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Sample records for alanine aminotransferase ggt

  1. Alanine aminotransferase, gamma-glutamyltransferase (GGT) and all-cause mortality: results from a population-based Danish twins study alanine aminotransferase, GGT and mortality in elderly twins

    DEFF Research Database (Denmark)

    Fraser, Abigail; Thinggaard, Mikael; Christensen, Kaare;

    2009-01-01

    Abstract Background/Aims: Alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) are widely used markers of liver disease. Several population-based cohort studies have found associations of these liver enzymes with all-cause mortality. None of these studies controlled for genetic...

  2. Serum γ-glutamyltransferase, alanine aminotransferase, and aspartate aminotransferase activity in Iranian healthy blood donor men

    Institute of Scientific and Technical Information of China (English)

    Hossein Khedmat; Nasrin Zarei; Farahnaz Fallahian; Hassan Abolghasemi; Bashir Hajibeigi; Zohre Attarchi; Farshid Alaeddini; Mohammad Taghi Holisaz; Masoumeh Pourali; Shahin Sharifi

    2007-01-01

    AIM: To determine serum γ-glutamyltransferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity, and to assess their correlation with demographic and clinical findings in healthy blood donors.METHODS: This cross-sectional study was performed in 934 male blood donors, aged 18 to 68 years, who consecutively attended Tehran blood transfusion service in 2006. All participants were seronegative for HBV or HCV infections, non alcohol users, and all underwent a standard interview and anthropometric tests. Clinical and biochemical parameters including AST, ALT, and GGT activities were determined. Patients taking drugs known to cause hepatic fat deposition were excluded. For AST, ALT, and GGT variables, we used 33.33 and 66.66 percentiles, so that each of them was divided into three tertiles.RESULTS: Mean AST, ALT, and GGT activities were 25.26 ± 12.58 U/L (normal range 5-35 U/L), 33.13 ± 22.98 (normal range 5-35 U/L), and 25.11 ± 18.32 (normal range 6-37 U/L), respectively. By univariate analyses, there were significant associations between increasing AST, ALT, or GGT tertiles and age, body weight, body mass index, and waist and hip circumferences (P < 0.05). By multiple linear regression analyses, ALT was found to be positively correlated with dyslipidemia (B = 6.988, P = 0.038), whereas ALT and AST were negatively correlated with age. AST, ALT, and GGT levels had positive correlation with family history of liver disease (B = 15.763, P < 0.001), (B = 32.345, P < 0.001), (B =24.415, P < 0.001), respectively.CONCLUSION: Although we did not determine the cutoffs of the upper normal limits for AST, ALT, and GGT levels, we would suggest screening asymptomatic patients with dyslipidemia and also subjects with a family history of liver disease.

  3. Alanine aminotransferase controls seed dormancy in barley

    Science.gov (United States)

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

    2016-01-01

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

  4. High alanine aminotransferase is associated with decreased hepatic insulin sensitivity and predicts the development of type 2 diabetes

    DEFF Research Database (Denmark)

    Vozarova, Barbora; Stefan, Norbert; Lindsay, Robert S

    2002-01-01

    with prospective changes in liver or whole-body insulin sensitivity and/or insulin secretion and whether these elevated enzymes predict the development of type 2 diabetes in Pima Indians. We measured ALT, AST, and GGT in 451 nondiabetic (75-g oral glucose tolerance test) Pima Indians (aged 30 +/- 6 years, body fat......It has been proposed that liver dysfunction may contribute to the development of type 2 diabetes. The aim of the present study was to examine whether elevated hepatic enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], or gamma -glutamyltranspeptidase [GGT]) are associated...... were available. At baseline, ALT, AST, and GGT were related to percent body fat (r = 0.16, 0.17, and 0.11, respectively), M (r = -0.32, - 0.28, and -0.24), and HGO (r = 0.27, 0.12, and 0.14; all P fat, M, and AIR, higher ALT...

  5. Crystal structures of Aedes aegypti alanine glyoxylate aminotransferase.

    Science.gov (United States)

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

    2006-12-01

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

  6. Crystal Structures of Aedes Aegypt Alanine Glyoxylate Aminotransferase

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-01

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

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

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    Chandra H McAllister

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

  8. Normal serum alanine aminotransferase activity in uncomplicated obesity

    Institute of Scientific and Technical Information of China (English)

    Gianluca Iacobellis; Antonio Moschetta; Maria Cristina Ribaudo; Alessandra Zappaterreno; Concetta Valeria Iannucci; Frida Leonetti

    2005-01-01

    AIM: To evaluate serum alanine aminotransferase (ALT)activity in a well-characterized group of uncomplicated obese subjects and its correlation with insulin resistance,plasma adiponectin, and leptin concentrations.METHODS: One hundred and five uncomplicatedobese subjects (87 women, 18 men, age 34.3±9.6 years,BMI 39.9±8.3 kg/m2)were studied. Serum ALT activity was evaluated. Insulin sensitivity was assessed by euglycemic hyperinsulinemic clamp (M index) and fasting insulin. Plasma leptin and adiponectin levels were also measured.RESULTS: Serum ALT concentration in the whole group of uncomplicated obese subjects was 17.73±6.33 U/L with none of the subjects presenting ALT levels greater than 43 U/L and only 9 (11%) women and 3 (19%) men showed ALT levels >19 and >30 U/L for women and men,respectively. No significant difference was detected in serum ALT levels between severe obese subjects (BMI >40 kg/m2) and those with BMI <40 kg/m2 (18.63±6.25 vs 17.26±6.02 U/L). ALT was significantly correlated with fasting insulin (r = 0.485, P = 0.02) and triglycerides (r= 0.358, P= 0.03).CONCLUSION: Serum ALT activity is practically normal in uncomplicated obese subjects, independently of their obesity degree. These findings suggest the role of obesityrelated comorbidities and not of BMI as main risk factors for elevated ALT levels in obese subjects.

  9. A COMPARATIVE STUDY ON THE ACTIVITY OF ALANIN-AMINOTRANSFERASE IN HYPOPHTHALMICHTHYS MOLITRIX AND ARISTICHTHYS NOBILIS

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    Gabriela Vasile

    2006-08-01

    Full Text Available The present paper represents a comparative study on the activity of one aminotransferase - alaninaminotransferase, in the digestive tube of Hypophthalmichthys molitrix (silver carp and Aristichthys nobilis (bighead carp. The enzymatic activity has been determined colorimetrically, with 2, 4 - dinitrophenyl hydrazine, the results obtained being expressed as UE / g / min. It was observed that, comparatively with the alanin-aminotransferase activity recorded in silver carp, in the case of bighead carp, the values recorded are much lower.

  10. A gene duplication led to specialized gamma-aminobutyrate and beta-alanine aminotransferase in yeast

    DEFF Research Database (Denmark)

    Andersen, Gorm; Andersen, Birgit; Dobritzsch, D.

    2007-01-01

    In humans, beta-alanine (BAL) and the neurotransmitter gamma-aminobutyrate (GABA) are transaminated by a single aminotransferase enzyme. Apparently, yeast originally also had a single enzyme, but the corresponding gene was duplicated in the Saccharomyces kluyveri lineage. SkUGA1 encodes a homologue...

  11. Liver alanine aminotransferase, insulin resistance and endothelial dysfunction in normotriglyceridaemic subjects with type 2 diabetes mellitus

    NARCIS (Netherlands)

    Schindhelm, RK; Diamant, M; Bakker, SJL; van Dijk, RAJM; Scheffer, PG; Teerlink, T; Kostense, PJ; Heine, RJ

    2005-01-01

    Background Plasma levels of liver transaminases, including alanine aminotransferase (ALT), are elevated in most cases of nonalcoholic fatty liver disease (NAFLD). Elevated ALT levels are associated with insulin resistance, and subjects with NAFLD have features of the metabolic syndrome that confer h

  12. Beta-alanine/alpha-ketoglutarate aminotransferase for 3-hydroxypropionic acid production

    Energy Technology Data Exchange (ETDEWEB)

    Jessen, Holly Jean; Liao, Hans H; Gort, Steven John; Selifonova, Olga V

    2014-11-18

    The present disclosure provides novel beta-alanine/alpha ketoglutarate aminotransferase nucleic acid and protein sequences having increased biological activity. Also provided are cells containing such enzymes, as well as methods of their use, for example to produce malonyl semialdehyde and downstream products thereof, such as 3-hydroxypropionic acid and derivatives thereof.

  13. Beta-alanine/alpha-ketoglutarate aminotransferase for 3-hydroxypropionic acid production

    Energy Technology Data Exchange (ETDEWEB)

    Jessen, Holly Jean [Chanhassen, MN; Liao, Hans H [Eden Prairie, MN; Gort, Steven John [Apple Valley, MN; Selifonova, Olga V [Plymouth, MN

    2011-10-04

    The present disclosure provides novel beta-alanine/alpha ketoglutarate aminotransferase nucleic acid and protein sequences having increased biological activity. Also provided are cells containing such enzymes, as well as methods of their use, for example to produce malonyl semialdehyde and downstream products thereof, such as 3-hydroxypropionic acid and derivatives thereof.

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

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    Angel L. Pey

    2013-01-01

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

  15. Alanine aminotransferase is an inadequate surrogate marker for detecting lamivudine resistance

    Institute of Scientific and Technical Information of China (English)

    Lee; Guan; Lim; Myat; Oo; Aung; Bee; Leng; Seet; Cindy; Tan; Yock; Young; Dan; Yin; Mei; Lee; Dede; Selamat; Sutedja; Mark; Fernandes; Guan; Huei; Lee; Evelyn; Koay; Seng; Gee; Lim

    2010-01-01

    AIM: To investigate the accuracy of serum alanine aminotransferase (ALT) in diagnosing lamivudine resistance and factors that contributed to abnormal serum ALT.METHODS: This was a retrospective study of chronic hepatitis B patients on lamivudine therapy who were followed for 3-mo with liver function tests and hepatitis B virus (HBV) DNA measurement. Lamivudine resistance was defined as HBV DNA ≥ 1 log from nadir on at least 2 occasions, confirmed by genotyping. Serum ALT levels in patients with lamivudine r...

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

    Science.gov (United States)

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

    2017-01-01

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

  17. The effect of ammonium ions on the activity of glutamate dehydrogenase, alanine aminotransferase and aspartate aminotransferase in Cucumis sativus L. seedlings

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    Genowefa Kubiak-Dobosz

    2014-02-01

    Full Text Available Changes in the activity of glutamate dehydrogenase (GDH, alanine aminotransferase (GPT and aspartate aminotransferase (GOT were studied in various organs of Cucumis sativus L. seedlings in relation to the uptake of mineral nitrogen (in form of N03- or NH4+ from the medium. Activity of GDH, GPT, and GOT was higher in young leaves and roots of cucumber seedlings if the plants developed- in an ammonium medium. No similar changes of aminotransferases activity were noted in the cotyledons. Factors affecting varying effect of ammonium ions upon GPT and GOT activity are discussed for particular organs of cucumber seedlings.

  18. Propylthiouracyl-induced severe liver toxicity: An indication for alanine aminotransferase monitoring?

    Institute of Scientific and Technical Information of China (English)

    M Benyounes; C Sempoux; C Daumerie; J Rahier; AP Geubel

    2006-01-01

    Propylthiouracyl (PTU)-related liver toxicity is likely to occur in about 1% of treated patients. In case of acute or subacute hepatitis, liver failure may occur in about one third. We report two further cases of PTU-induced subacute hepatitis, in whom the delay between occurrence of liver damage after the initiation of treatment, the underestimation of its severity and the delayed withdrawal of the drug were all likely responsible for liver failure.The high incidence of liver toxicity related to PTU, its potential severity and delayed occurrence after initiation of treatment are in favor of monthly alanine aminotransferase monitoring, at least during the first six months of therapy.

  19. The antioxidant effects of vitamin C on liver enzymes: aspartate aminotransferase, alanine aminotranferease, alkaline phosphatase and gamma-glutamyltransferase activities in rats under Paraquat insult

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    Benjamin Nnamdi Okolonkwo

    2013-06-01

    Full Text Available Paraquat (PQ is a bipyridylium herbicide; applied around trees in orchards and between crop rows to control broad-leaved and grassy weeds. Its oxidation results in the formation of superoxides which causes damage to cellular components. In this study, we determined the antioxidant effect vitamin C has on the liver enzymes [aspartate aminotransferase (SGOT, alanine aminotranferease (SGPT, alkaline phosphatase (ALP, and gamma-glutamyltransferase (GGT] of rats under this toxic insult. Male rats in groups (A, B, C and D were intraperitoneally injected with different sublethal increasing doses (0, 0.02, 0.04 and 0.06 g/kg body weigh of PQ respectively on monthly basis. Subsequently, the subgroups (A2, B2, C2 and D2 were given orally, 200 mg/L vitamin C, while the subgroups A1, B1, C1, and D1, received only water. Four animals per subgroup were decapitated on monthly basis and blood samples taken for enzyme assay. The parameters studied were - SGOT, SGPT, ALP and GGT - liver enzymes. The dose and time dependent PQ toxicity effect resulted in highly elevated Liver enzymes activities. The subgroups on vitamin C had significantly lower enzyme activities when compared to the same subgroups on only PQ insult. But the values were high when compared to the control subgroups (A1 and A2. These results were indication that vitamin C when given at moderate doses and maintained for a longer period could be a life saving adjunct to toxic insult.

  20. A better parameter in predicting insulin resistance: Obesity plus elevated alanine aminotransferase

    Institute of Scientific and Technical Information of China (English)

    Ping-Hao Chen; Jong-Dar Chen; Yu-Cheng Lin

    2009-01-01

    AIM: To investigate the association of obesity and elevated alanine aminotransferase with insulin resistance and compare these factors with metabolic syndrome.METHODS: We enrolled a total of 1308 male workers aged from 22 to 63 years. Data was extracted from the workers’ periodic health check-ups in hospitals. All cases were from the community of northern Taiwan.This was a cross-sectional observational study from July to September in 2004. We grouped all cases into four groups, based on the quartile of homeostasis model assessment. The top fourth quartile group was defined as the group with insulin resistance. We performed multivariate logistic regression analysis for the odds ratio of the risk factors for insulin resistance.RESULTS: Compared with metabolic syndrome, the coexistence of both factors had a 4.3-fold (95% CI: 2.7-6.8) increased risk, which was more than metabolic syndrome with a 3.6-fold (95% CI: 2.6-5.0) increased risk. The two factors had a synergistic effect. The synergistic index of obesity and elevated alanine aminotransferase (ALT) was 2.1 (95% CI: 1.01-4.3).CONCLUSION: Obesity and elevated ALT are associatedwith insulin resistance. The effects are synergistic.Coexistence of them is better than metabolic syndrome in predicting insulin resistance.

  1. Analysis of the enzymatic properties of a broad family of alanine aminotransferases.

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    Chandra H McAllister

    Full Text Available Alanine aminotransferase (AlaAT has been studied in a variety of organisms due to the involvement of this enzyme in mammalian processes such as non-alcoholic hepatocellular damage, and in plant processes such as C4 photosynthesis, post-hypoxic stress response and nitrogen use efficiency. To date, very few studies have made direct comparisons of AlaAT enzymes and fewer still have made direct comparisons of this enzyme across a broad spectrum of organisms. In this study we present a direct kinetic comparison of glutamate:pyruvate aminotransferase (GPAT activity for seven AlaATs and two glutamate:glyoxylate aminotransferases (GGAT, measuring the K(M values for the enzymes analyzed. We also demonstrate that recombinant expression of AlaAT enzymes in Eschericia coli results in differences in bacterial growth inhibition, supporting previous reports of AlaAT possessing bactericidal properties, attributed to lipopolysaccharide endotoxin recognition and binding. A probable lipopolysaccharide binding region within the AlaAT enzymes, homologous to a region of a lipopolysaccharide binding protein (LBP in humans, was also identified in this study. The AlaAT enzyme differences identified here indicate that AlaAT homologues have differentiated significantly and the roles these homologues play in vivo may also have diverged significantly. Specifically, the differing kinetics of AlaAT enzymes and how this may alter the nitrogen use efficiency in plants is discussed.

  2. Multiple adaptive losses of alanine-glyoxylate aminotransferase mitochondrial targeting in fruit-eating bats.

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    Liu, Yang; Xu, Huihui; Yuan, Xinpu; Rossiter, Stephen J; Zhang, Shuyi

    2012-06-01

    The enzyme alanine-glyoxylate aminotransferase 1 (AGT) functions to detoxify glyoxylate before it is converted into harmful oxalate. In mammals, mitochondrial targeting of AGT in carnivorous species versus peroxisomal targeting in herbivores is controlled by two signal peptides that correspond to these respective organelles. Differential expression of the mitochondrial targeting sequence (MTS) is considered an adaptation to diet-specific subcellular localization of glyoxylate precursors. Bats are an excellent group in which to study adaptive changes in dietary enzymes; they show unparalleled mammalian dietary diversification as well as independent origins of carnivory, frugivory, and nectarivory. We studied the AGT gene in bats and other mammals with diverse diets and found that the MTS has been lost in unrelated lineages of frugivorous bats. Conversely, species exhibiting piscivory, carnivory, insectivory, and sanguinivory possessed intact MTSs. Detected positive selection in the AGT of ancestral fruit bats further supports adaptations related to evolutionary changes in diet.

  3. Increased alanine aminotransferase levels and associated characteristics among newly diagnosed type 2 diabetes patients: Results from the DD2 study

    DEFF Research Database (Denmark)

    Mor, Anil; Thomsen, Reimar W.; Rungby, Jørgen

    Objectives: Elevated levels of serum alanine aminotransferase (ALAT) have been linked with non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), insulin resistance and the metabolic syndrome in type 2 diabetes (T2D) patients. We examined ALAT levels in newly diagnosed T2D...

  4. Alanine and aspartate aminotransferase and glutamine-cycling pathway: Their roles in pathogenesis of metabolic syndrome

    Institute of Scientific and Technical Information of China (English)

    Silvia Sookoian; Carlos J Pirola

    2012-01-01

    Although new research technologies are constantly used to look either for genes or biomarkers in the prediction of metabolic syndrome (MS),the pathogenesis and pathophysiology of this complex disease remains a major challenge.Interestingly,Cheng et al recently investigated possible pathways underlying MS by high-throughput metabolite profiling in two large and well characterized community-based cohorts.The authors explored by liquid chromatography and mass spectrometry the plasma concentrations of 45distinct metabolites and examined their relation to cardiometabolic risk,and observed that metabolic risk factors such as obesity,insulin resistance (IR),high blood pressure,and dyslipidemia were associated with several metabolites,including branched-chain amino acids,other hydrophobic amino acids,tryptophan breakdown products,and nucleotide metabolites.In addition,the authors found a significant association of IR traits with glutamine,glutamate and the glutamineto-glutamate ratio.These data provide new insight into the pathogenesis of MS-associated phenotypes and introduce a crucial role of glutamine-cycling pathway as prominently involved in the development of metabolic risk.We consider that the hypothesis about the role of abnormal glutamate metabolism in the pathogenesis of the MS is certainly challenging and suggests the critical role of the liver in the global metabolic modulation as glutamate metabolism is linked with aminotransferase reactions.We discuss here the critical role of the "liver metabolism" in the pathogenesis of the MS and IR,and postulate that before fatty liver develops,abnormal levels of liver enzymes,such as alanine and aspartate aminotransferases might reflect high levels of hepatic transamination of amino acids in the liver.

