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Sample records for acids glycine l-alanine

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

    PubMed

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

    2015-01-01

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

  2. 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. PMID:25096519

  3. 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.

  4. Determination of β-Cyano-L-alanine, γ-Glutamyl-β-cyano-L-alanine, and Common Free Amino Acids in Vicia sativa (Fabaceae) Seeds by Reversed-Phase High-Performance Liquid Chromatography

    PubMed Central

    Megías, Cristina; Cortés-Giraldo, Isabel; Girón-Calle, Julio; Vioque, Javier; Alaiz, Manuel

    2014-01-01

    A method for determination of β-cyano-L-alanine, γ-glutamyl-β-cyano-L-alanine and other free amino acids in Vicia sativa is presented. Seed extracts were derivatized by reaction with diethyl ethoxymethylenemalonate and analyzed by reverse-phase high-performance liquid chromatography. Calibration curves showed very good linearity of the response. The limit of detection and quantification was 0.15 and 0.50 μM, respectively. The method has high intra- (RSD = 0.28–0.31%) and interrepeatability (RSD = 2.76–3.08%) and remarkable accuracy with a 99% recovery in spiked samples. The method is very easy to carry out and allows for ready analysis of large number of samples using very basic HPLC equipment because the derivatized samples are very stable and have very good chromatographic properties. The method has been applied to the determination of γ-glutamyl-β-cyano-L-alanine, β-cyano-L-alanine, and common free amino acids in eight wild populations of V. sativa from southwestern Spain. PMID:25587488

  5. Synthesis, growth and optical properties of an efficient nonlinear optical single crystal: L-alanine DL-malic acid

    NASA Astrophysics Data System (ADS)

    Kirubagaran, R.; Madhavan, J.

    2015-02-01

    Single crystals of L-alanine DL-malic acid (LADLMA) have been grown from aqueous solution by slow-cooling technique. Powder X-ray diffraction studies reveal the structure of the crystal to be orthorhombic. The nonlinear optical conversion efficiency test was carried out for the grown crystals using the Kurtz powder technique. The third order nonlinear refractive index and the nonlinear absorption coefficient where evaluated by Z-scan measurements. As the material have a negative refractive index it could be used in the protection of optical sensors such as night vision devices.

  6. The cyanobacterial amino acid β-N-methylamino-l-alanine perturbs the intermediary metabolism in neonatal rats.

    PubMed

    Engskog, Mikael K R; Karlsson, Oskar; Haglöf, Jakob; Elmsjö, Albert; Brittebo, Eva; Arvidsson, Torbjörn; Pettersson, Curt

    2013-10-01

    The neurotoxic amino acid β-N-methylamino-l-alanine (BMAA) is produced by most cyanobacteria. BMAA is considered as a potential health threat because of its putative role in neurodegenerative diseases. We have previously observed cognitive disturbances and morphological brain changes in adult rodents exposed to BMAA during the development. The aim of this study was to characterize changes of major intermediary metabolites in serum following neonatal exposure to BMAA using a non-targeted metabolomic approach. NMR spectroscopy was used to obtain serum metabolic profiles from neonatal rats exposed to BMAA (40, 150, 460mg/kg) or vehicle on postnatal days 9-10. Multivariate data analysis of binned NMR data indicated metabolic pattern differences between the different treatment groups. In particular five metabolites, d-glucose, lactate, 3-hydroxybutyrate, creatine and acetate, were changed in serum of BMAA-treated neonatal rats. These metabolites are associated with changes in energy metabolism and amino acid metabolism. Further statistical analysis disclosed that all the identified serum metabolites in the lowest dose group were significantly (p<0.05) decreased. The neonatal rat model used in this study is so far the only animal model that displays significant biochemical and behavioral effects after a low short-term dose of BMAA. The demonstrated perturbation of intermediary metabolism may contribute to BMAA-induced developmental changes that result in long-term effects on adult brain function. PMID:23886855

  7. Amino acids (L-arginine and L-alanine) passivated CdS nanoparticles: Synthesis of spherical hierarchical structure and nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Talwatkar, S. S.; Tamgadge, Y. S.; Sunatkari, A. L.; Gambhire, A. B.; Muley, G. G.

    2014-12-01

    CdS nanoparticles (NPs) passivated with amino acids (L-alanine and L-arginine) having spherical hierarchical morphology were synthesized by room temperature wet chemical method. Synthesized NPs were characterized by ultraviolet-visible (UV-vis) spectroscopy to study the variation of band gaps with concentration of surface modifying agents. Increase in band gap has been observed with the increase in concentration of surface modifying agents and was found more prominent for CdS NPs passivated with L-alanine. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis were carried out for the study of crystal structure and morphology of CdS NPs. The average particle size of CdS NPs calculated from Debye-Scherer formula was found to less than 5 nm and agrees well with those determined from UV-vis spectra and TEM data. Fourier transform infrared (FT-IR) spectroscopy was performed to know the functional groups of the grown NPs. Peaks in FT-IR spectra indicate the formation of CdS NPs and capping with L-alanine and L-arginine. Photoluminescence spectra of these NPs were also studied. Finally, colloidal solution of CdS-PVAc was subjected to Z-scan experiment under low power cw laser illumination to characterize them for third order nonlinear optical properties. CdS-PVAc colloidal solution shows enhanced nonlinear absorption due to RSA and weak FCA on account of two photon absorption processes triggered by thermal effect.

  8. The metabolism of the non-proteinogenic amino acid β-N-methylamino-L-alanine (BMAA) in the cyanobacterium Synechocystis PCC6803.

    PubMed

    Downing, Simoné; Downing, Timothy Grant

    2016-06-01

    The neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) is produced by cyanobacteria under nitrogen starvation conditions and its metabolism is closely associated with cellular nitrogen control. Very little is known regarding the metabolism or biosynthesis of this amino acid in the producing organisms and current knowledge is limited to the spontaneous formation of carbamate adducts in the presence of aqueous carbon dioxide, the rapid removal of free cellular BMAA upon the addition of ammonia to nitrogen-starved cyanobacterial cultures, and the link between cellular nitrogen status and BMAA synthesis. Data presented here show that exogenous BMAA is readily metabolised by cyanobacteria during which, the primary amino group is rapidly transferred to other cellular amino acids. Furthermore, data suggest that BMAA is metabolised in cyanobacteria via a reversible transamination reaction. This study presents novel data on BMAA metabolism in cyanobacteria and provides the first proposed biosynthetic precursor to BMAA biosynthesis in cyanobacteria. PMID:26948425

  9. Protein association of the neurotoxin and non-protein amino acid BMAA (β-N-methylamino-L-alanine) in the liver and brain following neonatal administration in rats.

    PubMed

    Karlsson, Oskar; Jiang, Liying; Andersson, Marie; Ilag, Leopold L; Brittebo, Eva B

    2014-04-01

    The environmental neurotoxin β-N-methylamino-L-alanine (BMAA) is not an amino acid that is normally found in proteins. Our previous autoradiographic study of (3)H-labeled BMAA in adult mice unexpectedly revealed a tissue distribution similar to that of protein amino acids. The aim of this study was to characterize the distribution of free and protein-bound BMAA in neonatal rat tissues following a short exposure using autoradiographic imaging and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The autoradiographic imaging of (14)C-L-BMAA demonstrated a distinct uptake of radioactivity that was retained following acid extraction in tissues with a high rate of cell turnover and/or protein synthesis. The UHPLC-MS/MS analysis conclusively demonstrated a dose-dependent increase of protein-associated BMAA in neonatal rat tissues. The level of protein-associated BMAA in the liver was more than 10 times higher than that in brain regions not fully protected by the blood-brain barrier which may be due to the higher rate of protein synthesis in the liver. In conclusion, this study demonstrated that BMAA was associated with rat proteins suggesting that BMAA may be misincorporated into proteins. However, protein-associated BMAA seemed to be cleared over time, as none of the samples from adult rats had any detectable free or protein-associated BMAA. PMID:24472610

  10. Combined use of l-alanine tert butyl ester lactate and trimethyl-β-cyclodextrin for the enantiomeric separations of 2-arylpropionic acids nonsteroidal anti-inflammatory drugs.

    PubMed

    Mavroudi, Maria C; Kapnissi-Christodoulou, Constantina P

    2015-10-01

    In this study, a new CE method, employing a binary system of trimethyl-β-CD (TM-β-CD) and a chiral amino acid ester-based ionic liquid (AAIL), was developed for the chiral separation of seven 2-arylpropionic acid nonsteroidal anti-inflammatory drugs (NSAIDs). In particular, the enantioseparation of ibuprofen, ketoprofen, carprofen, indoprofen, flurbiprofen, naproxen, and fenoprofen was improved significantly by supporting the BGE with the chiral AAIL l-alanine tert butyl ester lactate (l-AlaC4 Lac). Parameters, such as concentrations of TM-β-CD and l-AlaC4 Lac, and buffer pH, were systematically examined in order to optimize the chiral separation of each NSAID. It was observed that the addition of the AAIL into the BGE improved both resolution and efficiency significantly. After optimization of separation conditions, baseline separation (Rs >1.5) of five of the analytes was achieved in less than 11 min, while the resolution of ibuprofen and flurbiprofen was approximately 1.2. The optimized enantioseparation conditions for all analytes involve a BGE of 5 mM sodium acetate/acetic acid (pH 5.0), an applied voltage of 30 kV, and a temperature of 20°C. In addition, the results obtained by computing the %-RSD values of the EOF and the two enantiomer peaks, demonstrated excellent run-to-run, batch-to-batch, and day-to-day reproducibilities. PMID:26080944

  11. 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.

  12. Atomic Layer Deposition of L-Alanine Polypeptide

    DOE PAGESBeta

    Fu, Yaqin; Li, Binsong; Jiang, Ying-Bing; Dunphy, Darren R.; Tsai, Andy; Tam, Siu-Yue; Fan, Hongyou Y.; Zhang, Hongxia; Rogers, David; Rempe, Susan; et al

    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.

  13. L-alanine uptake in membrane vesicles from Mytilus edulis gills

    SciTech Connect

    Pajor, A.M.; Wright, S.H.

    1986-03-05

    Previous studies have shown that gills from M. edulis can accumulate L-alanine from seawater by a saturable process specific for ..cap alpha..-neutral amino acids. This uptake occurs against chemical gradients in excess of 10/sup 6/ to 1. To further characterize this uptake, membrane vesicles were prepared from M. edulis gill tissue by differential centrifugation. Enrichments of putative enzyme markers (relative to that in combined initial fractions) were as follows: ..gamma..-Glutamyltranspeptidase, 25-30x; Alkaline Phosphatase, 5-6x; K/sup +/-dependent para-Nitrophenyl Phosphatase, 3-5x; Succinate Dehydrogenase 0.1-0.2x. These results suggest that the preparation is enriched in plasma membranes, although histochemical studies will be needed to verify this. The time course of /sup 14/C-L-alanine uptake in the presence of inwardly-directed Na/sup +/ gradient showed a transient overshoot (3-5 fold) at 10 minutes which decreased to equilibrium after six hours. The size of the overshoot and early uptake rates depended on the size of the inwardly-directed Na/sup +/ gradient. No overshoot was seen in the presence of inwardly-directed gradients of LiCl or choline-Cl, or with equilibrium concentrations NaCl or mannitol. A reduced overshoot was seen with a gradient of NaSCN. A small overshoot was seen with an inwardly-directed gradient of KCl. Transport of L-alanine included saturable and diffusive components. Uptake of 6 ..mu..M L-alanine was inhibited more than 80% by 100 ..mu..M ..cap alpha..-zwitterionic amino acids (alanine, leucine, glycine); by 30 to 75% by proline, aspartate and lysine; and less than 20% by a ..beta..-amino acid, taurine. The results of these experiments agree with those from intact gill studies and support the hypothesis that L-alanine is transported into gill epithelial cells by a secondary active transport process involving Na/sup +/.

  14. Systematic detection of BMAA (β-N-methylamino-l-alanine) and DAB (2,4-diaminobutyric acid) in mollusks collected in shellfish production areas along the French coasts.

    PubMed

    Réveillon, Damien; Séchet, Véronique; Hess, Philipp; Amzil, Zouher

    2016-02-01

    The neurotoxin β-N-methylamino-l-alanine (BMAA) is naturally present in some microalgal species in the marine environment. The accumulation of BMAA has widely been observed in filter-feeding bivalves that are known to consume primary producers constituting the base of complex aquatic food webs. This study was performed to assess the occurrence of BMAA and isomers in mollusks collected from nine representative shellfish production areas located on the three French coasts (Channel, Atlantic and Mediterranean sites). The use of a highly selective and sensitive HILIC-MS/MS method, with D5DAB as internal standard, revealed the systematic detection of BMAA and DAB, in concentrations ranging from 0.20 to 6.7 μg g(-1) dry weight of digestive gland tissues of mollusks. While we detected BMAA in four strains of diatoms in a previous study, here BMAA was only detected in one diatom species previously not investigated out of the 23 microalgal species examined (belonging to seven classes). The concentrations of BMAA and DAB in mussels and oysters were similar at different sampling locations and despite the high diversity of phytoplankton populations that mollusks feed on at these locations. Only small variations of BMAA and DAB levels were observed and these were not correlated to any of the phytoplankton species reported. Therefore, extensive research should be performed on both origin and metabolism of BMAA in shellfish. The levels observed in this study are similar to those found in other studies in France or elsewhere. A previous study had related such levels to a cluster of Amyotrophic Lateral Sclerosis in the South of France; hence the widespread occurrence of BMAA in shellfish from all coasts in France found in this study suggests the need for further epidemiological and toxicological studies to establish the levels that are relevant for a link between the consumption of BMAA-containing foodstuffs and neurodegenerative diseases. PMID:26615827

  15. Initiation of Spore Germination in Bacillus subtilis: Relationship to Inhibition of l-Alanine Metabolism

    PubMed Central

    Prasad, Chandan

    1974-01-01

    The inhibitory effects of anthranilic acid esters (methyl anthranilate and N-methyl anthranilate) on the l-alanine-induced initiation of spore germination was examined in Bacillus subtilis 168. Methyl anthranilate irreversibly inhibited alanine initiation by a competitive mechanism. In its presence, the inhibition could be reversed only by the combined addition of d-glucose, d-fructose, and K+. Both l-alanine dehydrogenase and l-glutamate-pyruvate transaminase, enzymes which catalyze the first reaction in l-alanine metabolism, were competitively inhibited by methyl anthranilate. The Ki values for germination initiation (0.053 mM) and of l-glutamate-pyruvate transaminase (0.068 mM) were similar, whereas that for l-alanine dehydrogenase (0.4 mM) was six to seven times higher. Since a mutant lacking l-alanine dehydrogenase activity germinated normally in l-alanine alone, it is speculated that the major pathway of l-alanine metabolism during initiation may be via transmination reaction. PMID:4212093

  16. Improved detection of β-N-methylamino-L-alanine using N-hydroxysuccinimide ester of N-butylnicotinic acid for the localization of BMAA in blue mussels (Mytilus edulis).

    PubMed

    Andrýs, Rudolf; Zurita, Javier; Zguna, Nadezda; Verschueren, Klaas; De Borggraeve, Wim M; Ilag, Leopold L

    2015-05-01

    β-N-Methylamino-L-alanine (BMAA) is an important non-protein amino acid linked to neurodegenerative diseases, specifically amyotrophic lateral sclerosis (ALS). Because it can be transferred and bioaccumulated higher up the food chain, it poses significant public health concerns; thus, improved detection methods are of prime importance for the identification and management of these toxins. Here, we report the successful use of N-hydroxysuccinimide ester of N-butylnicotinic acid (C4-NA-NHS) for the efficient separation of BMAA from its isomers and higher sensitivity in detecting BMAA compared to the current method of choice using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) derivatization. Implementation of this efficient method allowed localization of BMAA in the non-visceral tissues of blue mussels, suggesting that more efficient depuration may be required to remove this toxin prior to consumption. This is a crucial method in establishing the absence or presence of the neurotoxic amino acid BMAA in food, environmental or biomedical samples. PMID:25821115

  17. Effect of L-tryptophan injection in rats on some enzymes of amino acid metabolism in liver. I. In vitro studies of the effect of L-tryptophan and its metabolites on the extramitochondrial L-alanine: 2-ketoglutaric aminotransferase.

    PubMed

    Katsos, A; Philippidis, H; Palaiologos, G

    1981-02-01

    Fed and fasted rats were injected with L-tryptophan (12.5 mg/100 g body weight) and the specific activities of L-glutamic: NAD oxidoreductase (deaminating) (EC 1.4.1.2) (GDH), L-aspartic-2-ketoglutaric aminotransferase (EC 2.6.1.1) (GOT) and L-alanine-2-ketoglutaric aminotransferase (EC 2.6.1.2) (GPT) from hepatic mitochondria and cytosol were compared. L-tryptophan results in a decrease of mitochondrial GDH activity by 22% and of cytosolic GPT and GOT by 42% and 38% respectively in the liver of fasted rats. Xanthurenate is a potent inhibitor of purified extramitochondrial GPT, whereas anthranilate and quinolinate are less potent inhibitors. L-tryptophan, 5-OH-tryptophan and indole exert a slight inhibition. Kynurenine, 5-OH-tryptamine, tryptamine, picolinic acid, nicotinic acid and indoloacetic acid do not show any inhibition of GPT. It is suggested that L-tryptophan injection inhibits extramitochondrial GPT by its transformation to xanthurenate and anthranilate. PMID:7227974

  18. Sodium dependency of L-alanine absorption in canine Thiry-Vella loops.

    PubMed

    Fleshler, B; Nelson, R A

    1970-03-01

    The effect of sodium on the absorption of L-alanine in vivo was tested by measuring the absorption of L-alanine from Thiry-Vella loops in dogs. Solutions containing L-alanine (10 or 50 mM) sodium at concentrations of 0, 74, or 145 m-equiv/1 and mannitol, as needed to maintain isotonicity were instilled into the loops for 10 minutes. Similar studies were done with L-alanine 50 mM and either 0 or 145 m-equiv/1 of sodium for five minutes. Under all conditions absorption of alanine was significantly less from the solution initially free of sodium. Although these differences were statistically significant, the physiological significance was not great since the actual differences in amounts of L-alanine absorbed were small. Insorption of sodium was low from the fluid which initially had no sodium, but exsorption proceeded rapidly and was unaffected by the luminal sodium concentration. This resulted in a rapid rise of intraluminal sodium concentration when no sodium was initially present. This persistent exsorption of sodium was, therefore, adequate to provide sodium in the lumen to activate the sodium-dependent carrier, postulated on the basis of studies in vitro. These data in vivo are consistent with the view that sodium at the intraluminal surface is important in accelerating amino acid transport, but indicate that in the absence of added intraluminal sodium the gut mucosa itself, under normal circumstances, provides the sodium needed for L-alanine absorption. PMID:5423904

  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

    Rathgeb, Anna; Böhm, Andreas; Novak, Maria S; Gavriluta, Anatolie; Dömötör, Orsolya; Tommasino, Jean Bernard; Enyedy, Eva A; Shova, Sergiu; Meier, Samuel; Jakupec, Michael A; Luneau, Dominique; Arion, Vladimir B

    2014-03-01

    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), (1)H 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. 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

  1. Exchange interactions and magnetic dimension in Cu(L-alanine)2

    NASA Astrophysics Data System (ADS)

    Calvo, R.; Passeggi, M. C. G.; Novak, M. A.; Symko, O. G.; Oseroff, S. B.; Nascimento, O. R.; Terrile, M. C.

    1991-01-01

    A study of the magnetic properties of the copper (II) complex of the amino acid l-alanine [Cu(l-alanine)2] is reported. The susceptibility of a powder sample has been measured between 0.013 and 240 K. A linear-spin-chain model with antiferromagnetic exchange coupling J=-0.52 K fits well the susceptibility data above 0.3 K. Room-temperature electron paramagnetic resonance (EPR) spectra of single crystals of Cu(l-alanine)2 at 9 and 35 GHz show a single, exchange-narrowed resonance. The g tensor, with principal values g1=2.0554+/-0.0005, g2=2.1064+/-0.0005, and g3=2.2056+/-0.0005, reflects the crystal structure of Cu(l-alanine)2 and the electronic properties of the copper ions. The observed angular variation of the linewidth is attributed to the magnetic interactions, narrowed by the exchange coupling between copper ions, and shows a contribution characteristic of the dipole-dipole interaction in a spin system with a predominant two-dimensional spin dynamics. Considering the exchange-collapsed resonance corresponding to the two lattice sites for copper in Cu(l-alanine)2, we evaluate an exchange constant ||J(AB1)||=0.47 K between nonequivalent copper neighbors in a spin chain, similar to the value obtained from the susceptibility data. The one-dimensional magnetic behavior suggested by the susceptibility data in Cu(l-alanine)2, where the metal ions are distributed in layers, is explained by proposing that carboxylate bridges provide electronic paths for superexchange interactions between coppers. Considering the characteristics of the molecular structure of Cu(l-alanine)2, the layers seem to be magnetically split off into one-dimensional zigzag ribbons. The apparent disagreement between the one-dimensional behavior suggested by the susceptibility data and the two-dimensional behavior of the spin dynamics suggested by the EPR linewidth is analyzed.

  2. L-alanine in a droplet of water: a density-functional molecular dynamics study.

    PubMed

    Degtyarenko, Ivan M; Jalkanen, Karl J; Gurtovenko, Andrey A; Nieminen, Risto M

    2007-04-26

    We report the results of a Born-Oppenheimer molecular dynamics study on an L-alanine amino acid in neutral aqueous solution. The whole system, the L-alanine zwitterion and 50 water molecules, was treated quantum mechanically. We found that the hydrophobic side chain (R = CH3) defines the trajectory path of the molecule. Initially fully hydrated in an isolated droplet of water, the amino acid moves to the droplet's surface, exposing its hydrophobic methyl group and alpha-hydrogen out of the water. The structure of an L-alanine with the methyl group exposed to the water surface was found to be energetically favorable compared to a fully hydrated molecule. The dynamic behavior of the system suggests that the first hydration shell of the amino acid is localized around carboxylate (CO2-) and ammonium (NH3+) functional groups; it is highly ordered and quite rigid. In contrast, the hydration shell around the side chain is much less structured, suggesting a modest influence of the methyl group on the structure of water. The number of water molecules in the first hydration shell of an alanine molecule is constantly changing; the average number was found to equal 7. The molecular dynamics results show that L-alanine in water does not have a preferred conformation, as all three of the molecule's functional sites (i.e., CH3, NH3+, CO2-) perform rotational movements around the C(alpha)-site bond. PMID:17407339

  3. Functional differentiation of human jejunum and ileum: A comparison of the handling of glucose, peptides, and amino acids

    PubMed Central

    Silk, D. B. A.; Webb, Joan P. W.; Lane, Annette E.; Clark, M. L.; Dawson, A. M.

    1974-01-01

    The characteristics of glucose, glycine, L-alanine, and glycyl-L-alanine absorption from the jejunum and ileum have been compared in normal human subjects. A perfusion technique has been used, and correct positioning of the perfusion tube has been confirmed by measuring the differential jejunal and ileal handling of bicarbonate. Glucose and glycine were absorbed faster from the jejunum than from the ileum of all subjects studied, and L-alanine was absorbed faster from the jejunum than from the ileum in five out of six subjects studied. In contrast, the dipeptide glycyl-L-alanine was absorbed at comparable rates from the jejunum and ileum. Higher concentrations of free amino acids were detected in the luminal contents aspirated during the ileal dipeptide perfusions. These results emphasize the importance of oligopeptide transport in the absorption of protein digestion products, especially in the human ileum, and the practical implications of these findings are discussed. PMID:4852103

  4. Rapid Crystallization of L-Alanine on Engineered Surfaces using Metal-Assisted and Microwave-Accelerated Evaporative Crystallization.

    PubMed

    Alabanza, Anginelle M; Pozharski, Edwin; Aslan, Kadir

    2012-01-01

    This study demonstrates the application of metal-assisted and microwave-accelerated evaporative crystallization (MA-MAEC) technique to rapid crystallization of L-alanine on surface engineered silver nanostructures. In this regard, silver island films (SIFs) were modified with hexamethylenediamine (HMA), 1-undecanethiol (UDET), and 11-mercaptoundecanoic acid (MUDA), which introduced -NH(2), -CH(3) and -COOH functional groups to SIFs, respectively. L-Alanine was crystallized on these engineered surfaces and blank SIFs at room temperature and using MA-MAEC technique. Significant improvements in crystal size, shape, and quality were observed on HMA-, MUDA- and UDET-modified SIFs at room temperature (crystallization time = 144, 40 and 147 min, respectively) as compared to those crystals grown on blank SIFs. Using the MA-MAEC technique, the crystallization time of L-alanine on engineered surfaces were reduced to 17 sec for microwave power level 10 (i.e., duty cycle 100%) and 7 min for microwave power level 1 (duty cycle 10%). Raman spectroscopy and powder x-ray diffraction (XRD) measurements showed that L-Alanine crystals grown on engineered surfaces using MA-MAEC technique had identical characteristic peaks of L-alanine crystals grown using traditional evaporative crystallization. PMID:22267957

  5. Functionalization of single-walled carbon nanotubes with uracil, guanine, thymine and L-alanine

    NASA Astrophysics Data System (ADS)

    Silambarasan, D.; Iyakutti, K.; Vasu, V.

    2014-06-01

    Experimental investigation of functionalization of oxidized single-walled carbon nanotubes (OSWCNTs) with three nucleic acid bases such as uracil, guanine, thymine and one amino acid, L-alanine is carried out. Initially, the SWCNTs are oxidized by acid treatment. Further, the oxidized SWCNTs are effectively functionalized with aforementioned biological compounds by ultrasonication. The diameter of OSWCNTs has increased after the adsorption of biological compounds. The cumulative Π-Π stacking, hydrogen bond and polar interaction are the key factors to realize the adsorption. The amount of adsorption of each biological compound is estimated. The adsorption of guanine is more among all the four biological compounds.

  6. Selective potentiation of alpha 1 glycine receptors by ginkgolic acid

    PubMed Central

    Maleeva, Galyna; Buldakova, Svetlana; Bregestovski, Piotr

    2015-01-01

    Glycine receptors (GlyRs) belong to the superfamily of pentameric cys-loop receptor-operated channels and are involved in numerous physiological functions, including movement, vision, and pain. In search for compounds performing subunit-specific modulation of GlyRs we studied action of ginkgolic acid, an abundant Ginkgo biloba product. Using patch-clamp recordings, we analyzed the effects of ginkgolic acid in concentrations from 30 nM to 25 μM on α1–α3 and α1/β, α2/β configurations of GlyR and on GABAARs expressed in cultured CHO-K1 cells and mouse neuroblastoma (N2a) cells. Ginkgolic acid caused an increase in the amplitude of currents mediated by homomeric α1 and heteromeric α1/β GlyRs and provoked a left-shift of the concentration-dependent curves for glycine. Even at high concentrations (10–25 μM) ginkgolic acid was not able to augment ionic currents mediated by α2, α2/β, and α3 GlyRs, or by GABAAR consisting of α1/β2/γ2 subunits. Mutation of three residues (T59A/A261G/A303S) in the α2 GlyR subunit to the corresponding ones from the α1 converted the action of ginkgolic acid to potentiation with a distinct decrease in EC50 for glycine, suggesting an important role for these residues in modulation by ginkgolic acid. Our results suggest that ginkgolic acid is a novel selective enhancer of α1 GlyRs. PMID:26578878

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

    PubMed

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

    2015-12-01

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

  8. Combination of amino acids reduces pigmentation in B16F0 melanoma cells.

    PubMed

    Ishikawa, Masago; Kawase, Ichiro; Ishii, Fumio

    2007-04-01

    Amino acids, the building blocks of proteins, play significant roles in numerous physiological events in mammals. As the effects of amino acids on melanogenesis have yet to be demonstrated, the present study was conducted to identify whether amino acids, in particular alanine, glycine, isoleucine and leucine, influence melanogenesis in B16F0 melanoma cells. Glycine and L-isoleucine, but not D-isoleucine, reduced melanogenesis in a concentration-dependent manner without any morphological changes in B16F0 melanoma cells. L-Alanine and L-leucine, but not D-alanine and D-leucine, also reduced melanogenesis without any morphological changes in B16F0 melanoma cells. However these amino acids did not show a concentration-dependency. Combination of L-alanine and the other amino acids, particularly 4 amino acids combination, had an additive effect on the inhibition of melanogenesis compared with single treatment of L-alanine. None of the amino acids affected the activity of tyrosinase, a key enzyme in melanogenesis. These results suggest that L-alanine, glycine, L-isoleucine and L-leucine, but not the D-form amino acids, have a hypopigmenting effect in B16F0 melanoma cells, and that these effects are not due to the inhibition of tyrosinase activity. Combination of these 4 amino acids had the additive effect on hypopigmentation that was as similar as that of kojic acid. PMID:17409501

  9. Detection of cyanotoxins, β-N-methylamino-L-alanine and microcystins, from a lake surrounded by cases of amyotrophic lateral sclerosis.

    PubMed

    Banack, Sandra Anne; Caller, Tracie; Henegan, Patricia; Haney, James; Murby, Amanda; Metcalf, James S; Powell, James; Cox, Paul Alan; Stommel, Elijah

    2015-02-01

    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

  10. 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

  11. Glycine as a d-amino acid surrogate in the K+-selectivity filter

    PubMed Central

    Valiyaveetil, Francis I.; Sekedat, Matthew; MacKinnon, Roderick; Muir, Tom W.

    2004-01-01

    The K+ channel-selectivity filter consists of two absolutely conserved glycine residues. Crystal structures show that the first glycine in the selectivity filter, Gly-77 in KcsA, is in a left-handed helical conformation. Although the left-handed helical conformation is not favorable for the naturally occurring l-amino acids, it is favorable for the chirally opposite d-amino acids. Here, we demonstrate that Gly-77 can be replaced by d-Ala with almost complete retention of function. In contrast, substitution with an l-amino acid results in a nonfunctional channel. This finding suggests that glycine is used as a surrogate d-amino acid in the selectivity filter. The absolute conservation of glycine in the K+-selectivity filter can be explained as a result of glycine being the only natural amino acid that can play this role. PMID:15563591

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

    SciTech Connect

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

    1989-05-01

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

  13. Controlled radical polymerization of an acrylamide containing L-alanine moiety via ATRP.

    PubMed

    Rafiee, Zahra

    2016-02-01

    Homopolymerization of an optically active acrylamide having an amino acid moiety in the side chain, N-acryloyl-L-alanine (AAla) was carried out via atom transfer radical polymerization (ATRP) at room temperature using 2-hydroxyethyl-2'-methyl-2'-bromopropionate (HMB) or sodium-4-(bromomethyl)benzoate (SBB) as initiator in pure water, methanol/water mixture and pure methanol solvents. The polymerization reaction resulted in the optically active biocompatible amino acid-based homopolymer in good yield with narrow molecular weight distribution. The number average molecular weight increased with conversion and polydispersity was low. The structure and molecular weight of synthesized polymer were characterized by (1)H NMR, FT-IR spectroscopic techniques and size-exclusion chromatography. PMID:26385362

  14. Expression of an L-alanine dehydrogenase gene in Zymomonas mobilis and excretion of L-alanine

    SciTech Connect

    Uhlenbusch, I.; Sahm, H.; Sprenger, G.A. )

    1991-05-01

    Gene alaD for L-alanine dehydrogenase from Bacillus sphaericus was cloned and introduced into Z. mobilis. Under the control of the strong promoter of the pyruvate decarboxylase (pdc) gene, the enzyme was expressed up to a specific activity of nearly 1 {mu}mol {center dot} min{sup {minus}1} {center dot} mg of protein{sup {minus}1} in recombinant cells. As a result of this high L-alanine dehydrogenase activity, growing cells excreted up to 10 mmol of alanine per 280 mmol of glucose utilized into a mineral salts medium. By the addition of 85 mM NH{sub 4}{sup +} to the medium, growth of the recombinant cells stopped, and up to 41 mmol of alanine was secreted. As alanine dehydrogenase competed with pyruvate decarboxylase (PDC) for the same substrate (pyruvate), PDC activity was reduced by starvation for the essential PDC cofactor thiamine PP{sub i}. A thiamine auxotrophy mutant of Z. mobilis which carried the alaD gene was starved for 40 h in glucose-supplemented mineral salts medium and then shifted to mineral salts medium with 85 mM NH {sub 4}{sup +} and 280 mmol of glucose. The recombinants excreted up to 84 mmol of alanine over 25 h. Alanine excretion proceeded at an initial velocity of 238 nmol {center dot} min{sup {minus}1} {center dot} mg(dry weight){sup {minus}1}. Despite this high activity, the excretion rate seemed to be a limiting factor, as the intracellular concentration of alanine was as high as 260 mM at the beginning of the excretion phase and decreased to 80 to 90 mM over 24 h.

  15. An Anhydro-N-Acetylmuramyl-l-Alanine Amidase with Broad Specificity Tethered to the Outer Membrane of Escherichia coli▿

    PubMed Central

    Uehara, Tsuyoshi; Park, James T.

    2007-01-01

    From its amino acid sequence homology with AmpD, we recognized YbjR, now renamed AmiD, as a possible second 1,6-anhydro-N-acetylmuramic acid (anhMurNAc)-l-alanine amidase in Escherichia coli. We have now confirmed that AmiD is an anhMurNAc-l-Ala amidase and demonstrated that AmpD and AmiD are the only enzymes present in E. coli that are able to cleave the anhMurNAc-l-Ala bond. The activity was present only in the outer membrane fraction obtained from an ampD mutant. In contrast to AmpD, which is specific for the anhMurNAc-l-alanine bond, AmiD also cleaved the bond between MurNAc and l-alanine in both muropeptides and murein sacculi. Unlike the periplasmic murein amidases, AmiD did not participate in cell separation. ampG mutants, which are unable to import GlcNAc-anhMurNAc-peptides into the cytoplasm, released mainly peptides into the medium due to AmiD activity, whereas an ampG amiD double mutant released a large amount of intact GlcNAc-anhMurNAc-peptides into the medium. PMID:17526703

  16. 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. PMID:26254582

  17. Catalytic properties of Sepharose-bound L-alanine dehydrogenase from Bacillus cereus.

    PubMed

    Mureşan, L; Vancea, D; Presecan, E; Porumb, H; Lascu, I; Oargă, M; Matinca, D; Abrudan, I; Bârzu, O

    1983-02-15

    (1) L-Alanine dehydrogenase from Bacillus cereus was purified by a two-step chromatographic procedure involving Cibacron-Blue 3G-A Sepharose 4B-CL, and Sepharose 6B-CL, and immobilized on CNBr-activated Sepharose 4B. (2) Following immobilization via two of the six subunits, L-alanine dehydrogenase retained 66% of the specific activity of the soluble enzyme. The affinity of the immobilized enzyme for NH4+, pyruvate and L-alanine, was not different to that of the soluble form. The Km of the Sepharose-bound L-alanine dehydrogenase for pyridine coenzymes was 6-8-times higher than in the soluble case. (3) The stability of L-alanine dehydrogenase towards urea or thermal denaturation was increased by immobilization. (4) The incubation at 37 degrees C for 24 h of the immobilized L-alanine dehydrogenase with 3 M NH4Cl/NH4OH buffer (pH 9) released 70% of the enzyme. The specific activity and the affinity of the 'solubilized' L-alanine dehydrogenase for the pyridine coenzymes was the same as that obtained with the original, soluble L-alanine dehydrogenase. PMID:6404304

  18. Gliotoxicity of the cyanotoxin, β-methyl-amino-L-alanine (BMAA)

    PubMed Central

    Chiu, Alexander S.; Gehringer, Michelle M.; Braidy, Nady; Guillemin, Gilles J.; Welch, Jeffrey H.; Neilan, Brett A.

    2013-01-01

    The amino acid variant β-methyl-amino-L-alanine (BMAA) has long been associated with the increased incidence and progression of the amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC). Previous studies have indicated that BMAA damages neurons via excitotoxic mechanisms. We have challenged rat olfactory ensheathing cells (OECs) with exogenous BMAA and found it to be cytotoxic. BMAA also induces a significant increase in Ca2+ influx, enhanced production of reactive oxygen species (ROS), and disrupts mitochondrial activity in OECs. This is the first study investigating BMAA toxicity using pure glial cells. These findings align BMAA with the three proposed mechanisms of degeneration in ALS, those being non-cell autonomous death, excitotoxicity and mitochondrial dysfunction. PMID:23508043

  19. The fate of the cyanobacterial toxin β-N-methylamino-L-alanine in freshwater mussels.

    PubMed

    Downing, Simoné; Contardo-Jara, Valeska; Pflugmacher, Stephan; Downing, Timothy Grant

    2014-03-01

    The cyanobacterial neurotoxin, β-N-methylamino-l-alanine (BMAA) has been suggested as a causative agent for certain neurodegenerative diseases. This cyanotoxin bioaccumulates in an array of aquatic organisms, in which it occurs as both a free amino acid and in a protein-associated form. This study was intended to investigate the environmental fate of BMAA by examining the metabolism of isotopically labeled BMAA in four freshwater mussel species. All species showed substantial uptake of BMAA from the culture media. Data showed no significant evidence for BMAA catabolism in any of the animals but did suggest metabolism via the reversible covalent modification of BMAA in freshwater mussels, a process that appears to be variable in different species. PMID:24507126

  20. Gliotoxicity of the cyanotoxin, β-methyl-amino-L-alanine (BMAA).

    PubMed

    Chiu, Alexander S; Gehringer, Michelle M; Braidy, Nady; Guillemin, Gilles J; Welch, Jeffrey H; Neilan, Brett A

    2013-01-01

    The amino acid variant β-methyl-amino-L-alanine (BMAA) has long been associated with the increased incidence and progression of the amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC). Previous studies have indicated that BMAA damages neurons via excitotoxic mechanisms. We have challenged rat olfactory ensheathing cells (OECs) with exogenous BMAA and found it to be cytotoxic. BMAA also induces a significant increase in Ca2+ influx, enhanced production of reactive oxygen species (ROS), and disrupts mitochondrial activity in OECs. This is the first study investigating BMAA toxicity using pure glial cells. These findings align BMAA with the three proposed mechanisms of degeneration in ALS, those being non-cell autonomous death, excitotoxicity and mitochondrial dysfunction. PMID:23508043

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

    PubMed

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

    2015-08-01

    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. PMID:26119066

  2. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

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

    PubMed Central

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

    1973-01-01

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

  4. 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. PMID:26453031

  5. Structural, functional and optical studies on the amino acid doped glycine crystal

    NASA Astrophysics Data System (ADS)

    Manikandan, M. R.; Mahalingam, T.; Ravi, G.

    2012-06-01

    Single crystals of pure and amino acid (L-arginine) doped γ-glycine single crystals have been grown from aqueous solution by employing slow evaporation method. Morphological changes in different crystallographic planes were observed in the L-arginine doped γ-glycine crystals. Incorporation of L-arginine was confirmed qualitatively by FTIR spectroscopy. Powder X-ray diffraction was carried out to confirm γ-glycine and assess the single phase nature of the crystals. The lower cutoff wavelength was decreased by the influence of L-arginine in γ-glycine and this leads to an increase in the band gap. Nonlinear optical study revealed that L-arginine doping increases the SHG efficiency of the glycine crystal.

  6. 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 Central

    Kim, Seryoung; Ihara, Kohei; Katsube, Satoshi; Hori, Hatsuhiro; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2015-01-01

    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 [3H]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 [3H]l-alanine accumulation occurred under either condition. This energy-dependent uphill accumulation of [3H]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. PMID:26073055

  7. 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. PMID:26073055

  8. Heat-initiated prebiotic formation of peptides from glycine/aspartic acid and glycine/valine in aqueous environment and clay suspension

    NASA Astrophysics Data System (ADS)

    Pant, Chandra Kala; Lata, Hem; Pathak, Hari Datt; Mehata, Mohan Singh

    2009-04-01

    The effect of heat on the reaction system of glycine/aspartic acid and glycine/valine in the aqueous environment as well as in montmorillonite clay suspension with or without divalent cations (Ca2+, Mg2+ and Ni2+) has been investigated at 85°C±5°C for varying periods under prebiotic drying and wetting conditions. The resulting products were analysed and characterized by chromatographic and spectroscopic methods. Peptide formation appears to depend on the duration of heat effect, nature of reactant amino acids and, to some extent, on montmorillonite clay incorporated with divalent cations. In the glycine/aspartic acid system, oligomerization of glycine was limited up to trimer level (Gly)3 along with the formation of glycyl-aspartic acid, while linear and cyclic peptides of aspartic acid were not formed, whereas the glycine/valine system preferentially elongated homo-oligopeptide of glycine up to pentamer level (Gly)5 along with formation of hetero-peptides (Gly-Val and Val-Gly). These studies are relevant in the context of the prebiotic origin of proteins and the role of clay and metal ions in condensation and oligomerization of amino acids. The length of the bio-oligomer chain depends upon the reaction conditions. However, condensation into even a small length seems significant, as the same process would have taken millions of years in the primitive era of the Earth, leading to the first proteins.

  9. Glycine restores the anabolic response to leucine in a mouse model of acute inflammation.

    PubMed

    Ham, Daniel J; Caldow, Marissa K; Chhen, Victoria; Chee, Annabel; Wang, Xuemin; Proud, Christopher G; Lynch, Gordon S; Koopman, René

    2016-06-01

    Amino acids, especially leucine, potently stimulate protein synthesis and reduce protein breakdown in healthy skeletal muscle and as a result have received considerable attention as potential treatments for muscle wasting. However, the normal anabolic response to amino acids is impaired during muscle-wasting conditions. Although the exact mechanisms of this anabolic resistance are unclear, inflammation and ROS are believed to play a central role. The nonessential amino acid glycine has anti-inflammatory and antioxidant properties and preserves muscle mass in calorie-restricted and tumor-bearing mice. We hypothesized that glycine would restore the normal muscle anabolic response to amino acids under inflammatory conditions. Relative rates of basal and leucine-stimulated protein synthesis were measured using SUnSET methodology 4 h after an injection of 1 mg/kg lipopolysaccharide (LPS). Whereas leucine failed to stimulate muscle protein synthesis in LPS-treated mice pretreated with l-alanine (isonitrogenous control), leucine robustly stimulated protein synthesis (+51%) in mice pretreated with 1 g/kg glycine. The improvement in leucine-stimulated protein synthesis was accompanied by a higher phosphorylation status of mTOR, S6, and 4E-BP1 compared with l-alanine-treated controls. Despite its known anti-inflammatory action in inflammatory cells, glycine did not alter the skeletal muscle inflammatory response to LPS in vivo or in vitro but markedly reduced DHE staining intensity, a marker of oxidative stress, in muscle cross-sections and attenuated LPS-induced wasting in C2C12 myotubes. Our observations in male C57BL/6 mice suggest that glycine may represent a promising nutritional intervention for the attenuation of skeletal muscle wasting. PMID:27094036

  10. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Glycine (aminoacetic acid) in food for human consumption. 170.50 Section 170.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... (aminoacetic acid) in food for human consumption. (a) Heretofore, the Food and Drug Administration...

  11. Quantification of neurotoxin BMAA (β-N-methylamino-L-alanine) in seafood from Swedish markets

    NASA Astrophysics Data System (ADS)

    Jiang, Liying; Kiselova, Nadezda; Rosén, Johan; Ilag, Leopold L.

    2014-11-01

    The neurotoxin β-N-methylamino-L-alanine (BMAA) produced naturally by cyanobacteria, diatoms and dinoflagellates can be transferred and accumulated up the food chain, and may be a risk factor for neurodegenerative diseases. This study provides the first systematic screening of BMAA exposure of a large population through the consumption of seafood sold in metropolitan markets. BMAA was distinguished from known isomers by liquid chromatography tandem mass spectrometry after acidic hydrolysis and derivatization. Using deuterium-labeled internal standard, BMAA was quantified as 0.01-0.90 μg/g wet weight of tissues in blue mussel, oyster, shrimp, plaice, char and herring, but was undetectable (<0.01 μg/g) in other samples (salmon, cod, perch and crayfish). Provided that the content of BMAA detected is relevant for intake calculations, the data presented may be used for a first estimation of BMAA exposure through seafood from Swedish markets, and to refine the design of future toxicological experiments and assessments.

  12. Biotransfer of β-N-methylamino-L-alanine (BMAA) in a eutrophicated freshwater lake.

    PubMed

    Lage, Sandra; Annadotter, Heléne; Rasmussen, Ulla; Rydberg, Sara

    2015-03-01

    β-N-Methylamino-L-alanine (BMAA), a neurotoxic non-protein amino acid, plays a significant role as an environmental risk factor in neurodegenerative diseases, such as amyotrophic lateral sclerosis. BMAA producers occur globally, colonizing almost all habitats and represent species from distinct phytoplanktonic groups, i.e., cyanobacteria, diatoms, and dinoflagellates. Bioaccumulation of BMAA in invertebrate and vertebrate organisms has also been registered around the globe. In the Baltic Sea, BMAA has been detected in several commercial fish species, raising the question of the bioaccumulation of BMAA in Swedish limnic systems. Here we find the presence of BMAA in water samples from Lake Finjasjön and identify its bioaccumulation patterns in both plankti-benthivorous and piscivorous fish, according to fish species, total weight, gender, and season of collection. For the first time, a large number of fish individuals were used in order to draw conclusions on BMAA bioaccumulation in a closed ecological community based on a statistical approach. We may, therefore, conclude that feeding patterns (plankti-benthivorous) and increased age of fish may lead to a higher tissue concentration of BMAA. PMID:25738330

  13. β-N-methylamino-L-alanine (BMAA) metabolism in the aquatic macrophyte Ceratophyllum demersum.

    PubMed

    Downing, Simoné; Esterhuizen-Londt, Maranda; Grant Downing, Timothy

    2015-10-01

    The cyanobacterial neurotoxin, β-N-methylamino-l-alanine (BMAA) bioaccumulates and biomagnifies within the environment. However, most reports on the environmental presence of BMAA focus on the presence of BMAA in animals rather than in plants. Various laboratory studies have reported that this neurotoxin, implicated in neurodegenerative disease, is rapidly taken up by various aquatic and terrestrial plants, including crop plants. In this study the metabolism of BMAA in the aquatic macrophyte, Ceratophyllum demersum, was investigated using stable isotopically labelled BMAA. Data show that the toxin is rapidly removed from the environment by the plant. However, during depuration cellular BMAA concentrations decrease considerably, without excretion of the toxin back into the environment and without catabolism of BMAA, evidenced by the absence of label transfer to other amino acids. This strongly suggests that BMAA is metabolised via covalent modification and sequestered inside the plant as a BMAA-derivative. This modification may be reversed in humans following consumption of BMAA-containing plant material. These data therefore impact on the assessment of the risk of human exposure to this neurotoxin. PMID:26036420

  14. Bacteria do not incorporate β-N-methylamino-L-alanine into their proteins.

    PubMed

    van Onselen, Rianita; Cook, Niall A; Phelan, Richard R; Downing, Tim G

    2015-08-01

    β-N-methylamino-l-alanine (BMAA), is commonly found in both a free and proteinassociated form in various organisms exposed to the toxin. The long latency of development of neurodegeneration attributed to BMAA, is hypothesized to be the result of excitotoxicity following slow release of the toxin from protein reservoirs. It was recently suggested that these BMAA-protein associations may reflect misincorporation of BMAA in place of serine, as occurs, for example, when canavanine misincorporates in place of arginine. We therefore compared BMAA and canavanine toxicty in various bacterial species, and misincorporation of these amino acids into proteins in a bacterial protein expression system. None of the bacterial species showed any physiological stress responses to BMAA in contrast to the growth reduction observed when cultures were incubated in media containing canavanine. LC-MS analysis confirmed uptake of BMAA from growth media. However, after immobilized metal affinity chromatography and SDS-PAGE purification of proteins produced in an E scherichia coli expression system, no BMAA was detected by either LC-MS or LC-MS/MS analysis using two derivatization methods, or by orbitrap MS of trypsin digests of the protein. We therefore conclude that BMAA is not misincorporated into proteins in bacteria and that the observed BMAA-protein association in bacteria is superficial. PMID:26051985

  15. Quantification of neurotoxin BMAA (β-N-methylamino-L-alanine) in seafood from Swedish markets.

    PubMed

    Jiang, Liying; Kiselova, Nadezda; Rosén, Johan; Ilag, Leopold L

    2014-01-01

    The neurotoxin β-N-methylamino-L-alanine (BMAA) produced naturally by cyanobacteria, diatoms and dinoflagellates can be transferred and accumulated up the food chain, and may be a risk factor for neurodegenerative diseases. This study provides the first systematic screening of BMAA exposure of a large population through the consumption of seafood sold in metropolitan markets. BMAA was distinguished from known isomers by liquid chromatography tandem mass spectrometry after acidic hydrolysis and derivatization. Using deuterium-labeled internal standard, BMAA was quantified as 0.01-0.90 μg/g wet weight of tissues in blue mussel, oyster, shrimp, plaice, char and herring, but was undetectable (<0.01 μg/g) in other samples (salmon, cod, perch and crayfish). Provided that the content of BMAA detected is relevant for intake calculations, the data presented may be used for a first estimation of BMAA exposure through seafood from Swedish markets, and to refine the design of future toxicological experiments and assessments. PMID:25373604

  16. Biotransfer of β-N-Methylamino-l-alanine (BMAA) in a Eutrophicated Freshwater Lake

    PubMed Central

    Lage, Sandra; Annadotter, Heléne; Rasmussen, Ulla; Rydberg, Sara

    2015-01-01

    β-N-Methylamino-l-alanine (BMAA), a neurotoxic non-protein amino acid, plays a significant role as an environmental risk factor in neurodegenerative diseases, such as amyotrophic lateral sclerosis. BMAA producers occur globally, colonizing almost all habitats and represent species from distinct phytoplanktonic groups, i.e., cyanobacteria, diatoms, and dinoflagellates. Bioaccumulation of BMAA in invertebrate and vertebrate organisms has also been registered around the globe. In the Baltic Sea, BMAA has been detected in several commercial fish species, raising the question of the bioaccumulation of BMAA in Swedish limnic systems. Here we find the presence of BMAA in water samples from Lake Finjasjön and identify its bioaccumulation patterns in both plankti-benthivorous and piscivorous fish, according to fish species, total weight, gender, and season of collection. For the first time, a large number of fish individuals were used in order to draw conclusions on BMAA bioaccumulation in a closed ecological community based on a statistical approach. We may, therefore, conclude that feeding patterns (plankti-benthivorous) and increased age of fish may lead to a higher tissue concentration of BMAA. PMID:25738330

  17. Cerebral uptake and protein incorporation of cyanobacterial toxin β-N-methylamino-L-alanine.

    PubMed

    Xie, Xiaobin; Basile, Margaret; Mash, Deborah C

    2013-10-01

    β-N-methylamino-L-alanine (BMAA) is a nonprotein amino acid produced by diverse species of free-living cyanobacteria found in terrestrial and aquatic environments worldwide. BMAA has been detected as a soluble (free) and insoluble protein-bound (bound) amino acid in brains of Alzheimer's disease, amyotrophic lateral sclerosis, and Guamanian amyotrophic lateral sclerosis/Parkinsonism dementia complex patients. A toxic reservoir of BMAA in the brain may be excitotoxic to neurons or serve to disrupt cerebral protein homeostasis. Here, we report tracer uptake kinetics and a time course for protein incorporation of [C]-L-BMAA into the brain of C57/BL6 mice. BMAA pharmacokinetic parameters measured in plasma show a rapid distribution phase and a terminal elimination half-life of 1.7 days following bolus intravenous administration. Total [C]-L-BMAA uptake to the brain reached a maximum at 1.5 h. Ex-vivo autoradiography of [C]-labeled BMAA showed dense labeling within the ventricles, choroid plexus, and whole-brain gray matter structures. Radioactivity measured in soluble and trichloroacetic acid precipitates was compared to determine the incorporation of [C]-L-BMAA into total brain protein. The maximal concentration of [C]-L-BMAA was measured in protein-bound fractions of brain at 4 h, followed by a corresponding decrease in the free pool of this nonprotein amino acid. The time-dependent association of [C]-L-BMAA in the protein-bound fraction suggests that BMAA may be trapped in new proteins by protein synthesis-dependent processes. BMAA may accumulate into growing polypeptide chains and recycle to the free pool with protein turnover. PMID:23979257

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  19. Origin of Glycine from Acid Hydrolysis of the β-Lactam Antibiotic A16886B

    PubMed Central

    Brannon, D. R.; Mabe, J. A.; Ellis, R.; Whitney, J. G.; Nagarajan, R.

    1972-01-01

    Structural analysis of two new β-lactam antibiotics, A16884A and A16886B, indicated that they, like cephalosporin C, were composed of modified valine and cysteine residues, and α-aminoadipic acid. However, acid hydrolysis of A16886B and A16884A produced three times as much glycine as did hydrolysis of cephalosporin C under the same conditions. Samples of A16886B-14C-6 and A16886B-14C-8 were prepared by the addition of cysteine-14C-3 and cystine-14C-1 to fermentations of Streptomyces clavuligerus. The specific activity of glycine obtained from hydrolysis of A16886B-14C-6 was considerably higher than that from hydrolysis of A16886B-14C-8. An explanation for the difference in amounts of glycine obtained from hydrolysis of these antibiotics is discussed. PMID:5045470

  20. 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

  1. A study of conformational stability of poly(L-alanine), poly(L-valine), and poly(L-alanine)/poly(L-valine) blends in the solid state by (13)C cross-polarization/magic angle spinning NMR.

    PubMed

    Murata, Katsuyoshi; Kuroki, Shigeki; Kimura, Hideaki; Ando, Isao

    2002-06-01

    13C cross-polarization/magic angle spinning (CP/MAS) NMR and (1)H T(1rho) experiments of poly(L-alanine) (PLA), poly(L-valine) (PLV), and PLA/PLV blends have been carried out in order to elucidate the conformational stability of the polypeptides in the solid state. These were prepared by adding a trifluoroacetic acid (TFA) solution of the polymer with a 2.0 wt/wt % of sulfuric acid (H(2)SO(4)) to alkaline water. From these experimental results, it is clarified that the conformations of PLA and PLV in their blends are strongly influenced by intermolecular hydrogen-bonding interactions that cause their miscibility at the molecular level. PMID:11948439

  2. A study of L-leucine, L-phenylalanine and L-alanine transport in the perfused rat mammary gland: possible involvement of LAT1 and LAT2.

    PubMed

    Shennan, D B; Calvert, D T; Travers, M T; Kudo, Y; Boyd, C A R

    2002-08-19

    The transport of L-leucine, L-phenylalanine and L-alanine by the perfused lactating rat mammary gland has been examined using a rapid, paired-tracer dilution technique. The clearances of all three amino acids by the mammary gland consisted of a rising phase followed by a rapid fall-off, respectively, reflecting influx and efflux of the radiotracers. The peak clearance of L-leucine was inhibited by BCH (65%) and D-leucine (58%) but not by L-proline. The inhibition of L-leucine clearance by BCH and D-leucine was not additive. L-leucine inhibited the peak clearance of radiolabelled L-leucine by 78%. BCH also inhibited the peak clearance of L-phenylalanine (66%) and L-alanine (33%) by the perfused mammary gland. Lactating rat mammary tissue was found to express both LAT1 and LAT2 mRNA. The results suggest that system L is situated in the basolateral aspect of the lactating rat mammary epithelium and thus probably plays a central role in neutral amino acid uptake from blood. The finding that L-alanine uptake by the gland was inhibited by BCH suggests that LAT2 may make a significant contribution to neutral amino acid uptake by the mammary epithelium. PMID:12101005

  3. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Glycine (aminoacetic acid) in food for human consumption. 170.50 Section 170.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES Specific Administrative...

  4. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glycine (aminoacetic acid) in food for human consumption. 170.50 Section 170.50 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES Specific Administrative...

  5. 21 CFR 170.50 - Glycine (aminoacetic acid) in food for human consumption.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  6. Growth and characterization of pure and semiorganic nonlinear optical Lithium Sulphate admixtured l-alanine crystal

    NASA Astrophysics Data System (ADS)

    Vela, T.; Selvarajan, P.; Freeda, T. H.; Balasubramanian, K.

    2013-04-01

    Lithium sulphate admixtured l-alanine (LSLA) salt was synthesized and the solubility of the commercially available l-alanine and the synthesized LSLA sample was determined in de-ionized water at various temperatures. In accordance with the solubility data, the saturated aqueous solutions of l-alanine and lithium admixtured l-alanine were prepared separately and the single crystals of the samples were grown by the solution method with a slow evaporation technique. Studying single x-ray diffraction shows that pure and LSLA crystal belong to the orthorhombic system with a non-centrosymmetric space group P212121. Using the powder x-ray diffraction study, the crystallinity of the grown crystals is confirmed and the diffraction peaks are indexed. The various functional groups present in the pure and LSLA crystal are elucidated from Fourier transform infrared spectroscopy study. UV-visible transmittance is recorded to study the optical transmittance range for the grown crystals. The powder second harmonic generation test confirms the nonlinear optical property of the grown crystals. From the microhardness test, the hardness of the grown crystals is estimated. The dielectric behaviour, such as the dielectric constant and the loss of the sample, are measured as a function of temperature and frequency. The ac conductivity of the grown crystals is also studied and the activation energy is calculated.

  7. β-N-methylamino-L-alanine induces changes in both GSK3 and TDP-43 in human neuroblastoma.

    PubMed

    Muñoz-Saez, Emma; de Munck, Estefanía; Arahuetes, Rosa M; Solas, M Teresa; Martínez, Ana M; Miguel, Begoña G

    2013-01-01

    β-N-methylamino-L-alanine (L-BMAA) is a neurotoxic amino acid produced by most cyanobacteria, which are extensively distributed in different environments all over the world. L-BMAA has been linked to a variety of neurodegenerative diseases. This work aims to analyze the toxicological action of L-BMAA related to alterations observed in different neurodegenerative illness as Alzheimer disease and amyotrophic lateral sclerosis. Our results demonstrate that neuroblastoma cells treated with L-BMAA show an increase in glycogen synthase kinase 3 β (GSk3β) and induce accumulation of TAR DNA-binding protein 43 (TDP-43) truncated forms (C-terminal fragments), phosphorylated  and high molecular weight forms of TDP-43, that appears frequently in some neurodegenerative diseases. PMID:23665941

  8. Addition of amino acids and dipeptides to fullerene C{sub 60} giving rise to monoadducts

    SciTech Connect

    Romanova, V.S.; Tsyryapkin, V.A.; Vol`pin, M.E.

    1994-12-01

    The authors have developed a general method for the direct addition of amino acids and dipeptides of various structures to fullerene C{sub 60}. In all cases the addition involves the amino group. The reaction proceeds when the solutions of fullerene and an amino acid (or dipeptide) are mixed at 50-100 {degrees}C. The fullerene derivatives of the following amino acids and dipeptides have been obtained: glycine, p-aminobenzoic acid, {omega}-aminocaproic acid, L-proline, L-alanine, L-alanyl-Lalanine, D,L-alanyl-D,L-alanine, glycyl-L-valine. The adduct of methyl L-ananinate with C{sub 60} was also prepared.

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

    SciTech Connect

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

    2015-08-21

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  11. Amino acid and peptide absorption in patients with coeliac disease and dermatitis herpetiformis

    PubMed Central

    Silk, D. B. A.; Kumar, Parveen J.; Perrett, D.; Clark, M. L.; Dawson, A. M.

    1974-01-01

    A double-lumen perfusion technique has been used to study amino acid and peptide absorption in eight normal control subjects, 13 patients with untreated adult coeliac disease, and 16 patients with dermatitis herpetiformis who had varying morphological abnormalities of the small bowel. All subjects were perfused with isotonic solutions containing 10 mM glycyl-L-alanine and 10 mM glycine + 10 mM L-alanine. Patients with adult coeliac disease had impaired absorption of glycine (p < 0·01) and L-alanine (p < 0·05) from the amino acid solution compared with the control subjects. Amino acid uptake from the dipeptide solution was not significantly impaired, although four individual patients had impaired uptake of both amino acids. In contrast to these findings, very few patients with dermatitis herpetiformis had impaired amino acid absorption from either solution. Sodium absorption was impaired from both solutions when the groups of patients with adult coeliac disease and dermatitis herpetiformis with subtotal villous atrophy and partial villous atrophy were studied, and there were patients in each group who secreted sodium and water. The results suggest that malabsorption of dietary protein is unlikely to occur in dermatitis herpetiformis but may occur and contribute to protein deficiency seen in some severe cases of adult coeliac disease. The impairment of sodium and water absorption provides evidence that there may be functional impairment of the jejunal mucosa in dermatitis herpetiformis as well as in adult coeliac disease. PMID:4820629

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

    PubMed

    Molaakbari, Elahe; Mostafavi, Ali; Beitollahi, Hadi

    2014-03-01

    In this study, a carbon paste electrode modified with TiO2 nanoparticles and ferrocene monocarboxylic acid (FM) was used to prepare a novel electrochemical sensor. The objective of this novel electrode modification was to seek new electrochemical performances for the detection of methyldopa in the presence of folic acid and glycine. The peak potentials recorded in a phosphate buffer solution (PBS) of pH7.0 were 325, 750 and 880 mV vs. Ag/AgCl/KCl (3.0M) for methyldopa, folic acid and glycine, respectively. Under the optimum pH of 7.0, the oxidation of methyldopa occurred at a potential about 160 mV less positive than that of the unmodified carbon paste electrode (CPE). The response of catalytic current with methyldopa concentration showed a linear relation in the range from 2.0×10(-7) to 1.0×10(-4)M with a detection limit of 8.0 (± 0.2)×10(-8)M. PMID:24433900

  13. The Aspergillus nidulans proline permease as a model for understanding the factors determining substrate binding and specificity of fungal amino acid transporters.

