies. Saturation experiments revealed the occurrence of one population of binding sites of nanomolar affinity (KD = 33 nm) and low capacity (Bmax = 79 fmol/mg protein) for [(3)H]strychnine. The addition of glycine or taurine (0.1 microm-1 mm) produced a dose-dependent inhibition of [(3)H]strychnine binding. Beta-alanine (0.1-1 mm) did not significantly affect [(3)H]strychnine binding. The pharmacological properties of these receptors compare with those of vertebrate glycine receptors. Stimulation of Hydra polyps by reduced glutathione resulted in a significant increase in the duration of mouth opening in the presence of glycine, taurine or beta-alanine. The enhancement of the response was related both to amino acid (10-100 microm) and to glutathione concentration (1-10 microm). The effects of glycine or its agonists were suppressed by strychnine (1-10 microm). D-serine, a glycine agonist at the vertebrate NMDA receptor, produced opposite effects to those of glycine. The effects of d-serine were suppressed by 5,7-dichlorokynurenic acid but not by strychnine. In vitro, [(3)H]strychnine binding was not displaced by d-serine. These results indicate a dual action of glycine in Hydra tissues. The hypothesis that NMDA receptors may also be present in this elementary nervous system is proposed.

  6. Formation of simple biomolecules from alanine in ocean by impacts

    NASA Astrophysics Data System (ADS)

    Umeda, Y.; Sekine, T.; Furukawa, Y.; Kakegawa, T.; Kobayashi, T.

    2013-12-01

    The biomolecules on the Earth are thought either to have originated from the extraterrestrial parts carried with flying meteorites or to have been formed from the inorganic materials on the Earth through given energy. From the standpoint to address the importance of impact energy, it is required to simulate experimentally the chemical reactions during impacts, because violent impacts may have occurred 3.8-4.0 Gyr ago to create biomolecules initially. It has been demonstrated that shock reactions among ocean (H2O), atmospheric nitrogen, and meteoritic constitution (Fe) can induce locally reduction environment to form simple bioorganic molecules such as ammonia and amino acid (Nakazawa et al., 2005; Furukawa et al., 2009). We need to know possible processes for alanine how chemical reactions proceed during repeated impacts and how complicated biomolecules are formed. Alanine can be formed from glycine (Umeda et al., in preparation). In this study, we carried out shock recovery experiments at pressures of 4.4-5.7 GPa to investigate the chemical reactions of alanine. Experiments were carried out with a propellant gun. Stainless steel containers (30 mm in diameter, 30 mm long) with 13C-labeled alanine aqueous solution immersed in olivine or hematite powders were used as targets. Air gap was present in the sample room (18 mm in diameter, 2 mm thick) behind the sample. The powder, solution, and air represent meteorite, ocean, and atmosphere on early Earth, respectively. Two powders of olivine and hematite help to keep the oxygen fugacity low and high during experiments, respectively in order to investigate the effect of oxygen fugacity on chemical processes of alanine. The recovered containers, after cleaned completely, were immersed into liquid nitrogen to freeze sample solution and then we drilled on the impact surface to extract water-soluble run products using pure water. Thus obtained products were analyzed by LC/MS for four amino acids (glycine, alanine, valine, and

  7. Effect of dietary lysine on hepatic lysine catabolism in broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lysine is frequently a first- or second-limiting amino acid in poultry diets. Improving the efficiency of lysine use for protein synthesis would effectively lower the lysine requirement and decrease feed costs. Understanding how lysine is degraded and how the degradation is regulated would identif...

  8. In vitro degradation of lysine by ruminal fluid-based fermentations and by Fusobacterium necrophorum.

    PubMed

    Elwakeel, E A; Amachawadi, R G; Nour, A M; Nasser, M E A; Nagaraja, T G; Titgemeyer, E C

    2013-01-01

    The objective of these studies was to characterize some factors affecting lysine degradation by mixed ruminal bacteria and by ruminal Fusobacterium necrophorum. Mixed ruminal bacteria degraded lysine, and addition of pure cultures of F. necrophorum did not increase lysine degradation. Addition of acetic or propionic acid strikingly reduced NH(3) production from lysine by mixed ruminal bacteria at pH 6, but not at pH 7. Although typical ruminal environments with acidic pH and normal concentrations of volatile fatty acids might inhibit lysine degradation by F. necrophorum, ruminal fluid contained enough bacteria with a lysine-degrading capacity to ferment 50 mM lysine in vitro. Of 7 strains of ruminal F. necrophorum tested, all grew on both lactate and lysine as the primary energy source. Both subspecies of ruminal F. necrophorum (necrophorum and funduliforme) used lysine as a primary C and energy source. Lysine and glutamic acid were effectively fermented by F. necrophorum, but alanine and tryptophan were not, and histidine and methionine were fermented only to a minor extent. The end products of lactate fermentation by F. necrophorum were propionate and acetate, and those of lysine degradation were butyrate and acetate. Fermentation of glutamic acid by F. necrophorum yielded acetate and butyrate in a ratio near to 2:1. The minimum inhibitory concentration of tylosin for F. necrophorum was not dependent on whether bacteria were grown with lactate or lysine, but F. necrophorum was more susceptible to monensin when grown on lysine than on lactate. Although F. necrophorum is generally resistant to monensin, the ionophore may reduce lysine degradation by F. necrophorum in the rumen. The essential oil components limonene, at 20 or 100 μg/mL, and thymol, at 100 μg/mL, inhibited F. necrophorum growth, whereas eugenol, guaiacol, and vanillin had no effect. Our findings may lead to ways to minimize ruminal lysine degradation and thus increase its availability to the animal.

  9. Structural features and activity of Brazzein and its mutants upon substitution of a surfaced exposed alanine.

    PubMed

    Ghanavatian, Parisa; Khalifeh, Khosrow; Jafarian, Vahab

    2016-12-01

    Brazzein (Brz) is a member of sweet-tasting protein containing four disulfide bonds. It was reported as a compact and heat-resistant protein. Here, we have used site-directed mutagenesis and replaced a surface-exposed alanine with aspartic acid (A19D mutant), lysine (A19K mutant) and glycine (A19G mutant). Activity comparisons of wild-type (WT) and mutants using taste panel test procedure showed that A19G variant has the same activity as WT protein. However, introduction of a positive charge in A19K mutant led to significant increase in Brz's sweetness, while A19D has reduced sweetness compared to WT protein. Docking studies showed that mutation at position 19 results in slight chain mobility of protein at the binding surface and changing the patterns of interactions toward more effective binding of E9K variant in the concave surface of sweet taste receptor. Far-UV CD data spectra have a characteristic shape of beta structure for all variants, however different magnitudes of spectra suggest that beta-sheet structure in WT and A19G is more stable than that of A19D and A19K. Equilibrium unfolding studies with fluorescence spectroscopy and using urea and dithiothritol (DTT) as chemical denaturants indicates that A19G mutant gains more stability against urea denaturation; while conformational stability of A19D and A19K decreases when compared with WT and A19G variants. We concluded that the positive charge at the surface of protein is important factor responsible for the interaction of protein with the human sweet receptor and Ala(19) can be considered as a key region for investigating the mechanism of the interaction of Brz with corresponding receptor.

  10. Synthesis of Lysine Methyltransferase Inhibitors

    NASA Astrophysics Data System (ADS)

    Ye, Tao; Hui, Chunngai

    2015-07-01

    Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  11. Enhancement of glycine receptor function by ethanol: role of phosphorylation

    PubMed Central

    Paola Mascia, Maria; Wick, Marilee J; Martinez, Larry D; Harris, R Adron

    1998-01-01

    The effects of several kinase inhibitors (staurosporine, GF 109203X, H89, KN62, genistein) and of the phosphatase inhibitor calyculin A were studied on the ethanol potentiation and on the function of homomeric α1 glycine receptor expressed in Xenopus oocytes using a two electrode voltage clamp recording technique.The function of the homomeric α1 glycine receptor was not modified in Xenopus oocytes pretreated with kinase inhibitors or with the phosphatase inhibitor calyculin A.The potentiation of the glycine receptor function induced by ethanol (10–200 mM) was significantly reduced in Xenopus oocytes pretreated with the PKC inhibitors staurosporine or GF 109203X.No differences in propofol (2.5 μM) or halothane (250 μM) actions were found after exposure of Xenopus oocytes to staurosporine.No differences in ethanol sensitivity were found after exposure of Xenopus oocytes expressing glycine α1 receptors to H89, KN62, genistein or to the phosphatase inhibitor calyculin A.The mutant α1 (S391A), in which the PKC phosphorylation site at serine 391 was mutated to alanine, was less sensitive to the effects of ethanol than was the α1 wild type receptor. Moreover, the ethanol potentiation of the glycine receptor function was not affected by treatment with staurosporine in oocytes expressing α1 (S391A).The splice variant of the α1 glycine receptor subunit, α1ins, containing eight additional amino acids and a potential phosphorylation site for PKA, did not differ from wild type for sensitivity to ethanol.These results indicate that phosphorylation by PKC of the homomeric α1 glycine receptor subunit modulates ethanol potentiation, but not the function of the glycine receptor. PMID:9786497

  12. Use of the guanidination reaction for determining reactive lysine, bioavailable lysine and gut endogenous lysine.

    PubMed

    Rutherfurd, Shane M

    2015-09-01

    Determining the bioavailability of lysine in foods and feedstuffs is important since lysine is often the first limiting indispensable amino acid in diets for intensively farmed livestock (pigs and poultry) and also in many cereal-based diets consumed by humans. When foods or feedstuffs are heat processed, lysine can undergo Maillard reactions to produce nutritionally unavailable products. The guanidination reaction, the reaction of O-methylisourea with the side chain amino group of lysine that produces homoarginine, has been used to determine the unmodified lysine (reactive lysine) in processed foods and feedstuffs and also true ileal digestible reactive lysine (bioavailable lysine). The advantages of the guanidination method in comparison with other reactive lysine methods such as the fluorodinitrobenzene, trinitrobenzenesulphonic acid and dye-binding methods are that it is very specific for reactive lysine and also that the method is relatively straightforward to conduct. The specificity of the guanidination reaction for the lysine side chain amino group is particularly important, since ileal digesta will contain N-terminal groups in the form of free amino acids and peptides. The main disadvantage is that complete conversion of lysine to homoarginine is required, yet it is not straightforward to test for complete guanidination in processed foods and feedstuffs. Another disadvantage is that the guanidination reaction conditions may vary for different food types and sometimes within the same food type. Consequently, food-specific guanidination reaction conditions may be required and more work is needed to optimise the reaction conditions across different foods and feedstuffs.

  13. Glycine receptors mediate excitation of subplate neurons in neonatal rat cerebral cortex.

    PubMed

    Kilb, W; Hanganu, I L; Okabe, A; Sava, B A; Shimizu-Okabe, C; Fukuda, A; Luhmann, H J

    2008-08-01

    The development of the cerebral cortex depends on genetic factors and early electrical activity patterns that form immature neuronal networks. Subplate neurons (SPn) are involved in the construction of thalamocortical innervation, generation of oscillatory network activity, and in the proper formation of the cortical columnar architecture. Because glycine receptors play an important role during early corticogenesis, we analyzed the functional consequences of glycine receptor activation in visually identified SPn in neocortical slices from postnatal day 0 (P0) to P4 rats using whole cell and perforated patch-clamp recordings. In all SPn the glycinergic agonists glycine, beta-alanine, and taurine induced dose-dependent inward currents with the affinity for glycine being higher than that for beta-alanine and taurine. Glycine-induced responses were blocked by the glycinergic antagonist strychnine, but were unaffected by either the GABAergic antagonist gabazine, the N-methyl-d-aspartate-receptor antagonist d-2-amino-5-phosphonopentanoic acid, or picrotoxin and cyanotriphenylborate, antagonists of alpha-homomeric and alpha1-subunit-containing glycine receptors, respectively. Under perforated-patch conditions, glycine induced membrane depolarizations that were sufficient to trigger action potentials (APs) in most cells. Furthermore, glycine and taurine decreased the injection currents as well as the synaptic stimulation strength required to elicit APs, indicating that glycine receptors have a consistent excitatory effect on SPn. Inhibition of taurine transport and application of hypoosmolar solutions induced strychnine-sensitive inward currents, suggesting that taurine can act as a possible endogenous agonist on SPn. In summary, these results demonstrate that SPn express glycine receptors that mediate robust excitatory membrane responses during early postnatal development.

  14. 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 ...

  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. Amperometric biosensor based on diamond paste for the enantioanalysis of L-lysine.

    PubMed

    Stefan-van Staden, Raluca-Ioana; Nejem, R'afat Mahmoud; van Staden, Jacobus Frederick; Aboul-Enein, Hassan Y

    2012-05-15

    An amperometric biosensor was proposed for the enantioanalysis of L-lysine. The biosensor is based on the impregnation of L-lysine oxidase in diamond paste. The potential used for the determination of l-lysine was 650 mV. The biosensor exhibited a linear concentration range between 1 and 100 nmol/L with a limit of detection of 4 pmol/L. The selectivity of the biosensor is high over other amino acids, such as L-serine, L-leucine, L-aspartic acid, L-glutamic acid, histamine, glycine. The proposed biosensor can be applied for the determination of L-lysine in serum samples and pharmaceutical compounds.

  17. N. sup. var epsilon. -acetyl-. beta. -lysine: An osmolyte synthesized by mothanogenic archaebacteria

    SciTech Connect

    Sowers, K.R.; Gunsalus, R.P. ); Robertson, D.E.; Noll, D.; Roberts, M.F. )

    1990-12-01

    Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified {beta}-amino acid that was identified as N{sup {var epsilon}}-acetyl-{beta}-lysine by NMR spectroscopy and ion-exchange HPLC. This {beta}-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined - Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological compatible solute, N{sup {var epsilon}}-acetyl-{beta}-lysine synthesis was repressed and glycine betaine was accumulated. N{sup {var epsilon}}-Acetyl-{beta}-lysine was synthesized by species from three phylogenetic families when grown in high solute concentrations, suggesting that it may be ubiquitous among the methanogens. The ability to control the biosynthesis of N{sup {var epsilon}}-acetyl-{beta}-lysine in response to extracellular solute concentration indicates that the methanogenic archaebacteria have a unique {beta}-amino acid biosynthetic pathway that is osmotically regulated.

  18. Conformational variability of the glycine receptor M2 domain in response to activation by different agonists.

    PubMed

    Pless, Stephan A; Dibas, Mohammed I; Lester, Henry A; Lynch, Joseph W

    2007-12-07

    Models describing the structural changes mediating Cys loop receptor activation generally give little attention to the possibility that different agonists may promote activation via distinct M2 pore-lining domain structural rearrangements. We investigated this question by comparing the effects of different ligands on the conformation of the external portion of the homomeric alpha1 glycine receptor M2 domain. Conformational flexibility was assessed by tethering a rhodamine fluorophore to cysteines introduced at the 19' or 22' positions and monitoring fluorescence and current changes during channel activation. During glycine activation, fluorescence of the label attached to R19'C increased by approximately 20%, and the emission peak shifted to lower wavelengths, consistent with a more hydrophobic fluorophore environment. In contrast, ivermectin activated the receptors without producing a fluorescence change. Although taurine and beta-alanine were weak partial agonists at the alpha1R19'C glycine receptor, they induced large fluorescence changes. Propofol, which drastically enhanced these currents, did not induce a glycine-like blue shift in the spectral emission peak. The inhibitors strychnine and picrotoxin elicited fluorescence and current changes as expected for a competitive antagonist and an open channel blocker, respectively. Glycine and taurine (or beta-alanine) also produced an increase and a decrease, respectively, in the fluorescence of a label attached to the nearby L22'C residue. Thus, results from two separate labeled residues support the conclusion that the glycine receptor M2 domain responds with distinct conformational changes to activation by different agonists.

  19. GLYCINE RESISTANCE IN AGROBACTERIUM TUMEFACIENS

    PubMed Central

    Beardsley, Robert E.

    1962-01-01

    Beardsley, Robert E. (Manhattan College, New York, N. Y.). Glycine resistance in Agrobacterium tumefaciens. J. Bacteriol. 83:6–13. 1962.—The application of the fluctuation test of Luria and Delbrück to the distribution of glycine-resistant bacteria among cultures of Agrobacterium tumefaciens strain B6 indicates that resistance arises by mutation in the absence of glycine. On glycine-supplemented medium, additional resistant colonies arise during prolonged periods of incubation. Their appearance is proceded by L-form growth. In general, the number of generations over which glycine resistance is inherited in the absence of glycine is increased by serial transfers on the selection medium. In liquid medium containing glycine, sensitive bacteria form spheroplasts. Resistant bacteria continue to grow as rod forms. In the medium employed, spheroplasts are unstable. Images PMID:13866159

  20. beta-Alanine elevates dopamine levels in the rat nucleus accumbens: antagonism by strychnine.

    PubMed

    Ericson, Mia; Clarke, Rhona B C; Chau, PeiPei; Adermark, Louise; Söderpalm, Bo

    2010-04-01

    Glycine receptors (GlyRs) in the nucleus accumbens (nAc) have recently been suggested to be involved in the reinforcing and dopamine-elevating properties of ethanol via a neuronal circuitry involving the VTA. Apart from ethanol, both glycine and taurine have the ability to modulate dopamine output via GlyRs in the same brain region. In the present study, we wanted to explore whether yet another endogenous ligand for the GlyR, beta-alanine, had similar effects. To this end, we monitored dopamine in the nAc by means of in vivo microdialysis and found that local perfusion of beta-alanine increased dopamine output. In line with previous observations investigating ethanol, glycine and taurine, the competitive GlyR antagonist strychnine completely blocked the dopamine elevation. The present results suggest that beta-alanine has the ability to modulate dopamine levels in the nAc via strychnine-sensitive GlyRs, and are consistent with previous studies suggesting the importance of this receptor for modulating dopamine output.

  1. Crystal Structures of Aedes Aegypt Alanine Glyoxylate Aminotransferase

    SciTech Connect

    Han,Q.; Robinson, H.; Gao, Y.; Vogelaar, N.; Wilson, S.; Rizzi, M.; Li, J.

    2006-01-01

    Mosquitoes are unique in having evolved two alanine glyoxylate aminotransferases (AGTs). One is 3-hydroxykynurenine transaminase (HKT), which is primarily responsible for catalyzing the transamination of 3-hydroxykynurenine (3-HK) to xanthurenic acid (XA). Interestingly, XA is used by malaria parasites as a chemical trigger for their development within the mosquito. This 3-HK to XA conversion is considered the major mechanism mosquitoes use to detoxify the chemically reactive and potentially toxic 3-HK. The other AGT is a typical dipteran insect AGT and is specific for converting glyoxylic acid to glycine. Here we report the 1.75{angstrom} high-resolution three-dimensional crystal structure of AGT from the mosquito Aedes aegypti (AeAGT) and structures of its complexes with reactants glyoxylic acid and alanine at 1.75 and 2.1{angstrom} resolution, respectively. This is the first time that the three-dimensional crystal structures of an AGT with its amino acceptor, glyoxylic acid, and amino donor, alanine, have been determined. The protein is dimeric and adopts the type I-fold of pyridoxal 5-phosphate (PLP)-dependent aminotransferases. The PLP co-factor is covalently bound to the active site in the crystal structure, and its binding site is similar to those of other AGTs. The comparison of the AeAGT-glyoxylic acid structure with other AGT structures revealed that these glyoxylic acid binding residues are conserved in most AGTs. Comparison of the AeAGT-alanine structure with that of the Anopheles HKT-inhibitor complex suggests that a Ser-Asn-Phe motif in the latter may be responsible for the substrate specificity of HKT enzymes for 3-HK.

  2. Crystal structures of Aedes aegypti alanine glyoxylate aminotransferase.

    PubMed

    Han, Qian; Robinson, Howard; Gao, Yi Gui; Vogelaar, Nancy; Wilson, Scott R; Rizzi, Menico; Li, Jianyong

    2006-12-01

    Mosquitoes are unique in having evolved two alanine glyoxylate aminotransferases (AGTs). One is 3-hydroxykynurenine transaminase (HKT), which is primarily responsible for catalyzing the transamination of 3-hydroxykynurenine (3-HK) to xanthurenic acid (XA). Interestingly, XA is used by malaria parasites as a chemical trigger for their development within the mosquito. This 3-HK to XA conversion is considered the major mechanism mosquitoes use to detoxify the chemically reactive and potentially toxic 3-HK. The other AGT is a typical dipteran insect AGT and is specific for converting glyoxylic acid to glycine. Here we report the 1.75A high-resolution three-dimensional crystal structure of AGT from the mosquito Aedes aegypti (AeAGT) and structures of its complexes with reactants glyoxylic acid and alanine at 1.75 and 2.1A resolution, respectively. This is the first time that the three-dimensional crystal structures of an AGT with its amino acceptor, glyoxylic acid, and amino donor, alanine, have been determined. The protein is dimeric and adopts the type I-fold of pyridoxal 5-phosphate (PLP)-dependent aminotransferases. The PLP co-factor is covalently bound to the active site in the crystal structure, and its binding site is similar to those of other AGTs. The comparison of the AeAGT-glyoxylic acid structure with other AGT structures revealed that these glyoxylic acid binding residues are conserved in most AGTs. Comparison of the AeAGT-alanine structure with that of the Anopheles HKT-inhibitor complex suggests that a Ser-Asn-Phe motif in the latter may be responsible for the substrate specificity of HKT enzymes for 3-HK.

  3. On the roles of the alanine and serine in the β-sheet structure of fibroin.

    PubMed

    Carrascoza Mayen, Juan Francisco; Lupan, Alexandru; Cosar, Ciprian; Kun, Attila-Zsolt; Silaghi-Dumitrescu, Radu

    2015-02-01

    In its silk II form, fibroin is almost exclusively formed from layers of β-sheets, rich in glycine, alanine and serine. Reported here are computational results on fibroin models at semi-empirical, DFT levels of theory and molecular dynamics (MD) for (Gly)10, (Gly-Ala)5 and (Gly-Ser)5 decapeptides. While alanine and serine introduce steric repulsions, the alanine side-chain adds to the rigidity of the sheet, allowing it to maintain a properly pleated structure even in a single β-sheet, and thus avoiding two alternative conformations which would interfere with the formation of the multi-layer pleated-sheet structure. The role of the serine is proposed to involve modulation of the hydrophobicity in order to construct the supramolecular assembly as opposed to random precipitation due to hydrophobicity.

  4. 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

  5. Purification and characterization of the glycine receptor of pig spinal cord

    SciTech Connect

    Graham, D.; Pfeiffer, F.; Simler, R.; Betz, H.

    1985-02-12

    A large-scale purification procedure was developed to isolate the glycine receptor of pig spinal cord by affinity chromatography on aminostrychnine agarose. After an overall purification of about 10,000-fold, the glycine receptor preparations contained three major polypeptides of Mr 48,000, 58,000, and 93,000. Photoaffinity labeling with (/sup 3/H)strychnine showed that the (/sup 3/H)strychnine binding site is associated with the Mr 48,000 and, to a much lesser extent, the Mr 58,000 polypeptides. (/sup 3/H)Strychnine binding to the purified receptor exhibited a dissociation constant K /sub D/ of 13.8 nM and was inhibited by the agonists glycine, taurine, and beta-alanine. Gel filtration and sucrose gradient centrifugation gave a Stokes radius of 7.1 nm and an apparent sedimentation coefficient of 9.6 S. Peptide mapping of the (/sup 3/H)strychnine-labeled Mr 48,000 polypeptides of purified pig and rat glycine receptor preparations showed that the strychnine binding region of this receptor subunit is highly conserved between these species. Also, three out of six monoclonal antibodies against the glycine receptor of rat spinal cord significantly cross-reacted with their corresponding polypeptides of the pig glycine receptor. These results show that the glycine receptor of pig spinal cord is very similar to the well-characterized rat receptor protein and can be purified in quantities sufficient for protein chemical analysis.

  6. Effect of ruminal ammonia supply on lysine utilization by growing steers.

    PubMed

    Hussein, A H; Batista, E D; Miesner, M D; Titgemeyer, E C

    2016-02-01

    Six ruminally cannulated Holstein steers (202 ± 15 kg) were used to study the effects of ruminal ammonia loading on whole-body lysine (Lys) utilization. Steers were housed in metabolism crates and used in a 6 × 6 Latin square design. All steers received 2.52 kg DM/d of a diet (10.1% CP) containing 82% soybean hulls, 8% wheat straw, 5% cane molasses, and 5% vitamins and minerals, and 10 g/d of urea (considered to be part of the basal diet) was ruminally infused continuously to ensure adequate ruminal ammonia concentrations. All steers were ruminally infused continuously with 200 g/d of acetic acid, 200 g/d of propionic acid, and 50 g/d of butyric acid and abomasally infused with 300 g/d of glucose continuously to increase energy supply without increasing microbial protein supply. Steers were also abomasally infused continuously with an excess of all essential AA except Lys to ensure that Lys was the only limiting AA. Treatments were arranged as a 3 × 2 factorial with 3 levels of urea (0, 40, or 80 g/d) continuously infused ruminally to induce ammonia loading and 2 levels of Lys (0 or 6 g/d) continuously infused abomasally. Treatments did not affect fecal N output ( = 0.37). Lysine supplementation decreased ( < 0.01) urinary N excretion from 51.9 g/d to 44.3 g/d, increased ( < 0.01) retained N from 24.8 to 33.8 g/d, increased ( < 0.01) plasma Lys, and decreased ( ≤ 0.05) plasma serine, tyrosine, valine, leucine, and phenylalanine. Lysine supplementation also tended ( = 0.09) to reduce plasma urea-N. Urea infusions linearly increased ( = 0.05) retained N (27.1, 29.3, and 31.5 g/d) and also linearly increased ( < 0.01) urinary N excretion (31.8, 48.1, and 64.4 g/d), urinary urea (21.9, 37.7, and 54.3 g/d), urinary ammonia (1.1, 1.4, and 1.9 g/d), and plasma urea (2.7, 4.0, and 5.1 mM), and linearly decreased plasma alanine ( = 0.04) and plasma glycine ( < 0.01). Assuming that retained protein is 6.25 × retained N and contains 6.4% Lys, the incremental

  7. Role of Alanine Dehydrogenase of Mycobacterium tuberculosis during Recovery from Hypoxic Nonreplicating Persistence

    PubMed Central

    Giffin, Michelle M.; Shi, Lanbo; Gennaro, Maria L.; Sohaskey, Charles D.

    2016-01-01

    Mycobacterium tuberculosis can maintain a nonreplicating persistent state in the host for decades, but must maintain the ability to efficiently reactivate and produce active disease to survive and spread in a population. Among the enzymes expressed during this dormancy is alanine dehydrogenase, which converts pyruvate to alanine, and glyoxylate to glycine concurrent with the oxidation of NADH to NAD. It is involved in the metabolic remodeling of M. tuberculosis through its possible interactions with both the glyoxylate and methylcitrate cycle. Both mRNA levels and enzymatic activities of isocitrate lyase, the first enzyme of the glyoxylate cycle, and alanine dehydrogenase increased during entry into nonreplicating persistence, while the gene and activity for the second enzyme of the glyoxylate cycle, malate synthase were not. This could suggest a shift in carbon flow away from the glyoxylate cycle and instead through alanine dehydrogenase. Expression of ald was also induced in vitro by other persistence-inducing stresses such as nitric oxide, and was expressed at high levels in vivo during the initial lung infection in mice. Enzyme activity was maintained during extended hypoxia even after transcription levels decreased. An ald knockout mutant of M. tuberculosis showed no reduction in anaerobic survival in vitro, but resulted in a significant lag in the resumption of growth after reoxygenation. During reactivation the ald mutant had an altered NADH/NAD ratio, and alanine dehydrogenase is proposed to maintain the optimal NADH/NAD ratio during anaerobiosis in preparation of eventual regrowth, and during the initial response during reoxygenation. PMID:27203084

  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. [Raman scattering study of DL-alanine].

    PubMed

    Gong, Yan; Wang, Wen-qing

    2006-01-01

    Studies of Raman vibration spectra are useful to obtaining information on biomolecular crystals. The cell dimensions of the L- and DL-alanine crystals are nearly identical, and both structures belong to the orthorhombic system, but the space group is P2(1) 2(1) 2(1) for the L-isomer, and Pna2(1) for the racemate crystal. The Raman spectrum of L-alanine has been measured by many authors. The present work is focusing on the Raman scattering study of DL-alanine powder. Based on the analysis of the differences between DL-alanine and L-alanine Raman spectra, the authors obtained indispensable information on hydrogen bond and the motion of the molecular conformation in alanine crystals.

  10. Vibrational dynamics of crystalline L-alanine

    SciTech Connect

    Bordallo, H.N.; Eckert, J.; Barthes, M.

    1997-11-01

    The authors report a new, complete vibrational analysis of L-alanine and L-alanine-d{sub 4} which utilizes IINS intensities in addition to frequency information. The use of both isotopomers resulted in a self-consistent force field for and assignment of the molecular vibrations in L-alanine. Some details of the calculation as well as a comparison of calculated and observed IINS spectra are presented. The study clarifies a number of important issues on the vibrational dynamics of this molecule and presents a self-consistent force field for the molecular vibrations in crystalline L-alanine.

  11. Paradox of mistranslation of serine for alanine caused by AlaRS recognition dilemma.

    PubMed

    Guo, Min; Chong, Yeeting E; Shapiro, Ryan; Beebe, Kirk; Yang, Xiang-Lei; Schimmel, Paul

    2009-12-10

    Mistranslation arising from confusion of serine for alanine by alanyl-tRNA synthetases (AlaRSs) has profound functional consequences. Throughout evolution, two editing checkpoints prevent disease-causing mistranslation from confusing glycine or serine for alanine at the active site of AlaRS. In both bacteria and mice, Ser poses a bigger challenge than Gly. One checkpoint is the AlaRS editing centre, and the other is from widely distributed AlaXps-free-standing, genome-encoded editing proteins that clear Ser-tRNA(Ala). The paradox of misincorporating both a smaller (glycine) and a larger (serine) amino acid suggests a deep conflict for nature-designed AlaRS. Here we show the chemical basis for this conflict. Nine crystal structures, together with kinetic and mutational analysis, provided snapshots of adenylate formation for each amino acid. An inherent dilemma is posed by constraints of a structural design that pins down the alpha-amino group of the bound amino acid by using an acidic residue. This design, dating back more than 3 billion years, creates a serendipitous interaction with the serine OH that is difficult to avoid. Apparently because no better architecture for the recognition of alanine could be found, the serine misactivation problem was solved through free-standing AlaXps, which appeared contemporaneously with early AlaRSs. The results reveal unconventional problems and solutions arising from the historical design of the protein synthesis machinery.

  12. Catalytic Stereoinversion of L-Alanine to Deuterated D-Alanine.

    PubMed

    Moozeh, Kimia; So, Soon Mog; Chin, Jik

    2015-08-03

    A combination of an achiral pyridoxal analogue and a chiral base has been developed for catalytic deuteration of L-alanine with inversion of stereochemistry to give deuterated D-alanine under mild conditions (neutral pD and 25 °C) without the use of any protecting groups. This system can also be used for catalytic deuteration of D-alanine with retention of stereochemistry to give deuterated D-alanine. Thus a racemic mixture of alanine can be catalytically deuterated to give an enantiomeric excess of deuterated D-alanine. While catalytic deracemization of alanine is forbidden by the second law of thermodynamics, this system can be used for catalytic deracemization of alanine with deuteration. Such green and biomimetic approach to catalytic stereocontrol provides insights into efficient amino acid transformations.

  13. Allosteric modulation of glycine receptors is more efficacious for partial rather than full agonists.

    PubMed

    Bíró, Tímea; Maksay, Gábor

    2004-06-01

    Allosteric modulation of [3H]strychnine binding to glycine receptors (GlyRs) was examined in synaptosomal membranes of rat spinal cord. An allosteric model enabled us to determine the cooperativity factors of the allosteric agents with [3H]strychnine and glycine bindings (alpha and beta, respectively). We modified the allosteric model with a slope factor because the slope values of the displacement curves of partial agonists (beta-alanine, taurine and gamma-aminobutyric acid) were beyond unity. The slope factor was reduced only by 100 microM propofol. Further, propofol showed positive cooperativity (beta < 1) stronger with taurine than with glycine. The extent of the positive cooperativity of propofol was nearly independent from the potencies and structures of partial agonists. The steroidal alphaxalone and minaxolone also potentiated taurine better than glycine. Alphaxalone exerted weak negative cooperativity with [3H]strychnine binding. Displacement by taurine is attenuated by granisetron and m-chlorophenylbiguanide representing negative cooperativity (beta > 1) greater than with glycine. The results suggest a developmental role of elevated perinatal levels of taurine and neurosteroids as well as a better allosteric modulation of decreased agonist efficacies for impaired glycine receptor-ionophores.

  14. Role of choline and glycine betaine in the formation of N,N-dimethylpiperidinium (mepiquat) under Maillard reaction conditions.

    PubMed

    Bessaire, Thomas; Tarres, Adrienne; Stadler, Richard H; Delatour, Thierry

    2014-01-01

    This study is the first to examine the role of choline and glycine betaine, naturally present in some foods, in particular in cereal grains, to generate N,N-dimethylpiperidinium (mepiquat) under Maillard conditions via transmethylation reactions involving the nucleophile piperidine. The formation of mepiquat and its intermediates piperidine - formed by cyclisation of free lysine in the presence of reducing sugars - and N-methylpiperidine were monitored over time (240°C, up to 180 min) using high-resolution mass spectrometry in a model system comprised of a ternary mixture of lysine/fructose/alkylating agent (choline or betaine). The reaction yield was compared with data recently determined for trigonelline, a known methylation agent present naturally in coffee beans. The role of choline and glycine betaine in nucleophilic displacement reactions was further supported by experiments carried out with stable isotope-labelled precursors (¹³C- and deuterium-labelled). The results unequivocally demonstrated that the piperidine ring of mepiquat originates from the carbon chain of lysine, and that either choline or glycine betaine furnishes the N-methyl groups. The kinetics of formation of the corresponding demethylated products of both choline and glycine betaine, N,N-demethyl-2-aminoethanol and N,N-dimethylglycine, respectively, were also determined using high-resolution mass spectrometry.

  15. Protein Homeostasis Defects of Alanine-Glyoxylate Aminotransferase: New Therapeutic Strategies in Primary Hyperoxaluria Type I

    PubMed Central

    Pey, Angel L.; Albert, Armando; Salido, Eduardo

    2013-01-01

    Alanine-glyoxylate aminotransferase catalyzes the transamination between L-alanine and glyoxylate to produce pyruvate and glycine using pyridoxal 5′-phosphate (PLP) as cofactor. Human alanine-glyoxylate aminotransferase is a peroxisomal enzyme expressed in the hepatocytes, the main site of glyoxylate detoxification. Its deficit causes primary hyperoxaluria type I, a rare but severe inborn error of metabolism. Single amino acid changes are the main type of mutation causing this disease, and considerable effort has been dedicated to the understanding of the molecular consequences of such missense mutations. In this review, we summarize the role of protein homeostasis in the basic mechanisms of primary hyperoxaluria. Intrinsic physicochemical properties of polypeptide chains such as thermodynamic stability, folding, unfolding, and misfolding rates as well as the interaction of different folding states with protein homeostasis networks are essential to understand this disease. The view presented has important implications for the development of new therapeutic strategies based on targeting specific elements of alanine-glyoxylate aminotransferase homeostasis. PMID:23956997

  16. Possible Transfer of Resistance to Heterodera glycines from Glycine tomentella to Glycine max

    PubMed Central

    Riggs, R. D.; Wang, S.; Singh, R. J.; Hymowitz, T.

    1998-01-01

    Eight wild perennial Glycine species (G. argyrea, G. canescens, G. curvata, G. cyrtoloba, G. latifolia, G. microphylla, G. tabacina, and G. tomentella) were evaluated for resistance to isolates of races 1, 3, and 14 of Heterodera glycines. In a second experiment, reproduction of isolates of races 3, 5, and 14 of H. glycines on five of the wild perennial species was determined. Seventy-one derived fertile lines (2n = 40) that were hybrids between G. max cv Clark 63 and G. tomentella also were evaluated for resistance to isolates of races 3, 5, and 14. All of the wild perennial Glycine species were resistant (Female Indices [FI] less than 10) to all of the isolates that were tested on them. In most cases no females matured. The soybean cvs. Clark 63 and Altona, which were tested at the same time as the hybrids, were susceptible to all isolates of H. glycines tested. When the tests were combined and a single FI calculated with the average number of females on Lee 74, one derived fertile line was resistant to race 3, three derived fertile lines were resistant to race 5, and five derived fertile lines were resistant to race 14. Thus, transfer of resistance to H. glycines from G. tomentella to G. max apparently occurred. PMID:19274245

  17. Alanine increases blood pressure during hypotension

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Maher, T. J.; Wurtman, R. J.

    1990-01-01

    The effect of L-alanine administration on blood pressure (BP) during haemorrhagic shock was investigated using anesthetized rats whose left carotid arteries were cannulated for BP measurement, blood removal, and drug administration. It was found that L-alanine, in doses of 10, 25, 50, 100, and 200 mg/kg, increased the systolic BP of hypotensive rats by 38 to 80 percent (while 100 mg/kg pyruvate increased BP by only 9.4 mmhg, not significantly different from saline). The results suggest that L-alanine might influence cardiovascular function.

  18. 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.

  19. Quantification of hydroxyl radical-derived oxidation products in peptides containing glycine, alanine, valine, and proline.

    PubMed

    Morgan, Philip E; Pattison, David I; Davies, Michael J

    2012-01-15

    Proteins are a major target for oxidation due to their abundance and high reactivity. Despite extensive investigation over many years, only limited quantitative data exist on the contributions of different pathways to the oxidation of peptides and proteins. This study was designed to obtain quantitative data on the nature and yields of oxidation products (alcohols, carbonyls, hydroperoxides, fragment species) formed by a prototypic oxidant system (HO(•)/O(2)) on small peptides of limited, but known, amino acid composition. Peptides composed of Gly, Ala, Val, and Pro were examined with particular emphasis on the peptide Val-Gly-Val-Ala-Pro-Gly, a repeat motif in elastin with chemotactic activity and metalloproteinase regulation properties. The data obtained indicate that hydroperoxide formation occurs nonrandomly (Pro > Val > Ala > Gly) with this inversely related to carbonyl yields (both peptide-bound and released). Multiple alcohols are generated at both side-chain and backbone sites. Backbone fragmentation has been characterized at multiple positions, with sites adjacent to Pro residues being of major importance. Summation of the product concentrations provides clear evidence for the occurrence of chain reactions in peptides exposed to HO(•)/O(2), with the overall product yields exceeding that of the initial HO(•) generated.

  20. Barrier-Free Intermolecular Proton Transfer Induced by Excess Electron Attachment to the Complex of Alanine with Uracil

    SciTech Connect

    Dabkowska, Iwona; Rak, Janusz; Gutowski, Maciej S.; Nilles, J.M.; Stokes, Sarah; Bowen, Kit H.

    2004-04-01

    The photoelectron spectrum of the uracil-alanine anionic complex (UA)- has been recorded with 2.540 eV photons. This spectrum reveals a broad feature with a maximum between 1.6-2.1 eV. The vertical electron detachment energy is too large to be attributed to an (UA)- anionic complex in which an intact uracil anion is solvated by alanine, or vice versa. The neutral and anionic complexes of uracil and alanine were studied at the B3LYP and second order Moeller-Plesset level of theory with 6-31++G** basis sets. The neutral complexes form cyclic hydrogen bonds and the three most stable neutral complexes are bound by 0.72, 0.61 and 0.57 eV. The electron hole in complexes of uracil with alaninie is localized on uracil, but the formation of a complex with alanine strongly modulates the vertical ionization energy of uracil. The theoretical results indicate that the excess electron in (UA)- occupies a p* orbital localized on uracil. The excess electron attachment to the complex can induce a barrier-free proton transfer (BFPT) from the carboxylic group of alanine to the O8 atom of uracil. As a result, the four most stable structures of the uracil-alanine anionic complex can be characterized as the neutral radical of hydrogenated uracil solvated by the anion of deprotonated alanine. Our current results for the anionic complex of uracil with alanine are similar to our previous results for the anion of uracil with glycine [Eur. Phys. J. D 20, 431 (2002)], and together they indicate that the BFPT process is not very sensitive to the nature of the amino acid's hydrophobic residual group. The BFPT to the O8 atom of uracil may be relevant to the damage suffered by nucleic acid bases due to exposure to low energy electrons.

  1. Solved? The reductive radiation chemistry of alanine.

    PubMed

    Pauwels, Ewald; De Cooman, Hendrik; Waroquier, Michel; Hole, Eli O; Sagstuen, Einar

    2014-02-14

    The structural changes throughout the entire reductive radiation-induced pathway of l-α-alanine are solved on an atomistic level with the aid of periodic DFT and nudged elastic band (NEB) simulations. This yields unprecedented information on the conformational changes taking place, including the protonation state of the carboxyl group in the "unstable" and "stable" alanine radicals and the internal transformation converting these two radical variants at temperatures above 220 K. The structures of all stable radicals were verified by calculating EPR properties and comparing those with experimental data. The variation of the energy throughout the full radiochemical process provides crucial insight into the reason why these structural changes and rearrangements occur. Starting from electron capture, the excess electron quickly localizes on the carbon of a carboxyl group, which pyramidalizes and receives a proton from the amino group of a neighboring alanine molecule, forming a first stable radical species (up to 150 K). In the temperature interval 150-220 K, this radical deaminates and deprotonates at the carboxyl group, the detached amino group undergoes inversion and its methyl group sustains an internal rotation. This yields the so-called "unstable alanine radical". Above 220 K, triggered by the attachment of an additional proton on the detached amino group, the radical then undergoes an internal rotation in the reverse direction, giving rise to the "stable alanine radical", which is the final stage in the reductive radiation-induced decay of alanine.

  2. 76 FR 55109 - Glycine From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ... COMMISSION Glycine From China Determination On the basis of the record \\1\\ developed in the subject five-year... glycine from China would be likely to lead to continuation or recurrence of material injury to an industry... 2011), entitled Glycine from China: Investigation No. 731-TA-718 (Third Review). By order of...

  3. Monopeptide versus Monopeptoid: Insights on Structure and Hydration of Aqueous Alanine and Sarcosine via X-ray Absorption Spectroscopy

    SciTech Connect

    Uejio, Janel S.; Schwartz, Craig P.; Duffin, Andrew M.; England, Alice; Prendergast, David; Saykally, Richard J.

    2009-11-19

    Despite the obvious significance, the aqueous interactions of peptides remain incompletely understood. Their synthetic analogues called peptoids (poly-N-substituted glycines), have recently emerged as a promising biomimetic material, particularly due to their robust secondary structure and resistance to denaturation. We describe comparative near-edge x-ray absorption fine structure (NEXAFS) spectroscopy studies of aqueous sarcosine, the simplest peptoid, and alanine, its peptide isomer, interpreted by density functional theory calculations. The sarcosine nitrogen K-edge spectrum is blue-shifted with respect to that of alanine, in agreement with our calculations; we conclude that this shift results primarily from the methyl group substitution on the nitrogen of sarcosine. Our calculations indicate that the nitrogen K-edge spectrum of alanine differs significantly between dehydrated and hydrated scenarios, while that of the sarcosine zwitterion is less affected by hydration. In contrast, the computed sarcosine spectrum is greatly impacted by conformational variations, while the alanine spectrum is not. This relates to a predicted solvent dependence for alanine, as compared to sarcosine. Additionally, we show the theoretical nitrogen K-edge spectra to be sensitive to the degree of hydration, indicating that experimental X-ray spectroscopy may be able to distinguish between bulk and partial hydration, such as found in confined environments near proteins and in reverse micelles.

  4. Global Proteomics Analysis of Protein Lysine Methylation

    PubMed Central

    Cao, Xing-Jun; Garcia, Benjamin A.

    2017-01-01

    Lysine methylation is a common protein post-translational modification dynamically mediated by protein lysine methyltransferases (PKMTs) and demethylases (PKDMs). Beyond histone proteins, lysine methylation on non-histone proteins play substantial roles in a variety of functions in cells, and is closely associated with diseases such as cancer. A large body of evidence indicates that the dysregulation of some PKMTs lead to tumorigenesis via their non-histone substrates. However, more studies on other PKMTs have made slow progress owing to the lack of the approaches for extensive screening of lysine methylation sites. Recently a series of publications to perform large-scale analysis of protein lysine methylation have emerged. In this unit, we introduce a protocol for the global analysis of protein lysine methylation in cells by means of immunoaffinity enrichment and mass spectrometry. PMID:27801517

  5. First Comprehensive Proteome Analyses of Lysine Acetylation and Succinylation in Seedling Leaves of Brachypodium distachyon L.

    PubMed Central

    Zhen, Shoumin; Deng, Xiong; Wang, Jian; Zhu, Gengrui; Cao, Hui; Yuan, Linlin; Yan, Yueming

    2016-01-01

    Protein acetylation and succinylation are the most crucial protein post-translational modifications (PTMs) involved in the regulation of plant growth and development. In this study, we present the first lysine-acetylation and lysine-succinylation proteome analysis of seedling leaves in Brachypodium distachyon L (Bd). Using high accuracy nano LC-MS/MS combined with affinity purification, we identified a total of 636 lysine-acetylated sites in 353 proteins and 605 lysine-succinylated sites in 262 proteins. These proteins participated in many biology processes, with various molecular functions. In particular, 119 proteins and 115 sites were found to be both acetylated and succinylated, simultaneously. Among the 353 acetylated proteins, 148 had acetylation orthologs in Oryza sativa L., Arabidopsis thaliana, Synechocystis sp. PCC 6803, and Glycine max L. Among the 262 succinylated proteins, 170 of them were found to have homologous proteins in Oryza sativa L., Escherichia coli, Sacchayromyces cerevisiae, or Homo sapiens. Motif-X analysis of the acetylated and succinylated sites identified two new acetylated motifs (K---K and K-I-K) and twelve significantly enriched succinylated motifs for the first time, which could serve as possible binding loci for future studies in plants. Our comprehensive dataset provides a promising starting point for further functional analysis of acetylation and succinylation in Bd and other plant species. PMID:27515067

  6. Adding a Lysine Mimic in the Design of Potent Inhibitors of Histone Lysine Methyltransferases

    SciTech Connect

    Chang, Yanqi; Ganesh, Thota; Horton, John R.; Spannhoff, Astrid; Liu, Jin; Sun, Aiming; Zhang, Xing; Bedford, Mark T.; Shinkai, Yoichi; Snyder, James P.; Cheng, Xiaodong

    2010-07-19

    Dynamic histone lysine methylation involves the activities of modifying enzymes (writers), enzymes removing modifications (erasers), and readers of the histone code. One common feature of these activities is the recognition of lysines in methylated and unmethylated states, whether they are substrates, reaction products, or binding partners. We applied the concept of adding a lysine mimic to an established inhibitor (BIX-01294) of histone H3 lysine 9 methyltransferases G9a and G9a-like protein by including a 5-aminopentyloxy moiety, which is inserted into the target lysine-binding channel and becomes methylated by G9a-like protein, albeit slowly. The compound enhances its potency in vitro and reduces cell toxicity in vivo. We suggest that adding a lysine or methyl-lysine mimic should be considered in the design of small-molecule inhibitors for other methyl-lysine writers, erasers, and readers.

  7. The mGluR5 antagonist MPEP elevates accumbal dopamine and glycine levels; interaction with strychnine-sensitive glycine receptors.

    PubMed

    Chau, PeiPei; Söderpalm, Bo; Ericson, Mia

    2011-10-01

    Studies have indicated that the metabotropic glutamate receptor 5 (mGluR5) antagonist 6-methyl-2-(phenylethynyl)-pyridine (MPEP) decreases ethanol self-administration, and the same receptor type was also suggested to be involved in the mechanism of action of the anti-craving substance acamprosate. Our previous research suggested that glycine receptors (GlyRs) in the nucleus accumbens (nAc) play a major part in mediating the dopamine-elevating properties of ethanol and are highly involved in the ethanol intake-reducing effect of acamprosate. The aim of this study was to examine if modulation of nAc dopamine via mGluR5 antagonism or GlyR agonism is a linked or separated phenomena. The extracellular levels of dopamine as well as of the GlyR ligands, glycine, taurine and β-alanine were measured in the nAc by means of microdialysis after local perfusion of MPEP (100 or 500 µM) with or without pre-treatment with strychnine. MPEP increased dopamine levels, an effect that was blocked by pre-treatment with strychnine. In addition, the higher MPEP concentration increased glycine output, whereas no alterations of taurine or β-alanine were observed. These results indicate a relationship between the glutamatergic and glycinergic transmitter systems in regulating dopamine output, possibly via alteration of extracellular glycine levels. Taken together with our previous data demonstrating the importance of accumbal GlyRs both in ethanol-induced elevation of nAc dopamine and in ethanol consumption, it is plausible that the effects of MPEP treatment, on dopamine output and on ethanol intake, may be mediated via interaction with the same neuronal circuitry that previously has been demonstrated for ethanol, taurine and acamprosate.

  8. Druggability of methyl-lysine binding sites

    NASA Astrophysics Data System (ADS)

    Santiago, C.; Nguyen, K.; Schapira, M.

    2011-12-01

    Structural modules that specifically recognize—or read—methylated or acetylated lysine residues on histone peptides are important components of chromatin-mediated signaling and epigenetic regulation of gene expression. Deregulation of epigenetic mechanisms is associated with disease conditions, and antagonists of acetyl-lysine binding bromodomains are efficacious in animal models of cancer and inflammation, but little is known regarding the druggability of methyl-lysine binding modules. We conducted a systematic structural analysis of readers of methyl marks and derived a predictive druggability landscape of methyl-lysine binding modules. We show that these target classes are generally less druggable than bromodomains, but that some proteins stand as notable exceptions.

  9. CPLM: a database of protein lysine modifications

    PubMed Central

    Liu, Zexian; Wang, Yongbo; Gao, Tianshun; Pan, Zhicheng; Cheng, Han; Yang, Qing; Cheng, Zhongyi; Guo, Anyuan; Ren, Jian; Xue, Yu

    2014-01-01

    We reported an integrated database of Compendium of Protein Lysine Modifications (CPLM; http://cplm.biocuckoo.org) for protein lysine modifications (PLMs), which occur at active ε-amino groups of specific lysine residues in proteins and are critical for orchestrating various biological processes. The CPLM database was updated from our previously developed database of Compendium of Protein Lysine Acetylation (CPLA), which contained 7151 lysine acetylation sites in 3311 proteins. Here, we manually collected experimentally identified substrates and sites for 12 types of PLMs, including acetylation, ubiquitination, sumoylation, methylation, butyrylation, crotonylation, glycation, malonylation, phosphoglycerylation, propionylation, succinylation and pupylation. In total, the CPLM database contained 203 972 modification events on 189 919 modified lysines in 45 748 proteins for 122 species. With the dataset, we totally identified 76 types of co-occurrences of various PLMs on the same lysine residues, and the most abundant PLM crosstalk is between acetylation and ubiquitination. Up to 53.5% of acetylation and 33.1% of ubiquitination events co-occur at 10 746 lysine sites. Thus, the various PLM crosstalks suggested that a considerable proportion of lysines were competitively and dynamically regulated in a complicated manner. Taken together, the CPLM database can serve as a useful resource for further research of PLMs. PMID:24214993

  10. Glycine Substitutions in Collagen Heterotrimers Alter Triple Helical Assembly.

    PubMed

    Clements, Katherine A; Acevedo-Jake, Amanda M; Walker, Douglas R; Hartgerink, Jeffrey D

    2017-02-13

    Osteogenesis imperfecta typically results from missense mutations in the collagen genome where the required glycine residues are replaced with another amino acid. Many models have attempted to replicate the structure of mutated collagen on the triple helix level. However, composition and register control of the triple helix is complicated and requires extreme precision, especially when these destabilizing mutations are present. Here we present mutations to a composition- and register-controlled AAB helix where one of the requisite glycines in the A chain of the triple helix is changed to serine or alanine. We see a loss of compositional control when the A chain is mutated, resulting in an A'BB composition that minimizes the number of mutations included in the triple helix. However, when both A and B chains are mutated and no nonmutated peptide chains are available, the designed A'A'B' composition is reestablished. Our work shows the ability of the mutations to influence and alter the composition and register of the collagen triple helix.

  11. Production of L-lysine on different silage juices using genetically engineered Corynebacterium glutamicum.

    PubMed

    Neuner, Andreas; Wagner, Ines; Sieker, Tim; Ulber, Roland; Schneider, Konstantin; Peifer, Susanne; Heinzle, Elmar

    2013-01-20

    Corynebacterium glutamicum, the best established industrial producer organism for lysine was genetically modified to allow the production of lysine on grass and corn silages. The resulting strain C. glutamicum lysC(fbr)dld(Psod)pyc(Psod)malE(Psod)fbp(Psod)gapX(Psod) was based on earlier work (Neuner and Heinzle, 2011). That mutant carries a point mutation in the aspartokinase (lysC) regulatory subunit gene as well as overexpression of D-lactate dehydrogenase (dld), pyruvate carboxylase (pyc) and malic enzyme (malE) using the strong Psod promoter. Here, we additionally overexpressed fructose 1,6-bisphosphatase (fbp) and glyceraldehyde 3-phosphate dehydrogenase (gapX) using the same promoter. The resulting strain grew readily on grass and corn silages with a specific growth rate of 0.35 h⁻¹ and lysine carbon yields of approximately 90 C-mmol (C-mol)⁻¹. Lysine yields were hardly affected by oxygen limitation whereas linear growth was observed under oxygen limiting conditions. Overall, this strain seems very robust with respect to the composition of silage utilizing all quantified low molecular weight substrates, e.g. lactate, glucose, fructose, maltose, quinate, fumarate, glutamate, leucine, isoleucine and alanine.

  12. Hemoglobin Labeled by Radioactive Lysine

    DOE R&D Accomplishments Database

    Bale, W. F.; Yuile, C. L.; DeLaVergne, L.; Miller, L. L.; Whipple, G. H.

    1949-12-08

    This paper reports on the utilization of tagged epsilon carbon of DL-lysine by a dog both anemic and hypoproteinemic due to repeated bleeding plus a diet low in protein. The experiment extended over period of 234 days, a time sufficient to indicate an erythrocyte life span of at least 115 days based upon the rate of replacement of labeled red cell proteins. The proteins of broken down red cells seem not to be used with any great preference for the synthesis of new hemoglobin.

  13. Identification and expression analyses of the alanine aminotransferase (AlaAT) gene family in poplar seedlings.

    PubMed

    Xu, Zhiru; Ma, Jing; Qu, Chunpu; Hu, Yanbo; Hao, Bingqing; Sun, Yan; Liu, Zhongye; Yang, Han; Yang, Chengjun; Wang, Hongwei; Li, Ying; Liu, Guanjun

    2017-04-05

    Alanine aminotransferase (AlaAT, E.C.2.6.1.2) catalyzes the reversible conversion of pyruvate and glutamate to alanine and α-oxoglutarate. The AlaAT gene family has been well studied in some herbaceous plants, but has not been well characterized in woody plants. In this study, we identified four alanine aminotransferase homologues in Populus trichocarpa, which could be classified into two subgroups, A and B. AlaAT3 and AlaAT4 in subgroup A encode AlaAT, while AlaAT1 and AlaAT2 in subgroup B encode glutamate:glyoxylate aminotransferase (GGAT), which catalyzes the reaction of glutamate and glyoxylate to α-oxoglutarate and glycine. Four AlaAT genes were cloned from P. simonii × P. nigra. PnAlaAT1 and PnAlaAT2 were expressed predominantly in leaves and induced by exogenous nitrogen and exhibited a diurnal fluctuation in leaves, but was inhibited in roots. PnAlaAT3 and PnAlaAT4 were mainly expressed in roots, stems and leaves, and was induced by exogenous nitrogen. The expression of PnAlaAT3 gene could be regulated by glutamine or its related metabolites in roots. Our results suggest that PnAlaAT3 gene may play an important role in nitrogen metabolism and is regulated by glutamine or its related metabolites in the roots of P. simonii × P. nigra.