  5. A Micro-Platinum Wire Biosensor for Fast and Selective Detection of Alanine Aminotransferase

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    Tran Nguyen Thanh Thuy

    2016-05-01

    Full Text Available In this study, a miniaturized biosensor based on permselective polymer layers (overoxidized polypyrrole (Ppy and Nafion® modified and enzyme (glutamate oxidase (GlutOx immobilized micro-platinum wire electrode for the detection of alanine aminotransferase (ALT was fabricated. The proposed ALT biosensor was measured electrochemically by constant potential amperometry at +0.7 V vs. Ag/AgCl. The ALT biosensor provides fast response time (~5 s and superior selectivity towards ALT against both negatively and positively charged species (e.g., ascorbic acid (AA and dopamine (DA, respectively. The detection range of the ALT biosensor is found to be 10–900 U/L which covers the range of normal ALT levels presented in the serum and the detection limit and sensitivity are found to be 8.48 U/L and 0.059 nA/(U/L·mm2 (N = 10, respectively. We also found that one-day storage of the ALT biosensor at −20 °C right after the sensor being fabricated can enhance the sensor sensitivity (1.74 times higher than that of the sensor stored at 4 °C. The ALT biosensor is stable after eight weeks of storage at −20 °C. The sensor was tested in spiked ALT samples (ALT activities: 20, 200, 400, and 900 U/L and reasonable recoveries (70%~107% were obtained.

  6. Healthy ranges of serum alanine aminotransferase levels in Tranian blood donors

    Institute of Scientific and Technical Information of China (English)

    Mehdi Mohamadnejad; Akram Pourshams; Reza Malekzadeh; Ashraf Mohamadkhani; Afsaneh Rajabiani; Ali Ali Asgari; Seyed Meysam Alimohamadi; Hadi Razjooyan; Mamar-Abadi

    2003-01-01

    AIM:The healthy ranges for serum alanine aminotransferase (ALT) levels are less well studied. The aim of this study was to define the upper limit of normal (ULN) for serum ALT levels, and to assess factors associated with serum ALT activity in apparently healthy blood donors.METHODS: A total of 1 939 blood donors were included.ALT measurements were performed for all cases using the same laboratory method. Healthy ranges for ALT levels were computed from the population at the lowest risk for liver disease. Univariate and multivariate analyses were performed to evaluate associations between clinical factors and ALT levels.RESULTS: Serum ALT activity was independently associated with body mass index (BMI) and male gender, but not associated with age. Association of ALT with BMI was more prominent in males than in females. Upper limit of normal for non-overweight women (BMI of less than 25) was 34 U/L,and for non-overweight men was 40 U/L.CONCLUSION: Serum ALT is strongly associated with sex and BMI. The normal range of ALT should be defined for male and female separately.

  7. Clinical significance of serum alanine aminotransferase and lifestyle intervention in children with nonalcoholic fatty liver disease

    Science.gov (United States)

    Kwon, Kyoung Ah; Chun, Peter

    2016-01-01

    Purpose This study aimed to investigate the clinical significance of serum alanine aminotransferase (ALT) levels in children with nonalcoholic fatty liver disease (NAFLD) and the effect of lifestyle intervention on NAFLD. Methods The clinical data of 86 children diagnosed with NAFLD were reviewed retrospectively. Forty-six patients belonged to the elevated ALT group and 40 to the normal ALT group. The clinical parameters of patients with NAFLD were also compared based on the status of ALT levels after lifestyle intervention. Results Patients with elevated ALT had significantly higher body mass index (BMI) scores than those with normal ALT (P<0.05). Of all the patients with elevated ALT, 89% exhibited moderate or severe degree of fatty change in the liver on ultrasonographic examination, whereas most patients with normal ALT exhibited mild or moderate degree changes. Liver biopsy was performed in 15 children with elevated ALT and all showed mild histological changes. Of all patients with elevated ALT, 49% achieved normal ALT levels after lifestyle intervention. Those with more severe histological changes tended to have continuously increasing ALT levels. There was no correlation between the normalization of posttreatment ALT level and BMI, as well as ultrasonographic findings at diagnosis. Conclusion ALT elevation in NAFLD is highly associated with higher BMI scores and more severe degree of fatty changes on ultrasonographic examination. Lifestyle intervention can significantly improve ALT in children with NAFLD. The degree of histologic changes appears to be a predictor of the treatment response to NAFLD.

  8. Molecular requirements for peroxisomal targeting of alanine-glyoxylate aminotransferase as an essential determinant in primary hyperoxaluria type 1.

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    Krisztián Fodor

    Full Text Available Alanine-glyoxylate aminotransferase is a peroxisomal enzyme, of which various missense mutations lead to irreversible kidney damage via primary hyperoxaluria type 1, in part caused by improper peroxisomal targeting. To unravel the molecular mechanism of its recognition by the peroxisomal receptor Pex5p, we have determined the crystal structure of the respective cargo-receptor complex. It shows an extensive protein/protein interface, with contributions from residues of the peroxisomal targeting signal 1 and additional loops of the C-terminal domain of the cargo. Sequence segments that are crucial for receptor recognition and hydrophobic core interactions within alanine-glyoxylate aminotransferase are overlapping, explaining why receptor recognition highly depends on a properly folded protein. We subsequently characterized several enzyme variants in vitro and in vivo and show that even minor protein fold perturbations are sufficient to impair Pex5p receptor recognition. We discuss how the knowledge of the molecular parameters for alanine-glyoxylate aminotransferase required for peroxisomal translocation could become useful for improved hyperoxaluria type 1 treatment.

  9. Persistent alanine aminotransferase elevation among the general Iranian population: Prevalence and causes

    Institute of Scientific and Technical Information of China (English)

    Raika Jamali; Mohammad Reza Deyhim; Houri Rezvan; Akram Pourshams; Mahmoodreza Khonsari; Shahin Merat; Masoud Khoshnia; Elham Jafari; Alireza Bahram Kalhori; Hassan Abolghasemi; Sedighe Amini; Mahtab Maghsoudlu

    2008-01-01

    AIM: To determine the prevalence and causes of persistently elevated alanine aminotransferase (ALT)levels among the general population in northern Iran.METHODS: A total of 2292 (1376 female, aged 18-75year), were selected by systematic clustered random sampling from the cities and villages of Gonbad and Kalaleh in Golestan Province and invited to participate in the study. A comprehensive history regarding alcohol drinking and medication was taken. Body mass index (BMI), viral markers and ALT levels were measured. If ALT level was ≥ 40 U/L, it was rechecked twice within 6 mo. Those with ≥ 2 times elevation of ALT were considered as having persistently elevated ALT level.Non-alcoholic fatty liver disease (NAFLD) was diagnosed based on evidence of fatty liver upon sonography and excluding other etiology.RESULTS: A total of 2049 (1351 female) patients participated in the study, 162 (7.9%) had elevated ALT level at the first measurement. Persistently elevated ALT level was detected in 64 (3.1%) participants, with 51 (79.6%) with no obvious etiology, six (9.3%) with Hepatitis B, four (6.2%) with Hepatitis C virus (HCV)infection and three (4.6%) with alcoholic hepatitis.The prevalence of NAFLD and alcoholic hepatitis was 2.04% (42 patients) and 0.1% (three), respectively.There was correlation between NAFLD and male gender,overweight, diabetes and living in an urban area [odds ratio = 3.03 (95% CI: 1.6-5.72), 4.21 (95% CI:1.83-9.68), 2.86 (95% CI: 1.05-7.79) and 2.04 (95% CI:1.00-4.16) respectively].CONCLUSION: NAFLD is the most common cause of persistently elevated serum ALT level among the general population of Iran.

  10. A community-based epidemiological study of elevated serum alanine aminotransferase levels in Kinmen, Taiwan

    Institute of Scientific and Technical Information of China (English)

    Chi-Ming Liu; Tao-Hsin Tung; Jorn-Hon Liu; Victor Tze-Kai Chen; Ching-Heng Lin; Chung-Te Hsu; Pesus Chou

    2005-01-01

    AIM: To explore any gender-related differences in prevalence of and condition-associated factors related to an elevated serum alanine aminotransferase (ALT) level amongst residents of Kinmen, Taiwan.METHODS: A total of 11 898 of a potential 20 112 regional residents aged 30 years or more completed a related questionnaire that was carried out by the Yang-Ming Crusade between 1991 and 1994 inclusively, with blood samples being collected by public nurses. The overall questionnaire response rate was 59.3% (52.4% for males and 66.0% for females).RESULTS: The prevalence of an elevated serum ALT level for this sub-population was found to be 7,2%, the prevalence revealing a statistically significant decrease with increasing population age (P<0.0001). Males exhibited a greater prevalence of elevated serum ALT level than did females (9.4% vs 5.3%, P<0.0001). Using multiple logistic regression analysis, in addition to male gender, a younger age, greater waist circumference,presence of type-2 diabetes and hyperuricemia were the significant factors associated with an elevated serum ALT level for both males and females. Gender-related differences as regards associated factors were also revealed. For males, obesity was significantly related to an elevated serum ALT level (OR = 1.28, 95%CI: 1.00-1.66)but this was not so for females (OR = 1.09, 95%CI:0.84-1.42). Hypertriglyceridemia (OR = 1.80, 95%CI:1.36-2.39) and hyperuricemia (OR = 1.61, 95%CI:1.03-2.52) were significantly related to elevated serum ALT levels only for females.CONCLUSION: Several gender-related differences were noted pertaining to the prevalence of and relationship between obesity, hypertriglyceridemia and hyperuricemia and elevated serum ALT level in the present study.(c)2005 The WJG Press and Elsevier Ihc. All rights reserved.

  11. Alanine aminotransferase and risk of the metabolic syndrome: a linear dose-response relationship.

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    Setor K Kunutsor

    Full Text Available BACKGROUND: Elevated baseline circulating alanine aminotransferase (ALT level has been demonstrated to be associated with an increased risk of the metabolic syndrome (MetS, but the nature of the dose-response relationship is uncertain. METHODS: We performed a systematic review and meta-analysis of published prospective cohort studies to characterize in detail the nature of the dose-response relationship between baseline ALT level and risk of incident MetS in the general population. Relevant studies were identified in a literature search of MEDLINE, EMBASE, and Web of Science up to December 2013. Prospective studies in which investigators reported relative risks (RRs of MetS for 3 or more categories of ALT levels were eligible. A potential nonlinear relationship between ALT levels and MetS was examined using restricted cubic splines. RESULTS: Of the 489 studies reviewed, relevant data were available on 29,815 non-overlapping participants comprising 2,125 incident MetS events from five prospective cohort studies. There was evidence of a linear association (P for nonlinearity=0.38 between ALT level and risk of MetS, characterised by a graded increase in MetS risk at ALT levels 6-40 U/L. The risk of MetS increased by 14% for every 5 U/L increment in circulating ALT level (95% CI: 12-17%. Evidence was lacking of heterogeneity and publication bias among the contributing studies. CONCLUSIONS: Baseline ALT level is associated with risk of the MetS in a linear dose-response manner. Studies are needed to determine whether the association represents a causal relationship.

  12. Reconfiguration of N Metabolism upon Hypoxia Stress and Recovery: Roles of Alanine Aminotransferase (AlaAT) and Glutamate Dehydrogenase (GDH)

    Science.gov (United States)

    Diab, Houssein; Limami, Anis M.

    2016-01-01

    In the context of climatic change, more heavy precipitation and more frequent flooding and waterlogging events threaten the productivity of arable farmland. Furthermore, crops were not selected to cope with flooding- and waterlogging-induced oxygen limitation. In general, low oxygen stress, unlike other abiotic stresses (e.g., cold, high temperature, drought and saline stress), received little interest from the scientific community and less financial support from stakeholders. Accordingly, breeding programs should be developed and agronomical practices should be adapted in order to save plants’ growth and yield—even under conditions of low oxygen availability (e.g., submergence and waterlogging). The prerequisite to the success of such breeding programs and changes in agronomical practices is a good knowledge of how plants adapt to low oxygen stress at the cellular and the whole plant level. In the present paper, we summarized the recent knowledge on metabolic adjustment in general under low oxygen stress and highlighted thereafter the major changes pertaining to the reconfiguration of amino acids syntheses. We propose a model showing (i) how pyruvate derived from active glycolysis upon hypoxia is competitively used by the alanine aminotransferase/glutamate synthase cycle, leading to alanine accumulation and NAD+ regeneration. Carbon is then saved in a nitrogen store instead of being lost through ethanol fermentative pathway. (ii) During the post-hypoxia recovery period, the alanine aminotransferase/glutamate dehydrogenase cycle mobilizes this carbon from alanine store. Pyruvate produced by the reverse reaction of alanine aminotransferase is funneled to the TCA cycle, while deaminating glutamate dehydrogenase regenerates, reducing equivalent (NADH) and 2-oxoglutarate to maintain the cycle function. PMID:27258319

  13. Reconfiguration of N Metabolism upon Hypoxia Stress and Recovery: Roles of Alanine Aminotransferase (AlaAT and Glutamate Dehydrogenase (GDH

    Directory of Open Access Journals (Sweden)

    Houssein Diab

    2016-05-01

    Full Text Available In the context of climatic change, more heavy precipitation and more frequent flooding and waterlogging events threaten the productivity of arable farmland. Furthermore, crops were not selected to cope with flooding- and waterlogging-induced oxygen limitation. In general, low oxygen stress, unlike other abiotic stresses (e.g., cold, high temperature, drought and saline stress, received little interest from the scientific community and less financial support from stakeholders. Accordingly, breeding programs should be developed and agronomical practices should be adapted in order to save plants’ growth and yield—even under conditions of low oxygen availability (e.g., submergence and waterlogging. The prerequisite to the success of such breeding programs and changes in agronomical practices is a good knowledge of how plants adapt to low oxygen stress at the cellular and the whole plant level. In the present paper, we summarized the recent knowledge on metabolic adjustment in general under low oxygen stress and highlighted thereafter the major changes pertaining to the reconfiguration of amino acids syntheses. We propose a model showing (i how pyruvate derived from active glycolysis upon hypoxia is competitively used by the alanine aminotransferase/glutamate synthase cycle, leading to alanine accumulation and NAD+ regeneration. Carbon is then saved in a nitrogen store instead of being lost through ethanol fermentative pathway. (ii During the post-hypoxia recovery period, the alanine aminotransferase/glutamate dehydrogenase cycle mobilizes this carbon from alanine store. Pyruvate produced by the reverse reaction of alanine aminotransferase is funneled to the TCA cycle, while deaminating glutamate dehydrogenase regenerates, reducing equivalent (NADH and 2-oxoglutarate to maintain the cycle function.

  14. Relationship between alanine aminotransferase levels and metabolic syndrome in nonalcoholic fatty liver disease

    Institute of Scientific and Technical Information of China (English)

    Zhou-wen CHEN; Li-ying CHEN; Hong-lei DAI; Jian-hua CHEN; Li-zheng FANG

    2008-01-01

    Objective:To investigate the relationship between alanine aminotransferase (ALT)levels and metabolic syndrome (MS)in nonalcoholic fatty liver disease(NAFLD).Methods:A total of 26527 subjects who received medical health checkup in our hospital from January 2005 to July 2007 were enrolled in the study.The diagnosis of fatty liver was based on ultrasound imaging.MS Was defined according to the criteria of the Adult Treatment Panel Ⅲ.ALT,triglyceride(TG),high density lipoprotein cholesterol(HDL-c),fasting plasma glucose(FPG),height,weight,waist circumference(WC),systolic blood pressure (SBP)and diastolic blood pressure(DBP)were measured in each subject to analyze the relationship between MS and ALT activity.Results:(1)The prevalence of NAFLD in men(30.94%)was significantly higher than that in women(15.65%);(2)The incidence of MS in NAFLD(33.83%)was significantly greater than that in non-NAFLD(10.62%);(3)Of the 6470 subjects with NAFLD,in the age-adjusted partial correlation analysis,there were statistically significant correlations between the ALT levels and most metabolic risk factors in each sex(P<0.01),except that ALT levels had no correlation with HDL-c in women.Moreover,in the multiple stepwise regression analysis,SBP lost its significance,and WC,body mass index(BMI),age,DBP,TG and FPG were independently associated with ALT levels in both sexes (P<0.05).HDL-c remained significant and was independently related to ALT leveis in men;(4)ALT levels were significantly higher in subjects with MS compared to those without MS(P<0.001).Mean ALT levels increased with the number of MS cornponents in each sex (P.<0.05 for trend).Conelusion:We found a strong relationship between ALT leveIs and MS in NAFLD and revealed that the cluster of MS components might be the predictor for ALT elevations.

  15. Effect of heavy metals (Cu, Cd and Pb) on aspartate and alanine aminotransferase in Ruditapes philippinarum (Mollusca: Bivalvia)

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    Blasco, J.; Puppo, J. [Instituto de Ciencias Marinas de Andalucia, Campus Univ. Rio S. Pedro, 11510 Puerto Real, Cadiz (Spain)

    1999-02-01

    The accumulation of cadmium, copper and lead and their effects on aspartate and alanine aminotransferases in digestive gland, gills, foot and soft body in the clam Ruditapes philippinarum were examined. The animals were exposed to different concentrations: Cd (200-600 {mu}g{center_dot}l{sup -1}), Pb (350-700 {mu}g{center_dot}l{sup -1}) and Cu (10-20 {mu}g{center_dot}l{sup -1}) for 7 days. The highest concentrations were found in digestive gland for cadmium and copper, and in gills for lead, and the lowest values were observed in the foot. Aspartate aminotransferase activity (AST), in general, was not inhibited by cadmium, lead or copper during the exposure. Only in clams exposed to cadmium (600 {mu}g{center_dot}l{sup -1}, 7 days) and copper (20 {mu}g{center_dot}l{sup -1}, 5 days) were observed significant differences (P<0.05) in foot and gills, respectively, with respect to control. In the case of alanine aminotransferase activity (ALT), significant differences were observed for cadmium and lead in treated animals with respect to control. With regard to copper, a decrease in ALT was observed in gills and foot exposed to 20 {mu}g{center_dot}l{sup -1}. A significant correlation (P<0.05) was observed between ALT and metal accumulation for cadmium, copper and lead in gills. In the case of soft body, only cadmium and lead showed a significant correlation. In summary, R. philippinarum can be considered a bioindicator species for cadmium and lead accumulation and ALT could be useful as biomarker of sublethal stress for these metals in soft tissues and gills. Only gills can be considered an adequate target tissue for copper. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Effect of streptococcal preparation (picibanil on the postoperative rise in serum alanine aminotransferase activity in patients with urogenital cancer.

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    Taketa,Kazuhisa

    1980-12-01

    Full Text Available The effect of Picibanil, a streptococcal agent, on the development of liver injury after operations for urogenital cancer was studied retrospectively in the light of serum alanine aminotransferase (ALT activity. The series comprised 32 cases receiving Picibanil and 33 controls with otherwise comparable clinical backgrounds. Picibanil reduced the incidence of postoperative ALT rise over 50 U/l within 6 weeks but increased it thereafter. The increase in ALT activity after 6 weeks was relatively small and was seen more often in patients given blood transfusions. It was interpreted as retardation and suppression of ALT rise and as being related to the induction of interferon or to immunopotentiation. Other antihepatotoxic effects of Picibanil, due to its antioxidant activity, for example, may also account for the prevention of the early postoperative rise in ALT activity.

  17. Modifiable clinical and lifestyle factors are associated with elevated alanine aminotransferase levels in newly diagnosed type 2 diabetes patients

    DEFF Research Database (Denmark)

    Mor, Anil; Svensson, Elisabeth; Rungby, Jørgen;

    2014-01-01

    />21 drinks per week for women/men) (aPR: 1.60, 95% CI: 1.03-2.50), and in those with no regular physical activity (aPR: 1.42, 95% CI: 1.04-1.93). Obesity and metabolic syndrome per se showed no association with elevated ALT when adjusted for other markers, whereas we found positive associations of ALT...... aminotransferase (ALT) levels as a marker of NAFLD in new T2DM patients. METHODS: Alanine aminotransferase levels were measured in 1026 incident T2DM patients enrolled in the nationwide Danish Centre for Strategic Research in Type 2 Diabetes (DD2) cohort. We examined prevalence of elevated ALT (>38 IU/L for women...... and >50 IU/L for men) and calculated prevalence ratios associated with clinical and lifestyle factors using Poisson regression. We examined the association with other biomarkers by linear regression. RESULTS: The median value of ALT was 24 IU/L (interquartile range: 18-32 IU/L) in women and 30 IU...