    PubMed

    Gournas, Christos; Evangelidis, Thomas; Athanasopoulos, Alexandros; Mikros, Emmanuel; Sophianopoulou, Vicky

    2015-03-01

    Amino acid uptake in fungi is mediated by general and specialized members of the yeast amino acid transporter (YAT) family, a branch of the amino acid polyamine organocation (APC) transporter superfamily. PrnB, a highly specific l-proline transporter, only weakly recognizes other Put4p substrates, its Saccharomyces cerevisiae orthologue. Taking advantage of the high sequence similarity between the two transporters, we combined molecular modeling, induced fit docking, genetic, and biochemical approaches to investigate the molecular basis of this difference and identify residues governing substrate binding and specificity. We demonstrate that l-proline is recognized by PrnB via interactions with residues within TMS1 (Gly(56), Thr(57)), TMS3 (Glu(138)), and TMS6 (Phe(248)), which are evolutionary conserved in YATs, whereas specificity is achieved by subtle amino acid substitutions in variable residues. Put4p-mimicking substitutions in TMS3 (S130C), TMS6 (F252L, S253G), TMS8 (W351F), and TMS10 (T414S) broadened the specificity of PrnB, enabling it to recognize more efficiently l-alanine, l-azetidine-2-carboxylic acid, and glycine without significantly affecting the apparent Km for l-proline. S253G and W351F could transport l-alanine, whereas T414S, despite displaying reduced proline uptake, could transport l-alanine and glycine, a phenotype suppressed by the S130C mutation. A combination of all five Put4p-ressembling substitutions resulted in a functional allele that could also transport l-alanine and glycine, displaying a specificity profile impressively similar to that of Put4p. Our results support a model where residues in these positions determine specificity by interacting with the substrates, acting as gating elements, altering the flexibility of the substrate binding core, or affecting conformational changes of the transport cycle. PMID:25572393

  14. Modulation of antimicrobial effects of beta-lactams by amino acids in vitro.

    PubMed

    Gillissen, G; Schumacher, M; Breuer-Werle, M

    1991-06-01

    Glycine as well as 11 and 10, respectively, out of a total of 12 D-amino-acids tested increased the antimicrobial efficacy of imipenem (IMI) and of ampicillin (AMP) using the serosensitive strain E. coli ATCC 8739. D-proline was ineffective in assays with IMI as well as D-proline and D-leucine in assays with AMP. - In contrast, L-amino-acids behaved differently: In assays with IMI, 9 out of 13 isomers were ineffective whereas 3 were antagonistic (L-phenylalanine, L-serine, L-tryptophan). In combination with AMP, however, 10 L-amino acids had an antagonistic effect and 2 (L-leucine, L-methionine) were ineffective. L-alanine was an exception and showed a synergism with both antibiotics which was assumed to have been due to a racemase activity of cells. - Seroresistance of E. coli apparently reduced the synergistic effect of glycine and beta-lactams. - Glycine, alanine and tryptophan lost their typical synergistic or antagonistic effect with AMP when tested as di- or tri-amino-acid compounds. This was not the case with di-L-alanine - It is supposed that the synergistic effect of glycine or of D-amino-acids with beta-lactams can be explained mainly by an inhibition of carboxypeptidases. PMID:1930574

  15. Effect of β-N-methylamino-L-alanine on oxidative stress of liver and kidney in rat.

    PubMed

    de Munck, Estefanía; Muñoz-Sáez, Emma; Antonio, María Teresa; Pineda, Javier; Herrera, Amparo; Miguel, Begoña G; Arahuetes, Rosa María

    2013-03-01

    β-N-methylamino-(L)-alanine (L)-BMAA) is a neurotoxic amino acid, found in the majority of cyanbacterial genera tested. Evidence for implication of (L)-BMAA in neurodegenerative disorders, like amyotrophic lateral sclerosis (ALS), relies on bioaccumulation and biomagnification from symbiotic cyanobacteria. The involvement of (L)-BMAA in oxidative stress was demonstrated in several studies in the central nervous system. In the present study, we investigated the effect of (L)-BMAA on the oxidative stress responses of liver and kidney in rats treated by intraperitoneal administration with this amino acid. Oxidative stress was demonstrated by the quantification of lipid peroxidation, the measurement of both catalase and glutathione peroxidase activities, as well as the quantification of glutathione (GSH) levels and the total antioxidant capacity. It was observed that (L)-BMAA caused a significant increase in the degree of lipid peroxidation and catalase activity in both organs. A significant increase in glutathione peroxidase activity was obtained only in liver, whereas glutathione levels were also increased in both organs. The total antioxidant capacity decreased in liver and increased in kidney. These results suggest that the oxidative stress was higher in liver than in kidney, and might be crucial for (L)-BMAA toxicological action. PMID:23328118

  16. Quantitative proteomics analysis of zebrafish exposed to sub-lethal dosages of β-methyl-amino-L-alanine (BMAA)

    PubMed Central

    Frøyset, Ann Kristin; Khan, Essa Ahsan; Fladmark, Kari Espolin

    2016-01-01

    The non-protein amino acid β-methylamino-L-alanine (BMAA) is a neurotoxin present in microalgae and shown to accumulate in the food web. BMAA has been linked to the complex neurodegenerative disorder of Guam and to increased incidents sporadic ALS. Two main neurotoxic routes are suggested; an excitotoxic by acting as an agonist towards glutamate receptors and a metabolic by misincorporating into cellular proteins. We have used zebrafish, an increasingly used model for neurodegenerative diseases, to further identify signaling components involved in BMAA-induced toxicity. Zebrafish embryos were exposed to sub-lethal dosages of BMAA and a label-free proteomics analysis was conducted on larvae 4 days post fertilization. The exposed larvae showed no developmental abnormalities, but a reduced heart rate and increased expression of GSK3 isoforms. Search towards a reviewed database containing 2968 entries identified 480 proteins. Only 17 of these were regulated 2-fold or more in the exposed larvae. Seven of these proteins could be associated to glutamate receptor signaling and recycling. The remaining nine have all been linked to disturbance in protein homeostasis, reactive oxygen species (ROS) development or neuronal cell death. We also found that BMAA influenced the endocannabinoid system by up-regulation of fatty acid amide hydrolase (FAAH) and that FAAH inhibitor URB597 reduced the BMAA effect on heart rate and GSK3 expression. PMID:27404450

  17. Quantitative proteomics analysis of zebrafish exposed to sub-lethal dosages of β-methyl-amino-L-alanine (BMAA).

    PubMed

    Frøyset, Ann Kristin; Khan, Essa Ahsan; Fladmark, Kari Espolin

    2016-01-01

    The non-protein amino acid β-methylamino-L-alanine (BMAA) is a neurotoxin present in microalgae and shown to accumulate in the food web. BMAA has been linked to the complex neurodegenerative disorder of Guam and to increased incidents sporadic ALS. Two main neurotoxic routes are suggested; an excitotoxic by acting as an agonist towards glutamate receptors and a metabolic by misincorporating into cellular proteins. We have used zebrafish, an increasingly used model for neurodegenerative diseases, to further identify signaling components involved in BMAA-induced toxicity. Zebrafish embryos were exposed to sub-lethal dosages of BMAA and a label-free proteomics analysis was conducted on larvae 4 days post fertilization. The exposed larvae showed no developmental abnormalities, but a reduced heart rate and increased expression of GSK3 isoforms. Search towards a reviewed database containing 2968 entries identified 480 proteins. Only 17 of these were regulated 2-fold or more in the exposed larvae. Seven of these proteins could be associated to glutamate receptor signaling and recycling. The remaining nine have all been linked to disturbance in protein homeostasis, reactive oxygen species (ROS) development or neuronal cell death. We also found that BMAA influenced the endocannabinoid system by up-regulation of fatty acid amide hydrolase (FAAH) and that FAAH inhibitor URB597 reduced the BMAA effect on heart rate and GSK3 expression. PMID:27404450

  18. Equilibrium Dynamics of β-N-Methylamino-L-Alanine (BMAA) and Its Carbamate Adducts at Physiological Conditions.

    PubMed

    Zimmerman, David; Goto, Joy J; Krishnan, Viswanathan V

    2016-01-01

    Elevated incidences of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia complex (ALS/PDC) is associated with β-methylamino-L-alanine (BMAA), a non-protein amino acid. In particular, the native Chamorro people living in the island of Guam were exposed to BMAA by consuming a diet based on the cycad seeds. Carbamylated forms of BMAA are glutamate analogues. The mechanism of neurotoxicity of the BMAA is not completely understood, and BMAA acting as a glutamate receptor agonist may lead to excitotoxicity that interferes with glutamate transport systems. Though the interaction of BMAA with bicarbonate is known to produce carbamate adducts, here we demonstrate that BMAA and its primary and secondary adducts coexist in solution and undergoes a chemical exchange among them. Furthermore, we determined the rates of formation/cleavage of the carbamate adducts under equilibrium conditions using two-dimensional proton exchange NMR spectroscopy (EXSY). The coexistence of the multiple forms of BMAA at physiological conditions adds to the complexity of the mechanisms by which BMAA functions as a neurotoxin. PMID:27513925

  19. The use of L-serine to prevent β-methylamino-L-alanine (BMAA)-induced proteotoxic stress in vitro.

    PubMed

    Main, Brendan J; Dunlop, Rachael A; Rodgers, Kenneth J

    2016-01-01

    β-methylamino-L-alanine (BMAA), a non-protein amino acid synthesised by cyanobacteria, has been linked to a complex neurological disorder on Guam and more recently to other cases of sporadic ALS (sALS), however the mechanisms of BMAA toxicity are not completely understood. We have previously demonstrated that BMAA is misincorporated into newly synthesised proteins by human neuroblastoma cells and fibroblasts, resulting in the formation of autofluorescent material and the induction of apoptotic cell death. In the present study we show that BMAA at low levels does not cause an acute toxicity in neuroblastoma cells but increases the expression of the ER stress marker, C/EBP homologous protein (CHOP) and increases the activity of the pro-apoptotic enzyme caspase-3. We also observed an increase in the activity of the lysosomal cysteine proteases cathepsin B and L, characteristic of the accumulation of proteins in the lysosomal system. We were able to prevent these proteotoxic effects in neuroblastoma cells through co-treatment with l-serine suggesting that they resulted from incorporation of BMAA into proteins. Misincorporation provides a possible mechanism whereby BMAA could initiate misfolding, and the accumulation of aggregate-prone proteins in neurons. This build-up of misfolded proteins could explain the long latency period of the disease previously reported on Guam. PMID:26559613

  20. Is there a role for naturally occurring cyanobacterial toxins in neurodegeneration? The beta-N-methylamino-L-alanine (BMAA) paradigm.

    PubMed

    Papapetropoulos, Spiridon

    2007-06-01

    The naturally occurring, non-essential amino acid beta-N-methylamino-L-alanine (BMAA) has been recently found in high concentrations in brain tissues of patients with tauopathies such as the Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia Complex (ALS/PDC) in the South Pacific island of Guam and in a small number of Caucasian, North American patients with sporadic Alzheimer's disease. BMAA is produced by cyanobacteria that are present in all conceivable aquatic and/or terrestrial ecosystems and may be accumulated in living tissues in free and protein-bound forms through the process of biomagnification. Although its role in human degenerative disease is highly debated, there is mounting evidence in support of the neurotoxic properties of BMAA that may be mediated via mechanisms involving among others the regulation of glutamate. Glutamate-related excitotoxicity is among the most prominent factors in the etiopathogenesis of human neurodegenerative diseases. Due to the wide geographical distribution of cyanobacteria and the possible implications of BMAA neurotoxic properties in public health more research towards this direction is warranted. PMID:17296249

  1. Assessment of the mutagenic and genotoxic activity of cyanobacterial toxin beta-N-methyl-amino-L-alanine in Salmonella typhimurium.

    PubMed

    Novak, Matjaž; Hercog, Klara; Žegura, Bojana

    2016-08-01

    A neurotoxin β-N-methylamino-L-alanine (L-BMAA) is a non-protein amino acid produced by most cyanobacteria ubiquitously present in aquatic and terrestrial environments. Due to its global presence in surface waters, a widespread human exposure is possible and therefore this toxin represents a health risk for humans and animals. L-BMAA has been linked to the development of a variety of neurodegenerative diseases. Its neurotoxic activity has been extensively studied, while nothing is known on its genotoxic properties. In the present study we evaluated for the first time L-BMAA mutagenic potential using Ames assay on several Salmonella typhimurium strains (TA97a, TA98, TA100, TA102 and TA1535). The results showed that the toxin (up to 0.9 mg/plate) did not induce mutations without or with S9 metabolic activation. Its genotoxic activity was further studied with the SOS/umuC assay on S. typhimurium TA1535/pSK1002 and the results showed that it was not cytotoxic nor genotoxic for bacteria. The present study represents the first evidence that L-BMAA is not mutagenic nor genotoxic for bacteria even at concentrations much higher than those typically found in the environment. However, as most of the cyanobacterial toxins are not bacterial mutagens it is very important to further elucidate its genotoxic activity in eukaryotic cells. PMID:27137670

  2. Equilibrium Dynamics of β-N-Methylamino-L-Alanine (BMAA) and Its Carbamate Adducts at Physiological Conditions

    PubMed Central

    Zimmerman, David; Goto, Joy J.; Krishnan, Viswanathan V

    2016-01-01

    Elevated incidences of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia complex (ALS/PDC) is associated with β-methylamino-L-alanine (BMAA), a non-protein amino acid. In particular, the native Chamorro people living in the island of Guam were exposed to BMAA by consuming a diet based on the cycad seeds. Carbamylated forms of BMAA are glutamate analogues. The mechanism of neurotoxicity of the BMAA is not completely understood, and BMAA acting as a glutamate receptor agonist may lead to excitotoxicity that interferes with glutamate transport systems. Though the interaction of BMAA with bicarbonate is known to produce carbamate adducts, here we demonstrate that BMAA and its primary and secondary adducts coexist in solution and undergoes a chemical exchange among them. Furthermore, we determined the rates of formation/cleavage of the carbamate adducts under equilibrium conditions using two-dimensional proton exchange NMR spectroscopy (EXSY). The coexistence of the multiple forms of BMAA at physiological conditions adds to the complexity of the mechanisms by which BMAA functions as a neurotoxin. PMID:27513925

  3. Autolytic system of Staphylococcus simulans 22: influence of cationic peptides on activity of N-acetylmuramoyl-L-alanine amidase.

    PubMed Central

    Bierbaum, G; Sahl, H G

    1987-01-01

    Pep 5 and nisin are cationic peptide antibiotics which in addition to their membrane-disruptive action induce autolysis in staphylococci. To investigate the mechanism of lysis induction, the influence of the peptides on the activity of the N-acetylmuramoyl-L-alanine amidase of Staphylococcus simulans 22 was studied. In experiments with isolated cell walls at low ionic strength, the amidase activity was stimulated by the addition of Pep 5 and nisin, as well as by polylysine, streptomycin, and mono- and divalent cations. The concentrations necessary for activation depended on the nature of the cation and ranged from 5 microM for poly-L-lysine (n = 17) to 150 mM for Na+ at a cell wall concentration of 100 micrograms of cell walls per ml. No effect was observed if the cell walls were devoid of polyanionic constituents. Kinetic data suggested that the amidase bound to the teichoic and teichuronic acids of the cell wall and was thereby inhibited. Cationic molecules reversed this inhibition, most likely by displacing the enzyme from the polyanions. If the concentrations of the larger peptides were high in relation to cell wall concentration, the activation turned into inhibition, presumably by interfering with the access of the enzyme to its substrate. These experiments demonstrate that the activity of the amidase is modulated by basic peptides in vitro and help to explain how Pep 5 and nisin may cause lysis of treated cells. Images PMID:2890620

  4. Genetics Home Reference: glycine encephalopathy

    MedlinePlus

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

  5. Temperature-sensitive mutants of Escherichia coli K-12 with low activities of the L-alanine adding enzyme and the D-alanyl-D-alanine adding enzyme.

    PubMed

    Lugtenberg, E J; v Schijndel-van Dam, A

    1972-04-01

    A number of properties of temperature-sensitive mutants in murein synthesis are described. The mutants grow at 30 C but lyse at 42 C. One mutant possesses a temperature-sensitive d-alanyl-d-alanine adding enzyme, has an impaired rate of murein synthesis in vivo at both 30 and 42 C, and contains elevated levels of uridine diphosphate-N-acetyl-muramyl-tripeptide (UDP-MurNAc-l-Ala-d-Glu-m-diaminopimelic acid) at 42 C. The other mutant possesses an l-alanine adding enzyme with a very low in vitro activity at both 30 and 42 C. Its in vivo rate of murein synthesis is almost normal at 30 C but is much less at 42 C. When the murein precursors were isolated after incubation of the cells in the presence of (14)C-l-alanine, they contained only a fraction of the radioactivity that could be obtained from a wild-type strain. A genetic nomenclature for genes concerned with murein synthesis is proposed. PMID:4552998

  6. The Use of p-Aminobenzoic Acid as a Probe Substance for the Targeted Profiling of Glycine Conjugation.

    PubMed

    Nortje, Carla; van der Sluis, Rencia; van Dijk, Alberdina Aike; Erasmus, Elardus

    2016-03-01

    Glycine conjugation facilitates the metabolism of toxic aromatic acids, capable of disrupting mitochondrial integrity. Owing to the high exposure to toxic substrates, characterization of individual glycine conjugation capacity, and its regulatory factors has become increasingly important. Aspirin and benzoate have been employed for this purpose; however, adverse reactions, aspirin intolerance, and Reye's syndrome in children are substantial drawbacks. The goal of this study was to investigate p-aminobenzoic acid (PABA) as an alternative glycine conjugation probe. Ten human volunteers participated in a PABA challenge test, and p-aminohippuric acid (PAHA), p-acetamidobenzoic acid, and p-acetamidohippuric acid were quantified in urine. The glycine N-acyltransferase gene of the volunteers was also screened for two polymorphisms associated with normal and increased enzyme activity. All of the individuals were homozygous for increased enzyme activity, but excretion of PAHA varied significantly (16-56%, hippurate ratio). The intricacies of PABA metabolism revealed possible limiting factors and the potential of PABA as an indicator of Phase 0 biotransformation. PMID:26484797

  7. Pharmacological PPARα Activation Markedly Alters Plasma Turnover of the Amino Acids Glycine, Serine and Arginine in the Rat

    PubMed Central

    Ericsson, Anette; Turner, Nigel; Hansson, Göran I.; Wallenius, Kristina; Oakes, Nicholas D.

    2014-01-01

    The current study extends previously reported PPARα agonist WY 14,643 (30 µmol/kg/day for 4 weeks) effects on circulating amino acid concentrations in rats fed a 48% saturated fat diet. Steady-state tracer experiments were used to examine in vivo kinetic mechanisms underlying altered plasma serine, glycine and arginine levels. Urinary urea and creatinine excretion were measured to assess whole-body amino acid catabolism. WY 14,643 treated animals demonstrated reduced efficiency to convert food consumed to body weight gain while liver weight was increased compared to controls. WY 14,643 raised total amino acid concentration (38%), largely explained by glycine, serine and threonine increases. 3H-glycine, 14C-serine and 14C-arginine tracer studies revealed elevated rates of appearance (Ra) for glycine (45.5±5.8 versus 17.4±2.7 µmol/kg/min) and serine (21.0±1.4 versus 12.0±1.0) in WY 14,643 versus control. Arginine was substantially decreased (−62%) in plasma with estimated Ra reduced from 3.1±0.3 to 1.2±0.2 µmol/kg/min in control versus WY 14,643. Nitrogen excretion over 24 hours was unaltered. Hepatic arginase activity was substantially decreased by WY 14,643 treatment. In conclusion, PPARα agonism potently alters metabolism of several specific amino acids in the rat. The changes in circulating levels of serine, glycine and arginine reflected altered fluxes into the plasma rather than changes in clearance or catabolism. This suggests that PPARα has an important role in modulating serine, glycine and arginine de novo synthesis. PMID:25486018

  8. Polymerization of amino acids under primitive earth conditions.

    NASA Technical Reports Server (NTRS)

    Flores, J. J.; Ponnamperuma, C.

    1972-01-01

    Small amounts of peptides were obtained when equal amounts of methane and ammonia were reacted with vaporized aqueous solutions of C14-labeled glycine, L-alanine, L-aspartic acid, L-glutamic acid and L-threonine in the presence of a continuous spark discharge in a 24-hr cyclic process. The experiment was designed to demonstrate the possibility of peptide synthesis under simulated primeval earth conditions. It is theorized that some dehydration-condensation processes may have taken place, with ammonium cyanide, the hydrogencyanide tetramer or aminonitriles as intermediate products, during the early chemical evolution of the earth.

  9. Growth, Structural And Optical Studies On Bis L-alanine Lithium Chloride (BLALC) Single Crystal

    NASA Astrophysics Data System (ADS)

    Rose, A. S. J. Lucia; Selvarajan, P.; Perumal, S.

    2011-10-01

    Bis L-alanine Lithium Chloride (BLALC) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 15 x 9 x 4 mm3 have been obtained in 28 days. The grown crystals were colourless and transparent. Single crystal X-ray diffraction (XRD) study showed that BLALC belongs to orthorhombic system with a non-centro-symmetric space group P212121. The crystallinity of BLALC crystal was confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. The functional groups of the grown crystals have been identified by FTIR studies. UV-visible transmittance spectrum was recorded to study the optical transparency of BLALC crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique.

  10. Experimental and DFT computational studies of L-alanine cadmium chloride crystals

    NASA Astrophysics Data System (ADS)

    Ignatius, I. Cicili; Dheivamalar, S.; Kirubavathi, K.; Selvaraju, K.

    2016-05-01

    In this work, we report the combined experimental and theoretical study on molecular structure and vibrational spectra of nonlinear optical crystal L-alanine cadmium chloride (LACC). The single X-ray diffraction studies have revealed that the compound crystallizes in monoclinic system C2 space group with cell parameters a = 16.270, b = 7.358, c = 7.887 and Z = 4. FTIR and Raman spectra of the nonlinear optical materials LACC have been recorded and analyzed. The optimized geometric bond length and bond angles are obtained with the help of density functional theory (DFT) (B3LYP) calculation. The optimized geometric bond lengths and bond angles obtained by using DFT show good agreement with the experimental data. Using the natural bond orbital analysis the electronic effect and hydrogen bonding were confirmed. The HOMO-LUMO energy gap and the first order hyperpolarizability were calculated and it supports the nonlinear optical activity of LACC crystal.

  11. Linking β-methylamino-L-alanine exposure to sporadic amyotrophic lateral sclerosis in Annapolis, MD.

    PubMed

    Field, Nicholas C; Metcalf, James S; Caller, Tracie A; Banack, Sandra A; Cox, Paul A; Stommel, Elijah W

    2013-08-01

    Most amyotrophic lateral sclerosis (ALS) cases occur sporadically. Some environmental triggers have been implicated, including beta-methylamino-L-alanine (BMAA), a cyanobacteria produced neurotoxin. This study aimed to identify environmental risk factors common to three sporadic ALS patients who lived in Annapolis, Maryland, USA and developed the disease within a relatively short time and within close proximity to each other. A questionnaire was used to identify potential risk factors for ALS among the cohort of patients. One common factor among the ALS patients was the frequent consumption of blue crab. Samples of blue crab from the patients' local fish market were tested for BMAA using LC-MS/MS. BMAA was identified in these Chesapeake Bay blue crabs. We conclude that the presence of BMAA in the Chesapeake Bay food web and the lifetime consumption of blue crab contaminated with BMAA may be a common risk factor for sporadic ALS in all three patients. PMID:23660330

  12. Discovery of an L-alanine ester prodrug of the Hsp90 inhibitor, MPC-3100.

    PubMed

    Kim, Se-Ho; Tangallapally, Rajendra; Kim, In Chul; Trovato, Richard; Parker, Daniel; Patton, J Scott; Reeves, Leslie; Bradford, Chad; Wettstein, Daniel; Baichwal, Vijay; Papac, Damon; Bajji, Ashok; Carlson, Robert; Yager, Kraig M

    2015-11-15

    Various types of Hsp90 inhibitors have been and continue to undergo clinical investigation. One development candidate is the purine-based, synthetic Hsp90 inhibitor 1 (MPC-3100), which successfully completed a phase I clinical study. However, further clinical development of 1 was hindered by poor solubility and consequent formulation issues and promoted development of a more water soluble prodrug. Towards this end, numerous pro-moieties were explored in vitro and in vivo. These studies resulted in identification of L-alanine ester mesylate, 2i (MPC-0767), which exhibited improved aqueous solubility, adequate chemical stability, and rapid bioconversion without the need for solubilizing excipients. Based on improved physical characteristics and favorable PK and PD profiles, 2i mesylate was selected for further development. A convergent, scalable, chromatography-free synthesis for 2i mesylate was developed to support further clinical evaluation. PMID:26483201

  13. Fibrous biodegradable l-alanine-based scaffolds for vascular tissue engineering.

    PubMed

    Srinath, Deepta; Lin, Shigang; Knight, Darryl K; Rizkalla, Amin S; Mequanint, Kibret

    2014-07-01

    In vascular tissue engineering, three-dimensional (3D) biodegradable scaffolds play an important role in guiding seeded cells to produce matrix components by providing both mechanical and biological cues. The objective of this work was to fabricate fibrous biodegradable scaffolds from novel poly(ester amide)s (PEAs) derived from l-alanine by electrospinning, and to study the degradation profiles and its suitability for vascular tissue-engineering applications. In view of this, l-alanine-derived PEAs (dissolved in chloroform) were electrospun together with 18-30% w/w polycaprolactone (PCL) to improve spinnability. A minimum of 18% was required to effectively electrospin the solution while the upper value was set in order to limit the influence of PCL on the electrospun PEA fibres. Electrospun fibre mats with average fibre diameters of ~0.4 µm were obtained. Both fibre diameter and porosity increased with increasing PEA content and solution concentration. The degradation of a PEA fibre mat over a period of 28 days indicated that mass loss kinetics was linear, and no change in molecular weight was found, suggesting a surface erosion mechanism. Human coronary artery smooth muscle cells (HCASMCs) cultured for 7 days on the fibre mats showed significantly higher viability (p < 0.0001), suggesting that PEA scaffolds provided a better microenvironment for seeded cells compared with control PCL fibre mats of similar fibre diameter and porosity. Furthermore, elastin expression on the PEA fibre mats was significantly higher than the pure PEA discs and pure PCL fibre mat controls (p < 0.0001). These novel biodegradable PEA fibrous scaffolds could be strong candidates for vascular tissue-engineering applications. PMID:22899439

  14. High-temperature Raman study of L-alanine, L-threonine and taurine crystals related to thermal decomposition

    NASA Astrophysics Data System (ADS)

    Cavaignac, A. L. O.; Lima, R. J. C.; Façanha Filho, P. F.; Moreno, A. J. D.; Freire, P. T. C.

    2016-03-01

    In this work high-temperature Raman spectra are used to compare temperature dependence of the lattice mode wavenumber of L-alanine, L-threonine and taurine crystals. Anharmonic effects observed are associated with intermolecular N-H· · ·O hydrogen bond that plays an important role in thermal decomposition process of these materials. Short and strong hydrogen bonds in L-alanine crystal were associated with anharmonic effects in lattice modes leading to low thermal stability compared to taurine crystals. Connection between thermal decomposition process and anharmonic effects is furnished for the first time.

  15. Maternal transfer of the cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) via milk to suckling offspring.

    PubMed

    Andersson, Marie; Karlsson, Oskar; Bergström, Ulrika; Brittebo, Eva B; Brandt, Ingvar

    2013-01-01

    The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been implicated in the etiology of neurodegenerative disease and proposed to be biomagnified in terrestrial and aquatic food chains. We have previously shown that the neonatal period in rats, which in humans corresponds to the last trimester of pregnancy and the first few years of age, is a particularly sensitive period for exposure to BMAA. The present study aimed to examine the secretion of (14)C-labeled L- and D-BMAA into milk in lactating mice and the subsequent transfer of BMAA into the developing brain. The results suggest that secretion into milk is an important elimination pathway of BMAA in lactating mothers and an efficient exposure route predominantly for L-BMAA but also for D-BMAA in suckling mice. Following secretion of [(14)C]L-BMAA into milk, the levels of [(14)C]L-BMAA in the brains of the suckling neonatal mice significantly exceeded the levels in the maternal brains. In vitro studies using the mouse mammary epithelial HC11 cell line confirmed a more efficient influx and efflux of L-BMAA than of D-BMAA in cells, suggesting enantiomer-selective transport. Competition experiments with other amino acids and a low sodium dependency of the influx suggests that the amino acid transporters LAT1 and LAT2 are involved in the transport of L-BMAA into milk. Given the persistent neurodevelopmental toxicity following injection of L-BMAA to neonatal rodent pups, the current results highlight the need to determine whether BMAA is enriched mother's and cow's milk. PMID:24194910

  16. Maternal Transfer of the Cyanobacterial Neurotoxin β-N-Methylamino-L-Alanine (BMAA) via Milk to Suckling Offspring

    PubMed Central

    Andersson, Marie; Karlsson, Oskar; Bergström, Ulrika; Brittebo, Eva B.; Brandt, Ingvar

    2013-01-01

    The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been implicated in the etiology of neurodegenerative disease and proposed to be biomagnified in terrestrial and aquatic food chains. We have previously shown that the neonatal period in rats, which in humans corresponds to the last trimester of pregnancy and the first few years of age, is a particularly sensitive period for exposure to BMAA. The present study aimed to examine the secretion of 14C-labeled L- and D-BMAA into milk in lactating mice and the subsequent transfer of BMAA into the developing brain. The results suggest that secretion into milk is an important elimination pathway of BMAA in lactating mothers and an efficient exposure route predominantly for L-BMAA but also for D-BMAA in suckling mice. Following secretion of [14C]L-BMAA into milk, the levels of [14C]L-BMAA in the brains of the suckling neonatal mice significantly exceeded the levels in the maternal brains. In vitro studies using the mouse mammary epithelial HC11 cell line confirmed a more efficient influx and efflux of L-BMAA than of D-BMAA in cells, suggesting enantiomer-selective transport. Competition experiments with other amino acids and a low sodium dependency of the influx suggests that the amino acid transporters LAT1 and LAT2 are involved in the transport of L-BMAA into milk. Given the persistent neurodevelopmental toxicity following injection of L-BMAA to neonatal rodent pups, the current results highlight the need to determine whether BMAA is enriched mother's and cow's milk. PMID:24194910

  17. Toxicity and intracellular accumulation of bile acids in sandwich-cultured rat hepatocytes: role of glycine conjugates.

    PubMed

    Chatterjee, Sagnik; Bijsmans, Ingrid T G W; van Mil, Saskia W C; Augustijns, Patrick; Annaert, Pieter

    2014-03-01

    Excessive intrahepatic accumulation of bile acids (BAs) is a key mechanism underlying cholestasis. The aim of this study was to quantitatively explore the relationship between cytotoxicity of BAs and their intracellular accumulation in sandwich-cultured rat hepatocytes (SCRH). Following exposure of SCRH (on day-1 after seeding) to various BAs for 24h, glycine-conjugated BAs were most potent in exerting toxicity. Moreover, unconjugated BAs showed significantly higher toxicity in day-1 compared to day-3 SCRH. When day-1/-3 SCRH were exposed (0.5-4h) to 5-100μM (C)DCA, intracellular levels of unconjugated (C)DCA were similar, while intracellular levels of glycine conjugates were up to 4-fold lower in day-3 compared to day-1 SCRH. Sinusoidal efflux was by far the predominant efflux pathway of conjugated BAs both in day-1 and day-3 SCRH, while canalicular BA efflux showed substantial interbatch variability. After 4h exposure to (C)DCA, intracellular glycine conjugate levels were at least 10-fold higher than taurine conjugate levels. Taken together, reduced BA conjugate formation in day-3 SCRH results in lower intracellular glycine conjugate concentrations, explaining decreased toxicity of (C)DCA in day-3 versus day-1 SCRH. Our data provide for the first time a direct link between BA toxicity and glycine conjugate exposure in SCRH. PMID:24211540

  18. Development of an analytical procedure for quantifying the underivatized neurotoxin β-N-methylamino-L-alanine in brain tissues.

    PubMed

    Combes, Audrey; El Abdellaoui, Saïda; Vial, Jérome; Lagrange, Emmeline; Pichon, Valérie

    2014-07-01

    The cyanotoxin β-methylamino-L-alanine (BMAA) has received renewed attention as an environmental risk factor for sporadic cases of amyotrophic lateral sclerosis (ALS) (Nunn et al., Brain Res 410:375-379, 1987). The aim of the present study was to develop and to validate an analytical procedure that allows the quantification of native BMAA and of its natural isomer, 2,4 diaminobutyric acid (DAB), in brain tissues. An analytical procedure was previously reported by our group for the determination of underivatized BMAA in environmental samples. It included a step of sample clean-up by solid phase extraction (SPE) with a mixed-mode sorbent and the analyses were performed by LC/MS-MS using hydrophilic interaction chromatography and multiple reactions monitoring scan mode. As brain tissues have a higher lipid content, the crucial step of sample clean-up had been optimized by evaluating the efficiency of the addition of a liquid/liquid extraction step prior to the SPE procedure or alternatively, of washing steps to the SPE extraction procedure. The efficiency was checked by visualizing the complexity of the resulting chromatograms in LC/MS and their performance by using spiked brain samples. The optimized analytical procedure, including a washing step with cyclohexane to the SPE with a recovery yield close to 100%, was validated using the total error approach and allowed the quantification of BMAA in a concentration level ranging from 20 to 1,500 ng/g in brain samples. Finally, the feasibility of implementation of this procedure was verified in human brain samples from two patients who died of ALS. PMID:24858470

  19. Synthesis of a molecularly imprinted sorbent for selective solid-phase extraction of β-N-methylamino-L-alanine.

    PubMed

    Svoboda, Pavel; Combes, Audrey; Petit, Julia; Nováková, Lucie; Pichon, Valérie

    2015-11-01

    The aim of the work was to synthesize a molecularly imprinted material for the selective solid-phase extraction (SPE) of β-N-methylamino-L-alanine (L-2-amino-3-methylpropionic acid; BMAA) from cyanobacterial extracts. BMAA and its structural analogs that can be used as template are small, polar and hydrophilic molecules. These molecules are poorly soluble in organic solvents that are commonly used for the synthesis of acrylic-based polymers. Therefore, a sol gel approach was chosen to carry out the synthesis and the resulting sorbents were evaluated with different extraction procedures in order to determine their ability to selectively retain BMAA. The presence of imprinted cavities in the sorbent was demonstrated by comparing elution profiles obtained by using molecularly imprinted silica (MIS) and non-imprinted silica (NIS) as a control. The molecularly imprinted solid-phase extraction (MISPE) procedure was first developed in a pure medium (acetonitrile) and further optimized for the treatment of cyanobacterial samples. It was characterized by high elution recoveries (89% and 77% respectively in pure and in real media).The repeatability of the extraction procedure in pure medium, in real medium and the reproducibility of MIS synthesis all expressed as RSD values of extraction recovery of BMAA were equal to 3%, 12% and 5%, respectively. A MIS capacity of 0.34 µmol/g was measured. The matrix effects, which affected the quantification of BMAA when employing a mixed mode sorbent, were completely removed by adding a clean-up step of the mixed-mode sorbent extract on the MIS. PMID:26452922

  20. Reactivity of β-methylamino-L-alanine in complex sample matrixes complicating detection and quantification by mass spectrometry.

    PubMed

    Glover, W Broc; Liberto, Caitlyn M; McNeil, W Stephen; Banack, Sandra Anne; Shipley, Paul R; Murch, Susan J

    2012-09-18

    β-methylamino-l-alanine (BMAA) is a naturally occurring nonprotein amino acid originally discovered in cycad seeds and traditional foods of the Chamorro people of Guam. Recent research has implicated BMAA as a potential factor in neurodegenerative disease and described the production of BMAA in cyanobacteria, but conflicting results have complicated the interpretation of data. We hypothesized that the reactivity of BMAA with metal ions in the sample matrix and the formation of metal adducts in electrospray ionization mass spectrometry (MS) analysis confound results. Dilute solutions of TCA, MgCl(2), NaCl, CuCl(2), ZnCl(2) (0.01 M), or artificial ocean water (Instant Ocean, 3.5 g/L) reduced the signal attributable to the BMAA M + H(+) peak by 78-99.7%. The degree of adduct formation was significantly affected by MS settings such as induction voltage. A number of the detected ion peaks in BMAA standards were consistent with the formation of metal-BMAA complexes in addition to the adduct formation. A standard of Zn(BMAA)(2) was synthesized, and the effects of sample preparation, derivatization, column chromatography, pH, and interactions with serine were determined. Together, these data demonstrate that sample matrix, formation of adducts, and mass spectrometry settings complicate analysis of BMAA, that analysis by detection of the parent ion and daughter ion fragmentation patterns are highly susceptible to false negative findings, and that failure to detect BMAA cannot be considered proof of absence of the compound. PMID:22905767

  1. Acute β-N-Methylamino-L-alanine Toxicity in a Mouse Model.

    PubMed

    Al-Sammak, Maitham Ahmed; Rogers, Douglas G; Hoagland, Kyle D

    2015-01-01

    The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) is considered to be an "excitotoxin," and its suggested mechanism of action is killing neurons. Long-term exposure to L-BMAA is believed to lead to neurodegenerative diseases including Parkinson's and Alzheimer's diseases and amyotrophic lateral sclerosis (Lou Gehrig's disease). Objectives of this study were to determine the presumptive median lethal dose (LD50), the Lowest-Observed-Adverse-Effect Level (LOAEL), and histopathologic lesions caused by the naturally occurring BMAA isomer, L-BMAA, in mice. Seventy NIH Swiss Outbred mice (35 male and 35 female) were used. Treatment group mice were injected intraperitoneally with 0.03, 0.3, 1, 2, and 3 mg/g body weight L-BMAA, respectively, and control mice were sham-injected. The presumptive LD50 of L-BMAA was 3 mg/g BW and the LOAEL was 2 mg/g BW. There were no histopathologic lesions in brain, liver, heart, kidney, lung, or spleen in any of the mice during the 14-day study. L-BMAA was detected in brains and livers in all of treated mice but not in control mice. Males injected with 0.03 mg/g BW, 0.3 mg/g BW, and 3.0 mg/g BW L-BMAA showed consistently higher concentrations (P < 0.01) in brain and liver samples as compared to females in those respective groups. PMID:26604922

  2. Growth and characterization of L-alanine cadmium bromide a semiorganic nonlinear optical crystals.

    PubMed

    Ilayabarathi, P; Chandrasekaran, J

    2012-10-01

    A new semiorganic nonlinear optical crystal, l-alanine cadmium bromide (LACB) was grown from aqueous solution by slow solvent evaporation method at room temperature. As grown crystals were characterized for its spectral, thermal, linear and second order nonlinear optical properties. LACB crystallizes in orthorhombic system and unit cell parameters a=5.771(2)Å, b=6.014(4)Å, c=12.298(2)Å, α=β=γ=90° and volume=426.8(3)Å(3). The mode of vibrations of different molecular groups present in the crystal was identified by FTIR study. The grown crystals were found to be transparent in the entire visible region. The thermal strength and the decomposition of the grown crystals were studied using TG/DTA and DSC analysis. Dielectric measurement revealed that the crystals had very low dielectric constant at higher frequency in room temperature. The mechanical behavior was studied by Vicker's microhardness tester. The grown crystal has negative photoconductivity nature. The fluorescence spectrum of the crystal was recorded and its optical band gap is about 3.356 eV. The NLO property of crystal using modified Kurtz-Perry powder technique with Nd:YAG laser light of wavelength 1064nm indicated that their second harmonic generation (SHG) efficiency was half that of pure KDP. PMID:22885081

  3. Transcription and genetic analyses of a putative N-acetylmuramyl-L-alanine amidase in Borrelia burgdorferi

    PubMed Central

    Yang, Yu; Li, Chunhao

    2010-01-01

    In this study, a putative N-acetylmuramyl-L-alanine amidase gene (bb0666) was identified in the genome of the Lyme disease spirochete Borrelia burgdorferi. This protein shares c. 30% identity with its counterparts from other bacteria. Reverse transcriptase-PCR analysis showed that bb0666 along with two other genes (bb0665 and bb0667) are cotranscribed with the motility and chemotaxis genes. This newly identified operon is termed as pami. Sequence and primer extension analyses showed that pami was regulated by a σ70-like promoter, which is designated as Pami. Transcriptional analysis using a gene encoding green fluorescence protein as a reporter demonstrated that Pami functions in both Escherichia coli and B. burgdorferi. Genetic studies showed that the Δbb0666 mutant grows in long chains of unseparated cells, whose phenotype is similar to its counterparts in E. coli. Taken together, these results demonstrate that bb0666 is a homolog of MurNac-LAAs that contributes to the cell division of B. burgdorferi. PMID:19025570

  4. Moments and distribution functions for polypeptide chains. Poly-L-alanine.

    PubMed

    Conrad, J C; Flory, P J

    1976-01-01

    Statistical mechanical averages of vectors and tensors characterizing the configurations of polypeptides have been calculated for poly-L-alanines (PLA) of xu = 2-400 peptide units. These quantities are expressed in the reference frame of the first peptide unit, the X axis being situated along the virtual bond, the Y axis in the plane of the peptide unit. The persistence vector a identical to (r) converges rapidly with chain length to its limit a infinity which lies virtually in the XZ plane. Configurational averages of Cartesian tensors up to the sixth rank formed from the displacement vector p = r-a have been computed. For xu greater than 50 the even moments of fourth and sixth rank formed from the reduced vector p for the real chain are well repreented by the freely jointed chain with 21.7 virtual bonds equivalent to one of the model. The moments of p display assymmetry for xu less than 50. Density distribution functions Wa(p), evaluated from the three-dimensional Hermite series truncated at the term in the polynomial involving the tensors of p of sixth rank, display no obvious symmetry for xu less than 50. Approximate spherical symmetry of the distribution of p about a is observed only for xu greater than or equal to 100. PMID:1249990

  5. Uptake of a cyanotoxin, β-N-methylamino-L-alanine, by wheat (Triticum aestivum).

    PubMed

    Contardo-Jara, Valeska; Schwanemann, Torsten; Pflugmacher, Stephan

    2014-06-01

    In order to study the uptake of the cyanobacterial neurotoxin β-N-methylamino-l-alanine (BMAA) into the crop plant Triticum aestivum during germination and primary growth imbibed grains and 7-day-old seedlings were irrigated with 100 and 1000µg l(-1) BMAA for 4 days and 100µg l(-1) BMAA for 28 days. Content of derivatized free and protein-associated BMAA in seedlings, root and shoot tissue, respectively, were analyzed by LC-MS/MS. Free BMAA was only detected in seedlings exposed to 1000µg l(-1) BMAA, whereas protein-associated BMAA was found at both exposure concentrations. Irrigation with 100µgl(-1) BMAA led to an uptake of the neurotoxin into roots and shoots and to immediate protein-association. In roots, protein-associated BMAA was detectable after 5 days with peaking amounts after 14 days. Longer exposure did not cause further accumulation in roots. In contrast, protein-associated BMAA was detected in shoot samples after only 1 day. In shoots the highest amounts of protein-associated BMAA were found after 28 days. In turn, in both plant compartments free BMAA was below the measurable concentration. PMID:24675440

  6. Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA) in Shark Fins

    PubMed Central

    Mondo, Kiyo; Hammerschlag, Neil; Basile, Margaret; Pablo, John; Banack, Sandra A.; Mash, Deborah C.

    2012-01-01

    Sharks are among the most threatened groups of marine species. Populations are declining globally to support the growing demand for shark fin soup. Sharks are known to bioaccumulate toxins that may pose health risks to consumers of shark products. The feeding habits of sharks are varied, including fish, mammals, crustaceans and plankton. The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been detected in species of free-living marine cyanobacteria and may bioaccumulate in the marine food web. In this study, we sampled fin clips from seven different species of sharks in South Florida to survey the occurrence of BMAA using HPLC-FD and Triple Quadrupole LC/MS/MS methods. BMAA was detected in the fins of all species examined with concentrations ranging from 144 to 1836 ng/mg wet weight. Since BMAA has been linked to neurodegenerative diseases, these results may have important relevance to human health. We suggest that consumption of shark fins may increase the risk for human exposure to the cyanobacterial neurotoxin BMAA. PMID:22412816

  7. Cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) in shark fins.

    PubMed

    Mondo, Kiyo; Hammerschlag, Neil; Basile, Margaret; Pablo, John; Banack, Sandra A; Mash, Deborah C

    2012-02-01

    Sharks are among the most threatened groups of marine species. Populations are declining globally to support the growing demand for shark fin soup. Sharks are known to bioaccumulate toxins that may pose health risks to consumers of shark products. The feeding habits of sharks are varied, including fish, mammals, crustaceans and plankton. The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been detected in species of free-living marine cyanobacteria and may bioaccumulate in the marine food web. In this study, we sampled fin clips from seven different species of sharks in South Florida to survey the occurrence of BMAA using HPLC-FD and Triple Quadrupole LC/MS/MS methods. BMAA was detected in the fins of all species examined with concentrations ranging from 144 to 1836 ng/mg wet weight. Since BMAA has been linked to neurodegenerative diseases, these results may have important relevance to human health. We suggest that consumption of shark fins may increase the risk for human exposure to the cyanobacterial neurotoxin BMAA. PMID:22412816

  8. In vivo dose evaluation during gynaecological radiotherapy using L-alanine/ESR dosimetry.

    PubMed

    Rech, Amanda Burg; Barbi, Gustavo Lazzaro; Ventura, Luiz Henrique Almeida; Guimarães, Flavio Silva; Oliveira, Harley Francisco; Baffa, Oswaldo

    2014-06-01

    The dose delivered by in vivo 3-D external beam radiation therapy (EBRT) was verified with L-alanine/electron spin resonance (ESR) dosimetry for patients diagnosed with gynaecological cancer. Measurements were performed with an X-band ESR spectrometer. Dosemeters were positioned inside the vaginal cavity with the assistance of an apparatus specially designed for this study. Previous phantom studies were performed using the same conditions as in the in vivo treatment. Four patients participated in this study during 20-irradiation sessions, giving 220 dosemeters to be analysed. The doses were determined with the treatment planning system, providing dose confirmation. The phantom study resulted in a deviation between -2.5 and 2.1 %, and for the in vivo study a deviation between -9.2 and 14.2 % was observed. In all cases, the use of alanine with ESR was effective for dose assessment, yielding results consistent with the values set forth in the International Commission on Radiation Units and Measurements (ICRU) reports. PMID:24751984

  9. 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.

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

    PubMed Central

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

    2014-01-01

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

  11. Extracellular matrix-like surfactant polymers containing arginine-glycine-aspartic acid (RGD) peptides.

    PubMed

    Anderson, Eric H; Ruegsegger, Mark A; Murugesan, Gurunathan; Kottke-Marchant, Kandice; Marchant, Roger E

    2004-08-01

    We report on a novel series of biomimetic polymers exhibiting interfacial properties similar to the extracellular matrix. A series of well-defined surfactant polymers were synthesized by simultaneously incorporating arginine-glycine-aspartic acid (RGD) peptide, dextran oligosaccharide, and hexyl ligands with controlled feed ratios onto a poly(vinyl amine) (PVAm) backbone. The peptide sequence was H-GSSSGRGDSPA-NH(2) (Pep) having a hydrophilic extender at the amino terminus and capped carboxy terminus. The peptide-to-dextran (Pep:Dex) ratios were varied to create surfactants having 0, 25, 50, 75, and 100 mol-% peptide relative to dextran. The surfactants were characterized by IR, NMR and atomic force microscopy (AFM) for composition and surface active properties. AFM confirmed full surface coverage of PVAm(Pep)(100%) on graphite, and supported the mechanism of interdigitation of hexyl ligands between surfactant molecules within a specified range of hexyl chain densities. the attachment and growth of human pulmonary artery endothelial cells on the PVAm(Pep)(100%) surface was identical to the fibronectin positive control. Cell adhesion decreased dramatically with decreasing peptide density on the surfactant polymers. Molecular model of a peptide surfactant polymer, consisting of poly(vinyl amine) backbone with peptide, dextran oligosaccharide and hexyl branches coupled to the polymer chain. PMID:15468270

  12. Acute β-N-Methylamino-L-alanine Toxicity in a Mouse Model

    PubMed Central

    Al-Sammak, Maitham Ahmed; Rogers, Douglas G.; Hoagland, Kyle D.

    2015-01-01

    The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) is considered to be an “excitotoxin,” and its suggested mechanism of action is killing neurons. Long-term exposure to L-BMAA is believed to lead to neurodegenerative diseases including Parkinson's and Alzheimer's diseases and amyotrophic lateral sclerosis (Lou Gehrig's disease). Objectives of this study were to determine the presumptive median lethal dose (LD50), the Lowest-Observed-Adverse-Effect Level (LOAEL), and histopathologic lesions caused by the naturally occurring BMAA isomer, L-BMAA, in mice. Seventy NIH Swiss Outbred mice (35 male and 35 female) were used. Treatment group mice were injected intraperitoneally with 0.03, 0.3, 1, 2, and 3 mg/g body weight L-BMAA, respectively, and control mice were sham-injected. The presumptive LD50 of L-BMAA was 3 mg/g BW and the LOAEL was 2 mg/g BW. There were no histopathologic lesions in brain, liver, heart, kidney, lung, or spleen in any of the mice during the 14-day study. L-BMAA was detected in brains and livers in all of treated mice but not in control mice. Males injected with 0.03 mg/g BW, 0.3 mg/g BW, and 3.0 mg/g BW L-BMAA showed consistently higher concentrations (P < 0.01) in brain and liver samples as compared to females in those respective groups. PMID:26604922

  13. Solvated states of poly-L-alanine α-helix explored by Raman optical activity.

    PubMed

    Yamamoto, Shigeki; Furukawa, Tatsuya; Bouř, Petr; Ozaki, Yukihiro

    2014-05-22

    Raman optical activity (ROA) reveals surprising details of the secondary structure of polypeptides and proteins in solution phase. Yet specific spectral features, such as in the extended amide III region of hydrated α-helix, did not seem explicable by the generally accepted sensitivity of ROA to the local conformation. This is reconciled in the present study by simulations of ROA spectra for model α-helical structures. Two positive ROA peaks often observed at around 1340 and 1300 cm(-1) for polypeptides and proteins have been assigned to two types of solvated α-helices; one is stable in hydrophilic environment where amide groups make hydrogen bonds to solvent molecules or polar side chains (∼1340 cm(-1)), and the other is supported by a hydrophobic environment without the possibility of external hydrogen bonds (∼1300 cm(-1)). For poly-L-alanine (PLA), regarded as a good model of α-helical structure, the experimentally observed relative intensity ratio of the two ROA bands has been explained by a conformational equilibrium depending on the solvent polarity. The intensities of the bands reflect solvated and unsolvated α-helical geometries, with peptide backbone torsional angles (ϕi+1, ψi) of (-66°, -41°) and (-59°, -44°), respectively. Quantum-mechanical simulations of the ROA spectra utilizing the normal mode optimization and Cartesian tensor transfer methods indicate, however, that the change in dielectric constant of the solvent is the main factor for the spectral intensity change, whereas the influence of the conformational change is minor. PMID:24758541

  14. Environmental neurotoxins β-N-methylamino-l-alanine (BMAA) and mercury in shark cartilage dietary supplements.

    PubMed

    Mondo, Kiyo; Broc Glover, W; Murch, Susan J; Liu, Guangliang; Cai, Yong; Davis, David A; Mash, Deborah C

    2014-08-01

    Shark cartilage products are marketed as dietary supplements with claimed health benefits for animal and human use. Shark fin and cartilage products sold as extracts, dry powders and in capsules are marketed based on traditional Chinese medicine claims that it nourishes the blood, enhances appetite, and energizes multiple internal organs. Shark cartilage contains a mixture of chondroitin and glucosamine, a popular nutritional supplement ingested to improve cartilage function. Sharks are long-lived apex predators, that bioaccumulate environmental marine toxins and methylmercury from dietary exposures. We recently reported detection of the cyanobacterial toxin β-N-methylamino-l-alanine (BMAA) in the fins of seven different species of sharks from South Florida coastal waters. Since BMAA has been linked to degenerative brain diseases, the consumption of shark products may pose a human risk for BMAA exposures. In this report, we tested sixteen commercial shark cartilage supplements for BMAA by high performance liquid chromatography (HPLC-FD) with fluorescence detection and ultra performance liquid chromatography/mass spectrometry/mass spectrometry (UPLC-MS/MS). Total mercury (Hg) levels were measured in the same shark cartilage products by cold vapor atomic fluorescence spectrometry (CVAFS). We report here that BMAA was detected in fifteen out of sixteen products with concentrations ranging from 86 to 265μg/g (dry weight). All of the shark fin products contained low concentrations of Hg. While Hg contamination is a known risk, the results of the present study demonstrate that shark cartilage products also may contain the neurotoxin BMAA. Although the neurotoxic potential of dietary exposure to BMAA is currently unknown, the results demonstrate that shark cartilage products may contain two environmental neurotoxins that have synergistic toxicities. PMID:24755394

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

    SciTech Connect

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

    1994-09-01

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

  16. (3H) 5,7-dichlorokynurenic acid, a high affinity ligand for the NMDA receptor glycine regulatory site

    SciTech Connect

    Hurt, S.D.; Baron, B.M. )

    1991-01-01

    The NMDA subtype of glutamate receptors is allosterically linked to a strychnine-insensitive glycine regulatory site. Kynurenic acid and its halogenated derivatives are non-competitive NMDA antagonists acting at the glycine site. The authors have prepared (3H) 5,7-dichlorokyrurenic acid (DCKA) as an antagonist radioligand and have characterized its binding. 3-Bromo-5,7-DCKA was catalytically dehalogenated in the presence of tritium gas and HPLC purified to yield (3H) 5,7-DCKA with a specific activity of 17.6 Ci/mmol. (3H) 5,7-DCKA bound to rat brain synaptosomes with a Kd of 69 {plus minus} 23 nM and Bmax = 14.5 {plus minus} 3.2 pmoles/mg protein. Binding was 65-70% specific at 10 nM (3H) 5,7-DCKA. This ligand is thus more selective and has higher affinity than (3H) glycine, in addition to being an antagonist.

  17. Is the reaction between formic acid and protonated aminomethanol a possible source of glycine precursors in the interstellar medium?

    NASA Astrophysics Data System (ADS)

    Redondo, Pilar; Largo, Antonio; Barrientos, Carmen

    2015-07-01

    Context. One of the most interesting questions in interstellar chemistry concerns whether we can detect the basic building blocks of proteins in astronomical sources. In ascertaining whether amino acids could be possible interstellar molecules, a crucial point is how they could be synthesized in the interstellar medium. Aims: We do a theoretical study of the ion-molecule reaction involving protonated aminomethanol and formic acid to establish its viability in space. This ion-molecule reaction has been proposed by other authors as a possible way to produce glycine in the interstellar medium. Methods: The relevant stationary points on the potential energy surface of the reaction between protonated aminomethanol and formic acid have been theoretically studied by using ab initio methods. The second-order Moller-Plesset level was employed, in conjunction with the correlation-consistent polarized valence triple-zeta (cc-pVTZ) basis set. In addition, the electronic energies were refined by means of single-point calculations at the CCSD(T) level (coupled cluster single and double excitation model augmented with a non-iterative treatment of triple excitations) on the MP2/cc-pVTZ geometries with the aug-cc-pVTZ basis set. Results: Formation of protonated glycine is an exothermic process; however, the process presents a net activation barrier that makes this reaction unfeasible under interstellar conditions. Conclusions: The reaction of protonated aminomethanol with formic acid does not seem to be a plausible source of interstellar glycine. This particular case is a clear example that a detailed study of the potential energy surface is needed to establish the relevance of a process in the interstellar medium.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    PubMed

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

    2012-01-12

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

  20. Detection of cyanobacterial neurotoxin β-N-methylamino-l-alanine within shellfish in the diet of an ALS patient in Florida.

    PubMed

    Banack, Sandra Anne; Metcalf, James S; Bradley, Walter G; Cox, Paul Alan

    2014-11-01

    Cyanobacteria produce the neurotoxic amino acid β-N-methylamino-l-alanine (BMAA), which in contaminated marine waters has been found to accumulate in shellfish. Exposure to BMAA has been associated with an increased risk of neurodegenerative disease. Analysis of blinded samples found BMAA to be present in neuroproteins of individuals who died from ALS and ALS/PDC, but generally not in the brains of patients who died of causes unrelated to neurodegeneration or Huntington's disease, an autosomal dominant neurodegenerative disease. We here report support for a link between a patient with ALS and chronic exposure to the cyanobacterial neurotoxin BMAA via shellfish consumption. The patient had frequently eaten lobsters collected in Florida Bay for approximately 30 years. LC-MS/MS analysis of two lobsters which this ALS patient had placed in his freezer revealed BMAA at concentrations of 27 and 4 μg/g, respectively, as well as the presence of 2,4-diaminobutyric acid (DAB), a BMAA isomer. Two additional lobsters recently collected from Florida Bay also contained the neurotoxins BMAA and DAB. These data suggest that invertebrates collected in water where cyanobacterial blooms are present, if consumed, may result in direct human exposure to these neurotoxic amino acids. The data support the assertion that prolonged exposure to BMAA may have played a role in the etiology of ALS in this patient. PMID:25123936

  1. Novel NMDA receptor-specific desensitization/inactivation produced by ingestion of the neurotoxins, β-N-methylamino-L-alanine (BMAA) or β-N-oxalylamino-L-alanine (BOAA/β-ODAP).

    PubMed

    Koenig, Jane H; Goto, Joy J; Ikeda, Kazuo

    2015-01-01

    The environmental neurotoxins BMAA (β-N-methylamino-L-alanine) and BOAA (β-N-oxalylamino-L-alanine) are implicated as possible causative agents for the neurodegenerative diseases, amyotrophic lateral sclerosis/ParkinsonismDementia complex (ALS/PDC) and neurolathyrism, respectively. Both are structural analogs of the neurotransmitter, glutamate, and bind postsynaptic glutamate receptors. In this study, the effect of ingestion of these toxins on the response of a singly-innervated, identified, glutamatergic postsynaptic cell in a living, undissected Drosophila is observed by intracellular recording. Previously we have reported that ingested BMAA behaves as an NMDA agonist that produces an abnormal NMDA response in the postsynaptic cell. It is shown here that BOAA also behaves as an NMDA agonist, and produces an effect very similar to that of BMAA on the postsynaptic response. In response to a single stimulus, the amplitude of the NMDA component is decreased, while the time to peak and duration of the NMDA component are greatly increased. No discernable effect on the AMPA component of the response was observed. Furthermore, both BMAA and BOAA cause an NMDAR-specific desensitization in response to repetitive stimulation at the physiological frequency for the postsynaptic cell (5 Hz). The possibility that this phenomenon may represent a response to excessive Ca(2+) entry through NMDAR channels is discussed. This desensitization phenomenon, as well as the abnormal NMDAR gating characteristics induced by BMAA, appears to be rescued during higher frequency stimulation (e.g. 10, 20 Hz). PMID:25193276

  2. Transfer of developmental neurotoxin β-N-methylamino-l-alanine (BMAA) via milk to nursed offspring: Studies by mass spectrometry and image analysis.

    PubMed

    Andersson, Marie; Karlsson, Oskar; Banack, Sandra Anne; Brandt, Ingvar

    2016-09-01

    The cyanobacterial non-proteinogenic amino acid β-N-methylamino-l-alanine (BMAA) is proposed to be involved in the etiology of amyotrophic lateral sclerosis/parkinsonism dementia complex. When administered as single doses to neonatal rats, BMAA gives rise to cognitive and neurodegenerative impairments in the adult animal. Here, we employed mass spectrometry (LC-MS/MS) and autoradiographic imaging to examine the mother-to-pup transfer of BMAA in rats. The results show that unchanged BMAA was secreted into the milk and distributed to the suckling pups. The concentration of BMAA in pup stomach milk and the neonatal liver peaked after 8h, while the concentration in the pup brain increased throughout the study period. About 1 and 6% of the BMAA recovered from adult liver and brain were released following hydrolysis, suggesting that this fraction was associated with protein. No association to milk protein was observed. Injection of rat pups with [methyl-(14)C]-l-BMAA or [carboxyl-(14)C]-l-BMAA resulted in highly similar distribution patterns, indicating no or low metabolic elimination of the methylamino- or carboxyl groups. In conclusion, BMAA is transported as a free amino acid to rat milk and suckling pups. The results strengthen the proposal that mothers' milk could be a source of exposure for BMAA in human infants. PMID:27320960

  3. Immobilization by Polyurethane of Pseudomonas dacunhae Cells Containing l-Aspartate β-Decarboxylase Activity and Application to l-Alanine Production

    PubMed Central

    Fusee, Murray C.; Weber, Jennifer E.

    1984-01-01

    Whole cells of Pseudomonas dacunhae containing l-aspartate β-decarboxylase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol; W. R. Grace & Co., Lexington, Mass.). The immobilized cell preparation was used to convert l-aspartic acid to l-alanine. Properties of the immobilized P. dacunhae cells containing aspartate β-decarboxylase activity were investigated with batch reactors. Retention of enzyme activity was observed to be as much as 100% when cell lysis was allowed to occur before immobilization. The pH and temperature optima were determined to be 5.5 and 45°C, respectively. Immobilized P. dacunhael-aspartate β-decarboxylase activity was stabilized by the addition of 0.1 mM pyridoxal-5-phosphate and 0.1 mM α-ketoglutaric acid to a 1.7 M ammonium aspartate (pH 5.5) substrate solution. Under conditions of semicontinuous use in a batch reactor, a 2.5% loss in immobilized l-aspartate β-decarboxylase activity was observed over a 31-day period. PMID:16346636

  4. Carbon-Nanotube-Mediated Electrochemical Transition in a Redox-Active Supramolecular Hydrogel Derived from Viologen and an l-Alanine-Based Amphiphile.