  14. Identification and expression analyses of the alanine aminotransferase (AlaAT) gene family in poplar seedlings

    PubMed Central

    Xu, Zhiru; Ma, Jing; Qu, Chunpu; Hu, Yanbo; Hao, Bingqing; Sun, Yan; Liu, Zhongye; Yang, Han; Yang, Chengjun; Wang, Hongwei; Li, Ying; Liu, Guanjun

    2017-01-01

    Alanine aminotransferase (AlaAT, E.C.2.6.1.2) catalyzes the reversible conversion of pyruvate and glutamate to alanine and α-oxoglutarate. The AlaAT gene family has been well studied in some herbaceous plants, but has not been well characterized in woody plants. In this study, we identified four alanine aminotransferase homologues in Populus trichocarpa, which could be classified into two subgroups, A and B. AlaAT3 and AlaAT4 in subgroup A encode AlaAT, while AlaAT1 and AlaAT2 in subgroup B encode glutamate:glyoxylate aminotransferase (GGAT), which catalyzes the reaction of glutamate and glyoxylate to α-oxoglutarate and glycine. Four AlaAT genes were cloned from P. simonii × P. nigra. PnAlaAT1 and PnAlaAT2 were expressed predominantly in leaves and induced by exogenous nitrogen and exhibited a diurnal fluctuation in leaves, but was inhibited in roots. PnAlaAT3 and PnAlaAT4 were mainly expressed in roots, stems and leaves, and was induced by exogenous nitrogen. The expression of PnAlaAT3 gene could be regulated by glutamine or its related metabolites in roots. Our results suggest that PnAlaAT3 gene may play an important role in nitrogen metabolism and is regulated by glutamine or its related metabolites in the roots of P. simonii × P. nigra. PMID:28378825

  15. Aboveground Feeding by Soybean Aphid, Aphis glycines, Affects Soybean Cyst Nematode, Heterodera glycines, Reproduction Belowground

    PubMed Central

    McCarville, Michael T.; Soh, David H.; Tylka, Gregory L.; O’Neal, Matthew E.

    2014-01-01

    Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect of A. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27–52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H. glycines females and cysts (dead females) and the number of eggs within were counted. In general, H. glycines were less abundant on the resistant than the susceptible cultivar, and H. glycines abundance increased from 30 to 60 d. At 30 d, 33% more H. glycines females and eggs were produced on the resistant cultivar in the ten-aphid treatment compared to the zero-aphid treatment. However, at 30 d the susceptible cultivar had 50% fewer H. glycines females and eggs when infested with ten aphids. At 60 d, numbers of H. glycines females and cysts and numbers of eggs on the resistant cultivar were unaffected by A. glycines feeding, while numbers of both were decreased by A. glycines on the susceptible cultivar. These results indicate that A. glycines feeding improves the quality of soybean as a host for H. glycines, but at higher herbivore population densities, this effect is offset by a decrease in resource quantity. PMID:24466080

  16. Adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization in swine.

    PubMed

    van Kempen, T A; van Heugten, E; Trottier, N L

    2001-09-01

    Adipic acid, upon catabolism, results in intermediates that bear a structural similarity to lysine degradation products. The objectives of this research were to determine whether adipic acid affects lysine concentrations in plasma and to evaluate whether adipic acid improves the efficiency of lysine utilization in pigs. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on plasma amino acid concentrations (plasma collected on d 7). In Exp. 2, nursery pigs (n = 56) were fed (for a period of 15 d) either a control diet or the same diet but deficient in either lysine, threonine, or tryptophan with or without supplemental adipic acid to assess the effects of adipic acid on the efficiency of amino acid utilization. The results from Exp. 1 showed that adipic acid increased plasma lysine (by 18%) but not alpha-amino adipic acid, an intermediate in lysine degradation. Experiment 2 demonstrated that adipic acid did not increase the efficiency of utilization of lysine, threonine, or tryptophan. The lack of effects on alpha-amino adipic acid in Exp. 1 and the lack of a positive effect on the efficiency of utilization of lysine, threonine, and tryptophan suggest that adipic acid does not inhibit the mitochondrial uptake of lysine and(or) its degradation in the mitochondrion. It is concluded that feeding adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization.

  17. Beneficial Effects of the Amino Acid Glycine.

    PubMed

    Pérez-Torres, Israel; Zuniga-Munoz, Alejandra María; Guarner-Lans, Veronica

    2017-01-01

    Glycine is the smallest non-essential, neutral and metabolically inert amino acid, with a carbon atom bound to two hydrogen atoms, and to an amino and a carboxyl group. This amino acid is an essential substrate for the synthesis of several biologically important biomolecules and compounds. It participates in the synthesis of proteins, of the tripeptide glutathione and in detoxification reactions. It has a broad spectrum of anti-inflammatory, cytoprotective and immunomodulatory properties. To exert its actions, glycine binds to different receptors. The GlyR anion channel is the most studied receptor for glycine. However, there are GlyR-independent mechanisms for glycine cytoprotection and other possible binding molecules of glycine are the NMDA receptor and receptors GlyT1 and GlyT2. Although, in humans, the normal serum level of glycine is approximately 300 μM, increasing glycine intake can lead to blood levels of more than 900 μM that increase its benefic actions without having harmful side effects. The herbal pesticide glyphosate might disrupt glycine homeostasis. Many in vitro studies involving different cell types have demonstrated beneficial effects of the addition of glycine. Glycine also improved conditions of isolated perfused or stored organs. In vivo studies in experimental animals have also tested glycine as a protector molecule and some studies on the beneficial effects of glycine after its clinical application have been done. Although at high-doses, glycine may cause toxic effects, further studies are needed to investigate the safe range of usage of this aminoacid and to test the diverse routes of administration.

  18. 21 CFR 582.5118 - Alanine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Alanine. 582.5118 Section 582.5118 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 Supplements...

  19. 21 CFR 582.5118 - Alanine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Alanine. 582.5118 Section 582.5118 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 Supplements...

  20. 21 CFR 582.5118 - Alanine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Alanine. 582.5118 Section 582.5118 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 Supplements...

  1. 21 CFR 582.5118 - Alanine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Alanine. 582.5118 Section 582.5118 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 Supplements...

  2. 21 CFR 582.5118 - Alanine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Alanine. 582.5118 Section 582.5118 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 Supplements...

  3. Effect of mutation of lysine-128 of the large subunit of ribulose bisphosphate carboxylase/oxygenase from Anacystis nidulans.

    PubMed

    Bainbridge, G; Anralojc, P J; Madgwick, P J; Pitts, J E; Parry, M A

    1998-12-01

    The contribution of lysine-128 within the active site of Anacystis nidulans d-ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) was investigated by the characterization of mutants in which lysine-128 was replaced with arginine, glycine, glutamine, histidine or aspartic acid. Mutated genes encoding the Rubisco large subunit were expressed in Escherichia coli and the resultant polypeptides assembled into active complexes. All of the mutant enzymes had a lower affinity for ribulose 1,5-bisphosphate (RuBP) and lower rates of carboxylation. Substitution of lysine-128 with glutamine, histidine or aspartic acid decreased the specificity factor and led to the production of an additional monophosphate reaction product. We show that this product results from the loss of the phosphate from C-1 of RuBP, most probably by beta-elimination from the 2,3-enediolate derivative of RuBP. The results confirm that lysine-128 is important in determining the position of the essential epsilon-amino group of lysine-334 within the active site and in loop dynamics. This further demonstrates that residues remote from the active site can be manipulated to modify catalytic function.

  4. Lysine Fermentation: History and Genome Breeding.

    PubMed

    Ikeda, Masato

    2016-11-11

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

  5. Investigations of the contribution of a putative glycine hinge to ryanodine receptor channel gating.

    PubMed

    Euden, Joanne; Mason, Sammy A; Viero, Cedric; Thomas, N Lowri; Williams, Alan J

    2013-06-07

    Ryanodine receptor channels (RyR) are key components of striated muscle excitation-contraction coupling, and alterations in their function underlie both inherited and acquired disease. A full understanding of the disease process will require a detailed knowledge of the mechanisms and structures involved in RyR function. Unfortunately, high-resolution structural data, such as exist for K(+)-selective channels, are not available for RyR. In the absence of these data, we have used modeling to identify similarities in the structural elements of K(+) channel pore-forming regions and postulated equivalent regions of RyR. This has identified a sequence of residues in the cytosolic cavity-lining transmembrane helix of RyR (G(4864)LIIDA(4869) in RyR2) analogous to the glycine hinge motif present in many K(+) channels. Gating in these K(+) channels can be disrupted by substitution of residues for the hinge glycine. We investigated the involvement of glycine 4864 in RyR2 gating by monitoring properties of recombinant human RyR2 channels in which this glycine is replaced by residues that alter gating in K(+) channels. Our data demonstrate that introducing alanine at position 4864 produces no significant change in RyR2 function. In contrast, function is altered when glycine 4864 is replaced by either valine or proline, the former preventing channel opening and the latter modifying both ion translocation and gating. Our studies reveal novel information on the structural basis of RyR gating, identifying both similarities with, and differences from, K(+) channels. Glycine 4864 is not absolutely required for channel gating, but some flexibility at this point in the cavity-lining transmembrane helix is necessary for normal RyR function.

  6. Lysine acetylation and cancer: A proteomics perspective.

    PubMed

    Gil, Jeovanis; Ramírez-Torres, Alberto; Encarnación-Guevara, Sergio

    2017-01-06

    Lysine acetylation is a reversible modification controlled by two groups of enzymes: lysine acetyltransferases (KATs) and lysine deacetylases (KDACs). Acetylated lysine residues are recognized by bromodomains, a family of evolutionarily conserved domains. The use of high-resolution mass spectrometry-based proteomics, in combination with the enrichment of acetylated peptides through immunoprecipitation with anti-acetyl-lysine antibodies, has expanded the number of acetylated proteins from histones and a few nuclear proteins to more than 2000 human proteins. Because acetylation targets almost all cellular processes, this modification has been associated with cancer. Several KATs, KDACs and bromodomain-containing proteins have been linked to cancer development. Many small molecules targeting some of these proteins have been or are being tested as potential cancer therapies. The stoichiometry of lysine acetylation has not been explored in cancer, representing a promising field in which to increase our knowledge of how this modification is affected in cancer. In this review, we will focus on the strategies that can be used to go deeper in the characterization of the protein lysine acetylation emphasizing in cancer research.

  7. Roles of Osteonectin in Breast Cancer Metastasis to Bone

    DTIC Science & Technology

    2005-05-01

    sample is illustrated in Figure 4. The substitutions resulted in 1) threonine to alanine, 2) valine to glycine, 3) serine to proline, 4) aspartic acid to...glutamic acid, 5) alanine to glycine, 6) glutamic acid to aspartic acid , 7) glutamine to glutamic acid, and 8) lysine to glutamine. However, at the...numbered 1-8. The substitutions are 1.) threonine to alanine, 2.) valine to glycine, 3.) serine to proline, 4.) aspartic acid to glutamic acid, 5

  8. Preparation and Bioavailability Analysis of Ferrous Bis Alanine Chelate as a New Micronutrient for Treatment of Iron Deficiency Anemia.

    PubMed

    Zargaran, Marzieh; Saadat, Ebrahim; Dinarvand, Rassoul; Sharifzadeh, Mohammad; Dorkoosh, Farid

    2016-09-01

    Purpose: One of the most nutritional disorders around the world is iron deficiency. A novel iron compound was synthesized by chelating ferrous ions with alanine for prevention and treatment of iron deficiency anemia. Methods: The newly synthesized compound was characterized both qualitatively and quantitatively by Fourier Transform Infrared (FT-IR) spectroscopy. The bioavailability of newly synthesized iron micronutrient was evaluated in four groups of Wistar rats. The group I was a negative control group and the other three groups received three different iron formulations. After 14 days, the blood samples were taken and analyzed accordingly. Results: Calculations showed that more than 91.8% of iron was incorporated in the chelate formulation. In vivo studies showed that serum iron, total iron binding capacity and hemoglobin concentrations were significantly increased in group IV, which received ferrous bis alanine chelate compared with the negative control group (p<0.05) and also group II, which received ferrous sulfate.7H2O (p<0.05). It indicates that the new formulation considerably improves the blood iron status compared with the conventional iron compounds. There were no significant differences (p<0.05) in the serum iron between group IV and group III, which received ferrous bis glycine. Conclusion: The results showed better bioavailability of ferrous bis alanine as a new micronutrient for treatment of iron deficiency anemia in comparison with ferrous sulfate. Ferrous bis alanine could be considered as a suitable supplement for prevention and treatment of iron deficiency anemia.

  9. Preparation and Bioavailability Analysis of Ferrous Bis Alanine Chelate as a New Micronutrient for Treatment of Iron Deficiency Anemia

    PubMed Central

    Zargaran, Marzieh; Saadat, Ebrahim; Dinarvand, Rassoul; Sharifzadeh, Mohammad; Dorkoosh, Farid

    2016-01-01

    Purpose: One of the most nutritional disorders around the world is iron deficiency. A novel iron compound was synthesized by chelating ferrous ions with alanine for prevention and treatment of iron deficiency anemia. Methods: The newly synthesized compound was characterized both qualitatively and quantitatively by Fourier Transform Infrared (FT-IR) spectroscopy. The bioavailability of newly synthesized iron micronutrient was evaluated in four groups of Wistar rats. The group I was a negative control group and the other three groups received three different iron formulations. After 14 days, the blood samples were taken and analyzed accordingly. Results: Calculations showed that more than 91.8% of iron was incorporated in the chelate formulation. In vivo studies showed that serum iron, total iron binding capacity and hemoglobin concentrations were significantly increased in group IV, which received ferrous bis alanine chelate compared with the negative control group (p<0.05) and also group II, which received ferrous sulfate.7H2O (p<0.05). It indicates that the new formulation considerably improves the blood iron status compared with the conventional iron compounds. There were no significant differences (p<0.05) in the serum iron between group IV and group III, which received ferrous bis glycine. Conclusion: The results showed better bioavailability of ferrous bis alanine as a new micronutrient for treatment of iron deficiency anemia in comparison with ferrous sulfate. Ferrous bis alanine could be considered as a suitable supplement for prevention and treatment of iron deficiency anemia. PMID:27766225

  10. Linkages in thermal copolymers of lysine

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Suzuki, F.

    1976-01-01

    The thermal copolymerization of lysine with other alpha-amino acids has been studied further. The identity of the second amino acid influences various properties of the polymer obtained, including the proportion of alpha and epsilon linkages of lysine. A review of linkages in proteinoids indicates alpha and beta linkages for aspartic acid, alpha and gamma linkages for glutamic acid, alpha and epsilon linkages for lysine, and alpha linkages for other amino acids. Thermal proteinoids are thus more complex in types of linkage than are proteins

  11. Linkages in thermal copolymers of lysine

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Suzuki, F.

    1975-01-01

    The thermal copolymerization of lysine with other alpha-amino acids was studied. The identity of the second amino acid influences various properties of the polymer obtained, including the proportion of alpha and epsilon linkages of lysine. A review of linkages in proteinoids indicates alpha and beta linkages for aspartic acid, alpha and gamma linkages for glutamic acid, alpha and epsilon linkages for lysine, and alpha linkages for other amino acids. Thermal proteinoids are thus more complex in types of linkage than are proteins.

  12. L-allo-threonine aldolase from Aeromonas jandaei DK-39: gene cloning, nucleotide sequencing, and identification of the pyridoxal 5'-phosphate-binding lysine residue by site-directed mutagenesis.

    PubMed Central

    Liu, J Q; Dairi, T; Kataoka, M; Shimizu, S; Yamada, H

    1997-01-01

    We have isolated the gene encoding L-allo-threonine aldolase (L-allo-TA) from Aeromonas jandaei DK-39, a pyridoxal 5'-phosphate (PLP)-dependent enzyme that stereospecifically catalyzes the interconversion of L-allo-threonine and glycine. The gene contains an open reading frame consisting of 1,014 nucleotides corresponding to 338 amino acid residues. The protein molecular weight was estimated to be 36,294, which is in good agreement with the subunit molecular weight of the enzyme determined by polyacrylamide gel electrophoresis. The enzyme was overexpressed in recombinant Escherichia coli cells and purified to homogeneity by one hydrophobic column chromatography step. The predicted amino acid sequence showed no significant similarity to those of the currently known PLP-dependent enzymes but displayed 40 and 41% identity with those of the hypothetical GLY1 protein of Saccharomyces cerevisiae and the GLY1-like protein of Caenorhabditis elegans, respectively. Accordingly, L-allo-TA might represent a new type of PLP-dependent enzyme. To determine the PLP-binding site of the enzyme, all of the three conserved lysine residues of L-allo-TA were replaced by alanine by site-directed mutagenesis. The purified mutant enzymes, K51A and K224A, showed properties similar to those of the wild type, while the mutant enzyme K199A was catalytically inactive, with corresponding disappearance of the absorption maximum at 420 nm. Thus, Lys199 of L-allo-TA probably functions as an essential catalytic residue forming an internal Schiff base with PLP of the enzyme to catalyze the reversible aldol reaction. PMID:9171400

  13. 21 CFR 172.540 - DL-Alanine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true DL-Alanine. 172.540 Section 172.540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents and Related Substances § 172.540 DL-Alanine. DL-Alanine (a racemic mixture of D- and...

  14. On the existence of ‘L-alanine cadmium bromide'

    NASA Astrophysics Data System (ADS)

    Srinivasan, Bikshandarkoil R.

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  15. On the existence of 'L-alanine cadmium bromide'.

    PubMed

    Srinivasan, Bikshandarkoil R

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  16. The influence of various cations on the catalytic properties of clays. [polymerization of alanine adenylate

    NASA Technical Reports Server (NTRS)

    Paecht-Horowitz, M.

    1978-01-01

    The polymerization of alanine adenylate in the presence of the sodium form of various clays was studied, and hectorite was found to cause more polymerization than nontronite and montmorillonite (in that order) although the differences were not great. The effect on polymerization of presaturating montmorillonite with different cations was determined. Hectorite, with increased basicity of the interspatial planes, allows polymerization of lysine, which montmorillonite does not. The general trend is that, for the same amino acid, higher degrees of polymerization are obtained when the cation in the octahedral lattice of the clay is divalent rather than trivalent. With the exchangeable cations the order is reversed, for a reason that is explained. The main role of clays in the polymerization mechanism of amino acids is concentration and neutralization of charges.

  17. Distinguishing the cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) from other diamino acids.

    PubMed

    Banack, S A; Metcalf, J S; Spáčil, Z; Downing, T G; Downing, S; Long, A; Nunn, P B; Cox, P A

    2011-04-01

    β-N-methylamino-L-alanine (BMAA) is produced by diverse taxa of cyanobacteria, and has been detected by many investigators who have searched for it in cyanobacterial blooms, cultures and collections. Although BMAA is distinguishable from proteinogenic amino acids and its isomer 2,4-DAB using standard chromatographic and mass spectroscopy techniques routinely used for the analysis of amino acids, we studied whether BMAA could be reliably distinguished from other diamino acids, particularly 2,6-diaminopimelic acid which has been isolated from the cell walls of many bacterial species. We used HPLC-FD, UHPLC-UV, UHPLC-MS, and triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) to differentiate BMAA from the diamino acids 2,6-diaminopimelic acid, N-2(amino)ethylglycine, lysine, ornithine, 2,4-diaminosuccinic acid, homocystine, cystine, tryptophan, as well as other amino acids including asparagine, glutamine, and methionine methylsulfonium.

  18. Histone lysine methylation and chromatin replication.

    PubMed

    Rivera, Carlos; Gurard-Levin, Zachary A; Almouzni, Geneviève; Loyola, Alejandra

    2014-12-01

    In eukaryotic organisms, the replication of the DNA sequence and its organization into chromatin are critical to maintain genome integrity. Chromatin components, such as histone variants and histone post-translational modifications, along with the higher-order chromatin structure, impact several DNA metabolic processes, including replication, transcription, and repair. In this review we focus on lysine methylation and the relationships between this histone mark and chromatin replication. We first describe studies implicating lysine methylation in regulating early steps in the replication process. We then discuss chromatin reassembly following replication fork passage, where the incorporation of a combination of newly synthesized histones and parental histones can impact the inheritance of lysine methylation marks on the daughter strands. Finally, we elaborate on how the inheritance of lysine methylation can impact maintenance of the chromatin landscape, using heterochromatin as a model chromatin domain, and we discuss the potential mechanisms involved in this process.

  19. SPOTing Acetyl-Lysine Dependent Interactions

    PubMed Central

    Picaud, Sarah; Filippakopoulos, Panagis

    2015-01-01

    Post translational modifications have been recognized as chemical signals that create docking sites for evolutionary conserved effector modules, allowing for signal integration within large networks of interactions. Lysine acetylation in particular has attracted attention as a regulatory modification, affecting chromatin structure and linking to transcriptional activation. Advances in peptide array technologies have facilitated the study of acetyl-lysine-containing linear motifs interacting with the evolutionary conserved bromodomain module, which specifically recognizes and binds to acetylated sequences in histones and other proteins. Here we summarize recent work employing SPOT peptide technology to identify acetyl-lysine dependent interactions and document the protocols adapted in our lab, as well as our efforts to characterize such bromodomain-histone interactions. Our results highlight the versatility of SPOT methods and establish an affordable tool for rapid access to potential protein/modified-peptide interactions involving lysine acetylation. PMID:27600229

  20. 76 FR 8771 - Glycine From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... COMMISSION Glycine From China AGENCY: United States International Trade Commission. ACTION: Notice of... concerning the antidumping duty order on glycine from China. SUMMARY: The Commission hereby gives notice that... China would be likely to lead to continuation or recurrence of material injury within a...

  1. 75 FR 62141 - Glycine From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... COMMISSION Glycine From China AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on glycine from China. SUMMARY: The Commission... from China would be likely to lead to continuation or recurrence of material injury. Pursuant...

  2. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The food additive glycine may be safely used for technological purposes in food in accordance with the following prescribed conditions: (a) The additive complies with...

  3. A Method to determine lysine acetylation stoichiometries

    SciTech Connect

    Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; Shukla, Anil K.; Weitz, Karl K.; Moore, Ronald J.; Hixson, Kim K.; Kim, Jong Seo; Petyuk, Vladislav A.; Monroe, Matthew E.; Pasa-Tolic, Ljiljana; Qian, Weijun; Smith, Richard D.; Adkins, Joshua N.; Ansong, Charles

    2014-07-21

    A major bottleneck to fully understanding the functional aspects of lysine acetylation is the lack of stoichiometry information. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of lysine acetylation on proteins globally. Using this technique, we determined the modification occupancy on hundreds of acetylated peptides from cell lysates and cross-validated the measurements via immunoblotting.

  4. Factors affecting lysine degradation by ruminal fusobacteria.

    PubMed

    Russell, James B

    2006-04-01

    Fusobacterium necrophorum can readily be enriched from the rumen with lysine, and its deamination rate is very rapid. The addition of F. necrophorum JB2 to mixed ruminal bacteria significantly increased lysine degradation, but only if the ratio of ruminal fluid to basal medium was less than 25%. If more ruminal fluid (pH 6.1) was added, ammonia production decreased by as much as 80%. Clarified, autoclaved ruminal fluid was also inhibitory. When F. necrophorum JB2 was grown in a lysine-limited continuous culture (0.1 h(-1) dilution rate) and pH was decreased using HCl, optical density decreased linearly, and the culture washed out at pH 5.6. Batch cultures of F. necrophorum JB2 deaminated as much lysine at pH 6.1 as at pH 6.6, but only if fermentation acids were not present. Sodium acetate (100 mM) had little effect at pH 6.6, but the same concentration inhibited ammonia production by 80% at pH 6.1. The idea that fermentation acids could prevent the enrichment of fusobacteria in vivo was supported by the observation that dietary lysine supplementation did not enhance the lysine deamination rate of the mixed ruminal bacteria.

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

    PubMed

    Yang, Edward; Arvin, Ann M; Oliver, Stefan L

    2017-01-01

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

  6. [Protein utilization in lysine-supplemented barley protein and effectiveness of the limiting amino acid lysine in growing pigs].

    PubMed

    Wecke, C; Gebhardt, G

    1982-04-01

    In 57 N-balance experiments with castrated male pigs (20 ... 65 kg live weight) the influence of graded lysine supplements to crushed barley enriched with energy, minerals and vitamins on nitrogen metabolism and lysine effectiveness was tested. Close correlative relations between lysine concentration and the b-value, the NPU-value, N-balance and N-excretion in urine could be detected. In agreement with the law of minimum a constant lysine effectiveness could be observed within the limiting range. The supplemented synthetic lysine distinguished itself by the same effectiveness as the protein-bound barley lysine. When barley supplemented with lysine is used, an amount of lysine supplement should be chosen from the point of view of nutrition physiology which raises the total lysine content to a maximum level of 6.3 g/16 g N because lysine supplementation exceeding this value without the simultaneous supplementation of limiting threonine remains ineffective.

  7. Limits of cooperativity in a structurally modular protein: response of the Notch ankyrin domain to analogous alanine substitutions in each repeat.

    PubMed

    Bradley, Christina Marchetti; Barrick, Doug

    2002-11-22

    To determine the limits of cooperativity in a structurally modular protein, we characterized the structure and stability of glycine variants of the ankyrin repeat domain from the Drosophila melangaster Notch receptor. The substitutions are of analogous alanine residues to glycine in each repeat, and allow the same perturbation to be examined at different positions in the protein. The ankyrin domain is insensitive to substitution in repeat one, suggesting that the first repeat is not fully-folded. Glycine substitutions in repeat two through seven are strongly destabilizing, but the variants retain their overall secondary and tertiary structures. Spectroscopic and calorimetric data are consistent with two-state unfolding transitions for the repeat-two through repeat-five glycine variants, and for the wild-type protein. These data indicate that, despite its modular structure, the Notch ankyrin domain unfolds as a cooperative unit consisting of the six C-terminal repeats, and that this cooperativity is maintained in the presence of severely destabilizing substitutions in the N-terminal and central repeats. In contrast, glycine substitution in repeat six leads to a multi-state unfolding transition, suggesting that the coupling that gives rise to long-range cooperativity in the wild-type protein may have a weak link in the C-terminal region. Such behavior is captured by a simple statistical thermodynamic model in which an unstable C-terminal region is coupled to a stable N-terminal region through a strongly stabilizing interface.

  8. Glycine receptors and brain development

    PubMed Central

    Avila, Ariel; Nguyen, Laurent; Rigo, Jean-Michel

    2013-01-01

    Glycine receptors (GlyRs) are ligand-gated chloride ion channels that mediate fast inhibitory neurotransmission in the spinal cord and the brainstem. There, they are mainly involved in motor control and pain perception in the adult. However, these receptors are also expressed in upper regions of the central nervous system, where they participate in different processes including synaptic neurotransmission. Moreover, GlyRs are present since early stages of brain development and might influence this process. Here, we discuss the current state of the art regarding GlyRs during embryonic and postnatal brain development in light of recent findings about the cellular and molecular mechanisms that control brain development. PMID:24155690

  9. Influence of Heterodera glycines on Interspecific and Intraspecific Competition Associated with Glycine max and Chenopodium album.

    PubMed

    Chen, J; Bird, G W; Renner, K A

    1995-03-01

    The influence of Heterodera glycines (soybean cyst nematode) on the interspecific and intraspecific competition associated with Glycine max (soybean) and Chenopodium album (common lambsquarters) was studied in 1988 and 1989 in three de Wit replacement series experiments in growth chambers and microplots. Glycine max was grown alone (1 plant/experimental unit), in intraspecific competition (2 plants/experimental unit), in interspecific competition with C. album, and in presence or absence of H. glycines. No significant effects of H. glycines and C. album on G. max growth were observed 14 days after planting. By 42 days after planting, both H. glycines and C. album had a negative (P = 0.05) influence on the growth of G. max. Relative crowding coefficients for G. max were lower and deviated (P = 0.05 and P = 0.001) from 1.0 in the presence of H. glycines, compared to that of C. album and early emerged C. album in the absence of the nematode, respectively. Glycine max, therefore, became less competitive than C. album. There was a trend that the presence of H. glycines decreased the competitiveness of G. max on measures of the aggressivity and relative mixture response. Heterodera glycines decreased the aggressivity of G. max (ca. 150-350%) and increased the relative effects of intraspecific interference on G. max (ca. 10-50%) and interspecific interference (ca. 60-350%) after 42 days of plant growth, compared with plants grown in the absence of H. glycines. No H. glycines x C. album interactions were detected. Observations showed that H. glycines and early emerged C. album inhibited the growth of G. max 5-13%, as measured by plant dry weight.

  10. Modifications of the acyl-d-alanyl-d-alanine terminus affecting complex-formation with vancomycin

    PubMed Central

    Nieto, M.; Perkins, H. R.

    1971-01-01

    Vancomycin forms complexes with peptides terminating in d-alanyl-d-alanine that are analogous to the biosynthetic precursors of bacterial mucopeptides. The specificity of complex-formation has been studied by means of many synthetic peptides, prepared by both solid-phase and conventional methods. The following conclusions can be drawn: (a) three amide linkages are required to form a stable complex; (b) the terminal carboxyl group must be free; (c) the carboxyl terminal and subterminal residues must be either glycine or of the d-configuration; (d) the size of the side chain in these residues greatly influences the affinity for vancomycin, a methyl group being the optimum in each case; (e) the nature of the side chain in the third and fourth residues has a smaller effect on complex-formation, but an l-configuration was somewhat better than a d-configuration in the third position. In addition to acyl-d-alanyl-d-alanine, other peptides that occur in bacterial cell walls will combine with vancomycin, although less strongly, e.g. acyl-d-alanyl-d-α-amino acid (where the terminal d-residue may form the cross-link in mucopeptide structure) and acyl-l-alanyl-d-glutamylglycine (a sequence found in the mucopeptide of Micrococcus lysodeikticus and related organisms). These results throw some light on the specificity of the uptake of vancomycin by living bacteria. PMID:5124386

  11. Unique Immunogenic Proteins in Heterodera glycines Eggshells

    PubMed Central

    Kennedy, M. J.; Schoelz, J. E.; Donald, P. A.; Niblack, T. L.

    1997-01-01

    Polyclonal antibodies were raised against Heterodera glycines eggshells to determine the feasibility of developing an immunoassay for H. glycines eggs. An indirect enzyme-linked immunosorbent assay (ELISA) was developed from anfisera collected 10 weeks after the initial injection. From serial dilutions of sonicated eggshells or whole eggs, a sensitivity of detection to 5 ng/ml sonicated eggshells or 1 egg of H. glycines was determined. The method of eggshell preparation had no effect on the antibodies produced; however, the antibodies cross-reacted with sonicated J2 of H. glycines and eggs of Meloidogyne incognita and H. schachtii. Most of the proteins in both life stages of H. glycines and eggs of M. incognita and H. schachtii had similar migration properties when separated on SDS-PAGE gels and stained with Coomassie blue. Western blot analysis, with antisera adsorbed with homogenized J2 of H. glycines, showed proteins that were specifically localized to eggshells of H. glycines. Monoclonal antibodies might provide a useful immunoassay where polyclonal antibodies lack sufficient specificity. PMID:19274159

  12. Simultaneous analysis of Nε-(carboxymethyl)lysine, reducing sugars, and lysine during the dairy thermal process.

    PubMed

    Xu, Xian-Bing; Ma, Fei; Yu, Shu-Juan; Guan, Yong-Guang

    2013-09-01

    A new analytical method allowing the simultaneous quantification of Nε-(carboxymethyl)lysine (CML), lysine, and reducing sugars (glucose, lactose, and galactose) is described. It is based on high performance anion-exchange chromatography with pulsed amperometric electrochemical detection. This method demonstrated a low limit of quantification (0.385 to 0.866 mg/L), excellent linear correlation (R(2)>0.997), and desired calibration range (3.125 to 25 mg/L). In addition, lactose-lysine solutions containing sulfite (4 to 400 mmol/L) were heated at 110°C for 2h. The results showed that sulfite inhibited the formation of CML and promoted the consumption of reducing sugars and lysine in the Maillard reaction model. The method proved to be useful for simultaneous analysis of CML, lysine, and reducing sugars (glucose, galactose, and lactose) in the Maillard reaction system. Moreover, sulfite was an effective inhibitor of CML formation.

  13. Crystallization and preliminary crystallographic analysis of d-alanine-d-alanine ligase from Streptococcus mutans

    SciTech Connect

    Lu, Yong-Zhi; Sheng, Yu; Li, Lan-Fen; Tang, De-Wei; Liu, Xiang-Yu; Zhao, Xiaojun; Liang, Yu-He Su, Xiao-Dong

    2007-09-01

    A potential target for antibiotic drug design, d-alanine-d-alanine ligase from S. mutans, was expressed in E. coli, purified and crystallized. Diffraction data were collected to 2.4 Å resolution. d-Alanine-d-alanine ligase is encoded by the gene ddl (SMU-599) in Streptococcus mutans. This ligase plays a very important role in cell-wall biosynthesis and may be a potential target for drug design. To study the structure and function of this ligase, the gene ddl was amplified from S. mutans genomic DNA and cloned into the expression vector pET28a. The protein was expressed in soluble form in Escherichia coli strain BL21 (DE3). Homogeneous protein was obtained using a two-step procedure consisting of Ni{sup 2+}-chelating and size-exclusion chromatography. Purified protein was crystallized and the cube-shaped crystal diffracted to 2.4 Å. The crystal belongs to space group P3{sub 1}21 or P3{sub 2}21, with unit-cell parameters a = b = 79.50, c = 108.97 Å. There is one molecule per asymmetric unit.

  14. Racemization of alanine by the alanine racemases from Salmonella typhimurium and Bacillus stearothermophilus: energetic reaction profiles

    SciTech Connect

    Faraci, W.S.; Walsh, C.T.

    1988-05-03

    Alanine racemases are bacterial pyridoxal 5'-phosphate (PLP) dependent enzymes providing D-alanine as an essential building block for biosynthesis of the peptidoglycan layer of the cell wall. Two isozymic alanine racemases, encoded by the dadB gene and the alr gene, from the Gram-negative mesophilic Salmonella typhimurium and one from the Gram-positive thermophilic Bacillus stearothermophilus have been examined for the racemization mechanism. Substrate deuterium isotope effects and solvent deuterium isotope effects have been measured in both L ..-->.. D and D..-->.. L directions for all three enzymes to assess the degree to which abstraction of the ..cap alpha..-proton or protonation of substrate PLP carbanion is limiting in catalysis. Additionally, experiments measuring internal return of ..cap alpha..-/sup 3/H from substrate to product and solvent exchange/substrate conversion experiments in /sup 3/H/sub 2/O have been used with each enzyme to examine the partitioning of substrate PLP carbanion intermediates and to obtain the relative heights of kinetically significant energy barriers in alanine racemase catalysis.

  15. A Method to Determine Lysine Acetylation Stoichiometries

    DOE PAGES

    Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; ...

    2014-01-01

    Lysine acetylation is a common protein posttranslational modification that regulates a variety of biological processes. A major bottleneck to fully understanding the functional aspects of lysine acetylation is the difficulty in measuring the proportion of lysine residues that are acetylated. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of protein lysine acetylation. Using this technique, we determined the modification occupancy for ~750 acetylated peptides from mammalian cell lysates. Furthermore, the acetylation on N-terminal tail of histone H4 was cross-validated by treating cells with sodiummore » butyrate, a potent deacetylase inhibitor, and comparing changes in stoichiometry levels measured by our method with immunoblotting measurements. Of note we observe that acetylation stoichiometry is high in nuclear proteins, but very low in mitochondrial and cytosolic proteins. In summary, our method opens new opportunities to study in detail the relationship of lysine acetylation levels of proteins with their biological functions.« less

  16. The glycine transport inhibitor sarcosine is an NMDA receptor co-agonist that differs from glycine

    PubMed Central

    Zhang, Hai Xia; Hyrc, Krzysztof; Thio, Liu Lin

    2009-01-01

    Sarcosine is an amino acid involved in one-carbon metabolism and a promising therapy for schizophrenia because it enhances NMDA receptor (NMDAR) function by inhibiting glycine uptake. The structural similarity between sarcosine and glycine led us to hypothesize that sarcosine is also an agonist like glycine. We examined this possibility using whole-cell recordings from cultured embryonic mouse hippocampal neurons. We found that sarcosine is an NMDAR co-agonist at the glycine binding site. However, sarcosine differed from glycine because less NMDAR desensitization occurred with sarcosine than with glycine as the co-agonist. This finding led us to examine whether the physiological effects of NMDAR activation with these two co-agonists are the same. The difference in desensitization probably accounts for rises in intracellular Ca2+, as assessed by the fluorescent indicator fura-FF, being larger when NMDAR activation occurred with sarcosine than with glycine. In addition, Ca2+-activated K+ currents following NMDAR activation were larger with sarcosine than with glycine. Compared to glycine, NMDAR-mediated autaptic currents decayed faster with sarcosine suggesting that NMDAR deactivation also differs with these two co-agonists. Despite these differences, NMDAR-dependent neuronal death as assessed by propidium iodide was similar with both co-agonists. The same was true for neuronal bursting. Thus, sarcosine may enhance NMDAR function by more than one mechanism and may have different effects from other NMDAR co-agonists. PMID:19433577

  17. Mutation of aspartic acid-351, lysine-352, and lysine-515 alters the Ca2+ transport activity of the Ca2+-ATPase expressed in COS-1 cells.

    PubMed Central

    Maruyama, K; MacLennan, D H

    1988-01-01

    Full-length cDNAs encoding neonatal and adult isoforms of the Ca2+-ATPase of rabbit fast-twitch skeletal muscle sarcoplasmic reticulum were expressed transiently in COS-1 cells. The microsomal fraction isolated from transfected COS-1 cells contained immunoreactive Ca2+-ATPase and catalyzed Ca2+ transport at rates at least 15-fold above controls. No differences were observed in either the rates or Ca2+ dependency of Ca2+ transport catalyzed by the two isoforms. Aspartic acid-351, the site of formation of the catalytic acyl phosphate in the enzyme, was mutated to asparagine, glutamic acid, serine, threonine, histidine, or alanine. In every case, Ca2+ transport activity and Ca2+-dependent phosphorylation were eliminated. Ca2+ transport was also eliminated by mutation of lysine-352 to arginine, glutamine, or glutamic acid or by mutation of Asp351-Lys352 to Lys351-Asp352. Mutation of lysine-515, the site of fluorescein isothiocyanate modification in the enzyme, resulted in diminished Ca2+ transport activity as follows: arginine, 60%; glutamine, 25%; glutamic acid, 5%. These results demonstrate the absolute requirement of acylphosphate formation for the Ca2+ transport function and define a residue important for ATP binding. They also demonstrate the feasibility of a thorough analysis of active sites in the Ca2+-ATPase by expression and site-specific mutagenesis. Images PMID:2966962

  18. International society of sports nutrition position stand: Beta-Alanine.

    PubMed

    Trexler, Eric T; Smith-Ryan, Abbie E; Stout, Jeffrey R; Hoffman, Jay R; Wilborn, Colin D; Sale, Craig; Kreider, Richard B; Jäger, Ralf; Earnest, Conrad P; Bannock, Laurent; Campbell, Bill; Kalman, Douglas; Ziegenfuss, Tim N; Antonio, Jose

    2015-01-01

    The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of beta-alanine supplementation. Based on the current available literature, the conclusions of the ISSN are as follows: 1) Four weeks of beta-alanine supplementation (4-6 g daily) significantly augments muscle carnosine concentrations, thereby acting as an intracellular pH buffer; 2) Beta-alanine supplementation currently appears to be safe in healthy populations at recommended doses; 3) The only reported side effect is paraesthesia (tingling), but studies indicate this can be attenuated by using divided lower doses (1.6 g) or using a sustained-release formula; 4) Daily supplementation with 4 to 6 g of beta-alanine for at least 2 to 4 weeks has been shown to improve exercise performance, with more pronounced effects in open end-point tasks/time trials lasting 1 to 4 min in duration; 5) Beta-alanine attenuates neuromuscular fatigue, particularly in older subjects, and preliminary evidence indicates that beta-alanine may improve tactical performance; 6) Combining beta-alanine with other single or multi-ingredient supplements may be advantageous when supplementation of beta-alanine is high enough (4-6 g daily) and long enough (minimum 4 weeks); 7) More research is needed to determine the effects of beta-alanine on strength, endurance performance beyond 25 min in duration, and other health-related benefits associated with carnosine.

  19. Alanine aminotransferase controls seed dormancy in barley

    PubMed Central

    Sato, Kazuhiro; Yamane, Miki; Yamaji, Nami; Kanamori, Hiroyuki; Tagiri, Akemi; Schwerdt, Julian G.; Fincher, Geoffrey B.; Matsumoto, Takashi; Takeda, Kazuyoshi; Komatsuda, Takao

    2016-01-01

    Dormancy allows wild barley grains to survive dry summers in the Near East. After domestication, barley was selected for shorter dormancy periods. Here we isolate the major seed dormancy gene qsd1 from wild barley, which encodes an alanine aminotransferase (AlaAT). The seed dormancy gene is expressed specifically in the embryo. The AlaAT isoenzymes encoded by the long and short dormancy alleles differ in a single amino acid residue. The reduced dormancy allele Qsd1 evolved from barleys that were first domesticated in the southern Levant and had the long dormancy qsd1 allele that can be traced back to wild barleys. The reduced dormancy mutation likely contributed to the enhanced performance of barley in industrial applications such as beer and whisky production, which involve controlled germination. In contrast, the long dormancy allele might be used to control pre-harvest sprouting in higher rainfall areas to enhance global adaptation of barley. PMID:27188711

  20. Crystal structure of the Apo form of D-Alanine:D-Alanine ligase (DDl) from Streptococcus mutans.

    PubMed

    Lu, Yongzhi; Xu, Hongyan; Zhao, Xiaojun

    2010-08-01

    D-Alanine:D-Alanine ligase (DDl) catalyzes the formation of D-Alanine:D-Alanine dipeptide and is an essential enzyme in bacterial cell wall biosynthesis.. This enzyme does not have a human ortholog, making it an attractive target for developing new antibiotic drugs. We determined the crystal structure at 2.23 A resolution of DDl from Streptococcus mutans (SmDDl), the principal aetiological agent of human dental caries. This structure reveals that SmDDl is a dimer and has a disordered omega-loop region.

  1. 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...

  2. Changes in Heterodera glycines Egg Population Density in Continuous Glycine max over Four Years

    PubMed Central

    Donald, P. A.; Donald, W. W.; Keaster, A. J.; Kremer, R. J.; Kendig, J. A.; Sims, B. S.; Mihail, J. D.

    1999-01-01

    Soybean cyst nematode, Heterodera glycines, is found throughout soybean production areas of the United States, but the nematode's distribution is not uniform within states, counties, and individual fields. The goal of this research was to determine the spatial pattern of H. glycines population density in a field in southeastern Missouri and whether it changed over time in the absence of management practices. Geostatistical methods were used to describe and map the distribution of H. glycines over 4 years in a soybean (Glycine max) field in southeastern Missouri. Semivariograms and kriging, an interpolation method, were used to prepare isoarithmic contour maps and associated error maps. In the field studied, fall H. glycines population density (Pf) was poorly related to density the following spring (Pi). The distribution of peak H. glycines population density within the field changed from year to year, although high densities were often detected in the same general region of the field. The patchiness of H. glycines distribution within a field was verified. Yield was not related to H. glycines egg population density at planting, indicating that unmeasured variables were also reducing yield. PMID:19270874

  3. 21 CFR 582.5411 - Lysine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lysine. 582.5411 Section 582.5411 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 Supplements...

  4. 21 CFR 582.5411 - Lysine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lysine. 582.5411 Section 582.5411 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 Supplements...

  5. 21 CFR 582.5411 - Lysine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lysine. 582.5411 Section 582.5411 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 Supplements...

  6. 21 CFR 582.5411 - Lysine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Lysine. 582.5411 Section 582.5411 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 Supplements...

  7. 21 CFR 582.5411 - Lysine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Lysine. 582.5411 Section 582.5411 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 Supplements...

  8. Radioactive Lysine in Protein Metabolism Studies

    DOE R&D Accomplishments Database

    Miller, L. L.; Bale, W. F.; Yuile, C. L.; Masters, R. E.; Tishkoff, G. H.; Whipple,, G. H.

    1950-01-09

    Studies of incorporation of DL-lysine in various body proteins of the dog; the time course of labeled blood proteins; and apparent rate of disappearance of labeled plasma proteins for comparison of behavior of the plasma albumin and globulin fractions; shows more rapid turn over of globulin fraction.

  9. 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

  10. Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine.

    PubMed

    Huang, Rui; Furukawa, Yoshihiro; Otake, Tsubasa; Kakegawa, Takeshi

    2016-09-23

    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

  11. Role of Channel Lysines and the “Push Through a One-Way Valve” Mechanism of the Viral DNA Packaging Motor

    PubMed Central

    Fang, Huaming; Jing, Peng; Haque, Farzin; Guo, Peixuan

    2012-01-01

    Linear double-stranded DNA (dsDNA) viruses package their genomes into preformed protein shells via nanomotors using ATP as an energy source. The central hub of the bacteriophage ϕ29 DNA-packaging motor contains a 3.6-nm channel for dsDNA to enter during packaging and to exit during infection. The negatively charged interior channel wall is decorated with a total of 48 positively charged lysine residues displayed as four 12-lysine rings from the 12 gp10 subunits that enclose the channel. The standard notion derived from many models is that these uniquely arranged, positively charged rings play active roles in DNA translocation through the channel. In this study, we tested this prevailing view by examining the effect of mutating these basic lysines to alanines, and assessing the impact of altering the pH environment. Unexpectedly, mutating these basic lysine residues or changing the pH to 4 or 10, which could alter the charge of lysines, did not measurably impair DNA translocation or affect the one-way traffic property of the channel. The results support our recent findings regarding the dsDNA packaging mechanism known as the “push through a one-way valve”. PMID:22225806

  12. 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.

  13. Alanine Scanning Mutagenesis Identifies an Asparagine–Arginine–Lysine Triad Essential to Assembly of the Shell of the Pdu Microcompartment

    SciTech Connect

    Sinha, Sharmistha; Cheng, Shouqiang; Sung, Yea Won; McNamara, Dan E.; Sawaya, Michael R.; Yeates, Todd O.; Bobik, Thomas A.

    2014-06-01

    Bacterial microcompartments (MCPs) are the simplest organelles known. They function to enhance metabolic pathways by confining several related enzymes inside an all-protein envelope called the shell. In this study, we investigated the factors that govern MCP assembly by performing scanning mutagenesis on the surface residues of PduA, a major shell protein of the MCP used for 1,2-propanediol degradation. Biochemical, genetic, and structural analysis of 20 mutants allowed us to determine that PduA K26, N29, and R79 are crucial residues that stabilize the shell of the 1,2-propanediol MCP. In addition, we identify two PduA mutants (K37A and K55A) that impair MCP function most likely by altering the permeability of its protein shell. These are the first studies to examine the phenotypic effects of shell protein structural mutations in an MCP system. The findings reported here may be applicable to engineering protein containers with improved stability for biotechnology applications.

  14. Identification and Characterization of the Lysine-Rich Matrix Protein Family in Pinctada fucata: Indicative of Roles in Shell Formation.

    PubMed

    Liang, Jian; Xie, Jun; Gao, Jing; Xu, Chao-Qun; Yan, Yi; Jia, Gan-Chu; Xiang, Liang; Xie, Li-Ping; Zhang, Rong-Qing

    2016-12-01

    Mantle can secret matrix proteins playing key roles in regulating the process of shell formation. The genes encoding lysine-rich matrix proteins (KRMPs) are one of the most highly expressed matrix genes in pearl oysters. However, the expression pattern of KRMPs is limited and the functions of them still remain unknown. In this study, we isolated and identified six new members of lysine-rich matrix proteins, rich in lysine, glycine and tyrosine, and all of them are basic matrix proteins. Combined with four members of the KRMPs previously reported, all these proteins can be divided into three subclasses according to the results of phylogenetic analyses: KRMP1-3 belong to subclass KPI, KRMP4-5 belong to KPII, and KRMP6-10 belong to KPIII. Three subcategories of lysine-rich matrix proteins are highly expressed in the D-phase, the larvae and adult mantle. Lysine-rich matrix proteins are involved in the shell repairing process and associated with the formation of the shell and pearl. What's more, they can cause abnormal shell growth after RNA interference. In detail, KPI subgroup was critical for the beginning formation of the prismatic layer; both KPII and KPIII subgroups participated in the formation of prismatic layer and nacreous layer. Compared with different temperatures and salinity stimulation treatments, the influence of changes in pH on KRMPs gene expression was the greatest. Recombinant KRMP7 significantly inhibited CaCO3 precipitation, changed the morphology of calcite, and inhibited the growth of aragonite in vitro. Our results are beneficial to understand the functions of the KRMP genes during shell formation.

  15. Lysine-poly(2-hydroxyethyl methacrylate) modified polyurethane surface with high lysine density and fibrinolytic activity.

    PubMed

    Li, Dan; Chen, Hong; Wang, Shasha; Wu, Zhaoqiang; Brash, John L

    2011-03-01

    We have developed a potentially fibrinolytic surface in which a bioinert polymer is used as a spacer to immobilize lysine such that the ε-amino group is free to capture plasminogen when in contact with blood. Adsorbed plasminogen can be activated to plasmin and potentially dissolve nascent clots formed on the surface. In previous work lysine was immobilized through a poly(ethylene glycol) (PEG) spacer; however, the graft density of PEG was limited and the resulting adsorbed quantity of plasminogen was insufficient to dissolve clots efficiently. The aim of the present work was to optimize the surface using graft-polymerized poly(2-hydroxyethyl methacrylate) (poly(HEMA)) as a spacer to increase the grafting density of lysine. Such a poly(HEMA)-lysine modified polyurethane (PU) surface is expected to have increased plasminogen binding capacity and clot lysing efficiency compared with PEG-lysine modified PU. A lysine density of 2.81 nmol cm(-2) was measured on the PU-poly(HEMA)-Lys surface vs. 0.76 nmol cm(-2) on a comparable PU-PEG-Lys surface reported previously. The poly(HEMA)-lysine-modified surface was shown to reduce non-specific (fibrinogen) adsorption while binding plasminogen from plasma with high affinity. With increased plasminogen binding capacity these surfaces showed more rapid clot lysis (20 min) in a standard in vitro assay than the corresponding PEG-lysine system (40 min). The data suggest that poly(HEMA) is superior to PEG when used as a spacer in the immobilization of bioactive molecules at high density. This method of modification may also provide a generic approach for preparing bioactive PU surfaces of high activity and low non-specific adsorption of proteins.

  16. Alanine repeats influence protein localization in splicing speckles and paraspeckles.

    PubMed

    Chang, Shuo-Hsiu; Chang, Wei-Lun; Lu, Chia-Chen; Tarn, Woan-Yuh

    2014-12-16

    Mammalian splicing regulatory protein RNA-binding motif protein 4 (RBM4) has an alanine repeat-containing C-terminal domain (CAD) that confers both nuclear- and splicing speckle-targeting activities. Alanine-repeat expansion has pathological potential. Here we show that the alanine-repeat tracts influence the subnuclear targeting properties of the RBM4 CAD in cultured human cells. Notably, truncation of the alanine tracts redistributed a portion of RBM4 to paraspeckles. The alanine-deficient CAD was sufficient for paraspeckle targeting. On the other hand, alanine-repeat expansion reduced the mobility of RBM4 and impaired its splicing activity. We further took advantage of the putative coactivator activator (CoAA)-RBM4 conjoined splicing factor, CoAZ, to investigate the function of the CAD in subnuclear targeting. Transiently expressed CoAZ formed discrete nuclear foci that emerged and subsequently separated-fully or partially-from paraspeckles. Alanine-repeat expansion appeared to prevent CoAZ separation from paraspeckles, resulting in their complete colocalization. CoAZ foci were dynamic but, unlike paraspeckles, were resistant to RNase treatment. Our results indicate that the alanine-rich CAD, in conjunction with its conjoined RNA-binding domain(s), differentially influences the subnuclear localization and biogenesis of RBM4 and CoAZ.

  17. The structure of alanine racemase from Acinetobacter baumannii.

    PubMed

    Davis, Emily; Scaletti-Hutchinson, Emma; Opel-Reading, Helen; Nakatani, Yoshio; Krause, Kurt L

    2014-09-01

    Acinetobacter baumannii is an opportunistic Gram-negative bacterium which is a common cause of hospital-acquired infections. Numerous antibiotic-resistant strains exist, emphasizing the need for the development of new antimicrobials. Alanine racemase (Alr) is a pyridoxal 5'-phosphate dependent enzyme that is responsible for racemization between enantiomers of alanine. As D-alanine is an essential component of the bacterial cell wall, its inhibition is lethal to prokaryotes, making it an excellent antibiotic drug target. The crystal structure of A. baumannii alanine racemase (AlrAba) from the highly antibiotic-resistant NCTC13302 strain has been solved to 1.9 Å resolution. Comparison of AlrAba with alanine racemases from closely related bacteria demonstrates a conserved overall fold. The substrate entryway and active site of the enzymes were shown to be highly conserved. The structure of AlrAba will provide the template required for future structure-based drug-design studies.

  18. 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-

  19. Comparison of EPR response of alanine and Gd₂O₃-alanine dosimeters exposed to TRIGA Mainz reactor.

    PubMed

    Marrale, M; Schmitz, T; Gallo, S; Hampel, G; Longo, A; Panzeca, S; Tranchina, L

    2015-12-01

    In this work we report some preliminary results regarding the analysis of electron paramagnetic resonance (EPR) response of alanine pellets and alanine pellets added with gadolinium used for dosimetry at the TRIGA research reactor in Mainz, Germany. Two set-ups were evaluated: irradiation inside PMMA phantom and irradiation inside boric acid phantom. We observed that the presence of Gd2O3 inside alanine pellets increases the EPR signal by a factor of 3.45 and 1.24 in case of PMMA and boric acid phantoms, respectively. We can conclude that in the case of neutron beam with a predominant thermal neutron component the addition of gadolinium oxide can significantly improve neutron sensitivity of alanine pellets. Monte Carlo (MC) simulations of both response of alanine and Gd-added alanine pellets with FLUKA code were performed and a good agreement was achieved for pure alanine dosimeters. For Gd2O3-alanine deviations between MC simulations and experimental data were observed and discussed.

  20. Excess of L-alanine in amino acids synthesized in a plasma torch generated by a hypervelocity meteorite impact reproduced in the laboratory

    NASA Astrophysics Data System (ADS)

    Managadze, George G.; Engel, Michael H.; Getty, Stephanie; Wurz, Peter; Brinckerhoff, William B.; Shokolov, Anatoly G.; Sholin, Gennady V.; Terent'ev, Sergey A.; Chumikov, Alexander E.; Skalkin, Alexander S.; Blank, Vladimir D.; Prokhorov, Vyacheslav M.; Managadze, Nina G.; Luchnikov, Konstantin A.

    2016-10-01

    We present a laboratory reproduction of hypervelocity impacts of a carbon containing meteorite on a mineral substance representative of planetary surfaces. The physical conditions of the resulting impact plasma torch provide favorable conditions for abiogenic synthesis of protein amino acids: We identified glycine and alanine, and in smaller quantities serine, in the produced material. Moreover, we observe breaking of alanine mirror symmetry with L excess, which coincides with the bioorganic world. Therefore the selection of L-amino acids for the formation of proteins for living matter could have been the result from plasma processes occurring during the impact meteorites on the surface. This indicates that the plasma torch from meteorite impacts could play an important role in the formation of biomolecular homochirality. Thus, meteorite impacts possibly were the initial stage of this process and promoted conditions for the emergence of a living matter.