  18. Structural implications of a G170R mutation of alanine:glyoxylate aminotransferase that is associated with peroxisome-to-mitochondrion mistargeting

    OpenAIRE

    Djordjevic, Snezana; Zhang, Xiaoxuan; Bartlam, Mark; Ye, Sheng; Rao, Zihe; Danpure, Christopher J

    2010-01-01

    The crystal structure of the G170R mutant form of human alanine:glyoxylate aminotransferase has been determined at 2.6 Å resolution. This mutation is associated with enzyme mistargeting in the hereditary kidney-stone disease primary hyperoxaluria type 1.

  19. BarR, an Lrp-type transcription factor in Sulfolobus acidocaldarius, regulates an aminotransferase gene in a β-alanine responsive manner.

    Science.gov (United States)

    Liu, Han; Orell, Alvaro; Maes, Dominique; van Wolferen, Marleen; Lindås, Ann-Christin; Bernander, Rolf; Albers, Sonja-Verena; Charlier, Daniel; Peeters, Eveline

    2014-05-01

    In archaea, nothing is known about the β-alanine degradation pathway or its regulation. In this work, we identify and characterize BarR, a novel Lrp-like transcription factor and the first one that has a non-proteinogenic amino acid ligand. BarR is conserved in Sulfolobus acidocaldarius and Sulfolobus tokodaii and is located in a divergent operon with a gene predicted to encode β-alanine aminotransferase. Deletion of barR resulted in a reduced exponential growth rate in the presence of β-alanine. Furthermore, qRT-PCR and promoter activity assays demonstrated that BarR activates the expression of the adjacent aminotransferase gene, but only upon β-alanine supplementation. In contrast, auto-activation proved to be β-alanine independent. Heterologously produced BarR is an octamer in solution and forms a single complex by interacting with multiple sites in the 170 bp long intergenic region separating the divergently transcribed genes. In vitro, DNA binding is specifically responsive to β-alanine and site-mutant analyses indicated that β-alanine directly interacts with the ligand-binding pocket. Altogether, this work contributes to the growing body of evidence that in archaea, Lrp-like transcription factors have physiological roles that go beyond the regulation of α-amino acid metabolism.

  20. Associations of White Blood Cell Count,Alanine Aminotransferase,and Aspartate Aminotransferase in the First Trimester withGestational Diabetes Mellitus.

    Science.gov (United States)

    2016-06-10

    Objective To explore the associations of white blood cell (WBC) count,alanine aminotransferase (ALT),and aspartate aminotransferase(AST) in the first trimester of pregnancy with gestational diabetes mellitus (GDM). Methods Totally 725 GDM women and 935 women who remained euglycemic throughout pregnancy were enrolled in this study. Pre-pregnancy weight/height were recorded. WBC,ALT,and AST levels were detected between 8 and 12 weeks of pregnancy.At 24 to 28 weeks of pregnancy,the glucose and insulin levels were measured. The WBC,ALT,and AST levels were compared between two groups,and the associations of WBC,ALT,and AST levels with the blood glucose and insulin levels were retrospectively analyzed. Meanwhile,the potential associations of those factors with the occurrence of GDM were analzyed. Results WBC count [9.41(8.15,10.84)?10(9)/L vs. 9.04 (7.64,10.37)?10(9)/L,P=1.0?10(-5)] and ALT levels [18.00(12.00,30.00)U/L vs. 16.00 (11.00,26.00)U/L,P=0.004] in the first trimester of pregnancy were significantly increased in GDM subjects than in normal glucose tolerance(NGT)subjects;however,the AST level showed no significant difference between these two groups [41.00 (26.00,43.00)U/L vs. 41.00 (23.00,43.00)U/L,P=0.588]. Logistic regression analysis illustrated that elevated WBC count was an independent risk factor for GDM after adjustment for age,pre-pregnancy body mass index,blood pressure,and family history of diabetes(OR=1.119,P=0.001). The ROC curve revealed that threshold of WBC count was 7.965?10(9)/L(AUC=0.566,P=1?10(-5)),which had a sensitivity of 79.4% and a specificity of 31.3%. Multivariate linear regression analysis showed that homeostasis model assessment of insulin resistance was positively correlated with WBC count(B=0.051,P=0.022,R(2)=0.083);1-hour blood glucose after oral 50 grams of sugar (B=0.044,P=0.001,R(2)=0.044) and fasting plasma true insulin(B=0.214,P=0.032,R(2)=0.066) were positively correlated with WBC count;1-hour true insulin after 100 grams

  1. Hubungan Kadar Trigliserida dan Kolesterol-HDL Terhadap Kadar Alanine Aminotransferase pada Pasien Non Alcoholic Fatty Liver Disease

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    Bayu Gemilang

    2016-01-01

    Full Text Available AbstrakTrigliserida dan Kolesterol HDL (c-HDL merupakan beberapa dari komponen Sindroma Metabolik (SM. SM dipercaya merupakan faktor utama penyebab Non Alcoholic Fatty Liver Disease (NAFLD. NAFLD merupakan penyakit hati kronik yang nantinya dapat menyebabkan fibrosis sel-sel hepar dan juga keganasan. NAFLD tidak menunjukkan manifestasi klinis yang khas, sehingga diperlukan pemeriksaan penunjang seperti pemeriksaan enzim hati untuk menegakkan diagnosis. Alanine Aminotransferase (ALT menjadi pilihan sebagai marker pada penyakit NAFLD. Tujuan penelitian ini adalah menentukan hubungan antara trigliserida dan c-HDL dengan ALT pada penderita NAFLD. Ini merupakan penelitian analitik deskriptif dengan desain retrospektif menggunakan data pasien NAFLD di instalasi rekam medik RSUP dr.M.Djamil Padang. Sampel penelitian ini adalah 51 pasien NAFLD. Hasil penelitian didapatkan dari uji korelasi pearson terdapat derajat hubungan yang kuat (r=0,512 dan hubungan yang bermakna (p<0,001 antara kadar trigliserida dengan kadar ALT serum dan derajat hubungan yang sedang (r=0,26 dan hubungan yang tidak bermakna (p=0,065 antara c-HDL dengan ALT serum. Kesimpulan penelitian ini adalah kadar ALT berhubungan dengan kadar trigliserida pada penderita NAFLD, namun tidak dengan c-HDLKata kunci: NAFLD, trigliserida, HDL, ALT, sindroma metabolik AbstractTriglyceride and HDL Cholesterol (HDL-C are some of the Metabolic Syndrome (MS components. MS is believed as the main factor for the Non Alcoholic Fatty Liver Disease (NAFLD. NAFLD is a chronic liver disease, which later can cause hepatocyte fibrosis and also malignancy. NAFLD does not show a typical clinical appearance, so it is important to do workups such as liver enzyme test to make the diagnosis. Alanine Aminotransferase (ALT is considered as the marker of NAFLD.The objective of this study was to determine the relationship between triglycerides and HDL-C to ALT level in NAFLD patients.This  was a descriptive analytical

  2. Peroxisomal alanine: glyoxylate aminotransferase AGT1 is indispensable for appressorium function of the rice blast pathogen, Magnaporthe oryzae.

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    Vijai Bhadauria

    Full Text Available The role of β-oxidation and the glyoxylate cycle in fungal pathogenesis is well documented. However, an ambiguity still remains over their interaction in peroxisomes to facilitate fungal pathogenicity and virulence. In this report, we characterize a gene encoding an alanine, glyoxylate aminotransferase 1 (AGT1 in Magnaporthe oryzae, the causative agent of rice blast disease, and demonstrate that AGT1 is required for pathogenicity of M. oryzae. Targeted deletion of AGT1 resulted in the failure of penetration via appressoria; therefore, mutants lacking the gene were unable to induce blast symptoms on the hosts rice and barley. This penetration failure may be associated with a disruption in lipid mobilization during conidial germination as turgor generation in the appressorium requires mobilization of lipid reserves from the conidium. Analysis of enhanced green fluorescent protein expression using the transcriptional and translational fusion with the AGT1 promoter and open reading frame, respectively, revealed that AGT1 expressed constitutively in all in vitro grown cell types and during in planta colonization, and localized in peroxisomes. Peroxisomal localization was further confirmed by colocalization with red fluorescent protein fused with the peroxisomal targeting signal 1. Surprisingly, conidia produced by the Δagt1 mutant were unable to form appressoria on artificial inductive surfaces, even after prolonged incubation. When supplemented with nicotinamide adenine dinucleotide (NAD(++pyruvate, appressorium formation was restored on an artificial inductive surface. Taken together, our data indicate that AGT1-dependent pyruvate formation by transferring an amino group of alanine to glyoxylate, an intermediate of the glyoxylate cycle is required for lipid mobilization and utilization. This pyruvate can be converted to non-fermentable carbon sources, which may require reoxidation of NADH generated by the β-oxidation of fatty acids to NAD(+ in

  3. Diet and the frequency of the alanine:glyoxylate aminotransferase Pro11Leu polymorphism in different human populations.

    Science.gov (United States)

    Caldwell, Elizabeth F; Mayor, Lianne R; Thomas, Mark G; Danpure, Christopher J

    2004-11-01

    The intermediary metabolic enzyme alanine:glyoxylate aminotransferase (AGT) contains a Pro11Leu polymorphism that decreases its catalytic activity by a factor of three and causes a small proportion to be mistargeted from its normal intracellular location in the peroxisomes to the mitochondria. These changes are predicted to have significant effects on the synthesis and excretion of the metabolic end-product oxalate and the deposition of insoluble calcium oxalate in the kidney and urinary tract. Based on the evolution of AGT targeting in mammals, we have previously hypothesised that this polymorphism would be advantageous for individuals who have a meat-rich diet, but disadvantageous for those who do not. If true, the frequency distribution of Pro11Leu in different extant human populations should have been shaped by their dietary history so that it should be more common in populations with predominantly meat-eating ancestral diets than it is in populations in which the ancestral diets were predominantly vegetarian. In the present study, we have determined frequency of Pro11Leu in 11 different human populations with divergent ancestral dietary lifestyles. We show that the Pro11Leu allelic frequency varies widely from 27.9% in the Saami, a population with a very meat-rich ancestral diet, to 2.3% in Chinese, who are likely to have had a more mixed ancestral diet. FST analysis shows that the differences in Pro11Leu frequency between some populations (particularly Saami vs Chinese) was very high when compared with neutral loci, suggesting that its frequency might have been shaped by dietary selection pressure.

  4. Population-based Risk Factors for Elevated Alanine Aminotransferase in a South Texas Mexican–American Population

    Science.gov (United States)

    Qu, Hui-Qi; Li, Quan; Grove, Megan L.; Lu, Yang; Pan, Jen-Jung; Rentfro, Anne R.; Bickel, Perry E.; Fallon, Michael B.; Hanis, Craig L.; Boerwinkle, Eric; McCormick, Joseph B.; Fisher-Hoch, Susan P.

    2013-01-01

    Background and Aims Elevated alanine aminotransferase (ALT >40 IU/mL) is a marker of liver injury but provides little insight into etiology. We aimed to identify and stratify risk factors associated with elevated ALT in a randomly selected population with a high prevalence of elevated ALT (39%), obesity (49%) and diabetes (30%). Methods Two machine learning methods, the support vector machine (SVM) and Bayesian logistic regression (BLR), were used to capture risk factors in a community cohort of 1532 adults from the Cameron County Hispanic Cohort (CCHC). A total of 28 predictor variables were used in the prediction models. The recently identified genetic marker rs738409 on the PNPLA3 gene was genotyped using the Sequenom iPLEX assay. Results The four major risk factors for elevated ALT were fasting plasma insulin level and insulin resistance, increased BMI and total body weight, plasma triglycerides and non-HDL cholesterol, and diastolic hypertension. In spite of the highly significant association of rs738409 in females, the role of rs738409 in the prediction model is minimal, compared to other epidemiological risk factors. Age and drug and alcohol consumption were not independent determinants of elevated ALT in this analysis. Conclusions The risk factors most strongly associated with elevated ALT in this population are components of the metabolic syndrome and point to nonalcoholic fatty liver disease (NAFLD). This population-based model identifies the likely cause of liver disease without the requirement of individual pathological diagnosis of liver diseases. Use of such a model can greatly contribute to a population-based approach to prevention of liver disease. PMID:22959976

  5. Association of Alanine Aminotransferase Levels (ALT with the Hepatic Insulin Resistance Index (HIRI: a cross-sectional study

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    Gómez-Sámano Miguel

    2012-09-01

    Full Text Available Abstract Background The association between serum alanine aminotransferase (ALT levels and hepatic insulin resistance (IR has been evaluated with the hyperinsulinemic-euglycemic clamp. However, there is no information about the association of ALT with the Hepatic Insulin Resistance Index (HIRI. The aim of this study was to evaluate the association between serum ALT levels and HIRI in subjects with differing degrees of impaired glucose metabolism. Methods This cross-sectional study included subjects that had an indication for testing for type 2 diabetes mellitus (T2DM with an oral glucose tolerance test (OGTT. Clinical and biochemical evaluations were carried out including serum ALT level quantification. HIRI was calculated for each participant. Correlation analyses and lineal regression models were used to evaluate the association between ALT levels and HIRI. Results A total of 324 subjects (37.6% male were included. The mean age was 40.4 ± 14.3 years and the mean body mass index (BMI was 32.0 ± 7.3 kg/m2. Individuals were divided into 1 of 5 groups: without metabolic abnormalities (n = 113, 34.8%; with the metabolic syndrome (MetS, n = 179, 55.2%, impaired fasting glucose (IFG, n = 85, 26.2%; impaired glucose tolerance (IGT, n = 91, 28.0%, and T2DM (n = 23, 7.0%. The ALT (p  Conclusions ALT levels are independently associated with HIRI in subjects with the MetS, IFG, IGT, and T2DM. The ALT value in these subjects may be an indirect parameter to evaluate hepatic IR.

  6. ALT (Alanine Aminotransferase) Test

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  7. Trihalomethane exposure and biomonitoring for the liver injury indicator, alanine aminotransferase, in the United States population (NHANES 1999–2006)

    Science.gov (United States)

    Burch, James B.; Everson, Todd M.; Seth, Ratanesh K.; Wirth, Michael D.; Chatterjee, Saurabh

    2015-01-01

    Exposure to trihalomethanes (or THMs: chloroform, bromoform, bromodichloromethane, and dibromochloromethane [DBCM]) formed via drinking water disinfection has been associated with adverse reproductive outcomes and cancers of the digestive or genitourinary organs. However, few studies have examined potential associations between THMs and liver injury in humans, even though experimental studies suggest that these agents exert hepatotoxic effects, particularly among obese individuals. This study examined participants in the National Health and Nutrition Examination Survey (1999–2006, N = 2781) to test the hypothesis that THMs are associated with liver injury as assessed by alanine aminotransferase (ALT) activity in circulation. Effect modification by body mass index (BMI) or alcohol consumption also was examined. Associations between blood THM concentrations and ALT activity were assessed using unconditional multiple logistic regression to calculate prevalence odds ratios (ORs) with 95% confidence intervals (CIs) for exposure among cases with elevated ALT activity (men: >40 IU/L, women: >30 IU/L) relative to those with normal ALT, after adjustment for variables that may confound the relationship between ALT and THMs. Compared to controls, cases were 1.35 times more likely (95% CI: 1.02, 1.79) to have circulating DBCM concentrations exceeding median values in the population. There was little evidence for effect modification by BMI, although the association varied by alcohol consumption. Among non-drinkers, cases were more likely than controls to be exposed to DBCM (OR: 3.30, 95% CI: 1.37–7.90), bromoform (OR: 2.88, 95% CI: 1.21–6.81), or brominated THMs (OR: 4.00, 95% CI: 1.31–12.1), but no association was observed among participants with low, or moderate to heavy alcohol consumption. Total THM levels exceeding benchmark exposure limits continue to be reported both in the United States and globally. Results from this study suggest a need for further

  8. The enzymology of alanine aminotransferase (AlaAT) isoforms from Hordeum vulgare and other organisms, and the HvAlaAT crystal structure.

    Science.gov (United States)

    Duff, Stephen M G; Rydel, Timothy J; McClerren, Amanda L; Zhang, Wenlan; Li, Jimmy Y; Sturman, Eric J; Halls, Coralie; Chen, Songyang; Zeng, Jiamin; Peng, Jiexin; Kretzler, Crystal N; Evdokimov, Artem

    2012-12-01

    In this paper we describe the expression, purification, kinetics and biophysical characterization of alanine aminotransferase (AlaAT) from the barley plant (Hordeum vulgare). This dimeric PLP-dependent enzyme is a pivotal element of several key metabolic pathways from nitrogen assimilation to carbon metabolism, and its introduction into transgenic plants results in increased yield. The enzyme exhibits a bi-bi ping-pong reaction mechanism with a K(m) for alanine, 2-oxoglutarate, glutamate and pyruvate of 3.8, 0.3, 0.8 and 0.2 mM, respectively. Barley AlaAT catalyzes the forward (alanine-forming) reaction with a k(cat) of 25.6 s(-1), the reverse (glutamate-forming) reaction with k(cat) of 12.1 s(-1) and an equilibrium constant of ~0.5. The enzyme is also able to utilize aspartate and oxaloacetate with ~10% efficiency as compared to the native substrates, which makes it much more specific than related bacterial/archaeal enzymes (that also have lower K(m) values). We have crystallized barley AlaAT in complex with PLP and l-cycloserine and solved the structure of this complex at 2.7 Å resolution. This is the first example of a plant AlaAT structure, and it reveals a canonical aminotransferase fold similar to structures of the Thermotoga maritima, Pyrococcus furiosus, and human enzymes. This structure bridges our structural understanding of AlaAT mechanism between three kingdoms of life and allows us to shed some light on the specifics of the catalysis performed by these proteins.

  9. Impact of elevated aspartate and alanine aminotransferase on metabolic syndrome and its components among adult people living in Ningxia, China

    Institute of Scientific and Technical Information of China (English)

    Kun-Peng He; Chuan Zhao; Yan Qiang; He-Rong Liu; Nan Chen; Xiu-Juan Tao; Li-Li Chen; Hui Song

    2015-01-01

    Objective: Metabolic syndrome (MS) is a combination of medical disorders that increase the risk for cardiovascular disease and diabetes mellitus. It suggests an association between an elevated serum aminotransferase level and MS. Little data show the relationship between the levels of serum aminotransferase and the incidence of MS in Ningxia, China. Methods: A total of 5415 subjects who received medical health checkups from 2007 to 2009 were enrolled in the study. The participants were interviewed by trained health workers under a structured questionnaire. MS was defined according to the modified ATPIII criteria for Asian Americans by the American Heart Association (AHA-ATP III). Results: The prevalence of elevated aspartate aminotransferase (AST) and ALT (>40 U/L) were 7.1%and 22.2%in males, and 2.1%and 4.8%in females respectively. The prevalence of MS was 32.1%in males and 15.4%in females. The components of MS were significantly more in the group with elevated aminotransferase levels than in the group with normal amino-transferase levels. The odds ratios (95%CI) for elevated AST were 1.90 (1.49, 2.42), 2.59 (2.01, 3.39), 1.68 (1.32, 2.15), and 1.81 (1.36, 2.42) in the adults with abdominal obesity, high serum triglycerides levels, high blood pressure, and high plasma glucose levels respectively. After adjustment for age, the odds ratios (95%CI) for elevated ALT were 3.08 (2.63, 3.61), 4.30 (3.64, 5.08), 1.26 (1.08, 1.48), 2.16 (1.93, 2.65) and 2.38 (1.96, 2.87) in adults with abdominal obesity, high serum tri-glycerides levels, low serum high-density lipoproteincholesterol (HDL-C), high blood pressure, and high plasma glucose levels respectively. The odds ratios (95%CI) for elevated AST were 1.67 (1.06, 2.63), 2.28 (1.46, 3.63), 2.59 (1.59, 4.21) and for elevated ALT 2.02 (1.50, 2.73), 2.68 (1.96, 3.65), 3.94 (2.86, 5.43) for the subjects with 1, 2, and ?3 risk factors after adjustment for age, gender, and BMI. Conclusion: The serum aminotransferase levels were

  10. Alanine Aminotransferase Elevation in Obese Infants and Children: A Marker of Early Onset Non Alcoholic Fatty Liver Disease

    OpenAIRE

    Engelmann, Guido; Hoffmann, Georg Friedrich; Grulich-Henn, Juergen; Teufel, Ulrike

    2014-01-01

    Background: Elevated aminotransferases serve as surrogate markers of non-alcoholic fatty liver disease, a feature commonly associated with the metabolic syndrome. Studies on the prevalence of fatty liver disease in obese children comprise small patient samples or focus on those patients with liver enzyme elevation. Objectives: We have prospectively analyzed liver enzymes in all overweight and obese children coming to our tertiary care centre. Patients and Methods: In a prospective study 224 h...