    PubMed

    Datta, Sougata; Bhattacharya, Santanu

    2016-05-23

    A two-component hydrogelator (16-A)2 -V(2+) , comprising an l-alanine-based amphiphile (16-A) and a redox-active viologen based partner (V(2+) ), is reported. The formation the hydrogel depended, not only on the acid-to-amine stoichiometric ratio, but on the choice of the l-amino acid group and also on the hydrocarbon chain length of the amphiphilic component. The redox responsive property and the electrochemical behavior of this two-component system were further examined by step-wise chemical and electrochemical reduction of the viologen nucleus (V(2+) /V(+) and V(+) /V(0) ). The half-wave reduction potentials (E1/2 ) associated with the viologen ring shifted to more negative values with increasing amine component. This indicates that higher extent of salt formation hinders reduction of the viologen moiety. Interestingly, the incorporation of single-walled carbon nanotubes in the electrochemically irreversible hydrogel (16-A)2 -V(2+) transformed it into a quasi-reversible electrochemical system. PMID:27059107

  5. Effects of inhibitory amino acids on expression of GABAA Rα and glycine Rα1 in hypoxic rat cortical neurons during development

    PubMed Central

    Qian, H; Feng, Y; He, XZ; Yang, YL; Sung, JH; Xia, Y

    2011-01-01

    Recent studies suggest that GABA and glycine are protective to mature but toxic to immature cortical neurons during prolonged hypoxia. Since the action of these inhibitory amino acids is mediated by GABA and glycine receptors, the expression of these receptors is a critical factor in determining neuronal response to GABAA and glycine in hypoxia. Therefore, we asked whether in rat cortical neurons, 1) hypoxia alters the expression of the GABA and glycine receptors; 2) inhibitory amino acids change the course of GABA and glycine receptor expression; and 3) there are any differences between the immature and mature neurons. In cultured rat cortical neurons from day 4 (4 Days in Vitro or DIV 4) to day 20 (DIV 20), we observed that 1) GABAARα and GlyRα1 underwent differential changes in expression during the development in-vitro; 2) hypoxia for 3 days decreased GABAARα and GlyRα1 density in the neurons in-between DIV 4 and DIV 20, but did not induce a major change in immature (DIV 4) and mature (DIV 20) neurons; 3) during normoxia GABA, glycine and taurine decreased GABAARα and GlyRα1 density in the immature neurons, but had a tendency to increase the density in the mature neurons, except for taurine; 4) under hypoxia, all these amino acids decreased GABAARα and GlyRα1 density in most groups of the immature neurons with a slight effect on the mature neurons; and 5) δ-opioid receptor activation with DADLE increased GABAARα and GlyRα1 density in both the immature and mature neurons under normoxia and in the mature neurons under hypoxic condition. These data suggest that inhibitory amino acids differentially regulate the expression of GABAA and glycine receptors in rat cortical neurons in normoxic and hypoxic conditions with major differences between the immature and mature neurons. PMID:22018691

  6. Growth and characterization of nonlinear optical active L-alanine formate crystal by modified Sankaranarayanan Ramasamy (SR) method

    NASA Astrophysics Data System (ADS)

    Justin Raj, C.; Jerome Das, S.

    2007-06-01

    Single crystals of L-alanine formate ( L-AlFo) have been grown from aqueous solution by using the novel uniaxial crystal growth method of Sankaranarayanan and Ramasamy (SR) with a due modification in the growth assembly. A vertical bottom-seed ampoule was rotated by 90°/s using a stepper motor and was used for the growth of single crystal and ring heater was replaced by alternating 40 W filament lamps for maintaining the evaporation rate. L-alanine formate crystals of 10 mm diameter and 50 mm length have been grown with a growth rate 5 mm per day. The grown crystal was subjected to single-crystal X-ray analysis, which confirms that the crystal belongs to orthorhombic structure with space group P 212121. The presence of formate functional groups in L-AlFo and the protanation of ions were confirmed by Fourier transform infrared transmission (FTIR) analysis. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz powder test. The DRS UV-vis spectrum of the crystal shows that the crystal has UV cut-off at 205 nm. TGA/DTA studies revealed that the crystal was thermally stable up to 234 °C.

  7. Domain Motions and Functionally-Key Residues of L-Alanine Dehydrogenase Revealed by an Elastic Network Model.

    PubMed

    Li, Xing-Yuan; Zhang, Jing-Chao; Zhu, Yan-Ying; Su, Ji-Guo

    2015-01-01

    Mycobacterium tuberculosis L-alanine dehydrogenase (L-MtAlaDH) plays an important role in catalyzing L-alanine to ammonia and pyruvate, which has been considered to be a potential target for tuberculosis treatment. In the present work, the functional domain motions encoded in the structure of L-MtAlaDH were investigated by using the Gaussian network model (GNM) and the anisotropy network model (ANM). The slowest modes for the open-apo and closed-holo structures of the enzyme show that the domain motions have a common hinge axis centered in residues Met133 and Met301. Accompanying the conformational transition, both the 1,4-dihydronicotinamide adenine dinucleotide (NAD)-binding domain (NBD) and the substrate-binding domain (SBD) move in a highly coupled way. The first three slowest modes of ANM exhibit the open-closed, rotation and twist motions of L-MtAlaDH, respectively. The calculation of the fast modes reveals the residues responsible for the stability of the protein, and some of them are involved in the interaction with the ligand. Then, the functionally-important residues relevant to the binding of the ligand were identified by using a thermodynamic method. Our computational results are consistent with the experimental data, which will help us to understand the physical mechanism for the function of L-MtAlaDH. PMID:26690143

  8. Response of L-alanine and 2-methylalanine minidosimeters for K-Band (24 GHz) EPR dosimetry

    NASA Astrophysics Data System (ADS)

    Chen, F.; Graeff, C. F. O.; Baffa, O.

    2007-11-01

    Minidosimeters of L-alanine and 2-methylalanine (2MA) were prepared and tested as potential candidates for small radiation field dosimetry. To quantify the free radicals created by radiation a K-Band (24 GHz) EPR spectrometer was used. X-rays provided by a 6 MV clinical linear accelerator were used to irradiate the minidosimeters in the dose range of 0.5-30 Gy. The dose-response curves for both radiation sensitive materials displayed a good linear behavior in the dose range indicated with 2MA being more radiation sensitive than L-alanine. Moreover, 2MA showed a smaller LLD (lower limit detection) value. The proposed system minidosimeter/K-Band spectrometer was able to detect 10 Gy EPR spectra with good signal-to-noise ratio (S/N). The overall uncertainty indicates that this system shows a good performance for the detection of dose values of 20 Gy and above, which are dose values typically used in radiosurgery treatments.

  9. Enantioselective Collision-Activated Dissociation of Gas-Phase Tryptophan Induced by Chiral Recognition of Protonated uc(l)-Alanine Peptides

    NASA Astrophysics Data System (ADS)

    Fujihara, Akimasa; Matsuyama, Hiroki; Tajiri, Michiko; Wada, Yoshinao; Hayakawa, Shigeo

    2016-06-01

    Enantioselective dissociation in the gas phase is important for enantiomeric enrichment and chiral transmission processes in molecular clouds regarding the origin of homochirality in biomolecules. Enantioselective collision-activated dissociation (CAD) of tryptophan (Trp) and the chiral recognition ability of uc(l)-alanine peptides (uc(l)-Ala n ; n = 2-4) were examined using a linear ion trap mass spectrometer. CAD spectra of gas-phase heterochiral H+(uc(d)-Trp)(uc(l)-Ala n ) and homochiral H+(uc(l)-Trp)(uc(l)-Ala n ) noncovalent complexes were obtained as a function of the peptide size n. The H2O-elimination product was observed in CAD spectra of both heterochiral and homochiral complexes for n = 2 and 4, and in homochiral H+(uc(l)-Trp)(uc(l)-Ala3), indicating that the proton is attached to the uc(l)-alanine peptide, and H2O loss occurs from H+(uc(l)-Ala n ) in the noncovalent complexes. H2O loss did not occur in heterochiral H+(uc(d)-Trp)(uc(l)-Ala3), where NH3 loss and (H2O + CO) loss were the primary dissociation pathways. In heterochiral H+(uc(d)-Trp)(uc(l)-Ala3), the protonation site is the amino group of uc(d)-Trp, and NH3 loss and (H2O + CO) loss occur from H+(uc(d)-Trp). uc(l)-Ala peptides recognize uc(d)-Trp through protonation of the amino group for peptide size n = 3. NH3 loss and (H2O + CO) loss from H+(uc(d)-Trp) proceeds via enantioselective CAD in gas-phase heterochiral H+(uc(d)-Trp)(uc(l)-Ala3) at room temperature, whereas uc(l)-Trp dissociation was not observed in homochiral H+(uc(l)-Trp)(uc(l)-Ala3). These results suggest that enantioselective dissociation induced by chiral recognition of uc(l)-Ala peptides through protonation could play an important role in enantiomeric enrichment and chiral transmission processes of amino acids.

  10. Crystal Engineering of l-Alanine with l-Leucine Additive using Metal-Assisted and Microwave-Accelerated Evaporative Crystallization

    PubMed Central

    2015-01-01

    In this work, we demonstrated that the change in the morphology of l-alanine crystals can be controlled with the addition of l-leucine using the metal-assisted and microwave accelerated evaporative crystallization (MA-MAEC) technique. Crystallization experiments, where an increasing stoichiometric amount of l-leucine is added to initial l-alanine solutions, were carried out on circular poly(methyl methacrylate) (PMMA) disks modified with a 21-well capacity silicon isolator and silver nanoparticle films using microwave heating (MA-MAEC) and at room temperature (control experiments). The use of the MA-MAEC technique afforded for the growth of l-alanine crystals with different morphologies up to ∼10-fold faster than those grown at room temperature. In addition, the length of l-alanine crystals was systematically increased from ∼380 to ∼2000 μm using the MA-MAEC technique. Optical microscope images revealed that the shape of l-alanine crystals was changed from tetragonal shape (without l-leucine additive) to more elongated and wire-like structures with the addition of the l-leucine additive. Further characterization of l-alanine crystals was undertaken by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy and powder X-ray diffraction (PXRD) measurements. In order to elucidate the growth mechanism of l-alanine crystals, theoretical simulations of l-alanine’s morphology with and without l-leucine additive were carried out using Materials Studio software in conjunction with our experimental data. Theoretical simulations revealed that the growth of l-alanine’s {011} and {120} crystal faces were inhibited due to the incorporation of l-leucine into these crystal faces in selected positions. PMID:24839404

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

    SciTech Connect

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

    2005-05-01

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

  12. Conformational characterization of peptides rich in the cycloaliphatic C alpha,alpha-disubstituted glycine 1-aminocyclononane-1-carboxylic acid.

    PubMed

    Gatos, M; Formaggio, F; Crisma, M; Valle, G; Toniolo, C; Bonora, G M; Saviano, M; Iacovino, R; Menchise, V; Galdiero, S; Pedone, C; Benedetti, E

    1997-01-01

    A series of N- and C-protected, monodispersed homo-oligopeptides (to the pentamer level) from the cycloaliphatic C alpha,alpha-dialkylated glycine 1-aminocyclononane-1-carboxylic acid (Ac9c) and two Ala/Ac9c tripeptides have been synthesized by solution methods and fully characterized. The conformational preferences of all the model peptides were determined in deuterochloroform solution by FT-IR absorption and 1H-NMR. The molecular structures of the amino acid derivatives mCIAc-Ac9c-OH and Z-Ac9c-OtBu, the dipeptide pBrBz-(Ac9c)2-OtBu, the tetrapeptide Z-(Ac9c)4-OtBu, and the pentapeptide Z-(Ac9c)5-OtBu were determined in the crystal state by X-ray diffraction. Based on this information, the average geometry and the preferred conformation for the cyclononyl moiety of the Ac9c residue have been assessed. The backbone conformational data are strongly in favour of the conclusion that the Ac9c residue is a strong beta-turn and helix former. A comparison with the structural propensity of alpha-aminoisobutyric acid, the prototype of C alpha,alpha-dialkylated glycines, and the other extensively investigated members of the family of 1-aminocycloalkane-1-carboxylic acids (Acnc, with n = 3-8) is made and the implications for the use of the Ac9c residue in conformationally constrained analogues of bioactive peptides are briefly examined. PMID:9391912

  13. Beta-N-methylamino-L-alanine: LC-MS/MS optimization, screening of cyanobacterial strains and occurrence in shellfish from Thau, a French Mediterranean lagoon.

    PubMed

    Réveillon, Damien; Abadie, Eric; Séchet, Véronique; Brient, Luc; Savar, Véronique; Bardouil, Michèle; Hess, Philipp; Amzil, Zouher

    2014-11-01

    β-N-methylamino-L-alanine (BMAA) is a neurotoxic non-protein amino acid suggested to be involved in neurodegenerative diseases. It was reported to be produced by cyanobacteria, but also found in edible aquatic organisms, thus raising concern of a widespread human exposure. However, the chemical analysis of BMAA and its isomers are controversial, mainly due to the lack of selectivity of the analytical methods. Using factorial design, we have optimized the chromatographic separation of underivatized analogues by a hydrophilic interaction chromatography coupled to tandem mass spectrometry (HILIC-MS/MS) method. A combination of an effective solid phase extraction (SPE) clean-up, appropriate chromatographic resolution and the use of specific mass spectral transitions allowed for the development of a highly selective and sensitive analytical procedure to identify and quantify BMAA and its isomers (in both free and total form) in cyanobacteria and mollusk matrices (LOQ of 0.225 and 0.15 µg/g dry weight, respectively). Ten species of cyanobacteria (six are reported to be BMAA producers) were screened with this method, and neither free nor bound BMAA could be found, while both free and bound DAB were present in almost all samples. Mussels and oysters collected in 2009 in the Thau Lagoon, France, were also screened, and bound BMAA and its two isomers, DAB and AEG, were observed in all samples (from 0.6 to 14.4 µg/g DW), while only several samples contained quantifiable free BMAA. PMID:25405857

  14. Beta-N-methylamino-l-alanine: LC-MS/MS Optimization, Screening of Cyanobacterial Strains and Occurrence in Shellfish from Thau, a French Mediterranean Lagoon

    PubMed Central

    Réveillon, Damien; Abadie, Eric; Séchet, Véronique; Brient, Luc; Savar, Véronique; Bardouil, Michèle; Hess, Philipp; Amzil, Zouher

    2014-01-01

    β-N-methylamino-l-alanine (BMAA) is a neurotoxic non-protein amino acid suggested to be involved in neurodegenerative diseases. It was reported to be produced by cyanobacteria, but also found in edible aquatic organisms, thus raising concern of a widespread human exposure. However, the chemical analysis of BMAA and its isomers are controversial, mainly due to the lack of selectivity of the analytical methods. Using factorial design, we have optimized the chromatographic separation of underivatized analogues by a hydrophilic interaction chromatography coupled to tandem mass spectrometry (HILIC-MS/MS) method. A combination of an effective solid phase extraction (SPE) clean-up, appropriate chromatographic resolution and the use of specific mass spectral transitions allowed for the development of a highly selective and sensitive analytical procedure to identify and quantify BMAA and its isomers (in both free and total form) in cyanobacteria and mollusk matrices (LOQ of 0.225 and 0.15 µg/g dry weight, respectively). Ten species of cyanobacteria (six are reported to be BMAA producers) were screened with this method, and neither free nor bound BMAA could be found, while both free and bound DAB were present in almost all samples. Mussels and oysters collected in 2009 in the Thau Lagoon, France, were also screened, and bound BMAA and its two isomers, DAB and AEG, were observed in all samples (from 0.6 to 14.4 µg/g DW), while only several samples contained quantifiable free BMAA. PMID:25405857

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

    SciTech Connect

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

    2006-09-14

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

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

    PubMed

    Tang, Ning; Skibsted, Leif H

    2016-06-01

    Deprotonation of amino acids as occurs during transfer from stomach to intestines during food digestion was found by comparison of complex formation constants as determined electrochemically for increasing pH to increase calcium binding (i) by a factor of around 6 for the neutral amino acids, (ii) by a factor of around 4 for anions of the acidic amino acids aspartic and glutamic acid, and (iii) by a factor of around 5.5 for basic amino acids. Optimized structures of the 1:1 complexes and ΔHbinding for calcium binding as calculated by density functional theory (DFT) confirmed in all complexes a stronger calcium binding and shorter calcium-oxygen bond length in the deprotonated form. In addition, the stronger calcium binding was also accompanied by a binding site shift from carboxylate binding to chelation by α-amino group and carboxylate oxygen for leucine, aspartate, glutamate, alanine, and asparagine. For binary amino acid mixtures, the calcium-binding constant was close to the predicted geometric mean of the individual amino acid binding constants indicating separate binding of calcium to two amino acids when present together in solution. At high pH, corresponding to conditions for calcium absorption, the binding affinity increased in the order Lys < Arg < Cys < Gln < Gly ∼ Ala < Asn < His < Leu < Glu< Asp. In a series of glycine peptides, calcium-binding affinity was found to increase in the order Gly-Leu ∼ Gly-Gly < Ala-Gly < Gly-His ∼ Gly-Lys-Gly < Glu-Cys-Gly < Gly-Glu, an ordering confirmed by DFT calculations for the dipeptides and which also accounted for large synergistic effects in calcium binding for up to 6 kJ/mol when compared to the corresponding amino acid mixtures. PMID:27159329

  17. Remarkable regioisomer control in the hydrogel formation from a two-component mixture of pyridine-end oligo(p-phenylenevinylene)s and N-decanoyl-L-alanine.

    PubMed

    Bhattacharjee, Subham; Datta, Sougata; Bhattacharya, Santanu

    2013-12-01

    N-Decanoyl-L-alanine (DA) was mixed with either colorless 4,4'-bipyridine (BP) or various derivatives such as chromogenic oligo(p-phenylenevinylene) (OPV) functionalized with isomeric pyridine termini in specific molar ratios. This mixtures form salt-type gels in a water/ethanol (2:1, v/v) mixture. The gelation properties of these two-component mixtures could be modulated by variation of the position of the ''N'' atom of the end pyridyl groups in OPVs. The presence of acid-base interactions in the self-assembly of these two-component systems leading to gelation was probed in detail by using stoichiometry-dependent UV/Vis and FTIR spectroscopy. Furthermore, temperature-dependent UV/Vis and fluorescence spectroscopy clearly demonstrated a J-type aggregation mode of these gelator molecules during the sol-to-gel transition process. Morphological features and the arrangement of the molecules in the gels were examined by using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) techniques. Calculation of the length of each molecular system by energy minimization in its extended conformation and comparison with the XRD patterns revealed that this class of gelator molecules adopts lamellar organizations. Rheological properties of these two-component systems provided clear evidence that the flow behavior could be modulated by varying the acid/amine ratio. Polarized optical microscopy (POM), differential scanning calorimetry (DSC), and XRD results revealed that the solid-phase behavior of such two-component mixtures (acid/base=2:1) varied significantly upon changing the proton-acceptor part from BP to OPV. Interestingly, the XRD pattern of these acid/base mixtures after annealing at their associated isotropic temperature was significantly different from that of their xerogels. PMID:24194380

  18. Structural and catalytic properties of L-alanine dehydrogenase from Bacillus cereus.

    PubMed

    Porumb, H; Vancea, D; Mureşan, L; Presecan, E; Lascu, I; Petrescu, I; Porumb, T; Pop, R; Bârzu, O

    1987-04-01

    Alanine dehydrogenase from Bacillus cereus, a non-allosteric enzyme composed of six identical subunits, was purified to homogeneity by chromatography on blue-Sepharose and Sepharose 6B-CL. Like other pyridine-linked dehydrogenases, alanine dehydrogenase is inhibited by Cibacron blue, competitively with respect to NADH and noncompetitively with respect to pyruvate. The enzyme was inactivated by 0.1 M glycine/HCl (pH 2) and reactivated by 0.1 M phosphate (pH 8) supplemented with NAD+ or NADH. The reactivation was characterized by sigmoidal kinetics indicating a complex mechanism involving rate-limiting folding and association steps. Cibacron blue interfered with renaturation, presumably by competition with NADH. Chromatography on Sepharose 6B-CL of the partially renatured alanine dehydrogenase led to the separation of several intermediates, but only the hexamer was characterized by enzymatic activity. By immobilization on Sepharose 4B, alanine dehydrogenase from B. cereus retained 66% of the specific activity of the soluble enzyme. After denaturation of immobilized alanine dehydrogenase with 7 M urea, 37% of the initial protein was still bound to Sepharose, indicating that on the average the hexamer was attached to the matrix via, at most, two subunits. The ability of the denatured, immobilized subunits to pick up subunits from solution shows their capacity to fold back to the native conformation after urea treatment. The formation of "hybrids" between subunits of enzyme from B. cereus and Bacillus subtilis demonstrates the close resemblance of the tertiary and quaternary structures of alanine dehydrogenases from these species. PMID:3104322

  19. Energetics of the molecular interactions of L-alanine and L-serine with xylitol, D-sorbitol, and D-mannitol in aqueous solutions at 298.15 K

    NASA Astrophysics Data System (ADS)

    Mezhevoi, I. N.; Badelin, V. G.

    2013-04-01

    Integral enthalpies of dissolution Δsol H m of L-alanine and L-serine are measured via the calorimetry of dissolution in aqueous solutions of xylitol, D-sorbitol, and D-mannitol. Standard enthalpies of dissolution (Δsol H ○) and the transfer (Δtr H ○) of amino acids from water to binary solvent are calculated from the experimental data. Using the McMillan-Mayer theory, enthalpy coefficients of pairwise interactions h xy of amino acids with molecules of polyols are calculated that are negative. The obtained results are discussed within the theory of the prevalence of different types of interactions in mixed solutions and the effect of the structural features of interacting biomolecules on the thermochemical parameters of dissolution of amino acids.

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

    NASA Astrophysics Data System (ADS)

    Suresh, Sagadevan

    2016-07-01

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

  1. An Optical Overview of Poly[μ2-L-alanine-μ3-nitrato-sodium(I)] Crystals

    PubMed Central

    Gallegos-Loya, E.; Orrantia-Borunda, E.; Duarte-Moller, A.

    2012-01-01

    Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN) and D-alanine sodium nitrate (DASN), were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD) studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-Vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR) spectrum of single crystal has been measured in the 4000–400 cm−1 range. The assignment of the observed vibrational modes to corresponding symmetry type has been performed. A thermogravimetric study was carried out to determine the thermal properties of the grown crystal. The efficiency of second harmonic generation was obtained by a variant of the Kurtz-Perry method. PMID:22566774

  2. Vibrational spectral characterization, NLO studies and charge transfer analysis of the organometallic material L-Alanine cadmium chloride

    NASA Astrophysics Data System (ADS)

    Arun Sasi, B. S.; Bright, K. C.; James, C.

    2016-01-01

    An organometallic nonlinear crystal, L-Alanine Cadmium Chloride (LACC) was synthesized by slow evaporation technique. The effects of hydrogen bonding on the structure, binding of ligand to metal ion, natural orbital occupancies, and vibrational frequencies were investigated using density functional theory (DFT) with the combined B3LYP and LANL2DZ basis set. Vibrational assignments were made on the basis of calculated potential energy distribution values from MOLVIB program. The topological analysis of electron localization function (ELF) provides basin population N (integrated density over the attractor basin), standard deviation (σ), and their relative fluctuation, defined as λ = σ2/N, which are sensitive criteria of delocalization. The molecular stability, electronic exchange interaction, and bond strength of the molecule were studied by natural bond orbital (NBO) analysis. The second harmonic generation (SHG) efficiency was determined using Kurtz and Perry method. Natural bond orbital analysis was carried out to study various intramolecular interactions that are responsible for the stabilization of the molecule.

  3. Environmental modulation of microcystin and β-N-methylamino-L-alanine as a function of nitrogen availability.

    PubMed

    Scott, L L; Downing, S; Phelan, R R; Downing, T G

    2014-09-01

    The most significant modulators of the cyanotoxins microcystin and β-N-methylamino-L-alanine in laboratory cyanobacterial cultures are the concentration of growth-medium combined nitrogen and nitrogen uptake rate. The lack of field studies that support these observations led us to investigate the cellular content of these cyanotoxins in cyanobacterial bloom material isolated from a freshwater impoundment and to compare these to the combined nitrogen availability. We established that these toxins typically occur in an inverse relationship in nature and that their presence is mainly dependent on the environmental combined nitrogen concentration, with cellular microcystin present at exogenous combined nitrogen concentrations of 29 μM and higher and cellular BMAA correlating negatively with exogenous nitrogen at concentrations below 40 μM. Furthermore, opposing nutrient and light gradients that form in dense cyanobacterial blooms may result in both microcystin and BMAA being present at a single sampling site. PMID:24878376

  4. Synthesis and biological evaluation of a new set of pyrazolo[1,5-c]quinazolines as glycine/N-methyl-D-aspartic acid receptor antagonists.

    PubMed

    Varano, Flavia; Catarzi, Daniela; Colotta, Vittoria; Poli, Daniela; Filacchioni, Guido; Galli, Alessandro; Costagli, Chiara

    2009-08-01

    Previous studies have shown that 8-chloro-5,6-dihydro-5-oxo-pyrazolo[1,5-c]quinazoline-2-carboxylates (PQZ series) represent a family of glycine/N-methyl-D-aspartic acid (NMDA) and/or (R,S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) and/or kainic acid (KA) receptor antagonists. Moreover, some groups have been identified that introduced in suitable positions of the PQZ 2-carboxylate framework shift affinity and selectivity toward glycine/NMDA receptor. These substituents are a carboxylate function at position-1 and/or a chlorine atom at position-9. In this paper we report a study on some new 5,6-dihydro-5-oxo-pyrazolo[1,5-c]quinazoline-1-carboxylates bearing at position-2 a lipophilic amide group or lacking substituent at this same position. All the newly synthesised compounds were evaluated for their binding at glycine/NMDA, AMPA and KA receptors. These studies led to the identification of some new PQZ derivatives endowed with good glycine/NMDA receptor affinity and selectivity and to better definition of the structure-activity relationship (SAR) of this class of compounds. PMID:19652407

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

    PubMed Central

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

    1999-01-01

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

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

    PubMed

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

    2013-12-15

    Soybean (Glycine max (L.) Merrill) is one of the most important food crops for human and animal consumption, providing oil and protein at relatively low cost. The least expensive source of nitrogen for soybean is the biological fixation of atmospheric nitrogen by the symbiotic association with soil bacteria, belonging mainly to the genus Bradyrhizobium. This study was conducted to assess the effect of the inoculation of G. max with Bradyrhizobium japonicum on the metabolite profile and antioxidant potential of its seeds. Phenolic compounds, sterols, triterpenes, organic acids, fatty acids and volatiles profiles were characterised by different chromatographic techniques. The antioxidant activity was evaluated against DPPH, superoxide and nitric oxide radicals. Inoculation with B. japonicum induced changes in the profiles of primary and secondary metabolites of G. max seeds, without affecting their antioxidant capacity. The increase of organic and fatty acids and volatiles suggest a positive effect of the inoculation process. These findings indicate that the inoculation with nodulating B. japonicum is a beneficial agricultural practice, increasing the content of bioactive metabolites in G. max seeds owing to the establishment of symbiosis between plant and microorganism, with direct effects on seed quality. PMID:23993531

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

    SciTech Connect

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

    1988-01-01

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

  8. Self-Assembly, Supramolecular Organization, and Phase Behavior of L-Alanine Alkyl Esters (n = 9-18) and Characterization of Equimolar L-Alanine Lauryl Ester/Lauryl Sulfate Catanionic Complex.

    PubMed

    Sivaramakrishna, D; Swamy, Musti J

    2015-09-01

    A homologous series of l-alanine alkyl ester hydrochlorides (AEs) bearing 9-18 C atoms in the alkyl chain have been synthesized and characterized with respect to self-assembly, supramolecular structure, and phase transitions. The CMCs of AEs bearing 11-18 C atoms were found to range between 0.1 and 10 mM. Differential scanning calorimetric (DSC) studies showed that the transition temperatures (Tt), enthalpies (ΔHt) and entropies (ΔSt) of AEs in the dry state exhibit odd-even alternation, with the odd-chain-length compounds having higher Tt values, but the even-chain-length homologues showing higher values of ΔHt and ΔSt. In DSC measurements on hydrated samples, carried out at pH 5.0 and pH 10.0 (where they exist in cationic and neutral forms, respectively), compounds with 13-18 C atoms in the alkyl chain showed sharp gel-to-liquid crystalline phase transitions, and odd-even alternation was not seen in the thermodynamic parameters. The molecular structure, packing properties, and intermolecular interactions of AEs with 9 and 10 C atoms in the alkyl chain were determined by single crystal X-ray diffraction, which showed that the alkyl chains are packed in a tilted interdigitated bilayer format. d-Spacings obtained from powder X-ray diffraction studies exhibited a linear dependence on the alkyl chain length, suggesting that the other AEs also adopt an interdigitated bilayer structure. Turbidimetric, fluorescence spectroscopic, and isothermal titration calorimetric (ITC) studies established that in aqueous dispersions l-alanine lauryl ester hydrochloride (ALE·HCl) and sodium dodecyl sulfate (SDS) form an equimolar complex. Transmission electron microscopic and DSC studies indicate that the complex exists as unilamellar liposomes, which exhibit a sharp phase transition at ∼39 °C. The aggregates were disrupted at high pH, suggesting that the catanionic complex would be useful to develop a base-labile drug delivery system. ITC studies indicated that ALE·HCl forms

  9. D-cycloserine transport in human intestinal epithelial (Caco-2) cells: mediation by a H(+)-coupled amino acid transporter.

    PubMed Central

    Thwaites, D. T.; Armstrong, G.; Hirst, B. H.; Simmons, N. L.

    1995-01-01

    1. The ability of D-cycloserine to act as a substrate for H+/amino acid symport has been tested in epithelial layers of Caco-2 human intestinal cells. 2. In Na(+)-free media with the apical bathing media held at pH 6.0, D-cycloserine (20 mM) is an effective inhibitor of net transepithelial transport (Jnet) of L-alanine (100 microM) and its accumulation (across the apical membrane) in a similar manner to amino acid substrates (L-alanine, beta-alanine, L-proline and glycine). In contrast L-valine was ineffective as an inhibitor for H+/amino acid symport. Both inhibition of L-alanine Jnet and its accumulation by D-cycloserine were dose-dependent, maximal inhibition being achieved by 5-10 mM. 3. Both D-cycloserine and known substrates for H+/amino acid symport stimulated an inward short circuit current (Isc) when voltage-clamped monolayers of Caco-2 epithelia, mounted in Ussing chambers, were exposed to apical substrate in Na(+)-free media, with apical pH held at 6.0. The D-cycloserine dependent increase in Isc was dose-dependent with an apparent Km = 15.8 +/- 2.0 (mean +/- s.e. mean) mM, and Vmax = 373 +/- 21 nmol cm-2h-1. 4. D-Cycloserine (20 mM) induced a prompt acidification of Caco-2 cell cytosol when superfused at the apical surface in both Na+ and Na(+)-free conditions. Cytosolic acidification in response to D-cycloserine was dependent upon superfusate pH, being attenuated at pH 8 and enhanced in acidic media. 5. The increment in Isc with 20 mM D-cycloserine was non-additive with other amino acid substrates for H+/amino acid symport. PMID:8548174

  10. β-N-methylamino-l-alanine causes neurological and pathological phenotypes mimicking Amyotrophic Lateral Sclerosis (ALS): the first step towards an experimental model for sporadic ALS.

    PubMed

    de Munck, Estefanía; Muñoz-Sáez, Emma; Miguel, Begoña G; Solas, M Teresa; Ojeda, Irene; Martínez, Ana; Gil, Carmen; Arahuetes, Rosa Ma

    2013-09-01

    β-N-methylamino-l-alanine (L-BMAA) is a neurotoxic amino acid that has been related to various neurodegenerative diseases. The aim of this work was to analyze the biotoxicity produced by L-BMAA in vivo in rats, trying to elucidate its physiopathological mechanisms and to search for analogies between the found effects and pathologies like Amyotrophic Lateral Sclerosis (ALS). Our data demonstrated that the neurotoxic effects in vivo were dosage-dependent. For evaluating the state of the animals, a neurological evaluation scale was developed as well as a set of functional tests. Ultrastructural cell analysis of spinal motoneurons has revealed alterations both in endoplasmic reticulum and mitochondria. Since GSK3β could play a role in some neuropathological processes, we analyzed the alterations occurring in GSK3β levels in L-BMAA treated rats, we have observed an increase in the active form of GSK3β levels in lumbar spinal cord and motor cerebral cortex. On the other hand, (TAR)-DNA-binding protein 43 (TDP-43) increased in L-BMAA treated animals. Our results indicated that N-acetylaspartate (NAA) declined in animals treated with L-BMAA, and the ratio of N-acetylaspartate/choline (NAA/Cho), N-acetylaspartate/creatine (NAA/Cr) and N-acetylaspartate/choline+creatine (NAA/Cho+Cr) tended to decrease in lumbar spinal cord and motor cortex. This project offers some encouraging results that could help establishing the progress in the development of an animal model of sporadic ALS and L-BMAA could be a useful tool for this purpose. PMID:23688553

  11. Analysis of β-N-methylamino-L-alanine (BMAA) in spirulina-containing supplements by liquid chromatography-tandem mass spectrometry

    PubMed Central

    2014-01-01

    Over the last decade the amino acid beta-N-methylamino-L-alanine (BMAA) has come under intense scrutiny. International laboratory and epidemiological research continues to support the hypothesis that environmental exposure to BMAA (e.g., through dietary practices, water supply) can promote the risk of various neurodegenerative diseases. A wide variety of cyanobacteria spp. have previously been reported to produce BMAA, with production levels dependent upon species, strain and environmental conditions. Since spirulina (Arthrospira spp.) is a member of the cyanobacteria phylum frequently consumed via dietary supplements, the presence of BMAA in such products may have public health implications. In the current work, we have analyzed ten spirulina-containing samples for the presence of BMAA; six pure spirulina samples from two separate raw materials suppliers, and four commercially-available multi-ingredient products containing 1.45 g of spirulina per 8.5 g serving. Because of controversy surrounding the measurement of BMAA, we have used two complementary liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods: one based on reversed phase LC (RPLC) with derivatization and the other based on hydrophilic interaction LC (HILIC). Potential matrix effects were corrected for by internal standardization using a stable isotope labeled BMAA standard. BMAA was not detected at low limits of detection (80 ng/g dry weight) in any of these product samples. Although these results are reassuring, BMAA analyses should be conducted on a wider sample selection and, perhaps, as part of ongoing spirulina production quality control testing and specifications. PMID:25120905

  12. Analysis of β-N-methylamino-L-alanine (BMAA) in spirulina-containing supplements by liquid chromatography-tandem mass spectrometry.

    PubMed

    McCarron, Pearse; Logan, Alan C; Giddings, Sabrina D; Quilliam, Michael A

    2014-01-01

    Over the last decade the amino acid beta-N-methylamino-L-alanine (BMAA) has come under intense scrutiny. International laboratory and epidemiological research continues to support the hypothesis that environmental exposure to BMAA (e.g., through dietary practices, water supply) can promote the risk of various neurodegenerative diseases. A wide variety of cyanobacteria spp. have previously been reported to produce BMAA, with production levels dependent upon species, strain and environmental conditions. Since spirulina (Arthrospira spp.) is a member of the cyanobacteria phylum frequently consumed via dietary supplements, the presence of BMAA in such products may have public health implications. In the current work, we have analyzed ten spirulina-containing samples for the presence of BMAA; six pure spirulina samples from two separate raw materials suppliers, and four commercially-available multi-ingredient products containing 1.45 g of spirulina per 8.5 g serving. Because of controversy surrounding the measurement of BMAA, we have used two complementary liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods: one based on reversed phase LC (RPLC) with derivatization and the other based on hydrophilic interaction LC (HILIC). Potential matrix effects were corrected for by internal standardization using a stable isotope labeled BMAA standard. BMAA was not detected at low limits of detection (80 ng/g dry weight) in any of these product samples. Although these results are reassuring, BMAA analyses should be conducted on a wider sample selection and, perhaps, as part of ongoing spirulina production quality control testing and specifications. PMID:25120905

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  15. Chiral effects on helicity studied via the energy landscape of short (d, l)-alanine peptides

    NASA Astrophysics Data System (ADS)

    Neelamraju, Sridhar; Oakley, Mark T.; Johnston, Roy L.

    2015-10-01

    The homochirality of natural amino acids facilitates the formation of regular secondary structures such as α-helices and β-sheets. Here, we study the relationship between chirality and backbone structure for the example of hexa-alanine. The most stable stereoisomers are identified through global optimisation. Further, the energy landscape, a database of connected low-energy local minima and transition points, is constructed for various neutral and zwitterionic stereoisomers of hexa-alanine. Three order parameters for partial helicity are applied and metric disconnectivity graphs are presented with partial helicity as a metric. We also apply the Zimm-Bragg model to derive average partial helicities for Ace-(l-Ala)6-NHMe, Ace-(d-Ala-l-Ala)3-NHMe, and Ace-(l-Ala)3-(d-Ala)3-NHMe from the database of local minima and compare with previous studies.

  16. Excitotoxic potential of the cyanotoxin β-methyl-amino-L-alanine (BMAA) in primary human neurons.

    PubMed

    Chiu, Alexander S; Gehringer, Michelle M; Braidy, Nady; Guillemin, Gilles J; Welch, Jeffrey H; Neilan, Brett A

    2012-11-01

    The toxicity of the cyanobacterial modified amino acid, BMAA, has been described in rat, mouse and leech neurons. Particular emphasis has been placed on the potential ability of BMAA to induce neuronal damage via excitotoxic mechanisms. Here we present data indicating that the effects observed on lower organisms are also evident in a human model. Our data indicates that BMAA induces increased intracellular Ca²⁺ influx, DNA damage, mitochondrial activity, lactate dehydrogenase (LDH) release and generation of reactive oxygen species (ROS). The amelioration of LDH release in the presence of the N-methyl-D-aspartate (NMDA) receptor antagonist MK801 indicates that the neurotoxic effects of BMAA are mediated via NMDA receptor activation. Additionally, we have shown that BMAA induces the expression of neuronal nitric oxide synthase (nNOS) and caspase-3 indicating that it can stimulate apoptosis in human neurons, presumably via activation of NMDA receptors. PMID:22885173

  17. Relative output factor and beam profile measurements of small radiation fields with an L-alanine/K-Band EPR minidosimeter

    SciTech Connect

    Chen Abrego, Felipe; Calcina, Carmen Sandra Guzman; Almeida, Adelaide de; Almeida, Carlos Eduardo de; Baffa, Oswaldo

    2007-05-15

    The performance of an L-alanine dosimeter with millimeter dimensions was evaluated for dosimetry in small radiation fields. Relative output factor (ROF) measurements were made for 0.5x0.5, 1x1, 3x3, 5x5, 10x10 cm{sup 2} square fields and for 5-, 10-, 20-, 40-mm-diam circular fields. In beam profile (BP) measurements, only 1x1, 3x3, 5x5 cm{sup 2} square fields and 10-, 20-, 40-mm-diam circular fields were used. For square and circular field irradiations, Varian/Clinac 2100, and a Siemens/Mevatron 6 MV linear accelerators were used, respectively. For a batch of 800 L-alanine minidosimeters (miniALAs) the average mass was 4.3{+-}0.5 (1{sigma}) mg, the diameter was 1.22{+-}0.07 (1{sigma}) mm, and the length was 3.5{+-}0.2 (1{sigma}) mm. A K-Band (24 GHz) electron paramagnetic resonance (EPR) spectrometer was used for recording the spectrum of irradiated and nonirradiated miniALAs. To evaluate the performance of the miniALAs, their ROF and BP results were compared with those of other types of detectors, such as an ionization chamber (PTW 0.125 cc), a miniTLD (LiF: Mg,Cu,P), and Kodak/X-Omat V radiographic film. Compared to other dosimeters, the ROF results for miniALA show differences of up to 3% for the smallest fields and 7% for the largest ones. These differences were within the miniALA experimental uncertainty ({approx}5-6% at 1{sigma}). For BP measurements, the maximum penumbra width difference observed between miniALA and film (10%-90% width) was less than 1 mm for square fields and within 1-2 mm for circular fields. These penumbra width results indicate that the spatial resolution of the miniALA is comparable to that of radiographic film and its dimensions are adequate for the field sizes used in this experiment. The K-Band EPR spectrometer provided adequate sensitivity for assessment of miniALAs with doses of the order of tens of Grays, making this dosimetry system (K-Band/miniALA) a potential candidate for use in radiosurgery dosimetry.

  18. Heterogeneity of L-alanine transport systems in brush-border membrane vesicles from rat placenta during late gestation.

    PubMed Central

    Alonso-Torre, S R; Serrano, M A; Medina, J M; Alvarado, F

    1992-01-01

    The placental uptake of L-alanine was studied by using purified brush-border membrane vesicles from rat trophoblasts. Saturation curves were carried out at 37 degrees C in buffers containing 100 mM (zero-trans)-NaSCN, -NaCl, -KSCN, -KCl, or -N-methyl-D-glucamine gluconate. The uncorrected uptake results were fitted by non-linear regression analysis to an equation involving one diffusional component either one or two saturable Michaelian transport terms. In the presence of NaCl, two distinct L-alanine transport systems were distinguished, named respectively System 1 (S-1; Vm1 about 760 pmol/s per mg of protein; KT1 = 0.5 mM) and System 2 (S-2; Vm2 about 1700 pmol/s per mg; KT2 = 9 mM). In contrast, in the presence of K+ (KCl = KSCN) or in the absence of any alkali-metal ions (N-methyl-D-glucamine gluconate), only one saturable system was apparent, which we identify as S-2. When Na+ is present, S-1, but not S-2, appears to be rheogenic, since its maximal transport capacity significantly increases in the presence of an inside-negative membrane potential, created either by replacing Cl- with the permeant anion thiocyanate (NaSCN > NaCl) or by applying an appropriate K+ gradient and valinomycin. alpha-(Methylamino)isobutyrate (methyl-AIB) appears to be a substrate of S-1, but not of S-2. For reasons that remain to be explained, however, methyl-AIB inhibits S-2. We conclude that S-1 represents a truly Na(+)-dependent mechanism, where Na+ behaves as an obligatory activator, whereas S-2 cannot discriminate between Na+ and K+, although its activity is higher in the presence of alkali-metal ions than in their absence (Na+ = K+ > N-methyl-D-glucammonium ion). S-2 appears to be fully developed 2 days before birth, whereas S-1 undergoes a capacity-type activation between days 19.5 and 21.5 of gestation, i.e. its apparent Vmax. nearly doubles, whereas its KT remains constant. PMID:1445280

  19. Gustatory responsiveness to the 20 proteinogenic amino acids in the spider monkey (Ateles geoffroyi).

    PubMed

    Larsson, Jenny; Maitz, Anna; Hernandez Salazar, Laura Teresa; Laska, Matthias

    2014-03-29

    The gustatory responsiveness of four adult spider monkeys to the 20 proteinogenic amino acids was assessed in two-bottle preference tests of brief duration (1min). We found that Ateles geoffroyi responded with significant preferences for seven amino acids (glycine, l-proline, l-alanine, l-serine, l-glutamic acid, l-aspartic acid, and l-lysine) when presented at a concentration of 100mM and/or 200mM and tested against water. At the same concentrations, the animals significantly rejected five amino acids (l-tryptophan, l-tyrosine, l-valine, l-cysteine, and l-isoleucine) and were indifferent to the remaining tastants. Further, the results show that the spider monkeys discriminated concentrations as low as 0.2mM l-lysine, 2mM l-glutamic acid, 10mM l-proline, 20mM l-valine, 40mM glycine, l-serine, and l-aspartic acid, and 80mM l-alanine from the alternative stimulus, with individual animals even scoring lower threshold values. A comparison between the taste qualities of the proteinogenic amino acids as described by humans and the preferences and aversions observed in the spider monkeys suggests a fairly high degree of agreement in the taste quality perception of these tastants between the two species. A comparison between the taste preference thresholds obtained with the spider monkeys and taste detection thresholds reported in human subjects suggests that the taste sensitivity of A. geoffroyi for the amino acids tested here might match that of Homo sapiens. The results support the assumption that the taste responses of spider monkeys to proteinogenic amino acids might reflect an evolutionary adaptation to their frugivorous and thus protein-poor diet. PMID:24480073

  20. The glycine deportation system and its pharmacological consequences.

    PubMed

    Beyoğlu, Diren; Idle, Jeffrey R

    2012-08-01

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

  1. The glycine deportation system and its pharmacological consequences☆

    PubMed Central

    Beyoğlu, Diren; Idle, Jeffrey R.

    2013-01-01

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

  2. The cyanobacterial neurotoxin β-N-methylamino-l-alanine (BMAA) induces neuronal and behavioral changes in honeybees.

    PubMed

    Okle, Oliver; Rath, Lisa; Galizia, C Giovanni; Dietrich, Daniel R

    2013-07-01

    The cyanobacterially produced neurotoxin beta-N-methylamino-l-alanine (BMAA) is thought to induce amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC)-like symptoms. However, its mechanism of action and its pathway of intoxication are yet unknown. In vivo animal models suitable for investigating the neurotoxic effect of BMAA with applicability to the human are scarce. Hence, we used the honeybee (Apis mellifera) since its nervous system is relatively simple, yet having cognitive capabilities. Bees fed with BMAA-spiked sugar water had an increased mortality rate and a reduced ability to learn odors in a classical conditioning paradigm. Using (14)C-BMAA we demonstrated that BMAA is biologically available to the bee, and is found in the head, thorax and abdomen with little to no excretion. BMAA is also transferred from one bee to the next via trophallaxis resulting in an exposure of the whole beehive. BMAA bath application directly onto the brain leads to an altered Ca(2+) homeostasis and to generation of reactive oxygen species. These behavioral and physiological observations suggest that BMAA may have effects on bee brains similar to those assumed to occur in humans. Therefore the bee could serve as a surrogate model system for investigating the neurological effects of BMAA. PMID:23591064

  3. The physiological effect of ingested β-N-methylamino-L-alanine on a glutamatergic synapse in an in vivo preparation.

    PubMed

    Goto, Joy J; Koenig, Jane H; Ikeda, Kazuo

    2012-11-01

    The neurotoxin, BMAA (β-N-methylamino-L-alanine), may be a risk factor for amyotrophic lateral sclerosis (ALS), Parkinson's (PD) and Alzheimer's (AD) disease. In vivo experiments have demonstrated that BMAA can cause a number of motor dysfunctions if ingested or injected, and in vitro experiments show that this toxin binds to glutamate receptors with deleterious results. Also, BMAA exists in the human food chain worldwide, and has been detected in the brains of ALS and AD patients. This paper offers the first demonstration by intracellular recording of the effect of ingested BMAA on the postsynaptic response of an identified glutamatergic cell in a living, undissected organism (Drosophila melanogaster), and correlates these observations with the specific motor dysfunctions that result from ingestion. The results suggest that BMAA acts as a glutamate agonist, causing NMDA receptor channels to remain open for prolonged periods of time, thereby damaging the cell by excitotoxicity. The effect on the postsynaptic response became apparent days before the function of the postsynaptic cell (wing beat) became affected. Severely depolarized cells were able to fully recover with the removal of BMAA from the food source, suggesting that blocking BMAA binding in the brain might be a good treatment strategy. PMID:22841708

  4. β-N-methylamino-L-alanine (BMAA) uptake by the animal model, Daphnia magna and subsequent oxidative stress.

    PubMed

    Esterhuizen-Londt, Maranda; Wiegand, Claudia; Downing, Tim G

    2015-06-15

    β-N-methylamino-l-alanine (BMAA), produced by cyanobacteria, is a neurotoxin implicated in Amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC). BMAA concentrations in cyanobacteria are lower than those thought to be necessary to result in neurological damage thus bioaccumulation or biomagnification is required to achieve concentrations able to cause neurodegeneration. Many cyanobacteria produce BMAA and uptake routes into the food web require examination. In this study we investigate the uptake of BMAA by adult phytoplanktivorus Daphnia magna via exposure to dissolved pure BMAA and BMAA containing cyanobacteria, as well as the subsequent oxidative stress response in the daphnia. Free BMAA and protein-associated BMAA were quantified by LC-MS/MS. Dissolved BMAA was taken up and was found as free BMAA in D. magna. No protein-associated BMAA was detected in D. magna after a 24-h exposure period. No BMAA was detectable in D. magna after exposure to BMAA containing cyanobacteria. BMAA inhibited the oxidative stress defence and biotransformation enzymes within 24-h exposure in the tested Daphnia and could therefore impair the oxidant status and the capability of detoxifying other substances in D. magna. PMID:25841344

  5. Comparison of oleic acid metabolism in the soybean (Glycine max (L. ) Merr. ) genotypes Williams and A5, a mutant with decreased linoleic acid in the seed

    SciTech Connect

    Martin, B.A.; Rinne, R.W.

    1986-05-01

    The metabolism of oleoyl coenzyme A (CoA) was examined in developing seed from two soybean (Glycine max (L.) Merr.) genotypes: Williams, a standard cultivar and A5, a mutant containing nearly twice the oleic acid (18:1) content of Williams. The in vitro rates of esterification of oleoyl-CoA to lysophosphatides by acyl-CoA: lysophosphatidylcholine acyltransferase was similar in both genotypes and lysophosphatidyl-ethanolamine was a poor substrate. Crude extracts desaturated exogenous (1-/sup 14/C)dioleoyl phosphatidylcholine at 14% of the rate achieved with (1-/sup 14/C)oleoyl-CoA, and 50 micromolar lysophosphaatidylcholine. The desaturase enzyme also required NADH for full activity. Extracts from Williams contained 1.5-fold more oleoyl phosphatidylcholine desaturase activity, on a fresh weight basis, than did A5 and appeared to have a similar affinity for oleoyl-CoA. There was 1.2- to 1.9-fold more linoleic acid (18:2) in phosphatidylcholine from Williams than from A5, measured at two stages of development, but both genotypes had a similar distribution of fatty acids in the one and two positions. Phosphatidylethanolamine in A5 contained relatively more linoleic acid (18:2) in the one position than did Williams. The increased oleic acid (18:1) content in A5 appeared to be a result of decreased rates of 18:1 desaturation of oleoyl-phosphatidylcholine in this genotype.

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

    PubMed Central

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

    2015-01-01

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

  7. Arginine-glycine-aspartic acid-conjugated dendrimer-modified quantum dots for targeting and imaging melanoma.

    PubMed

    Li, Zhiming; Huang, Peng; Lin, Jing; He, Rong; Liu, Bing; Zhang, Xiaomin; Yang, Sen; Xi, Peng; Zhang, Xuejun; Ren, Qiushi; Cui, Daxiang

    2010-08-01

    Angiogenesis is essential for the development of malignant tumors and provides important targets for tumor diagnosis and therapy. Quantum dots have been broadly investigated for their potential application in cancer molecular imaging. In present work, CdSe quantum dots were synthesized, polyamidoamine dendrimers were used to modify surface of quantum dots and improve their solubility in water solution. Then, dendrimer-modified CdSe quantum dots were conjugated with arginine-glycine-aspartic acid (RGD) peptides. These prepared nanoprobes were injected into nude mice loaded with melanoma (A375) tumor xenografts via tail vessels, IVIS imaging system was used to image the targeting and bio-distribution of as-prepared nanoprobes. The dendrimer-modified quantum dots exhibit water-soluble, high quantum yield, and good biocompatibility. RGD-conjugated quantum dots can specifically target human umbilical vein endothelial cells (HUVEC) and A375 melanoma cells, as well as nude mice loaded with A735 melanoma cells. High-performance RGD-conjugated dendrimers modified quantum dot-based nanoprobes have great potential in application such as tumor diagnosis and therapy. PMID:21125820

  8. Characterization of an acidic chitinase from seeds of black soybean (Glycine max (L) Merr Tainan No. 3).

    PubMed

    Chang, Ya-Min; Chen, Li-Chun; Wang, Hsin-Yi; Chiang, Chui-Liang; Chang, Chen-Tien; Chung, Yun-Chin

    2014-01-01

    Using 4-methylumbelliferyl-β-D-N,N',N″-triacetylchitotrioside (4-MU-GlcNAc3) as a substrate, an acidic chitinase was purified from seeds of black soybean (Glycine max Tainan no. 3) by ammonium sulfate fractionation and three successive steps of column chromatography. The purified chitinase was a monomeric enzyme with molecular mass of 20.1 kDa and isoelectric point of 4.34. The enzyme catalyzed the hydrolysis of synthetic substrates p-nitrophenyl N-acetyl chitooligosaccharides with chain length from 3 to 5 (GlcNAcn, n = 3-5), and pNp-GlcNAc4 was the most degradable substrate. Using pNp-GlcNAc4 as a substrate, the optimal pH for the enzyme reaction was 4.0; kinetic parameters Km and kcat were 245 µM and 10.31 min-1, respectively. This enzyme also showed activity toward CM-chitin-RBV, a polymer form of chitin, and N-acetyl chitooligosaccharides, an oligomer form of chitin. The smallest oligomer substrate was an N-acetylglucosamine tetramer. These results suggested that this enzyme was an endo-splitting chitinase with short substrate cleavage activity and useful for biotechnological applications, in particular for the production of N-acetyl chitooligosaccharides. PMID:25437446

  9. Covariation Analysis of Serumal and Urinary Metabolites Suggests Aberrant Glycine and Fatty Acid Metabolism in Chronic Hepatitis B

    PubMed Central

    Yang, Xue; Kong, Xiangliang; Cao, Zhiwei; Zhang, Yongyu; Hu, Yiyang; Tang, Kailin

    2016-01-01

    Background Chronic hepatitis b (CHB) is one of the most serious viral diseases threatening human health by putting patients at lifelong risk of cirrhosis and hepatocellular carcinoma (HCC). Although some proofs of altered metabolites in CHB were accumulated, its metabolic mechanism remains poorly understood. Analyzing covariations between metabolites may provide new hints toward underlying metabolic pathogenesis in CHB patients. Methods The present study collected paired urine and serum samples from the same subjects including 145 CHB and 23 healthy controls. A large-scale analysis of metabolites’ covariation within and across biofluids was systematically done to explore the underlying biological evidences for reprogrammed metabolism in CHB. Randomization and relative ranking difference were introduced to reduce bias caused by different sample size. More importantly, functional indication was interpreted by mapping differentially changed covariations to known metabolic pathways. Results Our results suggested reprogrammed pathways related to glycine metabolism, fatty acids metabolism and TCA cycle in CHB patients. With further improvement, the covariation analysis combined with network association study would pave new alternative way to interpret functional clues in clinical multi-omics data. PMID:27228119

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

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

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

    PubMed

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

    2015-04-01

    Improving the reduction kinetics is crucial in the electroreduction process of Cr(VI). In this study, we developed a novel adsorption-electroreduction system for accelerated removal of Cr(VI) by employing reticulated vitreous carbon electrode modified with sulfuric acid-glycine co-doped polyaniline (RVC/PANI-SA-GLY). Firstly, response surface methodology confirmed the optimum polymerization condition of co-doped polyaniline for modifying electrodes (Aniline, sulfuric acid and glycine, respectively, of 0.2 mol/L, 0.85 mol/L, 0.93 mol/L) when untraditional dopant glycine was added. Subsequently, RVC/PANI-SA-GLY showed higher Cr(VI) removal percentages in electroreduction experiments over RVC electrode modified with sulfuric acid doped polyaniline (RVC/PANI-SA) and bare RVC electrode. In contrast to RVC/PANI-SA, the improvement by RVC/PANI-SA-GLY was more significant and especially obvious at more negative potential, lower initial Cr(VI) concentration, relatively less acidic solution and higher current densities, best achieving 7.84% higher removal efficiency with entire Cr(VI) eliminated after 900 s. Current efficiencies were likewise enhanced by RVC/PANI-SA-GLY under quite negative potentials. Fourier transform infrared (FTIR) and energy dispersive spectrometer (EDS) analysis revealed a possible adsorption-reduction mechanism of RVC/PANI-SA-GLY, which greatly contributed to the faster reduction kinetics and was probably relative to the absorption between protonated amine groups of glycine and HCrO4(-). Eventually, the stability of RVC/PANI-SA-GLY was proven relatively satisfactory. PMID:25603298

  12. Effect of glycine supplementation in low protein diets with amino acids from soy protein isolate or free amino acids on broiler growth and nitrogen utilisation.

    PubMed

    Siegert, W; Wild, K J; Schollenberger, M; Helmbrecht, A; Rodehutscord, M

    2016-06-01

    Here, it was investigated whether substitution of amino acids (AA) from soy protein isolate with free AA in low crude protein diets influences the growth performance and N utilisation in broilers, and whether interactions with dietary glycine equivalent (Glyequi) concentration exist. Birds were distributed in two 2 × 2 factorial arrangements of 48 floor pens containing 10 birds each, plus 48 metabolism cages containing two birds each. Experimental feed was provided for ad libitum consumption from d 7 to 22. Diets contained either a soy protein isolate at 79 g/kg or a mix of free AA, which supplied the same amount of 18 proteinogenic AA. A mix of free glycine and l-serine was used to obtain low and high (12.0 and 20.5 g/kg dry matter) levels of dietary Glyequi. Substitution of soy protein isolate with free AA reduced the average daily gain and feed efficiency, mainly due to reduced feed intake. Efficiency of N accretion was not influenced by the AA source or Glyequi concentration on d 21, possibly due to the lower AA digestibility of soy protein isolate and higher urinary excretion of nitrogenous substances in the treatments with the AA mix. The average daily weight gain of the treatments with high Glyequi concentration was higher for both AA sources. This increase was due to higher average daily feed intake by broilers in the treatments with soy protein isolate and due to the increased feed efficiency in the treatments with the AA mix. Broilers exhibited different growth responses to dietary Glyequi between the AA sources; however, these responses could not be attributed to the different utilisation of Glyequi for uric acid synthesis. PMID:26955743

  13. Crystal growth, structural and thermal studies of amino acids admixtured L-arginine phosphate monohydrate single crystals

    NASA Astrophysics Data System (ADS)

    Anandan, P.; Saravanan, T.; Parthipan, G.; Kumar, R. Mohan; Bhagavannarayana, G.; Ravi, G.; Jayavel, R.

    2011-05-01

    To study the improved characteristics of L-arginine phosphate monohydrate (LAP) crystals, amino acids mixed LAP crystals have been grown by slow cooling method. Amino acids like glycine, L-alanine, and L-valine have been selected for doping. Optical quality bulk crystals have been harvested after a typical growth period of about twenty days. The effect of amino acids in the crystal lattice and molecular vibrational frequencies of various functional groups in the crystals have been studied using X-ray powder diffraction and Fourier Transform infrared (FTIR) analyses respectively. Thermal behavior of the amino acids mixed LAP crystals have been studied from the TG and DTG analyses. High-resolution X-ray diffraction studies have been carried out to find the crystalline nature. Optical transmission studies have been carried out by UV-vis spectrophotometer. The cut off wavelength is below 240 nm for the grown crystals.

  14. Evaluation of a thiodipeptide, L-phenylalanyl-Ψ[CS-N]-L-alanine, as a novel probe for peptide transporter 1.

    PubMed

    Arakawa, Hiroshi; Saito, Sachi; Kanagawa, Masahiko; Kamioka, Hiroki; Yano, Kentaro; Morimoto, Kaori; Ogihara, Takuo

    2014-01-01

    L-Phenylalanyl-Ψ[CS-N]-l-alanine (Phe-Ψ-Ala), a thiourea dipeptide, was evaluated as a probe for peptide transporter 1 (PEPT1). Uptake of Phe-Ψ-Ala in PEPT1-overexpressing HeLa cells was significantly higher than that in vector-transfected HeLa cells and the Km value was 275 ± 32 µM. The uptake was pH-dependent, being highest at pH 6.0, and was significantly decreased in the presence of PEPT1 inhibitors [glycylsarcosine (Gly-Sar), cephalexin, valaciclovir, glycylglycine, and glycylproline]. In metabolism assay using rat intestinal mucosa, rat hepatic microsomes, and human hepatocytes, the amount of Phe-Ψ-Ala was unchanged, whereas phenylalanylalanine was extensively decomposed. The clearance, distribution volume, and half-life of intravenously administered Phe-Ψ-Ala in rats were 0.151 ± 0.008 L/h/kg, 0.235 ± 0.012 L/kg, and 1.14 ± 0.07 h, respectively. The maximum plasma concentration of orally administered Phe-Ψ-Ala (2.31 ± 0.60 µg/mL) in the presence of Gly-Sar was significantly decreased compared with that in the absence of glycylsarcosine (3.74 ± 0.44 µg/mL), suggesting that the intestinal absorption of Phe-Ψ-Ala is mediated by intestinal PEPT1. In conclusion, our results indicate that Phe-Ψ-Ala is a high-affinity, metabolically stable, non-radioactive probe for PEPT1, and it should prove useful in studies of PEPT1, e.g., for predicting drug-drug interactions mediated by PEPT1 in vitro and in vivo. PMID:25008848

  15. Global cellular responses to β-methyl-amino-L-alanine (BMAA) by olfactory ensheathing glial cells (OEC).

    PubMed

    Chiu, Alexander S; Braidy, Nady; Marçal, Helder; Welch, Jeffrey H; Gehringer, Michelle M; Guillemin, Gilles J; Neilan, Brett A

    2015-06-01

    This study utilised a proteomics approach to identify any differential protein expression in a glial cell line, rat olfactory ensheathing cells (OECs), treated with the cyanotoxin β-methylamino-l-alanine (BMAA). Five proteins of interest were identified, namely Rho GDP-dissociation inhibitor 1 (RhoGDP1), Nck-associated protein 1 (NCKAP1), voltage-dependent anion-selective channel protein 1 (VDAC1), 3-hydroxyacyl-CoA dehydrogenase type-2 (3hCoAdh2), and ubiquilin-4 (UBQLN4). Four of these candidates, nuclear receptor subfamily 4 group A member 1 (Nur77), cyclophilin A (CyPA), RhoGDP1 and VDAC1, have been reported to be involved in cell growth. A microarray identified UBQLN4, palladin and CyPA, which have been implicated to have roles in excitotoxicity. Moreover, the NCKAP1, UBQLN4, CyPA and 3hCoAdh2 genes have been associated with abnormal protein aggregation. Differential expression of genes involved in mitochondrial activity, Nur77, 3hCoAdh2, VDAC1 and UBQLN4, were also identified. Confirmatory reverse transcription quantitative PCR (RT-qPCR) analysis of transcripts generated from the genes of interest corroborated the differential expression trends identified in the global protein analysis. BMAA induced cell cycle arrest in the G2/M phase of OEC and apoptosis after 48 h at concentrations of 250 μM and 500 μM. Collectively, this work advances our understanding of the mechanism of BMAA-mediated glial-toxicity in vitro. PMID:25797319

  16. The cyanobacterial neurotoxin beta-N-methylamino-L-alanine (BMAA) induces neuronal and behavioral changes in honeybees

    SciTech Connect

    Okle, Oliver; Rath, Lisa; Galizia, C. Giovanni; Dietrich, Daniel R.