  1. Low cytotoxic tissue adhesive based on oxidized dextran and epsilon-poly-L-lysine.

    PubMed

    Hyon, Suong-Hyu; Nakajima, Naoki; Sugai, Hajime; Matsumura, Kazuaki

    2014-08-01

    A novel adhesive hydrogel consisting of dextran and epsilon-poly(L-lysine) (dextran-PL) with multiple biomedical applications was developed. Periodate oxidation in aqueous media almost stoichiometrically introduces aldehyde groups in dextran molecules, and aldehyde dextran can react with the primary amino groups in epsilon-PL (ɛ-PL) at neutral pH to form a hydrogel. The gelation time of the hydrogel can be easily controlled by the extent of oxidation in dextran and of the acylation in ɛ-PL by anhydrides. The shear adhesion strength of dextran-PL was 10 times higher than that of fibrin glue, when wet collagen sheets were selected as test specimens. The cytotoxicity of aldehyde dextran and ɛ-PL were 1000 times lower than that of glutaraldehyde and poly(allylamine). The considerably low cytotoxicity of aldehyde dextran could be ascribed to its low reactivity with amine species when compared with glutaraldehyde. In contrast, a high reactivity of amino groups in ɛ-PL was observed when compared with glycine, L-lysine, and gelatin, which could be explained by their poor dissociation at neutral pH, thus leading to low cytotoxicity.

  2. Reduction of dietary lysine increases free glutamate content in chicken meat and improves its taste.

    PubMed

    Watanabe, Genya; Kobayashi, Hiroyuki; Shibata, Masahiro; Kubota, Masatoshi; Kadowaki, Motoni; Fujimura, Shinobu

    2017-02-01

    Taste is a crucial factor of meat quality, and amino acids are important taste-active components in meat. Here, the effects of dietary lysine (Lys) content on taste-active components in meat, especially free glutamate (Glu), were investigated. Twenty-eight-day-old broilers (Gallus gallus) were fed diets with graded Lys content of 90% or 100% of the recommended Lys requirement, (according to the National Research Council, ) for 10 days. Free amino acid content in meat and sensory scores of meat soup were estimated. Free Glu content, the main taste-active component of meat, was significantly increased by a reduction of dietary Lys. Compared with the Lys 100% group (control), free Glu concentrations of meat were increased by 35.7% in the Lys 90% group (P < 0.05). In addition, free glycine, valine, isoleucine, leucine, histidine and threonine concentrations of meat were significantly increased in the Lys 90% group (P < 0.05). Sensory evaluation of meat soup made from the Lys 100% and 90% groups indicated different meat tastes. Sensory scores of taste intensity, umami and kokumi tastes were significantly higher in the Lys 90% group. These results suggest that a reduction of dietary lysine increased free glutamate content in meat and improved its taste.

  3. 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.

  4. 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

  5. Molecular dynamic and docking interaction study of Heterodera glycines serine proteinase with Vigna mungo proteinase inhibitor.

    PubMed

    Prasad, C V S Siva; Gupta, Saurabh; Gaponenko, Alex; Tiwari, Murlidhar

    2013-08-01

    Many plants do produce various defense proteins like proteinase inhibitors (PIs) to protect them against various pests. PIs function as pseudosubstrates of digestive proteinase, which inhibits proteolysis in pests and leads to amino acid deficiency-based mortality. This work reports the structural interaction studies of serine proteinase of Heterodera glycines (SPHG) with Vigna mungo proteinase inhibitor (VMPI). 3D protein structure modeling, validation of SPHG and VMPI, and their putative protein-protein binding sites were predicted. Protein-protein docking followed by molecular dynamic simulation was performed to find the reliable confirmation of SPHG-VMPI complex. Trajectory analysis of each successive conformation concludes better interaction of first loop in comparison with second loop. Lysine residues of first loop were actively participating in complex formation. Overall, this study discloses the structural aspects and interaction mechanisms of VMPI with SPHG, and it would be helpful in the development of pest-resistant genetically modified crops.

  6. 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.

  7. Isolation and characterization of a novel phage lysin active against Paenibacillus larvae, a honeybee pathogen

    PubMed Central

    LeBlanc, Lucy; Nezami, Sara; Yost, Diane; Tsourkas, Philippos; Amy, Penny S

    2015-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB) disease which affects early larval stages during honeybee development. Due to its virulence, transmissibility, capacity to develop antibiotic resistance, and the inherent resilience of its endospores, Paenibacillus larvae is extremely difficult to eradicate from infected hives which often must be burned. AFB contributes to the worldwide decline of honeybee populations, which are crucial for pollination and the food supply. We have isolated a novel bacteriophage lysin, PlyPalA, from the genome of a novel Paenibacillus larvae bacteriophage originally extracted from an environmental sample. PlyPalA has an N-terminal N-acetylmuramoyl-L-alanine amidase catalytic domain and possesses lytic activity against infectious strains of Paenibacillus larvae without harming commensal bacteria known to compose the honeybee larval microbiota. A single dose of PlyPalA rescued 75% of larvae infected with endospores, showing that it represents a powerful tool for future treatment of AFB. This represents the first time that lysins have been tested for therapeutic use in invertebrates. PMID:26904379

  8. Anticoagulant Effects of Heparin Complexes with Prolyl-Glycine Peptide and Glycine and Proline Amino Acids.

    PubMed

    Grigorieva, M E; Obergan, T Yu; Maystrenko, E S; Kalugina, M D

    2016-05-01

    The study demonstrates the formation of heparin complexes with prolyl-glycine peptide and proline and glycine amino acids. The method was developed for in vitro production of these complexes at 1:1 dipeptide to heparin molar ratio and 2:1 amino acid to heparin molar ratio. These complexes, unlike the constituents, proline and glycine, exhibited significant anticoagulant, antiplatelet, and fibrin-depolymerization activities of varying degree in vitro and in vivo. The heparin-dipeptide complex produced maximum effect. The dipeptide by itself also showed anticoagulant properties, but less pronounced than in the complex with heparin.

  9. Optimization of Direct Lysine Decarboxylase Biotransformation for Cadaverine Production with Whole-Cell Biocatalysts at High Lysine Concentration.

    PubMed

    Kim, Hyun Joong; Kim, Yong Hyun; Shin, Ji-Hyun; Bhatia, Shashi Kant; Sathiyanarayanan, Ganesan; Seo, Hyung-Min; Choi, Kwon Young; Yang, Yung-Hun; Park, Kyungmoon

    2015-07-01

    Cadaverine (1,5-diaminopentane) is an important industrial chemical with a wide range of applications. Although there have been many efforts to produce cadaverine through fermentation, there are not many reports of the direct cadaverine production from lysine using biotransformation. Whole-cell reactions were examined using a recombinant Escherichia coli strain overexpressing the E. coli MG1655 cadA gene, and various parameters were investigated for the whole-cell bioconversion of lysine to cadaverine. A high concentration of lysine resulted in the synthesis of pyridoxal-5'-phosphate (PLP) and it was found to be a critical control factor for the biotransformation of lysine to cadaverine. When 0.025 mM PLP and 1.75 M lysine in 500 mM sodium acetate buffer (pH6) were used, consumption of 91% lysine and conversion of about 80% lysine to cadaverine were successfully achieved.

  10. Unexpected Trypsin Cleavage at Ubiquitinated Lysines

    PubMed Central

    2015-01-01

    Unexpected tryptic cleavage has been characterized at modified K48 residues in polyubiquitins. In particular, the tryptic products of all seven of the lysine-linked dimers of ubiquitin and of three trimers—linear Ub–48Ub–48Ub, linear Ub–63Ub–63Ub, and the branched trimer [Ub]2–6,48Ub—have been analyzed. In addition to the peptide products expected under commonly used tryptic conditions, we observe that peptides are formed with an unexpected ε-glycinylglycinyl-Lys carboxyl terminus when the site of linkage is Lys48. Trypsin from three different commercial sources exhibited this aberration. Initial cleavage at R74 is proposed in a distal ubiquitin to produce a glycinylglycinyl-lysine residue which is bound by trypsin. PMID:26182167

  11. Motility-indole-lysine-sulfide medium.

    PubMed

    Ederer, G M; Lund, M E; Blazevic, D J; Reller, L B; Mirrett, S

    1975-09-01

    A medium designed for the detection of motility, indole, lysine decarboxylase and deaminase reactions, and H2S production was devised and evaluated. Results, using 157 strains of enteric pathogens, were in agreement with reference methods. When 300 isolates from fecal cultures were screened using this medium, Shigella was easily differentiated from Escherichia and more of the Proteus species, especially P. morganii, could be eliminated from further study.

  12. Alanine and proline content modulate global sensitivity to discrete perturbations in disordered proteins.

    PubMed

    Perez, Romel B; Tischer, Alexander; Auton, Matthew; Whitten, Steven T

    2014-12-01

    Molecular transduction of biological signals is understood primarily in terms of the cooperative structural transitions of protein macromolecules, providing a mechanism through which discrete local structure perturbations affect global macromolecular properties. The recognition that proteins lacking tertiary stability, commonly referred to as intrinsically disordered proteins (IDPs), mediate key signaling pathways suggests that protein structures without cooperative intramolecular interactions may also have the ability to couple local and global structure changes. Presented here are results from experiments that measured and tested the ability of disordered proteins to couple local changes in structure to global changes in structure. Using the intrinsically disordered N-terminal region of the p53 protein as an experimental model, a set of proline (PRO) and alanine (ALA) to glycine (GLY) substitution variants were designed to modulate backbone conformational propensities without introducing non-native intramolecular interactions. The hydrodynamic radius (R(h)) was used to monitor changes in global structure. Circular dichroism spectroscopy showed that the GLY substitutions decreased polyproline II (PP(II)) propensities relative to the wild type, as expected, and fluorescence methods indicated that substitution-induced changes in R(h) were not associated with folding. The experiments showed that changes in local PP(II) structure cause changes in R(h) that are variable and that depend on the intrinsic chain propensities of PRO and ALA residues, demonstrating a mechanism for coupling local and global structure changes. Molecular simulations that model our results were used to extend the analysis to other proteins and illustrate the generality of the observed PRO and alanine effects on the structures of IDPs.

  13. Efficiency of lysine or threonine retention in growing rats fed diets limiting in either lysine or threonine.

    PubMed

    Gahl, M J; Finke, M D; Crenshaw, T D; Benevenga, N J

    1996-12-01

    Over a 21-d experiment, the efficiency of lysine and threonine retention was determined in 80 male Sprague-Dawley rats (65.9 +/- 0.3 g, means +/- SE) fed purified diets containing an amino acid mix limiting in either lysine or threonine. With additional increments of the first limiting amino acid, lysine concentration in total body protein (g/16 g N) increased (P < 0.01) in rats fed lysine-limiting diets but, when fed threonine-limiting diets, lysine concentration in body protein first increased and then decreased (P < 0.01). As increments of the first limiting amino acid were added, the threonine concentration in total body protein increased then decreased when both lysine- (P < 0.01) and threonine- (P < 0.06) limiting diets were fed. Lysine and threonine retention were calculated based on comparative slaughter. Sixteen rats were killed on d 0 to estimate the grams of amino acid in the body. Retention responses were analyzed using a logistic equation in which lysine or threonine intake was used to predict retention. The maximum marginal efficiency (dr/dI, retention/intake) was observed at <40% of maximum retention. For lysine retention, it was 81% when lysine was limiting and 70% when threonine was limiting. For threonine retention, it was 58% when threonine was limiting and 49% when lysine was limiting. The maximum cumulative efficiency (retention adjusted for maintenance relative to cumulative intake) for lysine retention was 62% when lysine was limiting or 58% when threonine was limiting. For threonine retention, it was 51% when threonine was limiting and 35% when lysine was limiting. Thus, amino acid concentration in body protein is not constant, and amino acids are used with higher efficiency when first limiting.

  14. 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....

  15. 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....

  16. 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....

  17. 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....

  18. Charge and geometry of residues in the loop 2 β hairpin differentially affect agonist and ethanol sensitivity in glycine receptors.

    PubMed

    Perkins, Daya I; Trudell, James R; Asatryan, Liana; Davies, Daryl L; Alkana, Ronald L

    2012-05-01

    Recent studies highlighted the importance of loop 2 of α1 glycine receptors (GlyRs) in the propagation of ligand-binding energy to the channel gate. Mutations that changed polarity at position 52 in the β hairpin of loop 2 significantly affected sensitivity to ethanol. The present study extends the investigation to charged residues. We found that substituting alanine with the negative glutamate at position 52 (A52E) significantly left-shifted the glycine concentration response curve and increased sensitivity to ethanol, whereas the negative aspartate substitution (A52D) significantly right-shifted the glycine EC₅₀ but did not affect ethanol sensitivity. It is noteworthy that the uncharged glutamine at position 52 (A52Q) caused only a small right shift of the glycine EC₅₀ while increasing ethanol sensitivity as much as A52E. In contrast, the shorter uncharged asparagine (A52N) caused the greatest right shift of glycine EC₅₀ and reduced ethanol sensitivity to half of wild type. Collectively, these findings suggest that charge interactions determined by the specific geometry of the amino acid at position 52 (e.g., the 1-Å chain length difference between aspartate and glutamate) play differential roles in receptor sensitivity to agonist and ethanol. We interpret these results in terms of a new homology model of GlyR based on a prokaryotic ion channel and propose that these mutations form salt bridges to residues across the β hairpin (A52E-R59 and A52N-D57). We hypothesize that these electrostatic interactions distort loop 2, thereby changing agonist activation and ethanol modulation. This knowledge will help to define the key physical-chemical parameters that cause the actions of ethanol in GlyRs.

  19. GABA and glycine actions on spinal motoneurons.

    PubMed

    Krnjević, K; Puil, E; Werman, R

    1977-06-01

    Applied microiontophoretically in the spinal cord of cats, glycine is consistently more powerful than gamma-aminobutyric acid (GABA) in raising the membrane conductance of lumbosacral motoneurons (mean ratio of equipotent iontophoretic currents tested on same cells is 5.6:1). This is the reverse of the situation in cerebral cortex. The effect of glycine is well maintained during applications lasting about 1 min, but that of GABA, after an early peak, drops to a much lower plateau (mean plateau-over-peak ratio is 0.23). The reversal potentials for the action of GABA and glycine are initially similar but they behave differently during a prolonged application; that for glycine usually remains constant or becomes more negative whereas that for GABA tends to shift in the positive direction. Various explanations of these phenomena are considered. It is suggested that a single process, electrogenic uptake of GABA, may account for both desensitization (by removing GABA from its site of action) and the positive shift in GABA reversal potential (became uptake is probably associated with an influx of Na+).

  20. 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

  1. 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....

  2. Function of the D-alanine:D-alanine ligase lid loop: a molecular modeling and bioactivity study.

    PubMed

    Hrast, Martina; Vehar, Blaž; Turk, Samo; Konc, Janez; Gobec, Stanislav; Janežič, Dušanka

    2012-08-09

    D-Alanine:D-alanine ligase (Ddl) is an essential ATP-dependent bacterial enzyme involved in peptidoglycan biosynthesis. Discovery of Ddl inhibitors not competitive with ATP has proven to be difficult because the Ddl bimolecular d-alanine binding pocket is very restricted, as is accessibility to the active site for larger molecules in the catalytically active closed conformation of Ddl. A molecular dynamics study of the opening and closing of the Ddl lid loop informs future structure-based design efforts that allow for the flexibility of Ddl. A virtual screen on generated enzyme conformations yielded some hit inhibitors whose bioactivity was determined.

  3. 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

  4. Oral glycine administration increases brain glycine/creatine ratios in men: a proton magnetic resonance spectroscopy study

    PubMed Central

    Kaufman, Marc J.; Prescot, Andrew P.; Ongur, Dost; Evins, A. Eden; Barros, Tanya L.; Medeiros, Carissa L.; Covell, Julie; Wang, Liqun; Fava, Maurizio; Renshaw, Perry F.

    2009-01-01

    Oral high-dose glycine administration has been used as an adjuvant treatment for schizophrenia to enhance glutamate neurotransmission and mitigate glutamate system hypofunction thought to contribute to the disorder. Prior studies in schizophrenia subjects documented clinical improvements after 2 weeks of oral glycine administration, suggesting that brain glycine levels are sufficiently elevated to evoke a clinical response within that time frame. However, no human study has reported on brain glycine changes induced by its administration. We utilized a noninvasive proton magnetic resonance spectroscopy (1H-MRS) technique termed echo time-averaged (TEAV) 1H-MRS, which permits noninvasive quantification of brain glycine in vivo, to determine whether 2 weeks of oral glycine administration (peak dose of 0.8g/kg/day) increased brain glycine/creatine (Gly/Cr) ratios in 11 healthy adult men. In scans obtained 17 hours after the last glycine dose, brain (Gly/Cr) ratios were significantly increased. The data indicate that it is possible to measure brain glycine changes with proton spectroscopy. Developing a more comprehensive understanding of human brain glycine dynamics may lead to optimized use of glycine site agonists and glycine transporter inhibitors to treat schizophrenia, and possibly to treat other disorders associated with glutamate system dysfunction. PMID:19556112

  5. Enzymatic characterization of a lysin encoded by bacteriophage EL.

    PubMed

    Tafoya, Diana A; Hildenbrand, Zacariah L; Herrera, Nadia; Molugu, Sudheer K; Mesyanzhinov, Vadim V; Miroshnikov, Konstantin A; Bernal, Ricardo A

    2013-04-01

    The bacteriophage EL is a virus that specifically attacks the human pathogen Pseudomonas aeruginosa. This phage carries a large genome that encodes for its own chaperonin which presumably facilitates the proper folding of phage proteins independently of the host chaperonin system. EL also encodes a lysin enzyme, a critical component of the lytic cycle that is responsible for digesting the peptidoglycan layer of the host cell wall. Previously, this lysin was believed to be a substrate of the chaperonin encoded by phage EL. In order to characterize the activity of the EL lysin, and to determine whether lysin activity is contingent on chaperonin-mediated folding, a series of peptidoglycan hydrolysis activity assays were performed. Results indicate that the EL-encoded lysin has similar enzymatic activity to that of the Gallus gallus lysozyme and that the EL lysin folds into a functional enzyme in the absence of phage chaperonin and should not be considered a substrate.

  6. Stereospecificity of isotopic exchange of C-α-protons of glycine catalyzed by three PLP-dependent lyases: the unusual case of tyrosine phenol-lyase.

    PubMed

    Koulikova, Vitalia V; Zakomirdina, Lyudmila N; Gogoleva, Olga I; Tsvetikova, Marina A; Morozova, Elena A; Komissarov, Vsevolod V; Tkachev, Yaroslav V; Timofeev, Vladimir P; Demidkina, Tatyana V; Faleev, Nicolai G

    2011-11-01

    A comparative study of the kinetics and stereospecificity of isotopic exchange of the pro-2R- and pro-2S protons of glycine in (2)H(2)O under the action of tyrosine phenol-lyase (TPL), tryptophan indole-lyase (TIL) and methionine γ-lyase (MGL) was undertaken. The kinetics of exchange was monitored using both (1)H- and (13)C-NMR. In the three compared lyases the stereospecificities of the main reactions with natural substrates dictate orthogonal orientation of the pro-2R proton of glycine with respect to the cofactor pyridoxal 5'-phosphate (PLP) plane. Consequently, according to Dunathan's postulate with all the three enzymes pro-2R proton should exchange faster than does the pro-2S one. In fact the found ratios of 2R:2S reactivities are 1:20 for TPL, 108:1 for TIL, and 1,440:1 for MGL. Thus, TPL displays an unprecedented inversion of stereospecificity. A probable mechanism of the observed phenomenon is suggested, which is based on the X-ray data for the quinonoid intermediate, formed in the reaction of TPL with L-alanine. The mechanism implies different conformational changes in the active site upon binding of glycine and alanine. These changes can lead to relative stabilization of either the neutral amino group, accepting the α-proton, or the respective ammonium group, which is formed after the proton abstraction.

  7. Global analysis of lysine acetylation in strawberry leaves

    PubMed Central

    Fang, Xianping; Chen, Wenyue; Zhao, Yun; Ruan, Songlin; Zhang, Hengmu; Yan, Chengqi; Jin, Liang; Cao, Lingling; Zhu, Jun; Ma, Huasheng; Cheng, Zhongyi

    2015-01-01

    Protein lysine acetylation is a reversible and dynamic post-translational modification. It plays an important role in regulating diverse cellular processes including chromatin dynamic, metabolic pathways, and transcription in both prokaryotes and eukaryotes. Although studies of lysine acetylome in plants have been reported, the throughput was not high enough, hindering the deep understanding of lysine acetylation in plant physiology and pathology. In this study, taking advantages of anti-acetyllysine-based enrichment and high-sensitive-mass spectrometer, we applied an integrated proteomic approach to comprehensively investigate lysine acetylome in strawberry. In total, we identified 1392 acetylation sites in 684 proteins, representing the largest dataset of acetylome in plants to date. To reveal the functional impacts of lysine acetylation in strawberry, intensive bioinformatic analysis was performed. The results significantly expanded our current understanding of plant acetylome and demonstrated that lysine acetylation is involved in multiple cellular metabolism and cellular processes. More interestingly, nearly 50% of all acetylated proteins identified in this work were localized in chloroplast and the vital role of lysine acetylation in photosynthesis was also revealed. Taken together, this study not only established the most extensive lysine acetylome in plants to date, but also systematically suggests the significant and unique roles of lysine acetylation in plants. PMID:26442052

  8. Assessing functional diversity in the soybean β-substituted alanine synthase enzyme family.

    PubMed

    Yi, Hankuil; Jez, Joseph M

    2012-11-01

    In plants, proteins of the β-substituted alanine synthase (BSAS) enzyme family perform a diverse range of reactions, including formation of cysteine from O-acetylserine and sulfide, detoxification of cyanide by its addition to cysteine, the breakdown of cysteine into pyruvate, ammonia, and sulfide, and the synthesis of S-sulfocysteine. With the completed genome sequence of soybean (Glycine max (L.) Merr. cv. Williams 82), the functional diversity of the BSAS in this highly duplicated plant species was examined to determine whether soybean BSAS enzymes catalyze the various reactions connected to cysteine metabolism. The 16 soybean BSAS can be grouped into clades that are similar to those observed in Arabidopsis. Biochemical analysis of soybean BSAS proteins demonstrate that enzymes of clades I and III function as O-acetylserine sulfhydrylases for cysteine synthesis, clade II encodes cysteine desulfhydrase activity, and that clade V proteins function as β-cyanoalanine synthase for cyanide detoxification. Although clade IV is similar to Arabidopsis S-sulfocysteine synthase, this activity was not detected in the soybean homolog. Overall, our results show that bioinformatics approach provides a useful method to assess the biochemical properties of BSAS enzymes in plant species.

  9. Physical reasons for the unusual α-helix stabilization afforded by charged or neutral polar residues in alanine-rich peptides

    PubMed Central

    Vila, Jorge A.; Ripoll, Daniel R.; Scheraga, H. A.

    2000-01-01

    We have carried out conformational energy calculations on alanine-based copolymers with the sequence Ac-AAAAAXAAAA-NH2 in water, where X stands for lysine or glutamine, to identify the underlying source of stability of alanine-based polypeptides containing charged or highly soluble polar residues in the absence of charge–charge interactions. The results indicate that ionizable or neutral polar residues introduced into the sequence to make them soluble sequester the water away from the CO and NH groups of the backbone, thereby enabling them to form internal hydrogen bonds. This solvation effect dictates the conformational preference and, hence, modifies the conformational propensity of alanine residues. Even though we carried out simulations for specific amino acid sequences, our results provide an understanding of some of the basic principles that govern the process of folding of these short sequences independently of the kind of residues introduced to make them soluble. In addition, we have investigated through simulations the effect of the bulk dielectric constant on the conformational preferences of these peptides. Extensive conformational Monte Carlo searches on terminally blocked 10-mer and 16-mer homopolymers of alanine in the absence of salt were carried out assuming values for the dielectric constant of the solvent ɛ of 80, 40, and 2. Our simulations show a clear tendency of these oligopeptides to augment the α-helix content as the bulk dielectric constant of the solvent is lowered. This behavior is due mainly to a loss of exposure of the CO and NH groups to the aqueous solvent. Experimental evidence indicates that the helical propensity of the amino acids in water shows a dramatic increase on addition of certain alcohols, such us trifluoroethanol. Our results provide a possible explanation of the mechanism by which alcohol/water mixtures affect the free energy of helical alanine oligopeptides relative to nonhelical ones. PMID:11078529

  10. Noncovalent and covalent functionalization of a (5, 0) single-walled carbon nanotube with alanine and alanine radicals.

    PubMed

    Rajarajeswari, Muthusivarajan; Iyakutti, Kombiah; Kawazoe, Yoshiyuki

    2012-02-01

    We have systematically investigated the noncovalent and covalent adsorption of alanine and alanine radicals, respectively, onto a (5, 0) single-walled carbon nanotube using first-principles calculation. It was found that XH···π (X = N, O, C) interactions play a crucial role in the non-ovalent adsorption and that the functional group close to the carbon nanotube exhibits a significant influence on the binding strength. Noncovalent functionalization of the carbon nanotube with alanine enhances the conductivity of the metallic (5, 0) nanotube. In the covalent adsorption of each alanine radical onto a carbon nanotube, the binding energy depends on the adsorption site on CNT and the electronegative atom that binds with the CNT. The strongest complex is formed when the alanine radical interacts with a (5, 0) carbon nanotube through the amine group. In some cases, the covalent interaction of the alanine radical introduces a half-filled band at the Fermi level due to the local sp (3) hybridization, which modifies the conductivity of the tube.

  11. Structure of D-alanine-D-alanine ligase from Yersinia pestis: nucleotide phosphate recognition by the serine loop.

    PubMed

    Tran, Huyen Thi; Hong, Myoung Ki; Ngo, Ho Phuong Thuy; Huynh, Kim Hung; Ahn, Yeh Jin; Wang, Zhong; Kang, Lin Woo

    2016-01-01

    D-Alanyl-D-alanine is an essential precursor of bacterial peptidoglycan and is synthesized by D-alanine-D-alanine ligase (DDL) with hydrolysis of ATP; this reaction makes DDL an important drug target for the development of antibacterial agents. Five crystal structures of DDL from Yersinia pestis (YpDDL) were determined at 1.7-2.5 Å resolution: apo, AMP-bound, ADP-bound, adenosine 5'-(β,γ-imido)triphosphate-bound, and D-alanyl-D-alanine- and ADP-bound structures. YpDDL consists of three domains, in which four loops, loop 1, loop 2 (the serine loop), loop 3 (the ω-loop) and loop 4, constitute the binding sites for two D-alanine molecules and one ATP molecule. Some of them, especially the serine loop and the ω-loop, show flexible conformations, and the serine loop is mainly responsible for the conformational change in substrate nucleotide phosphates. Enzyme-kinetics assays were carried out for both the D-alanine and ATP substrates and a substrate-binding mechanism was proposed for YpDDL involving conformational changes of the loops.

  12. Liver peroxisomal alanine:glyoxylate aminotransferase and the effects of mutations associated with Primary Hyperoxaluria Type I: An overview.

    PubMed

    Oppici, Elisa; Montioli, Riccardo; Cellini, Barbara

    2015-09-01

    Liver peroxisomal alanine:glyoxylate aminotransferase (AGT) (EC 2.6.1.44) catalyses the conversion of l-alanine and glyoxylate to pyruvate and glycine, a reaction that allows glyoxylate detoxification. Inherited mutations on the AGXT gene encoding AGT lead to Primary Hyperoxaluria Type I (PH1), a rare disorder characterized by the deposition of calcium oxalate crystals primarily in the urinary tract. Here we describe the results obtained on the biochemical features of AGT as well as on the molecular and cellular effects of polymorphic and pathogenic mutations. A complex scenario on the molecular pathogenesis of PH1 emerges in which the co-inheritance of polymorphic changes and the condition of homozygosis or compound heterozygosis are two important factors that determine the enzymatic phenotype of PH1 patients. All the reported data represent relevant steps toward the understanding of genotype/phenotype correlations, the prediction of the response of the patients to the available therapies, and the development of new therapeutic approaches. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.

  13. Comprehensive profiling of lysine acetylproteome analysis reveals diverse functions of lysine acetylation in common wheat

    PubMed Central

    Zhang, Yumei; Song, Limin; Liang, Wenxing; Mu, Ping; Wang, Shu; Lin, Qi

    2016-01-01

    Lysine acetylation of proteins, a dynamic and reversible post-translational modification, plays a critical regulatory role in both eukaryotes and prokaryotes. Several researches have been carried out on acetylproteome in plants. However, until now, there have been no data on common wheat, the major cereal crop in the world. In this study, we performed a global acetylproteome analysis of common wheat variety (Triticum aestivum L.), Chinese Spring. In total, 416 lysine modification sites were identified on 277 proteins, which are involved in a wide variety of biological processes. Consistent with previous studies, a large proportion of the acetylated proteins are involved in metabolic process. Interestingly, according to the functional enrichment analysis, 26 acetylated proteins are involved in photosynthesis and Calvin cycle, suggesting an important role of lysine acetylation in these processes. Moreover, protein interaction network analysis reveals that diverse interactions are modulated by protein acetylation. These data represent the first report of acetylome in common wheat and serve as an important resource for exploring the physiological role of lysine acetylation in this organism and likely in all plants. PMID:26875666

  14. Bacteriophage phi11 lysin: physicochemical characterization and comparison with phage phi80a lysin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phage lytic enzymes are promising antimicrobial agents. Lysins of phage phi11 (LysPhi11) and phi80a (LysPhi80a) can lyse (destroy) biofilms and cells of antibiotic-resistant strains of Staphylococcus aureus. Stability of enzymes is one of the parameters making their practical use possible. The obj...

  15. The polyproline II conformation in short alanine peptides is noncooperative.

    PubMed

    Chen, Kang; Liu, Zhigang; Kallenbach, Neville R

    2004-10-26

    The finding that short alanine peptides possess a high fraction of polyproline II (PII) structure (Phi=-75 degrees, Psi=+145 degrees ) at low temperature has broad implications for unfolded states of proteins. An important question concerns whether or not this structure is locally determined or cooperative. We have monitored the conformation of alanine in a series of model peptides AcGGAnGGNH2 (n=1-3) over a temperature range from -10 degrees C to +80 degrees C. Use of 15N-labeled alanine substitutions makes it possible to measure 3JalphaN coupling constants accurately over the full temperature range. Based on a 1D next-neighbor model, the cooperative parameter sigma of PII nucleation is evaluated from the coupling constant data. The finding that sigma is close to unity (1 +/- 0.2) indicates a noncooperative role for alanine in PII structure formation, consistent with statistical surveys of the Protein Data Bank that suggest that most PII structure occurs in isolated residues. Lack of cooperativity in these models implies that hydration effects that influence PII conformation in water are highly localized. Using a nuclear Overhauser effect ratio strategy to define the alanine Psi angle, we estimate that, at 40 degrees C, the time-averaged alanine conformation (Phi=-80 degrees, Psi=+170 degrees ) deviates from canonical PII structure, indicating that PII melts at high temperature. Thus, the high-temperature state of short alanine peptides seems to be an unfolded ensemble with higher distribution in the extended beta structure basin, but not a coil.

  16. EPR/alanine dosimetry for two therapeutic proton beams

    NASA Astrophysics Data System (ADS)

    Marrale, Maurizio; Carlino, Antonio; Gallo, Salvatore; Longo, Anna; Panzeca, Salvatore; Bolsi, Alessandra; Hrbacek, Jan; Lomax, Tony

    2016-02-01

    In this work the analysis of the electron paramagnetic resonance (EPR) response of alanine pellets exposed to two different clinical proton beams employed for radiotherapy is performed. One beam is characterized by a passive delivery technique and is dedicated to the eyes treatment (OPTIS2 beam line). Alanine pellets were irradiated with a 70 MeV proton beam corresponding to 35 mm range in eye tissue. We investigated how collimators with different sizes and shape used to conform the dose to the planned target volume influence the delivered dose. For this purpose we performed measurements with varying the collimator size (Output Factor) and the results were compared with those obtained with other dosimetric techniques (such as Markus chamber and diode detector). This analysis showed that the dosimeter response is independent of collimator diameter if this is larger than or equal to 10 mm. The other beam is characterized by an active spot-scanning technique, the Gantry1 beam line (maximum energy 230 MeV), and is used to treat deep-seated tumors. The dose linearity of alanine response in the clinical dose range was tested and the alanine dose response at selected locations in depth was measured and compared with the TPS planned dose in a quasi-clinical scenario. The alanine response was found to be linear in the dose in the clinical explored range (from 10 to 70 Gy). Furthermore, a depth dose profile in a quasi-clinical scenario was measured and compared to the dose computed by the Treatment Planning System PSIPLAN. The comparison of calibrated proton alanine measurements and TPS dose shows a difference under 1% in the SOBP and a "quenching" effect up to 4% in the distal part of SOBP. The positive dosimetric characteristics of the alanine pellets confirm the feasibility to use these detectors for "in vivo" dosimetry in clinical proton beams.

  17. 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.

  18. Compositions containing poly (.gamma.-glutamylcysteinyl)glycines

    DOEpatents

    Jackson, Paul J.; Delhaize, Emmanuel; Robinson, Nigel J.; Unkefer, Clifford J.; Furlong, Clement

    1992-01-01

    A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. 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.

  19. Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review

    PubMed Central

    Razak, Meerza Abdul; Begum, Pathan Shajahan

    2017-01-01

    Glycine is most important and simple, nonessential amino acid in humans, animals, and many mammals. Generally, glycine is synthesized from choline, serine, hydroxyproline, and threonine through interorgan metabolism in which kidneys and liver are the primarily involved. Generally in common feeding conditions, glycine is not sufficiently synthesized in humans, animals, and birds. Glycine acts as precursor for several key metabolites of low molecular weight such as creatine, glutathione, haem, purines, and porphyrins. Glycine is very effective in improving the health and supports the growth and well-being of humans and animals. There are overwhelming reports supporting the role of supplementary glycine in prevention of many diseases and disorders including cancer. Dietary supplementation of proper dose of glycine is effectual in treating metabolic disorders in patients with cardiovascular diseases, several inflammatory diseases, obesity, cancers, and diabetes. Glycine also has the property to enhance the quality of sleep and neurological functions. In this review we will focus on the metabolism of glycine in humans and animals and the recent findings and advances about the beneficial effects and protection of glycine in different disease states. PMID:28337245

  20. 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.

  1. Lysine carboxylation: unveiling a spontaneous post-translational modification

    SciTech Connect

    Jimenez-Morales, David; Adamian, Larisa; Shi, Dashuang; Liang, Jie

    2014-01-01

    A computational method for the prediction of lysine carboxylation (KCX) in protein structures is described. The method accurately identifies misreported KCXs and predicts previously unknown KCX sites. The carboxylation of lysine residues is a post-translational modification (PTM) that plays a critical role in the catalytic mechanisms of several important enzymes. It occurs spontaneously under certain physicochemical conditions, but is difficult to detect experimentally. Its full impact is unknown. In this work, the signature microenvironment of lysine-carboxylation sites has been characterized. In addition, a computational method called Predictor of Lysine Carboxylation (PreLysCar) for the detection of lysine carboxylation in proteins with available three-dimensional structures has been developed. The likely prevalence of lysine carboxylation in the proteome was assessed through large-scale computations. The results suggest that about 1.3% of large proteins may contain a carboxylated lysine residue. This unexpected prevalence of lysine carboxylation implies an enrichment of reactions in which it may play functional roles. The results also suggest that by switching enzymes on and off under appropriate physicochemical conditions spontaneous PTMs may serve as an important and widely used efficient biological machinery for regulation.

  2. 40 CFR 721.10250 - Zirconium lysine complex (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Zirconium lysine complex (generic... Specific Chemical Substances § 721.10250 Zirconium lysine complex (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  3. 40 CFR 721.10250 - Zirconium lysine complex (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Zirconium lysine complex (generic... Specific Chemical Substances § 721.10250 Zirconium lysine complex (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  4. 40 CFR 721.10250 - Zirconium lysine complex (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Zirconium lysine complex (generic... Specific Chemical Substances § 721.10250 Zirconium lysine complex (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  5. On the existence of ``l-threonine formate'', ``l-alanine lithium chloride'' and ``bis l-alanine lithium chloride'' crystals

    NASA Astrophysics Data System (ADS)

    Petrosyan, A. M.; Ghazaryan, V. V.; Fleck, M.

    2013-03-01

    We argue that the recently reported crystals "L-threonine formate" as well as "L-alanine lithium chloride" and "bis L-alanine lithium chloride" actually are the well-known crystals L-threonine and L-alanine, respectively.

  6. [Effects of ß-alanine supplementation on athletic performance].

    PubMed

    Domínguez, Raúl; Hernández Lougedo, Juan; Maté-Muñoz, José Luis; Garnacho-Castaño, Manuel Vicente

    2014-10-06

    Carnosine, dipeptide formed by amino acids ß-alanine and L-histidine, has important physiological functions among which its antioxidant and related memory and learning. However, in connection with the exercise, the most important functions would be associated with muscle contractility, improving calcium sensitivity in muscle fibers, and the regulatory function of pH. Thus, it is proposed that carnosine is the major intracellular buffer, but could contribute to 7-10% in buffer or buffer capacity. Since carnosine synthesis seems to be limited by the availability of ß-alanine supplementation with this compound has been gaining increasing popularity among the athlete population. Therefore, the objective of this study literature review was to examine all those research works have shown the effect of ß-alanine supplementation on athletic performance. Moreover, it also has attempted to establish a specific dosage that maximizing the potential benefits, minimize paresthesia, the main side effect presented in response to supplementation.

  7. First-principles studies of pure and fluorine substituted alanines

    NASA Astrophysics Data System (ADS)

    Ahmad, Sardar; Vaizie, Hamide; Rahnamaye Aliabad, H. A.; Ahmad, Rashid; Khan, Imad; Ali, Zahid; Jalali-Asadabadi, S.; Ahmad, Iftikhar; Khan, Amir Abdullah

    2016-05-01

    This paper communicates the structural, electronic and optical properties of L-alanine, monofluoro and difluoro substituted alanines using density functional calculations. These compounds exist in orthorhombic crystal structure and the calculated structural parameters such as lattice constants, bond angles and bond lengths are in agreement with the experimental results. L-alanine is an indirect band gap insulator, while its fluorine substituted compounds (monofluoroalanine and difluoroalanine) are direct band gap insulators. The substitution causes reduction in the band gap and hence these optically tailored direct wide band gap materials have enhanced optical properties in the ultraviolet (UV) region of electromagnetic spectrum. Therefore, optical properties like dielectric function, refractive index, reflectivity and energy loss function are also investigated. These compounds have almost isotropic nature in the lower frequency range while at higher energies, they have a significant anisotropic nature.

  8. Lysine catabolism in Rhizoctonia leguminicola and related fungi.

    PubMed Central

    Guengerich, F P; Broquist, H P

    1976-01-01

    The catabolism of lysine was studied in several yeasts and fungi. Results with cell-free extracts of Rhizoctonia leguminicola support a proposed pathway involving (D- and L-) EPSILON-N-acetyllysine, alpha-keto-epsilon-acetamidohexanoic acid, delta-acetamidovaleric acid, and delta-aminovaleric acid in the conversion of L-lysine to shortchain organic acids. Label from radioactive L-lysine was found to accumulate in D- and L-epsilon-N-acetyllysine, delta-acetamidovaleric acid, delta-aminovaleric acid, and glutaric acid in cultures of R. leguminicola, Neurospora crassa, Saccharomyces cerevisiae, and Hansenula saturnus, suggesting that the proposed omega-acetyl pathway of lysine catabolism is generalized among yeasts and fungi. In N. crassa, as is the case in R. leguminicola, the major precursor of L-pipecolic acid was the L-isomer of lysine; 15N experiments were consistent with delta1-piperideine-2-carboxylic acid as an intermediate in the transformation. PMID:131119

  9. Lysine catabolism in Rhizoctonia leguminicola and related fungi.

    PubMed

    Guengerich, F P; Broquist, H P

    1976-04-01

    The catabolism of lysine was studied in several yeasts and fungi. Results with cell-free extracts of Rhizoctonia leguminicola support a proposed pathway involving (D- and L-) EPSILON-N-acetyllysine, alpha-keto-epsilon-acetamidohexanoic acid, delta-acetamidovaleric acid, and delta-aminovaleric acid in the conversion of L-lysine to shortchain organic acids. Label from radioactive L-lysine was found to accumulate in D- and L-epsilon-N-acetyllysine, delta-acetamidovaleric acid, delta-aminovaleric acid, and glutaric acid in cultures of R. leguminicola, Neurospora crassa, Saccharomyces cerevisiae, and Hansenula saturnus, suggesting that the proposed omega-acetyl pathway of lysine catabolism is generalized among yeasts and fungi. In N. crassa, as is the case in R. leguminicola, the major precursor of L-pipecolic acid was the L-isomer of lysine; 15N experiments were consistent with delta1-piperideine-2-carboxylic acid as an intermediate in the transformation.

  10. Quantification of Nε-(2-Furoylmethyl)-L-lysine (furosine), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL) and total lysine through stable isotope dilution assay and tandem mass spectrometry.

    PubMed

    Troise, Antonio Dario; Fiore, Alberto; Wiltafsky, Markus; Fogliano, Vincenzo

    2015-12-01

    The control of Maillard reaction (MR) is a key point to ensure processed foods quality. Due to the presence of a primary amino group on its side chain, lysine is particularly prone to chemical modifications with the formation of Amadori products (AP), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL). A new analytical strategy was proposed which allowed to simultaneously quantify lysine, CML, CEL and the Nε-(2-Furoylmethyl)-L-lysine (furosine), the indirect marker of AP. The procedure is based on stable isotope dilution assay followed by liquid chromatography tandem mass spectrometry. It showed high sensitivity and good reproducibility and repeatability in different foods. The limit of detection and the RSD% were lower than 5 ppb and below 8%, respectively. Results obtained with the new procedure not only improved the knowledge about the reliability of thermal treatment markers, but also defined new insights in the relationship between Maillard reaction products and their precursors.

  11. Cysteamine inhibition of (/sup 15/N)-glycine turnover in cystinosis and of glycine cleavage system in vitro

    SciTech Connect

    Yudkoff, M.; Nissim, I.; Schneider, A.; Segal, S.

    1981-01-01

    In order to clarify the hyperglycinemic effect of cysteamine treatment in children with nephropathic cystinosis, we measured (/sup 15/N)-glycine turnover in three affected patients. Administration of cysteamine lowered the glycine flux and the glycine metabolic clearance rate but did not alter the glycine pool size. Formation of (/sup 15/N)-serine from (/sup 15/N)-glycine was lower in untreated patients than in control subjects and was reduced still further by cysteamine. Studies in vitro with isolated rat liver mitochondria and acetone extracts of mitochondria indicated that even low cysteamine concentrations (0.1 mM) inhibited the glycine cleavage system in both the direction of glycine oxidation and glycine synthesis. Cysteamine was a more potent inhibitor of the glycine cleavage system than any other sulfhydryl containing compound. Although no ill effects of cysteamine treatment were immediately apparent, patients receiving cysteamine should be monitored carefully for the appearance of any neurologic symptoms which might be referable to inhibition of the glycine cleavage system.

  12. DNA Oxidative Cleavage Induced by the Novel Peptide Derivatives of 3-(quinoxalin-6-yl)alanine in Combination with Cu(II) or Fe(II) Ions

    PubMed Central

    Szczepanik, Wojciech; Kucharczyk-Klamińska, Marzena; Stefanowicz, Piotr; Staszewska, Anna; Szewczuk, Zbigniew; Skała, Jacek; Mysiak, Andrzej; Jeżowska-Bojczuk, Małgorzata

    2009-01-01

    Three model dipeptides containing 3-(2,3-di(pyridin-2-yl)quinoxalin-6-yl)alanine, 3-(dipyrido[3,2-a:2,3-c]phenazin-11-yl)alanine, and 3-(2,3-diphenylquinoxalin-6-yl)alanine were studied with respect to their ability to bind selected transition metal ions, such as Cu(II), Fe(II), Ni(II), Co(II), Mn(II), and Cr(III). It was found that only Cu(II) and Fe(II) ions could form stable complex species with the studied compounds. The ability to form the complexes correlated well with DNA damage experiments. Only the ferrous and cupric complexes are capable of generating both single- and double-strand scissions. However, double-strand breakages appear to be dominating lesions in the presence of hydrogen peroxide, especially for copper(II) containing systems. The quantity of breakage products in the presence of N-(3-(dipyrido[3,2-a:2,3-c]phenazine-11-yl)alanyl)glycine complexes was the highest as compared to the complexes of the remaining compounds. Moreover, this ligand was the only one that cleaved DNA in the absence of either Cu(II) or Fe(II) ions. PMID:20224817

  13. Atomic Layer Deposition of L-Alanine Polypeptide

    SciTech Connect

    Fu, Yaqin; Li, Binsong; Jiang, Ying-Bing; Dunphy, Darren R.; Tsai, Andy; Tam, Siu-Yue; Fan, Hongyou Y.; Zhang, Hongxia; Rogers, David; Rempe, Susan; Atanassov, Plamen; Cecchi, Joseph L.; Brinker, C. Jeffrey

    2014-10-30

    L-Alanine polypeptide thin films were synthesized via atomic layer deposition (ALD). Rather, instead of using an amino acid monomer as the precursor, an L-alanine amino acid derivatized with a protecting group was used to prevent self-polymerization, increase the vapor pressure, and allow linear cycle-by-cycle growth emblematic of ALD. Moreover, the successful deposition of a conformal polypeptide film has been confirmed by FTIR, TEM, and Mass Spectrometry, and the ALD process has been extended to polyvaline.

  14. Implications for glycine receptors and astrocytes in ethanol-induced elevation of dopamine levels in the nucleus accumbens.

    PubMed

    Adermark, Louise; Clarke, Rhona B C; Olsson, Torsten; Hansson, Elisabeth; Söderpalm, Bo; Ericson, Mia

    2011-01-01

    Elevated dopamine levels are believed to contribute to the rewarding sensation of ethanol (EtOH), and previous research has shown that strychnine-sensitive glycine receptors in the nucleus accumbens (nAc) are involved in regulating dopamine release and in mediating the reinforcing effects of EtOH. Furthermore, the osmoregulator taurine, which is released from astrocytes treated with EtOH, can act as an endogenous ligand for the glycine receptor, and increase extracellular dopamine levels. The aim of this study was to address if EtOH-induced swelling of astrocytes could contribute to elevated dopamine levels by increasing the extracellular concentration of taurine. Cell swelling was estimated by optical sectioning of fluorescently labeled astrocytes in primary cultures from rat, and showed that EtOH (25-150 mM) increased astrocyte cell volumes in a concentration- and ion-dependent manner. The EtOH-induced cell swelling was inhibited in cultures treated with the Na(+) /K(+) /2Cl⁻ cotransporter blocker furosemide (1 mM), Na(+) /K(+) -ATPase inhibitor ouabain (0.1 mM), potassium channel inhibitor BaCl₂ (50 µM) and in cultures containing low extracellular sodium concentration (3 mM). In vivo microdialysis performed in the nAc of awake and freely moving rats showed that local treatment with EtOH enhanced the concentrations of dopamine and taurine in the microdialysate, while glycine and β-alanine levels were not significantly modulated. EtOH-induced dopamine release was antagonized by local treatment with the glycine receptor antagonist strychnine (20 µM) or furosemide (100 µM or 1 mM). Furosemide also prevented EtOH-induced taurine release in the nAc. In conclusion, our data suggest that extracellular concentrations of dopamine and taurine are interconnected and that swelling of astrocytes contributes to the acute rewarding sensation of EtOH.

  15. Disruption of a putative intersubunit electrostatic bond enhances agonist efficacy at the human α1 glycine receptor.

    PubMed

    Welsh, Brian T; Todorovic, Jelena; Kirson, Dean; Allen, Hunter M; Bayly, Michelle D; Mihic, S John

    2017-02-15

    Partial agonists have lower efficacies than compounds considered 'full agonists', eliciting submaximal responses even at saturating concentrations. Taurine is a partial agonist at the glycine receptor (GlyR), a member of the cys-loop ligand-gated ion channel superfamily. The molecular mechanisms responsible for agonism are not fully understood but evidence suggests that efficacy at these receptors is determined by conformational changes that occur early in the process of receptor activation. We previously identified a residue located near the human α1 glycine binding site (aspartate-97; D97) that, when mutated to arginine (D97R), results in GlyR channels opening spontaneously with a high open probability, mimicking the effects of saturating glycine concentrations on wildtype GlyR. This D97 residue is hypothesized to form an electrostatic interaction with arginine-119 on an adjacent subunit, stabilizing the channel in a shut state. Here we demonstrate that the disruption of this putative bond increases the efficacy of partial agonists including taurine, as well as two other β-amino acid partial agonists, β-aminobutyric acid (β-ABA) and β-aminoisobutyric acid (β-AIBA). Even the subtle charge-conserving mutation of D97 to glutamate (D97E) markedly affects partial agonist efficacy. Mutation to the neutral alanine residue in the D97A mutant mimics the effects seen with D97R, indicating that charge repulsion does not significantly affect these findings. Our findings suggest that the determination of efficacy following ligand binding to the glycine receptor may involve the disruption of an intersubunit electrostatic interaction occurring near the agonist binding site.

  16. 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.

  17. Stereoselective aminoacylation of a dinucleoside monophosphate by the imidazolides of DL-alanine and N-(tert-butoxycarbonyl)-DL-alanine

    NASA Technical Reports Server (NTRS)

    Profy, A. T.; Usher, D. A.

    1984-01-01

    The aminoacylation of diinosine monophosphate was studied experimentally. When the acylating agent was the imidazolide of N-(tert-butoxycarbonyl)-DL-alanine, a 40 percent enantiomeric excess of the isomer was incorporated at the 2' site and the positions of equilibrium for the reversible 2'-3' migration reaction differed for the D and L enantiomers. The reactivity of the nucleoside hydroxyl groups was found to decrease on the order 2'(3') less than internal 2' and less than 5', and the extent of the reaction was affected by the concentration of the imidazole buffer. Reaction of IpI with imidazolide of unprotected DL-alanine, by contrast, led to an excess of the D isomer at the internal 2' site. Finally, reaction with the N-carboxy anhydride of DL-alanine occurred without stereoselection. These results are found to be relevant to the study of the evolution of optical chemical activity and the origin of genetically directed protein synthesis.

  18. 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.

  19. [Regulation of key enzymes of L-alanine biosynthesis by Brevibacterium flavum producer strains].

    PubMed

    Melkonian, L O; Avetisova, G E; Ambartsumian, A A; Chakhalian, A Kh; Sagian, A S

    2013-01-01

    The mechanisms of L-alanine overproduction by Brevibacterium flavum producer strains were studied. It was shown that beta-CI-L-alanine is an inhibitor of some key enzymes involved in the synthesis of L-alanine, including alanine transaminase and valine-pyruvate transaminase. Two highly active B. flavum GL1 and GL1 8 producer strains, which are resistant to the inhibitory effect of beta-Cl-L-alanine, were obtained using a parental B. flavum AA5 producer strain, characterized by a reduced activity of alanine racemase (>or=98%). It was demonstrated that the increased L-alanine synthesis efficiency observed in the producer strains developed in this work is associated with the absence of inhibition of alanine transaminase by the end product of the biosynthesis reaction, as well as with the effect of derepression of both alanine transaminase and valine-pyruvate transaminase synthesis by the studied compound.

  20. Glycine-coated photoluminescent silver nanoclusters

    NASA Astrophysics Data System (ADS)

    Kravets, Vira V.; Culhane, Kyle; Dmitruk, Igor M.; Pinchuk, Anatoliy O.

    2012-03-01

    We present experimental results on the multicolor (blue and green) photoluminescence from glycine-coated silver nanoclusters and small nanoparticles which can be used as novel probes for bio-imaging. Glycine-coated silver nanoclusters and nanoparticles were synthesized using thermal reduction of silver nitrate in a glycine matrix, according to a modified procedure described in literature. The size characterization with mass spectrometry, scanning electron microscopy and dynamic light scattering showed that the diameters of luminescent silver nanoclusters and small nanoparticles vary from 0.5 nm to 17 nm. Extinction spectroscopy revealed that the absorption band of the luminescent nanoclusters and nanoparticles was blue-shifted as compared to the nonluminescent larger silver nanoparticles. This effect indicated the well-known size dependence of the surface plasmon resonance in silver. The most pronounced photoluminescence peak was observed around 410 nm (characteristic SPR wavelength for silver) which strongly suggests the enhancement of the photoluminescence from silver nanoparticles by the SPR. The relative quantum yield of the photoluminescence of silver nanoclusters and nanoparticles was evaluated to be 0.09. In terms of their small size, brightness and photostability, noble metal nanoclusters and nanoparticles hold the most promise as candidates for biological cell imaging, competing with commonly used semiconductor quantum dots, fluorescent proteins and organic dyes. When applied to the problem of intracellular imaging, metal nanoclusters and small nanoparticles offer advantages over their much larger sized semiconductor counterparts in terms of ease of biological delivery. In addition, noble metal nanoparticles and nanoclusters are photostable. The high quantum yield (QY) of the photoluminescence emission signal enables the isolation of their photoluminescence from the cellular autofluorescence in cell imaging, improving the image contrast.

  1. The Glycine Transport Inhibitor Sarcosine Is an Inhibitory Glycine Receptor Agonist

    PubMed Central

    Zhang, Hai Xia; Lyons-Warren, Ariel; Thio, Liu Lin

    2009-01-01

    Summary Sarcosine is an endogenous amino acid that is a competitive inhibitor of the type I glycine transporter (GlyT1), an N-methyl-D-aspartate receptor (NMDAR) co-agonist, and an important intermediate in one-carbon metabolism. Its therapeutic potential for schizophrenia further underscores its clinical importance. The structural similarity between sarcosine and glycine and sarcosine's ability to serve as an NMDAR co-agonist led us to examine whether sarcosine is also an agonist at the inhibitory glycine receptor (GlyR). We examined this possibility using whole-cell recordings from cultured embryonic mouse hippocampal neurons and found that sarcosine evoked a dose-dependent, strychnine sensitive, Cl- current that cross-inhibited glycine currents. Sarcosine evoked this current with Li+ in the extracellular solution to block GlyT1, in neurons treated with the essentially irreversible GlyT1 inhibitor N[3-(4′-fluorophenyl)-3-(4′-phenylphenoxy)propyl]sarcosine (NFPS), and in neurons plated in the absence of glia. These results indicate that the sarcosine currents did not result from GlyT1 inhibition or heteroexchange. We conclude that sarcosine is a GlyR agonist. PMID:19619564

  2. Evaluating Progeny of Glycine max by Glycine tomentella for Novel Disease Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybridization with wild relatives of crops is an important tool for improving traits such as disease resistance and our objective is to expand the use of wild relatives for disease resistance in soybean. Glycine tomentella (2n=78) is a wild, perennial species in the tertiary gene pool of soybean (G....

  3. Acute copper toxicity following copper glycinate injection.

    PubMed

    Oon, S; Yap, C-H; Ihle, B U

    2006-11-01

    We present a patient who developed multi-organ failure due to severe copper toxicity following attempted suicide by s.c. injection of copper glycinate. Acute copper toxicity is rare in the developed world, although it occurs more frequently in developing world countries, where it is a common mode of suicide. Acute toxicity usually results from oral ingestion and there are several local and systemic effects. Specific management can be difficult as there is little evidence regarding the efficacy of chelating agents in acute toxicity.

  4. Solubility Behavior of Cyanophycin Depending on Lysine Content

    PubMed Central

    Wiefel, Lars

    2014-01-01

    Study of the synthesis of cyanophycin (CGP) in recombinant organisms focused for a long time mostly on the insoluble form of CGP, due to its easy purification and its putative use as a precursor for biodegradable chemicals. Recently, another form of CGP, which, in contrast to the insoluble form, was soluble at neutral pH, became interesting due to its high lysine content, which was also assumed to be the reason for the solubility of the polymer. In this study, we demonstrate that lysine incorporated into insoluble CGP affected the solubility of the polymer in relation to its lysine content. Insoluble CGP can be separated along a temperature gradient of 90°C to 30°C, where CGP showed an increasing lysine content corresponding to a decreasing temperature needed for solubilization. CGP with less than 3 to 4 mol% lysine did not become soluble even at 90°C, while CGP with 31 mol% lysine was soluble at 30°C. In lysine fractions at higher than 31 mol%, CGP was soluble. The temperature separation will be suitable for improving the downstream processing of CGP synthesized in large-scale fermentations, including faster and more efficient purification of CGP, as well as enrichment and separation of dipeptides and CGP with specific amino acid compositions. PMID:24271185

  5. Formation of {gamma}-alumina nanorods in presence of alanine

    SciTech Connect

    Dabbagh, Hossein A.; Rasti, Elham; Yalfani, Mohammad S.; Medina, Francesc

    2011-02-15

    Graphical abstract: Nanorod aluminas with a possible hexagonal symmetry, high surface area and relatively narrow pore size distribution were obtained. Research highlights: {yields} Research highlights {yields} Boehmite was prepared using a green sol-gel process in the presence of alanine. {yields} Nanorod aluminas with a high surface area were obtained. {yields} Addition of alanine would shape the size of the holes and crevices. {yields} The morphologies of the nanorods were revealed by transmission electron microscope. -- Abstract: Boehmite and alumina nanostructures were prepared using a simple green sol-gel process in the presence of alanine in water medium at room temperature. The uncalcined (dried at 200 {sup o}C) and the calcined materials (at 500, 600 and 700 {sup o}C for 4 h) were characterized using XRD, TEM, SEM, N{sub 2} physisorption and TGA. Nanorod aluminas with a possible hexagonal symmetry, high surface area and relatively narrow pore size distribution were obtained. The surface area was enhanced and crystallization was retarded as the alanine content increased. The morphologies of the nanoparticles and nanorods were revealed by a transmission electron microscope (TEM).