  11. The Association of Elevated Serum Alanine Aminotransferase with Metabolic Syndrome in A Military Population in Southern Iran

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    B Sabayan

    2010-06-01

    Full Text Available Background: Metabolic syndrome (MetS is rapidly rising at an alarming rate through all parts of the world. Elevated serum aminotransferase was proposed as a marker for early detection of MetS. In this investigation we primarily aimed to evaluate the prevalence of MetS and its components among army and secondly to explore the association between elevated serum aminotransferase and the components of metabolic syndrome. Methods: A total of 380 army personnel from a military camp in Southern Iran participated in this cross-sectional study. Life style related characteristics, anthropometric features, serum aminotransferase and components of MetS, based on National Cholesterol Education Program—Adult Treatment Panel III, were measured. Statistical significant was set as p value less than 0.05. Results: The mean age of participants was 35.0± 7.5 year-old and the prevalence of metabolic syndrome was 8.1%. The prevalence of the components of MetS including; central obesity, abnormal fasting blood glucose, hypertension, hypertriglycridemia and low HDL cholesterol level was 8.6%, 10.4%, 18.5%, 31%, and 45.5% respectively. MetS had significant relationship with obesity (P<0.001 and abnormal Waist Circumferance/Hip Circumference ratio (P<0.001. Twenty-six percent of subjects had ALT ≥ 41 U/L and 4.9% of them had ALT ≥ 81. Elevated serum aminotransferase had significant association with presence of MetS (P= 0.007. Conclusion: Although prevalence of metabolic syndrome among the studied army population was not high, life style modification of army members is recommended. Liver function tests should be included in routine health checkup of military personnel.

  12. The effect of pyridoxal-5-phosphate on serum alanine aminotransferase activity in dogs suffering from canine babesiosis

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    E.C. Myburgh

    2009-09-01

    Full Text Available Accurate measurements of serum aminotransferase (ALT activity in dogs relies on the endogenous pro-enzyme pyridoxal 5-phosphate (P5P. The purpose of this study was to determine whether the exclusion of P5P from the analytical method causes an underestimation of serum ALT activity in dogs suffering from babesiosis and in those manifesting evidence of hepatocellular damage, and to determine if anorexia causes sufficient P5P depletion to affect in vitro serum ALT activity. One-hundred-and-twenty healthy control dogs and 105 Babesia-infected dogs were included in the study. Two methods for ALT measurement were used: Method 1 included P5P, and Method 2 excluded P5P from the reaction mixture. Higher serum ALT activity was measured with Method 1 in the Babesia-infected dogs (P < 0.001, as well as in 14 dogs with suspected hepatocellular damage (P = 0.03. Duration of anorexia had no effect, irrespective of the method used. Although inclusion of P5P to the reaction mixture consistently resulted in higher measured serum ALT activity, the differences were too small to have led to incorrect diagnoses in the Babesia-infected dogs suspected of liver disease.

  13. Postoperative day one serum alanine amino-transferase does not predict patient morbidity and mortality after elective liver resection in non-cirrhotic patients

    Institute of Scientific and Technical Information of China (English)

    RickY Harminder Bhogal; Amit Nair; Davide Papis; Zaed Hamady; Jawad Ahmad; For Tai Lam; Saboor Khan; Gabriele Marangoni

    2016-01-01

    Serum aminotransferases have been used as sur-rogate markers for liver ischemia-reperfusion injury that fol-lows liver surgery. Some studies have suggested that rises in serum alanine aminotransferase (ALT) correlate with patient outcome after liver resection. We assessed whether postopera-tive day 1 (POD 1) ALT could be used to predict patient mor-bidity and mortality following liver resection. We reviewed our prospectively held database and included consecutive adult patients undergoing elective liver resection in our in-stitution between January 2013 and December 2014. Primary outcome assessed was correlation of POD 1 ALT with patient’s morbidity and mortality. We also assessed whether concurrent radiofrequency ablation, neoadjuvant chemotherapy and use of the Pringle maneuver signiifcantly affected the level of POD 1 ALT. A total of 110 liver resections were included in the study. The overall in-hospital patient morbidity and mortality were 31.8% and 0.9%, respectively. The median level of POD 1 ALT was 275 IU/L. No correlation was found between POD 1 serum ALT levels and patient morbidity after elective liver resection, whilst correlation with mortality was not possible because of the low number of mortalities. Patients undergoing concur-rent radiofrequency ablation were noted to have an increased level of POD 1 serum ALT but not those given neoadjuvant chemotherapy and those in whom the Pringle maneuver was used. Our study demonstrates POD 1 serum ALT does not cor-relate with patient morbidity after elective liver resection.

  14. Crystal structure of the S187F variant of human liver alanine: glyoxylate [corrected] aminotransferase associated with primary hyperoxaluria type I and its functional implications.

    Science.gov (United States)

    Oppici, Elisa; Fodor, Krisztian; Paiardini, Alessandro; Williams, Chris; Voltattorni, Carla Borri; Wilmanns, Matthias; Cellini, Barbara

    2013-08-01

    The substitution of Ser187, a residue located far from the active site of human liver peroxisomal alanine:glyoxylate aminotransferase (AGT), by Phe gives rise to a variant associated with primary hyperoxaluria type I. Unexpectedly, previous studies revealed that the recombinant form of S187F exhibits a remarkable loss of catalytic activity, an increased pyridoxal 5'-phosphate (PLP) binding affinity and a different coenzyme binding mode compared with normal AGT. To shed light on the structural elements responsible for these defects, we solved the crystal structure of the variant to a resolution of 2.9 Å. Although the overall conformation of the variant is similar to that of normal AGT, we noticed: (i) a displacement of the PLP-binding Lys209 and Val185, located on the re and si side of PLP, respectively, and (ii) slight conformational changes of other active site residues, in particular Trp108, the base stacking residue with the pyridine cofactor moiety. This active site perturbation results in a mispositioning of the AGT-pyridoxamine 5'-phosphate (PMP) complex and of the external aldimine, as predicted by molecular modeling studies. Taken together, both predicted and observed movements caused by the S187F mutation are consistent with the following functional properties of the variant: (i) a 300- to 500-fold decrease in both the rate constant of L-alanine half-transamination and the kcat of the overall transamination, (ii) a different PMP binding mode and affinity, and (iii) a different microenvironment of the external aldimine. Proposals for the treatment of patients bearing S187F mutation are discussed on the basis of these results.

  15. Risk factors associated with hepatitis B or C markers or elevated alanine aminotransferase level among blood donors on a tropical island: the Guadeloupe experience.

    Science.gov (United States)

    Fest, T; Viel, J F; Agis, F; Coffe, C; Dupond, J L; Hervé, P

    1992-10-01

    Donated blood is currently screened for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc), antibody to hepatitis C virus (anti-HCV), and alanine aminotransferase (ALT) levels to prevent posttransfusion hepatitis. A prospective study of 2368 blood donors was carried out in Guadeloupe (French West Indies) with a view to determining the risk factors associated with serologic abnormalities. Blood donors included in the study had to complete a questionnaire. Statistical analysis was performed on the data thus obtained: 571 donations (24%) were positive for at least one of the four analyzed markers. The results were that 3.2 percent were positive for HBsAg, 22 percent for anti-HBc, and 0.8 percent for anti-HCV, and 1.4 percent had ALT > or = 45 IU per L. A good correlation was found between anti-HCV and elevated ALT. Transfusion history and two socioeconomic categories (working class, military personnel) were found to be risk factors. Other risk factors were lifelong residence in Guadeloupe (with risk increasing with the number of years), birthplace and current residence in the southern part of the island, and the existence of gastrointestinal discomfort unrelated to viral hepatitis (odds ratio = 2.98). The results of this study illustrate the difficulty of implementing a preventive policy against posttransfusion hepatitis in a tropical area. The unique epidemiologic situation of Guadeloupe as regards hepatitis B virus has led to more restrictive criteria for the acceptance of blood donors.

  16. Correlation of hepatitis C RNA and serum alanine aminotransferase in hepatitis B and C seronegative healthy blood donors

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    Ali Natasha

    2010-07-01

    Full Text Available Introduction: Historically, serum alanine transaminase (ALT has been used as a surrogate marker in the detection of hepatitis viruses in blood donors. With the availability of newer sensitive technologies for the detection of seroconversion, the value of ALT becomes questionable but continues to be used for this purpose with subsequent discarding of ALT elevated blood units. Objective: The present study aims to evaluate the significance and cost effectiveness of ALT as a surrogate marker for hepatitis C virus infection in healthy asymptomatic blood donors who were serologically negative. Materials and Methods: The study was conducted at clinical laboratory of a tertiary care hospital for a period of one year from November 2006 to October 2007. All donors were screened serologically for hepatitis B, C and HIV I and II, syphilis and malaria and those tested positive were excluded from further evaluation. Gender-wise reference ranges and minimal and markedly raised results for ALT (described respectively as one and two folds increase above reference range were defined and, accordingly, donors were grouped into three. Two hundred seronegative blood donors were randomly selected from all three groups of ALT results and tested for hepatitis C nucleic acid through Amplicor; HCV RNA test. The cost of discarding an ALT -only elevated blood unit was also assessed. During the study period, 25117 subjects donated blood. Eight hundred and Results: seventy two donors (3.4% were positive for one or more serological tests. ALT of all donors ranged from 0-1501 U/L (Mean ± SD; 33.4 ± 25.45U/L. The donors seronegative for all disease markers were 24245 (96.6%. Of these, 21164 (87.2% donors had their ALT within reference range while 2874 (11.8% and 207 (0.8% of donors had minimal and markedly elevated results. Thus, 621 blood bags (red cells, platelets and plasma costing $ 39200.0 were discarded based on ALT results alone. Of 200 seronegative donors evaluated

  17. Higher Ratio of Serum Alpha-Fetoprotein Could Predict Outcomes in Patients with Hepatitis B Virus-Associated Hepatocellular Carcinoma and Normal Alanine Aminotransferase.

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    Young-Il Kim

    Full Text Available The role of serum alpha-fetoprotein (AFP levels in the surveillance and diagnosis of hepatocellular carcinoma (HCC is controversial. The aim of this study was to investigate the value of serially measured serum AFP levels in HCC progression or recurrence after initial treatment.A total of 722 consecutive patients newly diagnosed with HCC and treated at the National Cancer Center, Korea, between January 2004 and December 2009 were enrolled. The AFP ratios between 4-8 weeks post-treatment and those at the time of HCC progression or recurrence were obtained. Multivariate logistic regression analysis was performed to correlate the post-treatment AFP ratios with the presence of HCC progression or recurrence.The etiology of HCC was related to chronic hepatitis B virus (HBV infection in 562 patients (77.8%, chronic hepatitis C virus (HCV infection in 74 (10.2%, and non-viral cause in 86 (11.9%. There was a significant decrease in serum AFP levels from the baseline to 4 to 8 weeks after treatment (median AFP, 319.6 ng/mL vs. 49.6 ng/mL; p 1.0 was an independently associated with HCC progression or recurrence. Among the different causes of HCC analyzed, this association was significant only for HCC related to chronic hepatitis B (p< 0.001 and non-viral causes (p<0.05, and limited only to patients who had normal alanine aminotransferase (ALT levels.Serial measurements of serum AFP ratios could be helpful in detecting progression or recurrence in treated patients with HBV-HCC and normal ALT.

  18. Alanine-glyoxylate aminotransferase 2 (AGXT2) polymorphisms have considerable impact on methylarginine and β-aminoisobutyrate metabolism in healthy volunteers.

    Science.gov (United States)

    Kittel, Anja; Müller, Fabian; König, Jörg; Mieth, Maren; Sticht, Heinrich; Zolk, Oliver; Kralj, Ana; Heinrich, Markus R; Fromm, Martin F; Maas, Renke

    2014-01-01

    Elevated plasma concentrations of asymmetric (ADMA) and symmetric (SDMA) dimethylarginine have repeatedly been linked to adverse clinical outcomes. Both methylarginines are substrates of alanine-glyoxylate aminotransferase 2 (AGXT2). It was the aim of the present study to simultaneously investigate the functional relevance and relative contributions of common AGXT2 single nucleotide polymorphisms (SNPs) to plasma and urinary concentrations of methylarginines as well as β-aminoisobutyrate (BAIB), a prototypic substrate of AGXT2. In a cohort of 400 healthy volunteers ADMA, SDMA and BAIB concentrations were determined in plasma and urine using HPLC-MS/MS and were related to the coding AGXT2 SNPs rs37369 (p.Val140Ile) and rs16899974 (p.Val498Leu). Volunteers heterozygous or homozygous for the AGXT2 SNP rs37369 had higher SDMA plasma concentrations by 5% and 20% (p = 0.002) as well as higher BAIB concentrations by 54% and 146%, respectively, in plasma and 237% and 1661%, respectively, in urine (both pimpact of the amino acid exchange p.Val140Ile, we established human embryonic kidney cell lines stably overexpressing wild-type or mutant (p.Val140Ile) AGXT2 protein and assessed enzyme activity using BAIB and stable-isotope labeled [²H₆]-SDMA as substrate. In vitro, the amino acid exchange of the mutant protein resulted in a significantly lower enzyme activity compared to wild-type AGXT2 (p<0.05). In silico modeling of the SNPs indicated reduced enzyme stability and substrate binding. In conclusion, SNPs of AGXT2 affect plasma as well as urinary BAIB and SDMA concentrations linking methylarginine metabolism to the common genetic trait of hyper-β-aminoisobutyric aciduria.

  19. Misfolding caused by the pathogenic mutation G47R on the minor allele of alanine:glyoxylate aminotransferase and chaperoning activity of pyridoxine.

    Science.gov (United States)

    Montioli, Riccardo; Oppici, Elisa; Dindo, Mirco; Roncador, Alessandro; Gotte, Giovanni; Cellini, Barbara; Borri Voltattorni, Carla

    2015-10-01

    Liver peroxisomal alanine:glyoxylate aminotransferase (AGT), a pyridoxal 5'-phosphate (PLP) enzyme, exists as two polymorphic forms, the major (AGT-Ma) and the minor (AGT-Mi) haplotype. Deficit of AGT causes Primary Hyperoxaluria Type 1 (PH1), an autosomal recessive rare disease. Although ~one-third of the 79 disease-causing missense mutations segregates on AGT-Mi, only few of them are well characterized. Here for the first time the molecular and cellular defects of G47R-Mi are reported. When expressed in Escherichia coli, the recombinant purified G47R-Mi variant exhibits only a 2.5-fold reduction of its kcat, and its apo form displays a remarkably decreased PLP binding affinity, increased dimer-monomer equilibrium dissociation constant value, susceptibility to thermal denaturation and to N-terminal region proteolytic cleavage, and aggregation propensity. When stably expressed in a mammalian cell line, we found ~95% of the intact form of the variant in the insoluble fraction, and proteolyzed (within the N-terminal region) and aggregated forms both in the soluble and insoluble fractions. Moreover, the intact and nicked forms have a peroxisomal and a mitochondrial localization, respectively. Unlike what already seen for G41R-Mi, exposure of G47R-Mi expressing cells to pyridoxine (PN) remarkably increases the expression level and the specific activity in a dose-dependent manner, reroutes all the protein to peroxisomes, and rescues its functionality. Although the mechanism of the different effect of PN on the variants G47R-Mi and G41R-Mi remains elusive, the chaperoning activity of PN may be of value in the therapy of patients bearing the G47R mutation.

  20. Peginterferon alfa-2a is associated with elevations in alanine aminotransferase at the end of treatment in chronic hepatitis C patients with sustained virologic response.

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    Chih-Wei Tseng

    Full Text Available The purpose of this study was to investigate the incidence and demographic/clinical factors of alanine aminotransferase (ALT abnormalities at the end of treatment (EOT in chronic hepatitis C (CHC patients with sustained virologic response (SVR.Seven hundred naïve CHC patients who underwent combination treatment between January 2003 and December 2010 were included in the study. The patients with SVR and serum ALT>upper limit of normal (ULN at the EOT were further analyzed. The effects of clinical characteristics, treatment regimen, and virologic variables were evaluated by logistic regression. Of the 700 included patients, 488 (69.7% achieved an SVR after treatment, and 235 (33.6% had serum ALT levels>ULN at the EOT. Of those 488 patients, 137 (28.1% had abnormal ALT values at the EOT. A multivariate analysis showed that the occurrence of ALT abnormalities at the EOT was significantly associated with pegylated interferon (PEG-IFN alfa-2a (odds ratio [OR], 2.24; 95% confidence interval [CI], 1.45-3.45; P<0.001, baseline fatty liver (OR, 1.76; 95% CI, 1.16-2.76; P = 0.007, and baseline liver cirrhosis (OR, 2.35; 95% CI, 1.35-4.09; P = 0.002.Use of PEG-IFN-alfa-2a, fatty liver, and cirrhosis are important factors associated with EOT-ALT abnormality in CHC patients receiving combination therapy that achieve an SVR. PEG-IFN-alfa-2a-related EOT-ALT elevation will become normal at the end of follow-up, but fatty liver and cirrhosis-related ALT elevation will not be resolved.

  1. Performance of an Optimized Paper-Based Test for Rapid Visual Measurement of Alanine Aminotransferase (ALT in Fingerstick and Venipuncture Samples.

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    Sidhartha Jain

    Full Text Available A paper-based, multiplexed, microfluidic assay has been developed to visually measure alanine aminotransferase (ALT in a fingerstick sample, generating rapid, semi-quantitative results. Prior studies indicated a need for improved accuracy; the device was subsequently optimized using an FDA-approved automated platform (Abaxis Piccolo Xpress as a comparator. Here, we evaluated the performance of the optimized paper test for measurement of ALT in fingerstick blood and serum, as compared to Abaxis and Roche/Hitachi platforms. To evaluate feasibility of remote results interpretation, we also compared reading cell phone camera images of completed tests to reading the device in real time.96 ambulatory patients with varied baseline ALT concentration underwent fingerstick testing using the paper device; cell phone images of completed devices were taken and texted to a blinded off-site reader. Venipuncture serum was obtained from 93/96 participants for routine clinical testing (Roche/Hitachi; subsequently, 88/93 serum samples were captured and applied to paper and Abaxis platforms. Paper test and reference standard results were compared by Bland-Altman analysis.For serum, there was excellent agreement between paper test and Abaxis results, with negligible bias (+4.5 U/L. Abaxis results were systematically 8.6% lower than Roche/Hitachi results. ALT values in fingerstick samples tested on paper were systematically lower than values in paired serum tested on paper (bias -23.6 U/L or Abaxis (bias -18.4 U/L; a correction factor was developed for the paper device to match fingerstick blood to serum. Visual reads of cell phone images closely matched reads made in real time (bias +5.5 U/L.The paper ALT test is highly accurate for serum testing, matching the reference method against which it was optimized better than the reference methods matched each other. A systematic difference exists between ALT values in fingerstick and paired serum samples, and can be

  2. Alanine-glyoxylate aminotransferase 2 (AGXT2 polymorphisms have considerable impact on methylarginine and β-aminoisobutyrate metabolism in healthy volunteers.