    2013-07-01

    The cyanobacterially produced neurotoxin beta-N-methylamino-L-alanine (BMAA) is thought to induce amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC)-like symptoms. However, its mechanism of action and its pathway of intoxication are yet unknown. In vivo animal models suitable for investigating the neurotoxic effect of BMAA with applicability to the human are scarce. Hence, we used the honeybee (Apis mellifera) since its nervous system is relatively simple, yet having cognitive capabilities. Bees fed with BMAA-spiked sugar water had an increased mortality rate and a reduced ability to learn odors in a classical conditioning paradigm. Using {sup 14}C-BMAA we demonstrated that BMAA is biologically available to the bee, and is found in the head, thorax and abdomen with little to no excretion. BMAA is also transferred from one bee to the next via trophallaxis resulting in an exposure of the whole beehive. BMAA bath application directly onto the brain leads to an altered Ca{sup 2+} homeostasis and to generation of reactive oxygen species. These behavioral and physiological observations suggest that BMAA may have effects on bee brains similar to those assumed to occur in humans. Therefore the bee could serve as a surrogate model system for investigating the neurological effects of BMAA. - Highlights: • Investigating of neurotoxic effects of BMAA in honeybees • BMAA impairs ALS markers (ROS, Ca{sup 2+}, learning, memory, odor) in bees. • A method for the observation of ROS development in living bees brain was established. • Honeybees are a suitable model to explore neurodegenerative processes. • Neurotoxic BMAA can be spread in bee populations by trophallaxis.

  17. Acquisition of Raman spectra of amino acids using portable instruments: Outdoor measurements and comparison

    NASA Astrophysics Data System (ADS)

    Culka, A.; Jehlička, J.; Edwards, H. G. M.

    2010-12-01

    Raman spectra of 13 amino acids: L-alanine, β-alanine, L-asparagine, L-aspartic acid, L-glutamic acid, L-glutamine, glycine, L-methionine, L-proline, L-serine, L-threonine, L-tryptophan and L-tyrosine were acquired outdoors using two portable Raman instruments from the Ahura and Delta Nu manufacturers, both with 785 nm laser excitation. Both instruments provide quality Raman spectra with nevertheless a variable dependence upon the prevailing experimental conditions. The data acquired in these experiments will inform the selection of suitable Raman spectrometers for the in-field detection of biomolecules of relevance to the search for life signatures spectroscopically in terrestrial extreme environments and in extraterrestrial exploration, especially of planetary surfaces and subsurfaces using robotic instrumentation.

  18. Production and physicochemical assessment of new stevia amino acid sweeteners from the natural stevioside.

    PubMed

    Khattab, Sherine N; Massoud, Mona I; Jad, Yahya El-Sayed; Bekhit, Adnan A; El-Faham, Ayman

    2015-04-15

    New stevia amino acid sweeteners, stevia glycine ethyl ester (ST-GL) and stevia l-alanine methyl ester (ST-GL), were synthesised and characterised by IR, NMR ((1)H NMR and (13)C NMR) and elemental analysis. The purity of the new sweeteners was determined by HPLC and their sensory properties were evaluated relative to sucrose in an aqueous system. Furthermore, the stevia derivatives (ST-GL and ST-AL) were evaluated for their acute toxicity, melting point, solubility and heat stability. The novel sweeteners were stable in acidic, neutral or basic aqueous solutions maintained at 100 °C for 2 h. The sweetness intensity rate of the novel sweeteners was higher than sucrose. Stevia amino acid (ST-GL and ST-AL) solutions had a clean sweetness taste without bitterness when compared to stevioside. The novel sweeteners can be utilised as non-caloric sweeteners in the production of low-calorie food. PMID:25466115

  19. Acquisition of Raman spectra of amino acids using portable instruments: outdoor measurements and comparison.

    PubMed

    Culka, A; Jehlička, J; Edwards, H G M

    2010-12-01

    Raman spectra of 13 amino acids: L-alanine, β-alanine, L-asparagine, L-aspartic acid, L-glutamic acid, L-glutamine, glycine, L-methionine, L-proline, L-serine, L-threonine, L-tryptophan and L-tyrosine were acquired outdoors using two portable Raman instruments from the Ahura and Delta Nu manufacturers, both with 785 nm laser excitation. Both instruments provide quality Raman spectra with nevertheless a variable dependence upon the prevailing experimental conditions. The data acquired in these experiments will inform the selection of suitable Raman spectrometers for the in-field detection of biomolecules of relevance to the search for life signatures spectroscopically in terrestrial extreme environments and in extraterrestrial exploration, especially of planetary surfaces and subsurfaces using robotic instrumentation. PMID:20863748

  20. Kinetics of acid hydrolysis and reactivity of some antibacterial hydrophilic iron(II) imino-complexes

    NASA Astrophysics Data System (ADS)

    Shaker, Ali Mohamed; Nassr, Lobna Abdel-Mohsen Ebaid; Adam, Mohamed Shaker Saied; Mohamed, Ibrahim Mohamed Abdelhalim

    2015-05-01

    Kinetic study of acid hydrolysis of some hydrophilic Fe(II) Schiff base amino acid complexes with antibacterial properties was performed using spectrophotometry. The Schiff base ligands were derived from sodium 2-hydroxybenzaldehyde-5-sulfonate and glycine, L-alanine, L-leucine, L-isoleucine, DL-methionine, DL-serine, or L-phenylalanine. The reaction was studied in aqueous media under conditions of pseudo-first order kinetics. Moreover, the acid hydrolysis was studied at different temperatures and the activation parameters were calculated. The general rate equation was suggested as follows: rate = k obs [Complex], where k obs = k 2 [H+]. The evaluated rate constants and activation parameters are consistent with the hydrophilicity of the investigated complexes.

  1. Efficient Enzymatic Preparation of (13) N-Labelled Amino Acids: Towards Multipurpose Synthetic Systems.

    PubMed

    da Silva, Eunice S; Gómez-Vallejo, Vanessa; Baz, Zuriñe; Llop, Jordi; López-Gallego, Fernando

    2016-09-12

    Nitrogen-13 can be efficiently produced in biomedical cyclotrons in different chemical forms, and its stable isotopes are present in the majority of biologically active molecules. Hence, it may constitute a convenient alternative to Fluorine-18 and Carbon-11 for the preparation of positron-emitter-labelled radiotracers; however, its short half-life demands for the development of simple, fast, and efficient synthetic processes. Herein, we report the one-pot, enzymatic and non-carrier-added synthesis of the (13) N-labelled amino acids l-[(13) N]alanine, [(13) N]glycine, and l-[(13) N]serine by using l-alanine dehydrogenase from Bacillus subtilis, an enzyme that catalyses the reductive amination of α-keto acids by using nicotinamide adenine dinucleotide (NADH) as the redox cofactor and ammonia as the amine source. The integration of both l-alanine dehydrogenase and formate dehydrogenase from Candida boidinii in the same reaction vessel to facilitate the in situ regeneration of NADH during the radiochemical synthesis of the amino acids allowed a 50-fold decrease in the concentration of the cofactor without compromising reaction yields. After optimization of the experimental conditions, radiochemical yields were sufficient to carry out in vivo imaging studies in small rodents. PMID:27515007

  2. PREPARATIVE ISOLATION AND PURIFICATION OF THREE GLYCINE-CONJUGATED CHOLIC ACIDS FROM PULVIS FELLIS SUIS BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY COUPLED WITH ELSD DETECTION

    PubMed Central

    He, Jiao; Li, Jing; Sun, Wenji; Zhang, Tianyou; Ito, Yoichiro

    2011-01-01

    Coupled with evaporative light scattering detection, a high-speed counter-current chromatography (HSCCC) method was developed for preparative isolation and purification of three glycine-conjugated cholic acids, glycochenodeoxycholic acid (GCDCA), glycohyodeoxycholic acid (GHDCA) and glycohyocholic acid (GHCA) from Pulvis Fellis Suis (Pig gallbladder bile) for the first time. The separation was performed with a two-phase solvent system consisted of chloroform-methanol-water-acetic acid (65:30:10:1.5, v/v/v/v) by eluting the lower phase in the head-to-tail elution mode. The revolution speed of the separation column, flow rate of the mobile phase and separation temperature were 800 rpm, 2 ml/min and 25 °C, respectively. In a single operation, 33 mg of GCDCA, 38 mg of GHDCA and 23 mg of GHCA were obtained from 200 mg of crude extract with the purity of 95.65%, 96.72% and 96.63%, respectively, in one step separation. The HSCCC fractions were analyzed by high-performance liquid chromatography (HPLC) and the structures of the three glycine-conjugated cholic acids were identified by ESI-MS, 1H NMR and 13C NMR. PMID:23008527

  3. Betaine: New Oxidant in the Stickland Reaction and Methanogenesis from Betaine and l-Alanine by a Clostridium sporogenes-Methanosarcina barkeri Coculture

    PubMed Central

    Naumann, Evelyn; Hippe, Hans; Gottschalk, Gerhard

    1983-01-01

    Growing and nongrowing cells of Clostridium sporogenes fermented betaine with l-alanine, l-valine, l-leucine, and l-isoleucine as electron donors in a coupled oxidation-reduction reaction (Stickland reaction). For the substrate combinations betaine and l-alanine and betaine and l-valine balance studies were performed; the results were in agreement with the following fermentation equation: 1 R- CH(NH2)-COOH + 2 betaine + 2 H2O → 1 R-COOH + 1 CO2 + 1 NH3 + 2 trimethylamine + 2 acetate. Growth and production of trimethylamine were strictly dependent on the presence of selenite in the medium. With cell suspensions it was shown that C. sporogenes was unable to catabolize betaine as a single substrate. Betaine, however, was reduced to trimethylamine and acetate under an atmosphere of molecular hydrogen. For the reduction of betaine by cell extracts of C. sporogenes, dimercaptans such as 1,4-dithiothreitol could serve as electron donors. No betaine reductase activity was detected in cells grown in a complex medium without betaine. The pH optimum of betaine reductase was at pH 7.3. When C. sporogenes was cocultured with Methanosarcina barkeri strain Fusaro on betaine together with l-alanine, an almost complete conversion of the two substrates to CH4, NH3, and presumably CO2 was observed. PMID:16346196

  4. Dietary protein reduction in sheep and goats: different effects on L-alanine and L-leucine transport across the brush-border membrane of jejunal enterocytes.

    PubMed

    Schröder, B; Schöneberger, M; Rodehutscord, M; Pfeffer, E; Breves, G

    2003-08-01

    It was the aim of this study to examine the potential regulatory effects of a long-term low dietary protein supply on the transport capacity of the jejunal brush-border membrane for amino acids. For this purpose, we used the neutral amino acids L-alanine (representative for nonessential amino acids) and L-leucine (representative for essential amino acids) as model substances. Ten sheep lambs, 8 weeks of age and 19-27 kg body weight, were allotted to two dietary regimes with either adequate or reduced protein supply which was achieved by 17.9% and 9.7% of crude protein in the concentrated feed, respectively. The feeding periods were 4-6 weeks in length. Similarly, eight goat kids of 5-7 weeks of age and 8-14 kg body weight were allotted to either adequate (crude protein 20.1%, feeding period 9-12 weeks) or reduced protein supply (10.1%, feeding period 17-18 weeks). Dietary protein reduction in lambs caused a significant body weight loss of 0.6 +/- 0.7 kg, whereas the body weight in control animals increased by 1.9 +/- 0.7 kg (P<0.05). Plasma urea concentrations decreased significantly by 60% (low protein 2.3 +/- 0.1 versus control 5.7 +/- 0.2 mmol l(-1), P<0.001). In kids, reduction of dietary protein intake led to significant decreases of the daily weight gain by 48% from 181 +/- 8 g to 94 +/- 3 g (P<0.001) and daily dry matter intake by 27% from 568 +/- 13 g to 417 +/- 6 g (P<0.01). Respective urea concentrations in plasma were reduced by 77% from 5.2 +/- 0.4 to 1.2 +/- 0.2 mmol l(-1) (P<0.01). Kinetic analyses of the initial rates of alanine uptake into isolated jejunal brush-border membrane vesicles from sheep and goats as affected by low dietary protein supply yielded that the apparent Km was neither significantly different between the species nor significantly affected by the feeding regime thus ranging between 0.12 and 0.16 mmol.l(-1). Reduction of dietary protein, however, resulted in significantly decreased Vmax values of the transport system by 25

  5. Antiferromagnetic spin chain behavior and a transition to 3D magnetic order in Cu(D,L-alanine)2: Roles of H-bonds

    NASA Astrophysics Data System (ADS)

    Calvo, Rafael; Sartoris, Rosana P.; Calvo, Hernán L.; Chagas, Edson F.; Rapp, Raul E.

    2016-05-01

    We study the spin chain behavior, a transition to 3D magnetic order and the magnitudes of the exchange interactions for the metal-amino acid complex Cu(D,L-alanine)2•H2O, a model compound to investigate exchange couplings supported by chemical paths characteristic of biomolecules. Thermal and magnetic data were obtained as a function of temperature (T) and magnetic field (B0). The magnetic contribution to the specific heat, measured between 0.48 and 30 K, displays above 1.8 K a 1D spin-chain behavior that can be fitted with an intrachain antiferromagnetic (AFM) exchange coupling constant 2J0=(-2.12±0.08) cm-1 (defined as ℋex(i,i+1) = -2J0SiṡSi+1), between neighbor coppers at 4.49 Å along chains connected by non-covalent and H-bonds. We also observe a narrow specific heat peak at 0.89 K indicating a phase transition to a 3D magnetically ordered phase. Magnetization curves at fixed T = 2, 4 and 7 K with B0 between 0 and 9 T, and at T between 2 and 300 K with several fixed values of B0 were globally fitted by an intrachain AFM exchange coupling constant 2J0=(-2.27±0.02) cm-1 and g = 2.091±0.005. Interchain interactions J1 between coppers in neighbor chains connected through long chemical paths with total length of 9.51 Å cannot be estimated from magnetization curves. However, observation of the phase transition in the specific heat data allows estimating the range 0.1≤|2J1|≤0.4 cm-1, covering the predictions of various approximations. We analyze the magnitudes of 2J0 and 2J1 in terms of the structure of the corresponding chemical paths. The main contribution in supporting the intrachain interaction is assigned to H-bonds while the interchain interactions are supported by paths containing H-bonds and carboxylate bridges, with the role of the H-bonds being predominant. We compare the obtained intrachain coupling with studies of compounds showing similar behavior and discuss the validity of the approximations allowing to calculate the interchain

  6. Quantum yields of decomposition and homo-dimerization of solid L-alanine induced by 7.2 eV Vacuum ultraviolet light irradiation: an estimate of the half-life of L-alanine on the surface of space objects.

    PubMed

    Izumi, Yudai; Nakagawa, Kazumichi

    2011-08-01

    One of the leading hypotheses regarding the origin of prebiotic molecules on primitive Earth is that they formed from inorganic molecules in extraterrestrial environments and were delivered by meteorites, space dust and comets. To evaluate the availability of extraterrestrial amino acids, it is necessary to examine their decomposition and oligomerization rates as induced by extraterrestrial energy sources, such as vacuum ultraviolet (VUV) and X-ray photons and high energy particles. This paper reports the quantum yields of decomposition ((8.2 ± 0.7) × 10(-2) photon(-1)) and homo-dimerization ((1.2 ± 0.3) × 10(-3) photon(-1)) and decomposition of the dimer (0.24 ± 0.06 photon(-1)) of solid L-alanine (Ala) induced by VUV light with an energy of 7.2 eV. Using these quantum yields, the half-life of L-Ala on the surface of a space object in the present earth orbit was estimated to be about 52 days, even when only photons with an energy of 7.2 eV emitted from the present Sun were considered. The actual half-life of solid L-Ala on the surface of a space object orbit around the present day Earth would certainly be much shorter than our estimate, because of the added effect of photons and particles of other energies. Thus, we propose that L-Ala needs to be shielded from solar VUV in protected environments, such as the interior of a meteorite, within a time scale of days after synthesis to ensure its arrival on the primitive Earth. PMID:21461647

  7. Mechanism of anion permeation through channels gated by glycine and gamma-aminobutyric acid in mouse cultured spinal neurones.

    PubMed Central

    Bormann, J; Hamill, O P; Sakmann, B

    1987-01-01

    1. The ion-selective and ion transport properties of glycine receptor (GlyR) and gamma-aminobutyric acid receptor (GABAR) channels in the soma membrane of mouse spinal cord neurones were investigated using the whole-cell, cell-attached and outside-out patch versions of the patch-clamp technique. 2. Current-voltage (I-V) relations of transmitter-activated currents obtained from whole-cell measurements with 145 mM-Cl- intracellularly and extracellularly, showed outward rectification. In voltage-jump experiments, the instantaneous I-V relations were linear, and the steady-state I-V relations were rectifying outwardly indicating that the gating of GlyR and GABAR channels is voltage sensitive. 3. The reversal potential of whole-cell currents shifted 56 mV per tenfold change in internal Cl- activity indicating activation of Cl(-)-selective channels. The permeability ratio of K+ to Cl- (PK/PCl) was smaller than 0.05 for both channels. 4. The permeability sequence for large polyatomic anions was formate greater than bicarbonate greater than acetate greater than phosphate greater than propionate for GABAR channels; phosphate and propionate were not measurably permeant in GlyR channels. This indicates that open GlyR and GABAR channels have effective pore diameters of 5.2 and 5.6 A, respectively. The sequence of relative permeabilities for small anions was SCN- greater than I- greater than Br- greater than Cl- greater than F- for both channels. 5. GlyR and GABAR channels are multi-conductance-state channels. In cell-attached patches the single-channel slope conductances close to 0 mV membrane potential were 29, 18 and 10 pS for glycine, and 28, 17 and 10 pS for GABA-activated channels. The most frequently observed (main) conductance states were 29 and 17 pS for the GlyR and GABAR channel, respectively. 6. In outside-out patches with equal extracellular and intracellular concentrations of 145 mM-Cl-, the conductance states were 46, 30, 20 and 12 pS for GlyR channels and 44, 30

  8. The Amino Acid Composition of the Sutter's Mill Carbonaceous Chondrite

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Burton, A. S.; Elsila, J. E.; Dworkin, J. P.; Yin, Q. Z.; Cooper, G.; Jenniskens, P.

    2012-01-01

    In contrast to the Murchison meteorite which had a complex distribution of amino acids with a total C2 to Cs amino acid abundance of approx.14,000 parts-per-billion (ppb) [2], the Sutters Mill meteorite was found to be highly depleted in amino acids. Much lower abundances (approx.30 to 180 ppb) of glycine, beta-alanine, L-alanine and L-serine were detected in SM2 above procedural blank levels indicating that this meteorite sample experienced only minimal terrestrial amino acid contamination after its fall to Earth. Carbon isotope measurements will be necessary to establish the origin of glycine and beta-alanine in SM2. Other non-protein amino acids that are rare on Earth, yet commonly found in other CM meteorites such as aaminoisobutyric acid (alpha-AIB) and isovaline, were not identified in SM2. However, traces of beta-AIB (approx.1 ppb) were detected in SM2 and could be" extraterrestrial in origin. The low abundances of amino acids in the Sutter's Mill meteorite is consistent with mineralogical evidence that at least some parts of the Sutter's Mill meteorite parent body experienced extensive aqueous and/or thermal alteration.

  9. Study of Glycine and Folic Acid Supplementation to Ameliorate Transfusion Dependence in Congenital SLC25A38 Mutated Sideroblastic Anemia.

    PubMed

    LeBlanc, Marissa A; Bettle, Amanda; Berman, Jason N; Price, Victoria E; Pambrun, Chantale; Yu, Zhijie; Tiller, Marilyn; McMaster, Christopher R; Fernandez, Conrad V

    2016-07-01

    Congenital sideroblastic anemia (CSA) is a hematological disorder characterized by the presence of ringed sideroblasts in bone marrow erythroid precursors. Mutations in the erythroid-specific glycine mitochondrial transporter gene SLC25A38 have been found in a subset of patients with transfusion-dependent congenital CSA. Further studies in a zebrafish model identified a promising ameliorative strategy with combined supplementation with glycine and folate. We tested this combination in three individuals with SLC25A38 CSA, with a primary objective to decrease red blood cell transfusion requirements. No significant impact was observed on transfusion requirements or any hematologic parameters. PMID:27038157

  10. Altered hepatic gluconeogenesis during L-alanine infusion in weight-losing lung cancer patients as observed by phosphorus magnetic resonance spectroscopy and turnover measurements.

    PubMed

    Leij-Halfwerk, S; van den Berg, J W; Sijens, P E; Wilson, J H; Oudkerk, M; Dagnelie, P C

    2000-02-01

    Profound alterations in host metabolism in lung cancer patients with weight loss have been reported, including elevated phosphomonoesters (PMEs) as detected by 31P magnetic resonance spectroscopy (MRS). In healthy subjects, infusion of L-alanine induced significant increases in hepatic PMEs and phosphodiesters (PDEs) due to rising concentrations of 3-phosphoglycerate and phosphoenolpyruvate, respectively. The aim of the present study was to monitor these changes in the tumor-free liver of lung cancer patients during L-alanine infusion by means of simultaneous 31P MRS and turnover measurements. Twenty-one lung cancer patients without liver metastases with (CaWL) or without weight loss (CaWS), and 12 healthy control subjects were studied during an i.v. L-alanine challenge of 1.4-2.8 mmol/kg followed by 2.8 mmol/kg/h for 90 min. Plasma L-alanine concentrations increased during alanine infusion, from 0.35-0.37 mM at baseline to 5.37 +/- 0.14 mM in the CaWL patients, 6.67 +/- 0.51 mM in the CaWS patients, and 8.47 +/- 0.88 mM in the controls (difference from baseline and between groups during alanine infusion, all P < 0.001). Glucose turnover and liver PME levels at baseline were significantly elevated in the CaWL patients. Alanine infusion increased whole-body glucose turnover by 8 +/- 3% in the CaWS patients (P = 0.03), whereas no significant change occurred in the CaWL and controls. PME levels increased by 50 +/- 16% in controls (area under the curve, P < 0.01) and by 87 +/- 31% in the CaWS patients (P < 0.05) after 45-90 min. In contrast, no significant changes in PME levels were observed in the CaWL patients. Plasma insulin concentrations increased during L-alanine infusion in all groups to levels that were lower in the CaWL patients than in the CaWS patients and controls (P < 0.05). In lung cancer patients, but not in controls, changes in PME and PDE levels during alanine infusion were inversely correlated with their respective baseline levels (r = -0.82 and -0

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

    PubMed Central

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

    2016-01-01

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

  12. The Hypothesis that the Genetic Code Originated in Coupled Synthesis of Proteins and the Evolutionary Predecessors of Nucleic Acids in Primitive Cells

    PubMed Central

    Francis, Brian R.

    2015-01-01

    Although analysis of the genetic code has allowed explanations for its evolution to be proposed, little evidence exists in biochemistry and molecular biology to offer an explanation for the origin of the genetic code. In particular, two features of biology make the origin of the genetic code difficult to understand. First, nucleic acids are highly complicated polymers requiring numerous enzymes for biosynthesis. Secondly, proteins have a simple backbone with a set of 20 different amino acid side chains synthesized by a highly complicated ribosomal process in which mRNA sequences are read in triplets. Apparently, both nucleic acid and protein syntheses have extensive evolutionary histories. Supporting these processes is a complex metabolism and at the hub of metabolism are the carboxylic acid cycles. This paper advances the hypothesis that the earliest predecessor of the nucleic acids was a β-linked polyester made from malic acid, a highly conserved metabolite in the carboxylic acid cycles. In the β-linked polyester, the side chains are carboxylic acid groups capable of forming interstrand double hydrogen bonds. Evolution of the nucleic acids involved changes to the backbone and side chain of poly(β-d-malic acid). Conversion of the side chain carboxylic acid into a carboxamide or a longer side chain bearing a carboxamide group, allowed information polymers to form amide pairs between polyester chains. Aminoacylation of the hydroxyl groups of malic acid and its derivatives with simple amino acids such as glycine and alanine allowed coupling of polyester synthesis and protein synthesis. Use of polypeptides containing glycine and l-alanine for activation of two different monomers with either glycine or l-alanine allowed simple coded autocatalytic synthesis of polyesters and polypeptides and established the first genetic code. A primitive cell capable of supporting electron transport, thioester synthesis, reduction reactions, and synthesis of polyesters and

  13. The Hypothesis that the Genetic Code Originated in Coupled Synthesis of Proteins and the Evolutionary Predecessors of Nucleic Acids in Primitive Cells.

    PubMed

    Francis, Brian R

    2015-01-01

    Although analysis of the genetic code has allowed explanations for its evolution to be proposed, little evidence exists in biochemistry and molecular biology to offer an explanation for the origin of the genetic code. In particular, two features of biology make the origin of the genetic code difficult to understand. First, nucleic acids are highly complicated polymers requiring numerous enzymes for biosynthesis. Secondly, proteins have a simple backbone with a set of 20 different amino acid side chains synthesized by a highly complicated ribosomal process in which mRNA sequences are read in triplets. Apparently, both nucleic acid and protein syntheses have extensive evolutionary histories. Supporting these processes is a complex metabolism and at the hub of metabolism are the carboxylic acid cycles. This paper advances the hypothesis that the earliest predecessor of the nucleic acids was a β-linked polyester made from malic acid, a highly conserved metabolite in the carboxylic acid cycles. In the β-linked polyester, the side chains are carboxylic acid groups capable of forming interstrand double hydrogen bonds. Evolution of the nucleic acids involved changes to the backbone and side chain of poly(β-d-malic acid). Conversion of the side chain carboxylic acid into a carboxamide or a longer side chain bearing a carboxamide group, allowed information polymers to form amide pairs between polyester chains. Aminoacylation of the hydroxyl groups of malic acid and its derivatives with simple amino acids such as glycine and alanine allowed coupling of polyester synthesis and protein synthesis. Use of polypeptides containing glycine and l-alanine for activation of two different monomers with either glycine or l-alanine allowed simple coded autocatalytic synthesis of polyesters and polypeptides and established the first genetic code. A primitive cell capable of supporting electron transport, thioester synthesis, reduction reactions, and synthesis of polyesters and

  14. Strecker degradation of amino acids promoted by a camphor-derived sulfonamide

    PubMed Central

    Ferreira, M João; Knittel, Ana S O; Oliveira, Maria da Conceição; Costa Pessoa, João; Herrmann, Rudolf; Wagner, Gabriele

    2016-01-01

    Summary A camphor-derived sulfonimine with a conjugated carbonyl group, oxoimine 1 (O2SNC10H13O), reacts with amino acids (glycine, L-alanine, L-phenylalanine, L-leucine) to form a compound O2SNC10H13NC10H14NSO2 (2) which was characterized by spectroscopic means (MS and NMR) and supported by DFT calculations. The product, a single diastereoisomer, contains two oxoimine units connected by a –N= bridge, and thus has a structural analogy to the colored product Ruhemann´s purple obtained by the ninhydrin reaction with amino acids. A plausible reaction mechanism that involves zwitterions, a Strecker degradation of an intermediate imine and water-catalyzed tautomerizations was developed by means of DFT calculations on potential transition states. PMID:27340465

  15. Strecker degradation of amino acids promoted by a camphor-derived sulfonamide.

    PubMed

    Carvalho, M Fernanda N N; Ferreira, M João; Knittel, Ana S O; Oliveira, Maria da Conceição; Costa Pessoa, João; Herrmann, Rudolf; Wagner, Gabriele

    2016-01-01

    A camphor-derived sulfonimine with a conjugated carbonyl group, oxoimine 1 (O2SNC10H13O), reacts with amino acids (glycine, L-alanine, L-phenylalanine, L-leucine) to form a compound O2SNC10H13NC10H14NSO2 (2) which was characterized by spectroscopic means (MS and NMR) and supported by DFT calculations. The product, a single diastereoisomer, contains two oxoimine units connected by a -N= bridge, and thus has a structural analogy to the colored product Ruhemann´s purple obtained by the ninhydrin reaction with amino acids. A plausible reaction mechanism that involves zwitterions, a Strecker degradation of an intermediate imine and water-catalyzed tautomerizations was developed by means of DFT calculations on potential transition states. PMID:27340465

  16. Defining Multiple Characteristic Raman Bands of α-Amino Acids as Biomarkers for Planetary Missions Using a Statistical Method.

    PubMed

    Rolfe, S M; Patel, M R; Gilmour, I; Olsson-Francis, K; Ringrose, T J

    2016-06-01

    Biomarker molecules, such as amino acids, are key to discovering whether life exists elsewhere in the Solar System. Raman spectroscopy, a technique capable of detecting biomarkers, will be on board future planetary missions including the ExoMars rover. Generally, the position of the strongest band in the spectra of amino acids is reported as the identifying band. However, for an unknown sample, it is desirable to define multiple characteristic bands for molecules to avoid any ambiguous identification. To date, there has been no definition of multiple characteristic bands for amino acids of interest to astrobiology. This study examined L-alanine, L-aspartic acid, L-cysteine, L-glutamine and glycine and defined several Raman bands per molecule for reference as characteristic identifiers. Per amino acid, 240 spectra were recorded and compared using established statistical tests including ANOVA. The number of characteristic bands defined were 10, 12, 12, 14 and 19 for L-alanine (strongest intensity band: 832 cm(-1)), L-aspartic acid (938 cm(-1)), L-cysteine (679 cm(-1)), L-glutamine (1090 cm(-1)) and glycine (875 cm(-1)), respectively. The intensity of bands differed by up to six times when several points on the crystal sample were rotated through 360 °; to reduce this effect when defining characteristic bands for other molecules, we find that spectra should be recorded at a statistically significant number of points per sample to remove the effect of sample rotation. It is crucial that sets of characteristic Raman bands are defined for biomarkers that are targets for future planetary missions to ensure a positive identification can be made. PMID:26744263

  17. Defining Multiple Characteristic Raman Bands of α-Amino Acids as Biomarkers for Planetary Missions Using a Statistical Method

    NASA Astrophysics Data System (ADS)

    Rolfe, S. M.; Patel, M. R.; Gilmour, I.; Olsson-Francis, K.; Ringrose, T. J.

    2016-06-01

    Biomarker molecules, such as amino acids, are key to discovering whether life exists elsewhere in the Solar System. Raman spectroscopy, a technique capable of detecting biomarkers, will be on board future planetary missions including the ExoMars rover. Generally, the position of the strongest band in the spectra of amino acids is reported as the identifying band. However, for an unknown sample, it is desirable to define multiple characteristic bands for molecules to avoid any ambiguous identification. To date, there has been no definition of multiple characteristic bands for amino acids of interest to astrobiology. This study examined l-alanine, l-aspartic acid, l-cysteine, l-glutamine and glycine and defined several Raman bands per molecule for reference as characteristic identifiers. Per amino acid, 240 spectra were recorded and compared using established statistical tests including ANOVA. The number of characteristic bands defined were 10, 12, 12, 14 and 19 for l-alanine (strongest intensity band: 832 cm-1), l-aspartic acid (938 cm-1), l-cysteine (679 cm-1), l-glutamine (1090 cm-1) and glycine (875 cm-1), respectively. The intensity of bands differed by up to six times when several points on the crystal sample were rotated through 360 °; to reduce this effect when defining characteristic bands for other molecules, we find that spectra should be recorded at a statistically significant number of points per sample to remove the effect of sample rotation. It is crucial that sets of characteristic Raman bands are defined for biomarkers that are targets for future planetary missions to ensure a positive identification can be made.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  1. Identification and Partial Characterization of a Novel UDP-N-Acetylenolpyruvoylglucosamine Reductase/UDP-N-Acetylmuramate:l-Alanine Ligase Fusion Enzyme from Verrucomicrobium spinosum DSM 4136T

    PubMed Central

    Naqvi, Kubra F.; Patin, Delphine; Wheatley, Matthew S.; Savka, Michael A.; Dobson, Renwick C. J.; Gan, Han Ming; Barreteau, Hélène; Blanot, Didier; Mengin-Lecreulx, Dominique; Hudson, André O.

    2016-01-01

    The enzymes involved in synthesizing the bacterial cell wall are attractive targets for the design of antibacterial compounds, since this pathway is essential for bacteria and is absent in animals, particularly humans. A survey of the genome of a bacterium that belongs to the phylum Verrucomicrobia, the closest free-living relative to bacteria from the Chlamydiales phylum, shows genetic evidence that Verrucomicrobium spinosum possesses a novel fusion open reading frame (ORF) annotated by the locus tag (VspiD_010100018130). The ORF, which is predicted to encode the enzymes UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) and UDP-N-acetylmuramate:l-alanine ligase (MurC) that are involved in the cytoplasmic steps of peptidoglycan biosynthesis, was cloned. In vivo analyses using functional complementation showed that the fusion gene was able to complement Escherichia coli murB and murC temperature sensitive mutants. The purified recombinant fusion enzyme (MurB/CVs) was shown to be endowed with UDP-N-acetylmuramate:l-alanine ligase activity. In vitro analyses demonstrated that the latter enzyme had a pH optimum of 9.0, a magnesium optimum of 10 mM and a temperature optimum of 44–46°C. Its apparent Km values for ATP, UDP-MurNAc, and l-alanine were 470, 90, and 25 μM, respectively. However, all attempts to demonstrate an in vitro UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) activity were unsuccessful. Lastly, Hidden Markov Model-based similarity search and phylogenetic analysis revealed that this fusion enzyme could only be identified in specific lineages within the Verrucomicrobia phylum. PMID:27047475

  2. Determination of the anti-inflammatory and cytoprotective effects of l-glutamine and l-alanine, or dipeptide, supplementation in rats submitted to resistance exercise.

    PubMed

    Raizel, Raquel; Leite, Jaqueline Santos Moreira; Hypólito, Thaís Menezes; Coqueiro, Audrey Yule; Newsholme, Philip; Cruzat, Vinicius Fernandes; Tirapegui, Julio

    2016-08-01

    We evaluated the effects of chronic oral supplementation with l-glutamine and l-alanine in their free form or as the dipeptide l-alanyl-l-glutamine (DIP) on muscle damage, inflammation and cytoprotection, in rats submitted to progressive resistance exercise (RE). Wistar rats (n 8/group) were submitted to 8-week RE, which consisted of climbing a ladder with progressive loads. In the final 21 d before euthanasia, supplements were delivered in a 4 % solution in drinking water. Glutamine, creatine kinase (CK), lactate dehydrogenase (LDH), TNF-α, specific IL (IL-1β, IL-6 and IL-10) and monocyte chemoattractant protein-1 (MCP-1) levels were evaluated in plasma. The concentrations of glutamine, TNF-α, IL-6 and IL-10, as well as NF-κB activation, were determined in extensor digitorum longus (EDL) skeletal muscle. HSP70 level was assayed in EDL and peripheral blood mononuclear cells (PBMC). RE reduced glutamine concentration in plasma and EDL (P<0·05 v. sedentary group). However, l-glutamine supplements (l-alanine plus l-glutamine (GLN+ALA) and DIP groups) restored glutamine levels in plasma (by 40 and 58 %, respectively) and muscle (by 93 and 105 %, respectively). GLN+ALA and DIP groups also exhibited increased level of HSP70 in EDL and PBMC, consistent with the reduction of NF-κB p65 activation and cytokines in EDL. Muscle protection was also indicated by attenuation in plasma levels of CK, LDH, TNF-α and IL-1β, as well as an increase in IL-6, IL-10 and MCP-1. Our study demonstrates that chronic oral l-glutamine treatment (given with l-alanine or as dipeptide) following progressive RE induces cyprotective effects mediated by HSP70-associated responses to muscle damage and inflammation. PMID:27215379

  3. Effective production of 3,4-dihydroxyphenyl-L-alanine (L-DOPA) with Erwinia herbicola cells carrying a mutant transcriptional regulator TyrR.

    PubMed

    Koyanagi, Takashi; Katayama, Takane; Suzuki, Hideyuki; Nakazawa, Hidetsugu; Yokozeki, Kenzo; Kumagai, Hidehiko

    2005-02-01

    The enzymatic production of 3,4-dihydroxyphenyl-L-alanine (L-DOPA) using Erwinia herbicola cells involves the action of tyrosine phenol-lyase (Tpl, EC 4.1.99.2). Since Tpl is only synthesized under L-tyrosine-induced conditions, the addition of L-tyrosine to the medium is unavoidable when preparing cells (the enzyme source), but severely impedes the pure preparation of the final product L-DOPA. We circumvented this problem by using recombinant E. herbicola cells carrying a mutant transcriptional regulator TyrR, which is capable of activating the tpl promoter in the absence of L-tyrosine. PMID:15639092

  4. Hyperproduction of 3,4-dihydroxyphenyl-L-alanine (L-Dopa) using Erwinia herbicola cells carrying a mutant transcriptional regulator TyrR.

    PubMed

    Koyanagi, Takashi; Katayama, Takane; Suzuki, Hideyuki; Onishi, Akiko; Yokozeki, Kenzo; Kumagai, Hidehiko

    2009-05-01

    In the last few decades, enzymatic production of 3,4-dihydroxyphenyl-L-alanine (L-dopa) using tyrosine phenol-lyase (Tpl) has been industrialized. This method has an intrinsic problem of tyrosine contamination because Tpl is synthesized under tyrosine-induced conditions. Herein, we constructed a hyper-L-dopa-producing strain by exploiting a mutant TyrR, an activator of tpl. The highest productivity was obtained for the strain grown under non-induced conditions. It was 30-fold higher than that obtained for tyrosine-induced wild-type cells. PMID:19420686

  5. Cyanobacterial Blooms and the Occurrence of the neurotoxin beta-N-methylamino-L-alanine (BMAA) in South Florida Aquatic Food Webs.

    PubMed

    Brand, Larry E; Pablo, John; Compton, Angela; Hammerschlag, Neil; Mash, Deborah C

    2010-09-01

    Recent studies demonstrate that most cyanobacteria produce the neurotoxin beta-N-methylamino-L-alanine (BMAA) and that it can biomagnify in at least one terrestrial food chain. BMAA has been implicated as a significant environmental risk in the development of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis (ALS). We examined several blooms of cyanobacteria in South Florida, and the BMAA content of resident animals, including species used as human food. A wide range of BMAA concentrations were found, ranging from below assay detection limits to approximately 7000 μg/g, a concentration associated with a potential long-term human health hazard. PMID:21057660

  6. Radiolysis of amino acids by heavy and energetic cosmic ray analogues in simulated space environments: α-glycine zwitterion form

    NASA Astrophysics Data System (ADS)

    Portugal, Williamary; Pilling, Sergio; Boduch, Philippe; Rothard, Hermann; Andrade, Diana P. P.

    2014-07-01

    In this work, we studied the stability of the glycine molecule in the crystalline zwitterion form, known as α-glycine (+NH3CH2COO-), under the action of heavy cosmic ray analogues. The experiments were conducted in a high vacuum chamber at the heavy-ion accelerator Grand Accélérateur National d'Ions Lourds (GANIL), in Caen, France. The samples were bombarded at two temperatures (14 and 300 K) by 58Ni11+ ions of 46 MeV, up to a final fluence of 1013 ion cm-2. The chemical evolution of the sample was evaluated in situ using a Fourier Transform Infrared Spectrometer (FTIR). The bombardment at 14 K produced several daughter species, such as OCN-, CO, CO2 and CN-. The results also suggest the appearance of peptide bonds during irradiation, but this must be confirmed by further experiments. The half-life of glycine in the interstellar medium was estimated to be 7.8 × 103 yr (300 K) and 2.8 × 103 yr (14 K). In the Solar system, the values were 8.4 × 102 yr (300 K) and 3.6 × 103 yr (14 K). It is believed that glycine could be present in space environments that suffered aqueous changes, such as the interiors of comets, meteorites and planetesimals. This molecule is present in the proteins of all living beings. Therefore, studying its stability in these environments will provide further understanding of the role of this species in prebiotic chemistry on Earth.

  7. Serine and glycine metabolism in cancer☆

    PubMed Central

    Amelio, Ivano; Cutruzzolá, Francesca; Antonov, Alexey; Agostini, Massimiliano; Melino, Gerry

    2014-01-01

    Serine and glycine are biosynthetically linked, and together provide the essential precursors for the synthesis of proteins, nucleic acids, and lipids that are crucial to cancer cell growth. Moreover, serine/glycine biosynthesis also affects cellular antioxidative capacity, thus supporting tumour homeostasis. A crucial contribution of serine/glycine to cellular metabolism is through the glycine cleavage system, which refuels one-carbon metabolism; a complex cyclic metabolic network based on chemical reactions of folate compounds. The importance of serine/glycine metabolism is further highlighted by genetic and functional evidence indicating that hyperactivation of the serine/glycine biosynthetic pathway drives oncogenesis. Recent developments in our understanding of these pathways provide novel translational opportunities for drug development, dietary intervention, and biomarker identification of human cancers. PMID:24657017

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  9. The Origin of Amino Acids in Lunar Regolith Samples

    NASA Technical Reports Server (NTRS)

    Cook, Jamie E.; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; McLain, Hannah L.; Noble, Sarah K.; Gibson, Everett K., Jr.

    2016-01-01

    We analyzed the amino acid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed amino acids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5 ppb to 651.1 ppb in 6M HCl acid-vapor-hydrolyzed, hot-water extracts. Amino acids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: -aminoisobutyric acid (AIB), D-and L-amino-n-butyric acid (-ABA), DL-amino-n-butyric acid, -amino-n-butyric acid, -alanine, and -amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic amino acids, but racemic alanine and racemic -ABA were present in some samples.

  10. Isovaleric, methylmalonic, and propionic acid decrease anesthetic EC50 in tadpoles, modulate glycine receptor function, and interact with the lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine

    PubMed Central

    Weng, Yun; Hsu, Tienyi Theresa; Zhao, Jing; Nishimura, Stefanie; Fuller, Gerald G.; Sonner, James M.

    2010-01-01

    Introduction Elevated concentrations of isovaleric, methylmalonic, and propionic acid are associated with impaired consciousness in genetic diseases (organic acidemias). We conjectured that part of the central nervous system depression observed in these disorders was due to anesthetic effects of these metabolites. We tested three hypotheses. First, that these metabolites would have anesthetic-sparing effects, possibly being anesthetics by themselves. Second, that these compounds would modulate glycine and GABAA receptor function, increasing chloride currents through these channels as potent clinical inhaled anesthetics do. Third, that these compounds would affect physical properties of lipids. Methods Anesthetic EC50’s were measured in Xenopus laevis tadpoles. Glycine and GABAA receptors were expressed in Xenopus laevis oocytes and studied using two-electrode voltage clamping. Pressure-area isotherms of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers were measured with and without added organic acids. Results Isovaleric acid was an anesthetic in tadpoles, while methylmalonic and propionic acid decreased isoflurane’s EC50 by half. All three organic acids concentration-dependently increased current through α1 glycine receptors. There were minimal effects on α1β2γ2s GABAA receptors. The organic acids increased total lateral pressure (surface pressure) of DPPC monolayers, including at mean molecular areas typical of bilayers. Conclusion Isovaleric, methylmalonic, and propionic acid have anesthetic affects in tadpoles, positively modulate glycine receptor fuction, and affect physical properties of DPPC monolayers. PMID:19372333

  11. 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....

  12. Occurrence and transfer of a cyanobacterial neurotoxin β-methylamino-L-alanine within the aquatic food webs of Gonghu Bay (Lake Taihu, China) to evaluate the potential human health risk.

    PubMed

    Jiao, Yiying; Chen, Qiankun; Chen, Xu; Wang, Xin; Liao, Xuewei; Jiang, Lijuan; Wu, Jun; Yang, Liuyan

    2014-01-15

    To evaluate the health risk of cyanobacterial blooms, the levels of the neurotoxic non-protein amino acid, β-methylamino-l-alanine (BMAA), was investigated in the freshwater ecosystem of Gonghu Bay in Lake Taihu. Lake Taihu is a large shallow lake contaminated by the excessive growth of Microcystis. Since BMAA has been measured in diverse cyanobacteria in different ecosystems all over the world, BMAA might also occur in Gonghu Bay. A long term monitoring of BMAA was done by HPLC-MS/MS method in cyanobacteria, mollusks, crustaceans and various fish species at different trophic levels of ecosystems in Gonghu Bay, some of which were popularly consumed by humans. Over the entire sampling period, the total average BMAA content in cyanobacteria, mollusks, crustaceans and various fish species were 4.12, 3.21, 3.76, and 6.05μgBMAA/g dry weight, respectively. Thus, BMAA could be biosynthesized by the blooming cyanobacteria in which Microcystis dominates. This toxin can be transferred through ascending trophic levels of the aquatic ecosystem in Gonghu Bay. The bioaccumulation of BMAA was observed in aquatic animals, especially in some fish species during the bloom-outbreak and bloom-decline phases. The discovery of the chronic neurotoxin BMAA in a large limnic ecosystem together with possible pathways of accumulation within major food webs deserves serious consideration due to its potential long-term risk to human health. PMID:24055662

  13. High-performance liquid chromatographic mass spectrometric method for the determination of ursodeoxycholic acid and its glycine and taurine conjugates in human plasma.

    PubMed

    Tessier, E; Neirinck, L; Zhu, Z

    2003-12-25

    A novel sensitive high-performance liquid chromatography-electrospray mass spectrometry method has been developed for the determination of ursodeoxycholic acid (UDCA) and its glycine and taurine conjugates, glycoursodeoxycholic acid (GDCA) and tauroursodeoxycholic acid (TDCA). The procedure involved a solid phase extraction of UDCA, GDCA, TDCA and the internal standard, 23-nordeoxycholic acid from human plasma on a C18 Bond Elut cartridge. Chromatography was performed by isocratic reverse phase separation with methanol/25 mM ammonium acetate (40/60, v/v) containing 0.05% acetic acid on a C18 column with embedded polar functional group. Detection was achieved using an LC-MS/MS system. The standard curve was linear over a working range of 10-3000 ng/ml for all analytes and gave an average correlation coefficient of 0.9992 or better during validation. The absolute recovery for UDCA, GDCA, TDCA and the internal standard was 87.3, 83.7, 79.5 and 95.8%, respectively. This method is simple, sensitive and suitable for pharmacokinetics, bioequivalence or clinical studies. PMID:14643509

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

    SciTech Connect

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

    2012-04-01

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

  15. Host-pathogen interactions. XXIX. Oligogalacturonides released from sodium polypectate by endopolygalacturonic acid lyase are elicitors of phytoalexins in soybean. [Glycine max L

    SciTech Connect

    Davis, K.R.; Darvill, A.G.; Albersheim, P.; Dell, A.

    1986-02-01

    Recent studies have demonstrated that an apparently homogeneous preparation of an ..cap alpha..-1,4-D-endopolygalacturonic acid lyase (EC 4.2,2.2) isolated from the phytopathogenic bacterium Erwinia carotovora induced phytoalexin accumulation in cotyledons of soybean (Glycine max (L.) Merr. cv Wayne) and that this pectin-degrading enzyme released heat-stable elicitors of phytoalexins from soybean cell walls, citrus pectin, and sodium polypectate. The present paper reports the purification, by anion-exchange chromatography on QAE-Sephadex columns followed by gel-permeation chromatography on a Bio-Gel P-6 column, of the two fractions with highest specific elicitor activity present in a crude elicitor-preparation obtained by lyase treatment of sodium polypectate. Structural analysis of the fraction with highest specific elicitor activity indicated that the major, if not only, component was a decasaccharide of ..cap alpha..-1,4-D-galactosyluronic acid that contained the expected product of lyase cleavage, 4-deoxy-..beta..-L-5-threo-hexopyranos-4-enyluronic acid (4,5-unsaturated galactosyluronic acid), at the nonreducing terminus. This modified decagalacturonide fraction exhibited half-maximum and maximum elicitor activity at 1 microgram/cotyledon (6 micromolar) and 5 micrograms/cotyledon (32 micromolar) galactosyluronic acid equivalents, respectively. Reducing 90 to 95% of the carboxyl groups of the galactosyluronic acid residues abolished the elicitor activity of the decagalacturonide fraction. The second most elicitor-active fraction contained mostly undeca-..cap alpha..-1,4-D-galactosyluronic acid that contained 4,5-unsaturated galactosyluronic acid at the nonreducing termini. This fraction exhibited half-maximum and maximum elicitor activity at approximately 3 micrograms/cotyledon (17 micromolar) and 6 micrograms/cotyledon (34 micromolar) galactosyluronic acid equivalents, respectively.

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2015-04-01

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

  18. Studies on optical, mechanical and transport properties of NLO active L-alanine formate single crystal grown by modified Sankaranarayanan Ramasamy (SR) method

    NASA Astrophysics Data System (ADS)

    Justin Raj, C.; Dinakaran, S.; Krishnan, S.; Milton Boaz, B.; Robert, R.; Jerome Das, S.

    2008-04-01

    Bulk single crystals of L-alanine formate of 10 mm diameter and 50 mm length have been grown with an aid of modified Sankaranarayanan-Ramasamy (SR) uniaxial crystal growth method within a period of ten days. The optical properties of the grown crystal were calculated from UV transmission spectral analysis. The second harmonic generation efficiency of the grown crystal was confirmed by Kurtz powder test. In order to determine the mechanical strength of the crystal, Vicker's microhardness test was carried along the growth plane (0 0 1). Dielectric studies reveal that both dielectric constant and dielectric loss decreases with increase in frequency. Photoconductivity study confirms the negative photoconducting nature of the crystal.

  19. Cyanobacterial Blooms and the Occurrence of the neurotoxin beta-N-methylamino-L-alanine (BMAA) in South Florida Aquatic Food Webs

    PubMed Central

    Brand, Larry E.; Pablo, John; Compton, Angela; Hammerschlag, Neil; Mash, Deborah C.

    2010-01-01

    Recent studies demonstrate that most cyanobacteria produce the neurotoxin beta-N-methylamino-L-alanine (BMAA) and that it can biomagnify in at least one terrestrial food chain. BMAA has been implicated as a significant environmental risk in the development of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and Amyotrophic Lateral Sclerosis (ALS). We examined several blooms of cyanobacteria in South Florida, and the BMAA content of resident animals, including species used as human food. A wide range of BMAA concentrations were found, ranging from below assay detection limits to approximately 7000 μg/g, a concentration associated with a potential long-term human health hazard. PMID:21057660

  20. Liquid chromatography and mass spectrometry for the analysis of N-β-methylamino-L-alanine with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate.

    PubMed

    Glover, W Broc; Cohen, Steven A; Murch, Susan J

    2015-01-01

    Numerous studies in the past decade have identified N-β-methylamino-L-alanine (BMAA) as a putative environmental neurotoxin. Produced by cyanobacteria and accumulated at different levels of the trophic system, BMAA has been detected in the brain tissue of human patients that died from progressive neurodegenerative disease. Research into the mechanism of neurotoxicity has been hampered by conflicting results and disagreement in the literature over analytical methods used for quantification and detection. While several research approaches have been tested, the use of the derivatizing reagent 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate is presented here as an effective and selective means for the analysis of BMAA and two co-occurring biological isomers, DAB and AEG, by liquid chromatography and tandem mass spectrometry. PMID:25323521

  1. Tetra­kis-μ-l-alanine-κ8 O:O′-bis­[tetra­aqua­terbium(III)] hexa­perchlorate

    PubMed Central

    Mohamed, Musa E.; Chopra, Deepak; Venugopal, K. N.; Govender, Thavendran; Kruger, Hendrik G.; Maguire, Glenn E. M.

    2010-01-01

    The asymmetric unit of the title compound, [Tb2(C3H7NO2)4(H2O)8](ClO4)6, contains a dinuclear cation and six perchlorate anions, one of which is disordered. In the cation, the four l-alanine mol­ecules are present in their zwitterionic form and bridge two Tb3+ ions through their carboxyl­ate O atoms. Each Tb atom is also coordinated by four water mol­ecules in a square-anti­prismatic geometry. In the crystal structure, the cations and anions are held together via inter­molecular O—H⋯O and N—H⋯O hydrogen bonds. PMID:21579659

  2. Kinetic Studies and Mechanism of Hydrogen Peroxide Catalytic Decomposition by Cu(II) Complexes with Polyelectrolytes Derived from L-Alanine and Glycylglycine

    PubMed Central

    Skounas, Spyridon; Methenitis, Constantinos; Pneumatikakis, George; Morcellet, Michel

    2010-01-01

    The catalytic decomposition of hydrogen peroxide by Cu(II) complexes with polymers bearing L-alanine (PAla) and glycylglycine (PGlygly) in their side chain was studied in alkaline aqueous media. The reactions were of pseudo-first order with respect to [H2O2] and [L-Cu(II)] (L stands for PAla or PGlygly) and the reaction rate was increased with pH increase. The energies of activation for the reactions were determined at pH 8.8, in a temperature range of 293–308 K. A suitable mechanism is proposed to account for the kinetic data, which involves the Cu(II)/Cu(I) redox pair, as has been demonstrated by ESR spectroscopy. The trend in catalytic efficiency is in the order PGlygly>PAla, due to differences in modes of complexation and in the conformation of the macromolecular ligands. PMID:20721280

  3. Animal model of acid-reflux esophagitis: pathogenic roles of acid/pepsin, prostaglandins, and amino acids.

    PubMed

    Takeuchi, Koji; Nagahama, Kenji

    2014-01-01

    Esophagitis was induced in rats within 3 h by ligating both the pylorus and transitional region between the forestomach and glandular portion under ether anesthesia. This esophageal injury was prevented by the administration of acid suppressants and antipepsin drug and aggravated by exogenous pepsin. Damage was also aggravated by pretreatment with indomethacin and the selective COX-1 but not COX-2 inhibitor, whereas PGE2 showed a biphasic effect depending on the dose; a protection at low doses, and an aggravation at high doses, with both being mediated by EP1 receptors. Various amino acids also affected this esophagitis in different ways; L-alanine and L-glutamine had a deleterious effect, while L-arginine and glycine were highly protective, both due to yet unidentified mechanisms. It is assumed that acid/pepsin plays a major pathogenic role in this model of esophagitis; PGs derived from COX-1 are involved in mucosal defense of the esophagus; and some amino acids are protective against esophagitis. These findings also suggest a novel therapeutic approach in the treatment of esophagitis, in addition to acid suppressant therapy. The model introduced may be useful to test the protective effects of drugs on esophagitis and investigate the mucosal defense mechanism in the esophagus. PMID:24672789

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  5. Raman spectra of amino acids and their aqueous solutions

    NASA Astrophysics Data System (ADS)

    Zhu, Guangyong; Zhu, Xian; Fan, Qi; Wan, Xueliang

    2011-03-01

    Amino acids are the basic "building blocks" that combine to form proteins and play an important physiological role in all life-forms. Amino acids can be used as models for the examination of the importance of intermolecular bonding in life processes. Raman spectra serve to obtain information regarding molecular conformation, giving valuable insights into the topology of more complex molecules (peptides and proteins). In this paper, amino acids and their aqueous solution have been studied by Raman spectroscopy. Comparisons of certain values for these frequencies in amino acids and their aqueous solutions are given. Spectra of solids when compared to those of the solute in solution are invariably much more complex and almost always sharper. We present a collection of Raman spectra of 18 kinds of amino acids ( L-alanine, L-arginine, L-aspartic acid, cystine, L-glutamic acid, L-glycine, L-histidine, L-isoluecine, L-leucine, L-lysine, L-phenylalanine, L-methionone, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, L-valine) and their aqueous solutions that can serve as references for the interpretation of Raman spectra of proteins and biological materials.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

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

    PubMed

    Kumari, Shweta; Chang, Sam K C

    2016-07-01

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

  8. Transfer Partial Molar Isentropic Compressibilities of ( l-Alanine/ l-Glutamine/Glycylglycine) from Water to 0.512 {mol} \\cdot {kg}^{-1} Aqueous {KNO}3/0.512 {mol} \\cdot {kg}^{-1} Aqueous {K}2{SO}4 Solutions Between 298.15 K and 323.15 K

    NASA Astrophysics Data System (ADS)

    Riyazuddeen; Gazal, Umaima

    2013-03-01

    Speeds of sound of ( l-alanine/ l-glutamine/glycylglycine + 0.512 {mol}\\cdot {kg}^{-1} aqueous {KNO}3/0.512 {mol}\\cdot {kg}^{-1} aqueous {K}2{SO}4) systems have been measured for several molal concentrations of amino acid/peptide at different temperatures: T = (298.15 to 323.15) K. Using the speed-of-sound and density data, the parameters, partial molar isentropic compressibilities φ _{kappa }0 and transfer partial molar isentropic compressibilities Δ _{tr} φ _{kappa }0, have been computed. The trends of variation of φ _{kappa }0 and Δ _{tr} φ _{kappa }0 with changes in molal concentration of the solute and temperature have been discussed in terms of zwitterion-ion, zwitterion-water dipole, ion-water dipole, and ion-ion interactions operative in the systems.

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

    PubMed

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

    2016-04-19

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

  10. Environmental neurotoxin interaction with proteins: Dose-dependent increase of free and protein-associated BMAA (β-N-methylamino-L-alanine) in neonatal rat brain.

    PubMed

    Karlsson, Oskar; Jiang, Liying; Ersson, Lisa; Malmström, Tim; Ilag, Leopold L; Brittebo, Eva B

    2015-01-01

    β-Methylamino-L-alanine (BMAA) is implicated in the aetiology of neurodegenerative disorders. Neonatal exposure to BMAA induces cognitive impairments and progressive neurodegenerative changes including intracellular fibril formation in the hippocampus of adult rats. It is unclear why the neonatal hippocampus is especially vulnerable and the critical cellular perturbations preceding BMAA-induced toxicity remains to be elucidated. The aim of this study was to compare the level of free and protein-associated BMAA in neonatal rat brain and peripheral tissues after different exposures to BMAA. Ultra-high performance liquid chromatography-tandem mass spectrometry analysis revealed that BMAA passed the neonatal blood-brain barrier and was distributed to all studied brain areas. BMAA was also associated to proteins in the brain, especially in the hippocampus. The level in the brain was, however, considerably lower compared to the liver that is not a target organ for BMAA. In contrast to the liver there was a significantly increased level of protein-association of BMAA in the hippocampus and other brain areas following repeated administration suggesting that the degradation of BMAA-associated proteins may be lower in neonatal brain than in the liver. Additional evidence is needed in support of a role for protein misincorporation in the neonatal hippocampus for long-term effects of BMAA. PMID:26498001

  11. 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.

  12. Structural, vibrational spectroscopic studies and quantum chemical calculations of n-(2,4-dinitrophenyl)-L-alanine methyl ester by density functional theory

    NASA Astrophysics Data System (ADS)

    Govindarasu, K.; Kavitha, E.

    2015-05-01

    In this paper, the vibrational wavenumbers of N-(2,4-dinitrophenyl)-L-alanine methyl ester (abbreviated as Dnp-ala-ome) were obtained from ab initio studies based on the density functional theory approach with B3LYP and M06-2X/6-31G(d,p) level of theories. The optimized geometry and structural features of the most potential nonlinear optical crystal Dnp-ala-ome and the vibrational spectral investigations have been thoroughly described with the FT-Raman and FT-IR spectra supported by the DFT computations. FT-IR (4000-400 cm-1) and FT-Raman spectra (3500-50 cm-1) in the solid phase and the UV-Vis spectra that dissolved in ethanol were recorded in the range of 200-800 nm. The Natural population analysis and natural bond orbital (NBO) analysis have also been carried out to analyze the effects of intramolecular charge transfer, intramolecular and hyperconjugative interactions on the geometries. The effects of frontier orbitals, HOMO and LUMO, transition of electron density transfer have also been discussed. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of Dnp-ala-ome were calculated. In addition, molecular electrostatic potential (MEP) was investigated using theoretical calculations. The chemical reactivity and thermodynamic properties (heat capacity, entropy and enthalpy) of at different temperature are calculated.

  13. Environmental neurotoxin interaction with proteins: Dose-dependent increase of free and protein-associated BMAA (β-N-methylamino-L-alanine) in neonatal rat brain

    PubMed Central

    Karlsson, Oskar; Jiang, Liying; Ersson, Lisa; Malmström, Tim; Ilag, Leopold L.; Brittebo, Eva B.

    2015-01-01

    β-Methylamino-L-alanine (BMAA) is implicated in the aetiology of neurodegenerative disorders. Neonatal exposure to BMAA induces cognitive impairments and progressive neurodegenerative changes including intracellular fibril formation in the hippocampus of adult rats. It is unclear why the neonatal hippocampus is especially vulnerable and the critical cellular perturbations preceding BMAA-induced toxicity remains to be elucidated. The aim of this study was to compare the level of free and protein-associated BMAA in neonatal rat brain and peripheral tissues after different exposures to BMAA. Ultra-high performance liquid chromatography-tandem mass spectrometry analysis revealed that BMAA passed the neonatal blood-brain barrier and was distributed to all studied brain areas. BMAA was also associated to proteins in the brain, especially in the hippocampus. The level in the brain was, however, considerably lower compared to the liver that is not a target organ for BMAA. In contrast to the liver there was a significantly increased level of protein-association of BMAA in the hippocampus and other brain areas following repeated administration suggesting that the degradation of BMAA-associated proteins may be lower in neonatal brain than in the liver. Additional evidence is needed in support of a role for protein misincorporation in the neonatal hippocampus for long-term effects of BMAA. PMID:26498001

  14. Model Studies on the Antioxidative Effect of Polyphenols in Thermally Treated D-Glucose/L-Alanine Solutions with Added Metal Ions.

