Science.gov

Sample records for amino acid taurine

  1. Taurine Bromamine: Reactivity of an Endogenous and Exogenous Anti-Inflammatory and Antimicrobial Amino Acid Derivative

    PubMed Central

    Bertozo, Luiza De Carvalho; Morgon, Nelson Henrique; De Souza, Aguinaldo Robinson; Ximenes, Valdecir Farias

    2016-01-01

    Taurine bromamine (Tau-NHBr) is produced by the reaction between hypobromous acid (HOBr) and the amino acid taurine. There are increasing number of applications of Tau-NHBr as an anti-inflammatory and microbicidal drug for topical usage. Here, we performed a comprehensive study of the chemical reactivity of Tau-NHBr with endogenous and non-endogenous compounds. Tau-NHBr reactivity was compared with HOBr, hypochlorous acid (HOCl) and taurine chloramine (Tau-NHCl). The second-order rate constants (k2) for the reactions between Tau-NHBr and tryptophan (7.7 × 102 M−1s−1), melatonin (7.3 × 103 M−1s−1), serotonin (2.9 × 103 M−1s−1), dansylglycine (9.5 × 101 M−1s−1), tetramethylbenzidine (6.4 × 102 M−1s−1) and H2O2 (3.9 × M−1s−1) were obtained. Tau-NHBr demonstrated the following selectivity regarding its reactivity with free amino acids: tryptophan > cysteine ~ methionine > tyrosine. The reactivity of Tau-NHBr was strongly affected by the pH of the medium (for instance with dansylglycine: pH 5.0, 1.1 × 104 M−1s−1, pH 7.0, 9.5 × 10 M−1s−1 and pH 9.0, 1.7 × 10 M−1s−1), a property that is related to the formation of the dibromamine form at acidic pH (Tau-NBr2). The formation of singlet oxygen was observed in the reaction between Tau-NHBr and H2O2. Tau-NHBr was also able to react with linoleic acid, but with low efficiency compared with HOBr and HOCl. Compared with HOBr, Tau-NHBr was not able to react with nucleosides. In conclusion, the following reactivity sequence was established: HOBr > HOCl > Tau-NHBr > Tau-NHCl. These findings can be very helpful for researchers interested in biological applications of taurine haloamines. PMID:27110829

  2. Indications and contraindications for infusing specific amino acids (leucine, glutamine, arginine, citrulline, and taurine) in critical illness.

    PubMed

    Ginguay, Antonin; De Bandt, Jean-Pascal; Cynober, Luc

    2016-03-01

    The review assesses the utility of supplementing parenteral or enteral nutrition of ICU patients with each of five specific amino acids that display pharmacological properties. Specifying indications implies also stating contraindications.Combined supplementation of amino acids with ω3-fatty acids and/or trace elements (immune-enhancing diets) will not be considered in this review because these mixtures do not allow the role of amino acids in the effect (positive or negative) of the mixture to be isolated, and so cannot show whether or not supplementation of a given amino acid is indicated. After decades of unbridled use of glutamine (GLN) supplementation in critically ill patients, recent large trials have brought a note of caution, indicating for example that GLN should not be used in patients with multiple organ failure. Yet these large trials do not change the conclusions of recent meta-analyses. Arginine (ARG), as a single dietary supplement, is probably not harmful in critical illness, in particular in a situation of ARG deficiency syndrome with low nitric oxide production. Citrulline supplementation strongly improves microcirculation in animal models with gut injury, but clinical studies are lacking. Taurine has a potent protective effect against ischemic reperfusion injury. Amino acid-based pharmaconutrition has displayed familiar 'big project' stages: enthusiasm (citrulline and taurine), doubt (GLN), hunt for the guilty (ARG), and backpedalling (leucine). Progress in this field is very slow, and sometimes gives way to retreat, as demonstrated by recent large trials on GLN supplementation.

  3. Taurine and taurine-deficiency in the perinatal period.

    PubMed

    Aerts, Leona; Van Assche, Frans André

    2002-01-01

    Taurine, a non-protein sulfur amino-acid, is the most abundant free amino-acid in the body and plays an important role in several essential biological processes. Apart from its role in cholesterol degradation, it acts as neurotransmitter, and has a function as osmoregulator and antioxidant in most body tissues. During pregnancy, taurine accumulates in the maternal tissues, to be released in the perinatal period to the fetus via the placenta and to the newborn via the maternal milk. It is accumulated especially in the fetal and neonatal brain. Low maternal taurine levels result in low fetal taurine levels. Taurine-deficiency in the mother leads to growth retardation of the offspring, and to impaired perinatal development of the central nervous system and of the endocrine pancreas. The adult offspring of taurine-deficient mothers display signs of impaired neurological function, impaired glucose tolerance and vascular dysfunction; they may develop gestational diabetes and transmit the effects to the next generation. This transgeneration effect of taurine-deficiency in the perinatal period fits into the concept of fetal origin of adult disease.

  4. Taurine is absent from amino components in fruits of Opuntia ficus-indica.

    PubMed

    Ali, Hatem Salama Mohamed; Al-Khalifa, Abdulrahman Saleh; Brückner, Hans

    2014-01-01

    Juices of edible fruits from Opuntia ficus-indica (L.) Miller, commonly named prickly pears or Indian figs, were analysed for amino acids using an automated amino acid analyser run in the high-resolution physiological mode. Emphasis was put on the detection of free taurine (Tau), but Tau could be detected neither in different cultivars of prickly pears from Italy, South Africa and the Near East nor in commercially available prickly pear juices from the market.

  5. Free amino acids in spider hemolymph.

    PubMed

    Tillinghast, Edward K; Townley, Mark A

    2008-11-01

    We examined the free amino acid composition of hemolymph from representatives of five spider families with an interest in knowing if the amino acid profile in the hemolymph of orb-web-building spiders reflects the high demands for small organic compounds in the sticky droplets of their webs. In nearly all analyses, on both orb and non-orb builders, glutamine was the most abundant free amino acid. Glycine, taurine, proline, histidine, and alanine also tended to be well-represented in orb and non-orb builders. While indications of taxon-specific differences in amino acid composition were observed, it was not apparent that two presumptive precursors (glutamine, taurine) of orb web sticky droplet compounds were uniquely enriched in araneids (orb builders). However, total amino acid concentrations were invariably highest in the araneids and especially so in overwintering juveniles, even as several of the essential amino acids declined during this winter diapause. Comparing the data from this study with those from earlier studies revealed a number of discrepancies. The possible origins of these differences are discussed.

  6. 21 CFR 573.980 - Taurine.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.980 Taurine. The food additive taurine (2-amino-ethanesulfonic acid) may be safely used in... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Taurine. 573.980 Section 573.980 Food and Drugs...

  7. 21 CFR 573.980 - Taurine.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.980 Taurine. The food additive taurine (2-amino-ethanesulfonic acid) may be safely used in... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Taurine. 573.980 Section 573.980 Food and Drugs...

  8. 21 CFR 573.980 - Taurine.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.980 Taurine. The food additive taurine (2-amino-ethanesulfonic acid) may be safely used in... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Taurine. 573.980 Section 573.980 Food and Drugs...

  9. 21 CFR 573.980 - Taurine.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.980 Taurine. The food additive taurine (2-amino-ethanesulfonic acid) may be safely used in... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Taurine. 573.980 Section 573.980 Food and Drugs...

  10. 21 CFR 573.980 - Taurine.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.980 Taurine. The food additive taurine (2-amino-ethanesulfonic acid) may be safely used in... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Taurine. 573.980 Section 573.980 Food and Drugs...

  11. Characteristics of basal taurine release in the rat striatum measured by microdialysis.

    PubMed

    Molchanova, S; Oja, S S; Saransaari, P

    2004-12-01

    Taurine is a sulfur-containing amino acid thought to be an osmoregulator, neurotransmitter or neuromodulator in the brain. Our objective was to establish how much taurine is released in the striatum and examine the mechanisms controlling extracellular taurine concentrations under resting conditions. The experiments were made on rats by microdialysis in vivo. Changes in taurine were compared with those in glutamate, glycine and the non-neuroactive amino acid threonine. Using the zero net flux approach we showed the extracellular concentration of taurine to be 25.2 +/- 5.1 muM. Glutamate was increased by tetrodotoxin and decreased by Ca2+ omission, glycine and threonine were not affected and both treatments increased extracellular taurine. The basal taurine release was increased by the taurine transport inhibitor guanidinoethanesulfonate and reduced by the anion channel blocker 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid.

  12. Forced swimming and imipramine modify plasma and brain amino acid concentrations in mice.

    PubMed

    Murakami, Tatsuro; Yamane, Haruka; Tomonaga, Shozo; Furuse, Mitsuhiro

    2009-01-05

    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.

  13. Effects of graded taurine levels on juvenile cobia

    USDA-ARS?s Scientific Manuscript database

    Taurine, which has multiple important physiological roles in teleost fish and mammals, is an amino acid not found in alternative protein sources not derived from animals. Although taurine is found in fish-meal-based feeds, its high water solubility leads to lower taurine levels in reduction-process-...

  14. Physiological roles of taurine in heart and muscle

    PubMed Central

    2010-01-01

    Taurine (aminoethane sulfonic acid) is an ubiquitous compound, found in very high concentrations in heart and muscle. Although taurine is classified as an amino acid, it does not participate in peptide bond formation. Nonetheless, the amino group of taurine is involved in a number of important conjugation reactions as well as in the scavenging of hypochlorous acid. Because taurine is a fairly inert compound, it is an ideal modulator of basic processes, such as osmotic pressure, cation homeostasis, enzyme activity, receptor regulation, cell development and cell signalling. The present review discusses several physiological functions of taurine. First, the observation that taurine depletion leads to the development of a cardiomyopathy indicates a role for taurine in the maintenance of normal contractile function. Evidence is provided that this function of taurine is mediated by changes in the activity of key Ca2+ transporters and the modulation Ca2+ sensitivity of the myofibrils. Second, in some species, taurine is an established osmoregulator, however, in mammalian heart the osmoregulatory function of taurine has recently been questioned. Third, taurine functions as an indirect regulator of oxidative stress. Although this action of taurine has been widely discussed, its mechanism of action is unclear. A potential mechanism for the antioxidant activity of taurine is discussed. Fourth, taurine stabilizes membranes through direct interactions with phospholipids. However, its inhibition of the enzyme, phospholipid N-methyltransferase, alters the phosphatidylcholine and phosphatidylethanolamine content of membranes, which in turn affects the function of key proteins within the membrane. Finally, taurine serves as a modulator of protein kinases and phosphatases within the cardiomyocyte. The mechanism of this action has not been studied. Taurine is a chemically simple compound, but it has profound effects on cells. This has led to the suggestion that taurine is an

  15. Physiological roles of taurine in heart and muscle.

    PubMed

    Schaffer, Stephen W; Jong, Chian Ju; Ramila, K C; Azuma, Junichi

    2010-08-24

    Taurine (aminoethane sulfonic acid) is an ubiquitous compound, found in very high concentrations in heart and muscle. Although taurine is classified as an amino acid, it does not participate in peptide bond formation. Nonetheless, the amino group of taurine is involved in a number of important conjugation reactions as well as in the scavenging of hypochlorous acid. Because taurine is a fairly inert compound, it is an ideal modulator of basic processes, such as osmotic pressure, cation homeostasis, enzyme activity, receptor regulation, cell development and cell signalling. The present review discusses several physiological functions of taurine. First, the observation that taurine depletion leads to the development of a cardiomyopathy indicates a role for taurine in the maintenance of normal contractile function. Evidence is provided that this function of taurine is mediated by changes in the activity of key Ca2+ transporters and the modulation Ca2+ sensitivity of the myofibrils. Second, in some species, taurine is an established osmoregulator, however, in mammalian heart the osmoregulatory function of taurine has recently been questioned. Third, taurine functions as an indirect regulator of oxidative stress. Although this action of taurine has been widely discussed, its mechanism of action is unclear. A potential mechanism for the antioxidant activity of taurine is discussed. Fourth, taurine stabilizes membranes through direct interactions with phospholipids. However, its inhibition of the enzyme, phospholipid N-methyltransferase, alters the phosphatidylcholine and phosphatidylethanolamine content of membranes, which in turn affects the function of key proteins within the membrane. Finally, taurine serves as a modulator of protein kinases and phosphatases within the cardiomyocyte. The mechanism of this action has not been studied. Taurine is a chemically simple compound, but it has profound effects on cells. This has led to the suggestion that taurine is an

  16. Effect of supplemental taurine on juvenile channel catfish Ictalurus punctatus growth

    USDA-ARS?s Scientific Manuscript database

    Taurine is a beta-amino sulfur amino acid found in most animal tissues. It has many important biological functions in mammals including membrane stabilization, antioxidation, cellular osmoregulation, detoxification, neuromodulation, and brain and eye development. Taurine supplementation in juvenil...

  17. Protective and therapeutic effectiveness of taurine in diabetes mellitus: a rationale for antioxidant supplementation.

    PubMed

    Sirdah, Mahmoud M

    2015-01-01

    Taurine, 2-amino ethanesulfonic acid, is a conditionally essential β amino acid which is not utilized in protein synthesis. Taurine is one of the most abundant free amino acids in mammals tissues and is one of the three well-known sulfur-containing amino acids; the others are methionine and cysteine which are considered as the precursors for taurine synthesis. Different scientific studies emphasize on the cytoprotective properties of taurine which included antioxidation, antiapoptosis, membrane stabilization, osmoregulation, and neurotransmission. Protective and therapeutic ameliorations of oxidative stress-induced pathologies were also attributed to taurine both in experimental and human models. Data demonstrating the beneficial effectiveness of taurine against type 1 and type 2 diabetes mellitus and their complications are growing and providing a better understanding of the underlying molecular mechanisms. Although the clinical studies are limited compared to the experimental ones, the present updated systematic review of the literature is set up to provide experimental and clinical evidences regarding the effectiveness of taurine in the context of diabetes mellitus and its complications. Gathering these scientific effects of taurine on diabetes mellitus could provide the physicians and specially the endocrinologists with a comprehensive overview on possible trends in the prevention and management of the disease and its complications through antioxidant supplementation. Copyright © 2014 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  18. Taurine transport across hepatocyte plasma membranes: analysis in isolated rat liver sinusoidal plasma membrane vesicles.

    PubMed

    Inoue, M; Arias, I M

    1988-07-01

    To elucidate the mechanism of taurine transport across the hepatic plasma membranes, rat liver sinusoidal plasma membrane vesicles were isolated and the transport process was analyzed. In the presence of a sodium gradient across the membranes (vesicle inside less than vesicle outside), an overshooting uptake of taurine occurred. In the presence of other ion gradients (K+, Li+, and choline+), taurine uptake was very small and no such overshoot was observed. Sodium-dependent uptake of taurine occurred into an osmotically active intravesicular space. Taurine uptake was stimulated by preloading vesicles with unlabeled taurine (transstimulation) in the presence of NaCl, but not in the presence of KCl. Sodium-dependent transport followed saturation kinetics with respect to taurine concentration; double-reciprocal plots of uptake versus taurine concentration gave a straight line from which an apparent Km value of 0.38 mM and Vmax of 0.27 nmol/20 s x mg of protein were obtained. Valinomycin-induced K+-diffusion potential failed to enhance the rate of taurine uptake, suggesting that taurine transport does not depend on membrane potential. Taurine transport was inhibited by structurally related omega-amino acids, such as beta-alanine and gamma-aminobutyric acid, but not by glycine, epsilon-aminocaproic acid, or other alpha-amino acids, such as L-alanine. These results suggest that Na+-dependent uptake of taurine might occur across the hepatic sinusoidal plasma membranes via a transport system that is specific for omega-amino acids having 2-3 carbon chain length.

  19. Content and traffic of taurine in hippocampal reactive astrocytes.

    PubMed

    Junyent, Fèlix; De Lemos, Luisa; Utrera, Juana; Paco, Sonia; Aguado, Fernando; Camins, Antoni; Pallàs, Mercè; Romero, Rafael; Auladell, Carme

    2011-02-01

    Taurine is one of the most abundant free amino acids in the mammalian central nervous system, where it is crucial to proper development. Moreover, taurine acts as a neuroprotectant in various diseases; in epilepsy, for example, it has the capacity to reduce or abolish seizures. In the present study, taurine levels has been determine in mice treated with Kainic Acid (KA) and results showed an increase of this amino acid in hippocampus but not in whole brain after 3 and 7 days of KA treatment. This increase occurs when gliosis was observed. Moreover, taurine transporter (TAUT) was found in astrocytes 3 and 7 days after KA treatment, together with an increase in cysteine sulfinic acid decarboxylase (csd) mRNA, that codifies for the rate-limiting enzyme of taurine synthesis, in the hippocampus at the same times after KA treatment. Glial cultures enriched in astrocytes were developed to demonstrate that these cells are responsible for changes in taurine levels after an injury to the brain. The cultures were treated with proinflammatory cytokines to reproduce gliosis. In this experimental model, an increase in the immunoreactivity of GFAP was observed, together with an increase in CSD and taurine levels. Moreover, an alteration in the taurine uptake-release kinetics was detected in glial cells treated with cytokine. All data obtained indicate that astrocytes could play a key role in taurine level changes induced by neuronal damage. More studies are, therefore, needed to clarify the role taurine has in relation to neuronal death and repair. Copyright © 2009 Wiley-Liss, Inc.

  20. Effect of supplemental taurine on juvenile channel catfish Ictalurus punctatus growth performance

    USDA-ARS?s Scientific Manuscript database

    Taurine is a beta-amino sulfur amino acid found in most animal tissues that has many important biological functions including bile salt conjugation, cellular osmoregulation, neuromodulation, calcium signaling. The benefits of supplementing diets with taurine are just beginning to be realized in a n...

  1. Restraint stress in lactating mice alters the levels of sulfur-containing amino acids in milk.

    PubMed

    Nishigawa, Takuma; Nagamachi, Satsuki; Ikeda, Hiromi; Chowdhury, Vishwajit S; Furuse, Mitsuhiro

    2018-03-30

    It is well known that maternal stress during the gestation and lactation periods induces abnormal behavior in the offspring and causes a lowering of the offspring's body weight. Various causes of maternal stress during the lactation period, relating to, for example, maternal nutritional status and reduced maternal care, have been considered. However, little is known about the effects on milk of maternal stress during the lactation period. The current study aimed to determine whether free amino acids, with special reference to sulfur-containing amino acids in milk, are altered by restraint stress in lactating mice. The dams in the stress group were restrained for 30 min at postnatal days 2, 4, 6, 8, 10 and 12. Restraint stress caused a reduction in the body weight of lactating mice. The concentration of taurine and cystathionine in milk was significantly higher in the stress group, though stress did not alter their concentration in maternal plasma. The ratio of taurine concentration in milk to its concentration in maternal plasma was significantly higher in the stress group, suggesting that stress promoted taurine transportation into milk. Furthermore, taurine concentration in milk was positively correlated with corticosterone levels in plasma. In conclusion, restraint stress in lactating mice caused the changes in the metabolism and in the transportation of sulfur-containing amino acids and resulted in higher taurine concentration in milk. Taurine concentration in milk could also be a good parameter for determining stress status in dams.

  2. Taurine and neural cell damage.

    PubMed

    Saransaari, P; Oja, S S

    2000-01-01

    The inhibitory amino acid taurine is an osmoregulator and neuromodulator, also exerting neuroprotective actions in neural tissue. We review now the involvement of taurine in neuron-damaging conditions, including hypoxia, hypoglycemia, ischemia, oxidative stress, and the presence of free radicals, metabolic poisons and an excess of ammonia. The brain concentration of taurine is increased in several models of ischemic injury in vivo. Cell-damaging conditions which perturb the oxidative metabolism needed for active transport across cell membranes generally reduce taurine uptake in vitro, immature brain tissue being more tolerant to the lack of oxygen. In ischemia nonsaturable diffusion increases considerably. Both basal and K+-stimulated release of taurine in the hippocampus in vitro is markedly enhanced under cell-damaging conditions, ischemia, free radicals and metabolic poisons being the most potent. Hypoxia, hypoglycemia, ischemia, free radicals and oxidative stress also increase the initial basal release of taurine in cerebellar granule neurons, while the release is only moderately enhanced in hypoxia and ischemia in cerebral cortical astrocytes. The taurine release induced by ischemia is for the most part Ca2+-independent, a Ca2+-dependent mechanism being discernible only in hippocampal slices from developing mice. Moreover, a considerable portion of hippocampal taurine release in ischemia is mediated by the reversal of Na+-dependent transporters. The enhanced release in adults may comprise a swelling-induced component through Cl- channels, which is not discernible in developing mice. Excitotoxic concentrations of glutamate also potentiate taurine release in mouse hippocampal slices. The ability of ionotropic glutamate receptor agonists to evoke taurine release varies under different cell-damaging conditions, the N-methyl-D-aspartate-evoked release being clearly receptor-mediated in ischemia. Neurotoxic ammonia has been shown to provoke taurine release from

  3. Amino acid neurotransmitter release and learning: a study of visual imprinting.

    PubMed

    Meredith, R M; McCabe, B J; Kendrick, K M; Horn, G

    2004-01-01

    The intermediate and medial part of the hyperstriatum ventrale (IMHV) is an area of the domestic chick forebrain that stores information acquired through the learning process of imprinting. The effects of visual imprinting on the release of the amino acids aspartate, arginine, citrulline, gamma-aminobutyric acid (GABA), glutamate, glycine and taurine from the left and right IMHVs in vitro were measured at 3.5, 10 and 24 h after training. Chicks were exposed to an imprinting stimulus for 1 h, their preferences measured 10 min afterward and a preference score calculated as a measure of the strength of learning. Potassium stimulation was used to evoke amino acid release from the IMHVs of trained and untrained chicks in the presence and absence of extracellular Ca2+. Ca2+-dependent, K+-evoked release of glutamate was significantly (34.4%) higher in trained than in untrained chicks. This effect was not influenced by time after training or by side (left or right IMHV). Training influenced the evoked release of GABA and taurine from the left IMHV at both 3.5 and 10 h. The training effects at the two times were statistically homogeneous so data (< or = 10 h group) were combined for each amino acid respectively. For this < or = 10 h group, evoked release increased significantly with preference score. In contrast, for the 24 h group, evoked release of GABA and taurine was not significantly correlated with preference score. There were no significant correlations between preference score and GABA or taurine release in the right IMHV at any time, nor in the absence of extracellular calcium. No significant effects of training condition, time or side were observed for any other amino acid in the study. The present findings suggest that soon after chicks have been exposed to an imprinting stimulus glutamatergic excitatory transmission in IMHV is enhanced, and remains enhanced for at least 24 h. In contrast, the learning-related elevations in taurine and GABA release are not

  4. Taurine transport into fetal cord blood cells: inhibition by cyclosporine A.

    PubMed

    Speake, Paul F; Zipitis, Christos S; Houston, Angela; D'Souza, Stephen

    2004-10-01

    Pregnant women undergoing long-term organ transplant treatment have an increased incidence of delivering infants with intrauterine growth restriction (IUGR). Cyclosporine A is used as an immunosuppressant in such women and indirect evidence suggests that IUGR might result from an effect of cyclosporine A on amino acid transport by the placenta. In this study we tested the hypothesis that the transport of an essential amino acid, taurine, by fetal tissue other than the placenta is modulated by cyclosporine A. Cord blood cells (CBCs) were used to test this hypothesis as an easily obtainable fetal tissue. Transport of taurine into CBCs was measured using standard tracer flux assays. Uptake of [(3)H] taurine by CBCs was linear over 15 minutes (76.2 +/- 16.6 fmol/10(6) cells/min, mean +/- SEM, n = 6) and inhibitable by 10 mM beta-alanine, a substrate of the system-beta taurine transport protein (6.7 +/- 1.0 fmol/10(6) cells/min, n = 6, P <.05, paired Student t test). Pre-incubation with cyclosporine A (5 microM) inhibited [(3)H] taurine uptake by 29.3%-5.3% (n = 8, P <.05, paired Student t test). These data show that amino acid transport via system-beta can be measured in CBCs and may be a useful model for amino acid transport studies in fetal cells. We also show that system-beta was inhibited by the immunosuppressant, cyclosporine A. This suggests that the increased incidence of IUGR reported in mothers treated with cyclosporine A may be due partially to effects on taurine uptake into fetal cells outside the placenta.

  5. Taurine in pediatric nutrition: review and update.

    PubMed

    Gaull, G E

    1989-03-01

    Taurine was long considered an end product of the metabolism of the sulfur-containing amino acids, methionine and cyst(e)ine. Its only clearly recognized biochemical role had been as a substrate in the conjugation of bile acids. Taurine is found free in millimolar concentrations in animal tissues, particularly those that are excitable, rich in membranes, and generate oxidants. Various lines of evidence suggest one major nutritional role as protecting cell membranes by attenuating toxic substances and/or by acting as an osmoregulator. The totality of evidence suggests that taurine is nonessential in the rodent, it is an essential amino acid in the cat, and it is conditionally essential in man and monkey. Absence from the diet of a conditionally essential nutrient does not produce immediate deficiency disease but, in the long term, can cause problems. Taurine is now added to many infant formulas as a measure of prudence to provide improved nourishment with the same margin of safety for its newly identified physiologic functions as that found in human milk. Such supplementation can be justified by the finding of improved fat absorption in preterm infants and in children with cystic fibrosis, as well as by salutary effects on auditory brainstem-evoked responses in preterm infants. Experimental findings in animal models and in human cell models provide further justification for taurine supplementation of infant formulas.

  6. [Influence of oral contraceptive agents on the concentration of amino acids in leukocytes of supposedly healthy women (author's transl)].

    PubMed

    Tarallo, P; Houpert, Y; Siest, G

    1977-12-15

    The concentration of amino acids has been measured in leukocytes of women taking oral contraceptive agents and also in controls. These assays were made by means of ion exchange chromatography. The amino acid pool in leukocytes was found to be smaller in those patients taking the "pill". Each amino acid concentration decreased except for taurine and glutamine. Taurine represented 64.1 percent of the pool in treated women and only 23.5 percent in controls. Glutamine represented 9.5 percent of the pool in patients and 3.7 percent in controls.

  7. Effects of ω-Amino Acids and Related Compounds on Staphylococcal Infections in Mice: a Combined Prophylactic-Therapeutic Procedure 1

    PubMed Central

    Tsuchiya, Yoshiki; Tanaka, Kinji; Cook, Elton S.; Nutini, Leo G.

    1970-01-01

    By a short-term combined prophylactic-therapeutic procedure, the following compounds were found to be active against staphylococcal infections in Swiss mice: γ-aminobutyric acid, γ-amino-β-hydroxybutyric acid (GABOB), δ-amino-valeric acid (DAVA), ε-aminocaproic acid (EACA), trans-4-aminomethylcyclohexanecarboxylic acid (trans-AMCHA), taurine, and cysteic acid. Many of these compounds had displayed limited or no activity by a previously used prophylactic procedure. Although DAVA and GABOB were the most potent of the straight-chain ω-amino acids, trans-AMCHA displayed the greatest antistaphylococcic activity of the ω-amino acids thus far investigated. Homocarnosine (γ-aminobutyrl histidine, which also was active by the prophylactic procedure) equalled trans-AMCHA in activity. Taurine was similar in potency to DAVA, and the activity of cysteic acid approximated that of EACA. PMID:5422309

  8. [Plasma levels of mediator amino acids in patients with Parkinson disease].

    PubMed

    Vitreshchak, T V; Poleshchuk, V V; Piradov, M A

    2004-01-01

    Content of neurotransmitter amino acids before and after treatment with He-Ne-laser was measured in blood of two groups of the Parkinson's disease patients distinguished by low (first group) and high (second group) activity of monoamine oxidase B and Cu/Zn-superoxide dismutase. An increase in taurine level at the early stage of the disease (first group of patients) suggests that taurine may be a marker of compensatory abilities of the organism. The violation of the glutamate/taurine balance at the later stages of the disease and its normalization following the laserotherapy accompanied improvement of neurological symptoms.

  9. Altered peripheral amino acid profile indicate a systemic impact of active celiac disease and a possible role of amino acids in disease pathogenesis.

    PubMed

    Torinsson Naluai, Åsa; Saadat Vafa, Ladan; Gudjonsdottir, Audur H; Arnell, Henrik; Browaldh, Lars; Nilsson, Staffan; Agardh, Daniel

    2018-01-01

    We have previously performed a Genome Wide Association and linkage study that indicated a new disease triggering mechanism involving amino acid metabolism and nutrient sensing signaling pathways. The aim of this study was to investigate if plasma amino acid levels differed among children with celiac disease compared with disease controls. Fasting plasma samples from 141 children with celiac disease and 129 non-celiac disease controls, were analyzed for amino acid levels by liquid chromatography-tandem mass spectrometry (LC/MS). A general linear model using age and experimental effects as covariates was used to compare amino acid levels between children with a diagnosis of celiac disease and controls. Seven out of twenty-three analyzed amino acids were elevated in children with celiac disease compared with controls (tryptophan, taurine, glutamic acid, proline, ornithine, alanine and methionine). The significance of the individual amino acids do not survive multiple correction, however, multivariate analyses of the amino acid profile showed significantly altered amino acid levels in children with celiac disease overall and after correction for age, sex and experimental effects (p = 8.4 × 10-8). These findings support the idea that amino acids could influence systemic inflammation and play a possible role in disease pathogenesis.

  10. Taurine decreased uric acid levels in hyperuricemic rats and alleviated kidney injury.

    PubMed

    Feng, Ying; Sun, Fang; Gao, Yongchao; Yang, Jiancheng; Wu, Gaofeng; Lin, Shumei; Hu, Jianmin

    2017-07-29

    Hyperuricemia can lead to direct kidney damage. Taurine participates in several renal physiological processes and has been shown as a renoprotective agent. It has been reported that taurine could reduce uric acid levels in diabetic rats, but to date there was no research on the effects of taurine on hyperuricemic rats with kidney injury. In present study, hyperuricemic rat models were induced by intragastric administration of adenine and ethambutol hydrochloride for 10 days, and taurine (1% or 2%) were added in the drinking water 7 days in advance for consecutively 17 days. The results showed that taurine alleviated renal morphological and pathological changes as well as kidney dysfunction in hyperuricemic rats. Taurine could efficiently decrease the elevated xanthine oxidase activities in hyperuricemic rats, indicating its effect on the regulation of uric acid formation. The reabsorption and secretion of uric acid are dependent on a number of urate transporters. Expressions of three urate transporters were significantly down-regulated in hyperuricemic rats, while taurine prevented the decrease of mRNA and protein expression levels of these urate transporters. The results indicate that taurine might play a role in the regulation of renal uric acid excretion. Therefore, taurine could be a promising agent for the treatment of hyperuricemia. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Amino acids as central synaptic transmitters or modulators in mammalian thermoregulation

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

    Bligh, J.

    1981-11-01

    Of the amino acids that affect the activity of central neurons, aspartate and glutamate (which exert generally excitatory influences) and glycine, taurine, and ..gamma..-aminobutyric acid (GABA) (which generally exert inhibitory influences) are the strongest neurotransmitter candidates. As with other putative transmitter substances, their effects on body temperature when injected into the cerebral ventricles or the preoptic hypothalamus tend to vary within and between species. These effects are uninterpretable without accompanying information regarding effector activity changes and the influences of dose and ambient temperature. Observations necessary for analysis of apparent action have been made in studies of the effects of intracerebroventricularmore » injections of these amino acids into sheep. Aspartate and glutamate have similar excitatory effects on the pathway from cold sensors, whereas taurine and GABA exert inhibitory influences on the neural pathways that activate both heat production and heat loss effectors. Glycine appears to be without effect.« less

  12. Sulphur-containing Amino Acids: Protective Role Against Free Radicals and Heavy Metals.

    PubMed

    Colovic, Mirjana B; Vasic, Vesna M; Djuric, Dragan M; Krstic, Danijela Z

    2018-01-30

    Sulphur is an abundant element in biological systems, which plays an important role in processes essential for life as a constituent of proteins, vitamins and other crucial biomolecules. The major source of sulphur for humans is plants being able to use inorganic sulphur in the purpose of sulphur-containing amino acids synthesis. Sulphur-containing amino acids include methionine, cysteine, homocysteine, and taurine. Methionine and cysteine are classified as proteinogenic, canonic amino acids incorporated in protein structure. Sulphur amino acids are involved in the synthesis of intracellular antioxidants such as glutathione and N-acetyl cysteine. Moreover, naturally occurring sulphur-containing ligands are effective and safe detoxifying agents, often used in order to prevent toxic metal ions effects and their accumulation in human body. Literature search for peer-reviewed articles was performed using PubMed and Scopus databases, and utilizing appropriate keywords. This review is focused on sulphur-containing amino acids - methionine, cysteine, taurine, and their derivatives - glutathione and N-acetylcysteine, and their defense effects as antioxidant agents against free radicals. Additionally, the protective effects of sulphur-containing ligands against the toxic effects of heavy and transition metal ions, and their reactivation role towards the enzyme inhibition are described. Sulphur-containing amino acids represent a powerful part of cell antioxidant system. Thus, they are essential in the maintenance of normal cellular functions and health. In addition to their worthy antioxidant action, sulphur-containing amino acids may offer a chelating site for heavy metals. Accordingly, they may be supplemented during chelating therapy, providing beneficial effects in eliminating toxic metals. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Acute intraperitoneal administration of taurine decreases the glycemia and reduces food intake in type 1 diabetic rats.

    PubMed

    Gomez, Rosane; Caletti, Greice; Arbo, Bruno Dutra; Hoefel, Ana Lúcia; Schneider, Ricardo; Hansen, Alana Witt; Pulcinelli, Rianne Remus; Freese, Luana; Bandiera, Solange; Kucharski, Luiz Carlos; Barros, Helena Maria Tanhauser

    2018-07-01

    Taurine, an amino acid with antioxidant and osmoregulatory properties, has been studied for its possible antidiabetic properties in type 1 and type 2 diabetic animals. In type 2 diabetic mice, taurine decreases blood glucose through increased insulin secretion and insulin receptor sensitization. However, insulin is absent in type 1 diabetic individuals. The aim of this study was to evaluate the effects of taurine on parameters related to the energy balance that could explain the metabolic action of this amino acid in type 1 diabetic rats. Control and streptozotocin-induced diabetic rats received saline or taurine (100 mg/kg/day), intraperitoneally, for 30 days. Parameters such as palatable food intake, gastrointestinal transit rate, serum glucose, insulin, leptin, and glucagon levels were measured 60 min after the last taurine administration. Liver, kidneys, heart, and retroperitoneal fat were dissected and weighted. Glycogen levels were measured in the liver and soleus muscle. Our results showed that acute taurine administration decreased glycemia. It also decreased food intake in diabetic rats, without affecting other metabolic parameters. Altogether, our results suggest that in type 1 diabetic rats, taurine decreases blood glucose by a non-insulin-dependent mechanism. Due to the safety profile of taurine, and its effect on glycemia, this amino acid may help to design new drugs to add benefit to insulin therapy in type 1 diabetic individuals. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  14. Proximate composition, amino acid and fatty acid profiles of marine snail Rapana venosa meat, visceral mass and operculum.

    PubMed

    Luo, Fenglei; Xing, Ronge; Wang, Xueqin; Peng, Quancai; Li, Pengcheng

    2017-12-01

    Rapana venosa (Rv), an important marine snail, demonstrates an increasing nutritional and economic importance. However, there is still limited information available on their nutritional composition. The present study highlights and provides new information on the proximate composition, amino acid and fatty acid profiles of different body parts of Rv, aiming for its better application and research. The operculum contained a high amount of protein and flavor amino acids. The edible tissues, including meat and visceral mass, were valuable sources of essential amino acids (EAA) apart from methionine and cysteine. In addition, the meat contained high amount of taurine. Fatty acid analysis indicated that the edible tissues contained high amounts of ω3 fatty acids, especially eicosapentaenoic acid (EPA) (C20:5ω3) and docosahexaenoic acid (DHA) (C22:6ω3), and had a low ω6/ω3 fatty acid ratio. Interestingly, significantly higher concentrations of most nutritional elements such as fat, EAA, EPA and DHA, were found in the visceral mass compared to those in the meat. The operculum of Rv may became a very interesting source for some protein and flavor peptide development, and the edible parts of Rv may be utilized for special dietary applications requiring high amounts of taurine, EPA, DHA and a lower ω6/ω3 fatty acid ratio. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. In vivo substitution of choline for sodium evokes a selective osmoinsensitive increase of extracellular taurine in the rat hippocampus.

    PubMed

    Lehmann, A; Sandberg, M

    1990-01-01

    Recent investigations have demonstrated that taurine and phosphoethanolamine (PEA) are the amino acids most sensitive to microdialysis-perfusion with reduced concentrations of NaCl. The aim of the present work was to assess the importance of Na+ deficiency in evoking this response. Further, the previously described selectivity of replacement of Cl- with acetate with respect to amino acid release was reinvestigated. The hippocampus of urethane-anesthetized rats was dialyzed with Krebs-Ringer bicarbonate buffer, and amino acid concentrations of the perfusate were determined. Choline chloride was then stepwise substituted for NaCl, and, in some cases, mannitol (122 mM) was included in low sodium-containing media. In other experiments, NaCl was replaced with sodium acetate. The dialysate levels of taurine increased selectively in response to Na+ substitution. The elevation of taurine was linearly related to the increase in choline chloride, and maximal levels amounted to 335% of basal levels. The increase in extracellular taurine was not inhibited by perfusion with medium made hyperosmotic with mannitol. Replacement of Cl- with acetate stimulated the release of taurine to 652% of resting levels. In addition, PEA levels increased to 250% of control concentration. Other amino acids were unaffected by Cl- substitution. The results show that taurine transport is considerably more sensitive to Na+ depletion than glutamate transport, which also is known to be Na+ dependent. The taurine increase evoked by low Na+ is not caused by cellular swelling as it was unaffected by hyperosmolar medium. Finally, substitution of acetate for Cl- causes a specific elevation of extracellular taurine and PEA, possibly as a result of cytotoxic edema.

  16. Effect of taurine on ischemia-reperfusion injury.

    PubMed

    Schaffer, Stephen W; Jong, Chian Ju; Ito, Takashi; Azuma, Junichi

    2014-01-01

    Taurine is an abundant β-amino acid that regulates several events that dramatically influence the development of ischemia-reperfusion injury. One of these events is the extrusion of taurine and Na+ from the cell via the taurine/Na+ symport. The loss of Na+ during the ischemia-reperfusion insult limits the amount of available Na+ for Na+/Ca2+ exchange, an important process in the development of Ca2+ overload and the activation of the mitochondrial permeability transition, a key process in ischemia-reperfusion mediated cell death. Taurine also prevents excessive generation of reactive oxygen species by the respiratory chain, an event that also limits the activation of the MPT. Because taurine is an osmoregulator, changes in taurine concentration trigger "osmotic preconditioning," a process that activates an Akt-dependent cytoprotective signaling pathway that inhibits MPT pore formation. These effects of taurine have clinical implications, as experimental evidence reveals potential promise of taurine therapy in preventing cardiac damage during bypass surgery, heart transplantation and myocardial infarction. Moreover, severe loss of taurine from the heart during an ischemia-reperfusion insult may increase the risk of ventricular remodeling and development of heart failure.

  17. Taurine-induced attenuation of MPP+ neurotoxicity in vitro: a possible role for the GABA(A) subclass of GABA receptors.

    PubMed

    O'Byrne, M B; Tipton, K F

    2000-05-01

    Taurine is a sulphur-containing beta-amino acid found in high (millimolar) concentrations in excitable tissues such as brain and heart. Its suggested roles include osmoregulator, thermoregulator, neuromodulator, and potential neurotransmitter. This amino acid has also been shown to be released in large concentrations during ischaemia and excitotoxin-induced neuronal damage. Here we report a protective effect of taurine against MPP(+)-induced neurotoxicity in coronal slices from rat brain. Significant protective effects were observed at taurine concentrations of 20 and 1 mM, suggesting a potential role for taurine in cases of neuronal insult. Studies with the synthetic taurine analogues taurine phosphonate, guanidinoethane sulphonate, and trimethyltaurine suggested the observed effect to be mediated via an extracellular mechanism. The use of GABA receptor ligands muscimol and bicuculline indicated the effect to be mediated through activation of GABA(A) receptors.

  18. Comparison of taurine, GABA, Glu, and Asp as scavengers of malondialdehyde in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Deng, Yan; Wang, Wei; Yu, Pingfeng; Xi, Zhijiang; Xu, Lijian; Li, Xiaolong; He, Nongyue

    2013-04-01

    The purpose of this study is to determine if amino acid neurotransmitters such as gamma-aminobutyric acid (GABA), taurine, glutamate (Glu), and aspartate (Asp) can scavenge activated carbonyl toxicants. In vitro, direct reaction between malondialdehyde (MDA) and amino acids was researched using different analytical methods. The results indicated that scavenging activated carbonyl function of taurine and GABA is very strong and that of Glu and Asp is very weak in pathophysiological situations. The results provided perspective into the reaction mechanism of taurine and GABA as targets of activated carbonyl such as MDA in protecting nerve terminals. In vivo, we studied the effect of taurine and GABA as antioxidants by detecting MDA concentration and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. It was shown that MDA concentration was decreased significantly, and the activities of SOD and GSH-Px were increased significantly in the cerebral cortex and hippocampus of acute epileptic state rats, after the administration of taurine and GABA. The results indicated that the peripherally administered taurine and GABA can scavenge free radicals and protect the tissue against activated carbonyl in vivo and in vitro.

  19. Taurine suppresses osteoblastic differentiation of aortic valve interstitial cells induced by beta-glycerophosphate disodium, dexamethasone and ascorbic acid via the ERK pathway.

    PubMed

    Feng, Xiang; Li, Jian-ming; Liao, Xiao-bo; Hu, Ye-rong; Shang, Bao-peng; Zhang, Zhi-yuan; Yuan, Ling-qing; Xie, Hui; Sheng, Zhi-feng; Tang, Hao; Zhang, Wei; Gu, Lu; Zhou, Xin-min

    2012-10-01

    Aortic valve calcification (AVC) is an active process characterized by osteoblastic differentiation of the aortic valve interstitial cells (AVICs). Taurine is a free β-amino acid and plays important physiological roles including protective effect of cardiovascular events. To evaluate the possible role of taurine in AVC, we isolated human AVICs from patients with type A dissection without leaflet disease. We demonstrated that the cultured AVICs express SM α-actin, vimentin and taurine transporter (TAUT), but not CD31, SM-myosin or desmin. We also established the osteoblastic differentiation model of the AVICs induced by pro-calcific medium (PCM) containing β-glycerophosphate disodium, dexamethasone and ascorbic acid in vitro. The results showed that taurine attenuated the PCM-induced osteoblastic differentiation of AVICs by decreasing the alkaline phosphate (ALP) activity/expression and the expression of the core binding factor α1 (Cbfα1) in a dose-dependent manner (reaching the maximum protective effect at 10 mM), and taurine (10 mM) inhibited the mineralization level of AVICs in the form of calcium content significantly. Furthermore, taurine activated the extracellular signal-regulated protein kinase (ERK) pathway via TAUT, and the inhibitor of ERK (PD98059) abolished the effect of taurine on both ALP activity/expression and Cbfα1 expression. These results suggested that taurine could inhibit osteoblastic differentiation of AVIC via the ERK pathway.

  20. Enhanced taurine release in cell-damaging conditions in the developing and ageing mouse hippocampus.

    PubMed

    Saransaari, P; Oja, S S

    1997-08-01

    Taurine has been shown to be essential for neuronal development and survival in the central nervous system. The release of preloaded [3H]taurine was studied in hippocampal slices from seven-day-, three-month- and 18-22-month-old mice in cell-damaging conditions. The slices were superfused in hypoxic, hypoglycemic and ischemic conditions and exposed to free radicals and oxidative stress. The release of taurine was greatly enhanced in the above conditions in all age groups, except in oxidative stress. The release was large in ischemia, particularly in the hippocampus of aged mice. Potassium stimulation was still able to release taurine in cell-damaging conditions in immature mice, whereas in adult and aged animals the release was so substantial that this additional stimulus failed to work. Taurine release was partially Ca2+-dependent in all cases. The massive release of the inhibitory amino acid taurine in ischemic conditions could act neuroprotectively, counteracting in several ways the effects of simultaneous release of excitatory amino acids. This protection could be of great importance in developing brain tissue, while also having an effect in aged brains.

  1. Amino acid transmitters in patients with headache during the acute phase of cerebrovascular ischemic disease.

    PubMed

    Castillo, J; Martínez, F; Corredera, E; Aldrey, J M; Noya, M

    1995-11-01

    The pathophysiology of headache occurring at stroke onset is unknown. Migraine and ischemia share an excessive release of neuroexcitatory amino acids. Inhibitory amino acids also may be implicated in both diseases. We investigated whether fluctuations of these amino acids occur in headache accompanying cerebral infarction. We studied 100 patients with infarction in the territory of the middle cerebral artery. Neurological impairment was assessed using the Canadian Neurological Scale and Barthel Index. Size of infarction was determined with CT. Twenty-eight patients developed headache. Glutamate, aspartate, and taurine were quantified in blood and cerebrospinal fluid (CSF) within 24 hours of stroke onset with cationic exchange chromatography. Stroke subtypes, size of infarct on CT, and clinical scales were similar in patients with and without headache. Plasma glutamate level was 321.14 +/- 149.53 mumol/L in patients with headache and 233 +/- 107.23 mumol/L in those without headache (P < .005). Glutamate in CSF was higher in patients with headache (4.6 +/- 1.49 mumol/L) than in patients without headache (3.11 +/- 1.18 mumol/L) (P < .001). Aspartate concentrations in plasma and CSF were similar in both groups. Taurine concentrations in plasma were 103.10 +/- 52.82 mumol/L and 177.49 +/- 90.92 mumol/L in headache and nonheadache patients, respectively (P < .001). Taurine levels in CSF were 5.42 +/- 2.42 mumol/L in patients with headache and 9.27 +/- 5.31 mumol/L in those without headache (P < .001). No significant correlation was found between amino acid levels in plasma or CSF and size of infarction. Amino acid neurotransmitters play a role in the pathophysiology of headache that occurs at the onset of stroke. The ischemic penumbral area, more than the infarction itself, may cause a state of cortical hyperexcitability that would be responsible for the cortical release of amino acids and the induction of headache by altering pain perception mechanisms.

  2. Release of endogenous amino acids from the hippocampus and brain stem from developing and adult mice in ischemia.

    PubMed

    Oja, Simo S; Saransaari, Pirjo

    2009-09-01

    The release of neurotransmitters and modulators has been studied mostly using labeled preloaded compounds. For several reasons, however, the estimated release may not reliably reflect the release of endogenous compounds. The basal and K(+)-evoked release of the neuroactive endogenous amino acids GABA, glycine, taurine, L-glutamate and L-aspartate was now studied in slices from the hippocampus and brain stem from 7-day-old and 3-month-old mice under control and ischemic conditions. The release of synaptically not active L-glutamine, L-alanine, L-threonine and L-serine was assessed for comparison. The estimates for the hippocampus and brainstem were markedly different and also different in developing and adult mice. GABA release was much greater in 3-month-old than in 7-day-old mice, whereas with taurine the situation was the opposite, in the hippocampus in particular. K(+) stimulation enhanced glycine release more in the mature than immature brain stem while in the hippocampus the converse was observed. Ischemia enhanced the release of all neuroactive amino acids in both brain regions, the effects being relatively most pronounced in the case of GABA, aspartate and glutamate in the hippocampus in 3-month-old mice, and taurine in 7-day-old and glycine in 3-month-old mice in the brain stem. These results are qualitatively similar to those obtained on earlier experiments with labeled preloaded amino acids. However, the magnitudes of the release cannot be quite correctly estimated using radioactive labels. In developing mice only taurine release may counteract the harmful effects of excitatory amino acids in ischemia in both hippocampus and brain stem.

  3. Amino acid composition in parenteral nutrition: what is the evidence?

    PubMed Central

    Yarandi, Shadi S.; Zhao, Vivian M.; Hebbar, Gautam; Ziegler, Thomas R.

    2011-01-01

    Purpose of review Complete parenteral nutrition solutions contain mixed amino acid products providing all nine essential amino acids and a varying composition of nonessential amino acids. Relatively little rigorous comparative efficacy research on altered parenteral nutrition amino acid composition has been published in recent years. Recent findings Limited data from randomized, double-blind, adequately powered clinical trials to define optimal doses of total or individual amino acids in parenteral nutrition are available. An exception is the growing number of studies on the efficacy of glutamine supplementation of parenteral nutrition or given as a single parenteral agent. Parenteral glutamine appears to confer benefit in selected patients; however, additional data to define optimal glutamine dosing and the patient subgroups who may most benefit from this amino acid are needed. Although some promising studies have been published, little data are available in the current era of nutrition support on the clinical efficacy of altered doses of arginine, branched chain amino acids, cysteine, or taurine supplementation of parenteral nutrition. Summary Despite routine use of parenteral nutrition, surprisingly little clinical efficacy data are available to guide total or specific amino acid dosing in adult and pediatric patients requiring this therapy. This warrants increased attention by the research community and funding agencies to better define optimal amino acid administration strategies in patient subgroups requiring parenteral nutrition. PMID:21076291

  4. Modelling cortical cataractogenesis 22: is in vitro reduction of damage in model diabetic rat cataract by taurine due to its antioxidant activity?

    PubMed

    Kilic, F; Bhardwaj, R; Caulfeild, J; Trevithick, J R

    1999-09-01

    The protective effect of taurine in model in vitro diabetic cataract and the mechanism of this effect were investigated in isolated rat lenses. Isolated rat lenses were incubated in medium 199 in elevated glucose (55.6 m m) with taurine (5 m m). Taurine concentrations in the lenses were determined by amino acid analysis. Accumulative leakage of the intracellular enzyme lactate dehydrogenase (LDH) was used to estimate damage to the lens, as previously reported. In the clear lenses, prior to vacuole formation, after 1 or 2 days of incubation, the taurine and amino acids in lenses decreased progressively in concentration. In lenses incubated with 5 m m taurine, the level of taurine was increased towards that of control lenses. In taurine-treated lenses LDH leakage was significantly decreased, and lens clarity was maintained, similarly to that found previously for vitamin C and lipoic acid. To test whether taurine has similar antioxidant activity, we tested its ability to decrease luminol luminescence generated by (1) superoxide from hypoxanthine/xanthine oxidase and (2) peroxide from diluted glucose/glucose oxidase. For either superoxide or peroxide, the luminescence was decreased to zero, as a function of increasing taurine concentration, at 30 m m, approximately the physiological concentration of taurine in the lens. Spin trapping confirmed that taurine scavenged superoxide. This is consistent with a role for taurine as an important antioxidant protecting the lens against oxidative insults. Amino acids also had antioxidant activity in this assay, and as a group, when all activities were summed, their loss also contributed significantly to the antioxidant loss. Taken in conjunction with Wolff and Crabbe's observation of increased free radical generation by glucose auto-oxidation in diabetes, this suggests a push-pull mechanism for increased oxidative stress in diabetic cataract, involving both increased free radicals and decreased radical scavenging antioxidants

  5. Dietary taurine alters ascorbic acid metabolism in rats fed diets containing polychlorinated biphenyls.

    PubMed

    Mochizuki, H; Oda, H; Yokogoshi, H

    2000-04-01

    The effect of dietary taurine on ascorbic acid metabolism and hepatic drug-metabolizing enzymes was investigated in rats fed diets containing polychlorinated biphenyls (PCB) to determine whether taurine has an adaptive and protective function in xenobiotic-treated animals. Young male Wistar rats (60 g) were fed diets containing 0 or 0.2 g/kg diet PCB with or without 30 g/kg diet of taurine for 14 d. The rats fed the PCB-containing diets had greater liver weight, higher ascorbic acid concentrations in the liver and spleen and greater hepatic cytochrome P-450 contents than control rats that were not treated with PCB (P < 0.01). In PCB-fed rats, urinary ascorbic acid excretion was enhanced, and serum cholesterol concentration (especially HDL-cholesterol) was significantly elevated compared with those in control rats. Dietary taurine significantly potentiated the increases in the urinary excretion of ascorbic acid and the rise in the levels of cytochrome P-450 which were caused by PCB treatment. On the other hand, the supplementation of taurine to control diet did not alter these variables. Taurine may enhance the hepatic drug-metabolizing systems, leading to the stimulation of the ascorbic acid metabolism in rats fed diets containing PCB.

  6. Neuroprotective Mechanisms of Taurine against Ischemic Stroke.

    PubMed

    Menzie, Janet; Prentice, Howard; Wu, Jang-Yen

    2013-06-03

    Ischemic stroke exhibits a multiplicity of pathophysiological mechanisms. To address the diverse pathophysiological mechanisms observed in ischemic stroke investigators seek to find therapeutic strategies that are multifaceted in their action by either investigating multipotential compounds or by using a combination of compounds. Taurine, an endogenous amino acid, exhibits a plethora of physiological functions. It exhibits antioxidative properties, stabilizes membrane, functions as an osmoregulator, modulates ionic movements, reduces the level of pro-inflammators, regulates intracellular calcium concentration; all of which contributes to its neuroprotective effect. Data are accumulating that show the neuroprotective mechanisms of taurine against stroke pathophysiology. In this review, we describe the neuroprotective mechanisms employed by taurine against ischemic stroke and its use in clinical trial for ischemic stroke.

  7. Neuroprotective Mechanisms of Taurine against Ischemic Stroke

    PubMed Central

    Menzie, Janet; Prentice, Howard; Wu, Jang-Yen

    2013-01-01

    Ischemic stroke exhibits a multiplicity of pathophysiological mechanisms. To address the diverse pathophysiological mechanisms observed in ischemic stroke investigators seek to find therapeutic strategies that are multifaceted in their action by either investigating multipotential compounds or by using a combination of compounds. Taurine, an endogenous amino acid, exhibits a plethora of physiological functions. It exhibits antioxidative properties, stabilizes membrane, functions as an osmoregulator, modulates ionic movements, reduces the level of pro-inflammators, regulates intracellular calcium concentration; all of which contributes to its neuroprotective effect. Data are accumulating that show the neuroprotective mechanisms of taurine against stroke pathophysiology. In this review, we describe the neuroprotective mechanisms employed by taurine against ischemic stroke and its use in clinical trial for ischemic stroke. PMID:24961429

  8. Extracellular levels of amino acids and choline in human high grade gliomas: an intraoperative microdialysis study.

    PubMed

    Bianchi, L; De Micheli, E; Bricolo, A; Ballini, C; Fattori, M; Venturi, C; Pedata, F; Tipton, K F; Della Corte, L

    2004-01-01

    The concentrations of endogenous amino acids and choline in the extracellular fluid of human cerebral gliomas have been measured, for the first time, by in vivo microdialysis. Glioblastoma growth was associated with increased concentrations of choline, GABA, isoleucine, leucine, lysine, phenylalanine, taurine, tyrosine, and valine. There was no difference between grade III and grade IV tumors in the concentrations of phenylalanine, isoleucine, tyrosine, valine, and lysine, whereas the concentrations of choline, aspartate, taurine, GABA, leucine, and glutamate were significantly different in the two tumor-grade subgroups. In contrast to the other compounds, the concentration of glutamate was decreased in glioma. The parenchyma adjacent to the tumor showed significant changes only in the extracellular concentration of glutamate, isoleucine, and valine. The concentrations of choline and the amino acids, glutamate, leucine, taurine, and tyrosine showed significant positive correlations with the degree of cell proliferation. Epilepsy, which is relatively common in subjects with gliomas, was shown to be a significant confounding variable when the extracellular concentrations of aspartate, glutamate and GABA were considered.

  9. Taurine release from the developing and ageing hippocampus: stimulation by agonists of ionotropic glutamate receptors.

    PubMed

    Saransaari, P; Oja, S S

    1997-12-30

    The inhibitory amino acid taurine has been held to function as a modulator and osmoregulator in the brain, being of particular importance in the immature brain. The release of preloaded [3H]taurine was now studied in hippocampal slices from developing (7-day-old), adult (3-month-old) and ageing (6-24-month-old) mice focussing on the effects of agonists of ionotropic glutamate receptors. N-methyl-D-aspartate (NMDA), kainate and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) potentiated taurine release concentration-dependently at each age, more so in the immature than in the adult and ageing hippocampus. The effect of kainate was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) in the developing and aged hippocampus and those of AMPA and NMDA by 6-nitro-7-sulphamoylbenzo[f]quinoxaline-2,3-dione (NBQX) and dizocilpine a(MK-801) at every age studied. This indicates the involvement of NMDA and AMPA receptors in taurine release throughout the life-span of mice, while the kainate-receptor-mediated release does not appear to function in adults. The increased hippocampal taurine release evoked by ionotropic glutamate receptors could act neuroprotectively, counteracting by several mechanisms the harmful effects of the simultaneous release of excitatory amino acids. The substantial release of taurine in the immature hippocampus might be particularly significant in view of the vulnerability of brain tissue to excitotoxicity at early age.

  10. Monthly changes of glycogen, lipid and free amino acid of oyster

    NASA Astrophysics Data System (ADS)

    Zhicui, Zhang; Changhu, Xue; Xin, Gao; Zhaojie, Li; Qi, Wang

    2006-07-01

    Monthly difference of the chemical composition of oyster cultured along the eastern coast of Shandong Province was analyzed. The components analyzed included glycogen, fatty acid and free amino acid (FAA). The content of glycogen was high in January and March (2.89 and 2.82 g(100g)-1 on average, respectively) and low in October (2.07 g(100g)-1 on avarage). The low content of neutral lipids in October reflected a relatively poor nutritional value of oyster (1.42 g(100 g)-1 on average). The main fatty acids of oyster were palmitic acid (16:0), oleic acid (18:1), eicosapentaenoic acid (EPA, 20: 5ω-3) and docosahexaenoic acid (DHA, 22:6ω-3). The major FAAs of oyster were Taurine, Glutamicacid, Glycin, Alanine, Arginine and Proline. Taurine was the most abundant FAA with its content ranging from 603 mg (100g)-1 to 1139 mg(100g)-1. The high contents of glycogen, polyunsaturated fatty acid and FAA showed that oyster cultured along the eastern coast of Shandong Province was nutritionally good in January and March.

  11. Role of taurine in the pathogenesis of obesity.

    PubMed

    Murakami, Shigeru

    2015-07-01

    Taurine is a sulfur-containing amino acid that is present in mammalian tissues in millimolar concentrations. Taurine is involved in a diverse array of biological and physiological functions, including bile salt conjugation, osmoregulation, membrane stabilization, calcium modulation, anti-oxidation, and immunomodulation. The prevalence of obesity and being overweight continues to rise worldwide at an alarming rate. Obesity is associated with a higher risk of metabolic and cardiovascular diseases, cancer, and other clinical conditions. Ingestion of taurine has been shown to alleviate metabolic diseases such as hyperlipidemia, diabetes, hypertension, and obesity in animal models. A global epidemiological survey showed that 24-h urinary taurine excretion, as a marker of dietary taurine intake, was inversely associated with BMI, blood pressure, and plasma cholesterol in humans. In addition, taurine chloramine, an endogenous product derived from activated neutrophils, has been reported to suppress obesity-induced oxidative stress and inflammation in adipocytes. Synthetic activity and concentration of taurine in adipose tissues and plasma have been shown to decrease in humans and animals during the development of obesity, suggesting a relationship between taurine deficiency and obesity. In this review, I summarize the effects of taurine on the progression of obesity in animal models and humans. Furthermore, I discuss possible mechanisms underlying the antiobesity effects of taurine. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Modulation of taurine release by glutamate receptors and nitric oxide.

    PubMed

    Oja, S S; Saransaari, P

    2000-11-01

    Taurine is held to function as a modulator and osmoregulator in the central nervous system, being of particular importance in the immature brain. In view of the possible involvement of excitatory pathways in the regulation of taurine function in the brain, the interference of glutamate receptors with taurine release from different tissue preparations in vitro and from the brain in vivo is of special interest. The release of taurine from the brain is enhanced by glutamate receptor agonists. This enhancement is inhibited by the respective receptor antagonists both in vitro and in vivo. The ionotropic N-methyl-D-aspartate (NMDA) and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor agonists appear to be the most effective in enhancing taurine release, their effects being receptor-mediated. Kainate is less effective, particularly in adults. Of the glutamate receptors, the NMDA class seems to be the most susceptible to modulation by nitric oxide. Nitric oxide also modulates taurine release, enhancing the basal release in both immature and mature hippocampus, whereas the K(+)-stimulated release is generally inhibited. Metabotropic glutamate receptors also participate in the regulation of taurine release, group I metabotropic glutamate receptors potentiating the release in the developing hippocampus, while group III receptors may be involved in the adult. Under various cell-damaging conditions, including ischemia, hypoxia and hypoglycemia, taurine release is enhanced, together with an enhanced release of excitatory amino acids. The increase in extracellular taurine upon excessive stimulation of glutamate receptors and under cell-damaging conditions may serve as an important protective mechanism against excitotoxicity, being particularly effective in the immature brain.