    Directory of Open Access Journals (Sweden)

    Anja Kittel

    Full Text Available Elevated plasma concentrations of asymmetric (ADMA and symmetric (SDMA dimethylarginine have repeatedly been linked to adverse clinical outcomes. Both methylarginines are substrates of alanine-glyoxylate aminotransferase 2 (AGXT2. It was the aim of the present study to simultaneously investigate the functional relevance and relative contributions of common AGXT2 single nucleotide polymorphisms (SNPs to plasma and urinary concentrations of methylarginines as well as β-aminoisobutyrate (BAIB, a prototypic substrate of AGXT2. In a cohort of 400 healthy volunteers ADMA, SDMA and BAIB concentrations were determined in plasma and urine using HPLC-MS/MS and were related to the coding AGXT2 SNPs rs37369 (p.Val140Ile and rs16899974 (p.Val498Leu. Volunteers heterozygous or homozygous for the AGXT2 SNP rs37369 had higher SDMA plasma concentrations by 5% and 20% (p = 0.002 as well as higher BAIB concentrations by 54% and 146%, respectively, in plasma and 237% and 1661%, respectively, in urine (both p<0.001. ADMA concentrations were not affected by both SNPs. A haplotype analysis revealed that the second investigated AGXT2 SNP rs16899974, which was not significantly linked to the other AGXT2 SNP, further aggravates the effect of rs37369 with respect to BAIB concentrations in plasma and urine. To investigate the impact of the amino acid exchange p.Val140Ile, we established human embryonic kidney cell lines stably overexpressing wild-type or mutant (p.Val140Ile AGXT2 protein and assessed enzyme activity using BAIB and stable-isotope labeled [²H₆]-SDMA as substrate. In vitro, the amino acid exchange of the mutant protein resulted in a significantly lower enzyme activity compared to wild-type AGXT2 (p<0.05. In silico modeling of the SNPs indicated reduced enzyme stability and substrate binding. In conclusion, SNPs of AGXT2 affect plasma as well as urinary BAIB and SDMA concentrations linking methylarginine metabolism to the common genetic trait of hyper

  3. Effect of Capreolus capreolus and Sus scrofa excreta on alanine aminotransferase activity in Glechoma hederacea leaves in conditions of Cd pollution

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    O. M. Vasilyuk

    2015-06-01

    Full Text Available The paper reflects the analysis of Cd impact on the total activity (nM pyruvic acid/ml s of alanine aminotransferase (ALT, EC 2.6.1.2 nitrogen metabolism and the content (mg/ml of water-soluble protein fraction (albumin in Glechoma hederacea L. leaves subject, which dominated in the research area (natural floodplain oak with Stellaria holostea L.. Cd was introduced in the form of salts Cd(NO32 in the concentrations of 0.25, 1.25 and 2.50 g/m2, equivalent to Cd in 1, 5 and 10 doses of MAC. The content of doses of MAC of Cd (5 mg/kg soil was taken into account during introduction. We observed the inhibition of the activity of ALT 3–4 times (with adding the Cd salts at a dose of 1 and 5 МAС compared to controls (area without pollution of Cd and excreta of mammals. This stress reaction took place in the protein complex as well. Thus, albumin content was equal to 72% and 80% (with Cd 1 and 5 MAC compared to control (the area without pollution and excretory functions of mammals. It proved nonspecific response to stress. Using excreta of Capreolus capreolus L. and Sus scrofa L. shows the reduction of Cd effects and increasing the metabolic activity of ALT by 41% and 105%, respectively (with adding of Cd 1 MAC compared to control (pollution by Cd at a dose 1 MAC. The effect of Cd 5 MAC is offset (only with the introduction of C. capreolus excreta compared to control (pollution by Cd at a dose 5 MAC. Normalization of the albumin content (with adding of Cd 1 and 5 MAC compared to control (сontrol of Cd at a dose 1 MAC and сontrol of Cd at a dose 5 MAC with using of excreta of C. capreolus was observed. In conditions of Cd at a doze 10 MAC the ALT activity was reduced 2 times with the introduction of excreta of C. capreolus as S. scrofa compared to control (Cd at a dose 10 MAC. The introduction of excreta of S. scrofa compared with C. capreolus restored the albumin content by 10% to the control. Thus, the feasibility of using different biological

  4. Studies on the influence of combustion exhaust gases and the products of their reaction with ammonia on the living organism. II. The influence on aspartate aminotransferase (AspAT) and alanine aminotransferase (AiAt) activities in the liver of guinea pig

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowska-Tokarz, A.; Stanosek, J.; Ludyga, K.; Kochanski, L.

    1981-01-01

    The behaviour of aspartate aminotransferase (AspAT) an alanine aminotransferase (AIAT) in the whole homogenate and subcellular liver fractions of guinea pigs exposed to combustion exhaust gases and the neutralization products of these gases is presented in this paper. In the liver of animals exposed to the chronic action of combustion exhaust gases a decrease of both enzyme activities in the whole homogenate as well as in the subcellular fractions could be noted. Statistically significant changes are shown by AspAT. In the group of animals subjected to the action of neutralization products an increase of AIAT activity was observed. The activity of AspAT still shows a decrease, but less distinct in comparison with group I.

  5. Studies on the influence of combustion exhaust gases and the products of their reaction with ammonia on the living organism. II. The influence on aspartate aminotransferase (AspAT) and alanine aminotransferase (AiAt) activities in the liver of guinea pig.

    Science.gov (United States)

    Lewandowska-Tokarz, A; Stanosek, J; Ludyga, K; Kochanski, L

    1981-01-01

    The behaviour of aspartate aminotransferase (AspAT) an alanine aminotransferase (AIAT) in the whole homogenate and subcellular liver fractions of guinea pigs exposed to combustion exhaust gases and the neutralization products of these gases is presented in this paper. In the liver of animals exposed to the chronic action of combustion exhaust gases a decrease of both enzyme activities in the whole homogenate as well as in the subcellular fractions could be noted. Statistically significant changes are shown by AspAT. In the group of animals subjected to the action of neutralization products an increase of AIAT activity was observed. The activity of AspAT still shows a decrease, but less distinct in comparison with group I. An exception here is the mitochondrial fraction in which the AspAT activity is distinctly increased.

  6. Alanine-aminotransferase: an early marker for insulin resistance? Alanino-aminotransferasa: ¿un marcador temprano de resistencia a la insulina?

    Directory of Open Access Journals (Sweden)

    Martín R. Salazar

    2007-04-01

    Full Text Available In a population-based sample, after excluding alcohol consumption, hepatotoxic drugs and hepatitis Band C infected, we investigated if alanine-aminotransferase (ALT was associated with metabolic syndrome and insulin resistance, and if this association was caused by non-alcoholic fatty liver disease (NAFLD. The sample (432 female and 119 male was divided into two ALT thresholds corresponding to the 50th and 75th percentiles (P (female ≤ 15 and ≤ 19 U/L; male ≤ 17 and ≤ 23 U/l, respectively. Blood pressure, body mass index, waist circumference, cholesterol, HDL cholesterol (HDLc, triglyceride (TG, TG/HDLc ratio, glycemia and homeostasis model assessment of insulin resistance (HOMA-IR were compared between those above and below each ALT threshold. Female placed above the 50th P of ALT had higher levels of TG/HDLc ratio (p=0.029, glycemia (p=0.028, and homeostasis model assessment of insulin resistance, (p=0.045, and above the 75th P had higher SBP (p=0.036, DBP (p=0.018, TG (p=0.024, TG/HDLc ratio (p=0.028, glycemia (p=0.004 and HOMA-IR (p=0.0014. Male placed above the 50th P of ALT had higher BMI (p=0.017 and TG/HDLc ratio (p=0.048, and above the 75th P had lower values of HDLc (p=0.042. Only 16.5% of women and 14.5% of men, above the 75th P of ALT, showed an increase in liver brightness in the echography. This work shows in woman an early association of ALT with TG/HDLc ratio and HOMA-IR. Since the last two are independent predictors of cardiovascular risk, attention should be drawn to ALT values near the upper limit of the normal range even in the absence of NAFLD and obesity.En una muestra poblacional, luego de excluir a quienes consumían alcohol y drogas hepatotóxicas y a los infectados con virus B y C de la hepatitis, investigamos si la alanino-aminotransferasa (ALT, o transaminasa glutámico pirúvica (TGP, se asociaba con el síndrome metabólico y con resistencia a la insulina y si esta asociación se explicaba por enfermedad hep

  7. Low normal thyroid function attenuates serum alanine aminotransferase elevations in the context of metabolic syndrome and insulin resistance in white people

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; van den Berg, Eline H.; van der Klauw, Melanie; Blokzijl, Hans

    2014-01-01

    Objectives: Thyroid hormones play a key role in hepatic lipid metabolism. Although hypothyroidismis associated with increased prevalence of non-alcoholic fatty liver disease (NAFLD), the relationship of NAFLD with low normal thyroid function is unclear. We tested the association of serum alanine tra

  8. IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 degrees C. International Federation of Clinical Chemistry and Laboratory Medicine. Part 4. Reference procedure for the measurement of catalytic concentration of alanine aminotransferase.

    Science.gov (United States)

    Schumann, Gerhard; Bonora, Roberto; Ceriotti, Ferruccio; Férard, Georges; Ferrero, Carlo A; Franck, Paul F H; Gella, F Javier; Hoelzel, Wieland; Jørgensen, Poul Jørgen; Kanno, Takashi; Kessner, Art; Klauke, Rainer; Kristiansen, Nina; Lessinger, Jean-Marc; Linsinger, Thomas P J; Misaki, Hideo; Panteghini, Mauro; Pauwels, Jean; Schiele, Françoise; Schimmel, Heinz G; Weidemann, Gerhard; Siekmann, Lothar

    2002-07-01

    This paper is the fourth in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 degrees C and the certification of reference preparations. Other parts deal with: Part 1. The Concept of Reference Procedures for the Measurement of Catalytic Activity Concentrations of Enzymes; Part 2. Reference Procedure for the Measurement of Catalytic Concentration of Creatine Kinase; Part 3. Reference Procedure for the Measurement of Catalytic Concentration of Lactate Dehydrogenase; Part 5. Reference Procedure for the Measurement of Catalytic Concentration of Aspartate Aminotransferase; Part 6. Reference Procedure for the Measurement of Catalytic Concentration of Gamma-Glutamyltransferase; Part 7. Certification of Four Reference Materials for the Determination of Enzymatic Activity of Gamma-Glutamyltransferase, Lactate Dehydrogenase, Alanine Aminotransferase and Creatine Kinase at 37 degrees C. A document describing the determination of preliminary upper reference limits is also in preparation. The procedure described here is deduced from the previously described 30 degrees C IFCC reference method. Differences are tabulated and commented on in Appendix 2.

  9. Levamlodipine Besylate Induced Elevated Alanine Aminotransferase:Report of 1 Cases%1例苯磺酸左旋氨氯地平致谷丙转氨酶升高报告

    Institute of Scientific and Technical Information of China (English)

    王惠英; 张志辉; 康岩; 时新超

    2015-01-01

    Levamlodipine besylate two dihydropyridine calcium antagonist, is a kind of high curative ef ect, high safety, high compliance, less adverse reaction of the ideal anti hypertension drugs, can be used as the first choice of antihypertensive drugs. But considering the many old people have the function of liver and kidney and heart dysfunction, and associated with other diseases and cor esponding drug treatment, general lower bounds using initial drug dose range. Prevent elevated alanine aminotransferase.%苯磺酸左旋氨氯地平是二氢吡啶类钙拮抗剂,是一种疗效高,安全性高,依从性高,不良反应少的理想抗高血压药物,可以作为抗高血压的首选药物。但考虑到老年人多有肝肾功能和心功能减退,并伴有其它疾病和相应的药物治疗,一般起始用药采用剂量范围的下限。防止谷丙转氨酶升高。

  10. Identificação de ponto de corte no nível sérico da alanina aminotransferase para rastreamento da hepatite C em pacientes com insuficiência renal crônica em hemodiálise Identification of the cutoff value for serum alanine aminotransferase in hepatitis C screening of patients with chronic renal failure on hemodialysis

    Directory of Open Access Journals (Sweden)

    Ericson Cavalcanti Gouveia

    2004-02-01

    Full Text Available Pacientes com insuficiência renal crônica em hemodiálise apresentam níveis séricos mais baixos de alanina aminotransferase. Para estabelecer melhor ponto de corte nos níveis de ALT, no diagnóstico da hepatite C, avaliaram-se mensalmente, durante 6 meses os níveis desta enzima em 235 pacientes em hemodiálise, sendo excluídos aqueles que apresentassem média acima do limite superior da normalidade. O ponto de corte foi identificado através da construção de curva ROC. Entre 202 pacientes, 15 (7,4% apresentavam anti-VHC positivo e 187 (92,6% negativo, com média de ALT de 0,7 e de 0,5 do limite superior (p The patients with chronic renal failure in hemodialysis present low levels of serum alanine aminotransferases. In order to establish a better cutoff value for ALT in hepatitis C screening of hemodialysis patients, the ALT levels were measured monthly in 235 patients, being excluded those that presented average above the upper limit of normality. The cutoff value was identified by construction of a ROC curve (receiver operating characteristic. Among 202 patients, 15 (7.4% presented antibodies to hepatitis C virus (anti-HCV and 187 (92.6% were anti-HCV negative , with an ALT average of 0.7 and of 0.5 from ULN (p <0.0001, respectively. The better cutoff value for ALT was at 0.6 from ULN, with sensitivity of 67% and specificity of 75% in anti-HCV screening. These results suggest that ULN of ALT could be reduced for 60% from conventional limit, when we are evaluating patients with CRF in hemodialysis.

  11. γ-glutamyl transpeptidase in men and alanine aminotransferase in women are the most suitable parameters among liver function tests for the prediction of metabolic syndrome in nonviral hepatitis and nonfatty liver in the elderly

    Directory of Open Access Journals (Sweden)

    Dee Pei

    2015-01-01

    Full Text Available Background/Aims: Nonalchoholic fatty liver disease (NAFLD has been reported as a hepatic manifestation of metabolic syndrome (MetS; it is common and accounts for 80% of the cases with abnormal liver function tests (LFTs. In addition, several studies have proved that there is a correlation between abnormal LFTs and MetS. Therefore, LFTs may represent the abnormal metabolic status of livers in the patients with MetS. To identify the early state of metabolic dysfunction, we investigate the value of LFTs for the future MetS development in the relatively healthy (non-NAFLD elderly. Patients and Methods: A total of 16,912 subjects met the criteria for analysis. In the first stage of this study, subjects were enrolled in the cross-sectional study in order to find out the optimal cutoff value in different LFTs with higher chances to have MetS. In the second stage of the present study, subjects with MetS at baseline were excluded from the same study group, and a median 5.6-year longitudinal study was conducted on the rest of the group. Results: Among all LFTs, only aspartate aminotransferase in both genders and the α-fetal protein in women failed to show the significance in distinguishing subjects with MetS by the receiver operating characteristic curve. In the Kaplan-Meier plot, only γ-glutamyl transpeptidase (γ-GT in men and the alanine aminotransferase (ALT in women could be used to successfully separate subjects with higher risk of developing the MetS from those with lower risk. Finally, in the multivariant Cox regression model, similar results were identified. Still, the hazard ratio (HR to have future MetS, γ-GT in men, and ALT in women showed significance (HR = 1.511 in men and 1.504 in women. Conclusion: Among all the different LFTs, γ-GT (>16 U/L in male and ALT (>21 U/L in female were the best predictors for the development of MetS in healthy elderly. These two liver markers could be an ancillary test in predicting future MetS development

  12. Development of dry chemistry method for alanine aminotransferase%丙氨酸氨基转移酶干化学检测方法的建立及试纸条的制备

    Institute of Scientific and Technical Information of China (English)

    田漪; 陈汉艳; 王缦

    2012-01-01

    Objective To develop a dry chemistry method for alanine aminotransferase (ALT) based on pyruvate oxidase method and prepare the test strip. Methods The test strip consisted of a sample spreading layer,a substrate layer and a color de-velopment layer,which was coated with reaction agent for determination of ALT activity by reflectance photometer. The prepared test strip was verified. Results The intra-CV of the test strip for low (48. 7 U/L) and high (127 U/L) level quality controls were 7. 4% and 4. 9% respectively. The linear range of the test strip was 10 ~ 1 000 U/L No significant difference was observed between the determination results of heparinized blood and plasma by the test strip (P > 0. 05). The determination results of ALT were uninfluenced when the bilirubin content in sample was not more than 257 μmol / L,the ascorbic acid content was not more than 50 mg / L,and the pyruvate content was not more than 0. 5 mmol / L. The developed dry chemistry method showed good relationship to the method recommended by International Federation of Clinical Chemistry (IFCC)(r = 0. 988 9). The reference range of 95% confidence interval of the test strip was 0 ~ 40 U / L. Conclusion The developed dry chemistry method was rapid,accurate and simple,which was suitable for immediate determination of ALT.%目的 建立一种以丙酮酸氧化酶法为反应原理的丙氨酸氨基转移酶( Alanine aminotransferase,ALT)干化学检测方法,并制备试纸条.方法 试纸条由扩散层、底物层和显色层组成,包被有反应试剂,用反射式光度计测定ALT活性.对制备的试纸条进行各项验证.结果 试纸条测定罗氏低、高值质控品的批内变异系数分别为7.4%和4.9%;线性范围为10~1000U/L;试纸条测定肝素锂抗凝全血及其血浆的结果差异无统计学意义(P>0.05);标本中胆红素≤257 mol/L,抗坏血酸≤50 mg/L,丙酮酸≤0.5 mmol/L时,ALT测定结果不受影响;建立的干化学法与国际临床化学

  13. Lingmao Formula Combined with Entecavir for HBeAg-Positive Chronic Hepatitis B Patients with Mildly Elevated Alanine Aminotransferase: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

    Directory of Open Access Journals (Sweden)

    Xiao-Jun Zhu

    2013-01-01

    Full Text Available Objective. To determine the efficacy and safety of Lingmao Formula combined with entecavir for HBeAg-positive chronic hepatitis B patients with mildly elevated alanine aminotransferase (ALT. Methods. 301 patients were randomly assigned to receive Lingmao Formula combined with entecavir (treatment group or placebo combined with entecavir (control group for 52 weeks. The outcomes of interest included the reduction of serum HBV DNA level, HBeAg loss, HBeAg seroconversion, ALT normalization, and histological improvement. Results. The mean decrease of serum HBV DNA level from baseline and the percentage of patients who had reduction in serum HBV DNA level ≥2 lg copies/mL in treatment group were significantly greater than that in control group (5.5 versus 5.4 lg copies/mL, P=0.010; 98.5% versus 92.6%, P=0.019. The percentage of HBeAg loss in treatment group was 22.8%, which was much higher than a percentage of 12.6% in control group (P=0.038. There was no significant difference between the two groups in histological improvement. Safety was similar in the two groups. Conclusions. The combination of Lingmao Formula with entecavir could result in significant decrease of serum HBV DNA and increase of HBeAg loss for HBeAg-positive chronic hepatitis B patients with mildly elevated ALT without any serious adverse events. Clinical trial registration number is ChiCTR-TRC-09000594.