    PubMed

    Wilker, Daniel; Heinrich, Anna B; Kroh, Lothar W

    2015-12-30

    The influence of different polyphenolic compounds (PPs) on the Maillard reaction in a d-glucose/l-alanine model system with or without metal ions was studied under various reaction conditions. At temperatures up to 100 °C the PPs showed pro-oxidative effects due to their reducing effects on metal ions. This can be explained by a combined redox cycling mechanism of metals and PPs that promotes oxidation in the Maillard reaction. The antioxidative capacities of the PPs were measured with three different assays and correlated directly with their pro-oxidative effects on d-glucosone formation. The degree of the pro-oxidative effect depended not only on the PPs' reducing potential and their antioxidative ability but also on their concentration, the temperature, and the pH value of the model system. At low pH values and temperatures, the PPs were more stable and therefore showed an increased pro-oxidative tendency. In contrast, some of the used PPs were almost completely degraded at temperatures of 130 °C, and the formed polymers were able to complex metal ions. In the absence of these catalyzing ions, the oxidation ratio of d-glucose to d-glucosone was decreased. PMID:26634406

  15. Characterization of mycosporine-serine-glycine methyl ester, a major mycosporine-like amino acid from dinoflagellates: a mass spectrometry study.

    PubMed

    Carignan, Mario O; Carreto, José I

    2013-08-01

    Several unknown mycosporine-like amino acids (MAAs) have been previously isolated from some cultured species of toxic dinoflagellates of the Alexandrium genus (Dinophyceae). One of them, originally called M-333, was tentatively identified as a shinorine methyl ester, but the precise nature of this compound is still unknown. Using a high-resolution reversed-phase liquid chromatography mass spectrometry analyses (HPLC/MS), we found that natural populations of the red tide dinoflagellate Prorocentrum micans Ehrenberg showed a net dominance of M-333 together with lesser amounts of other MAAs. We also documented the isolation and characterization of this MAA from natural dinoflagellate populations and from Alexandrium tamarense (Lebour) Balech cultures. Using a comparative fragmentation study in electrospray mass spectrometry between deuterated and non-deuterated M-333 compounds and synthesized mono and dimethyl esters of shinorine, this novel compound was characterized as mycosporine-serine-glycine methyl ester, a structure confirmed by nuclear magnetic resonance. These isobaric compounds can be differentiated by their fragmentation patterns in MS(3) experiments because the extension and the specific site of the methylation changed the fragmentation pathway. PMID:27007200

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

    PubMed

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

    2002-09-15

    Dengue virus infection causes life-threatening hemorrhagic fever. Increasing evidence implies that dengue viral nonstructural protein 1 (NS1) exhibits a tendency to elicit potentially hazardous autoantibodies, which show a wide spectrum of specificity against extracellular matrix and platelet antigens. How NS1 elicits autoantibodies remains unclear. To address the hypothesis that NS1 and matrix proteins may have structural and functional similarity, cell-matrix and cell-NS1 interactions were evaluated using a cell-adhesion assay. The present study showed that dengue NS1 immobilized on coverslips resulted in more cell adhesion than did the control proteins. This cell adhesion was inhibited by peptides containing arginine-glycine-aspartic acid (RGD), a motif important for integrin-mediated cell adhesion. In addition, anti-NS1 antibodies blocked RGD-mediated cell adhesion. Although there is no RGD motif in the NS1 protein sequence, these data indicate that RGD structural mimicry exists within the NS1 antigen. PMID:12198607

  17. Glycine max cultivar Dare chloroplast fatty acid desaturase 7 (FAD7) gene, complete cds; nuclear gene for chloroplast product

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genomic sequence of soybean GmFAD7 (2455 nucleotides) was determined and reported to GenBank and assigned the accession number HM769340. The structure and deduced amino acid sequence of soybean FAD7 is similar to other higher plant plastidal omega-3 desaturases: 8 exons and 7 introns, predicted...

  18. Glycine max cultivar Dare chloroplast fatty acid desaturase 8 (FAD8) gene, complete cds; nuclear gene for chloroplast product

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genomic sequence of soybean GmFAD8 (2480 nucleotides) was determined and reported to GenBank and assigned the accession number HM769341. The structure and deduced amino acid sequence of soybean FAD8 is similar to other higher plant plastidal omega-3 desaturases: 8 exons and 7 introns, predicted...

  19. Plant and Soil Emissions of Amines and Amino Acids: A Source of Secondary Aerosol Precursors

    NASA Astrophysics Data System (ADS)

    Jackson, M. L.; Doskey, P. V.; Pypker, T. G.

    2011-12-01

    Ammonia (NH3) is the most abundant alkaline gas in the atmosphere and forms secondary aerosol by neutralizing sulfuric and nitric acids that are released during combustion of fossil fuels. Ammonia is primarily emitted by cropping and livestock operations. However, C2 and C3 amines (pKb 3.3-3.4), which are stronger bases than NH3 (pKb 4.7) have been observed in nuclei mode aerosol that is the precursor to secondary aerosol. Mixtures of amines and amino acids have been identified in diverse environments in aerosol, fog water, cloud water, the soluble fraction of precipitation, and in dew. Glycine (pKb 4.2), serine (pKb 4.8) and alanine (pKb 3.7 and 4.1 for the D and L forms, respectively) are typically the most abundant species. The only reported values of gas-phase glycine, serine and alanine were in marine air and ranged from 6-14 pptv. The origin of atmospheric amines and amino acids has not been fully identified, although sources are likely similar to NH3. Nitrate assimilation in plants forms glycine, serine, and L-alanine, while D-alanine is present in bacterial cell walls. Glycine is converted to serine during C3 plant photorespiration, producing CO2 and NH3. Bacteria metabolize glycine and alanine to methylamine and ethylamine via decarboxylation. Likely sources of amino acids are plants and bacteria, thus concentrations near continental sources are likely greater than those measured in marine air. The overall goal of the research is to examine seasonal variations and relationships between the exchange of CO2, NH3, amines, and amino acids with a corn/soybean rotation in the Midwest Corn Belt. The study presents gaseous profiles of organic amine compounds from various species of vegetation using a mist chamber trapping technique and analysis of the derivatized species by high pressure liquid chromatography with fluorescence detection. Amino acid and amine profiles were obtained for red oak (Quercus rubra), sugar maple (Acer saccharinum), white pine (Pinus

  20. Advanced asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by alkylation/cyclization of newly designed axially chiral Ni(II) complex of glycine Schiff base.

    PubMed

    Kawashima, Aki; Shu, Shuangjie; Takeda, Ryosuke; Kawamura, Akie; Sato, Tatsunori; Moriwaki, Hiroki; Wang, Jiang; Izawa, Kunisuke; Aceña, José Luis; Soloshonok, Vadim A; Liu, Hong

    2016-04-01

    Asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is in extremely high demand due to the pharmaceutical importance of this tailor-made, sterically constrained α-amino acid. Here we report the development of an advanced procedure for preparation of the target amino acid via two-step SN2 and SN2' alkylation of novel axially chiral nucleophilic glycine equivalent. Excellent yields and diastereoselectivity coupled with reliable and easy scalability render this method of immediate use for practical synthesis of (1R,2S)-vinyl-ACCA. PMID:26661034

  1. Glycine production in severe childhood undernutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Although nutritionally dispensable amino acids are not essential in the diet, from a biochemical standpoint, dispensable amino acids such as glycine are essential for life. This is especially true under unique circumstances, such as when the availability of labile nitrogen for dispensabl...

  2. Synthesis, spectroscopic, mutagenic, and cytotoxicity studies of some mixed-ligand platinum(II) complexes of 2,2'-bipyridine and amino acids.

    PubMed

    Jain, N; Mital, R; Ray, K S; Srivastava, T S; Bhattacharya, R K

    1987-09-01

    Seven platinum(II) complexes of the type [Pt(bipy)(AA)]n+ (where n = 1 or 0 and AA is anion of L-valine, L-isoleucine, L-aspartic acid (dianion), L-glutamic acid (dianion), L-glutamine, L-proline, or S-methyl-L-cysteine) have been prepared and characterized. The modes of binding of amino acids in these complexes have been ascertained particularly by infrared and 1H NMR spectral studies. The L-glutamine complex shows a ID50 value (50% inhibitory dose) in the range of greater than 20 micrograms/ml to 100 micrograms/ml of the complex. However, the complexes of L-valine, L-isoleucine, L-aspartic acid, L-glutamic acid, L-proline, and S-methyl-L-cysteine show ID50 values greater than 100 micrograms/ml of the complex. The above complexes also show inferior growth inhibition of P-388 cells than platinum(II) complexes of 2,2'-bipyridine with L-alanine, L-leucine, L-methionine, and L-aspargine as reported earlier. The platinum(II) complexes of 2,2'-bipyridine with glycine (Gly), L-alanine (Ala), L-leucine (leu), L-valine (Val), L-methionine (Met), L-phenylalanine (Phe), L-serine (Ser), L-tyrosine (Tyr) and L-tryptophan (Trp) have been tested for mutagenesis using TA 100 and TA 98 strains. They show nonmutagenicity. This is in contrast to the cis-[Pt(NH3)2Cl2] showing a base pair substitution mutagenesis. PMID:3320273

  3. β-N-Methylamino-L-alanine exposure alters defense against oxidative stress in aquatic plants Lomariopsis lineata, Fontinalis antipyretica, Riccia fluitans and Taxiphyllum barbieri.

    PubMed

    Contardo-Jara, Valeska; Funke, Marc Sebastian; Peuthert, Anja; Pflugmacher, Stephan

    2013-02-01

    Four different aquatic plants, the Pteridophyte Lomariopsis lineata and the Bryophytes Fontinalis antipyretica, Riccia fluitans and Taxiphyllum barbieri, were tested for their capacity to absorb the neurotoxin β-N-Methylamino-L-alanine (BMAA) from water and thus their possible applicability in a "Green Liver System". After exposure to 10 and 100 μg L(-1) BMAA for 1, 3, 7 and 14 days exposure concentration of medium and tissue were analyzed by LC-MS/MS. The amount removed by the plants within only 1 day was equal to the biological degradation of 14 days. Comparing the "BMAA-removal" capacity of the 4 tested aquatic plants R. fluitans, L. lineata and T. barbieri turned out to be most effective in cleaning the water from this cyanobacterial toxin by up to 97% within 14 days. Activity of the antioxidant enzymes peroxidase (POD) and catalase (CAT), as well as biotransformation enzyme glutathione S-transferase (GST) was compared between exposed and control plants to determine possible harmful effects induced by BMAA. Whereas the Bryophytes displayed increased POD activity and subsequent adaptation when exposed to the lower concentration, as well as partly inhibited antioxidant response at the higher applied BMAA concentration, the Pteridophyte L. lineata reacted with increased POD activity during the whole experiment and increased GST activity after longer exposure for 14 days. To give a recommendation of the suitability of an aquatic plant to be used for sustainable phytoremediation of contaminated water, testing of removal capacity of specific contaminants as well as studying general physiological parameters giving hint on survivability in such environments has to be combined. PMID:23177931

  4. Genetics of Amino Acid Taste and Appetite.

    PubMed

    Bachmanov, Alexander A; Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Reed, Danielle R; Tordoff, Michael G; Beauchamp, Gary K

    2016-07-01

    The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite. PMID:27422518

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

    PubMed

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

    2011-10-01

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

  6. Optical imaging of head and neck squamous cell carcinoma in vivo using arginine-glycine-aspartic acid peptide conjugated near-infrared quantum dots

    PubMed Central

    Huang, Hao; Bai, Yun-Long; Yang, Kai; Tang, Hong; Wang, You-Wei

    2013-01-01

    Molecular imaging plays a key role in personalized medicine and tumor diagnosis. Quantum dots with near-infrared emission spectra demonstrate excellent tissue penetration and photostability, and have recently emerged as important tools for in vivo tumor imaging. Integrin αvβ3 has been shown to be highly and specifically expressed in endothelial cells of tumor angiogenic vessels in almost all types of tumors, and specifically binds to the peptide containing arginine-glycine-aspartic acid (RGD). In this study, we conjugated RGD with quantum dots with emission wavelength of 800 nm (QD800) to generate QD800-RGD, and used it via intravenous injection as a probe to image tumors in nude mice bearing head and neck squamous cell carcinoma (HNSCC). Twelve hours after the injection, the mice were still alive and were sacrificed to isolate tumors and ten major organs for ex vivo analysis to localize the probe in these tissues. The results showed that QD800-RGD was specifically targeted to integrin αvβ3 in vitro and in vivo, producing clear tumor fluorescence images after the intravenous injection. The tumor-to-background ratio and size of tumor image were highest within 6 hours of the injection and declined significantly at 9 hours after the injection, but there was still a clearly visible tumor image at 12 hours. The greatest amount of QD800-RGD was found in liver and spleen, followed by tumor and lung, and a weak fluorescence signal was seen in tibia. No detectable signal of QD800-RGD was found in brain, heart, kidney, testis, stomach, or intestine. Our study demonstrated that using integrin αvβ3 as target, it is possible to use intravenously injected QD800-RGD to generate high quality images of HNSCC, and the technique offers great potential in the diagnosis and personalized therapy for HNSCC. PMID:24324343

  7. Amino acid specificity of fibers of the facial/trigeminal complex innervating the maxillary barbel in the Japanese sea catfish, Plotosus japonicus.

    PubMed

    Caprio, John; Shimohara, Mami; Marui, Takayuki; Kohbara, Jun; Harada, Shuitsu; Kiyohara, Sadao

    2015-12-01

    The Japanese sea catfish, Plotosus japonicus, possesses taste and solitary chemoreceptor cells (SCCs) located on the external body surface that detect specific water-soluble substances. Here, we identify two major fiber types of the facial/trigeminal complex that transmit amino acid information to the medulla. Both single and few fiber preparations respond to amino acid stimulation in the 0.1 μM to mM range. One fiber type responds best to glycine and l-alanine (i.e. Gly/Ala fibers) whereas the other fiber type is best stimulated by l-proline and glycine betaine (hereafter referred to only as betaine) (i.e. Pro/Bet fibers). We demonstrate that betaine, which does not alter the pH of the seawater and therefore does not activate the animals' highly sensitive pH sensors (Caprio et al., Science 344:1154-1156, 2014), is sufficient to elicit appetitive food search behavior. We further show that the amino acid specificity of fibers of the facial/trigeminal complex in P. japonicus is different from that in Ariopsis felis (Michel and Caprio, J. Neurophysiol. 66:247-260, 1991; Michel et al., J. Comp. Physiol. A. 172:129-138, 1993), a representative member of the only other family (Ariidae) of extant marine catfishes. PMID:26459116

  8. 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.

  9. Shock synthesis of amino acids from impacting cometary and icy planet surface analogues

    NASA Astrophysics Data System (ADS)

    Martins, Zita; Price, Mark C.; Goldman, Nir; Sephton, Mark A.; Burchell, Mark J.

    2013-12-01

    Comets are known to harbour simple ices and the organic precursors of the building blocks of proteins--amino acids--that are essential to life. Indeed, glycine, the simplest amino acid, was recently confirmed to be present on comet 81P/Wild-2 from samples returned by NASA's Stardust spacecraft. Impacts of icy bodies (such as comets) onto rocky surfaces, and, equally, impacts of rocky bodies onto icy surfaces (such as the jovian and saturnian satellites), could have been responsible for the manufacture of these complex organic molecules through a process of shock synthesis. Here we present laboratory experiments in which we shocked ice mixtures analogous to those found in a comet with a steel projectile fired at high velocities in a light gas gun to test whether amino acids could be produced. We found that the hypervelocity impact shock of a typical comet ice mixture produced several amino acids after hydrolysis. These include equal amounts of D- and L-alanine, and the non-protein amino acids α-aminoisobutyric acid and isovaline as well as their precursors. Our findings suggest a pathway for the synthetic production of the components of proteins within our Solar System, and thus a potential pathway towards life through icy impacts.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Amide-conjugated indole-3-acetic acid and adventitious root formation in mung bean cuttings

    SciTech Connect

    Norcini, J.G.

    1986-01-01

    The purpose of this research was to investigate further the relationship between amide-conjugated auxin and adventitious root formation. Indoleacetylaspartic acid (IAA-aspartate) was positively identified as the predominant conjugate isolated from mung bean cuttings after the cuttings has been treated with 10/sup -3/ M IAA. In cuttings treated with (1-/sup 14/C)IAA immediately after excision (0 hr), the percent of extractable /sup 14/C in IAA-aspartate in the hypocotyl sharply increased until 36 hr, then steadily declined. (/sup 14/C)IAA was completely metabolized between 12 and 24 hr. The rooting activities of IAA-L-aspartate, IAA-L-alanine, and IAA-glycine were determined at various stages of root formation; some cuttings were pretreated with 10/sup -3/ M IAA at 0 hr. Pretreated cuttings that were treated with IAA-glycine at 12, 24, 36 hr exhibited the greatest consistency between replications, the greatest number of long roots, and the longest roots. The conjugates did not stimulate rooting as effectively as IAA, yet like IAA, generally enhanced rooting the greatest when applied before the first cell division (24 hr).

  12. ALS-linked SOD1 in glial cells enhances ß-N-Methylamino L-Alanine (BMAA)-induced toxicity in Drosophila

    PubMed Central

    Islam, Rafique; Zhang, Bing

    2012-01-01

    Environmental factors have been implicated in the etiology of a number of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). However, the role of environmental agents in ALS remains poorly understood. To this end, we used transgenic fruit flies (Drosophila melanogaster) to explore the interaction between mutant superoxide dismutase 1 (SOD1) and chemicals such as ß-N-methylamino L-alanine (BMAA), the herbicide agent paraquat, and superoxide species. We expressed ALS-linked human SOD1 (hSOD1A4V, and hSOD1G85R), hSOD1wt as well as the Drosophila native SOD1 (dSOD1) in motoneurons (MNs) or in glial cells alone and simultaneously in both types of cells. We then examined the effect of BMAA (3 mM), paraquat (20 mM), and hydrogen peroxide (H2O2, 1%) on the lifespan of SOD1-expressing flies. Our data show that glial expression of mutant and wild type hSOD1s reduces the ability of flies to climb. Further, we show that while all three chemicals significantly shorten the lifespan of flies, mutant SOD1 does not have a significant additional effect on the lifespan of flies fed on paraquat, but further shortens the lifespan of flies fed on H2O2. Finally, we show that BMAA shows a dramatic cell-type specific effect with mutant SOD1. Flies with expression of mutant hSOD1 in MNs survived longer on BMAA compared to control flies. In contrast, BMAA significantly shortened the lifespan of flies expressing mutant hSOD1 in glia. Consistent with a neuronal protection role, flies expressing these mutant hSOD1s in both MNs and glia also lived longer. Hence, our studies reveal a synergistic effect of mutant SOD1 with H2O2 and novel roles for mutant hSOD1s in neurons to reduce BMAA toxicity and in glia to enhance the toxicity of BMAA in flies. PMID:24627764

  13. Identification and functional characterization of a novel low affinity aromatic-preferring amino acid transporter (arpAT). One of the few proteins silenced during primate evolution.

    PubMed

    Fernández, Esperanza; Torrents, David; Zorzano, Antonio; Palacín, Manuel; Chillarón, Josep

    2005-05-13

    We have identified in silico arpAT, a gene encoding a new member of the LSHAT family, and cloned it from kidney. Co-expression of arpAT with the heavy subunits rBAT or 4F2hc elicited a sodium-independent alanine transport activity in HeLa cells. L-tyrosine, l-3,4-dihydroxyphenylalanine (L-DOPA), L-glutamine, L-serine, L-cystine, and L-arginine were also transported. Kinetic and cis-inhibition studies showed a K(m) = 1.59 +/- 0.24 mM for L-alanine or IC50 in the millimolar range for most amino acids, except L-proline, glycine, anionic and D-amino acids, which were not inhibitory. L-DOPA and L-tyrosine were the most effective competitive inhibitors of L-alanine transport, with IC50 values of 272.2 +/- 57.1 and 716.3 +/- 112.4 microM, respectively. In the small intestine, arpAT mRNA was located at the enterocytes, in a decreasing gradient from the crypts to the tip of the villi. It was also expressed in neurons from different brain areas. Finally, we show that while the arpAT gene is conserved in rat, dog, and chicken, it has become silenced in humans and chimpanzee. Actually, it has been recently reported that it is one of the 33 recently inactivated genes in the human lineage. The evolutionary implications of the silencing process and the roles of arpAT in transport of L-DOPA in the brain and in aromatic amino acid absorption are discussed. PMID:15757906

  14. Peptide coupling between amino acids and the carboxylic acid of a functionalized chlorido-gold(I)-phosphane.

    PubMed

    Kriechbaum, Margit; List, Manuela; Himmelsbach, Markus; Redhammer, Günther J; Monkowius, Uwe

    2014-10-01

    We have developed a protocol for the direct coupling between methyl ester protected amino acids and the chlorido-gold(I)-phosphane (p-HOOC(C6H4)PPh2)AuCl. By applying the EDC·HCl/NHS strategy (EDC·HCl = N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide hydrochloride, NHS = N-hydroxysuccinimide), the methyl esters of l-phenylalanine, glycine, l-leucine, l-alanine, and l-methionine are coupled with the carboxylic acid of the gold complex in moderate to good yields (62-88%). All amino acid tagged gold complexes were characterized by (1)H and (13)C NMR spectroscopy and high-resolution mass spectrometry. As corroborated by measurement of the angle of optical rotation, no racemization occurred during the reaction. The molecular structure of the leucine derivative was determined by single-crystal X-ray diffraction. In the course of developing an efficient coupling protocol, the acyl chlorides (p-Cl(O)C(C6H4)PPh2)AuX (X = Cl, Br) were also prepared and characterized. PMID:25203269

  15. Spectroscopic studies on covalent functionalization of single-walled carbon nanotubes with glycine.

    PubMed

    Deborah, M; Jawahar, A; Mathavan, T; Kumara Dhas, M; Benial, A Milton Franklin

    2014-10-22

    Single-walled carbon nanotubes (SWCNTs) have a great potential in a wide range of applications, but faces limitation in terms of dispersion feasibility. The functionalization process of SWCNTs with the amino acid, glycine involves oxidation reaction using a mild aqueous acid mixture of HNO3 and H2SO4 (1:3), via ultrasonication technique and the resulted oxidized SWCNTs were again treated with the amino acid glycine suspension. The resulted glycine functionalized carbon nanotubes have been characterized by XRD, UV-Vis, FTIR, EPR, SEM, and EDX, spectroscopic techniques. The enhanced XRD peak (002) intensity was observed for glycine functionalized SWCNTs compared with oxidized SWCNTs, which is likely due to sample purification by acid washing. The red shift was observed in the UV-Vis spectra of glycine functionalized SWCNTs, which reveals that the covalent bond formation between glycine molecule and SWCNTs. The functional groups of oxidized SWCNTs and glycine functionalized SWCNTs were identified and assigned. EPR results indicate that the unpaired electron undergoes reduction process in glycine functionalized SWCNTs. SEM images show that the increase in the diameter of the SWCNTs was observed for glycine functionalized SWCNTs, which indicates that the adsorption of glycine molecule on the sidewalls of oxidized SWCNTs. EDX elemental micro analysis confirms that the nitrogen element exists in glycine functionalized SWCNTs. The functionalization has been chosen due to CONH bioactive sites in glycine functionalized SWCNTs for future applications. PMID:25448929

  16. UDP-N-Acetylmuramic Acid l-Alanine Ligase (MurC) Inhibition in a tolC Mutant Escherichia coli Strain Leads to Cell Death

    PubMed Central

    Humnabadkar, Vaishali; Prabhakar, K. R.; Narayan, Ashwini; Sharma, Sreevalli; Guptha, Supreeth; Manjrekar, Praveena; Chinnapattu, Murugan; Ramachandran, Vasanthi; Hameed, Shahul P.; Ravishankar, Sudha

    2014-01-01

    The Mur ligases play an essential role in the biosynthesis of bacterial peptidoglycan and hence are attractive antibacterial targets. A screen of the AstraZeneca compound library led to the identification of compound A, a pyrazolopyrimidine, as a potent inhibitor of Escherichia coli and Pseudomonas aeruginosa MurC. However, cellular activity against E. coli or P. aeruginosa was not observed. Compound A was active against efflux pump mutants of both strains. Experiments using an E. coli tolC mutant revealed accumulation of the MurC substrate and a decrease in the level of product upon treatment with compound A, indicating inhibition of MurC enzyme in these cells. Such a modulation was not observed in the E. coli wild-type cells. Further, overexpression of MurC in the E. coli tolC mutant led to an increase in the compound A MIC by ≥16-fold, establishing a correlation between MurC inhibition and cellular activity. In addition, estimation of the intracellular compound A level showed an accumulation of the compound over time in the tolC mutant strain. A significant compound A level was not detected in the wild-type E. coli strain even upon treatment with high concentrations of the compound. Therefore, the lack of MIC and absence of MurC inhibition in wild-type E. coli were possibly due to suboptimal compound concentration as a consequence of a high efflux level and/or poor permeativity of compound A. PMID:25114134

  17. 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.

  18. Identification and characterization of heptapeptide modulators of the glycine receptor.

    PubMed

    Cornelison, Garrett L; Pflanz, Natasha C; Tipps, Megan E; Mihic, S John

    2016-06-01

    The glycine receptor is a member of the Cys-loop receptor superfamily of ligand-gated ion channels and is implicated as a possible therapeutic target for the treatment of diseases such as alcoholism and inflammatory pain. In humans, four glycine receptor subtypes (α1, α2, α3, and β) co-assemble to form pentameric channel proteins as either α homomers or αβ heteromers. To date, few agents have been identified that can selectively modulate the glycine receptor, especially those possessing subtype specificity. We used a cell-based method of phage display panning, coupled with two-electrode voltage-clamp electrophysiology in Xenopus laevis oocytes, to identify novel heptapeptide modulators of the α1β glycine receptor. This involved a panning procedure in which the phage library initially underwent subtractive panning against Human Embryonic Kidney (HEK) 293 cells expressing alternative glycine receptor subtypes before panning the remaining library over HEK 293 cells expressing the target, the α1β glycine receptor. Peptides were identified that act with selectivity on α1β and α3β, compared to α2β, glycine receptors. In addition, peptide activity at the glycine receptor decreased when zinc was chelated by tricine, similar to previous observations of a decrease in ethanol's enhancing actions at the receptor in the absence of zinc. Comparisons of the amino acid sequences of heptapeptides capable of potentiating glycine receptor function revealed several consensus sequences that may be predictive of a peptide's enhancing ability. PMID:27038522

  19. Preferential Treatment: Interaction Between Amino Acids and Minerals

    NASA Astrophysics Data System (ADS)

    Crapster-Pregont, E. J.; Cleaves, H. J.; Hazen, R. M.

    2008-12-01

    Amino acids are the building blocks of proteins and are important for some models of the origin of life. Polymerization of amino acids from dilute solution is unlikely without a scaffold or catalyst. The surfaces of early Earth minerals are the most likely candidates for this role. The surface adsorption behavior of 12 amino acids (L-alanine, L-serine, L-aspartic acid, L-proline, L- phenylalanine, L-valine, L-arginine, d-amino valeric acid, glycine, L-lysine, L-isoleucine, and B-alanine) on 21 minerals (quartz, calcite, enstatite, illite, olivine, pyrrhotite, pyrite, alkali basalt, albite, analcime, chlorite, barite, hydroxyl apatite, hematite, magnetite, aluminum hydroxide, kaolin, silica gel, corundum, rutile, and montmorillonite) was determined via batch adsorption experiments. Absorption was determined for concentrations between 10-4M and 10-6M in the presence of 0.1M NaCl, and between pH values of 3 and 9 at 25 degrees C. The equilibrated solutions were centrifuged, filtered, derivatized using a fluorescent amino group tag (dansyl-chloride) and analyzed by HPLC. Adsorption was standardized using BET surface area measurements for each mineral to give the number of mols of each amino acid adsorbed per square meter for each mineral. The results indicate an enormous difference in the adsorption of amino acids between minerals, along with major differences in the adsorption of individual amino acids on the same mineral surface. There is also a change in the absorbance of amino acids as the pH changes. Many previous studies of amino acid concentration and catalysis by minerals have used clay minerals because of their high surface areas, however, this data suggests that the surfaces of minerals such as calcite, quartz and pyrite have even higher affinities for amino acids. The results suggest mineral surfaces that could be optimal locations for the polymerization of molecules linked to the origin of life.

  20. The origin of amino acids in lunar regolith samples

    NASA Astrophysics Data System (ADS)

    Elsila, Jamie E.; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; McLain, Hannah L.; Noble, Sarah K.; Gibson, Everett K.

    2016-01-01

    We analyzed the amino acid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed amino acids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5-651.1 ppb in 6 M HCl acid-vapor-hydrolyzed, hot-water extracts. Amino acids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: α-aminoisobutyric acid (AIB), D- and L-β-amino-n-butyric acid (β-ABA), DL-α-amino-n-butyric acid, γ-amino-n-butyric acid, β-alanine, and ε-amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic amino acids, but racemic alanine and racemic β-ABA were present in some samples. We also examined seven samples from Apollo 15, 16, and 17 that had been previously allocated to a non-curation laboratory, as well as two samples of terrestrial dunite from studies of lunar module engine exhaust that had been stored in the same laboratory. The amino acid content of these samples suggested that contamination had occurred during non-curatorial storage. We measured the compound-specific carbon isotopic ratios of glycine, β-alanine, and L-alanine in Apollo regolith sample 70011 and found values of -21‰ to -33‰. These values are consistent with those seen in terrestrial biology and, together with the enantiomeric compositions of the proteinogenic amino acids, suggest that terrestrial biological contamination is a primary source of the

  1. Effect of amino acid additives on the growth and physical properties of potassium acid phthalate (KAP) crystals

    NASA Astrophysics Data System (ADS)

    Kumaran, A. Elakkina; Kanchana, P.; Sekar, C.

    2012-06-01

    Single crystals of potassium acid phthalate (KAP) have been grown from aqueous solution by slow evaporation technique by adding L-alanine (LA), glycine (Gly) and L-tyrosine (LT) as additives. Powder X-ray diffraction studies confirmed the phase formation and amino acids doping into KAP crystals. The optical absorption studies reveal that the LA doped crystals possess less absorption of visible ray than the pristine, Gly and LT doped KAP crystals. Optical transmission is found to be low in LT doped KAP than in all the other crystals. TG-DTA studies show the decomposition temperatures to be 255 °C, 232 °C, 258 °C and 264 °C for pure, LA, Gly and LT doped KAP crystals respectively. SHG efficiency of LA doped KAP crystal was found to be 1.1 times (31 mV for KDP and 34 mV for LA doped KAP) that of potassium dihydrogen phosphate (KDP) crystal. This is much higher when compared to that of undoped KAP crystal (12 mV). The grown crystals were also subjected to FTIR, microhardness and dielectric studies.

  2. Zinc Modulation of Glycine Receptors

    PubMed Central

    Trombley, Paul Q.; Blakemore, Laura J.; Hill, Brook J.

    2011-01-01

    Glycine receptors are widely expressed in the mammalian central nervous system, and previous studies have demonstrated that glycine receptors are modulated by endogenous zinc. Zinc is concentrated in synaptic vesicles in several brain regions but is particularly abundant in the hippocampus and olfactory bulb. In the present study, we used patch-clamp electrophysiology of rat hippocampal and olfactory bulb neurons in primary culture to examine the effects of zinc on glycine receptors. Although glycine has been reported to reach millimolar concentrations during synaptic transmission, most previous studies on the effects of zinc on glycine receptors have used relatively low concentrations of glycine. High concentrations of glycine cause receptor desensitization. Our current results extend our previous demonstration that the modulatory actions of zinc are largely prevented when co-applied with desensitizing concentrations of glycine (300 μM), suggesting that the effects of zinc are dependent on the state of the receptor. In contrast, pre-application of 300 μM zinc, prior to glycine (300 μM) application, causes a slowly developing inhibition with a slow rate of recovery, suggesting that the timing of zinc and glycine release also influences the effects of zinc. Furthermore, previous evidence suggests that synaptically released zinc can gain intracellular access, and we provide the first demonstration that low concentrations of intracellular zinc can potentiate glycine receptors. These results support the notion that zinc has complex effects on glycine receptors and multiple factors may interact to influence the efficacy of glycinergic transmission. PMID:21530619

  3. Synthesis of 3,4-dihydro-2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxides and their evaluation as ligands for NMDA receptor glycine binding site.

    PubMed

    Bluke, Zanda; Paass, Einars; Sladek, Meik; Abel, Ulrich; Kauss, Valerjans

    2016-08-01

    A series of 2-substituted 3,4-dihydro-2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxides were synthesized and evaluated for their affinity to the glycine binding site of the N-methyl-d-aspartate (NMDA) receptor. The binding affinity was determined by the displacement of radioligand [(3)H]MDL-105,519 from rat cortical membrane preparations. The most attractive structures in the search for prospective NMDA receptor ligands were identified to be 2-arylcarbonylmethyl substituted 3,4-dihydro-2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxides. It has been demonstrated for the first time that the replacement of NH group in the ligand by sp(3) CH2 is tolerated. This finding may pave the way for previously unexplored approaches for designing new ligands of the NMDA receptor. PMID:26114309

  4. Aza-Glycine Induces Collagen Hyperstability.

    PubMed

    Zhang, Yitao; Malamakal, Roy M; Chenoweth, David M

    2015-10-01

    Hydrogen bonding is fundamental to life on our planet, and nature utilizes H-bonding in nearly all biomolecular interactions. Often, H-bonding is already maximized in natural biopolymer systems such as nucleic acids, where Watson-Crick H-bonds are fully paired in double-helical structures. Synthetic chemistry allows molecular editing of biopolymers beyond nature's capability. Here we demonstrate that substitution of glycine (Gly) with aza-glycine in collagen may increase the number of interfacial cross-strand H-bonds, leading to hyperstability in the triple-helical form. Gly is the only amino acid that has remained intolerant to substitution in collagen. Our results highlight the vital importance of maximizing H-bonding in higher order biopolymer systems using minimally perturbing alternatives to nature's building blocks. PMID:26368649

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

    SciTech Connect

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

    1985-01-01

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

  6. Identification of combined conjugation of nabumetone phase I metabolites with glucuronic acid and glycine in minipig biotransformation using coupling high-performance liquid chromatography with electrospray ionization mass spectrometry.

    PubMed

    Česlová, Lenka; Holčapek, Michal; Nobilis, Milan

    2014-01-01

    High-performance liquid chromatography (HPLC) coupled with electrospray ionization mass spectrometry (ESI-MS) was applied for the analysis of nabumetone metabolites during the biotransformation in minipigs. In addition to known phase I metabolites, the identification of phase II metabolites was achieved on the basis of their full-scan mass spectra and subsequent MS(n) analysis using both positive-ion and negative-ion ESI mode. Some phase I metabolites are conjugated with both glucuronide acid and glycine, which is quite unusual type of phase II metabolite not presented so far for nabumetone. These metabolites were found in small intestine content, but they were absent in minipigs urine. PMID:24083957

  7. Supported absorption of CO2 by tetrabutylphosphonium amino acid ionic liquids.

    PubMed

    Zhang, Jianmin; Zhang, Suojiang; Dong, Kun; Zhang, Yanqiang; Shen, Youqing; Lv, Xingmei

    2006-05-15

    A new type of "task specific ionic liquid", tetrabutylphosphonium amino acid [P(C4)4][AA], was synthesized by the reaction of tetrabutylphosphonium hydroxide [P(C4)4][OH] with amino acids, including glycine, L-alanine, L-beta-alanine, L-serine, and L-lysine. The liquids produced were characterized by NMR, IR spectroscopies, and elemental analysis, and their thermal decomposition temperature, glass transition temperature, electrical conductivity, density, and viscosity were recorded in detail. The [P(C4)4][AA] supported on porous silica gel effected fast and reversible CO2 absorption when compared with bubbling CO2 into the bulk of the ionic liquid. No changes in absorption capacity and kinetics were found after four cycles of absorption/desorption. The CO2 absorption capacity at equilibrium was 50 mol % of the ionic liquids. In the presence of water (1 wt %), the ionic liquids could absorb equimolar amounts of CO2. The CO2 absorption mechanisms of the ionic liquids with and without water were different. PMID:16528787

  8. Ultrasonic absorption in aqueous solutions of amino acids at neutral pH

    NASA Astrophysics Data System (ADS)

    Nishikawa, S.; Ohno, T.; Huang, H.; Yoshizuka, K.; Jordan, F.

    2003-05-01

    Ultrasonic absorption coefficients in aqueous solutions of glycine, L-alanine, imidazole, L-phenylalanine, L-histidine and L-tryptophan at neutral pH were measured in the range from 0.8 to 220 MHz at 25 °C. A characteristic ultrasonic relaxation phenomenon was observed only in the solution of L-histidine with a relaxation frequency at around 2 MHz at neutral pH. It was proposed from the concentration independent relaxation frequency and the linear concentration dependence of the maximum absorption per wavelength that the relaxation mechanism was associated with a perturbation of the rotational isomeric equilibrium of the L-histidine molecule. The existence of two rotational isomeric forms of L-histidine in water was examined by semiempirical quantum chemical methods, in order to determine the free energy difference between the two states. The forward and backward rate constants were determined from the relaxation frequency and the energy change. Also, the standard volume change of the reaction was estimated from the concentration dependence of the maximum absorption per wavelength. It was speculated that L-histidine fulfills a specific function among amino acids because of the rotational motion in the molecule, in addition to its well-established acid-base properties.

  9. Cometary Glycine Detected in Samples Returned by Stardust

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

  10. 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. PMID:26821380

  11. 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

  12. 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.

  13. 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.

  14. 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.

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

    PubMed

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

    2016-01-01

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

  16. 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

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2005-06-01

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

  19. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  20. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  1. Polymers from amino acids: development of dual ester-urethane melt condensation approach and mechanistic aspects.

    PubMed

    Anantharaj, S; Jayakannan, M

    2012-08-13

    A new dual ester-urethane melt condensation methodology for biological monomers-amino acids was developed to synthesize new classes of thermoplastic polymers under eco-friendly and solvent-free polymerization approach. Naturally abundant L-amino acids were converted into dual functional ester-urethane monomers by tailor-made synthetic approach. Direct polycondensation of these amino acid monomers with commercial diols under melt condition produced high molecular weight poly(ester-urethane)s. The occurrence of the dual ester-urethane process and the structure of the new poly(ester-urethane)s were confirmed by (1)H and (13)C NMR. The new dual ester-urethane condensation approach was demonstrated for variety of amino acids: glycine, β-alanine, L-alanine, L-leucine, L-valine, and L-phenylalanine. MALDI-TOF-MS end group analysis confirmed that the amino acid monomers were thermally stable under the melt polymerization condition. The mechanism of melt process and the kinetics of the polycondensation were studied by model reactions and it was found that the amino acid monomer was very special in the sense that their ester and urethane functionality could be selectively reacted by polymerization temperature or catalyst. The new polymers were self-organized as β-sheet in aqueous or organic solvents and their thermal properties such as glass transition temperature and crystallinity could be readily varied using different l-amino acid monomers or diols in the feed. Thus, the current investigation opens up new platform of research activates for making thermally stable and renewable engineering thermoplastics from natural resource amino acids. PMID:22713137

  2. 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. PMID:26563333

  3. Ditetraalkylammonium amino acid ionic liquids as CO₂ absorbents of high capacity.

    PubMed

    Ma, Jing-Wen; Zhou, Zheng; Zhang, Feng; Fang, Cheng-Gang; Wu, You-Ting; Zhang, Zhi-Bing; Li, Ai-Min

    2011-12-15

    By grafting butyl or ethyl onto tetramethylethylenediamine, quaternary ammonium salts with two positive charge centers were formed at the first step. Metathesis with Ag(2)O followed. Through neutralization with glycine, l-alanine, or valine, a series of new ditetraalkylammonium amino acid ionic liquids (DILs) for CO(2) capture were generated. The structures of DILs, as shown in Figure 1, were verified by using (1)H NMR and EA. These DILs were found to be of quite high viscosity which militated against their industrial application in CO(2) removal. Drawing on the experience of mixed amines' aqueous solutions, these DILs were blended with water or N-methyldiethanolamine (MDEA) aqueous solutions to act as special absorbents of CO(2). Using a Double-Tank Absorption System, the absorption performance of these DIL solutions was investigated in detail. The experimental results indicated that among the three aqueous solutions of DILs (20%, 40%, and 80 wt %), the solution of 40% DIL had a higher absorption rate of CO(2) than the other two, demonstrating the different effects of concentration and viscosity on the absorption. The solution of 40% DIL or the 15% DIL + 15% MDEA had much higher capacity for CO(2) than the corresponding monocation tetraalkylammonium AAILs, due to the special structure of the dication which could influence the solubility of CO(2) in the aqueous solution. PMID:22066493

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

    PubMed

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

    2010-10-01

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

  5. 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

  6. Glycine metabolism in rat kidney cortex slices.

    PubMed

    Rowsell, E V; Al-Naama, M M; Rowsell, K V

    1982-04-15

    When rat kidney cortex slices were incubated with glycine or [1-14C]glycine, after correcting for metabolite changes with control slices, product formation and glycine utilization fitted the requirements of the equation: 2 Glycine leads to ammonia + CO2 + serine. Evidence is presented that degradation via glyoxylate, by oxidation or transamination, is unlikely to have any significant role in kidney glycine catabolism. It is concluded that glycine metabolism in rat kidney is largely via glycine cleavage closely coupled with serine formation. 1-C decarboxylation and urea formation with glycine in rat hepatocyte suspensions were somewhat greater than decarboxylation or ammonia formation in kidney slices, showing that in the rat, potentially, the liver is quantitatively the more important organ in glycine catabolism. There was no evidence of ammonia formation from glycine with rat brain cortex, heart, spleen or diaphragm and 1-C decarboxylation was very weak. PMID:6810880

  7. 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.

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

    SciTech Connect

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

    2015-04-15

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

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

    PubMed

    Choudhary, Krishna Kumar; Agrawal, Shashi Bhushan

    2016-01-01

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

  10. Mathematical Model of Metabolism and Electrophysiology of Amino Acid and Glucose Stimulated Insulin Secretion: In Vitro Validation Using a β-Cell Line

    PubMed Central

    Salvucci, Manuela; Neufeld, Zoltan; Newsholme, Philip

    2013-01-01

    We integrated biological experimental data with mathematical modelling to gain insights into the role played by L-alanine in amino acid-stimulated insulin secretion (AASIS) and in D-glucose-stimulated insulin secretion (GSIS), details important to the understanding of complex β-cell metabolic coupling relationships. We present an ordinary differential equations (ODEs) based simplified kinetic model of core metabolic processes leading to ATP production (glycolysis, TCA cycle, L-alanine-specific reactions, respiratory chain, ATPase and proton leak) and Ca2+ handling (essential channels and pumps in the plasma membrane) in pancreatic β-cells and relate these to insulin secretion. Experimental work was performed using a clonal rat insulin-secreting cell line (BRIN-BD11) to measure the consumption or production of a range of important biochemical parameters (D-glucose, L-alanine, ATP, insulin secretion) and Ca2+ levels. These measurements were then used to validate the theoretical model and fine-tune the parameters. Mathematical modelling was used to predict L-lactate and L-glutamate concentrations following D-glucose and/or L-alanine challenge and Ca2+ levels upon stimulation with a non metabolizable L-alanine analogue. Experimental data and mathematical model simulations combined suggest that L-alanine produces a potent insulinotropic effect via both a stimulatory impact on β-cell metabolism and as a direct result of the membrane depolarization due to Ca2+ influx triggered by L-alanine/Na+ co-transport. Our simulations indicate that both high intracellular ATP and Ca2+ concentrations are required in order to develop full insulin secretory responses. The model confirmed that K+ATP channel independent mechanisms of stimulation of intracellular Ca2+ levels, via generation of mitochondrial coupling messengers, are essential for promotion of the full and sustained insulin secretion response in β-cells. PMID:23520444

  11. Validation of the analytical procedure for the determination of the neurotoxin β-N-methylamino-L-alanine in complex environmental samples.

    PubMed

    Combes, Audrey; El Abdellaoui, Saïda; Sarazin, Cédric; Vial, Jérome; Mejean, Annick; Ploux, Olivier; Pichon, Valérie

    2013-04-10

    The neurotoxic l-2-amino-3-methylaminopropionic acid (BMAA) was hypothesized to be involved in sporadic cases of amyotrophic lateral sclerosis (ALS). Studies highlighting a possible implication of environmental factors in the incidence of sporadic ALS have become more numerous over recent years. Over the past years, the most widely used method for quantifying BMAA was based on the derivatization of this polar and basic molecule with a fluorescent compound (6-aminoquinolonyl-N-hydroxysuccinimidyl, 6-AQC). This derivatization allows the retention of the conjugate by reversed-phase liquid chromatography and its detection by fluorescence. Nevertheless, recent findings have shown that this method applied to complex samples may cause false positive responses. We therefore developed an analytical procedure for the determination of underivatized BMAA at trace level in complex environmental matrices (river water, cyanobacteria and biofilm) using solid-phase extraction (SPE) based on mixed mode sorbent to concentrate and clean up real samples. Analyzes were performed by hydrophilic interaction chromatography (HILIC) coupled to electrospray ionization and tandem mass spectrometry used in multiple reaction monitoring scan mode. Analytical procedures were validated for the different natural samples using the total error approach. BMAA can be quantified by these reliable and highly selective analytical methods in a range of only a few ng mL(-1) in river water and a few ng mg(-1) dry weight in cyanobacteria and biofilm matrices. PMID:23522111

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

    PubMed

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

    2015-06-01

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

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

    PubMed

    Bualuang, Aporn; Incharoensakdi, Aran

    2015-02-01

    Alkaliphilic halotolerant cyanobacterium Aphanothece halophytica showed optimal growth in the medium containing 0.5 M NaCl. The increase of exogenously added glycine to the medium up to 10 mM significantly promoted cell growth under both normal (0.5 M NaCl) and salt stress (2.0 M NaCl) conditions. Salt stress imposed by either 2.0 or 3.0 M NaCl retarded cell growth; however, exogenously added glycine at 10 mM concentration to salt-stress medium resulted in the reduction of growth inhibition particularly under 3.0 M NaCl condition. The uptake of glycine by intact A. halophytica was shown to exhibit saturation kinetics with an apparent K s of 160 μM and V max of 3.9 nmol/min/mg protein. The optimal pH for glycine uptake was at pH 8.0. The uptake activity was decreased in the presence of high concentration of NaCl. Both metabolic inhibitors and ionophores decreased glycine uptake in A. halophytica suggesting an energy-dependent glycine uptake. Several neutral amino acids showed considerable inhibition of glycine uptake with higher than 50 % inhibition observed with serine, cysteine and alanine whereas acidic, basic and aromatic amino acids showed only slight inhibition of glycine uptake. PMID:25536900

  14. 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.

  15. Stereospecificity of reactions catalyzed by bacterial D-amino acid transaminase.

    PubMed

    Martínez del Pozo, A; Merola, M; Ueno, H; Manning, J M; Tanizawa, K; Nishimura, K; Soda, K; Ringe, D

    1989-10-25

    The spectral shift from 420 to 338 nm when pure bacterial D-amino acid transaminase binds D-amino acid substrates is also exhibited in part by high concentrations of L-amino acids (L-alanine and L-glutamate) but not by simple dicarboxylic acids or monoamines. Slow processing of L-alanine to D-alanine was observed both by coupled enzymatic assays using D-amino acid oxidase and by high pressure liquid chromatography analysis employing an optically active chromophore (Marfey's reagent). When the acceptor for L-alanine was alpha-ketoglutarate, D-glutamate was also formed. This minor activity of the transaminase involved both homologous (L-alanine and D-alanine) and heterologous (L-alanine and D-glutamate) substrate pairs and was a function of the nature of the keto acid acceptor. In the presence of alpha-ketoisovalerate, DL-alanine was almost completely processed to D-valine; within the limits of the assay no L-valine was detected. With alpha-ketoisocaproate, 90% of the DL-alanine was converted to D-leucine. In the mechanism of this transaminase reaction, there may be more stereoselective constraints for the protonation of the quinonoid intermediate during the second half-reaction of the transamination reaction, i.e. the donation of the amino group from the pyridoxamine 5'-phosphate coenzyme to a second keto acid acceptor, than during removal of the alpha proton in the initial steps of the reaction pathway. Thus, with this D-amino acid transaminase, the discrete steps of transamination ensure fidelity of the stereospecificity of reaction pathway. PMID:2808352

  16. 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.

  17. Felbamate increases [3H]glycine binding in rat brain and sections of human postmortem brain.

    PubMed

    McCabe, R T; Sofia, R D; Layer, R T; Leiner, K A; Faull, R L; Narang, N; Wamsley, J K

    1998-08-01

    The anticonvulsant compound felbamate (2-phenyl-1,3-propanediol dicarbamate; FBM) appears to inhibit the function of the N-methyl-D-aspartate (NMDA) receptor complex through an interaction with the strychnine-insensitive glycine recognition site. Since we have demonstrated previously that FBM inhibits the binding of [3H]5, 7-dichlorokynurenic acid (DCKA), a competitive antagonist at the glycine site, we assessed the ability of FBM to modulate the binding of an agonist, [3H]glycine, to rat forebrain membranes and human brain sections. In contrast to its ability to inhibit [3H]5,7-DCKA binding, FBM increased [3H]glycine binding (20 nM; EC50 = 485 microM; Emax = 211% of control; nH = 1.8). FBM, but not carbamazepine, phenytoin, valproic acid or phenobarbital, also increased [3H]glycine binding (50 nM; EC50 = 142 microM; Emax = 157% of control; nH = 1.6) in human cortex sections. Autoradiographic analysis of human brain slices demonstrated that FBM produced the largest increases in [3H]glycine binding in the cortex, hippocampus and the parahippocampal gyrus. Because various ions can influence the binding of glycine-site ligands, we assessed their effects on FBM-modulation of [3H]glycine binding. FBM-enhanced [3H]glycine binding was attenuated by Zn++ and not inhibited by Mg++ in human brain. These results suggest that FBM increases [3H]glycine binding in a manner sensitive to ions which modulate the NMDA receptor. These data support the hypothesis that FBM produces anticonvulsant and neuroprotective effects by inhibiting NMDA receptor function, likely through an allosteric modulation of the glycine site. PMID:9694960

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

    PubMed

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

    2016-01-01

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

  19. Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and Schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

    NASA Astrophysics Data System (ADS)

    Boghaei, Davar M.; Gharagozlou, Mehrnaz

    2007-07-01

    A series of new ternary zinc(II) complexes [Zn(L 1-10)(phen)], where phen is 1,10-phenanthroline and H 2L 1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, L-phenylalanine, L-valine, L-alanine, and L-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δ ν ( νas(COO) - νs(COO)) of 191-225 cm -1, indicating a monodentate coordination of the carboxylate group. Spectral data showed that in these ternary complexes the zinc atom is coordinated with the Schiff base ligand acts as a tridentate ONO moiety, coordinating to the metal through its phenolic oxygen, imine nitrogen, and carboxyl oxygen, and also with the neutral planar chelating ligand, 1,10-phenanthroline, coordinating through nitrogens.

  20. Fate of microbial nitrogen, carbon, hydrolysable amino acids, monosaccharides, and fatty acids in sediment

    NASA Astrophysics Data System (ADS)

    Veuger, Bart; van Oevelen, Dick; Middelburg, Jack J.

    2012-04-01

    The fate of microbial carbon, nitrogen, hydrolysable amino acids (HAAs), monosaccharides, and fatty acids in sediment was investigated experimentally. The microbial community of a tidal flat sediment was labeled with 13C-enriched glucose and 15N-enriched ammonium, and sediment was incubated for up to 371 days. Analysis of total concentrations and 13C- and 15N content of bulk sediment, hydrolysable amino acids (including D-alanine), monosaccharides, total fatty acids (TFAs), and phospholipid-derived fatty acids (PLFAs) allowed us to trace the fate of microbial biomass and -detritus and the major biochemical groups therein (proteins, carbohydrates, and lipids) over intermediate time scales (weeks-months). Moreover, the unidentified fraction of the labeled material (i.e. not analyzed as HAA, FA, or carbohydrate) provided information on the formation and fate of molecularly uncharacterizable organic matter. Loss of 13C and 15N from the sediment was slow (half live of 433 days) which may have been due to the permanently anoxic conditions in the experiment. Loss rates for the different biochemical groups were also low with the following order of loss rate constants: PLFA > TFA > HAA > monosaccharides. The unidentified 13C-pool was rapidly formed (within days) and then decreased relatively slowly, resulting in a gradual relative accumulation of this pool over time. Degradation and microbial reworking of the labeled material resulted in subtle, yet consistent, diagenetic changes within the different biochemical groups. In the HAA pool, glycine, lysine, and proline were lost relatively slowly (i.e. best preserved) while there was no accumulation of D-alanine relative to L-alanine, indicating no relative accumulation of bacterial macromolecules rich in D-alanine. In the fatty acid pool, there was very little difference between PLFAs and TFAs, indicating a very similar lability of these pools. Differences between individual fatty acids included a relatively slow loss of i15

  1. Quality measures of imaging mass spectrometry aids in revealing long-term striatal protein changes induced by neonatal exposure to the cyanobacterial toxin β-N-methylamino-L-alanine (BMAA).

    PubMed

    Karlsson, Oskar; Bergquist, Jonas; Andersson, Malin

    2014-01-01

    Many pathological processes are not directly correlated to dramatic alterations in protein levels. The changes in local concentrations of important proteins in a subset of cells or at specific loci are likely to play a significant role in disease etiologies, but the precise location might be unknown, or the concentration might be too small to be adequately sampled for traditional proteomic techniques. Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) is a unique analytical method that combines analysis of multiple molecular species and of their distribution in a single platform. As reproducibility is essential for successful biomarker discovery, it is important to systematically assess data quality in biologically relevant MALDI IMS experiments. In the present study, we applied four simple tools to study the reproducibility for individual sections, within-group variation, and between-group variation of data acquired from brain sections of 21 animals divided into three treatment groups. We also characterized protein changes in distinct regions of the striatum from six-month-old rats treated neonatally (postnatal days 9-10) with the cyanobacterial toxin β-N-methylamino-l-alanine (BMAA), which has been implicated in neurodegenerative diseases. The results showed that optimized experimental settings can yield high-quality MALDI IMS data with relatively low variation (14% to 15% coefficient of variance) that allow the characterization of subtle changes in protein expression in various subregions of the brain. This was further exemplified by the dose-dependent reduction of myelin basic protein in the caudate putamen and the nucleus accumbens of adult rats neonatally treated with BMAA (150 and 460 mg/kg). The reduction in myelin basic protein was confirmed through immunohistochemistry and indicates that developmental exposure to BMAA may induce structural effects on axonal growth and/or directly on the proliferation of oligodendrocytes

  2. Quality Measures of Imaging Mass Spectrometry Aids in Revealing Long-term Striatal Protein Changes Induced by Neonatal Exposure to the Cyanobacterial Toxin β-N-methylamino-L-alanine (BMAA)*

    PubMed Central

    Karlsson, Oskar; Bergquist, Jonas; Andersson, Malin

    2014-01-01

    Many pathological processes are not directly correlated to dramatic alterations in protein levels. The changes in local concentrations of important proteins in a subset of cells or at specific loci are likely to play a significant role in disease etiologies, but the precise location might be unknown, or the concentration might be too small to be adequately sampled for traditional proteomic techniques. Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) is a unique analytical method that combines analysis of multiple molecular species and of their distribution in a single platform. As reproducibility is essential for successful biomarker discovery, it is important to systematically assess data quality in biologically relevant MALDI IMS experiments. In the present study, we applied four simple tools to study the reproducibility for individual sections, within-group variation, and between-group variation of data acquired from brain sections of 21 animals divided into three treatment groups. We also characterized protein changes in distinct regions of the striatum from six-month-old rats treated neonatally (postnatal days 9–10) with the cyanobacterial toxin β-N-methylamino-l-alanine (BMAA), which has been implicated in neurodegenerative diseases. The results showed that optimized experimental settings can yield high-quality MALDI IMS data with relatively low variation (14% to 15% coefficient of variance) that allow the characterization of subtle changes in protein expression in various subregions of the brain. This was further exemplified by the dose-dependent reduction of myelin basic protein in the caudate putamen and the nucleus accumbens of adult rats neonatally treated with BMAA (150 and 460 mg/kg). The reduction in myelin basic protein was confirmed through immunohistochemistry and indicates that developmental exposure to BMAA may induce structural effects on axonal growth and/or directly on the proliferation of oligodendrocytes

  3. Association study of polymorphisms in the neutral amino acid transporter genes SLC1A4, SLC1A5 and the glycine transporter genes SLC6A5, SLC6A9 with schizophrenia

    PubMed Central

    Deng, Xiangdong; Sagata, Noriaki; Takeuchi, Naoko; Tanaka, Masami; Ninomiya, Hideaki; Iwata, Nakao; Ozaki, Norio; Shibata, Hiroki; Fukumaki, Yasuyuki

    2008-01-01

    Background Based on the glutamatergic dysfunction hypothesis for schizophrenia pathogenesis, we have been performing systematic association studies of schizophrenia with the genes involved in glutametergic transmission. We report here association studies of schizophrenia with SLC1A4, SLC1A5 encoding neutral amino acid transporters ASCT1, ASCT2, and SLC6A5, SLC6A9 encoding glycine transporters GLYT2, GLYT1, respectively. Methods We initially tested the association of 21 single nucleotide polymorphisms (SNPs) distributed in the four gene regions with schizophrenia using 100 Japanese cases-control pairs and examined allele, genotype and haplotype association with schizophrenia. The observed nominal significance were examined in the full-size samples (400 cases and 420 controls). Results We observed nominally significant single-marker associations with schizophrenia in SNP2 (P = 0.021) and SNP3 (P = 0.029) of SLC1A4, SNP1 (P = 0.009) and SNP2 (P = 0.022) of SLC6A5. We also observed nominally significant haplotype associations with schizophrenia in the combinations of SNP2-SNP7 (P = 0.037) of SLC1A4 and SNP1-SNP4 (P = 0.043) of SLC6A5. We examined all of the nominal significance in the Full-size Sample Set, except one haplotype with insufficient LD. The significant association of SNP1 of SLC6A5 with schizophrenia was confirmed in the Full-size Sample Set (P = 0.018). Conclusion We concluded that at least one susceptibility locus for schizophrenia may be located within or nearby SLC6A5, whereas SLC1A4, SLC1A5 and SLC6A9 are unlikely to be major susceptibility genes for schizophrenia in the Japanese population. PMID:18638388

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

    PubMed

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

    2014-08-01

    Phagocytes form engulfment pseudopodia at the contact area with their target particle by a process resembling cell volume (CV) regulatory mechanisms. We evaluated whether the osmoregulatory active neutral amino acid glycine, which contributes to CV regulation via activation of sodium-dependent neutral amino acid transporters (SNATs) improves phagocytosis in isotonic and hypertonic conditions in the murine microglial cell line BV-2 and primary microglial cells (pMG). In BV-2 cells and pMG, RT-PCR analysis revealed expression of SNATs (Slc38a1, Slc38a2), but not of GlyRs (Glra1-4). In BV-2 cells, glycine (5 mM) led to a rapid Na(+)-dependent depolarization of membrane potential (V mem). Furthermore, glycine increased CV by about 9%. Visualizing of phagocytosis of polystyrene microspheres by scanning electron microscopy revealed that glycine (1 mM) increased the number of BV-2 cells containing at least one microsphere by about 13%. Glycine-dependent increase in phagocytosis was suppressed by the SNAT inhibitor α-(methylamino)isobutyric acid (MeAIB), by replacing extracellular Na(+) with choline, and under hypertonic conditions, but not by the GlyR antagonist strychnine or the GlyR agonist taurine. Interestingly, hypertonicity-induced suppression of phagocytosis was rescued by glycine. These findings demonstrate that glycine increases phagocytosis in iso- and hypertonic conditions by activation of SNATs. PMID:24760586

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

    SciTech Connect

    Garrod, Robin T.

    2013-03-01

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

  6. A Three-phase Chemical Model of Hot Cores: The Formation of Glycine

    NASA Astrophysics Data System (ADS)

    Garrod, Robin T.

    2013-03-01

    A new chemical model is presented that simulates fully coupled gas-phase, grain-surface, and bulk-ice chemistry in hot cores. Glycine (NH2CH2COOH), the simplest amino acid, and related molecules such as glycinal, propionic acid, and propanal, are included in the chemical network. Glycine is found to form in moderate abundance within and upon dust-grain ices via three radical-addition mechanisms, with no single mechanism strongly dominant. Glycine production in the ice occurs over temperatures ~40-120 K. Peak gas-phase glycine fractional abundances lie in the range 8 × 10-11-8 × 10-9, occurring at ~200 K, the evaporation temperature of glycine. A gas-phase mechanism for glycine production is tested and found insignificant, even under optimal conditions. A new spectroscopic radiative-transfer model is used, allowing the translation and comparison of the chemical-model results with observations of specific sources. Comparison with the nearby hot-core source NGC 6334 IRS1 shows excellent agreement with integrated line intensities of observed species, including methyl formate. The results for glycine are consistent with the current lack of a detection of this molecule toward other sources; the high evaporation temperature of glycine renders the emission region extremely compact. Glycine detection with ALMA is predicted to be highly plausible, for bright, nearby sources with narrow emission lines. Photodissociation of water and subsequent hydrogen abstraction from organic molecules by OH, and NH2, are crucial to the buildup of complex organic species in the ice. The inclusion of alternative branches within the network of radical-addition reactions appears important to the abundances of hot-core molecules; less favorable branching ratios may remedy the anomalously high abundance of glycolaldehyde predicted by this and previous models.