  13. Influence of endogenous opiates on the hypotensive action of taurine in DOCA-salt rats.

    PubMed

    Sato, Y; Fujita, T

    1988-12-01

    We studied the role of endogenous opiate activation in the hypotensive action of taurine, a sulphur amino acid, in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Previous work had shown that supplementation with 1% taurine reduced blood pressure when given after DOCA-salt hypertension had been established. In the present study, in conscious rats, intraperitoneal injection of naloxone, an opiate antagonist, increased blood pressure in taurine-supplemented DOCA-salt rats, but not in DOCA-salt rats or vehicle-treated control rats. These results suggest that activation of an endogenous opiate might contribute to the hypotensive action of taurine in DOCA-salt hypertensive rats.

  14. Temporal changes in concentrations of amino acids in plasma and whole blood of healthy neonatal foals from birth to two days of age.

    PubMed

    Zicker, S C; Rogers, Q R

    1994-07-01

    Temporal changes, as well as differences in distribution, in concentrations of 24 amino acids in plasma and whole blood of neonatal foals were determined from birth to 2 days of age. In addition, differences in concentrations of amino acids in plasma between mare and foal pairs were determined at birth. Significant (P < 0.05) hypoaminoacidemia existed for 15 amino acids in plasma of foals at birth, compared with mares (paired t-test). Concentrations of 7 amino acids (aspartate, glutamate, glutamine, glycine, hydroxyproline, phenylalanine, proline) in plasma of foals were higher (P < 0.05) at birth than in mares, and concentrations of 2 (taurine, tryptophan) were not different (P > 0.05). Significant (P < 0.05) temporal changes for concentrations of 19 of 24 amino acids in plasma were observed during the 48-hour period. Concentrations of 13 of the 19 amino acids in plasma that had significant changes were higher (P < 0.05) at 48 hours. Significant (P > 0.05) effect of time on concentration of 5 amino acids (alanine, methionine, phenylalanine, taurine, threonine) in plasma was not found after birth. Temporal changes in concentrations of 7 amino acids (alanine, asparagine, glutamine, histidine, hydroxyproline, methionine, and threonine) in whole blood were not significantly (P > 0.05) different from those in plasma. Temporal changes for concentrations of the remaining 17 amino acids in whole blood were significantly (P < 0.05) different, compared with plasma. Distribution of the concentrations of 18 amino acids between whole blood and plasma was significantly (P < 0.05) different.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Attenuation of Diabetes-induced Cardiac and Subcellular Defects by Sulphur-containing Amino Acids.

    PubMed

    Tappia, Paramjit S; Adameova, Adriana; Dhalla, Naranjan S

    2018-01-30

    Patients with diabetes mellitus have an increased risk of mortality due to cardiovascular complications. Supplementation with specific sulphur-containing amino acids is rapidly emerging as a possible therapeutic adjuvant for diabetes and associated cardiovascular complications. It is well-known that oxidative stress plays an important role in the pathogenesis of diabetes-induced cardiovascular disease, which is invariably associated with abnormal blood lipid profile, insulin resistance and other symptoms of metabolic syndrome. Cysteine and taurine are among the most common sulphur-containing amino acids and their cellular levels decline during diabetes that may contribute to the development of the cardiomyopathy. Although sulphur-containing agents exert multiple actions on cellular and subcellular functions in the heart, they also exhibit antioxidant properties and thus may exert beneficial effects in different pathophysiological conditions. It is concluded that reduction of oxidative stress by cysteine and taurine may serve as an important mechanism for the attenuation of diabetes-induced subcellular and functional abnormalities in the heart. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Proximate Composition, Amino Acid, Mineral, and Heavy Metal Content of Dried Laver

    PubMed Central

    Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull

    2013-01-01

    Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and γ-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals. PMID:24471123

  17. Proximate composition, amino Acid, mineral, and heavy metal content of dried laver.

    PubMed

    Hwang, Eun-Sun; Ki, Kyung-Nam; Chung, Ha-Yull

    2013-06-01

    Laver, a red algae belonging to the genus Porphyra, is one of the most widely consumed edible seaweeds. The most popular commercial dried laver species, P. tenera and P. haitanensis, were collected from Korea and China, respectively, and evaluated for proximate composition, amino acids, minerals, trace heavy metals, and color. The moisture and ash contents of P. tenera and P. haitanensis ranged from 3.66~6.74% and 8.78~9.07%, respectively; crude lipid and protein contents were 1.96~2.25% and 32.16~36.88%, respectively. Dried lavers were found to be a good source of amino acids, such as asparagine, isoleucine, leucine, and taurine, and γ-aminobutyric acid. K, Ca, Mg, Na, P, I, Fe, and Se minerals were selected for analysis. A clear regional variation existed in the amino acid, mineral, and trace metal contents of lavers. Regular consumption of lavers may have heath benefits because they are relatively low in fat and high in protein, and contain functional amino acids and minerals.

  18. Body fluid levels of neuroactive amino acids in autism spectrum disorders: a review of the literature.

    PubMed

    Zheng, Hui-Fei; Wang, Wen-Qiang; Li, Xin-Min; Rauw, Gail; Baker, Glen B

    2017-01-01

    A review of studies on the body fluid levels of neuroactive amino acids, including glutamate, glutamine, taurine, gamma-aminobutyric acid (GABA), glycine, tryptophan, D-serine, and others, in autism spectrum disorders (ASD) is given. The results reported in the literature are generally inconclusive and contradictory, but there has been considerable variation among the previous studies in terms of factors such as age, gender, number of subjects, intelligence quotient, and psychoactive medication being taken. Future studies should include simultaneous analyses of a large number of amino acids [including D-serine and branched-chain amino acids (BCAAs)] and standardization of the factors mentioned above. It may also be appropriate to use saliva sampling to detect amino acids in ASD patients in the future-this is noninvasive testing that can be done easily more frequently than other sampling, thus providing more dynamic monitoring.

  19. Characterizing amino-acid biosignatures amongst individuals with schizophrenia: a case-control study.

    PubMed

    Cao, Bing; Wang, Dongfang; Brietzke, Elisa; McIntyre, Roger S; Pan, Zihang; Cha, Danielle; Rosenblat, Joshua D; Zuckerman, Hannah; Liu, Yaqiong; Xie, Qing; Wang, Jingyu

    2018-05-23

    Amino acids and derivatives participate in the biosynthesis and downstream effects of numerous neurotransmitters. Variations in specific amino acids have been implicated in the pathophysiology of schizophrenia. Herein, we sought to compare levels of amino acids and derivatives between subjects with schizophrenia and healthy controls (HC). Two hundred and eight subjects with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria (DSM-IV)-defined schizophrenia and 175 age- and sex-matched HC were enrolled. The levels of twenty-five amino acids and seven related derivatives were measured in plasma samples using hydrophilic interaction liquid chromatography (HILIC) liquid chromatography-tandem mass spectrometry (LC-MS). After controlling for age, sex and body mass index (BMI), four amino acids and derivatives (i.e., cysteine, GABA, glutamine and sarcosine) were observed to be higher in the schizophrenia group when compared with HC; seven amino acids and derivatives were lower in the schizophrenia group (i.e., arginine, L-ornithine, threonine, taurine, tryptophan, methylcysteine, and kynurenine). Statistically significant differences in plasma amino-acid profiles between subjects with first-episode vs. recurrent schizophrenia for aspartate and glutamine were also demonstrated using generalized linear models controlling for age, sex, and BMI. The differences in amino acids and derivatives among individuals with schizophrenia when compared to HC may represent underlying pathophysiology, including but not limited to dysfunctional proteinogenic processes, alterations in excitatory and inhibitory neurotransmission, changes in ammonia metabolism and the urea cycle. Taken together, amino-acid profiling may provide a novel stratification approach among individuals with schizophrenia.

  20. Influence of the amino acid moiety on deconjugation of bile acid amidates by cholylglycine hydrolase or human fecal cultures.

    PubMed

    Huijghebaert, S M; Hofmann, A F

    1986-07-01

    The influence of the chemical structure of the amino acid (or amino acid analogue) moiety of a number of synthetic cholyl amidates on deconjugation by cholylglycine hydrolase from Clostridium perfringens was studied in vitro at pH 5.4. Conjugates with alkyl homologues of glycine were hydrolyzed more slowly as the number of methylene units increased (cholylglycine greater than cholyl-beta-alanine greater than cholyl-gamma-aminobutyrate). In contrast, for conjugates with the alkyl homologues of taurine, cholylaminopropane sulfonate was hydrolyzed slightly faster than cholyltaurine, whereas cholylaminomethane sulfonate was hydrolyzed much more slowly. When glycine was replaced by other neutral alpha-amino acids, rates of hydrolysis decreased with increasing steric hindrance near the amide bond (cholyl-L-alpha-alanine much much greater than cholyl-L-leucine much greater than cholyl-L-valine greater than cholyl-L-tyrosine much greater than cholyl-D-valine). Conjugation with acidic or basic amino acids also greatly reduced the rates of hydrolysis, as cholyl-L-aspartate, cholyl-L-cysteate, cholyl-L-lysine, and cholyl-L-histidine were all hydrolyzed at a rate less than one-tenth that of cholylglycine. Methyl esterification of the carboxylic group of the amino acid moiety reduced the hydrolysis, but such substrates (cholylglycine methyl ester and cholyl-beta-alanine methyl ester) were completely hydrolyzed after overnight incubation with excess of enzyme. In contrast, cholyl-cholamine was not hydrolyzed at all, suggesting that a negative charge at the end of the side chain is required for optimal hydrolysis. Despite the lack of specificity for the amino acid moiety, a bile salt moiety was required, as the cholylglycine hydrolase did not display general carboxypeptidase activity for other non-bile acid substrates containing a terminal amide bond: hippuryl-L-phenylalanine and hippuryl-L-arginine, as well as oleyltaurine and oleylglycine, were not hydrolyzed. Fecal bacterial

  1. Changes in brain amino acid content induced by hyposmolar stress and energy deprivation.

    PubMed

    Haugstad, T S; Valø, E T; Langmoen, I A

    1995-12-01

    The changes in endogenous amino acids in brain extracellular and intracellular compartments evoked by hyposmotic stress and energy deprivation were compared. Tissue content and release of ten amino acids were measured simultaneously in rat hippocampal slices by means of high performance liquid chromatography. Hyposmotic stress induced a large release of taurine (25568 pmol mg-1 protein), and a smaller release of glutamate, accompanied by an inverse change in tissue content. Adding mannitol to correct osmolarity, blocked these changes. Energy deprivation caused an increase in the release of all amino acids except glutamine. The release was particularly large for glutamate and GABA (31141 and 13282 pmol mg-1, respectively). The intracellular concentrations were generally reduced, but the total amount of the released amino acids increased In contrast to the effect seen during hyposmolar stress, mannitol enhanced the changes due to energy deprivation. The results show that hyposmolar stress and energy deprivation cause different content and release profiles, suggesting that the mechanisms involved in the two situations are either different or modulated in different ways. The intracellular amino acid depletion seen during energy deprivation shows that increased outward transport is probably a primary event, and increased amino acid formation likely secondary to this release.

  2. Hemolymph amino acid analysis of individual Drosophila larvae.

    PubMed

    Piyankarage, Sujeewa C; Augustin, Hrvoje; Grosjean, Yael; Featherstone, David E; Shippy, Scott A

    2008-02-15

    One of the most widely used transgenic animal models in biology is Drosophila melanogaster, the fruit fly. Chemical information from this exceedingly small organism is usually accomplished by studying populations to attain sample volumes suitable for standard analysis methods. This paper describes a direct sampling technique capable of obtaining 50-300 nL of hemolymph from individual Drosophila larvae. Hemolymph sampling performed under mineral oil and in air at 30 s intervals up to 120 s after piercing larvae revealed that the effect of evaporation on amino acid concentrations is insignificant when the sample was collected within 60 s. Qualitative and quantitative amino acid analyses of obtained hemolymph were carried out in two optimized buffer conditions by capillary electrophoresis with laser-induced fluorescence detection after derivatizing with fluorescamine. Thirteen amino acids were identified from individual hemolymph samples of both wild-type (WT) control and the genderblind (gb) mutant larvae. The levels of glutamine, glutamate, and taurine in the gb hemolymph were significantly lower at 35%, 38%, and 57% of WT levels, respectively. The developed technique that samples only the hemolymph fluid is efficient and enables accurate organism-level chemical information while minimizing errors associated with possible sample contaminations, estimations, and effects of evaporation compared to the traditional hemolymph-sampling techniques.

  3. Free amino acids in fibromyalgia syndrome: relationship with clinical picture.

    PubMed

    Ruggiero, Valeria; Mura, Massimiliano; Cacace, Enrico; Era, Benedetta; Peri, Marcella; Sanna, Giuseppina; Fais, Antonella

    2017-04-01

    The objectives of our study were to evaluate free amino acid (FAA) concentrations in the serum of patients affected by fibromyalgia syndrome (FMS) and to determine the relationships between FAA levels and FMS clinical parameters. Thus, serum amino acid concentrations were quantified (HPLC analysis) in 23 females with fibromyalgia (according to the American College of Rheumatology classification criteria) and 20 healthy females. The results showed significantly higher serum concentrations of aspartate, cysteine, glutamate, glycine, isoleucine, leucine, methionine, ornithine, phenylalanine, sarcosine, serine, taurine, tyrosine and valine in FMS patients vs. healthy controls. Patients with higher Fibromyalgia Impact Questionnaire (FIQ) scores showed increased levels of alanine, glutamine, isoleucine, leucine, phenylalanine, proline and valine. In conclusion, our results indicate an imbalance in some FAAs in FMS patients. Increased Glu is particularly interesting, as it could explain the deficit in monoaminergic transmission involved in pain.

  4. Intracerebroventricular administration of taurine impairs learning and memory in rats.

    PubMed

    Ito, Koichi; Arko, Matevž; Kawaguchi, Tomohiro; Kikusui, Takefumi; Kuwahara, Masayoshi; Tsubone, Hirokazu

    2012-03-01

    Taurine is a semi-essential amino acid widely distributed in the body and we take in it from a wide range of nutritive-tonic drinks to improve health. To date, we have elucidated that oral supplementation of taurine does not affect learning and memory in the rat. However, there are few studies concerning the direct effects of taurine in the brain at the behavior level. In this study, we intracerebroventricularly administered taurine to rats and aimed to elucidate the acute effects on learning and memory using the Morris water maze method. Escape latency, swim distance, and distance to zone, which is the integral of the distance between the rats and the platform for every 0.16 seconds, were adopted as parameters of the ability of learning and memory. We also tried to evaluate the effect of intraperitoneal taurine administration. Escape latency, swim distance, and distance to zone were significantly longer in the intracerebroventricularly taurine-administered rats than in the saline-administered rats. Mean swimming velocity was comparable between these two groups, although the physical performance was improved by taurine administration. Probe trials showed that the manner of the rats in finding the platform was comparable. In contrast, no significant differences were found between the intraperitoneally taurine-administered rats and the saline-administered rats. These results indicate that taurine administered directly into the brain ventricle suppresses and delays the ability of learning and memory in rats. In contrast, it is implied that taurine administered peripherally was not involved in learning and memory.

  5. [Taurine as a regulator of fluid-electrolyte balance and arterial pressure].

    PubMed

    Ciechanowska, B

    1997-01-01

    Taurine is a sulfonic beta-amino acid which occurs in the highest concentration in the brain, the retina and in the myocardium. In cardiomyocytes it presents about 50% of free amino acids and plays a role as an osmoregulator, an inotropic factor and has an antiarrhythmic property. Moreover, taurine lowers arterial pressure by extension of diuresis and by vasodilatation. Similar effect on the vascular system and arterial pressure is exerted by atrial natriuretic peptide (ANP). Increase of both ANP secretion and myocardial taurine concentration is present in the same diseases as congestive cardiac failure, hypertension and hypernatremia. The aim of the study was the evaluation of general taurine depletion, caused by making the rats drink guanidinoethyl sulfonate (GES)--an inhibitor of taurine transport affecting fluid balance and arterial pressure as well as plasma ANP concentration under normal conditions and after increase of sodium load. The 103 male Wistar rats weighing 250-300 g were used. The animals were separated into 5 groups. Control group received tap water to drink. Group II was sodium-loaded by drinking 171 mmol/l NaCl. In group III depletion of taurine was obtained by the intake of 60 mmol/l GES. Rats in group IV were drinking 60 mmol/l GES in 171 mmol/l NaCl. Group V was made to drink 200 mmol/l taurine in 171 mmol/l NaCl. All animals had standard food and were able at any time to drink. Duration of the experiment was 20 days. At the onset and after 10 and 20 days the rats were weighed and their systolic blood pressure was measured by tail plethysmography. After 10 and 20 days of the study, plasma and myocardium taurine concentration, ANP, hematocrit, plasma osmolity, natremia, kalemia, urea and creatinine concentrations were determined. Taking GES for 20 days led to 43% decrease of plasma taurine and its myocardium content about 50% as compared to control group (Tab. 2). High, statistically significant correlation (r = 0.50, p < 0.001) between

  6. Increasing taurine intake and taurine synthesis improves skeletal muscle function in the mdx mouse model for Duchenne muscular dystrophy

    PubMed Central

    Pinniger, Gavin J.; Graves, Jamie A.; Grounds, Miranda D.; Arthur, Peter G.

    2016-01-01

    Key points Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease associated with increased inflammation, oxidative stress and myofibre necrosis.Cysteine precursor antioxidants such as N‐acetyl cysteine (NAC) and l‐2‐oxothiazolidine‐4‐carboxylate (OTC) reduce dystropathology in the mdx mouse model for DMD, and we propose this is via increased synthesis of the amino acid taurine.We compared the capacity of OTC and taurine treatment to increase taurine content of mdx muscle, as well as effects on in vivo and ex vivo muscle function, inflammation and oxidative stress.Both treatments increased taurine in muscles, and improved many aspects of muscle function and reduced inflammation. Taurine treatment also reduced protein thiol oxidation and was overall more effective, as OTC treatment reduced body and muscle weight, suggesting some adverse effects of this drug.These data suggest that increasing dietary taurine is a better candidate for a therapeutic intervention for DMD. Abstract Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease for which there is no widely available cure. Whilst the mechanism of loss of muscle function in DMD and the mdx mouse model are not fully understood, disruptions in intracellular calcium homeostasis, inflammation and oxidative stress are implicated. We have shown that protein thiol oxidation is increased in mdx muscle, and that the indirect thiol antioxidant l‐2‐oxothiazolidine‐4‐carboxylate (OTC), which increases cysteine availability, decreases pathology and increases in vivo strength. We propose that the protective effects of OTC are a consequence of conversion of cysteine to taurine, which has itself been shown to be beneficial to mdx pathology. This study compares the efficacy of taurine with OTC in decreasing dystropathology in mdx mice by measuring in vivo and ex vivo contractile function and measurements of inflammation and protein thiol oxidation. Increasing the taurine content of mdx

  7. GABA, 5-HT and amino acids in the rotifers Brachionus plicatilis and Brachionus rotundiformis.

    PubMed

    Gallardo, W G; Hagiwara, A; Hara, K; Soyano, K; Snell, T W

    2000-11-01

    gamma-Aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT) have been shown to increase the reproduction of the Brachionus plicatilis (NH3L strain). In the present study, the endogenous presence of GABA and 5-HT in the rotifers B. plicatilis (NH3L and Kamiura strains) and Brachionus rotundiformis (Langkawi strain) were confirmed by dot blot immunoassay and high-performance liquid chromatography (HPLC). HPLC showed that GABA and 5-HT concentrations in the three rotifer strains range from 71 to 188 pmol/mg and from 12 to 64 pmol/mg, respectively. A total of 33 amino acids were also detected in B. plicatilis and B. rotundiformis, with glutamic acid, serine, glycine, taurine, threonine, alanine, arginine, proline, valine and isoleucine in high concentrations relative to other amino acids.

  8. Protective role of taurine in developing offspring affected by maternal alcohol consumption

    PubMed Central

    Ananchaipatana-Auitragoon, Pilant; Ananchaipatana-Auitragoon, Yutthana; Siripornpanich, Vorasith; Kotchabhakdi, Naiphinich

    2015-01-01

    Maternal alcohol consumption is known to affect offspring growth and development, including growth deficits, physical anomalies, impaired brain functions and behavioral disturbances. Taurine, a sulfur-containing amino acid, is essential during development, and continually found to be protective against neurotoxicity and various tissue damages including those from alcohol exposure. However, it is still unknown whether taurine can exert its protection during development of central nervous system and whether it can reverse alcohol damages on developed brain later in life. This study aims to investigate protective roles of taurine against maternal alcohol consumption on growth and development of offspring. The experimental protocol was conducted using ICR-outbred pregnant mice given 10 % alcohol, with or without maternal taurine supplementation during gestation and lactation. Pregnancy outcomes, offspring mortality and successive bodyweight until adult were monitored. Adult offspring is supplemented taurine to verify its ability to reverse damages on learning and memory through a water maze task performance. Our results demonstrate that offspring of maternal alcohol exposure, together with maternal taurine supplementation show conserved learning and memory, while that of offspring treated taurine later in life are disturbed. Taurine provides neuroprotective effects and preserves learning and memory processes when given together with maternal alcohol consumption, but not shown such effects when given exclusively in offspring. PMID:26648819

  9. Effect of taurine on the concentrations of glutamate, GABA, glutamine and alanine in the rat striatum and hippocampus.

    PubMed

    Molchanova, Svetlana M; Oja, Simos S; Saransaari, Pirjo

    2007-01-01

    Taurine, a non-protein amino acid, acts as an osmoregulator and inhibitory neuromodulator in the brain. Here we studied the effects of intraperitoneal injections of taurine on the concentrations of glutamate and GABA, and their precursors, glutamine and alanine, in the rat striatum and hippocampus. Injections of 0.25, 0.5 and 1 g/kg taurine led to a gradual increase in taurine tissue concentrations in both hippocampus and striatum. Glutamate and GABA also increased in the hippocampus, but not in the striatum. Glutamine increased and alanine decreased markedly in both brain structures. The results corroborate the neuromodulatory role of taurine in the brain. Taurine administration results in an imbalance in inhibitory and excitatory neurotransmission in the glutamatergic (hippocampus) and GABAergic (striatum) brain structures, affecting more markedly the neurotransmitter precursors.

  10. K(+)- and temperature-evoked taurine efflux from hypothalamic astrocytes.

    PubMed

    Tigges, G A; Philibert, R A; Dutton, G R

    1990-10-30

    Hypothalamic astrocytes in culture released taurine, a suspected inhibitory amino acid neurotransmitter/neuromodulator/osmoregulator, in response to isoosmotically increasing extracellular K+ in a dose-dependent fashion. In the absence of added Ca2+, basal release levels rose to approach those obtained after exposure to 60 mM K+ in the presence of 2.5 mM Ca2+, and were only partially lowered by the addition of 10 mM Mg2+. Stimulation with K+ (60 mM) did not further increase taurine efflux above the high basal levels seen in the absence of Ca2+. Under standard conditions complete replacement of Na+ with choline Cl had little effect on basal taurine release, but reduced K(+)-evoked (60 mM) efflux by 60%. The temperature dependence of the basal levels of taurine released from hypothalamic astrocytes was similar to that seen for cultured cerebellar astrocytes and neurons over the range 5-50 degrees C. Taurine release increased from 5 to 15 degrees C, remained constant between 15 and 33 degrees C, decreased between 33 and 37 degrees C and increased thereafter. The infection point of increased basal taurine release seen around 37 degrees C (most prominent in astrocytes), may be of physiological significance. Results presented also show that the ion (Na+, Ca2+ and K+) sensitivities of taurine efflux for cultured hypothalamic astrocytes are similar to those previously reported for cultured astrocytes from the cerebellum.

  11. Role of taurine in the vasculature: an overview of experimental and human studies

    PubMed Central

    Abebe, Worku; Mozaffari, Mahmood S

    2011-01-01

    Taurine is a sulfur-containing amino acid-like endogenous compound found in substantial amounts in mammalian tissues. It exerts a diverse array of biological effects, including cardiovascular regulation, antioxidation, modulation of ion transport, membrane stabilization, osmoregulation, modulation of neurotransmission, bile acid conjugation, hypolipidemia, antiplatelet activity and modulation of fetal development. This brief review summarizes the role of taurine in the vasculature and modulation of blood pressure, based on experimental and human studies. Oral supplementation of taurine induces antihypertensive effects in various animal models of hypertension. These effects of taurine have been shown to be both centrally and peripherally mediated. Consistent with this, taurine produces endothelium-dependent and independent relaxant effects in isolated vascular tissue preparations. Oral administration of taurine also ameliorates impairment of vascular reactivity, intimal thickening, arteriosclerosis, endothelial apoptosis, oxidative stress and inflammation, associated primarily with diabetes and, to a lesser extent with obesity, hypertension and nicotine-induced vascular adverse events. In rat aortic vascular smooth muscle cells (VSMCs), taurine acts as an antiproliferative and antioxidant agent. In endothelial cells, taurine inhibits apoptosis, inflammation, oxidative stress and cell death while increasing NO generation. Oral taurine in hypertensive human patients alleviates the symptoms of hypertension and also reverses arterial stiffness and brachial artery reactivity in type 1 diabetic patients. However, despite these favorable findings, there is a need to further establish certain aspects of the reported results and also consider addressing unresolved related issues. In addition, the molecular mechanism (s) involved in the vascular effects of taurine is largely unknown and requires further investigations. Elucidation of the mechanisms through which taurine

  12. Effect of medium osmolarity and taurine on neuritic outgrowth from goldfish retinal explants.

    PubMed

    Cubillán, Lisbeth; Obregón, Francisco; Lima, Lucimey

    2009-01-01

    Taurine stimulates outgrowth of goldfish retinal explants in a concentration- and time-dependent manner, an effect related to calcium movement and protein phosphorylation. Since taurine is an osmoregulator in the central nervous system, and osmolality might influence regeneration, the purpose of this work was to evaluate the possible effect of hypo-osmolality on basal outgrowth and on the trophic action of the amino acid. Accordingly, goldfish retinal explants obtained after crushing the optic nerve were cultured in iso- and hypo-osmotic medium, the latter achieved by diluting the medium 10% 24 and 72 h after plating. The length and density of the neurites, measured after 5 days in culture, were significantly lower in the hypo- than in the iso-osmotic medium. Taurine stimulated the outgrowth under both conditions, but the percentage of increase was greater in iso-osmotic medium. Taurine concentration, determined by HPLC, did not significantly change in explants. Co-administration of beta-alanine and taurine impaired the trophic effect of taurine to a greater extent in the iso- than in hypo-osmotic medium, indicating a possible differential interaction with the taurine transporter which could be altered by osmotic stress. The exact mechanism of outgrowth regulation by hypotonicity requires further clarification, taking into considering possible modification of the taurine transporter.

  13. Taurine activates delayed rectifier KV channels via a metabotropic pathway in retinal neurons

    PubMed Central

    Bulley, Simon; Liu, Yufei; Ripps, Harris; Shen, Wen

    2013-01-01

    Taurine is one of the most abundant amino acids in the retina, throughout the CNS, and in heart and muscle cells. In keeping with its broad tissue distribution, taurine serves as a modulator of numerous basic processes, such as enzyme activity, cell development, myocardial function and cytoprotection. Despite this multitude of functional roles, the precise mechanism underlying taurine's actions has not yet been identified. In this study we report findings that indicate a novel role for taurine in the regulation of voltage-gated delayed rectifier potassium (KV) channels in retinal neurons by means of a metabotropic receptor pathway. The metabotropic taurine response was insensitive to the Cl− channel blockers, picrotoxin and strychnine, but it was inhibited by a specific serotonin 5-HT2A receptor antagonist, MDL11939. Moreover, we found that taurine enhanced KV channels via intracellular protein kinase C-mediated pathways. When 5-HT2A receptors were expressed in human embryonic kidney cells, taurine and AL34662, a non-specific 5-HT2 receptor activator, produced a similar regulation of KIR channels. In sum, this study provides new evidence that taurine activates a serotonin system, apparently via 5-HT2A receptors and related intracellular pathways. PMID:23045337

  14. The retention and recovery of amino acids from pork longissimus muscle following cooking to either 60°C or 75°C.

    PubMed

    Wilkinson, B H P; Lee, E; Purchas, R W; Morel, P C H

    2014-01-01

    Samples of pork longissimus muscle (n=16) cooked to either 60°C or 75°C in a water bath for 90 min were assessed for amino acid composition. Recovery of protein in the cooked meat plus the cooking juice was >93% and was slightly higher at 60°C (P=0.031), but retention in the meat was only 89% and 82% for the lower and higher temperatures (P<0.0001). Individual amino acids varied in recovery and retention with retention being particularly low for taurine and histidine. The balance of indispensable amino acids was less than ideal, with leucine and valine being the limiting amino acids by about 30% for both raw and cooked pork. Cooking had no detrimental effect on amino acid balance. Some examples of small effects of genotype and sex on amino acid composition of pork were shown. © 2013.

  15. Albumin dialysis has a favorable effect on amino acid profile in hepatic encephalopathy.

    PubMed

    Koivusalo, Anna-Maria; Teikari, Taru; Höckerstedt, Krister; Isoniemi, Helena

    2008-12-01

    According to one popular theory, hepatic encephalopathy (HE) is partly caused by an imbalance in plasma amino acid levels. The Fischer's ratio between branched chain amino acids (BCAAs) and aromatic amino acids (AAAs) correlates with the degree of HE; the lower Fischer's ratio, the higher the grade of HE. Extra-corporeal liver support systems, like MARS(R)-albumin dialysis (Molecular Adsorbents Recirculating System), can improve HE. The MARS(R) system uses a hyperosmolar albumin circuit to remove both water-soluble and albumin-bound substances. Plasma levels of neuroactive amino acids were analyzed in 82 consecutive patients with life-threatening liver failure admitted to our ICU. All patients fulfilled our indications for MARS treatment and most also fulfilled the criteria for liver transplantation (LTx). In patients with acute liver failure (ALF), as compared to those with acute decompensation of chronic liver failure (AcOChr), levels of leucine and isoleucine were significantly higher before MARS(R) treatment. In all patients, before MARS(R) treatment the higher the grade of HE grade the lower was the Fischer's ratio and higher were the levels of inhibitory neuroactive amino acids. During MARS(R) treatments the Fischer's ratio increased, and the grade of HE decreased. The increase in Fischer's ratio was mainly due to the decrease in AAAs. The plasma levels of neuroactive amino acids, methionine, glutamine, glutamate, histidine and taurine decreased during MARS(R)-treatment. In this study MARS(R)-albumin dialysis had a favorable effect on the plasma amino acid profile of patients with HE.

  16. Taurine Biosynthesis in a Fish Liver Cell Line (ZFL) Adapted to a Serum-Free Medium

    PubMed Central

    Liu, Chieh-Lun; Watson, Aaron M.; Place, Allen R.; Jagus, Rosemary

    2017-01-01

    Although taurine has been shown to play multiple important physiological roles in teleosts, little is known about the molecular mechanisms underlying dietary requirements. Cell lines can provide useful tools for deciphering biosynthetic pathways and their regulation. However, culture media and sera contain variable taurine levels. To provide a useful cell line for the investigation of taurine homeostasis, an adult zebrafish liver cell line (ZFL) has been adapted to a taurine-free medium by gradual accommodation to a commercially available synthetic medium, UltraMEM™-ITES. Here we show that ZFL cells are able to synthesize taurine and be maintained in medium without taurine. This has allowed for the investigation of the effects of taurine supplementation on cell growth, cellular amino acid pools, as well as the expression of the taurine biosynthetic pathway and taurine transporter genes in a defined fish cell type. After taurine supplementation, cellular taurine levels increase but hypotaurine levels stay constant, suggesting little suppression of taurine biosynthesis. Cellular methionine levels do not change after taurine addition, consistent with maintenance of taurine biosynthesis. The addition of taurine to cells grown in taurine-free medium has little effect on transcript levels of the biosynthetic pathway genes for cysteine dioxygenase (CDO), cysteine sulfinate decarboxylase (CSAD), or cysteamine dioxygenase (ADO). In contrast, supplementation with taurine causes a 30% reduction in transcript levels of the taurine transporter, TauT. This experimental approach can be tailored for the development of cell lines from aquaculture species for the elucidation of their taurine biosynthetic capacity. PMID:28587087

  17. Increasing taurine intake and taurine synthesis improves skeletal muscle function in the mdx mouse model for Duchenne muscular dystrophy.

    PubMed

    Terrill, Jessica R; Pinniger, Gavin J; Graves, Jamie A; Grounds, Miranda D; Arthur, Peter G

    2016-06-01

    Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease associated with increased inflammation, oxidative stress and myofibre necrosis. Cysteine precursor antioxidants such as N-acetyl cysteine (NAC) and l-2-oxothiazolidine-4-carboxylate (OTC) reduce dystropathology in the mdx mouse model for DMD, and we propose this is via increased synthesis of the amino acid taurine. We compared the capacity of OTC and taurine treatment to increase taurine content of mdx muscle, as well as effects on in vivo and ex vivo muscle function, inflammation and oxidative stress. Both treatments increased taurine in muscles, and improved many aspects of muscle function and reduced inflammation. Taurine treatment also reduced protein thiol oxidation and was overall more effective, as OTC treatment reduced body and muscle weight, suggesting some adverse effects of this drug. These data suggest that increasing dietary taurine is a better candidate for a therapeutic intervention for DMD. Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease for which there is no widely available cure. Whilst the mechanism of loss of muscle function in DMD and the mdx mouse model are not fully understood, disruptions in intracellular calcium homeostasis, inflammation and oxidative stress are implicated. We have shown that protein thiol oxidation is increased in mdx muscle, and that the indirect thiol antioxidant l-2-oxothiazolidine-4-carboxylate (OTC), which increases cysteine availability, decreases pathology and increases in vivo strength. We propose that the protective effects of OTC are a consequence of conversion of cysteine to taurine, which has itself been shown to be beneficial to mdx pathology. This study compares the efficacy of taurine with OTC in decreasing dystropathology in mdx mice by measuring in vivo and ex vivo contractile function and measurements of inflammation and protein thiol oxidation. Increasing the taurine content of mdx muscle improved both in vivo and ex

  18. Taurine deficiency, synthesis and transport in the mdx mouse model for Duchenne Muscular Dystrophy.

    PubMed

    Terrill, Jessica R; Grounds, Miranda D; Arthur, Peter G

    2015-09-01

    The amino acid taurine is essential for the function of skeletal muscle and administration is proposed as a treatment for Duchenne Muscular Dystrophy (DMD). Taurine homeostasis is dependent on multiple processes including absorption of taurine from food, endogenous synthesis from cysteine and reabsorption in the kidney. This study investigates the cause of reported taurine deficiency in the dystrophic mdx mouse model of DMD. Levels of metabolites (taurine, cysteine, cysteine sulfinate and hypotaurine) and proteins (taurine transporter [TauT], cysteine deoxygenase and cysteine sulfinate dehydrogenase) were quantified in juvenile control C57 and dystrophic mdx mice aged 18 days, 4 and 6 weeks. In C57 mice, taurine content was much higher in both liver and plasma at 18 days, and both cysteine and cysteine deoxygenase were increased. As taurine levels decreased in maturing C57 mice, there was increased transport (reabsorption) of taurine in the kidney and muscle. In mdx mice, taurine and cysteine levels were much lower in liver and plasma at 18 days, and in muscle cysteine was low at 18 days, whereas taurine was lower at 4: these changes were associated with perturbations in taurine transport in liver, kidney and muscle and altered metabolism in liver and kidney. These data suggest that the maintenance of adequate body taurine relies on sufficient dietary intake of taurine and cysteine availability and metabolism, as well as retention of taurine by the kidney. This research indicates dystrophin deficiency not only perturbs taurine metabolism in the muscle but also affects taurine metabolism in the liver and kidney, and supports targeting cysteine and taurine deficiency as a potential therapy for DMD. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  19. Quantification of taurine in energy drinks using ¹H NMR.

    PubMed

    Hohmann, Monika; Felbinger, Christine; Christoph, Norbert; Wachter, Helmut; Wiest, Johannes; Holzgrabe, Ulrike

    2014-05-01

    The consumption of so called energy drinks is increasing, especially among adolescents. These beverages commonly contain considerable amounts of the amino sulfonic acid taurine, which is related to a magnitude of various physiological effects. The customary method to control the legal limit of taurine in energy drinks is LC-UV/vis with postcolumn derivatization using ninhydrin. In this paper we describe the quantification of taurine in energy drinks by (1)H NMR as an alternative to existing methods of quantification. Variation of pH values revealed the separation of a distinct taurine signal in (1)H NMR spectra, which was applied for integration and quantification. Quantification was performed using external calibration (R(2)>0.9999; linearity verified by Mandel's fitting test with a 95% confidence level) and PULCON. Taurine concentrations in 20 different energy drinks were analyzed by both using (1)H NMR and LC-UV/vis. The deviation between (1)H NMR and LC-UV/vis results was always below the expanded measurement uncertainty of 12.2% for the LC-UV/vis method (95% confidence level) and at worst 10.4%. Due to the high accordance to LC-UV/vis data and adequate recovery rates (ranging between 97.1% and 108.2%), (1)H NMR measurement presents a suitable method to quantify taurine in energy drinks. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Amino and fatty acid dynamics of octopus (Octopus vulgaris) early life stages under ocean warming.

    PubMed

    Lopes, Vanessa M; Faleiro, Filipa; Baptista, Miguel; Pimentel, Marta S; Paula, José R; Couto, Ana; Bandarra, Narcisa; Anacleto, Patrícia; Marques, António; Rosa, Rui

    2016-01-01

    The oceans are becoming warmer, and the higher temperatures are expected to have a major impact on marine life at different levels of biological organization, especially at the most vulnerable early life stages. Thus, we hypothesize that the future warmer scenarios (here +3 °C) will affect the biochemical composition (amino acid - AA, and fatty acid-FA) of octopod (Octopus vulgaris) embryos and recently-hatched pelagic paralarvae. The main essential amino acids found in octopus embryos were arginine, leucine and lysine; while aspartic and glutamic acids, and taurine were the main non-essential amino acids. Palmitic, eicosapentaenoic and docosahexaenoic acids were the main FAs found in octopus tissues. Relevant ontogenetic changes were observed, namely a steep decrease in the content of many AAs, and a selective retention of FAs, thus evidencing the protein-based metabolism of these cephalopods. Temperature per si did not elicit significant changes in the overall FA composition, but was responsible for a significant decrease in the content of several AAs, indicating increased embryonic consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Radiosynthesis of N-¹¹C-Methyl-Taurine-Conjugated Bile Acids and Biodistribution Studies in Pigs by PET/CT.

    PubMed

    Schacht, Anna Christina; Sørensen, Michael; Munk, Ole Lajord; Frisch, Kim

    2016-04-01

    During cholestasis, accumulation of conjugated bile acids may occur in the liver and lead to hepatocellular damage. Inspired by our recent development of N-(11)C-methyl-glycocholic acid-that is, (11)C-cholylsarcosine-a tracer for PET of the endogenous glycine conjugate of cholic acid, we report here a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids and biodistribution studies in pigs by PET/CT. A radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids was developed and used to prepare N-(11)C-methyl-taurine conjugates derived from cholic, chenodeoxycholic, deoxycholic, ursodeoxycholic, and lithocholic acid. The lipophilicity of these new tracers was determined by reversed-phase thin-layer chromatography. The effect of lipophilicity and structure on the biodistribution was investigated in pigs by PET/CT using the tracers derived from cholic acid (3α-OH, 7α-OH, 12α-OH), ursodeoxycholic acid (3α-OH, 7β-OH), and lithocholic acid (3α-OH). The radiosyntheses of the N-(11)C-methyl-taurine-conjugated bile acids proceeded with radiochemical yields of 61% (decay-corrected) or greater and radiochemical purities greater than 99%. PET/CT in pigs revealed that the tracers were rapidly taken up by the liver and secreted into bile. There was no detectable radioactivity in urine. Significant reflux of N-(11)C-methyl-taurolithocholic acid into the stomach was observed. We have successfully developed a radiosynthesis of N-(11)C-methyl-taurine-conjugated bile acids. These tracers behave in a manner similar to endogenous taurine-conjugated bile acids in vivo and are thus promising for functional PET of patients with cholestatic diseases. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  2. Extracellular glutamate and other amino acids in experimental intracerebral hemorrhage: an in vivo microdialysis study.

    PubMed

    Qureshi, Adnan I; Ali, Zulfiqar; Suri, M Fareed K; Shuaib, Asfhaq; Baker, Glen; Todd, Kathryn; Guterman, Lee R; Hopkins, L Nelson

    2003-05-01

    To determine whether extracellular concentrations of glutamate and other amino acids are significantly elevated after intracerebral hemorrhage and, if so, the temporal characteristics of these changes. Although the role of excitotoxic amino acids, particularly that of glutamate, has been described in ischemic stroke and head trauma, no information exists regarding their possible contribution to the pathogenesis of neuronal injury in intracerebral hemorrhage. Prospective, controlled, laboratory trial. Animal research laboratory. Sixteen anesthetized New Zealand rabbits. We introduced intracerebral hemorrhage in each of eight anesthetized New Zealand rabbits by injecting 0.4 mL of autologous blood under arterial pressure into the deep gray matter of the cerebrum. Extracellular fluid samples were collected from the perihematoma region and contralateral (right) hemisphere by in vivo microdialysis at 30-min intervals for 6 hrs. Corresponding samples were similarly collected from both hemispheres in each of eight control animals that underwent needle placement without introduction of a hematoma. Concentrations of amino acids (glutamate, aspartate, asparagine, glycine, taurine, and gamma-aminobutyric acid) in the samples were measured by use of high-pressure liquid chromatography with fluorescence detection. Glutamate concentrations (mean +/- sem) were significantly higher in the hemisphere ipsilateral to the hematoma than in the contralateral hemisphere (92 +/- 22 pg/microL vs. 22 +/- 6 pg/microL) at 30 mins after hematoma creation. A significant increase was observed at 30 mins posthematoma creation in the hemisphere ipsilateral to the hematoma compared with the baseline value. A nonsignificant increase in glutamate concentration persisted in the hemisphere ipsilateral to the hematoma, ranging from 134% to 187% of baseline value between 1 and 5 hrs after hematoma creation. In the hemisphere ipsilateral to the hematoma, a three-fold increase in the concentration of

  3. Immune and cell modulation by amino acids.

    PubMed

    Roth, Erich

    2007-10-01

    Sir David Cuthbertson was the first to define metabolic alterations in post-aggression syndrome (PAS). From basic measurements of nitrogen loss and total protein synthesis/degradation, the current research has moved to genomics, proteomics and metabolomics. In this respect, first evidence was accumulated for the influence of acute catabolism, immobilisation by bed rest and sarcopenia of old age on the muscle-cell genome and proteome. Moreover, in post-aggression syndrome specific amino acids such as glutamine, arginine, glycine, taurine, tryptophan and cysteine are used for cell and immune modulation. Our laboratory has focused on the regulative capacity of glutamine. Glutamine deficiency as found in post-aggression syndrome reduces lymphocyte proliferation, alters monocyte/macrophage activity, decreases the formation of heat-shock proteins, stimulates cell apoptosis, shifts the cellular redox potential by altering the glutathione synthesis and increases the activity of the AMPK system. Investigating the molecular effect of glutamine on Hsp 70 induction, we tested the glutamine dependence on the formation of transfer-RNA and of heat-shock factor 1 (HSF 1), and on transcription and translation of Hsp 70. We could demonstrate that glutamine stabilises the mRNA of Hsp 70 thereby prolonging its half-life. The lecture also discusses the principal molecular targets of administered arginine, glycine, cysteine, taurine and tryptophan.

  4. Effect of starvation on free histidine and amino acids in white muscle of milkfish Chanos chanos.

    PubMed

    Shiau, C Y; Pong, Y P; Chiou, T K; Tin, Y Y

    2001-03-01

    Milkfish (Chanos chanos) decreased their body weight from 47 to 28 g over the 60-day period of starvation. Starvation also resulted in the reduction of muscle lipid and protein, and hepatosomatic index. The predominant free amino acid (FAA) in white muscle of milkfish was histidine, followed by taurine and glycine. In the first 25 days of starvation, no significant change in histidine was found. After 40 days of starvation, however, the histidine concentration was significantly decreased by 46%, and remained unchanged thereafter. As compared to control group fish, the 60-day-starved fish possessed only half the amount of histidine. Taurine and glycine, on the other hand, showed no significant changes throughout starvation. Taurine became the most predominant in the FAA pool after 40 days of starvation, and the concentration of 60-day-starved fish was two times higher than that of control group fish without starvation. The ratios of histidine, taurine, and glycine to total FAAs remained approximately the same although the individual contributions varied considerably to the total FAAs during starvation. The results of this study suggested that a good strategy would be to keep taurine and glycine in milkfish muscle at relatively high levels for physiological function as histidine decreased drastically for energy source under conditions of food deprivation.

  5. Characterization of N-methyl-D-aspartate-evoked taurine release in the developing and adult mouse hippocampus.

    PubMed

    Saransaari, P; Oja, S S

    2003-01-01

    Taurine is an inhibitory amino acid acting as an osmoregulator and neuroromodulator in the brain, with neuroprotective properties. The ionotropic glutamate receptor agonist N-methyl-D-aspartate (NMDA) greatly potentiates taurine release from brain preparations in both normal and ischemic conditions, the effect being particularly marked in the developing hippocampus. We now characterized the regulation of NMDA-stimulated taurine release from hippocampal slices from adult (3-month-old) and developing (7-day-old) mouse using a superfusion system. The NMDA-stimulated taurine release was receptor-mediated in both adult and developing mouse hippocampus. In adults, only NO-generating compounds, sodium nitroprusside, S-nitroso-N-acetylpenicillamine and hydroxylamine reduced the release, as did also NO synthase inhibitors, 7-nitroindazole and nitroarginine, indicating that the release is mediated by the NO/cGMP pathway. On the other hand, the regulation of the NMDA-evoked taurine release proved to be somewhat complex in the immature hippocampus. It was not affected by the NOergic compounds, but enhanced by the protein kinase C activator 4 beta-phorbol 12-myristate 13-acetate and adenosine receptor A(1) agonists, N(6)-cyclohexyladenosine and R(-)N(6)-(2-phenylisopropyl)adenosine in a receptor-mediated manner. The activation of both ionotropic 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors and metabotropic glutamate group I receptors also enhanced the evoked release. The NMDA-receptor-stimulated taurine release could be a part of the neuroprotective properties of taurine, being important particularly under cell-damaging conditions in the developing hippocampus and hence preventing excitotoxicity.

  6. Changes in urinary amino acids excretion in relationship with muscle activity markers over a professional cycling stage race: in search of fatigue markers.

    PubMed

    Corsetti, Roberto; Barassi, Alessandra; Perego, Silvia; Sansoni, Veronica; Rossi, Alessandra; Damele, Clara Anna Linda; Melzi D'Eril, Gianlodovico; Banfi, Giuseppe; Lombardi, Giovanni

    2016-01-01

    The aim of this study was to identify the relationship between metabolic effort, muscular damage/activity indices, and urinary amino acids profile over the course of a strenuous prolonged endurance activity, as a cycling stage race is, in order to identify possible fatigue markers. Nine professional cyclists belonging to a single team, competing in the Giro d'Italia cycling stage race, were anthropometrically characterized and sampled for blood and urine the day before the race started, and on days 12 and 23 of the race. Diet was kept the same over the race, and power output and energy expenditure were recorded. Sera were assayed for muscle markers (lactate dehydrogenase, aspartate aminotransferase, and creatine kinase activities, and blood urea nitrogen), and creatinine, all corrected for plasma volume changes. Urines were profiled for amino acid concentrations, normalized on creatinine excretion. Renal function, in terms of glomerular filtration rate, was monitored by MDRD equation corrected on body surface area. Creatine kinase activity and blood urea were increased during the race as did serum creatinine while kidney function remained stable. Among the amino acids, taurine, glycine, cysteine, leucine, carnosine, 1-methyl histidine, and 3-methyl histidine showed a net decreased, while homocysteine was increased. Taurine and the dipeptide carnosine (β-alanyl-L-histidine) were significantly correlated with the muscle activity markers and the indices of effort. In conclusion, the metabolic profile is modified strikingly due to the effort. Urinary taurine and carnosine seem useful tools to evaluate the muscle damage and possibly the fatigue status on a long-term basis.

  7. Taurine reverses sodium fluoride-mediated increase in inflammation, caspase-3 activity, and oxidative damage along the brain-pituitary-gonadal axis in male rats.

    PubMed

    Adedara, Isaac A; Olabiyi, Bolanle F; Ojuade, TeminiJesu D; Idris, Umar F; Onibiyo, Esther M; Farombi, Ebenezer O

    2017-09-01

    Excessive exposure to fluoride is associated with male reproductive dysfunction in humans and animals. Taurine (2-aminoethane sulfonic acid) is a free intracellular β-amino acid with antioxidant, anti-inflammatory, and neuroprotective properties. However, the effect of taurine on fluoride-induced reproductive toxicity has not been reported. The present study investigated the influence of taurine on sodium fluoride (NaF)-induced functional changes along the brain-pituitary-gonadal axis in male rats. NaF was administered singly in drinking water at 15 mg·L -1 alone or orally co-administered by gavage with taurine at 100 and 200 mg·(kg body mass) -1 for 45 consecutive days. Results showed that taurine significantly prevented NaF-induced increase in oxidative stress indices as well as augmented antioxidant enzymes activities and glutathione level in the brain, testes, and epididymis of the treated rats. Moreover, taurine reversed NaF-induced elevation in inflammatory biomarkers and caspase-3 activity as well as histological damage in the brain, testes, and epididymis of the treated rats. The significant reversal of NaF-induced decreases in testosterone level and testicular activities of acid phosphatase, alkaline phosphatase, and lactate dehydrogenase by taurine was accompanied by enhancement of sperm functional characteristics in the treated rats. Taurine may be a possible chemopreventive candidate against reproductive dysfunction resulting from fluoride exposure.

  8. Effect of infrared laser irradiation on amino acid neurotransmitters in an epileptic animal model induced by pilocarpine.

    PubMed

    Radwan, Nasr Mahmoud; El Hay Ahmed, Nawal Abd; Ibrahim, Khayria Mansour; Khedr, Mona Emam; Aziz, Mona A; Khadrawy, Yasser Ashry

    2009-06-01

    The aim of the present study was to investigate the effect of daily laser irradiation on the levels of amino acid neurotransmitters in the cortex and hippocampus in an epileptic animal model induced by pilocarpine. It has been claimed that at specific wavelengths and energy densities, laser irradiation is a novel and useful tool for the treatment of peripheral and central nervous system injuries and disorders. Adult male albino rats were divided into three groups: control rats, pilocarpinized rats (epileptic animal model), and pilocarpinized rats treated daily with laser irradiation (90 mW at 830 nm) for 7 d. The following parameters were assayed in cortex and hippocampus: amino acid neurotransmitters (excitatory: glutamic acid and aspartate; and inhibitory: gamma-aminobutyric acid [GABA], glycine, and taurine) by high-performance liquid chromatography (HPLC), glucose content, and the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), using a spectrophotometer. Significant increases in the concentrations of glutamic acid, glutamine, glycine, and taurine were recorded in the cortices of pilocarpinized rats, and they returned to initial levels after laser treatment. In the hippocampus, a moderate increase in aspartate accompanied by a significant increase in glycine were observed in the epileptic animal model, and these dropped to near-control values after laser treatment. In addition, a significant increase in cortical AST activity and a significant decrease in ALT activity and glucose content were obtained in the pilocarpinized animals and pilocarpinized rats treated with laser irradiation. In the hippocampus, significant decreases in the activity of AST and ALT and glucose content were recorded in the epileptic animals and in the epileptic animals treated with laser irradiation. Based on the results obtained in this study, it may be suggested that nearinfrared laser irradiation may reverse the neurochemical changes in amino acid

  9. Ammonia-induced mitochondrial dysfunction and energy metabolism disturbances in isolated brain and liver mitochondria, and the effect of taurine administration: relevance to hepatic encephalopathy treatment

    PubMed Central

    Niknahad, Hossein; Jamshidzadeh, Akram; Zarei, Mahdi; Ommati, Mohammad Mehdi

    2017-01-01

    Introduction Ammonia-induced oxidative stress, mitochondrial dysfunction, and energy crisis are known as some the major mechanisms of brain injury in hepatic encephalopathy (HE). Hyperammonemia also affects the liver and hepatocytes. Therefore, targeting mitochondria seems to be a therapeutic point of intervention in the treatment of HE. Taurine is an abundant amino acid in the human body. Several biological functions including the mitochondrial protective properties are attributed to this amino acid. The aim of this study is to evaluate the effect of taurine administration on ammonia-induced mitochondrial dysfunction. Material and methods Isolated mice liver and brain mitochondria were exposed to different concentrations of ammonia (1, 5, 10, and 20 mM) and taurine (1, 5, and 10 mM), and several mitochondrial indices were assessed. Results It was found that ammonia inhibited mitochondrial dehydrogenases activity caused collapse of mitochondrial membrane potential (MMP), induced mitochondrial swelling (MPP), and increased reactive oxygen species (ROS) in isolated liver and brain mitochondria. Furthermore, a significant amount of lipid peroxidation (LPO), along with glutathione (GSH) and ATP depletion, was detected in ammonia exposed mitochondria. Taurine administration (5 and 10 mM) mitigated ammonia-induced mitochondrial dysfunction. Conclusions The current investigation demonstrates that taurine is instrumental in preserving brain and liver mitochondrial function in a hyperammonemic environment. The data suggest taurine as a potential protective agent with a therapeutic capability against hepatic encephalopathy and hyperammonemia. PMID:29062904

  10. Taurine Supplementation Improves Functional Capacity, Myocardial Oxygen Consumption, and Electrical Activity in Heart Failure.

    PubMed

    Ahmadian, Mehdi; Dabidi Roshan, Valiollah; Ashourpore, Eadeh

    2017-07-04

    Taurine is an amino acid found abundantly in the heart in very high concentrations. It is assumed that taurine contributes to several physiological functions of mammalian cells, such as osmoregulation, anti-inflammation, membrane stabilization, ion transport modulation, and regulation of oxidative stress and mitochondrial protein synthesis. The objective of the current study was to evaluate the effectiveness of taurine supplementation on functional capacity, myocardial oxygen consumption, and electrical activity in patients with heart failure. In a double-blind and randomly designed study, 16 patients with heart failure were assigned to two groups: taurine (TG, n = 8) and placebo (PG, n = 8). TG received 500-mg taurine supplementation three times per day for two weeks. Significant decrease in the values of Q-T segments (p < 0.01) and significant increase in the values of P-R segments (p < 0.01) were detected following exercise post-supplementation in TG rather than in PG. Significantly higher values of taurine concentration, T wave, Q-T segment, physical capacities, and lower values of cardiovascular capacities were detected post-supplementation in TG as compared with PG (all p values <0.01). Taurine significantly enhanced the physical function and significantly reduced the cardiovascular function parameters following exercise. Our results also suggest that the short-term taurine supplementation is an effective strategy for improving some selected hemodynamic parameters in heart failure patients. Together, these findings support the view that taurine improves cardiac function and functional capacity in patients with heart failure. This idea warrants further study.

  11. Reciprocal regulation between taurine and glutamate response via Ca2+- dependent pathways in retinal third-order neurons

    PubMed Central

    2010-01-01

    Although taurine and glutamate are the most abundant amino acids conducting neural signals in the central nervous system, the communication between these two neurotransmitters is largely unknown. This study explores the interaction of taurine and glutamate in the retinal third-order neurons. Using specific antibodies, both taurine and taurine transporters were localized in photoreceptors and Off-bipolar cells, glutamatergic neurons in retinas. It is possible that Off-bipolar cells release juxtaposed glutamate and taurine to activate the third-order neurons in retina. The interaction of taurine and glutamate was studied in acutely dissociated third-order neurons in whole-cell patch-clamp recording and Ca2+ imaging. We find that taurine effectively reduces glutamate-induced Ca2+ influx via ionotropic glutamate receptors and voltage-dependent Ca2+ channels in the neurons, and the effect of taurine was selectively inhibited by strychnine and picrotoxin, but not GABA receptor antagonists, although GABA receptors are present in the neurons. A CaMKII inhibitor partially reversed the effect of taurine, suggesting that a Ca2+/calmodulin-dependent pathway is involved in taurine regulation. On the other hand, a rapid influx of Ca2+ through ionotropic glutamate receptors could inhibit the amplitude and kinetics of taurine-elicited currents in the third-order neurons, which could be controlled with intracellular application of BAPTA a fast Ca2+ chelator. This study indicates that taurine is a potential neuromodulator in glutamate transmission. The reciprocal inhibition between taurine and glutamate in the postsynaptic neurons contributes to computation of visual signals in the retinal neurons. PMID:20804625

  12. Impact of taurine depletion on glucose control and insulin secretion in mice.

    PubMed

    Ito, Takashi; Yoshikawa, Natsumi; Ito, Hiromi; Schaffer, Stephen W

    2015-09-01

    Taurine, an endogenous sulfur-containing amino acid, is found in millimolar concentrations in mammalian tissue, and its tissue content is altered by diet, disease and aging. The effectiveness of taurine administration against obesity and its related diseases, including type 2 diabetes, has been well documented. However, the impact of taurine depletion on glucose metabolism and fat deposition has not been elucidated. In this study, we investigated the effect of taurine depletion (in the taurine transporter (TauT) knockout mouse model) on blood glucose control and high fat diet-induced obesity. TauT-knockout (TauTKO) mice exhibited lower body weight and abdominal fat mass when maintained on normal chow than wild-type (WT) mice. Blood glucose disposal after an intraperitoneal glucose injection was faster in TauTKO mice than in WT mice despite lower serum insulin levels. Islet beta-cells (insulin positive area) were also decreased in TauTKO mice compared to WT mice. Meanwhile, overnutrition by high fat (60% fat)-diet could lead to obesity in TauTKO mice despite lower body weight under normal chow diet condition, indicating nutrition in normal diet is not enough for TauTKO mice to maintain body weight comparable to WT mice. In conclusion, taurine depletion causes enhanced glucose disposal despite lowering insulin levels and lower body weight, implying deterioration in tissue energy metabolism. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  13. Taurine, caffeine, and energy drinks: Reviewing the risks to the adolescent brain.

    PubMed

    Curran, Christine Perdan; Marczinski, Cecile A

    2017-12-01

    Energy drinks are emerging as a major component of the beverage market with sales projected to top $60 billion globally in the next five years. Energy drinks contain a variety of ingredients, but many of the top-selling brands include high doses of caffeine and the amino acid taurine. Energy drink consumption by children has raised concerns, due to potential caffeine toxicity. An additional risk has been noted among college-aged consumers of energy drinks who appear at higher risk of over-consumption of alcohol when the two drinks are consumed together. The differential and combinatorial effects of caffeine and taurine on the developing brain are reviewed here with an emphasis on the adolescent brain, which is still maturing. Key data from animal studies are summarized to highlight both reported benefits and adverse effects reported following acute and chronic exposures. The data suggest that age is an important factor in both caffeine and taurine toxicity. Although the aged or diseased brain might benefit from taurine or caffeine supplementation, it appears that adolescents are not likely to benefit from supplementation and may, in fact, suffer ill effects from chronic ingestion of high doses. Additional work is needed though to address gaps in our understanding of how taurine affects females, since the majority of animal studies focused exclusively on male subjects. © 2017 Wiley Periodicals, Inc.

  14. Effects of propofol, midazolam and thiopental sodium on outcome and amino acids accumulation in focal cerebral ischemia-reperfusion in rats.

    PubMed

    Chen, Lianhua; Gong, Qinyan; Xiao, Changsi

    2003-02-01

    To investigate the effects of propofol, midazolam and thiopental sodium on outcomes and amino acid accumulation in focal cerebral ischemia-reperfusion in rats. Male Sprague Dawley (SD) rats were scheduled to undergo 3-hour middle cerebral artery occlusion by intraluminal suture and 24-hour reperfusion. Neurologic outcomes were scored on a 0-5 grading scale. Infarct volume was shown with triphenyltetrazolium chloride staining and measured by an image analysis system. Concentrations of various amino acids (aspartate, glutamate, glycine, taurine, and gama-aminobutyric acid) were measured after 3 hours of reperfusion using high performance liquid chromatography. Propofol, midazolam and thiopental sodium were given intraperitoneally at the beginning of reperfusion. Both propofol and midazolam attenuated neurological deficits and reduced infarct and edema volumes. Propofol showed better neurological protection than midazolam while thiopental sodium did not exhibit any protective effect. Both propofol and midazolam decreased excitatory amino acids accumulation, while propofol increased gama-aminobutyric acid accumulation in ischemic areas in reperfusion. Propofol and midazolam, but not thiopental sodium, may provide protective effects against reperfusion induced injury in rats subjected to focal cerebral ischemia. This neurological protection may be due to the acceleration of excitatory amino acids elimination in reperfusion.