  6. A theoretical study of alanine dipeptide and analogs

    SciTech Connect

    Head-Gordon, T.; Head-Gordon, M.; Brooks, C. III; Pople, J. ); Frisch, M.J. )

    1989-01-01

    We Present a preliminary report on the conformational and energetic analysis of the molecule (S)-2-acetylamino-N-methylpropanamide (alanine dipeptide) and an analog molecule, (S)-{alpha}-formylaminopropanamide, using high-quality ab initio methods. Alanine dipeptide and its analogs are of interest since they incorporate many of the structural features found in proteins, such as intramolecular hydrogen bonds, conformational flexibility, and a variety of chemical functionality. One purpose of this study is to provide a useful benchmark calculation, MP2/6-31+G{sup **}//HF/6-31+G{sup *}, for a number of conformations of the alanine system. Based on the comparison of these benchmark calculations with lower-level basis sets, HF/3-21G was chosen to generate a fully relaxed {phi}, {psi} dihedral map. These calculations are the first of their kind on systems of this size. Features of the {phi},{psi} alanine dipeptide map that are discussed include the energetically accessible conformations and possible pathways for their interconversion. In addition, we illustrate the importance of fully optimized geometries and the proper evaluation of correlation energies,

  7. Spectrophotometric readout for an alanine dosimeter for food irradiation applications

    NASA Astrophysics Data System (ADS)

    Ebraheem, S.; Beshir, W. B.; Eid, S.; Sobhy, R.; Kovács, A.

    2003-06-01

    The alanine-electron spin resonance (EPR) readout system is well known as a reference and transfer dosimetry system for the evaluation of high doses in radiation processing. The high cost of an EPR/alanine dosimetry system is a serious handicap for large-scale routine application in irradiation facilities. In this study, the use of a complex produced by dissolving irradiated L-alanine in 1,4-phenyl diammonium dichloride solution was investigated for dosimetry purposes. This complex—having a purple colour—has an increasing absorbance with increasing dose in the range of 1-20 kGy. The applicability of spectrophotometric evaluation was studied by measuring the absorbance intensity of this complex at 360 and 505 nm, respectively. Fluorimetric evaluation was also investigated by measuring the emission of the complex at 435 nm as a function of dose. The present method is easy for routine application. The effect of the dye concentration as well as the suitable amount of irradiated alanine has been studied. With respect to routine application, the stability of the product complex after its formation was also investigated.

  8. Computational alanine scanning with linear scaling semiempirical quantum mechanical methods.

    PubMed

    Diller, David J; Humblet, Christine; Zhang, Xiaohua; Westerhoff, Lance M

    2010-08-01

    Alanine scanning is a powerful experimental tool for understanding the key interactions in protein-protein interfaces. Linear scaling semiempirical quantum mechanical calculations are now sufficiently fast and robust to allow meaningful calculations on large systems such as proteins, RNA and DNA. In particular, they have proven useful in understanding protein-ligand interactions. Here we ask the question: can these linear scaling quantum mechanical methods developed for protein-ligand scoring be useful for computational alanine scanning? To answer this question, we assembled 15 protein-protein complexes with available crystal structures and sufficient alanine scanning data. In all, the data set contains Delta Delta Gs for 400 single point alanine mutations of these 15 complexes. We show that with only one adjusted parameter the quantum mechanics-based methods outperform both buried accessible surface area and a potential of mean force and compare favorably to a variety of published empirical methods. Finally, we closely examined the outliers in the data set and discuss some of the challenges that arise from this examination.

  9. Myeloperoxidase-mediated protein lysine oxidation generates 2-aminoadipic acid and lysine nitrile in vivo.

    PubMed

    Lin, Hongqiao; Levison, Bruce S; Buffa, Jennifer A; Huang, Ying; Fu, Xiaoming; Wang, Zeneng; Gogonea, Valentin; DiDonato, Joseph A; Hazen, Stanley L

    2017-03-01

    Recent studies reveal 2-aminoadipic acid (2-AAA) is both elevated in subjects at risk for diabetes and mechanistically linked to glucose homeostasis. Prior studies also suggest enrichment of protein-bound 2-AAA as an oxidative post-translational modification of lysyl residues in tissues associated with degenerative diseases of aging. While in vitro studies suggest redox active transition metals or myeloperoxidase (MPO) generated hypochlorous acid (HOCl) may produce protein-bound 2-AAA, the mechanism(s) responsible for generation of 2-AAA during inflammatory diseases are unknown. In initial studies we observed that traditional acid- or base-catalyzed protein hydrolysis methods previously employed to measure tissue 2-AAA can artificially generate protein-bound 2-AAA from an alternative potential lysine oxidative product, lysine nitrile (LysCN). Using a validated protease-based digestion method coupled with stable isotope dilution LC/MS/MS, we now report protein bound 2-AAA and LysCN are both formed by hypochlorous acid (HOCl) and the MPO/H2O2/Cl(-) system of leukocytes. At low molar ratio of oxidant to target protein N(ε)-lysine moiety, 2-AAA is formed via an initial N(ε)-monochloramine intermediate, which ultimately produces the more stable 2-AAA end-product via sequential generation of transient imine and semialdehyde intermediates. At higher oxidant to target protein N(ε)-lysine amine ratios, protein-bound LysCN is formed via initial generation of a lysine N(ε)-dichloramine intermediate. In studies employing MPO knockout mice and an acute inflammation model, we show that both free and protein-bound 2-AAA, and in lower yield, protein-bound LysCN, are formed by MPO in vivo during inflammation. Finally, both 2-AAA and to lesser extent LysCN are shown to be enriched in human aortic atherosclerotic plaque, a tissue known to harbor multiple MPO-catalyzed protein oxidation products. Collectively, these results show that MPO-mediated oxidation of protein lysyl

  10. Basis for the equilibrium constant in the interconversion of l-lysine and l-beta-lysine by lysine 2,3-aminomutase.

    PubMed

    Chen, Dawei; Tanem, Justinn; Frey, Perry A

    2007-02-01

    l-beta-lysine and beta-glutamate are produced by the actions of lysine 2,3-aminomutase and glutamate 2,3-aminomutase, respectively. The pK(a) values have been titrimetrically measured and are for l-beta-lysine: pK(1)=3.25 (carboxyl), pK(2)=9.30 (beta-aminium), and pK(3)=10.5 (epsilon-aminium). For beta-glutamate the values are pK(1)=3.13 (carboxyl), pK(2)=3.73 (carboxyl), and pK(3)=10.1 (beta-aminium). The equilibrium constants for reactions of 2,3-aminomutases favor the beta-isomers. The pH and temperature dependencies of K(eq) have been measured for the reaction of lysine 2,3-aminomutase to determine the basis for preferential formation of beta-lysine. The value of K(eq) (8.5 at 37 degrees C) is independent of pH between pH 6 and pH 11; ruling out differences in pK-values as the basis for the equilibrium constant. The K(eq)-value is temperature-dependent and ranges from 10.9 at 4 degrees C to 6.8 at 65 degrees C. The linear van't Hoff plot shows the reaction to be enthalpy-driven, with DeltaH degrees =-1.4 kcal mol(-1) and DeltaS degrees =-0.25 cal deg(-1) mol(-1). Exothermicity is attributed to the greater strength of the bond C(beta)-N(beta) in l-beta-lysine than C(alpha)-N(alpha) in l-lysine, and this should hold for other amino acids.

  11. The unresolved puzzle why alanine extensions cause disease.

    PubMed

    Winter, Reno; Liebold, Jens; Schwarz, Elisabeth

    2013-08-01

    The prospective increase in life expectancy will be accompanied by a rise in the number of elderly people who suffer from ill health caused by old age. Many diseases caused by aging are protein misfolding diseases. The molecular mechanisms underlying these disorders receive constant scientific interest. In addition to old age, mutations also cause congenital protein misfolding disorders. Chorea Huntington, one of the most well-known examples, is caused by triplet extensions that can lead to more than 100 glutamines in the N-terminal region of huntingtin, accompanied by huntingtin aggregation. So far, nine disease-associated triplet extensions have also been described for alanine codons. The extensions lead primarily to skeletal malformations. Eight of these proteins represent transcription factors, while the nuclear poly-adenylate binding protein 1, PABPN1, is an RNA binding protein. Additional alanines in PABPN1 lead to the disease oculopharyngeal muscular dystrophy (OPMD). The alanine extension affects the N-terminal domain of the protein, which has been shown to lack tertiary contacts. Biochemical analyses of the N-terminal domain revealed an alanine-dependent fibril formation. However, fibril formation of full-length protein did not recapitulate the findings of the N-terminal domain. Fibril formation of intact PABPN1 was independent of the alanine segment, and the fibrils displayed biochemical properties that were completely different from those of the N-terminal domain. Although intranuclear inclusions have been shown to represent the histochemical hallmark of OPMD, their role in pathogenesis is currently unclear. Several cell culture and animal models have been generated to study the molecular processes involved in OPMD. These studies revealed a number of promising future therapeutic strategies that could one day improve the quality of life for the patients.

  12. METHANOGENS WITH PSEUDOMUREIN USE DIAMINOPIMELATE AMINOTRANSFERASE IN LYSINE BIOSYNTHESIS

    PubMed Central

    Graham, David E.; Huse, Holly K.

    2008-01-01

    Methanothermobacter thermautotrophicus uses lysine for both protein synthesis and cross-linking pseudomurein in its cell wall. A diaminopimelate aminotransferase enzyme from this methanogen (MTH0052) converts tetrahydrodipicolinate to L,L-diaminopimelate, a lysine precursor. This gene complemented an Escherichia coli diaminopimelate auxotrophy, and the purified protein catalyzed the transamination of diaminopimelate to tetrahydrodipicolinate. Phylogenetic analysis indicated this gene was recruited from anaerobic Gram-positive bacteria. These results expand the family of diaminopimelate aminotransferases to a diverse set of plant, bacterial and archaeal homologs. In contrast marine methanogens from the Methanococcales, which lack pseudomurein, appear to use a different diaminopimelate pathway for lysine biosynthesis. PMID:18371309

  13. Conformation of Lysine Vasopressin: A Comparison with Oxytocin

    PubMed Central

    Walter, Roderich; Glickson, J. D.; Schwartz, I. L.; Havran, R. T.; Meienhofer, Johannes; Urry, D. W.

    1972-01-01

    Starting with assignments of proton nuclear magnetic resonance previously made for oxytocin in deuterated dimethylsulfoxide at 220 MHz, we have assigned resonances for the mammalian antidiuretic hormone, lysine vasopressin. The results demonstrate that spectral assignments of neurohypophyseal hormones and their congeners can, within certain limits, be derived from each other. Comparison of the spectra of lysine vasopressin and oxytocin suggests that the gross backbone conformations of their 20-membered ring components are for the most part similar in deuterated dimethylsulfoxide, whereas the C-terminal acyclic amino-acid sequence of lysine vasopressin is more flexible than that of oxytocin. PMID:4505670

  14. Mutants of Saccharomycopsis lipolytica defective in lysine catabolism.

    PubMed Central

    Gaillardin, C; Fournier, P; Sylvestre, G; Heslot, H

    1976-01-01

    Wild-type strains of Saccharomycopsis lipolytica are able to use lysine as a carbon or a nitrogen source, but not as a unique source for both. Mutants were selected that could not use lysine either as a nitrogen or as a carbon source. Some of them, however, utilized N-6-acetyllysine or 5-aminovaleric acid. Many of the mutants appeared to be blocked in both utilizations, suggesting a unique pathway for lysine degradation (either as a carbon or as a nitrogen source). Genetic characterization of these mutants was achieved by complementation and recombination tests. PMID:1245461

  15. PKC-Dependent GlyT1 Ubiquitination Occurs Independent of Phosphorylation: Inespecificity in Lysine Selection for Ubiquitination

    PubMed Central

    Barrera, Susana P.; Castrejon-Tellez, Vicente; Trinidad, Margarita; Robles-Escajeda, Elisa; Vargas-Medrano, Javier; Varela-Ramirez, Armando; Miranda, Manuel

    2015-01-01

    Neurotransmitter transporter ubiquitination is emerging as the main mechanism for endocytosis and sorting of cargo into lysosomes. In this study, we demonstrate PKC-dependent ubiquitination of three different isoforms of the glycine transporter 1 (GlyT1). Incubation of cells expressing transporter with the PKC activator phorbol ester induced a dramatic, time-dependent increase in GlyT1 ubiquitination, followed by accumulation of GlyT1 in EEA1 positive early endosomes. This occurred via a mechanism that was abolished by inhibition of PKC. GlyT1 endocytosis was confirmed in both retinal sections and primary cultures of mouse amacrine neurons. Replacement of only all lysines in the N-and C-termini to arginines prevented ubiquitination and endocytosis, displaying redundancy in the mechanism of ubiquitination. Interestingly, a 40–50% reduction in glycine uptake was detected in phorbol-ester stimulated cells expressing the WT-GlyT1, whereas no significant change was for the mutant protein, demonstrating that endocytosis participates in the reduction of uptake. Consistent with previous findings for the dopamine transporter DAT, ubiquitination of GlyT1 tails functions as sorting signal to deliver transporter into the lysosome and removal of ubiquitination sites dramatically attenuated the rate of GlyT1 degradation. Finally, we showed for the first time that PKC-dependent GlyT1 phosphorylation was not affected by removal of ubiquitination sites, suggesting separate PKC-dependent signaling events for these posttranslational modifications. PMID:26418248

  16. Biotinylation of lysine method identifies acetylated histone H3 lysine 79 in Saccharomyces cerevisiae as a substrate for Sir2.

    PubMed

    Bheda, Poonam; Swatkoski, Stephen; Fiedler, Katherine L; Boeke, Jef D; Cotter, Robert J; Wolberger, Cynthia

    2012-04-17

    Although the biological roles of many members of the sirtuin family of lysine deacetylases have been well characterized, a broader understanding of their role in biology is limited by the challenges in identifying new substrates. We present here an in vitro method that combines biotinylation and mass spectrometry (MS) to identify substrates deacetylated by sirtuins. The method permits labeling of deacetylated residues with amine-reactive biotin on the ε-nitrogen of lysine. The biotin can be utilized to purify the substrate and identify the deacetylated lysine by MS. The biotinyl-lysine method was used to compare deacetylation of chemically acetylated histones by the yeast sirtuins, Sir2 and Hst2. Intriguingly, Sir2 preferentially deacetylates histone H3 lysine 79 as compared to Hst2. Although acetylation of K79 was not previously reported in Saccharomyces cerevisiae, we demonstrate that a minor population of this residue is indeed acetylated in vivo and show that Sir2, and not Hst2, regulates the acetylation state of H3 lysine 79. The in vitro biotinyl-lysine method combined with chemical acetylation made it possible to identify this previously unknown, low-abundance histone acetyl modification in vivo. This method has further potential to identify novel sirtuin deacetylation substrates in whole cell extracts, enabling large-scale screens for new deacetylase substrates.

  17. Crystal structures of d-alanine-d-alanine ligase from Xanthomonas oryzae pv. oryzae alone and in complex with nucleotides.

    PubMed

    Doan, Thanh Thi Ngoc; Kim, Jin-Kwang; Ngo, Ho-Phuong-Thuy; Tran, Huyen-Thi; Cha, Sun-Shin; Min Chung, Kyung; Huynh, Kim-Hung; Ahn, Yeh-Jin; Kang, Lin-Woo

    2014-03-01

    D-Alanine-D-alanine ligase (DDL) catalyzes the biosynthesis of d-alanyl-d-alanine, an essential bacterial peptidoglycan precursor, and is an important drug target for the development of antibacterials. We determined four different crystal structures of DDL from Xanthomonas oryzae pv. oryzae (Xoo) causing Bacteria Blight (BB), which include apo, ADP-bound, ATP-bound, and AMPPNP-bound structures at the resolution between 2.3 and 2.0 Å. Similarly with other DDLs, the active site of XoDDL is formed by three loops from three domains at the center of enzyme. Compared with d-alanyl-d-alanine and ATP-bound TtDDL structure, the γ-phosphate of ATP in XoDDL structure was shifted outside toward solution. We swapped the ω-loop (loop3) of XoDDL with those of Escherichia coli and Helicobacter pylori DDLs, and measured the enzymatic kinetics of wild-type XoDDL and two mutant XoDDLs with the swapped ω-loops. Results showed that the direct interactions between ω-loop and other two loops are essential for the active ATP conformation for D-ala-phosphate formation.

  18. Thinking outside the synapse: glycine at extrasynaptic NMDA receptors.

    PubMed

    Gray, John A; Nicoll, Roger A

    2012-08-03

    In this issue, Papouin et al. show that glycine is the endogenous coagonist for extrasynaptic NMDA receptors (NMDARs), unlike at synapses where the coagonist is d-serine. By enzymatically degrading endogenous glycine, they begin to address the enigmatic physiological and pathological roles for extrasynaptic NMDARs.

  19. Molecular dynamics simulation of aqueous solutions of glycine betaine

    NASA Astrophysics Data System (ADS)

    Civera, Monica; Fornili, Arianna; Sironi, Maurizio; Fornili, Sandro L.

    2003-01-01

    Molecular dynamics simulation is used to investigate hydration properties of glycine betaine in a large range of solute concentrations. Statistical analyses of the system trajectories evidence microscopic details suggesting an interpretation of experimental results recently obtained for aqueous solutions of trimethylamine- N-oxide, a bioprotectant closely related to glycine betaine.

  20. Glycine betaine as a direct substrate for methanogens (Methanococcoides spp.).

    PubMed

    Watkins, Andrew J; Roussel, Erwan G; Parkes, R John; Sass, Henrik

    2014-01-01

    Nine marine methanogenic Methanococcoides strains, including the type strains of Methanococcoides methylutens, M. burtonii, and M. alaskense, were tested for the utilization of N-methylated glycines. Three strains (NM1, PM2, and MKM1) used glycine betaine (N,N,N-trimethylglycine) as a substrate for methanogenesis, partially demethylating it to N,N-dimethylglycine, whereas none of the strains used N,N-dimethylglycine or sarcosine (N-methylglycine). Growth rates and growth yields per mole of substrate with glycine betaine (3.96 g [dry weight] per mol) were similar to those with trimethylamine (4.11 g [dry weight] per mol). However, as glycine betaine is only partially demethylated, the yield per methyl group was significantly higher than with trimethylamine. If glycine betaine and trimethylamine are provided together, trimethylamine is demethylated to dimethyl- and methylamine with limited glycine betaine utilization. After trimethylamine is depleted, dimethylamine and glycine betaine are consumed rapidly, before methylamine. Glycine betaine extends the range of substrates that can be directly utilized by some methanogens, allowing them to gain energy from the substrate without the need for syntrophic partners.

  1. Characterization of seed storage proteins of several perennial glycine species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial Glycine species, distant relatives of soybean, have been recognized as a potential source of new genetic diversity for soybean improvement. The subgenus Glycine includes around 30 perennial species, which are well adapted to drought conditions and possess resistance to a number of soybean ...

  2. New soybean accessions evaluated for reaction to Heterodera glycines populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean Cyst Nematode (SCN, Heterodera glycines Ichinohe) is a serious pest of soybean [Glycine max (L.) Merr.] in the USA and worldwide. Annual yield losses in the USA are estimated to be over $1 billion. These losses have remained stable with the use of resistant cultivars but over time nematode...

  3. New soybean accessions identified with resistance to Heterodera glycines populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean Cyst Nematode (SCN, Heterodera glycines Ichinohe) is a serious root-parasite of soybean [Glycine max (L.) Merr.], in USA and worldwide. Annual yield losses in USA are estimated to be nearly $1 billion. These losses have remained stable at current levels with the use of resistant cultivars bu...

  4. Population genetic structure of the soybean aphid, Aphis glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soybean aphid (Aphis glycines Matsumura) is an invasive pest of cultivated soybean [Glycine max (L.)] in North America. After the initial invasion in 2000, the aphid has quickly spread across most of the U.S. and Canada, suggesting large scale dispersals and rapid adaptations to new environment...

  5. Kinetic mechanism and inhibition of Mycobacterium tuberculosis D-alanine:D-alanine ligase by the antibiotic D-cycloserine.

    PubMed

    Prosser, Gareth A; de Carvalho, Luiz Pedro S

    2013-02-01

    D-cycloserine (DCS) is an antibiotic that is currently used in second-line treatment of tuberculosis. DCS is a structural analogue of D-alanine, and targets two enzymes involved in the cytosolic stages of peptidoglycan synthesis: alanine racemase (Alr) and D-alanine:D-alanine ligase (Ddl). The mechanisms of inhibition of DCS have been well-assessed using Alr and Ddl enzymes from various bacterial species, but little is known regarding the interactions of DCS with the mycobacterial orthologues of these enzymes. We have over-expressed and purified recombinant Mycobacterium tuberculosis Ddl (MtDdl; Rv2981c), and report a kinetic examination of the enzyme with both its native substrate and DCS. MtDdl is activated by K(+), follows an ordered ter ter mechanism and displays distinct affinities for D-Ala at each D-Ala binding site (K(m,D-Ala1) = 0.075 mm, K(m,D-Ala2) = 3.6 mm). ATP is the first substrate to bind and is necessary for subsequent binding of D-alanine or DCS. The pH dependence of MtDdl kinetic parameters indicate that general base chemistry is involved in the catalytic step. DCS was found to competitively inhibit D-Ala binding at both MtDdl D-Ala sites with equal affinity (K(i,DCS1) = 14 μm, K(i,DCS2) = 25 μm); however, each enzyme active site can only accommodate a single DCS molecule at a given time. The pH dependence of K(i,DCS2) revealed a loss of DCS binding affinity at high pH (pK(a) = 7.5), suggesting that DCS binds optimally in the zwitterionic form. The results of this study may assist in the design and development of novel Ddl-specific inhibitors for use as anti-mycobacterial agents.

  6. Structure of the Mycobacterium tuberculosis D-Alanine:D-Alanine Ligase, a Target of the Antituberculosis Drug D-Cycloserine

    SciTech Connect

    Bruning, John B.; Murillo, Ana C.; Chacon, Ofelia; Barletta, Raúl G.; Sacchettini, James C.

    2011-09-28

    D-Alanine:D-alanine ligase (EC 6.3.2.4; Ddl) catalyzes the ATP-driven ligation of two D-alanine (D-Ala) molecules to form the D-alanyl:D-alanine dipeptide. This molecule is a key building block in peptidoglycan biosynthesis, making Ddl an attractive target for drug development. D-Cycloserine (DCS), an analog of D-Ala and a prototype Ddl inhibitor, has shown promise for the treatment of tuberculosis. Here, we report the crystal structure of Mycobacterium tuberculosis Ddl at a resolution of 2.1 {angstrom}. This structure indicates that Ddl is a dimer and consists of three discrete domains; the ligand binding cavity is at the intersection of all three domains and conjoined by several loop regions. The M. tuberculosis apo Ddl structure shows a novel conformation that has not yet been observed in Ddl enzymes from other species. The nucleotide and D-alanine binding pockets are flexible, requiring significant structural rearrangement of the bordering regions for entry and binding of both ATP and D-Ala molecules. Solution affinity and kinetic studies showed that DCS interacts with Ddl in a manner similar to that observed for D-Ala. Each ligand binds to two binding sites that have significant differences in affinity, with the first binding site exhibiting high affinity. DCS inhibits the enzyme, with a 50% inhibitory concentration (IC{sub 50}) of 0.37 mM under standard assay conditions, implicating a preferential and weak inhibition at the second, lower-affinity binding site. Moreover, DCS binding is tighter at higher ATP concentrations. The crystal structure illustrates potential drugable sites that may result in the development of more-effective Ddl inhibitors.

  7. Glycine toxicity and unexpected intra-operative death.

    PubMed

    Byard, R W; Harrison, R; Wells, R; Gilbert, J D

    2001-09-01

    A rare complication of the use of glycine irrigation fluid during prostatic surgery in a 69-year-old man is described. Following cystolithopexy and transurethral resection of the prostate for benign prostatomegaly, abdominal distension developed with increasing ventilatory pressures. Despite retroperitoneal fluid evacuation at subsequent urgent laparotomy, cardiac arrest occurred that was not amenable to resuscitation. At autopsy a traumatic defect in the posterior bladder wall filled with calculus debris was confirmed that did not communicate with the peritoneal cavity. Hyponatremia with markedly elevated levels of blood, urine, and body fluid glycine were demonstrated. Death was, therefore, attributed to glycine toxicity following tracking of glycine through a surgical defect in the posterior bladder wall. Careful dissection of surgical sites is required in such cases to demonstrate any additional trauma that may be associated with the fatal episode. Analysis of body fluids for glycine and electrolytes is also necessary to assist in the determination of possible mechanisms of death.

  8. Cytochrome c catalyzes the in vitro synthesis of arachidonoyl glycine

    SciTech Connect

    McCue, Jeffrey M.; Driscoll, William J.; Mueller, Gregory P.

    2008-01-11

    Long chain fatty acyl glycines are an emerging class of biologically active molecules that occur naturally and produce a wide array of physiological effects. Their biosynthetic pathway, however, remains unknown. Here we report that cytochrome c catalyzes the synthesis of N-arachidonoyl glycine (NAGly) from arachidonoyl coenzyme A and glycine in the presence of hydrogen peroxide. The identity of the NAGly product was verified by isotope labeling and mass analysis. Other heme-containing proteins, hemoglobin and myoglobin, were considerably less effective in generating arachidonoyl glycine as compared to cytochrome c. The reaction catalyzed by cytochrome c in vitro points to its potential role in the formation of NAGly and other long chain fatty acyl glycines in vivo.

  9. Arachidonic acid inhibits glycine transport in cultured glial cells.

    PubMed Central

    Zafra, F; Alcantara, R; Gomeza, J; Aragon, C; Gimenez, C

    1990-01-01

    The effects of arachidonic acid on glycine uptake, exchange and efflux in C6 glioma cells were investigated. Arachidonic acid produced a dose-dependent inhibition of high-affinity glycine uptake. This effect was not due to a simple detergent-like action on membranes, as the inhibition of glycine transport was most pronounced with cis-unsaturated long-chain fatty acids, whereas saturated and trans-unsaturated fatty acids had relatively little or no effect. Endogenous unsaturated non-esterified fatty acids may exert a similar inhibitory effect on the transport of glycine. The mechanism for this inhibitory effect has been examined in a plasma membrane vesicle preparation derived from C6 cells, which avoids metabolic or compartmentation interferences. The results suggest that part of the selective inhibition of glycine transport by arachidonic acid could be due to the effects of the arachidonic acid on the lipid domain surrounding the carrier. PMID:2121132

  10. Data detailing the platelet acetyl-lysine proteome.

    PubMed

    Aslan, Joseph E; David, Larry L; McCarty, Owen J T

    2015-12-01

    Here we detail proteomics data that describe the acetyl-lysine proteome of blood platelets (Aslan et al., 2015 [1]). An affinity purification - mass spectrometry (AP-MS) approach was used to identify proteins modified by Nε-lysine acetylation in quiescent, washed human platelets. The data provide insights into potential regulatory mechanisms of platelet function mediated by protein lysine acetylation. Additionally, as platelets are anucleate and lack histone proteins, they offer a unique and valuable system to study the regulation of cytosolic proteins by lysine acetylation. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (Vizcaino et al., 2014 [2]) via with PRIDE partner repository with the dataset identifier PXD002332.

  11. 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.

  12. Glycine phases formed from frozen aqueous solutions: Revisited

    NASA Astrophysics Data System (ADS)

    Surovtsev, N. V.; Adichtchev, S. V.; Malinovsky, V. K.; Ogienko, A. G.; Drebushchak, V. A.; Manakov, A. Yu.; Ancharov, A. I.; Yunoshev, A. S.; Boldyreva, E. V.

    2012-08-01

    Glycine phases formed when aqueous solutions were frozen and subsequently heated under different conditions were studied by Raman scattering, x-ray diffraction, and differential scanning calorimetry (DSC) techniques. Crystallization of ice Ih was observed in all the cases. On cooling at the rates of 0.5 K/min and 5 K/min, glassy glycine was formed as an intermediate phase which lived about 1 min or less only, and then transformed into β-polymorph of glycine. Quench cooling of glycine solutions (15% w/w) in liquid nitrogen resulted in the formation of a mixture of crystalline water ice Ih and a glassy glycine, which could be preserved at cryogenic temperatures (80 K) for an indefinitely long time. This mixture remained also quite stable for some time after heating above the cryogenic temperature. Subsequent heating under various conditions resulted in the transformation of the glycine glass into an unknown crystalline phase (glycine "X-phase") at 209-216 K, which at 218-226 K transformed into β-polymorph of glycine. The "X-phase" was characterized by Raman spectroscopy; it could be obtained in noticeable amounts using a special preparation technique and tentatively characterized by x-ray powder diffraction (P2, a = 6.648 Å, b = 25.867 Å, c = 5.610 Å, β = 113.12°); the formation of "X-phase" from the glycine glassy phase and its transformation into β-polymorph were followed by DSC. Raman scattering technique with its power for unambiguous identification of the crystalline and glassy polymorphs without limitation on the crystallite size helped us to follow the phase transformations during quenching, heating, and annealing. The experimental findings are considered in relation to the problem of control of glycine polymorphism on crystallization.

  13. Arginine and Lysine Transporters Are Essential for Trypanosoma brucei

    PubMed Central

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

    2017-01-01

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

  14. Antitumor effect of lysine-isopeptides

    PubMed Central

    Szende, B; Szökán, Gy; Tyihá, E; Pál, K; Gáborjányi, R; Almás, M; Khlafulla, A R

    2002-01-01

    Isopeptides (ε-peptides) of lysine, with a given Mw and low polydispersity (10–400 units), were synthesized to study the relationship between their chemical structure and biological effect. The designed compounds were of high purity, low polydispersity and high stereochemical purity. The effect of the compounds was tested on a human erythroleukemia cell line (K-562) and on four transplantable mouse tumors (L1210 lymphoid leukemia, P38 macrophage derived tumor, Ehrlich ascites carcinoma, Lewis lung tumor /LLT/). In case of the L1210 and P388 tumors and the Ehrlich carcinoma, survival of the animals was used as an indicator of the effect. In case of the Lewis lung tumor, the number and size of metastases in the lung and/or liver of treated and untreated mice were used as indicators. The polymers of polymerisation degree 80–120 (Mw 10.2–15.4 KD) showed the strongest antiproliferative effect both on K562 cells and the tumors growing in vivo. This effect was manifest with a significantly higher survival rate as compared to the control (L1210, P38, Ehrlich ascites), furthermore, by a decrease in the number and size of liver and lung metastases (LLT). PMID:12076354

  15. Water reuse in the l-lysine fermentation process

    SciTech Connect

    Hsiao, T.Y.; Glatz, C.E.

    1996-02-05

    L-Lysine is produced commercially by fermentation. As is typical for fermentation processes, a large amount of liquid waste is generated. To minimize the waste, which is mostly the broth effluent from the cation exchange column used for l-lysine recovery, the authors investigated a strategy of recycling a large fraction of this broth effluent to the subsequent fermentation. This was done on a lab-scale process with Corynebacterium glutamicum ATCC 21253 as the l-lysine-producing organisms. Broth effluent from a fermentation in a defined medium was able to replace 75% of the water for the subsequent batch; this recycle ratio was maintained for 3 sequential batches without affecting cell mass and l-lysine production. Broth effluent was recycled at 50% recycle ratio in a fermentation in a complex medium containing beet molasses. The first recycle batch had an 8% lower final l-lysine level, but 8% higher maximum cell mass. In addition to reducing the volume of liquid waste, this recycle strategy has the additional advantage of utilizing the ammonium desorbed from the ion-exchange column as a nitrogen source in the recycle fermentation. The major problem of recycling the effluent from the complex medium was in the cation-exchange operation, where column capacity was 17% lower for the recycle batch. The loss of column capacity probably results from the buildup of cations competing with l-lysine for binding.

  16. Biofortification of rice with lysine using endogenous histones.

    PubMed

    Wong, H W; Liu, Q; Sun, S S M

    2015-02-01

    Rice is the most consumed cereal grain in the world, but deficient in the essential amino acid lysine. Therefore, people in developing countries with limited food diversity who rely on rice as their major food source may suffer from malnutrition. Biofortification of stable crops by genetic engineering provides a fast and sustainable method to solve this problem. In this study, two endogenous rice lysine-rich histone proteins, RLRH1 and RLRH2, were over-expressed in rice seeds to achieve lysine biofortification. Their protein sequences passed an allergic sequence-based homology test. Their accumulations in rice seeds were raised to a moderate level by the use of a modified rice glutelin 1 promoter with lowered expression strength to avoid the occurrence of physiological abnormalities like unfolded protein response. The expressed proteins were further targeted to protein storage vacuoles for stable storage using a glutelin 1 signal peptide. The lysine content in the transgenic rice seeds was enhanced by up to 35 %, while other essential amino acids remained balanced, meeting the nutritional standards of the World Health Organization. No obvious unfolded protein response was detected. Different degrees of chalkiness, however, were detected in the transgenic seeds, and were positively correlated with both the levels of accumulated protein and lysine enhancement. This study offered a solution to the lysine deficiency in rice, while at the same time addressing concerns about food safety and physiological abnormalities in biofortified crops.

  17. Differential agonist sensitivity of glycine receptor alpha2 subunit splice variants.

    PubMed

    Miller, Paul S; Harvey, Robert J; Smart, Trevor G

    2004-09-01

    1. The glycine receptor (GlyR) alpha2A and alpha2B splice variants differ by a dual, adjacent amino acid substitution from alpha2A(V58,T59) to alpha2B(I58,A59) in the N-terminal extracellular domain. 2. Comparing the effects of the GlyR agonists, glycine, beta-alanine and taurine, on the GlyR alpha2 isoforms, revealed a significant increase in potency for all three agonists at the alpha2B variant. 3. The sensitivities of the splice variants to the competitive antagonist, strychnine, and to the biphasic modulator Zn(2+), were comparable. In contrast, the allosteric inhibitor picrotoxin was more potent on GlyR alpha2A compared to GlyR alpha2B receptors. 4. Coexpression of alpha2A or alpha2B subunits with the GlyR beta subunit revealed that the higher agonist potencies observed with the alpha2B homomer were retained for the alpha2Bbeta heteromer. 5. The identical sensitivity to strychnine combined with a reduction in the maximum current induced by the partial agonist taurine at the GlyR alpha2A homomer, suggested that the changed sensitivity to agonists is in accordance with a modulation of agonist efficacy rather than agonist affinity. 6. An effect on agonist efficacy was also supported by using a structural model of the GlyR, localising the region of splice variation to the proposed docking region between GlyR loop 2 and the TM2-3 loop, an area associated with channel activation. 7. The existence of a spasmodic mouse phenotype linked to a GlyR alpha1(A52S) mutation, the equivalent position to the source of the alpha2 splice variation, raises the possibility that the GlyR alpha2 splice variants may be responsible for distinct roles in neuronal function.

  18. AF-2 activity and recruitment of steroid receptor coactivator 1 to the estrogen receptor depend on a lysine residue conserved in nuclear receptors.

    PubMed Central

    Henttu, P M; Kalkhoven, E; Parker, M G

    1997-01-01

    Hormone-dependent transcriptional activation by nuclear receptors depends on the presence of a conserved C-terminal amphipathic alpha-helix (helix 12) in the ligand-binding domain. Here we show that a lysine residue, which is conserved in most nuclear receptors in the predicted helix 3, is also required for estrogen-dependent transactivation. The replacement of lysine 366 with alanine appreciably reduced activation function 2 (AF-2) activity without affecting steroid- or DNA-binding activity in the mouse estrogen receptor. The mutation dramatically reduced the ability of the receptor to bind steroid receptor coactivator 1 (SRC-1) but had no effect on receptor-interacting protein 140 (RIP-140) binding, indicating that while their sites of interaction overlap, they are not entirely consistent and in keeping with the proposal that the recruitment of coactivators, such as SRC-1, is required for AF-2 activity. Although the function of RIP-140 remains to be established, RIP-140 appears to be capable of recruiting the basal transcription machinery, since overexpression of the protein markedly increased the transcriptional activity of the mutant receptor. Since the lysine residue is conserved, we propose that it is required, together with residues in helix 12, to form the surface by which members of the nuclear receptor family interact with coactivators. PMID:9121431

  19. Effect of Chitosan on Membrane Permeability of Suspension-Cultured Glycine max and Phaseolus vulgaris Cells 1

    PubMed Central

    Young, David H.; Köhle, Harald; Kauss, Heinrich

    1982-01-01

    Treatment of suspension-cultured Glycine max cv Harosoy 63 cells with soluble chitosan (20-500 micrograms per milliliter) increased membrane permeability as shown by leakage of electrolytes, protein, and UV absorbing material. Severe damage to the cell membrane by chitosan (100 and 500 μg/ml) was also indicated by reduced staining with fluorescein diacetate and the leakage of fluorescein from preloaded cells. Other basic polymers (poly-l-lysine, histone, DEAE-dextran, protamine sulfate, and glycol chitosan) also increased permeability, whereas the basic monomers l-lysine and d-glucosamine, and acidic or neutral polymers were not active. Chitosan-induced leakage was inhibited by divalent cations, the order of effectiveness being Ba2+ > Ca2+ > Sr2+ > Mg2+. Na polygalacturonate and Na poly-l-aspartate also reduced polycation-induced leakage, probably by formation of polycation-polyanion complexes. A chitosan-polygalacturonate complex precipitated on mixing solutions of the two polymers containing approximately equal numbers of galacturonate and glucosamine residues, but not with either polymer in excess. A similar concentration-dependent precipitation of chitosan by Na poly-l-aspartate was found. Leakage from Phaseolus vulgaris cv Grandessa cells was also induced by chitosan, and was inhibited by Ca2+ and Na polygalacturonate. PMID:16662696

  20. Free amino acid content and metabolic activities of setting and aborting soybean ovaries. [Glycine max (L. ) Merr

    SciTech Connect

    Ghiasi, H.; Paech, C.; Dybing, C.D.

    1987-09-01

    Fruits of soybean (glycine max (L.) Merr.) that are destined to abscise shortly after anthesis grow more slowly than fruits that will be retained. In this work, amino acid composition, protein metabolism, and nucleic acid metabolism were studied in setting and abscising soybean ovaries from anthesis to 6 days after anthesis. Principal free amino acids were asparagine, aspartic acid, glutamic acid, serine, and glutamine. Percent aspartate and glutamate declined as the ovaries grew, with aspartate declining more in abscising and glutamate more in setting ovaries. Percent glutamate was positively correlated to percent abscission throughout the period. Proline, serine, and leucine were positively correlated to abscission from 0 to 2 days after anthesis, whereas significant negative correlations were observed at these ages for ethanolamine and arginine. /sup 75/Se fed as selenate and /sup 14/C fed as sucrose, glycine, and alanine were readily incorporated into soluble and insoluble proteins in a 24-hour in vitro incubation. Radioactivity of total proteins, expressed on a per-ovary basis, was negatively correlated with percent abscission and positively correlated with ovary weight. (/sup 14/C)Glutamine and serine followed the opposite pattern, with greater protein labeling in abscising than in setting ovaries. When data were expressed as disintegrations per minute per milligram ovary fresh weight, protein labeling from alanine was seen to be significantly greater in abscising ovaries at anthesis and throughout the sampling period. Nucleic acid labeling from uridine was highly correlated to ovary weight; labeling from thymidine was greater in setting than abscising ovaries at anthesis and in abscising ovaries at later stages of development.

  1. Clinical applications of alanine/electron spin resonance dosimetry.

    PubMed

    Baffa, Oswaldo; Kinoshita, Angela

    2014-05-01

    This paper discusses the clinical applications of electron spin resonance (ESR) dosimetry focusing on the ESR/alanine system. A review of few past studies in this area is presented offering a critical overview of the challenges and opportunities for extending this system into clinical applications. Alanine/ESR dosimetry fulfills many of the required properties for several clinical applications such as water-equivalent composition, independence of the sensitivity for the energy range used in therapy and high precision. Improvements in sensitivity and the development of minidosimeters coupled with the use of a spectrometer of higher microwave frequency expanded the possibilities for clinical applications to the new modalities of radiotherapy (intensity-modulated radiation therapy and radiosurgery) and to the detection of low doses such as those present in some radiological image procedures.

  2. Physiological hypercortisolemia increases proteolysis, glutamine, and alanine production

    SciTech Connect

    Darmaun, D.; Matthews, D.E.; Bier, D.M. Cornell Univ. Medical College, New York, NY )

    1988-09-01

    Physiological elevations of plasma cortisol levels, as are encountered in stress and severe trauma, were produced in six normal subjects by infusing them with hydrocortisone for 64 h. Amino acid kinetics were measured in the postabsorptive state using three 4-h infusions of L-(1-{sup 13}C)leucine, L-phenyl({sup 2}H{sub 5})phenylalanine, L-(2-{sup 15}N)glutamine, and L-(1-{sup 13}C)alanine tracers (1) before, (2) at 12 h, and (3) at 60 h of cortisol infusion. Before and throughout the study, the subjects ate a normal diet of adequate protein and energy intake. The cortisol infusion raised plasma cortisol levels significantly from 10 {plus minus} 1 to 32 {plus minus} 4 {mu}g/dl, leucine flux from 83 {plus minus} 3 to 97 {plus minus} 3 {mu}mol{center dot}kg{sup {minus}1}{center dot}h{sup {minus}1}, and phenylalanine flux from 34 {plus minus} 1 to 39 {plus minus} 1 (SE) {mu}mol{center dot}kg{sup {minus}1}{center dot}h{sup {minus}1} after 12 h of cortisol infusion. These increases were maintained until the cortisol infusion was terminated. These nearly identical 15% increases in two different essential amino acid appearance rates are reflective of increased whole body protein breakdown. Glutamine flux rose by 12 h of cortisol infusion and remained elevated at the same level at 64 h. The increase in flux was primarily due to a 55% increase in glutamine de novo synthesis. Alanine flux increased with acute hypercortisolemia and increased further at 60 h of cortisol infusion, a result primarily of increased alanine de novo synthesis. Insulin, alanine, and lactate plasma levels responded similarly with significant rises between the acute and chronic periods of cortisol infusion. Thus hypercortisolemia increases both protein breakdown and the turnover of important nonessential amino acids for periods of up to 64 h.

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

    PubMed

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

    2017-02-20

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

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

    SciTech Connect

    Dwyer, B.P. )

    1991-04-23

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

  5. Quantum chemical calculations of glycine glutaric acid

    NASA Astrophysics Data System (ADS)

    Arioǧlu, ćaǧla; Tamer, Ömer; Avci, Davut; Atalay, Yusuf

    2017-02-01

    Density functional theory (DFT) calculations of glycine glutaric acid were performed by using B3LYP levels with 6-311++G(d,p) basis set. The theoretical structural parameters such as bond lengths and bond angles are in a good agreement with the experimental values of the title compound. HOMO and LUMO energies were calculated, and the obtained energy gap shows that charge transfer occurs in the title compound. Vibrational frequencies were calculated and compare with experimental ones. 3D molecular surfaces of the title compound were simulated using the same level and basis set. Finally, the 13C and 1H NMR chemical shift values were calculated by the application of the gauge independent atomic orbital (GIAO) method.

  6. Identification of dietary alanine toxicity and trafficking dysfunction in a Drosophila model of hereditary sensory and autonomic neuropathy type 1.

    PubMed

    Oswald, Matthew C W; West, Ryan J H; Lloyd-Evans, Emyr; Sweeney, Sean T

    2015-12-15

    Hereditary sensory and autonomic neuropathy type 1 (HSAN1) is characterized by a loss of distal peripheral sensory and motorneuronal function, neuropathic pain and tissue necrosis. The most common cause of HSAN1 is due to dominant mutations in serine palmitoyl-transferase subunit 1 (SPT1). SPT catalyses the condensation of serine with palmitoyl-CoA, the initial step in sphingolipid biogenesis. Identified mutations in SPT1 are known to both reduce sphingolipid synthesis and generate catalytic promiscuity, incorporating alanine or glycine into the precursor sphingolipid to generate a deoxysphingoid base (DSB). Why either loss of function in SPT1, or generation of DSBs should generate deficits in distal sensory function remains unclear. To address these questions, we generated a Drosophila model of HSAN1. Expression of dSpt1 bearing a disease-related mutation induced morphological deficits in synapse growth at the larval neuromuscular junction consistent with a dominant-negative action. Expression of mutant dSpt1 globally was found to be mildly toxic, but was completely toxic when the diet was supplemented with alanine, when DSBs were observed in abundance. Expression of mutant dSpt1 in sensory neurons generated developmental deficits in dendritic arborization with concomitant sensory deficits. A membrane trafficking defect was observed in soma of sensory neurons expressing mutant dSpt1, consistent with endoplasmic reticulum (ER) to Golgi block. We found that we could rescue sensory function in neurons expressing mutant dSpt1 by co-expressing an effector of ER-Golgi function, Rab1 suggesting compromised ER function in HSAN1 affected dendritic neurons. Our Drosophila model identifies a novel strategy to explore the pathological mechanisms of HSAN1.

  7. The natural non-protein amino acid N-β-methylamino-L-alanine (BMAA) is incorporated into protein during synthesis.

    PubMed

    Glover, W Broc; Mash, Deborah C; Murch, Susan J

    2014-11-01

    N-β-methylamino-L-alanine (BMAA) is an amino acid produced by cyanobacteria and accumulated through trophic levels in the environment and natural food webs. Human exposure to BMAA has been linked to progressive neurodegenerative diseases, potentially due to incorporation of BMAA into protein. The insertion of BMAA and other non-protein amino acids into proteins may trigger protein misfunction, misfolding and/or aggregation. However, the specific mechanism by which BMAA is associated with proteins remained unidentified. Such studies are challenging because of the complexity of biological systems and samples. A cell-free in vitro protein synthesis system offers an excellent approach for investigation of changing amino acid composition in protein. In this study, we report that BMAA incorporates into protein as an error in synthesis when a template DNA sequence is used. Bicinchoninic acid assay of total protein synthesis determined that BMAA effectively substituted for alanine and serine in protein product. LC-MS/MS confirmed that BMAA was selectively inserted into proteins in place of other amino acids, but isomers N-(2-aminoethyl)glycine (AEG) and 2,4-diaminobutyric acid (DAB) did not share this characteristic. Incorporation of BMAA into proteins was significantly higher when genomic DNA from post-mortem brain was the template. About half of BMAA in the synthetic proteins was released with denaturation with sodium dodecylsulfonate and dithiothreitol, but the remaining BMAA could only be released by acid hydrolysis. Together these data demonstrate that BMAA is incorporated into the amino acid backbone of proteins during synthesis and also associated with proteins through non-covalent bonding.

  8. Identification of dietary alanine toxicity and trafficking dysfunction in a Drosophila model of hereditary sensory and autonomic neuropathy type 1

    PubMed Central

    Oswald, Matthew C. W.; West, Ryan J. H.; Lloyd-Evans, Emyr; Sweeney, Sean T.

    2015-01-01

    Hereditary sensory and autonomic neuropathy type 1 (HSAN1) is characterized by a loss of distal peripheral sensory and motorneuronal function, neuropathic pain and tissue necrosis. The most common cause of HSAN1 is due to dominant mutations in serine palmitoyl-transferase subunit 1 (SPT1). SPT catalyses the condensation of serine with palmitoyl-CoA, the initial step in sphingolipid biogenesis. Identified mutations in SPT1 are known to both reduce sphingolipid synthesis and generate catalytic promiscuity, incorporating alanine or glycine into the precursor sphingolipid to generate a deoxysphingoid base (DSB). Why either loss of function in SPT1, or generation of DSBs should generate deficits in distal sensory function remains unclear. To address these questions, we generated a Drosophila model of HSAN1. Expression of dSpt1 bearing a disease-related mutation induced morphological deficits in synapse growth at the larval neuromuscular junction consistent with a dominant-negative action. Expression of mutant dSpt1 globally was found to be mildly toxic, but was completely toxic when the diet was supplemented with alanine, when DSBs were observed in abundance. Expression of mutant dSpt1 in sensory neurons generated developmental deficits in dendritic arborization with concomitant sensory deficits. A membrane trafficking defect was observed in soma of sensory neurons expressing mutant dSpt1, consistent with endoplasmic reticulum (ER) to Golgi block. We found that we could rescue sensory function in neurons expressing mutant dSpt1 by co-expressing an effector of ER–Golgi function, Rab1 suggesting compromised ER function in HSAN1 affected dendritic neurons. Our Drosophila model identifies a novel strategy to explore the pathological mechanisms of HSAN1. PMID:26395456

  9. Positive Modulation of the Glycine Receptor by Means of Glycine Receptor–Binding Aptamers

    PubMed Central

    Aneiros, Eduardo; Blank, Michael; Mueller, Johan; Nyman, Eva; Blind, Michael; Dabrowski, Michael A.; Andersson, Christin V.; Sandberg, Kristian

    2015-01-01

    According to the gate control theory of pain, the glycine receptors (GlyRs) are putative targets for development of therapeutic analgesics. A possible approach for novel analgesics is to develop a positive modulator of the glycine-activated Cl− channels. Unfortunately, there has been limited success in developing drug-like small molecules to study the impact of agonists or positive modulators on GlyRs. Eight RNA aptamers with low nanomolar affinity to GlyRα1 were generated, and their pharmacological properties analyzed. Cytochemistry using fluorescein-labeled aptamers demonstrated GlyRα1-dependent binding to the plasma membrane but also intracellular binding. Using a fluorescent membrane potential assay, we could identify five aptamers to be positive modulators. The positive modulation of one of the aptamers was confirmed by patch-clamp electrophysiology on L(tk) cells expressing GlyRα1 and/or GlyRα1β. This aptamer potentiated whole-cell Cl− currents in the presence of low concentrations of glycine. To our knowledge, this is the first demonstration ever of RNA aptamers acting as positive modulators for an ion channel. We believe that these aptamers are unique and valuable tools for further studies of GlyR biology and possibly also as tools for assay development in identifying small-molecule agonists and positive modulators. PMID:26071243

  10. [Changes of polyamines level in Glycine soja and Glycine max seedlings under NaCl stress].

    PubMed

    Yu, Bingjun; Ji, Xiaojia; Liu, Jun; Liu, Youliang

    2004-07-01

    With internationally common-used Glycine max (the salt-tolerant Lee68) and Glycine soja (the salt-sensitive N23232) as reference, this paper studied the polyamines (PAs) contents and polyamine oxidase (PAO) activities in the highly salt-tolerant BB52 (Glycine soja) seedlings, which showed that under 150mmol x L(-1) NaCl stress for 2d, the decrease of Put and Spd contents was more significant, but that of Spd content was less significant in roots of BB52 than in those of Lee68 and N23232. For leaves, the decrease of Put and increase of Spd contents were markedly observed in BB52. The ascent of (Spm + Spd)/Put ratios and descent of Put/PAs ratios showed a positive relation to their salt tolerance. The PAO activity in roots and leaves was all increased, and most obvious in N23232. The relationship between PAs levels in BB52 and its salt tolerance was also discussed.

  11. Pancreatic stellate cells support tumour metabolism through autophagic alanine secretion.

    PubMed

    Sousa, Cristovão M; Biancur, Douglas E; Wang, Xiaoxu; Halbrook, Christopher J; Sherman, Mara H; Zhang, Li; Kremer, Daniel; Hwang, Rosa F; Witkiewicz, Agnes K; Ying, Haoqiang; Asara, John M; Evans, Ronald M; Cantley, Lewis C; Lyssiotis, Costas A; Kimmelman, Alec C

    2016-08-25

    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by an intense fibrotic stromal response and deregulated metabolism. The role of the stroma in PDAC biology is complex and it has been shown to play critical roles that differ depending on the biological context. The stromal reaction also impairs the vasculature, leading to a highly hypoxic, nutrient-poor environment. As such, these tumours must alter how they capture and use nutrients to support their metabolic needs. Here we show that stroma-associated pancreatic stellate cells (PSCs) are critical for PDAC metabolism through the secretion of non-essential amino acids (NEAA). Specifically, we uncover a previously undescribed role for alanine, which outcompetes glucose and glutamine-derived carbon in PDAC to fuel the tricarboxylic acid (TCA) cycle, and thus NEAA and lipid biosynthesis. This shift in fuel source decreases the tumour’s dependence on glucose and serum-derived nutrients, which are limited in the pancreatic tumour microenvironment. Moreover, we demonstrate that alanine secretion by PSCs is dependent on PSC autophagy, a process that is stimulated by cancer cells. Thus, our results demonstrate a novel metabolic interaction between PSCs and cancer cells, in which PSC-derived alanine acts as an alternative carbon source. This finding highlights a previously unappreciated metabolic network within pancreatic tumours in which diverse fuel sources are used to promote growth in an austere tumour microenvironment.

  12. Characterization of psychrophilic alanine racemase from Bacillus psychrosaccharolyticus.

    PubMed

    Okubo, Y; Yokoigawa, K; Esaki, N; Soda, K; Kawai, H

    1999-03-16

    A psychrophilic alanine racemase gene from Bacillus psychrosaccharolyticus was cloned and expressed in Escherichia coli SOLR with a plasmid pYOK3. The gene starting with the unusual initiation codon GTG showed higher preference for codons ending in A or T. The enzyme purified to homogeneity showed the high catalytic activity even at 0 degrees C and was extremely labile over 35 degrees C. The enzyme was found to have a markedly large Km value (5.0 microM) for the pyridoxal 5'-phosphate (PLP) cofactor in comparison with other reported alanine racemases, and was stabilized up to 50 degrees C in the presence of excess amounts of PLP. The low affinity of the enzyme for PLP may be related to the thermolability, and may be related to the high catalytic activity, initiated by the transaldimination reaction, at low temperature. The enzyme has a distinguishing hydrophilic region around the residue no. 150 in the deduced amino acid sequence (383 residues), whereas the corresponding regions of other Bacillus alanine racemases are hydrophobic. The position of the region in the three dimensional structure of C atoms of the enzyme was predicted to be in a surface loop surrounding the active site. The region may interact with solvent and reduce the compactness of the active site.

  13. Probing alanine transaminase catalysis with hyperpolarized 13CD3-pyruvate

    PubMed Central

    Barb, A.W.; Hekmatyar, S.K.; Glushka, J.N.; Prestegard, J.H.