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

    PubMed

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

    1995-05-01

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

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

    PubMed Central

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

    1995-01-01

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

  9. Mutations in NADH:ubiquinone oxidoreductase of Escherichia coli affect growth on mixed amino acids.

    PubMed Central

    Prüss, B M; Nelms, J M; Park, C; Wolfe, A J

    1994-01-01

    We isolated and characterized mutants defective in nuo, encoding NADH dehydrogenase I, the multisubunit complex homologous to eucaryotic mitochondrial complex I. By Southern hybridization and/or sequence analysis, we characterized three distinct mutations: a polar insertion designated nuoG::Tn10-1, a nonpolar insertion designated nuoF::Km-1, and a large deletion designated delta(nuoFGHIJKL)-1. Cells carrying any of these three mutations exhibited identical phenotypes. Each mutant exhibited reduced NADH oxidase activity, grew poorly on minimal salts medium containing acetate as the sole carbon source, and failed to produce the inner, L-aspartate chemotactic band on tryptone swarm plates. During exponential growth in tryptone broth, nuo mutants grew as rapidly as wild-type cells and excreted similar amounts of acetate into the medium. As they began the transition to stationary phase, in contrast to wild-type cells, the mutant cells abruptly slowed their growth and continued to excrete acetate. The growth defect was entirely suppressed by L-serine or D-pyruvate, partially suppressed by alpha-ketoglutarate or acetate, and not suppressed by L-aspartate or L-glutamate. We extended these studies, analyzing the sequential consumption of amino acids by both wild-type and nuo mutant cells growing in tryptone broth. During the lag and exponential phases, both wild-type and mutant cells consumed, in order, L-serine and L-aspartate. As they began the transition to stationary phase, both cell types consumed L-tryptophan. Whereas wild-type cells then consumed L-glutamate, glycine, L-threonine, and L-alanine, mutant cells utilized these amino acids poorly. We propose that cells defective for NADH dehydrogenase I exhibit all these phenotypes, because large NADH/NAD+ ratios inhibit certain tricarboxylic acid cycle enzymes, e.g., citrate synthase and malate dehydrogenase. Images PMID:8157582

  10. Modulation of inhibitory glycine receptors in cultured embryonic mouse hippocampal neurons by zinc, thiol containing redox agents and carnosine.

    PubMed

    Thio, L L; Zhang, H X

    2006-01-01

    Modulation of inhibitory glycine receptors by zinc (Zn(2+)) and endogenous redox agents such as glutathione may alter inhibition in the mammalian brain. Despite the abundance of Zn(2+) in the hippocampus and its ability to modulate glycine receptors, few studies have examined Zn(2+) modulation of hippocampal glycine receptors. Whether redox agents modulate hippocampal glycine receptors also remains unknown. This study examined Zn(2+) and redox modulation of glycine receptor-mediated currents in cultured embryonic mouse hippocampal neurons using whole-cell recordings. Zn(2+) concentrations below 10 microM potentiated currents elicited by low glycine, beta-alanine, and taurine concentrations by 300-400%. Zn(2+) concentrations above 300 microM produced nearly complete inhibition. Potentiating Zn(2+) concentrations shifted the dose-response curves for the three agonists to the left and decreased the Hill coefficient for glycine and beta-alanine but not taurine. Inhibiting Zn(2+) concentrations shifted the dose-response curves for glycine and beta-alanine to the right but reduced the maximum taurine response. Histidine residues may participate in potentiation because diethyl pyrocarbonate and pH 5.4 diminished Zn(2+) enhancement of glycine currents. pH 5.4 diminished Zn(2+) block of glycine currents, but diethyl pyrocarbonate did not. These findings indicate that separate sites mediate Zn(2+) potentiation and inhibition. The redox agents glutathione, dithiothreitol, tris(2-carboxyethyl)phosphine, and 5,5'-dithiobis(2-nitrobenzoic acid) did not alter glycine currents by a redox mechanism. However, glutathione and dithiothreitol interfered with the effects of Zn(2+) on glycine currents by chelating it. Carnosine had similar effects. Thus, Zn(2+) and thiol containing redox agents that chelate Zn(2+) modulate hippocampal glycine receptors with the mechanism of Zn(2+) modulation being agonist dependent. PMID:16515845

  11. Electrophysiological Signature of Homomeric and Heteromeric Glycine Receptor Channels.

    PubMed

    Raltschev, Constanze; Hetsch, Florian; Winkelmann, Aline; Meier, Jochen C; Semtner, Marcus

    2016-08-19

    Glycine receptors are chloride-permeable, ligand-gated ion channels and contribute to the inhibition of neuronal firing in the central nervous system or to facilitation of neurotransmitter release if expressed at presynaptic sites. Recent structure-function studies have provided detailed insights into the mechanisms of channel gating, desensitization, and ion permeation. However, most of the work has focused only on comparing a few isoforms, and among studies, different cellular expression systems were used. Here, we performed a series of experiments using recombinantly expressed homomeric and heteromeric glycine receptor channels, including their splice variants, in the same cellular expression system to investigate and compare their electrophysiological properties. Our data show that the current-voltage relationships of homomeric channels formed by the α2 or α3 subunits change upon receptor desensitization from a linear to an inwardly rectifying shape, in contrast to their heteromeric counterparts. The results demonstrate that inward rectification depends on a single amino acid (Ala(254)) at the inner pore mouth of the channels and is closely linked to chloride permeation. We also show that the current-voltage relationships of glycine-evoked currents in primary hippocampal neurons are inwardly rectifying upon desensitization. Thus, the alanine residue Ala(254) determines voltage-dependent rectification upon receptor desensitization and reveals a physio-molecular signature of homomeric glycine receptor channels, which provides unprecedented opportunities for the identification of these channels at the single cell level. PMID:27382060

  12. 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.

  13. 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.

  14. 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.

  15. About the detectability of glycine in the interstellar medium

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

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

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

    SciTech Connect

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

    2014-08-08

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

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  18. Determination of glycine in biofluid by hydrophilic interaction chromatography coupled with tandem mass spectrometry and its application to the quantification of glycine released by embryonal carcinoma stem cells.

    PubMed

    Tang, Ya-Bin; Teng, Lin; Sun, Fan; Wang, Xiao-Lin; Peng, Liang; Cui, Yong-Yao; Hu, Jin-Jia; Luan, Xin; Zhu, Liang; Chen, Hong-Zhuan

    2012-09-15

    Because glycine plays a prominent role in living creatures, an accurate and precise quantitative analysis method for the compound is needed. Herein, a new approach to analyze glycine by hydrophilic interaction chromatography (HILIC) coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) was developed. This method avoids the use of derivatization and/or ion-pairing reagents. N-methyl-D-aspartate (NMDA) is used as the internal standard (IS). The mobile phase for the isocratic elution consisted of 10 mM ammonium formate in acetonitrile-water (70:30, v/v, adjusted to pH 2.8 with formic acid), and a flow rate of 250 μL/min was used. Two microliters of sample was injected for analysis. The signal was monitored in the positive multiple reaction monitoring (MRM) mode. The total run time was 5 min. The dynamic range was 40-2000 ng/mL for glycine in the biological matrix. The LLOQ (lower limit of quantification) of this method was 40 ng/mL (80 pg on column). The validated method was applied to determine the dynamic release of glycine from P19 embryonal carcinoma stem cells (ECSCs). Glycine spontaneously released from the ECSCs into the intercellular space gradually increased from 331.02±60.36 ng/mL at 2 min in the beginning to 963.52±283.80 ng/mL at 60 min and 948.27±235.09 ng/mL at 120 min, finally reaching a plateau, indicating that ECSCs consecutively release glycine until achieving equilibration between the release and the reuptake of the compound; on the contrary, the negative control NIH/3T3 embryonic fibroblast cells did not release glycine. This finding will help to improve our understanding of the novel effects of neurotransmitters, including glycine, on non-neural systems. PMID:22906796

  19. Ionic conductivity, sintering and thermal expansion behaviors of mixed ion conductor BaZr 0.1Ce 0.7Y 0.1Yb 0.1O 3- δ prepared by ethylene diamine tetraacetic acid assisted glycine nitrate process

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaoliang; Liu, Limin; Zhen, Jiangman; Zhu, Shengcai; Li, Baowen; Sun, Kening; Wang, Peng

    BaZr 0.1Ce 0.7Y 0.1Yb 0.1O 3- δ as a candidate electrolyte material is prepared by ethylene diamine tetraacetic acid assisted glycine-nitrate process. After calcining at 900 °C, the single-phase perovskite is obtained due to the better distribution of starting materials and the more feasible reaction kinetic conditions than solid state reaction method. The relative densities reach 96.8 and 98.4% respectively after sintering the pressed pellets at 1280 and 1400 °C for 10 h. In humidified oxygen the ionic conductivities are 0.015, 0.045, 0.101 and 0.207 S cm -1 at 500, 600, 700 and 800 °C, respectively. In air and humidified oxygen the activation energies for ionic conductivity are 66.1 and 68.9 kJ mol -1. In humidified hydrogen, however, different activation energies occur in low and high temperature ranges. The thermal expansion curve inflections at 500-800 °C with respect to possible phase changes are found. Zirconia aggregation possibly results in the higher activation energy and peculiar thermal expansion behavior. The results indicate the ethylene diamine tetraacetic acid assisted glycine-nitrate process is a very promising preparation method for solid oxide fuel cell practical application.

  20. Glycine transporter 1 is a target for the treatment of epilepsy.

    PubMed

    Shen, Hai-Ying; van Vliet, Erwin A; Bright, Kerry-Ann; Hanthorn, Marissa; Lytle, Nikki K; Gorter, Jan; Aronica, Eleonora; Boison, Detlev

    2015-12-01

    Glycine is the major inhibitory neurotransmitter in brainstem and spinal cord, whereas in hippocampus glycine exerts dual modulatory roles on strychnine-sensitive glycine receptors and on the strychnine-insensitive glycineB site of the N-methyl-D-aspartate receptor (NMDAR). In hippocampus, the synaptic availability of glycine is largely under control of glycine transporter 1 (GlyT1). Since epilepsy is a disorder of disrupted network homeostasis affecting the equilibrium of various neurotransmitters and neuromodulators, we hypothesized that changes in hippocampal GlyT1 expression and resulting disruption of glycine homeostasis might be implicated in the pathophysiology of epilepsy. Using two different rodent models of temporal lobe epilepsy (TLE)--the intrahippocampal kainic acid model of TLE in mice, and the rat model of tetanic stimulation-induced TLE--we first demonstrated robust overexpression of GlyT1 in the hippocampal formation, suggesting dysfunctional glycine signaling in epilepsy. Overexpression of GlyT1 in the hippocampal formation was corroborated in human TLE samples by quantitative real time PCR. In support of a role of dysfunctional glycine signaling in the pathophysiology of epilepsy, both the genetic deletion of GlyT1 in hippocampus and the GlyT1 inhibitor LY2365109 increased seizure thresholds in mice. Importantly, chronic seizures in the mouse model of TLE were robustly suppressed by systemic administration of the GlyT1 inhibitor LY2365109. We conclude that GlyT1 overexpression in the epileptic brain constitutes a new target for therapeutic intervention, and that GlyT1 inhibitors constitute a new class of antiictogenic drugs. These findings are of translational value since GlyT1 inhibitors are already in clinical development to treat cognitive symptoms in schizophrenia. PMID:26302655

  1. New Insights into Amino Acid Preservation in the Early Oceans using Modern Analytical Techniques

    NASA Astrophysics Data System (ADS)

    Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J.

    2015-12-01

    Protein- and non-protein-amino acids likely occupied the oceans at the time of the origin and evolution of life. Primordial soup-, hydrothermal vent-, and meteoritic-processes likely contributed to this early chemical inventory. Prebiotic synthesis and carbonaceous meteorite studies suggest that non-protein amino acids were likely more abundant than their protein-counterparts. Amino acid preservation before abiotic and biotic destruction is key to biomarker availability in paleoenvironments and remains an important uncertainty. To constrain primitive amino acid lifetimes, a 1992 archived seawater/beach sand mixture was spiked with D,L-alanine, D,L-valine (Val), α-aminoisobutyric acid (α-AIB), D,L-isovaline (Iva), and glycine (Gly). Analysis by high performance liquid chromatography with fluorescence detection (HPLC-FD) showed that only D-Val and non-protein amino acids were abundant after 2250 days. The mixture was re-analyzed in 2012 using HPLC-FD and a triple quadrupole mass spectrometer (QqQ-MS). The analytical results 20 years after the inception of the experiment were strikingly similar to those after 2250 days. To confirm that viable microorganisms were still present, the mixture was re-spiked with Gly in 2012. Aliquots were collected immediately after spiking, and at 5- and 9-month intervals thereafter. Final HPLC-FD/QqQ-MS analyses were performed in 2014. The 2014 analyses revealed that only α-AIB, D,L-Iva, and D-Val remained abundant. The disappearance of Gly indicated that microorganisms still lived in the mixture and were capable of consuming protein amino acids. These findings demonstrate that non-protein amino acids are minimally impacted by biological degradation and thus have very long lifetimes under these conditions. Primitive non-protein amino acids from terrestrial synthesis, or meteorite in-fall, likely experienced greater preservation than protein amino acids in paleo-oceanic environments. Such robust molecules may have reached a steady

  2. New Insights into Amino Acid Preservation in the Early Oceans Using Modern Analytical Techniques

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Brinton, Karen L.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.; Bada, Jeffrey L.

    2015-01-01

    Protein- and non-protein-amino acids likely occupied the oceans at the time of the origin and evolution of life. Primordial soup-, hydrothermal vent-, and meteoritic-processes likely contributed to this early chemical inventory. Prebiotic synthesis and carbonaceous meteorite studies suggest that non-protein amino acids were likely more abundant than their protein-counterparts. Amino acid preservation before abiotic and biotic destruction is key to biomarker availability in paleoenvironments and remains an important uncertainty. To constrain primitive amino acid lifetimes, a 1992 archived seawater/beach sand mixture was spiked with D,L-alanine, D,L-valine (Val), alpha-aminoisobutyric acid (alpha-AIB), D,L-isovaline (Iva), and glycine (Gly). Analysis by high performance liquid chromatography with fluorescence detection (HPLC-FD) showed that only D-Val and non-protein amino acids were abundant after 2250 days. The mixture was re-analyzed in 2012 using HPLC-FD and a triple quadrupole mass spectrometer (QqQ-MS). The analytical results 20 years after the inception of the experiment were strikingly similar to those after 2250 days. To confirm that viable microorganisms were still present, the mixture was re-spiked with Gly in 2012. Aliquots were collected immediately after spiking, and at 5- and 9-month intervals thereafter. Final HPLC-FD/QqQ-MS analyses were performed in 2014. The 2014 analyses revealed that only alpha-AIB, D,L-Iva, and D-Val remained abundant. The disappearance of Gly indicated that microorganisms still lived in the mixture and were capable of consuming protein amino acids. These findings demonstrate that non-protein amino acids are minimally impacted by biological degradation and thus have very long lifetimes under these conditions. Primitive non-protein amino acids from terrestrial synthesis, or meteorite in-fall, likely experienced great-er preservation than protein amino acids in paleo-oceanic environments. Such robust molecules may have reached a

  3. Theoretical model of the interaction of glycine with hydrogenated amorphous carbon (HAC).

    PubMed

    Timón, Vicente; Gálvez, Óscar; Maté, Belén; Tanarro, Isabel; Herrero, Víctor J; Escribano, Rafael

    2015-11-21

    A theoretical model of hydrogenated amorphous carbon (HAC) is developed and applied to study the interaction of glycine with HAC surfaces at astronomical temperatures. Two models with different H content are tried for the HAC surface. The theory is applied at the Density Functional Theory (DFT) level, including a semiempirical dispersion correlation potential, d-DFT or Grimme DFT-D2. The level of theory is tested on glycine adsorption on a Si(001) surface. Crystalline glycine is also studied in its two stable phases, α and β, and the metastable γ phase. For the adsorption on Si or HAC surfaces, molecular glycine is introduced in the neutral and zwitterionic forms, and the most stable configurations are searched. All theoretical predictions are checked against experimental observations. HAC films are prepared by plasma enhanced vapor deposition at room temperature. Glycine is deposited at 20 K into a high vacuum, cold temperature chamber, to simulate astronomical conditions. Adsorption takes place through the acidic group COO(-) and when several glycine molecules are present, they form H-bond chains among them. Comparison between experiments and predictions suggests that a possible way to improve the theoretical model would require the introduction of aliphatic chains or a polycyclic aromatic core. The lack of previous models to study the interaction of amino-acids with HAC surfaces provides a motivation for this work. PMID:26456640

  4. 75 FR 62141 - Glycine From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-07

    ... glycine from China (60 FR 16116). Following first five-year reviews by Commerce and the Commission... from China (65 FR 45752). Following second five-year reviews by Commerce and the Commission, effective... glycine from China (70 FR 69316). The Commission is now conducting a third review to determine...

  5. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The...

  6. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The...

  7. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The...

  8. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Glycine. 172.812 Section 172.812 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.812 Glycine. The...

  9. Dissociation of gaseous zwitterion glycine-betaine by slow electrons.

    PubMed

    Kopyra, J; Abdoul-Carime, H

    2010-05-28

    In this work, we investigate dissociation processes induced by low-energy electrons to gas phase N,N,N-trimethylglycine [glycine-betaine, (CH(3))(3)N(+)CH(2)COO(-)] 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[Single Bond]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. PMID:20515090

  10. Biological activities of indoleacetylamino acids and their use as auxins in tissue culture

    SciTech Connect

    Hangarter, R.P.; Peterson, M.D.; Good, N.E.

    1980-05-01

    The auxin activities of a number of indoleacetylamino acid conjugates have been determined in three test systems: growth of tomato hypocotyl explants (Lycopersicon esculentum Mill. cv. Marglobe); growth of tobacco callus cultures (Nicotiana tabacum L. cv. Wisconsin 38); and ethylene production from pea stems (Pisum sativum L. cv. Alaska). The activities of the conjugates differ greatly depending on the amino acid moiety. Indoleacetyl-L-alanine supports rapid callus growth from the tomato hypocotyls while inhibiting growth of shoots and roots. Indoleacetlyglycine behaves in a similar manner but is somewhat less effective in supporting callus growth and in inhibiting growth of shoots and roots. Indoleacetylglycine behaves in a similar manner but is somewhat less effective in supporting callus growth and in inhibiting shoot formation. The other amino acid conjugates tested (valine, leucine, aspartic acid, threonine, methionine, phenylalanine, and proline) support shoot formation without supporting root formation or much callus growth. The tobacco callus system, which forms abundant shoots in the presence or absence of free indoleacetic acid, produces only rapid undifferentiated growth in the presence of indoleacetyl-L-alanine and indoleacetylglycine. The other conjugates inhibit shoot formatin weakly if at all. Most of the conjugates induce sustained ethylene production from the pea stems but at rates well below the initial rates observed with free indoleacetic acid. Many, but not all of the effects of conjugates such as indoleacetyl-L-alanine can be mimicked by frequent renewals of the supply of free indoleacetic acid.

  11. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions

    PubMed Central

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard

    2015-01-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. 13C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using 3H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  12. Intracellular Accumulation of Glycine in Polyphosphate-Accumulating Organisms in Activated Sludge, a Novel Storage Mechanism under Dynamic Anaerobic-Aerobic Conditions.

    PubMed

    Nguyen, Hien Thi Thu; Kristiansen, Rikke; Vestergaard, Mette; Wimmer, Reinhard; Nielsen, Per Halkjær

    2015-07-01

    Dynamic anaerobic-aerobic feast-famine conditions are applied to wastewater treatment plants to select polyphosphate-accumulating organisms to carry out enhanced biological phosphorus removal. Acetate is a well-known substrate to stimulate this process, and here we show that different amino acids also are suitable substrates, with glycine as the most promising. (13)C-labeled glycine and nuclear magnetic resonance (NMR) were applied to investigate uptake and potential storage products when activated sludge was fed with glycine under anaerobic conditions. Glycine was consumed by the biomass, and the majority was stored intracellularly as free glycine and fermentation products. Subsequently, in the aerobic phase without addition of external substrate, the stored glycine was consumed. The uptake of glycine and oxidation of intracellular metabolites took place along with a release and uptake of orthophosphate, respectively. Fluorescence in situ hybridization combined with microautoradiography using (3)H-labeled glycine revealed uncultured actinobacterial Tetrasphaera as a dominant glycine consumer. Experiments with Tetrasphaera elongata as representative of uncultured Tetrasphaera showed that under anaerobic conditions it was able to take up labeled glycine and accumulate this and other labeled metabolites to an intracellular concentration of approximately 4 mM. All components were consumed under subsequent aerobic conditions. Intracellular accumulation of amino acids seems to be a novel storage strategy for polyphosphate-accumulating bacteria under dynamic anaerobic-aerobic feast-famine conditions. PMID:25956769

  13. Differential localization of putative amino acid receptors in taste buds of the channel catfish, Ictalurus punctatus.

    PubMed

    Finger, T E; Bryant, B P; Kalinoski, D L; Teeter, J H; Böttger, B; Grosvenor, W; Cagan, R H; Brand, J G

    1996-09-01

    The taste system of catfish, having distinct taste receptor sites for L-alanine and L-arginine, is highly sensitive to amino acids. A previously described monoclonal antibody (G-10), which inhibits L-alanine binding to a partial membrane fraction (P2) derived from catfish (Ictalurus punctatus) taste epithelium, was found in Western blots to recognize a single band, at apparent MW of 113,000 D. This MW differs from the apparent MW for the presumed arginine receptor identified previously by PHA-E lectin affinity. In order to test whether PHA-E lectin actually reacts with the arginine-receptor, reconstituted membrane proteins partially purified by PHA-E affinity were used in artificial lipid bilayers. These reconstituted channels exhibited L-arginine-activated activity similar to that found in taste cell membranes. Accordingly, we utilized the PHA-E lectin and G-10 antibody as probes to differentially localize the L-alanine and L-arginine binding sites on the apical surface of catfish taste buds. Each probe labels numerous, small (0.5-1.0 micron) patches within the taste pore of each taste bud. This observation suggests that each bud is not tuned to a single taste substance, but contains putative receptor sites for both L-arginine and L-alanine. Further, analysis of double-labeled tissue reveals that the PHA-E and G-10 sites tend to be separate within each taste pore. These findings imply that in catfish, individual taste cells preferentially express receptors to either L-arginine or L-alanine. In addition, PHA-E binds to the apices of solitary chemoreceptor cells in the epithelium, indicating that this independent chemoreceptor system may utilize some receptor sites similar to those in taste buds. PMID:8876468

  14. Dye-linked D-amino acid dehydrogenases: biochemical characteristics and applications in biotechnology.

    PubMed

    Satomura, Takenori; Sakuraba, Haruhiko; Suye, Shin-Ichiro; Ohshima, Toshihisa

    2015-11-01

    Dye-linked D-amino acid dehydrogenases (Dye-DADHs) catalyze the dehydrogenation of free D-amino acids in the presence of an artificial electron acceptor. Although Dye-DADHs functioning in catabolism of L-alanine and as primary enzymes in electron transport chains are widely distributed in mesophilic Gram-negative bacteria, biochemical and biotechnological information on these enzymes remains scanty. This is in large part due to their instability after isolation. On the other hand, in the last decade, several novel types of Dye-DADH have been found in thermophilic bacteria and hyperthermophilic archaea, where they contribute not only to L-alanine catabolism but also to the catabolism of other amino acids, including D-arginine and L-hydroxyproline. In this minireview, we summarize recent developments in our understanding of the biochemical characteristics of Dye-DADHs and their specific application to electrochemical biosensors. PMID:26362681

  15. The pathways for the removal of acrylamide in model systems using glycine based on the identification of reaction products.

    PubMed

    Liu, Jie; Chen, Fang; Man, Yong; Dong, Jing; Hu, Xiaosong

    2011-09-15

    The reaction between acrylamide and glycine was studied in the aqueous model system heated at 150°C. The main reaction products were identified as C5H10N2O3, C8H15N3O4, C7H12N2O5 and C10H17N3O6 using HPLC-MS/MS, IT-TOF and NMR. Both of the critical intermediates were identified as glyoxylic acid and iminodiacetic acid. The pathways for the removal of acrylamide by glycine were proposed as the Michael addition between acrylamide and glycine with or without the initial oxidation of glycine. The changes in the contents of reactants and products provided quantitative evidence for the above pathways. The addition products between acrylamide and other 14 amino acids were identified by HPLC-MS/MS also. PMID:25212154

  16. Effects of pH and surface pressure on morphology of glycine crystals formed beneath the phospholipid Langmuir monolayers

    NASA Astrophysics Data System (ADS)

    Mu, Ying-Di; Xiao, Fei; Zhang, Ren-Jie; Li, Hong-Ying; Huang, Wei; Feng, Xu-Sheng; Liu, Hong-Guo

    2005-11-01

    Ordered molecular monolayers of dipalmitoyl phosphatidylcholine (DPPC) were used as templates to induce the nucleation and growth of glycine crystals. It was found that α-glycine crystals were formed under the DPPC monolayers regardless of pH values of the aqueous supersaturated glycine solutions. The morphologies and orientations of the glycine crystals varied with pH of the solutions and surface pressures of the monolayers. When acidic and neutral aqueous supersaturated glycine solutions were used as subphases, the glycine crystals are plate-like habit with an elongated (0 1 0) crystal face preferentially oriented parallel to the plane of the monolayers; when basic solutions were used, the crystals are pyramidal habit. At surface pressures below 25 mN/m at the beginning of crystallization, plate-like α-glycine crystals were formed from the neutral solution; while at higher surface pressures, such as 35 and 40 mN/m, prismatic crystals were formed. The morphology of the glycine crystals can be tuned by changing the experimental conditions.

  17. 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.

  18. Glycine improves biochemical and biomechanical properties following inflammation of the achilles tendon.

    PubMed

    Vieira, Cristiano Pedrozo; De Oliveira, Letícia Prado; Da Ré Guerra, Flávia; Dos Santos De Almeida, Marcos; Marcondes, Maria Cristina Cintra Gomes; Pimentel, Edson Rosa

    2015-03-01

    Tendinopathy of the Achilles tendon is a clinical problem that motivates the scientific community to search for treatments that assist in restoring its functional properties. Glycine has broad biological effects, acting as a modulator of the inflammatory cascade, and is the predominant amino acid in collagen. A 5% glycine diet provided beneficial effects against toxicity and inflammation since glycine may restructure the collagen molecules faster due to its broad anti-inflammatory effects. The purpose was analyze the effects of a 5% glycine diet in rats as a treatment for the inflammatory process. The experimental groups were as follows: C (control group), G1 and G3 (inflammatory group), and G2 and G4 (glycine+inflammatory group). G1 and G2 were euthanized 8 days following injury, and G3 and G4 were euthanized 22 days following injury. The concentrations of hydroxyproline, non-collagenous proteins, and glycosaminoglycans, as well as the activity of MMP-2 and -9 were analyzed. Biomechanical and morphological tests were employed. Higher concentrations of hydroxyproline and glycosaminoglycans were found in G4 and an increased activity of MMP-2 was found in G2. Higher birefringence was noted in group G2. The biomechanical results indicated that the tendon was more resistant to loading to rupture upon treatment with a glycine diet in group G4. Glycine induced the synthesis of important components of the tendon. A rapid remodeling was noted when compared with the inflamed-only groups. These data suggest that glycine may be a beneficial supplement for individuals with inflammation of the Achilles tendon. PMID:25156668

  19. GABA and glycine in the developing brain.

    PubMed

    Ito, Susumu

    2016-09-01

    GABA and glycine are major inhibitory neurotransmitters in the CNS and act on receptors coupled to chloride channels. During early developmental periods, both GABA and glycine depolarize membrane potentials due to the relatively high intracellular Cl(-) concentration. Therefore, they can act as excitatory neurotransmitters. GABA and glycine are involved in spontaneous neural network activities in the immature CNS such as giant depolarizing potentials (GDPs) in neonatal hippocampal neurons, which are generated by the synchronous activity of GABAergic interneurons and glutamatergic principal neurons. GDPs and GDP-like activities in the developing brains are thought to be important for the activity-dependent functiogenesis through Ca(2+) influx and/or other intracellular signaling pathways activated by depolarization or stimulation of metabotropic receptors. However, if GABA and glycine do not shift from excitatory to inhibitory neurotransmitters at the birth and in maturation, it may result in neural disorders including autism spectrum disorders. PMID:26951057

  20. A Didactic Experience of Statistical Analysis for the Determination of Glycine in a Nonaqueous Medium Using ANOVA and a Computer Program

    ERIC Educational Resources Information Center

    Santos-Delgado, M. J.; Larrea-Tarruella, L.

    2004-01-01

    The back-titration methods are compared statistically to establish glycine in a nonaqueous medium of acetic acid. Important variations in the mean values of glycine are observed due to the interaction effects between the analysis of variance (ANOVA) technique and a statistical study through a computer software.

  1. Synthesis, structural elucidation, biological, antioxidant and nuclease activities of some 5-Fluorouracil-amino acid mixed ligand complexes

    NASA Astrophysics Data System (ADS)

    Shobana, Sutha; Subramaniam, Perumal; Mitu, Liviu; Dharmaraja, Jeyaprakash; Arvind Narayan, Sundaram

    2015-01-01

    Some biologically active mixed ligand complexes (1-9) have been synthesized from 5-Fluorouracil (5-FU; A) and amino acids (B) such as glycine (gly), L-alanine (ala) and L-valine (val) with Ni(II), Cu(II) and Zn(II) ions. The synthesized mixed ligand complexes (1-9) were characterized by various physico-chemical, spectral, thermal and morphological studies. 5-Fluorouracil and its mixed ligand complexes have been tested for their in vitro biological activities against some pathogenic bacterial and fungal species by the agar well diffusion method. The in vitro antioxidant activities of 5-Fluorouracil and its complexes have also been investigated by using the DPPH assay method. The results demonstrate that Cu(II) mixed ligand complexes (4-6) exhibit potent biological as well as antioxidant activities compared to 5-Fluorouracil and Ni(II) (1-3) and Zn(II) (7-9) mixed ligand complexes. Further, the cleaving activities of CT DNA under aerobic conditions show moderate activity with the synthesized Cu(II) and Ni(II) mixed ligand complexes (1-6) while no activity is seen with Zn(II) complexes (7-9). Binding studies of CT DNA with these complexes show a decrease in intensity of the charge transfer band to the extent of 5-15% along with a minor red shift. The free energy change values (Δ‡G) calculated from intrinsic binding constants indicate that the interaction between mixed ligand complex and DNA is spontaneous.

  2. Standard thermodynamic functions of complex formation between Cu2+ and glycine in aqueous solution

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    Heat effects of the interaction of copper(II) solutions with aminoacetic acid (glycine) are measured by the direct calorimetry at 298.15 K and ionic strengths of 0.5, 1.0, and 1.5 against a background of potassium nitrate. Standard enthalpy values for reactions of the formation of aminoacetic acid copper complexes in aqueous solutions are obtained using an equation with a single individual parameter by extrapolating it to zero ionic strength. The standard thermodynamic characteristics of complex formation in the Cu2+-glycine system are calculated. It is shown that glycine-like coordination is most likely in Cu(II) complexes with L-asparagine, L-glutamine, and L-valine.

  3. N-[[(Mercaptoacetyl)amino]benzoyl]glycines as mucolytic agents.

    PubMed

    Martin, T A; Comer, W T

    1985-07-01

    m- and p-aminobenzoic acids were converted to the title compounds by sequential use of ClCH2COCl, SOCl2, glycine methyl or ethyl ester, AcSK, and hydrolysis. The title compounds and a number of salts were compared for mucolytic activity, toxicity, stability, and hygroscopicity. When compared to N-acetyl-L-cysteine (NAC), the compounds exhibit several times the in vitro mucolytic activity of NAC on a molar basis. The most promising candidate appears to be the sodium salt 3.5H2O 2 of the meta series. PMID:4009614

  4. Consummatory feeding behavior to amino acids in intact and anosmic channel catfish Ictalurus punctatus.

    PubMed

    Valentincic, T; Caprio, J

    1994-05-01

    The entire sequence of feeding behavior patterns exhibited by intact and anosmic channel catfish to food extracts was also released by single amino acids. L-arginine (> 10(-6) M), L-alanine (> 10(-6) M), and L-proline (> 10(-4) M) were each highly effective at releasing consummatory behavior patterns, such as turning, increasing pumping of water across the gill arches, and biting-snapping. Swallowing required solid objects, whereas rhythmic movement of the hyoid was released by > 10(-2) M L-arginine alone. For the biting-snapping behavior, the number of bites depended upon both the number of eddies containing the amino acid above the behavioral threshold concentration and the amino acid applied. Multiple eddies of > 10(-3) M L-proline and L-alanine provoked up to 25 bites per test; however, the most effective stimulus for releasing biting-snapping behavior at low concentrations was L-arginine (behavioral threshold 3 x 10(-7) M). In comparison to 10(-4) M L-alanine and L-arginine, other amino acids were less effective stimuli. PMID:8022905

  5. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

    PubMed

    Umeda, Yuhei; Fukunaga, Nao; Sekine, Toshimori; Furukawa, Yoshihiro; Kakegawa, Takeshi; Kobayashi, Takamichi; Nakazawa, Hiromoto

    2016-01-01

    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well. PMID:26369758

  6. Electrophysiological responses of Xenopus oocytes to amino acids: criteria for expression of injected mRNA coding chemoreceptors.

    PubMed

    Etoh, M; Yoshii, K

    1994-10-01

    Responses of endogenous transporters/receptors of Xenopus oocytes to L-alanine, L-arginine, L-leucine and L-serine were investigated under voltage clamp conditions. (a) Concentration-response relations for the amino acids followed Langmuir's adsorption isotherm. (b) The neutral amino acids required Na+ to elicit the responses, whereas L-arginine did not. (c) The responses to L-alanine decreased with decreasing pH and became undetectable at pH 5.5. The present experiments supply criteria to judge if the oocytes translate exogenous mRNA coding taste or olfactory receptor proteins for the amino acids, the best characterized stimuli, especially in fishes. PMID:7956120

  7. Exploring Solute-Solvent Interactions of -Amino Acids in Aqueous [] Arrangements by Volumetric, Viscometric, Refractometric, and Acoustic Approach

    NASA Astrophysics Data System (ADS)

    Roy, Mahendra Nath; Roy, Milan Chandra; Basak, Saptarshi

    2014-05-01

    Qualitative and quantitative analysis of molecular interaction prevailing in glycine, l-alanine, l-valine, and aqueous solution of ionic liquid (IL) [1-ethylpyridinium tetrafluoroborate (] have been investigated by thermophysical properties. The apparent molar volume (), viscosity -coefficient, molal refraction (), and adiabatic compressibility ( of glycine, l-alanine, and l-valine have been studied in 0.001 mol , 0.003 mol , and 0.005 mol aqueous 1-ethylpyridinium tetrafluoroborate [] solutions at 298.15 K from the values of densities , viscosities (), refractive index (, and speed of sound , respectively. The extent of interaction, i.e., the solute-solvent interaction is expressed in terms of the limiting apparent molar volume (, viscosity -coefficient, and limiting apparent molar adiabatic compressibility (. The limiting apparent molar volumes (, experimental slopes ( derived from the Masson equation, and viscosity - and -coefficients using the Jones-Dole equation have been interpreted in terms of ion-ion and ion-solvent interactions, respectively. Molal refractions ( have been calculated with the help of the Lorentz-Lorenz equation. The role of the solvent (aqueous IL solution) and the contribution of solute-solute and solute-solvent interactions to the solution complexes have also been analyzed through the derived properties.

  8. Utilization of glycine and serine as nitrogen sources in the roots of Zea mays and Chamaegigas intrepidus.

    PubMed

    Hartung, W; Ratcliffe, R G

    2002-12-01

    Glycine and serine are potential sources of nitrogen for the aquatic resurrection plant Chamaegigas intrepidus Dinter in the rock pools that provide its natural habitat. The pathways by which these amino acids might be utilized were investigated by incubating C. intrepidus roots and maize (Zea mays) root tips with [(15)N]glycine, [(15)N]serine and [2-(13)C]glycine. The metabolic fate of the label was followed using in vivo NMR spectroscopy, and the results were consistent with the involvement of the glycine decarboxylase complex (GDC) and serine hydroxymethyltransferase (SHMT) in the utilization of glycine. In contrast, the labelling patterns provided no evidence for the involvement of serine:glyoxylate aminotransferase in the metabolism of glycine by the root tissues. The key observations were: (i) the release of [(15)N]ammonium during [(15)N]-labelling experiments; and (ii) the detection of a characteristic set of serine isotopomers in the [2-(13)C]glycine experiments. The effects of aminoacetonitrile, amino-oxyacetate, and isonicotinic acid hydrazide, all of which inhibit GDC and SHMT to some extent, and of methionine sulphoximine, which inhibited the reassimilation of the ammonium, supported the conclusion that GDC and SHMT were essential for the metabolism of glycine. C. intrepidus was observed to metabolize serine more readily than the maize root tips and this may be an adaptation to its nitrogen-deficient habitat. Overall, the results support the emerging view that GDC is an essential component of glycine catabolism in non-photosynthetic tissues. PMID:12432023

  9. 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...

  10. Glycine receptor antibodies in PERM and related syndromes: characteristics, clinical features and outcomes

    PubMed Central

    Carvajal-González, Alexander; Leite, M. Isabel; Waters, Patrick; Woodhall, Mark; Coutinho, Ester; Balint, Bettina; Lang, Bethan; Pettingill, Philippa; Carr, Aisling; Sheerin, Una-Marie; Press, Raomand; Lunn, Michael P.; Lim, Ming; Maddison, Paul; Meinck, H.-M.; Vandenberghe, Wim

    2014-01-01

    The clinical associations of glycine receptor antibodies have not yet been described fully. We identified prospectively 52 antibody-positive patients and collated their clinical features, investigations and immunotherapy responses. Serum glycine receptor antibody endpoint titres ranged from 1:20 to 1:60 000. In 11 paired samples, serum levels were higher than (n = 10) or equal to (n = 1) cerebrospinal fluid levels; there was intrathecal synthesis of glycine receptor antibodies in each of the six pairs available for detailed study. Four patients also had high glutamic acid decarboxylase antibodies (>1000 U/ml), and one had high voltage-gated potassium channel-complex antibody (2442 pM). Seven patients with very low titres (<1:50) and unknown or alternative diagnoses were excluded from further study. Three of the remaining 45 patients had newly-identified thymomas and one had a lymphoma. Thirty-three patients were classified as progressive encephalomyelitis with rigidity and myoclonus, and two as stiff person syndrome; five had a limbic encephalitis or epileptic encephalopathy, two had brainstem features mainly, two had demyelinating optic neuropathies and one had an unclear diagnosis. Four patients (9%) died during the acute disease, but most showed marked improvement with immunotherapies. At most recent follow-up, (2–7 years, median 3 years, since first antibody detection), the median modified Rankin scale scores (excluding the four deaths) decreased from 5 at maximal severity to 1 (P < 0.0001), but relapses have occurred in five patients and a proportion are on reducing steroids or other maintenance immunotherapies as well as symptomatic treatments. The glycine receptor antibodies activated complement on glycine receptor-transfected human embryonic kidney cells at room temperature, and caused internalization and lysosomal degradation of the glycine receptors at 37°C. Immunoglobulin G antibodies bound to rodent spinal cord and brainstem co-localizing with

  11. Kinetic determinants of agonist action at the recombinant human glycine receptor

    PubMed Central

    Lewis, Trevor M; Schofield, Peter R; McClellan, Annette M L

    2003-01-01

    The amino acids glycine, β-alanine and taurine are all endogenous agonists of the glycine receptor. In this study, a combination of rapid agonist application onto macropatches and steady-state single-channel recordings was used to compare the actions of glycine, β-alanine and taurine upon homomeric α1 human glycine receptors transiently expressed in human embryonic kidney (HEK 293) cells. The 10–90 % rise times determined from rapid application of 100 μm of each agonist were indistinguishable, indicating each agonist has a similar association rate. At saturating concentrations (30 mm) the rise time for glycine (0.26 ms) was 1.8-fold faster than that for β-alanine (0.47 ms) and 3.9-fold faster than that for taurine (1.01 ms), indicating clear differences in the maximum opening rate between agonists. The relaxation following rapid removal of agonist was fitted with a single exponential for β-alanine (3.0 ms) and taurine (2.2 ms), and two exponential components for glycine with a weighted mean time constant of 27.1 ms. This was consistent with differences in dissociation rates estimated from analysis of bursts, with taurine > β-alanine > glycine. Exponential fits to the open period distributions gave time constants that did not differ between agonists and the geometric distribution for the number of openings per burst indicated that all three agonists had a significant component of single-opening bursts. Based upon these data, we propose a kinetic scheme with three independent open states, where the opening rates are dependent upon the activating agonist, while the closing rates are an intrinsic characteristic of the receptor. PMID:12679369

  12. Methylammonium methylcarbamate thermal formation in interstellar ice analogs: a glycine salt precursor in protostellar environments

    NASA Astrophysics Data System (ADS)

    Bossa, J.-B.; Duvernay, F.; Theulé, P.; Borget, F.; D'Hendecourt, L.; Chiavassa, T.

    2009-11-01

    Context: Analyses of dust cometary grains collected by the Stardust spacecraft have shown the presence of amines and amino acids molecules, and among them glycine (NH{2}CH{2}COOH). We show how the glycine molecule could be produced in the protostellar environments before its introduction into comets. Aims: We study the evolution of the interstellar ice analogues affected by both thermal heating and vacuum ultraviolet (VUV) photons, in addition to the nature of the formed molecules and the confrontation of our experimental results with astronomical observations. Methods: Infrared spectroscopy and mass spectrometry are used to monitor the evolution of the H{2}O:CO{2}:CH{3}NH{2} and CO{2}:CH{3}NH{2} ice mixtures during both warming processes and VUV photolysis. Results: We first show how carbon dioxide (CO{2}) and methylamine (CH{3}NH{2}) thermally react in water-dominated ice to form methylammonium methylcarbamate [ CH{3}NH{3}+] [ CH{3}NHCOO-] noted C. We then determine the reaction rate and activation energy. We show that C thermal formation can occurs in the 50-70 K temperature range of a protostellar environment. Secondly, we report that a VUV photolysis of a pure C sample produces a glycine salt, methylammonium glycinate [ CH{3}NH{3}+] [ NH{2}CH{2}COO-] noted G. We propose a scenario explaining how C and subsequently G can be synthesized in interstellar ices and precometary grains. Conclusions: [ CH{3}NH{3}+] [ CH{3}NHCOO-] could be readily formed and would act as a glycine salt precursor in protostellar environments dominated by thermal and UV processing. We propose a new pathway leading to a glycine salt, which is consistent with the detection of glycine and methylamine within the returned samples of comet 81P/Wild 2 from the Stardust mission.

  13. Ir-Spectroscopy of Glycine and its Complexes with Water in Helium Nanodroplets

    NASA Astrophysics Data System (ADS)

    Letzner, M.; Grün, S. A.; Schwaab, G.; Havenith, M.

    2011-06-01

    Glycine is the smallest amino acid, and therefore it is of special interest as a model and starting point for theoretical and experimental studies. Whereas the crystalline form of glycine consists of zwitterions NH_3+-CH_2-COO-, gas phase glycine is known to exist in the nonionized form NH_2-CH_2-COOH. The interaction between glycine and water has been widely studied using a large variety of theoretical methods. Depending on the theoretical level used, a stabilisation of the zwitterionic form is predicted for complexes containing from 2 to 7 water molecules. In low-temperature Ar matrices a set of characteristic IR absorption bands for the zwitterionic form has been observed. The higher stoichiometry complexes (glycine)\\cdots(H_2O)_n with n larger than 3 are demonstrated to be zwitterionic H-bonded complexes. The multitude of conformations expected for these glycine-water complexes makes a combination of low temperature and high resolution spectroscopy essential. We want to use the advantages of our experiment to investigate glycine and its complexes with water in helium-nanodroplets at ultracold temperatures in the range from 3000-3800 Cm-1. Our measurements were carried out using a high power IR-OPO (cw: 2.7 W) as radiation source and a helium nanodroplet spectrometer. Helium-nanodroplets are formed by expansion of helium at 55 bar through a 5 μm nozzle which is kept at a temperature of 16 K. The status of the project is presented. P.-G. Jönsson et al., Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 28, 1827 (1972) G. Junk et al., J. Am. Chem. Soc. 85, 839 (1963) R. Ramaekers et al., J. Chem. Phys., 120 (2004)

  14. Kinetic study of carbon dioxide absorption into glycine promoted diethanolamine (DEA)

    NASA Astrophysics Data System (ADS)

    Pudjiastuti, Lily; Susianto, Altway, Ali; IC, Maria Hestia; Arsi, Kartika

    2015-12-01

    In industry, especially petrochemical, oil and natural gas industry, required separation process of CO2 gas which is a corrosive gas (acid gas). This characteristic can damage the plant utility and piping systems as well as reducing the caloric value of natural gas. Corrosive characteristic of CO2 will appear in areas where there is a decrease in temperature and pressure, such as at the elbow pipe, tubing, cooler and injector turbine. From disadvantages as described above, then it is important to do separation process in the CO2 gas stream, one of the method for remove CO2 from the gas stream is reactive absorption using alkanolamine based solution with promotor. Therefore, this study is done to determine the kinetics constant of CO2 absorption in diethanolamine (DEA) solution using a glycine promoter. Glycine is chosen as a promoter because glycine is a primary amine compound which is reactive, moreover, glycine has resistance to high temperatures so it will not easy to degradable and suitable for application in industry. The method used in this study is absorption using laboratory scale wetted wall column equipment at atmospheric of pressure. This study will to provide the reaction kinetics data information in order to optimize the separation process of CO2 in the industrialized world. The experimental results show that rising temperatures from 303,15 - 328,15 K and the increase of concentration of glycine from 1% - 3% weight will increase the absorption rate of carbon dioxide in DEA promoted with glycine by 24,2% and 59,764% respectively, also the reaction kinetic constant is 1.419 × 1012 exp (-3634/T) (m3/kmol.s). This result show that the addition of glycine as a promoter can increase absorption rate of carbon dioxide in diethanolamine solution and cover the weaknesses of diethanolamine solution.

  15. 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-

  16. Antidepressants modulate glycine action in rat hippocampus.

    PubMed

    Chang, Hyun-Kyung; Kim, Khae Hawn; Kang, Ki-Woon; Kang, Yoo-Jin; Kim, Tae-Wook; Park, Hun-Kyung; Kim, Sung-Eun; Kim, Chang-Ju

    2015-12-01

    Antidepressants are drugs that relieve symptoms of depressive disorders. Fluoxetine, tianeptine, and milnacipran are different types of antidepressants, and they have widely been used for relieving of depression symptoms. In the present study, the effects of fluoxetine, tianeptine, and milnacipran on the glycine-induced ion current by nystatin-perforated patch clamp and on the amplitude of field potential in the hippocampal CA1 region by multichannel extracellular recording, MED64, system, were studied. In the present results, fluoxetine, tianeptine, and milnacipran reduced glycine-induced ion current in the hippocampal CA1 neurons in nystatin-perforated patch clamp method. These drugs enhanced the amplitude of the field potential in the hippocampal CA1 region in MED64 system. These results suggest that antidepressants may increase neuronal activity by enhancing field potential through inhibition on glycine-induced ion current. PMID:26730381

  17. 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

  18. Chemical basis of glycine riboswitch cooperativity

    PubMed Central

    Kwon, Miyun; Strobel, Scott A.

    2008-01-01

    The glycine binding riboswitch forms a unique tandem aptamer structure that binds glycine cooperatively. We employed nucleotide analog interference mapping (NAIM) and mutagenesis to explore the chemical basis of glycine riboswitch cooperativity. Based on the interference pattern, at least two sites appear to facilitate cooperative tertiary interactions, namely, the minor groove of the P1 helix from aptamer 1 and the major groove of the P3a helix from both aptamers. Mutation of these residues altered both the cooperativity and binding affinity of the riboswitch. The data support a model in which the P1 helix of the first aptamer participates in a tertiary interaction important for cooperativity, while nucleotides in the P1 helix of the second aptamer interface with the expression platform. These data have direct analogy to well-characterized mutations in hemoglobin, which provides a framework for considering cooperativity in this RNA-based system. PMID:18042658

  19. Expression, Purification, and Characterization of Mouse Glycine N-acyltransferase in Escherichia coli

    PubMed Central

    Dempsey, Daniel R.; Bond, Jason D.; Carpenter, Anne-Marie; Ospina, Santiago Rodriguez; Merkler, David J.

    2014-01-01

    Glycine N-acyltransferase (GLYAT) is a phase II metabolic detoxification enzyme for exogenous (xenobiotic) and endogenous carboxylic acids; consisting of fatty acids, benzoic acid, and salicylic acid. GLYAT catalyzes the formation of hippurate (N-benzoylglycine) from the corresponding glycine and benzoyl-CoA. Herein, we report the successful expression, purification, and characterization of recombinant mouse GLYAT (mGLYAT). A 34 kDa mGLYAT protein was expressed in Escherichia coli and purified to homogeneity by nickel affinity chromatography to a final yield of 2.5 mg/L culture. Characterization for both amino donors and amino acceptors were completed, with glycine serving as the best amino donor substrate, (kcat/Km)app = (5.2 ± 0.20) × 102M−1s−1, and benzoyl-CoA serving as the best the amino acceptor substrate, (kcat/Km)app = (4.5 ± 0.27) × 105M−1s−1. Our data demonstrate that mGLYAT will catalyzed the chain length specific (C2-C6) formation of N-acylglycines. The steady-state kinetic constants determined for recombinant mGLYAT for the substrates benzoyl-CoA and glycine, were shown to be consistent with other reported species (rat, human, bovine, ovine, and rhesus monkey). The successful recombinant expression and purification of mGLYAT can lead to solve unanswered questions associated with this enzyme, consisting of what is the chemical mechanism and what catalytic residues are essential for the how this phase II metabolic detoxification enzyme conjugates glycine to xenobiotic and endogenous carboxylic acids. PMID:24576660

  20. Expression of heteromeric glycine receptor-channels in rat spinal cultures and inhibition by neuroactive steroids.

    PubMed

    Fodor, László; Boros, András; Dezso, Péter; Maksay, Gábor

    2006-11-01

    Ionotropic glycine receptors were studied in cultured spinal cord neurons prepared from 17-day-old rat embryos, using whole-cell patch clamp electrophysiology. Glycine receptors of 3-17 days in vitro were characterized via subtype-specific channel blockade by micromolar picrotoxin and cyanotriphenylborate, as well as nanomolar strychnine. Potentiation by nanomolar tropisetron indicated coexpression of beta with alpha subunits. The neuroactive steroids pregnenolone sulfate and dehydroepiandrosterone sulfate, as well as alphaxalone and its 3beta epimer betaxalone inhibited the chloride current with IC(50) values of 19, 46, 16 and 208 microM, respectively, with no potentiation. Reverse transcription polymerase chain reaction and immunocytochemistry demonstrated mRNAs and proteins of alpha1, alpha2, alpha3 and beta subunits in rat spinal cord cultures. In conclusion, neuroactive steroids, both positive and negative modulators of gamma-aminobutyric-acid(A) receptors, inhibited heteromeric glycine receptors at micromolar concentrations. PMID:16784797

  1. Glycine as a regulator of tryptophan-dependent pigment synthesis in Malassezia furfur.

    PubMed

    Barchmann, Thorsten; Hort, Wiebke; Krämer, Hans-Joachim; Mayser, Peter

    2011-01-01

    The effects of the addition of different amino nitrogens on growth, morphology and secondary metabolism of Malassezia furfur were investigated. After primary culture on Dixon agar, M. furfur CBS 1878 was transferred into a fluid medium together with the nitrogen sources, glycine (Gly) or tryptophan (Trp), or a combination of both. Growth was measured by means of a direct cell counting method and pigment synthesis was photometrically assessed. Addition of glycine resulted in an exponential increase in biomass, but not in pigment production. Tryptophan as the sole nitrogen source caused distinct brown staining of the medium, without increasing biomass. Simultaneous equimolar addition of both amino acids resulted in an initial increase in biomass as a sign of preferential metabolism of glycine, followed by a growth plateau and pigment production which, caused by higher biomass, occurred more rapidly than after addition of tryptophan alone. The yeast-cell morphology changed from round to oval. Addition of glycine to the tryptophan-containing liquid culture stopped pigment formation with simultaneous growth induction. These in vitro on-off phenomena depending on the nitrogen source might be significant in the pathogenesis of pityriasis versicolor: hyperhidrosis followed by preferential consumption of individual nitrogen sources such as glycine with exponential growth and thereafter transamination of tryptophan and TRP-dependent pigment synthesis. PMID:19702622

  2. Glycine regulates the production of pro-inflammatory cytokines in lean and monosodium glutamate-obese mice.

    PubMed

    Alarcon-Aguilar, F J; Almanza-Perez, Julio; Blancas, Gerardo; Angeles, Selene; Garcia-Macedo, Rebeca; Roman, Ruben; Cruz, Miguel

    2008-12-01

    Fat tissue plays an important role in the regulation of inflammatory processes. Increased visceral fat has been associated with a higher production of cytokines that triggers a low-grade inflammatory response, which eventually may contribute to the development of insulin resistance. In the present study, we investigated whether glycine, an amino acid that represses the expression in vitro of pro-inflammatory cytokines in Kupffer and 3T3-L1 cells, can affect in vivo cytokine production in lean and monosodium glutamate-induced obese mice (MSG/Ob mice). Our data demonstrate that glycine treatment in lean mice suppressed TNF-alpha transcriptional expression in fat tissue, and serum protein levels of IL-6 were suppressed, while adiponectin levels were increased. In MSG/Ob mice, glycine suppressed TNF-alpha and IL-6 gene expression in fat tissue and significantly reduced protein levels of IL-6, resistin and leptin. To determine the role of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in the modulation of this inflammatory response evoked by glycine, we examined its expression levels in fat tissue. Glycine clearly increased PPAR-gamma expression in lean mice but not in MSG/Ob mice. Finally, to identify alterations in glucose metabolism by glycine, we also examined insulin levels and other biochemical parameters during an oral glucose tolerance test. Glycine significantly reduced glucose tolerance and raised insulin levels in lean but not in obese mice. In conclusion, our findings suggest that glycine suppresses the pro-inflammatory cytokines production and increases adiponectin secretion in vivo through the activation of PPAR-gamma. Glycine might prevent insulin resistance and associated inflammatory diseases. PMID:18930730

  3. Synchrotron x-ray photoemission study of soft x-ray processed ultrathin glycine-water ice films

    SciTech Connect

    Tzvetkov, George; Netzer, Falko P.

    2011-05-28

    Ultrathin glycine-water ice films have been prepared in ultrahigh vacuum by condensation of H{sub 2}O and glycine at 90 K on single crystalline alumina surfaces and processed by soft x-ray (610 eV) exposure for up to 60 min. The physicochemical changes in the films were monitored using synchrotron x-ray photoemission spectroscopy. Two films with different amounts of H{sub 2}O have been considered in order to evaluate the influence of the water ice content on the radiation-induced effects. The analysis of C1s, N1s, and O1s spectral regions together with the changes in the valence band spectra indicates that amino acid degradation occurs fast mainly via decarboxylation and deamination of pristine molecules. Enrichment of the x-ray exposed surfaces with fragments with carbon atoms without strong electronegative substituents (C-C and C-H) is documented as well. In the thinner glycine-water ice film (six layers of glycine + six layers of water) the 3D ice suffers strongly from the x-rays and is largely removed from the sample. The rate of photodecomposition of glycine in this film is about 30% higher than for glycine in the thicker film (6 layers of glycine + 60 layers of water). The photoemission results suggest that the destruction of amino acid molecules is caused by the direct interaction with the radiation and that no chemical attack of glycine by the species released by water radiolysis is detected.

  4. Effects of glycine and proline on the calcium activation properties of skinned muscle fibre segments from crayfish and rat.

    PubMed

    Powney, E L; West, J M; Stephenson, D G; Dooley, P C

    2003-01-01

    The effects of the polar amino acid glycine (20 mmol l(-1)) and the non-polar amino acid proline (20 mmol l(-1)) on Ca(2+)-activated contraction have been examined in four types of striated muscle fibres. Single fibres dissected from the claw muscle of a crustacean (long- and short-sarcomere) and the hindlimb muscles of the rat (slow-twitch from soleus and fast-twitch from extensor digitorum longus) were activated in matched solutions that either contained the amino acid ('test') or not ('control'). The steady-state force produced in these solutions was used to determine the relation between force production and pCa (-log10[Ca2+]). The results show that in the concentrations used, glycine and proline had only small effects on the maximum Ca(2+)-activated force, pCa corresponding to 10, 50 and 90% maximum force (pCa10, pCa50, pCa90, respectively) or on the slope of the force-pCa curves in the four different fibre types. The relative lack of effects of glycine and proline on contractile activation would confer a distinct physiological advantage to force production of muscle of Cherax, where the concentrations of glycine and proline vary considerably. Finally, the results show that glycine and proline may be useful to balance control solutions when the effects of other amino acids or zwitterions on contractile activation are examined. PMID:14677649

  5. GcsR, a TyrR-Like Enhancer-Binding Protein, Regulates Expression of the Glycine Cleavage System in Pseudomonas aeruginosa PAO1

    PubMed Central

    Sarwar, Zaara; Lundgren, Benjamin R.; Grassa, Michael T.; Wang, Michael X.; Gribble, Megan; Moffat, Jennifer F.

    2016-01-01

    ABSTRACT Glycine serves as a major source of single carbon units for biochemical reactions within bacterial cells. Utilization of glycine is tightly regulated and revolves around a key group of proteins known as the glycine cleavage system (GCS). Our lab previously identified the transcriptional regulator GcsR (PA2449) as being required for catabolism of glycine in the opportunistic pathogen Pseudomonas aeruginosa PAO1. In an effort to clarify and have an overall better understanding of the role of GcsR in glycine metabolism, a combination of transcriptome sequencing and electrophoretic mobility shift assays was used to identify target genes of this transcriptional regulator. It was found that GcsR binds to an 18-bp consensus sequence (TGTAACG-N4-CGTTCCG) upstream of the gcs2 operon, consisting of the gcvH2, gcvP2, glyA2, sdaA, and gcvT2 genes. The proteins encoded by these genes, namely, the GCS (GcvH2-GcvP2-GcvT2), serine hydroxymethyltransferase (GlyA2), and serine dehydratase (SdaA), form a metabolic pathway for the conversion of glycine into pyruvate, which can enter the central metabolism. GcsR activates transcription of the gcs2 operon in response to glycine. Interestingly, GcsR belongs to a family of transcriptional regulators known as TyrR-like enhancer-binding proteins (EBPs). Until this study, TyrR-like EBPs were only known to function in regulating aromatic amino acid metabolism. GcsR is the founding member of a new class of TyrR-like EBPs that function in the regulation of glycine metabolism. Indeed, homologs of GcsR and its target genes are present in almost all sequenced genomes of the Pseudomonadales order, suggesting that this genetic regulatory mechanism is a common theme for pseudomonads. IMPORTANCE Glycine is required for various cellular functions, including cell wall synthesis, protein synthesis, and the biosynthesis of several important metabolites. Regulating levels of glycine metabolism allows P. aeruginosa to maintain the metabolic flux

  6. A rare case of glycine encephalopathy unveiled by valproate therapy.

    PubMed

    Subramanian, Velusamy; Kadiyala, Pramila; Hariharan, Praveen; Neeraj, E

    2015-01-01

    Glycine encephalopathy (GE) or nonketotic hyperglycinemia is an autosomal recessive disorder due to a primary defect in glycine cleavage enzyme system. It is characterized by elevated levels of glycine in plasma and cerebrospinal fluid usually presenting with seizures, hypotonia, and developmental delay. In our case, paradoxical increase in seizure frequency on starting sodium valproate led us to diagnose GE. PMID:26167219

  7. 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....

  8. 21 CFR 172.812 - Glycine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES... food additive glycine may be safely used for technological purposes in food in accordance with the following prescribed conditions: (a) The additive meets the specifications of the Food Chemicals Codex,...