  15. Taurine ameliorated thyroid function in rats co-administered with chlorpyrifos and lead.

    PubMed

    Akande, Motunrayo Ganiyat; Shittu, Muftau; Uchendu, Chidiebere; Yaqub, Lukuman Surakat

    2016-12-01

    Chlorpyrifos is a widely used organophosphate insecticide for domestic, agricultural and industrial purposes. Lead is a toxic heavy metal and it is used for domestic and industrial purposes. Taurine is a semi essential amino acid with bioprotective properties. The aim of this study was to investigate the effects of taurine on thyroid function in Wistar rats co-administered with chlorpyrifos and lead. The rats were divided into 5 groups of 10 rats each. The first two groups were administered with distilled water and soya oil (1 ml/kg) respectively. The other groups received taurine (50 mg/kg), chlorpyrifos + lead [chlorpyrifos (4.25 mg/kg, 1/20 median lethal dose] and lead (233.25 mg/kg, 1/20 median lethal dose) and taurine + chlorpyrifos + lead respectively. The treatments were administered once daily by oral gavage for 16 weeks. The rats were euthanized after the completion of the study and the thyroid function and thyroid histoarchitecture were evaluated. The results revealed that co-administration of chlorpyrifos and lead to the rats induced perturbations in thyroid function and this was manifested by reductions in the concentrations of triiodothyronine and thyroxine, increased thyroid stimulating hormone concentration and degeneration of the follicular epithelia of the thyroid gland. Taurine alleviated the perturbations in thyroid function and improved thyroid gland histoarchitecture. The beneficial effects of taurine may be attributed to its ability to protect the body from toxicity and oxidative stress. Taurine may be useful for prophylaxis against disruptions in thyroid function in animals that are exposed to environmental chlorpyrifos and lead.

  16. Acute effects of sodium valproate and gamma-vinyl GABA on regional amino acid metabolism in the rat brain: incorporation of 2-[14C]glucose into amino acids.

    PubMed

    Chapman, A G; Riley, K; Evans, M C; Meldrum, B S

    1982-09-01

    Amino acid concentrations have been determined in rat brain regions (cortex, striatum, cerebellum, and hippocampus) by HPLC after administration of acute anticonvulsant doses of sodium valproate (400 mg/kg, i.p.) and gamma-vinyl-GABA (1 g/kg, i.p.). After valproate administration the GABA level increases only in the cortex; aspartic acid concentration decreases in the cortex and hippocampus, and glutamic acid decreases in the hippocampus and striatum and increases in the cortex and cerebellum. There are no changes in the concentrations of glutamine, taurine, glycine, serine, and alanine following valproate administration. Only the GABA level increases in all the regions after gamma-vinyl-GABA administration. Cortical analyses 2, 4 and 10 minutes after pulse labeling with 2-[14C]glucose, i.v., show no change in the rate of cortical glucose utilization in the valproate treated group. The rate of labeling of glutamic acid is also unchanged, but the rate of labeling of GABA is reduced following valproate administration. After gamma-vinyl-GABA administration there is no change in the rate of labeling of GABA. These biochemical findings can be interpreted in terms of a primary anticonvulsant action of valproate on membrane receptors with secondary effects on the metabolism of amino acid neurotransmitters. This contrasts with the primary action of gamma-vinyl-GABA on GABA-transaminase activity.

  17. Comparative Analysis of Microbicidal and Anti-inflammatory Properties of Novel Taurine Bromamine Derivatives and Bromamine T.

    PubMed

    Walczewska, M; Peruń, A; Białecka, A; Śróttek, M; Jamróz, W; Dorożyński, P; Jachowicz, R; Kulinowski, P; Nagl, M; Gottardi, W; Marcinkiewicz, J

    2017-01-01

    Taurine, the most abundant free amino acid in leukocyte cytosol traps hypohalous acids (HOCl and HOBr) to produce N-chlorotaurine (taurine chloramine, NCT and N-bromotaurine (taurine bromamine, Tau-NHBr,) respectively. Both haloamines show anti-inflammatory and antimicrobial properties. However, the therapeutic applicability of Tau-NHBr is limited due to its relatively poor stability. To overcome this disadvantage, we have synthesized the stable N-bromotaurine compounds N-monobromo-2,2-dimethyltaurine (Br-612) and N-dibromo-2,2-dimethyltaurine (Br-422). The aim of this study was to compare anti-inflammatory and microbicidal properties of Br-612 and Br-422 with that of Tau-NHBr and bromamine T (BAT). We have shown that all the tested compounds show similar anti-inflammatory properties. Importantly, the stable N-bromotaurine compounds exerted even stronger microbicidal activity than Tau-NHBr. Finally, for the purpose of topical application of these compounds we have developed a carbomer-based bioadhesive solid dosage form of BAT and Br-612, featuring sustained release of the active substance.

  18. Beneficial effects of high dose taurine treatment in juvenile dystrophic mdx mice are offset by growth restriction.

    PubMed

    Terrill, Jessica R; Pinniger, Gavin J; Nair, Keshav V; Grounds, Miranda D; Arthur, Peter G

    2017-01-01

    Duchenne Muscular Dystrophy (DMD) is a fatal muscle wasting disease manifested in young boys, for which there is no current cure. We have shown that the amino acid taurine is safe and effective at preventing dystropathology in the mdx mouse model for DMD. This study aimed to establish if treating growing mdx mice with a higher dose of taurine was more effective at improving strength and reducing inflammation and oxidative stress. Mice were treated with a dose of taurine estimated to be 16 g/kg/day, in drinking water from 1-6 weeks of age, after which in vivo and ex vivo muscle strength was assessed, as were measures of inflammation, oxidative stress and taurine metabolism. While the dose did decrease inflammation and protein oxidation in dystrophic muscles, there was no improvement in muscle strength (in contrast with benefits observed with the lower dose) and growth of the young mice was significantly restricted. We present novel data that a high taurine dose increases the cysteine content of both mdx liver and plasma, a possible result of down regulation of the taurine synthesis pathway in the liver (which functions to dispose of excess cysteine, which is toxic). These data caution that a high dose of taurine can have adverse effects and may be less efficacious than lower taurine doses. Therefore, monitoring of taurine dosage needs to be considered in future pre-clinical trials, in anticipation of using taurine as a clinical therapy for growing DMD boys (and other conditions).

  19. Beneficial effects of high dose taurine treatment in juvenile dystrophic mdx mice are offset by growth restriction

    PubMed Central

    Pinniger, Gavin J.; Nair, Keshav V.; Grounds, Miranda D.; Arthur, Peter G.

    2017-01-01

    Duchenne Muscular Dystrophy (DMD) is a fatal muscle wasting disease manifested in young boys, for which there is no current cure. We have shown that the amino acid taurine is safe and effective at preventing dystropathology in the mdx mouse model for DMD. This study aimed to establish if treating growing mdx mice with a higher dose of taurine was more effective at improving strength and reducing inflammation and oxidative stress. Mice were treated with a dose of taurine estimated to be 16 g/kg/day, in drinking water from 1–6 weeks of age, after which in vivo and ex vivo muscle strength was assessed, as were measures of inflammation, oxidative stress and taurine metabolism. While the dose did decrease inflammation and protein oxidation in dystrophic muscles, there was no improvement in muscle strength (in contrast with benefits observed with the lower dose) and growth of the young mice was significantly restricted. We present novel data that a high taurine dose increases the cysteine content of both mdx liver and plasma, a possible result of down regulation of the taurine synthesis pathway in the liver (which functions to dispose of excess cysteine, which is toxic). These data caution that a high dose of taurine can have adverse effects and may be less efficacious than lower taurine doses. Therefore, monitoring of taurine dosage needs to be considered in future pre-clinical trials, in anticipation of using taurine as a clinical therapy for growing DMD boys (and other conditions). PMID:29095865

  20. Amino acids

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  1. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  2. High extracellular concentration of excitatory amino acids glutamate and aspartate in human brain abscess.

    PubMed

    Dahlberg, Daniel; Ivanovic, Jugoslav; Hassel, Bjørnar

    2014-04-01

    Brain abscesses often cause symptoms of brain dysfunction, including seizures, suggesting interference with normal neurotransmission. We determined the concentration of extracellular neuroactive amino acids in brain abscesses from 16 human patients. Glutamate was present at 3.6 mmol/L (median value, range 0.5-10.8), aspartate at 1.0 mmol/L (range 0.09-6.8). For comparison, in cerebroventricular fluid glutamate was ∼0.6 μmol/L, and aspartate was not different from zero. The total concentration of amino acids was higher in eight patients with seizures: 66 mmol/L (median value, range 19-109) vs. 21 mmol/L (range 4-52) in eight patients without seizures (p=0.026). The concentration of aspartate and essential amino acids tryptophan, phenylalanine, tyrosine, leucine, and isoleucine was higher in pus from patients with seizures (p⩽0.040), whereas that of glutamate was not (p=0.095). The median concentration of the non-proteinogenic, inhibitory amino acid taurine was similar in the two groups, 0.7-0.8 mmol/L (range 0.1-6.1). GABA could not be detected in pus. The patient groups did not differ with respect to abscess volume, the cerebral lobe affected, age, or time from symptom onset to surgery. Seven patients with extracerebral, intracranial abscesses had significantly lower pus concentration of glutamate (352 μmol/L, range 83-1368) and aspartate (71 μmol/L, range 22-330) than intracerebral abscesses (p<0.001). We conclude that excitatory amino acids glutamate and aspartate may reach very high concentrations in brain abscesses, probably contributing to symptoms through activation of glutamate receptors in the surrounding brain tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Low temperature IR spectroscopic study of torsional vibrations of taurine

    NASA Astrophysics Data System (ADS)

    Bajaj, Naini; Bhatt, Himal; Vishwakarma, S. R.; Thomas, Susy; Murli, C.; Deo, M. N.

    2018-04-01

    The hydrogen bonding network in amino acids can give information about the structural stability under varying thermodynamic conditions such as temperature and pressure. We have carried out low temperature IR spectroscopic studies on Taurine, an amino acid with various bio-chemical applications in physiology and synthesis, in order to observe the behaviour of torsional modes, i.e. τ(CSH) and τ(NH3), which are very sensitive to the hydrogen bonding interactions. It was observed that the CSH torsional mode showed splitting at low temperature of nearly 250 K and the bandwidth shows linear temperature dependence, which can be attributed to anharmonicity. Another torsional mode, τ(NH3) showed no splitting, but the bandwidth has non-linear temperature dependence. This can be due to orientational changes at low temperature. These observations are strong evidences for a hydrogen bond reorientation induced phase transition at 250 K.

  4. Effects of glutamine, taurine and their association on inflammatory pathway markers in macrophages.

    PubMed

    Sartori, Talita; Galvão Dos Santos, Guilherme; Nogueira-Pedro, Amanda; Makiyama, Edson; Rogero, Marcelo Macedo; Borelli, Primavera; Fock, Ricardo Ambrósio

    2018-06-01

    The immune system is essential for the control and elimination of infections, and macrophages are cells that act as important players in orchestrating the various parts of the inflammatory/immune response. Amino acids play important role in mediating functionality of the inflammatory response, especially mediating macrophages functions and cytokines production. We investigated the influence of glutamine, taurine and their association on the modulation of inflammatory pathway markers in macrophages. The RAW 264.7 macrophage cell line was cultivated in the presence of glutamine and taurine and proliferation rates, cell viability, cell cycle phases, IL-1α, IL-6, IL-10 and TNF-α as well as H 2 O 2 production and the expression of the transcription factor, NFκB, and its inhibitor, IκBα, were evaluated. Our results showed an increase in viable cells and increased proliferation rates of cells treated with glutamine concentrations over 2 mM, as well as cells treated with both glutamine and taurine. The cell cycle showed a higher percentage of cells in the phases S, G2 and M when they were treated with 2 or 10 mM glutamine, or with glutamine and taurine in cells stimulated with lipopolysaccharide. The pNFκB/NFκB showed reduced ratio expression when cells were treated with 10 mM of glutamine or with glutamine in association with taurine. These conditions also resulted in reduced TNF-α, IL-1α and H 2 O 2 production, and higher production of IL-10. These findings demonstrate that glutamine and taurine are able to modulate macrophages inflammatory pathways, and that taurine can potentiate the effects of glutamine, illustrating their immunomodulatory properties.

  5. Changes in plasma osmolality, cortisol and amino acid levels of tongue sole ( Cynoglossus semilaevis) at different salinities

    NASA Astrophysics Data System (ADS)

    Wang, Guodong; Xu, Kefeng; Tian, Xiangli; Dong, Shuanglin; Fang, Ziheng

    2015-10-01

    A serial of salinity transferring treatments were performed to investigate the osmoregulation of tongue sole ( Cynoglossus semilaevis). Juvenile tongue sole were directly transferred from a salinity of 30 to 0, 10, 20, 30, 40 and 50. Blood sampling was performed for each treatment after 0, 1, 6 and 12 h, as well as after 1, 2, 4, 8, 16 and 32 d. The plasma osmolality, cortisol and free amino acids were assessed. Under the experimental conditions, no fish died after acute salinity transfer. The plasma cortisol level increased 1 h after the abrupt transfer from a salinity of 30 to that of 0, 40 and 50, and decreased from 6 h to 8 d after transfer. Similar trends were observed in the changes of plasma osmolality. The plasma free amino acids concentration showed a `U-shaped' relationship with salinity after being transferred to different salinities for 4 days. More obvious changes of plasma free amino acid concentration occurred under hyper-osmotic conditions than under hypo-osmotic conditions. The concentrations of valine, isoleucine, lysine, glutamic acid, glycine, proline and taurine increased with rising salinity. The plasma levels of threonine, leucine, arginine, serine, and alanine showed a `U-shaped' relationship with salinity. The results of this study suggested that free amino acids might have important effects on osmotic acclimation in tongue sole.

  6. [Effects of electromagnetic pulse on contents of amino acids in hippocampus of rats].

    PubMed

    Li, Yu-hong; Wang, De-wen; Peng, Rui-yun; Li, Zi-jian; Dong, Biao; Dong, Fang-ting; Liang, Yue-qin; Hu, Wen-hua

    2003-10-01

    To investigate the relationship between the changes of amino acids contents in hippocampus of rats and electromagnetic pulse (EMP) exposure. Rats were decapitated and hippocampus were removed after EMP (6 x 10(4) V/m, rise time 20 ns, pulse width 30 micro s, 5 pulses in 2 minutes) irradiation, and contents of amino acids were detected with high performance liquid chromatograpy (HPLC). The contents of aspartic acid (Asp) and glutamic acid (Glu) increased significantly 0, 3, 6 h after irradiation. The peak values of Asp [(17.25 +/- 1.63) pmol/ micro l] and Glu [(13.67 +/- 0.95) pmol/ micro l] were higher than those of control [(10.56 +/- 1.50), (6.94 +/- 1.10) pmol/ micro l respectively, P < 0.05]. Then both decreased gradually and reached the normal level 24 - 48 h after irradiation. The contents of glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA) also rose after exposure, the peak value of them [(4.51 +/- 0.60), (29.85 +/- 2.70), (5.14 +/- 0.73) pmol/ micro l respectively] were higher than those of control group [(2.18 +/- 0.31), (9.88 +/- 1.47), (2.84 +/- 0.67) pmol/ micro l, P < 0.05], then recovered 48 h after irradiation. The value of Glu/GABA increased immediately after exposure (3.45 +/- 0.25, P < 0.05), then decreased 24 h (1.62 +/- 0.23, P < 0.05) and recovered 48 h after exposure. The toxic effect of excess excitatory amino acids may be partly responsible for the early retardation (within 24 h) of learning of rats.

  7. Concentrations in beef and lamb of taurine, carnosine, coenzyme Q(10), and creatine.

    PubMed

    Purchas, R W; Rutherfurd, S M; Pearce, P D; Vather, R; Wilkinson, B H P

    2004-03-01

    Levels of taurine, carnosine, coenzyme Q(10), and creatine were measured in beef liver and several muscles of beef and lamb and in cooked and uncooked meat. The amino acid taurine has numerous biological functions, the dipeptide carnosine is a buffer as well as an antioxidant, coenzyme Q(10) is also an antioxidant present within mitochondria, and creatine along with creatine phosphate is involved with energy metabolism in muscle. Large differences were shown for all compounds between beef cheek muscle (predominantly red fibres) and beef semitendinosus muscle (mainly white fibres), with cheek muscle containing 9.9 times as much taurine, and 3.2 times as much coenzyme Q(10), but only 65% as much creatine and 9% as much carnosine. Levels in lamb relative to beef semitendinosus muscles were higher for taurine but slightly lower for carnosine, coenzyme Q(10) and creatine. Values for all the compounds varied significantly between eight lamb muscles, possibly due in part to differences in the proportion of muscle fibre types. Slow cooking (90 min at 70 °C) of lamb longissimus and semimembranosus muscles led to significant reductions in the content of taurine, carnosine, and creatine (P<0.001), but a slight increase in coenzyme Q(10). There was also a four-fold increase in creatinine, presumably due to its formation from creatine. It is concluded that biologically, and possibly nutritionally, significant levels of taurine, carnosine, coenzyme Q(10), and creatine are present in beef and lamb, but that these levels vary between muscles, between animals, and with cooking.

  8. The regulation of sulphurated amino acid junctions: fact or fiction in the field of inflammation?

    PubMed

    Santangelo, F

    2002-01-01

    The diet of industrialised countries is usually rich in amino acids, which are in part used as a source of calories. However, metabolic alterations are observed in diseased patients and a preferential retention of Sulphurated Amino Acids (SAA) occurs during the inflammatory response. Moreover, it has been demonstrated in a model of an acute sepsis phase of rats that the metabolism of Cysteine is modified. The liver converts Cysteine at a different ratio of Sulphate to Taurine (Tau) i.e. the sulphate production decreases while the Tau conversion increases. The Glutathione (GSH) concentration is greater in the liver, kidneys and other organs and the Cysteine incorporation into proteins is higher in the spleen, lungs and plasma (Acute Phase Proteins) while the Albumin level decreases. The pro-inflammatory cytokines such as Interleukin-1, Interleukin-6 and TNF- alpha are the main initiators that alter protein and amino acid metabolism. Another important phenomenon is the impairment of Methionine conversion to Cysteine during stress. For example, premature infants or AIDS patients are capable of synthesizing Cysteine from Methionine at a much lower rate. Thus, the metabolic flow through the trans-sulphuration path may be inadequate to meet the Cysteine demand under critical conditions. In this complex picture, an SAA supply may contribute to an immune system regulation.

  9. Racemic resolution of some DL-amino acids using Aspergillus fumigatus L-amino acid oxidase.

    PubMed

    Singh, Susmita; Gogoi, Binod K; Bezbaruah, Rajib L

    2011-07-01

    The ability of Aspergillus fumigatus L-amino acid oxidase (L-aao) to cause the resolution of racemic mixtures of DL-amino acids was investigated with DL-alanine, DL-phenylalanine, DL-tyrosine, and DL-aspartic acid. A chiral column, Crownpak CR+ was used for the analysis of the amino acids. The enzyme was able to cause the resolution of the three DL-amino acids resulting in the production of optically pure D-alanine (100% resolution), D-phenylalanine (80.2%), and D-tyrosine (84.1%), respectively. The optically pure D-amino acids have many uses and thus can be exploited industrially. This is the first report of the use of A. fumigatus L: -amino acid oxidase for racemic resolution of DL-amino acids.

  10. Concentrations of amino acids in plasma and whole blood in response to food deprivation and refeeding in healthy two-day-old foals.

    PubMed

    Zicker, S C; Rogers, Q R

    1994-07-01

    Concentrations of amino acids in plasma and whole blood in response to 10 hours of food deprivation were determined in healthy 2-day-old foals (n = 8) and were compared with control values in foals of the same age (n = 8) allowed free access to suckle. In addition, response of concentrations of amino acids in plasma to 15 minutes of free-access suckling was determined at the end of the 10-hour period in both groups. Response of 13 amino acids in plasma of food-deprived foals was significantly (P < 0.05) different, compared with that in control foals. Concentrations of 3 amino acids (alanine, glycine, and phenylalanine) in plasma increased significantly (P < 0.05), whereas concentrations of 7 amino acids (asparagine, citrulline, histidine, ornithine, proline, tryptophan, and tyrosine) in plasma decreased significantly (P < 0.05) during food deprivation. Response of concentrations of 2 amino acids (glycine and histidine) in whole blood was significantly (P < 0.05) different from that in plasma of food-deprived vs control foals. Refeeding of food-deprived foals resulted in significantly (P < 0.05) different responses for concentrations of all but 2 amino acids (cystine and taurine) in plasma, compared with responses in controls. Changes in concentrations of amino acids in plasma and whole blood of foals in response to food deprivation are similar to those in foals with septicemia and in children with grade 1 or 2 kwashiorkor. The significantly different response of food-deprived foals to refeeding may be attributable to increased protein intake or altered physiologic state.

  11. Effects of aniracetam on extracellular levels of transmitter amino acids in the hippocampus of the conscious gerbils: an intracranial microdialysis study.

    PubMed

    Yu, Siming; Cai, Jingxia

    2003-03-27

    The effects of aniracetam on extracellular amino acid levels in the hippocampus of conscious gerbils, with or without transient cerebral ischemia/reperfusion, were measured by microdialysis and reverse phase-high performance liquid chromatography. Increased extracellular levels of aspartate and glutamate that were observed in the hippocampus of conscious gerbils during transient global forebrain ischemia were reversed by aniracetam. In contrast, the level of extracellular gamma-aminobutyric acid was increased, while taurine was maintained at a higher level than other amino acids by administration of aniracetam (100 mg/kg, p.o.) 60 min before ischemia. Further, in contrast to ischemic animals, administration of aniracetam (100 mg/kg, p.o.) enhanced the release of glutamate and aspartate in the normal gerbil hippocampus. The results suggest that these effects might be due to a partial calcium agonist activity of aniracetam, and that the effects of aniracetam on amino acid levels might be a mechanism of protection against delayed neuronal death in the ischemic hippocampus, thereby improving memory dysfunction induced by ischemia/reperfusion.

  12. UNSATURATED AMINO ACIDS V.

    PubMed Central

    Shapira, Jacob; Dittmer, Karl

    1961-01-01

    Shapira, Jacob (Department of Chemistry, Florida State University, Tallahassee) and Karl Dittmer. Unsaturated amino acids. V. Microbiological properties of some halogenated olefinic amino acids. J. Bacteriol. 82:640–647. 1961.—It has been shown previously that several amino acid analogues containing unsaturated linkages were inhibitors of the growth of Escherichia coli and Saccharomyces cerevisiae. This paper reports the results obtained when a series of unsaturated halogen-containing amino acids was examined. The cis isomer of ω-chloroallylglycine showed the greatest toxicity yet found in this series of unsaturated amino acids toward E. coli, whereas the trans-isomer was usually far less toxic. The major effect of cis-ω-chloroallylglycine in E. coli appeared to be to extend the lag phase before the normal rate of growth began. A wide variety of amino acids was capable of partially or completely preventing the toxicity of low levels of these compounds. At higher levels, relatively few amino acids (primarily valine, leucine, and glutamic acid) were effective. In E. coli, cis-ω-chloroallylglycine showed an unusual [Formula: see text] relationship with both glutamic acid and valine over a wide range in concentration. PMID:13911278

  13. Involvement of metabotropic glutamate receptors in taurine release in the adult and developing mouse hippocampus.

    PubMed

    Saransaari, P; Oja, S S

    1999-01-01

    The inhibitory amino acid taurine has been held to function as an osmoregulator and modulator of neural activity, being particularly important in the immature brain. Ionotropic glutamate receptor agonists are known markedly to potentiate taurine release. The effects of different metabotropic glutamate receptor (mGluR) agonists and antagonists on the basal and K(+)-stimulated release of [3H]taurine from hippocampal slices from 3-month-old (adult) and 7-day-old mice were now investigated using a superfusion system. Of group I metabotropic glutamate receptor agonists, quisqualate potentiated basal taurine release in both age groups, more markedly in the immature hippocampus. This action was not antagonized by the specific antagonists of group I but by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 6-nitro-7-sulphamoylbenzo[f]quinoxaline-2,3-dione (NBQX), which would suggest an involvement of ionotropic glutamate receptors. (S)-3,5-dihydroxyphenylglycine (DHPG) potentiated the basal release by a receptor-mediated mechanism in the immature hippocampus. The group II agonist (2S, 2'R, 3'R)-2-(2',3'-dicarboxycyclopropyl)glycine (DCG IV) markedly potentiated basal taurine release at both ages. These effects were antagonized by dizocilpine, indicating again the participation of ionotropic receptors. Group III agonists slightly potentiated basal taurine release, as did several antagonists of the three metabotropic receptor groups. Potassium-stimulated (50 mM K+) taurine release was generally significantly reduced by mGluR agents, mainly by group I and II compounds. This may be harmful to neurons in hyperexcitatory states. On the other hand, the potentiation by mGluRs of basal taurine release, particularly in the immature hippocampus, together with the earlier demonstrated pronounced enhancement by activation of ionotropic glutamate receptors, may protect neurons against excitotoxicity.

  14. Chlorine transfer between glycine, taurine, and histamine: reaction rates and impact on cellular reactivity.

    PubMed

    Peskin, Alexander V; Midwinter, Robyn G; Harwood, David T; Winterbourn, Christine C

    2005-02-01

    Hypochlorous acid formed by activated neutrophils reacts with amines to produce chloramines. Chloramines vary in stability, reactivity, and cell permeability. We have examined whether chloramine exchange occurs between physiologically important amines or amino acids and if this affects interactions of chloramines with cells. We have demonstrated transchlorination reactions between histamine, glycine, and taurine chloramines by measuring chloramine decay rates with mixtures as well as by mass spectrometry. Kinetic analysis suggested the formation of an intermediate complex with a high Km. Apparent second-order rate constants, determined for concentrations taurine, Gly-Cl and histamine, histamine chloramine and glycine, and taurine chloramine (Tau-Cl) and glycine, respectively. Thus with 10 mM amine concentrations, half-lives for chloramine exchange are of the order of a few minutes. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity in cells was measured as an indicator of permeability of the chloramines. When endothelial or Jurkat cells were treated in Hanks' buffer, Gly-Cl inhibited GAPDH, whereas Tau-Cl, which does not penetrate the cells, did not. Adding glycine to Tau-Cl brought about inhibition, whereas taurine mitigated the effect of Gly-Cl. For cells in full medium, high chloramine concentrations were needed to inhibit GAPDH because of scavenging by methionine and other constituents. In methionine-free medium, chlorine exchange resulted in GAPDH inhibition by Tau-Cl, whereas Gly-Cl was less effective than in Hanks' buffer. Thus interchange between chloramines occurs readily and modulates their cellular effects.

  15. Chlorine transfer between glycine, taurine, and histamine: reaction rates and impact on cellular reactivity.

    PubMed

    Peskin, Alexander V; Midwinter, Robyn G; Harwood, David T; Winterbourn, Christine C

    2004-11-15

    Hypochlorous acid formed by activated neutrophils reacts with amines to produce chloramines. Chloramines vary in stability, reactivity, and cell permeability. We have examined whether chloramine exchange occurs between physiologically important amines or amino acids and if this affects interactions of chloramines with cells. We have demonstrated transchlorination reactions between histamine, glycine, and taurine chloramines by measuring chloramine decay rates with mixtures as well as by mass spectrometry. Kinetic analysis suggested the formation of an intermediate complex with a high K(m). Apparent second-order rate constants, determined for concentrations taurine, Gly-Cl and histamine, histamine chloramine and glycine, and taurine chloramine (Tau-Cl) and glycine, respectively. Thus with 10 mM amine concentrations, half-lives for chloramine exchange are on the order of a few minutes. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity in cells was measured as an indicator of permeability of the chloramines. When endothelial or Jurkat cells were treated in Hanks' buffer, Gly-Cl inhibited GAPDH, whereas Tau-Cl, which does not penetrate the cells, did not. Adding glycine to Tau-Cl brought about inhibition, whereas taurine mitigated the effect of Gly-Cl. For cells in full medium, high chloramine concentrations were needed to inhibit GAPDH because of scavenging by methionine and other constituents. In methionine-free medium, chlorine exchange resulted in GAPDH inhibition by Tau-Cl, whereas Gly-Cl was less effective than in Hanks' buffer. Thus interchange between chloramines occurs readily and modulates their cellular effects.

  16. Downregulation of hepatic betaine:homocysteine methyltransferase (BHMT) expression in taurine-deficient mice is reversed by taurine supplementation in vivo

    PubMed Central

    Jurkowska, Halina; Niewiadomski, Julie; Hirschberger, Lawrence L.; Roman, Heather B.; Mazor, Kevin M.; Liu, Xiaojing; Locasale, Jason W.; Park, Eunkyue

    2016-01-01

    The cysteine dioxygenase (Cdo1)-null and the cysteine sulfinic acid decarboxylase (Csad)-null mouse are not able to synthesize hypotaurine/taurine by the cysteine/cysteine sulfinate pathway and have very low tissue taurine levels. These mice provide excellent models for studying the effects of taurine on biological processes. Using these mouse models, we identified betaine:homocysteine methyltransferase (BHMT) as a protein whose in vivo expression is robustly regulated by taurine. BHMT levels are low in liver of both Cdo1-null and Csad-null mice, but are restored to wild-type levels by dietary taurine supplementation. A lack of BHMT activity was indicated by an increase in the hepatic betaine level. In contrast to observations in liver of Cdo1-null and Csad-null mice, BHMT was not affected by taurine supplementation of primary hepatocytes from these mice. Likewise, CSAD abundance was not affected by taurine supplementation of primary hepatocytes, although it was robustly upregulated in liver of Cdo1-null and Csad-null mice and lowered to wild-type levels by dietary taurine supplementation. The mechanism by which taurine status affects hepatic CSAD and BHMT expression appears to be complex and to require factors outside of hepatocytes. Within the liver, mRNA abundance for both CSAD and BHMT was upregulated in parallel with protein levels, indicating regulation of BHMT and CSAD mRNA synthesis or degradation. PMID:26481005

  17. Behavioral correlates of cerebrospinal fluid amino acid and biogenic amine neurotransmitter alterations in dementia.

    PubMed

    Vermeiren, Yannick; Le Bastard, Nathalie; Van Hemelrijck, An; Drinkenburg, Wilhelmus H; Engelborghs, Sebastiaan; De Deyn, Peter P

    2013-09-01

    Behavioral and psychological signs and symptoms of dementia (BPSD) are a heterogeneous group of behavioral and psychiatric disturbances occurring in dementia patients of any etiology. Research suggests that altered activities of dopaminergic, serotonergic, (nor)adrenergic, as well as amino acid neurotransmitter systems play a role in the etiopathogenesis of BPSD. In this study we attempted to identify cerebrospinal fluid (CSF) neurochemical correlates of BPSD to provide further insight into its underlying neurochemical pathophysiological mechanisms. Patients with probable Alzheimer's disease (AD; n = 202), probable AD with cerebrovascular disease (n = 37), probable frontotemporal dementia (FTD; n = 32), and probable dementia with Lewy bodies (DLB; n = 26) underwent behavioral assessment and lumbar puncture. CSF levels of six amino acids and several biogenic amines and metabolites were analyzed using ultraperformance liquid chromatography with fluorescence detection and reversed-phase high-performance liquid chromatography with fluorescence detection. In the AD patients, CSF homovanillic acid/5-hydroxyindoleacetic acid (HVA/5HIAA) ratios correlated positively with anxieties/phobias, whereas CSF levels of taurine correlated negatively with depression and behavioral disturbances in general. In FTD patients, CSF levels of glutamate correlated negatively with verbally agitated behavior. In DLB patients, CSF levels of HVA correlated negatively with hallucinations. Several neurotransmitter systems can be linked to one specific behavioral syndrome depending on the dementia subtype. In addition to biogenic amines and metabolites, amino acids seem to play a major role in the neurochemical etiology of BPSD as well. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  18. Microbial degradation of poly(amino acid)s.

    PubMed

    Obst, Martin; Steinbüchel, Alexander

    2004-01-01

    Natural poly(amino acid)s are a group of poly(ionic) molecules (ionomers) with various biological functions and putative technical applications and play, therefore, an important role both in nature and in human life. Because of their biocompatibility and their synthesis from renewable resources, poly(amino acid)s may be employed for many different purposes covering a broad spectrum of medical, pharmaceutical, and personal care applications as well as the domains of agriculture and of environmental applications. Biodegradability is one important advantage of naturally occurring poly(amino acid)s over many synthetic polymers. The intention of this review is to give an overview about the enzyme systems catalyzing the initial steps in poly(amino acid) degradation. The focus is on the naturally occurring poly(amino acid)s cyanophycin, poly(epsilon-L-lysine) and poly(gamma-glutamic acid); but biodegradation of structurally related synthetic polyamides such as poly(aspartic acid) and nylons, which are known from various technical applications, is also included.

  19. Food Overconsumption in Healthy Adults Triggers Early and Sustained Increases in Serum Branched-Chain Amino Acids and Changes in Cysteine Linked to Fat Gain.

    PubMed

    Elshorbagy, Amany K; Samocha-Bonet, Dorit; Jernerén, Fredrik; Turner, Cheryl; Refsum, Helga; Heilbronn, Leonie K

    2018-06-13

    Plasma concentrations of branched-chain amino acids (BCAAs) and the sulfur-containing amino acid cysteine are associated with obesity and insulin resistance. BCAAs predict future diabetes. We investigated amino acid changes during food overconsumption. Forty healthy men and women with a body mass index (mean ± SEM) of 25.6 ± 0.6 were overfed by 1250 kcal/d for 28 d, increasing consumption of all macronutrients. Insulin sensitivity and body composition were assessed at baseline (day 0) and day 28. Fasting serum amino acids were measured at days 0, 3, and 28. Linear mixed-effects models evaluated the effect of time in the total group and separately in those with low and high body fat gain (below compared with at or above median fat gain, 1.95 kg). At days 0 and 28, insulin-induced suppression of serum amino acids during a hyperinsulinemic-euglycemic clamp test and, in a subset (n = 20), adipose tissue mRNA expression of selected amino acid metabolizing enzymes were assessed. Weight increased by 2.8 kg. High fat gainers gained 2.6 kg fat mass compared with 1.1 kg in low fat gainers. Valine and isoleucine increased at day 3 (+17% and +22%, respectively; P ≤ 0.002) and remained elevated at day 28, despite a decline in valine (P = 0.019) from day 3 values. Methionine, cystathionine, and taurine were unaffected. Serum total cysteine (tCys) transiently increased at day 3 (+11%; P = 0.022) only in high fat gainers (P-interaction = 0.043), in whom the cysteine catabolic enzyme cysteine dioxygenase (CDO1) was induced (+26%; P = 0.025) in adipose tissue (P-interaction = 0.045). Overconsumption did not alter adipose tissue mRNA expression of the BCAA-metabolizing enzymes branched-chain keto acid dehydrogenase E1α polypeptide (BCKDHA) or branched-chain amino transferase 1 (BCAT1). In the total population at day 0, insulin infusion decreased all serum amino acids (-11% to -47%; P < 0.01), except for homocysteine and tCys, which were unchanged, and

  20. Fmoc/Trt-amino acids: comparison to Fmoc/tBu-amino acids in peptide synthesis.

    PubMed

    Barlos, K; Gatos, D; Koutsogianni, S

    1998-03-01

    Model peptides containing the nucleophilic amino acids Trp and Met have been synthesized with the application of Fmoc/Trt- and Fmoc/tBu-amino acids, for comparison. The deprotection of the peptides synthesized using Fmoc/Trt-amino acids in all cases leads to crude peptides of higher purity than that of the same peptides synthesized using Fmoc/tBu-amino acids.

  1. Levels of inflammation and oxidative stress, and a role for taurine in dystropathology of the Golden Retriever Muscular Dystrophy dog model for Duchenne Muscular Dystrophy.

    PubMed

    Terrill, Jessica R; Duong, Marisa N; Turner, Rufus; Le Guiner, Caroline; Boyatzis, Amber; Kettle, Anthony J; Grounds, Miranda D; Arthur, Peter G

    2016-10-01

    Duchenne Muscular Dystrophy (DMD) is a fatal skeletal muscle wasting disease presenting with excessive myofibre necrosis and increased inflammation and oxidative stress. In the mdx mouse model of DMD, homeostasis of the amino acid taurine is altered, and taurine administration drastically decreases muscle necrosis, dystropathology, inflammation and protein thiol oxidation. Since the severe pathology of the Golden Retriever Muscular Dystrophy (GRMD) dog model more closely resembles the human DMD condition, we aimed to assess the generation of oxidants by inflammatory cells and taurine metabolism in this species. In muscles of 8 month GRMD dogs there was an increase in the content of neutrophils and macrophages, and an associated increase in elevated myeloperoxidase, a protein secreted by neutrophils that catalyses production of the highly reactive hypochlorous acid (HOCl). There was also increased chlorination of tyrosines, a marker of HOCl generation, increased thiol oxidation of many proteins and irreversible oxidative protein damage. Taurine, which functions as an antioxidant by trapping HOCl, was reduced in GRMD plasma; however taurine was increased in GRMD muscle tissue, potentially due to increased muscle taurine transport and synthesis. These data indicate a role for HOCl generated by neutrophils in the severe dystropathology of GRMD dogs, which may be exacerbated by decreased availability of taurine in the blood. These novel data support continued research into the precise roles of oxidative stress and taurine in DMD and emphasise the value of the GRMD dogs as a suitable pre-clinical model for testing taurine as a therapeutic intervention for DMD boys. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Conversion of taurine into N-chlorotaurine (taurine chloramine) and sulphoacetaldehyde in response to oxidative stress.

    PubMed

    Cunningham, C; Tipton, K F; Dixon, H B

    1998-03-01

    N-Chlorotaurine (taurine chloramine), formed by treating taurine with hypochlorous acid, was shown to decompose to sulphoacetaldehyde with a first-order rate constant of 9.9+/-0.5 x 10(-4).h-1 at 37 degrees C in 0.1 M phosphate buffer, pH 7.4. Rat liver homogenates accelerated this decay in a process that was proportional to tissue-protein concentration and saturable, with maximum velocity (Vmax) and Km values of 0.28+/-0.01 nmol/min per mg of protein and 37+/-9 microM respectively. This activity was found to be lost on heat denaturation, but retained after dialysis. There was no detectable formation of sulphoacetaldehyde when taurine itself was incubated with the tissue homogenates under the same conditions. Activation of human neutrophils (1.67 x 10(6) cells/ml) with latex beads resulted in a respiratory burst of oxygen-radical production, the products of which were partially sequestered by 12.5 mM taurine. Under these conditions sulphoacetaldehyde was generated at a constant rate of 637+/-18 pmol/h per ml for over 7 h. A non-activated neutrophil suspension contained constant levels of 1.42+/-0.02 nmol/ml sulphoacetaldehyde, as did activated cells incubated in the absence of taurine, a basal level which may indicate a steady turnover of taurine in these cells. Such formation of chlorotaurine and its decay to the aldehyde may be the first steps in the metabolism of taurine to isethionate (2-hydroxyethanesulphonate) that has been demonstrated by various authors to occur in vivo.

  3. Taurine elevates dopamine levels in the rat nucleus accumbens; antagonism by strychnine.

    PubMed

    Ericson, Mia; Molander, Anna; Stomberg, Rosita; Söderpalm, Bo

    2006-06-01

    The mesolimbic dopamine (DA) system, projecting from the ventral tegmental area (VTA) to the nucleus accumbens (nAcc), is involved in reward-related behaviours and addictive processes, such as alcoholism and drug addiction. It was recently suggested that strychnine-sensitive glycine receptors (GlyR) in the nAcc regulate both basal and ethanol-induced mesolimbic DA activity via a neuronal loop involving endogenous activation of nicotinic acetylcholine receptors (nAChR) in the VTA. However, as the nAcc appears to contain few glycine-immunoreactive cell bodies or fibres, the question as to what may be the endogenous ligand for GlyRs in this brain region remains open. Here we have investigated whether the amino acid taurine could serve this purpose using in vivo microdialysis in awake, freely moving male Wistar rats. Local perfusion of taurine (1, 10 or 100 mm in the perfusate) increased DA levels in the nAcc. The taurine (10 mm)-induced DA increase was, similarly to that previously observed after ethanol, completely blocked by (i) perfusion of the competitive GlyR antagonist strychnine in the nAcc, (ii) perfusion of the nAChR antagonist mecamylamine (100 microm) in the VTA, and (iii) systemic administration of the acetylcholine-depleting drug vesamicol (0.4 mg/kg, i.p). The present results suggest that taurine may be an endogenous ligand for GlyRs in the nAcc and that the taurine-induced elevation of DA levels in this area, similarly to that observed after local ethanol, is mediated via a neuronal loop involving endogenous activation of nAChRs in the VTA.

  4. α-Amino Acid-Isosteric α-Amino Tetrazoles

    PubMed Central

    Zhao, Ting; Kurpiewska, Katarzyna; Kalinowska-Tłuścik, Justyna; Herdtweck, Eberhardt

    2016-01-01

    The synthesis of all 20 common natural proteinogenic and 4 otherα-amino acid-isosteric α-amino tetrazoles has been accomplished, whereby the carboxyl group is replaced by the isosteric 5-tetrazolyl group. The short process involves the use of the key Ugi tetrazole reaction followed by deprotection chemistries. The tetrazole group is bioisosteric to the carboxylic acid and is widely used in medicinal chemistry and drug design. Surprisingly, several of the common α-amino acid-isosteric α-amino tetrazoles are unknown up to now. Therefore a rapid synthetic access to this compound class and non-natural derivatives is of high interest to advance the field. PMID:26817531

  5. New Enzymatic Method of Chiral Amino Acid Synthesis by Dynamic Kinetic Resolution of Amino Acid Amides: Use of Stereoselective Amino Acid Amidases in the Presence of α-Amino-ɛ-Caprolactam Racemase▿

    PubMed Central

    Yamaguchi, Shigenori; Komeda, Hidenobu; Asano, Yasuhisa

    2007-01-01

    d- and l-amino acids were produced from l- and d-amino acid amides by d-aminopeptidase from Ochrobactrum anthropi C1-38 and l-amino acid amidase from Pseudomonas azotoformans IAM 1603, respectively, in the presence of α-amino-ɛ-caprolactam racemase from Achromobacter obae as the catalyst by dynamic kinetic resolution of amino acid amides. PMID:17586677

  6. Anharmonicity in Amino Acids

    NASA Astrophysics Data System (ADS)

    Martinho, Herculano; Lima, Thamires; Ishikawa, Mariana

    2012-02-01

    Two special dynamical transitions of universal character have been recently observed in macromolecules (lysozyme, myoglobin, bacteriorhodopsin, DNA, and RNA) at T^*˜100 - 150 K and TD˜180 - 220 K. The underlying mechanisms governing these transitions have been subject of debate. In the present work it is reported a survey on the temperature dependence of structural, vibrational and thermodynamical properties of a nearly anhydrous amino acid (orthorhombic polymorph of the amino acids L-cysteine and L-proline at a hydration level of 3.5%). The temperature dependence of X-Ray diffraction, Raman spectroscopy, and specific heat were considered. The data were analyzed considering amino acid-amino acid, amino acid-water, and water-water phonon-phonon interactions, and molecular rotors activation. Our results indicated that the two referred temperatures define the triggering of very simple and specific events that govern all the interactions of the biomolecule: activation of CH2 rigid rotors (Tamino acid and water dimer vibrational modes (T^*TD).

  7. Effect of Buyang Huanwu decoction on amino acid content in cerebrospinal fluid of rats during ischemic/reperfusion injury.

    PubMed

    Wang, Lisheng; Huang, Yuwei; Wu, Junhong; Lv, Gengbin; Zhou, Liling; Jia, Jie

    2013-12-01

    The inhibitory effect of Buyang Huanwu decoction (BYHWD) on ischemic injury has been proven, but it is not clear how amino acid levels in cerebrospinal fluid (CSF) are associated with BYHWD treatment, nor the mechanism by which BYHWD protects the brain from ischemia/reperfusion injury. We investigated the effect of BYHWD on the amino acid content of CSF in rats during ischemia-reperfusion injury. Ischemia was imposed by right middle cerebral artery occlusion (MCAO). CSF was continuously collected from the striatum via brain microdialysis before and after ischemia/reperfusion. We used on-line derivatization combined with high-performance liquid chromatography with fluorescence detection (HPLC-FD) to determine levels of glutamate (Glu), aspartate (Asp), glycine (Gly), taurine (Tau), and γ-aminobutyric acid (GABA) in CSF. The MCAO model displayed an infarct lesion in the ipsilateral hemisphere and nerve injuries, as the left upper limb was unable to extend and turn leftward. Significant increases in excitatory and inhibitory amino acids were observed in the CSF of the ischemic rats relative to the sham-operated group (P<0.01). Treatment with BYHWD reduced the areas of cerebral infarction and improved the neurological behavior scores of rats after MCAO. BYHWD treatment was also associated with a significant decrease in excitatory amino acids and increase in inhibitory amino acids in the CSF. Only the higher dose of BYHWD (20mg/kg) affected all these levels significantly. Attenuated excitatory toxicity and reduced areas of cerebral infarction associated with BYHWD treatment might be due to a protective mechanism induced by BYHWD against ischemia/reperfusion injury. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Effect of ligustrazine on levels of amino acid neurotransmitters in rat striatum after cerebral ischemia-reperfusion injury.

    PubMed

    Han, Jin; Wan, Hai-Tong; Yang, Jie-Hong; Zhang, Yu-Yan; Ge, Li-Jun; Bie, Xiao-Dong

    2014-01-01

    This study aimed to evaluate the effect of ligustrazine on levels of amino acid transmitters in the extracellular fluid of striatum following cerebral ischemia/reperfusion (I/R) in male Sprague-Dawley rats. A microdialysis cannula guide was implanted into the right striatum. After recovery, animals underwent a sham operation or middle cerebral artery occlusion (MCAO). Those that developed cerebral ischemia after MCAO were randomized to receive propylene glycol salt water and ligustrazine respectively. Striatal fluid samples were collected from all animals at 15-min intervals after treatment and were subjected to HPLC analysis of aspartic acid, glutamic acid, taurine, and γ-amino butyric acid. Upon the last sample collection, animals were sacrificed and brain tissue specimens were collected for triphenyltetrazolium chloride staining and NeuN staining. Compared with the sham operation, MCAO induced significant neurological deficits and increased striatal concentrations of the four neurotransmitters assessed in a time-dependent manner (P < 0.01). Ligustrazine effectively attenuated the detrimental effects of MCAO on the brain. These observations suggest that ligustrazine as a novel cerebral infarction-protective agent may have potential clinical implications for I/R-related brain damage.

  9. Amino acid ionic liquids.

    PubMed

    Ohno, Hiroyuki; Fukumoto, Kenta

    2007-11-01

    The preparation of ionic liquids derived from amino acids, and their properties, are outlined. Since amino acids have both a carboxylic acid residue and an amino group in a single molecule, they can be used as either anions or cations. These groups are also useful in their ability to introduce functional group(s). Twenty different natural amino acids were used as anions, to couple with the 1-ethyl-3-methylimidazolium cation. The salts obtained were all liquid at room temperature. The properties of the resulting ionic liquids (AAILs) depend on the side groups of the amino acids involved. These AAILs, composed of an amino acid with some functional groups such as a hydrogen bonding group, a charged group, or an aromatic ring, had an increased glass transition (or melting) temperature and/or higher viscosity as a result of additional interactions among the ions. Viscosity is reduced and the decomposition temperature of imidazolium-type salts is improved by using the tetrabutylphosphonium cation. The chirality of AAILs was maintained even upon heating to 150 degrees C after acetylation of the free amino group. The amino group was also modified to introduce a strong acid group so as to form hydrophobic and chiral ionic liquids. Unique phase behavior of the resulting hydrophobic ionic liquids and water mixture is found; the mixture is clearly phase separated at room temperature, but the solubility of water in this IL increases upon cooling, to give a homogeneous solution. This phase change is reversible, and separation occurs again by raising the temperature a few degrees. It is extraordinary for an IL/water mixture to display such behavior with a lower critical solution temperature. Some likely applications are proposed for these amino acid derived ionic liquids.

  10. β-Alanine and taurine as endogenous agonists at glycine receptors in rat hippocampus in vitro

    PubMed Central

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

    2002-01-01

    Electrophysiological and pharmacological properties of glycine receptors were characterized in hippocampal organotypic slice cultures. In the presence of ionotropic glutamate and GABAB receptor antagonists, pressure-application of glycine onto CA3 pyramidal cells induced a current associated with increased chloride conductance, which was inhibited by strychnine. Similar chloride currents could also be induced with β-alanine or taurine. Whole-cell glycine responses were significantly greater in CA3 pyramidal cells than in CA1 pyramidal cells and dentate granule cells, while responses to GABA were similar among these three cell types. Although these results demonstrate the presence of functional glycine receptors in the hippocampus, no evidence for their activation during synaptic stimulation was found. Gabazine, a selective GABAA receptor antagonist, totally blocked evoked IPSCs in CA3 pyramidal cells. Glycine receptor activation is not dependent on transporter-controlled levels of extracellular glycine, as no chloride current was observed in response to sarcosine, an inhibitor of glycine transporters. In contrast, application of guanidinoethanesulfonic acid, an uptake inhibitor of β-alanine and taurine, induced strychnine-sensitive chloride current in the presence of gabazine. These data indicate that modulation of transporters for the endogenous amino acids, β-alanine and taurine, can regulate tonic activation of glycine receptors, which may function in maintenance of inhibitory tone in the hippocampus. PMID:11850512

  11. Taurine chloramine: a possible oxidant reservoir.

    PubMed

    Ogino, Tetsuya; Than, Tin Aung; Hosako, Mutsumi; Ozaki, Michitaka; Omori, Masako; Okada, Shigeru

    2009-01-01

    Taurine is abundant in polymorphonuclear leukocytes (PMNs) where it reacts with PMN-derived hypochlorous acid to form taurine chloramine (Tau-NHCl), a substance that does not readily cross the cell membrane. When PMNs were stimulated in PBS lacking taurine, extracellular oxidant concentration was low, but the concentration increased 3-4 fold when 15 mM taurine was added, indicating that taurine lowers oxidant levels inside the cell. When Tau-NHCl was added to Jurkat cells in suspension, its half life was about 75 min. In contrast, membrane-permeable ammonia mono-chloramine (NH2Cl) has a half life of only 6 min. Accordingly, NH2Cl oxidizes cytosolic proteins, such as IkappaB, and inhibits NF-kappaB activation, whereas Tau-NHCl exhibits no comparable effect. However, when NH4+ was added to the medium, Tau-NHCl oxidizes IkappaB and inhibits NF-kappaB activation, probably through oxidant transfer to NH4+ leading to NH2Cl formation. These results indicate that Tau-NHCl can serve as an oxidant reservoir, exhibiting either delayed oxidant effects or acting as an oxidant at a distant site.

  12. Dietary supplementation with an amino acid blend enhances intestinal function in piglets.

    PubMed

    Yi, Dan; Li, Baocheng; Hou, Yongqing; Wang, Lei; Zhao, Di; Chen, Hongbo; Wu, Tao; Zhou, Ying; Ding, Binying; Wu, Guoyao

    2018-05-16

    The traditionally classified nutritionally non-essential amino acids are now known to be insufficiently synthesized for maximal growth and optimal health in piglets. This study determined the effects of dietary supplementation with an amino acid blend (AAB; glutamate:glutamine:glycine:arginine:N-acetylcysteine = 5:2:2:1:0.5) on piglet growth performance and intestinal functions. Sixteen piglets (24-day-old) were randomly assigned to a corn and soybean meal-based diet supplemented with 0.99% alanine (isonitrogenous control) or 1% AAB. On day 20 of the trial, blood and intestinal tissue samples were obtained from piglets. Compared with the control, AAB supplementation reduced (P < 0.05) diarrhoea incidence; plasma alanine aminotransferase and diamine oxidase activities; intestinal concentrations of hydrogen peroxide, malondialdehyde, and heat shock protein-70, and intestinal mRNA levels for interleukin-1β, interferon-γ, and chemokine (C-X-C motif) ligand-9; and the numbers of Enterobacterium family, Enterococcus genus and Clostridium coccoides in the colon digesta. Furthermore, AAB supplementation enhanced (P < 0.05): the plasma concentrations of serine, aspartate, glutamate, cysteine, tyrosine, phenylalanine, tryptophan, lysine, arginine, citrulline, ornithine, taurine, and γ-aminobutyric acid; intestinal villus height and surface area, villus height/crypt depth ratio, antioxidative enzyme activities, and mRNA levels for porcine β-defensin-1, sodium-independent amino acid transporters (b 0,+ AT and y + LAT1), aquaporin (AQP) 3, AQP8, AQP10, nuclear factor erythroid 2-related factor 2 and glutathione S-transferase omega-2, and protein abundances of AQP3, AQP4, claudin-1, occludin and myxovirus resistance 1; and the numbers of Bifidobacterium genus and Lactobacillus genus in the colon digesta. Collectively, these comprehensive results indicate that dietary AAB supplementation plays an important role in improving piglet growth and intestinal function.

  13. Effect of three different intensities of infrared laser energy on the levels of amino acid neurotransmitters in the cortex and hippocampus of rat brain.

    PubMed

    Ahmed, Nawal Abd El Hay; Radwan, Nasr Mahmoud; Ibrahim, Khayria Mansour; Khedr, Mona Emam; El Aziz, Mona A; Khadrawy, Yasser Ashry

    2008-10-01

    The aim of this study is to investigate the effects of three different intensities of infrared diode laser radiation on amino acid neurotransmitters in the cortex and hippocampus of rat brain. Lasers are known to induce different neurological effects such as pain relief, anesthesia, and neurosuppressive effects; however, the precise mechanisms of these effects are not clearly elucidated. Amino acid neurotransmitters (glutamate, aspartate, glutamine, gamma-aminobutyric acid [GABA], glycine, and taurine) play vital roles in the central nervous system (CNS). The shaved scalp of each rat was exposed to different intensities of infrared laser energy (500, 190, and 90 mW) and then the rats were sacrificed after 1 h, 7 d, and 14 d of daily laser irradiation. The control groups were exposed to the same conditions but without exposure to laser. The concentrations of amino acid neurotransmitters were measured by high-performance liquid chromatography (HPLC). The rats subjected to 500 mW of laser irradiation had a significant decrease in glutamate, aspartate, and taurine in the cortex, and a significant decrease in hippocampal GABA. In the cortices of rats exposed to 190 mW of laser irradiation, an increase in aspartate accompanied by a decrease in glutamine were observed. In the hippocampus, other changes were seen. The rats irradiated with 90 mW showed a decrease in cortical glutamate, aspartate, and glutamine, and an increase in glycine, while in the hippocampus an increase in glutamate, aspartate, and GABA were recorded. We conclude that daily laser irradiation at 90 mW produced the most pronounced inhibitory effect in the cortex after 7 d. This finding may explain the reported neurosuppressive effect of infrared laser energy on axonal conduction of hippocampal and cortical tissues of rat brain.

  14. Whole body creatine and protein kinetics in healthy men and women: effects of creatine and amino acid supplementation.

    PubMed

    Kalhan, Satish C; Gruca, Lourdes; Marczewski, Susan; Bennett, Carole; Kummitha, China

    2016-03-01

    Creatine kinetics were measured in young healthy subjects, eight males and seven females, age 20-30 years, after an overnight fast on creatine-free diet. Whole body turnover of glycine and its appearance in creatine was quantified using [1-(13)C] glycine and the rate of protein turnover was quantified using L-ring [(2)H5] phenylalanine. The creatine pool size was estimated by the dilution of a bolus [C(2)H3] creatine. Studies were repeated following a five days supplement creatine 21 g.day(-1) and following supplement amino acids 14.3 g day(-1). Creatine caused a ten-fold increase in the plasma concentration of creatine and a 50 % decrease in the concentration of guanidinoacetic acid. Plasma amino acids profile showed a significant decrease in glycine, glutamine, and taurine and a significant increase in citrulline, valine, lysine, and cysteine. There was a significant decrease in the rate of appearance of glycine, suggesting a decrease in de-novo synthesis (p = 0.006). The fractional and absolute rate of synthesis of creatine was significantly decreased by supplemental creatine. Amino acid supplement had no impact on any of the parameters. This is the first detailed analysis of creatine kinetics and the effects of creatine supplement in healthy young men and women. These methods can be applied for the analysis of creatine kinetics in different physiological states.

  15. Amino acid "little Big Bang": representing amino acid substitution matrices as dot products of Euclidian vectors.

    PubMed

    Zimmermann, Karel; Gibrat, Jean-François

    2010-01-04

    Sequence comparisons make use of a one-letter representation for amino acids, the necessary quantitative information being supplied by the substitution matrices. This paper deals with the problem of finding a representation that provides a comprehensive description of amino acid intrinsic properties consistent with the substitution matrices. We present a Euclidian vector representation of the amino acids, obtained by the singular value decomposition of the substitution matrices. The substitution matrix entries correspond to the dot product of amino acid vectors. We apply this vector encoding to the study of the relative importance of various amino acid physicochemical properties upon the substitution matrices. We also characterize and compare the PAM and BLOSUM series substitution matrices. This vector encoding introduces a Euclidian metric in the amino acid space, consistent with substitution matrices. Such a numerical description of the amino acid is useful when intrinsic properties of amino acids are necessary, for instance, building sequence profiles or finding consensus sequences, using machine learning algorithms such as Support Vector Machine and Neural Networks algorithms.

  16. Amino Acids and Chirality

    NASA Technical Reports Server (NTRS)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

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

    NASA Technical Reports Server (NTRS)

    Shapshak, P.; Okaji, M.

    1972-01-01

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

  18. Variation in plasma amino acid concentrations during a cycling competition.

    PubMed

    Medelli, J; Lounana, J; Hill, D

    2003-06-01

    The variations in plasma concentrations of 24 amino acids (AAs) were measured, taking into account modifications in plasma volume, in 7 male subjects, professional cyclists, during the first 2 stages (EI and EII) of the competition "4 Days of Dunkirk 1999". Blood samples were taken before the start and at the end of each stage. At the end of EI a significant reduction (p<0.02) in alpha-aminobutyric acid was observed (-38%) and a significant increase (Wilcoxon 0.01taurine (+33%) and tyrosine (+42%). Alanine in particular, and also the ramified AAs, remained relatively stable at this stage. At the end vs start of EII there was a significant reduction in several AAs, alpha-aminobutyric acid (33%), arginine (-21%), cystine (-15%), glycocholic acid (26%), hydroxyproline (-28%), leucine (-17%), lysine (-26%), methionine (-19%), threonine (-15%) and valine (-16%). The recovery period was characterised by increases in previously reduced AAs and vice versa. These results show that cellular use of plasma AAs in the endurance cyclist could differ between the first hours of competition and the subsequent stages, possibly in relation to the gradual increase in stress level as the stages progress; they also suggest that appropriate consideration should be given to the quality of protein inputs in the nutrition of cyclists involved in a high-level stage competition.

  19. The protective effects of taurine on acute ammonia toxicity in grass carp Ctenopharynodon idellus.

    PubMed

    Xing, Xiaodan; Li, Ming; Yuan, Lixia; Song, Meize; Ren, Qianyan; Shi, Ge; Meng, Fanxing; Wang, Rixin

    2016-09-01

    The four experimental groups were carried out to test the response of grass carp Ctenopharyngodon idella to ammonia toxicity and taurine: group 1 was injected with NaCl, group 2 was injected with ammonium acetate, group 3 was injected with ammonium acetate and taurine, and group 4 was injected taurine. Fish in group 2 had the highest ammonia content in the liver and brain, and alanine, arginine, glutamine, glutamate and glycine contents in liver. Brain alanine and glutamate of fish in group 2 were significantly higher than those of fish in group 1. Malondialdehyde content of fish in group 2 was the highest, but superoxide dismutase and glutathione activities were the lowest. Although fish in group 2 had the lowest red cell count and hemoglobin, the highest alkaline phosphatase, complement C3, C4 and total immunoglobulin contents appeared in this group. In addition, superoxide dismutase and glutathione activities, red cell count and hemoglobin of fish in group 3 were significantly higher than those of fish in group 2, but malondialdehyde content is the opposite. This study indicates that ammonia exerts its toxic effects by interfering with amino acid transport, inducing reactive oxygen species generation and malondialdehyde accumulation, leading to blood deterioration and over-activation of immune response. The exogenous taurine could mitigate the adverse effect of high ammonia level on fish physiological disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Amino Acid Concentrations in the Hamster Central Auditory System and Long-Term Effects of Intense Tone Exposure

    PubMed Central

    Godfrey, Donald A.; Kaltenbach, James A.; Chen, Kejian; Ilyas, Omer; Liu, Xiaochen; Licari, Frank; Sacks, Justin; McKnight, Darwin

    2015-01-01

    Exposure to intense sounds often leads to loss of hearing of environmental sounds and hearing of a monotonous tonal sound not actually present, a condition known as tinnitus. Chronic physiological effects of exposure to intense tones have been reported for animals and should be accompanied by chemical changes present at long times after the intense sound exposure. By using a microdissection mapping procedure combined with high-performance liquid chromatography (HPLC), we have measured concentrations of nine amino acids, including those used as neurotransmitters, in the cochlear nucleus, inferior colliculus, medial geniculate, and auditory cortex of hamsters 5 months after exposure to an intense tone, compared with control hamsters of the same age. No very large differences in amino acid concentrations were found between exposed and control hamsters. However, increases of glutamate and γ-aminobutyrate (GABA) in some parts of the inferior colliculus of exposed hamsters were statistically significant. The most consistent differences between exposed and control hamsters were higher aspartate and lower taurine concentrations in virtually all regions of exposed hamsters, which reached statistical significance in many cases. Although these amino acids are not considered likely neurotransmitters, they indirectly have roles in excitatory and inhibitory neurotransmission, respectively. Thus, there is evidence for small, widespread, long-term increases in excitatory transmission and decreases in inhibitory transmission after a level of acoustic trauma previously shown to produce hearing loss and tinnitus. PMID:22715056

  1. Permeability of membranes to amino acids and modified amino acids: mechanisms involved in translocation

    NASA Technical Reports Server (NTRS)

    Chakrabarti, A. C.; Deamer, D. W. (Principal Investigator); Miller, S. L. (Principal Investigator)

    1994-01-01

    The amino acid permeability of membranes is of interest because they are one of the key solutes involved in cell function. Membrane permeability coefficients (P) for amino acid classes, including neutral, polar, hydrophobic, and charged species, have been measured and compared using a variety of techniques. Decreasing lipid chain length increased permeability slightly (5-fold), while variations in pH had only minor effects on the permeability coefficients of the amino acids tested in liposomes. Increasing the membrane surface charge increased the permeability of amino acids of the opposite charge, while increasing the cholesterol content decreased membrane permeability. The permeability coefficients for most amino acids tested were surprisingly similar to those previously measured for monovalent cations such as sodium and potassium (approximately 10(-12)-10(-13) cm s-1). This observation suggests that the permeation rates for the neutral, polar and charged amino acids are controlled by bilayer fluctuations and transient defects, rather than partition coefficients and Born energy barriers. Hydrophobic amino acids were 10(2) more permeable than the hydrophilic forms, reflecting their increased partition coefficient values. External pH had dramatic effects on the permeation rates for the modified amino acid lysine methyl ester in response to transmembrane pH gradients. It was established that lysine methyl ester and other modified short peptides permeate rapidly (P = 10(-2) cm s-1) as neutral (deprotonated) molecules. It was also shown that charge distributions dramatically alter permeation rates for modified di-peptides. These results may relate to the movement of peptides through membranes during protein translocation and to the origin of cellular membrane transport on the early Earth.