  14. The Campylobacter jejuni RacRS two-component system activates the glutamate synthesis by directly upregulating γ-glutamyltranspeptidase (GGT

    Directory of Open Access Journals (Sweden)

    Anne-Xander evan der Stel

    2015-06-01

    Full Text Available The highly conserved enzyme γ-glutamyltranspeptidase (GGT plays an important role in metabolism of glutathione and glutamine. Yet, the regulation of ggt transcription in prokaryotes is poorly understood. In the human pathogen Campylobacter jejuni, GGT is important as it contributes to persistent colonization of the gut. Here we show that the GGT activity in C. jejuni is dependent on a functional RacRS (reduced ability to colonize two-component system. Electrophoretic mobility shift and luciferase reporter assays indicate that the response regulator RacR binds to a promoter region ~80 bp upstream of the ggt transcriptional start site, which contains a recently identified RacR DNA binding consensus sequence. RacR needs to be phosphorylated to activate the transcription of the ggt gene, which is the case under low oxygen conditions in presence of alternative electron acceptors. A functional GGT and RacR are needed to allow C. jejuni to grow optimally on glutamine as sole carbon source under RacR inducing conditions. However, when additional carbon sources are present C. jejuni is capable of utilizing glutamine independently of GGT. RacR is the first prokaryotic transcription factor known to directly upregulate both the cytoplasmic (glutamine-2-oxoglutarate aminotransferase (GOGAT as well as the periplasmic (GGT production of glutamate.

  15. Relationship between anthropometric parameters and alanine aminotransferase in Qinhuangdao college students%秦皇岛市大学生人体测量指标与丙氨酸氨基转移酶相关性研究

    Institute of Scientific and Technical Information of China (English)

    秦春梅; 王锐; 陆强; 张文丽; 玄续敏; 刘波; 刘晓丽; 马春明

    2010-01-01

    目的 探讨大学生人体测量指标与丙氨酸氨基转移酶(ALT)的关系.方法 通过分层整群随机抽样的方法,选取秦皇岛市789名在校大学生(男性369例,女性420例)作为研究对象,测量身高、体重、腰围、臀围、血压和ALT,计算体质指数、腰围身高比和腰臀比.结果 本研究共检出ALT升高大学生77例,其中男性60例(16.3%),女性17例(4.0%),男性检出率高于女性(P0.05).男性各肥胖指标识别ALT升高的ROC曲线下面积均在0.8~0.9之间(P0.05),准确性较低.结论 男性大学生ALT升高比女性更为普遍.男性肥胖指标可作为识别ALT升高的有效指标,而女性效能较差.无论男女,血压识别ALT升高的效能均较差.%Objective To investigate the correlation of anthropometric parameters with alanine aminotransferase (ALT) in Qinhuangdao college students.Methods A total of 789 subjects from two colleges in Qinhuangdao City (369 men and 420 women) were recruited using a cluster-stratified sampling method.Anthropometric measurements included height,body weight,waist circumference,hip circumference,blood pressure.and ALT.Body mass index,waist to height ratio,and waist to hip ratio were calculated.Results Elevated ALT was found in 16.3% of male participants and 4.0% of females(P0.05).Receiver operating characteristie curve analysis also showed that obesity indices predicted elevated ALT only in men [area under the curve:0.8-0.9(P0.05) in wonlen].Blood pressure did not predict elevated ALT in both men and women (area under the curve:0.5-0.7).Conclusion Dender difference of obesity indices could be found in Qinhuangdao college students.Obesity indices may be independent predictors of elevated ALT in men.However,blood pressure seems not to be an independent predictor of elevated ALT.

  16. Application of reference method in the standardization for the determination of alanine aminotransferase%参考方法在丙氨酸氨基转移酶测定标准化中的应用

    Institute of Scientific and Technical Information of China (English)

    郑松柏; 王建兵; 黄宪章; 马艳; 庄俊华; 徐宁; 周华友; 陈茶

    2012-01-01

    Objective To investigate the accuracy and comparability of alanine aminotransferase(ALT) measurement results in human serum samples and commercial materials before and after calibration with frozen human serum calibrator assigned by reference method. Methods Five frozen human-pooled serum samples were assigned values by the reference method without pyridoxal 5-phosphate for ALT in four candidate reference laboratories, which were used to evaluate the results of ALT catalytic activity detected by ten testing systems in Guangzhou. One of the serum sample was used as the common calibrator. The results of serum samples and commercial materials from different systems before and after calibration were analyzed for biases and intersystem variations. Results After calibration,the variance of the systems for the results of serum samples decreased from between 11. 90% and 8. 60% to between 6. 78% and 2. 30% ,and the bias decreased dramatically from between - 12. 52% and - 8. 44 % to between - 3. 36% and -0. 08%. Slopes of the regression lines of ALT results of serum samples between reference systems and routine systems after calibration were closer to 1 and intercepts closer to 0 than those obtained before calibration. Conclusion Accuracy and comparability of ALT measurements could be improved by using a common human serum calibrator. But commercial materials might not be commutable for human serum in ALT measurements.%目的 调查不同检测系统使用经参考方法赋值的冰冻人血清样本作为校准品进行校准后,不同来源样本丙氨酸氨基转移酶(ALT)测定结果的可比性与准确性的改变程度.方法 5份经4家候选参考实验室应用不含磷酸吡哆醛的ALT参考方法定值的冰冻人混合血清样本用于评价广州地区10个不同检测系统ALT催化活性结果的可比性与准确性.其中一个样本用作校准品校准各系统.比较校准前后各系统间新鲜血清样本与商品制备物测定

  17. Association between Serum Alanine Aminotransferase Level and Coronary Heart Disease%血清丙氨酸氨基转移酶水平与冠心病的相关性研究

    Institute of Scientific and Technical Information of China (English)

    余慧珍; 杨万松

    2013-01-01

    Objective To study the relationship between the serum alanine aminotransferase ( ALT ) level and coronary heart disease ( CHD ). Methods A total of 426 inpatients from the Second Hospital of Tianjin Medical University in 2011 were enrolled in this study and their serum ALT levels were determined and the coronary artery angiography was performed. Based on the results of coronary artery angiography, these patients were divided in the CHD group ( n = 294 ) and control group ( n = 132 ). The CHD group was further divided into three subgroups: single - branch subgroup ( n = 89 ), double - branch subgroup ( n = 91 ), and multiple - branch subgroup ( n = 114 ). The levels of serum ALT were compared among these groups. Results The serum ALT level was significantly higher in the CHD group than in the control group [ ( 23. 4 ± 18. 7 ) U/L vs. ( 17. 8 ± 13.2) U/L, P < 0. 01 ]. The three subgroups also showed significantly different ALT level when compared with the control group ( F = 5. 137, P =0. 002 ). Multivariate Logistic regression analysis showed the higher serum ALT level was associated with the occurrence of CHD [ 0R= 0.966, 95%CI (0.944, 0.988), P<0.0l]. Conclusion CHD patients have higher serum ALT level than non - CHD patients. Serum ALT level can be used for predicting the severity of CHD.%目的 探讨血清丙氨酸氨基转移酶(ALT)与冠心病(CHD)的关系.方法 选择2011年在天津医科大学第二医院心脏科住院的426例患者,均检测血清ALT水平,并行冠状动脉造影评价冠状动脉病变程度.根据冠状动脉造影结果分为冠心病组(294例)和对照组(132例).冠心病组再根据病变支数分为单支病变组(89例)、双支病变组(91例)和多支病变组(114例);分析血清ALT水平与冠状动脉病变严重程度的相关性.结果 冠心病组血清ALT水平明显高于对照组,差异有统计学意义[(23.4±18.7)U/L和(17.8±13.2)U/L,P<0.01];冠心病3个亚组及对照组ALT水平

  18. 茶树丙氨酸氨基转移酶基因的克隆与表达分析%Cloning and Expression Analysis of Alanine Aminotransferase Gene in Camellia sinensis

    Institute of Scientific and Technical Information of China (English)

    白培贤; 王丽鸳; 韦康; 阮丽; 成浩; 张芬; 张成才

    2016-01-01

    丙氨酸氨基转移酶(Alanine Aminotransferase,AlaAT)是与碳氮代谢相关的一种重要酶类。采用反转录PCR 的方法克隆了茶树 CsAlaAT1的 cDNA 序列,该序列全长1747 bp,包含一个完整的 ORF(1626 bp),编码541个氨基酸,推导的蛋白质分子量为59.4 kD,理论等电点(pI)为5.82。同源比对结果表明,CsAlaAT1含有丙氨酸氨基转移酶亚家族保守的辅酶磷酸吡哆醛结合位点,其氨基酸序列与拟南芥 AtAlaAT1蛋白的相似性为84%。二级结构预测显示该蛋白由α-螺旋(40.67%)、无规则卷曲(29.57%)、β-折叠(13.68%)和延伸链(16.08%)组成,定位于线粒体,不含信号肽与跨膜结构。实时荧光定量 PCR(RT-PCR)检测发现 CsAlaAT1在茶树各组织中均有表达,在根中的表达量最高;CsAlaAT1基因表达对氮素的响应研究表明,成熟叶中CsAlaAT1受氮素诱导上调表达,高浓度(1 mmol·L-1 NH4NO3)氮素的诱导效应比低浓度(0.1 mmol·L-1 NH4NO3)氮素诱导效应更强烈;在根中,处理24 h 后,高氮诱导 CsAlaAT1上调表达,低氮诱导 CsAlaAT1下调表达。%Alanine Aminotransferase (AlaAT) is a critical enzyme involved in carbohydrate and nitrogen metabolisms. In this study, a cDNA (1 747 bp) with a complete ORF (1 626 bp) of AlaAT1 was isolated from tea plant (Camellia sinensis). The cDNA encodes a protein with 541 amino acids, which has a molecular mass of 59.4 kD and a theoretical isoelectric point (pI) of 5.82. The deduced sequence of protein CsAlaAT1 shared 84% similarity with AlaAT1 in Arabidopsis thaliana, which contains a highly-conserved pyridoxal 5′-phosphate binding site. Secondary structure prediction showed that the CsAlaAT1 was comprised of alpha helix (40.67%), random coil (29.57%), beta turn (13.68%) and extended strand (16.08%), localized in mitochondrion and had no signal peptide or transmembrane structure. The expression levels of CsAlaAT1 in

  19. Correlations of serum alanine aminotransferase and insulin resistance, pancreatic B-cell function%丙氨酸转氨酶水平与胰岛素抵抗及胰岛β细胞功能的关系

    Institute of Scientific and Technical Information of China (English)

    王永慧; 黎明; 高珊; 张秀娟; 李连霞; 张葵

    2011-01-01

    Objective To explore the correlations of serum alanine aminotransferase (ALT),insulin resistance and pancreatic B-cell function.Methods A total of 351 first-degree relatives of type 2 diabetes mellitus received a standard oral glucose tolerance test (OGTT) at our outpatient clinic.All subjects were analyzed for the parameters of body mass index ( BMI),waist-hip ratio,blood pressure ( BP),serum lipids,ALT,aspartate aminotransferase (AST),plasma glucose (PG),true-insulin and proinsulin.Homeostasis model assessment (HOMA) was applied to assess the status of insulin resistance and pancreatic B-cell function. They were divided into 4 groups according to the quartiles of ALT:ALT1 group (<12.9 U/L),ALT2 group (12.9- 17.3 U/L),ALT3 group (17.4-24.2 U/L) and ALT4 group ( ≥24.2 U/L).The diagnosis of metabolic syndrome was made according to the definition of Chinese Diabetic Society.Results With the rising serum ALT levels (ALT4 vs ALT1 ),the levels of BMI [ (26.3 ± 2.9) kg/m2 vs (23.2±3.7) kg/m2,P<0.01],HOMA-IR [1.93(1.21 -3.26) vs 1.06(0.65 -1.54),P<0.01] and LnHOMA-beta (2.00 ±0.32 vs 1.87 ±0.28,P<0.05) were elevated; BP,serum lipids,PG,true-insulin and proinsulin also increased ( P < 0.05 or P < 0.01 ).The levels of serum ALT [ 23.3(16.3-37.6) vs 14.3 (10.3-18.5) U/L,P<0.01] and AST [21.5 (18.3-32.8) U/L vs 17.9( 15.5 -22.1 ) U/L,P <0.01 ] increased with the rising number of metabolic disorders (0 vs 3 -4 metabolic disorders).After adjustments for gender,age,BMI and waist-hip ratio,serum ALT were still positively correlated with BP,serum lipids,PG,fasting true-insulin,2 h proinsulin,2 h proinsulin/true-insulin,HOMA-IR and the numbers of metabolic disorder (r=0.117 -0.236,P<0.05 or P<0.01).After adjustments for gender,age,BMI,waist-hip ratio and HOMA-IR,the serum ALT level remained positively correlated with the numbers of metabolic disorders (r =0.120,P < 0.05).Multiple stepwise regression analysis showed that triglyceride

  20. Physiological and biochemical effects of morphactin IT 3233 on callus and tumour tissues of Nicotiana tabacum L. cultured in vitro III. Transamination processes catalysed by aminotransferase L-alanine: 2-oxoglutarate

    Directory of Open Access Journals (Sweden)

    Z. Chirek

    2015-01-01

    Full Text Available An active alanine transaminase was found both in callus and tumour tissues of tobacco. The enzyme is more active in the latter tissue, and the reaction balance is strongly shifted towards alanine production, while in callus tissue towards glutamic acid formation. Morphactin applied to the tissue cultures stimulates markedly the enzyme activity only in callus. A negative correlation was observed between the intensity of transamination processes and enhanced synthesis of proteins in the tissues studied. Morphactin disturbs nitrogen metabolism in the callus tissue. Tumour tissue is more resistant to the action of this substance. The different hormonal activities in these tissues may be the cause of the different effects of morphactin.

  1. Degradation of pyrimidines in Saccharomyces kluyveri: transamination of beta-alanine

    DEFF Research Database (Denmark)

    Schnackerz, K D; Andersen, G; Dobritzsch, D

    2008-01-01

    Beta-alanine is an intermediate in the reductive degradation of uracil. Recently we have identified and characterized the Saccharomyces kluyveri PYD4 gene and the corresponding enzyme beta -alanine aminotransferase ((Sk)Pyd4p), highly homologous to eukaryotic gamma-aminobutyrate aminotransferase...... (GABA-AT). S. kluyveri has two aminotransferases, GABA aminotransferase ((Sk)Uga1p) with 80% and (Sk)Pyd4p with 55% identity to S. cerevisiae GABA-AT. (Sk)Pyd4p is a typical pyridoxal phosphate-dependent aminotransferase, specific for alpha-ketoglutarate (alpha KG), beta-alanine (BAL) and gamma...

  2. Effection of Pyridoxal- 5 '- phosphate on Determination of Alanine Aminotransferase activities%5'-磷酸吡哆醛对血清丙氨酸氨基转移酶活性测定的影响

    Institute of Scientific and Technical Information of China (English)

    朱柏林

    2012-01-01

    目的 研究丙氨酸氨基转移酶(Alanine Aminotraasferase,ALT) 检测试剂中 5'- 磷酸吡哆醛(Pyrldoxal - 5'-phosphate,PLP )的添加对血清ALT活性测定的影响.方法 以山东潍坊康华生物技术有限公司生产的丙氨酸氨基转移酶试剂(按照IFCC推荐方法配制,不含PLP)和在该品牌试剂中加入5'-磷酸吡哆醛溶液,分别用这两种试剂测定相同的新鲜临床标本280例,并对检测结果进行统计学比较.结果 使用含PLP的IFCC配方试剂较不含 PLP试剂的检测结果明显增高.结论 康华公司生产的丙氨酸氨基转移酶试剂添加PLP比较不添加PLP ALT活性增加近5%-40%,且两种试剂的ALT检测结果不能通过简单系数实现转换.

  3. 5'-磷酸吡哆醛影响血清丙氨酸氨基转移酶测定的研究%Effection of Pyridoxal -5'-phosphate on Determination of Alanine Aminotransferase activities

    Institute of Scientific and Technical Information of China (English)

    张宗彬; 鲍杰; 陈龙泉; 李传胜; 马洪波

    2007-01-01

    目的 研究丙氨酸氨基转移酶(Alanine Aminotraasferase,ALT)检测试剂中5'-磷酸吡哆醛(Pyrldoxal-5'-phos-phate,PLP)的添加对血清ALT活力测定的影响.方法 按IFCC推荐方法,自配ALT检测试剂(含PLP)和相应不添加PLP的检测试剂,分别用这两种试剂测定相同的新鲜临床标本,并对检测结果进行统计学比较.结果 使用含PLP的IFCC配方试剂较不含PLP试剂的检测结果明显增高.结论 健康人群和不同疾病人群由于个体差异,体内PLP含量不一,各组数据表明不含PLP配方试剂较IFCC配方检测结果明显偏低,因此两种配方的检测结果不能通过简单系数实现转换.

  4. PROPERTIES OF AMINOTRANSFERASES FROM TELADORSAGIA CIRCUMCINCTA

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    Noorzaid MUHAMAD

    2014-12-01

    Full Text Available Activities of several aminotransferases were measured in L3 and adult Teladorsagia circumcincta, but most of these had maximal activity of less than 8 nmol min-1 mg-1 protein. Only aspartate aminotransferase (AspAT and alanine aminotransferase (AlaAT activities exceeded this value and some kinetic properties of these enzymes were characterised. For L3 AspAT, the apparent Kms were 1.2 mM, 0.13 mM, 0.11 mM and 0.04 mM for aspartate, -ketoglutarate, glutamate and oxaloacetate, respectively, and the apparent Vmaxs were 960 nmol min-1 mg-1 protein for aspartate deamination and 420 nmol min-1 mg-1 protein in the direction of glutamate deamination. For L3 AlaAT, the apparent Kms were 5.2 mM, 0.5 mM, 0.5 mM and 1.2 mM for alanine, -ketoglutarate, glutamate and pyruvate, respectively, and apparent Vmaxs were 107 nmol min-1 mg-1 protein for alanine deamination and 48 nmol min-1 mg-1 protein for alanine formation. Both enzymes required exogenous pyridoxal 5′-phosphate for optimal activity. The equilibrium constants for the AspAT and AlaAT reactions were consistent with those estimated from the estimated kinetic parameters. From these parameters we infer that T. circumcincta AlaAT is present predominantly as a mitochondrial enzyme favouring pyruvate formation while AspAT is predominantly a cytosolic enzyme favouring glutamate formation.

  5. Non-alcoholic steatohepatitis with normal aminotransferase values

    Institute of Scientific and Technical Information of China (English)

    H(u)eyin Saadettin Uslusoy; Selim Giray Nak; Macit G(u)lten; Zeynep Biyikli

    2009-01-01

    AIM: To investigate the aspects of liver histology in patients with non-alcoholic steatohepatitis (NASH) who had normal aminotransferase levels. METHODS: Thirty-four patients diagnosed with liver steatosis by ultrasonographic examination participated in the study. We compared all nonalcoholic fatty liver disease and NASH cases, according to aminotransferase level, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio and presence of metabolic syndrome. RESULTS: Si x t e en of 25 pa t i ent s wi th high aminotransferase levels were diagnosed with NASH and nine with simple fatty liver according to liver histology. Among the nine patients with normal aminotransferase levels, seven had NASH and two had simple fatty liver. The patients with normal and high liver enzyme levels had almost the same prevalence of NASH and metabolic syndrome. Liver histology did not reveal any difference according to aminotransferase levels and AST/ALT ratio. CONCLUSION: Aminotransferase levels and AST/ALT ratio do not seem to be reliable predictors for NASH. Despite numerous non-invasive biomarkers, all patients with fatty liver should undergo liver biopsy.