  9. 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

  10. Engineering and characterization of fluorogenic glycine riboswitches.

    PubMed

    Ketterer, Simon; Gladis, Lukas; Kozica, Adnan; Meier, Matthias

    2016-07-01

    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 (k(on)), and dissociation (k(off)) rates, and corresponding energy barriers of the 10 strongest fluorescence response riboswitches were determined with the same chip platform. k(on) and k(off) were in the order of 10(-3)s(-1) and 10(-2)s(-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

  11. 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

  12. The total synthesis of pantocin B.

    PubMed

    Sutton, A E; Clardy, J

    2000-02-10

    [reaction: see text] Pantocin B, an unusual antibiotic produced by Erwinia herbicola, effectively controls E. amylovora, the pathogen causing the plant disease fire blight. A total synthesis of pantocin B from L-alanine, glycine, and L-malic acid is reported. PMID:10814312

  13. Glycine Betaine Biosynthesized from Glycine Provides an Osmolyte for Cell Growth and Spore Germination during Osmotic Stress in Myxococcus xanthus▿

    PubMed Central

    Kimura, Yoshio; Kawasaki, Shinji; Yoshimoto, Hinae; Takegawa, Kaoru

    2010-01-01

    Glycine sarcosine methyltransferase (Gsm) and sarcosine dimethylglycine methyltransferase (Sdm) catalyze glycine betaine synthesis from glycine. Disruption of the M. xanthus gsmA (MXAN 7068) or sdmA (MXAN 3190) gene, encoding Gsm or Sdm homologue proteins, respectively, generated mutants that exhibited a longer lag period of growth and delayed spore germination under osmostress. PMID:20023011

  14. Sorption of Cu(II) complexes with ligands tartrate, glycine and quadrol by chitosan.

    PubMed

    Gyliene, Ona; Binkiene, Rima; Butkiene, Rita

    2009-11-15

    The sorption by chitosan in Cu(II) solutions containing tartrate, glycine (amino acetic acid) and quadrol (N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine) as ligands has been investigated. The degree of sorbate removal strongly depends on pH. In solutions containing tartrate almost complete sorption of both Cu(II) and tartrate proceeds in mildly acidic and neutral solutions. The sorption of Cu(II) is also complete in alkaline solutions containing glycine; meanwhile a substantial sorption of glycine proceeds at pH approximately 6. The Cu(II) sorption in solutions containing quadrol is insignificant. Any sorption of quadrol does not proceed in the whole range of pH investigated. The investigations under equilibrium conditions showed that the Cu(II) sorption from tartrate containing solutions obeys Freundlich equation and in solutions containing glycine and quadrol it fits Langmuir equation. Supposedly, Cu(II) sorption onto chitosan proceeds with formation of amino complexes onto the surface of chitosan; the sorption of tartrate proceeds as electrostatic as well as with formation of amide bonds. Applying of electrolysis enables a complete removal of sorbed Cu(II) and ligands without changes in physical and chemical properties of chitosan. This is confirmed by sorption ability of regenerated chitosan, measurements of its molecular weight, the deacetylation degree and FT-IR spectra. PMID:19540041

  15. Bioinformatics analysis of the serine and glycine pathway in cancer cells

    PubMed Central

    Morello, Maria; Minieri, Marilena; Melino, Gerry; Amelio, Ivano

    2014-01-01

    Serine and glycine are amino acids that provide the essential precursors for the synthesis of proteins, nucleic acids and lipids. Employing 3 subsequent enzymes, phosphoglycerate dehydrogenase (PHGDH), phosphoserine phosphatase (PSPH), phosphoserine aminotransferase 1 (PSAT1), 3-phosphoglycerate from glycolysis can be converted in serine, which in turn can by converted in glycine by serine methyl transferase (SHMT). Besides proving precursors for macromolecules, serine/glycine biosynthesis is also required for the maintenance of cellular redox state. Therefore, this metabolic pathway has a pivotal role in proliferating cells, including cancer cells. In the last few years an emerging literature provides genetic and functional evidences that hyperactivation of serine/glycine biosynthetic pathway drives tumorigenesis. Here, we extend these observations performing a bioinformatics analysis using public cancer datasets. Our analysis highlighted the relevance of PHGDH and SHMT2 expression as prognostic factor for breast cancer, revealing a substantial ability of these enzymes to predict patient survival outcome. However analyzing patient datasets of lung cancer our analysis reveled that some other enzymes of the pathways, rather than PHGDH, might be associated to prognosis. Although these observations require further investigations they might suggest a selective requirement of some enzymes in specific cancer types, recommending more cautions in the development of novel translational opportunities and biomarker identification of human cancers. PMID:25436979

  16. Thermal formation of methylammonium methylcarbamate in interstellar ice analogs: a glycine salt precursor under VUV irradiation

    NASA Astrophysics Data System (ADS)

    Duvernay, Fabrice; Borget, Fabien; Bossa, Jean-Baptiste; Theule, Patrice; Dhendecourt, Louis; Chiavassa, Thierry

    Dust grains in the interstellar medium (ISM) play an important role in dense molecular clouds chemistry of providing a surface (catalyst) upon which atoms and molecules can freeze out, forming icy mantles. Dense molecular clouds are characterized by low temperature (10 -50 K) and represent the birth sites of stars. After a gravitationnal breakdown, a part of the dense molecular cloud collapses toward the formation of star and subsequently a protoplanetary disk from which planets, asteroids and comets will appear. During this evolution, interstellar or-ganic material inside ices undergoes different range of chemical alterations (thermal cycling process, ultraviolet photons, electron scattering and cosmic rays irradiation) hence increasing the molecular complexity before their incorporation inside precometary ices. To date, it is supposed that comets could have delivered to the early Earth the organic materials essential to a prebiotic chemistry, one of the prerequisites toward the origin of living systems. The for-mation of prebiotical molecules such as the simplest amino acids (glycine) is proposed in this current study mainly based on laboratory experiments simulating the chemistry occuring on ices within protostellar environments. Infrared spectroscopy and mass spectroscopy are used to monitor the thermal formation of glycine isomer form: the methylammonium methylcarbamate [CH3NH3+][CH3NHCOO-] in interstellar ice analogs made up of two astrophysical relevant molecules: carbon dioxide (CO2) and methylamine (CH3NH2). Using infrared spectroscopy, we study the photochemical behaviour of a pure sample of methylammonium methylcarbamate under vacuum ultraviolet (VUV) field. We show that a glycine isomer salt could readily enter into the composition of ices in colder region of protostellar environments. Upon ultraviolet irra-diation, this latter can undergo an isomerization process induced by photons yielding a glycine salt: the methylammonium glycinate [CH3NH3+][NH2CH2

  17. Activation of glycine receptor phase-shifts the circadian rhythm in neuronal activity in the mouse suprachiasmatic nucleus

    PubMed Central

    Mordel, Jérôme; Karnas, Diana; Inyushkin, Alexey; Challet, Etienne; Pévet, Paul; Meissl, Hilmar

    2011-01-01

    Abstract In mammals, the master clock in the suprachiasmatic nucleus (SCN) of the hypothalamus is composed of numerous synchronized oscillating cells that drive daily behavioural and physiological processes. Several entrainment pathways, afferent inputs to the SCN with their neurotransmitter and neuromodulator systems, can reset the circadian system regularly and also modulate neuronal activity within the SCN. In the present study, we investigated the function of the inhibitory neurotransmitter glycine on neuronal activity in the mouse SCN and on resetting of the circadian clock. The effects of glycine on the electrical activity of SCN cells from C57Bl/6 mice were studied either by patch-clamp recordings from acute brain slices or by long-term recordings from organotypic brain slices using multi-microelectrode arrays (MEA). Voltage-clamp recordings confirmed the existence of glycine-induced, chloride-selective currents in SCN neurons. These currents were reversibly suppressed by strychnine, phenylbenzene ω-phosphono-α-amino acid (PMBA) or ginkgolide B, selective blockers of glycine receptors (GlyRs). Long-term recordings of the spontaneous activity of SCN neurons revealed that glycine application induces a phase advance during the subjective day and a phase delay during the early subjective night. Both effects were suppressed by strychnine or by PMBA. These results suggest that glycine is able to modulate circadian activity by acting directly on its specific receptors in SCN neurons. PMID:21486797

  18. Activation of glycine receptor phase-shifts the circadian rhythm in neuronal activity in the mouse suprachiasmatic nucleus.

    PubMed

    Mordel, Jérôme; Karnas, Diana; Inyushkin, Alexey; Challet, Etienne; Pévet, Paul; Meissl, Hilmar

    2011-05-01

    In mammals, the master clock in the suprachiasmatic nucleus (SCN) of the hypothalamus is composed of numerous synchronized oscillating cells that drive daily behavioural and physiological processes. Several entrainment pathways, afferent inputs to the SCN with their neurotransmitter and neuromodulator systems, can reset the circadian system regularly and also modulate neuronal activity within the SCN. In the present study, we investigated the function of the inhibitory neurotransmitter glycine on neuronal activity in the mouse SCN and on resetting of the circadian clock. The effects of glycine on the electrical activity of SCN cells from C57Bl/6 mice were studied either by patch-clamp recordings from acute brain slices or by long-term recordings from organotypic brain slices using multi-microelectrode arrays(MEA). Voltage-clamp recordings confirmed the existence of glycine-induced, chloride-selective currents in SCN neurons. These currents were reversibly suppressed by strychnine, phenylbenzeneω-phosphono-α-amino acid (PMBA) or ginkgolide B, selective blockers of glycine receptors(GlyRs). Long-term recordings of the spontaneous activity of SCN neurons revealed that glycine application induces a phase advance during the subjective day and a phase delay during the early subjective night. Both effects were suppressed by strychnine or by PMBA. These results suggest that glycine is able to modulate circadian activity by acting directly on its specific receptors in SCN neurons. PMID:21486797

  19. STRUCTURES AND PHYSICOCHEMICAL PROPERTIES OF STARCH FROM IMMATURE SEEDS OF SOYBEAN VARIETIES (GLYCINE MAX (L.) MERR.) EXHIBITING NORMAL, LOW-LINOLENIC OR LOW-SATURATED FATTY ACID OIL PROFILES AT MATURITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean variety exhibiting at maturity, normal (NM), low-linolenic (LL) or low-saturate (LS) fatty acid seed oil composition had starch structure and functional properties studied from seeds collected 20 days prior to harvest. Soybean starch had small granules (0.4-4.5 micrometers diameter), and CB...

  20. THE AMPHOTERIC PROPERTIES OF SOME AMINO-ACIDS AND PEPTIDES.

    PubMed

    Eckweiler, H; Noyes, H M; Falk, K G

    1921-01-20

    The titration curves of solutions of glycine, alanine, alpha-ammo-butyric acid, leucine, glycyl-glycine, alanyl-glycine, alanyl-alanine, acetone, acetamide, urea, acetic acid, and aceturic acid were determined and some of the relations as dependent upon the chemical structures discussed. The isoelectric points of some of the amphoteric electrolytes were found experimentally. The definition of isoelectric point, its theoretical significance, and method of calculation were considered in some detail. PMID:19871865

  1. Structure and reaction mechanism of L-arginine:glycine amidinotransferase.

    PubMed

    Humm, A; Fritsche, E; Steinbacher, S

    1997-01-01

    L-Arginine:glycine amidinotransferase (AT) catalyzes the committed step in creatine biosynthesis by formation of guanidinoacetic acid, the direct precursor of creatine. The X-ray structure of the human enzyme shows a novel fold with fivefold pseudosymmetry of beta beta alphabeta-modules. These modules enclose the active site compartment of the basket-like structure. The active site of AT lies at the bottom of a very narrow channel and contains a catalytic triad with the residues Cys-His-Asp. The transamidination reaction follows a ping-pong mechanism and is accompanied by large conformational changes. During catalysis the amidino group is covalently attached to the active site cysteine to give an amidino-cysteine intermediate. PMID:9165070

  2. Degradation of Glycine and Alanine on Irradiated Quartz

    NASA Astrophysics Data System (ADS)

    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. Studies on Dyeing Process Variables for Salt Free Reactive Dyeing of Glycine Modified Cationized Cotton Muslin Fabric

    NASA Astrophysics Data System (ADS)

    Samanta, Ashis Kumar; Kar, Tapas Ranjan; Mukhopadhyay, Asis; Shome, Debashis; Konar, Adwaita

    2015-04-01

    Bleached cotton muslin fabric with or without pre-oxidized with NaIO4 (oxy-cotton) was chemically modified with glycine (amino acid) by pad dry calendar process to investigate the changes in textile properties and its dyeability with reactive dye. This glycine modified cotton incorporates new functional groups producing -NH3 + or -C=NH+ -ion (cationic groups) in acid bath to obtain cationized cotton making it amenable to a newer route of salt free reactive dyeing in acid bath. In the present work the process variables of reactive dyeing in the salt free acid bath for dyeing of amine (glycine) modified cationized cotton were studied and optimized. The present study also includes thorough investigation of changes in important textile related properties and dyeability with reactive dye after such chemical modifications. Between oxidized and unoxidized cotton muslin fabric, unoxidized cotton fabric shows better reactive dye uptake in both conventional alkaline bath dyeing and nonconventional salt free acid bath dyeing particularly for high exhaustion class of reactive dye with acceptable level of colour fastness and overall balance of other textile related properties. Moreover, application of dye fixing agent further improves surface colour depth (K/S) of the glycine treated cotton fabric for HE brand of reactive dyes. Corresponding reaction mechanisms for such modifications were supported by FTIR spectroscopy. Finally unoxidized cotton and pre-oxidized cotton further treated with glycine (amino acid) provide a new route of acid bath salt free reactive dyeing showing much higher dye uptake and higher degree of surface cover with amino acid residue anchored to modified cotton.

  4. Further Characterization of Glycine-Containing Microcystins from the McMurdo Dry Valleys of Antarctica

    PubMed Central

    Puddick, Jonathan; Prinsep, Michèle R.; Wood, Susanna A.; Cary, Stephen Craig; Hamilton, David P.; Holland, Patrick T.

    2015-01-01

    Microcystins are hepatotoxic cyclic peptides produced by several cyanobacterial genera worldwide. In 2008, our research group identified eight new glycine-containing microcystin congeners in two hydro-terrestrial mat samples from the McMurdo Dry Valleys of Eastern Antarctica. During the present study, high-resolution mass spectrometry, amino acid analysis and micro-scale thiol derivatization were used to further elucidate their structures. The Antarctic microcystin congeners contained the rare substitution of the position-1 d-alanine for glycine, as well as the acetyl desmethyl modification of the position-5 Adda moiety (3S-amino-9S-methoxy-2S,6,8S-trimethyl-10-phenyldeca-4E,6E-dienoic acid). Amino acid analysis was used to determine the stereochemistry of several of the amino acids and conclusively demonstrated the presence of glycine in the microcystins. A recently developed thiol derivatization technique showed that each microcystin contained dehydrobutyrine in position-7 instead of the commonly observed N-methyl dehydroalanine. PMID:25675414

  5. Iminoglycinuria and hyperglycinuria are discrete human phenotypes resulting from complex mutations in proline and glycine transporters

    PubMed Central

    Bröer, Stefan; Bailey, Charles G.; Kowalczuk, Sonja; Ng, Cynthia; Vanslambrouck, Jessica M.; Rodgers, Helen; Auray-Blais, Christiane; Cavanaugh, Juleen A.; Bröer, Angelika; Rasko, John E.J.

    2008-01-01

    Iminoglycinuria (IG) is an autosomal recessive abnormality of renal transport of glycine and the imino acids proline and hydroxyproline, but the specific genetic defect(s) have not been determined. Similarly, although the related disorder hyperglycinuria (HG) without iminoaciduria has been attributed to heterozygosity of a putative defective glycine, proline, and hydroxyproline transporter, confirming the underlying genetic defect(s) has been difficult. Here we applied a candidate gene sequencing approach in 7 families first identified through newborn IG screening programs. Both inheritance and functional studies identified the gene encoding the proton amino acid transporter SLC36A2 (PAT2) as the major gene responsible for IG in these families, and its inheritance was consistent with a classical semidominant pattern in which 2 inherited nonfunctional alleles conferred the IG phenotype, while 1 nonfunctional allele was sufficient to confer the HG phenotype. Mutations in SLC36A2 that retained residual transport activity resulted in the IG phenotype when combined with mutations in the gene encoding the imino acid transporter SLC6A20 (IMINO). Additional mutations were identified in the genes encoding the putative glycine transporter SLC6A18 (XT2) and the neutral amino acid transporter SLC6A19 (B0AT1) in families with either IG or HG, suggesting that mutations in the genes encoding these transporters may also contribute to these phenotypes. In summary, although recognized as apparently simple Mendelian disorders, IG and HG exhibit complex molecular explanations depending on a major gene and accompanying modifier genes. PMID:19033659

  6. Dicationic Surfactants with Glycine Counter Ions for Oligonucleotide Transportation.

    PubMed

    Pietralik, Zuzanna; Skrzypczak, Andrzej; Kozak, Maciej

    2016-08-01

    Gemini surfactants are good candidates to bind, protect, and deliver nucleic acids. Herein, the concept of amino acids (namely glycine) as counter ions of gemini surfactants for gene therapy application was explored. This study was conducted on DNA and RNA oligomers and two quaternary bis-imidazolium salts, having 2,5-dioxahexane and 2,8-dioxanonane spacer groups. The toxicity level of surfactants was assessed by an MTT assay, and their ability to bind nucleic acids was tested through electrophoresis. The nucleic acid conformation was established based on circular dichroism and infrared spectroscopic analyses. The structures of the formed complexes were characterized by small-angle scattering of synchrotron radiation. Both studied surfactants appear to be suitable for gene therapy; however, although they vary by only three methylene groups in the spacer, they differ in binding ability and toxicity. The tested oligonucleotides maintained their native conformations upon surfactant addition and the studied lipoplexes formed a variety of structures. In systems based on a 2,5-dioxahexane spacer, a hexagonal phase was observed for DNA-surfactant complexes and a micellar phase was dominant with RNA. For the surfactant with a 2,8-dioxanonane spacer group, the primitive cubic phase prevailed. PMID:27214208

  7. The influence of crystallinity degree on the glycine decomposition induced by 1 MeV proton bombardment in space analog conditions.

    PubMed

    Pilling, Sergio; Mendes, Luiz A V; Bordalo, Vinicius; Guaman, Christian F M; Ponciano, Cássia R; da Silveira, Enio F

    2013-01-01

    Glycine is the simplest proteinaceous amino acid and is present in all life-forms on Earth. In aqueous solutions, it appears mainly as zwitterion glycine (+NH3CH2COO-); however, in solid phase, it may be found in amorphous or crystalline (α, β, and γ) forms. The crystalline forms differ from each other by the packing of zwitterions in the unitary cells and by the number of intermolecular hydrogen bonds. This molecular species has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, glycine is exposed to several radiation fields at different temperatures. We present an experimental study on the destruction of zwitterionic glycine crystals at room temperature by 1 MeV protons, in which the dependence of the destruction rates of the α-glycine and β-glycine crystals on bombardment fluence is investigated. The samples were analyzed in situ by Fourier transform infrared spectrometry at different proton fluences. The experiments occurred under ultrahigh vacuum conditions at the Van de Graaff accelerator lab at the Pontifical Catholic University at Rio de Janeiro (PUC-Rio), Brazil. For low fluences, the dissociation cross section of α-glycine was observed to be 2.5×10(-14) cm2, a value roughly 5 times higher than the dissociation cross section found for β-glycine. The estimated half-lives of α-glycine and β-glycine zwitterionic forms extrapolated to the Earth orbit environment are 9×10(5) and 4×10(6) years, respectively. In the diffuse interstellar medium the estimated values are 1 order of magnitude lower. These results suggest that pristine interstellar β-glycine is the one most likely to survive the hostile environments of space radiation. A small feature around 1650-1700 cm(-1), tentatively attributed to an amide functional group, was observed in the IR spectra of irradiated samples, suggesting that cosmic rays may induce peptide bond synthesis in

  8. Polyamine synthesis in plants. Purification and properties of amidinotransferase from soybean (Glycine max) axes.

    PubMed

    Lee, Geun Taek; Kim, Woo Jeung; Cho, Young Dong

    2002-12-01

    Three-day-old soybean (Glycine max) seedlings were exposed to 0.4 M sorbitol solution for 4 h to induce amidinotransferase activity, with the corresponding enzyme being purified to homogeneity by chromatographic separation on DEAE-Sephacel, Sephacryl S-300 and L-arginine Sepharose 4B. The purified enzyme used L-arginine and L-glycine as the major donor/acceptor of the amidino group, respectively, with formation of guanidinoacetic acid and ornithine products being confirmed by ESI-MS. The enzyme is a tetrameric protein having a molecular mass of 240,000 Da, whose thiol group is needed for enzymatic activity. The K(M)s for arginine and glycine were 3.8 and 0.89 mM, respectively, with optimal temperature and pH being 37 degrees C and 9.5, respectively. The soybean amidinotransferase could be indirectly involved in nitrogen metabolism, as suggested by the observation that arginine:glycine amidinotransferase in soybean axes is indirectly involved in putrescine biosynthesis and displays feedback control at high levels of an endogenous regulator, putrescine. PMID:12453570

  9. Effect of Liquid Swine Manure on Hatch and Viability of Heterodera glycines

    PubMed Central

    Xiao, Jianli; Chen, Senyu; Zhu, Jun; Ruan, Weibin

    2008-01-01

    Experiments were conducted in the laboratory and greenhouse to determine the effect of raw and anaerobically digested liquid swine manures on the hatch and viability of Heterodera glycines, the soybean cyst nematode. Anaerobic digestion was performed for 15 and 35 days to enrich volatile fatty acids (VFA) and ammonium (NH4 +), respectively. All filtrates of the raw, VFA-enriched, and NH4 +-enriched manures at 10−1 to 250−1 dilutions inhibited H. glycines hatch, and the reduction of hatch was increased with increasing concentration of the manure. Cumulative hatch at day 21 was only 2.1% to 3.7% in the 10−1 dilution manures, while the hatch in water was 21% to 27.3%. The high concentrations appeared to be lethal to some eggs. Most second-stage juveniles (J2) of H. glycines were killed when incubated for 8 hours in the manure filtrate at the original concentration (>90% mortality) or for 48 hours at the 64−1 dilution (> 82% mortality). When J2 were treated with the manures at 10−1 to 250−1 dilutions for 4 hours, only the 10−1 dilution of VFA-enriched and raw manures resulted in a lower number of J2 that penetrated soybean roots as compared with lower concentrations. The VFA-enriched manure was the best, raw manure intermediate, and NH4 +-enriched manure the least effective in inhibiting H. glycines hatch and killing eggs and J2. PMID:19259532

  10. Exposure to the Proton Scavenger Glycine under Alkaline Conditions Induces Escherichia coli Viability Loss

    PubMed Central

    Vanhauteghem, Donna; Janssens, Geert Paul Jules; Lauwaerts, Angelo; Sys, Stanislas; Boyen, Filip; Cox, Eric; Meyer, Evelyne

    2013-01-01

    Our previous work described a clear loss of Escherichia coli (E. coli) membrane integrity after incubation with glycine or its N-methylated derivatives N-methylglycine (sarcosine) and N,N-dimethylglycine (DMG), but not N,N,N-trimethylglycine (betaine), under alkaline stress conditions. The current study offers a thorough viability analysis, based on a combination of real-time physiological techniques, of E. coli exposed to glycine and its N-methylated derivatives at alkaline pH. Flow cytometry was applied to assess various physiological parameters such as membrane permeability, esterase activity, respiratory activity and membrane potential. ATP and inorganic phosphate concentrations were also determined. Membrane damage was confirmed through the measurement of nucleic acid leakage. Results further showed no loss of esterase or respiratory activity, while an instant and significant decrease in the ATP concentration occurred upon exposure to either glycine, sarcosine or DMG, but not betaine. There was a clear membrane hyperpolarization as well as a significant increase in cellular inorganic phosphate concentration. Based on these results, we suggest that the inability to sustain an adequate level of ATP combined with a decrease in membrane functionality leads to the loss of bacterial viability when exposed to the proton scavengers glycine, sarcosine and DMG at alkaline pH. PMID:23544135

  11. Exposure to the proton scavenger glycine under alkaline conditions induces Escherichia coli viability loss.

    PubMed

    Vanhauteghem, Donna; Janssens, Geert Paul Jules; Lauwaerts, Angelo; Sys, Stanislas; Boyen, Filip; Cox, Eric; Meyer, Evelyne

    2013-01-01

    Our previous work described a clear loss of Escherichia coli (E. coli) membrane integrity after incubation with glycine or its N-methylated derivatives N-methylglycine (sarcosine) and N,N-dimethylglycine (DMG), but not N,N,N-trimethylglycine (betaine), under alkaline stress conditions. The current study offers a thorough viability analysis, based on a combination of real-time physiological techniques, of E. coli exposed to glycine and its N-methylated derivatives at alkaline pH. Flow cytometry was applied to assess various physiological parameters such as membrane permeability, esterase activity, respiratory activity and membrane potential. ATP and inorganic phosphate concentrations were also determined. Membrane damage was confirmed through the measurement of nucleic acid leakage. Results further showed no loss of esterase or respiratory activity, while an instant and significant decrease in the ATP concentration occurred upon exposure to either glycine, sarcosine or DMG, but not betaine. There was a clear membrane hyperpolarization as well as a significant increase in cellular inorganic phosphate concentration. Based on these results, we suggest that the inability to sustain an adequate level of ATP combined with a decrease in membrane functionality leads to the loss of bacterial viability when exposed to the proton scavengers glycine, sarcosine and DMG at alkaline pH. PMID:23544135

  12. Glycine: an alternative transmitter candidate of the pallidosubthalamic projection neurons in the rat

    SciTech Connect

    Takada, M.; Hattori, T.

    1987-08-22

    Autoradiographic retrograde tracing techniques with radioactive transmitters were used to analyse the identity of a putative transmitter in the rat pallidosubthalamic (GP-STN) pathway. One to 2 hours after the stereotaxic injection of /sup 3/H-glycine restricted to the STN, a large number of neuronal somata were radiolabeled in the GP. No comparable labeling was observed following the injection of /sup 3/H-gamma-aminobutyric acid (/sup 3/H-GABA) into the same nucleus even with survival times as long as 6 hours. Specifically, no significant somatic labeling was detected either in the GP or in the caudoputamen (CPU). Only when /sup 3/H-GABA was injected into the substantia nigra did CPU and GP neurons become labeled. On the contrary, STN neuronal somata were invariably labeled 6 hours after the intrapallidal injection of /sup 3/H-GABA, whereas no perikaryal labeling was observed in the STN after /sup 3/H-glycine injection into the GP. The perikaryal labeling was prevented in all cases by intraventricular administration of colchicine 1 day before the isotope injections. The observations suggest that /sup 3/H-glycine was preferentially transported retrogradely through the GP-STN pathway, and /sup 3/H-GABA through the STN-GP projection. In view of the recent controversy on the role of GABA as a putative transmitter of the GP-STN projection, we now propose glycine as an alternative transmitter candidate of these critically situated neurons in the basal ganglia.

  13. Spectrophotometric Determination of Iron(III)-Glycine Formation Constant in Aqueous Medium Using Competitive Ligand Binding

    ERIC Educational Resources Information Center

    Prasad, Rajendra; Prasad, Surendra

    2009-01-01

    The formation constant of iron(III) complex with glycine (Gly) ligand in aqueous acidic medium (0.2 M HNO[subscript 3], I = 0.2 M at 28 plus or minus 1 degree C) was determined spectrophotometrically in which a competing color reaction between Fe(III) and SCN[superscript -] was used as an indicator reaction. Under the specified conditions Fe(III)…

  14. Evaluation of mechanical properties of some glycine complexes

    NASA Astrophysics Data System (ADS)

    Nagaraju, D.; Raja Shekar, P. V.; Chandra, Ch. Sateesh; Rao, K. Kishan; Krishna, N. Gopi

    2014-04-01

    The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young's modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

  15. 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.

  16. 21 CFR 176.160 - Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Chromium (Cr III) complex of N-ethyl-N... § 176.160 Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine. The chromium... by weight of the chromium (Cr III) complex of heptadecylfluoro-octane sulfonic acid may be...

  17. Glyphosate resistant and susceptible soybean (Glycine max) and canola (Brassica napus) dose response and metabolism relationships with glyphosate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to determine 1) dose response of glyphosate-resistant (GR) and –susceptible (non-GR) soybean [Glycine max (L.) Merr.] and canola (Brassica napus L.) to glyphosate, 2) if differential metabolism of glyphosate to aminomethylphosphonic acid (AMPA) is the underlying mechanism ...

  18. Novel Pectate Lyase Genes of Heterodera glycines Play Key Roles in the Early Stage of Parasitism.

    PubMed

    Peng, Huan; Cui, Jiangkuan; Long, Haibo; Huang, Wenkun; Kong, Lingan; Liu, Shiming; He, Wenting; Hu, Xianqi; Peng, Deliang

    2016-01-01

    Pectate lyases are known to play a key role in pectin degradation by catalyzing the random cleavage of internal polymer linkages (endo-pectinases). In this paper, four novel cDNAs, designated Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7, that encode pectate lyases were cloned and characterized from the soybean cyst nematode, Heterodera glycines. The predicted protein sequences of HG-PEL-3, HG-PEL-4 and HG-PEL-6 differed significantly in both their amino acid sequences and their genomic structures from other pectate lyases of H. glycines (HG-PEL-1, HG-PEL-2 and HG-PEL-7). A phylogenetic study revealed that the pectate lyase proteins of H. glycines are clustered into distinct clades and have distinct numbers and positioning of introns, which suggests that the pectate lyase genes of H. glycines may have evolved from at least two ancestral genes. A Southern blot analysis revealed that multiple Hg-pel-6-like genes were present in the H. glycines genome. In situ hybridization showed that four novel pectate lyases (Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7) were actively transcribed in the subventral esophageal gland cells. A semi-quantitative RT-PCR assay supported the finding that the expression of these genes was strong in the egg, pre-parasitic second-stage juvenile (J2) and early parasitic J2 stages and that it declined in further developmental stages of the nematode. This expression pattern suggests that these proteins play a role in the migratory phase of the nematode life cycle. Knocking down Hg-pel-6 using in vitro RNA interference resulted in a 46.9% reduction of the number of nematodes that invaded the plants and a 61.5% suppression of the development of H. glycines females within roots compared to the GFP-dsRNA control. Plant host-derived RNAi induced the silencing of the Hg-pel-6gene, which significantly reduced the nematode infection levels at 7 Days post inoculation (dpi). Similarly, this procedure reduced the number of female adults at 40 dpi, which suggests

  19. Novel Pectate Lyase Genes of Heterodera glycines Play Key Roles in the Early Stage of Parasitism

    PubMed Central

    Peng, Huan; Cui, Jiangkuan; Long, Haibo; Huang, Wenkun; Kong, Lingan; Liu, Shiming; He, Wenting; Hu, Xianqi; Peng, Deliang

    2016-01-01

    Pectate lyases are known to play a key role in pectin degradation by catalyzing the random cleavage of internal polymer linkages (endo-pectinases). In this paper, four novel cDNAs, designated Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7, that encode pectate lyases were cloned and characterized from the soybean cyst nematode, Heterodera glycines. The predicted protein sequences of HG-PEL-3, HG-PEL-4 and HG-PEL-6 differed significantly in both their amino acid sequences and their genomic structures from other pectate lyases of H. glycines (HG-PEL-1, HG-PEL-2 and HG-PEL-7). A phylogenetic study revealed that the pectate lyase proteins of H. glycines are clustered into distinct clades and have distinct numbers and positioning of introns, which suggests that the pectate lyase genes of H. glycines may have evolved from at least two ancestral genes. A Southern blot analysis revealed that multiple Hg-pel-6-like genes were present in the H. glycines genome. In situ hybridization showed that four novel pectate lyases (Hg-pel-3, Hg-pel-4, Hg-pel-6 and Hg-pel-7) were actively transcribed in the subventral esophageal gland cells. A semi-quantitative RT-PCR assay supported the finding that the expression of these genes was strong in the egg, pre-parasitic second-stage juvenile (J2) and early parasitic J2 stages and that it declined in further developmental stages of the nematode. This expression pattern suggests that these proteins play a role in the migratory phase of the nematode life cycle. Knocking down Hg-pel-6 using in vitro RNA interference resulted in a 46.9% reduction of the number of nematodes that invaded the plants and a 61.5% suppression of the development of H. glycines females within roots compared to the GFP-dsRNA control. Plant host-derived RNAi induced the silencing of the Hg-pel-6gene, which significantly reduced the nematode infection levels at 7 Days post inoculation (dpi). Similarly, this procedure reduced the number of female adults at 40 dpi, which suggests

  20. Linear free energy relationship rate constants and basicities of N-substituted phenyl glycines in positronium-glycine complex formation

    NASA Astrophysics Data System (ADS)

    Chen, Rongti; Liang, Jiachang; Du, Youming; Cao, Chun; Yin, Dinzhen; Wang, Shuying; Zhang, Tianbao

    1987-06-01

    Complex formation between positronium and glycine derivatives in solution is discussed and the complex reaction rate constants obtained by means of a positron annihilation lifetime spectrometer with BaF 2 detectors. Rate constants mainly depend on the conjugation effect at the benzene ring and the induction effect of the substituents at the phenyl. There is a linear free energy relationship between rate constants and basicities of N-substituted phenyl glycines in orthopositronium-glycine complex formation.

  1. D-Galacturonic Acid: A Highly Reactive Compound in Nonenzymatic Browning. 2. Formation of Amino-Specific Degradation Products.

    PubMed

    Wegener, Steffen; Bornik, Maria-Anna; Kroh, Lothar W

    2015-07-22

    Thermal treatment of aqueous solutions of D-galacturonic acid and L-alanine at pH 3, 5, and 8 led to rapid and more intensive nonenzymatic browning reactions compared to similar solutions of other uronic acids and to Maillard reactions of reducing sugars. The hemiacetal ring structures of uronic acids had a high impact on browning behavior and reaction pathways. Besides reductic acid (1,2-dihydroxy-2-cyclopenten-1-one), 4,5-dihydroxy-2-cyclopenten-1-one (DHCP), furan-2-carboxaldehyde, and norfuraneol (4-hydroxy-5-methyl-3-(2H)-furanone) could be detected as typical products of nonenzymatic uronic acid browning reactions. 2-(2-Formyl-1H-pyrrole-1-yl)propanoic acid (FPA) and 1-(1-carboxyethyl)-3-hydroxypyridin-1-ium (HPA) were identified as specific reaction products of uronic acids with amine participation like l-alanine. In contrast, the structurally related D-galacturonic acid methyl ester showed less browning activity and degradation under equal reaction conditions. Pectin-specific degradation products such as 5-formyl-2-furanoic acid and 2-furanoic acid were found but could not be verified for d-galacturonic acid monomers alone. PMID:26111613

  2. Arginine-glycine-aspartic acid- and fibrinogen gamma-chain carboxyterminal peptides inhibit platelet adherence to arterial subendothelium at high wall shear rates. An effect dissociable from interference with adhesive protein binding.

    PubMed Central

    Lawrence, J B; Kramer, W S; McKeown, L P; Williams, S B; Gralnick, H R

    1990-01-01

    Arg-Gly-Asp (RGD)- and fibrinogen gamma-chain carboxyterminal (GQQHHLGGAKQAGDV) peptides inhibit fibrinogen, fibronectin (Fn), vitronectin, and von Willebrand factor (vWF) binding to the platelet glycoprotein IIb-IIIa complex (GP IIb-IIIa). GP IIb-IIIa, vWF, and Fn are essential for normal platelet adherence to subendothelium. We added peptides to normal citrated whole blood before perfusion over human umbilical artery subendothelium and evaluated platelet adherence morphometrically at high (2,600 s-1) and low (800 s-1) wall shear rates. We also examined the effects of the peptides on platelet adhesion to collagen in a static system. At the high wall shear rate, RGDS and GQQHHLGGAKQAGDV caused dose-dependent reduction in the surface coverage with spread and adherent platelets. Amino acid transposition and conservative substitutions of RGD peptides and the AGDV peptide significantly inhibited platelet adherence at 2,600 s-1. By contrast, the modified RGD peptides and AGDV do not affect adhesive protein binding to platelets. None of the native or modified RGD- or fibrinogen gamma-chain peptides significantly inhibited either platelet adherence to subendothelium at 800 s-1 or platelet adhesion to collagen. Our findings demonstrate that peptides that interfere with adhesive protein binding to GP IIb-IIIa inhibit platelet adherence to vascular subendothelium with flowing blood only at high wall shear rates. Platelet adherence to subendothelium at high wall shear rates appears to be mediated by different recognition specificities from those required for fluid-phase adhesive protein binding or static platelet adhesion. PMID:2243140

  3. Effect of bromide ion on the reaction pathway between hydroxyl radical and glycine.

    PubMed

    Ying, Liwen; Dong, Wenbo; Yuan, Haixia; Liu, Yan; Ma, Luming

    2015-06-01

    Br(-) and nitrogen-containing organic pollutants, such as amino acids, protein, etc., were often detected in water and wastewater treatment plants using advanced oxidation technologies. All these technologies have one common characteristic, that is, the removal processes involve ·OH. Therefore, it is necessary to study the different reaction pathways among ·OH, Br(-), and amino acids. In this research, glycine was chosen as the representative of amino acids and H2O2 was selected as ·OH precursor. Results showed that Br(-) had a shielding effect on [Formula: see text] of α-carbon in glycine, when it was abstracted by ·OH. The main reaction pathway in the system containing Br(-) was the abstraction of H from amino group in glycine by ·OH, contributing 85 % of total abstracted H. This system had a prominent phenomenon of decarboxylation and performed as alkali production dominating. However, in the system not containing Br(-), the main reaction pathway was the abstraction of H from α-carbon in glycine by ·OH, contributing 97 % of total abstracted H. This system performed as acid production dominating. By laser flash photolysis, the second-order rate constants of abstraction of H from both α-carbon and amino group in glycine by ·OH were obtained as (3.3 ± 0.5) × 10(7) M(-1)·s(-1) and (8.2 ± 0.8) × 10(8) M(-1)·s(-1), respectively. The second-order rate constants of the reaction between [Formula: see text], HṄCH2COO(-) and H2O2 were (1.5 ± 1.1) × 10(7) M(-1)·s(-1) and (4.4 ± 0.3) × 10(7) M(-1)·s(-1), respectively. In addition, Br(-) was found to play a catalytic role in the decomposition of H2O2 under UV radiation. The results mentioned above were significant for the application of advanced oxidation technologies for water containing both amino acids and Br(-) in water and wastewater treatment plants. PMID:25548016

  4. The N-methyl D-aspartate receptor glycine site and D-serine metabolism: an evolutionary perspective.

    PubMed Central

    Schell, Michael J

    2004-01-01

    The N-methyl D-aspartate (NMDA) type of glutamate receptor requires two distinct agonists to operate. Glycine is assumed to be the endogenous ligand for the NMDA receptor glycine site, but this notion has been challenged by the discovery of high levels of endogenous d-serine in the mammalian forebrain. I have outlined an evolutionary framework for the appearance of a glycine site in animals and the metabolic events leading to high levels of D-serine in brain. Sequence alignments of the glycine-binding regions, along with the scant experimental data available, suggest that the properties of invertebrate NMDA receptor glycine sites are probably different from those in vertebrates. The synthesis of D-serine in brain is due to a pyridoxal-5'-phosphate (B(6))-requiring serine racemase in glia. Although it remains unknown when serine racemase first evolved, data concerning the evolution of B(6) enzymes, along with the known occurrences of serine racemases in animals, point to D-serine synthesis arising around the divergence time of arthropods. D-Serine catabolism occurs via the ancient peroxisomal enzyme d-amino acid oxidase (DAO), whose ontogenetic expression in the hindbrain of mammals is delayed until the postnatal period and absent from the forebrain. The phylogeny of D-serine metabolism has relevance to our understanding of brain ontogeny, schizophrenia and neurotransmitter dynamics. PMID:15306409

  5. Inhibition of homocysteine-induced endoplasmic reticulum stress and endothelial cell damage by l-serine and glycine.

    PubMed

    Sim, Woo-Cheol; Han, Inhoi; Lee, Wonseok; Choi, You-Jin; Lee, Kang-Yo; Kim, Dong Gwang; Jung, Seung-Hwan; Oh, Seon-Hee; Lee, Byung-Hoon

    2016-08-01

    Hyperhomocysteinemia is an independent risk factor for several cardiovascular diseases. The use of vitamins to modulate homocysteine metabolism substantially lowers the risk by reducing plasma homocysteine levels. In this study, we evaluated the effects of l-serine and related amino acids on homocysteine-induced endoplasmic reticulum (ER) stress and endothelial cell damage using EA.hy926 human endothelial cells. Homocysteine treatment decreased cell viability and increased apoptosis, which were reversed by cotreatment with l-serine. l-Serine inhibited homocysteine-induced ER stress as verified by decreased glucose-regulated protein 78kDa (GRP78) and C/EBP homologous protein (CHOP) expression as well as X-box binding protein 1 (xbp1) mRNA splicing. The effects of l-serine on homocysteine-induced ER stress are not attributed to intracellular homocysteine metabolism, but instead to decreased homocysteine uptake. Glycine exerted effects on homocysteine-induced ER stress, apoptosis, and cell viability that were comparable to those of l-serine. Although glycine did not affect homocysteine uptake or export, coincubation of homocysteine with glycine for 24h reduced the intracellular concentration of homocysteine. Taken together, l-serine and glycine cause homocysteine-induced endothelial cell damage by reducing the level of intracellular homocysteine. l-Serine acts by competitively inhibiting homocysteine uptake in the cells. However, the mechanism(s) by which glycine lowers homocysteine levels are unclear. PMID:27064126

  6. COMPUTATIONAL STUDY OF INTERSTELLAR GLYCINE FORMATION OCCURRING AT RADICAL SURFACES OF WATER-ICE DUST PARTICLES

    SciTech Connect

    Rimola, Albert; Sodupe, Mariona; Ugliengo, Piero

    2012-07-20

    Glycine is the simplest amino acid, and due to the significant astrobiological implications that suppose its detection, the search for it in the interstellar medium (ISM), meteorites, and comets is intensively investigated. In the present work, quantum mechanical calculations based on density functional theory have been used to model the glycine formation on water-ice clusters present in the ISM. The removal of either one H atom or one electron from the water-ice cluster has been considered to simulate the effect of photolytic radiation and of ionizing particles, respectively, which lead to the formation of OH{sup .} radical and H{sub 3}O{sup +} surface defects. The coupling of incoming CO molecules with the surface OH{sup .} radicals on the ice clusters yields the formation of the COOH{sup .} radicals via ZPE-corrected energy barriers and reaction energies of about 4-5 kcal mol{sup -1} and -22 kcal mol{sup -1}, respectively. The COOH{sup .} radicals couple with incoming NH=CH{sub 2} molecules (experimentally detected in the ISM) to form the NHCH{sub 2}COOH{sup .} radical glycine through energy barriers of 12 kcal mol{sup -1}, exceedingly high at ISM cryogenic temperatures. Nonetheless, when H{sub 3}O{sup +} is present, one proton may be barrierless transferred to NH=CH{sub 2} to give NH{sub 2}=CH{sub 2}{sup +}. This latter may react with the COOH{sup .} radical to give the NH{sub 2}CH{sub 2}COOH{sup +.} glycine radical cation which can then be transformed into the NH{sub 2}CHC(OH){sub 2}{sup +.} species (the most stable form of glycine in its radical cation state) or into the NH{sub 2}CHCOOH{sup .} neutral radical glycine. Estimated rate constants of these events suggest that they are kinetically feasible at temperatures of 100-200 K, which indicate that their occurrence may take place in hot molecular cores or in comets exposed to warmer regions of solar systems. Present results provide quantum chemical evidence that defects formed on water ices due to the harsh

  7. Regulation of Glucagon Secretion in Normal and Diabetic Human Islets by γ-Hydroxybutyrate and Glycine*

    PubMed Central

    Li, Changhong; Liu, Chengyang; Nissim, Itzhak; Chen, Jie; Chen, Pan; Doliba, Nicolai; Zhang, Tingting; Nissim, Ilana; Daikhin, Yevgeny; Stokes, David; Yudkoff, Marc; Bennett, Michael J.; Stanley, Charles A.; Matschinsky, Franz M.; Naji, Ali

    2013-01-01

    Paracrine signaling between pancreatic islet β-cells and α-cells has been proposed to play a role in regulating glucagon responses to elevated glucose and hypoglycemia. To examine this possibility in human islets, we used a metabolomic approach to trace the responses of amino acids and other potential neurotransmitters to stimulation with [U-13C]glucose in both normal individuals and type 2 diabetics. Islets from type 2 diabetics uniformly showed decreased glucose stimulation of insulin secretion and respiratory rate but demonstrated two different patterns of glucagon responses to glucose: one group responded normally to suppression of glucagon by glucose, but the second group was non-responsive. The non-responsive group showed evidence of suppressed islet GABA levels and of GABA shunt activity. In further studies with normal human islets, we found that γ-hydroxybutyrate (GHB), a potent inhibitory neurotransmitter, is generated in β-cells by an extension of the GABA shunt during glucose stimulation and interacts with α-cell GHB receptors, thus mediating the suppressive effect of glucose on glucagon release. We also identified glycine, acting via α-cell glycine receptors, as the predominant amino acid stimulator of glucagon release. The results suggest that glycine and GHB provide a counterbalancing receptor-based mechanism for controlling α-cell secretory responses to metabolic fuels. PMID:23266825

  8. Regulation of glucagon secretion in normal and diabetic human islets by γ-hydroxybutyrate and glycine.

    PubMed

    Li, Changhong; Liu, Chengyang; Nissim, Itzhak; Chen, Jie; Chen, Pan; Doliba, Nicolai; Zhang, Tingting; Nissim, Ilana; Daikhin, Yevgeny; Stokes, David; Yudkoff, Marc; Bennett, Michael J; Stanley, Charles A; Matschinsky, Franz M; Naji, Ali

    2013-02-01

    Paracrine signaling between pancreatic islet β-cells and α-cells has been proposed to play a role in regulating glucagon responses to elevated glucose and hypoglycemia. To examine this possibility in human islets, we used a metabolomic approach to trace the responses of amino acids and other potential neurotransmitters to stimulation with [U-(13)C]glucose in both normal individuals and type 2 diabetics. Islets from type 2 diabetics uniformly showed decreased glucose stimulation of insulin secretion and respiratory rate but demonstrated two different patterns of glucagon responses to glucose: one group responded normally to suppression of glucagon by glucose, but the second group was non-responsive. The non-responsive group showed evidence of suppressed islet GABA levels and of GABA shunt activity. In further studies with normal human islets, we found that γ-hydroxybutyrate (GHB), a potent inhibitory neurotransmitter, is generated in β-cells by an extension of the GABA shunt during glucose stimulation and interacts with α-cell GHB receptors, thus mediating the suppressive effect of glucose on glucagon release. We also identified glycine, acting via α-cell glycine receptors, as the predominant amino acid stimulator of glucagon release. The results suggest that glycine and GHB provide a counterbalancing receptor-based mechanism for controlling α-cell secretory responses to metabolic fuels. PMID:23266825

  9. Protein synthesis in cancer patients with inflammatory response: investigations with [15N]glycine.

    PubMed

    McMillan, D C; Preston, T; Fearon, K C; Burns, H J; Slater, C; Shenkin, A

    1994-01-01

    It has been proposed that the increase in amino acid flux and derived protein synthesis rates observed in weight-losing cancer patients may contribute to an ongoing negative energy balance. The mediators and tissues responsible for such apparent increased protein synthesis have not been clearly identified. The aim of this study was to examine the relationship between protein synthetic rates in whole-body, skeletal muscle, and circulating cortisol concentrations in healthy subjects (n = 6) and cancer patients with evidence of an inflammatory response (n = 6). Protein synthetic rates were measured with a primed continuous 20-h infusion of [15N]glycine. Skeletal muscle was biopsied at laparotomy. Serum cortisol, resting energy expenditure, plasma proteins, nitrogen metabolites in urine, and skeletal muscle free amino acids were also measured. Derived whole-body and skeletal muscle protein synthetic rates in the cancer group were increased significantly (by 70 and 93%, respectively, p < 0.05). Circulating concentrations of cortisol, fibrinogen, and C-reactive protein were also significantly increased in the cancer group and indicated the presence of an inflammatory response. However, there was no significant increase in resting energy expenditure. Mechanisms by which apparent increases in whole-body and skeletal protein synthesis do not result in an increase in resting energy expenditure are discussed. We conclude that glycine utilization is increased in cancer patients but that rates of protein synthesis derived from [15N]glycine kinetics may not be valid in such patients. PMID:7919675

  10. The effect of hyperphenylalaninaemia on glycine metabolism in developing rat brain.

    PubMed Central

    Isaacs, C E; Greengard, O

    1980-01-01

    The brains of 3--16-day-old rats that were rendered hyperphenylalaninaemic by daily injections of alpha-methylphenylalanine plus phenylalanine were subjected to biochemical analysis. Fluctuations throughout the treatment period in the concentrations of branched-chain amino acids, methionine and serotonin were in agreement with the known interference of excess plasma phenylalanine with transport. The glycine content, however, became abnormal only by day 5, remained so through the treatment, and the elevation was equally apparent at 4, 8 or 24 h after the last daily injections. On the last day of treatment there were small increases in the taurine, glutamate, aspartate and 4-aminobutyrate concentrations, attributable mainly to the diencephalon or brain stem. After day 3 of treatment there were persistent elevations in the specific activity of phosphoserine phosphatase and glycine synthase (but not serine hydroxymethyltransferase) of the brain in each of the regions analysed. The observations indicate that chronic hyperphenylalaninaemia interferes with the normal regulation of intracerebral glycine metabolism during a critical period of early postnatal development, and suggest that the resulting excess in this amino acid (particularly marked in the cortex) contributes to the behavioural abnormalities that these animals exhibit in later life. PMID:6112983

  11. 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. PMID:25421789

  12. Activation of presynaptic glycine receptors facilitates glycine release from presynaptic terminals synapsing onto rat spinal sacral dorsal commissural nucleus neurons

    PubMed Central

    Jeong, Hyo-Jin; Jang, Il-Sung; Moorhouse, Andrew J; Akaike, Norio

    2003-01-01

    Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Here we report the novel finding that presynaptic glycine autoreceptors modulate release from terminals synapsing onto rat spinal sacral dorsal commissural nucleus (SDCN) neurons. In mechanically dissociated SDCN neurons, in which functional presynaptic nerve terminals remain adherent to the isolated neurons, exogenously applied glycine (3 μM) increased the frequency of glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) without affecting their amplitudes or decay times. This suggests that glycine acts presynaptically to increase glycine release probability. Picrotoxin, at a concentration that had little direct effect on sIPSC frequency and amplitude (30 μM), significantly attenuated glycine-induced presynaptic sIPSC facilitation. The glycine-induced sIPSC frequency facilitation was completely abolished either in a Ca2+-free external solution or in the presence of 100 μM Cd2+, suggesting the involvement of extracellular Ca2+ influx into the nerve terminals. The glycine action was also completely occluded in the presence of 300 nM tetrodotoxin. In recordings from SDCN neurons in spinal cord slices, glycine (10 μM) increased evoked IPSC (eIPSC) amplitude and decreased the extent of paired-pulse facilitation. In response to brief high frequency stimulus trains the eIPSCs displayed a profound frequency-dependent facilitation that was greatly reduced by picrotoxin (30 μM). These results indicate that glycine acts at presynaptic autoreceptors, causing depolarization of the glycinergic nerve terminals, the subsequent activation of voltage-dependent Na+ and Ca2+ channels, and facilitation of glycine release. Furthermore, this presynaptic facilitation was observed under more physiological conditions, suggesting that these glycinergic autoreceptors may contribute to the integration of local inhibitory inputs to SDCN neurons. PMID:12754315

  13. 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...

  14. 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...

  15. 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. PMID:24162571

  16. Glycine receptor mechanism elucidated by electron cryo-microscopy.

    PubMed

    Du, Juan; Lü, Wei; Wu, Shenping; Cheng, Yifan; Gouaux, Eric

    2015-10-01

    The strychnine-sensitive glycine receptor (GlyR) mediates inhibitory synaptic transmission in the spinal cord and brainstem and is linked to neurological disorders, including autism and hyperekplexia. Understanding of molecular mechanisms and pharmacology of glycine receptors has been hindered by a lack of high-resolution structures. Here we report electron cryo-microscopy structures of the zebrafish α1 GlyR with strychnine, glycine, or glycine and ivermectin (glycine/ivermectin). Strychnine arrests the receptor in an antagonist-bound closed ion channel state, glycine stabilizes the receptor in an agonist-bound open channel state, and the glycine/ivermectin complex adopts a potentially desensitized or partially open state. Relative to the glycine-bound state, strychnine expands the agonist-binding pocket via outward movement of the C loop, promotes rearrangement of the extracellular and transmembrane domain 'wrist' interface, and leads to rotation of the transmembrane domain towards the pore axis, occluding the ion conduction pathway. These structures illuminate the GlyR mechanism and define a rubric to interpret structures of Cys-loop receptors. PMID:26344198

  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 520.550 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 Glucose/glycine/electrolyte. (a) Specifications. The product...

  18. Glycine transporter2 inhibitors: Getting the balance right.

    PubMed

    Vandenberg, Robert J; Mostyn, Shannon N; Carland, Jane E; Ryan, Renae M

    2016-09-01

    Neurotransmitter transporters are targets for a wide range of therapeutically useful drugs. This is because they have the capacity to selectively manipulate the dynamics of neurotransmitter concentrations and thereby enhance or diminish signalling through particular brain pathways. High affinity glycine transporters (GlyTs) regulate extracellular concentrations of glycine and provide novel therapeutic targets for neurological disorders. PMID:26723543

  19. NECTAR COMPOSITION OF WILD PERENNIAL GLYCINE (SOYBEAN) SPECIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Glycine contains the cultivated annual soybean G. max, the wild annual, G. soja, and about 21 wild perennial Glycine species. The perennials are largely indigenous to Australia, but are found in Papua New Guinea, Timor, Philippines, Japan and Taiwan. Outcrossing rates in the cultivated s...

  20. 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...

  1. Glycine Betaine as a Direct Substrate for Methanogens (Methanococcoides spp.)

    PubMed Central

    Watkins, Andrew J.; Roussel, Erwan G.; Parkes, R. John

    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. PMID:24162571

  2. -aminobutyric acid as a required germinant for mutant spores of Bacillus megaterium.

    PubMed

    Foerster, H F

    1971-11-01

    Germinated spores of Bacillus megaterium QM B1551 were irradiated with ultraviolet light, and spore-forming survivors were screened for germination requirements. Spore strains which failed to germinate in a variety of defined solutions germinative for spores of the parent strain were obtained. Mutant spores germinated readily in solutions containing yeast extract or one of numerous complex preparations. gamma-Aminobutyric acid, obtained from yeast extract by column chromatography, was shown to be required for germination by the mutant spores. gamma-Aminobutyric acid and l-alanine at final concentrations of 1 mm each, in solutions of KI (40 mm), equaled the potency of yeast extract (1 mg/ml) in the germination of the mutant spores. One of several other amino acids could be substituted, though less effectively, for l-alanine. alpha-Aminobutyric acid, beta-aminobutyric acid, beta-alanine, and 5-aminovaleric acid were ineffective substitutes for gamma-aminobutyric acid in mutant spore germination. PMID:5001872

  3. 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.

  4. Transgenic soybean overexpressing GmSamT1 exhibits resistance to multiple-HG types of soybean cysts nematode heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyzes the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heter...

  5. 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

  6. Extrinsic factors regulate partial agonist efficacy of strychnine-sensitive glycine receptors

    PubMed Central

    Farroni, Jeffrey S; McCool, Brian A

    2004-01-01

    Background Strychnine-sensitive glycine receptors in many adult forebrain regions consist of alpha2 + beta heteromeric channels. This subunit composition is distinct from the alpha1 + beta channels found throughout the adult spinal cord. Unfortunately, the pharmacology of forebrain alpha2beta receptors are poorly defined compared to 'neonatal' alpha2 homomeric channels or 'spinal' alpha1beta heteromers. In addition, the pharmacologic properties of native alpha2beta glycine receptors have been generally distinct from receptors produced by heterologous expression. To identify subtype-specific pharmacologic tools for the forebrain alpha2beta receptors, it is important to identify a heterologous expression system that closely resembles these native glycine-gated chloride channels. Results While exploring pharmacological properties of alpha2beta glycine receptors compared to alpha2-homomers, we found that distinct heterologous expression systems appeared to differentially influence partial agonist pharmacology. The β-amino acid taurine possessed 30–50% efficacy for alpha2-containing receptor isoforms when expressed in HEK 293 cells. However, taurine efficacy was dramatically reduced in L-cell fibroblasts. Similar results were obtained for β-alanine. The efficacy of these partial agonists was also strongly reduced by the beta subunit. There were no significant differences in apparent strychnine affinity values calculated from concentration-response data between expression systems or subunit combinations. Nor did relative levels of expression correlate with partial agonist efficacy when compared within or between several different expression systems. Finally, disruption of the tubulin cytoskeleton reduced the efficacy of partial agonists in a subunit-dependent, but system-independent, fashion. Conclusions Our results suggest that different heterologous expression systems can dramatically influence the agonist pharmacology of strychnine-sensitive glycine receptors. In

  7. Glycine uptake in heath plants and soil microbes responds to elevated temperature, CO 2 and drought

    NASA Astrophysics Data System (ADS)

    Andresen, Louise C.; Michelsen, Anders; Jonasson, Sven; Beier, Claus; Ambus, Per

    2009-11-01

    Temperate terrestrial ecosystems are currently exposed to climatic and air quality changes with increased atmospheric CO 2, increased temperature and prolonged droughts. The responses of natural ecosystems to these changes are focus for research, due to the potential feedbacks to the climate. We here present results from a field experiment in which the effects of these three climate change factors are investigated solely and in all combinations at a temperate heath dominated by heather ( Calluna vulgaris) and wavy hair-grass ( Deschampsia flexuosa). Climate induced increases in plant production may increase plant root exudation of dissolved organic compounds such as amino acids, and the release of amino acids during decomposition of organic matter. Such free amino acids in soil serve as substrates for soil microorganisms and are also acquired as nutrients directly by plants. We investigated the magnitude of the response to the potential climate change treatments on uptake of organic nitrogen in an in situ pulse labelling experiment with 15N 13C 2-labelled glycine (amino acid) injected into the soil. In situ root nitrogen acquisition by grasses responded significantly to the climate change treatments, with larger 15N uptake in response to warming and elevated CO 2 but not additively when the treatments were combined. Also, a larger grass leaf biomass in the combined T and CO 2 treatment than in individual treatments suggest that responses to combined climate change factors cannot be predicted from the responses to single factors treatments. The soil microbes were superior to plants in the short-term competition for the added glycine, as indicated by an 18 times larger 15N recovery in the microbial biomass compared to the plant biomass. The soil microbes acquired glycine largely as an intact compound (87%), with no effects of the multi factorial climate change treatment through one year.

  8. Evolution of threonine aldolases, a diverse family involved in the second pathway of glycine biosynthesis.

    PubMed

    Liu, Guangxiu; Zhang, Manxiao; Chen, Ximing; Zhang, Wei; Ding, Wei; Zhang, Qi

    2015-02-01

    Threonine aldolases (TAs) catalyze the interconversion of threonine and glycine plus acetaldehyde in a pyridoxal phosphate-dependent manner. This class of enzymes complements the primary glycine biosynthetic pathway catalyzed by serine hydroxymethyltransferase (SHMT), and was shown to be necessary for yeast glycine auxotrophy. Because the reverse reaction of TA involves carbon-carbon bond formation, resulting in a β-hydroxyl-α-amino acid with two adjacent chiral centers, TAs are of high interests in synthetic chemistry and bioengineering studies. Here, we report systematic phylogenetic analysis of TAs. Our results demonstrated that L-TAs and D-TAs that are specific for L- and D-threonine, respectively, are two phylogenetically unique families, and both enzymes are different from their closely related enzymes SHMTs and bacterial alanine racemases (ARs). Interestingly, L-TAs can be further grouped into two evolutionarily distinct families, which share low sequence similarity with each other but likely possess the same structural fold, suggesting a convergent evolution of these enzymes. The first L-TA family contains enzymes of both prokaryotic and eukaryotic origins, and is related to fungal ARs, whereas the second contains only prokaryotic L-TAs. Furthermore, we show that horizontal gene transfer may occur frequently during the evolution of both L-TA families. Our results indicate the complex, dynamic, and convergent evolution process of TAs and suggest an updated classification scheme for L-TAs. PMID:25644973

  9. Poly(gamma-glutamylcysteinyl)glycine: its role in cadmium resistance in plant cells

    SciTech Connect

    Jackson, P.J.; Unkefer, C.J.; Doolen, J.A.; Watt, K.; Robinson, N.J.

    1987-10-01

    Angiosperms can be selected for the ability to grow in the presence of normally toxic concentrations of certain trace metal ions. Addition of Cd and Cu to Cd-resistant Datura innoxia cell cultures results in the rapid synthesis and accumulation of sulfur-rich, metal-binding polypeptides. The structure of these compounds was determined using amino acid analysis, /sup 13/C NMR, and site-specific enzymic digestion. These compounds are poly(gamma-glutamylcysteinyl)glycines. Greater than 80% of the cellular Cd is bound to the bis and tris forms in Cd-resistant cells. There is a direct correlation between the maximum accumulation of the metal-binding polypeptides and the concentration of toxic ions to which the cells are resistant. In the presence of metal ions, the polypeptides form multimeric aggregates that can be resolved by gel chromatography. Cd binds to both the high and low molecular weight aggregates, whereas Cu preferentially binds to the higher molecular weight forms. The presence of gamma-carboxamide linkages between glutamyl and adjacent cysteinyl residues indicates that these polypeptides are products of biosynthetic pathways. Poly(gamma-glutamylcysteinyl)glycines bind metals and, in this respect, appear to be functional analogs of the protein metallothionein. However, in the absence of supraoptimal concentrations of trace metal ions, the functions of metallothionein in animals and microorganisms and poly(gamma-glutamylcysteinyl)glycines in plants may differ.

  10. Surface modification of ultrafiltration membranes by grafting glycine-functionalized PVA based on polydopamine coatings

    NASA Astrophysics Data System (ADS)

    Li, Fang; Ye, Jianfeng; Yang, Linming; Deng, Chunhua; Tian, Qing; Yang, Bo

    2015-08-01

    Due to the ease of processing and stability during filtration, polydopamine (PD) coatings with grafted hydrophilic polymers have recently received significant attention. In this study, glycine-functionalized PVA was synthesized and grafted to a PD-coated ultrafiltration (UF) membrane to improve its performance during wastewater filtration. The membranes were modified by grafting PD with glycine-functionalized PVA (PD-g-PVA), and the resultant materials were characterized using surface morphology analyses, contact angle measurements, flux, oil/water emulsion separation tests, and grafted layer stability tests. The performance of the PD-g-PVA membrane was compared to that of the membrane modified with PD-g-polyethylene glycol (PEG). After grafting the PD-g-PVA, the surface roughness of the membranes decreased significantly. The grafted PVA layer, which was stable under acidic and alkaline conditions, protected the PD layer. The filtration experiments with an oil/water emulsion indicated that modifying the glycine-functionalized PVA by grafting can significantly improve the antifouling ability of membranes.

  11. Oligo(N-aryl glycines): a new twist on structured peptoids.

    PubMed

    Shah, Neel H; Butterfoss, Glenn L; Nguyen, Khanh; Yoo, Barney; Bonneau, Richard; Rabenstein, Dallas L; Kirshenbaum, Kent

    2008-12-10

    We explore strategies to enhance conformational ordering of N-substituted glycine peptoid oligomers. Peptoids bearing bulky N-alkyl side chains have previously been studied as important examples of biomimetic "foldamer" compounds, as they exhibit a capacity to populate helical structures featuring repeating cis-amide bonds. Substantial cis/trans amide bond isomerization, however, gives rise to conformational heterogeneity. Here, we report the use of N-aryl side chains as a tool to enforce the presence of trans-amide bonds, thereby engendering structural stability. Aniline derivatives and bromoacetic acid are used in the facile solid-phase synthesis of a diverse family of sequence-specific N-aryl glycine oligomers. Quantum mechanics calculations yield a detailed energy profile of the folding landscape and substantiate the hypothesis that the presence of anilide groups establishes a strong energetic preference for trans-amide bonds. X-ray crystallographic analysis and solution NMR studies verify this preference. Molecular modeling indicates that the linear oligomers can adopt helical structures resembling a polyproline type II helix. High resolution structures of macrocyclic oligomers incorporating both N-alkyl and N-aryl glycine units confirm the ability to direct the presence of trans-amide bonds specifically at N-aryl positions. These results are an important step in developing strategies for the rational de novo design of new structural motifs in biomimetic oligopeptoid systems. PMID:19049458

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

    SciTech Connect

    Keefer, J.F. Jr.