  2. Pairwise amino acid secondary structural propensities

    NASA Astrophysics Data System (ADS)

    Chemmama, Ilan E.; Chapagain, Prem P.; Gerstman, Bernard S.

    2015-04-01

    We investigate the propensities for amino acids to form a specific secondary structure when they are paired with other amino acids. Our investigations use molecular dynamics (MD) computer simulations, and we compare the results to those from the Protein Data Bank (PDB). Proper comparison requires weighting of the MD results in a manner consistent with the relative frequency of appearance in the PDB of each possible pair of amino acids. We find that the propensity for an amino acid to assume a secondary structure varies dramatically depending on the amino acid that is before or after it in the primary sequence. This cooperative effect means that when selecting amino acids to facilitate the formation of a secondary structure in peptide engineering experiments, the adjacent amino acids must be considered. We also examine the preference for a secondary structure in bacterial proteins and compare the results to those of human proteins.

  3. PCI-GC-MS-MS approach for identification of non-amino organic acid and amino acid profiles.

    PubMed

    Luan, Hemi; Yang, Lin; Ji, Fenfen; Cai, Zongwei

    2017-03-15

    Alkyl chloroformate have been wildly used for the fast derivatization of metabolites with amino and/or carboxyl groups, coupling of powerful separation and detection systems, such as GC-MS, which allows the comprehensive analysis of non-amino organic acids and amino acids. The reagents involving n-alkyl chloroformate and n-alcohol are generally employed for providing symmetric labeling terminal alkyl chain with the same length. Here, we developed an asymmetric labeling strategy and positive chemical ionization gas chromatography-tandem mass spectrometry (PCI-GC-MS-MS) approach for determination of non-amino organic acids and amino acids, as well as the short chain fatty acids. Carboxylic and amino groups could be selectively labelled by propyl and ethyl groups, respectively. The specific neutral loss of C 3 H 8 O (60Da), C 3 H 5 O 2 (74Da) and C 4 H 8 O 2 (88Da) were useful in the selective identification for qualitative analysis of organic acids and amino acid derivatives. PCI-GC-MS-MS using multiple reaction monitoring (MRM) was applied for semi-quantification of typical non-amino organic acids and amino acids. This method exhibited a wide range of linear range, good regression coefficient (R 2 ) and repeatability. The relative standard deviation (RSD) of targeted metabolites showed excellent intra- and inter-day precision (<5%). Our method provided a qualitative and semi-quantitative PCI-GC-MS-MS, coupled with alkyl chloroformate derivatization. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Effect of extender and amino acid supplementation on sperm quality of cooled-preserved Andalusian donkey (Equus asinus) spermatozoa.

    PubMed

    Dorado, J; Acha, D; Ortiz, I; Gálvez, M J; Carrasco, J J; Gómez-Arrones, V; Calero-Carretero, R; Hidalgo, M

    2014-04-01

    The main aim of this study was to evaluate the efficacy of two commercially available liquid stallion semen extenders for the preservation of Andalusian donkey semen at 5°C for up to 72h, and to evaluate the effect of amino acid addition on sperm quality of cooled donkey semen. In addition, this study investigated the effect of seasons on semen characteristics of Andalusian jackasses. Throughout a year, 50 ejaculates were collected from ten adult donkeys and a complete semen evaluation was performed immediately after collection. In Experiment 1, semen samples (n=32) were pooled, divided into two aliquots, and cooled in either Gent(®) A or INRA 96(®). In Experiment 2, pooled semen samples (n=9) were cooled in Gent A(®) supplemented with 0 (as control), 20, 40, or 60mM for each glutamine, proline, or taurine. Fresh semen and chilled samples were assessed for sperm motility, morphology, acrosome integrity, and plasma membrane integrity. Sperm motility variables were greater (P<0.05) in Gent(®) A than in INRA 96(®). The presence of glutamine, proline, or taurine in Gent(®) A improved (P<0.001) the motility of Andalusian donkey spermatozoa. Differences (P<0.05) in some sperm variables were observed among seasons. In conclusion, Gent(®) A maintained sperm motility characteristics after 72h of cold storage to a greater extent than INRA 96(®). Moreover, motility was greater when Gent(®) A supplemented at different concentrations of amino acids than Gent(®) A with no supplementation. An effect of seasons on the semen quality of the Andalusian donkey was demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways.

    PubMed

    Chang, Chun-Yu; Shen, Chao-Yu; Kang, Chao-Kai; Sher, Yuh-Pyng; Sheu, Wayne H-H; Chang, Chia-Che; Lee, Tsung-Han

    2014-09-15

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Dealing with methionine/homocysteine sulfur: cysteine metabolism to taurine and inorganic sulfur

    PubMed Central

    Ueki, Iori

    2010-01-01

    Synthesis of cysteine as a product of the transsulfuration pathway can be viewed as part of methionine or homocysteine degradation, with cysteine being the vehicle for sulfur conversion to end products (sulfate, taurine) that can be excreted in the urine. Transsulfuration is regulated by stimulation of cystathionine β-synthase and inhibition of methylene tetrahydrofolate reductase in response to changes in the level of S-adenosylmethionine, and this promotes homocysteine degradation when methionine availability is high. Cysteine is catabolized by several desulfuration reactions that release sulfur in a reduced oxidation state, generating sulfane sulfur or hydrogen sulfide (H2S), which can be further oxidized to sulfate. Cysteine desulfuration is accomplished by alternate reactions catalyzed by cystathionine β-synthase and cystathionine γ-lyase. Cysteine is also catabolized by pathways that require the initial oxidation of the cysteine thiol by cysteine dioxygenase to form cysteinesulfinate. The oxidative pathway leads to production of taurine and sulfate in a ratio of approximately 2:1. Relative metabolism of cysteine by desulfuration versus oxidative pathways is influenced by cysteine dioxygenase activity, which is low in animals fed low-protein diets and high in animals fed excess sulfur amino acids. Thus, desulfuration reactions dominate when cysteine is deficient, whereas oxidative catabolism dominates when cysteine is in excess. In rats consuming a diet with an adequate level of sulfur amino acids, about two thirds of cysteine catabolism occurs by oxidative pathways and one third by desulfuration pathways. Cysteine dioxygenase is robustly regulated in response to cysteine availability and may function to provide a pathway to siphon cysteine to less toxic metabolites than those produced by cysteine desulfuration reactions. PMID:20162368

  7. Exploring the Lean Phenotype of Glutathione-Depleted Mice: Thiol, Amino Acid and Fatty Acid Profiles

    PubMed Central

    Elshorbagy, Amany K.; Jernerén, Fredrik; Scudamore, Cheryl L.; McMurray, Fiona; Cater, Heather; Hough, Tertius; Cox, Roger; Refsum, Helga

    2016-01-01

    Background Although reduced glutathione (rGSH) is decreased in obese mice and humans, block of GSH synthesis by buthionine sulfoximine (BSO) results in a lean, insulin-sensitive phenotype. Data is lacking about the effect of BSO on GSH precursors, cysteine and glutamate. Plasma total cysteine (tCys) is positively associated with stearoyl-coenzyme A desaturase (SCD) activity and adiposity in humans and animal models. Objective To explore the phenotype, amino acid and fatty acid profiles in BSO-treated mice. Design Male C3H/HeH mice aged 11 weeks were fed a high-fat diet with or without BSO in drinking water (30 mmol/L) for 8 weeks. Amino acid and fatty acid changes were assessed, as well as food consumption, energy expenditure, locomotor activity, body composition and liver vacuolation (steatosis). Results Despite higher food intake, BSO decreased particularly fat mass but also lean mass (both P<0.001), and prevented fatty liver vacuolation. Physical activity increased during the dark phase. BSO decreased plasma free fatty acids and enhanced insulin sensitivity. BSO did not alter liver rGSH, but decreased plasma total GSH (tGSH) and rGSH (by ~70%), and liver tGSH (by 82%). Glutamate accumulated in plasma and liver. Urine excretion of cysteine and its precursors was increased by BSO. tCys, rCys and cystine decreased in plasma (by 23–45%, P<0.001 for all), but were maintained in liver, at the expense of decreased taurine. Free and total plasma concentrations of the SCD products, oleic and palmitoleic acids were decreased (by 27–38%, P <0.001 for all). Conclusion Counterintuitively, block of GSH synthesis decreases circulating tCys, raising the question of whether the BSO-induced obesity-resistance is linked to cysteine depletion. Cysteine-supplementation of BSO-treated mice is warranted to dissect the effects of cysteine and GSH depletion on energy metabolism. PMID:27788147

  8. D-Amino Acids in Living Higher Organisms

    NASA Astrophysics Data System (ADS)

    Fujii, Noriko

    2002-04-01

    The homochirality of biological amino acids (L-amino acids) and of the RNA/DNA backbone (D-ribose) might have become established before the origin of life. It has been considered that D-amino acids and L-sugars were eliminated on the primitive Earth. Therefore, the presence and function of D-amino acids in living organisms have not been studied except for D-amino acids in the cell walls of microorganisms. However, D-amino acids were recently found in various living higher organisms in the form of free amino acids, peptides, and proteins. Free D-aspartate and D-serine are present and may have important physiological functions in mammals. D-amino acids in peptides are well known as opioid peptides and neuropeptides. In protein, D-aspartate residues increase during aging. This review deals with recent advances in the study of D-amino acids in higher organisms.

  9. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, M.M.; Shoup, T.

    1998-09-15

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

  10. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, M.M.; Shoup, T.

    1998-10-06

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

  11. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, Mark M.; Shoup, Timothy

    1998-09-15

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

  12. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, Mark M.; Shoup, Timothy

    1998-10-06

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

  13. Amino acid and acetylcholine chemistry in the central auditory system of young, middle-aged and old rats.

    PubMed

    Godfrey, Donald A; Chen, Kejian; O'Toole, Thomas R; Mustapha, Abdurrahman I A A

    2017-07-01

    Older adults generally experience difficulties with hearing. Age-related changes in the chemistry of central auditory regions, especially the chemistry underlying synaptic transmission between neurons, may be of particular relevance for hearing changes. In this study, we used quantitative microchemical methods to map concentrations of amino acids, including the major neurotransmitters of the brain, in all the major central auditory structures of young (6 months), middle-aged (22 months), and old (33 months old) Fischer 344 x Brown Norway rats. In addition, some amino acid measurements were made for vestibular nuclei, and activities of choline acetyltransferase, the enzyme for acetylcholine synthesis, were mapped in the superior olive and auditory cortex. In old, as compared to young, rats, glutamate concentrations were lower throughout central auditory regions. Aspartate and glycine concentrations were significantly lower in many and GABA and taurine concentrations in some cochlear nucleus and superior olive regions. Glutamine concentrations and choline acetyltransferase activities were higher in most auditory cortex layers of old rats as compared to young. Where there were differences between young and old rats, amino acid concentrations in middle-aged rats often lay between those in young and old rats, suggesting gradual changes during adult life. The results suggest that hearing deficits in older adults may relate to decreases in excitatory (glutamate) as well as inhibitory (glycine and GABA) neurotransmitter amino acid functions. Chemical changes measured in aged rats often differed from changes measured after manipulations that directly damage the cochlea, suggesting that chemical changes during aging may not all be secondary to cochlear damage. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Enantiomeric excesses in meteoritic amino acids

    NASA Technical Reports Server (NTRS)

    Cronin, J. R.; Pizzarello, S.

    1997-01-01

    Gas chromatographic-mass spectral analyses of the four stereoisomers of 2-amino-2,3-dimethylpentanoic acid (dl-alpha-methylisoleucine and dl-alpha-methylalloisoleucine) obtained from the Murchison meteorite show that the L enantiomer occurs in excess (7.0 and 9.1%, respectively) in both of the enantiomeric pairs. Similar results were obtained for two other alpha-methyl amino acids, isovaline and alpha-methylnorvaline, although the alpha hydrogen analogs of these amino acids, alpha-amino-n-butyric acid and norvaline, were found to be racemates. With the exception of alpha-amino-n-butyric acid, these amino acids are either unknown or of limited occurrence in the biosphere. Because carbonaceous chondrites formed 4.5 billion years ago, the results are indicative of an asymmetric influence on organic chemical evolution before the origin of life.

  15. Physiological role of D-amino acid-N-acetyltransferase of Saccharomyces cerevisiae: detoxification of D-amino acids.

    PubMed

    Yow, Geok-Yong; Uo, Takuma; Yoshimura, Tohru; Esaki, Nobuyoshi

    2006-03-01

    Saccharomyces cerevisiae is sensitive to D-amino acids: those corresponding to almost all proteinous L-amino acids inhibit the growth of yeast even at low concentrations (e.g. 0.1 mM). We have determined that D-amino acid-N-acetyltransferase (DNT) of the yeast is involved in the detoxification of D-amino acids on the basis of the following findings. When the DNT gene was disrupted, the resulting mutant was far less tolerant to D-amino acids than the wild type. However, when the gene was overexpressed with a vector plasmid p426Gal1 in the wild type or the mutant S. cerevisiae as a host, the recombinant yeast, which was found to show more than 100 times higher DNT activity than the wild type, was much more tolerant to D-amino acids than the wild type. We further confirmed that, upon cultivation with D-phenylalanine, N-acetyl-D-phenylalanine was accumulated in the culture but not in the wild type and hpa3Delta cells overproducing DNT cells. Thus, D-amino acids are toxic to S. cerevisiae but are detoxified with DNT by N-acetylation preceding removal from yeast cells.

  16. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

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

    Chang, Chun-Yu; Shen, Chao-Yu; Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased themore » contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation.« less

  17. Whole Body Creatine and Protein Kinetics in Healthy Men and Women: Effects of creatine and amino acid supplementation

    PubMed Central

    Kalhan, Satish C; Gruca, Lourdes; Marczewski, Susan; Bennett, Carole; Kummitha, China

    2015-01-01

    Creatine kinetics were measured in young healthy subjects, eight males and seven females, age 20–30 years, after an overnight fast on creatine free diet. Whole body turnover of glycine and its appearance in creatine was quantified using [1-13C] glycine and the rate of protein turnover was quantified using L-ring [2H5] phenylalanine. The creatine pool size was estimated by the dilution of a bolus [C2H3] creatine. Studies were repeated following a five days supplement creatine 21g.day−1 and following supplement amino acids 14.3 g.day−1. Creatine caused a ten folds increase in the plasma concentration of creatine and a 50% decrease in the concentration of guanidinoacetic acid. Plasma amino acids profile showed a significant decrease in glycine, glutamine and taurine and a significant increase in citrulline, valine, lysine and cysteine. There was a significant decrease in the rate of appearance of glycine, suggesting a decrease in de-novo synthesis (p=0.006). The fractional and absolute rate of synthesis of creatine was significantly decreased by supplemental creatine. Amino acid supplement had no impact on any of the parameters. Creatine supplement caused a significant decrease in the rate of synthesis of creatine. This is the first detailed analysis of creatine kinetics and the effects of creatine supplement in healthy young men and women. These methods can be applied for the analysis of creatine kinetics in different physiological states. PMID:26480831

  18. An amino acid depleted cell-free protein synthesis system for the incorporation of non-canonical amino acid analogs into proteins.

    PubMed

    Singh-Blom, Amrita; Hughes, Randall A; Ellington, Andrew D

    2014-05-20

    Residue-specific incorporation of non-canonical amino acids into proteins is usually performed in vivo using amino acid auxotrophic strains and replacing the natural amino acid with an unnatural amino acid analog. Herein, we present an efficient amino acid depleted cell-free protein synthesis system that can be used to study residue-specific replacement of a natural amino acid by an unnatural amino acid analog. This system combines a simple methodology and high protein expression titers with a high-efficiency analog substitution into a target protein. To demonstrate the productivity and efficacy of a cell-free synthesis system for residue-specific incorporation of unnatural amino acids in vitro, we use this system to show that 5-fluorotryptophan and 6-fluorotryptophan substituted streptavidin retain the ability to bind biotin despite protein-wide replacement of a natural amino acid for the amino acid analog. We envisage this amino acid depleted cell-free synthesis system being an economical and convenient format for the high-throughput screening of a myriad of amino acid analogs with a variety of protein targets for the study and functional characterization of proteins substituted with unnatural amino acids when compared to the currently employed in vivo methodologies. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Utilization of acidic α-amino acids as acyl donors: an effective stereo-controllable synthesis of aryl-keto α-amino acids and their derivatives.

    PubMed

    Wang, Lei; Murai, Yuta; Yoshida, Takuma; Okamoto, Masashi; Tachrim, Zetryana Puteri; Hashidoko, Yasuyuki; Hashimoto, Makoto

    2014-05-16

    Aryl-keto-containing α-amino acids are of great importance in organic chemistry and biochemistry. They are valuable intermediates for the construction of hydroxyl α-amino acids, nonproteinogenic α-amino acids, as well as other biofunctional components. Friedel-Crafts acylation is an effective method to prepare aryl-keto derivatives. In this review, we summarize the preparation of aryl-keto containing α-amino acids by Friedel-Crafts acylation using acidic α-amino acids as acyl-donors and Lewis acids or Brönsted acids as catalysts.

  20. Nonprotein Amino Acids in the Murchison Meteorite

    PubMed Central

    Kvenvolden, Keith A.; Lawless, James G.; Ponnamperuma, Cyril

    1971-01-01

    Twelve nonprotein amino acids appear to be present in the Murchison meteorite. The identity of eight of them has been conclusively established as N-methylglycine, β-alanine, 2-methylalanine, α-amino-n-butyric acid, β-amino-n-butyric acid, γ-amino-n-butyric acid, isovaline, and pipecolic acid. Tentative evidence is presented for the presence of N-methylalanine, N-ethylglycine, β-aminoisobutyric acid, and norvaline. These amino acids appear to be extraterrestrial in origin and may provide new evidence for the hypothesis of chemical evolution. PMID:16591908

  1. Effect of proteolysis index level on instrumental adhesiveness, free amino acids content and volatile compounds profile of dry-cured ham.

    PubMed

    Pérez-Santaescolástica, C; Carballo, J; Fulladosa, E; Garcia-Perez, José V; Benedito, J; Lorenzo, J M

    2018-05-01

    Defective textures in dry-cured ham are a common problem that causes important economic losses in the ham industry. An increase of proteolysis during the dry-cured ham processing may lead to high adhesiveness and consumer rejection of the product. Therefore, the influence of proteolysis index (PI) on instrumental adhesiveness, free amino acids and volatile profile of dry-cured ham was assessed. Two hundred Spanish dry-cured ham units were firstly classified according to their PI: low PI (<32%), medium PI (32-36%) and high PI (>36%). Instrumental adhesiveness was affected by PI, showing the lowest values in the batch with low PI. Significant differences (P < 0.05) among groups were found in six amino acids: serine, taurine, cysteine, methionine, isoleucine and leucine. The content of leucine, serine, methionine, and isoleucine significantly (P < 0.05) increased as the proteolysis index rose. However, taurine and cysteine content showed an opposite behaviour, reaching the highest values in the dry-cured hams with low PI. Significant differences (P < 0.001) in the total content of volatile compounds among ham groups were observed, with the highest concentration in the batch with low PI, and decreasing the concentration as the PI increased. Regarding the different chemical families of volatiles, the hydrocarbons (the main family), alcohols, aldehydes, ketones and acids were more abundant in the hams showing the lowest PI. Esters did not show significant differences among the three batches of hams studied. The present study demonstrated that, apart from the effect on the adhesiveness, an excessive proteolysis seems to be associated with negative effects on the taste and aroma of the dry-cured ham. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Amelioration of nandrolone decanoate-induced testicular and sperm toxicity in rats by taurine: effects on steroidogenesis, redox and inflammatory cascades, and intrinsic apoptotic pathway.

    PubMed

    Ahmed, Maha A E

    2015-02-01

    The wide abuse of the anabolic steroid nandrolone decanoate by athletes and adolescents for enhancement of sporting performance and physical appearance may be associated with testicular toxicity and infertility. On the other hand, taurine; a free β-amino acid with remarkable antioxidant activity, is used in taurine-enriched beverages to boost the muscular power of athletes. Therefore, the purpose of this study was to investigate the mechanisms of the possible protective effects of taurine on nandrolone decanoate-induced testicular and sperm toxicity in rats. To achieve this aim, male Wistar rats were randomly distributed into four groups and administered either vehicle, nandrolone decanoate (10mg/kg/week, I.M.), taurine (100mg/kg/day, p.o.) or combination of taurine and nandrolone decanoate, for 8 successive weeks. Results of the present study showed that taurine reversed nandrolone decanoate-induced perturbations in sperm characteristics, normalized serum testosterone level, and restored the activities of the key steroidogenic enzymes; 3β-HSD, and 17β-HSD. Moreover, taurine prevented nandrolone decanoate-induced testicular toxicity and DNA damage by virtue of its antioxidant, anti-inflammatory, and anti-apoptotic effects. This was evidenced by taurine-induced modulation of testicular LDH-x activity, redox markers (MDA, NO, GSH contents, and SOD activity), inflammatory indices (TNF-α, ICAM-1 levels, and MMP-9 gene expression), intrinsic apoptotic pathway (cytochrome c gene expression and caspase-3 content), and oxidative DNA damage markers (8-OHdG level and comet assay). In conclusion, at the biochemical and histological levels, taurine attenuated nandrolone decanoate-induced poor sperm quality and testicular toxicity in rats. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Effects of hippocampal high-frequency electrical stimulation in memory formation and their association with amino acid tissue content and release in normal rats.

    PubMed

    Luna-Munguía, Hiram; Meneses, Alfredo; Peña-Ortega, Fernando; Gaona, Andres; Rocha, Luisa

    2012-01-01

    Hippocampal high frequency electrical stimulation (HFS) at 130 Hz has been proposed as a therapeutical strategy to control neurological disorders such as intractable temporal lobe epilepsy (TLE). This study was carried out to determine the effects of hippocampal HFS on the memory process and the probable involvement of amino acids. Using the autoshaping task, we found that animals receiving hippocampal HFS showed augmented short-term, but not long-term memory formation, an effect blocked by bicuculline pretreatment and associated with enhanced tissue levels of amino acids in hippocampus. In addition, microdialysis experiments revealed high extracellular levels of glutamate, aspartate, glycine, taurine, and alanine during the application of hippocampal HFS. In contrast, GABA release augmented during HFS and remained elevated for more than 1 h after the stimulation was ended. HFS had minimal effects on glutamine release. The present results suggest that HFS has an activating effect on specific amino acids in normal hippocampus that may be involved in the enhanced short-term memory formation. These data further provide experimental support for the concept that hippocampus may be a promising target for focal stimulation to treat intractable seizures in humans. Copyright © 2010 Wiley Periodicals, Inc., Inc.

  4. Urinary amino acid analysis: a comparison of iTRAQ-LC-MS/MS, GC-MS, and amino acid analyzer.

    PubMed

    Kaspar, Hannelore; Dettmer, Katja; Chan, Queenie; Daniels, Scott; Nimkar, Subodh; Daviglus, Martha L; Stamler, Jeremiah; Elliott, Paul; Oefner, Peter J

    2009-07-01

    Urinary amino acid analysis is typically done by cation-exchange chromatography followed by post-column derivatization with ninhydrin and UV detection. This method lacks throughput and specificity. Two recently introduced stable isotope ratio mass spectrometric methods promise to overcome those shortcomings. Using two blinded sets of urine replicates and a certified amino acid standard, we compared the precision and accuracy of gas chromatography/mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) of propyl chloroformate and iTRAQ derivatized amino acids, respectively, to conventional amino acid analysis. The GC-MS method builds on the direct derivatization of amino acids in diluted urine with propyl chloroformate, GC separation and mass spectrometric quantification of derivatives using stable isotope labeled standards. The LC-MS/MS method requires prior urinary protein precipitation followed by labeling of urinary and standard amino acids with iTRAQ tags containing different cleavable reporter ions distinguishable by MS/MS fragmentation. Means and standard deviations of percent technical error (%TE) computed for 20 amino acids determined by amino acid analyzer, GC-MS, and iTRAQ-LC-MS/MS analyses of 33 duplicate and triplicate urine specimens were 7.27+/-5.22, 21.18+/-10.94, and 18.34+/-14.67, respectively. Corresponding values for 13 amino acids determined in a second batch of 144 urine specimens measured in duplicate or triplicate were 8.39+/-5.35, 6.23+/-3.84, and 35.37+/-29.42. Both GC-MS and iTRAQ-LC-MS/MS are suited for high-throughput amino acid analysis, with the former offering at present higher reproducibility and completely automated sample pretreatment, while the latter covers more amino acids and related amines.

  5. Effect of combination of taurine and azelaic acid on antimelanogenesis in murine melanoma cells

    PubMed Central

    2010-01-01

    Background Pigmentation in human skin is an important defense mechanism against sunlight or oxidative stress. Despite the protective role of melanin, abnormal hyperpigmentation such as freckles and chloasma sometimes can be serious aesthetic problems. Because of these effects of hyperpigmentation, people have considered the effect of depigmentation. Azelaic acid (AZ) is a saturated dicarboxylic acid found naturally in wheat, rye, and barley. Previously, we showed that AZ inhibited melanogenesis. In this study, we investigated the antimelanogenic activity of combination of AZ and taurine (Tau) in B16F10 mouse melanoma cells. Methods The mouse melanoma cell line B16F10 was used in the study. We measured melanin contents and tyrosinase activity. To gain the change of protein expression, we carried out western blotting. Results We investigated that AZ combined with taurine (Tau) show more inhibitory effects in melanocytes than the treatment of AZ alone. AZ combined with Tau inhibited the melanin production and tyrosinase activity of B16F10 melanoma cells without significant cytotoxicity. Also inhibitory effects after treatment with these combined chemical are stronger than AZ alone on melanogenesis. Conclusions These findings indicate that AZ with Tau might play an important role in the regulation of melanin formation and be useful as effective ingredients in antimelanogesis. PMID:20804622

  6. Effect of combination of taurine and azelaic acid on antimelanogenesis in murine melanoma cells.

    PubMed

    Yu, Ji Sun; Kim, An Keun

    2010-08-24

    Pigmentation in human skin is an important defense mechanism against sunlight or oxidative stress. Despite the protective role of melanin, abnormal hyperpigmentation such as freckles and chloasma sometimes can be serious aesthetic problems. Because of these effects of hyperpigmentation, people have considered the effect of depigmentation. Azelaic acid (AZ) is a saturated dicarboxylic acid found naturally in wheat, rye, and barley. Previously, we showed that AZ inhibited melanogenesis. In this study, we investigated the antimelanogenic activity of combination of AZ and taurine (Tau) in B16F10 mouse melanoma cells. The mouse melanoma cell line B16F10 was used in the study. We measured melanin contents and tyrosinase activity. To gain the change of protein expression, we carried out western blotting. We investigated that AZ combined with taurine (Tau) show more inhibitory effects in melanocytes than the treatment of AZ alone. AZ combined with Tau inhibited the melanin production and tyrosinase activity of B16F10 melanoma cells without significant cytotoxicity. Also inhibitory effects after treatment with these combined chemical are stronger than AZ alone on melanogenesis. These findings indicate that AZ with Tau might play an important role in the regulation of melanin formation and be useful as effective ingredients in antimelanogesis.

  7. Taurine flux in chicken erythrocytes.

    PubMed

    Porter, D W; Martin, W G

    1992-05-01

    1. The intracellular taurine concentration in chick erythrocytes increased with age. 2. Erythrocyte taurine influx and efflux rates increased with age. 3. Erythrocyte taurine influx decreased when the extracellular sodium concentration was below normal physiological concentrations. 4. Under hypo-osmotic conditions, taurine efflux from erythrocytes increased. 5. The data suggest that chick erythrocyte taurine metabolism changes during early post-hatch development and that one taurine function may be as an osmoregulator.

  8. Differential distribution of amino acids in plants.

    PubMed

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

    2017-05-01

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

  9. Synthesis of new kojic acid based unnatural α-amino acid derivatives.

    PubMed

    Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Uma Devi, P; Behera, Manoranjan

    2015-11-01

    An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Nutritional and medicinal aspects of D-amino acids.

    PubMed

    Friedman, Mendel; Levin, Carol E

    2012-05-01

    This paper reviews and interprets a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential amino acid such as L-lysine (L-Lys), L-methionine (L-Met), L-phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential amino acids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any amino acid derivative as a potential nutritional source of the corresponding L-amino acid. Because the organism is forced to use the D-amino acid or amino acid derivative as the sole source of the essential or semi-essential amino acid being replaced, and because a free amino acid diet allows better control of composition, the use of all-amino-acid diets for such determinations may be preferable to protein-based diets. Also covered are brief summaries of the widely scattered literature on dietary and pharmacological aspects of 27 individual D-amino acids, D-peptides, and isomeric amino acid derivatives and suggested research needs in each of these areas. The described results provide a valuable record and resource for further progress on the multifaceted aspects of D-amino acids in food and biological samples.

  11. Amino Acid Properties Conserved in Molecular Evolution

    PubMed Central

    Rudnicki, Witold R.; Mroczek, Teresa; Cudek, Paweł

    2014-01-01

    That amino acid properties are responsible for the way protein molecules evolve is natural and is also reasonably well supported both by the structure of the genetic code and, to a large extent, by the experimental measures of the amino acid similarity. Nevertheless, there remains a significant gap between observed similarity matrices and their reconstructions from amino acid properties. Therefore, we introduce a simple theoretical model of amino acid similarity matrices, which allows splitting the matrix into two parts – one that depends only on mutabilities of amino acids and another that depends on pairwise similarities between them. Then the new synthetic amino acid properties are derived from the pairwise similarities and used to reconstruct similarity matrices covering a wide range of information entropies. Our model allows us to explain up to 94% of the variability in the BLOSUM family of the amino acids similarity matrices in terms of amino acid properties. The new properties derived from amino acid similarity matrices correlate highly with properties known to be important for molecular evolution such as hydrophobicity, size, shape and charge of amino acids. This result closes the gap in our understanding of the influence of amino acids on evolution at the molecular level. The methods were applied to the single family of similarity matrices used often in general sequence homology searches, but it is general and can be used also for more specific matrices. The new synthetic properties can be used in analyzes of protein sequences in various biological applications. PMID:24967708

  12. Urinary Amino Acid Analysis: A Comparison of iTRAQ®-LC-MS/MS, GC-MS, and Amino Acid Analyzer

    PubMed Central

    Kaspar, Hannelore; Dettmer, Katja; Chan, Queenie; Daniels, Scott; Nimkar, Subodh; Daviglus, Martha L.; Stamler, Jeremiah; Elliott, Paul; Oefner, Peter J.

    2009-01-01

    Urinary amino acid analysis is typically done by cation-exchange chromatography followed by post-column derivatization with ninhydrin and UV detection. This method lacks throughput and specificity. Two recently introduced stable isotope ratio mass spectrometric methods promise to overcome those shortcomings. Using two blinded sets of urine replicates and a certified amino acid standard, we compared the precision and accuracy of gas chromatography/mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) of propyl chloroformate and iTRAQ® derivatized amino acids, respectively, to conventional amino acid analysis. The GC-MS method builds on the direct derivatization of amino acids in diluted urine with propyl chloroformate, GC separation and mass spectrometric quantification of derivatives using stable isotope labeled standards. The LC-MS/MS method requires prior urinary protein precipitation followed by labeling of urinary and standard amino acids with iTRAQ® tags containing different cleavable reporter ions distinguishable by MS/MS fragmentation. Means and standard deviations of percent technical error (%TE) computed for 20 amino acids determined by amino acid analyzer, GC-MS, and iTRAQ®-LC-MS/MS analyses of 33 duplicate and triplicate urine specimens were 7.27±5.22, 21.18±10.94, and 18.34±14.67, respectively. Corresponding values for 13 amino acids determined in a second batch of 144 urine specimens measured in duplicate or triplicate were 8.39±5.35, 6.23±3.84, and 35.37±29.42. Both GC-MS and iTRAQ®-LC-MS/MS are suited for high-throughput amino acid analysis, with the former offering at present higher reproducibility and completely automated sample pretreatment, while the latter covers more amino acids and related amines. PMID:19481989

  13. Molecular characteristics of mammalian and insect amino acid transporters: implications for amino acid homeostasis.

    PubMed

    Castagna, M; Shayakul, C; Trotti, D; Sacchi, V F; Harvey, W R; Hediger, M A

    1997-01-01

    In mammalian cells, the uptake of amino acids is mediated by specialized, energy-dependent and passive transporters with overlapping substrate specificities. Most energy-dependent transporters are coupled either to the cotransport of Na+ or Cl- or to the countertransport of K+. Passive transporters are either facilitated transporters or channels. As a prelude to the molecular characterization of the different classes of transporters, we have isolated transporter cDNAs by expression-cloning with Xenopus laevis oocytes and we have characterized the cloned transporters functionally by uptake studies into oocytes using radiolabelled substrates and by electrophysiology to determine substrate-evoked currents. Mammalian transporters investigated include the dibasic and neutral amino acid transport protein D2/NBAT (system b0+) and the Na(+)- and K(+)-dependent neuronal and epithelial high-affinity glutamate transporter EAAC1 (system XAG-). A detailed characterization of these proteins has provided new information on transport characteristics and mechanisms for coupling to different inorganic ions. This work has furthermore advanced our understanding of the roles these transporters play in amino acid homeostasis and in various pathologies. For example, in the central nervous system, glutamate transporters are critically important in maintaining the extracellular glutamate concentration below neurotoxic levels, and defects of the human D2 gene have been shown to account for the formation of kidney stones in patients with cystinuria. Using similar approaches, we are investigating the molecular characteristics of K(+)-coupled amino acid transporters in the larval lepidopteran insect midgut. In the larval midgut, K+ is actively secreted into the lumen through the concerted action of an apical H+ V-ATPase and an apical K+/2H+ antiporter, thereby providing the driving force for absorption of amino acids. In vivo, the uptake occurs at extremely high pH (pH 10) and is driven by a

  14. Human Protein and Amino Acid Requirements.

    PubMed

    Hoffer, L John

    2016-05-01

    Human protein and amino acid nutrition encompasses a wide, complex, frequently misunderstood, and often contentious area of clinical research and practice. This tutorial explains the basic biochemical and physiologic principles that underlie our current understanding of protein and amino acid nutrition. The following topics are discussed: (1) the identity, measurement, and essentiality of nutritional proteins; (2) the definition and determination of minimum requirements; (3) nutrition adaptation; (4) obligatory nitrogen excretion and the minimum protein requirement; (5) minimum versus optimum protein intakes; (6) metabolic responses to surfeit and deficient protein intakes; (7) body composition and protein requirements; (8) labile protein; (9) N balance; (10) the principles of protein and amino acid turnover, including an analysis of the controversial indicator amino acid oxidation technique; (11) general guidelines for evaluating protein turnover articles; (12) amino acid turnover versus clearance; (13) the protein content of hydrated amino acid solutions; (14) protein requirements in special situations, including protein-catabolic critical illness; (15) amino acid supplements and additives, including monosodium glutamate and glutamine; and (16) a perspective on the future of protein and amino acid nutrition research. In addition to providing practical information, this tutorial aims to demonstrate the importance of rigorous physiologic reasoning, stimulate intellectual curiosity, and encourage fresh ideas in this dynamic area of human nutrition. In general, references are provided only for topics that are not well covered in modern textbooks. © 2016 American Society for Parenteral and Enteral Nutrition.

  15. Amino Acid Transporters and Release of Hydrophobic Amino Acids in the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120.

    PubMed

    Pernil, Rafael; Picossi, Silvia; Herrero, Antonia; Flores, Enrique; Mariscal, Vicente

    2015-04-23

    Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of amino acid uptake, and three ABC-type transporters for amino acids have been previously characterized. Seven new loci encoding predicted amino acid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in amino acid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic amino acid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/amino acid:cation symporter (DAACS) family whose inactivation resulted in an increased uptake of a broad range of amino acids. An assay to study amino acid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB) was observed when transport system N-I (a hydrophobic amino acid ABC-type transporter) was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

  16. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  17. The essential oil of bergamot enhances the levels of amino acid neurotransmitters in the hippocampus of rat: implication of monoterpene hydrocarbons.

    PubMed

    Morrone, Luigi A; Rombolà, Laura; Pelle, Cinzia; Corasaniti, Maria T; Zappettini, Simona; Paudice, Paolo; Bonanno, Giambattista; Bagetta, Giacinto

    2007-04-01

    The effects of bergamot essential oil (BEO) on the release of amino acid neurotransmitters in rat hippocampus have been studied by in vivo microdialysis and by in vitro superfusion of isolated nerve terminals. Intraperitoneal administration of BEO (100microl/kg) significantly elevated the extracellular concentration of aspartate, glycine and taurine in a Ca(2+)-dependent manner. A dose-relation study generated a bell-shaped curve. When perfused into the hippocampus via the dialysis probe (20microl/20min), BEO produced a significant increase of extracellular aspartate, glycine, taurine as well as of GABA and glutamate. The augmentation of all amino acids was Ca(2+)-independent. Focally injected 1:1 diluted BEO preferentially caused extracellular increase of glutamate. Interestingly, this release appeared to be strictly Ca(2+)-dependent. BEO concentration-dependently enhanced the release of [(3)H]D-aspartate from superfused hippocampal synaptosomes. Similar results were obtained by monitoring the BEO-evoked release of endogenous glutamate. At relatively high concentrations, the BEO-induced [(3)H]d-aspartate release was almost entirely prevented by the glutamate transporter blocker dl-threo-beta-benzyloxyaspartic acid (DL-TBOA) and was Ca(2+)-independent. At relatively low concentrations the release of [(3)H]D-aspartate was only in part ( approximately 50%) DL-TBOA-sensitive and Ca(2+)-independent; the remaining portion of release was dependent on extracellular Ca(2+). Interestingly, the monoterpene hydrocarbon-free fraction of the essential oil appeared to be inactive while the bergapten-free fraction superimposed the releasing effect of BEO supporting the deduction that psoralens may not be implicated. To conclude, BEO contains into its volatile fraction still unidentified monoterpene hydrocarbons able to stimulate glutamate release by transporter reversal and/or by exocytosis, depending on the dose administered.

  18. Amelioration of nandrolone decanoate-induced testicular and sperm toxicity in rats by taurine: Effects on steroidogenesis, redox and inflammatory cascades, and intrinsic apoptotic pathway

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

    Ahmed, Maha A.E., E-mail: mahapharm@yahoo.com

    The wide abuse of the anabolic steroid nandrolone decanoate by athletes and adolescents for enhancement of sporting performance and physical appearance may be associated with testicular toxicity and infertility. On the other hand, taurine; a free β-amino acid with remarkable antioxidant activity, is used in taurine-enriched beverages to boost the muscular power of athletes. Therefore, the purpose of this study was to investigate the mechanisms of the possible protective effects of taurine on nandrolone decanoate-induced testicular and sperm toxicity in rats. To achieve this aim, male Wistar rats were randomly distributed into four groups and administered either vehicle, nandrolone decanoatemore » (10 mg/kg/week, I.M.), taurine (100 mg/kg/day, p.o.) or combination of taurine and nandrolone decanoate, for 8 successive weeks. Results of the present study showed that taurine reversed nandrolone decanoate-induced perturbations in sperm characteristics, normalized serum testosterone level, and restored the activities of the key steroidogenic enzymes; 3β-HSD, and 17β-HSD. Moreover, taurine prevented nandrolone decanoate-induced testicular toxicity and DNA damage by virtue of its antioxidant, anti-inflammatory, and anti-apoptotic effects. This was evidenced by taurine-induced modulation of testicular LDH-x activity, redox markers (MDA, NO, GSH contents, and SOD activity), inflammatory indices (TNF-α, ICAM-1 levels, and MMP-9 gene expression), intrinsic apoptotic pathway (cytochrome c gene expression and caspase-3 content), and oxidative DNA damage markers (8-OHdG level and comet assay). In conclusion, at the biochemical and histological levels, taurine attenuated nandrolone decanoate-induced poor sperm quality and testicular toxicity in rats. - Highlights: • Nandrolone decanoate (ND) disrupts sperm profile and steroidogenesis in rats. • ND upregulates gene expression of inflammatory and apoptotic markers. • Taurine normalizes sperm profile and serum

  19. Amino acid composition of some Mexican foods.

    PubMed

    Morales de León, Josefina; Camacho, M Elena; Bourges, Héctor

    2005-06-01

    Knowledge of the amino acid composition of foods is essential to calculate their chemical score, which is used to predict protein quality of foods and diets. Though amino acid composition of many foods is reasonably well established, better knowledge is needed on native foods consumed in different regions and countries. This paper presents the amino acid composition of different presentations of raw and processed foods produced and consumed in Mexico. The amino acid composition was determined using Beckman amino acid analyzers (models 116 and 6300). Tryptophan was determined using the Spies and Chambers method. Of the different foods analyzed, some comments are made on native or basic foods in Mexico: Spirulin, where lysine is the limiting amino acid, with a chemical score of 67%, is a good source of tryptophan (1.16g/16 gN); amaranth contains high levels of sulphur amino acids (4.09 to 5.34 g/16gN), with a protein content of 15 g/100g; and pulque, a Pre-Hispanic beverage that contains high levels of tryptophan (2.58 g/16 gN) and sulphur amino acids (2.72 g/16 gN). Finally, insects are good sources of sulphur amino acids and lysine.

  20. Present Global Situation of Amino Acids in Industry.

    PubMed

    Tonouchi, Naoto; Ito, Hisao

    At present, amino acids are widely produced and utilized industrially. Initially, monosodium glutamate (MSG) was produced by extraction from a gluten hydrolysate. The amino acid industry started using the residual of the lysate. The discovery of the functions of amino acids has led to the expansion of their field of use. In addition to seasoning and other food use, amino acids are used in many fields such as animal nutrients, pharmaceuticals, and cosmetics. On the other hand, the invention of the glutamate fermentation process, followed by the development of fermentation methods for many other amino acids, is no less important. The supply of these amino acids at a low price is very essential for their industrial use. Most amino acids are now produced by fermentation. The consumption of many amino acids such as MSG or feed-use amino acids is still rapidly increasing.

  1. Enantiomer-specific selection of amino acids.

    PubMed

    Ren, Xueying; Tellez, Luis A; de Araujo, Ivan E

    2013-12-01

    Dietary intake of L-amino acids impacts on several physiological functions, including the control of gastrointestinal motility, pancreatic secretion, and appetite. However, the biological mechanisms regulating behavioral predilections for certain amino acid types remain poorly understood. We tested the hypothesis that, in mice, the potency with which a given glucogenic amino acid increases glucose utilization reflects its rewarding properties. We have found that: (1) during long-, but not short-, term preference tests, L-alanine and L-serine were preferred over their D-enantiomer counterparts, while no such effect was observed for L-threonine vs. D-threonine; (2) these behavioral patterns were closely associated with the ability of L-amino acids to promote increases in respiratory exchange ratios such that those, and only those, L-amino acids able to promote increases in respiratory exchange ratios were preferred over their D-isomers; (3) these behavioral preferences were independent of gustatory influences, since taste-deficient Trpm5 knockout mice displayed ingestive responses very similar to those of their wild-type counterparts. We conclude that the ability to promote increases in respiratory exchange ratios enhances the reward value of nutritionally relevant amino acids and suggest a mechanistic link between substrate utilization and amino acid preferences.

  2. Enantiomer-specific selection of amino acids

    PubMed Central

    Ren, Xueying; Tellez, Luis A; de Araujo, Ivan E

    2013-01-01

    Dietary intake of L-amino acids impacts on several physiological functions, including the control of gastrointestinal motility, pancreatic secretion, and appetite. However, the biological mechanisms regulating behavioral predilections for certain amino acid types remain poorly understood. We tested the hypothesis that, in mice, the potency with which a given glucogenic amino acid increases glucose utilization reflects its rewarding properties. We have found that: 1. During long-, but not short-, term preference tests, L-alanine and L-serine were preferred over their D-enantiomer counterparts, while no such effect was observed for L-threonine vs. D-threonine; 2. These behavioral patterns were closely associated with the ability of L-amino acids to promote increases in respiratory exchange ratios such that those, and only those, L-amino acids able to promote increases in respiratory exchange ratios were preferred over their D-isomers; 3. These behavioral preferences were independent of gustatory influences, since taste-deficient Trpm5 knockout mice displayed ingestive responses very similar to those of their wild-type counterparts. We conclude that the ability to promote increases in respiratory exchange ratios enhances the reward value of nutritionally relevant amino acids, and suggest a mechanistic link between substrate utilization and amino acid preferences. PMID:24072505

  3. Novel families of vacuolar amino acid transporters.

    PubMed

    Sekito, Takayuki; Fujiki, Yuki; Ohsumi, Yoshinori; Kakinuma, Yoshimi

    2008-08-01

    Amino acids are compartmentalized in the vacuoles of microorganisms and plants. In Saccharomyces cerevisiae, basic amino acids accumulate preferentially into vacuoles but acidic amino acids are almost excluded from them. This indicates that selective machineries operate at the vacuolar membrane. The members of the amino acid/auxin permease family and the major facilitator superfamily involved in the vacuolar compartmentalization of amino acids have been recently identified in studies using S. cerevisiae. Homologous genes for these transporters are also found in plant and mammalian genomes. The physiological significance in response to nitrogen starvation can now be discussed. (c) 2008 IUBMB

  4. 40 CFR 721.1705 - Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid, diazotized, (3-aminophenyl)phosphonic acid and... Significant New Uses for Specific Chemical Substances § 721.1705 Benzoic acid, 3-amino-, diazotized, coupled...

  5. 40 CFR 721.1705 - Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzoic acid, 3-amino-, diazotized, coupled with 6-amino-4-hydroxy-2-naphthalenesulfonic acid, diazotized, (3-aminophenyl)phosphonic acid and... Significant New Uses for Specific Chemical Substances § 721.1705 Benzoic acid, 3-amino-, diazotized, coupled...

  6. Impact of chronic administration of anabolic androgenic steroids and taurine on blood pressure in rats

    PubMed Central

    Roşca, A.E.; Stoian, I.; Badiu, C.; Gaman, L.; Popescu, B.O.; Iosif, L.; Mirica, R.; Tivig, I.C.; Stancu, C.S.; Căruntu, C.; Voiculescu, S.E.; Zăgrean, L.

    2016-01-01

    Supraphysiological administration of anabolic androgenic steroids has been linked to increased blood pressure. The widely distributed amino acid taurine seems to be an effective depressor agent in drug-induced hypertension. The purpose of this study was to assess the impact of chronic high dose administration of nandrolone decanoate (DECA) and taurine on blood pressure in rats and to verify the potentially involved mechanisms. The study was conducted in 4 groups of 8 adult male Wistar rats, aged 14 weeks, treated for 12 weeks with: DECA (A group); vehicle (C group); taurine (T group), or with both drugs (AT group). Systolic blood pressure (SBP) was measured at the beginning of the study (SBP1), 2 (SBP2) and 3 months (SBP3) later. Plasma angiotensin-converting enzyme (ACE) activity and plasma end products of nitric oxide metabolism (NOx) were also determined. SBP3 and SBP2 were significantly increased compared to SBP1 only in the A group (P<0.002 for both). SBP2, SBP3 and ACE activity showed a statistically significant increase in the A vs C (P<0.005), andvs AT groups (P<0.05), while NOx was significantly decreased in the A and AT groups vs controls (P=0.01). ACE activity was strongly correlated with SBP3 in the A group (r=0.71, P=0.04). These findings suggest that oral supplementation of taurine may prevent the increase in SBP induced by DECA, an effect potentially mediated by angiotensin-converting enzyme. PMID:27254659

  7. A reexamination of amino acids in lunar soil

    NASA Technical Reports Server (NTRS)

    Brinton, K. L. F.; Bada, J. L.; Arnold, J. R.

    1993-01-01

    Amino acids in lunar soils provide an important indicator of the level of prebiotic organic compounds on the moon. The results provide insight into the chemistry of amino acid precursors, and furthermore, given the flux of carbonaceous material to the moon, we can evaluate the survival of organics upon impact. The amino acid contents of both hydrolyzed and unhydrolyzed hot-water extracts of Apollo 17 lunar soil were determined using ophthaldialdehyde/N-acetyl cysteine (OPA/NAC) derivatization followed by HPLC analysis. Previous studies of lunar amino acids were inconclusive, as the technique used (derivatization with ninhydrin followed by HPLC analysis) was unable to discriminate between cosmogenic amino acids and terrestrial contaminants. Cosmogenic amino acids are racemic, and many of the amino acids found in carbonaceous meteorites such as Murchison, i.e., alpha-amino-i-butyric acid (aib), are extremely rare on Earth. The ninhydrin method does not distinguish amino acid enantiomers, nor does it detect alpha-alkyl amino acids such as aib, whereas the OPA/NAC technique does both.

  8. Interaction of metal ions and amino acids - Possible mechanisms for the adsorption of amino acids on homoionic smectite clays

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Loew, G. H.; Lawless, J.

    1983-01-01

    A semiempirical molecular orbital method is used to characterize the binding of amino acids to hexahydrated Cu(2+) and Ni(2+), a process presumed to occur when they are adsorbed in the interlamellar space of homoionic smectite clays. Five alpha-amino acids, beta-alanine, and gamma-aminobutyric acid were used to investigate the metal ion and amino acid specificity in binding. It was assumed that the alpha, beta, and gamma-amino acids would bind as bidentate anionic ligands, forming either 1:1 or 1:2 six-coordinated five, six, and seven-membered-ring chelate complexes, respectively. Energies of complex formation, optimized geometries, and electron and spin distribution were determined; and steric constraints of binding of the amino acids to the ion-exchanged cations in the interlamellar spacing of a clay were examined. Results indicate that hexahydrated Cu(2+) forms more stable complexes than hexahydrated Ni(2+) with all the amino acids studied. However, among these amino acids, complex formation does not favor the adsorption of the biological subset. Calculated energetics of complex formation and steric constraints are shown to predict that 1:1 rather than 1:2 metal-amino acid complexes are generally favored in the clay.

  9. Amino acid changes during transition to a vegan diet supplemented with fish in healthy humans.

    PubMed

    Elshorbagy, Amany; Jernerén, Fredrik; Basta, Marianne; Basta, Caroline; Turner, Cheryl; Khaled, Maram; Refsum, Helga

    2017-08-01

    To explore whether changes in dietary protein sources can lower plasma branched-chain amino acids (BCAAs), aromatic amino acids and sulfur amino acids (SAAs) that are often elevated in the obese, insulin-resistant state and in type 2 diabetes. Thirty-six subjects (mean age 31 ± 2 years) underwent a voluntary abstinence from meat, poultry, eggs, and dairy products for 6 weeks, while enriching the diet with fish, in fulfillment of a religious fast. Subjects were assessed 1 week before the fast (V1), 1 week after initiation of the fast (V2) and in the last week of the fast (V3). Thirty-four subjects completed all three visits. Fasting plasma BCAAs decreased at V2 and remained low at V3 (P < 0.001 for all). Valine showed the greatest decline, by 20 and 19 % at V2 and V3, respectively. Phenylalanine and tryptophan, but not tyrosine, also decreased at V2 and V3. The two proteinogenic SAAs, methionine and cysteine, remained stable, but the cysteine product, taurine, decreased from 92 ± 7 μmol/L to 66 ± 6 (V2; P = 0.003) and 65 ± 6 μmol/L (V3; P = 0.003). A progressive decline in plasma glutamic acid, coupled with an increase in glutamine, was observed. Plasma total and LDL cholesterol decreased at V2 and V3 (P < 0.001 for all). Changing dietary protein sources to plant- and fish-based sources in an ad libitum setting lowers the plasma BCAAs that have been linked to diabetes risk. These findings point to habitual diet as a potentially modifiable determinant of fasting plasma BCAA concentrations.

  10. Cerebral Taurine Levels are Associated with Brain Edema and Delayed Cerebral Infarction in Patients with Aneurysmal Subarachnoid Hemorrhage.

    PubMed

    Kofler, Mario; Schiefecker, Alois; Ferger, Boris; Beer, Ronny; Sohm, Florian; Broessner, Gregor; Hackl, Werner; Rhomberg, Paul; Lackner, Peter; Pfausler, Bettina; Thomé, Claudius; Schmutzhard, Erich; Helbok, Raimund

    2015-12-01

    Cerebral edema and delayed cerebral infarction (DCI) are common complications after aneurysmal subarachnoid hemorrhage (aSAH) and associated with poor functional outcome. Experimental data suggest that the amino acid taurine is released into the brain extracellular space secondary to cytotoxic edema and brain tissue hypoxia, and therefore may serve as a biomarker for secondary brain injury after aSAH. On the other hand, neuroprotective mechanisms of taurine treatment have been described in the experimental setting. We analyzed cerebral taurine levels using high-performance liquid chromatography in the brain extracellular fluid of 25 consecutive aSAH patients with multimodal neuromonitoring including cerebral microdialysis (CMD). Patient characteristics and clinical course were prospectively recorded. Associations with CMD-taurine levels were analyzed using generalized estimating equations with an autoregressive process to handle repeated observations within subjects. CMD-taurine levels were highest in the first days after aSAH (11.2 ± 3.2 µM/l) and significantly decreased over time (p < 0.001). Patients with brain edema on admission or during hospitalization (N = 20; 80 %) and patients developing DCI (N = 5; 20 %) had higher brain extracellular taurine levels compared to those without (Wald = 7.3, df = 1, p < 0.01; Wald = 10.1, df = 1, p = 0.001, respectively) even after adjusting for disease severity and CMD-probe location. There was no correlation between parenteral taurine supplementation and brain extracellular taurine (p = 0.6). Moreover, a significant correlation with brain extracellular glutamate (r = 0.82, p < 0.001), lactate (r = 0.56, p < 0.02), pyruvate (r = 0.39, p < 0.01), potassium (r = 0.37, p = 0.01), and lactate-to-pyruvate ratio (r = 0.24, p = 0.02) was found. Significantly higher CMD-taurine levels were found in patients with brain edema or DCI after aneurysmal subarachnoid hemorrhage. Its value as a

  11. Extraterrestrial Amino Acids in the Almahata Sitta Meteorite

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Aubrey, Andrew D.; Callahan, Michael P.; Dworkin, Jason P.; Elsila, Jamie E.; Parker, Eric T.; Bada, Jeffrey L.

    2010-01-01

    Amino acid analysis of a meteorite fragment of asteroid 2008 TC3 called Almahata Sitta was carried out using reverse-phase liquid chromatography coupled with UV fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS) as part of a sample analysis consortium. LC-FD/ToF-MS analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to seven-carbon aliphatic amino acids and one- to three-carbon amines with abundances ranging from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the amino acids alanine, R-amino-n-butyric acid (beta-ABA), 2-amino-2-methylbutanoic acid (isovaline), and 2-aminopentanoic acid (norvaline) in the meteorite were racemic (D/L approximately 1), indicating that these amino acids are indigenous to the meteorite and not terrestrial contaminants. Several other non-protein amino acids were also identified in the meteorite above background levels including alpha-aminoisobutyric acid (alpha-AIB), 4-amino-2- methylbutanoic acid, 4-amino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. The total abundances of isovaline and alpha-AIB in Almahata Sitta are 1000 times lower than the abundances of these amino acids found in the CM carbonaceous chondrite Murchison. The extremely low abundances and unusual distribution of five carbon amino acids in Almahata Sitta compared to Cl, CM, and CR carbonaceous chondrites may reflect extensive thermal alteration of amino acids on the parent asteroid by partial melting during formation or subsequent impact shock heating. It is also possible that amino acids were synthesized by catalytic reactions on the parent body after asteroid 2008 TC3 cooled to lower temperatures.

  12. Amino Acid Stability in the Early Oceans

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

    It is likely that a variety of amino acids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" amino acids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein amino acids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these amino acids could have persisted before their destruction by abiotic and biotic processes. Prior to life, amino acid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine amino acid life-time would have been shorter. After life, amino acids in the oceans could have been assimilated by primitive organisms.

  13. Effects of streptozotocin-induced diabetes in domestic pigs with focus on the amino acid metabolism.

    PubMed

    Jensen-Waern, M; Andersson, M; Kruse, R; Nilsson, B; Larsson, R; Korsgren, O; Essén-Gustavsson, B

    2009-07-01

    Streptozotocin (STZ) given intravenously destroys pancreatic beta cells and is widely used in animal models to mimic type 1 diabetes. The effects of STZ on the clinical state of health and metabolism were studied in six high health certified domestic pigs weighing 19+/-1.3 kg at the start of the experiment. A single STZ dose of 150 mg/kg of body weight successfully induced hyperglycaemia and alterations in amino acid metabolism. Within 9 h after STZ administration, the blood glucose values fell from 5.4-7.5 mmol/L to 0.8-2.2 mmol/L. Hypoglycaemia was treated with 0.5 g glucose/kg body weight. In all pigs, hyperglycaemia was produced 24 h after STZ treatment, and 3 days after STZ injection, the glucose concentration was >25 mmol/L. Mean C-peptide concentration was 0.25+/-0.16 microg/L since 2 days after STZ injection until the end of the study. The serum concentration of the branched-chain amino acids (BCAA) increased four-fold, and alanine and taurine decreased by approximately 70% and 50%, respectively, after STZ treatment. All but one pig remained brisk and the physical examination was normal except for a retarded growth rate and a reduction of the skeletal muscle. At the end of the study, the pigs were moderately emaciated. Postmortem examination confirmed muscle wasting and a reduction of abdominal and subcutaneous fat. In conclusion, STZ-induced diabetes in pigs fulfils the requirements for a good animal model for type 1 diabetes with respect to clinical signs of the disease and alterations in the carbohydrate and amino acid metabolism.

  14. Optical Sensors for Detection of Amino Acids.

    PubMed

    Pettiwala, Aafrin M; Singh, Prabhat K

    2017-11-06

    Amino acids are crucially involved in a myriad of biological processes. Any aberrant changes in physiological level of amino acids often manifest in common metabolic disorders, serious neurological conditions and cardiovascular diseases. Thus, devising methods for detection of trace amounts of amino acids becomes highly elemental to their efficient clinical diagnosis. Recently, the domain of developing optical sensors for detection of amino acids has witnessed significant activity which is the focus of the current review article. We undertook a detailed search of the peer-reviewed literature that primarily deals with optical sensors for amino acids and focuses on the use of different type of materials as a sensing platform. Ninety-five papers have been included in the review, majority of which deals with optical sensors. We attempt to systematically classify these contributions based on applications of various chemical and biological scaffolds such as polymers, supramolecular assemblies, nanoparticles, DNA, heparin etc. for the sensing of amino acids. This review identifies that supramolecular assemblies and nanomaterial continue to be commonly used materials to devise sensors for amino acids followed by surfactant assemblies. The broad implications of amino acids in human health and diagnosis have stirred a lot of interest to develop optimized optical detection systems for amino acids in recent years, using different materials based on chemical and biological scaffolds. We have also attempted to highlight the merits and demerits of some of the noteworthy sensor systems to instigate further efforts for constructing amino acids sensor based on unconventional concepts. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Amino acids in the Tagish Lake Meteorite

    NASA Technical Reports Server (NTRS)

    Kminek, G.; Botta, O.; Glavin, D. P.; Bada, J. L.