  6. Inverse linear associations between liver aminotransferases and incident cardiovascular disease risk : The PREVEND study

    NARCIS (Netherlands)

    Kunutsor, Setor K.; Bakker, Stephan J. L.; Kootstra-Ros, Jenny E.; Blokzijl, Hans; Gansevoort, Ronald T.; Dullaart, Robin P. F.

    2015-01-01

    Background: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) have been linked with an increased risk of type 2 diabetes, but their relationships with cardiovascular disease (CVD) are uncertain. We aimed to assess the associations of ALT and AST with CVD risk and determine their po

  7. Genetic and bibliographic information: Ggt1 [GenLibi

    Lifescience Database Archive (English)

    Full Text Available Ggt1 gamma-glutamyltransferase 1 rat Precursor B-Cell Lymphoblastic Leukemia-Lympho...hoid (C04.557.337.428) > Precursor Cell Lymphoblastic Leukemia-Lymphoma (C04.557.337.428.600) > Precursor B-Cell Lymphoblastic... Leukemia-Lymphoma (C04.557.337.428.600.600) Hemic and Lymphatic... Diseases (C15) > Lymphatic Diseases (C15.604) > Lymphoproliferative Disorders (C15.604.515) > Leukemia, Ly...mphoid (C15.604.515.560) > Precursor Cell Lymphoblastic Leukemia-Lymphoma (C15.604.515.560.600) > Precursor B-Cell Lymphoblastic

  8. Mammalian alanine/glyoxylate aminotransferase 1 is imported into peroxisomes via the PTS1 translocation pathway. Increased degeneracy and context specificity of the mammalian PTS1 motif and implications for the peroxisome-to-mitochondrion mistargeting of AGT in primary hyperoxaluria type 1.

    Science.gov (United States)

    Motley, A; Lumb, M J; Oatey, P B; Jennings, P R; De Zoysa, P A; Wanders, R J; Tabak, H F; Danpure, C J

    1995-10-01

    Alanine/glyoxylate aminotransferase 1 (AGT) is peroxisomal in most normal humans, but in some patients with the hereditary disease primary hyperoxaluria type 1 (PH1), AGT is mislocalized to the mitochondria. In an attempt to identify the sequences in AGT that mediate its targeting to peroxisomes, and to determine the mechanism by which AGT is mistargeted in PH1, we have studied the intracellular compartmentalization of various normal and mutant AGT polypeptides in normal human fibroblasts and cell lines with selective deficiencies of peroxisomal protein import, using immunofluorescence microscopy after intranuclear microinjection of AGT expression plasmids. The results show that AGT is imported into peroxisomes via the peroxisomal targeting sequence type 1 (PTS1) translocation pathway. Although the COOH-terminal KKL of human AGT was shown to be necessary for its peroxisomal import, this tripeptide was unable to direct the peroxisomal import of the bona fide peroxisomal protein firefly luciferase or the reporter protein bacterial chloramphenicol acetyltransferase. An ill-defined region immediately upstream of the COOH-terminal KKL was also found to be necessary for the peroxisomal import of AGT, but again this region was found to be insufficient to direct the peroxisomal import of chloramphenicol acetyltransferase. Substitution of the COOH-terminal KKL of human AGT by the COOH-terminal tripeptides found in the AGTs of other mammalian species (SQL, NKL), the prototypical PTS1 (SKL), or the glycosomal PTS1 (SSL) also allowed peroxisomal targeting, showing that the allowable PTS1 motif in AGT is considerably more degenerate than, or at least very different from, that acceptable in luciferase. AGT possessing the two amino acid substitutions responsible for its mistargeting in PH1 (i.e., Pro11-->Leu and Gly170-->Arg) was targeted mainly to the mitochondria. However, AGTs possessing each amino acid substitution on its own were targeted normally to the peroxisomes. This

  9. AMINOTRANSFERASE ACTIVITY IN THE LIVER OF RAINBOW TROUT (ONCORHYNCHUS MYKISS UNDER VIRAL INFECTION

    Directory of Open Access Journals (Sweden)

    L. Dragan

    2015-10-01

    Full Text Available Purpose. To study the effect of the use of indirect (express- method for the detection of infectious pancreatic necrosis virus of trout by investigating aspartate aminotransferase and alanine aminotransferase activities in fish liver, as the most sensitive enzymes for the diagnostics of many pathological conditions of human and animal organisms associated with liver diseases. Methodology. The determination of aspartate aminotransferase and alanine aminotransferase activities in trout liver was performed by Reitman-Frankel method. The functional status of liver was also evaluated using De Ritis coefficient (AST/ALT ratio, which serves as an integral index of the changes related to the degree of the damage of this organ. Findings. The determination of aspartate aminotransferase and alanine aminotransferase activities in the liver of rainbow trout (Oncorhynchus mykiss found out a considerable increase in the activity of these enzymes under the effect of the virus of infectious pancreatic necrosis. It is set that direction of aspartate aminotransferase reactions in the conditions of viral infection takes place mainly in the side of formation of keto-acids, providing the synthesis of glucose which is needed above all things for energetic supply of synthetic processes. The increase of activity of AsAT plays an important role in synchronization of energetic and nitrous exchange which is carried out at the level of mitochondrias. Increase of DeRitisa (DRr coefficient in the conditions of our experiment characteristic for viral hepatitis and can specify on activating of synthesis of glucose which is needed for support of adequate level in the conditions of viral intoxication and determines the orientation of metabolic streams toward predominance of catabolytic reactions. According to the results of the performed tests, the most informative was the test of the determination of alanine aminotransferase activity. Originality. Evaluation of the effect of

  10. 肝脏转氨酶与空腹血糖受损和2型糖尿病的关系研究%Study on the relationship between impaired fasting glucose and type 2 diabetes mellitus with serum aminotransferase activities

    Institute of Scientific and Technical Information of China (English)

    赵立芸; 李雪; 冯任南; 孔庆滨; 李颖

    2013-01-01

    目的 探讨人群中肝脏转氨酶与空腹血糖受损(impaired fasting glucose,IFG)和2型糖尿病(type 2 diabetes mellitus,T2DM)的关系.方法 通过对2 402名18 ~ 75岁成年人进行体格检查,检测血清谷丙转氨酶(alanine aminotransferase,ALT)、天门冬氨酸氨基转移酶(aspartate aminotransferase,AST)、谷氨酰转肽酶(gamma-glutamyltransferase,GGT)、血糖、血脂等血清学指标.对ALT、AST、GGT从低到高按四分位间距分组(Q1到Q4),分析3种转氨酶与IFG、T2DM之间的关系.结果 ALT、AST、GGT各自四分位分组中,Q4组与Q1组相比,空腹血糖,年龄、体质指数(body mass index,BMI)、收缩压、舒张压、总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)、低密度脂蛋白指标间差异均有统计学意义(均有P <0.05).多元Logistic回归分析表明,在校正了BMI、吸烟、饮酒、咖啡的因素之后,ALT、GGT是IFG和T2DM独立的危险因素,与Q1相比,Q4组ALT与IFG、T2DM的OR值分别为:1.74(1.30~2.34),1.47(1.09 ~2.41);Q4组GGT与IFG、T2DM的OR值分别为:3.15(2.01 ~4.45),4.08(1.88 ~7.65).结论 高水平的血清ALT、GGT与多种代谢异常密切相关,两者是IFG、T2DM患病的危险因素.%Objective To investigate the relationships between impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM) with the elevated serum aminotransferase activities. Methods The association between IFG and T2DM with serum aminotransferase activities was examined by detecting serum alanine aminotransferase (ALT) , gamma-glutamyltransferase (GGT) , and aspartate aminotransferase (AST). 2 402 adults aged from 18 to 75 were selected to conduct physical examinations and questionnaire surveys. Then the values of serum aminotransferases were divided into four groups according to interquartiles range to analyze the associations of these 3 aminotransferases with IFG and T2DM. Re-sults Compared with Q1, fasting blood glucose (FBG) , age, body mass index (BMI

  11. Clinical characteristics of elders with elevated alanine aminotransferase and its association with ultrasound diagnosis of fatty liver%丙氨酸氨基转移酶升高的老年人的临床特征与超声诊断脂肪肝的相关性

    Institute of Scientific and Technical Information of China (English)

    王健生; 徐惠明; 陈小芳; 薛骏明; 周明霞

    2012-01-01

    Objective To evaluate clinical characteristics associated withof elders with elevated alanine aminotransferase (ALT) and its association with ultrasound diagnosis of fatty liver. Methods The physical examination data of 1 054 elders were cross - sectionally analyzed from May. 2010 to Jun. 2012. There were 154 persons with elevated ALT, in which 54 cases were caused by hepatitis B and alcohol abuse. 100 subjects were included into the present study. Subjects were divided into NAFLD group (50 cases) and control group (50 cases). BMI, lipid metabolism, ALT, diabetes mellitus and so on were analyzed. Results In 100 cases of included individuals, 50% were diagnosed as NAFLD using ultrasonography. Patients with NAFLD showed higher (BMI) (P =0.013) , diabetes prevalence (P =0.019) and tri-glycerides (P =0.022) compared with individuals without NAFLD. Multivariate regression analysis showed that BMI (OR = 1.454; 95% CI: 1.139 -1.856; P= 0.003) and diabetes mellitus (OR =3. 378; 95% CI: 1.343 -8.494, P = 0.01) were independent risk factor associated with NAFLD. Conclusion Clinical features such as history of diabetes and high BMI may predict the presence of NAFLD on ultrasonography inpatients with elevated ALT but negative hepatitis.%目的 评估丙氨酸氨基转移酶(ALT)升高的老年人的临床特征与脂肪肝的相关性.方法 通过对2010年5月-2010年6月来我院行健康体检的1 054例老年体检者进行横断面研究,发现154例ALT升高,其中54例有乙型肝炎或者酒精摄入过量,最终100例入选本组研究.被分为非酒精性脂肪肝组(NAFLD)50例和对照组50例.分别进行体格检查计算体质量指数(BMI)、脂质代谢、ALT及糖尿病等调查.结果 在100例患者中,超声诊断50%有非酒精性脂肪肝,与无脂肪肝的患者相比,非酒精性脂肪肝患者有糖尿病史(P=0.019),并有较高的BMI (P=0.013)和甘油三脂(P=0.022).多变量回归分析显示BMI和糖尿病为脂肪

  12. Complete genome sequence of Enterobacter cloacae GGT036: a furfural tolerant soil bacterium.

    Science.gov (United States)

    Gong, Gyeongtaek; Um, Youngsoon; Park, Tai Hyun; Woo, Han Min

    2015-01-10

    Enterobacter cloacae is a facultative anaerobic bacterium to be an important cause of nosocomial infection. However, the isolated E. cloacae GGT036 showed higher furfural-tolerant cellular growth, compared to industrial relevant strains such as Escherichia coli and Corynebacterium glutamicum. Here, we report the complete genome sequence of E. cloacae GGT036 isolated from Mt. Gwanak, Seoul, Republic of Korea. The genomic DNA sequence of E. cloacae GGT036 will provide valuable genetic resources for engineering of industrially relevant strains being tolerant to cellular inhibitors present in lignocellulosic hydrolysates.

  13. Extreme furfural tolerance of a soil bacterium Enterobacter cloacae GGT036.

    Science.gov (United States)

    Choi, Sun Young; Gong, Gyeongtaek; Park, Hong-Sil; Um, Youngsoon; Sim, Sang Jun; Woo, Han Min

    2015-01-10

    Detoxification process of cellular inhibitors including furfural is essential for production of bio-based chemicals from lignocellulosic biomass. Here we isolated an extreme furfural-tolerant bacterium Enterobacter cloacae GGT036 from soil sample collected in Mt. Gwanak, Republic of Korea. Among isolated bacteria, only E. cloacae GGT036 showed cell growth with 35 mM furfural under aerobic culture. Compared to the maximal half inhibitory concentration (IC50) of well-known industrial strains Escherichia coli (24.9 mM furfural) and Corynebacterium glutamicum (10 mM furfural) based on the cell density, IC50 of E. cloacae GGT036 (47.7 mM) was significantly higher after 24 h, compared to E. coli and C. glutamicum. Since bacterial cell growth was exponentially inhibited depending on linearly increased furfural concentrations in the medium, we concluded that E. cloacae GGT036 is an extreme furfural-tolerant bacterium. Recently, the complete genome sequence of E. cloacae GGT036 was announced and this could provide an insight for engineering of E. cloacae GGT036 itself or other industrially relevant bacteria.

  14. DETERMINAÇÃO DOS VALORES MÉDIOS DAS ENZIMAS AST, DHL, gGT E FAS NO SORO DE EQUINOS SADIOS EM SANTA MARIA, RS

    Directory of Open Access Journals (Sweden)

    Sônia Terezinha dos Anjos Lopes

    1993-12-01

    Full Text Available Foram usados 50 eqüinos sadios provenientes do Batalhão de Polícia Montada da Brigada Militar em Santa Maria, RS, sendo 43 machos e 7 fêmeas com idade variadas a partir de 3 anos. Foram colhidos 10ml de sangue da jugular para determinação dos valores da atividade sérica das enzimas aspartato-aminotransferase (AST, desidrogenase lática (DHL, gama-glutamiltransferase (gGT e fosfatase alcalina sérica (FAS. Os resultados encontrados para AST foi de 101 - 190U/I com média de 130UI; DHL foi de 100 - 421 U/l com média de 182U/I; gGT foi de 2 - 27U/I com média de 6.5U/I e FAS foi de 103 - 335U/I com média de 190U/I. A partir de outubro/1992 estes valores passaram a ser referência no laboratório de Patologia Clínica do Hospital de Clinicas Veterinárias da Universidade Federal de Santa Maria.

  15. Prospective association of liver function biomarkers with development of hepatobiliary cancers

    NARCIS (Netherlands)

    Stepien, Magdalena; Fedirko, Veronika; Duarte-Salles, Talita; Ferrari, Pietro; Freisling, Heinz; Trepo, Elisabeth; Trichopoulou, Antonia; Bamia, Christina; Weiderpass, Elisabete; Olsen, Anja; Tjønneland, Anne; Overvad, Kim; Boutron-Ruault, Marie Christine; Fagherazzi, Guy; Racine, Antoine; Kühn, Tilman; Kaaks, Rudolf; Aleksandrova, Krasimira; Boeing, Heiner; Lagiou, Pagona; Benetou, Vassiliki; Trichopoulos, Dimitrios; Palli, Domenico; Grioni, Sara; Tumino, Rosario; Naccarati, Alessio; Panico, Salvatore; Bueno-de-Mesquita, H. Bas; Peeters, Petra H.; Lund, Eiliv; Quirós, J. Ramón; Nápoles, Osmel Companioni; Sánchez, María José; Dorronsoro, Miren; Huerta, José María; Ardanaz, Eva; Ohlsson, Bodil; Sjöberg, Klas; Werner, Mårten; Nystrom, Hanna; Khaw, Kay Tee; Key, Timothy J.; Gunter, Marc; Cross, Amanda; Riboli, Elio; Romieu, Isabelle; Jenab, Mazda

    2016-01-01

    Introduction: Serum liver biomarkers (gamma-glutamyl transferase, GGT; alanine aminotransferase, ALT; aspartate aminotransferase, AST; alkaline phosphatase, ALP; total bilirubin) are used as indicators of liver disease, but there is currently little data on their prospective association with risk of

  16. 4073对夫妻孕前优生健康检查传染病感染指标及丙氨酸氨基转移酶检测结果分析%Analysis of Detection Results of Communicable Disease Infectious Indicators and Alanine Aminotransferase of 4 073 Couples After Pre-pregnancy Eugenics Health Examination

    Institute of Scientific and Technical Information of China (English)

    赵庆伟; 马书军; 张凌薇; 刘云

    2016-01-01

    Objective To understand the infectious situation of hepatitis B virus( HBV),treponema pallidum (TP),human immunodeficiency virus( HIV)and abnormal rate of alanine aminotransferase( ALT)of the pre - pregnancy couples,so as to take effective measures to prevent the mutual diffusion between couples and the vertical transmission from mother to child and ensure their health. Methods 4 073 couples,who met the inclusion criteria and had taken the pre - pregnancy physical examination in Hebei Women and Children's Health Center from 2012 to 2014,were selected as the research objects retrospectively. The detection results of HBV,TP,HIV,and ALT were collected and analyzed. Results Among 4 073 coupes,the positive rate of hepatitis B virus surface antigen(HBsAg)was 3. 44% (280 / 8 146),the positive rate of TP rapid plasma reagin(RPR)and TP particle agglutination(TPPA)test was 0. 34% (28 / 8 146),the positive rate of anti - HIV1 / 2 was 0, and the abnormal rate of ALT was 4. 82% (393 / 8 146). The positive - HBsAg rate and the ALT abnormal rate of male were higher than those of the female(P ﹤ 0. 05). Among 168 males with positive - HBsAg,115 were all positive HBsAg,hepatitis B virus e antibody(HBeAb)and hepatitis B virus core antibody(HBcAb),23 all positive HBsAg,hepatitis B virus e antigen (HBeAg)and HBcAb,and 30 with other conditions;among the spouses of 115 males,34 were all negative HBsAg,hepatitis B virus surface antibody( HBsAb),HBeAg、HBeAb、HBcAb. Among the 112 females with positive - HBsAg,75 were all positive HBsAg,HBeAb and HBcAb,16 all positive HBsAg,HBeAg,and HBcAb,21 with other conditions;among the spouses of 112 females,13 were all negative HBsAg,HBsAb,HBeAg,HBeAb,and HBcAb. Among 28 participants with RPR and TPPA of positive attributes,9 couples were all positive RPR and TPPA. Among 236 males with abnormal ALT,14 were all positive HBsAg,HBeAg and HBcAb;among 157 females with abnormal ALT,7 were all positive HBsAg,HBeAg and HBcAb. The positive rate of HBsAg in

  17. The Use of Postoperative Serum HS-AFP and GGT Ⅱ for Judgment of the Prognosis for Hepatocellular Carcinoma patients

    Institute of Scientific and Technical Information of China (English)

    Runzhou Ni; Lei Yang; Mingbing Xiao; Feng Li; Cuihua Lu

    2006-01-01

    OBJECTIVE To investigate the clinical value of hepatoma-specific alpha-fetoprotein (HS-AFP) and gamma-glutamyltransferase Ⅱ (GGT Ⅱ) for judgment of postoperative prognosis of patients with hepatocellular carcinoma (HCC).METHODS HS-AFP was separated and determined using native polyacrylamide electrophoresis with a discontinuous buffer system and Western blots. GGT Ⅱ was separated with native polyacrylamide electrophoresis with a discontinuous buffer system and detected by enzyme staining. Forty cases with HCC underwent serial determination of HS-AFP and GGT Ⅱ before and after radical excision. The correlations were analyzed between the two indices and survival time.RESULTS In the 40 cases with HCC, before radical excision the positive rates of HS-AFP and GGT Ⅱ were 57.5% and 67.5% respectively, with the positive rate of combined HS-AFP and GGT Ⅱ reaching 80.0%. After operation, the recurrence and metastasis rate in the groups with positive HS-AFP and GGT Ⅱ were 90.9% and 58.8% respectively, while in the groups with negative HS-AFP and GGT Ⅱ the rates were 20.7% and 26.1% respectively. Recurrence and metastasis occurred in all cases with both postoperative positive HS-AFP and GGT Ⅱ but only in 9.5% of the cases in whom both postoperative HS-AFP and GGT Ⅱ were negative. Univariate analysis revealed that postoperative HS-AFP and GGT Ⅱ were related to the prognosis in HCC.CONCLUSION Postoperative serum HS-AFP and GGT Ⅱ are very useful in predicting the prognosis of HCC patients.