    2013-01-01

    Hyperpolarized metabolites offer a tremendous sensitivity advantage (>104 fold) when measuring flux and enzyme activity in living tissues by magnetic resonance methods. These sensitivity gains can also be applied to mechanistic studies that impose time and metabolite concentration limitations. Here we explore the use of hyperpolarization by dissolution dynamic nuclear polarization (DNP) in mechanistic studies of alanine transaminase (ALT), a well-established biomarker of liver disease and cancer that converts pyruvate to alanine using glutamate as a nitrogen donor. A specific deuterated, 13C-enriched analog of pyruvic acid, 13C3D3-pyruvic acid, is demonstrated to have advantages in terms of detection by both direct 13C observation and indirect observation through methyl protons introduced by ALT-catalyzed H–D exchange. Exchange on injecting hyperpolarized 13C3D3-pyruvate into ALT dissolved in buffered 1H2O, combined with an experimental approach to measure proton incorporation, provided information on mechanistic details of transaminase action on a 1.5 s timescale. ALT introduced, on average, 0.8 new protons into the methyl group of the alanine produced, indicating the presence of an off-pathway enamine intermediate. The opportunities for exploiting mechanism-dependent molecular signatures as well as indirect detection of hyperpolarized 13C3-pyruvate and products in imaging applications are discussed. PMID:23357427

  14. Pressure-induced phase transitions in L-alanine, revisited.

    PubMed

    Tumanov, N A; Boldyreva, E V; Kolesov, B A; Kurnosov, A V; Quesada Cabrera, R

    2010-08-01

    The effect of pressure on L-alanine has been studied by X-ray powder diffraction (up to 12.3 GPa), single-crystal X-ray diffraction, Raman spectroscopy and optical microscopy (up to approximately 6 GPa). No structural phase transitions have been observed. At approximately 2 GPa the cell parameters a and b become accidentally equal to each other, but without a change in space-group symmetry. Neither of two transitions reported by others (to a tetragonal phase at approximately 2 GPa and to a monoclinic phase at approximately 9 GPa) was observed. The changes in cell parameters were continuous up to the highest measured pressures and the cells remained orthorhombic. Some important changes in the intermolecular interactions occur, which also manifest themselves in the Raman spectra. Two new orthorhombic phases could be crystallized from a MeOH/EtOH/H(2)O pressure-transmitting mixture in the pressure range 0.8-4.7 GPa, but only if the sample was kept at these pressures for at least 1-2 d. The new phases converted back to L-alanine on decompression. Judging from the Raman spectra and cell parameters, the new phases are most probably not L-alanine but its solvates.

  15. A novel potentiometric biosensor for determination of L-lysine in commercial pharmaceutical L-lysine tablet and capsule.

    PubMed

    Yarar, Saniye; Karakuş, Emine

    2016-01-01

    The construction of an L-lysine biosensor on ammonium-selective poly(vinylchloride) (PVC) membrane electrode is described in this study. The construction procedure occurs in two stages: (I) the preparation of ammonium-selective poly(vinylchloride) (PVC) membrane electrode and (II) the chemical immobilization of lysine oxidase on this ammonium-selective electrode by using glutaraldehyde. The ammonium ions produced after enzymatic reaction were determined potentiometrically. The sensitivity of the lysine biosensor against ammonium ions and lysine were studied. The response time, linear working range, reproducibility and life time of the biosensor were also determined. The interfering effect of other amino acids on the biosensor performance was also studied and potentiometric selectivity coefficients were calculated. Although the biosensor responded mainly against tyrosine, a lot of amino acids and ascorbic acid that can be present in some real samples did not show any important interference. Additionally, lysine assay in commercial pharmaceutical lysine tablets and capsules was also successfully carried out. The results were in good agreement with previously reported values.

  16. Glycine input induces the synaptic facilitation in salamander rod photoreceptors.

    PubMed

    Shen, Wen; Jiang, Zheng; Li, Baoqin

    2008-11-01

    Glycinergic synapses in photoreceptors are made by centrifugal feedback neurons in the network, but the function of the synapses is largely unknown. Here we report that glycinergic input enhances photoreceptor synapses in amphibian retinas. Using specific antibodies against a glycine transporter (GlyT2) and glycine receptor beta subunit, we identified the morphology of glycinergic input in photoreceptor terminals. Electrophysiological recordings indicated that 10 muM glycine depolarized rods and activated voltage-gated Ca(2+) channels in the neurons. The effects facilitated glutamate vesicle release in photoreceptors, meanwhile increased the spontaneous excitatory postsynaptic currents in Off-bipolar cells. Endogenous glycine feedback also enhanced glutamate transmission in photoreceptors. Additionally, inhibition of a Cl(-) uptake transporter NKCC1 with bumetanid effectively eliminated glycine-evoked a weak depolarization in rods, suggesting that NKCC1 maintains a high Cl(-) level in rods, which causes to depolarize in responding to glycine input. This study reveals a new function of glycine in retinal synaptic transmission.

  17. Isotopic effects in mechanistic studies of biotransformations of fluorine derivatives of L-alanine catalysed by L-alanine dehydrogenase.

    PubMed

    Szymańska-Majchrzak, Jolanta; Pałka, Katarzyna; Kańska, Marianna

    2017-05-01

    Synthesis of 3-fluoro-[2-(2)H]-L-alanine (3-F-[(2)H]-L-Ala) in reductive amination of 3-fluoropyruvic acid catalysed by L-alanine dehydrogenase (AlaDH) was described. Fluorine derivative was used to study oxidative deamination catalysed by AlaDH applied kinetic (for 3-F-L-Ala in H2O - KIE's on Vmax: 1.1; on Vmax/KM: 1.2; for 3-F-L-Ala in (2)H2O - on Vmax: 1.4; on Vmax/KM: 2.1) and solvent isotope effect methods (for 3-F-L-Ala - SIE's on Vmax: 1.0; on Vmax/KM: 0.87; for 3-F-[2-(2)H]-L-Ala - on Vmax: 1.4; on Vmax/KM: 1.5). Studies explain some details of reaction mechanism.

  18. 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.

  19. Strychnine-sensitive glycine responses of neonatal rat hippocampal neurones.

    PubMed Central

    Ito, S; Cherubini, E

    1991-01-01

    1. Intracellular recordings employing current and voltage clamp techniques were used to study the effects of glycine on rat CA3 hippocampal neurones during the first 3 weeks of postnatal (P) life. 2. Glycine (0.3-1 mM) depolarized neurones from rats less than 4 days old (P4). Neurones from older neonates (P5-P7) were hyperpolarized by glycine, whereas adult neurones were unaffected. 3. Both depolarizing and hyperpolarizing responses were associated with large conductance increases; they reversed polarity at a potential which changed with the extracellular chloride concentration. The responses persisted in tetrodotoxin (1 microM) or in a solution with a much reduced calcium concentration. 4. Strychnine (1 microM) but not bicuculline (10-50 microM) antagonized the effects of glycine. The action of strychnine was apparently competitive with a dissociation constant of 350 nM. 5. In voltage clamp experiments, glycine elicited a non-desensitizing outward current at -60 mV. When a maximal concentration of glycine was applied at the same time as gamma-aminobutyric acid (GABA), the conductance increase induced by the two agonists was additive, suggesting the activation of different populations of channels. 6. Concentrations of glycine lower than 100 microM did not affect membrane potential. However, at 30-50 microM glycine increased the frequency of spontaneous GABA-mediated synaptic responses; this action was not blocked by strychnine. 7. It is concluded that during the first 2 weeks of life glycine acts at strychnine-sensitive receptors to open chloride channels. PMID:1804982

  20. 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

  1. 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.

  2. Nucleotide Accumulation Induced in Staphylococcus aureus by Glycine

    PubMed Central

    Strominger, Jack L.; Birge, Claire H.

    1965-01-01

    Strominger, Jack L. (Washington University School of Medicine, St. Louis, Mo.), and Claire H. Birge. Nucleotide accumulation induced in Staphylococcus aureus by glycine. J. Bacteriol. 89:1124–1127. 1965.—High concentrations of glycine induce accumulation of four uridine nucleotides in Staphylococcus aureus. Investigations of their structure suggest that these compounds are uridine diphosphate (UDP)-acetylmuramic acid, UDP-acetylmuramyl-gly-d-glu-l-lys, UDP-acetylmuramyl-l-ala-d-glu-l-lys and UDP-acetylmuramyl-gly-d-glu-l-lys-d-ala-d-ala. The mechanism by which glycine may induce uridine nucleotide accumulation and protoplast formation is discussed. Images PMID:14276106

  3. Cyanide Formation from Oxidation of Glycine by a Pseudomonas Species

    PubMed Central

    Wissing, Frode

    1974-01-01

    With whole cells of a hydrogen cyanide-producing bacterium strain C, of the genus Pseudomonas, it was found that the oxygen necessary for the oxidation of glycine to cyanide could be replaced by various artificial electron acceptors. The order of reactivity was: oxygen > phenazine methosulphate > methylene blue > 2,6-dichlorophenolindophenol > ferricyanide. Cyanide production was inhibited by pyrrolnitrin, a well-known inhibitor of many flavine enzymes. The molar ratio of added glycine to cyanide produced was found to be 1.09. With whole bacteria the apparent Km (glycine) for the cyanide production was found to be 5.0 × 10−4 M. PMID:4813896

  4. Cyanide formation from oxidation of glycine of Pseudomonas species.

    PubMed

    Wissing, F

    1974-03-01

    With whole cells of a hydrogen cyanide-producing bacterium strain C, of the genus Pseudomonas, it was found that the oxygen necessary for the oxidation of glycine to cyanide could be replaced by various artificial electron acceptors. The order of reactivity was: oxygen > phenazine methosulphate > methylene blue > 2,6-dichlorophenolindophenol > ferricyanide. Cyanide production was inhibited by pyrrolnitrin, a well-known inhibitor of many flavine enzymes. The molar ratio of added glycine to cyanide produced was found to be 1.09. With whole bacteria the apparent K(m) (glycine) for the cyanide production was found to be 5.0 x 10(-4) M.

  5. Glycine receptor heterogeneity in rat spinal cord during postnatal development.

    PubMed Central

    Becker, C M; Hoch, W; Betz, H

    1988-01-01

    Two different isoforms of the inhibitory glycine receptor were identified during postnatal development of rat spinal cord. A neonatal form characterized by low strychnine binding affinity, altered antigenicity, and a ligand binding subunit differing in mol. wt (49 kd) from that of the adult receptor (48 kd) predominates at birth (70% of the total receptor protein). Separation from the adult form could be achieved by either use of a selective antibody or glycine gradient elution of 2-aminostrychnine affinity columns. Both isoforms co-purify with the mol. wt 93 kd peripheral membrane protein of the postsynaptic glycine receptor complex. Images PMID:2850172

  6. An automated and efficient conformational search of glycine and a glycine-water heterodimer both in vacuum and in aqueous solution

    NASA Astrophysics Data System (ADS)

    Kishimoto, Naoki

    2017-01-01

    Stable conformers and the conformational isomerization pathways of glycine and the glycine-H2O heterodimer were explored using an efficient automated conformational searching method. The Gibbs energies of the conformers and transition structures of glycine and a glycine-H2O heterodimer at 400, 298, and 150 K were also calculated. In addition, estimated ratios of conformers, assuming thermodynamic equilibrium, were calculated and compared with the results of spectroscopic experiments. Solvent effects were introduced into the exploration process using the polarizable continuum model (PCM), and conversion (tautomerization) pathways from neutral to zwitterionic states for both glycine and a glycine-H2O heterodimer in aqueous solution were compared.

  7. 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

    ... that certain Chinese glycine further processed in India did not change the country of origin of such... determine whether U.S. imports of glycine exported by AICO and Paras, and made from Chinese- origin glycine... from companies in China, processing and/or repackaging the Chinese-origin glycine, and then...

  8. Design of Highly Stabilized β-Hairpin Peptides through Cation-π interactions of Lysine and N-Methyl Lysine with an Aromatic Pocket‡

    PubMed Central

    Riemen, Alexander J.; Waters, Marcey L.

    2009-01-01

    Two tryptophan residues were incorporated on one face of a β-hairpin peptide to form an aromatic pocket that interacts with a lysine or N-methylated lysine via cation-π interactions. The two tryptophan residues were found to pack against the lysine side chain forming an aromatic pocket similar to those observed in trimethylated lysine receptor proteins. Thermal analysis of methylated lysine variant hairpin peptides revealed an increase in thermal stability as the degree of methylation was increased resulting in the most thermally stable β-hairpin reported to date. PMID:19191524

  9. An Alternative Strategy for Pan-acetyl-lysine Antibody Generation.

    PubMed

    Kim, Sun-Yee; Sim, Choon Kiat; Zhang, Qiongyi; Tang, Hui; Brunmeir, Reinhard; Pan, Hong; Karnani, Neerja; Han, Weiping; Zhang, Kangling; Xu, Feng

    2016-01-01

    Lysine acetylation is an important post-translational modification in cell signaling. In acetylome studies, a high-quality pan-acetyl-lysine antibody is key to successful enrichment of acetylated peptides for subsequent mass spectrometry analysis. Here we show an alternative method to generate polyclonal pan-acetyl-lysine antibodies using a synthesized random library of acetylated peptides as the antigen. Our antibodies are tested to be specific for acetyl-lysine peptides/proteins via ELISA and dot blot. When pooled, five of our antibodies show broad reactivity to acetyl-lysine peptides, complementing a commercial antibody in terms of peptide coverage. The consensus sequence of peptides bound by our antibody cocktail differs slightly from that of the commercial antibody. Lastly, our antibodies are tested in a proof-of-concept to analyze the acetylome of HEK293 cells. In total we identified 1557 acetylated peptides from 416 proteins. We thus demonstrated that our antibodies are well-qualified for acetylome studies and can complement existing commercial antibodies.

  10. Effects of lysine-induced acute renal failure in dogs.

    PubMed

    Asanuma, Kentaro; Adachi, Kenji; Sugimoto, Tetsuro; Chiba, Shuichi

    2006-05-01

    This study investigates the effects of lysine-induced acute renal failure. Female dogs received a lysine hydrochloride (lysine) of 4500 mg/kg/day (3.75 ml/kg/hr) for 3 consecutive days. The dogs were observed for clinical signs. Body weights were recorded, food consumption and water consumption calculated, and urinalysis and blood biochemistry were performed daily. Plasma samples for amino acid determinations were obtained from all dogs, which were necropsied on Day 3. Histopathological examinations were done on all test animals. Compound-related findings include the following. Blood biochemistry results showed increases in ammonia, blood urea nitrogen, blood urea nitrogen/creatinine ratio, and creatinine. Urinary changes consisted of increases in urine volume, total protein, albumin, gamma-glutamyl transpeptidase, and N-acetyl-beta-D-glucosaminidase. In addition, macroscopic findings consisted of pale, congested capsule; microscopic findings consisted of hypertrophy of proximal convoluted tubule (mainly S1 segment), and degeneration/desquamation of urinary tubule (mainly S3 segment with hyaline casts) in the kidney. From these findings, it can be concluded that lysine is nephrotoxic in dogs. Nephrotoxicity of lysine may relate to direct tubular toxicity and to tubular obstruction.

  11. Characterization of a second lysine decarboxylase isolated from Escherichia coli.

    PubMed Central

    Kikuchi, Y; Kojima, H; Tanaka, T; Takatsuka, Y; Kamio, Y

    1997-01-01

    We report here on the existence of a new gene for lysine decarboxylase in Escherichia coli K-12. The hybridization experiments with a cadA probe at low stringency showed that the homologous region of cadA was located in lambda Kohara phage clone 6F5 at 4.7 min on the E. coli chromosome. We cloned the 5.0-kb HindIII fragment of this phage clone and sequenced the homologous region of cadA. This region contained a 2,139-nucleotide open reading frame encoding a 713-amino-acid protein with a calculated molecular weight of 80,589. Overexpression of the protein and determination of its N-terminal amino acid sequence defined the translational start site of this gene. The deduced amino acid sequence showed 69.4% identity to that of lysine decarboxylase encoded by cadA at 93.7 min on the E. coli chromosome. In addition, the level of lysine decarboxylase activity increased in strains carrying multiple copies of the gene. Therefore, the gene encoding this lysine decarboxylase was designated Idc. Analysis of the lysine decarboxylase activity of strains containing cadA, ldc, or cadA ldc mutations indicated that ldc was weakly expressed under various conditions but is a functional gene in E. coli. PMID:9226257

  12. Detection of serum AFB1-lysine adduct in Malaysia and its association with liver and kidney functions.

    PubMed

    Mohd Redzwan, S; Rosita, Jamaluddin; Mohd Sokhini, A M; Nurul 'Aqilah, A R; Wang, Jia-Sheng; Kang, Min-Su; Zuraini, Ahmad

    2014-01-01

    Aflatoxin is ubiquitously found in many foodstuffs and produced by Aspergillus species of fungi. Of many aflatoxin metabolites, AFB1 is classified by the International Agency for Research on Cancer (IARC) as group one carcinogen and linked to the development of hepatocellular carcinoma (HCC). The study on molecular biomarker of aflatoxin provides a better assessment on the extent of human exposure to aflatoxin. In Malaysia, the occurrences of aflatoxin-contaminated foods have been documented, but there is a lack of data on human exposure to aflatoxin. Hence, this study investigated the occurrence of AFB1-lysine adduct in serum samples and its association with liver and kidney functions. 5ml fasting blood samples were collected from seventy-one subjects (n=71) for the measurement of AFB1-lysine adduct, albumin, total bilirubin, AST (aspartate aminotransferase), ALT (alanine transaminase), ALP (alkaline phosphatase), GGT (gamma-glutamyl transpeptidase), creatinine and BUN (blood urea nitrogen). The AFB1-lysine adduct was detected in all serum samples (100% detection rate) with a mean of 6.85±3.20pg/mg albumin (range: 1.13-18.85pg/mg albumin). Male subjects (mean: 8.03±3.41pg/mg albumin) had significantly higher adduct levels than female subjects (mean: 5.64±2.46pg/mg albumin) (p<0.01). It was noteworthy that subjects with adduct levels greater than average (>6.85pg/mg albumin) had significantly elevated level of total bilirubin (p<0.01), GGT (p<0.05) and creatinine (p<0.01). Nevertheless, only the level of total bilirubin, (r=0.347, p-value=0.003) and creatinine (r=0.318, p-value=0.007) showed significant and positive correlation with the level of AFB1-lysine adduct. This study provides a valuable insight on human exposure to aflatoxin in Malaysia. Given that aflatoxin can pose serious problem to the health, intervention strategies should be implemented to limit/reduce human exposure to aflatoxin. Besides, a study with a big sample size should be warranted in

  13. Seed-specific expression of a lysine-rich protein gene, GhLRP, from cotton significantly increases the lysine content in maize seeds.

    PubMed

    Yue, Jing; Li, Cong; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2014-03-27

    Maize seed storage proteins are a major source of human and livestock consumption. However, these proteins have poor nutritional value, because they are deficient in lysine and tryptophan. Much research has been done to elevate the lysine content by reducing zein content or regulating the activities of key enzymes in lysine metabolism. Using the naturally lysine-rich protein genes, sb401 and SBgLR, from potato, we previously increased the lysine and protein contents of maize seeds. Here, we examined another natural lysine-rich protein gene, GhLRP, from cotton, which increased the lysine content of transgenic maize seeds at levels varying from 16.2% to 65.0% relative to the wild-type. The total protein content was not distinctly different, except in the six transgenic lines. The lipid and starch levels did not differ substantially in Gossypium hirsutum L. lysine-rich protein (GhLRP) transgenic kernels when compared to wild-type. The agronomic characteristics of all the transgenic maize were also normal. GhLRP is a high-lysine protein candidate gene for increasing the lysine content of maize. This study provided a valuable model system for improving maize lysine content.

  14. New Typical Vector of Neurotoxin β-N-Methylamino-l-Alanine (BMAA) in the Marine Benthic Ecosystem

    PubMed Central

    Li, Aifeng; Song, Jialiang; Hu, Yang; Deng, Longji; Ding, Ling; Li, Meihui

    2016-01-01

    The neurotoxin β-N-methylamino-l-alanine (BMAA) has been identified as an environmental factor triggering neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS) and Alzheimer’s disease (AD). We investigated the possible vectors of BMAA and its isomers 2,4-diaminobutyric acid (DAB) and N-2(aminoethyl)glycine (AEG) in marine mollusks collected from the Chinese coast. Sixty-eight samples of marine mollusks were collected along the Chinese coast in 2016, and were analyzed by an HILIC-MS/MS (hydrophilic interaction liquid chromatography with tandem quadrupole mass spectrometer) method without derivatization. BMAA was detected in a total of five samples from three species: Neverita didyma, Solen strictus, and Mytilus coruscus. The top three concentrations of free-form BMAA (0.99~3.97 μg·g−1 wet weight) were detected in N. didyma. DAB was universally detected in most of the mollusk samples (53/68) with no species-specific or regional differences (0.051~2.65 μg·g−1 wet weight). No AEG was detected in any mollusk samples tested here. The results indicate that the gastropod N. didyma might be an important vector of the neurotoxin BMAA in the Chinese marine ecosystem. The neurotoxin DAB was universally present in marine bivalve and gastropod mollusks. Since N. didyma is consumed by humans, we suggest that the origin and risk of BMAA and DAB toxins in the marine ecosystem should be further investigated in the future. PMID:27827914

  15. New Typical Vector of Neurotoxin β-N-Methylamino-l-Alanine (BMAA) in the Marine Benthic Ecosystem.

    PubMed

    Li, Aifeng; Song, Jialiang; Hu, Yang; Deng, Longji; Ding, Ling; Li, Meihui

    2016-11-04

    The neurotoxin β-N-methylamino-l-alanine (BMAA) has been identified as an environmental factor triggering neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS) and Alzheimer's disease (AD). We investigated the possible vectors of BMAA and its isomers 2,4-diaminobutyric acid (DAB) and N-2(aminoethyl)glycine (AEG) in marine mollusks collected from the Chinese coast. Sixty-eight samples of marine mollusks were collected along the Chinese coast in 2016, and were analyzed by an HILIC-MS/MS (hydrophilic interaction liquid chromatography with tandem quadrupole mass spectrometer) method without derivatization. BMAA was detected in a total of five samples from three species: Neverita didyma, Solen strictus, and Mytilus coruscus. The top three concentrations of free-form BMAA (0.99~3.97 μg·g(-1) wet weight) were detected in N. didyma. DAB was universally detected in most of the mollusk samples (53/68) with no species-specific or regional differences (0.051~2.65 μg·g(-1) wet weight). No AEG was detected in any mollusk samples tested here. The results indicate that the gastropod N. didyma might be an important vector of the neurotoxin BMAA in the Chinese marine ecosystem. The neurotoxin DAB was universally present in marine bivalve and gastropod mollusks. Since N. didyma is consumed by humans, we suggest that the origin and risk of BMAA and DAB toxins in the marine ecosystem should be further investigated in the future.

  16. Spectral Luminescent Properties of the Glycine Molecule in a Gas Discharge

    NASA Astrophysics Data System (ADS)

    General, A. A.; Migovich, M. I.; Kelman, V. A.; Zhmenyak, Yu. V.; Zvenigorodsky, V. V.

    2016-01-01

    We have experimentally studied the luminescence spectra of glycine powder in the plasma of a repetitively pulsed longitudinal discharge in argon-glycine and helium-glycine mixtures. We have identified the main fragments of the glycine molecule emitting in the 200-1000 nm region. The emitting molecules due to fragmentation of glycine and dissociation of the carboxyl (-COOH) and amino (-NH2) groups are nitrogen, carbon monoxide, and cyanogen molecules.

  17. Drug Discovery Toward Antagonists of Methyl-Lysine Binding Proteins

    PubMed Central

    Herold, J. Martin; Ingerman, Lindsey A; Gao, Cen; Frye, Stephen V

    2011-01-01

    The recognition of methyl-lysine and -arginine residues on both histone and other proteins by specific “reader” elements is important for chromatin regulation, gene expression, and control of cell-cycle progression. Recently the crucial role of these reader proteins in cancer development and dedifferentiation has emerged, owing to the increased interest among the scientific community. The methyl-lysine and -arginine readers are a large and very diverse set of effector proteins and targeting them with small molecule probes in drug discovery will inevitably require a detailed understanding of their structural biology and mechanism of binding. In the following review, the critical elements of methyl-lysine and -arginine recognition will be summarized with respect to each protein family and initial results in assay development, probe design, and drug discovery will be highlighted. PMID:22145013

  18. Growth of gamma glycine crystal and its characterisation.

    PubMed

    Peter, M Esthaku; Ramasamy, P

    2010-05-01

    Single crystal of gamma-glycine, an organic nonlinear optical material, has been grown by solvent evaporation technique from a mixture of aqueous solutions of glycine and potassium nitrate, lithium nitrate at room temperature. Gamma glycine crystals have been grown up to the dimension of 20mmx15mmx12mm. Powder X-ray diffraction of the grown crystal was recorded and indexed. Single crystal X-ray diffraction studies were carried out and the unit cell parameters were compared with the literature values. The gamma-phase of glycine is confirmed by single crystal XRD and FTIR spectral analysis. The crystals were characterised by UV-vis-NIR transmission spectrum in the range 200-1100nm. The second harmonic generation conversion efficiency of gamma-glycine crystal was twice the efficiency of KDP crystal. Thermal characteristics of gamma-glycine crystals were determined by thermogravimetric analysis (TGA) and differential thermal analysis, which shows the thermal stability of the grown crystals. Dielectric constant and dielectric loss measurements were carried out at different temperatures and frequencies. The microhardness of the grown crystals has been studied using Vicker's microhardness tester.

  19. Glycine betaine uptake after hyperosmotic shift in Corynebacterium glutamicum.

    PubMed Central

    Farwick, M; Siewe, R M; Krämer, R

    1995-01-01

    Osmoregulatory uptake of glycine betaine in whole cells of Corynebacterium glutamicum ATCC 13032 (wild type) was studied. The cells actively take up glycine betaine when they are osmotically shocked. The total accumulation and uptake rate were dependent on the osmotic strength of the medium. Kinetic analysis revealed a high-affinity transport system (Km, 8.6 +/- 0.4 microM) with high maximum velocity (110 nmol.min-1.mg [dry weight]-1). Glycine betaine functioned as a compatible solute when added to the medium and allowed growth at an otherwise inhibitory osmotic strength of 1.5 M NaCl. Proline and ectoine could also be used as osmoprotectants. Glycine betaine is neither synthesized nor metabolized by C. glutamicum. The glycine betaine transport system is constitutively expressed at a basal level of activity. It can be induced up to eightfold by osmotic stress and is strongly regulated at the level of activity. The transport system is highly specific and has its pH optimum in the slightly alkaline range at about pH 8. The uptake of the zwitterionic glycine betaine is mediated by a secondary symport system coupled to cotransport of at least two Na+ ions. It is thus driven both by the membrane potential and the Na+ gradient. An extremely high accumulation (internal/external) ratio of up to 4 x 10(6) was measured, which represents the highest accumulation ratio observed for any transport system. PMID:7642496

  20. Effect of temperature and pressure on the protonation of glycine

    PubMed Central

    Izatt, R. M.; Oscarson, J. L.; Gillespie, S. E.; Grimsrud, H.; Renuncio, J. A. R.; Pando, C.

    1992-01-01

    Flow calorimetry has been used to study the interaction of glycine with protons in water at temperatures of 298.15, 323.15, and 348.15 K and pressures up to 12.50 MPa. By combining the measured heat for glycine solutions titrated with NaOH with the heat of ionization for water, the enthalpy of protonation of glycine is obtained. The reaction is exothermic at all temperatures and pressures studied. The effect of pressure on the enthalpy of reaction is very small. The experimental heat data are analyzed to yield equilibrium constant (K), enthalpy change (ΔH), and entropy change (ΔS) values for the protonation reaction as a function of temperature. These values are compared with those reported previously at 298.15 K. The ΔH and ΔS values increase (become more positive), whereas log K values decrease, as temperature increases. The trends for ΔH and ΔS with temperature are opposite to those reported previously for the protonation of several alkanolamines. However, log K values for proton interaction with both glycine and the alkanolamines decrease with increasing temperature. The effect of the nitrogen atom substituent on log K for protonation of glycine and alkanolamines is discussed in terms of changes in long-range and short-range solvent effects. These effects are used to explain the difference in ΔH and ΔS trends between glycine protonation and those found earlier for alkanolamine protonation. PMID:19431832

  1. Molecular basis for substrate discrimination by glycine transporters.

    PubMed

    Vandenberg, Robert J; Shaddick, Kim; Ju, Pengchu

    2007-05-11

    Glycine is an inhibitory neurotransmitter in the spinal cord and brain stem, where it acts on strychnine-sensitive glycine receptors, and is also an excitatory neurotransmitter throughout the brain and spinal cord, where it acts on the N-methyl-d-aspartate family of receptors. There are two Na(+)/Cl(-)-dependent glycine transporters, GLYT1 and GLYT2, which control extracellular glycine concentrations and these transporters show differences in substrate selectivity and blocker sensitivity. A bacterial Na(+)-dependent leucine transporter (LeuT(Aa)) has recently been crystallized and its structure determined. When the amino acid residues within the leucine binding site of LeuT(Aa) are aligned with residues of the two glycine transporters there are a number of identical residues and also some key differences. In this report, we demonstrate that the LeuT(Aa) structure represents a good working model of the Na(+)/Cl(-)-dependent neurotransmitters and that differences in substrate selectivity can be attributed to a single difference of a glycine residue in transmembrane domain 6 of GLYT1 for a serine residue at the corresponding position of GLYT2.

  2. Residues Asp164 and Glu165 at the substrate entryway function potently in substrate orientation of alanine racemase from E. coli: Enzymatic characterization with crystal structure analysis.

    PubMed

    Wu, Dalei; Hu, Tiancen; Zhang, Liang; Chen, Jing; Du, Jiamu; Ding, Jianping; Jiang, Hualiang; Shen, Xu

    2008-06-01

    Alanine racemase (Alr) is an important enzyme that catalyzes the interconversion of L-alanine and D-alanine, an essential building block in the peptidoglycan biosynthesis. For the small size of the Alr active site, its conserved substrate entryway has been proposed as a potential choice for drug design. In this work, we fully analyzed the crystal structures of the native, the D-cycloserine-bound, and four mutants (P219A, E221A, E221K, and E221P) of biosynthetic Alr from Escherichia coli (EcAlr) and studied the potential roles in substrate orientation for the key residues involved in the substrate entryway in conjunction with the enzymatic assays. Structurally, it was discovered that EcAlr is similar to the Pseudomonas aeruginosa catabolic Alr in both overall and active site geometries. Mutation of the conserved negatively charged residue aspartate 164 or glutamate 165 at the substrate entryway could obviously reduce the binding affinity of enzyme against the substrate and decrease the turnover numbers in both D- to L-Ala and L- to D-Ala directions, especially when mutated to lysine with the opposite charge. However, mutation of Pro219 or Glu221 had only negligible or a small influence on the enzymatic activity. Together with the enzymatic and structural investigation results, we thus proposed that the negatively charged residues Asp164 and Glu165 around the substrate entryway play an important role in substrate orientation with cooperation of the positively charged Arg280 and Arg300 on the opposite monomer. Our findings are expected to provide some useful structural information for inhibitor design targeting the substrate entryway of Alr.

  3. Sugar Substrates for l-Lysine Fermentation by Ustilago maydis

    PubMed Central

    Sánchez-Marroquín, A.; Ledezma, M.; Carreño, R.

    1970-01-01

    The extracellular production of l-lysine in media with cane sugar, blackstrap molasses, or clarified sugar-cane juice by a previously obtained mutant of Ustilago maydis was studied. Enzymatically inverted clarified juice (medium J-3) gave 2.9 g of lysine per liter under the following conditions: inoculum, 5%; pH 5.8; temperature, 30 C; KLa in the fermentors, 0.41 mmoles of O2 per liter per min; fermentation time, 72 hr. The concentrate, obtained by direct evaporation and drying of the fermentation broth, could be used as a possible feed supplement because of its amino-acid and vitamin content. PMID:5485081

  4. Lysine-iron agar in the detection of Arizona cultures.

    PubMed

    EDWARDS, P R; FIFE, M A

    1961-11-01

    A lysine-iron agar is described and recommended for the detection of Arizona strains which ferment lactose rapidly. Black colonies which appear on bismuth sulfite agar should be transferred to the medium. Salmonellae and Arizona cultures produce a distinctive reaction since they are the only recognized groups of enteric bacteria which regularly produce lysine decarboxylase rapidly and form large amounts of hydrogen sulfide. Use of the medium is particularly recommended in the examination of specimens from enteric infections in which shigellae and salmonellae are not detected.

  5. Comparative mapping of the wild perennial Glycine latifolia and soybean (G. max) reveals extensive chromosome rearrangements in the genus Glycine.

    PubMed

    Chang, Sungyul; Thurber, Carrie S; Brown, Patrick J; Hartman, Glen L; Lambert, Kris N; Domier, Leslie L

    2014-01-01

    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, one of the 26 perennial wild Glycine species related to soybean in the subgenus Glycine Willd., shows high levels of resistance to multiple soybean pathogens and pests including Alfalfa mosaic virus, Heterodera glycines Ichinohe and Sclerotinia sclerotiorum (Lib.) de Bary. However, limited information is available on the genomes of these perennial Glycine species. To generate molecular resources for gene mapping and identification, high-density linkage maps were constructed for G. latifolia using single nucleotide polymorphism (SNP) markers generated by genotyping by sequencing and evaluated in an F2 population and confirmed in an F5 population. In each population, greater than 2,300 SNP markers were selected for analysis and segregated to form 20 large linkage groups. Marker orders were similar in the F2 and F5 populations. The relationships between G. latifolia linkage groups and G. max and common bean (Phaseolus vulgaris L.) chromosomes were examined by aligning SNP-containing sequences from G. latifolia to the genome sequences of G. max and P. vulgaris. Twelve of the 20 G. latifolia linkage groups were nearly collinear with G. max chromosomes. The remaining eight G. latifolia linkage groups appeared to be products of multiple interchromosomal translocations relative to G. max. Large syntenic blocks also were observed between G. latifolia and P. vulgaris. These experiments are the first to compare genome organizations among annual and perennial Glycine species and common bean. The development of molecular resources for species closely related to G. max provides information into the evolution of genomes within the genus Glycine and tools to identify genes within perennial wild relatives of cultivated soybean that could be beneficial to soybean production.

  6. Formation and inhibition of Nε-(carboxymethyl)lysine in saccharide-lysine model systems during microwave heating.

    PubMed

    Li, Lin; Han, Lipeng; Fu, Quanyi; Li, Yuting; Liang, Zhili; Su, Jianyu; Li, Bing

    2012-10-31

    N(ε)-(carboxymethyl) lysine (CML) is the most abundant advanced glycation end product (AGE), and frequently selected as an AGEs marker in laboratory studies. In this paper, the formation and inhibition of N(ε)-(carboxymethyl)lysine in saccharide-lysine model systems during microwave heating have been studied. The microwave heating treatment significantly promoted the formation of CML during Maillard reactions, which was related to the reaction temperature, time and type of saccharide. The order of CML formation for different saccharides was lactose > glucose > sucrose. Then, the inhibition effect on CML by five inhibitors was further examined. According to the results, ascorbic acid and tocopherol did not affect inhibition of CML, in contrast, thiamin, rutin and quercetin inhibited CML formation, and the inhibitory effects were concentration dependent.

  7. Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation

    SciTech Connect

    Carnevale, V.; Raugei, S.

    2009-12-14

    Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

  8. Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation.

    PubMed

    Carnevale, V; Raugei, S

    2009-12-14

    Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

  9. Thermodynamics of Deca-alanine Folding in Water.

    PubMed

    Hazel, Anthony; Chipot, Christophe; Gumbart, James C

    2014-07-08

    The determination of the folding dynamics of polypeptides and proteins is critical in characterizing their functions in biological systems. Numerous computational models and methods have been developed for studying structure formation at the atomic level. Due to its small size and simple structure, deca-alanine is used as a model system in molecular dynamics (MD) simulations. The free energy of unfolding in vacuum has been studied extensively using the end-to-end distance of the peptide as the reaction coordinate. However, few studies have been conducted in the presence of explicit solvent. Previous results show a significant decrease in the free energy of extended conformations in water, but the α-helical state is still notably favored over the extended state. Although sufficient in vacuum, we show that end-to-end distance is incapable of capturing the full complexity of deca-alanine folding in water. Using α-helical content as a second reaction coordinate, we deduce a more descriptive free-energy landscape, one which reveals a second energy minimum in the extended conformations that is of comparable free energy to the α-helical state. Equilibrium simulations demonstrate the relative stability of the extended and α-helical states in water as well as the transition between the two states. This work reveals both the necessity and challenge of determining a proper reaction coordinate to fully characterize a given process.

  10. The effect of immunonutrition (glutamine, alanine) on fracture healing

    PubMed Central

    Küçükalp, Abdullah; Durak, Kemal; Bayyurt, Sarp; Sönmez, Gürsel; Bilgen, Muhammed S.

    2014-01-01

    Background There have been various studies related to fracture healing. Glutamine is an amino acid with an important role in many cell and organ functions. This study aimed to make a clinical, radiological, and histopathological evaluation of the effects of glutamine on fracture healing. Methods Twenty rabbits were randomly allocated into two groups of control and immunonutrition. A fracture of the fibula was made to the right hind leg. All rabbits received standard food and water. From post-operative first day for 30 days, the study group received an additional 2 ml/kg/day 20% L-alanine L-glutamine solution via a gastric catheter, and the control group received 2 ml/kg/day isotonic via gastric catheter. At the end of 30 days, the rabbits were sacrificed and the fractures were examined clinically, radiologically, and histopathologically in respect to the degree of union. Results Radiological evaluation of the control group determined a mean score of 2.5 according to the orthopaedists and 2.65 according to the radiologists. In the clinical evaluation, the mean score was 1.875 for the control group and 2.0 for the study group. Histopathological evaluation determined a mean score of 8.5 for the control group and 9.0 for the study group. Conclusion One month after orally administered glutamine–alanine, positive effects were observed on fracture healing radiologically, clinically, and histopathologically, although no statistically significant difference was determined.

  11. Formation of chloroform during chlorination of alanine in drinking water.

    PubMed

    Chu, Wen-Hai; Gao, Nai-Yun; Deng, Yang; Dong, Bing-Zhi

    2009-11-01

    Currently, dissolved nitrogenous organic matters in water, important precursors of disinfection by-products (DBPs), are of significant concern. This study was to explore the formation of chloroform (CF) during chlorination of alanine (Ala), an important nitrogenous organic compound commonly present in water sources. Our results indicated that the CF yield reached a maximum value of 0.143% at the molar ratio of chlorine atom to nitrogen atom (Cl/N)=1.0 over a Cl/N range of 0.2-5.0 (pH=7.0, reaction time=5d, and initial Ala=0.1mM). At an acidic-neutral condition (pH 4-7), the formation of CF was suppressed. However, the highest CF yield (0.227%) occurred at weakly alkaline condition (pH 8.0) (initial Ala=0.1mM, and Cl/N=1.0). The increase of Br(-) in water can increase total trihalomethanes (THMs) and bromo-THMs. However, the bromo-THMs level reached a plateau at Br(-)/Cl>0.04. Finally, based on the computation of frontier electron density and identification and measurement of key intermediates during Ala chlorination, we proposed a formation pathway of CF from Ala chlorination: Ala-->monochloro-N-alanine (MC-N-Ala)-->acetaldehyde (AAld)-->monochloroacetaldehyde acetaldehyde (MCAld)-->dichloroacetaldehyde (DCAld)-->trichloroacetaldehyde (TCAld)-->CF.

  12. Inoculation Method for Studying Early Responses of Glycine max to Heterodera glycines

    PubMed Central

    Mahalingam, R.; Knap, H. T.; Lewis, S. A.

    1998-01-01

    An inoculation technique was developed for studying molecular responses of soybean to the soybean cyst nematode (Heterodera glycines). Effect of inoculum age (0-7 days after eggs were released from cysts) and inoculation site (meristem, elongation, or differentiation zone) on infection were tested on four soybean genotypes. Two genotypes (PI 437654 and cv. Peking) were resistant and two (cv. Essex and cv. Hutcheson) were susceptible to race 3 of H. glycines. Inoculum consisting of second-stage juveniles (J2) was prepared by gently agitating nematode eggs at 75 revolutions per minute at 28 °C for various intervals. Infection rates were monitored cytologically. The most consistent infection rate was obtained with 48-hour-old inoculum containing more than 80% J2. More than 100 juveniles/root were observed after inoculation with the 48-hour-old inoculum placed at the root elongation zone, in both resistant and susceptible soybeans. Horizontal orientation of roots during inoculation, the use of concentrated J2 inoculurn (500 J2 in 125 μl/root), and restriction of inoculum to the root elongation zone facilitated synchronous root infection. PMID:19274216

  13. [Relationship between chloride tolerance and polyamine accumulation in Glycine max, Glycine soja, and their hybrid seedlings].

    PubMed

    Chen, Xuan-Qin; Yu, Bing-Jun; Liu, You-Liang

    2007-02-01

    The seedlings of the F4 hybrid strain 'JB185' selected for salt tolerance generation by generation, their parents Glycine max cv. Jackson and Glycine soja population 'BB52' were treated with different NaCl concentrations and iso-osmotic (-0.53 MPa) PEG-6000, NaCl, Na+ (without Cl-) and Cl- (without Na+) solutions for 6 d. The results showed that: (1) The relative electrolyte leakage and malondialdehyde (MDA) content in leaves of the above three soybean seedlings showed an increase trend when the NaCl concentration was elevated, but chlorophyll contents decreased except the significant increase in 'BB52' and 'JB185' under NaCl 50 mmol/L stress. The change in 'JB185' was between its parents. (2) Under different iso-osmotic stresses, the relative electrolyte leakage and MDA contents in leaves of three soybean seedlings also increased mostly, the changes in 'BB52' and 'JB185' under Na+ (without Cl-) stress were more than those under Cl- (without Na+) stress. The free and bound Put, Spd and Spm contents in leaves all increased when compared with the control, the ratios of free (Spd+Spm)/Put and total bound polyamines in 'BB52' and 'JB185' seedlings under Na+ (without Cl-) treatment were the lowest one among three iso-osmotic salt stresses. The results indicate that the F4 hybrid strain 'JB185' is more sensitive to Na+ than Cl- as its wild parent 'BB52' population.

  14. A Chemical Proteomics Approach for Global Analysis of Lysine Monomethylome Profiling*

    PubMed Central

    Wu, Zhixiang; Cheng, Zhongyi; Sun, Mingwei; Wan, Xuelian; Liu, Ping; He, Tieming; Tan, Minjia; Zhao, Yingming

    2015-01-01

    Methylation of lysine residues on histone proteins is known to play an important role in chromatin structure and function. However, non-histone protein substrates of this modification remain largely unknown. An effective approach for system-wide analysis of protein lysine methylation, particularly lysine monomethylation, is lacking. Here we describe a chemical proteomics approach for global screening for monomethyllysine substrates, involving chemical propionylation of monomethylated lysine, affinity enrichment of the modified monomethylated peptides, and HPLC/MS/MS analysis. Using this approach, we identified with high confidence 446 lysine monomethylation sites in 398 proteins, including three previously unknown histone monomethylation marks, representing the largest data set of protein lysine monomethylation described to date. Our data not only confirms previously discovered lysine methylation substrates in the nucleus and spliceosome, but also reveals new substrates associated with diverse biological processes. This method hence offers a powerful approach for dynamic study of protein lysine monomethylation under diverse cellular conditions and in human diseases. PMID:25505155

  15. Lysine requirement of broiler chicks as affected by protein source and method of statistical evaluation.

    PubMed

    Barbour, G; Latshaw, J D; Bishop, B

    1993-09-01

    1. An experiment was designed to test if the lysine requirement, expressed as g lysine/kg CP, was the same for several protein sources. 2. Groundnut meal, groundnut meal adjusted with indispensable amino acids or sesame meal supplied the dietary CP at 180 g/kg diet. Increments of lysine (1.5 g/kg diet) were added to each of these diets. 3. The gain, food intake and food efficiency responses of broiler chicks were analysed using a quadratic equation and a two-slope method. An estimate of lysine requirements was also obtained from a survey of college students. 4. The different methods produced widely different estimates of lysine requirement. 5. The average lysine requirement was estimated at 50.1 g lysine/kg CP for groundnut meal, 61.7 for adjusted groundnut meal and 54.9 for sesame meal. 6. Reasons for the effect of statistical analysis and protein source on lysine requirement are discussed.

  16. Involvement of alanine racemase in germination of Bacillus cereus spores lacking an intact exosporium.

    PubMed

    Venir, Elena; Del Torre, Manuela; Cunsolo, Vincenzo; Saletti, Rosaria; Musetti, Rita; Stecchini, Mara Lucia

    2014-02-01

    The L-alanine mediated germination of food isolated Bacillus cereus DSA 1 spores, which lacked an intact exosporium, increased in the presence of D-cycloserine (DCS), which is an alanine racemase (Alr) inhibitor, reflecting the activity of the Alr enzyme, capable of converting L-alanine to the germination inhibitor D-alanine. Proteomic analysis of the alkaline extracts of the spore proteins, which include exosporium and coat proteins, confirmed that Alr was present in the B. cereus DSA 1 spores and matched to that encoded by B. cereus ATCC 14579, whose spore germination was strongly affected by the block of conversion of L- to D-alanine. Unlike ATCC 14579 spores, L-alanine germination of B. cereus DSA 1 spores was not affected by the preincubation with DCS, suggesting a lack of restriction in the reactant accessibility.

  17. The Helical Alanine Controversy: An (Ala)6 Insertion Dramatically Increases Helicity

    PubMed Central

    Lin, Jasper C.; Barua, Bipasha

    2013-01-01

    Employing chemical shift melts and hydrogen/deuterium exchange NMR techniques, we have determined the stabilization of the Trp-cage miniprotein due to multiple alanine insertions within the N-terminal α-helix. Alanine is shown to be uniquely helix-stabilizing and this stabilization is reflected in the global fold stability of the Trp-cage. The associated free energy change per alanine can be utilized to calculate the alanine propagation value. From the Lifson–Roig formulation, the calculated value (wAla = 1.6) is comparable to those obtained for short, solubilized, alanine-rich helices and is much larger than the values obtained by prior host–guest techniques or in N-terminally templated helices and peptides bearing long contiguous strings of alanines with no capping or solubilizing units present. PMID:15493925

  18. Expression, crystallization and preliminary X-ray crystallographic analysis of Xoo0352, D-alanine-D-alanine ligase A, from Xanthomonas oryzae pv. oryzae.

    PubMed

    Doan, Thanh Thi Ngoc; Kim, Jin-Kwang; Kim, Hyesoon; Ahn, Yeh-Jin; Kim, Jeong-Gu; Lee, Byoung-Moo; Kang, Lin-Woo

    2008-12-01

    Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB), which is one of the most devastating diseases of rice in most rice-growing countries. D-Alanine-D-alanine ligase A (DdlA), coded by the Xoo0352 gene, was expressed, purified and crystallized. DdlA is an enzyme that is involved in D-alanine metabolism and the biosynthesis of an essential bacterial peptidoglycan precursor, in which it catalyzes the formation of D-alanyl-D-alanine from two D-alanines, and is thus an attractive antibacterial drug target against Xoo. The DdlA crystals diffracted to 2.3 A resolution and belonged to the primitive tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 83.0, c = 97.6 A. There is one molecule in the asymmetric unit, with a corresponding V(M) of 1.88 A(3) Da(-1) and a solvent content of 34.6%. The initial structure was determined by molecular replacement using D-alanine-D-alanine ligase from Staphylococcus aureus (PDB code 2i87) as a template model.

  19. The glycine reuptake inhibitor Org24598 and acamprosate reduce ethanol intake in the rat; tolerance development to acamprosate but not to Org24598.

    PubMed

    Lidö, Helga H; Marston, Hugh; Ericson, Mia; Söderpalm, Bo

    2012-09-01

    Extracellular glycine modulates accumbal dopamine levels as well as ethanol-induced dopamine overflow. Glycine availability is also crucial for regulating alcohol consumption and the glycine transporter 1 (GlyT-1) inhibitor Org25935 robustly decreases alcohol intake in rats. To explore whether the alcohol-intake reducing effect of Org25935 is substance bound, we examined the effect of a different selective GlyT-1 inhibitor, Org24598, on ethanol consumption in rats and compared the effect with that of acamprosate, a drug currently in clinical use. We studied the effects of daily Org24598 and acamprosate injections on male Wistar rats with ~60% ethanol preference in a limited access two bottle free-choice model for 12 days, followed by alcohol deprivation for 14 days before a second test period of 10 days. Finally, rats underwent in vivo microdialysis where dopamine, glycine, taurine and β-alanine in n. accumbens were measured. Org24598 profoundly reduced ethanol intake and the effect remained throughout both treatment periods. Acamprosate promptly reduced ethanol intake, but on the third day tolerance developed to this effect and acamprosate failed to influence alcohol consumption during the second test period. Neither Org24598 nor acamprosate reduced water intake. Following the drinking study, the Org24598 group displayed higher basal accumbal dopamine levels compared with acamprosate and vehicle groups. Both Org24598 and acamprosate reduced the ethanol-induced dopamine response in n. accumbens. The study demonstrates a robust anti-alcohol intake effect of the GlyT-1 inhibitor Org24598, supporting the new concept that GlyT-1 inhibition reduces ethanol consumption. GlyT-1 inhibition may represent a new treatment principle for alcoholism that is superior to acamprosate.

  20. Diversity of endophytic fungi in Glycine max.

    PubMed

    Fernandes, Elio Gomes; Pereira, Olinto Liparini; da Silva, Cynthia Cânedo; Bento, Claudia Braga Pereira; de Queiroz, Marisa Vieira

    2015-12-01

    Endophytic fungi are microorganisms that live within plant tissues without causing disease during part of their life cycle. With the isolation and identification of these fungi, new species are being discovered, and ecological relationships with their hosts have also been studied. In Glycine max, limited studies have investigated the isolation and distribution of endophytic fungi throughout leaves and roots. The distribution of these fungi in various plant organs differs in diversity and abundance, even when analyzed using molecular techniques that can evaluate fungal communities in different parts of the plants, such as denaturing gradient gel electrophoresis (DGGE). Our results show there is greater species richness of culturable endophytic filamentous fungi in the leaves G. max as compared to roots. Additionally, the leaves had high values for diversity indices, i.e. Simpsons, Shannon and Equitability. Conversely, dominance index was higher in roots as compared to leaves. The fungi Ampelomyces sp., Cladosporium cladosporioides, Colletotrichum gloeosporioides, Diaporthe helianthi, Guignardia mangiferae and Phoma sp. were more frequently isolated from the leaves, whereas the fungi Fusarium oxysporum, Fusarium solani and Fusarium sp. were prevalent in the roots. However, by evaluating the two communities by DGGE, we concluded that the species richness was higher in the roots than in the leaves. UPGMA analysis showed consistent clustering of isolates; however, the fungus Leptospora rubella, which belongs to the order Dothideales, was grouped among species of the order Pleosporales. The presence of endophytic Fusarium species in G. max roots is unsurprising, since Fusarium spp. isolates have been previously described as endophyte in other reports. However, it remains to be determined whether the G. max Fusarium endophytes are latent pathogens or non-pathogenic forms that benefit the plant. This study provides a broader knowledge of the distribution of the fungal

  1. Small Molecule Ligands of Methyl-Lysine Binding Proteins

    PubMed Central

    Herold, J. Martin; Wigle, Tim J.; Norris, Jacqueline L.; Lam, Robert; Korboukh, Victoria K.; Gao, Cen; Ingerman, Lindsey A.; Kireev, Dmitri B.; Senisterra, Guillermo; Vedadi, Masoud; Tripathy, Ashutosh; Brown, Peter J.; Arrowsmith, Cheryl H.; Jin, Jian; Janzen, William P.; Frye, Stephen V.

    2011-01-01

    Proteins which bind methylated lysines (“readers” of the histone code) are important components in the epigenetic regulation of gene expression and can also modulate other proteins that contain methyl-lysine such as p53 and Rb. Recognition of methyl-lysine marks by MBT domains leads to compaction of chromatin and a repressed transcriptional state. Antagonists of MBT domains would serve as probes to interrogate the functional role of these proteins and initiate the chemical biology of methyl-lysine readers as a target class. Small molecule MBT antagonists were designed based on the structure of histone peptide-MBT complexes and their interaction with MBT domains determined using a chemiluminescent assay and ITC. The ligands discovered antagonize native histone peptide binding, exhibiting 5-fold stronger binding affinity to L3MBTL1 than its preferred histone peptide. The first co-crystal structure of a small molecule bound to L3MBTL1 was determined and provides new insights into binding requirements for further ligand design. PMID:21417280

  2. Small-molecule ligands of methyl-lysine binding proteins.

    PubMed

    Herold, J Martin; Wigle, Tim J; Norris, Jacqueline L; Lam, Robert; Korboukh, Victoria K; Gao, Cen; Ingerman, Lindsey A; Kireev, Dmitri B; Senisterra, Guillermo; Vedadi, Masoud; Tripathy, Ashutosh; Brown, Peter J; Arrowsmith, Cheryl H; Jin, Jian; Janzen, William P; Frye, Stephen V

    2011-04-14

    Proteins which bind methylated lysines ("readers" of the histone code) are important components in the epigenetic regulation of gene expression and can also modulate other proteins that contain methyl-lysine such as p53 and Rb. Recognition of methyl-lysine marks by MBT domains leads to compaction of chromatin and a repressed transcriptional state. Antagonists of MBT domains would serve as probes to interrogate the functional role of these proteins and initiate the chemical biology of methyl-lysine readers as a target class. Small-molecule MBT antagonists were designed based on the structure of histone peptide-MBT complexes and their interaction with MBT domains determined using a chemiluminescent assay and ITC. The ligands discovered antagonize native histone peptide binding, exhibiting 5-fold stronger binding affinity to L3MBTL1 than its preferred histone peptide. The first cocrystal structure of a small molecule bound to L3MBTL1 was determined and provides new insights into binding requirements for further ligand design.

  3. Therapeutic use of chimeric bacteriophage (phage) lysins in staphylococcal endophthalmitis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: Phage endolysins are peptidoglycan hydrolases that are produced at the end of the phage lytic cycle to digest the host bacterial cell wall, facilitating the release of mature phage progeny. The aim of this study is to determine the antimicrobial activity of chimeric phage lysins against cli...

  4. [Modification of the lysine-iron agar (author's transl)].

    PubMed

    Wauters, G

    1975-12-01

    The addition of L-phenylalanine to the lysine-iron agar described by Edwards and Fife ]1] allows a more valuable screening of the Proteus group based on its deamination properties. Some minor modifications of the indicator and thiosulfate content lead to improve and earlier recording of the results.

  5. [L-lysine-alpha-oxidase activity of some Trichoderma species].

    PubMed

    Smirnova, I P; Khaduev, S Kh

    1984-01-01

    Trichoderma cultures were tested for their ability to produce L-lysine-alpha-oxidase. The highest enzyme activity was manifested by T. harzianum (MGU), T. longibrachiatum Rifai VKM F-2025 and T. aureoviride Rifai VKM F-2026. The biosynthesis of the enzyme did not depend on the growth of the cultures and did not vary among the species.

  6. MYST protein acetyltransferase activity requires active site lysine autoacetylation.

    PubMed

    Yuan, Hua; Rossetto, Dorine; Mellert, Hestia; Dang, Weiwei; Srinivasan, Madhusudan; Johnson, Jamel; Hodawadekar, Santosh; Ding, Emily C; Speicher, Kaye; Abshiru, Nebiyu; Perry, Rocco; Wu, Jiang; Yang, Chao; Zheng, Y George; Speicher, David W; Thibault, Pierre; Verreault, Alain; Johnson, F Bradley; Berger, Shelley L; Sternglanz, Rolf; McMahon, Steven B; Côté, Jacques; Marmorstein, Ronen

    2012-01-04

    The MYST protein lysine acetyltransferases are evolutionarily conserved throughout eukaryotes and acetylate proteins to regulate diverse biological processes including gene regulation, DNA repair, cell-cycle regulation, stem cell homeostasis and development. Here, we demonstrate that MYST protein acetyltransferase activity requires active site lysine autoacetylation. The X-ray crystal structures of yeast Esa1 (yEsa1/KAT5) bound to a bisubstrate H4K16CoA inhibitor and human MOF (hMOF/KAT8/MYST1) reveal that they are autoacetylated at a strictly conserved lysine residue in MYST proteins (yEsa1-K262 and hMOF-K274) in the enzyme active site. The structure of hMOF also shows partial occupancy of K274 in the unacetylated form, revealing that the side chain reorients to a position that engages the catalytic glutamate residue and would block cognate protein substrate binding. Consistent with the structural findings, we present mass spectrometry data and biochemical experiments to demonstrate that this lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro. We also show that this autoacetylation occurs in vivo and is required for the cellular functions of these MYST proteins. These findings provide an avenue for the autoposttranslational regulation of MYST proteins that is distinct from other acetyltransferases but draws similarities to the phosphoregulation of protein kinases.