    2002-01-01

    High-performance liquid chromatography (HPLC) based amino acid analysis of a Tagish Lake meteorite sample recovered 3 months after the meteorite fell to Earth have revealed that the amino acid composition of Tagish Lake is strikingly different from that of the CM and CI carbonaceous chondrites. We found that the Tagish Lake meteorite contains only trace levels of amino acids (total abundance = 880 ppb), which is much lower than the total abundance of amino acids in the CI Orgueil (4100 ppb) and the CM Murchison (16 900 ppb). Because most of the same amino acids found in the Tagish Lake meteorite are also present in the Tagish Lake ice melt water, we conclude that the amino acids detected in the meteorite are terrestrial contamination. We found that the exposure of a sample of Murchison to cold water lead to a substantial reduction over a period of several weeks in the amount of amino acids that are not strongly bound to the meteorite matrix. However, strongly bound amino acids that are extracted by direct HCl hydrolysis are not affected by the leaching process. Thus even if there had been leaching of amino acids from our Tagish Lake meteorite sample during its 3 month residence in Tagish Lake ice and melt water, a Murchison type abundance of endogenous amino acids in the meteorite would have still been readily detectable. The low amino acid content of Tagish Lake indicates that this meteorite originated fiom a different type of parent body than the CM and CI chondrites. The parent body was apparently devoid of the reagents such as aldehyldes/ketones, HCN and ammonia needed for the effective abiotic synthesis of amino acids. Based on reflectance spectral measurements, Tagish Lake has been associated with P- or D-type asteroids. If the Tagish Lake meteorite was indeed derived fiom these types of parent bodies, our understanding of these primitive asteroids needs to be reevaluated with respect to their potential inventory of biologically important organic compounds.

  16. Development and validation of a hydrophilic interaction chromatography-mass spectrometry assay for taurine and methionine in matrices rich in carbohydrates.

    PubMed

    de Person, Marine; Hazotte, Aurélie; Elfakir, Claire; Lafosse, Michel

    2005-07-22

    A new procedure based on hydrophilic interaction chromatography coupled to tandem mass spectrometry (ionisation process by pneumatically assisted electrospray in negative ion mode), is developed and validated for the simultaneous determination of underivatised taurine and methionine in beverages rich in carbohydrates such as energy drinks. No initial clean-up procedure and no sample derivatisation are required. Satisfactory analysis was obtained on an Astec apHera NH2 (150 mm x 4.6 mm; 5 microm) column with methanol-water (60/40) as mobile phase. The method was validated in terms of specificity, detection limits, linearity, accuracy, precision and stability, using threonine as internal standard. The potential effects of matrix and endogenous amino acid content were also examined. The limits of detection in the beverage varied from 20 microg L(-1) for taurine to 50 micro L(-1) for methionine.

  17. Amino acids in the Martian meteorite Nakhla

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Bada, J. L.; Brinton, K. L.; McDonald, G. D.

    1999-01-01

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, beta-alanine, and gamma-amino-n-butyric acid (gamma-ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the D/L ratios (values range from <0.1 to 0.5), is similar to what is found in bacterially degraded organic matter. The amino acids in Nakhla appear to be derived from terrestrial organic matter that infiltrated the meteorite soon after its fall to Earth, although it is possible that some of the amino acids are endogenous to the meteorite. The rapid amino acid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

  18. Amino acids in the Martian meteorite Nakhla.

    PubMed

    Glavin, D P; Bada, J L; Brinton, K L; McDonald, G D

    1999-08-03

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, beta-alanine, and gamma-amino-n-butyric acid (gamma-ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the D/L ratios (values range from <0.1 to 0.5), is similar to what is found in bacterially degraded organic matter. The amino acids in Nakhla appear to be derived from terrestrial organic matter that infiltrated the meteorite soon after its fall to Earth, although it is possible that some of the amino acids are endogenous to the meteorite. The rapid amino acid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

  19. Amino acids in the Martian meteorite Nakhla

    PubMed Central

    Glavin, Daniel P.; Bada, Jeffrey L.; Brinton, Karen L. F.; McDonald, Gene D.

    1999-01-01

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, β-alanine, and γ-amino-n-butyric acid (γ-ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the d/l ratios (values range from <0.1 to 0.5), is similar to what is found in bacterially degraded organic matter. The amino acids in Nakhla appear to be derived from terrestrial organic matter that infiltrated the meteorite soon after its fall to Earth, although it is possible that some of the amino acids are endogenous to the meteorite. The rapid amino acid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth. PMID:10430856

  20. Searching for Extraterrestrial Amino Acids in a Contaminated Meteorite: Amino Acid Analyses of the Canakkale L6 Chondrite

    NASA Technical Reports Server (NTRS)

    Burton, A. S.; Elsila, J. E.; Glavin, D. P.; Dworkin, J. P.; Ornek, C. Y.; Esenoglu, H. H.; Unsalan, O.; Ozturk, B.

    2016-01-01

    Amino acids can serve as important markers of cosmochemistry, as their abundances and isomeric and isotopic compositions have been found to vary predictably with changes in parent body chemistry and alteration processes. Amino acids are also of astrobiological interest because they are essential for life on Earth. Analyses of a range of meteorites, including all groups of carbonaceous chondrites, along with H, R, and LL chondrites, ureilites, and a martian shergottite, have revealed that amino acids of plausible extraterrestrial origin can be formed in and persist after a wide range of parent body conditions. However, amino acid analyses of L6 chondrites to date have not provided evidence for indigenous amino acids. In the present study, we performed amino acid analysis on larger samples of a different L6 chondite, Canakkale, to determine whether or not trace levels of indigenous amino acids could be found. The Canakkale meteor was an observed fall in late July, 1964, near Canakkale, Turkey. The meteorite samples (1.36 and 1.09 g) analyzed in this study were allocated by C. Y. Ornek, along with a soil sample (1.5 g) collected near the Canakkale recovery site.

  1. Sites that Can Produce Left-handed Amino Acids in the Supernova Neutrino Amino Acid Processing Model

    NASA Astrophysics Data System (ADS)

    Boyd, Richard N.; Famiano, Michael A.; Onaka, Takashi; Kajino, Toshitaka

    2018-03-01

    The Supernova Neutrino Amino Acid Processing model, which uses electron anti-neutrinos and the magnetic field from a source object such as a supernova to selectively destroy one amino acid chirality, is studied for possible sites that would produce meteoroids with partially left-handed amino acids. Several sites appear to provide the requisite magnetic field intensities and electron anti-neutrino fluxes. These results have obvious implications for the origin of life on Earth.

  2. Biopolymers Containing Unnatural Amino Acids

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

    Schultz, Peter

    Although the main chain structure of polymers has a profound effect on their materials properties, the side groups can also have dramatic effects on their properties including conductivity, liquid crystallinity, hydrophobicity, elasticity and biodegradability. Unfortunately control over the side chain structure of polymers remains a challenge – it is difficult to control the sequence of chain elongation when mixtures of monomers are polymerized, and postpolymerization side chain modification is made difficult by polymer effects on side chain reactivity. In contrast, the mRNA templated synthesis of polypeptides on the ribosome affords absolute control over the primary sequence of the twenty aminomore » acid monomers. Moreover, the length of the biopolymer is precisely controlled as are sites of crosslinking. However, whereas synthetic polymers can be synthesized from monomers with a wide range of chemically defined structures, ribosomal biosynthesis is largely limited to the 20 canonical amino acids. For many applications in material sciences, additional building blocks would be desirable, for example, amino acids containing metallocene, photoactive, and halogenated side chains. To overcome this natural constraint we have developed a method that allows unnatural amino acids, beyond the common twenty, to be genetically encoded in response to nonsense or frameshift codons in bacteria, yeast and mammalian cells with high fidelity and good yields. Here we have developed methods that allow identical or distinct noncanonical amino acids to be incorporated at multiple sites in a polypeptide chain, potentially leading to a new class of templated biopolymers. We have also developed improved methods for genetically encoding unnatural amino acids. In addition, we have genetically encoded new amino acids with novel physical and chemical properties that allow selective modification of proteins with synthetic agents. Finally, we have evolved new metal-ion binding sites in

  3. 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. © 2016 American Society for Nutrition.

  4. Protein and amino acid nutrition

    USDA-ARS?s Scientific Manuscript database

    Dairy cow protein and amino acid nutrition have a significant role in sustainable dairying. Protein, amino acids, and nitrogen are inextricably linked through effects in the rumen, metabolism of the cow, and environmental nutrient management. Feeding systems have been making progress toward emphasiz...

  5. Synthesis and biological activity of amino acid conjugates of abscisic acid.

    PubMed

    Todoroki, Yasushi; Narita, Kenta; Muramatsu, Taku; Shimomura, Hajime; Ohnishi, Toshiyuki; Mizutani, Masaharu; Ueno, Kotomi; Hirai, Nobuhiro

    2011-03-01

    We prepared 19 amino acid conjugates of the plant hormone abscisic acid (ABA) and investigated their biological activity, enzymatic hydrolysis by a recombinant Arabidopsis amidohydrolases GST-ILR1 and GST-IAR3, and metabolic fate in rice seedlings. Different sets of ABA-amino acids induced ABA-like responses in different plants. Some ABA-amino acids, including some that were active in bioassays, were hydrolyzed by recombinant Arabidopsis GST-IAR3, although GST-ILR1 did not show hydrolysis activity for any of the ABA-amino acids. ABA-L-Ala, which was active in all the bioassays, an Arabidopsis seed germination, spinach seed germination, and rice seedling elongation assays, except in a lettuce seed germination assay and was hydrolyzed by GST-IAR3, was hydrolyzed to free ABA in rice seedlings. These findings suggest that some plant amidohydrolases hydrolyze some ABA-amino acid conjugates. Because our study indicates the possibility that different plants have hydrolyzing activity toward different ABA-amino acids, an ABA-amino acid may function as a species-selective pro-hormone of ABA. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Amino Acid Contents of Meteorite Mineral Separates

    NASA Technical Reports Server (NTRS)

    Berger, E. L.; Burton, A. S; Locke, D.

    2017-01-01

    Indigenous amino acids have been found indigenous all 8 carbonaceous chondrite groups. However, the abundances, structural, enantiomeric and isotopic compositions of amino acids differ significantly among meteorites of different groups and petrologic types. This suggests that parent-body conditions (thermal or aqueous alteration), mineralogy, and the preservation of amino acids are linked. Previously, elucidating specific relationships between amino acids and mineralogy was not possible because the samples analyzed for amino acids were much larger than the scale at which petrologic heterogeneity is observed (sub mm-scale differences corresponding to sub-mg samples). Recent advances in amino acid measurements and application of techniques such as high resolution X-ray diffraction (HR-XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) for mineralogical characterizations allow us to perform coordinated analyses on the scale at which mineral heterogeneity is observed.

  7. Amino acids of the Murchison meteorite. II - Five carbon acyclic primary beta-, gamma-, and delta-amino alkanoic acids

    NASA Technical Reports Server (NTRS)

    Cronin, J. R.; Pizzarello, S.; Yuen, G. U.

    1985-01-01

    The five-carbon acyclic primary beta, gamma, and delta amino alkanoic acids of the Murchison meteorite are studied using gas chromatography-mass spectrometry and ion exchange chromatography. The chromatograms reveal that alpha is the most abundant monoamino alkanoic acid followed by gamma and beta, and an exponential increase in the amount of amino acid is observed as the carbon number increases in the homologous series. The influence of frictional heating, spontaneous thermal decomposition, and radiation of the synthesis of amino acids is examined. The data obtained support an amino acid synthesis process involving random combination of single-carbon precursors.

  8. The Physiological Mechanisms of Effect of Vitamins and Amino Acids on Tendon and Muscle Healing: A Systematic Review.

    PubMed

    Tack, Christopher; Shorthouse, Faye; Kass, Lindsy

    2018-05-01

    To evaluate the current literature via systematic review to ascertain whether amino acids/vitamins provide any influence on musculotendinous healing and if so, by which physiological mechanisms. EBSCO, PubMed, ScienceDirect, Embase Classic/Embase, and MEDLINE were searched using terms including "vitamins," "amino acids," "healing," "muscle," and "tendon." The primary search had 479 citations, of which 466 were excluded predominantly due to nonrandomized design. Randomized human and animal studies investigating all supplement types/forms of administration were included. Critical appraisal of internal validity was assessed using the Cochrane risk of Bias Tool or the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool for human and animal studies, respectively. Two reviewers performed duel data extraction. Twelve studies met criteria for inclusion: eight examined tendon healing and four examined muscle healing. All studies used animal models, except two human trials using a combined integrator. Narrative synthesis was performed via content analysis of demonstrated statistically significant effects and thematic analysis of proposed physiological mechanisms of intervention. Vitamin C/taurine demonstrated indirect effects on tendon healing through antioxidant activity. Vitamin A/glycine showed direct effects on extracellular matrix tissue synthesis. Vitamin E shows an antiproliferative influence on collagen deposition. Leucine directly influences signaling pathways to promote muscle protein synthesis. Preliminary evidence exists, demonstrating that vitamins and amino acids may facilitate multilevel changes in musculotendinous healing; however, recommendations on clinical utility should be made with caution. All animal studies and one human study showed high risk of bias with moderate interobserver agreement (k = 0.46). Currently, there is limited evidence to support the use of vitamins and amino acids for musculotendinous injury. Both

  9. Discovery and History of Amino Acid Fermentation.

    PubMed

    Hashimoto, Shin-Ichi

    There has been a strong demand in Japan and East Asia for L-glutamic acid as a seasoning since monosodium glutamate was found to present umami taste in 1907. The discovery of glutamate fermentation by Corynebacterium glutamicum in 1956 enabled abundant and low-cost production of the amino acid, creating a large market. The discovery also prompted researchers to develop fermentative production processes for other L-amino acids, such as lysine. Currently, the amino acid fermentation industry is so huge that more than 5 million metric tons of amino acids are manufactured annually all over the world, and this number continues to grow. Research on amino acid fermentation fostered the notion and skills of metabolic engineering which has been applied for the production of other compounds from renewable resources. The discovery of glutamate fermentation has had revolutionary impacts on both the industry and science. In this chapter, the history and development of glutamate fermentation, including the very early stage of fermentation of other amino acids, are reviewed.

  10. Research for amino acids in lunar samples.

    NASA Technical Reports Server (NTRS)

    Gehrke, C. W.; Zumwalt, R. W.; Kuo, K.; Rash, J. J.; Aue , W. A.; Stalling, D. L.; Kvenvolden, K. A.; Ponnamperuma, C.

    1972-01-01

    The study was primarily directed toward the examination of Apollo 14 lunar fines for indigenous amino acids or materials which could be converted to amino acids on hydrolysis with 6 N hydrochloric acid. Initial experiments were conducted to confirm the integrity of the derivatization reactions and reagents, and to optimize the gas-liquid chromatographic (GLC) instrumental and chromatographic system for the separation and flame ionization detection of the amino acid derivatives. In studies on the recovery of amino acids added to lunar fines, low recoveries were obtained when 10 ng of each amino acid were added to 50 mg of virgin fines, but the subsequent addition of 50 ng of each to the previously extracted sample resulted in much higher recoveries.

  11. Extraterrestrial Amino Acids in the Almahata Sitta Meteorite

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Aubrey, Andrew D.; Callahan, Michael P.; Dworkin, Jason P.; Elsila, Jamie E.; Parker, Eric T.; Bada, Jeffrey L.

    2009-01-01

    Amino acid analysis of a meteorite fragment of asteroid 2008 TC(sub 3) called Almahata Sitta was carried out using reverse-phase high-perfo rmance liquid chromatography coupled with UV fluorescence detection a nd time-of-flight mass spectrometry (HPLC-FD/ToF-MS) as part of a sam ple analysis consortium. HPLC analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to six-carbon aliph atic amino acids and one- to three carbon amines with abundances rang ing from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the amino acids alanine, Beta-amino-n-butyric acid (Beta-ABA), 2-amino-2- methylbutanoic acid (isovaline), and 2-aminopentanoic acid (no rvaline) in the meteorite were racemic (D/L approximately 1), indicat ing that these amino acids are indigenous to the meteorite and not te rrestrial contaminants. Several other non-protein amino acids were also identified in the meteorite above background levels including alpha -aminoisobutyric acid (alpha-AIB), 4-amino-2- methybutanoic acid, 4-a mino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. Th e total abundances of isovaline and AlB in Almahata Sitta are approximately 1000 times lower than the abundances of these amino acids found in the CM carbonaceous meteorite Murchison. The extremely love abund ances and unusual distribution of five carbon amino acids in Almahata Sitta compared to Cl, CM, and CR carbonaceous meteorites and may be due to extensive thermal alteration of amino acids on the parent aster oid by partial melting during formation or impact shock heating.

  12. Amino acids in the Yamato carbonaceous chrondrite from Antarctica

    NASA Technical Reports Server (NTRS)

    Shimoyama, A.; Ponnamperuma, C.; Yanai, K.

    1979-01-01

    Evidence for the presence of amino acids of extraterrestrial origin in the Antarctic Yamato carbonaceous chrondrite is presented. Hydrolyzed and nonhydrolyzed water-extracted amino acid samples from exterior, middle and interior portions of the meteorite were analyzed by an amino acid analyzer and by gas chromatography of N-TFA-isopropyl amino acid derivatives. Nine protein and six nonprotein amino acids were detected in the meteorite at abundances between 34 and less than one nmole/g, with equal amounts in interior and exterior portions. Nearly equal abundances of the D and L enantiomers of alanine, aspartic acid and glutamic acid were found, indicating the abiotic, therefore extraterrestrial, origin of the amino acids. The Antarctic environment and the uniformity of protein amino acid abundances are discussed as evidence against the racemization of terrestrially acquired amino acids, and similarities between Yamato amino acid compositions and the amino acid compositions of the Murchison and Murray type II carbonaceous chrondrites are indicated.

  13. Extraterrestrial material analysis: loss of amino acids during liquid-phase acid hydrolysis

    NASA Astrophysics Data System (ADS)

    Buch, Arnaud; Brault, Amaury; Szopa, Cyril; Freissinet, Caroline

    2015-04-01

    Searching for building blocks of life in extraterrestrial material is a way to learn more about how life could have appeared on Earth. With this aim, liquid-phase acid hydrolysis has been used, since at least 1970 , in order to extract amino acids and other organic molecules from extraterrestrial materials (e.g. meteorites, lunar fines) or Earth analogues (e.g. Atacama desert soil). This procedure involves drastic conditions such as heating samples in 6N HCl for 24 h, either under inert atmosphere/vacuum, or air. Analysis of the hydrolyzed part of the sample should give its total (free plus bound) amino acid content. The present work deals with the influence of the 6N HCl hydrolysis on amino acid degradation. Our experiments have been performed on a standard solution of 17 amino acids. After liquid-phase acid hydrolysis (6N HCl) under argon atmosphere (24 h at 100°C), the liquid phase was evaporated and the dry residue was derivatized with N-Methyl-N-(t-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and dimethylformamide (DMF), followed by gas chromatography-mass spectrometry analysis. After comparison with derivatized amino acids from the standard solution, a significant reduction of the chromatographic peak areas was observed for most of the amino acids after liquid-phase acid hydrolysis. Furthermore, the same loss pattern was observed when the amino acids were exposed to cold 6N HCl for a short amount of time. The least affected amino acid, i.e. glycine, was found to be 73,93% percent less abundant compared to the non-hydrolyzed standard, while the most affected, i.e. histidine, was not found in the chromatograms after hydrolysis. Our experiments thereby indicate that liquid-phase acid hydrolysis, even under inert atmosphere, leads to a partial or total loss of all of the 17 amino acids present in the standard solution, and that a quick cold contact with 6N HCl is sufficient to lead to a loss of amino acids. Therefore, in the literature, the reported increase

  14. Distribution of Amino Acids in Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; Noble, S. K.; Gibson, E. K., Jr.

    2014-01-01

    One of the most eagerly studied questions upon initial return of lunar samples was whether significant amounts of organic compounds, including amino acids, were present. Analyses during the 1970s produced only tentative and inconclusive identifications of indigenous amino acids. Those analyses were hampered by analytical difficulties including relative insensitivity to certain compounds, the inability to separate chiral enantiomers, and the lack of compound-specific isotopic measurements, which made it impossible to determine whether the detected amino acids were indigenous to the lunar samples or the results of contamination. Numerous advances have been made in instrumentation and methodology for amino acid characterization in extraterrestrial samples in the intervening years, yet the origin of amino acids in lunar regolith samples has been revisited only once for a single lunar sample, (3) and remains unclear. Here, we present initial data from the analyses of amino acid abundances in 12 lunar regolith samples. We discuss these abundances in the context of four potential amino acid sources: (1) terrestrial biological contamination; (2) contamination from lunar module (LM) exhaust; (3) derivation from solar windimplanted precursors; and (4) exogenous delivery from meteorites.

  15. Amino acids as antioxidants for frying oil

    USDA-ARS?s Scientific Manuscript database

    Amino acids, proteins and hydrolysates of proteins have been known to protect edible oils from oxidation. While amino acids and related materials have high potential as antioxidants for frying oil, effectiveness of each amino acid and mechanisms of their activities are not well understood yet. Propo...

  16. Plasma free amino acid kinetics in rainbow trout (Oncorhynchus mykiss) using a bolus injection of 15N-labeled amino acids.

    PubMed

    Robinson, Jacob William; Yanke, Dan; Mirza, Jeff; Ballantyne, James Stuart

    2011-02-01

    To gain insight into the metabolic design of the amino acid carrier systems in fish, we injected a bolus of (15)N amino acids into the dorsal aorta in mature rainbow trout (Oncorhynchus mykiss). The plasma kinetic parameters including concentration, pool size, rate of disappearance (R(d)), half-life and turnover rate were determined for 15 amino acids. When corrected for metabolic rate, the R(d) values obtained for trout for most amino acids were largely comparable to human values, with the exception of glutamine (which was lower) and threonine (which was higher). R(d) values ranged from 0.9 μmol 100 g(-1) h(-1) (lysine) to 22.1 μmol 100 g(-1) h(-1) (threonine) with most values falling between 2 and 6 μmol 100 g(-1) h(-1). There was a significant correlation between R(d) and the molar proportion of amino acids in rainbow trout whole body protein hydrolysate. Other kinetic parameters did not correlate significantly with whole body amino acid composition. This indicates that an important design feature of the plasma-free amino acids system involves proportional delivery of amino acids to tissues for protein synthesis.

  17. Gemini surfactants from natural amino acids.

    PubMed

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa

    2014-03-01

    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed. © 2013.

  18. Distinctive Roles of D-Amino Acids in the Homochiral World: Chirality of Amino Acids Modulates Mammalian Physiology and Pathology.

    PubMed

    Sasabe, Jumpei; Suzuki, Masataka

    2018-05-22

    Living organisms enantioselectively employ L-amino acids as the molecular architecture of protein synthesized in the ribosome. Although L-amino acids are dominantly utilized in most biological processes, accumulating evidence points to the distinctive roles of D-amino acids in non-ribosomal physiology. Among the three domains of life, bacteria have the greatest capacity to produce a wide variety of D-amino acids. In contrast, archaea and eukaryotes are thought generally to synthesize only two kinds of D-amino acids: D-serine and D-aspartate. In mammals, D-serine is critical for neurotransmission as an endogenous coagonist of N-methyl D-aspartate receptors. Additionally, D-aspartate is associated with neurogenesis and endocrine systems. Furthermore, recognition of D-amino acids originating in bacteria is linked to systemic and mucosal innate immunity. Among the roles played by D-amino acids in human pathology, the dysfunction of neurotransmission mediated by D-serine is implicated in psychiatric and neurological disorders. Non-enzymatic conversion of L-aspartate or L-serine residues to their D-configurations is involved in age-associated protein degeneration. Moreover, the measurement of plasma or urinary D-/L-serine or D-/L-aspartate levels may have diagnostic or prognostic value in the treatment of kidney diseases. This review aims to summarize current understanding of D-amino-acid-associated biology with a major focus on mammalian physiology and pathology.

  19. Amino Acids Regulate Transgene Expression in MDCK Cells

    PubMed Central

    Torrente, Marta; Guetg, Adriano; Sass, Jörn Oliver; Arps, Lisa; Ruckstuhl, Lisa; Camargo, Simone M. R.; Verrey, François

    2014-01-01

    Gene expression and cell growth rely on the intracellular concentration of amino acids, which in metazoans depends on extracellular amino acid availability and transmembrane transport. To investigate the impact of extracellular amino acid concentrations on the expression of a concentrative amino acid transporter, we overexpressed the main kidney proximal tubule luminal neutral amino acid transporter B0AT1-collectrin (SLC6A19-TMEM27) in MDCK cell epithelia. Exogenously expressed proteins co-localized at the luminal membrane and mediated neutral amino acid uptake. However, the transgenes were lost over few cell culture passages. In contrast, the expression of a control transgene remained stable. To test whether this loss was due to inappropriately high amino acid uptake, freshly transduced MDCK cell lines were cultivated either with physiological amounts of amino acids or with the high concentration found in standard cell culture media. Expression of exogenous transporters was unaffected by physiological amino acid concentration in the media. Interestingly, mycoplasma infection resulted in a significant increase in transgene expression and correlated with the rapid metabolism of L-arginine. However, L-arginine metabolites were shown to play no role in transgene expression. In contrast, activation of the GCN2 pathway revealed by an increase in eIF2α phosphorylation may trigger transgene derepression. Taken together, high extracellular amino acid concentration provided by cell culture media appears to inhibit the constitutive expression of concentrative amino acid transporters whereas L-arginine depletion by mycoplasma induces the expression of transgenes possibly via stimulation of the GCN2 pathway. PMID:24797296

  20. Amino acid homeostasis and signalling in mammalian cells and organisms

    PubMed Central

    Bröer, Angelika

    2017-01-01

    Cells have a constant turnover of proteins that recycle most amino acids over time. Net loss is mainly due to amino acid oxidation. Homeostasis is achieved through exchange of essential amino acids with non-essential amino acids and the transfer of amino groups from oxidised amino acids to amino acid biosynthesis. This homeostatic condition is maintained through an active mTORC1 complex. Under amino acid depletion, mTORC1 is inactivated. This increases the breakdown of cellular proteins through autophagy and reduces protein biosynthesis. The general control non-derepressable 2/ATF4 pathway may be activated in addition, resulting in transcription of genes involved in amino acid transport and biosynthesis of non-essential amino acids. Metabolism is autoregulated to minimise oxidation of amino acids. Systemic amino acid levels are also tightly regulated. Food intake briefly increases plasma amino acid levels, which stimulates insulin release and mTOR-dependent protein synthesis in muscle. Excess amino acids are oxidised, resulting in increased urea production. Short-term fasting does not result in depletion of plasma amino acids due to reduced protein synthesis and the onset of autophagy. Owing to the fact that half of all amino acids are essential, reduction in protein synthesis and amino acid oxidation are the only two measures to reduce amino acid demand. Long-term malnutrition causes depletion of plasma amino acids. The CNS appears to generate a protein-specific response upon amino acid depletion, resulting in avoidance of an inadequate diet. High protein levels, in contrast, contribute together with other nutrients to a reduction in food intake. PMID:28546457

  1. Concentration variations of amino acids in mammalian fossils: effects of diagenesis and the implications for amino acid racemization analysis

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

    Blackwell, B.; Rutter, N.W.

    Detailed amino acid analysis of bones, teeth, and antler from several mammal species have shown that concentrations of several amino acids can be related to three factors: type of material analyzed, diagenetic alteration of the material, and relative age of the fossil. Concentrations of several amino acids are significantly different in enamel compared to those of dentine or cement. This can be used to check that no contamination of one material by another has occurred, which is critical for using the data for amino acid dating, since all three materials have different racemization rates for some acids. With increased inmore » growth of secondary minerals, generally reduced amino acid concentrations are observed. Interacid ratios and concentrations vary significantly the norms expected for the type of material with increasing degrees of alteration. These effects can be linked to abnormal racemization ratios observed in the same samples. Therefore, abnormal concentrations and/or interacid ratios can be used to detect samples in which the D/L amino acid ratios otherwise appear normal, thereby insuring better accuracy of amino acid racemization analysis. For unaltered fossils, with increasing sample age regardless the type of material, some amino acids steadily degrade, while others actually increase in concentration initially due to their generation as by-products of decay. Preliminary studies indicate that this progressive alteration can used to complement racemization data for determining relative stratigraphic sequences.« less

  2. Amino Acid Sensing in Skeletal Muscle

    PubMed Central

    Moro, Tatiana; Ebert, Scott M.; Adams, Christopher M.; Rasmussen, Blake B.

    2016-01-01

    Aging impairs skeletal muscle protein synthesis, leading to muscle weakness and atrophy. However, the underlying molecular mechanisms remain poorly understood. Here, we review evidence that mTORC1- and ATF4-mediated amino acid sensing pathways, triggered by impaired amino acid delivery to aged skeletal muscle, may play important roles in skeletal muscle aging. Interventions that alleviate age-related impairments in muscle protein synthesis, strength and/or muscle mass appear to do so by reversing age-related changes in skeletal muscle amino acid delivery, mTORC1 activity and/or ATF4 activity. An improved understanding of the mechanisms and roles of amino acid sensing pathways in skeletal muscle may lead to evidence-based strategies to attenuate sarcopenia. PMID:27444066

  3. The physiological and pathophysiological roles of taurine in adipose tissue in relation to obesity.

    PubMed

    Murakami, Shigeru

    2017-10-01

    Obesity is caused by an imbalance between energy intake and energy expenditure. It is established that obesity is a state of low-grade chronic inflammation, which is characterized by enlarged hypertrophied adipocytes, increased infiltration by macrophages and marked changes in the secretion of adipokines and free fatty acids. The effects of taurine on the pathogenesis of obesity have been reported in animals and humans. Although the mechanisms underlying the anti-obesity action of taurine remain to be defined, taurine seems to ameliorate obesity through stimulation of energy expenditure, modulation of lipid metabolism, anorexic effect, anti-inflammatory and anti-oxidative effects. Recent studies revealed that taurine supplementation reduces the infiltration of macrophages and modulates the polarization of adipose tissue macrophages in high-fat diet-induced obese mice. In addition, taurine downregulates the production of pro-inflammatory cytokines by adipocytes, suggesting that taurine plays an anti-inflammatory role in adipose tissue. This article reviews the effects and mechanisms of taurine on the development of obesity, focusing on the role of taurine in white adipose tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Effects of clofibric acid on the biliary excretion of benoxaprofen glucuronide and taurine conjugate in rats.

    PubMed

    Okada, K; Kanoh, H; Mohri, K

    2011-10-01

    Benoxaprofen (BOP) is a 2-methyl propionic acid derivative with anti-inflammatory activity. BOP has an asymmetric carbon, and receives chiral inversion from R to S in vivo. BOP is metabolized to glucuronide (BOP-G) and taurine conjugate (BOP-T). The configuration of BOP-G is mainly S, and that of BOP-T is R. Chiral inversion of R to S of the propionic acid moiety and amino acid conjugation of carboxyl compounds proceed via an acyl CoA intermediate. It is known that fibrates, used in hyperlipidemia, induce acyl CoA synthetase and increase CoA concentration. We administered racemic BOP (10 mg/kg body weight) to rats (CFA+) pre-administered clofibric acid (CFA, 280 mg/kg/day), and studied BOP, BOP-G, and BOP-T enantiomer concentrations in plasma and bile up to 12 h after administration. The findings were compared with those in rats (CFA-) that had not received CFA. Furthermore, we studied the amounts of BOP-G enantiomer produced by glucuronidation in vitro using microsomes pretreated with CFA. The amounts of (S)-BOP-G in CFA+ rats were 2.7-fold larger than that in CFA- rats. Although (R)-BOP-T was excreted in CFA- rats, BOP-T could not be detected in CFA+ rats. Plasma clearance values of racemic BOP and (S)-BOP in CFA+ rats were 5-fold and 6-fold larger than those in CFA- rats, respectively. (S)-BOP-G formation activities were higher than (R)-BOP-G formation activities in both CFA+and CFA- microsomes. These findings suggest that CFA increases biliary excretion of (S)-BOP-G and facilitates plasma elimination of BOP, and further suggests that CFA predominantly induces chiral inversion to S rather than metabolic reaction to (R)-BOP-T, resulting in an increase of (S)-BOP-G.

  5. Formation of Amino Acid Thioesters for Prebiotic Peptide Synthesis: Catalysis By Amino Acid Products

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    The origin of life can be described as a series of events in which a prebiotic chemical process came increasingly under the control of its catalytic products. In our search for this prebiotic process that yielded catalytic takeover products (such as polypeptides), we have been investigating a reaction system that generates peptide-forming amino acid thioesters from formaldehyde, glycolaldehyde, and ammonia in the presence of thiols. As shown below, this model process begins by aldol condensation of formaldehyde and glycolaldehyde to give trioses and releases. These sugars then undergo beta-dehydration yielding their respective alpha-ketoaldehydes. Addition of ammonia to the alpha-ketoaldehydes yields imines which can either: (a) rearrange in the presence of thesis to give amino acid thioesters or (be react with another molecule of aldehyde to give imidazoles. This 'one-pot' reaction system operates under mild aqueous conditions, and like modem amino acid biosynthesis, uses sugar intermediates which are converted to products by energy-yielding redox reactions. Recently, we discovered that amino acids, such as the alanine reaction product, catalyze the first and second steps of the process. In the presence of ammonia the process also generates other synthetically useful products, like the important biochemical -- pyruvic acid.

  6. Amino Acid Metabolism in Acute Renal Failure: Influence of Intravenous Essential L-Amino Acid Hyperalimentation Therapy

    PubMed Central

    Abel, Ronald M.; Shih, Vivian E.; Abbott, William M.; Beck, Clyde H.; Fischer, Josef E.

    1974-01-01

    A solution of 8 essential I-amino acids and hypertonic dextrose was administered to 5 patients in acute postoperative renal failure in a program of hyperalimentation designed to decrease the patient's catabolic state and to accrue certain metabolic benefits. A sixth patient receiving intravenous glucose alone served as a control. The pretreatment plasma concentrations of amino acids in all 6 patients did not differ significantly from normal; following intravenous essential amino acids at a dose of approximately 12.6 gm/24 hours, no significant elevations out of the normal range of these substances occurred. Since urinary excretion rates did not dramatically increase, urinary loss was excluded as a possible cause for the failure of increase of plasma concentrations. The results suggest that the administration of an intravenous solution of 1-amino acids and hypertonic dextrose is associated with rapid clearance from the blood of these substances and, with a failure of increased urinary excretion, indirect evidence of amino acid utilization for protein synthesis has been obtained. Histidine supplementation in patients with acute renal failure is probably unnecessary based on the lack of significant decreases in histidine concentrations in these patients. PMID:4850497

  7. Amino acids derived from Titan tholins

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Sagan, C.; Ogino, H.; Nagy, B.; Er, C.; Schram, K. H.; Arakawa, E. T.

    1986-01-01

    An organic heteropolymer (Titan tholin) was produced by continuous dc discharge through a 0.9 N2/0.1 CH4 gas mixture at 0.2 mbar pressure, roughly simulating the cloudtop atmosphere of Titan. Treatment of this tholin with 6N HCl yielded 16 amino acids by gas chromatography after derivatization of N-trifluroacetyl isopropyl esters on two different capillary columns. Identifications were confirmed by GC/MS. Glycine, aspartic acid, and alpha- and beta-alanine were produced in greatest abundance; the total yield of amino acids was approximately 10(-2), approximately equal to the yield of urea. The presence of "nonbiological" amino acids, the absence of serine, and the fact that the amino acids are racemic within experimental error together indicate that these molecules are not due to microbial or other contamination, but are derived from the tholin. In addition to the HCN, HC2CN, and (CN)2 found by Voyager, nitriles and aminonitriles should be sought in the Titanian atmosphere and, eventually, amino acids on the surface. These results suggest that episodes of liquid water in the past or future of Titan might lead to major further steps in prebiological organic chemistry on that body.

  8. Biosensors for D-amino acid detection.

    PubMed

    Sacchi, Silvia; Rosini, Elena; Caldinelli, Laura; Pollegioni, Loredano

    2012-01-01

    The presence of D-amino acids in foods is promoted by harsh technological processes (e.g., high temperature or extreme pH values) or can be the consequence of adulteration or microbial contamination (D-amino acids are major components of the bacterial cell wall). For this reason, quality control is becoming more and more important both for the industry (as a cost factor) and for consumer protection. For routine food analysis and quality control, simple and easily applicable analytical methods are needed: biosensors can often satisfy these requirements. The use of an enzymatic, stereospecific reaction could confer selectivity to a biosensor for detecting and quantifying D-amino acids in foodstuffs. The flavoenzyme D-amino acid oxidase from the yeast Rhodotorula gracilis is an ideal biocatalyst for this kind of application because of its absolute stereospecificity, very high turnover number with various substrates, tight binding with the FAD cofactor, and broad substrate specificity. Furthermore, alterations in the local brain concentrations of D-serine (predominantly D-amino acid in the mammalian central nervous system) have been related to several neurological and psychiatric diseases. Therefore, quantifying this neuromodulator represents an important task in biological, medical, and pharmaceutical research. Recently, an enzymatic microbiosensor, also using R. gracilis D-amino acid oxidase as biocatalyst, was developed for detecting D-serine in vivo.

  9. Benzylserine inhibits breast cancer cell growth by disrupting intracellular amino acid homeostasis and triggering amino acid response pathways.

    PubMed

    van Geldermalsen, Michelle; Quek, Lake-Ee; Turner, Nigel; Freidman, Natasha; Pang, Angel; Guan, Yi Fang; Krycer, James R; Ryan, Renae; Wang, Qian; Holst, Jeff

    2018-06-26

    Cancer cells require increased levels of nutrients such as amino acids to sustain their rapid growth. In particular, leucine and glutamine have been shown to be important for growth and proliferation of some breast cancers, and therefore targeting the primary cell-surface transporters that mediate their uptake, L-type amino acid transporter 1 (LAT1) and alanine, serine, cysteine-preferring transporter 2 (ASCT2), is a potential therapeutic strategy. The ASCT2 inhibitor, benzylserine (BenSer), is also able to block LAT1 activity, thus inhibiting both leucine and glutamine uptake. We therefore aimed to investigate the effects of BenSer in breast cancer cell lines to determine whether combined LAT1 and ASCT2 inhibition could inhibit cell growth and proliferation. BenSer treatment significantly inhibited both leucine and glutamine uptake in MCF-7, HCC1806 and MDA-MB-231 breast cancer cells, causing decreased cell viability and cell cycle progression. These effects were not primarily leucine-mediated, as BenSer was more cytostatic than the LAT family inhibitor, BCH. Oocyte uptake assays with ectopically expressed amino acid transporters identified four additional targets of BenSer, and gas chromatography-mass spectrometry (GCMS) analysis of intracellular amino acid concentrations revealed that this BenSer-mediated inhibition of amino acid uptake was sufficient to disrupt multiple pathways of amino acid metabolism, causing reduced lactate production and activation of an amino acid response (AAR) through activating transcription factor 4 (ATF4). Together these data showed that BenSer blockade inhibited breast cancer cell growth and viability through disruption of intracellular amino acid homeostasis and inhibition of downstream metabolic and growth pathways.

  10. Amino acids precursors in lunar finds

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Harada, K.; Hare, P. E.; Hinsch, G.; Mueller, G.

    1975-01-01

    The consistent pattern is discussed of amino acids found in lunar dust from Apollo missions. The evidence indicates that compounds yielding amino acids were implanted into the surface of the moon by the solar wind, and the kind and amounts of amino acids found on the moon are closely similar to those found in meteorites. It is concluded that there is a common cosmochemical pattern for the moom and meteorites, and this offers evidence of a common course of cosmochemical reactions for carbon.

  11. Amino Acid Degradation after Meteoritic Impact Simulation

    NASA Technical Reports Server (NTRS)

    Bertrand, M.; Westall, F.; vanderGaast, S.; Vilas, F.; Hoerz, F.; Barnes, G.; Chabin, A.; Brack, A.

    2008-01-01

    Amino acids are among the most important prebiotic molecules as it is from these precursors that the building blocks of life were formed [1]. Although organic molecules were among the components of the planetesimals making up the terrestrial planets, large amounts of primitive organic precursor molecules are believed to be exogenous in origin and to have been imported to the Earth via micrometeorites, carbonaceous meteorites and comets, especially during the early stages of the formation of the Solar System [1,2]. Our study concerns the hypothesis that prebiotic organic matter, present on Earth, was synthesized in the interstellar environment, and then imported to Earth by meteorites or micrometeorites. We are particularly concerned with the formation and fate of amino acids. We have already shown that amino acid synthesis is possible inside cometary grains under interstellar environment conditions [3]. We are now interested in the effects of space conditions and meteoritic impact on these amino acids [4-6]. Most of the extraterrestrial organic molecules known today have been identified in carbonaceous chondrite meteorites [7]. One of the components of these meteorites is a clay with a composition close to that of saponite, used in our experiments. Two American teams have studied the effects of impact on various amino acids [8,9]. [8] investigated amino acids in saturated solution in water with pressure ranges between 5.1 and 21 GPa and temperature ranges between 412 and 870 K. [9] studied amino acids in solid form associated with and without minerals (Murchison and Allende meteorite extracts) and pressure ranges between 3 and 30 GPa. In these two experiments, the amino acids survived up to 15 GPa. At higher pressure, the quantity of preserved amino acids decreases quickly. Some secondary products such as dipeptides and diketopiperazins were identified in the [8] experiment.

  12. Amino Acids from a Comet

    NASA Technical Reports Server (NTRS)

    Cook, Jamie Elisla

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a coetary amino acid.

  13. Impact of a Specific Amino Acid Composition with Micronutrients on Well-Being in Subjects with Chronic Psychological Stress and Exhaustion Conditions: A Pilot Study

    PubMed Central

    Armborst, Deborah; Metzner, Christine; Alteheld, Birgit; Bitterlich, Norman; Rösler, Daniela; Siener, Roswitha

    2018-01-01

    Chronic work-life stress leads to dysfunction of the hypothalamus–pituitary–adrenal axis, the autonomic nervous system, and the serotonergic system, with resultant impairment of overall well-being. Aim of the study was to improve perceived stress by a specific amino acid composition with micronutrients in the verum versus placebo group. A total of 59 participants (18–65 years) with self-reported perceived chronic stress and exhaustion conditions participated in this randomized, double-blind, placebo-controlled study. The Perceived Stress Questionnaire (PSQ30), amino acid profile, anthropometric, clinical, blood, urine parameters, and dietary intake were assessed. After 12 weeks, the verum group achieved significantly greater improvements in the total PSQ30 score compared with the placebo group. In the verum group, serum taurine concentration, folic acid concentration, urinary magnesium excretion, and the ratio of l-tryptophan to the sum of competing amino acids rose significantly. In the placebo group, serum concentrations of serotonin, protein, and magnesium decreased significantly, whereas the cardiometabolic risk parameters body weight, body mass index, waist circumference, and waist-to-height ratio increased significantly. Compared with placebo, the verum supplementation resulted in a higher improvement in perceived stress. Beneficial effects on the serotonergic system and preventive effects on magnesium homeostasis and some cardiometabolic risk factors were supposed. Additional effects might be caused by the optimized food intake. PMID:29710825

  14. PHYSIOLOGY OF THE AMINO ACIDS.

    PubMed

    VAN Slyke, D D

    1942-03-13

    We have followed the amino acids from their entrance into the alimentary tract in the form of food proteins through the successive steps of digestion, absorption into the blood stream and passage from the blood stream into the tissues, where they are concentrated by some unknown mechanism to many times their concentration in the blood plasma. We have seen something of the way in which certain of the amino acids can be transformed into one another in the body or synthesized from ammonia and keto acids. However, we have had to admit that our bodies can form in such ways only about half of the different amino acids that are required, and that the other half must be made for us by plants, bacteria or other organisms which have greater synthetic powers than we. And finally we have seen something of the manifold fates of the amino acids after they have entered our tissues; how they may be destroyed and their nitrogenous parts turned into urea in the liver before it is possible to put them to their more specialized uses, how their carbon fractions can be used to form glucose, how they may sacrifice themselves to protect us from toxic products, how they can serve as source material for certain vitamins, hormones and other compounds with physiological functions still to be identified, and how finally those amino acids which are not deflected to these various fates may enter into the proteins of the tissues and become for a time parts of our living structures.

  15. Effects of alkali or acid treatment on the isomerization of amino acids.

    PubMed

    Ohmori, Taketo; Mutaguchi, Yuta; Doi, Katsumi; Ohshima, Toshihisa

    2012-10-01

    The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue. Copyright © 2012. Published by Elsevier B.V.

  16. Relative reactivity of amino acids with chlorine in mixtures.

    PubMed

    Na, Chongzheng; Olson, Terese M

    2007-05-01

    The relative reactivity of chlorine with amino acids is an important determinant of the resulting chlorination products in systems where chlorine is the limiting reagent, for example, in the human gastrointestinal tract after consumption of chlorine-containing water, or during food preparation with chlorinated water. Since few direct determinations of the initial reactivity of chlorine with amino acids have been made, 17 amino acids were compared in this study using competitive kinetic principles. The experimental results showed that (1) most amino acids have similar initial reactivities at neutral pH; (2) amino acids with thiol groups such as methionine and cysteine are exceptionally reactive and produce sulfoxides; (3) amino acids without thiol groups primarily undergo monochlorination of the amino nitrogen; and (4) glycine and proline are the least reactive. Dichlorination was estimated to occur with approximately 26% of the amino acid groups when the total amino acid: chlorine concentrations were equal.

  17. Unnatural reactive amino acid genetic code additions

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

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  18. Unnatural reactive amino acid genetic code additions

    DOEpatents

    Deiters, Alexander; Cropp, Ashton T; Chin, Jason W; Anderson, Christopher J; Schultz, Peter G

    2013-05-21

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  19. Unnatural reactive amino acid genetic code additions

    DOEpatents

    Deiters, Alexander [La Jolla, CA; Cropp, T Ashton [San Diego, CA; Chin, Jason W [Cambridge, GB; Anderson, J Christopher [San Francisco, CA; Schultz, Peter G [La Jolla, CA

    2011-02-15

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  20. Unnatural reactive amino acid genetic code additions

    DOEpatents

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2014-08-26

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  1. Unnatural reactive amino acid genetic code additions

    DOEpatents

    Deiters, Alexander [La Jolla, CA; Cropp, T Ashton [Bethesda, MD; Chin, Jason W [Cambridge, GB; Anderson, J Christopher [San Francisco, CA; Schultz, Peter G [La Jolla, CA

    2011-08-09

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNAsyn-thetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  2. Profiling of Amino Acids and Their Derivatives Biogenic Amines Before and After Antipsychotic Treatment in First-Episode Psychosis.

    PubMed

    Leppik, Liisa; Kriisa, Kärt; Koido, Kati; Koch, Kadri; Kajalaid, Kärolin; Haring, Liina; Vasar, Eero; Zilmer, Mihkel

    2018-01-01

    Schizophrenia (SCH) is a heterogeneous disorder, deriving from a potential multitude of etiopathogenetic factors. During the past few years there has been an increasing interest in the role of circulating amino acids (AAs) and biogenic amines (BAs) in the pathophysiology of SCH. In the present study, we aimed to provide an insight into the potential role of alterations in levels of AAs and BAs as well as examine their more specific metabolic shifts in relation to early stage of SCH. We measured 21 AAs and 17 BAs in serum samples of patients with first-episode psychosis (FEP) before and after 7-month antipsychotic treatment in comparison to control subjects (CSs). According to multivariate analysis, antipsychotic-naïve FEP patients had significantly higher levels of taurine and spermine, whereas values of proline (Pro), alpha-aminoadipic acid (alpha-AAA), kynurenine (Kyn), valine (Val), tyrosine (Tyr), citrulline (Citr), tryptophan (Trp), and histidine (His) were diminished compared to CSs. Increased levels of taurine and spermine, as well as reduced levels of alpha-AAA and Kyn probably reflect the compromised function of N -methyl-D-aspartate (NMDA) receptors in patients. The decreased levels of Pro (AA modulating the function of glutamate decarboxylase) likely reflect the imbalanced function of gamma-aminobutyric acid (GABA) system in the brain of FEP patients. The alterations in ratio between Tyr and phenylalanine (Phe) can be taken as a sign of compromised function of dopaminergic system. These metabolic shifts were reinstated by 7-month antipsychotic treatment. Serum metabolic profiles can be regarded as important indicators to investigate clinical course of SCH and treatment response.

  3. Amino Acid Availability Modulates Vacuolar H+-ATPase Assembly*

    PubMed Central

    Stransky, Laura A.; Forgac, Michael

    2015-01-01

    The vacuolar H+-ATPase (V-ATPase) is an ATP-dependent proton pump composed of a peripheral ATPase domain (V1) and a membrane-integral proton-translocating domain (V0) and is involved in many normal and disease processes. An important mechanism of regulating V-ATPase activity is reversible assembly of the V1 and V0 domains. Increased assembly in mammalian cells occurs under various conditions and has been shown to involve PI3K. The V-ATPase is necessary for amino acid-induced activation of mechanistic target of rapamycin complex 1 (mTORC1), which is important in controlling cell growth in response to nutrient availability and growth signals. The V-ATPase undergoes amino acid-dependent interactions with the Ragulator complex, which is involved in recruitment of mTORC1 to the lysosomal membrane during amino acid sensing. We hypothesized that changes in the V-ATPase/Ragulator interaction might involve amino acid-dependent changes in V-ATPase assembly. To test this, we measured V-ATPase assembly by cell fractionation in HEK293T cells treated with and without amino acids. V-ATPase assembly increases upon amino acid starvation, and this effect is reversed upon readdition of amino acids. Lysosomes from amino acid-starved cells possess greater V-ATPase-dependent proton transport, indicating that assembled pumps are catalytically active. Amino acid-dependent changes in both V-ATPase assembly and activity are independent of PI3K and mTORC1 activity, indicating the involvement of signaling pathways distinct from those implicated previously in controlling assembly. By contrast, lysosomal neutralization blocks the amino acid-dependent change in assembly and reactivation of mTORC1 after amino acid starvation. These results identify an important new stimulus for controlling V-ATPase assembly. PMID:26378229

  4. Effects of Taurine Supplementation on Growth in Low Birth Weight Infants: A Systematic Review and Meta-Analysis.

    PubMed

    Cao, Shun-Li; Jiang, Hong; Niu, Shi-Ping; Wang, Xiao-Hu; Du, Shan

    2018-01-25

    To summarize the available randomized controlled trials (RCTs) to evaluate the effect of taurine supplementation on growth in low birth weight infants (LBW). PubMed, EmBase, and Cochrane Library electronic databases were searched for published articles through March 2017. Analysis was done to examine the effect of taurine supplementation on growth, and sensitivity analysis was performed by removing each individual study from meta-analysis. Results of 9 trials totaling 216 LBW infants in the present meta-analysis were collected and analyzed. The conclusion of included studies demonstrated that taurine supplementation significantly reduced length gain (WMD:-0.18; P < 0.001), plasma glycine (WMD:-106.71; P = 0.033), alanine (WMD:-229.30; P = 0.002), leucine (WMD:-64.76; P < 0.001), tyrosine (WMD:-118.11; P < 0.001), histidine (WMD:-52.16; P < 0.001), proline (WMD: -84.29; P = 0.033), and asparagine-glutamine (WMD:-356.30; P < 0.001). However, taurine supplementation was associated with higher levels of acidic sterols (WMD:0.61; P = 0.024), total fatty acids (WMD:7.94; P = 0.050), total saturated fatty acids (WMD:9.70; P < 0.001), and unsaturated fatty acids (WMD:6.63; P < 0.001). Finally, taurine supplementation had little or no significant effect on weight gain, head circumference gain, plasma taurine, threonine, serine, citrulline, valine, methionine, isoleucine, phenylalanine, ornithine, lysine, arginine, glutamate, hydroxyproline, aspartate, dietary cholesterol, endogenous neutral sterols, cholesterol synthesis, and medium-chain triglycerides. The findings suggest that although there are several significant differences in plasma indeces, no significant effect on growth in LBW infants was observed with taurine supplementation.

  5. Amino acid analyses of Apollo 14 samples.

    NASA Technical Reports Server (NTRS)

    Gehrke, C. W.; Zumwalt, R. W.; Kuo, K.; Aue, W. A.; Stalling, D. L.; Kvenvolden, K. A.; Ponnamperuma, C.

    1972-01-01

    Detection limits were between 300 pg and 1 ng for different amino acids, in an analysis by gas-liquid chromatography of water extracts from Apollo 14 lunar fines in which amino acids were converted to their N-trifluoro-acetyl-n-butyl esters. Initial analyses of water and HCl extracts of sample 14240 and 14298 samples showed no amino acids above background levels.

  6. Rapid and reliable quantitation of amino acids and myo-inositol in mouse brain by high performance liquid chromatography and tandem mass spectrometry.

    PubMed

    Bathena, Sai P; Huang, Jiangeng; Epstein, Adrian A; Gendelman, Howard E; Boska, Michael D; Alnouti, Yazen

    2012-04-15

    Amino acids and myo-inositol have long been proposed as putative biomarkers for neurodegenerative diseases. Accurate measures and stability have precluded their selective use. To this end, a sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method based on multiple reaction monitoring was developed to simultaneously quantify glutamine, glutamate, γ-aminobutyric acid (GABA), aspartic acid, N-acetyl aspartic acid, taurine, choline, creatine, phosphocholine and myo-inositol in mouse brain by methanol extractions. Chromatography was performed using a hydrophilic interaction chromatography silica column within in a total run time of 15 min. The validated method is selective, sensitive, accurate, and precise. The method has a limit of quantification ranging from 2.5 to 20 ng/ml for a range of analytes and a dynamic range from 2.5-20 to 500-4000 ng/ml. This LC-MS/MS method was validated for biomarker discovery in models of human neurological disorders. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Genetics of Amino Acid Taste and Appetite123

    PubMed Central

    Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Beauchamp, Gary K

    2016-01-01

    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

  8. Amino acids in the cultivation of mammalian cells.

    PubMed

    Salazar, Andrew; Keusgen, Michael; von Hagen, Jörg

    2016-05-01

    Amino acids are crucial for the cultivation of mammalian cells. This importance of amino acids was realized soon after the development of the first cell lines, and a solution of a mixture of amino acids has been supplied to cultured cells ever since. The importance of amino acids is further pronounced in chemically defined mammalian cell culture media, making the consideration of their biological and chemical properties necessary. Amino acids concentrations have been traditionally adjusted to their cellular consumption rates. However, since changes in the metabolic equilibrium of amino acids can be caused by changes in extracellular concentrations, metabolomics in conjunction with flux balance analysis is being used in the development of culture media. The study of amino acid transporters is also gaining importance since they control the intracellular concentrations of these molecules and are influenced by conditions in cell culture media. A better understanding of the solubility, stability, dissolution kinetics, and interactions of these molecules is needed for an exploitation of these properties in the development of dry powdered chemically defined media for mammalian cells. Due to the complexity of these mixtures however, this has proven to be challenging. Studying amino acids in mammalian cell culture media will help provide a better understanding of how mammalian cells in culture interact with their environment. It would also provide insight into the chemical behavior of these molecules in solutions of complex mixtures, which is important in the understanding of the contribution of individual amino acids to protein structure.

  9. Distribution, industrial applications, and enzymatic synthesis of D-amino acids.

    PubMed

    Gao, Xiuzhen; Ma, Qinyuan; Zhu, Hailiang

    2015-04-01

    D-Amino acids exist widely in microbes, plants, animals, and food and can be applied in pharmaceutical, food, and cosmetics. Because of their widespread applications in industry, D-amino acids have recently received more and more attention. Enzymes including D-hydantoinase, N-acyl-D-amino acid amidohydrolase, D-amino acid amidase, D-aminopeptidase, D-peptidase, L-amino acid oxidase, D-amino acid aminotransferase, and D-amino acid dehydrogenase can be used for D-amino acids synthesis by kinetic resolution or asymmetric amination. In this review, the distribution, industrial applications, and enzymatic synthesis methods are summarized. And, among all the current enzymatic methods, D-amino acid dehydrogenase method not only produces D-amino acid by a one-step reaction but also takes environment and atom economics into consideration; therefore, it is deserved to be paid more attention.

  10. Regulation of the proteome by amino acids.

    PubMed

    Bourgoin-Voillard, Sandrine; Goron, Arthur; Seve, Michel; Moinard, Christophe

    2016-03-01

    Besides their main contribution as substrates for protein synthesis, amino acids as signaling molecules could exert some regulatory functions on protein synthesis and/or proteolysis that have been emphasized in a number of recent studies. Several publications have highlighted supplemental roles of those amino acids in protein metabolism as well as in immunity, heat shock response, or apoptosis processes. In this way, via their regulatory properties, selected amino acids (such as leucine, glutamine, arginine, citrulline, or methionine) directly influence the proteome. In this review, we are proposing an overview of the regulation of the proteome by amino acids in mammals. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The Apollo Program and Amino Acids

    ERIC Educational Resources Information Center

    Fox, Sidney W.

    1973-01-01

    Discusses the determination of hydrolyzable amino acid precursors and a group of six amino acids in the returned lunar samples of the Apollo programs. Indicates that molecular evolution is arrested at the precursor stage on the Moon because of lack of water. (CC)

  12. Amino and fatty acids in carbonaceous meteorites

    NASA Technical Reports Server (NTRS)

    Kvenvolden, K. A.

    1974-01-01

    Analyses of two carbonaceous meteorites have provided much of the latest evidence which seems to support Oparin's theory on the origin of life. The meteorites involved are the Murray meteorite, which fell in 1950, and the Murchison meteorite, which fell in 1969. The amino acids in the two meteorites are similar in composition. Eight of the twenty amino acids found belong to amino acids present in proteins. A number of monocarboxylic and dicarboxylic fatty acids were also found in the meteorites.

  13. Osmoregulated taurine transport in H4IIE hepatoma cells and perfused rat liver.

    PubMed Central

    Warskulat, U; Wettstein, M; Häussinger, D

    1997-01-01

    The effects of aniso-osmotic exposure on taurine transport were studied in H4IIE rat hepatoma cells. Hyperosmotic (405 mosmol/l) exposure of H4IIE cells stimulated Na+-dependent taurine uptake and led to an increase in taurine transporter (TAUT) mRNA levels, whereas hypo-osmotic (205 mosmol/l) exposure diminished both taurine uptake and TAUT mRNA levels when compared with normo-osmotic (305 mosmol/l) control incubations. Taurine uptake increased 30-40-fold upon raising the ambient osmolarity from 205 to 405 mosmol/l. When H4IIE cells and perfused livers were preloaded with taurine, hypo-osmotic cell swelling led to a rapid release of taurine from the cells. The taurine efflux, but not taurine uptake, was sensitive to 4,4'-di-isothiocyanatostilbene-2,2'-disulphonic acid (DIDS), suggestive of an involvement of DIDS-sensitive channels in mediating volume-regulatory taurine efflux. Whereas in both H4IIE rat hepatoma cells and primary hepatocytes TAUT mRNA levels were strongly dependent upon ambient osmolarity, mRNAs for other osmolyte transporters, i.e. the betaine transporter BGT-1 and the Na+/myo-inositol transporter SMIT, were not detectable. In line with this, myo-inositol uptake by H4IIE hepatoma cells was low and was not stimulated by hyperosmolarity. However, despite the absence of BGT-1 mRNA, a slight osmosensitive uptake of betaine was observed, but the rate was less than 10% of that of taurine transport. This study identifies a constitutively expressed and osmosensitive TAUT in H4IIE cells and the use of taurine as a main osmolyte, whereas betaine and myo-inositol play little or no role in the osmolyte strategy in these cells. This is in contrast with rat liver macrophages, in which betaine has been shown to be a major osmolyte. PMID:9032454

  14. Relative Amino Acid Composition Signatures of Organisms and Environments

    PubMed Central

    Moura, Alexandra; Savageau, Michael A.; Alves, Rui

    2013-01-01

    Background Identifying organism-environment interactions at the molecular level is crucial to understanding how organisms adapt to and change the chemical and molecular landscape of their habitats. In this work we investigated whether relative amino acid compositions could be used as a molecular signature of an environment and whether such a signature could also be observed at the level of the cellular amino acid composition of the microorganisms that inhabit that environment. Methodologies/Principal Findings To address these questions we collected and analyzed environmental amino acid determinations from the literature, and estimated from complete genomic sequences the global relative amino acid abundances of organisms that are cognate to the different types of environment. Environmental relative amino acid abundances clustered into broad groups (ocean waters, host-associated environments, grass land environments, sandy soils and sediments, and forest soils), indicating the presence of amino acid signatures specific for each environment. These signatures correlate to those found in organisms. Nevertheless, relative amino acid abundance of organisms was more influenced by GC content than habitat or phylogeny. Conclusions Our results suggest that relative amino acid composition can be used as a signature of an environment. In addition, we observed that the relative amino acid composition of organisms is not highly determined by environment, reinforcing previous studies that find GC content to be the major factor correlating to amino acid composition in living organisms. PMID:24204807

  15. Relative amino acid composition signatures of organisms and environments.

    PubMed

    Moura, Alexandra; Savageau, Michael A; Alves, Rui

    2013-01-01

    Identifying organism-environment interactions at the molecular level is crucial to understanding how organisms adapt to and change the chemical and molecular landscape of their habitats. In this work we investigated whether relative amino acid compositions could be used as a molecular signature of an environment and whether such a signature could also be observed at the level of the cellular amino acid composition of the microorganisms that inhabit that environment. To address these questions we collected and analyzed environmental amino acid determinations from the literature, and estimated from complete genomic sequences the global relative amino acid abundances of organisms that are cognate to the different types of environment. Environmental relative amino acid abundances clustered into broad groups (ocean waters, host-associated environments, grass land environments, sandy soils and sediments, and forest soils), indicating the presence of amino acid signatures specific for each environment. These signatures correlate to those found in organisms. Nevertheless, relative amino acid abundance of organisms was more influenced by GC content than habitat or phylogeny. Our results suggest that relative amino acid composition can be used as a signature of an environment. In addition, we observed that the relative amino acid composition of organisms is not highly determined by environment, reinforcing previous studies that find GC content to be the major factor correlating to amino acid composition in living organisms.