    1986-01-01

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

  13. Identification and disruption of BetL, a secondary glycine betaine transport system linked to the salt tolerance of Listeria monocytogenes LO28.

    PubMed

    Sleator, R D; Gahan, C G; Abee, T; Hill, C

    1999-05-01

    The trimethylammonium compound glycine betaine (N,N, N-trimethylglycine) can be accumulated to high intracellular concentrations, conferring enhanced osmo- and cryotolerance upon Listeria monocytogenes. We report the identification of betL, a gene encoding a glycine betaine uptake system in L. monocytogenes, isolated by functional complementation of the betaine uptake mutant Escherichia coli MKH13. The betL gene is preceded by a consensus sigmaB-dependent promoter and is predicted to encode a 55-kDa protein (507 amino acid residues) with 12 transmembrane regions. BetL exhibits significant sequence homologies to other glycine betaine transporters, including OpuD from Bacillus subtilis (57% identity) and BetP from Corynebacterium glutamicum (41% identity). These high-affinity secondary transporters form a subset of the trimethylammonium transporter family specific for glycine betaine, whose substrates possess a fully methylated quaternary ammonium group. The observed Km value of 7.9 microM for glycine betaine uptake after heterologous expression of betL in E. coli MKH13 is consistent with values obtained for L. monocytogenes in other studies. In addition, a betL knockout mutant which is significantly affected in its ability to accumulate glycine betaine in the presence or absence of NaCl has been constructed in L. monocytogenes. This mutant is also unable to withstand concentrations of salt as high as can the BetL+ parent, signifying the role of the transporter in Listeria osmotolerance. PMID:10224004

  14. Effect of glutamine or glycine containing oral electrolyte solutions on mucosal morphology, clinical and biochemical findings, in calves with viral induced diarrhea.

    PubMed Central

    Naylor, J M; Leibel, T; Middleton, D M

    1997-01-01

    Twenty-one diarrheic calves were randomly assigned to 1 of 3 oral electrolyte treatments. The treatments were either a conventional oral electrolyte containing glycine (40 mmol/L) as the amino acid, an oral electrolyte in which glutamine (40 mmol/L) replaced glycine or an electrolyte in which high concentrations of glutamine (400 mmol/L) replaced glycine. The calves were monitored while on trial and at the end of the treatment they were euthanized and a necropsy was immediately performed. Calves fed the high glutamine electrolyte had more treatment failures (2/7 versus 0/7 for each of the other 2 treatments). There was a significant effect of type of electrolyte on fecal consistency. Calves fed the glycine containing electrolyte had the most solid feces. Duodenal villus height was significantly affected by the type of electrolyte: values (mean +/- 1 SEM) were 0.61 +/- 0.09, 0.46 +/- 0.05, and 0.59 +/- 0.07 mm for high glutamine, low glutamine and glycine electrolytes respectively. There was no significant difference in small intestinal surface area between groups. High glutamine treated calves had the greatest capacity to absorb xylose from the small intestine but this difference was not statistically significant. Overall, this trial does not suggest that substituting glutamine for glycine in oral electrolyte solutions improves treatment of diarrheic calves or speeds mucosal healing. PMID:9008800

  15. Identification of a Vibrio cholerae chemoreceptor that senses taurine and amino acids as attractants.

    PubMed

    Nishiyama, So-ichiro; Takahashi, Yohei; Yamamoto, Kentaro; Suzuki, Daisuke; Itoh, Yasuaki; Sumita, Kazumasa; Uchida, Yumiko; Homma, Michio; Imada, Katsumi; Kawagishi, Ikuro

    2016-01-01

    Vibrio cholerae, the etiological agent of cholera, was found to be attracted by taurine (2-aminoethanesulfonic acid), a major constituent of human bile. Mlp37, the closest homolog of the previously identified amino acid chemoreceptor Mlp24, was found to mediate taxis to taurine as well as L-serine, L-alanine, L-arginine, and other amino acids. Methylation of Mlp37 was enhanced upon the addition of taurine and amino acids. Isothermal titration calorimetry demonstrated that a purified periplasmic fragment of Mlp37 binds directly to taurine, L-serine, L-alanine and L-arginine. Crystal structures of the periplamic domain of Mlp37 revealed that L-serine and taurine bind to the membrane-distal PAS domain in essentially in the same way. The structural information was supported by characterising the in vivo properties of alanine-substituted mutant forms of Mlp37. The fact that the ligand-binding domain of the L-serine complex had a small opening, which would accommodate a larger R group, accounts for the broad ligand specificity of Mlp37 and allowed us to visualise ligand binding to Mlp37 with fluorescently labelled L-serine. Taken together, we conclude that Mlp37 serves as the major chemoreceptor for taurine and various amino acids. PMID:26878914

  16. Forced swimming and imipramine modify plasma and brain amino acid concentrations in mice.

    PubMed

    Murakami, Tatsuro; Yamane, Haruka; Tomonaga, Shozo; Furuse, Mitsuhiro

    2009-01-01

    The relationships between monoamine metabolism and forced swimming or antidepressants have been well studied, however information is lacking regarding amino acid metabolism under these conditions. Therefore, the aim of the present study was to investigate the effects of forced swimming and imipramine on amino acid concentrations in plasma, the cerebral cortex and the hypothalamus in mice. Forced swimming caused cerebral cortex concentrations of L-glutamine, L-alanine, and taurine to be increased, while imipramine treatment caused decreased concentrations of L-glutamate, L-alanine, L-tyrosine, L-methionine, and L-ornithine. In the hypothalamus, forced swimming decreased the concentration of L-serine while imipramine treatment caused increased concentration of beta-alanine. Forced swimming caused increased plasma concentration of taurine, while concentrations of L-serine, L-asparagine, L-glutamine and beta-alanine were decreased. Imipramine treatment caused increased plasma concentration of all amino acid, except for L-aspartate and taurine. In conclusion, forced swimming and imipramine treatment modify central and peripheral amino acid metabolism. These results may aid in the identification of amino acids that have antidepressant-like effects, or may help to refine the dosages of antidepressant drugs. PMID:19010319

  17. Identification of a Vibrio cholerae chemoreceptor that senses taurine and amino acids as attractants

    PubMed Central

    Nishiyama, So-ichiro; Takahashi, Yohei; Yamamoto, Kentaro; Suzuki, Daisuke; Itoh, Yasuaki; Sumita, Kazumasa; Uchida, Yumiko; Homma, Michio; Imada, Katsumi; Kawagishi, Ikuro

    2016-01-01

    Vibrio cholerae, the etiological agent of cholera, was found to be attracted by taurine (2-aminoethanesulfonic acid), a major constituent of human bile. Mlp37, the closest homolog of the previously identified amino acid chemoreceptor Mlp24, was found to mediate taxis to taurine as well as L-serine, L-alanine, L-arginine, and other amino acids. Methylation of Mlp37 was enhanced upon the addition of taurine and amino acids. Isothermal titration calorimetry demonstrated that a purified periplasmic fragment of Mlp37 binds directly to taurine, L-serine, L-alanine and L-arginine. Crystal structures of the periplamic domain of Mlp37 revealed that L-serine and taurine bind to the membrane-distal PAS domain in essentially in the same way. The structural information was supported by characterising the in vivo properties of alanine-substituted mutant forms of Mlp37. The fact that the ligand-binding domain of the L-serine complex had a small opening, which would accommodate a larger R group, accounts for the broad ligand specificity of Mlp37 and allowed us to visualise ligand binding to Mlp37 with fluorescently labelled L-serine. Taken together, we conclude that Mlp37 serves as the major chemoreceptor for taurine and various amino acids. PMID:26878914

  18. Comparative study of glycine, alanine or casein as inert nitrogen sources in endotoxemic rats.

    PubMed

    Chambon-Savanovitch, C; Felgines, C; Farges, M C; Raul, F; Cézard, J P; Davot, P; Vasson, M P; Cynober, L A

    1999-10-01

    Pharmacological effects of dietary amino acids (AA) and peptides must be compared to an isonitrogenous control that is as inert as possible. To establish a rationale for the choice of such a control, potential metabolic and nutritional effects of three currently used nitrogenous controls (glycine, alanine, and casein) were evaluated in an endotoxemic rat model that has well-defined alterations in AA and protein metabolism. Five-week-old male Sprague-Dawley rats (113 +/- 1 g) were randomly assigned to four groups and received at d 0 an intraperitoneal injection of endotoxin (3 mg/kg). After withdrawal of food for 24 h, the rats were enterally refed for 48 h with a liquid diet (Osmolite((R))) supplemented with 0.19 g N. kg(-1). d(-1) in the form of glycine [lipopolysaccharide (LPS)-GLY group], alanine (LPS-ALA group) or casein (LPS-CAS group). One group (LPS group) received only Osmolite((R)). Plasma, two skeletal muscles, the liver and the intestine were then removed. Body and tissue weights and tissue protein contents did not differ among the four groups. Intestine histomorphometry showed no significant difference among groups. Jejunal hydrolase activities were significantly affected by the nitrogenous supplementations, but no effect was observed in the ileum. Only limited significant effects were observed on plasma and tissue-free AA concentrations, except for an accumulation of glycine in the plasma and tissues from the LPS-GLY group, compared to other groups. Overall, whereas glycine as a nitrogenous control should be used with care, either alanine or casein may be used as the "placebo," with the choice depending on the study to be performed. PMID:10498760

  19. Improvement of glycine oxidase by DNA shuffling, and site-saturation mutagenesis of F247 residue.

    PubMed

    Yao, Pei; Lin, Yongjun; Wu, Gaobing; Lu, Yulin; Zhan, Tao; Kumar, Ashok; Zhang, Lili; Liu, Ziduo

    2015-08-01

    Glyphosate is a broad spectrum herbicide widely used throughout the world, and it could be degraded by glycine oxidase (GO) through CN bond cleavage. For a better understanding of the structure-function relationship and improving the activity of B3S1 (GO from Bacillus cereus), DNA shuffling was performed. A mutant B4S7 (The Km, Vmax, kcat and kcat/Km values on glyphosate were 0.1 mM, 0.002401 mM min(-1), 3.62 min(-1) and 36.2 mM(-1) min(-1), respectively. The four parameters on glycine were 50.34 mM, 0.001983 mM min(-1), 2.18 min(-1) and 0.04 mM(-1) min(-1), respectively) was obtained from 10,000 clones, which presented a 3.9-fold increase of the specificity constant (the kcat/Km ratio between glyphosate and glycine) compared with B3S1. Especially, the Km value of B4S7 to glyphosate was much less than those of the reported GO. Structure modeling and molecular docking indicated that the novel mutation point F247S was close to the active site of the enzyme. To identify the role of the site, the remaining 19 amino acids were introduced into the site by site-saturation mutagenesis. The result showed that compared with B3S1, the specificity constant of mutant F247S and F247R increased 0.64-fold and 1.04-fold, respectively. While the specificity constant of mutant F247E decreased 2.01-fold. Therefore, the site 247 plays a crucial role in regulating the substrate specificity. This study provides new information on the structure-function relationship of glycine oxidase and the development of glyphosate-tolerant crops. PMID:26025077

  20. Mixed ligand complex formation of 2-aminobenzamide with Cu(II) in the presence of some amino acids: synthesis, structural, biological, pH-metric, spectrophotometric and thermodynamic studies.

    PubMed

    Dharmaraja, Jeyaprakash; Esakkidurai, Thirugnanasamy; Subbaraj, Paramasivam; Shobana, Sutha

    2013-10-01

    Mixed ligand Cu(II) complexes of 2-aminobenzamide (2AB) and amino acids viz., glycine (gly), L-alanine (ala), L-valine (val) and L-phenylalanine (phe) have been synthesised and characterized by various physico-chemical and spectral techniques. The calculated g-tensor values for Cu(II) complexes at 77 K and 300 K, show the distorted octahedral geometry which has been confirmed from the absorption studies. Consequently, the thermal studies illustrate that the loss of water and acetate molecules in the initial stage which are followed by the decomposition of organic residues. The powder X-ray diffraction and SEM analysis reflect that all the complexes have well-defined crystallinity nature with homogeneous morphology. The binding activities of CT DNA with CuAB complexes have been examined by absorption studies. Further, the oxidative cleavage interactions of 2-aminobenzamide and CuAB complexes with DNA were studied by gel electrophoresis method in H2O2 medium. Also, the complex formation of Cu(II) involving 2-aminobenzamide and amino acids were carried out by a combined pH-metric and spectrophotometric techniques in 50% (v/v) water-ethanol mixture at 300, 310, 320 and 330±0.1 K with I=0.15 mol dm(-3) (NaClO4). In solution, CuAB and CuAB2 species has been detected and the binding modes of 2-aminobenzamide and amino acids in both binary and mixed ligand complexes are same. The calculated stabilization value of ΔlogK, log X and log X' indicates higher stabilities for the mixed ligand complexes rather than their binary species. The thermodynamic parameters like ΔG, ΔH and ΔS have been determined from temperature dependence of the stability constant. In vitro biological activities of 2-aminobenzamide, CuA and CuAB complexes show remarkable activities against some bacterial and fungal strains. The percentage distribution of various binary and mixed ligand species in solution at dissimilar pH intervals were also evaluated. PMID:23811147

  1. Mixed ligand complex formation of 2-aminobenzamide with Cu(II) in the presence of some amino acids: Synthesis, structural, biological, pH-metric, spectrophotometric and thermodynamic studies

    NASA Astrophysics Data System (ADS)

    Dharmaraja, Jeyaprakash; Esakkidurai, Thirugnanasamy; Subbaraj, Paramasivam; Shobana, Sutha

    2013-10-01

    Mixed ligand Cu(II) complexes of 2-aminobenzamide (2AB) and amino acids viz., glycine (gly), L-alanine (ala), L-valine (val) and L-phenylalanine (phe) have been synthesised and characterized by various physico-chemical and spectral techniques. The calculated g-tensor values for Cu(II) complexes at 77 K and 300 K, show the distorted octahedral geometry which has been confirmed from the absorption studies. Consequently, the thermal studies illustrate that the loss of water and acetate molecules in the initial stage which are followed by the decomposition of organic residues. The powder X-ray diffraction and SEM analysis reflect that all the complexes have well-defined crystallinity nature with homogeneous morphology. The binding activities of CT DNA with CuAB complexes have been examined by absorption studies. Further, the oxidative cleavage interactions of 2-aminobenzamide and CuAB complexes with DNA were studied by gel electrophoresis method in H2O2 medium. Also, the complex formation of Cu(II) involving 2-aminobenzamide and amino acids were carried out by a combined pH-metric and spectrophotometric techniques in 50% (v/v) water-ethanol mixture at 300, 310, 320 and 330 ± 0.1 K with I = 0.15 mol dm-3 (NaClO4). In solution, CuAB and CuAB2 species has been detected and the binding modes of 2-aminobenzamide and amino acids in both binary and mixed ligand complexes are same. The calculated stabilization value of Δ log K, log X and log X' indicates higher stabilities for the mixed ligand complexes rather than their binary species. The thermodynamic parameters like ΔG, ΔH and ΔS have been determined from temperature dependence of the stability constant. In vitro biological activities of 2-aminobenzamide, CuA and CuAB complexes show remarkable activities against some bacterial and fungal strains. The percentage distribution of various binary and mixed ligand species in solution at dissimilar pH intervals were also evaluated.

  2. Benzyl isothiocyanate affects development, hatching and reproduction of the soybean cyst nematode Heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzyl isothiocyanate (BITC) applied at micromolar doses decreased Heterodera glycines J2 movement, H. glycines hatching, and reproduction of H. glycines on soybean, Glycine max. Direct exposure of J2 to 30 microM BITC caused an immediate decrease (17%; P < 0.05) in J2 movement relative to 1% methan...

  3. Simultaneous Determination of Glutamate, Glycine, and Alanine in Human Plasma Using Precolumn Derivatization with 6-Aminoquinolyl-N-hydroxysuccinimidyl Carbamate and High-Performance Liquid Chromatography

    PubMed Central

    Huang, Qing Xian; Li, Shu Cui; Yang, Mei Zi; Rao, Bin

    2012-01-01

    A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) method has been validated for determining concentrations of glutamate, glycine, and alanine in human plasma. Proteins in plasma were precipitated with perchloric acid, followed by derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC). Simultaneous analysis of glutamate, glycine, and alanine is achieved using reversed-phase HPLC conditions and ultraviolet detection. Excellent linearity was observed for these three amino acids over their concentration ranges with correlation coefficients (r)>0.999. The intra- and inter-day precision were below 10%. This method utilizes quality control samples and demonstrates excellent plasma recovery and accuracy. The developed method has been successfully applied to measure plasma glutamate, glycine, and alanine in twenty volunteers. PMID:23118561

  4. In-situ Measurements Of The Radiolytic Destruction Of Glycine In Ices: Applications To The Martian Subsurface

    NASA Astrophysics Data System (ADS)

    Gerakines, Perry A.; Hudson, R. L.

    2012-10-01

    Amino acids and other organic molecules are thought to be easily destroyed on the surface of Mars by the high flux of incident ultraviolet rays or by chemical interactions with oxidizing substances in the soil. However, organic molecules may survive in the subsurface, where chemical processes are driven by penetrating galactic cosmic rays such as MeV protons. Models of the radiation dose as a function of depth on Mars have shown that the contribution of galactic cosmic rays dominates from about one centimeter to a few meters [1]. Theoretical models have also been published to aid in understanding molecular destruction at these depths, but these usually are based on room-temperature laboratory data, studies of single-component samples, and ex-situ methods of chemical analysis. Recent studies of amino-acid survivability include those involving UV photolysis [2, 3] and gamma radiolysis [4], but nearly all chemical and kinetic analyses from such experiments involved room-temperature measurements on samples irradiated and then removed from sealed containers. We report new laboratory studies of the radiation-induced destruction of glycine-containing ices. In-situ infrared spectroscopy was used to study decay rates as a function of temperature and initial glycine concentrations. Our results indicate that glycine's destruction rate depends on temperature, the presence of H2O-ice, and the initial relative abundance of glycine. These trends are not obvious in previous work, suggesting that room-temperature measurements on pure glycine's radiation stability are not directly applicable to Mars and other environments. This work has been supported by the Goddard Center for Astrobiology. [1] Dartnell, L. R., et al., 2007. Geophys. Res. Letters 34:L02207. [2] ten Kate, I. L., et al., 2006. Planet. Space Sci. 54, 296-302. [3] Orzechowska, G. E., et al., 2007. Icarus 187, 584-591. [4] Kminek, G., Bada, J. L., 2006. Earth Planet. Sci. Lett. 245, 1-5.

  5. 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.

  6. Glycine receptor mechanism illuminated by electron cryo-microscopy

    PubMed Central

    Du, Juan; Lü, Wei; Wu, Shenping; Cheng, Yifan; Gouaux, Eric

    2015-01-01

    Summary The strychnine-sensitive glycine receptor (GlyR) mediates inhibitory synaptic transmission in the spinal cord and brainstem and is linked to neurological disorders including autism and hyperekplexia. Understanding of molecular mechanisms and pharmacology of GlyRs has been hindered by a dearth of high-resolution structures. Here we report electron cryo-microscopy structures of the α1 GlyR with strychnine, glycine, or glycine/ivermectin. Strychnine arrests the receptor in an antagonist-bound, closed ion channel state, glycine stabilizes the receptor in an agonist-bound open channel state, and the glycine/ivermectin complex adopts a potentially desensitized or partially open state. Relative to the glycine-bound state, strychnine expands the agonist-binding pocket via outward movement of the C loop, promotes rearrangement of the extracellular and transmembrane domain ‘wrist’ interface, and leads to rotation of the transmembrane domain toward the pore axis, occluding the ion conduction pathway. These structures illuminate GlyR mechanism and define a rubric to interpret structures of Cys-loop receptors. PMID:26344198

  7. 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

  8. Regulation of Serine, Glycine, and One-Carbon Biosynthesis.

    PubMed

    Stauffer, George V

    2004-12-01

    The biosynthesis of serine, glycine, and one-carbon (C1) units constitutes a major metabolic pathway in Escherichia coli and Salmonella enterica serovar Typhimurium. C1 units derived from serine and glycine are used in the synthesis of purines, histidine, thymine, pantothenate, and methionine and in the formylation of the aminoacylated initiator fMet-TRNAfMet used to start translation in E. coli and serovar Typhimurium. The need for serine, glycine, and C1 units in many cellular functions makes it necessary for the genes encoding enzymes for their synthesis to be carefully regulated to meet the changing demands of the cell for these intermediates. This review discusses the regulation of the following genes: serA, serB, and serC; gly gene; gcvTHP operon; lpdA; gcvA and gcvR; and gcvB genes. Threonine utilization (the Tut cycle) constitutes a secondary pathway for serine and glycine biosynthesis. L-Serine inhibits the growth of E. coli cells in GM medium, and isoleucine releases this growth inhibition. The E. coli glycine transport system (Cyc) has been shown to transport glycine, D-alanine, D-serine, and the antibiotic D-cycloserine. Transport systems often play roles in the regulation of gene expression, by transporting effector molecules into the cell, where they are sensed by soluble or membrane-bound regulatory proteins. PMID:26443363

  9. Glycine crystallization during spray drying: the pH effect on salt and polymorphic forms.

    PubMed

    Yu, Lian; Ng, Kingman

    2002-11-01

    Spray drying of aqueous solutions of glycine revealed a strong pH effect on the salt and polymorphic forms of the resulting powders. Adjusting pH by aqueous HCl or NaOH between 1.7 and 10.0 caused the glycine solutions to crystallize as two polymorphs (alpha and gamma) of the neutral glycine ((+)H(3)NCH(2)CO(2) (-)) and as three salts (diglycine HCl, (+)H(3)NCH(2)CO(2) (-). (+)H(3)NCH(2)CO(2)H. C1(-); glycine HCl, (+)H(3)NCH(2)CO(2)H. C1(-); and sodium glycinate, H(2)NCH(2)CO(2) (-). Na(+)). Although alpha-glycine crystallized from solutions without pH adjustment (pH 6.2), changing the pH to 4.0 and 8.0 caused gamma-glycine to crystallize as the preferred polymorph. This phenomenon is attributed to the pH effect on the dimeric growth unit of alpha-glycine. The formation of alpha-glycine by spray drying solutions of neutral glycine contrasts the outcome of freeze drying, which yields beta-glycine. Because gamma-glycine is thermodynamically more stable than alpha-glycine, the crystallization of gamma-glycine by pH adjustment provides a way to improve the physical stability of glycine-containing formulations. Spray drying at low pH yielded various mixtures of neutral glycine and its HCl salts: pH 3.0, gamma-glycine and diglycine HCl; pH 2.0, diglycine HCl; and pH 1.7 (the natural pH of glycine HCl), diglycine HCl (major component) and glycine HCl (minor component). Spray drying glycine HCl solutions (pH 1.7) yielded the same diglycine HCl/glycine HCl mixture as did spray drying neutral glycine solutions acidified to pH 1.7. Obtaining diglycine HCl by spray drying glycine HCl solutions indicates a 50% loss of HCl during processing. The extent of HCl loss could be altered by changing the inlet temperature of the spray drier. Spray drying glycine solutions at pH 9.0 and 10.0 gave predominantly gamma-glycine and an additional crystalline product, possibly sodium glycinate. The glycine powders spray dried at different pH had different particle morphologies and sizes, which

  10. Serine, glycine and the one-carbon cycle: cancer metabolism in full circle

    PubMed Central

    Locasale, Jason W

    2013-01-01

    One carbon metabolism involving the folate and methionine cycle integrates carbon units from amino acids, including serine and glycine, and generates diverse outputs, such as the biosynthesis of lipids, nucleotides and proteins, the maintenance of redox status, and the substrates for methylation reactions. Long considered a ‘housekeeping’ process, this pathway has been recently shown to have additional complexity. Recent genetic and functional evidence also suggests that hyperactivation of this pathway is a possible driver of oncogenesis and establishes links to cellular epigenetic status. Given the wealth of clinically available agents that target one carbon metabolism, these new findings could present opportunities for translation into precision cancer medicine. PMID:23822983

  11. Identification and upregulation of biosynthetic genes required for accumulation of Mycosporine-2-glycine under salt stress conditions in the halotolerant cyanobacterium Aphanothece halophytica.

    PubMed

    Waditee-Sirisattha, Rungaroon; Kageyama, Hakuto; Sopun, Warangkana; Tanaka, Yoshito; Takabe, Teruhiro

    2014-03-01

    Mycosporine-like amino acids (MAAs) are valuable molecules that are the basis for important photoprotective constituents. Here we report molecular analysis of mycosporine-like amino acid biosynthetic genes from the halotolerant cyanobacterium Aphanothece halophytica, which can survive at high salinity and alkaline pH. This extremophile was found to have a unique MAA core (4-deoxygadusol)-synthesizing gene separated from three other genes. In vivo analysis showed accumulation of the mycosporine-2-glycine but not shinorine or mycosporine-glycine. Mycosporine-2-glycine accumulation was stimulated more under the stress condition of high salinity than UV-B radiation. The Aphanothece MAA biosynthetic genes also manifested a strong transcript level response to salt stress. Furthermore, the transformed Escherichia coli and Synechococcus strains expressing four putative Aphanothece MAA genes under the control of a native promoter were found to be capable of synthesizing mycosporine-2-glycine. The accumulation level of mycosporine-2-glycine was again higher under the high-salinity condition. In the transformed E. coli cells, its level was approximately 85.2 ± 0.7 μmol/g (dry weight). Successful production of a large amount of mycosporine in these cells provides a new opportunity in the search for an alternative natural sunscreen compound source. PMID:24375141

  12. Blockade of glycine transporter 1 by SSR-504734 promotes cognitive flexibility in glycine/NMDA receptor-dependent manner.

    PubMed

    Nikiforuk, Agnieszka; Kos, Tomasz; Rafa, Dominik; Behl, Berthold; Bespalov, Anton; Popik, Piotr

    2011-01-01

    Accumulating evidence suggests that cognitive processes may be regulated by glycine concentration in the local environment of glutamate N-methyl-d-aspartate receptor (NMDAR). The concentration of glycine is controlled, among other factors, by the glycine transporter 1 (GlyT1). While GlyT1 inhibitors are developed for a number of indications including cognitive improvement, little is known about their effects in tasks depending on prefrontal cortical function. We examined the effect of GlyT1 inhibitor SSR-504734 on cognitive flexibility assessed in the attentional set-shifting task in rats (ASST). The second goal was to elucidate whether SSR-504734 effect has been due to the compound's action at glycine/NMDAR site. Rats treated with SSR-504734 (3 and 10 mg/kg, IP) required significantly less trials to criteria during extra-dimensional shift (EDs) phase of the ASST. The effect of SSR-504734 (3 mg/kg) was completely prevented by the glycine/NMDAR site antagonist, L-687,414 (30 mg/kg, IP) that by itself exerted no effect on cognitive flexibility. Present study demonstrates that the elevation of glycine concentration through the blockade of its reuptake facilitates cognitive flexibility. As this effect was fully blocked by glycine/NMDAR antagonist, SSR-504734-induced cognitive improvement is likely mediated through glycine action at NMDAR. It is suggested that GlyT1 inhibitors like SSR-504734 may represent a useful pharmacological approach for cognitive enhancement, especially in domains critically affected in schizophrenia. PMID:21530555

  13. 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. PMID

  14. Electronic structure analysis of glycine oligopeptides and glycine-tryptophan oligopeptides

    NASA Astrophysics Data System (ADS)

    Li, Xin; Yu, Shuai; Yang, Mengshi; Xu, Can; Wang, Yu; Chen, Liang

    2014-03-01

    Using the density functional theory (DFT), we have studied the energy gap, charge distribution, density of states and chemical activity of glycine (Gn) oligopeptides and glycine-tryptophan (GWn) oligopeptides. The results show that: (1) with the increasing of Gn residues, the chemical activity of Gn oligopeptides focuses on the terminal amino and carboxyl groups, which may be the main cause of self-assembly behaviors in Gn oligopeptide chains; (2) the chemical reaction activity has size effect. The size effect disappears when the residue number exceeds 7. The Gn oligopeptides with 7 residues is the shortest chain which has the same reaction activity as that of longer size peptide; (3) the activity of GWn oligopeptides presents size effect and odd-even effect. However, the size effect and odd-even effect both vanish when the chain of GWn oligopeptides is longer than 12 residues. (4) It is difficult in self-assembly for GWn oligopeptide chains, because its activity mainly focuses on the indole ring and the Gn residues at the end of oligopeptides. (5) The big side groups result in the very near energy level of LUMO and LUMO+1 of GWn oligopeptide chains. It shows that the electron-accepting ability of oligopeptide chainsis composed of two orbitals addition. The results in the paper may help us understand the changes of physical and chemical properties of peptide synthesis process.

  15. Copper-Catalyzed Aerobic Enantioselective Cross-Dehydrogenative Coupling of N-Aryl Glycine Esters with Terminal Alkynes.

    PubMed

    Xie, Zhiyu; Liu, Xigong; Liu, Lei

    2016-06-17

    A copper-catalyzed enantioselective cross-coupling of a Csp3-H moiety (N-aryl glycine ester) with a Csp-H component (terminal alkyne) using molecular oxygen as the terminal oxidant is described for the first time. The sustainable method provides an efficient and environmentally friendly approach to rapidly prepare a diverse array of optically active non-natural α-amino acids. PMID:27269737

  16. The syntaxin 31-induced gene, LESION SIMULATING DISEASE1 (LSD1), functions in Glycine max defense to the root parasite Heterodera glycines.

    PubMed

    Pant, Shankar R; Krishnavajhala, Aparna; McNeece, Brant T; Lawrence, Gary W; Klink, Vincent P

    2015-01-01

    Experiments show the membrane fusion genes α soluble NSF attachment protein (α-SNAP) and syntaxin 31 (Gm-SYP38) contribute to the ability of Glycine max to defend itself from infection by the plant parasitic nematode Heterodera glycines. Accompanying their expression is the transcriptional activation of the defense genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and NONEXPRESSOR OF PR1 (NPR1) that function in salicylic acid (SA) signaling. These results implicate the added involvement of the antiapoptotic, environmental response gene LESION SIMULATING DISEASE1 (LSD1) in defense. Roots engineered to overexpress the G. max defense genes Gm-α-SNAP, SYP38, EDS1, NPR1, BOTRYTIS INDUCED KINASE1 (BIK1) and xyloglucan endotransglycosylase/hydrolase (XTH) in the susceptible genotype G. max[Williams 82/PI 518671] have induced Gm-LSD1 (Gm-LSD1-2) transcriptional activity. In reciprocal experiments, roots engineered to overexpress Gm-LSD1-2 in the susceptible genotype G. max[Williams 82/PI 518671] have induced levels of SYP38, EDS1, NPR1, BIK1 and XTH, but not α-SNAP prior to infection. In tests examining the role of Gm-LSD1-2 in defense, its overexpression results in ∼52 to 68% reduction in nematode parasitism. In contrast, RNA interference (RNAi) of Gm-LSD1-2 in the resistant genotype G. max[Peking/PI 548402] results in an 3.24-10.42 fold increased ability of H. glycines to parasitize. The results identify that Gm-LSD1-2 functions in the defense response of G. max to H. glycines parasitism. It is proposed that LSD1, as an antiapoptotic protein, may establish an environment whereby the protected, living plant cell could secrete materials in the vicinity of the parasitizing nematode to disarm it. After the targeted incapacitation of the nematode the parasitized cell succumbs to its targeted demise as the infected root region is becoming fortified. PMID:25530246

  17. The syntaxin 31-induced gene, LESION SIMULATING DISEASE1 (LSD1), functions in Glycine max defense to the root parasite Heterodera glycines

    PubMed Central

    Pant, Shankar R; Krishnavajhala, Aparna; McNeece, Brant T; Lawrence, Gary W; Klink, Vincent P

    2015-01-01

    Experiments show the membrane fusion genes α soluble NSF attachment protein (α-SNAP) and syntaxin 31 (Gm-SYP38) contribute to the ability of Glycine max to defend itself from infection by the plant parasitic nematode Heterodera glycines. Accompanying their expression is the transcriptional activation of the defense genes ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and NONEXPRESSOR OF PR1 (NPR1) that function in salicylic acid (SA) signaling. These results implicate the added involvement of the antiapoptotic, environmental response gene LESION SIMULATING DISEASE1 (LSD1) in defense. Roots engineered to overexpress the G. max defense genes Gm-α-SNAP, SYP38, EDS1, NPR1, BOTRYTIS INDUCED KINASE1 (BIK1) and xyloglucan endotransglycosylase/hydrolase (XTH) in the susceptible genotype G. max[Williams 82/PI 518671] have induced Gm-LSD1 (Gm-LSD1–2) transcriptional activity. In reciprocal experiments, roots engineered to overexpress Gm-LSD1–2 in the susceptible genotype G. max[Williams 82/PI 518671] have induced levels of SYP38, EDS1, NPR1, BIK1 and XTH, but not α-SNAP prior to infection. In tests examining the role of Gm-LSD1–2 in defense, its overexpression results in ∼52 to 68% reduction in nematode parasitism. In contrast, RNA interference (RNAi) of Gm-LSD1–2 in the resistant genotype G. max[Peking/PI 548402] results in an 3.24–10.42 fold increased ability of H. glycines to parasitize. The results identify that Gm-LSD1–2 functions in the defense response of G. max to H. glycines parasitism. It is proposed that LSD1, as an antiapoptotic protein, may establish an environment whereby the protected, living plant cell could secrete materials in the vicinity of the parasitizing nematode to disarm it. After the targeted incapacitation of the nematode the parasitized cell succumbs to its targeted demise as the infected root region is becoming fortified. PMID:25530246

  18. Peptide purification using the chemoselective reaction between N-(methoxy)glycine and isothiocyanato-functionalized resin.

    PubMed

    Hara, Toshiaki; Tainosyo, Akira; Kawakami, Toru; Aimoto, Saburo; Murata, Michio

    2016-06-01

    An efficient peptide purification strategy is established, comprising the selective reaction of an N-terminal N-(methoxy)glycine residue of the peptide and isothiocyanato-functionalized resins, and subsequent Edman degradation. These reactions take place in acidic media; in particular, the Edman degradation proceeds smoothly in media containing more than 50% trifluoroacetic acid (v/v). These acidic conditions offer increased solubility, making them advantageous for the purification of hydrophobic and aggregation-prone peptides. The effectiveness of this method, together with scope and limitations, is demonstrated using model peptides and the practical purification of the loop region of the human dopamine D2 receptor long isoform (residues 240-272). Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27282134

  19. 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

  20. Ensifer glycinis sp. nov., a rhizobial species associated with species of the genus Glycine.

    PubMed

    Yan, Hui; Yan, Jun; Sui, Xin Hua; Wang, En Tao; Chen, Wen Xin; Zhang, Xiao Xia; Chen, Wen Feng

    2016-09-01

    Rhizobial strains from root nodules of Astragalus mongholicus and soybean (Glycine max) were characterized phylogenetically as members of the genus Ensifer (formerly named Sinorhizobium), based on 16S rRNA gene sequence comparisons. Results based upon concatenated sequence analysis of three housekeeping genes (recA, atpD and glnII, ≤ 93.8 % similarities to known species) and average nucleotide identity (ANI) values of whole genome sequence comparisons (ranging from 89.6 % to 83.4 % to Ensifer fredii and Ensifer saheli, respectively) indicated the distinct positions of these novel strains within the genus Ensifer. Phylogeny of symbiotic genes (nodC and nifH) of three novel strains clustered them with rhizobial species Ensifer fredii and Ensifer sojae, both isolated from nodules of Glycine max. Cross-nodulation tests showed that the representative strain CCBAU 23380T could form root nodules with nitrogen fixation capability on Glycine soja, Albizia julibrissin, Vigna unguiculata and Cajanus cajan, but failed to nodulate Astragalus mongholicus, its original host legume. Strain CCBAU 23380T formed inefficient nodules on G. max, and it did not contain 18 : 0, 18 : 1ω7c 11-methyl or summed feature 1 fatty acids, which differed from other related strains. Failure to utilize malonic acid as a carbon source distinguished strain CCBAU 23380T from the type strains of related species. The genome size of CCBAU 23380T was 6.0 Mbp, comprising 5624 predicted genes with DNA G+C content of 62.4 mol%. Based on the results above, a novel species, Ensifer glycinis sp. nov., is proposed, with CCBAU 23380T (=LMG 29231T =HAMBI 3645T) as the type strain. PMID:27125987

  1. Regulation of scallop myosin by the regulatory light chain depends on a single glycine residue.

    PubMed Central

    Jancso, A; Szent-Györgyi, A G

    1994-01-01

    Specific Ca2+ binding and Ca2+ activation of ATPase activity in scallop myosin require a regulatory light chain (RLC) from regulated (molluscan or vertebrate smooth) myosin; hybrids containing vertebrate skeletal RLCs do not bind Ca2+ and their ATPase activity is inhibited. Chimeras between scallop and chicken skeletal RLCs restore Ca2+ sensitivity to RLC-free myosin provided that residues 81-117 are derived from scallop. Six mutants (R90M, A94K, D98P, N105K, M116Q, and G117C) were generated by replacing amino acids of the scallop RLC with the corresponding skeletal RLC residues in positions conserved in either regulated or nonregulated myosins. Ca2+ binding was abolished by a G117C and a G117A mutation; however, these mutants have a decreased affinity for the heavy chain. None of the other mutations affected RLC function. Replacement of the respective cysteine with glycine in the skeletal RLC has markedly changed the regulatory properties of the molecule. The single cysteine to glycine mutation conferred to this light chain the ability to restore Ca2+ binding and regulated ATPase activity, although Ca2+ activation of the actin-activated ATPase was lower than with scallop RLC. The presence of amino acids other than glycine at this position in vertebrate skeletal myosin RLCs may explain why these are not fully functional in the scallop system. The results are in agreement with x-ray crystallography data showing the central role of G117 in stabilizing the Ca(2+)-binding site of scallop myosin. Images PMID:8090720

  2. 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

  3. The temperature effect on the glycine decomposition induced by 2 keV electron bombardment in space analog conditions

    NASA Astrophysics Data System (ADS)

    Pilling, Sergio; Nair, Binu G.; Escobar, Antonio; Fraser, Helen; Mason, Nigel

    2014-03-01

    Glycine is the simplest proteinaceous amino acid that has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, such species is exposed to several radiation fields at different temperatures. In aqueous solutions, this species appears mainly as zwitterionic glycine (+NH3CH2COO-) however, in solid phase, it may be found in amorphous or crystalline forms. Here, we present an experimental study on the destruction of two zwitterionic glycine crystals ( α- and β-form) at two different temperatures (300 K and 14 K) by 2 keV electrons in an attempt to test the behavior and stability of this molecular species in different space environments. The samples were analyzed in situ by Fourier transform infrared spectrometry at electron fluences. The experiments were carried out under ultra-high vacuum conditions at the Molecular Physics Laboratory at the Open University at Milton Keynes, UK. The dissociation cross section of glycine is approximately 5 times higher for the 14 K samples when compared to the 300 K samples. In contrast, no significant differences emerged between the dissociation cross sections of α- and β-forms of glycine for fixed temperature experiments. We therefore conclude that the destruction cross section is more heavily dependent on temperature than the phase of the condensed glycine material. This may be associated with the opening of additional reaction routes in the frozen samples involving the trapped daughter species (e.g. CO2 and CO). The half-life of studied samples extrapolated to space conditions shows that glycine molecules on the surface of interstellar grains has less survivability and they are highly sensitive to ambient radiations, however, they can survive extended period of time in the solar system like environments. Survivability increases by a factor of 5 if the samples are at 300 K when compared to low temperature experiments at 14

  4. Glycine adsorption and photo-reaction over ZnO(000ī) single crystal

    NASA Astrophysics Data System (ADS)

    Gao, Y. K.; Traeger, F.; Wöll, C.; Idriss, H.

    2014-06-01

    The adsorption and reaction of the amino acid glycine (NH2CH2COOH) are studied experimentally on the polar single crystal surface of zinc oxide, ZnO(000ī), by X-ray photoelectron spectroscopy (XPS) under UV light in presence and absence of molecular O2. Deposition at 350 K mainly resulted in a largely deprotonated monolayer (NH2CH2COO-(a) + OH(s); where O is surface oxygen, (a) is for adsorbed and (s) is for surface species) identified by its XPS C1s binding energy at 289.3 eV (COO), 286.7 eV (CH2) and XPS O1s at 531.8 eV (COO). A decrease in the signals of all functional groups of the adsorbed glycine (monitored by their C1s, O1s, and N1s lines) is seen upon UV excitation in the absence and presence of O2 pressures up to 5 × 10- 6 mbar. The photoreaction cross sections extracted from the decrease in the C1s peaks were found to be = 2.6 × 10- 18 (COO(a)) and 1.4 × 10- 18(CH2) cm2. The photoactivity of the ZnO(000ī) surface under UHV-conditions is found to be comparable to that seen in direct photolysis of amino acids in solution.

  5. Effect alteration of methamphetamine by amino acids or their salts on ambulatory activity in mice.

    PubMed

    Kuribara, H; Tadokoro, S

    1983-02-01

    Effect alterations of methamphetamine by pretreatment of amino acids or their salts on ambulatory activity in mice were investigated to confirm a fact that certain amino acids, particularly monosodium L-glutamate, are added to methamphetamine by the street users, and that the amino acids augment the effect of methamphetamine. The ambulatory activity of mouse was measured by a tilting-type round activity cage of 25 cm in diameter. The amino acids or their salts tested were monosodium L-glutamate, monosodium L-aspartate, gamma-amino-butyric acid, L-alanine, L-lysine hydrochloride and L-arginine hydrochloride. A single administration of each chemical at doses of 1 and 2 g/kg i.p. did not induce a marked change in the ambulatory activity in mice. Methamphetamine 2 mg/kg s.c. induced an increase in the ambulatory activity with a peak at 40 min after the administration, and the increased ambulatory activity persisted for 3 hr. The ambulation-increasing effect of methamphetamine was augmented by the pretreatment of monosodium L-glutamate and monosodium L-aspartate at 30 min before the methamphetamine administration, while attenuated by the pretreatment of L-lysine hydrochloride and L-arginine hydrochloride in a dose-dependent manner. Gamma-aminobutyric acid and L-alanine did not affect the effect of methamphetamine. Similar augmentation and attenuation in the ambulation-increasing effect of methamphetamine were induced by the pretreatment of sodium bicarbonate 0.9 g/kg i.p. (urinary alkalizer) and ammonium chloride 0.07 g/kg i.p. (urinary acidifier), respectively. The urinary pH level was elevated by the administration of monosodium L-glutamate, monosodium L-aspartate and sodium bicarbonate, and decreased by L-lysine hydrochloride, L-arginine hydrochloride and ammonium chloride. Gamma-aminobutyric acid and L-alanine did not elicit a marked change in the urinary pH level. The present experiment confirms the fact in human that monosodium L-glutamate augments the effect of

  6. Positron Binding Properties of Glycine and Its Aqueous Complexes.

    PubMed

    Nummela, Mikko; Raebiger, Hannes; Yoshida, Daisuke; Tachikawa, Masanori

    2016-06-16

    We investigate positron binding to glycine and its aqueous complexes by first-principles calculation. We show that while glycine in its ground state (Gly) does not bind positrons, several of its strongly polar conformers do, and in particular, its zwitterion form (GlyZI) binds positrons strongly. Aqueous complexes Gly·nH2O and GlyZI·nH2O also bind positrons, if their dipole moment μ > μcr. However, μ is not a sufficient quantity to describe positron binding to these complexes. We show that in addition to μ, positron binding strongly depends on the intramolecular bonding of glycine. In Gly·nH2O, positrons are weakly bound to the nitrogen in Gly, whereas in GlyZI·nH2O, the ionic oxygen in GlyZI is a strong "positron attractor". PMID:27232201

  7. Accumulation of 52 kDa glycine rich protein in auxin-deprived strawberry fruits and its role in fruit growth. [Fragaria ananassa

    SciTech Connect

    Reddy, A.S.N.; Poovaiah, B.W.

    1987-04-01

    Growth of strawberry (Fragaria ananassa Duch) receptacles can be stopped at any stage by deachening the fruits and can be resumed by exogenous application of auxin. In their earlier studies they demonstrated auxin regulated polypeptide changes at different stages of strawberry fruit development. Removal of achenes from fruits to deprive auxin resulted in the accumulation of 52 KDa polypeptide. This polypeptide is associated with cell wall and its concentration is increased in a time-dependent manner in auxin deprived receptacles. Incorporation studies with (/sup 35/S) methionine showed the promotion of labelling of 52 kDa polypeptide in the auxin-deprived receptacles within 12 h after removal of the achenes. Amino acid analysis revealed that the 52 KDa polypeptide is rich in glycine. Their studies, with normal and mutant strawberry receptacles, indicate that the synthesis and accumulation of this glycine rich protein correlates with cessation of receptacle growth. These results suggest a role for the glycine rich protein in growth.

  8. Modification of olfactory-related behavior in juvenile Atlantic salmon by changes in pH.

    PubMed

    Royce-Malmgren, C H; Watson, W H

    1987-03-01

    The hypothesis that low pH modifies the response of salmonids to certain olfactory stimuli was tested. An interactive video-computer system was used to monitor the behavior of juvenile Atlantic salmon (Salmo salar). At a pH of 7.6, animals were attracted to glycine and avoidedL-alanine. These effects were dose-dependent, with a threshold of 10(-7) M. The response of the fish to both amino acids changed when the pH of the test chamber was gradually lowered from 7.6 to 5.1; they became attracted toL-alanine and indifferent to glycine. These effects were reversible with a return to pH 7.6. Our findings suggest that acid rain may contribute to reductions in salmonid populations in acidified rivers by impairing the recognition of olfactory cues by salmon during their spawning migration. PMID:24301892

  9. Propofol restores the function of "hyperekplexic" mutant glycine receptors in Xenopus oocytes and mice.

    PubMed

    O'Shea, Sean Michael; Becker, Lore; Weiher, Hans; Betz, Heinrich; Laube, Bodo

    2004-03-01

    Human hereditary hyperekplexia ("startle disease") is a neurological disorder characterized by exaggerated, convulsive movements in response to unexpected stimuli. Molecular genetic studies have shown that this disease is often caused by amino acid substitutions at arginine 271 to glutamine or leucine of the alpha1 subunit of the inhibitory glycine receptor (GlyR). When exogenously expressed in Xenopus oocytes, agonist responses of mutant alpha1(R271Q) and alpha1(R271L) GlyRs show higher EC50 values and lower maximal inducible responses (relative efficacies) compared with oocytes expressing wild-type alpha1 GlyR subunits. Here, we report that the maximal glycine-induced currents (I(max)) of mutant alpha1(R271Q) and alpha1(R271L) GlyRs were dramatically potentiated in the presence of the anesthetic propofol (PRO), whereas the I(max) of wild-type alpha(1) receptors was not affected. Quantitative analysis of the agonist responses of the isofunctionally substituted alpha1(R271K) mutant GlyR revealed that saturating concentrations of PRO decreased the EC50 values of both glycine and the partial agonist beta-alanine by >10-fold, with relative efficacies increasing by 4- and 16-fold, respectively. Transgenic (tg) mice carrying the alpha1(R271Q) mutation (tg271Q-300) have both spontaneous and induced tremor episodes that closely resemble the movements of startled hyperekplexic patients. After treatment with subanesthetic doses of PRO, the tg271Q-300 mutant mice showed temporary reflexive and locomotor improvements that made them indistinguishable from wild-type mice. Together, these results demonstrate that the functional and behavioral effects of hyperekplexia mutations can be effectively reversed by drugs that potentiate GlyR responses. PMID:14999083

  10. Reduced glycine transporter type 1 expression leads to major changes in glutamatergic neurotransmission of CA1 hippocampal neurones in mice

    PubMed Central

    Martina, Marzia; Turcotte, Marie-Eve B; Halman, Samantha; Tsai, Guochuan; Tiberi, Mario; Coyle, Joseph T; Bergeron, Richard

    2005-01-01

    To investigate the effects of persistent elevation of synaptic glycine at Schaffer collateral–CA1 synapses of the hippocampus, we studied the glutamatergic synaptic transmission in acute brain slices from mice with reduced expression of glycine transporter type 1 (GlyT1+/−) as compared to wild type (WT) littermates using whole-cell patch-clamp recordings of CA1 pyramidal cells. We observed faster decay kinetics, reduced ifenprodil sensitivity and increased zinc-induced antagonism in N-methyl-d-aspartate receptor (NMDAR) currents of GlyT1+/− mice. Moreover, the ratio α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR)/NMDAR was decreased in mutants compared to WT. Surprisingly, this change was associated with a reduction in the number of AMPARs expressed at the CA1 synapses in the mutants compared to WT. Overall, these findings highlight the importance of GlyT1 in regulating glutamatergic neurotransmission. PMID:15661817

  11. Synthesis of Glycine and Other Prebiotic Compounds in the Interstellar Medium - An Example of Radiation Chemistry.

    NASA Astrophysics Data System (ADS)

    Mason, N. J.; Sivaraman, B.; Jeetha, S.; Dawes, A.; Hunniford, A.; McCullough, R. W.

    2007-08-01

    To understand how life can begin on a habitable planet such as the Earth, it is essential to know what organic compounds were likely to have been available, and how they interacted with the planetary environment. Therefore an understanding of the mechanisms by which organic chemical compounds are formed (so called /prebiotic chemistry/) is essential. Recent data from space based telescopes are revealing the interstellar medium as a rich 'chemical factory' in which many hydrocarbon speices are present (e.g. formic and acetic acid, alcohols and esters). Whether larger more complex species such as amino acids can form remains unknown since they can not, at present, be detected. However laboratory experiments that recreate the conditions of the ISM and the conditions under which stars and planets evolve have recently shown that such 'prebiotic compounds' may be formed through radiation induced chemistry. Details of these experiments will be discussed with the example of glycine formation used as an exemplar for such molecular synthesis.

  12. Free amino acid composition of quince (Cydonia oblonga Miller) fruit (pulp and peel) and jam.

    PubMed

    Silva, Branca M; Casal, Susana; Andrade, Paula B; Seabra, Rosa M; Oliveira, M Beatriz P P; Ferreira, Margarida A

    2004-03-10

    Twenty-one free amino acids present in several samples of quince fruit (pulp and peel) and quince jam (homemade and industrially manufactured) were analyzed by GC/FID. The analyses showed some differences between quince pulps and peels. Generally, the highest content in total free amino acids and in glycine was found in peels. As a general rule, the three major free amino acids detected in pulps were aspartic acid, asparagine, and hydroxyproline. For quince peels, usually, the three most abundant amino acids were glycine, aspartic acid, and asparagine. Similarly, for quince jams the most important free amino acids were aspartic acid, asparagine, and glycine or hydroxyproline. This study suggests that the free amino acid analysis can be useful for the evaluation of quince jam authenticity. It seems that glycine percentage can be used for the detection of quince peel addition while high alanine content can be related to pear addition. PMID:14995121

  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. 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.

  15. Glycine max (soybean) roots and syncytia isolated by laser capture microdissection (LCM) exhibit differential gene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soybean cyst nematode (Heterodera glycines) is an obligate parasite of soybean (Glycine max). It is the most destructive pathogen of G. max, accounting for approximately 0.46-0.82 billion dollars in crop losses, annually, in the U.S. Part of the infection process involves H. glycines establishin...

  16. 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

    ... find that Paras is not circumventing the Order because it is producing glycine from raw materials of... find that there is no record evidence that AICO self produces glycine from Indian raw materials... exported to the United States glycine that it produced only from Indian raw materials. For a...

  17. Heterodera glycines Population Development on Soybean Treated with Glyphosate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean cyst nematode (Heterodera glycines) is a major yield limiting pest in all major soybean producing countries. In the last decade genetically modified soybean tolerant to glyphosate has become widely planted and postemergence application of glyphosate has increased exponentially. Genetically m...

  18. Pathway of Glycine Betaine Biosynthesis in Aspergillus fumigatus

    PubMed Central

    Lambou, Karine; Pennati, Andrea; Valsecchi, Isabel; Tada, Rui; Sherman, Stephen; Sato, Hajime; Beau, Remi

    2013-01-01

    The choline oxidase (CHOA) and betaine aldehyde dehydrogenase (BADH) genes identified in Aspergillus fumigatus are present as a cluster specific for fungal genomes. Biochemical and molecular analyses of this cluster showed that it has very specific biochemical and functional features that make it unique and different from its plant and bacterial homologs. A. fumigatus ChoAp catalyzed the oxidation of choline to glycine betaine with betaine aldehyde as an intermediate and reduced molecular oxygen to hydrogen peroxide using FAD as a cofactor. A. fumigatus Badhp oxidized betaine aldehyde to glycine betaine with reduction of NAD+ to NADH. Analysis of the AfchoAΔ::HPH and AfbadAΔ::HPH single mutants and the AfchoAΔAfbadAΔ::HPH double mutant showed that AfChoAp is essential for the use of choline as the sole nitrogen, carbon, or carbon and nitrogen source during the germination process. AfChoAp and AfBadAp were localized in the cytosol of germinating conidia and mycelia but were absent from resting conidia. Characterization of the mutant phenotypes showed that glycine betaine in A. fumigatus functions exclusively as a metabolic intermediate in the catabolism of choline and not as a stress protectant. This study in A. fumigatus is the first molecular, cellular, and biochemical characterization of the glycine betaine biosynthetic pathway in the fungal kingdom. PMID:23563483

  19. Variable temperature NMR characterization of α-glycine

    NASA Astrophysics Data System (ADS)

    Taylor, R. E.; Dybowski, C.

    2008-10-01

    Proton NMR spin-lattice relaxation times in the laboratory frame ( T1) and in the rotating frame ( T1ρ) were measured as a function of temperature for a static sample of α-glycine. Both T1 and T1ρ data can be fit quantitatively by a single thermally-activated motion (the modulation of the dipolar coupling by random hopping about the threefold axis of the -NH 3 group), with no addition of other mechanisms at any temperature between 173 and 415 K. An activation energy of 21.7 ± 1 kJ/mol was extracted and is compared with previously reported values for both α- and γ-glycine. Such comparisons allow the correction of glycine polymorphs misidentified in the literature. The minimum in T1 at 325 K corresponds to a correlation time of 0.53 ns. Chemical shifts as a function of temperature were measured by 1H CRAMPS and by 13C and 15N CP/MAS experiments. These results are discussed relative to a previous report of anomalous electrical behavior in α-glycine within this temperature range.

  20. 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...

  1. Phenotypic characterization of roots responding to Heterodera glycines CLE peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasitism genes coding for secreted CLAVATA3/ESR(CLE)-like peptides are expressed in the dorsal gland cell of the soybean cyst nematode (SCN), Heterodera glycines, during syncytium induction and maintenance. Recent data indicate that there are two predominant forms of SCN CLEs, HgCLEA and HgCLEB, ...

  2. 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 §...

  3. Dietary glycine and threonine interactive effects in broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is little information regarding the interaction of dietary threonine and glycine on potential metabolic sparing effects, live production, or breast meat yield of broilers. To test these potential interactions, 432 one-day-old Ross 308 male broilers were fed a common diet up to 21 days of age a...

  4. 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...

  5. SSR diversity of vegetable soybean [Glycine max (L.) Merr.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edamame [Glycine max (L.) Merr.] is a type of soybean selected for fresh or frozen vegetable use at an immature stage. Since edamame has a similar protein content, milder flavor, nuttier texture, and is easier to cook when compared to grain soybean, it is being promoted as a new vegetable for global...

  6. Alkylamine-Dependent Amino-Acid Oxidation by Lysine Monooxygenase—Fragmented Substrate of Oxygenase

    PubMed Central

    Yamamoto, Shozo; Yamauchi, Takashi; Hayaishi, Osamu

    1972-01-01

    Lysine monooxygenase catalyzes the oxygenative decarboxylation of L-lysine and produces a corresponding acid amide. L-Alanine was inactive as substrate. However, when propylamine was present, oxidation, but not oxygenation, of alanine was demonstrated with the oxygenase. Alanine was converted to pyruvate, with the liberation of ammonia and hydrogen peroxide, but propylamine remained unchanged. Other α-monoamino acids were also oxidized in the presence of alkylamines with various carbon chain lengths. The highest oxidase activity was observed when the total chain length of both amino acid and amine was nearly identical with that of lysine. Available evidence indicates that the amine-dependent amino-acid oxidase activity is associated with the lysine oxygenase activity. PMID:4509334

  7. 21 CFR 582.5049 - Aminoacetic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aminoacetic acid. 582.5049 Section 582.5049 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5049 Aminoacetic acid. (a) Product. Glycine (aminoacetic acid). (b) (c)...

  8. 21 CFR 582.5049 - Aminoacetic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aminoacetic acid. 582.5049 Section 582.5049 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5049 Aminoacetic acid. (a) Product. Glycine (aminoacetic acid). (b) (c)...

  9. 21 CFR 582.5049 - Aminoacetic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aminoacetic acid. 582.5049 Section 582.5049 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5049 Aminoacetic acid. (a) Product. Glycine (aminoacetic acid). (b) (c)...

  10. 21 CFR 582.5049 - Aminoacetic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aminoacetic acid. 582.5049 Section 582.5049 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5049 Aminoacetic acid. (a) Product. Glycine (aminoacetic acid). (b) (c)...

  11. 21 CFR 582.5049 - Aminoacetic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aminoacetic acid. 582.5049 Section 582.5049 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5049 Aminoacetic acid. (a) Product. Glycine (aminoacetic acid). (b) (c)...

  12. Identification in Marinomonas mediterranea of a novel quinoprotein with glycine oxidase activity

    PubMed Central

    Campillo-Brocal, Jonatan Cristian; Lucas-Elio, Patricia; Sanchez-Amat, Antonio

    2013-01-01

    Abstract A novel enzyme with lysine-epsilon oxidase activity was previously described in the marine bacterium Marinomonas mediterranea. This enzyme differs from other l-amino acid oxidases in not being a flavoprotein but containing a quinone cofactor. It is encoded by an operon with two genes lodA and lodB. The first one codes for the oxidase, while the second one encodes a protein required for the expression of the former. Genome sequencing of M. mediterranea has revealed that it contains two additional operons encoding proteins with sequence similarity to LodA. In this study, it is shown that the product of one of such genes, Marme_1655, encodes a protein with glycine oxidase activity. This activity shows important differences in terms of substrate range and sensitivity to inhibitors to other glycine oxidases previously described which are flavoproteins synthesized by Bacillus. The results presented in this study indicate that the products of the genes with different degrees of similarity to lodA detected in bacterial genomes could constitute a reservoir of different oxidases. PMID:23873697

  13. Shifts in Buchnera aphidicola density in soybean aphids (Aphis glycines) feeding on virus-infected soybean.

    PubMed

    Cassone, Bryan J; Redinbaugh, Margaret G; Dorrance, Anne E; Michel, Andrew P

    2015-08-01

    Vertically transmitted bacterial symbionts are common in arthropods. Aphids undergo an obligate symbiosis with Buchnera aphidicola, which provides essential amino acids to its host and contributes directly to nymph growth and reproduction. We previously found that newly adult Aphis glycines feeding on soybean infected with the beetle-transmitted Bean pod mottle virus (BPMV) had significantly reduced fecundity. We hypothesized that the reduced fecundity was attributable to detrimental impacts of the virus on the aphid microbiome, namely Buchnera. To test this, mRNA sequencing and quantitative real-time PCR were used to assay Buchnera transcript abundance and titre in A. glycines feeding on Soybean mosaic virus-infected, BPMV-infected, and healthy soybean for up to 14 days. Our results indicated that Buchnera density was lower and ultimately suppressed in aphids feeding on virus-infected soybean. While the decreased Buchnera titre may be associated with reduced aphid fecundity, additional mechanisms are probably involved. The present report begins to describe how interactions among insects, plants, and plant pathogens influence endosymbiont population dynamics. PMID:25845267

  14. 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...

  15. 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...

  16. Osmoregulation of vasopressin secretion via activation of neurohypophysial nerve terminals glycine receptors by glial taurine.

    PubMed

    Hussy, N; Brès, V; Rochette, M; Duvoid, A; Alonso, G; Dayanithi, G; Moos, F C

    2001-09-15

    Osmotic regulation of supraoptic nucleus (SON) neuron activity depends in part on activation of neuronal glycine receptors (GlyRs), most probably by taurine released from adjacent astrocytes. In the neurohypophysis in which the axons of SON neurons terminate, taurine is also concentrated in and osmo-dependently released by pituicytes, the specialized glial cells ensheathing nerve terminals. We now show that taurine release from isolated neurohypophyses is enhanced by hypo-osmotic and decreased by hyper-osmotic stimulation. The high osmosensitivity is shown by the significant increase on only 3.3% reduction in osmolarity. Inhibition of taurine release by 5-nitro-2-(3-phenylpropylamino)benzoic acid, niflumic acid, and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid suggests the involvement of volume-sensitive anion channels. On purified neurohypophysial nerve endings, activation of strychnine-sensitive GlyRs by taurine or glycine primarily inhibits the high K(+)-induced rise in [Ca(2+)](i) and subsequent release of vasopressin. Expression of GlyRs in vasopressin and oxytocin terminals is confirmed by immunohistochemistry. Their implication in the osmoregulation of neurohormone secretion was assessed on isolated whole neurohypophyses. A 6.6% hypo-osmotic stimulus reduces by half the depolarization-evoked vasopressin secretion, an inhibition totally prevent