  7. MYST protein acetyltransferase activity requires active site lysine autoacetylation

    PubMed Central

    Yuan, Hua; Rossetto, Dorine; Mellert, Hestia; Dang, Weiwei; Srinivasan, Madhusudan; Johnson, Jamel; Hodawadekar, Santosh; Ding, Emily C; Speicher, Kaye; Abshiru, Nebiyu; Perry, Rocco; Wu, Jiang; Yang, Chao; Zheng, Y George; Speicher, David W; Thibault, Pierre; Verreault, Alain; Johnson, F Bradley; Berger, Shelley L; Sternglanz, Rolf; McMahon, Steven B; Côté, Jacques; Marmorstein, Ronen

    2012-01-01

    The MYST protein lysine acetyltransferases are evolutionarily conserved throughout eukaryotes and acetylate proteins to regulate diverse biological processes including gene regulation, DNA repair, cell-cycle regulation, stem cell homeostasis and development. Here, we demonstrate that MYST protein acetyltransferase activity requires active site lysine autoacetylation. The X-ray crystal structures of yeast Esa1 (yEsa1/KAT5) bound to a bisubstrate H4K16CoA inhibitor and human MOF (hMOF/KAT8/MYST1) reveal that they are autoacetylated at a strictly conserved lysine residue in MYST proteins (yEsa1-K262 and hMOF-K274) in the enzyme active site. The structure of hMOF also shows partial occupancy of K274 in the unacetylated form, revealing that the side chain reorients to a position that engages the catalytic glutamate residue and would block cognate protein substrate binding. Consistent with the structural findings, we present mass spectrometry data and biochemical experiments to demonstrate that this lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro. We also show that this autoacetylation occurs in vivo and is required for the cellular functions of these MYST proteins. These findings provide an avenue for the autoposttranslational regulation of MYST proteins that is distinct from other acetyltransferases but draws similarities to the phosphoregulation of protein kinases. PMID:22020126

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Histone H4 lysine 16 acetylation breaks the genome's silence

    PubMed Central

    Shia, Wei-Jong; Pattenden, Samantha G; Workman, Jerry L

    2006-01-01

    Acetylation at histone H4 lysine 16 is involved in many cellular processes in organisms as diverse as yeast and humans. A recent biochemical study pinpoints this particular acetylation mark as a switch for changing chromatin from a repressive to a transcriptionally active state. PMID:16689998

  10. Lysine metabolism in antisense C-hordein barley grains.

    PubMed

    Schmidt, Daiana; Rizzi, Vanessa; Gaziola, Salete A; Medici, Leonardo O; Vincze, Eva; Kozak, Marcin; Lea, Peter J; Azevedo, Ricardo A

    2015-02-01

    The grain proteins of barley are deficient in lysine and threonine due to their low concentrations in the major storage protein class, the hordeins, especially in the C-hordein subgroup. Previously produced antisense C-hordein transgenic barley lines have an improved amino acid composition, with increased lysine, methionine and threonine contents. The objective of the study was to investigate the possible changes in the regulation of key enzymes of the aspartate metabolic pathway and the contents of aspartate-derived amino acids in the nontransgenic line (Hordeum vulgare L. cv. Golden Promise) and five antisense C-hordein transgenic barley lines. Considering the amounts of soluble and protein-bound aspartate-derived amino acids together with the analysis of key enzymes of aspartate metabolic pathway, we suggest that the C-hordein suppression did not only alter the metabolism of at least one aspartate-derived amino acid (threonine), but major changes were also detected in the metabolism of lysine and methionine. Modifications in the activities and regulation of aspartate kinase, dihydrodipicolinate synthase and homoserine dehydrogenase were observed in most transgenic lines. Furthermore the activities of lysine α-ketoglutarate reductase and saccharopine dehydrogenase were also altered, although the extent varied among the transgenic lines.

  11. A Role for Accumbal Glycine Receptors in Modulation of Dopamine Release by the Glycine Transporter-1 Inhibitor Org25935

    PubMed Central

    Lidö, Helga Höifödt; Ericson, Mia; Marston, Hugh; Söderpalm, Bo

    2010-01-01

    Accumbal glycine modulates basal and ethanol-induced dopamine levels in the nucleus accumbens (nAc) as well as voluntary ethanol consumption. Also, systemic administration of the glycine transporter-1 inhibitor Org25935 elevates dopamine levels in nAc, prevents a further ethanol-induced dopamine elevation and robustly and dose-dependently decreases ethanol consumption in rats. Here we investigated whether Org25935 applied locally in nAc modulates dopamine release, and whether accumbal glycine receptors or NMDA receptors are involved in this tentative effect. We also addressed whether Org25935 and ethanol applied locally in nAc interact with dopamine levels, as seen after systemic administration. We used in vivo microdialysis coupled to HPLC-ED in freely moving male Wistar rats to monitor dopamine output in nAc after local perfusion of Org25935 alone, with ethanol, or Org25935-perfusion after pre-treatment with the glycine receptor antagonist strychnine or the NMDA receptor glycine site antagonist L-701.324. Local Org25935 increased extracellular dopamine levels in a subpopulation of rats. Local strychnine, but not systemic L-701.324, antagonized the dopamine-activating effect of Org25935. Ethanol failed to induce a dopamine overflow in the subpopulation responding to Org25935 with a dopamine elevation. The study supports a role for accumbal glycine receptors rather than NMDA receptor signaling in the dopamine-activating effect of Org25935. The results further indicate that the previously reported systemic Org25935–ethanol interaction with regard to accumbal dopamine is localized to the nAc. This adds to the growing evidence for the glycine receptor as an important player in the dopamine reward circuitry and in ethanol's effects within this system. PMID:21556278

  12. Antibacterial Activity of Alanine-Derived Gemini Quaternary Ammonium Compounds.

    PubMed

    Piecuch, Agata; Obłąk, Ewa; Guz-Regner, Katarzyna

    The antibacterial activity of alanine-derived gemini quaternary ammonium salts (chlorides and bromides) with various spacer and alkyl chain lengths was investigated. The studied compounds exhibited a strong bactericidal effect, especially bromides with 10 and 12 carbon alkyl chains and 3 carbon spacer groups (TMPAL-10 Br and TMPAL-12 Br), with a short contact time. Both salts dislodged biofilms of Pseudomonas aeruginosa and Staphylococcus epidermidis, and were lethal to adherent cells of S. epidermidis. Bromide with 2 carbon spacer groups and 12 carbon alkyl chains (TMEAL-12 Br) effectively reduced microbial adhesion by coating polystyrene and silicone surfaces. The results obtained suggest that, after further studies, gemini QAS might be considered as antimicrobial agents in medicine or industry.

  13. Charge dependent photodynamic activity of alanine based zinc phthalocyanines.

    PubMed

    Wang, Ao; Li, Yejing; Zhou, Lin; Yuan, Linxin; Lu, Shan; Lin, Yun; Zhou, Jiahong; Wei, Shaohua

    2014-12-01

    In this paper, to minimize the effects of different structure, three alanine-based zinc phthalocyanines (Pcs) of differing charges were engineered and synthesized with the same basic structure. On this premise, the relationship between nature of charge and photodynamic activity was studied. Besides, further verification and explanation of some inconsistent results were also carried out. The results showed that charge can influence the aggregation state, singlet oxygen generation ability and cellular uptake of Pcs, thereby affecting their photodynamic activity. In addition, the biomolecules inside cells may interact with Pcs of differing charges, which can also influence the aggregation state and singlet oxygen generation of the Pcs, and then influence the relationship between nature of charge and photodynamic activity.

  14. Radiolysis of alanine adsorbed in a clay mineral

    SciTech Connect

    Aguilar-Ovando, Ellen Y.; Negron-Mendoza, Alicia

    2013-07-03

    Optical activity in molecules is a chemical characteristic of living beings. In this work, we examine the hypothesis of the influence of different mineral surfaces on the development of a specific chirality in organic molecules when subjected to conditions simulating the primitive Earth during the period of chemical evolution. By using X-ray diffraction techniques and HPLC/ELSD to analyze aqueous suspensions of amino acids adsorbed on minerals irradiated in different doses with a cobalt-60 gamma source, the experiments attempt to prove the hypothesis that some solid surfaces (like clays and meteorite rocks) may have a concentration capacity and protective role against external sources of ionizing radiation (specifically {gamma}-ray) for some organic compounds (like some amino acids) adsorbed on them. Preliminary results show a slight difference in the adsorption and radiolysis of the D-and L-alanine.

  15. First-principles study of fluorination of L-Alanine

    NASA Astrophysics Data System (ADS)

    Sreepad, H. R.; Ravi, H. R.; Ahmed, Khaleel; Dayananda, H. M.; Umakanth, K.; Manohara, B. M.

    2013-02-01

    First-principles calculations based on Density Functional Theory have been done on effect of fluorination of an important amino acid - L-Alanine. Its structure has been simulated. The unit cell is orthorhombic with lattice parameters a=5.90Å, b=13.85Å and c=5.75Å with volume 470 (Å)3. Bond lengths and bond angles have been estimated. Electronic Density of States calculations show that the material has a band gap of 4.47eV. Electronic band structure indicates that the material can be effectively used for NLO applications. The electronic contribution to the dielectric constant has been calculated and its average value comes out to be 2.165.

  16. Effect of inhibitor compounds on Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) formation in model foods.

    PubMed

    Srey, Chou; Hull, George L J; Connolly, Lisa; Elliott, Christopher T; del Castillo, M Dolores; Ames, Jennifer M

    2010-11-24

    The possible adverse effects on health of diet-derived advanced glycation endproducts (AGEs) and advanced lipoxidation endproducts (ALEs) is of current interest. This study had the objective of determining the effects of the addition of AGE/ALE inhibitors and different types of sugar and cooking oil on Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) formation in model foods (sponge cakes). The cake baked using glucose produced the highest level of CML (2.07±0.24 mmol/mol lysine), whereas the cake baked using fructose produced the highest concentration of CEL (25.1±0.15 mmol/mol lysine). There were no significant differences between CML concentrations formed in the cakes prepared using different types of cooking oil, but significant differences (P<0.001) were observed between the cakes prepared using different proportions of cooking oil. The cakes containing oil generated greater concentrations of CML than sucrose. α-Tocopherol and rutin did not inhibit CML and CEL formation. In contrast, ferulic acid and thiamin, thiamin monophosphate, and thiamin pyrophosphate reduced CML and CEL formation.

  17. Alanine Aminotransferase Variants Conferring Diverse NUE Phenotypes in Arabidopsis thaliana

    PubMed Central

    McAllister, Chandra H.; Good, Allen G.

    2015-01-01

    Alanine aminotransferase (AlaAT, E.C. 2.6.1.2), is a pyridoxal-5’-phosphate-dependent (PLP) enzyme that catalyzes the reversible transfer of an amino group from alanine to 2-oxoglutarate to produce glutamate and pyruvate, or vice versa. It has been well documented in both greenhouse and field studies that tissue-specific over-expression of AlaAT from barley (Hordeum vulgare, HvAlaAT) results in a significant increase in plant NUE in both canola and rice. While the physical phenotypes associated with over-expression of HvAlaAT have been well characterized, the role this enzyme plays in vivo to create a more N efficient plant remains unknown. Furthermore, the importance of HvAlaAT, in contrast to other AlaAT enzyme homologues in creating this phenotype has not yet been explored. To address the role of AlaAT in NUE, AlaAT variants from diverse sources and different subcellular locations, were expressed in the wild-type Arabidopsis thaliana Col-0 background and alaat1;2 (alaat1-1;alaat2-1) knockout background in various N environments. The analysis and comparison of both the physical and physiological properties of AlaAT over-expressing transgenic plants demonstrated significant differences between plants expressing the different AlaAT enzymes under different external conditions. This analysis indicates that the over-expression of AlaAT variants other than HvAlaAT in crop plants could further increase the NUE phenotype(s) previously observed. PMID:25830496

  18. Alanine aminotransferase variants conferring diverse NUE phenotypes in Arabidopsis thaliana.

    PubMed

    McAllister, Chandra H; Good, Allen G

    2015-01-01

    Alanine aminotransferase (AlaAT, E.C. 2.6.1.2), is a pyridoxal-5'-phosphate-dependent (PLP) enzyme that catalyzes the reversible transfer of an amino group from alanine to 2-oxoglutarate to produce glutamate and pyruvate, or vice versa. It has been well documented in both greenhouse and field studies that tissue-specific over-expression of AlaAT from barley (Hordeum vulgare, HvAlaAT) results in a significant increase in plant NUE in both canola and rice. While the physical phenotypes associated with over-expression of HvAlaAT have been well characterized, the role this enzyme plays in vivo to create a more N efficient plant remains unknown. Furthermore, the importance of HvAlaAT, in contrast to other AlaAT enzyme homologues in creating this phenotype has not yet been explored. To address the role of AlaAT in NUE, AlaAT variants from diverse sources and different subcellular locations, were expressed in the wild-type Arabidopsis thaliana Col-0 background and alaat1;2 (alaat1-1;alaat2-1) knockout background in various N environments. The analysis and comparison of both the physical and physiological properties of AlaAT over-expressing transgenic plants demonstrated significant differences between plants expressing the different AlaAT enzymes under different external conditions. This analysis indicates that the over-expression of AlaAT variants other than HvAlaAT in crop plants could further increase the NUE phenotype(s) previously observed.

  19. Purification and characterization of two human erythrocyte arylamidases preferentially hydrolysing N-terminal arginine or lysine residues.

    PubMed Central

    Mäkinen, K K; Mäkinen, P L

    1978-01-01

    Two arylamidases (I and II) were purified from human erythrocytes by a procedure that comprised removal of haemoglobin from disrupted cells with CM-Sephadex D-50, followed by treatment of the haemoglobin-free preparation subsequently with DEAE-cellulose, gel-permeation chromatography on Sephadex G-200, gradient solubilization on Celite, isoelectric focusing in a pH gradient from 4 to 6, gel-permeation chromatography on Sephadex G-100 (superfine), and finally affinity chromatography on Sepharose 4B covalently coupled to L-arginine. In preparative-scale purifications, enzymes I and II were separated at the second gel-permeation chromatography. Enzyme II was obtained as a homogeneous protein, as shown by several criteria. Enzyme I hydrolysed, with decreasing rates, the L-amino acid 2-naphtylamides of lysine, arginine, alanine, methionine, phenylalanine and leucine, and the reactions were slightly inhibited by 0.2 M-NaCl. Enzyme II hydrolysed most rapidly the corresponding derivatives of arginine, leucine, valine, methionine, proline and alanine, in that order, and the hydrolyses were strongly dependent on Cl-. The hydrolysis of these substrates proceeded rapidly at physiological Cl- concentration (0.15 M). The molecular weights (by gel filtration) of enzymes I and II were 85 000 and 52 500 respectively. The pH optimum was approx. 7.2 for both enzymes. The isoelectric point of enzyme II was approx. 4.8. Enzyme I was activated by Co2+, which did not affect enzyme II to any noticeable extent. The kinetics of reactions catalysed by enzyme I were characterized by strong substrate inhibition, but enzyme II was not inhibited by high substrate concentrations. The Cl- activated enzyme II also showed endopeptidase activity in hydrolysing bradykinin. PMID:743227

  20. Comparison of Small RNA Profiles of Glycine max and Glycine soja at Early Developmental Stages

    PubMed Central

    Sun, Yuzhe; Mui, Zeta; Liu, Xuan; Yim, Aldrin Kay-Yuen; Qin, Hao; Wong, Fuk-Ling; Chan, Ting-Fung; Yiu, Siu-Ming; Lam, Hon-Ming; Lim, Boon Leong

    2016-01-01

    Small RNAs, including microRNAs (miRNAs) and phased small interfering RNAs (phasiRNAs; from PHAS loci), play key roles in plant development. Cultivated soybean, Glycine max, contributes a great deal to food production, but, compared to its wild kin, Glycine soja, it may lose some genetic information during domestication. In this work, we analyzed the sRNA profiles of different tissues in both cultivated (C08) and wild soybeans (W05) at three stages of development. A total of 443 known miRNAs and 15 novel miRNAs showed varying abundances between different samples, but the miRNA profiles were generally similar in both accessions. Based on a sliding window analysis workflow that we developed, 50 PHAS loci generating 55 21-nucleotide phasiRNAs were identified in C08, and 46 phasiRNAs from 41 PHAS loci were identified in W05. In germinated seedlings, phasiRNAs were more abundant in C08 than in W05. Disease resistant TIR-NB-LRR genes constitute a very large family of PHAS loci. PhasiRNAs were also generated from several loci that encode for NAC transcription factors, Dicer-like 2 (DCL2), Pentatricopeptide Repeat (PPR), and Auxin Signaling F-box 3 (AFB3) proteins. To investigate the possible involvement of miRNAs in initiating the PHAS-phasiRNA pathway, miRNA target predictions were performed and 17 C08 miRNAs and 15 W05 miRNAs were predicted to trigger phasiRNAs biogenesis. In summary, we provide a comprehensive description of the sRNA profiles of wild versus cultivated soybeans, and discuss the possible roles of sRNAs during soybean germination. PMID:27929436

  1. Comparison of Small RNA Profiles of Glycine max and Glycine soja at Early Developmental Stages.

    PubMed

    Sun, Yuzhe; Mui, Zeta; Liu, Xuan; Yim, Aldrin Kay-Yuen; Qin, Hao; Wong, Fuk-Ling; Chan, Ting-Fung; Yiu, Siu-Ming; Lam, Hon-Ming; Lim, Boon Leong

    2016-12-06

    Small RNAs, including microRNAs (miRNAs) and phased small interfering RNAs (phasiRNAs; from PHAS loci), play key roles in plant development. Cultivated soybean, Glycine max, contributes a great deal to food production, but, compared to its wild kin, Glycine soja, it may lose some genetic information during domestication. In this work, we analyzed the sRNA profiles of different tissues in both cultivated (C08) and wild soybeans (W05) at three stages of development. A total of 443 known miRNAs and 15 novel miRNAs showed varying abundances between different samples, but the miRNA profiles were generally similar in both accessions. Based on a sliding window analysis workflow that we developed, 50 PHAS loci generating 55 21-nucleotide phasiRNAs were identified in C08, and 46 phasiRNAs from 41 PHAS loci were identified in W05. In germinated seedlings, phasiRNAs were more abundant in C08 than in W05. Disease resistant TIR-NB-LRR genes constitute a very large family of PHAS loci. PhasiRNAs were also generated from several loci that encode for NAC transcription factors, Dicer-like 2 (DCL2), Pentatricopeptide Repeat (PPR), and Auxin Signaling F-box 3 (AFB3) proteins. To investigate the possible involvement of miRNAs in initiating the PHAS-phasiRNA pathway, miRNA target predictions were performed and 17 C08 miRNAs and 15 W05 miRNAs were predicted to trigger phasiRNAs biogenesis. In summary, we provide a comprehensive description of the sRNA profiles of wild versus cultivated soybeans, and discuss the possible roles of sRNAs during soybean germination.

  2. Impact of dry heating on physicochemical properties of corn starch and lysine mixture.

    PubMed

    Ji, Ying; Yu, Jicheng; Xu, Yongbin; Zhang, Yinghui

    2016-10-01

    Corn starch was modified with lysine by dry heat treatment and to investigate how they can affect the pasting and structural properties of the treated starches. Dry heating with lysine reduced the pasting temperature and resulting in viscosity increase. The particle size of heated starch-lysine mixture increased, suggesting that starch granules were cross-linked to lysine. After dry heating, the onset temperature, peak temperature and conclusion temperature of corn starch-lysine mixture were lower than those of other starches. The degree of crystallinity decreased for the starch after dry heat treatment while these heated starch samples still have the same X-ray diffraction types as the original starch.

  3. Efficient L-Alanine Production by a Thermo-Regulated Switch in Escherichia coli.

    PubMed

    Zhou, Li; Deng, Can; Cui, Wen-Jing; Liu, Zhong-Mei; Zhou, Zhe-Min

    2016-01-01

    L-Alanine has important applications in food, pharmaceutical and veterinary and is used as a substrate for production of engineered thermoplastics. Microbial fermentation could reduce the production cost and promote the application of L-alanine. However, the presence of L-alanine significantly inhibit cell growth rate and cause a decrease in the ultimate L-alanine productivity. For efficient L-alanine production, a thermo-regulated genetic switch was designed to dynamically control the expression of L-alanine dehydrogenase (alaD) from Geobacillus stearothermophilus on the Escherichia coli B0016-060BC chromosome. The optimal cultivation conditions for the genetically switched alanine production using B0016-060BC were the following: an aerobic growth phase at 33 °C with a 1-h thermo-induction at 42 °C followed by an oxygen-limited phase at 42 °C. In a bioreactor experiment using the scaled-up conditions optimized in a shake flask, B0016-060BC accumulated 50.3 g biomass/100 g glucose during the aerobic growth phase and 96 g alanine/100 g glucose during the oxygen-limited phase, respectively. The L-alanine titer reached 120.8 g/l with higher overall and oxygen-limited volumetric productivities of 3.09 and 4.18 g/l h, respectively, using glucose as the sole carbon source. Efficient cell growth and L-alanine production were reached separately, by switching cultivation temperature. The results revealed the application of a thermo-regulated strategy for heterologous metabolic production and pointed to strategies for improving L-alanine production.

  4. Glycine transporter inhibitors as therapeutic agents for schizophrenia.

    PubMed

    Hashimoto, Kenji

    2006-01-01

    Multiple lines of evidence suggest that a dysfunction in the glutamatergic neurotransmission via the N-methyl-D-aspartate (NMDA) receptors contributes to the pathophysiology of psychiatric diseases including schizophrenia. The potentiation of NMDA receptor function may be a useful approach for the treatment of diseases associated with NMDA receptor hypofunction. One possible strategy is to increase synaptic levels of glycine by blocking the glycine transporter-1 (GlyT-1) in glia cells, since glycine acts as a co-agonist site on the NMDA receptor. In this article, the author reviews the recent important patents on GlyT-1 inhibitors for treatment of schizophrenia and other psychiatric diseases associated with the NMDA receptor hypofunction.

  5. Gas-phase interactions of organotin compounds with glycine.

    PubMed

    Latrous, Latifa; Tortajada, Jeanine; Haldys, Violette; Léon, Emmanuelle; Correia, Catarina; Salpin, Jean-Yves

    2013-07-01

    Gas-phase interactions of organotins with glycine have been studied by combining mass spectrometry experiments and quantum calculations. Positive-ion electrospray spectra show that the interaction of di- and tri-organotins with glycine results in the formation of [(R)2Sn(Gly)-H](+) and [(R)3Sn(Gly)](+) ions, respectively. Di-organotin complexes appear much more reactive than those involving tri-organotins. (MS/MS) spectra of the [(R)3Sn(Gly)](+) ions are indeed simple and only show elimination of intact glycine, generating the [(R)3Sn](+) carbocation. On the other hand, MS/MS spectra of [(R)2Sn(Gly)-H](+) complexes are characterized by numerous fragmentation processes. Six of them, associated with elimination of H2O, CO, H2O + CO and formation of [(R)2SnOH](+) (-57 u),[(R)2SnNH2](+) (-58 u) and [(R)2SnH](+) (-73 u), are systematically observed. Use of labeled glycines notably concludes that the hydrogen atoms eliminated in water and H2O + CO are labile hydrogens. A similar conclusion can be made for hydrogens of [(R2)SnOH](+) and [(R2)SnNH2](+) ions. Interestingly, formation [(R)2SnH](+) ions is characterized by a migration of one the α hydrogen of glycine onto the metallic center. Finally, several dissociation routes are observed and are characteristic of a given organic substituent. Calculations indicated that the interaction between organotins and glycine is mostly electrostatic. For [(R)2Sn(Gly)-H](+) complexes, a preferable bidentate interaction of the type η(2)-O,NH2 is observed, similar to that encountered for other metal ions. [(R)3Sn](+) ions strongly stabilize the zwitterionic form of glycine, which is practically degenerate with respect to neutral glycine. In addition, the interconversion between both forms is almost barrierless. Suitable mechanisms are proposed in order to account for the most relevant fragmentation processes.

  6. 40 CFR 721.520 - Alanine, N-(2-carboxyethyl)-N-alkyl-, salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-, salt. 721.520 Section 721.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.520 Alanine, N-(2-carboxyethyl)-N-alkyl-, salt. (a) Chemical substance... alanine, N-(2-carboxyethyl)-N- alkyl-, salt (P-89-336) is subject to reporting under this section for...

  7. 40 CFR 721.520 - Alanine, N-(2-carboxyethyl)-N-alkyl-, salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-, salt. 721.520 Section 721.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.520 Alanine, N-(2-carboxyethyl)-N-alkyl-, salt. (a) Chemical substance... alanine, N-(2-carboxyethyl)-N- alkyl-, salt (P-89-336) is subject to reporting under this section for...

  8. Polymerization of alanine in the presence of a non-swelling montmorillonite

    NASA Technical Reports Server (NTRS)

    Paecht-Horowitz, M.; Lahav, N.

    1977-01-01

    Alanine, starting from alanine-adenylate, has been polymerized in the presence of non-swelling Al-montmorillonite. The yield of polymerization is much lower than that obtained in the presence of swelling Na-montmorillonite. The possibility that the changing interlayer spacing in Na-montmorillonite might be responsible for its catalytic properties, is discussed.

  9. Regulation of the ald gene encoding alanine dehydrogenase by AldR in Mycobacterium smegmatis.

    PubMed

    Jeong, Ji-A; Baek, Eun-Young; Kim, Si Wouk; Choi, Jong-Soon; Oh, Jeong-Il

    2013-08-01

    The regulatory gene aldR was identified 95 bp upstream of the ald gene encoding L-alanine dehydrogenase in Mycobacterium smegmatis. The AldR protein shows sequence similarity to the regulatory proteins of the Lrp/AsnC family. Using an aldR deletion mutant, we demonstrated that AldR serves as both activator and repressor for the regulation of ald gene expression, depending on the presence or absence of L-alanine. The purified AldR protein exists as a homodimer in the absence of L-alanine, while it adopts the quaternary structure of a homohexamer in the presence of L-alanine. The binding affinity of AldR for the ald control region was shown to be increased significantly by L-alanine. Two AldR binding sites (O1 and O2) with the consensus sequence GA-N₂-ATC-N₂-TC and one putative AldR binding site with the sequence GA-N₂-GTT-N₂-TC were identified upstream of the ald gene. Alanine and cysteine were demonstrated to be the effector molecules directly involved in the induction of ald expression. The cellular level of L-alanine was shown to be increased in M. smegmatis cells grown under hypoxic conditions, and the hypoxic induction of ald expression appears to be mediated by AldR, which senses the intracellular level of alanine.

  10. 40 CFR 721.520 - Alanine, N-(2-carboxyethyl)-N-alkyl-, salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-, salt. 721.520 Section 721.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.520 Alanine, N-(2-carboxyethyl)-N-alkyl-, salt. (a) Chemical substance... alanine, N-(2-carboxyethyl)-N- alkyl-, salt (P-89-336) is subject to reporting under this section for...

  11. 40 CFR 721.520 - Alanine, N-(2-carboxyethyl)-N-alkyl-, salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-, salt. 721.520 Section 721.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.520 Alanine, N-(2-carboxyethyl)-N-alkyl-, salt. (a) Chemical substance... alanine, N-(2-carboxyethyl)-N- alkyl-, salt (P-89-336) is subject to reporting under this section for...

  12. 40 CFR 721.520 - Alanine, N-(2-carboxyethyl)-N-alkyl-, salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-, salt. 721.520 Section 721.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.520 Alanine, N-(2-carboxyethyl)-N-alkyl-, salt. (a) Chemical substance... alanine, N-(2-carboxyethyl)-N- alkyl-, salt (P-89-336) is subject to reporting under this section for...

  13. Calculating chemical equilibria in the heparin-Co2+ ion-glycine system

    NASA Astrophysics Data System (ADS)

    Feofanova, M. A.; Frantseva, Yu. V.; Zhuravlev, E. V.; Ryasensky, S. S.; Baranova, N. V.

    2013-08-01

    Results from investigating interactions in the heparin-Co2+ ion-glycine system are presented. The stoichiometry of cobalt complexes with heparin and glycine compositions CoOHHtpGly4- and CoHepGly3- is established.

  14. Some Operational Characteristics of Glycine Release in Rat Retina: The Role of Reverse Mode Operation of Glycine Transporter Type-1 (GlyT-1) in Ischemic Conditions.

    PubMed

    Hanuska, Adrienn; Szénási, Gábor; Albert, Mihaly; Koles, Laszlo; Varga, Agoston; Szabo, Andras; Matyus, Peter; Harsing, Laszlo G

    2016-02-01

    Rat posterior eyecups containing the retina were prepared, loaded with [(3)H]glycine and superfused in order to determine its release originated from glycinergic amacrine cells and/or glial cells. Deprivation of oxygen and glucose from the Krebs-bicarbonate buffer used for superfusion evoked a marked increase of [(3)H]glycine release, an effect that was found to be external Ca(2+)-independent. Whereas oxygen and glucose deprivation increased [(3)H]glycine release, its uptake was reduced suggesting that energy deficiency shifts glycine transporter type-1 operation from normal to reverse mode. The increased release of [(3)H]glycine evoked by oxygen and glucose deprivation was suspended by addition of the non-competitive glycine transporter type-1 inhibitor NFPS and the competitive inhibitor ACPPB further suggesting the involvement of this transporter in the mediation of [(3)H]glycine release. Oxygen and glucose deprivation also evoked [(3)H]glutamate release from rat retina and the concomitantly occurring release of the NMDA receptor agonist glutamate and the coagonist glycine makes NMDA receptor pathological overstimulation possible in hypoxic conditions. [(3)H]Glutamate release was suspended by addition of the excitatory amino acid transporter inhibitor TBOA. Sarcosine, a substrate inhibitor of glycine transporter type-1, also increased [(3)H]glycine release probably by heteroexchange shifting transporter operation into reverse mode. This effect of sarcosine was also external Ca(2+)-independent and could be suspended by NFPS. Energy deficiency in retina induced by ouabain, an inhibitor of the Na(+)-K(+)-dependent ATPase, and by rotenone, a mitochondrial complex I inhibitor added with the glycolytic inhibitor 2-deoxy-D-glucose, led to increase of retinal [(3)H]glycine efflux. These effects of ouabain and rotenone/2-deoxy-D-glucose could also be blocked by NFPS pointed to the preferential reverse mode operation of glycine transporter type-1 as a consequence of

  15. Synthesis and GGCT Inhibitory Activity of N-Glutaryl-L-alanine Analogues.

    PubMed

    Ii, Hiromi; Yoshiki, Tatsuhiro; Hoshiya, Naoyuki; Uenishi, Jun'ichi

    2016-01-01

    γ-Glutamylcyclotransferase (GGCT) is an important enzyme that cleaves γ-glutamyl-amino acid in the γ-glutamyl cycle to release 5-oxoproline and amino acid. Eighteen N-acyl-L-alanine analogues including eleven new compounds have been synthesized and examined for their inhibitory activity against recombinant human GGCT protein. Simple N-glutaryl-L-alanine was found to be the most potent inhibitor for GGCT. Other N-glutaryl-L-alanine analogues having methyl and dimethyl substituents at the 2-position were moderately effective, while N-(3R-aminoglutary)-L-alanine, the substrate having an (R)-amino group at the 3-position or N-(N-methyl-3-azaglutaryl)-L-alanine, the substrate having an N-methyl substituent on the 3-azaglutaryl carbon, in constract, exhibited excellent inhibition properties.

  16. How similar is the electronic structures of β-lactam and alanine?

    NASA Astrophysics Data System (ADS)

    Chatterjee, Subhojyoti; Ahmed, Marawan; Wang, Feng

    2016-02-01

    The C1s spectra of β-lactam i.e. 2-azetidinone (C3H5NO), a drug and L-alanine (C3H7NO2), an amino acid, exhibit striking similarities, which may be responsible for the competition between 2-azetidinone and the alanyl-alanine moiety in biochemistry. The present study is to reveal the degree of similarities and differences between their electronic structures of the two model molecular pairs. It is found that the similarities in C1s and inner valence binding energy spectra are due to their bonding connections but other properties such as ring structure (in 2-azetidinone) and chiral carbon (alanine) can be very different. Further, the inner valence region of ionization potential greater than 18 eV for 2-azetidinone and alanine is also significantly similar. Finally the strained lactam ring exhibits more chemical reactivity measured at all non-hydrogen atoms by Fukui functions with respect to alanine.

  17. Impact of charged amino acid substitution in the transmembrane domain of L-alanine exporter, AlaE, of Escherichia coli on the L-alanine export.

    PubMed

    Kim, Seryoung; Ihara, Kohei; Katsube, Satoshi; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2017-01-01

    The Escherichia coli alaE gene encodes the L-alanine exporter, AlaE, that catalyzes active export of L-alanine using proton electrochemical potential. The transporter comprises only 149 amino acid residues and four predicted transmembrane domains (TMs), which contain three charged amino acid residues. The AlaE-deficient L-alanine non-metabolizing cells (ΔalaE cells) appeared hypersusceptible to L-alanyl-L-alanine showing a minimum inhibitory concentration (MIC) of 2.5 µg/ml for the dipeptide due to a toxic accumulation of L-alanine. To elucidate the mechanism by which AlaE exports L-alanine, we replaced charged amino acid residues in the TMs, glutamic acid-30 (TM-I), arginine-45 (TM-II), and aspartic acid-84 (TM-III) with their respective charge-conserved amino acid or a net neutral cysteine. The ΔalaE cells producing R45K or R45C appeared hypersusceptible to the dipeptide, indicating that arginine-45 is essential for AlaE activity. MIC of the dipeptide in the ΔalaE cells expressing E30D and E30C was 156 µg/ml and >10,000 µg/ml, respectively, thereby suggesting that a negative charge at this position is not essential. The ΔalaE cells expressing D84E or D84C showed an MIC >10,000 and 78 µg/ml, respectively, implying that a negative charge is required at this position. These results were generally consistent with that of the L-alanine accumulation experiments in intact cells. We therefore concluded that charged amino acid residues (R45 and D84) in the AlaE transmembrane domain play a pivotal role in L-alanine export. Replacement of three cysteine residues at C22, C28 (both in TM-I), and C135 (C-terminal region) with alanine showed only a marginal effect on L-alanine export.

  18. Infrared laser induced conformational and structural changes of glycine and glycine·water complex in low-temperature matrices

    NASA Astrophysics Data System (ADS)

    Coussan, Stéphane; Tarczay, György

    2016-01-01

    Conformational and structural changes of matrix-isolated glycine and glycine·water complexes induced by the selective MIR excitation of the fundamental OH and NH stretching vibrational modes were studied. The observed spectral changes are consistent with the former assignments based on matrix-isolation IR spectroscopy combined with NIR laser irradiation. Since fewer conformational barriers can be reached by MIR than by NIR excitations, fewer processes are promoted effectively by MIR radiation. The comparison of spectral changes induced by selective MIR and NIR excitations can facilitate the conformational analysis of complex molecular systems and it can also yield information on the barrier heights.

  19. Coacervate-like microspheres from lysine-rich proteinoid

    NASA Technical Reports Server (NTRS)

    Rohlfing, D. L.

    1975-01-01

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

  20. Transcriptional regulation by the Set7 lysine methyltransferase.

    PubMed

    Keating, Samuel T; El-Osta, Assam

    2013-04-01

    Posttranslational histone modifications define chromatin structure and function. In recent years, a number of studies have characterized many of the enzymatic activities and diverse regulatory components required for monomethylation of histone H3 lysine 4 (H3K4me1) and the expression of specific genes. The challenge now is to understand how this specific chemical modification is written and the Set7 methyltransferase has emerged as a key regulatory enzyme mediating methylation of lysine residues of histone and non-histone proteins. In this review, we comprehensively explore the regulatory proteins modified by Set7 and highlight mechanisms of specific co-recruitment of the enzyme to activating promoters. With a focus on signaling and transcriptional control in disease we discuss recent experimental data emphasizing specific components of diverse regulatory complexes that mediate chromatin modification and reinterpretation of Set7-mediated gene expression.

  1. Identification of valine/leucine/isoleucine and threonine/alanine/glycine proton-spin systems of Escherichia coli adenylate kinase by selective deuteration and selective protonation.

    PubMed Central

    Bock-Möbius, I; Brune, M; Wittinghofer, A; Zimmermann, H; Leberman, R; Dauvergne, M T; Zimmermann, S; Brandmeier, B; Rösch, P

    1991-01-01

    Adenylate kinase from two types of Escherichia coli strains, a wild-type and a leucine-auxotrophic strain, was purified. On the one hand, growing the leucine-auxotrophic bacteria on a medium containing deuterated leucine yielded E. coli adenylate kinase with all leucine residues deuterated. On the other hand, by growing the wild-type bacteria on deuterated medium with phenylalanine, threonine and isoleucine present as protonated specimens, 80% randomly deuterated enzyme with protonated phenylalanine, threonine and isoleucine residues could be prepared. Use of these proteins enabled identification of the spin systems of these amino acid residues in the n.m.r. spectra of the protein. PMID:1991031

  2. 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.

  3. The Glycine-Alanine Dipeptide Repeat from C9orf72 Hexanucleotide Expansions Forms Toxic Amyloids Possessing Cell-to-Cell Transmission Properties.

    PubMed

    Chang, Yu-Jen; Jeng, U-Ser; Chiang, Ya-Ling; Hwang, Ing-Shouh; Chen, Yun-Ru

    2016-03-04

    Hexanucleotide expansions, GGGGCC, in the non-coding regions of the C9orf72 gene were found in major frontotemporal lobar dementia and amyotrophic lateral sclerosis patients (C9FTD/ALS). In addition to possible RNA toxicity, several dipeptide repeats (DPRs) are translated through repeat-associated non-ATG-initiated translation. The DPRs, including poly(GA), poly(GR), poly(GP), poly(PR), and poly(PA), were found in the brains and spinal cords of C9FTD/ALS patients. Among the DPRs, poly(GA) is highly susceptible to form cytoplasmic inclusions, which is a characteristic of C9FTD/ALS. To elucidate DPR aggregation, we used synthetic (GA)15 DPR as a model system to examine the aggregation and structural properties in vitro. We found that (GA)15 with 15 repeats fibrillates rapidly and ultimately forms flat, ribbon-type fibrils evidenced by transmission electron microscopy and atomic force microscopy. The fibrils are capable of amyloid dye binding and contain a characteristic cross-β sheet structure, as revealed by x-ray scattering. Furthermore, using neuroblastoma cells, we demonstrated the neurotoxicity and cell-to-cell transmission property of (GA)15 DPR. Overall, our results show the structural and toxicity properties of GA DPR to facilitate future DPR-related therapeutic development.

  4. Influence of ionization on the conformational preferences of peptide models. Ramachandran surfaces of N-formyl-glycine amide and N-formyl-alanine amide radical cations.

    PubMed

    Gil, Adrià; Sodupe, Mariona; Bertran, Juan

    2009-09-01

    Ramachandran maps of neutral and ionized HCO-Gly-NH2 and HCO-Ala-NH2 peptide models have been built at the B3LYP/6-31++G(d,p) level of calculation. Direct optimizations using B3LYP and the recently developed MPWB1K functional have also been carried out, as well as single-point calculations at the CCSD(T) level of theory with the 6-311++G(2df,2p) basis set. Results indicate that for both peptide models ionization can cause drastic changes in the shape of the PES in such a way that highly disallowed regions in neutral PES become low-energy regions in the radical cation surface. The structures localized in such regions, epsilonL+* and epsilonD+* are highly stabilized due to the formation of 2-centre-3-electron interactions between the two carbonyl oxygens. Inclusion of solvent effects by the conductor-like polarizable continuum model (CPCM) shows that the solute-solvent interaction energy plays an important role in determining the stability order.

  5. Raman study of poly(alanine-glycine)-based peptides containing tyrosine, valine, and serine as model for the semicrystalline domains of Bombyx mori silk fibroin.

    PubMed

    Taddei, Paola; Asakura, Tetsuo; Yao, Juming; Monti, Patrizia

    2004-11-01

    For a deeper insight into the structure of Bombyx mori silk fibroin, some model peptides containing tyrosine (Y), valine (V), and serine (S) in the basic (AG)n sequence were synthesized by the solid-phase method and analyzed by Raman spectroscopy in order to clarify their conformation and to evaluate the formation and/or disruption of the ordered structure typical of B. mori silk fibroin upon incorporation of Y, V, and S residues into the basic (AG)n sequence. The Raman results indicated that the silk I structure remains stable only when the Y residue is positioned near the chain terminus; otherwise, a silk I --> silk II conformational transition occurs. The peptides AGVGAGYGAGVGAGYGAGVGAGYG(AG)3 and (AG)3YG(AG)2VGYG(AG)3YG(AG)3 treated with LiBr revealed a prevalent silk II conformation; moreover, the former contained a higher amount of random coil than the latter. This result was explained in relation to the different degrees of interruption of the (AG)n sequence. The Raman analysis of the AGSGAG-containing samples confirmed that the AGSGAG hexapeptide is a good model for the silk II crystalline domain. As the number of AGSGAG repeating units decreased, the random coil content increased. The study of the Y domain (I850/I830 intensity ratio) allowed us to hypothesize that in the packing characteristic of Silk I and Silk II conformations the Y residues experience different environments and hydrogen-bonding arrangements; the packing typical of silk I structure traps the tyrosyl side chains in environments more unfavorable to phenoxyl hydrogen-bonding interactions.

  6. Accessibility and mobility of lysine residues in. beta. -lactoglobulin

    SciTech Connect

    Brown, E.M.; Pfeffer, P.E.; Kumosinski, T.F.; Greenberg, R.

    1988-07-26

    N/sup epsilon/-(/sup 2/H/sub 6/)Isopropyllysyl-..beta..-lactoglobulin was prepared by reductive alkylation of ..beta..-lactoglobulin with (/sup 2/H/sub 6/)acetone and NaBH/sub 4/ to provide a /sup 2/H (NMR) probe for the study of lysine involvement in lipid-protein interactions. Amino acid analysis showed 80% of the protein's 15 lysine residues to be labeled. Unmodified lysine residues were located through peptide maps produced from CNBr, tryptic, and chymotryptic digests of the labeled protein. Average correlation times calculated from /sup 2/H NMR spectra were 20 and 320 ps for 8.7 and 3.3 residues, respectively, in 6 M guanidine hydrochloride; in nondenaturing solution, values of 70 and 320 ps were obtained for 6.5 and 3.2 residues, respectively, with the remaining 2.3 modified residues not observed, suggesting that side chains of lysine residues in unordered or flexible regions were more mobile than those in stable periodic structures. /sup 2/H NMR spectra of the protein complexed with dipalmitoylphosphatidylcholine confirmed the extrinsic membrane protein type behavior of ..beta..-lactoglobulin previously reported from /sup 31/P NMR studies of the phospholipids complexed with ..beta..-lactoglobulin. Although no physiological function has yet been identified, comparison of these results with the X-ray structure supports the hypothesis that residues not accessible for modification may help to stabilize the cone-shaped ..beta..-barrel thought to contain binding sites for small lipid-soluble molecules.

  7. Dynamics of Forward and Reverse Transport by the Glial Glycine Transporter, Glyt1b

    PubMed Central

    Aubrey, Karin R.; Vandenberg, Robert J.; Clements, John D.

    2005-01-01

    Glycine is a coagonist at the N-methyl-D-aspartate receptor. Changes in extracellular glycine concentration may modulate N-methyl-D-aspartate receptor function and excitatory synaptic transmission. The GLYT1 glycine transporter is present in glia surrounding excitatory synapses, and plays a key role in regulating extracellular glycine concentration. We investigated the kinetic and other biophysical properties of GLYT1b, stably expressed in CHO cells, using whole-cell patch-clamp techniques. Application of glycine produced an inward current, which decayed within a few seconds to a steady-state level. When glycine was removed, a transient outward current was observed, consistent with reverse transport of accumulated glycine. The outward current was enhanced by elevating intracellular or lowering extracellular [Na+], and was modulated by changes in extracellular [glycine] and time of glycine application. We developed a model of GLYT1b function, which accurately describes the time course of the transporter current under a range of experimental conditions. The model predicts that glial uptake of glycine will decay toward zero during a sustained period of elevated glycine concentration. This property of GLYT1b may permit spillover from glycinergic terminals to nearby excitatory terminals during a prolonged burst of inhibitory activity, and reverse transport may extend the period of elevated glycine concentration beyond the end of the inhibitory burst. PMID:15951392

  8. Specificity analysis of protein lysine methyltransferases using SPOT peptide arrays.

    PubMed

    Kudithipudi, Srikanth; Kusevic, Denis; Weirich, Sara; Jeltsch, Albert

    2014-11-29

    Lysine methylation is an emerging post-translation modification and it has been identified on several histone and non-histone proteins, where it plays crucial roles in cell development and many diseases. Approximately 5,000 lysine methylation sites were identified on different proteins, which are set by few dozens of protein lysine methyltransferases. This suggests that each PKMT methylates multiple proteins, however till now only one or two substrates have been identified for several of these enzymes. To approach this problem, we have introduced peptide array based substrate specificity analyses of PKMTs. Peptide arrays are powerful tools to characterize the specificity of PKMTs because methylation of several substrates with different sequences can be tested on one array. We synthesized peptide arrays on cellulose membrane using an Intavis SPOT synthesizer and analyzed the specificity of various PKMTs. Based on the results, for several of these enzymes, novel substrates could be identified. For example, for NSD1 by employing peptide arrays, we showed that it methylates K44 of H4 instead of the reported H4K20 and in addition H1.5K168 is the highly preferred substrate over the previously known H3K36. Hence, peptide arrays are powerful tools to biochemically characterize the PKMTs.

  9. Specificity Analysis of Protein Lysine Methyltransferases Using SPOT Peptide Arrays

    PubMed Central

    Kudithipudi, Srikanth; Kusevic, Denis; Weirich, Sara; Jeltsch, Albert

    2014-01-01

    Lysine methylation is an emerging post-translation modification and it has been identified on several histone and non-histone proteins, where it plays crucial roles in cell development and many diseases. Approximately 5,000 lysine methylation sites were identified on different proteins, which are set by few dozens of protein lysine methyltransferases. This suggests that each PKMT methylates multiple proteins, however till now only one or two substrates have been identified for several of these enzymes. To approach this problem, we have introduced peptide array based substrate specificity analyses of PKMTs. Peptide arrays are powerful tools to characterize the specificity of PKMTs because methylation of several substrates with different sequences can be tested on one array. We synthesized peptide arrays on cellulose membrane using an Intavis SPOT synthesizer and analyzed the specificity of various PKMTs. Based on the results, for several of these enzymes, novel substrates could be identified. For example, for NSD1 by employing peptide arrays, we showed that it methylates K44 of H4 instead of the reported H4K20 and in addition H1.5K168 is the highly preferred substrate over the previously known H3K36. Hence, peptide arrays are powerful tools to biochemically characterize the PKMTs. PMID:25489813

  10. Purification of cytochrome c oxidase by lysine-affinity chromatography.

    PubMed

    Felsch, J; Kotake, S; Copeland, R A

    1992-02-01

    A method for the purification of cytochrome c oxidase that is based on the affinity of this enzyme for polycations such as poly-L-lysine is described. When detergent extracts of bovine cardiac mitochondria were applied to either a poly-L-lysine-agarose or a lysine-Sepharose column at low ionic strength, cytochrome c oxidase was found to adhere tightly, whereas the bulk of the proteins were eluted by washing with the same buffer. The cytochrome c oxidase was eluted by application of a linear potassium chloride gradient to the columns. The resulting enzyme was identical to that obtained by more traditional purification methods in terms of its subunit composition, optical and resonance Raman spectra, and cytochrome c oxidizing activity. When detergent extracts of spheroplasts from Paracoccus denitrificans were applied to these columns, the cytochrome c oxidase from this organism was also found to adhere tightly. Thus this purification method appears applicable to both prokaryotic and eukaryotic forms of the enzyme. The advantages of this new purification method are that it is less labor intensive than the traditional procedure and less expensive than methods based on cytochrome c-affinity chromatography.

  11. Proteome-wide enrichment of proteins modified by lysine methylation

    PubMed Central

    Carlson, Scott M; Moore, Kaitlyn E; Green, Erin M; Martín, Glòria Mas; Gozani, Or

    2015-01-01

    We present a protocol for using the triple malignant brain tumor domains of L3MBTL1 (3×MBT), which bind to mono- and di-methylated lysine with minimal sequence specificity, in order to enrich for such methylated lysine from cell lysates. Cells in culture are grown with amino acids containing light or heavy stable isotopic labels. Methylated proteins are enriched by incubating cell lysates with 3×MBT, or with the binding-null D355N mutant as a negative control. Quantitative liquid chromatography and tandem mass spectrometry (LC-MS/MS) are then used to identify proteins that are specifically enriched by 3×MBT pull-down. The addition of a third isotopic label allows the comparison of protein lysine methylation between different biological conditions. Unlike most approaches, our strategy does not require a prior hypothesis of candidate methylated proteins, and it recognizes a wider range of methylated proteins than any available method using antibodies. Cells are prepared by growing in isotopic labeling medium for about 7 d; the process of enriching methylated proteins takes 3 d and analysis by LC-MS/MS takes another 1–2 d. PMID:24309976

  12. Glycine transport inhibitors for the treatment of schizophrenia.

    PubMed

    Hashimoto, Kenji

    2010-05-27

    Multiple lines of evidence indicate that hypofunction of glutamatergic neurotransmission via N-methyl-D-aspartate (NMDA) receptors might be implicated in the pathophysiology of schizophrenia, suggesting that increasing NMDA receptor function via pharmacological manipulation could provide a new strategy for the management of schizophrenia. Currently, the glycine modulatory sites on NMDA receptors present the most attractive therapeutic targets for the treatment of schizophrenia. One means of enhancing NMDA receptor neurotransmission is to increase the availability of the obligatory co-agonist glycine at modulatory sites on the NMDA receptors through the inhibition of glycine transporter-1 (GlyT-1) on glial cells. Clinical studies have demonstrated that the GlyT-1 inhibitor sarcosine (N-methyl glycine) shows antipsychotic activity in patients with schizophrenia. Accordingly, a number of pharmaceutical companies have developed novel and selective GlyT-1 inhibitors for the treatment of schizophrenia. This paper provides an overview of the various GlyT-1 inhibitors and their therapeutic potential.

  13. Glycine Transport Inhibitors for the Treatment of Schizophrenia

    PubMed Central

    Hashimoto, Kenji

    2010-01-01

    Multiple lines of evidence indicate that hypofunction of glutamatergic neurotransmission via N-methyl-D-aspartate (NMDA) receptors might be implicated in the pathophysiology of schizophrenia, suggesting that increasing NMDA receptor function via pharmacological manipulation could provide a new strategy for the management of schizophrenia. Currently, the glycine modulatory sites on NMDA receptors present the most attractive therapeutic targets for the treatment of schizophrenia. One means of enhancing NMDA receptor neurotransmission is to increase the availability of the obligatory co-agonist glycine at modulatory sites on the NMDA receptors through the inhibition of glycine transporter-1 (GlyT-1) on glial cells. Clinical studies have demonstrated that the GlyT-1 inhibitor sarcosine (N-methyl glycine) shows antipsychotic activity in patients with schizophrenia. Accordingly, a number of pharmaceutical companies have developed novel and selective GlyT-1 inhibitors for the treatment of schizophrenia. This paper provides an overview of the various GlyT-1 inhibitors and their therapeutic potential. PMID:21253021

  14. Glomus fasciculatum, a Weak Pathogen of Heterodera glycines

    PubMed Central

    Francl, L. J.; Dropkin, V. H.

    1985-01-01

    The occurrence ofchlamydospores of Glomus fasciculatum (Gf) within cysts of the soybean cyst nematode, Heterodera glycines, and the effects of vesicular-arbuscular mycorrhizae on nematode population dynamics and soybean (Glycine max) plant growth were investigated. Chlamydospores occupied 1-24% of cysts recovered from field soil samples. Hyphae of Missouri isolate Gfl penetrated the female nematode cuticle shortly after she ruptured the root epidermis. Convoluted hyphae filled infected eggs, and sporogenesis occurred within infected eggs. G. microcarpum, G. mosseae, and two isolates of Gf were inoculated with H. glycines on plants of 'Essex' soybeans. Each of the two Gf isolates infected about 1% of the nematode eggs in experimental pot cuhures. The Gfl isolate decreased the number of first-generation adult females 26%, compared with the nonmycorrhizal control. The total numbers of first-generation plus second-generation adult females were similar for both Gf isolates and 29-41% greater than the nonmycorrhizal control. Soybean plants with Gf and H. glycines produced more biomass than did nonmycorrhizal plants with nematodes, but only Gfl delayed leaf senescence. PMID:19294126

  15. Multicellular Secretory Trichome Development on Soybean and Related Glycine Gynoecia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multicellular glandular trichomes form on gynoecia of wild Glycine annual species, annual soybean cultivars, and wild perennial species. These trichomes occur on gynoecia of annual taxa from ovary base to style base, and along style of perennial species. Trichomes form at least two days prior to ant...

  16. Evaluation of Soybean [Glycine max (L.) Merr.] F1 Hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterosis is an important factor in development of hybrid cultivars. Few heterosis studies have been done in soybean [Glycine max (L.) Merr.]. This is because manual cross-pollination is difficult and time consuming, and not conducive as an economical way to produce large quantities of hybrid seed...

  17. 21 CFR 520.550 - Dextrose/glycine/electrolyte.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Dextrose/glycine... therapy. Oral therapy in these cases is too slow. Animals which cannot drink after initial...

  18. Lignin Degradation by Fusarium solani f. sp. glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sudden death syndrome (SDS), caused by the soilborne fungal pathogen Fusarium solani f. sp. glycines, is one of the most important diseases of soybean. Lignin degradation may play a role in the infection, colonization, and survival of the fungus in root tissue . Lignin degradation by F. solani f. sp...

  19. 21 CFR 522.518 - Cupric glycinate injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Cupric glycinate injection. 522.518 Section 522.518 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  20. 21 CFR 522.518 - Cupric glycinate injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Cupric glycinate injection. 522.518 Section 522.518 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  1. 21 CFR 522.518 - Cupric glycinate injection.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Cupric glycinate injection. 522.518 Section 522.518 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  2. 21 CFR 522.518 - Cupric glycinate injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Cupric glycinate injection. 522.518 Section 522.518 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  3. 21 CFR 522.518 - Cupric glycinate injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Cupric glycinate injection. 522.518 Section 522.518 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  4. Alanine racemase mutants of Mycobacterium tuberculosis require D-alanine for growth and are defective for survival in macrophages and mice.

    PubMed

    Awasthy, Disha; Bharath, Sowmya; Subbulakshmi, Venkita; Sharma, Umender

    2012-02-01

    Alanine racemase (Alr) is an essential enzyme in most bacteria; however, some species (e.g. Listeria monocytogenes) can utilize d-amino acid transaminase (Dat) to generate d-alanine, which renders Alr non-essential. In addition to the conflicting reports on gene knockout of alr in Mycobacterium smegmatis, a recent study concluded that depletion of Alr does not affect the growth of M. smegmatis. In order to get an unambiguous answer on the essentiality of Alr in Mycobacterium tuberculosis and validate it as a drug target in vitro and in vivo, we have inactivated the alr gene of M. tuberculosis and found that it was not possible to generate an alr knockout in the absence of a complementing gene copy or d-alanine in the growth medium. The growth kinetics of the alr mutant revealed that M. tuberculosis requires very low amounts of d-alanine (5-10 µg ml(-1)) for optimum growth. Survival kinetics of the mutant in the absence of d-alanine indicated that depletion of this amino acid results in rapid loss of viability. The alr mutant was found to be defective for growth in macrophages. Analysis of phenotype in mice suggested that non-availability of d-alanine in mice leads to clearance of bacteria followed by stabilization of bacterial number in lungs and spleen. Additionally, reversal of d-cycloserine inhibition in the presence of d-alanine in M. tuberculosis suggested that Alr is the primary target of d-cycloserine. Thus, Alr of M. tuberculosis is a valid drug target and inhibition of Alr alone should result in loss of viability in vitro and in vivo.