  16. Differential regulation of placental amino acid transport by saturated and unsaturated fatty acids.

    PubMed

    Lager, Susanne; Jansson, Thomas; Powell, Theresa L

    2014-10-15

    Fatty acids are critical for normal fetal development but may also influence placental function. We have previously reported that oleic acid (OA) stimulates amino acid transport in primary human trophoblasts (PHTs). In other tissues, saturated and unsaturated fatty acids have distinct effects on cellular signaling, for instance, palmitic acid (PA) but not OA reduces IκBα expression. We hypothesized that saturated and unsaturated fatty acids differentially affect trophoblast amino acid transport and cellular signaling. To test this hypothesis, PHTs were cultured in docosahexaenoic acid (DHA; 50 μM), OA (100 μM), or PA (100 μM). DHA and OA were also combined to test whether DHA could counteract the OA stimulatory effect on amino acid transport. The effects of fatty acids were compared against a vehicle control. Amino acid transport was measured by isotope-labeled tracers. Activation of inflammatory-related signaling pathways and the mechanistic target of rapamycin (mTOR) pathway were determined by Western blot analysis. Exposure of PHTs to DHA for 24 h reduced amino acid transport and phosphorylation of p38 MAPK, STAT3, mTOR, eukaryotic initiation factor 4E-binding protein 1, and ribosomal protein (rp)S6. In contrast, OA increased amino acid transport and phosphorylation of ERK, mTOR, S6 kinase 1, and rpS6. The combination of DHA with OA increased amino acid transport and rpS6 phosphorylation. PA did not affect amino acid transport but reduced IκBα expression. In conclusion, these fatty acids differentially regulated placental amino acid transport and cellular signaling. Taken together, these findings suggest that dietary fatty acids could alter the intrauterine environment by modifying placental function, thereby having long-lasting effects on the developing fetus. Copyright © 2014 the American Physiological Society.

  17. 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.

  18. The role of microbial amino acid metabolism in host metabolism.

    PubMed

    Neis, Evelien P J G; Dejong, Cornelis H C; Rensen, Sander S

    2015-04-16

    Disruptions in gut microbiota composition and function are increasingly implicated in the pathogenesis of obesity, insulin resistance, and type 2 diabetes mellitus. The functional output of the gut microbiota, including short-chain fatty acids and amino acids, are thought to be important modulators underlying the development of these disorders. Gut bacteria can alter the bioavailability of amino acids by utilization of several amino acids originating from both alimentary and endogenous proteins. In turn, gut bacteria also provide amino acids to the host. This could have significant implications in the context of insulin resistance and type 2 diabetes mellitus, conditions associated with elevated systemic concentrations of certain amino acids, in particular the aromatic and branched-chain amino acids. Moreover, several amino acids released by gut bacteria can serve as precursors for the synthesis of short-chain fatty acids, which also play a role in the development of obesity. In this review, we aim to compile the available evidence on the contribution of microbial amino acids to host amino acid homeostasis, and to assess the role of the gut microbiota as a determinant of amino acid and short-chain fatty acid perturbations in human obesity and type 2 diabetes mellitus.

  19. Effects of squat exercise and branched-chain amino acid supplementation on plasma free amino acid concentrations in young women.

    PubMed

    Shimomura, Yoshiharu; Kobayashi, Hisamine; Mawatari, Kazunori; Akita, Keiichi; Inaguma, Asami; Watanabe, Satoko; Bajotto, Gustavo; Sato, Juichi

    2009-06-01

    The present study was conducted to examine alterations in plasma free amino acid concentrations induced by squat exercise and branched-chain amino acid (BCAA) supplementation in young, untrained female subjects. In the morning on the exercise session day, participants ingested drinks containing either BCAA (isoleucine:leucine:valine=1:2.3:1.2) or dextrin (placebo) at 0.1 g/kg body weight 15 min before a squat exercise session, which consisted of 7 sets of 20 squats, with 3 min intervals between sets. In the placebo trial, plasma BCAA concentrations were decreased subsequent to exercise, whereas they were significantly increased in the BCAA trial until 2 h after exercise. Marked changes in other free amino acids in response to squat exercise and BCAA supplementation were observed. In particular, plasma concentrations of methionine and aromatic amino acids were temporarily decreased in the BCAA trial, being significantly lower than those in the placebo trial. These results suggest that BCAA intake before exercise affects methionine and aromatic amino acid metabolism.

  20. 21 CFR 172.320 - Amino acids.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... of total protein (expressed as free amino acid) L-Alanine 6.1 L-Arginine 6.6 L-Aspartic acid... DL-Methionine 3.1 L-Phenylalanine 5.8 L-Proline 4.2 L-Serine 8.4 L-Threonine 5.0 L-Tryptophan 1.6 L... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Amino acids. 172.320 Section 172.320 Food and...

  1. 21 CFR 172.320 - Amino acids.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of total protein (expressed as free amino acid) L-Alanine 6.1 L-Arginine 6.6 L-Aspartic acid... DL-Methionine 3.1 L-Phenylalanine 5.8 L-Proline 4.2 L-Serine 8.4 L-Threonine 5.0 L-Tryptophan 1.6 L... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Amino acids. 172.320 Section 172.320 Food and...

  2. 21 CFR 172.320 - Amino acids.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... of total protein (expressed as free amino acid) L-Alanine 6.1 L-Arginine 6.6 L-Aspartic acid... DL-Methionine 3.1 L-Phenylalanine 5.8 L-Proline 4.2 L-Serine 8.4 L-Threonine 5.0 L-Tryptophan 1.6 L... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Amino acids. 172.320 Section 172.320 Food and...

  3. 21 CFR 172.320 - Amino acids.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of total protein (expressed as free amino acid) L-Alanine 6.1 L-Arginine 6.6 L-Aspartic acid... DL-Methionine 3.1 L-Phenylalanine 5.8 L-Proline 4.2 L-Serine 8.4 L-Threonine 5.0 L-Tryptophan 1.6 L... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Amino acids. 172.320 Section 172.320 Food and Drugs...

  4. Identification of a novel amino acid racemase from a hyperthermophilic archaeon Pyrococcus horikoshii OT-3 induced by D-amino acids.

    PubMed

    Kawakami, Ryushi; Ohmori, Taketo; Sakuraba, Haruhiko; Ohshima, Toshihisa

    2015-08-01

    To date, there have been few reports analyzing the amino acid requirement for growth of hyperthermophilic archaea. We here found that the hyperthermophilic archaeon Pyrococcus horikoshii OT-3 requires Thr, Leu, Val, Phe, Tyr, Trp, His and Arg in the medium for growth, and shows slow growth in medium lacking Met or Ile. This largely corresponds to the presence, or absence, of genes related to amino acid biosynthesis in its genome, though there are exceptions. The amino acid requirements were dramatically lost by addition of D-isomers of Met, Leu, Val, allo-Ile, Phe, Tyr, Trp and Arg. Tracer analysis using (14)C-labeled D-Trp showed that D-Trp in the medium was used as a protein component in the cells, suggesting the presence of D-amino acid metabolic enzymes. Pyridoxal 5'-phosphate (PLP)-dependent racemase activity toward Met, Leu and Phe was detected in crude extract of P. horikoshii and was enhanced in cells grown in the medium supplemented with D-amino acids, especially D-allo-Ile. The gene encoding the racemase was narrowed down to one open reading frame on the basis of enzyme purification from P. horikoshii cells, and the recombinant enzyme exhibited PLP-dependent racemase activity toward several amino acids, including Met, Leu and Phe, but not Pro, Asp or Glu. This is the first report showing the presence in a hyperthermophilic archaeon of a PLP-dependent amino acid racemase with broad substrate specificity that is likely responsible for utilization of D-amino acids for growth.

  5. 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

  6. Characteristics of taurine release in slices from adult and developing mouse brain stem.

    PubMed

    Saransaari, P; Oja, S S

    2006-07-01

    Taurine has been thought to function as a regulator of neuronal activity, neuromodulator and osmoregulator. Moreover, it is essential for the development and survival of neural cells and protects them under cell-damaging conditions. Taurine is also involved in many vital functions regulated by the brain stem, including cardiovascular control and arterial blood pressure. The release of taurine has been studied both in vivo and in vitro in higher brain areas, whereas the mechanisms of release have not been systematically characterized in the brain stem. The properties of release of preloaded [(3)H]taurine were now characterized in slices prepared from the mouse brain stem from developing (7-day-old) and young adult (3-month-old) mice, using a superfusion system. In general, taurine release was found to be similar to that in other brain areas, consisting of both Ca(2+)-dependent and Ca(2+)-independent components. Moreover, the release was mediated by Na(+)-, Cl(-)-dependent transporters operating outwards, as both Na(+)-free and Cl(-) -free conditions greatly enhanced it. Cl(-) channel antagonists and a Cl(-) transport inhibitor reduced the release at both ages, indicating that a part of the release occurs through ion channels. Protein kinases appeared not to be involved in taurine release in the brain stem, since substances affecting the activity of protein kinase C or tyrosine kinase had no significant effects. The release was modulated by cAMP second messenger systems and phospholipases at both ages. Furthermore, the metabotropic glutamate receptor agonists likewise suppressed the K(+)-stimulated release at both ages. In the immature brain stem, the ionotropic glutamate receptor agonists N-methyl-D-aspartate (NMDA) and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) potentiated taurine release in a receptor-mediated manner. This could constitute an important mechanism against excitotoxicity, protecting the brain stem under cell-damaging conditions.

  7. Transport of amino acids in the kidney.

    PubMed

    Makrides, Victoria; Camargo, Simone M R; Verrey, François

    2014-01-01

    Amino acids are the building blocks of proteins and key intermediates in the synthesis of biologically important molecules, as well as energy sources, neurotransmitters, regulators of cellular metabolism, etc. The efficient recovery of amino acids from the primary filtrate is a well-conserved key role of the kidney proximal tubule. Additionally, renal metabolism participates in the whole body disposition of amino acids. Therefore, a wide array of axially heterogeneously expressed transporters is localized on both epithelial membranes. For transepithelial transport, luminal uptake, which is carried out mainly by active symporters, is coupled with a mostly passive basolateral efflux. Many transporters require partner proteins for appropriate localization, or to modulate transporter activity, and/or increase substrate supply. Interacting proteins include cell surface antigens (CD98), endoplasmic reticulum proteins (GTRAP3-18 or 41), or enzymes (ACE2 and aminopeptidase N). In the past two decades, the molecular identification of transporters has led to significant advances in our understanding of amino acid transport and aminoacidurias arising from defects in renal transport. Furthermore, the three-dimensional crystal structures of bacterial homologues have been used to yield new insights on the structure and function of mammalian transporters. Additionally, transgenic animal models have contributed to our understanding of the role of amino acid transporters in the kidney and other organs and/or at critical developmental stages. Progress in elucidation of the renal contribution to systemic amino acid homeostasis requires further integration of kinetic, regulatory, and expression data of amino acid transporters into our understanding of physiological regulatory networks controlling metabolism. © 2014 American Physiological Society.

  8. 6th Amino Acid Assessment Workshop

    USDA-ARS?s Scientific Manuscript database

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

  9. Combinatorics of aliphatic amino acids

    NASA Astrophysics Data System (ADS)

    Grützmann, Konrad; Böcker, Sebastian; Schuster, Stefan

    2011-01-01

    This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks.

  10. Survival of Amino Acids in Micrometeorites During Atmospheric Entry

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Bada, Jeffrey L.

    2003-01-01

    The delivery of amino acids by micrometeorites to the early Earth during the period of heavy bombardment could have been a significant source of the Earth's prebiotic amino acid inventory provided that these organic compounds survived atmospheric entry heating. To investigate the sublimation of amino acids from a micrometeorite analog at elevated temperature, grains from the CM-type carbonaceous chondrite Murchison were heated to 550 C inside a glass sublimation apparatus (SA) under reduced pressure. The sublimed residue that had collected on the cold finger of the SA after heating was analyzed for amino acids by HPLC. We found that when the temperature of the meteorite reached approx. 150 C, a large fraction of the amino acid glycine had vaporized from the meteorite, recondensed onto the end of the SA cold finger, and survived as the rest of the grains heated to 550 C. alpha-Aminoisobutryic acid and isovaline, which are two of the most abundant non-protein amino acids in Murchison, did not sublime from the meteorite and were completely destroyed during the heating experiment. Our experimental results suggest that sublimation of glycine present in micrometeorite grains may provide a way for this amino acid to survive atmospheric entry heating at temperatures less than 550 C; all other amino acids apparently are destroyed. Key Words: Amino acids-Exogenous delivery-Micrometeorites-Sublimation.

  11. Molecular basis of essential amino acid transport from studies of insect nutrient amino acid transporters of the SLC6 family (NAT-SLC6)

    PubMed Central

    Boudko, Dmitri Y.

    2012-01-01

    Two protein families that represent major components of essential amino acid transport in insects have been identified. They are annotated as the SLC6 and SLC7 families of transporters according to phylogenetic proximity to characterized amino acid transporters (HUGO nomenclature). Members of these families have been identified as important apical and basolateral parts of transepithelial essential amino acid absorption in the metazoan alimentary canal. Synergistically, they play critical physiological roles as essential substrate providers to diverse metabolic processes, including generic protein synthesis. This review briefly clarifies the requirements for amino acid transport and a variety of amino acid transport mechanisms, including the aforementioned families. Further it focuses on the large group of Nutrient Amino acid Transporters (NATs), which comprise a recently identified subfamily of the Neurotransmitter Sodium Symporter family (NSS or SLC6). The first insect NAT, cloned from the caterpillar gut, has a broad substrate spectrum similar to mammalian B0 transporters. Several new NAT-SLC6 members have been characterized in an effort to explore mechanisms for the essential amino acid absorption in model dipteran insects. The identification and functional characterization of new B0-like and narrow specificity transporters of essential amino acids in fruit fly and mosquitoes leads to a fundamentally important insight: that NATs evolved and act together as the integrated active core of a transport network that mediates active alimentary absorption and systemic distribution of essential amino acids. This role of NATs is projected from the most primitive prokaryotes to the most complex metazoan organisms, and represents an interesting platform for unraveling the molecular evolution of amino acid transport and modeling amino acid transport disorders. The comparative study of NATs elucidates important adaptive differences between essential amino acid transportomes

  12. Arrangement of Proteinogenic α-Amino Acids on a Cyclic Peptide Comprising Alternate Biphenyl-Cored ζ-Amino Acids.

    PubMed

    Tashiro, Shohei; Chiba, Masayuki; Shionoya, Mitsuhiko

    2017-05-18

    Aiming at precisely arranging several proteinogenic α-amino acids on a folded scaffold, we have developed a cyclic hexapeptide comprising an alternate sequence of biphenyl-cored ζ-amino acids and proteinogenic α-amino acids such as l-leucine. The amino acids were connected by typical peptide synthesis, and the resultant linear hexapeptide was intramolecularly cyclized to form a target cyclic peptide. Theoretical analyses and NMR spectroscopy suggested that the cyclic peptide was folded into an unsymmetrical conformation, and the structure was likely to be flexible in CHCl 3 . The optical properties including UV/Vis absorption, fluorescence, and circular dichroism (CD) were also evaluated. Furthermore, the cyclic peptide became soluble in water by introducing three carboxylate groups at the periphery of the cyclic skeleton. This α/ζ-alternating cyclic peptide is therefore expected to serve as a unique scaffold for arranging several functionalities. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Amino Acid Permeases and Virulence in Cryptococcus neoformans

    PubMed Central

    Takahashi, Juliana Possato Fernandes; Guerra, Juliana Mariotti; Santos, Dayane Cristina da Silva; Purisco, Sônia Ueda; Melhem, Márcia de Souza Carvalho; Fazioli, Raquel dos Anjos; Phanord, Clerlune; Sartorelli, Patrícia; Vallim, Marcelo A.

    2016-01-01

    Fungal opportunistic pathogens colonize various environments, from plants and wood to human and animal tissue. Regarding human pathogens, one great challenge during contrasting niche occupation is the adaptation to different conditions, such as temperature, osmolarity, salinity, pressure, oxidative stress and nutritional availability, which may constitute sources of stress that need to be tolerated and overcome. As an opportunistic pathogen, C. neoformans faces exactly these situations during the transition from the environment to the human host, encountering nutritional constraints. Our previous and current research on amino acid biosynthetic pathways indicates that amino acid permeases are regulated by the presence of the amino acids, nitrogen and temperature. Saccharomyces cerevisiae and Candida albicans have twenty-four and twenty-seven genes encoding amino acid permeases, respectively; conversely, they are scarce in number in Basidiomycetes (C. neoformans, Coprinopsis cinerea and Ustilago maydis), where nine to ten permease genes can be found depending on the species. In this study, we have demonstrated that two amino acid permeases are essential for virulence in C. neoformans. Our data showed that C. neoformans uses two global and redundant amino acid permeases, Aap4 and Aap5 to respond correctly to thermal and oxidative stress. Double deletion of these permeases causes growth arrest in C. neoformans at 37°C and in the presence of hydrogen peroxide. The inability to uptake amino acid at a higher temperature and under oxidative stress also led to virulence attenuation in vivo. Our data showed that thermosensitivity caused by the lack of permeases Aap4 and Aap5 can be remedied by alkaline conditions (higher pH) and salinity. Permeases Aap4 and Aap5 are also required during fluconazole stress and they are the target of the plant secondary metabolite eugenol, a potent antifungal inhibitor that targets amino acid permeases. In summary, our work unravels (i

  14. New Functions and Potential Applications of Amino Acids.

    PubMed

    Uneyama, Hisayuki; Kobayashi, Hisamine; Tonouchi, Naoto

    Currently, several types of amino acids are being produced and used worldwide. Nevertheless, several new functions of amino acids have been recently discovered that could result in other applications. For example, oral stimulation by glutamate triggers the cephalic phase response to prepare for food digestion. Further, the stomach and intestines have specific glutamate-recognizing systems in their epithelial mucosa. Regarding clinical applications, addition of monosodium glutamate to the medicinal diet has been shown to markedly enhance gastric secretion in a vagus-dependent manner. Branched-chain amino acids (BCAAs) are the major components of muscles, and ingestion of BCAAs has been found to be effective for decreasing muscle pain. BCAAs are expected to be a solution for the serious issue of aging. Further, ingestion of specific amino acids could be beneficial. Glycine can be ingested for good night's sleep: glycine ingestion before bedtime significantly improved subjective sleep quality. Ingestion of alanine and glutamine effectively accelerates alcohol metabolism, and ingestion of cystine and theanine effectively prevents colds. Finally, amino acids could be used in a novel clinical diagnostic method: the balance of amino acids in the blood could be an indicator of the risk of diseases such as cancer. These newly discovered functions of amino acids are expected to contribute to the resolution of various issues.

  15. On the abiotic formation of amino acids. I - HCN as a precursor of amino acids detected in extracts of lunar samples. II - Formation of HCN and amino acids from simulated mixtures of gases released from lunar samples

    NASA Technical Reports Server (NTRS)

    Yuasa, S.; Flory, D.; Basile, B.; Oro, J.

    1984-01-01

    Two studies on the abiotic formation of amino acids are presented. The first study demonstrates the role of hydrogen cyanide as a precursor of amino acids detected in extracts of lunar samples. The formation of several amino acids, including glycine, alanine, aspartic acid, and glutamic acid, under conditions similar to those used for the analysis of lunar samples is demonstrated. The second study investigates the formation of hydrogen cyanide as well as amino acids from lunar-sample gas mixtures under electrical discharge conditions. These results extend the possibility of synthesis of amino acids to planetary bodies with primordial atmospheres less reducing than a mixture of methane, ammonia, hydrogen and water.

  16. 40 CFR 721.2584 - Dodecanoic acid, 12-amino-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Dodecanoic acid, 12-amino-. 721.2584... Substances § 721.2584 Dodecanoic acid, 12-amino-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as dodecanoic acid, 12-amino- (PMN P-98-0823; CAS No. 693...

  17. 40 CFR 721.2584 - Dodecanoic acid, 12-amino-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dodecanoic acid, 12-amino-. 721.2584... Substances § 721.2584 Dodecanoic acid, 12-amino-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as dodecanoic acid, 12-amino- (PMN P-98-0823; CAS No. 693...

  18. Wet, Carbonaceous Asteroids: Altering Minerals, Changing Amino Acids

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2011-04-01

    Many carbonaceous chondrites contain alteration products from water-rock interactions at low temperature and organic compounds. A fascinating fact known for decades is the presence in some of them of an assortment of organic compounds, including amino acids, sometimes called the building blocks of life. Murchison and other CM carbonaceous chondrites contain hundreds of amino acids. Early measurements indicated that the amino acids in carbonaceous chondrites had equal proportions of L- and D-structures, a situation called racemic. This was in sharp contrast to life on Earth, which heavily favors L- forms. However, beginning in 1997, John Cronin and Sandra Pizzarello (Arizona State University) found L- excesses in isovaline and several other amino acids in the Murchison carbonaceous chondrite. In 2009, Daniel Glavin and Jason Dworkin (Astrobiology Analytical Lab, Goddard Space Flight Center) reported the first independent confirmation of L-isovaline excesses in Murchison using a different analytical technique than employed by Cronin and Pizzarello. Inspired by this work, Daniel Glavin, Michael Callahan, Jason Dworkin, and Jamie Elsila (Astrobiology Analytical Lab, Goddard Space Flight Center), have done an extensive study of the abundance and symmetry of amino acids in carbonaceous chondrites that experienced a range of alteration by water in their parent asteroids. The results show that amino acids are more abundant in the less altered meteorites, implying that aqueous processing changes the mix of amino acids. They also confirmed the enrichment in L-structures of some amino acids, especially isovaline, confirming earlier work. The authors suggest that aqueously-altered planetesimals might have seeded the early Earth with nonracemic amino acids, perhaps explaining why life from microorganisms to people use only L- forms to make proteins. The initial imbalance caused by non-biologic processes in wet asteroids might have been amplified by life on Earth. Alternatively

  19. Amino acids in modern and fossil woods

    NASA Technical Reports Server (NTRS)

    Lee, C.; Bada, J. L.; Peterson, E.

    1976-01-01

    The amino acid composition and the extent of racemization in several modern and fossil woods are reported. The method of analysis is described, and data are presented on the total amino acid concentration, the amino acid ratios, and the enantiomeric ratios in each sample. It is found that the amino acid concentration per gram of dry wood decreases with age of the sample, that the extent of racemization increases with increasing age, and that the amounts of aspartic acid, threonine, and serine decrease relative to valine with increasing age. The relative racemization rates of amino acids in wood, bone, and aqueous solution are compared, and it is shown that racemization in wood is much slower than in bone or aqueous solution. Racemization results for woods from the Kalambo Falls area of Zambia are used to calculate a minimum age of 110,000 years for the transition between the Sangoan and Acheulian industries at that site. This result is shown to be consistent with numerous radiometric dates for older Acheulian sites in Africa and to compare well with geologically inferred dates for the beginning of the Eemian and the end of the Acheulian industry in southern Africa.

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

    PubMed

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

    2002-10-01

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

  1. Supernovae, neutrinos and the chirality of amino acids.

    PubMed

    Boyd, Richard N; Kajino, Toshitaka; Onaka, Takashi

    2011-01-01

    A mechanism for creating an enantioenrichment in the amino acids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the amino acids and neutrinos from core-collapse supernovae is defined. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the (14)N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth's proteinaceous amino acids.

  2. Extraordinarily Adaptive Properties of the Genetically Encoded Amino Acids

    PubMed Central

    Ilardo, Melissa; Meringer, Markus; Freeland, Stephen; Rasulev, Bakhtiyor; Cleaves II, H. James

    2015-01-01

    Using novel advances in computational chemistry, we demonstrate that the set of 20 genetically encoded amino acids, used nearly universally to construct all coded terrestrial proteins, has been highly influenced by natural selection. We defined an adaptive set of amino acids as one whose members thoroughly cover relevant physico-chemical properties, or “chemistry space.” Using this metric, we compared the encoded amino acid alphabet to random sets of amino acids. These random sets were drawn from a computationally generated compound library containing 1913 alternative amino acids that lie within the molecular weight range of the encoded amino acids. Sets that cover chemistry space better than the genetically encoded alphabet are extremely rare and energetically costly. Further analysis of more adaptive sets reveals common features and anomalies, and we explore their implications for synthetic biology. We present these computations as evidence that the set of 20 amino acids found within the standard genetic code is the result of considerable natural selection. The amino acids used for constructing coded proteins may represent a largely global optimum, such that any aqueous biochemistry would use a very similar set. PMID:25802223

  3. RP-HPLC method for simultaneous estimation of vigabatrin, gamma-aminobutyric acid and taurine in biological samples.

    PubMed

    Police, Anitha; Shankar, Vijay Kumar; Narasimha Murthy, S

    2018-02-15

    Vigabatrin is used as first line drug in treatment of infantile spasms for its potential benefit overweighing risk of causing permanent peripheral visual field defects and retinal damage. Chronic administration of vigabatrin in rats has demonstrated these ocular events are result of GABA accumulation and depletion of taurine levels in retinal tissues. In vigabatrin clinical studies taurine plasma level is considered as biomarker for studying structure and function of retina. The analytical method is essential to monitor taurine levels along with vigabatrin and GABA. A RP-HPLC method has been developed and validated for simultaneous estimation of vigabatrin, GABA and taurine using surrogate matrix. Analytes were extracted from human plasma, rat plasma, retina and brain by simple protein precipitation method and derivatized by naphthalene 2, 3‑dicarboxaldehyde to produce stable fluorescent active isoindole derivatives. The chromatographic analysis was performed on Zorbax Eclipse AAA column using gradient elution profile and eluent was monitored using fluorescence detector. A linear plot of calibration curve was observed in concentration range of 64.6 to 6458, 51.5 to 5150 and 62.5 to 6258 ng/mL for vigabatrin, GABA and taurine, respectively with r 2  ≥ 0.997 for all analytes. The method was successfully applied for estimating levels of vigabatrin and its modulator effect on GABA and taurine levels in rat plasma, brain and retinal tissue. This RP-HPLC method can be applied in clinical and preclinical studies to explore the effect of taurine deficiency and to investigate novel approaches for alleviating vigabatrin induced ocular toxicity. Copyright © 2018. Published by Elsevier B.V.

  4. Metabolomics method to comprehensively analyze amino acids in different domains.

    PubMed

    Gu, Haiwei; Du, Jianhai; Carnevale Neto, Fausto; Carroll, Patrick A; Turner, Sally J; Chiorean, E Gabriela; Eisenman, Robert N; Raftery, Daniel

    2015-04-21

    Amino acids play essential roles in both metabolism and the proteome. Many studies have profiled free amino acids (FAAs) or proteins; however, few have connected the measurement of FAA with individual amino acids in the proteome. In this study, we developed a metabolomics method to comprehensively analyze amino acids in different domains, using two examples of different sample types and disease models. We first examined the responses of FAAs and insoluble-proteome amino acids (IPAAs) to the Myc oncogene in Tet21N human neuroblastoma cells. The metabolic and proteomic amino acid profiles were quite different, even under the same Myc condition, and their combination provided a better understanding of the biological status. In addition, amino acids were measured in 3 domains (FAAs, free and soluble-proteome amino acids (FSPAAs), and IPAAs) to study changes in serum amino acid profiles related to colon cancer. A penalized logistic regression model based on the amino acids from the three domains had better sensitivity and specificity than that from each individual domain. To the best of our knowledge, this is the first study to perform a combined analysis of amino acids in different domains, and indicates the useful biological information available from a metabolomics analysis of the protein pellet. This study lays the foundation for further quantitative tracking of the distribution of amino acids in different domains, with opportunities for better diagnosis and mechanistic studies of various diseases.

  5. Extraterrestrial Amino Acids in Ureilites Including Almahata Sitta

    NASA Technical Reports Server (NTRS)

    Burton, A. S.; Glavin, D. P.; Callahan, M. P.; Dworkin, J. P.

    2011-01-01

    Ureilites are a class of meteorites that lack chondrules (achondrites) but have relatively high carbon abundances, averaging approx.3 wt %. Using highly sensitive liquid chromatography coupled with UV fluorescence and time-of-flight mass spectrometry (LC-FD/ToF-MS), it was recently determined that there are amino acids in. fragment 94 of the Almahata Sitta ureilite[l]. Based on the presence of amino acids that are rare in the Earth's biosphere, as well as the near-racemic enantiomeric ratios of marry of the more common amino acids, it was concluded that most of the detected amino acids were indigenous to the meteorite. Although the composition of the Almahata Sitta ureilite appears to be unlike other recovered ureilites, the discovery of amino acids in this meteorite raises the question of whether other ureilites rnav also contain amino acids. Herein we present the results of LC-FDlTo.F-MS analyses of: a sand sample from the Almahata Sitta strewn held, Almahata Sitta fragments 425 (an ordinary H5 chondrite) and 427 (ureilite), as well as an Antarctic ureilite (Allan lulls, ALHA 77257).

  6. Complexes of polyadenylic acid and the methyl esters of amino acids

    NASA Technical Reports Server (NTRS)

    Khaled, M. A.; Mulins, D. W., Jr.; Swindle, M.; Lacey, J. C., Jr.

    1983-01-01

    A study of amino acid methyl esters binding to polyadenylic acid supports the theory that the genetic code originated through weak but selective affinities between amino acids and nucleotides. NMR, insoluble complex analysis, and ultraviolet spectroscopy are used to illustrate a correlation between the hydrophybicities of A amino acids and their binding constants, which, beginning with the largest, are in the order of Phe (having nominally a hydrophobic AAA anticodon), Ile, Leu, Val and Gly (having a hydrophilic anticodon with no A). In general, the binding constants are twice the values by Reuben and Polk (1980) for monomeric AMP, which suggests that polymer amino acids are interacting with only one base. No real differences are found betwen poly A binding for free Phe, Phe methyl ester or Phe amide, except that the amide value is slightly lower.

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

    PubMed

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

    2014-09-01

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

  8. Comparison of amino acid digestibility of feedstuffs determined with the precision-fed cecectomized rooster assay and the standardized ileal amino acid digestibility assay.

    PubMed

    Kim, E J; Utterback, P L; Applegate, T J; Parsons, C M

    2011-11-01

    The objective of this study was to evaluate and compare amino acid digestibility of several feedstuffs using 2 commonly accepted methods: the precision-fed cecectomized rooster assay (PFR) and the standardized ileal amino acid assay (SIAAD). Six corn, 6 corn distillers dried grains with or without solubles (DDGS/DDG), one wet distillers grains, one condensed solubles, 2 meat and bone meal (MBM) and a poultry byproduct meal were evaluated. Due to insufficient amounts, the wet distillers grains and condensed solubles were only evaluated in roosters. Standardized amino acid digestibility varied among the feed ingredients and among samples of the same ingredient for both methods. For corn, there were generally no differences in amino acid digestibility between the 2 methods. When differences did occur, there was no consistent pattern among the individual amino acids and methods. Standardized amino acid digestibility was not different between the 2 methods for 4 of the DDG samples; however, the PFR yielded higher digestibility values for a high protein DDG and a conventionally processed DDGS. The PFR yielded higher amino acid digestibility values than the SIAAD for several amino acids in 1 MBM and the poultry byproduct meal, but it yielded lower digestibility values for the other MBM. Overall, there were no consistent differences between methods for amino acid digestibility values. In conclusion, the PFR and SIAAD methods are acceptable for determining amino acid digestibility. However, these procedures do not always yield similar results for all feedstuffs evaluated. Thus, further studies are needed to understand the underlying causes in this variability.

  9. The role of amino acid profiles in diabetes risk assessment.

    PubMed

    Nagao, Kenji; Yamakado, Minoru

    2016-07-01

    The concentrations of plasma-free amino acids, such as branched-chain amino acids and aromatic amino acids, are associated with visceral obesity, insulin resistance, and the future development of diabetes and cardiovascular diseases. This review discusses recent progress in the early assessment of the risk of developing diabetes and the reversal of altered plasma-free amino acids through interventions. Additionally, recent developments that have increased the utility of amino acid profiling technology are also described. Plasma-free amino acid alterations in the early stage of lifestyle-related diseases are because of obesity and insulin resistance-related inflammation, and these alterations are reversed by appropriate (nutritional, drug, or surgical) interventions that improve insulin sensitivity. For clinical applications, procedures for measuring amino acids are being standardized and automated. Plasma-free amino acid profiles have potential as biomarkers for both assessing diabetes risk and monitoring the effects of strategies designed to lower that risk. In addition, the methodology for measuring amino acids has been refined, with the goal of routine clinical application.

  10. Supernovae, Neutrinos and the Chirality of Amino Acids

    PubMed Central

    Boyd, Richard N.; Kajino, Toshitaka; Onaka, Takashi

    2011-01-01

    A mechanism for creating an enantioenrichment in the amino acids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the amino acids and neutrinos from core-collapse supernovae is defined. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth’s proteinaceous amino acids. PMID:21747686

  11. Amino acids and sport: a true love story?

    PubMed

    Goron, Arthur; Moinard, Christophe

    2018-05-31

    Among a plethora of dietary supplements, amino acids are very popular with athletes for several reasons (e.g., to prevent nutritional deficiency, improve muscle function, and decrease muscle damages) whose purpose is to improve performance. However, it is difficult to get a clear idea of which amino acids have real ergogenic impact. Here, we review and analyze the clinical studies evaluating specific amino acids (glutamine, arginine, leucine, etc.) in athletes. Only english-language clinical studies evaluating a specific effect of one amino acid were considered. Despite promising results, many studies have methodological limits or specific flaws that do not allow definitive conclusions. To date, only chronic β-alanine supplementation demonstrated an ergogenic effect in athletes. Much research is still needed to gain evidence-based data before any other specific amino acid can be recommended for use in athletes.

  12. Effects of taurine and housing density on renal function in laying hens*

    PubMed Central

    Ma, Zi-li; Gao, Yang; Ma, Hai-tian; Zheng, Liu-hai; Dai, Bin; Miao, Jin-feng; Zhang, Yuan-shu

    2016-01-01

    This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid (taurine) and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-shell laying hens into three groups: a free range group, a low-density caged group, and a high-density caged group. Each group was further divided equally into a control group (C) and a taurine treatment group (T). After 15 d, we analyzed histological changes in kidney cells, inflammatory mediator levels, oxidation and anti-oxidation levels. Experimental data revealed taurine supplementation, and rearing free range or in low-density housing can lessen morphological renal damage, inflammatory mediator levels, and oxidation levels and increase anti-oxidation levels. Our data demonstrate that taurine supplementation and a reduction in housing density can ameliorate renal impairment, increase productivity, enhance health, and promote welfare in laying hens. PMID:27921400

  13. Adsorption of amino acids by fullerenes and fullerene nanowhiskers

    NASA Astrophysics Data System (ADS)

    Hashizume, Hideo; Hirata, Chika; Fujii, Kazuko; Miyazawa, Kun'ichi

    2015-12-01

    We have investigated the adsorption of some amino acids and an oligopeptide by fullerene (C60) and fullerene nanowhiskers (FNWs). C60 and FNWs hardly adsorbed amino acids. Most of the amino acids used have a hydrophobic side chain. Ala and Val, with an alkyl chain, were not adsorbed by the C60 or FNWs. Trp, Phe and Pro, with a cyclic structure, were not adsorbed by them either. The aromatic group of C60 did not interact with the side chain. The carboxyl or amino group, with the frame structure of an amino acid, has a positive or negative charge in solution. It is likely that the C60 and FNWs would not prefer the charged carboxyl or amino group. Tri-Ala was adsorbed slightly by the C60 and FNWs. The carboxyl or amino group is not close to the center of the methyl group of Tri-Ala. One of the methyl groups in Tri-Ala would interact with the aromatic structure of the C60 and FNWs. We compared our results with the theoretical interaction of 20 bio-amino acids with C60. The theoretical simulations showed the bonding distance between C60 and an amino acid and the dissociation energy. The dissociation energy was shown to increase in the order, Val < Phe < Pro < Asp < Ala < Trp < Tyr < Arg < Leu. However, the simulation was not consistent with our experimental results. The adsorption of albumin (a protein) by C60 showed the effect on the side chains of Try and Trp. The structure of albumin was changed a little by C60. In our study Try and Tyr were hardly adsorbed by C60 and FNWs. These amino acids did not show a different adsorption behavior compared with other amino acids. The adsorptive behavior of mono-amino acids might be different from that of polypeptides.

  14. MS-READ: Quantitative measurement of amino acid incorporation.

    PubMed

    Mohler, Kyle; Aerni, Hans-Rudolf; Gassaway, Brandon; Ling, Jiqiang; Ibba, Michael; Rinehart, Jesse

    2017-11-01

    Ribosomal protein synthesis results in the genetically programmed incorporation of amino acids into a growing polypeptide chain. Faithful amino acid incorporation that accurately reflects the genetic code is critical to the structure and function of proteins as well as overall proteome integrity. Errors in protein synthesis are generally detrimental to cellular processes yet emerging evidence suggest that proteome diversity generated through mistranslation may be beneficial under certain conditions. Cumulative translational error rates have been determined at the organismal level, however codon specific error rates and the spectrum of misincorporation errors from system to system remain largely unexplored. In particular, until recently technical challenges have limited the ability to detect and quantify comparatively rare amino acid misincorporation events, which occur orders of magnitude less frequently than canonical amino acid incorporation events. We now describe a technique for the quantitative analysis of amino acid incorporation that provides the sensitivity necessary to detect mistranslation events during translation of a single codon at frequencies as low as 1 in 10,000 for all 20 proteinogenic amino acids, as well as non-proteinogenic and modified amino acids. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Determination of amino acids in grape-derived products: a review.

    PubMed

    Callejón, R M; Troncoso, A M; Morales, M L

    2010-06-15

    The amino acids present in foods and beverages affect the quality of these products and they play an important role in enology. Amino acids are consumed by yeasts as a source of nitrogen during alcoholic fermentation and are precursors of aroma compounds. In this review various chromatographic methodologies for the determination of amino acids are described, and specific applications for the analysis of amino acid content are discussed. Amino acids usually need to be derivatized to make them more detectable. Several derivatizing reagents have been employed for the determination of amino acids in enological applications, and each has its advantages and disadvantages.

  16. Severity of experimental traumatic brain injury modulates changes in concentrations of cerebral free amino acids.

    PubMed

    Amorini, Angela Maria; Lazzarino, Giacomo; Di Pietro, Valentina; Signoretti, Stefano; Lazzarino, Giuseppe; Belli, Antonio; Tavazzi, Barbara

    2017-03-01

    In this study, concentrations of free amino acids (FAA) and amino group containing compounds (AGCC) following graded diffuse traumatic brain injury (mild TBI, mTBI; severe TBI, sTBI) were evaluated. After 6, 12, 24, 48 and 120 hr aspartate (Asp), glutamate (Glu), asparagine (Asn), serine (Ser), glutamine (Gln), histidine (His), glycine (Gly), threonine (Thr), citrulline (Cit), arginine (Arg), alanine (Ala), taurine (Tau), γ-aminobutyrate (GABA), tyrosine (Tyr), S-adenosylhomocysteine (SAH), l-cystathionine (l-Cystat), valine (Val), methionine (Met), tryptophane (Trp), phenylalanine (Phe), isoleucine (Ile), leucine (Leu), ornithine (Orn), lysine (Lys), plus N-acetylaspartate (NAA) were determined in whole brain extracts (n = 6 rats at each time for both TBI levels). Sham-operated animals (n = 6) were used as controls. Results demonstrated that mTBI caused modest, transient changes in NAA, Asp, GABA, Gly, Arg. Following sTBI, animals showed profound, long-lasting modifications of Glu, Gln, NAA, Asp, GABA, Ser, Gly, Ala, Arg, Citr, Tau, Met, SAH, l-Cystat, Tyr and Phe. Increase in Glu and Gln, depletion of NAA and Asp increase, suggested a link between NAA hydrolysis and excitotoxicity after sTBI. Additionally, sTBI rats showed net imbalances of the Glu-Gln/GABA cycle between neurons and astrocytes, and of the methyl-cycle (demonstrated by decrease in Met, and increase in SAH and l-Cystat), throughout the post-injury period. Besides evidencing new potential targets for novel pharmacological treatments, these results suggest that the force acting on the brain tissue at the time of the impact is the main determinant of the reactions ignited and involving amino acid metabolism. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  17. Free amino acids and 5'-nucleotides in Finnish forest mushrooms.

    PubMed

    Manninen, Hanna; Rotola-Pukkila, Minna; Aisala, Heikki; Hopia, Anu; Laaksonen, Timo

    2018-05-01

    Edible mushrooms are valued because of their umami taste and good nutritional values. Free amino acids, 5'-nucleotides and nucleosides were analyzed from four Nordic forest mushroom species (Lactarius camphoratus, Boletus edulis, Cantharellus cibarius, Craterellus tubaeformis) using high precision liquid chromatography analysis. To our knowledge, these taste components were studied for the first time from Craterellus tubaeformis and Lactarius camphoratus. The focus was on the umami amino acids and 5'-nucleotides. The free amino acid and 5'-nucleotide/nucleoside contents of studied species differed from each other. In all studied samples, umami amino acids were among five major free amino acids. The highest concentration of umami amino acids was on L. camphoratus whereas B. edulis had the highest content of sweet amino acids and C. cibarius had the highest content of bitter amino acids. The content of umami enhancing 5'-nucleotides were low in all studied species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. [Studies on interaction of acid-treated nanotube titanic acid and amino acids].

    PubMed

    Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

    2010-06-01

    Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination.

  19. Proximate composition, amino acid and fatty acid composition of fish maws.

    PubMed

    Wen, Jing; Zeng, Ling; Xu, Youhou; Sun, Yulin; Chen, Ziming; Fan, Sigang

    2016-01-01

    Fish maws are commonly recommended and consumed in Asia over many centuries because it is believed to have some traditional medical properties. This study highlights and provides new information on the proximate composition, amino acid and fatty acid composition of fish maws of Cynoscion acoupa, Congresox talabonoides and Sciades proops. The results indicated that fish maws were excellent protein sources and low in fat content. The proteins in fish maws were rich in functional amino acids (FAAs) and the ratio of FAAs and total amino acids in fish maws ranged from 0.68 to 0.69. Among species, croaker C. acoupa contained the most polyunsaturated fatty acids, arachidonic acid, docosahexaenoic acid and eicosapntemacnioc acid, showing the lowest value of index of atherogenicity and index of thrombogenicity, showing the highest value of hypocholesterolemic/hypercholesterolemic ratio, which is the most desirable.

  20. Taurine and its neuroprotective role.

    PubMed

    Kumari, Neeta; Prentice, Howard; Wu, Jang-Yen

    2013-01-01

    Taurine plays multiple roles in the CNS including acting as a -neuro-modulator, an osmoregulator, a regulator of cytoplasmic calcium levels, a trophic factor in development, and a neuroprotectant. In neurons taurine has been shown to prevent mitochondrial dysfunction and to protect against endoplasmic reticulum (ER) stress associated with neurological disorders. In cortical neurons in culture taurine protects against excitotoxicity through reversing an increase in levels of key ER signaling components including eIF-2-alpha and cleaved ATF6. The role of communication between the ER and mitochondrion is also important and examples are presented of protection by taurine against ER stress together with prevention of subsequent mitochondrial initiated apoptosis.

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

    PubMed

    Hayashi, Nobuyuki; Jin, Shigeki; Ujihara, Tomomi

    2012-11-02

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

  2. Polymerization of beta-amino acids in aqueous solution

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    We have compared carbonyl diimidazole (CDI) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as activating agents for the oligomerization of negatively-charged alpha- and beta-amino acids in homogeneous aqueous solution. alpha-Amino acids can be oligomerized efficiently using CDI, but not by EDAC. beta-Amino acids can be oligomerized efficiently using EDAC, but not by CDI. Aspartic acid, an alpha- and beta-dicarboxylic acid is oligomerized efficiently by both reagents. These results are explained in terms of the mechanisms of the reactions, and their relevance to prebiotic chemistry is discussed.

  3. Comparison of amino acids interaction with gold nanoparticle.

    PubMed

    Ramezani, Fatemeh; Amanlou, Massoud; Rafii-Tabar, Hashem

    2014-04-01

    The study of nanomaterial/biomolecule interface is an important emerging field in bionanoscience, and additionally in many biological processes such as hard-tissue growth and cell-surface adhesion. To have a deeper understanding of the amino acids/gold nanoparticle assemblies, the adsorption of these amino acids on the gold nanoparticles (GNPs) has been investigated via molecular dynamics simulation. In these simulations, all the constituent atoms of the nanoparticles were considered to be dynamic. The geometries of amino acids, when adsorbed on the nanoparticle, were studied and their flexibilities were compared with one another. The interaction of each of 20 amino acids was considered with 3 and 8 nm gold GNPs.

  4. Amino Acid Interaction (INTAA) web server.

    PubMed

    Galgonek, Jakub; Vymetal, Jirí; Jakubec, David; Vondrášek, Jirí

    2017-07-03

    Large biomolecules-proteins and nucleic acids-are composed of building blocks which define their identity, properties and binding capabilities. In order to shed light on the energetic side of interactions of amino acids between themselves and with deoxyribonucleotides, we present the Amino Acid Interaction web server (http://bioinfo.uochb.cas.cz/INTAA/). INTAA offers the calculation of the residue Interaction Energy Matrix for any protein structure (deposited in Protein Data Bank or submitted by the user) and a comprehensive analysis of the interfaces in protein-DNA complexes. The Interaction Energy Matrix web application aims to identify key residues within protein structures which contribute significantly to the stability of the protein. The application provides an interactive user interface enhanced by 3D structure viewer for efficient visualization of pairwise and net interaction energies of individual amino acids, side chains and backbones. The protein-DNA interaction analysis part of the web server allows the user to view the relative abundance of various configurations of amino acid-deoxyribonucleotide pairs found at the protein-DNA interface and the interaction energies corresponding to these configurations calculated using a molecular mechanical force field. The effects of the sugar-phosphate moiety and of the dielectric properties of the solvent on the interaction energies can be studied for the various configurations. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  5. Unprecedented concentrations of indigenous amino acids in primitive CR meteorites

    NASA Astrophysics Data System (ADS)

    Ehrenfreund, Pascale; Martins, Zita; Alexander, Conel; Orzechowska, Grazyna; Fogel, Marylin

    CR meteorites are among the most primitive meteorites. We have performed pioneering work determining the compositional characteristics of amino acids in this type of carbonaceous chondrites. We report the first measurements of amino acids in Antarctic CR meteorites, two of which show the highest amino acid concentrations ever found in a chondrite. We have analyzed the amino acid content of the Antarctic CRs EET92042, GRA95229 and GRO95577 using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatography-mass spectrometry (GC-MS). Additionally, compound-specific carbon isotopic measurements for most of the individual amino acids from the EET92042 and GRA95229 meteorites were achieved by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Our data show that EET92042 and GRA95229 are the most amino acid-rich chondrites ever analyzed, with total amino acid concentrations of 180 and 249 parts-per-million (ppm), respectively. GRO95577, however, is depleted in amino acids (<1 ppm). The most abundant amino acids present in the EET92042 and GRA95229 meteorites are the α-amino acids glycine, isovaline, α-aminoisobutyric acid (α-AIB), and alanine, with δ 13 C values ranging from +31.6% to +50.5%. The highly enriched carbon isotope results together with racemic enantiomeric ratios determined for most amino acids indicate that primitive organic matter was preserved in these meteorites. In addition, the relative abundances of α-AIB and β-alanine amongst Antarctic CR meteorites appear to correspond to the degree of aqueous alteration on their respective parent body. Investigating the abundances and isotopic composition of amino acids in primitive chondrites helps to understand the role of meteorites as a source of extraterrestrial prebiotic organic compounds to the early Earth.

  6. Real-time Measurements of Amino Acid and Protein Hydroperoxides Using Coumarin Boronic Acid*

    PubMed Central

    Michalski, Radoslaw; Zielonka, Jacek; Gapys, Ewa; Marcinek, Andrzej; Joseph, Joy; Kalyanaraman, Balaraman

    2014-01-01

    Hydroperoxides of amino acid and amino acid residues (tyrosine, cysteine, tryptophan, and histidine) in proteins are formed during oxidative modification induced by reactive oxygen species. Amino acid hydroperoxides are unstable intermediates that can further propagate oxidative damage in proteins. The existing assays (oxidation of ferrous cation and iodometric assays) cannot be used in real-time measurements. In this study, we show that the profluorescent coumarin boronic acid (CBA) probe reacts with amino acid and protein hydroperoxides to form the corresponding fluorescent product, 7-hydroxycoumarin. 7-Hydroxycoumarin formation was catalase-independent. Based on this observation, we have developed a fluorometric, real-time assay that is adapted to a multiwell plate format. This is the first report showing real-time monitoring of amino acid and protein hydroperoxides using the CBA-based assay. This approach was used to detect protein hydroperoxides in cell lysates obtained from macrophages exposed to visible light and photosensitizer (rose bengal). We also measured the rate constants for the reaction between amino acid hydroperoxides (tyrosyl, tryptophan, and histidine hydroperoxides) and CBA, and these values (7–23 m−1 s−1) were significantly higher than that measured for H2O2 (1.5 m−1 s−1). Using the CBA-based competition kinetics approach, the rate constants for amino acid hydroperoxides with ebselen, a glutathione peroxidase mimic, were also determined, and the values were within the range of 1.1–1.5 × 103 m−1 s−1. Both ebselen and boronates may be used as small molecule scavengers of amino acid and protein hydroperoxides. Here we also show formation of tryptophan hydroperoxide from tryptophan exposed to co-generated fluxes of nitric oxide and superoxide. This observation reveals a new mechanism for amino acid and protein hydroperoxide formation in biological systems. PMID:24928516

  7. Oral branched-chain amino acids decrease whole-body proteolysis

    NASA Technical Reports Server (NTRS)

    Ferrando, A. A.; Williams, B. D.; Stuart, C. A.; Lane, H. W.; Wolfe, R. R.

    1995-01-01

    BACKGROUND: This study reports the effects of ingesting branched-chain amino acids (leucine, valine, and isoleucine) on protein metabolism in four men. METHODS: To calculate leg protein synthesis and breakdown, we used a new model that utilized the infusion of L-[ring-13C6]phenylalanine and the sampling of the leg arterial-venous difference and muscle biopsies. In addition, protein-bound enrichments provided for the direct calculation of muscle fractional synthetic rate. Four control subjects ingested an equivalent amount of essential amino acids (threonine, methionine, and histidine) to discern the effects of branched-chain amino acid nitrogen vs the effects of essential amino acid nitrogen. Each drink also included 50 g of carbohydrate. RESULTS: Consumption of the branched-chain and the essential amino acid solutions produced significant threefold and fourfold elevations in their respective arterial concentrations. Protein synthesis and breakdown were unaffected by branched-chain amino acids, but they increased by 43% (p < .05) and 36% (p < .03), respectively, in the group consuming the essential amino acids. However, net leg balance of phenylalanine was unchanged by either drink. Direct measurement of protein synthesis by tracer incorporation into muscle protein (fractional synthetic rate) revealed no changes within or between drinks. Whole-body phenylalanine flux was significantly suppressed by each solution but to a greater extent by the branched-chain amino acids (15% and 20%, respectively) (p < .001). CONCLUSIONS: These results suggest that branched-chain amino acid ingestion suppresses whole-body proteolysis in tissues other than skeletal muscle in normal men.

  8. Preference for and learning of amino acids in larval Drosophila

    PubMed Central

    Kudow, Nana; Miura, Daisuke; Schleyer, Michael; Toshima, Naoko; Gerber, Bertram

    2017-01-01

    ABSTRACT Relative to other nutrients, less is known about how animals sense amino acids and how behaviour is organized accordingly. This is a significant gap in our knowledge because amino acids are required for protein synthesis − and hence for life as we know it. Choosing Drosophila larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical amino acids in Drosophila. We report that preference for individual amino acids differs according to the kind of amino acid, both in first-instar and in third-instar larvae. Our data suggest that this preference profile changes across larval instars, and that starvation during the third instar also alters this profile. Only aspartic acid turns out to be robustly attractive across all our experiments. The essentiality of amino acids does not appear to be a determinant of preference. Interestingly, although amino acids thus differ in their innate attractiveness, we find that all amino acids are equally rewarding. Similar discrepancies between innate attractiveness and reinforcing effect have previously been reported for other tastants, including sugars, bitter substances and salt. The present analyses will facilitate the ongoing search for the receptors, sensory neurons, and internal, homeostatic amino acid sensors in Drosophila. PMID:28193602

  9. Application of chemometrics to assess the influence of ultrasound frequency, Lactobacillus sakei culture and drying on beef jerky manufacture: Impact on amino acid profile, organic acids, texture and colour.

    PubMed

    Shikha Ojha, K; Granato, Daniel; Rajuria, Gaurav; Barba, Francisco J; Kerry, Joseph P; Tiwari, Brijesh K

    2018-01-15

    The effects of ultrasound (US) frequency, addition of Lactobacillus sakei culture and drying time on key nutritional (protein, amino acids, and organic acids) and physicochemical properties (texture and colour) of cultured and uncultured beef jerky were evaluated. Cultured and uncultured jerky samples were subjected to US frequencies of 25kHz, 33kHz and 45kHz for 30min prior to marination and drying. Principal component analysis demonstrated a significant effect of beef jerky processing conditions on physicochemical properties. Taurine content of jerky samples was found to increase with an increase in ultrasonic frequencies for cultured samples. No significant changes in colour values were observed for ultrasound pre-treated and control samples. Interactive effects of culture treatment, drying and ultrasonic frequency were observed. This study demonstrates that the nutritional profile of beef jerky can be improved through the incorporation of L. sakei. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Amino acid nutrition of fishes: requirements and supplementation of diets

    USGS Publications Warehouse

    Ketola, H.G.

    1982-01-01

    The purpose of this paper is: (1) to make a concise review of the published dietary requirements of fishes for amino acids, (2) to describe recent findings at the Tunison Laboratory concerning amino acid nutrition of trout, (3) to review specific signs of deficiency of amino acids, and (4) to discuss use of the fish egg amino acid pattern as a guideline to formulating new feeds or studying amino acid requirements of fishes for which there is limited information on their quantitative requirements.

  11. 40 CFR 721.1643 - Benzenesulfonic acid, amino substituted phenylazo-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Benzenesulfonic acid, amino... Specific Chemical Substances § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. (a) Chemical... as a benzenesulfonic acid, amino substituted phenylazo- (PMN P-95-86) is subject to reporting under...

  12. 40 CFR 721.1643 - Benzenesulfonic acid, amino substituted phenylazo-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Benzenesulfonic acid, amino... Specific Chemical Substances § 721.1643 Benzenesulfonic acid, amino substituted phenylazo-. (a) Chemical... as a benzenesulfonic acid, amino substituted phenylazo- (PMN P-95-86) is subject to reporting under...

  13. GC-Content of Synonymous Codons Profoundly Influences Amino Acid Usage

    PubMed Central

    Li, Jing; Zhou, Jun; Wu, Ying; Yang, Sihai; Tian, Dacheng

    2015-01-01

    Amino acids typically are encoded by multiple synonymous codons that are not used with the same frequency. Codon usage bias has drawn considerable attention, and several explanations have been offered, including variation in GC-content between species. Focusing on a simple parameter—combined GC proportion of all the synonymous codons for a particular amino acid, termed GCsyn—we try to deepen our understanding of the relationship between GC-content and amino acid/codon usage in more details. We analyzed 65 widely distributed representative species and found a close association between GCsyn, GC-content, and amino acids usage. The overall usages of the four amino acids with the greatest GCsyn and the five amino acids with the lowest GCsyn both vary with the regional GC-content, whereas the usage of the remaining 11 amino acids with intermediate GCsyn is less variable. More interesting, we discovered that codon usage frequencies are nearly constant in regions with similar GC-content. We further quantified the effects of regional GC-content variation (low to high) on amino acid usage and found that GC-content determines the usage variation of amino acids, especially those with extremely high GCsyn, which accounts for 76.7% of the changed GC-content for those regions. Our results suggest that GCsyn correlates with GC-content and has impact on codon/amino acid usage. These findings suggest a novel approach to understanding the role of codon and amino acid usage in shaping genomic architecture and evolutionary patterns of organisms. PMID:26248983

  14. Cyanobacteria as efficient producers of mycosporine-like amino acids.

    PubMed

    Jain, Shikha; Prajapat, Ganshyam; Abrar, Mustari; Ledwani, Lalita; Singh, Anoop; Agrawal, Akhil

    2017-09-01

    Mycosporine-like amino acids are the most common group of transparent ultraviolet radiation absorbing intracellular secondary metabolites. These molecules absorb light in the range of ultraviolet-A and -B with a maximum absorbance between 310 and 362 nm. Cyanobacteria might have faced the most deleterious ultraviolet radiation, which leads to an evolution of ultraviolet protecting mycosporine-like amino acids for efficient selection in the environment. In the last 30 years, scientists have investigated various cyanobacteria for novel mycosporine-like amino acids, applying different induction techniques. This review organizes all the cyanobacterial groups that produce various mycosporine-like amino acids. We found out that cyanobacteria belonging to orders Synechococcales, Chroococcales, Oscillatoriales, and Nostocales are frequently studied for the presence of mycosporine-like amino acids, while orders Gloeobacterales, Spirulinales, Pleurocapsales, and Chroococcidiopsidales are still need to be investigated. Nostoc and Anabaena strains are major studied genus for the mycosporine-like amino acids production. Hence, this review will give further insight to the readers about potential mycosporine-like amino acid producing cyanobacterial groups in future investigations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Abc Amino Acids: Design, Synthesis, and Properties of New Photoelastic Amino Acids

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

    Standaert, Robert F; Park, Dr Seung Bum

    2006-01-01

    Photoisomerizable amino acids provide a direct avenue to the experimental manipulation of bioactive polypeptides, potentially allowing real-time, remote control of biological systems and enabling useful applications in nanobiotechnology. Herein, we report a new class of photoisomerizable amino acids intended to cause pronounced expansion and contraction in the polypeptide backbone, i.e., to be photoelastic. These compounds, termed Abc amino acids, employ a photoisomerizable azobiphenyl chromophore to control the relative disposition of aminomethyl and carboxyl substituents. Molecular modeling of nine Abc isomers led to the identification of one with particularly attractive properties, including the ability to induce contractions up to 13A inmore » the backbone upon transa?cis photoisomerization. This isomer, designated mpAbc, has substituents at meta and para positions on the inner (azo-linked) and outer rings, respectively. An efficient synthesis of Fmoc-protected mpAbc was executed in which the biaryl components were formed via Suzuki couplings and the azo linkage was formed via amine/nitroso condensation; protected forms of three other Abc isomers were prepared similarly. A decapeptide incorporating mpAbc was synthesized by conventional solid-phase methods and displayed characteristic azobenzene photochemical behavior with optimal conversion to the cis isomer at 360 nm and a thermal cisa?trans half life of 100 min. at 80 AoC.« less

  16. Regulation of intestinal protein metabolism by amino acids.

    PubMed

    Bertrand, Julien; Goichon, Alexis; Déchelotte, Pierre; Coëffier, Moïse

    2013-09-01

    Gut homeostasis plays a major role in health and may be regulated by quantitative and qualitative food intake. In the intestinal mucosa, an intense renewal of proteins occurs, at approximately 50% per day in humans. In some pathophysiological conditions, protein turnover is altered and may contribute to intestinal or systemic diseases. Amino acids are key effectors of gut protein turnover, both as constituents of proteins and as regulatory molecules limiting intestinal injury and maintaining intestinal functions. Many studies have focused on two amino acids: glutamine, known as the preferential substrate of rapidly dividing cells, and arginine, another conditionally essential amino acid. The effects of glutamine and arginine on protein synthesis appear to be model and condition dependent, as are the involved signaling pathways. The regulation of gut protein degradation by amino acids has been minimally documented until now. This review will examine recent data, helping to better understand how amino acids regulate intestinal protein metabolism, and will explore perspectives for future studies.

  17. Amino acid fermentation at the origin of the genetic code.

    PubMed

    de Vladar, Harold P

    2012-02-10

    There is evidence that the genetic code was established prior to the existence of proteins, when metabolism was powered by ribozymes. Also, early proto-organisms had to rely on simple anaerobic bioenergetic processes. In this work I propose that amino acid fermentation powered metabolism in the RNA world, and that this was facilitated by proto-adapters, the precursors of the tRNAs. Amino acids were used as carbon sources rather than as catalytic or structural elements. In modern bacteria, amino acid fermentation is known as the Stickland reaction. This pathway involves two amino acids: the first undergoes oxidative deamination, and the second acts as an electron acceptor through reductive deamination. This redox reaction results in two keto acids that are employed to synthesise ATP via substrate-level phosphorylation. The Stickland reaction is the basic bioenergetic pathway of some bacteria of the genus Clostridium. Two other facts support Stickland fermentation in the RNA world. First, several Stickland amino acid pairs are synthesised in abiotic amino acid synthesis. This suggests that amino acids that could be used as an energy substrate were freely available. Second, anticodons that have complementary sequences often correspond to amino acids that form Stickland pairs. The main hypothesis of this paper is that pairs of complementary proto-adapters were assigned to Stickland amino acids pairs. There are signatures of this hypothesis in the genetic code. Furthermore, it is argued that the proto-adapters formed double strands that brought amino acid pairs into proximity to facilitate their mutual redox reaction, structurally constraining the anticodon pairs that are assigned to these amino acid pairs. Significance tests which randomise the code are performed to study the extent of the variability of the energetic (ATP) yield. Random assignments can lead to a substantial yield of ATP and maintain enough variability, thus selection can act and refine the assignments

  18. Formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations - A review.

    PubMed

    Zhao, Cindy J; Schieber, Andreas; Gänzle, Michael G

    2016-11-01

    Fermented foods are valued for their rich and complex odour and taste. The metabolic activity of food-fermenting microorganisms determines food quality and generates odour and taste compounds. This communication reviews the formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations. Pathways of the generation of taste compounds are presented for soy sauce, cheese, fermented meats, and bread. Proteolysis or autolysis during food fermentations generates taste-active amino acids and peptides; peptides derived from proteolysis particularly impart umami taste (e.g. α-glutamyl peptides) or bitter taste (e.g. hydrophobic peptides containing proline). Taste active peptide derivatives include pyroglutamyl peptides, γ-glutamyl peptides, and succinyl- or lactoyl amino acids. The influence of fermentation microbiota on proteolysis, and peptide hydrolysis, and the metabolism of glutamate and arginine is well understood, however, the understanding of microbial metabolic activities related to the formation of taste-active peptide derivatives is incomplete. Improved knowledge of the interactions between taste-active compounds will enable the development of novel fermentation strategies to develop tastier, less bitter, and low-salt food products, and may provide novel and "clean label" ingredients to improve the taste of other food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Amino acid composition and antioxidant capacity of Spanish honeys.

    PubMed

    Pérez, Rosa Ana; Iglesias, María Teresa; Pueyo, Encarnación; Gonzalez, Montserrat; de Lorenzo, Cristina

    2007-01-24

    The amino acid composition of 53 honey samples from Spain, consisting of 39 floral, 5 honeydew, and 9 blend honeys, has been determined. Physicochemical characteristics, polyphenolic content, amino acid composition, and estimation of the radical scavenging capacity against the stable free radical DPPH of the honey samples were analyzed. The resulting data have been statistically evaluated. The results showed that pH, acidity, net absorbance, electrical conductivity, and total polyphenolic contents of the honeys showed a strong correlation with the radical scavenging capacity. The correlation between the radical scavenging capacity of honey and amino acid contents was high with 18 of the 20 amino acids detected, with correlation values higher than those obtained for polyphenolic content. These results suggest that the amino acid composition of honey is an indicator of the sample's scavenging capacity.

  20. Toward Sustainable Amino Acid Production.

    PubMed

    Usuda, Yoshihiro; Hara, Yoshihiko; Kojima, Hiroyuki

    Because the global amino acid production industry has been growing steadily and is expected to grow even more in the future, efficient production by fermentation is of great importance from economic and sustainability viewpoints. Many systems biology technologies, such as genome breeding, omics analysis, metabolic flux analysis, and metabolic simulation, have been employed for the improvement of amino acid-producing strains of bacteria. Synthetic biological approaches have recently been applied to strain development. It is also important to use sustainable carbon sources, such as glycerol or pyrolytic sugars from cellulosic biomass, instead of conventional carbon sources, such as glucose or sucrose, which can be used as food. Furthermore, reduction of sub-raw substrates has been shown to lead to reduction of environmental burdens and cost. Recently, a new fermentation system for glutamate production under acidic pH was developed to decrease the amount of one sub-raw material, ammonium, for maintenance of culture pH. At the same time, the utilization of fermentation coproducts, such as cells, ammonium sulfate, and fermentation broth, is a useful approach to decrease waste. In this chapter, further perspectives for future amino acid fermentation from one-carbon compounds are described.

  1. Formation of specific amino acid sequences during carbodiimide-mediated condensation of amino acids in aqueous solution, and computer-simulated sequence generation

    NASA Astrophysics Data System (ADS)

    Hartmann, Jürgen; Nawroth, Thomas; Dose, Klaus

    1984-12-01

    Carbodiimide-mediated peptide synthesis in aqueous solution has been studied with respect to self-ordering of amino acids. The copolymerisation of amino acids in the presence of glutamic acid or pyroglutamic acid leads to short pyroglutamyl peptides. Without pyroglutamic acid the formation of higher polymers is favoured. The interactions of the amino acids and the peptides, however, are very complex. Therefore, the experimental results are rather difficult to explain. Some of the experimental results, however, can be explained with the aid of computer simulation programs. Regarding only the tripeptide fraction the copolymerisation of pyroGlu, Ala and Leu, as well as the simulated copolymerisation lead to pyroGlu-Ala-Leu as the main reaction product. The amino acid composition of the insoluble peptides formed during the copolymerisation of Ser, Gly, Ala, Val, Phe, Leu and Ile corresponds in part to the computer-simulated copolymerisation data.

  2. Modulatory Effects of Dietary Amino Acids on Neurodegenerative Diseases.

    PubMed

    Rajagopal, Senthilkumar; Sangam, Supraj Raja; Singh, Shubham; Joginapally, Venkateswara Rao

    2016-01-01

    Proteins are playing a vital role in maintaining the cellular integrity and function, as well as for brain cells. Protein intake and supplementation of individual amino acids can affect the brain functioning and mental health, and many of the neurotransmitters in the brain are made from amino acids. The amino acid supplementation has been found to reduce symptoms, as they are converted into neurotransmitters which in turn extenuate the mental disorders. The biosynthesis of amino acids in the brain is regulated by the concentration of amino acids in plasma. The brain diseases such as depression, bipolar disorder, schizophrenia, obsessive-compulsive disorder (OCD), and Alzheimer's (AD), Parkinson's (PD), and Huntington's diseases (HD) are the most common mental disorders that are currently widespread in numerous countries. The intricate biochemical and molecular machinery contributing to the neurological disorders is still unknown, and in this chapter, we revealed the involvement of dietary amino acids on neurological diseases.

  3. d-Amino acids in molecular evolution in space - Absolute asymmetric photolysis and synthesis of amino acids by circularly polarized light.

    PubMed

    Sugahara, Haruna; Meinert, Cornelia; Nahon, Laurent; Jones, Nykola C; Hoffmann, Søren V; Hamase, Kenji; Takano, Yoshinori; Meierhenrich, Uwe J

    2018-07-01

    Living organisms on the Earth almost exclusively use l-amino acids for the molecular architecture of proteins. The biological occurrence of d-amino acids is rare, although their functions in various organisms are being gradually understood. A possible explanation for the origin of biomolecular homochirality is the delivery of enantioenriched molecules via extraterrestrial bodies, such as asteroids and comets on early Earth. For the asymmetric formation of amino acids and their precursor molecules in interstellar environments, the interaction with circularly polarized photons is considered to have played a potential role in causing chiral asymmetry. In this review, we summarize recent progress in the investigation of chirality transfer from chiral photons to amino acids involving the two major processes of asymmetric photolysis and asymmetric synthesis. We will discuss analytical data on cometary and meteoritic amino acids and their potential impact delivery to the early Earth. The ongoing and future ambitious space missions, Hayabusa2, OSIRIS-REx, ExoMars 2020, and MMX, are scheduled to provide new insights into the chirality of extraterrestrial organic molecules and their potential relation to the terrestrial homochirality. This article is part of a Special Issue entitled: d-Amino acids: biology in the mirror, edited by Dr. Loredano Pollegioni, Dr. Jean-Pierre Mothet and Dr. Molla Gianluca. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo...

  5. 40 CFR 721.10126 - Alkyl amino substituted triazine amino substituted benezenesulfonic acid reaction product with...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo substituted phenyl azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo... substituted triazine amino substituted benezenesulfonic acid reaction product with naphthalenesulfonato azo...

  6. [Amino acid level in pastry with low caloric value].

    PubMed

    Barkhatov, V Iu; Vyskubova, N K; Felipas, T B; Pshemurzova, R M; Kamenetskaia, E V

    1988-01-01

    The effect of fruit paste additives on amino acid composition of farinaceous and decorative confectionery semifinished products was studied to decrease their fuel value. It was found that a partial replacement of sugar and fat for apple and quince pastes in apple biscuit and apple shortbread semiproducts led to an increase in the content of essential and sulfur-containing amino acids. Cream prepared from egg albumin and quince paste had reduced content of amino acids (except for glutamic acid) due to the diminished content of egg albumin, however, the balance of amino acid composition was improved.

  7. Stardust, Supernovae and the Chirality of the Amino Acids

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

    Boyd, R N; Kajino, T; Onaka, T

    A mechanism for creating enantiomerism in the amino acids, the building blocks of the proteins, that involves global selection of one chirality by interactions between the amino acids and neutrinos from core-collapse supernovae is described. The selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereofmore » on Earth, or could have triggered the chirality that was ultimately achieved for Earth's amino acids.« less

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  9. More than just sugar: allocation of nectar amino acids and fatty acids in a Lepidopteran.

    PubMed

    Levin, Eran; McCue, Marshall D; Davidowitz, Goggy

    2017-02-08

    The ability to allocate resources, even when limited, is essential for survival and fitness. We examine how nutrients that occur in minute amounts are allocated among reproductive, somatic, and metabolic demands. In addition to sugar, flower nectars contain two macronutrients-amino acids and fatty acids. We created artificial nectars spiked with 13 C-labelled amino acids and fatty acids and fed these to adult moths (Manduca sexta: Sphingidae) to understand how they allocate these nutrients among competing sinks (reproduction, somatic tissue, and metabolic fuel). We found that both essential and non-essential amino acids were allocated to eggs and flight muscles and were still detectable in early-instar larvae. Parental-derived essential amino acids were more conserved in the early-instars than non-essential amino acids. All amino acids were used as metabolic fuel, but the non-essential amino acids were oxidized at higher rates than essential amino acids. Surprisingly, the nectar fatty acids were not vertically transferred to offspring, but were readily used as a metabolic fuel by the moth, minimizing losses of endogenous nutrient stores. We conclude that the non-carbohydrate components of nectar may play important roles in both reproductive success and survival of these nectar-feeding animals. © 2017 The Author(s).

  10. More than just sugar: allocation of nectar amino acids and fatty acids in a Lepidopteran

    PubMed Central

    McCue, Marshall D.; Davidowitz, Goggy

    2017-01-01

    The ability to allocate resources, even when limited, is essential for survival and fitness. We examine how nutrients that occur in minute amounts are allocated among reproductive, somatic, and metabolic demands. In addition to sugar, flower nectars contain two macronutrients—amino acids and fatty acids. We created artificial nectars spiked with 13C-labelled amino acids and fatty acids and fed these to adult moths (Manduca sexta: Sphingidae) to understand how they allocate these nutrients among competing sinks (reproduction, somatic tissue, and metabolic fuel). We found that both essential and non-essential amino acids were allocated to eggs and flight muscles and were still detectable in early-instar larvae. Parental-derived essential amino acids were more conserved in the early-instars than non-essential amino acids. All amino acids were used as metabolic fuel, but the non-essential amino acids were oxidized at higher rates than essential amino acids. Surprisingly, the nectar fatty acids were not vertically transferred to offspring, but were readily used as a metabolic fuel by the moth, minimizing losses of endogenous nutrient stores. We conclude that the non-carbohydrate components of nectar may play important roles in both reproductive success and survival of these nectar-feeding animals. PMID:28148746

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

    PubMed

    Xu, Naijin; Chen, Guanqun; Liu, Hui

    2017-11-27

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

  12. Fortifying Horticultural Crops with Essential Amino Acids: A Review.

    PubMed

    Wang, Guoping; Xu, Mengyun; Wang, Wenyi; Galili, Gad

    2017-06-19

    To feed the world's growing population, increasing the yield of crops is not the only important factor, improving crop quality is also important, and it presents a significant challenge. Among the important crops, horticultural crops (particularly fruits and vegetables) provide numerous health compounds, such as vitamins, antioxidants, and amino acids. Essential amino acids are those that cannot be produced by the organism and, therefore, must be obtained from diet, particularly from meat, eggs, and milk, as well as a variety of plants. Extensive efforts have been devoted to increasing the levels of essential amino acids in plants. Yet, these efforts have been met with very little success due to the limited genetic resources for plant breeding and because high essential amino acid content is generally accompanied by limited plant growth. With a deep understanding of the biosynthetic pathways of essential amino acids and their interactions with the regulatory networks in plants, it should be possible to use genetic engineering to improve the essential amino acid content of horticultural plants, rendering these plants more nutritionally favorable crops. In the present report, we describe the recent advances in the enhancement of essential amino acids in horticultural plants and possible future directions towards their bio-fortification.

  13. Fasting Serum Taurine-Conjugated Bile Acids Are Elevated in Type 2 Diabetes and Do Not Change With Intensification of Insulin

    PubMed Central

    Wewalka, Marlene; Patti, Mary-Elizabeth; Barbato, Corinne; Houten, Sander M.

    2014-01-01

    Context: Bile acids (BAs) are newly recognized signaling molecules in glucose and energy homeostasis. Differences in BA profiles with type 2 diabetes mellitus (T2D) remain incompletely understood. Objective: The objective of the study was to assess serum BA composition in impaired glucose-tolerant, T2D, and normal glucose-tolerant persons and to monitor the effects of improving glycemia on serum BA composition in T2D patients. Design and Setting: This was a cross-sectional cohort study in a general population (cohort 1) and nonrandomized intervention (cohort 2). Patients and Interventions: Ninety-nine volunteers underwent oral glucose tolerance testing, and 12 persons with T2D and hyperglycemia underwent 8 weeks of intensification of treatment. Main Outcome Measures: Serum free BA and respective taurine and glycine conjugates were measured by HPLC tandem mass spectrometry. Results: Oral glucose tolerance testing identified 62 normal-, 25 impaired glucose-tolerant, and 12 T2D persons. Concentrations of total taurine-conjugated BA were higher in T2D and intermediate in impaired- compared with normal glucose-tolerant persons (P = .009). Univariate regression revealed a positive association between total taurine-BA and fasting glucose (R = 0.37, P < .001), postload glucose (R = 0.31, P < .002), hemoglobin A1c (R = 0.26, P < .001), fasting insulin (R = 0.21, P = .03), and homeostatic model assessment-estimated insulin resistance (R = 0.26, P = .01) and an inverse association with oral disposition index (R = −0.36, P < .001). Insulin-mediated glycemic improvement in T2D patients did not change fasting serum total BA or BA composition. Conclusion: Fasting taurine-conjugated BA concentrations are higher in T2D and intermediate in impaired compared with normal glucose-tolerant persons and are associated with fasting and postload glucose. Serum BAs are not altered in T2D in response to improved glycemia. Further study may elucidate whether this pattern of taurine

  14. Amino acid fermentation at the origin of the genetic code

    PubMed Central

    2012-01-01

    There is evidence that the genetic code was established prior to the existence of proteins, when metabolism was powered by ribozymes. Also, early proto-organisms had to rely on simple anaerobic bioenergetic processes. In this work I propose that amino acid fermentation powered metabolism in the RNA world, and that this was facilitated by proto-adapters, the precursors of the tRNAs. Amino acids were used as carbon sources rather than as catalytic or structural elements. In modern bacteria, amino acid fermentation is known as the Stickland reaction. This pathway involves two amino acids: the first undergoes oxidative deamination, and the second acts as an electron acceptor through reductive deamination. This redox reaction results in two keto acids that are employed to synthesise ATP via substrate-level phosphorylation. The Stickland reaction is the basic bioenergetic pathway of some bacteria of the genus Clostridium. Two other facts support Stickland fermentation in the RNA world. First, several Stickland amino acid pairs are synthesised in abiotic amino acid synthesis. This suggests that amino acids that could be used as an energy substrate were freely available. Second, anticodons that have complementary sequences often correspond to amino acids that form Stickland pairs. The main hypothesis of this paper is that pairs of complementary proto-adapters were assigned to Stickland amino acids pairs. There are signatures of this hypothesis in the genetic code. Furthermore, it is argued that the proto-adapters formed double strands that brought amino acid pairs into proximity to facilitate their mutual redox reaction, structurally constraining the anticodon pairs that are assigned to these amino acid pairs. Significance tests which randomise the code are performed to study the extent of the variability of the energetic (ATP) yield. Random assignments can lead to a substantial yield of ATP and maintain enough variability, thus selection can act and refine the assignments

  15. Meteoritic Amino Acids: Diversity in Compositions Reflects Parent Body Histories

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie E.; Aponte, Jose C.; Blackmond, Donna G.; Burton, Aaron S.; Dworkin, Jason P.; Glavin, Daniel P.

    2016-01-01

    The analysis of amino acids in meteorites dates back over 50 years; however, it is only in recent years that research has expanded beyond investigations of a narrow set of meteorite groups (exemplied by the Murchison meteorite) into meteorites of other types and classes. These new studies have shown a wide diversity in the abundance and distribution of amino acids across carbonaceous chondrite groups, highlighting the role of parent body processes and composition in the creation, preservation, or alteration of amino acids. Although most chiral amino acids are racemic in meteorites, the enantiomeric distribution of some amino acids, particularly of the nonprotein amino acid isovaline, has also been shown to vary both within certain meteorites and across carbonaceous meteorite groups. Large -enantiomeric excesses of some extraterrestrial protein amino acids (up to 60) have also been observed in rare cases and point to nonbiological enantiomeric enrichment processes prior to the emergence of life. In this Outlook, we review these recent meteoritic analyses, focusing on variations in abundance, structural distributions, and enantiomeric distributions of amino acids and discussing possible explanations for these observations and the potential for future work.

  16. Meteoritic Amino Acids: Diversity in Compositions Reflects Parent Body Histories

    PubMed Central

    2016-01-01

    The analysis of amino acids in meteorites dates back over 50 years; however, it is only in recent years that research has expanded beyond investigations of a narrow set of meteorite groups (exemplified by the Murchison meteorite) into meteorites of other types and classes. These new studies have shown a wide diversity in the abundance and distribution of amino acids across carbonaceous chondrite groups, highlighting the role of parent body processes and composition in the creation, preservation, or alteration of amino acids. Although most chiral amino acids are racemic in meteorites, the enantiomeric distribution of some amino acids, particularly of the nonprotein amino acid isovaline, has also been shown to vary both within certain meteorites and across carbonaceous meteorite groups. Large l-enantiomeric excesses of some extraterrestrial protein amino acids (up to ∼60%) have also been observed in rare cases and point to nonbiological enantiomeric enrichment processes prior to the emergence of life. In this Outlook, we review these recent meteoritic analyses, focusing on variations in abundance, structural distributions, and enantiomeric distributions of amino acids and discussing possible explanations for these observations and the potential for future work. PMID:27413780

  17. Polymers with complexing properties. Simple poly(amino acids)

    NASA Technical Reports Server (NTRS)

    Roque, J. M.

    1978-01-01

    The free amino (0.3 equiv/residue) and carboxyl (0.5 equiv/residue) groups of thermal polylysine increased dramatically on treatment with distilled water. The total hydrolysis of such a polymer was abnormal in that only about 50% of the expected amino acids were recovered. Poly (lysine-co-alanine-co-glycine) under usual conditions hydrolyzed completely in 8 hours; whereas, when it was pretreated with diazomethane, a normal period of 24 hours was required to give (nearly) the same amounts of each free amino acid as compared with those obtained from the untreated polymer. The amino groups of the basic thermal poly(amino acids) were sterically hindered. The existence of nitrogen atoms linking two or three chains and reactive groups (anhydride, imine) were proposed.

  18. Support Vector Machine-based classification of protein folds using the structural properties of amino acid residues and amino acid residue pairs.

    PubMed

    Shamim, Mohammad Tabrez Anwar; Anwaruddin, Mohammad; Nagarajaram, H A

    2007-12-15

    Fold recognition is a key step in the protein structure discovery process, especially when traditional sequence comparison methods fail to yield convincing structural homologies. Although many methods have been developed for protein fold recognition, their accuracies remain low. This can be attributed to insufficient exploitation of fold discriminatory features. We have developed a new method for protein fold recognition using structural information of amino acid residues and amino acid residue pairs. Since protein fold recognition can be treated as a protein fold classification problem, we have developed a Support Vector Machine (SVM) based classifier approach that uses secondary structural state and solvent accessibility state frequencies of amino acids and amino acid pairs as feature vectors. Among the individual properties examined secondary structural state frequencies of amino acids gave an overall accuracy of 65.2% for fold discrimination, which is better than the accuracy by any method reported so far in the literature. Combination of secondary structural state frequencies with solvent accessibility state frequencies of amino acids and amino acid pairs further improved the fold discrimination accuracy to more than 70%, which is approximately 8% higher than the best available method. In this study we have also tested, for the first time, an all-together multi-class method known as Crammer and Singer method for protein fold classification. Our studies reveal that the three multi-class classification methods, namely one versus all, one versus one and Crammer and Singer method, yield similar predictions. Dataset and stand-alone program are available upon request.

  19. Excitatory Amino Acids as Transmitters in the Brain

    DTIC Science & Technology

    1989-04-30

    Amino Acids as Transmitters in the Brain 12 PERSONAL AUTHOR(S) Cotman, C.W. 13a TYPE OF REPORT 1i3b TIME OYERED 14. DATE OF REPORT (Ye, Month, Day) 5s...necenearia i dentf by block number) FIEL.D GROUP SBGOP Excitatory receptors, excitatory amino acids , excitotoxicit N-methyl-D-aspartate, kainate...mediated by excitatory amino acids and their receptors. These receptors participate in both standard synaptic transmission as well as higher order

  20. Synthesis and chirality of amino acids under interstellar conditions.

    PubMed

    Giri, Chaitanya; Goesmann, Fred; Meinert, Cornelia; Evans, Amanda C; Meierhenrich, Uwe J

    2013-01-01

    Amino acids are the fundamental building blocks of proteins, the biomolecules that provide cellular structure and function in all living organisms. A majority of amino acids utilized within living systems possess pre-specified orientation geometry (chirality); however the original source for this specific orientation remains uncertain. In order to trace the chemical evolution of life, an appreciation of the synthetic and evolutional origins of the first chiral amino acids must first be gained. Given that the amino acids in our universe are likely to have been synthesized in molecular clouds in interstellar space, it is necessary to understand where and how the first synthesis might have occurred. The asymmetry of the original amino acid synthesis was probably the result of exposure to chiral photons in the form of circularly polarized light (CPL), which has been detected in interstellar molecular clouds. This chirality transfer event, from photons to amino acids, has been successfully recreated experimentally and is likely a combination of both asymmetric synthesis and enantioselective photolysis. A series of innovative studies have reported successful simulation of these environments and afforded production of chiral amino acids under realistic circumstellar and interstellar conditions: irradiation of interstellar ice analogues (CO, CO2, NH3, CH3OH, and H2O) with circularly polarized ultraviolet photons at low temperatures does result in enantiomer enriched amino acid structures (up to 1.3% ee). This topical review summarizes current knowledge and recent discoveries about the simulated interstellar environments within which amino acids were probably formed. A synopsis of the COSAC experiment onboard the ESA cometary mission ROSETTA concludes this review: the ROSETTA mission will soft-land on the nucleus of the comet 67P/Churyumov-Gerasimenko in November 2014, anticipating the first in situ detection of asymmetric organic molecules in cometary ices.

  1. Mechanisms of volatile production from non-sulfur amino acids by irradiation

    NASA Astrophysics Data System (ADS)

    Ahn, Dong Uk; Lee, Eun Joo; Feng, Xi; Zhang, Wangang; Lee, Ji Hwan; Jo, Cheorun; Nam, Kichang

    2016-02-01

    Non-sulfur amino acid monomers were used to study the mechanisms of volatile production in meat by irradiation. Irradiation not only produced many volatiles but also increased the amounts of volatiles from non-sulfur amino acid monomers. The major reaction mechanisms involved in volatile production from each group of the amino acids by irradiation differ significantly. However, we speculate that the radiolysis of amino acid side chains were the major mechanism. In addition, Strecker degradation, especially the production of aldehydes from aliphatic group amino acids, and deamination, isomerization, decarboxylation, cyclic reaction and dehydrogenation of the initial radiolytic products were also contributed to the production of volatile compounds. Each amino acid monomers produced different odor characteristics, but the intensities of odor from all non-sulfur amino acid groups were very weak. This indicated that the contribution of volatiles produced from non-sulfur amino acids was minor. If the volatile compounds from non-sulfur amino acids, especially aldehydes, interact with other volatiles compounds such as sulfur compounds, however, they can contribute to the off-odor of irradiated meat significantly.

  2. A microdialysis study of the novel antiepileptic drug levetiracetam: extracellular pharmacokinetics and effect on taurine in rat brain

    PubMed Central

    Tong, X; Patsalos, P N

    2001-01-01

    Using a rat model which allows serial blood sampling and concurrent brain microdialysis sampling, we have investigated the temporal kinetic inter-relationship of levetiracetam in serum and brain extracellular fluid (frontal cortex and hippocampus) following systemic administration of levetiracetam, a new antiepileptic drug. Concurrent extracellular amino acid concentrations were also determined. After administration (40 or 80 mg kg−1), levetiracetam rapidly appeared in both serum (Tmax, 0.4 – 0.7 h) and extracellular fluid (Tmax, 2.0 – 2.5 h) and concentrations rose linearly and dose-dependently, suggesting that transport across the blood-brain barrier is rapid and not rate-limiting. The serum free fraction (free/total serum concentration ratio; mean±s.e.mean range 0.93 – 1.05) was independent of concentration and confirms that levetiracetam is not bound to blood proteins. The kinetic profiles for the hippocampus and frontal cortex were indistinguishable suggesting that levetiracetam distribution in the brain is not brain region specific. However, t1/2 values were significantly larger than those for serum (mean range, 3.0 – 3.3 h vs 2.1 – 2.3 h) and concentrations did not attain equilibrium with respect to serum. Levetiracetam (80 mg kg−1) was associated with a significant reduction in taurine in the hippocampus and frontal cortex. Other amino acids were unaffected by levetiracetam. Levetiracetam readily and rapidly enters the brain without regional specificity. Its prolonged efflux from and slow equilibration within the brain may explain, in part, its long duration of action. The concurrent changes in taurine may contribute to its mechanism of action. PMID:11454660

  3. Transfer of Asymmetry between Proteinogenic Amino Acids under Harsh Conditions

    NASA Astrophysics Data System (ADS)

    Tarasevych, Arkadii V.; Vives, Thomas; Snytnikov, Valeriy N.; Guillemin, Jean-Claude

    2017-09-01

    The heating above 400 °C of serine, cysteine, selenocysteine and threonine leads to a complete decomposition of the amino acids and to the formation in low yields of alanine for the three formers and of 2-aminobutyric acid for the latter. At higher temperature, this amino acid is observed only when sublimable α-alkyl-α-amino acids are present, and with an enantiomeric excess dependent on several parameters. Enantiopure or enantioenriched Ser, Cys, Sel or Thr is not able to transmit its enantiomeric excess to the amino acid formed during its decomposition. The presence during the sublimation-decomposition of enantioenriched valine or isoleucine leads to the enantioenrichment of all sublimable amino acids independently of the presence of many decomposition products coming from the unstable derivative. All these studies give information on a potentially prebiotic key-reaction of abiotic transformations between α-amino acids and their evolution to homochirality.

  4. Amino acid catabolism: a pivotal regulator of innate and adaptive immunity

    PubMed Central

    McGaha, Tracy L.; Huang, Lei; Lemos, Henrique; Metz, Richard; Mautino, Mario; Prendergast, George C.; Mellor, Andrew L.

    2014-01-01

    Summary Enhanced amino acid catabolism is a common response to inflammation, but the immunologic significance of altered amino acid consumption remains unclear. The finding that tryptophan catabolism helped maintain fetal tolerance during pregnancy provided novel insights into the significance of amino acid metabolism in controlling immunity. Recent advances in identifying molecular pathways that enhance amino acid catabolism and downstream mechanisms that affect immune cells in response to inflammatory cues support the notion that amino acid catabolism regulates innate and adaptive immune cells in pathologic settings. Cells expressing enzymes that degrade amino acids modulate antigen-presenting cell and lymphocyte functions and reveal critical roles for amino acid- and catabolite-sensing pathways in controlling gene expression, functions, and survival of immune cells. Basal amino acid catabolism may contribute to immune homeostasis that prevents autoimmunity, whereas elevated amino acid catalytic activity may reinforce immune suppression to promote tumorigenesis and persistence of some pathogens that cause chronic infections. For these reasons, there is considerable interest in generating novel drugs that inhibit or induce amino acid consumption and target downstream molecular pathways that control immunity. In this review, we summarize recent developments and highlight novel concepts and key outstanding questions in this active research field. PMID:22889220

  5. Analysis of amino acids in nectar from pitchers of Sarracenia purpurea (Sarraceniaceae).

    PubMed

    Dress, W; Newell, S; Nastase, A; Ford, J

    1997-12-01

    Sarracenia purpurea L. (northern pitcher plant) is an insectivorous plant with extrafloral nectar that attracts insects to a water-filled pitfall trap. We identified and quantified the amino acids in extrafloral nectar produced by pitchers of S. purpurea. Nectar samples were collected from 32 pitchers using a wick-sampling technique. Samples were analyzed for amino acids with reverse-phase high-performance liquid chromatography with phenylisothiocyanate derivatization. Detectable amounts of amino acids were found in each of the 32 nectar samples tested. Mean number of amino acids in a nectar sample was 9 (SD = 2.2). No amino acid was detected in all 32 samples. Mean amount of amino acids in a nectar sample (i.e., amount per wick) was 351.4 ng (SD = 113.2). Nine amino acids occurred in 20 of the 32 samples (aspartic acid, cysteine, glutamic acid, glycine, histidine, hydroxyproline, methionine, serine, valine) averaging 263.4 ng (SD = 94.9), and accounting for ~75% of the total amino acid content. Nectar production may constitute a significant cost of carnivory since the nectar contains amino acids. However, some insects prefer nectar with amino acids and presence of amino acids may increase visitation and capture of insect prey.

  6. Amino acid repletion does not decrease muscle protein catabolism during hemodialysis.

    PubMed

    Raj, Dominic S C; Adeniyi, Oladipo; Dominic, Elizabeth A; Boivin, Michel A; McClelland, Sandra; Tzamaloukas, Antonios H; Morgan, Nancy; Gonzales, Lawrence; Wolfe, Robert; Ferrando, Arny

    2007-06-01

    Intradialytic protein catabolism is attributed to loss of amino acids in the dialysate. We investigated the effect of amino acid infusion during hemodialysis (HD) on muscle protein turnover and amino acid transport kinetics by using stable isotopes of phenylalanine, leucine, and lysine in eight patients with end-stage renal disease (ESRD). Subjects were studied at baseline (pre-HD), 2 h of HD without amino acid infusion (HD-O), and 2 h of HD with amino acid infusion (HD+AA). Amino acid depletion during HD-O augmented the outward transport of amino acids from muscle into the vein. Increased delivery of amino acids to the leg during HD+AA facilitated the transport of amino acids from the artery into the intracellular compartment. Increase in muscle protein breakdown was more than the increase in synthesis during HD-O (46.7 vs. 22.3%, P < 0.001). Net balance (nmol.min(-1).100 ml (-1)) was more negative during HD-O compared with pre-HD (-33.7 +/- 1.5 vs. -6.0 +/- 2.3, P < 0.001). Despite an abundant supply of amino acids, the net balance (-16.9 +/- 1.8) did not switch from net release to net uptake. HD+AA induced a proportional increase in muscle protein synthesis and catabolism. Branched chain amino acid catabolism increased significantly from baseline during HD-O and did not decrease during HD+AA. Protein synthesis efficiency, the fraction of amino acid in the intracellular pool that is utilized for muscle protein synthesis decreased from 42.1% pre-HD to 33.7 and 32.6% during HD-O and HD+AA, respectively (P < 0.01). Thus amino acid repletion during HD increased muscle protein synthesis but did not decrease muscle protein breakdown.

  7. 40 CFR 721.5279 - 2,7-Naphthalenedisulfonic acid, 4-amino-3-[[4′2-amino-4-[(3-butoxy-2-hydroxypropyl)amino]phebyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reporting. (1) The chemical substance identified as 2,7-naphthalenedisulfonic acid, 4-amino-3-[[4′2-amino-4... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 2,7-Naphthalenedisulfonic acid, 4-amino-3-[[4â²2-amino-4-[(3-butoxy-2-hydroxypropyl)amino]phebyl]azo]-3,3â²-dimethyl[1,1â²-biphenyl]-4-yl...

  8. 40 CFR 721.5279 - 2,7-Naphthalenedisulfonic acid, 4-amino-3-[[4′2-amino-4-[(3-butoxy-2-hydroxypropyl)amino]phebyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reporting. (1) The chemical substance identified as 2,7-naphthalenedisulfonic acid, 4-amino-3-[[4′2-amino-4... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 2,7-Naphthalenedisulfonic acid, 4-amino-3-[[4â²2-amino-4-[(3-butoxy-2-hydroxypropyl)amino]phebyl]azo]-3,3â²-dimethyl[1,1â²-biphenyl]-4-yl...

  9. The impacts of temperature, alcoholic degree and amino acids content on biogenic amines and their precursor amino acids content in red wine.

    PubMed

    Lorenzo, C; Bordiga, M; Pérez-Álvarez, E P; Travaglia, F; Arlorio, M; Salinas, M R; Coïsson, J D; Garde-Cerdán, T

    2017-09-01

    The aim was to study how factors such as temperature, alcoholic degree, and amino acids supplementation are able to influence the content of tyramine, histamine, 2-phenylethylamine, tryptamine and their precursor amino acids in winemaking process. Biogenic amines and amino acids were quantified at the beginning, middle and end of alcoholic fermentation, and at the end of malolactic fermentation. In general, samples produced with amino acid supplementation did not show the highest concentrations of biogenic amines, except for histamine, which content increased with the addition of the four amino acids. The synthesis of tyramine was mainly affected by the temperature and alcoholic degree, the formation of phenylethylamine was largely influenced by alcoholic degree, and tryptamine synthesis principally depended on temperature. Interestingly, there was interaction between these three factors for the biogenic amines studied. In conclusion, winemaking conditions should be established depending on the biogenic amine which synthesis is required to be controlled. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Evaluation of Prostate Cancer with Radiolabeled Amino Acid Analogs.

    PubMed

    Schuster, David M; Nanni, Cristina; Fanti, Stefano

    2016-10-01

    Conventional imaging of prostate cancer has limitations related to the frequently indolent biology of the disease. PET is a functional imaging method that can exploit various aspects of tumor biology to enable greater detection of prostate cancer than can be provided by morphologic imaging alone. Radiotracers that are in use or under investigation for targeting salient features of prostate cancer include those directed to glucose, choline, acetate, prostate-specific membrane antigen, bombesin, and amino acids. The tumor imaging features of this last class of radiotracers mirror the upregulation of transmembrane amino acid transport that is necessary in carcinomas because of increased amino acid use for energy requirements and protein synthesis. Natural and synthetic amino acids radiolabeled for PET imaging have been investigated in prostate cancer patients. Early work with naturally occurring amino acid-derived radiotracers, such as l- 11 C-methionine and l-1- 11 C-5-hydroxytryptophan, demonstrated promising results, including greater sensitivity than 18 F-FDG for intraprostatic and extraprostatic cancer detection. However, limitations with naturally occurring amino acid-derived compounds, including metabolism of the radiotracer itself, led to the development of synthetic amino acid radiotracers, which are not metabolized and therefore more accurately reflect transmembrane amino acid transport. Of the synthetic amino acid-derived PET radiotracers, anti-1-amino-3- 18 F-fluorocyclobutane-1-carboxylic acid ( 18 F-FACBC or 18 F-fluciclovine) has undergone the most promising translation to human use, including the availability of simplified radiosynthesis. Several studies have indicated advantageous biodistribution in the abdomen and pelvis with little renal excretion and bladder activity-characteristics beneficial for prostate cancer imaging. Studies have demonstrated improved lesion detection and diagnostic performance of 18 F-fluciclovine in comparison with

  11. The Path of Carbon in Photosynthesis II. Amino Acids

    DOE R&D Accomplishments Database

    Stepka, W.; Benson, A. A.; Calvin, M.

    1948-05-25

    The radioactive amino acid's synthesized from C{sup 14}O{sub 2} by green algae both in the light and in the dark after CO{sub 2}-free preillumination have been separated and identified using paper chromatography and radioautography. The radioactive amino acids identified were aspartic acid, alanine and smaller amounts of 3- and 4-carbon amino acids. This finding as well as the total absence of radioactive glutamic acid substantiates the mechanism for reduction of CO{sub 2} previously postulated by members of this laboratory.

  12. Updates on industrial production of amino acids using Corynebacterium glutamicum.

    PubMed

    Wendisch, Volker F; Jorge, João M P; Pérez-García, Fernando; Sgobba, Elvira

    2016-06-01

    L-Amino acids find various applications in biotechnology. L-Glutamic acid and its salts are used as flavor enhancers. Other L-amino acids are used as food or feed additives, in parenteral nutrition or as building blocks for the chemical and pharmaceutical industries. L-amino acids are synthesized from precursors of central carbon metabolism. Based on the knowledge of the biochemical pathways microbial fermentation processes of food, feed and pharma amino acids have been developed. Production strains of Corynebacterium glutamicum, which has been used safely for more than 50 years in food biotechnology, and Escherichia coli are constantly improved using metabolic engineering approaches. Research towards new processes is ongoing. Fermentative production of L-amino acids in the million-ton-scale has shaped modern biotechnology and its markets continue to grow steadily. This review focusses on recent achievements in strain development for amino acid production including the use of CRISPRi/dCas9, genome-reduced strains, biosensors and synthetic pathways to enable utilization of alternative carbon sources.

  13. 'Trophic' and 'source' amino acids in trophic estimation: a likely metabolic explanation.

    PubMed

    O'Connell, T C

    2017-06-01

    Amino acid nitrogen isotopic analysis is a relatively new method for estimating trophic position. It uses the isotopic difference between an individual's 'trophic' and 'source' amino acids to determine its trophic position. So far, there is no accepted explanation for the mechanism by which the isotopic signals in 'trophic' and 'source' amino acids arise. Yet without a metabolic understanding, the utility of nitrogen isotopic analyses as a method for probing trophic relations, at either bulk tissue or amino acid level, is limited. I draw on isotopic tracer studies of protein metabolism, together with a consideration of amino acid metabolic pathways, to suggest that the 'trophic'/'source' groupings have a fundamental metabolic origin, to do with the cycling of amino-nitrogen between amino acids. 'Trophic' amino acids are those whose amino-nitrogens are interchangeable, part of a metabolic amino-nitrogen pool, and 'source' amino acids are those whose amino-nitrogens are not interchangeable with the metabolic pool. Nitrogen isotopic values of 'trophic' amino acids will reflect an averaged isotopic signal of all such dietary amino acids, offset by the integrated effect of isotopic fractionation from nitrogen cycling, and modulated by metabolic and physiological effects. Isotopic values of 'source' amino acids will be more closely linked to those of equivalent dietary amino acids, but also modulated by metabolism and physiology. The complexity of nitrogen cycling suggests that a single identifiable value for 'trophic discrimination factors' is unlikely to exist. Greater consideration of physiology and metabolism should help in better understanding observed patterns in nitrogen isotopic values.

  14. Enzymes involved in branched-chain amino acid metabolism in humans.

    PubMed

    Adeva-Andany, María M; López-Maside, Laura; Donapetry-García, Cristóbal; Fernández-Fernández, Carlos; Sixto-Leal, Cristina

    2017-06-01

    Branched-chain amino acids (leucine, isoleucine and valine) are structurally related to branched-chain fatty acids. Leucine is 2-amino-4-methyl-pentanoic acid, isoleucine is 2-amino-3-methyl-pentanoic acid, and valine is 2-amino-3-methyl-butanoic acid. Similar to fatty acid oxidation, leucine and isoleucine produce acetyl-coA. Additionally, leucine generates acetoacetate and isoleucine yields propionyl-coA. Valine oxidation produces propionyl-coA, which is converted into methylmalonyl-coA and succinyl-coA. Branched-chain aminotransferase catalyzes the first reaction in the catabolic pathway of branched-chain amino acids, a reversible transamination that converts branched-chain amino acids into branched-chain ketoacids. Simultaneously, glutamate is converted in 2-ketoglutarate. The branched-chain ketoacid dehydrogenase complex catalyzes the irreversible oxidative decarboxylation of branched-chain ketoacids to produce branched-chain acyl-coA intermediates, which then follow separate catabolic pathways. Human tissue distribution and function of most of the enzymes involved in branched-chain amino acid catabolism is unknown. Congenital deficiencies of the enzymes involved in branched-chain amino acid metabolism are generally rare disorders. Some of them are associated with reduced pyruvate dehydrogenase complex activity and respiratory chain dysfunction that may contribute to their clinical phenotype. The biochemical phenotype is characterized by accumulation of the substrate to the deficient enzyme and its carnitine and/or glycine derivatives. It was established at the beginning of the twentieth century that the plasma level of the branched-chain amino acids is increased in conditions associated with insulin resistance such as obesity and diabetes mellitus. However, the potential clinical relevance of this elevation is uncertain.

  15. Cometary Amino Acids from the STARDUST Mission

    NASA Technical Reports Server (NTRS)

    Cook, Jamie Elsila

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81 P/WiId 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a cometary amino acid.

  16. Excitatory amino acid neurotoxicity and neurodegenerative disease.

    PubMed

    Meldrum, B; Garthwaite, J

    1990-09-01

    The progress over the last 30 years in defining the role of excitatory amino acids in normal physiological function and in the abnormal neuronal activity of epilepsy has been reviewed in earlier articles in this series. In the last five years it has become clear that excitatory amino acids also play a role in a wide range of neurodegenerative processes. The evidence is clearest where the degenerative process is acute, but is more controversial for slow degenerative processes. In this article Brian Meldrum and John Garthwaite review in vivo and in vitro studies of the cytotoxicity of amino acids and summarize the contribution of such toxicity to acute and chronic neurodegenerative disorders.

  17. Effect of amino acids on the interaction between cobalamin(II) and dehydroascorbic acid

    NASA Astrophysics Data System (ADS)

    Dereven'kov, I. A.; Thi, Thu Thuy Bui; Salnikov, D. S.; Makarov, S. V.

    2016-03-01

    The kinetics of the reaction between one-electron-reduced cobalamin (cobalamin(II), Cb(II)) and the two-electron-oxidized form of vitamin C (dehydroascorbic acid, DHA) with amino acids in an acidic medium is studied by conventional UV-Vis spectroscopy. It is shown that the oxidation of Cbl(II) by dehydroascorbic acid proceeds only in the presence of sulfur-containing amino acids (cysteine, acetylcysteine). A proposed reaction mechanism includes the step of amino acid coordination on the Co(II)-center through the sulfur atom, along with that of the interaction between this complex and DHA molecules, which results in the formation of ascorbyl radical and the corresponding Co(III) thiolate complex.

  18. Genetically encoded fluorescent coumarin amino acids

    DOEpatents

    Wang, Jiangyun; Xie, Jianming; Schultz, Peter G.

    2010-10-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl) ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  19. Genetically encoded fluorescent coumarin amino acids

    DOEpatents

    Wang, Jiangyun [San Diego, CA; Xie, Jianming [San Diego, CA; Schultz, Peter G [La Jolla, CA

    2012-06-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  20. Amino acids production focusing on fermentation technologies - A review.

    PubMed

    D'Este, Martina; Alvarado-Morales, Merlin; Angelidaki, Irini

    Amino acids are attractive and promising biochemicals with market capacity requirements constantly increasing. Their applicability ranges from animal feed additives, flavour enhancers and ingredients in cosmetic to specialty nutrients in pharmaceutical and medical fields. This review gives an overview of the processes applied for amino acids production and points out the main advantages and disadvantages of each. Due to the advances made in the genetic engineering techniques, the biotechnological processes, and in particular the fermentation with the aid of strains such as Corynebacterium glutamicum or Escherichia coli, play a significant role in the industrial production of amino acids. Despite the numerous advantages of the fermentative amino acids production, the process still needs significant improvements leading to increased productivity and reduction of the production costs. Although the production processes of amino acids have been extensively investigated in previous studies, a comprehensive overview of the developments in bioprocess technology has not been reported yet. This review states the importance of the fermentation process for industrial amino acids production, underlining the strengths and the weaknesses of the process. Moreover, the potential of innovative approaches utilizing macro and microalgae or bacteria are presented. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Catalytic amino acid production from biomass-derived intermediates

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

    Deng, Weiping; Wang, Yunzhu; Zhang, Sui

    Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived a-hydroxyl acids into a-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supportedmore » on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH 3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components.« less

  2. Catalytic amino acid production from biomass-derived intermediates

    PubMed Central

    Deng, Weiping; Zhang, Sui; Gupta, Krishna M.; Hülsey, Max J.; Asakura, Hiroyuki; Liu, Lingmei; Han, Yu; Karp, Eric M.; Jiang, Jianwen; Tanaka, Tsunehiro; Wang, Ye

    2018-01-01

    Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived α-hydroxyl acids into α-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supported on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components. PMID:29712826

  3. Catalytic amino acid production from biomass-derived intermediates.

    PubMed

    Deng, Weiping; Wang, Yunzhu; Zhang, Sui; Gupta, Krishna M; Hülsey, Max J; Asakura, Hiroyuki; Liu, Lingmei; Han, Yu; Karp, Eric M; Beckham, Gregg T; Dyson, Paul J; Jiang, Jianwen; Tanaka, Tsunehiro; Wang, Ye; Yan, Ning

    2018-05-15

    Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived α-hydroxyl acids into α-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supported on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH 3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components. Copyright © 2018 the Author(s). Published by PNAS.

  4. Catalytic amino acid production from biomass-derived intermediates

    DOE PAGES

    Deng, Weiping; Wang, Yunzhu; Zhang, Sui; ...

    2018-04-30

    Amino acids are the building blocks for protein biosynthesis and find use in myriad industrial applications including in food for humans, in animal feed, and as precursors for bio-based plastics, among others. However, the development of efficient chemical methods to convert abundant and renewable feedstocks into amino acids has been largely unsuccessful to date. To that end, here we report a heterogeneous catalyst that directly transforms lignocellulosic biomass-derived a-hydroxyl acids into a-amino acids, including alanine, leucine, valine, aspartic acid, and phenylalanine in high yields. The reaction follows a dehydrogenation-reductive amination pathway, with dehydrogenation as the rate-determining step. Ruthenium nanoparticles supportedmore » on carbon nanotubes (Ru/CNT) exhibit exceptional efficiency compared with catalysts based on other metals, due to the unique, reversible enhancement effect of NH 3 on Ru in dehydrogenation. Based on the catalytic system, a two-step chemical process was designed to convert glucose into alanine in 43% yield, comparable with the well-established microbial cultivation process, and therefore, the present strategy enables a route for the production of amino acids from renewable feedstocks. Moreover, a conceptual process design employing membrane distillation to facilitate product purification is proposed and validated. Overall, this study offers a rapid and potentially more efficient chemical method to produce amino acids from woody biomass components.« less

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

    NASA Astrophysics Data System (ADS)

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

    1988-05-01

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

  6. Distribution and Origin of Amino Acids in Lunar Regolith Samples

    NASA Technical Reports Server (NTRS)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; McLain, H. L.; Noble, S. K.; Gibson, E. K., Jr.

    2015-01-01

    The existence of organic compounds on the lunar surface has been a question of interest from the Apollo era to the present. Investigations of amino acids immediately after collection of lunar samples yielded inconclusive identifications, in part due to analytical limitations including insensitivity to certain compounds, an inability to separate enantiomers, and lack of compound-specific isotopic measurements. It was not possible to determine if the detected amino acids were indigenous to the lunar samples or the result of terrestrial contamination. Recently, we presented initial data from the analysis of amino acid abundances in 12 lunar regolith samples and discussed those results in the context of four potential amino acid sources [5]. Here, we expand on our previous work, focusing on amino acid abundances and distributions in seven regolith samples and presenting the first compound-specific carbon isotopic ratios measured for amino acids in a lunar sample.

  7. A Comparative Proteomic Analysis of the Simple Amino Acid Repeat Distributions in Plasmodia Reveals Lineage Specific Amino Acid Selection

    PubMed Central

    Dalby, Andrew R.

    2009-01-01

    Background Microsatellites have been used extensively in the field of comparative genomics. By studying microsatellites in coding regions we have a simple model of how genotypic changes undergo selection as they are directly expressed in the phenotype as altered proteins. The simplest of these tandem repeats in coding regions are the tri-nucleotide repeats which produce a repeat of a single amino acid when translated into proteins. Tri-nucleotide repeats are often disease associated, and are also known to be unstable to both expansion and contraction. This makes them sensitive markers for studying proteome evolution, in closely related species. Results The evolutionary history of the family of malarial causing parasites Plasmodia is complex because of the life-cycle of the organism, where it interacts with a number of different hosts and goes through a series of tissue specific stages. This study shows that the divergence between the primate and rodent malarial parasites has resulted in a lineage specific change in the simple amino acid repeat distribution that is correlated to A–T content. The paper also shows that this altered use of amino acids in SAARs is consistent with the repeat distributions being under selective pressure. Conclusions The study shows that simple amino acid repeat distributions can be used to group related species and to examine their phylogenetic relationships. This study also shows that an outgroup species with a similar A–T content can be distinguished based only on the amino acid usage in repeats, and suggest that this might be a useful feature for proteome clustering. The lineage specific use of amino acids in repeat regions suggests that comparative studies of SAAR distributions between proteomes gives an insight into the mechanisms of expansion and the selective pressures acting on the organism. PMID:19597555

  8. CSF/plasma ratios of amino acids: reference data and transports in children.

    PubMed

    Akiyama, Tomoyuki; Kobayashi, Katsuhiro; Higashikage, Akihito; Sato, Junko; Yoshinaga, Harumi

    2014-01-01

    We intended to investigate the effects of age, gender, and medications on amino acid cerebrospinal fluid (CSF)/plasma ratios in children, and to determine whether amino acid transports across the blood-CSF barrier in children differ from those in adults. Amino acid concentrations measured by ion-exchange high-performance liquid chromatography were used (CSF from 99 children, simultaneously collected plasma from 76 children). Influence of age, gender, and medications on the amino acid CSF concentrations and CSF/plasma ratios were analyzed by linear multiple regression. Interactions of amino acid transports were analyzed by correlation analysis of CSF/plasma ratios. CSF/plasma ratios of serine, valine, histidine, and arginine were higher in younger children. The glutamate CSF/plasma ratio was higher in older children. Serine, alanine, threonine, valine, and histidine CSF/plasma ratios were lower in females. Glutamine, methionine, tyrosine, and phenylalanine CSF/plasma ratios were elevated with valproate therapy. Serine, threonine, valine, leucine, and tyrosine CSF/plasma ratios were lower with clobazam therapy. The asparagine CSF/plasma ratio was elevated with pyridoxal phosphate therapy. Transports of most essential neutral amino acids interacted with each other, as did neutral amino acids with low molecular weights. Cationic amino acids interacted with each other and some essential neutral amino acids. Acidic amino acids had no interactions with other amino acids. Age, gender, and anti-epileptic drugs affect amino acid CSF/plasma ratios in children. Transport interactions between amino acids in children showed no remarkable difference from those of adults and generally followed the substrate specificities of multiple amino acid transport systems. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  9. Inhibitors of amino acids biosynthesis as antifungal agents.

    PubMed

    Jastrzębowska, Kamila; Gabriel, Iwona

    2015-02-01

    Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

  10. Hydration of amino acids: FTIR spectra and molecular dynamics studies.

    PubMed

    Panuszko, Aneta; Adamczak, Beata; Czub, Jacek; Gojło, Emilia; Stangret, Janusz

    2015-11-01

    The hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results, molecular dynamics simulations of amino acids were performed. The structural-energetic characteristic of these solute-affected water molecules shows that, on average, water affected by amino acids forms stronger and shorter H-bonds than those in pure water. Differences in the influence of amino acids on water structure have been noticed. The effect of the hydrophobic side chain of an amino acid on the solvent interactions seems to be enhanced because of the specific cooperative coupling of water strong H-bond chain, connecting the carboxyl and amino groups, with the clathrate-like H-bond network surrounding the hydrocarbon side chain. The parameter derived from the spectral data, which corresponds to the contributions of the population of weak hydrogen bonds of water molecules which have been substituted by the stronger ones in the hydration sphere of amino acids, correlated well with the amino acid hydrophobicity indexes.

  11. Distribution and enantiomeric composition of amino acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Engel, M. H.; Nagy, B.

    1982-01-01

    Studies of the amino acid contents and enantiomeric compositions of a single stone from the Murchison meteorite are reported. Water-extracted and 6M HCl-extracted samples from the meteorite interior of meteorite fragments were analyzed by gas chromatography and combined gas chromatography-chemical ionization mass spectrometry. Examination of the D/L ratios of glutamic acid, aspartic acid, proline, leucine and alanine reveals those amino acids extractable by water to be partially racemized, whereas the acid-extracted amino acids were less racemized. The amino acid composition of the stone is similar to those previously reported, including the absence of serine, threonine, tyrosine phenylalanine and methionine and the presence of unusual amino acids including such as isovaline, alpha-aminoisobutyric acid and pseudoleucine. It is concluded that the most likely mechanism accounting for the occurrence of nonracemic amino acid mixtures in the Murchison meteorite is by extraterrestrial stereoselective synthesis or decomposition reactions.

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

    PubMed

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

    1947-02-28

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

  13. Structure-based conformational preferences of amino acids

    PubMed Central

    Koehl, Patrice; Levitt, Michael

    1999-01-01

    Proteins can be very tolerant to amino acid substitution, even within their core. Understanding the factors responsible for this behavior is of critical importance for protein engineering and design. Mutations in proteins have been quantified in terms of the changes in stability they induce. For example, guest residues in specific secondary structures have been used as probes of conformational preferences of amino acids, yielding propensity scales. Predicting these amino acid propensities would be a good test of any new potential energy functions used to mimic protein stability. We have recently developed a protein design procedure that optimizes whole sequences for a given target conformation based on the knowledge of the template backbone and on a semiempirical potential energy function. This energy function is purely physical, including steric interactions based on a Lennard-Jones potential, electrostatics based on a Coulomb potential, and hydrophobicity in the form of an environment free energy based on accessible surface area and interatomic contact areas. Sequences designed by this procedure for 10 different proteins were analyzed to extract conformational preferences for amino acids. The resulting structure-based propensity scales show significant agreements with experimental propensity scale values, both for α-helices and β-sheets. These results indicate that amino acid conformational preferences are a natural consequence of the potential energy we use. This confirms the accuracy of our potential and indicates that such preferences should not be added as a design criterion. PMID:10535955

  14. Gustatory sensation of (L)- and (D)-amino acids in humans.

    PubMed

    Kawai, Misako; Sekine-Hayakawa, Yuki; Okiyama, Atsushi; Ninomiya, Yuzo

    2012-12-01

    Amino acids are known to elicit complex taste, but most human psychophysical studies on the taste of amino acids have focused on a single basic taste, such as umami (savory) taste, sweetness, or bitterness. In this study, we addressed the potential relationship between the structure and the taste properties of amino acids by measuring the human gustatory intensity and quality in response to aqueous solutions of proteogenic amino acids in comparison to D-enantiomers. Trained subjects tasted aqueous solution of each amino acid and evaluated the intensities of total taste and each basic taste using a category-ratio scale. Each basic taste of amino acids showed the dependency on its hydrophobicity, size, charge, functional groups on the side chain, and chirality of the alpha carbon. In addition, the overall taste of amino acid was found to be the combination of basic tastes according to the partial structure. For example, hydrophilic non-charged middle-sized amino acids elicited sweetness, and L-enantiomeric hydrophilic middle-sized structure was necessary for umami taste. For example, L-serine had mainly sweet and minor umami taste, and D-serine was sweet. We further applied Stevens' psychophysical function to relate the total-taste intensity and the concentration, and found that the slope values depended on the major quality of taste (e.g., bitter large, sour small).

  15. PLASMA PROTEIN PRODUCTION INFLUENCED BY AMINO ACID MIXTURES AND LACK OF ESSENTIAL AMINO ACIDS

    PubMed Central

    Madden, S. C.; Anderson, F. W.; Donovan, J. C.; Whipple, G. H.

    1945-01-01

    When blood plasma proteins are depleted by bleeding with return of red cells suspended in saline (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet nitrogen intake is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and intoxication and probably to vitamin deficiency. When the diet nitrogen is provided by certain mixtures of the ten growth essential amino acids plus glycine, given intravenously at a rapid rate, plasma protein production is good. The same mixture absorbed subcutaneously at a slower rate may be slightly better utilized. Fed orally the same mixture is better utilized and associated with a lower urinary nitrogen excretion. An ample amino acid mixture for the daily intake of a 10 kilo dog may contain in grams dl-threonine 1.4, dl-valine 3, dl-leucine 3, dl-isoleucine 2, l(+)-lysine·HCl·H2O 2.2, dl-tryptophane 0.3, dl-phenylalanine 2, dl-methionine 1.2, l(+)-histidine·HCl·H2O 1, l(+)-arginine·HCl 1, and glycine 2. Half this quantity is inadequate and not improved by addition of a mixture of alanine, serine, norleucine, proline, hydroxyproline, and tyrosine totalling 1.4 gm. Aspartic acid appears to induce vomiting when added to a mixture of amino acids. The same response has been reported for glutamic acid (8). Omission from the intake of leucine or of leucine and isoleucine results in negative nitrogen balance and rapid weight loss but plasma protein production may be temporarily maintained. It is possible that leucine may be captured from red blood cell destruction. Tryptophane deficiency causes an abrupt decline in plasma protein production. No decline occurred during 2 weeks of histidine deficiency but the urinary nitrogen increased to negative balance. Plasma protein production may be impaired during conditions of dietary deficiency not related to the protein or amino acid intake. Skin lesions and liver

  16. Rewiring protein synthesis: From natural to synthetic amino acids.

    PubMed

    Fan, Yongqiang; Evans, Christopher R; Ling, Jiqiang

    2017-11-01

    The protein synthesis machinery uses 22 natural amino acids as building blocks that faithfully decode the genetic information. Such fidelity is controlled at multiple steps and can be compromised in nature and in the laboratory to rewire protein synthesis with natural and synthetic amino acids. This review summarizes the major quality control mechanisms during protein synthesis, including aminoacyl-tRNA synthetases, elongation factors, and the ribosome. We will discuss evolution and engineering of such components that allow incorporation of natural and synthetic amino acids at positions that deviate from the standard genetic code. The protein synthesis machinery is highly selective, yet not fixed, for the correct amino acids that match the mRNA codons. Ambiguous translation of a codon with multiple amino acids or complete reassignment of a codon with a synthetic amino acid diversifies the proteome. Expanding the genetic code with synthetic amino acids through rewiring protein synthesis has broad applications in synthetic biology and chemical biology. Biochemical, structural, and genetic studies of the translational quality control mechanisms are not only crucial to understand the physiological role of translational fidelity and evolution of the genetic code, but also enable us to better design biological parts to expand the proteomes of synthetic organisms. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  18. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments.

    PubMed

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

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

    PubMed

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

    2017-04-01

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

  20. Accumulated analyses of amino acid precursors in returned lunar samples

    NASA Technical Reports Server (NTRS)

    Fox, S. W.; Harada, K.; Hare, P. E.

    1973-01-01

    Six amino acids (glycine, alanine, aspartic acid, glutamic acid, serine, and threonine) obtained by hydrolysis of extracts have been quantitatively determined in ten collections of fines from five Apollo missions. Although the amounts found, 7-45 ng/g, are small, the lunar amino acid/carbon ratios are comparable to those of the carbonaceous chondrites, Murchison and Murray, as analyzed by the same procedures. Since both the ratios of amino acid to carbon, and the four or five most common types of proteinous amino acid found, are comparable for the two extraterrestrial sources despite different cosmophysical histories of the moon and meteorites, common cosmochemical processes are suggested.

  1. Flavor Compounds in Pixian Broad-Bean Paste: Non-Volatile Organic Acids and Amino Acids.

    PubMed

    Lin, Hongbin; Yu, Xiaoyu; Fang, Jiaxing; Lu, Yunhao; Liu, Ping; Xing, Yage; Wang, Qin; Che, Zhenming; He, Qiang

    2018-05-29

    Non-volatile organic acids and amino acids are important flavor compounds in Pixian broad-bean paste, which is a traditional Chinese seasoning product. In this study, non-volatile organic acids, formed in the broad-bean paste due to the metabolism of large molecular compounds, are qualitatively and quantitatively determined by high-performance liquid chromatography (HPLC). Amino acids, mainly produced by hydrolysis of soybean proteins, were determined by the amino acid automatic analyzer. Results indicated that seven common organic acids and eighteen common amino acids were found in six Pixian broad-bean paste samples. The content of citric acid was found to be the highest in each sample, between 4.1 mg/g to 6.3 mg/g, and malic acid were between 2.1 mg/g to 3.6 mg/g ranked as the second. Moreover, fumaric acid was first detected in fermented bean pastes albeit with a low content. For amino acids, savory with lower sour taste including glutamine (Gln), glutamic acid (Glu), aspartic acid (Asp) and asparagines (Asn) were the most abundant, noted to be 6.5 mg/g, 4.0 mg/g, 6.4 mg/g, 4.9 mg/g, 6.2 mg/g and 10.2 mg/g, and bitter taste amino acids followed. More importantly, as important flavor materials in Pixian broad-bean paste, these two groups of substances are expected to be used to evaluate and represent the flavor quality of Pixian broad-bean paste. Moreover, the results revealed that citric acid, glutamic acid, methionine and proline were the most important flavor compounds. These findings are agreat contribution for evaluating the quality and further assessment of Pixian broad-bean paste.