  5. The effect of exogenous β-N-methylamino-L: -alanine on the growth of Synechocystis PCC6803.

    PubMed

    Downing, Simoné; van de Venter, Maryna; Downing, Timothy G

    2012-01-01

    β-N-Methylamino-L: -alanine (BMAA), a non-proteinogenic amino acid, has been detected in a range of cyanobacteria, including terrestrial, aquatic, free living and endosymbiotic species. The widespread occurrence of cyanobacteria in the environment raises concerns regarding the ecological and toxicological impact of BMAA, and consequently, studies have focussed extensively on the toxicity and environmental impact of BMAA, while no research has addressed the ecophysiological or metabolic role of the compound in cyanobacteria. In this study, both the uptake of exogenous BMAA by and the effect of exogenous BMAA on the growth of Synechocystis PCC6803 were investigated. BMAA was rapidly taken up by the non-diazotrophic cyanobacterium Synechocystis PCC6803 in a concentration dependent manner. The presence of exogenous BMAA resulted in a substantial and concentration-dependent decrease in cell growth and the substantial loss of photosynthetic pigmentation. Similar effects were seen in the presence of the non-proteinogenic amino acid, 2,4-diaminobutyric acid but to a lesser degree than that of BMAA. The effects were reversed when light was decreased from 16 to 10 μmol m(-2) s(-1). Control cultures grown in the presence of L: -arginine, L: -asparagine, L: -glutamate and glycine showed normal or slightly increased growth with no change in pigmentation. The decrease in growth rate coupled to bleaching indicates that BMAA may induce chlorosis in the presence of adequate photosynthetic radiation suggesting a connection between BMAA and the induction of conditions, such as nitrogen or sulphur depletion, that result in growth arrest and the induction of chlorosis.

  6. Preferential Pathway for Glycine Formation in Star-Forming Regions

    NASA Astrophysics Data System (ADS)

    Pilling, S.; Boechat-Roberty, H. M.; Baptista, L.; Santos A. C., F.

    Interstellar clouds, similar to that from which the solar system was formed, contain many organic molecules including aldehydes, acids, ketones, and sugars Ehrenfreund & Charnley (2000). Those organic compounds have important functions in terrestrial biochemistry and could also have been important in prebiotic synthesis. The simplest amino acid, glycine (NH2CH2COOH), was recently detected in the hot molecular cores Sgr B2(N-LMH), Orion KL, and W51 e1/e2 Kuan et al. (2003). The formic acid (HCOOH) and acetic acid(CH3COOH) have also been detected in those regions Liu et al. (2002), Remijan et al. (2004). The goal of this work is to study experimentally photoionization and photodissociation processes of glycine precursor molecules, acetic acid and formic acid to elucidate a possible preferentially in the glycine synthesis between ice and gas phase. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator TGM) beamline (100 - 310 eV). The experimental set up consists of a high vacuum chamber with a Time-Of-Flight Mass Spectrometer (TOF-MS). Mass spectra were obtained using PhotoElectron PhotoIon Coincidence (PEPICO) technique. Kinetic energy distributions and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Dissociative and non-dissociative photoionization cross sections for both molecules were also determined Boechat-Roberty, Pilling & Santos (2005). Due to the high photodissociation cross section of formic acid it is possible that in PDRs regions, just after molecules evaporation from the grains surface, it is almost destructed by soft X-rays, justifying the observed low abundance of HCOOH in gaseous phase Ehrenfreund et al. (2001). Acetic acid have shown to be more stable to the ionizing field, and its main outcomes from dissociation process were the reactive ionic fragments COOH+ and CH3CO+. To

  7. Controlled expression and structural organization of a Lactococcus lactis bacteriophage lysin encoded by two overlapping genes.

    PubMed Central

    Shearman, C A; Jury, K L; Gasson, M J

    1994-01-01

    The phi vML3 bacteriophage lysin is specific for lactococci and could be used to promote enzyme release during cheese manufacture. The level of lysin expression from the cloned gene using its own upstream sequences is very low. Expression in Escherichia coli by using a synthetic hybrid lysin gene and a series of BAL 31 deletions of the original cloned DNA fragment suggested that the start of the gene had previously been incorrectly assigned. Reevaluation of homology between the lysin and Bacillus subtilis PZA protein 15 led to the identification of a new potential ribosome binding site (RBS). A 0.72-kb PCR-generated fragment including this RBS and the complete lysin gene was expressed and inducibly controlled. The translational start of the lysin gene was identified as an isoleucine codon, and this may lead to a low translation rate. During the analysis of the BAL 31 deletion fragments, two proteins of 20 and 8 kDa were shown to be expressed from the originally defined lysin gene. The DNA sequence has a second open reading frame with a good RBS and two potential start methionines. The smaller lysin protein was isolated, and the N terminus was sequenced, confirming that one methionine codon acted as the start of a second gene. The larger lysin protein has homology with lysozymes. The smaller lysin protein has some features resembling those of a holin. The possible roles of these two proteins in lysis of lactococci are discussed. Images PMID:7944354

  8. Porcine alanine transaminase after liver allo-and xenotransplantation

    PubMed Central

    Ekser, Burcin; Gridelli, Bruno; Cooper, David K.C.

    2013-01-01

    Aspartate transaminase (AST) and alanine transaminase (ALT) are measured following liver transplantation as indicators of hepatocellular injury. During a series of orthotopic liver allo-and xenotransplants, we observed that there was an increase in AST in all cases. The anticipated concomitant rise in ALT did not occur when a wild-type (WT) pig was the source of the liver graft, but did occur when a baboon or a genetically engineered (α1,3-galactosyltransferase gene-knockout [GTKO]) pig was the source of the graft. We hypothesized that the cience of Galα1,3 Gal in GTKO pig livers may render pig hepatocytes similar to human and baboon hepatocytes in their response to hepatocellular injury. Reviewing the literature, after WT pig liver allotransplantation or xenotransplantation, in the majority of reports, although changes in AST were reported, no mention was made of changes in ALT, suggesting that there was no change in ALT. However, Ramirez et al. reported two cases of liver xenotransplants from hCD55 pigs, following which there were increases in both AST and ALT, suggesting that it is not simply the cience of expression of Galα1,3 Gal that is the cause. We acknowledge that our observation is based on a small number of experiments, but we believe it is worth recording. PMID:22360753

  9. Porcine alanine transaminase after liver allo-and xenotransplantation.

    PubMed

    Ekser, Burcin; Gridelli, Bruno; Cooper, David K C

    2012-01-01

    Aspartate transaminase (AST) and alanine transaminase (ALT) are measured following liver transplantation as indicators of hepatocellular injury. During a series of orthotopic liver allo-and xenotransplants, we observed that there was an increase in AST in all cases. The anticipated concomitant rise in ALT did not occur when a wild-type (WT) pig was the source of the liver graft, but did occur when a baboon or a genetically engineered (α1,3-galactosyltransferase gene-knockout [GTKO]) pig was the source of the graft. We hypothesized that the cience of Galα1,3Gal in GTKO pig livers may render pig hepatocytes similar to human and baboon hepatocytes in their response to hepatocellular injury. Reviewing the literature, after WT pig liver allotransplantation or xenotransplantation, in the majority of reports, although changes in AST were reported, no mention was made of changes in ALT, suggesting that there was no change in ALT. However, Ramirez et al. reported two cases of liver xenotransplants from hCD55 pigs, following which there were increases in both AST and ALT, suggesting that it is not simply the cience of expression of Galα1,3Gal that is the cause. We acknowledge that our observation is based on a small number of experiments, but we believe it is worth recording.

  10. Alanine synthesis from glyceraldehyde and ammonium ion in aqueous solution

    NASA Technical Reports Server (NTRS)

    Weber, A. L.

    1985-01-01

    The formation of alanine (ala) form C(14)-glyceraldehyde and ammonium phosphate in the presence or absence of a thiol is reported. At ambient temperature, ala synthesis was six times more rapid in the presence of 3-mercaptopropionic acid than in its absence (0.6 and 0.1 percent, respectively, after 60 days). Similarly, the presence of another thiol, N-acetylcysteinate, increased the production of ala, as well as of lactate. The reaction pathway of thiol-catalyzed synthesis of ala, with the lactic acid formed in a bypath, is suggested. In this, dehydration of glyceraldehyde is followed by the formation of hemithioacetal. In the presence of ammonia, an imine is formed, which eventually yields ala. This pathway is consistent with the observation that the rate ratio of ala/lactate remains constant throughout the process. The fact that the reaction takes place under anaerobic conditions in the presence of H2O and with the low concentrations of simple substrates and catalysts makes it an attractive model prebiotic reaction in the process of molecular evolution.

  11. Lysine 2,3-aminomutase. Support for a mechanism of hydrogen transfer involving S-adenosylmethionine.

    PubMed

    Baraniak, J; Moss, M L; Frey, P A

    1989-01-25

    The conversion of L-lysine to L-beta-lysine is catalyzed by lysine 2,3-aminomutase. The reaction involves the interchange of the 2-amino group of lysine with a hydrogen at carbon 3. As such the reaction is formally analogous to adenosylcobalamin-dependent rearrangements. However, the enzyme does not contain and is not activated by this coenzyme. Instead it contains iron and pyridoxal phosphate and is activated by S-adenosylmethionine. Earlier experiments implicated adenosyl-C-5' of S-adenosylmethionine in the hydrogen transfer mechanism, apparently in a role similar or analogous to that of adenosyl moiety of adenosylcobalamin in the B12-dependent rearrangements. The question of whether both hydrogens or only one hydrogen at adenosyl-C-5' participate in the hydrogen-transfer process has been addressed by carrying out the lysine 2,3-aminomutase reaction with S-[5'-3H] adenosylmethionine in the presence of 10 times its molar concentration of enzyme. Under these conditions all of the tritium appeared in lysine and beta-lysine, showing that C-5'-hydrogens participate. To determine whether hydrogen transfer is compulsorily intermolecular and intramolecular, various molar ratios of [3,3-2H2]lysine and unlabeled lysine were submitted to the action of lysine 2,3-aminomutase under conditions in which 10-15% conversion to beta-lysine occurred. Mass spectral analysis of the beta-lysine for monodeutero and dideutero species showed conclusively that hydrogen transfer is both intramolecular and intermolecular. The results quantitatively support our postulate that activation of the enzyme involves a transformation of S-adenosylmethionine into a form that promotes the generation of an adenosyl-5' free radical, which abstracts hydrogen from lysine to form 5'-deoxyadenosine as an intermediate.

  12. PKCβ–dependent phosphorylation of the glycine transporter 1

    PubMed Central

    Vargas-Medrano, Javier; Castrejon-Tellez, Vicente; Fernando, Plenge; Ramirez, Ivan; Miranda, Manuel

    2011-01-01

    The extracellular levels of the neurotransmitter glycine in the brain are tightly regulated by the glycine transporter 1 (GlyT1) and the clearance rate for glycine depends on its rate of transport and the levels of cell surface GlyT1. Over the years, it has been shown that PKC tightly regulates the activity of several neurotransmitter transporters. In the present work, by stably expressing three N-terminus GlyT1 isoforms in porcine aortic endothelial cells and assaying for [32P]-orthophosphate metabolic labeling, we demonstrated that the isoforms GlyT1a, GlyT1b, and GlyT1c were constitutively phosphorylated, and that phosphorylation was dramatically enhanced, in a time dependent fashion, after PKC activation by phorbol ester. The phosphorylation was PKC-dependent, since pre-incubation of the cells with bisindolylmaleimide I, a selective PKC inhibitor, abolished the phorbol ester-induced phosphorylation. Blotting with specific anti-phospho-tyrosine antibodies did not yield any signal that could correspond to GlyT1 tyrosine phosphorylation, suggesting that the phosphorylation occurs at serine and/or threonine residues. In addition, a 23-40% -inhibition on Vmax was obtained by incubation with phorbol ester without a significant change on the apparent Km value. Furthermore, pre-incubation of the cells with the selective PKCα/β inhibitor Gö6976 abolished the downregulation effect of phorbol ester on uptake and phosphorylation, whereas the selective PKCβ inhibitors (PKCβ inhibitor or LY333531) prevented the phosphorylation without affecting glycine uptake, defining a specific role of classical PKC on GlyT1 uptake and phosphorylation. Taken together, these data suggest that phosphorylation that conventional PKCα/β regulates the uptake of glycine, whereas PKCβ is responsible for GlyT1 phosphorylation. PMID:21864610

  13. P2Y Purinergic Regulation of the Glycine Neurotransmitter Transporters*

    PubMed Central

    Jiménez, Esperanza; Zafra, Francisco; Pérez-Sen, Raquel; Delicado, Esmerilda G.; Miras-Portugal, Maria Teresa; Aragón, Carmen; López-Corcuera, Beatriz

    2011-01-01

    The sodium- and chloride-coupled glycine neurotransmitter transporters (GLYTs) control the availability of glycine at glycine-mediated synapses. The mainly glial GLYT1 is the key regulator of the glycine levels in glycinergic and glutamatergic pathways, whereas the neuronal GLYT2 is involved in the recycling of synaptic glycine from the inhibitory synaptic cleft. In this study, we report that stimulation of P2Y purinergic receptors with 2-methylthioadenosine 5′-diphosphate in rat brainstem/spinal cord primary neuronal cultures and adult rat synaptosomes leads to the inhibition of GLYT2 and the stimulation of GLYT1 by a paracrine regulation. These effects are mainly mediated by the ADP-preferring subtypes P2Y1 and P2Y13 because the effects are partially reversed by the specific antagonists N6-methyl-2′-deoxyadenosine-3′,5′-bisphosphate and pyridoxal-5′-phosphate-6-azo(2-chloro-5-nitrophenyl)-2,4-disulfonate and are totally blocked by suramin. P2Y12 receptor is additionally involved in GLYT1 stimulation. Using pharmacological approaches and siRNA-mediated protein knockdown methodology, we elucidate the molecular mechanisms of GLYT regulation. Modulation takes place through a signaling cascade involving phospholipase C activation, inositol 1,4,5-trisphosphate production, intracellular Ca2+ mobilization, protein kinase C stimulation, nitric oxide formation, cyclic guanosine monophosphate production, and protein kinase G-I (PKG-I) activation. GLYT1 and GLYT2 are differentially sensitive to NO/cGMP/PKG-I both in brain-derived preparations and in heterologous systems expressing the recombinant transporters and P2Y1 receptor. Sensitivity to 2-methylthioadenosine 5′-diphosphate by GLYT1 and GLYT2 was abolished by small interfering RNA (siRNA)-mediated knockdown of nitric-oxide synthase. Our data may help define the role of GLYTs in nociception and pain sensitization. PMID:21245148

  14. Guanidinoethyl sulphonate is a glycine receptor antagonist in striatum.

    PubMed

    Sergeeva, Olga A; Chepkova, Aisa N; Haas, Helmut L

    2002-11-01

    1. Guanidinoethyl sulphonate (GES) is an analogue of taurine and an inhibitor of taurine transport. Interactions of GES with GABA(A) and glycine receptors are studied by whole cell recording and fast drug application in isolated striatal neurons of the mouse. 2. We confirm that GES is a weak agonist at GABA(A) receptors, and is able to antagonize GABA-evoked responses. GES did not gate GlyR. 3. GES antagonized glycine responses in a concentration-dependent and surmountable manner. Glycine dose-response curves were shifted to the right by GES (0.5 mM), yielding EC(50)s and Hill coefficients of 62 micro M and 2.5 in control, 154 micro M and 1.3 in the presence of GES. 4. GlyR-mediated taurine responses were competitively antagonized by GES. Taurine dose-response curves, in contrast to the glycine dose-response curves were shifted by GES to the right in a parallel manner. 5. The GlyR-block by GES was not voltage-dependent. 6. In contrast to our findings in the mouse, in rat striatal neurons which lack expression of the alpha3 GlyR subunit, GES shifted the glycine dose-response curve to the right in a parallel way without affecting the maximal response. Subtype-specificity of the GES action at GlyR must await further investigation in artificial expression systems. 7. We conclude that GES is a competitive antagonist at GlyR. The antagonistic action of GES at inhibitory ionotropic receptors can explain its epileptogenic action. Care must be taken with the interpretation of data on GES evoked taurine release.

  15. Enzymatic characterization and crystal structure analysis of the D-alanine-D-alanine ligase from Helicobacter pylori.

    PubMed

    Wu, Dalei; Zhang, Liang; Kong, Yunhua; Du, Jiamu; Chen, Shuai; Chen, Jing; Ding, Jianping; Jiang, Hualiang; Shen, Xu

    2008-09-01

    D-Alanine-D-alanine ligase is the second enzyme in the D-Ala branch of bacterial cell wall peptidoglycan assembly, and recognized as an attractive antimicrobial target. In this work, the D-Ala-D-Ala ligase of Helicobacter pylori strain SS1 (HpDdl) was kinetically and structurally characterized. The determined apparent K(m) of ATP (0.87 microM), the K(m1) (1.89 mM) and K(m2) of D-Ala (627 mM), and the k(cat) (115 min(-1)) at pH 8.0 indicated its relatively weak binding affinity and poor catalytic activity against the substrate D-Ala in vitro. However, by complementary assay of expressing HpDdl in Escherichia coli Delta ddl mutant, HpDdl was confirmed to be capable of D-Ala-D-Ala ligating in vivo. Through sequence alignment with other members of the D-Ala-D-X ligase superfamily, HpDdl keeps two conservatively substituted residues (Ile16 and Leu241) and two nonconserved residues (Leu308 and Tyr311) broadly located in the active region of the enzyme. Kinetic analyses against the corresponding HpDdl mutants (I16V, L241Y, L241F, L308T, and Y311S) suggested that these residues, especially Leu308 and Tyr311, might partly contribute to the unique catalytic properties of the enzyme. This was fairly proved by the crystal structure of HpDdl, which revealed that there is a 3(10)-helix (including residues from Gly306 to Leu312) near the D-Ala binding region in the C-terminal domain, where HpDdl has two sequence deletions compared with other homologs. Such 3(10)-helix may participate in D-Ala binding and conformational change of the enzyme. Our present work hopefully provides useful information for understanding the D-Ala-D-Ala ligase of Helicobacter pylori.

  16. Role of Charge and Solvation in the Structure and Dynamics of Alanine-Rich Peptide AKA2 in AOT Reverse Micelles

    PubMed Central

    2015-01-01

    The propensity of peptides to form α-helices has been intensely studied using theory, computation, and experiment. Important model peptides for the study of the coil-to-helix transition have been alanine–lysine (AKA) peptides in which the lysine residues are placed on opposite sides of the helix avoiding charge repulsion while enhancing solubility. In this study, the effects of capped versus zwitterionic peptide termini on the secondary structure of alanine-rich peptides in reverse micelles are explored. The reverse micelles are found to undergo substantial shape fluctuations, a property observed in previous studies of AOT reverse micelles in the absence of solvated peptide. The peptides are observed to interact with water, as well as the AOT surfactant, including interactions between the nonpolar residues and the aliphatic surfactant tails. Computation of IR spectra for the amide I band of the peptide allows for direct comparison with experimental spectra. The results demonstrate that capped AKA2 peptides form more stable α helices than zwitterionic AKA2 peptides in reverse micelles. The rotational anisotropy decay of water is found to be distinctly different in the presence or absence of peptide within the reverse micelle, suggesting that the introduction of peptide significantly alters the number of free waters within the reverse micelle nanopool. However, neither the nature of the peptide termini (capped or charged) nor the degree of peptide helicity is found to significantly alter the balance of interactions between the peptides and the environment. Observed changes in the degree of helicity in AKA2 peptides in bulk solution and in reverse micelle environments result from changes in peptide confinement and hydration as well as direct nonpolar and polar interactions with the water–surfactant interface. PMID:25337983

  17. Glycine and a glycine dehydrogenase (GLDC) SNP as citalopram/escitalopram response biomarkers in depression: pharmacometabolomics-informed pharmacogenomics.

    PubMed

    Ji, Y; Hebbring, S; Zhu, H; Jenkins, G D; Biernacka, J; Snyder, K; Drews, M; Fiehn, O; Zeng, Z; Schaid, D; Mrazek, D A; Kaddurah-Daouk, R; Weinshilboum, R M

    2011-01-01

    Major depressive disorder (MDD) is a common psychiatric disease. Selective serotonin reuptake inhibitors (SSRIs) are an important class of drugs used in the treatment of MDD. However, many patients do not respond adequately to SSRI therapy. We used a pharmacometabolomics-informed pharmacogenomic research strategy to identify citalopram/escitalopram treatment outcome biomarkers. Metabolomic assay of plasma samples from 20 escitalopram remitters and 20 nonremitters showed that glycine was negatively associated with treatment outcome (P = 0.0054). This observation was pursued by genotyping tag single-nucleotide polymorphisms (SNPs) for genes encoding glycine synthesis and degradation enzymes, using 529 DNA samples from SSRI-treated MDD patients. The rs10975641 SNP in the glycine dehydrogenase (GLDC) gene was associated with treatment outcome phenotypes. Genotyping for rs10975641 was carried out in 1,245 MDD patients in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, and its presence was significant (P = 0.02) in DNA taken from these patients. These results highlight a possible role for glycine in SSRI response and illustrate the use of pharmacometabolomics to "inform" pharmacogenomics.

  18. Genotype Response of Soybean (Glycine max) Whole Plants and Hairy Roots to Fusarium solani f. sp. glycines Infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium solani f. sp. Glycines, a soilborne fungus, infects soybean roots and causes sudden death syndrome. The response of 13 soybean genotypes to the pathogen infection was tested with potted greenhouse grown plants and with cultured hairy roots. The taproots of all genotypes grown plants measure...

  19. Syncytium gene expression in Glycine max [PI88788} roots undergoing a resistant reaction of the parasitic nematode Heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laser capture microdissection (LCM) was used to isolate Heterodera glycines feeding sites (syncytia) from the (G. max) genotype PI 88788. Syncytia at various stages of the resistant response were isolated from roots 3, 6 and 9 days post infection (dpi). At 3 dpi, the analyses revealed highly induced...

  20. Effects of Monovalent Cations on the Sodium-Alanine Interaction in Rabbit Ileum

    PubMed Central

    Frizzell, Raymond A.; Schultz, Stanley G.

    1970-01-01

    H, K, Rb, and Li inhibit Na-dependent alanine influx across the brush border of rabbit ileum. Kinetic analysis indicates that H and K behave as competitive inhibitors of influx so that increasing the concentration of H or K in the mucosal solution is kinetically indistinguishable from decreasing the Na concentration. In addition the coupling between alanine and Na influxes is markedly reduced at pH 2.5. With the exception of H and Li, none of these monovalent cations significantly affects carrier-mediated alanine influx in the absence of Na indicating that their inhibitory effects are largely restricted to the Na-dependent fraction of influx. Increasing H concentration from 0.03 to 3 mM does not affect influx in the absence of Na but markedly inhibits influx in the presence of Na. Li significantly enhances alanine influx in the absence of Na. Ag, UO2, and La also inhibit the Na-dependent fraction of alanine influx. These findings suggest that anionic groups having a pKa of approximately 4 are involved in the interaction between Na and the alanine-carrier complex; present evidence implicates carboxylate groups however, phosphoryl residues cannot be ruled out. The previously proposed kinetic model for the Na-alanine interaction has been extended to accommodate these effects of H and other monovalent cations. The mechanistic and physiological implications of these findings are discussed. PMID:5507092

  1. Revised mechanism of D-alanine incorporation into cell wall polymers in Gram-positive bacteria.

    PubMed

    Reichmann, Nathalie T; Cassona, Carolina Picarra; Gründling, Angelika

    2013-09-01

    Teichoic acids (TAs) are important for growth, biofilm formation, adhesion and virulence of Gram-positive bacterial pathogens. The chemical structures of the TAs vary between bacteria, though they typically consist of zwitterionic polymers that are anchored to either the peptidoglycan layer as in the case of wall teichoic acid (WTA) or the cell membrane and named lipoteichoic acid (LTA). The polymers are modified with D-alanines and a lack of this decoration leads to increased susceptibility to cationic antimicrobial peptides. Four proteins, DltA-D, are essential for the incorporation of d-alanines into cell wall polymers and it has been established that DltA transfers D-alanines in the cytoplasm of the cell onto the carrier protein DltC. However, two conflicting models have been proposed for the remainder of the mechanism. Using a cellular protein localization and membrane topology analysis, we show here that DltC does not traverse the membrane and that DltD is anchored to the outside of the cell. These data are in agreement with the originally proposed model for D-alanine incorporation through a process that has been proposed to proceed via a D-alanine undecaprenyl phosphate membrane intermediate. Furthermore, we found that WTA isolated from a Staphylococcus aureus strain lacking LTA contains only a small amount of D-alanine, indicating that LTA has a role, either direct or indirect, in the efficient D-alanine incorporation into WTA in living cells.

  2. Alanine-EPR as a transfer standard dosimetry system for low energy X radiation

    NASA Astrophysics Data System (ADS)

    Khoury, H. J.; da Silva, E. J.; Mehta, K.; de Barros, V. S.; Asfora, V. K.; Guzzo, P. L.; Parker, A. G.

    2015-11-01

    The purpose of this paper is to evaluate the use of alanine-EPR as a transfer standard dosimetry system for low energy X radiation, such as that in RS-2400, which operates in the range from 25 to 150 kV and 2 to 45 mA. Two types of alanine dosimeters were investigated. One is a commercial alanine pellets from Aérial-Centre de Ressources Technologiques, France and one was prepared in our laboratory (LMRI-DEN/UFPE). The EPR spectra of the irradiated dosimeters were recorded in the Nuclear Energy Department of UFPE, using a Bruker EMX10 EPR spectrometer operating in the X-band. The alanine-EPR dosimetry system was calibrated in the range of 20-220 Gy in this X-ray field, against an ionization chamber calibrated at the relevant X-ray energy with traceability to PTB. The results showed that both alanine dosimeters presented a linear dose response the same sensitivity, when the EPR signal was normalized to alanine mass. The total uncertainty in the measured dose was estimated to be about 3%. The results indicate that it is possible to use the alanine-EPR dosimetry system for validation of a low-energy X ray irradiator, such as RS-2400.

  3. Characterization of alanine catabolism in Pseudomonas aeruginosa and its importance for proliferation in vivo.

    PubMed

    Boulette, Megan L; Baynham, Patricia J; Jorth, Peter A; Kukavica-Ibrulj, Irena; Longoria, Aissa; Barrera, Karla; Levesque, Roger C; Whiteley, Marvin

    2009-10-01

    The opportunistic pathogen Pseudomonas aeruginosa causes a variety of infections in immunocompromised individuals, including individuals with the heritable disease cystic fibrosis. Like the carbon sources metabolized by many disease-causing bacteria, the carbon sources metabolized by P. aeruginosa at the host infection site are unknown. We recently reported that l-alanine is a preferred carbon source for P. aeruginosa and that two genes potentially involved in alanine catabolism (dadA and dadX) are induced during in vivo growth in the rat peritoneum and during in vitro growth in sputum (mucus) collected from the lungs of individuals with cystic fibrosis. The goals of this study were to characterize factors required for alanine catabolism in P. aeruginosa and to assess the importance of these factors for in vivo growth. Our results reveal that dadA and dadX are arranged in an operon and are required for catabolism of l-alanine. The dad operon is inducible by l-alanine, d-alanine, and l-valine, and induction is dependent on the transcriptional regulator Lrp. Finally, we show that a mutant unable to catabolize dl-alanine displays decreased competitiveness in a rat lung model of infection.

  4. Chiral glycine formation on cold interstellar grains by quantum tunneling hydrogen-deuterium substitution reactions

    NASA Astrophysics Data System (ADS)

    Oba, Yasuhiro; Watanabe, Naoki; Osamura, Yoshihiro; Kouchi, Akira

    2015-08-01

    We report experimental evidence that chiral glycine (NH2CHDCOOH) is formed by the surface reaction of normal glycine (NH2CH2COOH) solid with deuterium (D) atom at 12 K under the simulative conditions of interstellar molecular clouds. Chiral glycine formation is most likely initiated by the tunneling abstraction reaction of H atom by D atom followed by the addition of D atom to the glycine radical (NH2CHCOOH). Given that chiral glycine can form in such a primordial low-temperature environment, it might source molecular chirality as molecular clouds evolve into planetary systems.

  5. Importance of intrahepatic mechanisms to gluconeogenesis from alanine during exercise and recovery

    SciTech Connect

    Wasserman, D.H.; Williams, P.E.; Lacy, D.B.; Green, D.R.; Cherrington, A.D.

    1988-04-01

    These studies were performed to assess the importance of intrahepatic mechanisms to gluconeogenesis in the dog during 150 min of treadmill exercise and 90 min of recovery. Sampling catheters were implanted in an artery and portal and hepatic veins 16 days before experimentation. Infusions of (U-/sup 14/C)alanine, (3-/sup 3/H)glucose, and indocyanine green were used to assess gluconeogenesis. During exercise, a decline in arterial and portal vein plasma alanine and in hepatic blood flow led to a decrease in hepatic alanine delivery. During recovery, hepatic blood flow was restored to basal, causing an increase in hepatic alanine delivery beyond exercise rates but still below resting rates. Hepatic fractional alanine extraction increased from 0.26 +/- 0.02 at rest to 0.64 +/- 0.03 during exercise and remained elevated during recovery. Net hepatic alanine uptake was 2.5 +/- 0.2 mumol.kg-1.min-1 at rest and remained unchanged during exercise but was increased during recovery. The conversion rate of (/sup 14/C)alanine to glucose had increased by 248 +/- 38% by 150 min of exercise and had increased further during recovery. The efficiency with which alanine was channeled into glucose in the liver was accelerated to a rate of 338 +/- 55% above basal by 150 min of exercise but declined slightly during recovery. In conclusion, 1) gluconeogenesis from alanine is accelerated during exercise, due to an increase in the hepatic fractional extraction of the amino acid and through intrahepatic mechanisms that more efficiently channel it into glucose.

  6. Determination of D- and L-alanine concentrations using a pyruvic acid sensor.

    PubMed

    Inaba, Yohei; Hamada-Sato, Naoko; Kobayashi, Takeshi; Imada, Chiaki; Watanabe, Etsuo

    2003-08-01

    The concentrations of D- and L-alanine in bivalves are useful as indicators of environmental pollution. Amino acid oxidase with a low substrate specificity catalyzes the oxidation of various amino acids. Among the various amino acids, pyruvic acid can be generated from alanine only by the catalytic oxidative reaction of this oxidase. Therefore, in this study, the concentrations of D- and L-alanine were determined from the concentration of pyruvic acid, which was determined from the consumption of oxygen based on the oxidative reaction of pyruvate oxidase. From this point of view, there is a very strong possibility that biosensors utilizing enzymes with a low substrate specificity can be developed. The results obtained were as follows. (1) The optimum conditions for the use of pyruvic acid sensor were as follows: temperature of 25 degrees C, pH of 6.8, flow rate of 0.1 ml/min, thiamin diphosphate concentration of 1.5 mM, and injection volume of 50 microl. (2) D-Alanine and L-alanine optimally reacted with D- and L-amino acid oxidase at 30 degrees C, pH 8.2, for 30 min and at 37 degrees C, pH 7.8, for 90 min, respectively. (3) The linear relationships between the concentrations of D- and L-alanine and the output of the sensor were obtained at 3.56-106.8 microg of D-alanine and 5.34-71.3 microg of L-alanine. (4) The concentrations of D- and L-alanine in Meretrix iusoria, Patinopecten yessonsi, and Corbicula leana obtained by the proposed assay were in good agreement with those determined by a conventional method.

  7. Serum Alanine Aminotransferase Levels, Hematocrit Rate and Body Weight Correlations Before and After Hemodialysis Session

    PubMed Central

    Lopes, Edmundo Pessoa; Sette, Luis Henrique B. C.; Sette, Jorge Bezerra C.; Luna, Carlos F.; Andrade, Amaro M.; Moraes, Maviael; Sette, Paulo C. A.; Menezes, Roberto; Cavalcanti, Rui L.; Conceição, Sergio C.

    2009-01-01

    PURPOSE To evaluate alanine aminotransferase levels before and after a hemodialysis session and to correlate these values with the hematocrit rate and weight loss during hemodialysis. PATIENTS AND METHODS The serum alanine aminotransferase levels, hematocrit rate and body weight were measured and correlated before and after a single hemodialysis session for 146 patients with chronic renal failure. An receiver operating characteristic (ROC) curve for the serum alanine aminotransferase levels collected before and after hemodialysis was plotted to identify hepatitis C virus-infected patients. RESULTS The mean weight loss of the 146 patients during hemodialysis was 5.3% (p < 0.001). The mean alanine aminotransferase levels before and after hemodialysis were 18.8 and 23.9 IU/, respectively, denoting a significant 28.1% increase. An equally significant increase of 16.4% in the hematocrit rate also occurred after hemodialysis. The weight loss was inversely correlated with the rise in both the alanine aminotransferase level (r = 0.3; p < 0.001) and hematocrit rate (r = 0.5; p < 0.001). A direct correlation was found between the rise in alanine aminotransferase levels and the hematocrit during the hemodialysis session (r = 0.4; p < 0.001). Based on the ROC curve, the upper limit of the normal alanine aminotransferase level should be reduced by 40% relative to the upper limit of normal if the blood samples are collected before the hemodialysis session or by 60% if blood samples are collected after the session. CONCLUSION In the present study, significant elevations in the serum alanine aminotransferase levels and hematocrit rates occurred in parallel to a reduction in body weight after the hemodialysis session. These findings suggest that one of the factors for low alanine aminotransferase levels prior to hemodialysis could be hemodilution in patients with chronic renal failure. PMID:19841699

  8. 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.

  9. Characterization of the l-alanine exporter AlaE of Escherichia coli and its potential role in protecting cells from a toxic-level accumulation of l-alanine and its derivatives.

    PubMed

    Kim, Seryoung; Ihara, Kohei; Katsube, Satoshi; Hori, Hatsuhiro; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2015-08-01

    We previously reported that the alaE gene of Escherichia coli encodes the l-alanine exporter AlaE. The objective of this study was to elucidate the mechanism of the AlaE exporter. The minimum inhibitory concentration of l-alanine and l-alanyl-l-alanine in alaE-deficient l-alanine-nonmetabolizing cells MLA301ΔalaE was 4- and >4000-fold lower, respectively, than in the alaE-positive parent cells MLA301, suggesting that AlaE functions as an efflux pump to avoid a toxic-level accumulation of intracellular l-alanine and its derivatives. Furthermore, the growth of the alaE-deficient mutant derived from the l-alanine-metabolizing strain was strongly inhibited in the presence of a physiological level of l-alanyl-l-alanine. Intact MLA301ΔalaE and MLA301ΔalaE/pAlaE cells producing plasmid-borne AlaE, accumulated approximately 200% and 50%, respectively, of the [(3) H]l-alanine detected in MLA301 cells, suggesting that AlaE exports l-alanine. When 200 mmol/L l-alanine-loaded inverted membrane vesicles prepared from MLA301ΔalaE/pAlaE were placed in a solution containing 200 mmol/L or 0.34 μmol/L l-alanine, energy-dependent [(3) H]l-alanine accumulation occurred under either condition. This energy-dependent uphill accumulation of [(3) H]l-alanine was strongly inhibited in the presence of carbonyl cyanide m-chlorophenylhydrazone but not by dicyclohexylcarbodiimide, suggesting that the AlaE-mediated l-alanine extrusion was driven by proton motive force. Based on these results, physiological roles of the l-alanine exporter are discussed.

  10. Progress towards an alanine/ESR therapy level reference dosimetry service at NPL.

    PubMed

    Sharpe, P H; Rajendran, K; Sephton, J P

    1996-01-01

    This paper describes work being carried out at the National Physical Laboratory towards the establishment of an alanine reference dosimetry service for radiotherapy applications. A precision fused quartz holder has been constructed to allow precise positioning of alanine dosimeters in the ESR cavity. A novel method of signal analysis based on spectrum fitting has been developed to minimize the effect of baseline distortions. Data are also presented on the relative response of alanine to 60Co gamma rays and high energy photons (4-12 MeV).

  11. Applicability of EPR/alanine dosimetry for quality assurance in proton eye radiotherapy.

    PubMed

    Michalec, B; Mierzwinska, G; Ptaszkiewicz, M; Sowa, U; Stolarczyk, L; Weber, A

    2014-06-01

    A new quality assurance and quality control method for proton eye radiotherapy based on electron paramagnetic resonance (EPR)/alanine dosimetry has been developed. It is based on Spread-Out Bragg Peak entrance dose measurement with alanine detectors. The entrance dose is well correlated with the dose at the facility isocenter, where, during the therapeutic irradiation, the tumour is placed. The unique alanine detector features namely keeping the dose record in a form of stable radiation-induced free radicals trapped in the material structure, and the non-destructive read-out makes this type of detector a good candidate for additional documentation of the patient's exposure over the therapy course.

  12. Interactions of L-alanine with alumina as studied by vibrational spectroscopy.

    PubMed

    Garcia, Ana R; de Barros, Ricardo Brito; Fidalgo, Alexandra; Ilharco, Laura M

    2007-09-25

    The interactions of L-alanine with gamma- and alpha-alumina have been investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). L-alanine/alumina samples were dried from aqueous suspensions, at 36.5 degrees C, with two amino acid concentrations (0.4 and 0.8 mmol g-1) and at different pH values (1, 6, and 13). The vibrational spectra proved that the nature of L-alanine interactions with both aluminas is the same (hydrogen bonding), although the groups involved depend on the L-alanine form and on alumina surface groups, both controlled by the pH. For samples prepared at pH 1, cationic L-alanine [CH3CH(NH3+)COOH] displaces physisorbed water from alumina, and strong hydrogen bonds are established between the carbonyl groups of alanine, as electron donors, and the surface Al-OH2+ groups of alumina. This occurs at the expense of alanine dimer dissociation and breaking of intramolecular bonds. When samples are prepared at pH 6, the interacting groups are Al-OH2+ and the carboxylate groups of zwitterionic L-alanine [CH3CH(NH3+)COO-]. The affinity of L-alanine toward alumina decreases, as the strong NH3+...-OOC intermolecular hydrogen bonds prevail over the interactions with alumina. Thus, for a load of 0.8 mmol g-1, phase segregation is observed. On alpha-alumina, crystal deposition is even observed for a load of 0.4 mmol g-1. At pH 13, the carboxylate groups of anionic L-alanine [CH3CH(NH2)COO-] are not affected by alumina. Instead, hydrogen bond interactions occur between NH2 and the Al-OH surface groups of the substrate. Complementary N2 adsorption-desorption isotherms showed that adsorption of L-alanine occurs onto the alumina pore network for samples prepared at pH 1 and 13, whereas at pH 6 the amino acid/alumina interactions are not strong enough to promote adsorption. The mesoporous structure and the high specific surface area of gamma-alumina make it a more efficient substrate for adsorption of L-alanine. For each alumina, however, it is

  13. Temperature dependences of piezoelectric, elastic and dielectric constants of L-alanine crystal

    NASA Astrophysics Data System (ADS)

    Tylczyński, Z.; Sterczyńska, A.; Wiesner, M.

    2011-09-01

    Temperature changes in the components of piezoelectric, elastic and dielectric tensors were studied in L-alanine crystals in the range 100-300 K. A jumpwise increase in the c55 component of the elastic stiffness accompanied by maxima in damping of all face-shear modes observed at 199 K in L-alanine crystal were interpreted as a result of changes in the NH3+ vibrations occurring through electron-phonon coupling. All components of the piezoelectric tensor show small anomalies in this temperature range. The components of the electromechanical coupling coefficient determined indicate that L-alanine is a weak piezoelectric.

  14. Optical and Spectral Studies on β Alanine Metal Halide Hybrid Crystals

    NASA Astrophysics Data System (ADS)

    Sweetlin, M. Daniel; Selvarajan, P.; Perumal, S.; Ramalingom, S.

    2011-10-01

    We have synthesized and grown β alanine metal halide hybrid crystals viz. β alanine cadmium chloride (BACC), an amino acid transition metal halide complex crystal and β alanine potassium chloride (BAPC), an amino acid alkali metal halide complex crystal by slow evaporation method. The grown crystals were found to be transparent and have well defined morphology. The optical characteristics of the grown crystals were carried out with the help of UV-Vis Spectroscopy. The optical transmittances of the spectrums show that BAPC is more transparent than BACC. The Photoluminescence of the materials were determined by the Photoluminescent Spectroscopy

  15. Temperature dependences of piezoelectric, elastic and dielectric constants of L-alanine crystal.

    PubMed

    Tylczyński, Z; Sterczyńska, A; Wiesner, M

    2011-09-07

    Temperature changes in the components of piezoelectric, elastic and dielectric tensors were studied in L-alanine crystals in the range 100-300 K. A jumpwise increase in the c(55) component of the elastic stiffness accompanied by maxima in damping of all face-shear modes observed at 199 K in L-alanine crystal were interpreted as a result of changes in the NH(3)(+) vibrations occurring through electron-phonon coupling. All components of the piezoelectric tensor show small anomalies in this temperature range. The components of the electromechanical coupling coefficient determined indicate that L-alanine is a weak piezoelectric.

  16. Identification of lysine-acetylated mitochondrial proteins and their acetylation sites.

    PubMed

    Hartl, Markus; König, Ann-Christine; Finkemeier, Iris

    2015-01-01

    The (ε)N-acetylation of lysine side chains is a highly conserved posttranslational modification of both prokaryotic and eukaryotic proteins. Lysine acetylation not only occurs on histones in the nucleus but also on many mitochondrial proteins in plants and animals. As the transfer of the acetyl group to lysine eliminates its positive charge, lysine acetylation can affect the biological function of proteins. This chapter describes two methods for the identification of lysine-acetylated proteins in plant mitochondria using an anti-acetyllysine antibody. We describe the Western blot analysis of a two-dimensional blue native-polyacrylamide gel electrophoresis with an anti-acetyllysine antibody as well as the immuno-enrichment of lysine-acetylated peptides followed by liquid chromatography-tandem mass spectrometry data acquisition and analysis.

  17. Using a bacteriocin structure to engineer a phage lysin that targets Yersinia pestis.

    PubMed

    Lukacik, Petra; Barnard, Travis J; Buchanan, Susan K

    2012-12-01

    Purified phage lysins present an alternative to traditional antibiotics and work by hydrolysing peptidoglycan. Phage lysins have been developed against Gram-positive pathogens such as Bacillus anthracis and Streptococcus pneumoniae, where the peptidoglycan layer is exposed on the cell surface. Addition of the lysin to a bacterial culture results in rapid death of the organism. Gram-negative bacteria are resistant to phage lysins because they contain an outer membrane that protects the peptidoglycan from degradation. We solved crystal structures of a Yersinia pestis outer-membrane protein and the bacteriocin that targets it, which informed engineering of a bacterial-phage hybrid lysin that can be transported across the outer membrane to kill specific Gram-negative bacteria. This work provides a template for engineering phage lysins against a wide variety of bacterial pathogens.

  18. Homology modeling, substrate docking, and molecular simulation studies of mycobacteriophage Che12 lysin A.

    PubMed

    Saadhali, Shainaba A; Hassan, Sameer; Hanna, Luke Elizabeth; Ranganathan, Uma Devi; Kumar, Vanaja

    2016-08-01

    Mycobacteriophages produce lysins that break down the host cell wall at the end of lytic cycle to release their progenies. The ability to lyse mycobacterial cells makes the lysins significant. Mycobacteriophage Che12 is the first reported temperate phage capable of infecting and lysogenising Mycobacterium tuberculosis. Gp11 of Che12 was found to have Chitinase domain that serves as endolysin (lysin A) for Che12. Structure of gp11 was modeled and evaluated using Ramachandran plot in which 98 % of the residues are in the favored and allowed regions. Che12 lysin A was predicted to act on NAG-NAM-NAG molecules in the peptidoglycan of cell wall. The tautomers of NAG-NAM-NAG molecule were generated and docked with lysin A. The stability and binding affinity of lysin A - NAG-NAM-NAG tautomers were studied using molecular dynamics simulations.

  19. Solvation Free Energies of Alanine Peptides: The Effect of Flexibility

    SciTech Connect

    Kokubo, Hironori; Harris, Robert C.; Asthagiri, Dilip; Pettitt, Bernard M.

    2013-12-03

    The electrostatic (?Gel), cavity-formation (?Gvdw), and total (?G) solvation free energies for 10 alanine peptides ranging in length (n) from 1 to 10 monomers were calculated. The free energies were computed both with xed, extended conformations of the peptides and again for some of the peptides without constraints. The solvation free energies, ?Gel, ?Gvdw, and ?G, were found to be linear in n, with the slopes of the best-fit lines being gamma_el, gamma_vdw, and gamma, respectively. Both gamma_el and gamma were negative for fixed and flexible peptides, and gamma_vdw was negative for fixed peptides. That gamma_vdw was negative was surprising, as experimental data on alkanes, theoretical models, and MD computations on small molecules and model systems generally suggest that gamma_vdw should be positive. A negative gamma_vdw seemingly contradicts the notion that ?Gvdw drives the initial collapse of the protein when it folds by favoring conformations with small surface areas, but when we computed ?Gvdw for the flexible peptides, thereby allowing the peptides to assume natural ensembles of more compact conformations, gamma-vdw was positive. Because most proteins do not assume extended conformations, a ?Gvdw that increases with increasing surface area may be typical for globular proteins. An alternative hypothesis is that the collapse is driven by intramolecular interactions. We show that the intramolecular van der Waal's interaction energy is more favorable for the flexible than for the extended peptides, seemingly favoring this hypothesis, but the large fluctuations in this energy may make attributing the collapse of the peptide to this intramolecular energy difficult.

  20. Estrogen-like osteoprotective effects of glycine in in vitro and in vivo models of menopause.

    PubMed

    Kim, Min-Ho; Kim, Hyung-Min; Jeong, Hyun-Ja

    2016-03-01

    Recently, the placenta mesotherapy has been widely used to treat menopause. Placenta contains amino acids, peptides, minerals, and estrogen. Here, we investigated the estrogen-like osteoprotective effects of glycine (a main ingredient of placenta) in in vitro and in vivo models of menopause. We assessed the effect of glycine on MG-63 osteoblast cell line, MCF-7 estrogen-dependent cell line, and ovariectomized (OVX) mice. Glycine significantly increased the MG-63 cell proliferation in a dose-dependent manner. Activity of alkaline phosphatase (ALP) and phosphorylation of extracellular-signal-regulated kinase were increased by glycine in MG-63 cells. Glycine also increased the BrdU-incorporation and Ki-67 mRNA expression in MCF-7 cells. Glycine induced the up-regulation of estrogen receptor-β mRNA expression and estrogen-response element-luciferase activity in MG-63 and MCF-7 cells. In OVX mice, glycine was administered orally at a daily dose of 10 mg/kg per day for 8 weeks. Glycine resulted in the greatest decrease in weight gain caused by ovariectomy. Meanwhile, vaginal weight reduced by ovariectomy was increased by glycine. Glycine significantly increased the ALP activity in OVX mice. MicroCT-analysis showed that glycine significantly enhanced bone mineral density, trabecular number, and connectivity density in OVX mice. Moreover, glycine significantly increased the serum 17β-estradiol levels reduced by ovariectomy. Glycine has an estrogen-like osteoprotective effect in menopause models. Therefore, we suggest that glycine may be useful for the treatment of menopause.

  1. Rapid Ti(III) reduction of perchlorate in the presence of beta-alanine: kinetics, pH effect, complex formation, and beta-alanine effect.

    PubMed

    Wang, Chao; Huang, Zhengdao; Lippincott, Lee; Meng, Xiaoguang

    2010-03-15

    Ti(III) reduction of perchlorate might be a useful method for the treatment of highly perchlorate-contaminated water. Though the reaction rate was usually low, we observed that beta-alanine (HOOCCH(2)CH(2)NH(2)) could significantly promote the reaction. A complete (>99.9%) perchlorate removal was obtained in a solution containing [ClO(4)(-)]=1.0mM, [Ti(III)]=40 mM, and [beta-alanine]=120 mM after 2.5h of reaction under 50 degrees C. The effects of both pH and complex formation on the reaction were then studied. The results showed that without beta-alanine the optimal pH was 2.3. When pH increased from 1.6 to 2.3, the reduction rate increased remarkably. In the pH range >2.3, however, the reduction was significantly inhibited, attributed to the formation of Ti(III) precipitate. The presence of beta-alanine at a molar ratio of [beta-alanine]:[Ti(III)]=3:1 significantly increased the reduction rate of perchlorate even at near neutral pH. This is because beta-alanine formed complexes with Ti(III), which greatly improved the total soluble [Ti(III)] in the pH range between 3.5 and 6. The findings may lead to the development of rapid treatment methods for intermittent and small stream of highly perchlorate-contaminated water, which are resulted from the manufacturing, storage, handling, use and/or disposal of large quantities of perchlorate salts.

  2. Inducible l-Alanine Exporter Encoded by the Novel Gene ygaW (alaE) in Escherichia coli ▿

    PubMed Central

    Hori, Hatsuhiro; Yoneyama, Hiroshi; Tobe, Ryuta; Ando, Tasuke; Isogai, Emiko; Katsumata, Ryoichi

    2011-01-01

    We previously isolated a mutant hypersensitive to l-alanyl-l-alanine from a non-l-alanine-metabolizing Escherichia coli strain and found that it lacked an inducible l-alanine export system. Consequently, this mutant showed a significant accumulation of intracellular l-alanine and a reduction in the l-alanine export rate compared to the parent strain. When the mutant was used as a host to clone a gene(s) that complements the dipeptide-hypersensitive phenotype, two uncharacterized genes, ygaW and ytfF, and two characterized genes, yddG and yeaS, were identified. Overexpression of each gene in the mutant resulted in a decrease in the intracellular l-alanine level and enhancement of the l-alanine export rate in the presence of the dipeptide, suggesting that their products function as exporters of l-alanine. Since ygaW exhibited the most striking impact on both the intra- and the extracellular l-alanine levels among the four genes identified, we disrupted the ygaW gene in the non-l-alanine-metabolizing strain. The resulting isogenic mutant showed the same intra- and extracellular l-alanine levels as observed in the dipeptide-hypersensitive mutant obtained by chemical mutagenesis. When each gene was overexpressed in the wild-type strain, which does not intrinsically excrete alanine, only the ygaW gene conferred on the cells the ability to excrete alanine. In addition, expression of the ygaW gene was induced in the presence of the dipeptide. On the basis of these results, we concluded that YgaW is likely to be the physiologically most relevant exporter for l-alanine in E. coli and proposed that the gene be redesignated alaE for alanine export. PMID:21531828

  3. Interactions between glycine transporter type 1 (GlyT-1) and some inhibitor molecules - glycine transporter type 1 and its inhibitors (review).

    PubMed

    Harsing, Laszlo G; Zsilla, G; Matyus, P; Nagy, K M; Marko, B; Gyarmati, Zs; Timar, J

    2012-03-01

    Glycine is a mandatory positive allosteric modulator of N-methyl-D-aspartate (NMDA)-type ionotropic glutamate receptors in the central nervous system. Elevation of glycine concentrations by inhibition of its reuptake in the vicinity of NMDA receptors may positively influence receptor functions as glycine B binding site on NR1 receptor subunit is not saturated in physiological conditions. Synaptic and extrasynaptic concentrations of glycine are regulated by its type-1 glycine transporter, which is primarily expressed in astroglial and glutamatergic cell membranes. Alteration of synaptic glycine levels may have importance in the treatment of various forms of endogenous psychosis characterized by hypofunctional NMDA receptors. Several lines of evidence indicate that impaired NMDA receptor-mediated glutamatergic neurotransmission is involved in development of the negative (and partly the positive) symptoms and the cognitive deficit in schizophrenia. Inhibitors of glycine transporter type-1 may represent a newly developed therapeutic intervention in treatment of this mental illness. We have synthesized a novel series of N-substituted sarcosines, analogues of the glycine transporter-1 inhibitor NFPS (N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)-propyl]sarcosine). Of the pyridazinone-containing compounds, SzV-1997 was found to be a potent glycine transporter-1 inhibitor in rat brain synaptosomes and it markedly increased extracellular glycine concentrations in conscious rat striatum. SzV-1997 did not exhibit toxic symptoms such as hyperlocomotion, restless movements, respiratory depression, and lethality, characteristic for NFPS. Besides pyridazinone-based, sarcosine-containing glycine transporter-1 inhibitors, a series of substrate-type amino acid inhibitors was investigated in order to obtain better insight into the ligand-binding characteristics of the substrate binding cavity of the transporter.

  4. A comparative study on the growth and characterization of nonlinear optical amino acid crystals: L-alanine (LA) and L-alanine alaninium nitrate (LAAN).

    PubMed

    Aravindan, A; Srinivasan, P; Vijayan, N; Gopalakrishnan, R; Ramasamy, P

    2008-11-15

    A comparative study on the properties of L-alanine and LAAN crystals has been made and discussed. It may be concluded that the protonation of the amino group in the L-alanine molecule is the key factor in increasing the relative SHG efficiency of LAAN. The protonation is justified by the crystal structure analysis, FTIR and photoluminescence studies. The factor group vibrations are compared and found that there is an increase in vibrational modes of LA when reacted with nitric acid forming LAAN.

  5. Determination of the carbon, hydrogen and nitrogen contents of alanine and their uncertainties using the certified reference material L-alanine (NMIJ CRM 6011-a).

    PubMed

    Itoh, Nobuyasu; Sato, Ayako; Yamazaki, Taichi; Numata, Masahiko; Takatsu, Akiko

    2013-01-01

    The carbon, hydrogen, and nitrogen (CHN) contents of alanine and their uncertainties were estimated using a CHN analyzer and the certified reference material (CRM) L-alanine. The CHN contents and their uncertainties, as measured using the single-point calibration method, were 40.36 ± 0.20% for C, 7.86 ± 0.13% for H, and 15.66 ± 0.09% for N; the results obtained using the bracket calibration method were also comparable. The method described in this study is reasonable, convenient, and meets the general requirement of having uncertainties ≤ 0.4%.