  2. Quest for steroidomimetics: Amino acids derived steroidal and nonsteroidal architectures.

    PubMed

    Shagufta; Ahmad, Irshad; Panda, Gautam

    2017-06-16

    The chiral pool amino acids have been utilized for the construction of steroidal and non-steroidal architectures in the quest for steroidomimetics. Chirality derived from amino acid-based architectures provides new and easy to incorporate chiral chemical space, which is otherwise very difficult to introduce and comprised of several synthetic steps for asymmetric steroids. The different and exciting ligand-receptor interactions may arise from the use of each amino acid enantiomer that was introduced into the chiral steroidal backbone. The A and D rings of steroidal architectures can be mimicked by the phenyl group of the amino acid tyrosine. The Mitsunobu reaction, nucleophilic substitution and elimination, etc. were utilized for constructing diverse tri- and tetracyclic steroidal skeletons as well as benzofused seco-steroids from amino acids. These benzofused, amino acid-derived steroidal and nonsteroidal molecules had promising biological activity in hormonal related disorders. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Surface Propensity of Atmospherically Relevant Amino Acids Studied by XPS.

    PubMed

    Mocellin, Alexandra; Gomes, Anderson Herbert de Abreu; Araújo, Oscar Cardoso; de Brito, Arnaldo Naves; Björneholm, Olle

    2017-04-27

    Amino acids constitute an important fraction of the water-soluble organic nitrogen (WSON) compounds in aerosols and are involved in many processes in the atmosphere. In this work, we applied X-ray photoelectron spectroscopy (XPS) to study aqueous solutions of four amino acids, glycine, alanine, valine, and methionine, in their zwitterionic forms. We found that amino acids with hydrophilic side chains and smaller size, GLY and ALA, tend to stay in the bulk of the liquid, while the hydrophobic and bigger amino acids, VAL and MET, are found to concentrate more on the surface. We found experimental evidence that the amino acids have preferential orientation relative to the surface, with the hydrophobic side chain being closer to the surface than the hydrophilic carboxylate group. The observed amino acid surface propensity has implications in atmospheric science as the surface interactions play a central role in cloud droplet formation, and they should be considered in climate models.

  4. Geochemistry of amino acids in shells of the clam Saxidomus

    USGS Publications Warehouse

    Kvenvolden, K.A.; Blunt, D.J.; McMenamin, M.A.; Straham, S.E.

    1980-01-01

    Concentrations of amino acids and their corresponding d l enantiomeric ratios have been measured in shells of the bivalve mollusk Saxidomus from eleven localities, ranging in age from modern to probably more than 500,000 yr, along the Pacific coast of North America. Natural logarithms of amino acid concentrations correlate well with d l ratios, and the relationship provides a possible guide to the selection of fossils for use in amino acid dating. The relative order of the extents of racemization of amino acids at any given time appears to change with increasing sample age. Application of the amino acid dating method to shells from Whidbey Island, Washington, yields an age of about 80,000 yr, in contrast to the previously determined radiocarbon age of 36,000 yr which was measured on some shell carbonate and considered a minimum age. The amino acid age is compatible with the geologic record in the area. ?? 1980.

  5. The spark discharge synthesis of amino acids from various hydrocarbons

    NASA Technical Reports Server (NTRS)

    Ring, D.; Miller, S. L.

    1984-01-01

    The spark discharge synthesis of amino acids using an atmosphere of CH4+N2+H2O+NH3 has been investigated with variable pNH3. The amino acids produced using higher hydrocarbons (ethane, ethylene, acetylene, propane, butane, and isobutane) instead of CH4 were also investigated. There was considerable range in the absolute yields of amino acids, but the yields relative to glycine (or alpha-amino-n-butyric acid) were more uniform. The relative yields of the C3 to C6 aliphatic alpha-amino acids are nearly the same (with a few exceptions) with all the hydrocarbons. The glycine yields are more variable. The precursors to the C3-C6 aliphatic amino acids seem to be produced in the same process, which is separate from the synthesis of glycine precursors. It may be possible to use these relative yields as a signature for a spark discharge synthesis provided corrections can be made for subsequent decomposition events (e.g. in the Murchison meteorite).

  6. Variations of L- and D-amino acid levels in the brain of wild-type and mutant mice lacking D-amino acid oxidase activity.

    PubMed

    Du, Siqi; Wang, Yadi; Weatherly, Choyce A; Holden, Kylie; Armstrong, Daniel W

    2018-05-01

    D-amino acids are now recognized to be widely present in organisms and play essential roles in biological processes. Some D-amino acids are metabolized by D-amino acid oxidase (DAO), while D-Asp and D-Glu are metabolized by D-aspartate oxidase (DDO). In this study, levels of 22 amino acids and the enantiomeric compositions of the 19 chiral proteogenic entities have been determined in the whole brain of wild-type ddY mice (ddY/DAO +/+ ), mutant mice lacking DAO activity (ddY/DAO -/- ), and the heterozygous mice (ddY/DAO +/- ) using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). No significant differences were observed for L-amino acid levels among the three strains except for L-Trp which was markedly elevated in the DAO +/- and DAO -/- mice. The question arises as to whether this is an unknown effect of DAO inactivity. The three highest levels of L-amino acids were L-Glu, L-Asp, and L-Gln in all the three strains. The lowest L-amino acid level was L-Cys in ddY/DAO +/- and ddY/DAO -/- mice, while L-Trp showed the lowest level in ddY/DAO +/+ mice. The highest concentration of D-amino acid was found to be D-Ser, which also had the highest % D value (~ 25%). D-Glu had the lowest % D value (~ 0.01%) in all the three strains. Significant differences of D-Leu, D-Ala, D-Ser, D-Arg, and D-Ile were observed in ddY/DAO +/- and ddY/DAO -/- mice compared to ddY/DAO +/+ mice. This work provides the most complete baseline analysis of L- and D-amino acids in the brains of ddY/DAO +/+ , ddY/DAO +/- , and ddY/DAO -/- mice yet reported. It also provides the most effective and efficient analytical approach for measuring these analytes in biological samples. This study provides fundamental information on the role of DAO in the brain and may be relevant for future development involving novel drugs for DAO regulation.

  7. Regulation of renal amino acid transporters during metabolic acidosis.

    PubMed

    Moret, Caroline; Dave, Mital H; Schulz, Nicole; Jiang, Jean X; Verrey, Francois; Wagner, Carsten A

    2007-02-01

    The kidney plays a major role in acid-base homeostasis by adapting the excretion of acid equivalents to dietary intake and metabolism. Urinary acid excretion is mediated by the secretion of protons and titratable acids, particularly ammonia. NH(3) is synthesized in proximal tubule cells from glutamine taken up via specific amino acid transporters. We tested whether kidney amino acid transporters are regulated in mice in which metabolic acidosis was induced with NH(4)Cl. Blood gas and urine analysis confirmed metabolic acidosis. Real-time RT-PCR was performed to quantify the mRNAs of 16 amino acid transporters. The mRNA of phosphoenolpyruvate carboxykinase (PEPCK) was quantified as positive control for the regulation and that of GAPDH, as internal standard. In acidosis, the mRNA of kidney system N amino acid transporter SNAT3 (SLC38A3/SN1) showed a strong induction similar to that of PEPCK, whereas all other tested mRNAs encoding glutamine or glutamate transporters were unchanged or reduced in abundance. At the protein level, Western blotting and immunohistochemistry demonstrated an increased abundance of SNAT3 and reduced expression of the basolateral cationic amino acid/neutral amino acid exchanger subunit y(+)-LAT1 (SLC7A7). SNAT3 was localized to the basolateral membrane of the late proximal tubule S3 segment in control animals, whereas its expression was extended to the earlier S2 segment of the proximal tubule during acidosis. Our results suggest that the selective regulation of SNAT3 and y(+)LAT1 expression may serve a major role in the renal adaptation to acid secretion and thus for systemic acid-base balance.

  8. Preferential hydrophobic interactions are responsible for a preference of D-amino acids in the aminoacylation of 5'-AMP with hydrophobic amino acids

    NASA Technical Reports Server (NTRS)

    Lacey, J. C. Jr; Wickramasinghe, N. S.; Sabatini, R. S.

    1992-01-01

    We have studied the chemistry of aminoacyl AMP to model reactions at the 3' terminus of aminoacyl tRNA for the purpose of understanding the origin of protein synthesis. The present studies relate to the D, L preference in the esterification of 5'-AMP. All N-acetyl amino acids we studied showed faster reaction of the D-isomer, with a generally decreasing preference for D-isomer as the hydrophobicity of the amino acid decreased. The beta-branched amino acids, Ile and Val, showed an extreme preference for D-isomer. Ac-Leu, the gamma-branched amino acid, showed a slightly low D/L ratio relative to its hydrophobicity. The molecular basis for these preferences for D-isomer is understandable in the light of our previous studies and seems to be due to preferential hydrophobic interaction of the D-isomer with adenine. The preference for hydrophobic D-amino acids can be decreased by addition of an organic solvent to the reaction medium. Conversely, peptidylation with Ac-PhePhe shows a preference for the LL isomer over the DD isomer.

  9. Dipeptide Sequence Determination: Analyzing Phenylthiohydantoin Amino Acids by HPLC

    NASA Astrophysics Data System (ADS)

    Barton, Janice S.; Tang, Chung-Fei; Reed, Steven S.

    2000-02-01

    Amino acid composition and sequence determination, important techniques for characterizing peptides and proteins, are essential for predicting conformation and studying sequence alignment. This experiment presents improved, fundamental methods of sequence analysis for an upper-division biochemistry laboratory. Working in pairs, students use the Edman reagent to prepare phenylthiohydantoin derivatives of amino acids for determination of the sequence of an unknown dipeptide. With a single HPLC technique, students identify both the N-terminal amino acid and the composition of the dipeptide. This method yields good precision of retention times and allows use of a broad range of amino acids as components of the dipeptide. Students learn fundamental principles and techniques of sequence analysis and HPLC.

  10. 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.

  11. Characterization of taurine as inhibitor of sodium glucose transporter.

    PubMed

    Kim, Ha Won; Lee, Alexander John; You, Seungkwon; Park, Taesun; Lee, Dong Hee

    2006-01-01

    The most characterized roles of taurine include osmoregulator and membrane-stabilizing activities. However, much remains to be understood about its role in human physiology concerning its anti-hyperglycemic effect. Studies indicate that taurine-supplemented diet helps alleviate hyperglycemia or insulin resistance. This hypoglycemic effect has been postulated as taurine helping to increase the excretion of cholesterol. Alternatively, this study investigated the effect of taurine on glucose transporter using heterologous expression of sodium-glucose transporter-1 (SGLT-1). SGLT-1 was expressed in Xenopus oocytes and the effect of taurine on the expressed SGLT-1 was analyzed utilizing 2-deoxy-D-glucose (2-DOG) uptake and voltage clamp studies. In the oocytes expressing SGLT-1, taurine was shown to inhibit SGLT-1 activity compared to the non-treated controls in a dose-dependent manner. In the presence of taurine, the glucose uptake was greatly inhibited and the glucose-generated current was significantly inhibited. Synthetic taurine analogs were also shown to be effective in inhibiting SGLT-1 activity in a manner comparable to taurine. These effects might offer a promising opportunity in designing functional foods with anti-hyperglycemic potential by supplementing taurine and its analogs to the diet.

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

    PubMed

    Hamzalıoğlu, Aytül; Gökmen, Vural

    2018-02-01

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

  13. Evolution of a Genome-Encoded Bias in Amino Acid Biosynthetic Pathways Is a Potential Indicator of Amino Acid Dynamics in the Environment

    PubMed Central

    Fasani, Rick A.; Savageau, Michael A.

    2014-01-01

    Overcoming the stress of starvation is one of an organism’s most challenging phenotypic responses. Those organisms that frequently survive the challenge, by virtue of their fitness, will have evolved genomes that are shaped by their specific environments. Understanding this genotype–environment–phenotype relationship at a deep level will require quantitative predictive models of the complex molecular systems that link these aspects of an organism’s existence. Here, we treat one of the most fundamental molecular systems, protein synthesis, and the amino acid biosynthetic pathways involved in the stringent response to starvation. These systems face an inherent logical dilemma: Building an amino acid biosynthetic pathway to synthesize its product—the cognate amino acid of the pathway—may require that very amino acid when it is no longer available. To study this potential “catch-22,” we have created a generic model of amino acid biosynthesis in response to sudden starvation. Our mathematical analysis and computational results indicate that there are two distinctly different outcomes: Partial recovery to a new steady state, or full system failure. Moreover, the cell’s fate is dictated by the cognate bias, the number of cognate amino acids in the corresponding biosynthetic pathway relative to the average number of that amino acid in the proteome. We test these implications by analyzing the proteomes of over 1,800 sequenced microbes, which reveals statistically significant evidence of low cognate bias, a genetic trait that would avoid the biosynthetic quandary. Furthermore, these results suggest that the pattern of cognate bias, which is readily derived by genome sequencing, may provide evolutionary clues to an organism’s natural environment. PMID:25118252

  14. Isolation of Plasma Membrane Vesicles from Mouse Placenta at Term and Measurement of System A and System β Amino Acid Transporter Activity

    PubMed Central

    Kusinski, L.C.; Jones, C.J.P.; Baker, P.N.; Sibley, C.P.; Glazier, J.D.

    2010-01-01

    Placental amino acid transport is essential for optimal fetal growth and development, with a reduced fetal provision of amino acids being implicated as a potential cause of fetal growth restriction (FGR). Understanding placental insufficiency related FGR has been aided by the development of mouse models that have features of the human disease. However, to take maximal advantage of these, methods are required to study placental function in the mouse. Here, we report a method to isolate plasma membrane vesicles from mouse placenta near-term and have used these to investigate two amino acid transporters, systems A and β, the activities of which are reduced in human placental microvillous plasma membrane (MVM) vesicles from FGR pregnancies. Plasma membrane vesicles were isolated at embryonic day 18 by a protocol involving homogenisation, MgCl2 precipitation and centrifugation. Vesicles were enriched 11.3 ± 0.5-fold in alkaline phosphatase activity as compared to initial homogenate, with minimal intracellular organelle contamination as judged by marker analyses. Cytochemistry revealed alkaline phosphatase was localised between trophoblast layers I and II, with intense reaction product deposited on the maternal-facing plasma membrane of layer II, suggesting that vesicles were derived from this trophoblast membrane. System A and system β activity in mouse placental vesicles, measured as Na+-dependent uptake of 14C-methylaminoisobutyric acid (MeAIB) and 3H-taurine respectively confirmed localisation of these transporters to the maternal-facing plasma membrane of layer II. Comparison to human placental MVM showed that system A activity was comparable at initial rate between species whilst system β activity was significantly lower in mouse. This mirrored the lower expression of TAUT observed in mouse placental vesicles. We conclude that syncytiotrophoblast layer II-derived plasma membrane vesicles can be isolated and used to examine transporter function. PMID:19954844

  15. Urinary and plasma organic acids and amino acids in chronic fatigue syndrome.

    PubMed

    Jones, Mark G; Cooper, Elizabeth; Amjad, Saira; Goodwin, C Stewart; Barron, Jeffrey L; Chalmers, Ronald A

    2005-11-01

    Previous work by others have suggested the occurrence of one or more chemical or metabolic 'markers' for ME/CFS including specific amino acids and organic acids and a number of unidentified compounds (CFSUM1, CFSUM2). We have shown elsewhere that CFSUM1 is partially derivatised pyroglutamic acid and CFSUM2 partially derivatised serine and have suggested and demonstrated that the analytical methods used were unsuitable to identify or to accurately quantify urinary metabolites. We have now made a detailed analysis of plasma and urinary amino acids and of urinary organic acids from patients with ME/CFS and from three control groups. Fasting blood plasma and timed urine samples were obtained from 31 patients with CFS, 31 age and sex-matched healthy controls, 15 patients with depression and 22 patients with rheumatoid arthritis. Plasma and urinary amino acids and urinary organic acids were determined using established and validated methods and data compared by statistical analysis. None of the previously reported abnormalities in urinary amino acids or of organic acids could be confirmed. Results however provide some evidence in patients with ME/CFS for underlying inflammatory disease and for reduced intramuscular collagen with a lowered threshold for muscle micro-injury. These factors in combination may provide a basis for the fatigue and muscle pain that are the major symptoms in these patients.

  16. Protein Design Using Unnatural Amino Acids

    NASA Astrophysics Data System (ADS)

    Bilgiçer, Basar; Kumar, Krishna

    2003-11-01

    With the increasing availability of whole organism genome sequences, understanding protein structure and function is of capital importance. Recent developments in the methodology of incorporation of unnatural amino acids into proteins allow the exploration of proteins at a very detailed level. Furthermore, de novo design of novel protein structures and function is feasible with unprecedented sophistication. Using examples from the literature, this article describes the available methods for unnatural amino acid incorporation and highlights some recent applications including the design of hyperstable protein folds.

  17. Synthesis of new Cα-tetrasubstituted α-amino acids

    PubMed Central

    Grauer, Andreas A

    2009-01-01

    Summary Cα-Tetrasubstituted α-amino acids are important building blocks for the synthesis of peptidemimetics with stabilized secondary structure, because of their ability to rigidify the peptide backbone. Recently our group reported a new class of cyclic Cα-tetrasubstituted tetrahydrofuran α-amino acids prepared from methionine and aromatic aldehydes. We now report the extension of this methodology to aliphatic aldehydes. Although such aldehydes are prone to give aldol products under the reaction conditions used, we were able to obtain the target cyclic amino acids in low to moderate yields and in some cases with good diastereoselectivity. PMID:19259341

  18. Regulation of protein synthesis by amino acids in muscle of neonates

    PubMed Central

    Suryawan, Agus; Davis, Teresa A.

    2011-01-01

    The marked increase in skeletal muscle mass during the neonatal period is largely due to a high rate of postprandial protein synthesis that is modulated by an enhanced sensitivity to insulin and amino acids. The amino acid signaling pathway leading to the stimulation of protein synthesis has not been fully elucidated. Among the amino acids, leucine is considered to be a principal anabolic agent that regulates protein synthesis. mTORC1, which controls protein synthesis, has been implicated as a target for leucine. Until recently, there have been few studies exploring the role of amino acids in enhancing muscle protein synthesis in vivo. In this review, we discuss amino acid-induced protein synthesis in muscle in the neonate, focusing on current knowledge of the role of amino acids in the activation of mTORC1 leading to mRNA translation. The role of the amino acid transporters, SNAT2, LAT1, and PAT, in the modulation of mTORC1 activation and the role of amino acids in the activation of putative regulators of mTORC1, i.e., raptor, Rheb, MAP4K3, Vps34, and Rag GTPases, are discussed. PMID:21196241

  19. Amino Acid Control over Deoxyribonucleic Acid Synthesis in Escherichia coli Infected With T-Even Bacteriophage

    PubMed Central

    Donini, Pierluigi

    1970-01-01

    Starvation for a required amino acid of normal or RCstrEscherichia coli infected with T-even phages arrests further synthesis of phage deoxyribonucleic acid (DNA). This amino acid control over phage DNA synthesis does not occur in RCrelE. coli mutants. Heat inactivation of a temperature-sensitive aminoacyl-transfer ribonucleic acid (RNA) synthetase similarly causes an arrest of phage DNA synthesis in infected cells of RCstr phenotype but not in cells of RCrel phenotype. Inhibition of phage DNA synthesis in amino acid-starved RCstr host cells can be reversed by addition of chloramphenicol to the culture. Thus, the general features of amino acid control over T-even phage DNA synthesis are entirely analogous to those known for amino acid control over net RNA synthesis of uninfected bacteria. This analogy shows that the bacterial rel locus controls a wider range of macromolecular syntheses than had been previously thought. PMID:4914067

  20. Solubility calculations of branched and linear amino acids using lattice cluster theory

    NASA Astrophysics Data System (ADS)

    Fischlschweiger, Michael; Enders, Sabine; Zeiner, Tim

    2014-09-01

    In this work, the activity coefficients and the solubility of amino acids in water were calculated using the lattice cluster theory (LCT) combined with the extended chemical association lattice model allowing self-association as well as cross-association. This permits the study of the influence of the amino acids structure on the thermodynamic properties for the first time. By the used model, the activity coefficient and solubilities of the investigated fourteen amino acids (glycine, alanine, γ-aminobutyric acid, dl-valine, dl-threonine, dl-methionine, l-leucine, l-glutamic acid, l-proline, hydroxyproline, histidine, l-arginine, α-amino valeric acid) could be described in good accordance with experimental data. In the case of different α-amino acids, but different hydrocarbon chains, the same interaction energy parameter can be used within the LCT. All studied amino acids could be modelled using the same parameter for the description of the amino acid association properties. The formed cross-associates contain more amino acids than expressed by the overall mole fraction of the solution. Moreover, the composition of the cross-associates depends on temperature, where the amount of amino acids increases with increasing temperature.

  1. Developing Potential Energy Curves of Acidic and Basic Amino Acids Using Quantum Computational Techniques

    NASA Astrophysics Data System (ADS)

    de Guzman, C. P.; Andrianarijaona, M.; Yoshida, Y.; Kim, K.; Andrianarijaona, V. M.

    2017-04-01

    Proteins are made out of long chains of amino acids and are an integral part of many tasks of a cell. Because the function of a protein is caused by its structure, even minute changes in the molecular geometry of the protein can have large effects on how the protein can be used. This study investigated how manipulations in the structure of acidic and basic amino acids affected their potential energy. Acidic and basic amino acids were chosen because prior studies have suggested that the ionizable side chains of these amino acids can be very influential on a molecule's prefered conformation. Each atom in the molecule was pulled along x, y, and z axis to see how different types of changes affect the potential energy of the whole structure. The results of our calculations, which were done using ORCA, emphasize the vibronic couplings. The aggregated data was used to create a data set of potential energy curves to better understand the quantum dynamic properties of acidic and basic amino acids (preliminary data was presented in http://meetings.aps.org/Meeting/MAR16/Session/M1.273 andhttp://meetings.aps.org/Meeting/FWS16/Session/F2.6).

  2. Metal cation dependence of interactions with amino acids: bond dissociation energies of Rb(+) and Cs(+) to the acidic amino acids and their amide derivatives.

    PubMed

    Armentrout, P B; Yang, Bo; Rodgers, M T

    2014-04-24

    Metal cation-amino acid interactions are key components controlling the secondary structure and biological function of proteins, enzymes, and macromolecular complexes comprising these species. Determination of pairwise interactions of alkali metal cations with amino acids provides a thermodynamic vocabulary that begins to quantify these fundamental processes. In the present work, we expand a systematic study of such interactions by examining rubidium and cesium cations binding with the acidic amino acids (AA), aspartic acid (Asp) and glutamic acid (Glu), and their amide derivatives, asparagine (Asn) and glutamine (Gln). These eight complexes are formed using electrospray ionization and their bond dissociation energies (BDEs) are determined experimentally using threshold collision-induced dissociation with xenon in a guided ion beam tandem mass spectrometer. Analyses of the energy-dependent cross sections include consideration of unimolecular decay rates, internal energy of the reactant ions, and multiple ion-neutral collisions. Quantum chemical calculations are conducted at the B3LYP, MP2(full), and M06 levels of theory using def2-TZVPPD basis sets, with results showing reasonable agreement with experiment. At 0 and 298 K, most levels of theory predict that the ground-state conformers for M(+)(Asp) and M(+)(Asn) involve tridentate binding of the metal cation to the backbone carbonyl, amino, and side-chain carbonyl groups, although tridentate binding to the carboxylic acid group and side-chain carbonyl is competitive for M(+)(Asn). For the two longer side-chain amino acids, Glu and Gln, multiple structures are competitive. A comparison of these results to those for the smaller alkali cations, Na(+) and K(+), provides insight into the trends in binding energies associated with the molecular polarizability and dipole moment of the side chain. For all four metal cations, the BDEs are inversely correlated with the size of the metal cation and follow the order Asp < Glu

  3. Amino Acid Catabolism in Alzheimer's Disease Brain: Friend or Foe?

    PubMed Central

    2017-01-01

    There is a dire need to discover new targets for Alzheimer's disease (AD) drug development. Decreased neuronal glucose metabolism that occurs in AD brain could play a central role in disease progression. Little is known about the compensatory neuronal changes that occur to attempt to maintain energy homeostasis. In this review using the PubMed literature database, we summarize evidence that amino acid oxidation can temporarily compensate for the decreased glucose metabolism, but eventually altered amino acid and amino acid catabolite levels likely lead to toxicities contributing to AD progression. Because amino acids are involved in so many cellular metabolic and signaling pathways, the effects of altered amino acid metabolism in AD brain are far-reaching. Possible pathological results from changes in the levels of several important amino acids are discussed. Urea cycle function may be induced in endothelial cells of AD patient brains, possibly to remove excess ammonia produced from increased amino acid catabolism. Studying AD from a metabolic perspective provides new insights into AD pathogenesis and may lead to the discovery of dietary metabolite supplements that can partially compensate for alterations of enzymatic function to delay AD or alleviate some of the suffering caused by the disease. PMID:28261376

  4. Combined administration of taurine and monoisoamyl DMSA protects arsenic induced oxidative injury in rats

    PubMed Central

    Chouhan, Swapnila; Kannan, Gurusamy M; Mittal, Megha; Swarnkar, Harimohan

    2008-01-01

    Arsenic is a naturally occurring element that is ubiquitously present in the environment. High concentration of naturally occurring arsenic in drinking water is a major health problem in different parts of the world. Despite arsenic being a health hazard and a well documented carcinogen, no safe, effective and specific preventive or therapeutic measures are available. Among various recent strategies adopted, administration of an antioxidant has been reported to be the most effective. The present study was designed to evaluate the therapeutic efficacy of monoisoamyl dimercaptosuccinic acid (MiADMSA), administered either individually or in combination with taurine post chronic arsenic exposure in rats. Arsenic exposed male rats (25 ppm, sodium arsenite in drinking water for 24 weeks) were treated with taurine (100 mg/kg, i.p., once daily), monoisoamyl dimercaptosuccinic acid (MiADMSA) (50 mg/kg, oral, once daily) either individually or in combination for 5 consecutive days. Biochemical variables indicative of oxidative stress along-with arsenic concentration in blood, liver and kidney were measured. Arsenic exposure significantly reduced blood δ-aminolevulinic acid dehydratase (ALAD) activity, a key enzyme involved in the heme biosynthesis and enhanced zinc protoporphyrin (ZPP) level. Clinical hematological variables like white blood cells (WBC), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) showed significant decrease with a significant elevation in platelet (PLT) count. These changes were accompanied by significant decrease in superoxide dismutase (SOD) activity and increased catalase activity. Arsenic exposure caused a significant decrease in hepatic and renal glutathione (GSH) level and an increase in oxidized glutathione (GSSG). These biochemical changes were correlated with an increased uptake of arsenic in blood, liver and kidney. Administration of taurine significantly reduced hepatic oxidative stress however co-administration of

  5. How Amino Acids and Peptides Shaped the RNA World

    PubMed Central

    van der Gulik, Peter T.S.; Speijer, Dave

    2015-01-01

    The “RNA world” hypothesis is seen as one of the main contenders for a viable theory on the origin of life. Relatively small RNAs have catalytic power, RNA is everywhere in present-day life, the ribosome is seen as a ribozyme, and rRNA and tRNA are crucial for modern protein synthesis. However, this view is incomplete at best. The modern protein-RNA ribosome most probably is not a distorted form of a “pure RNA ribosome” evolution started out with. Though the oldest center of the ribosome seems “RNA only”, we cannot conclude from this that it ever functioned in an environment without amino acids and/or peptides. Very small RNAs (versatile and stable due to basepairing) and amino acids, as well as dipeptides, coevolved. Remember, it is the amino group of aminoacylated tRNA that attacks peptidyl-tRNA, destroying the bond between peptide and tRNA. This activity of the amino acid part of aminoacyl-tRNA illustrates the centrality of amino acids in life. With the rise of the “RNA world” view of early life, the pendulum seems to have swung too much towards the ribozymatic part of early biochemistry. The necessary presence and activity of amino acids and peptides is in need of highlighting. In this article, we try to bring the role of the peptide component of early life back into focus. We argue that an RNA world completely independent of amino acids never existed. PMID:25607813

  6. Characteristics and formation of amino acids and hydroxy acids of the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cronin, J. R.; Cooper, G. W.; Pizzarello, S.

    1995-01-01

    Eight characteristics of the unique suite of amino acids and hydroxy acids found in the Murchison meteorite can be recognized on the basis of detailed molecular and isotopic analyses. The marked structural correspondence between the alpha-amino acids and alpha-hydroxy acids and the high deuterium/hydrogen ratio argue persuasively for their formation by aqueous phase Strecker reactions in the meteorite parent body from presolar, i.e., interstellar, aldehydes, ketones, ammonia, and hydrogen cyanide. The characteristics of the meteoritic suite of amino acids and hydroxy acids are briefly enumerated and discussed with regard to their consonance with this interstellar-parent body formation hypothesis. The hypothesis has interesting implications for the organic composition of both the primitive parent body and the presolar nebula.

  7. Natural toxins that affect plant amino acid metabolism

    USDA-ARS?s Scientific Manuscript database

    A diverse range of natural compounds interfere with the synthesis and other aspects of amino acid metabolism. Some are amino acid analogues, but most are not. This review covers a number of specific natural phytotoxic compounds by molecular target site. Inhibition of glutamine synthetase is of part...

  8. A new family of extraterrestrial amino acids in the Murchison meteorite.

    PubMed

    Koga, Toshiki; Naraoka, Hiroshi

    2017-04-04

    The occurrence of extraterrestrial organic compounds is a key for understanding prebiotic organic synthesis in the universe. In particular, amino acids have been studied in carbonaceous meteorites for almost 50 years. Here we report ten new amino acids identified in the Murchison meteorite, including a new family of nine hydroxy amino acids. The discovery of mostly C 3 and C 4 structural isomers of hydroxy amino acids provides insight into the mechanisms of extraterrestrial synthesis of organic compounds. A complementary experiment suggests that these compounds could be produced from aldehydes and ammonia on the meteorite parent body. This study indicates that the meteoritic amino acids could be synthesized by mechanisms in addition to the Strecker reaction, which has been proposed to be the main synthetic pathway to produce amino acids.

  9. Transaminases for the synthesis of enantiopure beta-amino acids

    PubMed Central

    2012-01-01

    Optically pure β-amino acids constitute interesting building blocks for peptidomimetics and a great variety of pharmaceutically important compounds. Their efficient synthesis still poses a major challenge. Transaminases (also known as aminotransferases) possess a great potential for the synthesis of optically pure β-amino acids. These pyridoxal 5'-dependent enzymes catalyze the transfer of an amino group from a donor substrate to an acceptor, thus enabling the synthesis of a wide variety of chiral amines and amino acids. Transaminases can be applied either for the kinetic resolution of racemic compounds or the asymmetric synthesis starting from a prochiral substrate. This review gives an overview over microbial transaminases with activity towards β-amino acids and their substrate spectra. It also outlines current strategies for the screening of new biocatalysts. Particular emphasis is placed on activity assays which are applicable to high-throughput screening. PMID:22293122

  10. Enantiomeric Excesses of Acid Labile Amino Acid Precursors of the Murchison Meteorite

    NASA Astrophysics Data System (ADS)

    Pizzarello, Sandra

    1998-10-01

    Amino acids present in carbonaceous chondrite are extracted in water in part as free compounds and in approximately equal part as acid labile precursors. On the assumption that they would be free of contamination, the precursors of two Murchison amino acids that have terrestrial occurrence, alanine and glutamic acid, have been targeted for analysis of their enantiomeric ratios. Pyroglutamic acid, the precursor of glutamic acid, was found with an L-enantiomeric excess comparable to that of the free acid, while alanine's precursor, N-acetyl alanine, appears approximately racemic. Also alpha-imino propioacetic acid, a proposed end product of alanine synthesis in the meteorite, was analyzed and found racemic.

  11. Enantiomeric Excesses of Acid Labile Amino Acid Precursors of the Murchison Meteorite

    NASA Technical Reports Server (NTRS)

    Pizzarello, Sandra

    1998-01-01

    Amino acids present in carbonaceous chondrite are extracted in water in part as free compounds and in approximately equal part as acid labile precursors. On the assumption that they would be free of contamination, the precursors of two Murchison amino acids that have terrestrial occurrence, alanine and glutamic acid, have been targeted for analysis of their enantiomeric ratios. Pyroglutamic acid, the precursor of glutamic acid, was found with an L-enantiomeric excess comparable to that of the free acid, while alanine's precursor, N-acetyl alanine, appears approximately racemic. Also alpha-imino propioacetic acid, a proposed end product of alanine synthesis in the meteorite, was analyzed and found racemic.

  12. Expression patterns of regulatory RNAs, including lncRNAs and tRNAs, during postnatal growth of normal and dystrophic (mdx) mouse muscles, and their response to taurine treatment.

    PubMed

    Butchart, Lauren C; Terrill, Jessica R; Rossetti, Giulia; White, Robert; Filipovska, Aleksandra; Grounds, Miranda D

    2018-06-01

    Post-natal skeletal muscle growth in mice is very rapid and involves complex changes in many cells types over the first 6 weeks of life. The acute onset of dystropathology also occurs around 3 weeks of age in the mdx mouse model of the human disease Duchenne Muscular Dystrophy (DMD). This study investigated (i) alterations in expression patterns of regulatory non-coding RNAs (ncRNAs) in vivo, including miRNAs, lncRNAs and tRNAs, during early growth of skeletal muscles in normal control C57Bl/10Scsn (C57) compared with dystrophic mdx mice from 2 to 6 weeks of postnatal age, and revealed inherent differences in vivo for levels of 3 ncRNAs between C57 and mdx muscles before the onset of dystropathology. Since the amino acid taurine has many benefits and reduces disease severity in mdx mice, this study also (ii) determined the impact of taurine treatment on these expression patterns in mdx muscles at the onset of dystropathology (3 weeks) and after several bouts of myonecrosis and regeneration (6 weeks). Taurine treatment of mdx mice only altered ncRNA levels when administered from 18 days to 6 weeks of age, but a deficiency in tRNA levels was rectified earlier in mdx skeletal muscles treated from 14 days to 3 weeks. Myogenesis in tissue culture was also used to (iii) compare ncRNA expression patterns for both strains, and (iv) the response to taurine treatment. These analyses revealed intrinsic differences in ncRNA expression patterns during myogenesis between strains, as well as increased sensitivity of mdx ncRNA levels to taurine treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Computational Design of Thermostabilizing d-Amino Acid Substitutions

    PubMed Central

    Rodriguez-Granillo, Agustina; Annavarapu, Srinivas; Zhang, Lei; Koder, Ronald L.; Nanda, Vikas

    2012-01-01

    Judicious incorporation of d-amino acids in engineered proteins confer many advantages such as preventing degradation by endogenous proteases, and designing novel structures and functions not accessible to homochiral polypeptides. Glycine to d-alanine substitutions at the carboxy-termini can stabilize α-helices by reducing conformational entropy. Beyond alanine, we propose additional side chain effects on the degree of stabilization conferred by d-amino acid substitutions. A detailed, molecular understanding of backbone and side chain interactions is important for developing rational, broadly applicable strategies in using d-amino acids to increase protein thermostability. Insight from structural bioinformatics combined with computational protein design can successfully guide the selection of stabilizing d-amino acid mutations. Substituting a key glycine in the Trp-Cage mini-protein with d-Gln dramatically stabilizes the fold without altering the protein backbone. Stabilities of individual substitutions can be understood in terms of the balance of intramolecular forces at both the α-helix C-terminus and throughout the protein. PMID:21978298

  14. Application of cyanuric chloride-based six new chiral derivatizing reagents having amino acids and amino acid amides as chiral auxiliaries for enantioresolution of proteinogenic amino acids by reversed-phase high-performance liquid chromatography.

    PubMed

    Bhushan, Ravi; Dixit, Shuchi

    2012-04-01

    Six dichloro-s-triazine (DCT) reagents having L-Leu, D-Phg, L-Val, L-Met, L-Ala and L-Met-NH(2) as chiral auxiliaries in cyanuric chloride were introduced for enantioseparation of 13 proteinogenic amino acids. Four other DCTs and six monochloro-s-triazine (MCT) reagents having amino acid amides as chiral auxiliaries were also synthesized. These 16 chiral derivatizing reagents (CDRs) were used for synthesis of diastereomers of all the 13 analytes using microwave irradiation, which were resolved by reversed-phase high-performance liquid chromatography (RP-HPLC) using C18 column and gradient eluting mixture of aqueous TFA and acetonitrile with UV detection at 230 nm. It required only 60-90 s for derivatization using microwave irradiation. Better resolution and lower retention times were observed for the diastereomers prepared with CDRs having amino acids as chiral auxiliaries as compared to counterparts prepared with reagents having amino acid amides as chiral auxiliaries. As the best resolution of all the 13 analytes was observed for their diastereomers prepared using the DCT reagent having L-Leu as chiral auxiliary, this CDR was further employed for derivatization of Lys, Tyr, His and Arg followed by RP-HPLC analysis of resulting diastereomers. The results are discussed in light of acid and amide groups of chiral auxiliaries constituting CDRs, electronegativities of the atoms of achiral moieties constituting CDRs and hydrophobicities of side chains of amino acids constituting CDRs and analytes.

  15. Amino acid contribution to protein solubility: Asp, Glu, and Ser contribute more favorably than the other hydrophilic amino acids in RNase Sa.

    PubMed

    Trevino, Saul R; Scholtz, J Martin; Pace, C Nick

    2007-02-16

    Poor protein solubility is a common problem in high-resolution structural studies, formulation of protein pharmaceuticals, and biochemical characterization of proteins. One popular strategy to improve protein solubility is to use site-directed mutagenesis to make hydrophobic to hydrophilic mutations on the protein surface. However, a systematic investigation of the relative contributions of all 20 amino acids to protein solubility has not been done. Here, 20 variants at the completely solvent-exposed position 76 of ribonuclease (RNase) Sa are made to compare the contributions of each amino acid. Stability measurements were also made for these variants, which occur at the i+1 position of a type II beta-turn. Solubility measurements in ammonium sulfate solutions were made at high positive net charge, low net charge, and high negative net charge. Surprisingly, there was a wide range of contributions to protein solubility even among the hydrophilic amino acids. The results suggest that aspartic acid, glutamic acid, and serine contribute significantly more favorably than the other hydrophilic amino acids especially at high net charge. Therefore, to increase protein solubility, asparagine, glutamine, or threonine should be replaced with aspartic acid, glutamic acid or serine.

  16. Amino acid contribution to protein solubility: Asp, Glu, and Ser contribute more favorably than the other hydrophilic amino acids in RNase Sa

    PubMed Central

    Trevino, Saul R.; Scholtz, J. Martin; Pace, C. Nick

    2009-01-01

    SUMMARY Poor protein solubility is a common problem in high resolution structural studies, formulation of protein pharmaceuticals, and biochemical characterization of proteins. One popular strategy to improve protein solubility is to use site-directed mutagenesis to make hydrophobic to hydrophilic mutations on the protein surface. However, a systematic investigation of the relative contributions of all twenty amino acids to protein solubility has not been done. Here, twenty variants at the completely solvent-exposed position 76 of Ribonuclease (RNase) Sa are made to compare the contributions of each amino acid. Stability measurements were also made for these variants, which occur at the i+1 position of a type II β-turn. Solubility measurements in ammonium sulfate solutions were made at high positive net charge, low net charge, and high negative net charge. Surprisingly, there was a wide range of contributions to protein solubility even among the hydrophilic amino acids. The results suggest that aspartic acid, glutamic acid, and serine contribute significantly more favorably than the other hydrophilic amino acids especially at high net charge. Therefore, to increase protein solubility, asparagine, glutamine, or threonine should be replaced with aspartic acid, glutamic acid or serine. PMID:17174328

  17. Scaleable catalytic asymmetric Strecker syntheses of unnatural alpha-amino acids.

    PubMed

    Zuend, Stephan J; Coughlin, Matthew P; Lalonde, Mathieu P; Jacobsen, Eric N

    2009-10-15

    Alpha-amino acids are the building blocks of proteins and are widely used as components of medicinally active molecules and chiral catalysts. Efficient chemo-enzymatic methods for the synthesis of enantioenriched alpha-amino acids have been developed, but it is still a challenge to obtain non-natural amino acids. Alkene hydrogenation is broadly useful for the enantioselective catalytic synthesis of many classes of amino acids, but it is not possible to obtain alpha-amino acids bearing aryl or quaternary alkyl alpha-substituents using this method. The Strecker synthesis-the reaction of an imine or imine equivalent with hydrogen cyanide, followed by nitrile hydrolysis-is an especially versatile chemical method for the synthesis of racemic alpha-amino acids. Asymmetric Strecker syntheses using stoichiometric amounts of a chiral reagent have been applied successfully on gram-to-kilogram scales, yielding enantiomerically enriched alpha-amino acids. In principle, Strecker syntheses employing sub-stoichiometric quantities of a chiral reagent could provide a practical alternative to these approaches, but the reported catalytic asymmetric methods have seen limited use on preparative scales (more than a gram). The limited utility of existing catalytic methods may be due to several important factors, including the relatively complex and precious nature of the catalysts and the requisite use of hazardous cyanide sources. Here we report a new catalytic asymmetric method for the syntheses of highly enantiomerically enriched non-natural amino acids using a simple chiral amido-thiourea catalyst to control the key hydrocyanation step. This catalyst is robust, without sensitive functional groups, so it is compatible with aqueous cyanide salts, which are safer and easier to handle than other cyanide sources; this makes the method adaptable to large-scale synthesis. We have used this new method to obtain enantiopure amino acids that are not readily prepared by enzymatic methods or by

  18. Soil amino acid composition across a boreal forest successional sequence

    Treesearch

    Nancy R. Werdin-Pfisterer; Knut Kielland; Richard D. Boone

    2009-01-01

    Soil amino acids are important sources of organic nitrogen for plant nutrition, yet few studies have examined which amino acids are most prevalent in the soil. In this study, we examined the composition, concentration, and seasonal patterns of soil amino acids across a primary successional sequence encompassing a natural gradient of plant productivity and soil...

  19. The effect of taurine and β-alanine supplementation on taurine transporter protein and fatigue resistance in skeletal muscle from mdx mice.

    PubMed

    Horvath, Deanna M; Murphy, Robyn M; Mollica, Janelle P; Hayes, Alan; Goodman, Craig A

    2016-11-01

    This study investigated the effect of taurine and β-alanine supplementation on muscle function and muscle taurine transporter (TauT) protein expression in mdx mice. Wild-type (WT) and mdx mice (5 months) were supplemented with taurine or β-alanine for 4 weeks, after which in vitro contractile properties, fatigue resistance and force recovery, and the expression of the TauT protein and proteins involved in excitation-contraction (E-C) coupling were examined in fast-twitch muscle. There was no difference in basal TauT protein expression or basal taurine content between mdx than WT muscle. Supplementation with taurine and β-alanine increased and reduced taurine content, respectively, in muscle from WT and mdx mice but had no effect of TauT protein. Taurine supplementation reduced body and muscle mass, and enhanced fatigue resistance and force recovery in mdx muscle. β-Alanine supplementation enhanced fatigue resistance in WT and mdx muscle. There was no difference in the basal expression of key E-C coupling proteins [ryanodine receptor 1 (RyR1), dihydropyridine receptor (DHPR), sarco(endo)plasmic reticulum Ca 2+ -ATPase 1 (SERCA1) or calsequestrin 1 (CSQ1)] between WT and mdx mice, and the expression of these proteins was not altered by taurine or β-alanine supplementation. These findings suggest that TauT protein expression is relatively insensitive to changes in muscle taurine content in WT and mdx mice, and that taurine and β-alanine supplementation may be viable therapeutic strategies to improve fatigue resistance of dystrophic skeletal muscle.

  20. Far Infrared spectroscopy of proteinogenic and other less common amino acids

    NASA Astrophysics Data System (ADS)

    Iglesias-Groth, S.; Cataldo, F.

    2018-05-01

    Far infrared spectroscopy is a powerful tool complementing the potential of mid infrared spectroscopy for the search and identification of organic molecules in space. The far infrared spectra of a total of 29 amino acids are reported in this study. In addition to the spectra of 20 common proteinogenic amino acids, spectra of a selection of 9 non-proteinogenic amino acids are also reported, including the 2-aminoisobutyric acid or α-aminoisobutyric acid which, with glycine, it is one of the most abundant amino acids found in meteorites. The present database of 29 far infrared spectra may serve as reference in the search for amino acids in space environments, given the new apportunities that JWST offers for mid and far IR spectroscopy.

  1. Diverse characteristics of the urinary excretion of amino acids in humans and the use of amino acid supplementation to reduce fatigue and sub-health in adults.

    PubMed

    Dunstan, R H; Sparkes, D L; Macdonald, M M; De Jonge, X Janse; Dascombe, B J; Gottfries, J; Gottfries, C-G; Roberts, T K

    2017-03-23

    The excretion of amino acids in urine represents an important avenue for the loss of key nutrients. Some amino acids such as glycine and histidine are lost in higher abundance than others. These two amino acids perform important physiological functions and are required for the synthesis of key proteins such as haemoglobin and collagen. Stage 1 of this study involved healthy subjects (n = 151) who provided first of the morning urine samples and completed symptom questionnaires. Urine was analysed for amino acid composition by gas chromatography. Stage 2 involved a subset of the initial cohort (n = 37) who completed a 30 day trial of an amino acid supplement and subsequent symptom profile evaluation. Analyses of urinary amino acid profiles revealed that three groups could be objectively defined from the 151 participants using k-means clustering. The amino acid profiles were significantly different between each of the clusters (Wilks' Lambda = 0.13, p < 0.0001). Cluster 1 had the highest loss of amino acids with histidine being the most abundant component. Cluster 2 had glycine present as the most abundant urinary amino acid and cluster 3 had equivalent abundances of glycine and histidine. Strong associations were observed between urinary proline concentrations and fatigue/pain scores (r = .56 to .83) for females in cluster 1, with several other differential sets of associations observed for the other clusters. Different phenotypic subsets exist in the population based on amino acid excretion characteristics found in urine. Provision of the supplement resulted in significant improvements in reported fatigue and sleep for 81% of the trial cohort with all females reporting improvements in fatigue. The study was registered on the 18th April 2011 with the Australian New Zealand Clinical Trials Registry ( ACTRN12611000403932 ).

  2. Mated Drosophila melanogaster females consume more amino acids during the dark phase

    PubMed Central

    Uchizono, Shun; Tabuki, Yumi; Kawaguchi, Natsumi; Tanimura, Teiichi; Itoh, Taichi Q.

    2017-01-01

    To maintain homeostasis, animals must ingest appropriate quantities, determined by their internal nutritional state, of suitable nutrients. In the fruit fly Drosophila melanogaster, an amino acid deficit induces a specific appetite for amino acids and thus results in their increased consumption. Although multiple processes of physiology, metabolism, and behavior are under circadian control in many organisms, it is unclear whether the circadian clock also modulates such motivated behavior driven by an internal need. Differences in levels of amino acid consumption by flies between the light and dark phases of the day:night cycle were examined using a capillary feeder assay following amino acid deprivation. Female flies exhibited increased consumption of amino acids during the dark phase compared with the light phase. Investigation of mutants lacking a functional period gene (per0), a well-characterized clock gene in Drosophila, found no difference between the light and dark phases in amino acid consumption by per0 flies. Furthermore, increased consumption of amino acids during the dark phase was observed in mated but not in virgin females, which strongly suggested that mating is involved in the rhythmic modulation of amino acid intake. Egg production, which is induced by mating, did not affect the rhythmic change in amino acid consumption, although egg-laying behavior showed a per0-dependent change in rhythm. Elevated consumption of amino acids during the dark phase was partly induced by the action of a seminal protein, sex peptide (SP), on the sex peptide receptor (SPR) in females. Moreover, we showed that the increased consumption of amino acids during the dark phase is induced in mated females independently of their internal level of amino acids. These results suggest that a post-mating SP/SPR signal elevates amino acid consumption during the dark phase via the circadian clock. PMID:28241073

  3. Mated Drosophila melanogaster females consume more amino acids during the dark phase.

    PubMed

    Uchizono, Shun; Tabuki, Yumi; Kawaguchi, Natsumi; Tanimura, Teiichi; Itoh, Taichi Q

    2017-01-01

    To maintain homeostasis, animals must ingest appropriate quantities, determined by their internal nutritional state, of suitable nutrients. In the fruit fly Drosophila melanogaster, an amino acid deficit induces a specific appetite for amino acids and thus results in their increased consumption. Although multiple processes of physiology, metabolism, and behavior are under circadian control in many organisms, it is unclear whether the circadian clock also modulates such motivated behavior driven by an internal need. Differences in levels of amino acid consumption by flies between the light and dark phases of the day:night cycle were examined using a capillary feeder assay following amino acid deprivation. Female flies exhibited increased consumption of amino acids during the dark phase compared with the light phase. Investigation of mutants lacking a functional period gene (per0), a well-characterized clock gene in Drosophila, found no difference between the light and dark phases in amino acid consumption by per0 flies. Furthermore, increased consumption of amino acids during the dark phase was observed in mated but not in virgin females, which strongly suggested that mating is involved in the rhythmic modulation of amino acid intake. Egg production, which is induced by mating, did not affect the rhythmic change in amino acid consumption, although egg-laying behavior showed a per0-dependent change in rhythm. Elevated consumption of amino acids during the dark phase was partly induced by the action of a seminal protein, sex peptide (SP), on the sex peptide receptor (SPR) in females. Moreover, we showed that the increased consumption of amino acids during the dark phase is induced in mated females independently of their internal level of amino acids. These results suggest that a post-mating SP/SPR signal elevates amino acid consumption during the dark phase via the circadian clock.

  4. Amino acids of Diclidophora merlangi (Monogenea).

    PubMed

    Arme, C; Whyte, A

    1975-02-01

    The level of free amino acids in Diclidophora merlangi is high, comprising over 500 mu moles/g ethanol extracted dry weight. A single amino acid, proline, constitutes some 70% of the total pool. Analysis of parasite protein and host blood and mucus revealed low proline levels, suggesting that the high free pool content was not related to a requirement for protein systhesis or to its abundance in the diet of the worm. Experiments revealed that proline was not involved specifically in osmoregulation, and the reasons for the large amounts present in Diclidophora remain unknown.

  5. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    NASA Technical Reports Server (NTRS)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  6. 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.

  7. Synthesis and Anti-microbial Activity of Novel Phosphatidylethanolamine-N-amino Acid Derivatives.

    PubMed

    Vijeetha, Tadla; Balakrishna, Marrapu; Karuna, Mallampalli Sri Lakshmi; Surya Koppeswara Rao, Bhamidipati Venkata; Prasad, Rachapudi Badari Narayana; Kumar, Koochana Pranay; Surya Narayana Murthy, Upadyaula

    2015-01-01

    The study involved synthesis of five novel amino acid derivatives of phosphatidylethanolamine isolated from egg yolk lecithin employing a three step procedure i) N-protection of L-amino acids with BOC anhydride in alkaline medium ii) condensation of - CO2H group of N-protected amino acid with free -NH2 of PE by a peptide linkage and iii) deprotection of N-protected group of amino acids to obtain phosphatidylethanolamine-N-amino acid derivatives in 60-75% yield. The five L-amino acids used were L glycine, L-valine, L-leucine, L-isoleucine and L-phenylalanine. The amino acid derivatives were screened for anti-baterial activity against B. subtilis, S. aureus, P. aeroginosa and E. coli taking Streptomycin as reference compound and anti-fungal activity against C. albicans, S. cervisiae, A. niger taking AmphotericinB as reference compound. All the amino acid derivatives exhibited extraordinary anti-bacterial activities about 3 folds or comparable to Streptomycin and moderate or no anti-fungal activity against Amphotericin-B.

  8. Adaptation of in vivo amino acid kinetics facilitates increased amino acid availability for fetal growth in adolescent and adult pregnancies alike

    USDA-ARS?s Scientific Manuscript database

    During pregnancy, adult women with a normal BMI synthesize extra amino acids after an overnight fast by increasing body protein breakdown and decreasing amino acid oxidation. It is not known whether adolescent girls can make these adaptations during pregnancy. The present study aimed to measure and ...

  9. Evolution of a genome-encoded bias in amino acid biosynthetic pathways is a potential indicator of amino acid dynamics in the environment.

    PubMed

    Fasani, Rick A; Savageau, Michael A

    2014-11-01

    Overcoming the stress of starvation is one of an organism's most challenging phenotypic responses. Those organisms that frequently survive the challenge, by virtue of their fitness, will have evolved genomes that are shaped by their specific environments. Understanding this genotype-environment-phenotype relationship at a deep level will require quantitative predictive models of the complex molecular systems that link these aspects of an organism's existence. Here, we treat one of the most fundamental molecular systems, protein synthesis, and the amino acid biosynthetic pathways involved in the stringent response to starvation. These systems face an inherent logical dilemma: Building an amino acid biosynthetic pathway to synthesize its product-the cognate amino acid of the pathway-may require that very amino acid when it is no longer available. To study this potential "catch-22," we have created a generic model of amino acid biosynthesis in response to sudden starvation. Our mathematical analysis and computational results indicate that there are two distinctly different outcomes: Partial recovery to a new steady state, or full system failure. Moreover, the cell's fate is dictated by the cognate bias, the number of cognate amino acids in the corresponding biosynthetic pathway relative to the average number of that amino acid in the proteome. We test these implications by analyzing the proteomes of over 1,800 sequenced microbes, which reveals statistically significant evidence of low cognate bias, a genetic trait that would avoid the biosynthetic quandary. Furthermore, these results suggest that the pattern of cognate bias, which is readily derived by genome sequencing, may provide evolutionary clues to an organism's natural environment. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  10. Echinococcus granulosus: specificity of amino acid transport systems in protoscoleces.

    PubMed

    Jeffs, S A; Arme, C

    1987-08-01

    Protoscoleces of Echinococcus granulosus absorb the L-amino acids proline, methionine, leucine, alanine, serine, phenylalanine, lysine and glutamic acid by a combination of mediated transport and diffusion. All eight amino acids were accumulated against a concentration gradient. Comparison of Kt and Vmax values suggests that a low affinity for a particular compound is compensated for by a relatively larger number of transport sites for that compound. Four systems serve for the transport of the eight substrates studied: 2 for neutral (EgN1, EgN2) and 1 each for acidic (EgA) and basic (EgB) amino acids. All eight amino acids are incorporated into protein to varying degrees and substantial portions of absorbed L-alanine and L-methionine are metabolized into other compounds.

  11. Parsing the life-shortening effects of dietary protein: effects of individual amino acids

    PubMed Central

    Bouchebti, Sofia; Bazazi, Sepideh; Le Hesran, Sophie; Puga, Camille; Latil, Gérard; Simpson, Stephen J.

    2017-01-01

    High-protein diets shorten lifespan in many organisms. Is it because protein digestion is energetically costly or because the final products (the amino acids) are harmful? To answer this question while circumventing the life-history trade-off between reproduction and longevity, we fed sterile ant workers on diets based on whole proteins or free amino acids. We found that (i) free amino acids shortened lifespan even more than proteins; (ii) the higher the amino acid-to-carbohydrate ratio, the shorter ants lived and the lower their lipid reserves; (iii) for the same amino acid-to-carbohydrate ratio, ants eating free amino acids had more lipid reserves than those eating whole proteins; and (iv) on whole protein diets, ants seem to regulate food intake by prioritizing sugar, while on free amino acid diets, they seem to prioritize amino acids. To test the effect of the amino acid profile, we tested diets containing proportions of each amino acid that matched the ant's exome; surprisingly, longevity was unaffected by this change. We further tested diets with all amino acids under-represented except one, finding that methionine, serine, threonine and phenylalanine are especially harmful. All together, our results show certain amino acids are key elements behind the high-protein diet reduction in lifespan. PMID:28053059

  12. Parsing the life-shortening effects of dietary protein: effects of individual amino acids.

    PubMed

    Arganda, Sara; Bouchebti, Sofia; Bazazi, Sepideh; Le Hesran, Sophie; Puga, Camille; Latil, Gérard; Simpson, Stephen J; Dussutour, Audrey

    2017-01-11

    High-protein diets shorten lifespan in many organisms. Is it because protein digestion is energetically costly or because the final products (the amino acids) are harmful? To answer this question while circumventing the life-history trade-off between reproduction and longevity, we fed sterile ant workers on diets based on whole proteins or free amino acids. We found that (i) free amino acids shortened lifespan even more than proteins; (ii) the higher the amino acid-to-carbohydrate ratio, the shorter ants lived and the lower their lipid reserves; (iii) for the same amino acid-to-carbohydrate ratio, ants eating free amino acids had more lipid reserves than those eating whole proteins; and (iv) on whole protein diets, ants seem to regulate food intake by prioritizing sugar, while on free amino acid diets, they seem to prioritize amino acids. To test the effect of the amino acid profile, we tested diets containing proportions of each amino acid that matched the ant's exome; surprisingly, longevity was unaffected by this change. We further tested diets with all amino acids under-represented except one, finding that methionine, serine, threonine and phenylalanine are especially harmful. All together, our results show certain amino acids are key elements behind the high-protein diet reduction in lifespan. © 2017 The Author(s).

  13. Stereochemistry of amino acids in surface samples of a marine sediment

    NASA Technical Reports Server (NTRS)

    Pollock, G. E.; Kvenvolden, K. A.

    1978-01-01

    In two surface samples of marine sediment, the percentages of D-alanine and D-aspartic acid are significantly higher than the other D-amino acids and are similar to the range found in soils. The percentage of D-glutamic acid is also higher than the other amino acids but less than D-alanine and D-aspartic acid. These D-amino acids may come mainly from bacteria.

  14. Stereochemistry of amino acids in surface samples of a marine sediment

    USGS Publications Warehouse

    Pollock, G.E.; Kvenvolden, K.A.

    1978-01-01

    In two surface samples of marine sediment, the percentages of d-alanine and d-aspartic acid are significantly higher than the other d-amino acids and are similar to the range found in soils. The percentage of d-glutamic acid is also higher than the other amino acids but less than d-alanine and d-aspartic acid. These d-amino acids may come mainly from bacteria. ?? 1978.

  15. Emerging Role of D-Amino Acid Metabolism in the Innate Defense.

    PubMed

    Sasabe, Jumpei; Suzuki, Masataka

    2018-01-01

    Mammalian innate and adaptive immune systems use the pattern recognition receptors, such as toll-like receptors, to detect conserved bacterial and viral components. Bacteria synthesize diverse D-amino acids while eukaryotes and archaea generally produce two D-amino acids, raising the possibility that many of bacterial D-amino acids are bacteria-specific metabolites. Although D-amino acids have not been identified to bind to any known pattern recognition receptors, D-amino acids are enantioselectively recognized by some other receptors and enzymes including a flavoenzyme D-amino acid oxidase (DAO) in mammals. At host-microbe interfaces in the neutrophils and intestinal mucosa, DAO catalyzes oxidation of bacterial D-amino acids, such as D-alanine, and generates H 2 O 2 , which is linked to antimicrobial activity. Intestinal DAO also modifies the composition of microbiota through modulation of growth for some bacteria that are dependent on host nutrition. Furthermore, regulation and recognition of D-amino acids in mammals have additional meanings at various host-microbe interfaces; D-phenylalanine and D-tryptophan regulate chemotaxis of neutrophils through a G-coupled protein receptor, D-serine has a bacteriostatic role in the urinary tract, D-phenylalanine and D-leucine inhibit innate immunity through the sweet taste receptor in the upper airway, and D-tryptophan modulates immune tolerance in the lower airway. This mini-review highlights recent evidence supporting the hypothesis that D-amino acids are utilized as inter-kingdom communication at host-microbe interface to modulate bacterial colonization and host defense.

  16. Reference intervals for plasma-free amino acid in a Japanese population.

    PubMed

    Yamamoto, Hiroyuki; Kondo, Kazuhiro; Tanaka, Takayuki; Muramatsu, Takahiko; Yoshida, Hiroo; Imaizumi, Akira; Nagao, Kenji; Noguchi, Yasushi; Miyano, Hiroshi

    2016-05-01

    Plasma amino acid concentrations vary with various diseases. Although reference intervals are useful in daily clinical practice, no reference intervals have been reported for plasma amino acids in a large Japanese population. Reference individuals were selected from 7685 subjects examined with the Japanese Ningen Dock in 2008. A total of 1890 individuals were selected based on exclusion criteria, and the reference samples were selected after the outlier samples for each amino acid concentration were excluded. The lower limit of the reference intervals for the plasma amino acid concentrations was set at the 2.5th percentile and the upper limit at the 97.5th percentile. By use of the nested analysis of variance, we analysed a large dataset of plasma samples and the effects of background factors (sex, age and body mass index [BMI]) on the plasma amino acid concentrations. Most amino acid concentrations were related to sex, especially those of branched-chained amino acid. The citrulline, glutamine, ornithine and lysine concentrations w