  6. Growth and antioxidant status of broilers fed supplemental lysine and pyridoxine under high ambient temperature

    PubMed Central

    Khakpour Irani, Farzaneh; Daneshyar, Mohsen; Najafi, Ramin

    2015-01-01

    Three levels of lysine (90, 100 and 110% of Ross requirement) and of pyridoxine (3, 6 and 9 mg kg-1) were used in a 3 × 3 factorial experiment to investigate the growth and blood antioxidant ability of broilers under high ambient temperature. None of the dietary supplements affected the weight gain during the starter and grower periods. Although no significant differences were detected between the treatments during the entire period, high lysine level fed birds had a lower weight gain. At any levels of pyridoxine, high lysine fed birds were lighter than others. Neither the lysine nor pyridoxine changed the feed intake or feed conversion ratio during the starter, grower and entire period. However there was no significant difference between the treatments for blood malondialdehyde (MDA) concentration, medium lysine fed birds had lower blood MDA than other ones. No significant effects on blood triglyceride, total protein and blood superoxide dismutase activity were indicated with addition of any lysine or pyridoxine level. Medium lysine fed birds had decreased blood glutathione peroxidase activity compared to the birds of other treatments. It was concluded that providing the proposed dietary lysine requirement of Ross strain during heat stress ensuring the best body weight gain and body antioxidant ability. Higher lysine level causes the retarded weight gain due to higher excretion of arginine from the body and consequently higher lipid peroxidation. PMID:26261713

  7. Molecular Basis for Lysine Specificity in the Yeast Ubiquitin-Conjugating Enzyme Cdc34 ▿

    PubMed Central

    Sadowski, Martin; Suryadinata, Randy; Lai, Xianning; Heierhorst, Jörg; Sarcevic, Boris

    2010-01-01

    Ubiquitin (Ub)-conjugating enzymes (E2s) and ubiquitin ligases (E3s) catalyze the attachment of Ub to lysine residues in substrates and Ub during monoubiquitination and polyubiquitination. Lysine selection is important for the generation of diverse substrate-Ub structures, which provides versatility to this pathway in the targeting of proteins to different fates. The mechanisms of lysine selection remain poorly understood, with previous studies suggesting that the ubiquitination site(s) is selected by the E2/E3-mediated positioning of a lysine(s) toward the E2/E3 active site. By studying the polyubiquitination of Sic1 by the E2 protein Cdc34 and the RING E3 Skp1/Cul1/F-box (SCF) protein, we now demonstrate that in addition to E2/E3-mediated positioning, proximal amino acids surrounding the lysine residues in Sic1 and Ub are critical for ubiquitination. This mechanism is linked to key residues composing the catalytic core of Cdc34 and independent of SCF. Changes to these core residues altered the lysine preference of Cdc34 and specified whether this enzyme monoubiquitinated or polyubiquitinated Sic1. These new findings indicate that compatibility between amino acids surrounding acceptor lysine residues and key amino acids in the catalytic core of ubiquitin-conjugating enzymes is an important mechanism for lysine selection during ubiquitination. PMID:20194622

  8. Systematic identification of the lysine succinylation in the protozoan parasite Toxoplasma gondii.

    PubMed

    Li, Xiaolong; Hu, Xin; Wan, Yujing; Xie, Guizhen; Li, Xiangzhi; Chen, Di; Cheng, Zhongyi; Yi, Xingling; Liang, Shaohui; Tan, Feng

    2014-12-05

    Lysine succinylation is a new posttranslational modification identified in histone proteins of Toxoplasma gondii, an obligate intracellular parasite of the phylum Apicomplexa. However, very little is known about their scope and cellular distribution. Here, using LC-MS/MS to identify parasite peptides enriched by immunopurification with succinyl lysine antibody, we produced the first lysine succinylome in this parasite. Overall, a total of 425 lysine succinylation sites that occurred on 147 succinylated proteins were identified in extracellular Toxoplasma tachyzoites, which is a proliferative stage that results in acute toxoplasmosis. With the bioinformatics analysis, it is shown that these succinylated proteins are evolutionarily conserved and involved in a wide variety of cellular functions such as metabolism and epigenetic gene regulation and exhibit diverse subcellular localizations. Moreover, we defined five types of definitively conserved succinylation site motifs, and the results imply that lysine residue of a polypeptide with lysine on the +3 position and without lysine at the -1 to +2 position is a preferred substrate of lysine succinyltransferase. In conclusion, our findings suggest that lysine succinylation in Toxoplasma involves a diverse array of cellular functions, although the succinylation occurs at a low level.

  9. Bioavailability of lysine for kittens in overheated casein is underestimated by the rat growth assay method.

    PubMed

    Larsen, J A; Fascetti, A J; Calvert, C C; Rogers, Q R

    2010-10-01

    Growth assays were performed to determine lysine bioavailability for kittens and rats in untreated and heated casein; these values were compared with estimates obtained with an in vitro method. Body weight, food intake, nitrogen and dry matter digestibility, and plasma lysine were determined during an 80-day growth trial using kittens (n = 16). Body weight and food intake were determined during a 21-day growth trial using weanling rats (n = 80). The growth data showed bioavailable lysine to be 102.4% and 100.2% (for untreated casein) and 66.1% and 51.7% (for heated casein) for kittens and rats, respectively. There was no relationship between plasma lysine and dietary lysine concentrations for kittens. There were no significant differences in nitrogen or dry matter digestibility among diets for kittens. The chemically reactive lysine content of untreated casein was 99.6%, and of heated casein was 67.1%. Heat treatment of casein resulted in significantly decreased lysine bioavailability as estimated by all methods. For untreated casein, both growth assays showed good agreement with the in vitro method for available lysine. For heated casein, the rat growth assay significantly underestimated bioavailable lysine as determined in kittens while the in vitro method closely approximated this value for the cat.

  10. Structure-function validation of high lysine analogs of alpha-hordothionin designed by protein modeling.

    PubMed

    Rao, A G; Hassan, M; Hempel, J C

    1994-12-01

    Cereal grains and legume seeds, which are key protein sources for the vegetarian diet, are generally deficient in essential amino acids. Maize, in particular, is deficient in lysine. The inherent lack of lysine-rich proteins in maize has necessitated the search for heterologous proteins enriched in this amino acid, the isolation of the corresponding gene and its ultimate introduction into maize through plant transformation techniques. However, a rate-limiting step to this strategy has been the availability of plant-derived lysine-rich proteins. An appealing solution to the problem is to artificially increase the lysine content of a given protein by mutating appropriate residues to lysine. Here, we expound this strategy, starting with the protein alpha-hordothionin that is derived from barley seeds and consists of five lysine residues in a total of 45 amino acids (11% lysine). To facilitate rational substitutions, the 3-D structure of the protein has been determined by homology modeling with crambin. Based on this model, we have identified surface residues amenable to substitution with lysine. Furthermore, the acceptability of the mutations has been validated through the synthesis and characterization of the derivatives. To this end, our approach has permitted the creation of a modified alpha-hordothionin protein that has a lysine content of approximately 27% and retains the antifungal activity of the wild-type protein.

  11. 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.

  12. Titration of Alanine Monitored by NMR Spectroscopy: A Biochemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Waller, Francis J.; And Others

    1977-01-01

    The experiment described here involves simultaneous monitoring of pH and NMR chemical shifts during an aqueous titration of alpha- and beta-alanine. This experiment is designed for use in an undergraduate biochemistry course. (MR)

  13. Second harmonic generation studies in L-alanine single crystals grown from solution

    NASA Astrophysics Data System (ADS)

    Boomadevi, Shanmugam; Pandiyan, Krishnamoorthy

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm3 were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV-vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  14. Evaluating copper lysine and copper sulfate sources for heifers.

    PubMed

    Rabiansky, P A; McDowell, L R; Velasquez-Pereira, J; Wilkinson, N S; Percival, S S; Martin, F G; Bates, D B; Johnson, A B; Batra, T R; Salgado-Madriz, E

    1999-12-01

    The effects of feeding different sources and quantities of Cu to heifers were evaluated in a 211-d experiment. Forty crossbred predominantly Brahman x Hereford heifers averaging 13.5 mo of age and 301 kg were initially depleted of Cu. The depletion diet was fed for 70 d and consisted of low Cu and high antagonist minerals, Fe, S, and Mo at 1000 mg/kg, 0.5%, and 5 mg/kg (dry basis), respectively. On d 71, heifers continued to receive the antagonistic minerals and were allotted equally to five Cu treatments: 1) control, no additional Cu source; 2) 8 mg of Cu/kg from CuSO4; 3) 16 mg of Cu/kg from CuSO4; 4) 8 mg of Cu/kg from Cu lysine; and 5) 16 mg of Cu/kg from Cu lysine. When no notable change in concentration of Cu in the liver was observed, d 169, a second diet was formulated. The heifers were fed the same Cu treatments, but S and Mo were removed and Fe was lowered to 50 mg/kg. This diet was then fed for the final 42 d of the experiment. In addition to performance, concentrations of Cu, Fe, and Zn in the plasma and liver, plasma ceruloplasmin, hemoglobin, superoxide dismutase (SOD) activity of neutrophils and lymphocytes, and a cell mediated immune response (phytohemagglutinin-P, PHA) were measured. Heifers in this study had increased growth over time, but there were no treatment differences for growth and average daily gain. Liver and plasma Cu concentrations were not greatly influenced by different supplemental Cu sources. However, compared with other treatments, Cu lysine (16 mg/kg) increased liver Cu in cattle that were deficient and tended to increase plasma Cu in animals that were marginally deficient in Cu. Iron concentrations decreased over time in liver and plasma, but there was no difference in Fe and Zn concentrations in liver and plasma among treatments. Differences in ceruloplasmin and hemoglobin concentrations were significant over time but not among treatments. The SOD activity in neutrophils did not change over time, but SOD activity of lymphocytes

  15. Metabolic Regulation by Lysine Malonylation, Succinylation, and Glutarylation*

    PubMed Central

    Hirschey, Matthew D.; Zhao, Yingming

    2015-01-01

    Protein acetylation is a well-studied regulatory mechanism for several cellular processes, ranging from gene expression to metabolism. Recent discoveries of new post-translational modifications, including malonylation, succinylation, and glutarylation, have expanded our understanding of the types of modifications found on proteins. These three acidic lysine modifications are structurally similar but have the potential to regulate different proteins in different pathways. The deacylase sirtuin 5 (SIRT5) catalyzes the removal of these modifications from a wide range of proteins in different subcellular compartments. Here, we review these new modifications, their regulation by SIRT5, and their emerging role in cellular regulation and diseases. PMID:25717114

  16. Dissociation of gaseous zwitterion glycine-betaine by slow electrons

    NASA Astrophysics Data System (ADS)

    Kopyra, J.; Abdoul-Carime, H.

    2010-05-01

    In this work, we investigate dissociation processes induced by low-energy electrons to gas phase N,N,N-trimethylglycine [glycine-betaine, (CH3)3N+CH2COO-] molecules. Glycine-betaine represents a model system for zwitterions. All negative fragments are observed to be produced only at subelectronic excitation energies (<4 eV). With the exception of the loss of a neutral H atom that could arise from any CH bond breaking, we tentatively suggest that the zwitterion dissociates exclusively from the fragmentation of the cation site of the molecule, subsequent to the attachment of the excess electron. Within the context of radiation induced damage to biological systems, the present findings contribute to a more complete description of the fragmentation mechanism occurring to amino acids, peptides, and proteins since they adopt usually a zwitterion structure.

  17. Glycine: an important potential component of spinal shock.

    PubMed

    Simpson, R K; Robertson, C S; Goodman, J C

    1993-08-01

    Amino acid neurotransmitters (AANTs) play a major role in maintenance of muscle tone. Abnormal AANT concentrations are associated with hyper- or hypotonic states. Flaccidity from spinal shock commonly occurs after spinal cord injury (SCI) and may be associated with changes in AANT concentrations. Ischemic SCIs created in the lumbar region of rabbits by intraaortic balloon occlusion produced spastic or flaccid injuries. Microdialysis sampling of AANTs from the injured segmental structures was done 3 days after SCI. Evoked potentials were used to monitor spinal cord stability. No significant changes in AANT levels occurred in the spastic or flaccid group after 4 hour sampling. However, flaccid animals had baseline glycine levels 2-3 times higher (p < 0.001) than spastic animals or controls. High concentrations of the inhibitory AANT glycine is associated with flaccidity following SCI, or spinal shock, but not spasticity. Glycinergic compounds directed toward suppression of excess muscle tone deserve further study.

  18. Soft x-ray ionization induced fragmentation of glycine

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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-Cα bond and the presence of the CNH_2^+ fragment.

  19. Soft x-ray ionization induced fragmentation of glycine.

    PubMed

    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-Cα bond and the presence of the CNH(2)(+) fragment.

  20. 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.

  1. Microbial production of amino acids in Japan.

    PubMed

    Kumagai, H

    2000-01-01

    The microbial biotechnology of amino acids production which was developed and industrialized in Japan have been summarized. The amino acids include L-glutamic acid, L-lysine, L-threonine, L-aspartic acid, L-alanine, L-cysteine, L-dihydroxyphenylalanine, D-p-hydroxyphenyl-glycine, and hydroxy-L-proline.

  2. Repeated Supramaximal Exercise-Induced Oxidative Stress: Effect of β-Alanine Plus Creatine Supplementation

    PubMed Central

    Belviranli, Muaz; Okudan, Nilsel; Revan, Serkan; Balci, Serdar; Gokbel, Hakki

    2016-01-01

    Background: Carnosine is a dipeptide formed from the β-alanine and histidine amino acids and found in mainly in the brain and muscle, especially fast twitch muscle. Carnosine and creatine has an antioxidant effect and carnosine accounts for about 10% of the muscle's ability to buffer the H+ ions produced by exercise. Objectives: The aim of the study was to investigate the effects of beta alanine and/or creatine supplementation on oxidant and antioxidant status during repeated Wingate tests (WTs). Patients and Methods: Forty four sedentary males participated in the study. Participants performed three 30s WTs with 2 minutes rest between exercise bouts. After the first exercise session, the subjects were assigned to one of four groups: Placebo, Creatine, Beta-alanine and Beta-alanine plus creatine. Participants ingested twice per day for 22 consecutive days, then four times per day for the following 6 days. After the supplementation period the second exercise session was applied. Blood samples were taken before and immediately after the each exercise session for the analysis of oxidative stress and antioxidant markers. Results: Malondialdehyde levels and superoxide dismutase activities were affected by neither supplementation nor exercise. During the pre-supplementation session, protein carbonyl reduced and oxidized glutathione (GSH and GSSG) levels increased immediately after the exercise. However, during the post-supplementation session GSH and GSSG levels increased in beta-alanine and beta-alanine plus creatine groups immediately after the exercise compared to pre-exercise. In addition, during the post-supplementation session total antioxidant capacity increased in beta-alanine group immediately after the exercise. Conclusions: Beta-alanine supplementation has limited antioxidant effect during the repeated WTs. PMID:27217925

  3. SU-E-T-643: Pure Alanine Dosimeter for Verification Dosimetry in IMRT

    SciTech Connect

    Al-Karmi, Anan M.; Zraiqat, Fadi

    2015-06-15

    Purpose: The objective of this study was evaluation of accuracy of pure alanine dosimeters measuring intensity-modulated radiation therapy (IMRT) dose distributions in a thorax phantom. Methods: Alanine dosimeters were prepared in the form of 110 mg pure L-α-alanine powder filled into clear tissue-equivalent polymethylmethacrylate (PMMA) plastic tubes with the dimensions 25 mm length, 3 mm inner diameter, and 1 mm wall thickness. A dose-response calibration curve was established for the alanine by placing the dosimeters at 1.5 cm depth in a 30×30×30 cm{sup 3} solid water phantom and then irradiating on a linac with 6 MV photon beam at 10×10 cm{sup 2} field size to doses ranging from 1 to 5 Gy. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the absorbed dose in alanine. An IMRT treatment plan was designed for a commercial heterogeneous CIRS thorax phantom and the dose values were calculated at three different points located in tissue, lung, and bone equivalent materials. A set of dose measurements was carried out to compare measured and calculated dose values by placing the alanine dosimeters at those selected locations inside the thorax phantom and delivering the IMRT to the phantom. Results: The alanine dose measurements and the IMRT plan dose calculations were found to be in agreement within ±2%. Specifically, the deviations were −0.5%, 1.3%, and −1.7% for tissue, lung, and bone; respectively. The slightly large deviations observed for lung and bone may be attributed to tissue inhomogeneity, steep dose gradients in these regions, and uncontrollable changes in spectrometer conditions. Conclusion: The results described herein confirmed that pure alanine dosimeter was suitable for in-phantom dosimetry of IMRT beams because of its high sensitivity and acceptable accuracy. This makes the dosimeter a promising option for quality control of the therapeutic beams, complementing the commonly used ionization chambers, TLDs, and films.

  4. 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.

  5. Positive regulation of the Escherichia coli glycine cleavage enzyme system.

    PubMed Central

    Wilson, R L; Steiert, P S; Stauffer, G V

    1993-01-01

    A new mutation in Escherichia coli, designated gcvA1, that results in noninducible expression of both gcv and a gcvT-lacZ gene fusion was isolated. A plasmid carrying the wild-type gcvA gene complemented the mutation and restored glycine-inducible gcv and gcvT-lacZ gene expression. These results suggest that gcvA encodes a positive-acting regulatory protein that acts in trans to increase expression of gcv. PMID:8423160

  6. Ferroelectric films of deuterated glycine phosphite: Structure and dielectric properties

    NASA Astrophysics Data System (ADS)

    Balashova, E. V.; Krichevtsov, B. B.; Svinarev, F. B.; Lemanov, V. V.

    2013-05-01

    Polycrystalline textured films of deuterated glycine phosphite consisting of single-crystal blocks with lateral dimensions ˜(50-100) μm and a thickness d ˜ (1-5) μm have been grown by evaporation on NdGaO3(100) and α-Al2O3 substrates with preliminarily deposited interdigitated electrodes, as well as on Al substrates. The c* ( Z) crystallographic axis in the blocks is normal to the film plane, and the a ( X) axis and the polar axis b ( Y) are oriented in the film plane. The temperature dependences of the capacitance of the structures measured with the interdigitated electrode system reveal a strong dielectric anomaly at the film transition to the ferroelectric state. The phase transition temperature T c depends on the degree of deuteration D of the glycine phosphite. The maximum value T c = 275 K obtained in the structures studied corresponds to a degree of deuteration of the glycine phosphite D ˜ 50%. The frequency behavior of the dielectric hysteresis loops in glycine phosphite films differs radically from that of the previously studied films of deuterated betaine phosphite, which evidences that polarization switching in these structures proceeds by different mechanisms. It has been that application of a dc bias to the electrodes changes the shape of the dielectric hysteresis loops and shifts them along the electric field axis. The shift of the loops depends on the sign, magnitude, and time of application of the bias. Possible mechanisms underlying the induced unipolarity are discussed.

  7. Heterodera glycines cysts contain an extensive array of endoproteases as well as inhibitors of proteases in H. glycines and Meloidogyne incognita infective juvenile stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterodera glycines cysts contain proteases, and inhibitors of protease activities in various nematode species. In this investigation, proteases in H. glycines cysts were identified using a commercially available FRET-peptide library comprising 512 peptide pools qualified to detect up to 4 endoprot...

  8. Glycine transporter-1: a new potential therapeutic target for schizophrenia.

    PubMed

    Hashimoto, Kenji

    2011-01-01

    The hypofunction hypothesis of glutamatergic neurotransmission via N-methyl-D-aspartate (NMDA) receptors in the pathophysiology of schizophrenia suggests that increasing NMDA receptor function via pharmacological manipulation could provide a new therapeutic strategy for schizophrenia. The glycine modulatory site on NMDA receptor complex is the one of the most attractive therapeutic targets for schizophrenia. One means of enhancing NMDA receptor neurotransmission is to increase the availability of the obligatory co-agonist glycine at modulatory site on the NMDA receptors through the inhibition of glycine transporter-1 (GlyT-1) on glial cells. Some clinical studies have demonstrated that the GlyT-1 inhibitor sarcosine (N-methylglycine) shows antipsychotic activity in patients with schizophrenia. Currently, a number of pharmaceutical companies have been developing novel and selective GlyT-1 inhibitors for the treatment of schizophrenia. A recent double blind phase II study demonstrated that the novel GlyT-1 inhibitor RG1678 has a robust and clinically meaningful effect in patients with schizophrenia. In this article, the author reviews the recent findings on the GlyT-1 as a potential therapeutic target of schizophrenia.

  9. Interaction between ATP, metal ions, glycine, and several minerals

    NASA Technical Reports Server (NTRS)

    Rishpon, J.; Ohara, P. J.; Lawless, J. G.; Lahav, N.

    1982-01-01

    Interactions between ATP, glycine and montmorillonite and kaolinite clay minerals in the presence of various metal cations are investigated. The adsorption of adenine nucleotides on clays and Al(OH)3 was measured as a function of pH, and glycine condensation was followed in the presence of ATP, ZnCl2, MgCl2 and either kaolinite or montmorillonite. The amounts of ATP and ADP adsorbed are found to decrease with increasing Ph, and to be considerably enhanced in experiments with Mg(2+)- and Zn(2+)-montmorillonite with respect to Na(+)-montmorillonite. The effects of divalent cations are less marked in kaolinite. Results for Al(OH)3 show the importance of adsorption at clay platelet edges at high pH. The decomposition of ATP during drying at high temperature is observed to be inhibited by small amounts of clay, vacuum, or Mg(2+) or Zn(2+) ions, and to be accompanied by peptide formation in the presence of glycine. Results suggest the importance of Zn(2+) and Mg(2+) in chemical evolution.

  10. Flow Cytometric Analysis and Sorting of Heterodera glycines Eggs

    PubMed Central

    Tylka, G. L.; Niblack, T. L.; Walk, T. C.; Harkins, K. R.; Barnett, L.; Baker, N. K.

    1993-01-01

    A nondestructive technique was developed to characterize and separate eggs of soybean cyst nematode, Heterodera glycines, by developmental stage using flow cytometry. Eggs from cysts cultured on susceptible soybean roots were suspended in 0.1% xanthan gum or 59% sucrose and loaded into either a Coulter EPICS 752 or EPICS 753 flow cytometer. Eggs were analyzed and sorted according to forward angle and 90° light scatter, flow cytometric parameters that are relative measures of object size and granularity, respectively. Mature eggs containing vermiform juveniles were less granular and slightly larger than eggs in earlier stages of embryogeny, allowing for separation of mature eggs from immature eggs. The effectiveness of flow cytometric sorting was evaluated by comparing the developmental stages of subpopulations of unsorted and sorted eggs. Of a subpopulation of unsorted eggs, 62% contained vermiform juveniles, whereas 85 to 95% of sorted subpopulations of larger, less granular eggs contained vermiform juveniles. Suspending H. glycines eggs in 0.1% xanthan gum or 59% sucrose for flow cytometric analysis had no effect on subsequent egg hatch in vitro. This technique is an efficient and effective means to collect large, relatively homogeneous quantities of H. glycines eggs in early or late embryogeny, and would likely be useful for analyzing and sorting eggs of other nematode species for use in developmental, genetic, or physiological research, or for identification and collection of parasitized eggs. PMID:19279815

  11. The mitochondrial genome of the soybean cyst nematode, Heterodera glycines.

    PubMed

    Gibson, Tracey; Farrugia, Daniel; Barrett, Jeff; Chitwood, David J; Rowe, Janet; Subbotin, Sergei; Dowton, Mark

    2011-07-01

    We sequenced the entire coding region of the mitochondrial genome of Heterodera glycines. The sequence obtained comprised 14.9 kb, with PCR evidence indicating that the entire genome comprised a single, circular molecule of approximately 21-22 kb. The genome is the most T-rich nematode mitochondrial genome reported to date, with T representing over half of all nucleotides on the coding strand. The genome also contains the highest number of poly(T) tracts so far reported (to our knowledge), with 60 poly(T) tracts ≥ 12 Ts. All genes are transcribed from the same mitochondrial strand. The organization of the mitochondrial genome of H. glycines shows a number of similarities compared with Radopholus similis, but fewer similarities when compared with Meloidogyne javanica. Very few gene boundaries are shared with Globodera pallida or Globodera rostochiensis. Partial mitochondrial genome sequences were also obtained for Heterodera cardiolata (5.3 kb) and Punctodera chalcoensis (6.8 kb), and these had identical organizations compared with H. glycines. We found PCR evidence of a minicircular mitochondrial genome in P. chalcoensis, but at low levels and lacking a noncoding region. Such circularised genome fragments may be present at low levels in a range of nematodes, with multipartite mitochondrial genomes representing a shift to a condition in which these subgenomic circles predominate.

  12. FMRFamide-like Immunoactivity in Heterodera glycines (Nemata: Tylenchida)

    PubMed Central

    Masler, E. P.; Kovaleva, E. S.; Sardanelli, S.

    1999-01-01

    Material antigenically related to the neuromodulatory peptide FMRFamide was detected and examined in preparations of the soybean cyst nematode, Heterodera glycines, and in the free-living nematodes Caenorhabditis elegans and Panagrellus redivivus. FMRFamide-related peptides were quantified by an enzyme-linked immunosorbent assay. Specific activities were remarkably similar among all of the vermiform members of the three species. FMRFamide-related peptide immunoactivity was present in both sexes and all stages of H. glycines examined. The highest specific activity was present in second-stage juveniles and in males, and the lowest in white and yellow females. Total FMRFamide-related peptide level per individual was highest in brown females, with 90% of the activity associated with the eggs. Peptide levels in these eggs and in second-stage juveniles were comparable and increased in adults, especially in females. Chromatographic analysis of FMRFamide-related peptide preparations from H. glycines juveniles, C. elegans, and P. redivivus revealed distinct qualitative differences between the infective plant parasite and the free-living nematodes. PMID:19270893

  13. 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.

  14. Effect of abomasal glucose infusion on alanine metabolism and urea production in sheep.

    PubMed

    Obitsu, T; Bremner, D; Milne, E; Lobley, G E

    2000-08-01

    The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0.75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0.75), based on hay and grass pellets. Glucose provision reduced urinary N (P = 0.040) and urea (P = 0.009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822 v. 619 mmol/d, P = 0.024) by glucose while plasma alanine-N flux rate was elevated (295 v. 342 mmol/d, P = 0.011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127 v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15%). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.

  15. Acetyl-lysine analog peptides as mechanistic probes of protein deacetylases.

    PubMed

    Smith, Brian C; Denu, John M

    2007-12-21

    Class III histone deacetylases (Sir2 or sirtuins) catalyze the NAD+-dependent conversion of acetyl-lysine residues to nicotinamide, 2'-O-acetyl-ADP-ribose (OAADPr), and deacetylated lysine. Class I and II HDACs utilize a different deacetylation mechanism, utilizing an active site zinc to direct hydrolysis of acetyl-lysine residues to lysine and acetate. Here, using ten acetyl-lysine analog peptides, we have probed the substrate binding pockets of sirtuins and investigated the catalytic differences among sirtuins and class I and II deacetylases. For the sirtuin Hst2, acetyl-lysine analog peptide binding correlated with the hydrophobic substituent parameter pi with a slope of -0.35 from a plot of log Kd versus pi. Interestingly, propionyl- and butyryl-lysine peptides were found to bind tighter to Hst2 compared with acetyl-lysine peptide and showed measurable rates of catalysis with Hst2, Sirt1, Sirt2, and Sirt3, suggesting propionyl- and butyryl-lysine proteins may be sirtuin substrates in vivo. Unique among the acetyl-lysine analog peptides examined, homocitrulline peptide produced ADP-ribose instead of the corresponding OAADPr analog. The electron-withdrawing nature of each acetyl analog had a profound impact on the deacylation rate between deacetylase classes. The rate of catalysis with the acetyl-lysine analog peptides varied over five orders of magnitude with the class III deacetylase Hst2, revealing a linear free energy relationship with a slope of -1.57 when plotted versus the Taft constant, sigma*. HDAC8, a class I deacetylase, displayed the opposite trend with a slope of +0.79. These results are applicable toward the development of selective substrates and other mechanistic probes of protein deacetylases.

  16. Expression, crystallization and preliminary X-ray crystallographic analysis of D-alanine-D-alanine ligase from OXA-23-producing Acinetobacter baumannii K0420859.

    PubMed

    Huynh, Kim-Hung; Tran, Huyen-Thi; Pham, Tan-Viet; Ngo, Ho-Phuong-Thuy; Cha, Sun-Shin; Chung, Kyung Min; Lee, Sang Hee; Kang, Lin-Woo

    2014-04-01

    Acinetobacter baumannii causes bacteraemia, pneumonia, other respiratory-tract and urinary-tract infections in humans. OXA-23 carbapenemase-producing A. baumannii K0420859 (A. baumannii OXA-23) is resistant to carbapenem, a common antibacterial drug. To develop an efficient and novel antibacterial drug against A. baumannii OXA-23, D-alanine-D-alanine ligase, which is essential in bacterial cell-wall synthesis, is of interest. Here, the D-alanine-D-alanine ligase (AbDdl) gene from A. baumannii OXA-23 was cloned and expressed, and the AbDdl protein was purified and crystallized; this enzyme can be used as a novel target for an antibacterial drug against A. baumannii OXA-23. The AbDdl crystal diffracted to a resolution of 2.8 Å and belonged to the orthorhombic space group P212121, with unit-cell parameters a = 113.4, b = 116.7, c = 176.5 Å, a corresponding VM of 2.8 Å(3) Da(-1) and a solvent content of 56.3%, and six protomers in the asymmetric unit.

  17. Insight into structure-function relationship in phenol-soluble modulins using an alanine screen of the phenol-soluble modulin (PSM) α3 peptide.

    PubMed

    Cheung, Gordon Y C; Kretschmer, Dorothee; Queck, Shu Y; Joo, Hwang-Soo; Wang, Rong; Duong, Anthony C; Nguyen, Thuan H; Bach, Thanh-Huy L; Porter, Adeline R; DeLeo, Frank R; Peschel, Andreas; Otto, Michael

    2014-01-01

    Phenol-soluble modulins (PSMs) are a family of peptides with multiple functions in staphylococcal pathogenesis. To gain insight into the structural features affecting PSM functions, we analyzed an alanine substitution library of PSMα3, a strongly cytolytic and proinflammatory PSM of Staphylococcus aureus with a significant contribution to S. aureus virulence. Lysine residues were essential for both receptor-dependent proinflammatory and receptor-independent cytolytic activities. Both phenotypes also required additional structural features, with the C terminus being crucial for receptor activation. Biofilm formation was affected mostly by hydrophobic amino acid positions, suggesting that the capacity to disrupt hydrophobic interactions is responsible for the effect of PSMs on biofilm structure. Antimicrobial activity, absent from natural PSMα3, could be created by the exchange of large hydrophobic side chains, indicating that PSMα3 has evolved to exhibit cytolytic rather than antimicrobial activity. In addition to gaining insight into the structure-function relationship in PSMs, our study identifies nontoxic PSMα3 derivatives for active vaccination strategies and lays the foundation for future efforts aimed to understand the biological role of PSM recognition by innate host defense.

  18. SIRT5 regulates the mitochondrial lysine succinylome and metabolic networks.

    PubMed

    Rardin, Matthew J; He, Wenjuan; Nishida, Yuya; Newman, John C; Carrico, Chris; Danielson, Steven R; Guo, Ailan; Gut, Philipp; Sahu, Alexandria K; Li, Biao; Uppala, Radha; Fitch, Mark; Riiff, Timothy; Zhu, Lei; Zhou, Jing; Mulhern, Daniel; Stevens, Robert D; Ilkayeva, Olga R; Newgard, Christopher B; Jacobson, Matthew P; Hellerstein, Marc; Goetzman, Eric S; Gibson, Bradford W; Verdin, Eric

    2013-12-03

    Reversible posttranslational modifications are emerging as critical regulators of mitochondrial proteins and metabolism. Here, we use a label-free quantitative proteomic approach to characterize the lysine succinylome in liver mitochondria and its regulation by the desuccinylase SIRT5. A total of 1,190 unique sites were identified as succinylated, and 386 sites across 140 proteins representing several metabolic pathways including β-oxidation and ketogenesis were significantly hypersuccinylated in Sirt5(-/-) animals. Loss of SIRT5 leads to accumulation of medium- and long-chain acylcarnitines and decreased β-hydroxybutyrate production in vivo. In addition, we demonstrate that SIRT5 regulates succinylation of the rate-limiting ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) both in vivo and in vitro. Finally, mutation of hypersuccinylated residues K83 and K310 on HMGCS2 to glutamic acid strongly inhibits enzymatic activity. Taken together, these findings establish SIRT5 as a global regulator of lysine succinylation in mitochondria and present a mechanism for inhibition of ketogenesis through HMGCS2.

  19. Dendronized nanoconjugates of lysine and folate for treatment of cancer.

    PubMed

    Jain, Keerti; Gupta, Umesh; Jain, Narendra K

    2014-08-01

    Poly-L-lysine (PLL) dendrimers are currently being investigated as antiangiogenic agent for therapy of cancer. In this study, we report folate conjugated poly-l-lysine dendrimers (FPLL) as an efficient carrier for model anticancer drug, doxorubicin hydrochloride (Dox); for pH sensitive drug release, selective targeting to cancer cells, anticancer activity and antiangiogenic activity. This nanoconjugate of Dox showed initial rapid in vitro release followed by gradual slow release, and the drug release was found to be pH sensitive with greater release at acidic pH. In the CAM assay and tubule formation assay with HUVEC, Dox-FPLL formulation showed the significant antiangiogenic activity confirming that activity of PLL was not compromised by the presence of Dox and folic acid. The ex vivo investigations with human breast cancer cell lines MCF-7 showed enhanced cytotoxicity of Dox-FPLL with significantly enhanced intracellular uptake (p<0.001). The in vivo therapeutic potential of nanoconjugate was determined in MCF-7 breast cancer xenograft model in tumor-bearing mice. Dox-FPLL increased the concentration of Dox in tumor by 121.5-fold after 24 h in comparison with free Dox formulation. The folate conjugated dendrimeric Dox showed superior anti-tumor activity in tumor xenograft model with significantly prolonged survival determined by Kaplan Meier survival analysis (p<0.001).

  20. Lysine methylation represses p53 activity in teratocarcinoma cancer cells

    PubMed Central

    Zhu, Jiajun; Dou, Zhixun; Sammons, Morgan A.; Levine, Arnold J.; Berger, Shelley L.

    2016-01-01

    TP53 (which encodes the p53 protein) is the most frequently mutated gene among all human cancers, whereas tumors that retain the wild-type TP53 gene often use alternative mechanisms to repress the p53 tumor-suppressive function. Testicular teratocarcinoma cells rarely contain mutations in TP53, yet the transcriptional activity of wild-type p53 is compromised, despite its high expression level. Here we report that in the teratocarcinoma cell line NTera2, p53 is subject to lysine methylation at its carboxyl terminus, which has been shown to repress p53’s transcriptional activity. We show that reduction of the cognate methyltransferases reactivates p53 and promotes differentiation of the NTera2 cells. Furthermore, reconstitution of methylation-deficient p53 mutants into p53-depleted NTera2 cells results in elevated expression of p53 downstream targets and precocious loss of pluripotent gene expression compared with re-expression of wild-type p53. Our results provide evidence that lysine methylation of endogenous wild-type p53 represses its activity in cancer cells and suggest new therapeutic possibilities of targeting testicular teratocarcinoma. PMID:27535933

  1. Autoacetylation of the MYST lysine acetyltransferase MOF protein.

    PubMed

    Yang, Chao; Wu, Jiang; Sinha, Sarmistha H; Neveu, John M; Zheng, Yujun George

    2012-10-12

    The MYST family of histone acetyltransferases (HATs) plays critical roles in diverse cellular processes, such as the epigenetic regulation of gene expression. Lysine autoacetylation of the MYST HATs has recently received considerable attention. Nonetheless, the mechanism and function of the autoacetylation process are not well defined. To better understand the biochemical mechanism of MYST autoacetylation and the impact of autoacetylation on the cognate histone acetylation, we carried out detailed analyses of males-absent-on-the-first (MOF), a key member of the MYST family. A number of mutant MOF proteins were produced with point mutations at several key residues near the active site of the enzyme. Autoradiography and immunoblotting data showed that mutation of these residues affects the autoacetylation activity and HAT activity of MOF by various degrees demonstrating that MOF activity is highly sensitive to the chemical changes in those residues. We produced MOF protein in the deacetylated form by using a nonspecific lysine deacetylase. Interestingly, both the autoacetylation activity and the histone acetylation activity of the deacetylated MOF were found to be very close to that of wild-type MOF, suggesting that autoacetylation of MOF only marginally modulates the enzymatic activity. Also, we found that the autoacetylation rates of MOF and deacetylated MOF were much slower than the cognate substrate acetylation. Thus, autoacetylation does not seem to contribute to the intrinsic enzymatic activity in a significant manner. These data provide new insights into the mechanism and function of MYST HAT autoacetylation.

  2. Determination of Solubility Parameters of Ibuprofen and Ibuprofen Lysinate.

    PubMed

    Kitak, Teja; Dumičić, Aleksandra; Planinšek, Odon; Šibanc, Rok; Srčič, Stanko

    2015-12-03

    In recent years there has been a growing interest in formulating solid dispersions, which purposes mainly include solubility enhancement, sustained drug release and taste masking. The most notable problem by these dispersions is drug-carrier (in)solubility. Here we focus on solubility parameters as a tool for predicting the solubility of a drug in certain carriers. Solubility parameters were determined in two different ways: solely by using calculation methods, and by experimental approaches. Six different calculation methods were applied in order to calculate the solubility parameters of the drug ibuprofen and several excipients. However, we were not able to do so in the case of ibuprofen lysinate, as calculation models for salts are still not defined. Therefore, the extended Hansen's approach and inverse gas chromatography (IGC) were used for evaluating of solubility parameters for ibuprofen lysinate. The obtained values of the total solubility parameter did not differ much between the two methods: by the extended Hansen's approach it was δt = 31.15 MPa(0.5) and with IGC it was δt = 35.17 MPa(0.5). However, the values of partial solubility parameters, i.e., δd, δp and δh, did differ from each other, what might be due to the complex behaviour of a salt in the presence of various solvents.

  3. Ribosomes slide on lysine-encoding homopolymeric A stretches.

    PubMed

    Koutmou, Kristin S; Schuller, Anthony P; Brunelle, Julie L; Radhakrishnan, Aditya; Djuranovic, Sergej; Green, Rachel

    2015-02-19

    Protein output from synonymous codons is thought to be equivalent if appropriate tRNAs are sufficiently abundant. Here we show that mRNAs encoding iterated lysine codons, AAA or AAG, differentially impact protein synthesis: insertion of iterated AAA codons into an ORF diminishes protein expression more than insertion of synonymous AAG codons. Kinetic studies in E. coli reveal that differential protein production results from pausing on consecutive AAA-lysines followed by ribosome sliding on homopolymeric A sequence. Translation in a cell-free expression system demonstrates that diminished output from AAA-codon-containing reporters results from premature translation termination on out of frame stop codons following ribosome sliding. In eukaryotes, these premature termination events target the mRNAs for Nonsense-Mediated-Decay (NMD). The finding that ribosomes slide on homopolymeric A sequences explains bioinformatic analyses indicating that consecutive AAA codons are under-represented in gene-coding sequences. Ribosome 'sliding' represents an unexpected type of ribosome movement possible during translation.

  4. Glycine transporter type 1 blockade changes NMDA receptor-mediated responses and LTP in hippocampal CA1 pyramidal cells by altering extracellular glycine levels

    PubMed Central

    Martina, Marzia; Gorfinkel, Yelena; Halman, Samantha; Lowe, John A; Periyalwar, Pranav; Schmidt, Christopher J; Bergeron, Richard

    2004-01-01

    Long-term potentiation (LTP) in the hippocampal CA1 region requires the activation of NMDA receptors (NMDARs). NMDAR activation in turn requires membrane depolarization as well as the binding of glutamate and its coagonist glycine. Previous pharmacological studies suggest that the glycine transporter type 1 (GlyT1) maintains subsaturating concentrations of glycine at synaptic NMDARs. Antagonists of GlyT1 increase levels of glycine in the synaptic cleft and, like direct glycine site agonists, can augment NMDAR currents and NMDAR-mediated functions such as LTP. In addition, stimulation of the glycine site initiates signalling through the NMDAR complex, priming the receptors for clathrin-dependent endocytosis. We have used a new potent GlyT1 antagonist, CP-802,079, with whole-cell patch-clamp recordings in acute rat hippocampal slices to determine the effect of GlyT1 blockade on LTP. Reverse microdialysis experiments in the hippocampus of awake, freely moving rats, showed that this drug elevated only the extracellular concentration of glycine. We found that CP-802,079, sarcosine and glycine significantly increased the amplitude of the NMDAR currents and LTP. In contrast, application of higher concentrations of CP-802,079 and glycine slightly reduced NMDAR currents and did not increase LTP. Overall, these data suggest that the level of glycine present in the synaptic cleft tightly regulates the NMDAR activity. This level is kept below the ‘set point’ of the NMDAR internalization priming mechanism by the presence of GlyT1-dependent uptake. PMID:15064326

  5. Alanine 310 is important for the activity of 1,4-α-glucan branching enzyme from Geobacillus thermoglucosidans STB02.

    PubMed

    Liu, Yiting; Li, Caiming; Gu, Zhengbiao; Xin, Chenhao; Cheng, Li; Hong, Yan; Li, Zhaofeng

    2017-04-01

    1,4-α-Glucan branching enzyme (GBE) catalyzes the formation of α-1,6 branch points in starch or glycogen by hydrolyzing α-1,4-glucosidic linkages and then synthesizing α-1,6-glucosidic linkages. In the GBE from Geobacillus thermoglucosidans STB02, alanine 310 (Ala310) is located in conserved region II. An analysis of the amino acid sequence shows that Ala310 is highly conserved in the prokaryotic GBE subfamily. Site-directed mutagenesis was used to determine the function of Ala310 in GBE. Replacement of Ala310 with glycine, aspartate, asparagine, isoleucine, glutamate, or glutamine resulted in mutant enzymes with less than 10% to 25% of wild-type activity when amylopectin or amylose was used as substrate. Studies using high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) showed that A310G mutant had no effect on the transfer pattern, but the branching activity had been repressed to a large extent. Kinetic analysis also showed that mutations of Ala310 had an effect on the KM value that changed the preferred substrate from amylopectin to amylose. These results show that Ala310 is important for the catalytic activity of the GBE from G. thermoglucosidans STB02.

  6. Detection of Cyanotoxins, β-N-methylamino-l-alanine and Microcystins, from a Lake Surrounded by Cases of Amyotrophic Lateral Sclerosis

    PubMed Central

    Banack, Sandra Anne; Caller, Tracie; Henegan, Patricia; Haney, James; Murby, Amanda; Metcalf, James S.; Powell, James; Cox, Paul Alan; Stommel, Elijah

    2015-01-01

    A cluster of amyotrophic lateral sclerosis (ALS) has been previously described to border Lake Mascoma in Enfield, NH, with an incidence of ALS approximating 25 times expected. We hypothesize a possible association with cyanobacterial blooms that can produce β-N-methylamino-l-alanine (BMAA), a neurotoxic amino acid implicated as a possible cause of ALS/PDC in Guam. Muscle, liver, and brain tissue samples from a Lake Mascoma carp, as well as filtered aerosol samples, were analyzed for microcystins (MC), free and protein-bound BMAA, and the BMAA isomers 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl)glycine (AEG). In carp brain, BMAA and DAB concentrations were 0.043 μg/g ± 0.02 SD and 0.01 μg/g ± 0.002 SD respectively. In carp liver and muscle, the BMAA concentrations were 1.28 μg/g and 1.27 μg/g respectively, and DAB was not detected. BMAA was detected in the air filters, as were the isomers DAB and AEG. These results demonstrate that a putative cause for ALS, BMAA, exists in an environment that has a documented cluster of ALS. Although cause and effect have not been demonstrated, our observations and measurements strengthen the association. PMID:25643180

  7. β-N-methylamino-l-alanine (BMAA) and isomers: Distribution in different food web compartments of Thau lagoon, French Mediterranean Sea.

    PubMed

    Réveillon, Damien; Abadie, Eric; Séchet, Véronique; Masseret, Estelle; Hess, Philipp; Amzil, Zouher

    2015-09-01

    The neurotoxin BMAA (β-N-methylamino-l-alanine) and its isomer DAB (2,4-diaminobutyric acid) have been detected in seafood worldwide, including in Thau lagoon (French Mediterranean Sea). A cluster of amyotrophic lateral sclerosis (ALS), a neurodegenerative disease associated with BMAA, has also been observed in this region. Mussels, periphyton (i.e. biofilms attached to mussels) and plankton were sampled between July 2013 and October 2014, and analyzed using HILIC-MS/MS. BMAA, DAB and AEG (N-(2-aminoethyl)glycine) were found in almost all the samples of the lagoon. BMAA and DAB were present at 0.58 and 0.83, 2.6 and 3.3, 4.0 and 7.2 μg g(-1) dry weight in plankton collected with nets, periphyton and mussels, respectively. Synechococcus sp., Ostreococcus tauri, Alexandrium catenella and eight species of diatoms were cultured and screened for BMAA and analogs. While Synechococcus sp., O. tauri and A. catenella did not produce BMAA under our culture conditions, four diatoms species contained both BMAA and DAB. Hence, diatoms may be a source of BMAA for mussels. Unlike other toxins produced by microalgae, BMAA and DAB were detected in significant amounts in tissues other than digestive glands in mussels.

  8. Stimulation of L-asparate beta-decarboxylase formation by L-glutamate in Pseudomonas dacunhae and Improved production of L-alanine.

    PubMed

    Shibatani, T; Kakimoto, T; Chibata, I

    1979-09-01

    The formation of L-asparate beta-decarboxylase by Pseudomonas dacunhae was compared on media containing a variety of organic acids and amino acids as a carbon source. Although the enzyme was formed constitutively when the organism was grown on basal medium or on that containing tricarboxylic acid cycle intermediates, it was induced twofold by L-glutamate and repressed one-tenth by L-serine. L-Glutamine, L-proline, L-leucine, glycine, and L-threonine also showed induction effects lower than that of L-glutamate. L-Glutamate derepressed the serine effect. This glutamate effect was observed effect was observed with other microoganisms, e.g., Achromobacter pestifer and Achromobacter liquidum. Since the intermediates from L-glutamate metabolism had no effect, this induction effect was specific to L-glutamate. The formation of some glutamate-related enzymes was measured and is discussed in relation to the formation of L-asparate beta-decarboxylase. L-Asparate beta-decarboxylase was purified to an electrophoretically homogenous state from L-glutamate-grown cells of P. dacunhae, and some properties were compared with those of the enzyme from fumarate-grown cells. The two enzymes were identical in disc electrophoresis, molecular weight, and some enzymatic properties. The industrial production of L-alanine from L-aspartic acid acid was improved by using the culture broth with highly induced L-asparate beta-decarboxylase (9.4 U/ml of broth).

  9. Lysine malonylation is elevated in type 2 diabetic mouse models and enriched in metabolic associated proteins.

    PubMed

    Du, Yipeng; Cai, Tanxi; Li, Tingting; Xue, Peng; Zhou, Bo; He, Xiaolong; Wei, Peng; Liu, Pingsheng; Yang, Fuquan; Wei, Taotao

    2015-01-01

    Protein lysine malonylation, a newly identified protein post-translational modification (PTM), has been proved to be evolutionarily conserved and is present in both eukaryotic and prokaryotic cells. However, its potential roles associated with human diseases remain largely unknown. In the present study, we observed an elevated lysine malonylation in a screening of seven lysine acylations in liver tissues of db/db mice, which is a typical model of type 2 diabetes. We also detected an elevated lysine malonylation in ob/ob mice, which is another model of type 2 diabetes. We then performed affinity enrichment coupled with proteomic analysis on liver tissues of both wild-type (wt) and db/db mice and identified a total of 573 malonylated lysine sites from 268 proteins. There were more malonylated lysine sites and proteins in db/db than in wt mice. Five proteins with elevated malonylation were verified by immunoprecipitation coupled with Western blot analysis. Bioinformatic analysis of the proteomic results revealed the enrichment of malonylated proteins in metabolic pathways, especially those involved in glucose and fatty acid metabolism. In addition, the biological role of lysine malonylation was validated in an enzyme of the glycolysis pathway. Together, our findings support a potential role of protein lysine malonylation in type 2 diabetes with possible implications for its therapy in the future.

  10. Regulation of lysine biosynthesis and transport genes in bacteria: yet another RNA riboswitch?

    PubMed

    Rodionov, Dmitry A; Vitreschak, Alexey G; Mironov, Andrey A; Gelfand, Mikhail S

    2003-12-01

    Comparative analysis of genes, operons and regulatory elements was applied to the lysine biosynthetic pathway in available bacterial genomes. We report identification of a lysine-specific RNA element, named the LYS element, in the regulatory regions of bacterial genes involved in biosynthesis and transport of lysine. Similarly to the previously described RNA regulatory elements for three vitamins (riboflavin, thiamin and cobalamin), purine and methionine regulons, this regulatory RNA structure is highly conserved on the sequence and structural levels. The LYS element includes regions of lysine-constitutive mutations previously identified in Escherichia coli and Bacillus subtilis. A possible mechanism of the lysine-specific riboswitch is similar to the previously defined mechanisms for the other metabolite-specific riboswitches and involves either transcriptional or translational attenuation in various groups of bacteria. Identification of LYS elements in Gram-negative gamma-proteobacteria, Gram-positive bacteria from the Bacillus/Clostridium group, and Thermotogales resulted in description of the previously uncharacterized lysine regulon in these bacterial species. Positional analysis of LYS elements led to identification of a number of new candidate lysine transporters, namely LysW, YvsH and LysXY. Finally, the most likely candidates for genes of lysine biosynthesis missing in Gram- positive bacteria were identified using the genome context analysis.

  11. Lysine Acetylation Is a Widespread Protein Modification for Diverse Proteins in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lysine acetylation (LysAc), a form of reversible protein post translational modification previously known only for histone proteins in plants, is shown to be wide spread in Arabidopsis. Sixty five lysine modification sites were identified on 58 proteins, which operate in a wide variety of pathways/...

  12. Nucleotide sequence of a lysine transfer ribonucleic Acid from bakers' yeast.

    PubMed

    Madison, J T; Boguslawski, S J; Teetor, G H

    1972-05-12

    The nucleotide sequence of one of the two major lysine transfer RNA's from bakers' yeast has been determined. Its structure is compared to that of a lysine tRNA from a haploid yeast. A total of 21 nucleotides differ in the two molecules. Only the T-psi-C-G (thymidine-pseudouridine-cytidine-guanosine) loop and its supporting stem are identical.

  13. [Changes in the lysine of spiruline algae samples after various heat treatments].

    PubMed

    Adrian, J

    1975-01-01

    The spirulina algae are microorganisms which are cultivated on Mexican lakes for feeding use. After drying, they contain about 52 per cent of proteins, with 4 per cent of lysine and 1, 7 per cent of methionine. In the studied samples, pH is 6, 2; they are partially autolysed and contain 4 to 18 per cent of free lysine and methionine and 6, 5 per cent of soluble carbohydrates. During heating treatments, the spiurlina lysine reacts as the same as oilcak meal lysine; it resists rather well to autoclaving but less to roasting. The yeast lysine is more stable than the spirulina lysine. The thermic stability of spirulina lysine is caused first by the small amount of free reducing carbohydrates, and for a minor part by the natural acicity of these products. The lysine destruction is proportional to the autolysis stage of the samples, that is to say the presence of free aminoacids. All the behavior differences between the various spirulina samples disappear when are heated with xylose, which induces a strong Maillard reaction.

  14. Observed surface lysine acetylation of human carbonic anhydrase II expressed in Escherichia coli

    PubMed Central

    Mahon, Brian P; Lomelino, Carrie L; Salguero, Antonieta L; Driscoll, Jenna M; Pinard, Melissa A; McKenna, Robert

    2015-01-01

    Acetylation of surface lysine residues of proteins has been observed in Escherichia coli (E. coli), an organism that has been extensively utilized for recombinant protein expression. This post-translational modification is shown to be important in various processes such as metabolism, stress-response, transcription, and translation. As such, utilization of E. coli expression systems for protein production may yield non-native acetylation events of surface lysine residues. Here we present the crystal structures of wild-type and a variant of human carbonic anhydrase II (hCA II) that have been expressed in E. coli and exhibit surface lysine acetylation and we speculate on the effect this has on the conformational stability of each enzyme. Both structures were determined to 1.6 Å resolution and show clear electron density for lysine acetylation. The lysine acetylation does not distort the structure and the surface lysine acetylation events most likely do not interfere with the biological interpretation. However, there is a reduction in conformational stability in the hCA II variant compared to wild type (∼4°C decrease). This may be due to other lysine acetylation events that have occurred but are not visible in the crystal structure due to intrinsic disorder. Therefore, surface lysine acetylation events may affect overall protein stability and crystallization, and should be considered when using E. coli expression systems. PMID:26266677

  15. Lysine Malonylation Is Elevated in Type 2 Diabetic Mouse Models and Enriched in Metabolic Associated Proteins*

    PubMed Central

    Du, Yipeng; Cai, Tanxi; Li, Tingting; Xue, Peng; Zhou, Bo; He, Xiaolong; Wei, Peng; Liu, Pingsheng; Yang, Fuquan; Wei, Taotao

    2015-01-01

    Protein lysine malonylation, a newly identified protein post-translational modification (PTM), has been proved to be evolutionarily conserved and is present in both eukaryotic and prokaryotic cells. However, its potential roles associated with human diseases remain largely unknown. In the present study, we observed an elevated lysine malonylation in a screening of seven lysine acylations in liver tissues of db/db mice, which is a typical model of type 2 diabetes. We also detected an elevated lysine malonylation in ob/ob mice, which is another model of type 2 diabetes. We then performed affinity enrichment coupled with proteomic analysis on liver tissues of both wild-type (wt) and db/db mice and identified a total of 573 malonylated lysine sites from 268 proteins. There were more malonylated lysine sites and proteins in db/db than in wt mice. Five proteins with elevated malonylation were verified by immunoprecipitation coupled with Western blot analysis. Bioinformatic analysis of the proteomic results revealed the enrichment of malonylated proteins in metabolic pathways, especially those involved in glucose and fatty acid metabolism. In addition, the biological role of lysine malonylation was validated in an enzyme of the glycolysis pathway. Together, our findings support a potential role of protein lysine malonylation in type 2 diabetes with possible implications for its therapy in the future. PMID:25418362

  16. Widespread occurrence of lysine methylation in Plasmodium falciparum proteins at asexual blood stages

    PubMed Central

    Kaur, Inderjeet; Zeeshan, Mohammad; Saini, Ekta; Kaushik, Abhinav; Mohmmed, Asif; Gupta, Dinesh; Malhotra, Pawan

    2016-01-01

    Post-transcriptional and post-translational modifications play a major role in Plasmodium life cycle regulation. Lysine methylation of histone proteins is well documented in several organisms, however in recent years lysine methylation of proteins outside histone code is emerging out as an important post-translational modification (PTM). In the present study we have performed global analysis of lysine methylation of proteins in asexual blood stages of Plasmodium falciparum development. We immunoprecipitated stage specific Plasmodium lysates using anti-methyl lysine specific antibodies that immunostained the asexual blood stage parasites. Using liquid chromatography and tandem mass spectrometry analysis, 570 lysine methylated proteins at three different blood stages were identified. Analysis of the peptide sequences identified 605 methylated sites within 422 proteins. Functional classification of the methylated proteins revealed that the proteins are mainly involved in nucleotide metabolic processes, chromatin organization, transport, homeostatic processes and protein folding. The motif analysis of the methylated lysine peptides reveals novel motifs. Many of the identified lysine methylated proteins are also interacting partners/substrates of PfSET domain proteins as revealed by STRING database analysis. Our findings suggest that the protein methylation at lysine residues is widespread in Plasmodium and plays an important regulatory role in diverse set of the parasite pathways. PMID:27762281

  17. Mapping and genotypic analysis of NK-lysin gene in chicken

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Antimicrobial peptides (AMP) are important elements of the first line of defence against pathogens in animals. NK-lysin is a cationic AMP that plays a critical role in innate immunity. The chicken NK-lysin gene has been cloned and its antimicrobial and anticancer activity has been descri...

  18. Mapping and genotypic analysis of NK-lysin gene in chicken

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NK-lysin is a cationic anti-microbial peptide that plays a critical role in innate immunity against infectious pathogens. Chicken NK-lysin has been cloned and its antimicrobial and anticancer activity has been described but its location in the chicken genome prior this study was unknown. A 6000 rad ...

  19. Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protein lysine acetylation (LysAc) in bacteria has recently been demonstrated to be widespread in E. coli and Salmonella and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we report the lysine acetylome of Erwinia amylovo...

  20. Lysine-overproducing mutants of Saccharomyces cerevisiae baker's yeast isolated in continuous culture.

    PubMed Central

    Gasent-Ramírez, J M; Benítez, T

    1997-01-01

    Saccharomyces cerevisiae baker's yeast mutants which produce 3 to 17 times as much lysine as the wild type, depending on the nitrogen source, have been selected. The baker's yeast strain was growth in a pH-regulated chemostat in minimal medium with proline as the nitrogen source, supplemented with increasing concentrations of the toxic analog of the lysine S-2-aminoethyl-L-cysteine (AEC). The lysine-overproducing mutants, which were isolated as AEC-resistant mutants, were also resistant to high external concentrations of lysine and to alpha-aminoadipate and seemed to be affected in the lysine biosynthetic pathway but not in the biosynthetic pathways of other amino acids. Lysine overproduction by one of the mutants seemed to be due to, at least, the loss of repression of the homocitrate synthase encoded by the LYS20 gene. The mutant grew slower than the wild type, and its dough-raising capacity was reduced in in vitro assays, probably due to the toxic effects of lysine accumulation or of an intermediate produced in the pathway. This mutant can be added as a food supplement to enrich the nutritive qualities of bakery products, and its resistance to alpha-aminoadipate, AEC, and lysine can be used as a dominant marker. PMID:9406398