  18. Effect of Eight Weeks Forced Swimming Training with Methadone Supplementation on Aspartate Aminotransferase, Alanine Aminotransferase, and Alkaline Phosphatase of Rats

    Directory of Open Access Journals (Sweden)

    Seyed Ali Hoseini

    2016-12-01

    Full Text Available Background & Objective: Narcotics abuse can induce liver disorders; nevertheless, exercises improve liver disorders. The present research aimed to review the effect of eight weeks forced swimming training with methadone supplementation on liver enzymes of rats. Material & Method: In this experimental research, 48 rats were selected, and after one week adaptation to lab environment, they were randomly divided into four groups of 12 rats including (1 forced swimming training, (2 methadone supplementation, (3 forced swimming training with methadone supplementation, and (4 control. Groups 2 and 3 used 2 mg/kg methadone daily for 8 weeks. Also, groups 1 and 3 swam for 8 weeks, three sessions per week and each session for 30 minutes. For statistical analysis of data, one way ANOVA and Tukey post hoc tests were used (α≤0.05. Results: Findings showed that forced swimming training, methadone supplementation, and forced swimming training with methadone supplementation had no significant effect on AST (P=0.90 and ALT (P=0.99 enzymes; forced swimming training had significant effect on increase of ALP (P=0.001; also, forced swimming training, compared with methadone supplementation and combination of forced swimming training with methadone supplementation, had significant effect on increase of ALP (P=0.001. Conclusion: Accordingly, 8 weeks of forced swimming training with methadone has possibly no significant effect on liver enzymes.

  19. STUDY OF SERUM AMINOTRANSFERASE LEVELS IN DENGUE FEVER

    Directory of Open Access Journals (Sweden)

    Jnaneshwari

    2014-03-01

    aspartate aminotransferase was significantly raised compared to alanine aminotransferase levels in all forms of dengue infection. The degree of affection of serum albumin and prothrombin time which are absolute indicators of liver cell function correlated with severity of dengue infection.

  20. Role of aminotransferases in glutamate metabolism of human erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ellinger, James J. [University of Wisconsin-Madison, Department of Biochemistry (United States); Lewis, Ian A. [Princeton University, Lewis-Sigler Institute for Integrative Genomics (United States); Markley, John L., E-mail: markley@nmrfam.wisc.edu [University of Wisconsin-Madison, Department of Biochemistry (United States)

    2011-04-15

    Human erythrocytes require a continual supply of glutamate to support glutathione synthesis, but are unable to transport this amino acid across their cell membrane. Consequently, erythrocytes rely on de novo glutamate biosynthesis from {alpha}-ketoglutarate and glutamine to maintain intracellular levels of glutamate. Erythrocytic glutamate biosynthesis is catalyzed by three enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glutamine aminohydrolase (GA). Although the presence of these enzymes in RBCs has been well documented, the relative contributions of each pathway have not been established. Understanding the relative contributions of each biosynthetic pathway is critical for designing effective therapies for sickle cell disease, hemolytic anemia, pulmonary hypertension, and other glutathione-related disorders. In this study, we use multidimensional {sup 1}H-{sup 13}C nuclear magnetic resonance (NMR) spectroscopy and multiple reaction mode mass spectrometry (MRM-MS) to measure the kinetics of de novo glutamate biosynthesis via AST, ALT, and GA in intact cells and RBC lysates. We show that up to 89% of the erythrocyte glutamate pool can be derived from ALT and that ALT-derived glutamate is subsequently used for glutathione synthesis.

  1. Relationship Between Serum Aminotransferase Levels and Metabolic Disorders in Northern China

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    Jq Niu

    2012-02-01

    Full Text Available Background: Increasing evidence suggests an association between ele­vated serum aminotransferase levels and metabolic disorders (metabolic syndrome, hyperlipemia and diabetes mellitus. However, the significance of relatively low levels of aminotransferases in relation to metabolic disorders has not been fully investigated in the general population. We inves­tigated the association between serum amiontransferase levels and metabolic disorders using data from a survey in Jilin province, China.Methods: In 2007, a survey was conducted throughout Jilin, China, covering both urban and rural areas. A total of 3835 people, 18 to 79 years old including 1761 men and 2074 women, underwent real-time ultrasonography, blood tests including aspartate aminotransferase and alanine aminotransferase, and had interviews with a structured questionnaire.Results: Serum aminotransferase levels within the normal range were asso­ciated with metabolic syndrome independent of age, occupation, cultural and educational level, income, body mass index, waist circumference, smoking, and alcohol intake. Compared with the lowest level (50 IU/L were 1.92, 2.50, 2.97, and 3.52 in men, and 1.38 , 1.54, 3.06, and 2.62 in women, respectively. Near-normal serum aminotransferase levels asso­ciated with hyperlipemia, NAFLD, DM were also found in the study.Conclusions: Normal to near-normal serum aminotransferase levels are associated with metabolic disorders. Serum ALT levels of 21-25 IU/L for men, and 17-22 IU/L for women are suggested as cutoff levels that detect metabolic disorders affecting the liver.

  2. Properties of serine: glyoxylate aminotransferase purified from Arabidopsis thaliana leaves

    Institute of Scientific and Technical Information of China (English)

    Maria Kendziorek; Andrzej Paszkowski

    2008-01-01

    The photorespiratory enzyme L-serine: glyoxylate aminotransferase (SGAT; EC 2.6.1.45) was purified from Arabidopsis thaliana leaves. The final enzyme was approximately 80% pure as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with silver staining. The identity of the enzyme was confirmed by LC/MS/MS analysis.The molecular mass estimated by gel filtration chromatography on Sephadex G-150 under non-denaturing conditions, mass spectrometry (matrix-assisted laser desorption/ionization/time of flight technique) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 82.4 kDa,42.0 kDa, and 39.8 kDa, respectively, indicating dimer as the active form. The optimum Ph value was 9.2. The enzyme activity was inhibited by aminooxyacetate and β-chloro-L-alanine both compounds reacting with the carbonyl group of pyridoxal phosphate. The enzyme's transaminating activity with L-alanine and glyoxylate as substrates was approximately 55% of that observed with L-serine and glyoxylate, The lower Km value (1.25 Mm) for L-alanine, compared with that of other plant SGATs, and the kcat/Km(Ala) ratio being approximately 2-fold higher than kcat/Km(Ser) suggested that, during photorespiration, Ala and Ser are used by Arabidopsis SGAT with equal efficiency as amino group donors for glyoxylate. The equilibrium constant (Keq), derived from the Haldane relation, for the transamination reaction between L-serine and glyoxylate with the formation of hydroxypyruvate and glycine was 79.1, strongly favoring glycine synthesis. However, it was accompanied by a low Km value of 2.83 Mm for glycine. A comparison of some kinetic properties of the studied enzymes with the recombinant Arabidopsis SGATs previously obtained revealed substantial differences. The ratio of the velocity of the transamination reaction with L-alanine and glyoxylate as substrates versus that with L-serine and glyoxylate was 1:1.8 for the native enzyme, whereas it was 1: 7 for the recombinant SGAT

  3. Pathomechanism of Insulin Resistance in Men with Central Obesity: Correlation of GGT, GPx, hs-CRP and Plasma Total Cysteine

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    Ritawaty Ritawaty

    2013-08-01

    Full Text Available BACKGROUND: Gamma glutamyltransferase (GGT was reported recently to be associated with inflammation, oxidative stress and increased amino acid. However, role of GGT in insulin resistance pathomechanism is not exactly known. Therefore correlation of GGT with inflammation, oxidative stress and elevated amino acid, in men with central obesity need to be confirmed. METHODS: A cross-sectional study was designed. Men with central obesity were recruited and selected. Anthropometric parameters, creatinine, hs-CRP, fasting glucose, fasting insulin, glutathione peroxidase (GPx activity, GGT, plasma total cysteine (tCys and fatty liver were measured. Subjects were then divided in 4 groups based on waist circumference (WC and fatty liver: Group I: WC ≤100 cm, without fatty liver; Group II: WC ≤100 cm, with fatty liver; Group III: WC >100 cm, without fatty liver; Group IV: WC >100 cm, with fatty liver. All biochemical characteristics in each group were then statistically analyzed. RESULTS: Seventy-two men with central obesity were selected. Numbers of subjects in each group were: Group I: n=33; Group II: n=5; Group III: n=17; Group IV: n=17. We found significant difference of HOMA-IR between Group I and IV, significant correlation between GGT and HOMAIR, and significant negative correlation between tCys with HOMA-IR in Group IV. CONCLUSIONS: GGT was significantly correlated with HOMA-IR in men with WC >100 cm and fatty liver. Further investigation with more subjects is necessary to determine clear GGT cut-off to distinguish subjects with fatty liver and insulin resistance. KEYWORDS: GGT, hs-CRP, GPx, tCys, HOMA-IR, insulin resistance.

  4. Research of using GGT-Ⅱ for the PHC of the AFP decteeted to be negative%GGT-Ⅱ快速法检测AFP阴性肝癌的探讨

    Institute of Scientific and Technical Information of China (English)

    郭小林

    2003-01-01

    目的:鉴于GGT-Ⅱ对检测AFP表达为阴性的原发性肝癌有较高的诊断率,试图将GGT-Ⅱ和AFP联合应用以期提高AFP阴性肝癌的诊断率.方法:GGT-Ⅱ检测采用快速微量定性法;AFP检测采用酶标参比电泳法和双抗体夹心法.结果:GGT-Ⅱ特异性(阴性率)为92.21%;准确性为90.25%;敏感性(阳性率)为88.94%.AFP阳性率为71.07%.结论:单用AFP检测势必造成AFP表达为阴性的原发性肝癌的漏检(并非AFP检测方法的错误),采用GGT Ⅱ法联合应用,可明显提高这部分病例的检出率.

  5. Structural studies of Pseudomonas and Chromobacterium ω-aminotransferases provide insights into their differing substrate specificity

    Energy Technology Data Exchange (ETDEWEB)

    Sayer, Christopher; Isupov, Michail N.; Westlake, Aaron; Littlechild, Jennifer A., E-mail: j.a.littlechild@exeter.ac.uk [University of Exeter, Stocker Road, Exeter EX4 4QD (United Kingdom)

    2013-04-01

    The X-ray structures of two ω-aminotransferases from P. aeruginosa and C. violaceum in complex with an inhibitor offer the first detailed insight into the structural basis of the substrate specificity of these industrially important enzymes. The crystal structures and inhibitor complexes of two industrially important ω-aminotransferase enzymes from Pseudomonas aeruginosa and Chromobacterium violaceum have been determined in order to understand the differences in their substrate specificity. The two enzymes share 30% sequence identity and use the same amino acceptor, pyruvate; however, the Pseudomonas enzyme shows activity towards the amino donor β-alanine, whilst the Chromobacterium enzyme does not. Both enzymes show activity towards S-α-methylbenzylamine (MBA), with the Chromobacterium enzyme having a broader substrate range. The crystal structure of the P. aeruginosa enzyme has been solved in the holo form and with the inhibitor gabaculine bound. The C. violaceum enzyme has been solved in the apo and holo forms and with gabaculine bound. The structures of the holo forms of both enzymes are quite similar. There is little conformational difference observed between the inhibitor complex and the holoenzyme for the P. aeruginosa aminotransferase. In comparison, the crystal structure of the C. violaceum gabaculine complex shows significant structural rearrangements from the structures of both the apo and holo forms of the enzyme. It appears that the different rigidity of the protein scaffold contributes to the substrate specificity observed for the two ω-aminotransferases.

  6. Gender difference of alanine aminotransferase elevation may be associated with higher hemoglobin levels among male adolescents.

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    Solomon Chih-Cheng Chen

    Full Text Available BACKGROUND: To explore the gender difference of ALT elevation and its association with high hemoglobin levels. METHODS: A cross-sectional study of 3547 adolescents (2005 females, mean age of 16.5?.3 years who were negative for hepatitis B surface antigen received health checkups in 2006. Body mass index (BMI, levels of hemoglobin, ALT and cholesterol were measured. ALT >42 U/L was defined as elevated ALT. Elevated ALT levels were detected in 112 of the 3547 participants (3.3%, more prevalent in males than in females (5.4% vs. 1.4%, p11 g/dl in females or >13.5 g/dl in males, but the cumulative cases of elevated ALT increased more quickly in males. Proportion of elevated ALT increased as either the BMI or hemoglobin level rise, more apparent in male adolescents. Logistic regression modeling showed odds ratio (95% confidence interval were 24.7 (15.0-40.6 for BMI ≥27 kg/m(2; 5.5 (2.9-10.4 for BMI 24-27 kg/m(2; 2.7 (1.3-5.5 for Q5 (top 20th percentile hemoglobin level; and 2.6 (1.6-4.1 for male gender. Further separately fitting the logistic models for two genders, the significance of Q5 hemoglobin level only appeared in the males. CONCLUSIONS: High hemoglobin level is a significant risk factor of ALT elevation after control hepatitis B, obesity and gender. Males have greater risk of abnormal liver function which may be associated with higher hemoglobin levels.

  7. Effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of white pekin ducks.

    Science.gov (United States)

    Xie, Ming; Tang, Jing; Wen, Zhiguo; Huang, Wei; Hou, Shuisheng

    2014-12-01

    A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin B6-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (ppyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin B6 status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (ppyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine.

  8. Brain alanine formation as an ammonia-scavenging pathway during hyperammonemia

    DEFF Research Database (Denmark)

    Dadsetan, Sherry; Kukolj, Eva; Bak, Lasse Kristoffer

    2013-01-01

    (MSO) enhances incorporation of (15)NH4(+) in alanine during acute hyperammonemia. We observed a fourfold increased amount of (15)NH4 incorporation in brain alanine in rats treated with MSO. Furthermore, co-cultures of neurons and astrocytes exposed to (15)NH4Cl in the absence or presence of MSO......Hyperammonemia is a major etiological toxic factor in the development of hepatic encephalopathy. Brain ammonia detoxification occurs primarily in astrocytes by glutamine synthetase (GS), and it has been proposed that elevated glutamine levels during hyperammonemia lead to astrocyte swelling...... and cerebral edema. However, ammonia may also be detoxified by the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT) leading to trapping of ammonia in alanine, which in vivo likely leaves the brain. Our aim was to investigate whether the GS inhibitor methionine sulfoximine...

  9. Weaning Induced Hepatic Oxidative Stress, Apoptosis, and Aminotransferases through MAPK Signaling Pathways in Piglets

    Science.gov (United States)

    Luo, Zhen; Zhu, Wei; Guo, Qi; Luo, Wenli; Zhang, Jing; Xu, Weina

    2016-01-01

    This study investigated the effects of weaning on the hepatic redox status, apoptosis, function, and the mitogen-activated protein kinase (MAPK) signaling pathways during the first week after weaning in piglets. A total of 12 litters of piglets were weaned at d 21 and divided into the weaning group (WG) and the control group (CG). Six piglets from each group were slaughtered at d 0 (d 20, referred to weaning), d 1, d 4, and d 7 after weaning. Results showed that weaning significantly increased the concentrations of hepatic free radicals H2O2 and NO, malondialdehyde (MDA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG), while significantly decreasing the inhibitory hydroxyl ability (IHA) and glutathione peroxidase (GSH-Px), and altered the level of superoxide dismutase (SOD). The apoptosis results showed that weaning increased the concentrations of caspase-3, caspase-8, caspase-9 and the ratio of Bax/Bcl-2. In addition, aspartate aminotransferase transaminase (AST) and alanine aminotransferase (ALT) in liver homogenates increased after weaning. The phosphorylated JNK and ERK1/2 increased, while the activated p38 initially decreased and then increased. Our results suggested that weaning increased the hepatic oxidative stress and aminotransferases and initiated apoptosis, which may be related to the activated MAPK pathways in postweaning piglets.

  10. Value of two noninvasive methods to detect progression of fibrosis among HCV carriers with normal aminotransferases.

    Science.gov (United States)

    Colletta, Cosimo; Smirne, Carlo; Fabris, Carlo; Toniutto, Pierluigi; Rapetti, Rachele; Minisini, Rosalba; Pirisi, Mario

    2005-10-01

    The course of hepatitis C virus (HCV) infection carriers with normal/near-normal aminotransferases (NALT) is usually mild; however, in a few, fibrosis progression occurs. We aimed to verify whether monitoring by liver biopsy might be replaced by noninvasive methods and to identify factors associated with fibrosis progression in patients with persistently normal alanine aminotransferases. We studied 40 untreated HCV-RNA-positive subjects (22 male; median age, 44 years), who underwent two liver biopsies, with a median interval of 78.5 months, during which alanine aminotransferase concentrations (median number of determinations: 12) never exceeded 1.2 times the upper normal limit. Within 9 months from the second biopsy, they were tested by the shear elasticity probe (Fibroscan) and the artificial intelligence algorithm FibroTest. METAVIR fibrosis scores were analyzed in relationship to demographic, clinical, and viral parameters. Weighted kappa analysis was used to verify whether the results of noninvasive methods agreed with histology. Significant fibrosis (> or = F2), present at the first biopsy in only one patient (2.5%), was observed at the second biopsy in 14 patients (35%). At multivariate analysis, excess alcohol consumption in the past (>20 g/d; P = .017) and viral load (>8.0 x 10(6) copies/mL; P = .021) were independent predictors of progression. In identifying patients with significant fibrosis, inter-rater agreement was excellent for Fibroscan (weighted kappa = 1.0), and poor for FibroTest (weighted kappa = -0.041). In conclusion, among HCV carriers with NALT, Fibroscan is superior to the FibroTest in the noninvasive identification of fibrosis, for which excess alcohol consumption in the past and high viral load represent risk factors.

  11. 血清AFP、CEA、AFU和GGT-Ⅱ联检对早期PLC诊断的临床价值

    Institute of Scientific and Technical Information of China (English)

    郑盛; 王玉波; 刘海; 尹静; 朱为梅; 肖琼怡; 王建刚; 郭致平

    2010-01-01

    @@ 本文对85例原发性肝癌(Pximary liver cancer,PLC)患者进行AFP、CEA、α-L-岩藻糖苷酶(alpha-L-fucosidase,AFU)、γ-谷氨酰转肽酶同工酶Ⅱ(gammma-glutamyl transferase isoenzymes,GGT-Ⅱ)等四项肿瘤标志物联检,以探讨其在PLC早期诊断中的应用价值.

  12. Effect of Orthodontic Tooth Movement on Salivary Aspartate Aminotransferase Activity

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    Steiven Adhitya

    2013-07-01

    Full Text Available 72 1024x768 Aspartate aminotransferase is one of biological indicator in gingival crevicular fluid (CGF. Force orthodontic application could increase activity of aspartate aminotransferase in CGF. However, the increase activity of aspartate aminotransferase in saliva due to orthodontic force and its correlation between aspartate aminotransferase activity and tooth movement remains unclear. Objectives: To evaluate application orthodontic force on the aspartate aminotransferase activity in saliva based on the duration of force and finding correlation between tooth movement and aspartate aminotransferase activity. Methods: Twenty saliva samples collected before extraction of first premolar, at the time of force application for canine retraction and after force application. The canines retraction used 100 grams of interrupted force (module chain for thirty days. The collection of saliva and the measurement of tooth movement were carried out 1 day, 7 days, 14 days, 21 days, and 28 days after force application. The measurement of aspartate aminotransferase activity in saliva was done using spectrophotometer. Results: Application of orthodontic force influences the salivary aspartate aminotransferase activity (F=25.290, p=0.000. Furthermore, tooth movement correlated with aspartate aminotransferase activity (F=0.429, p=0.000. Conclusion: Aspartate aminotransferase activity could be used as tooth movement indicator that related to the duration of force application.DOI : 10.14693/jdi.v20i1.128

  13. Clinical relevance and discriminatory value of elevated liver aminotransferase levels for dengue severity.

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    Linda K Lee

    Full Text Available BACKGROUND: Elevation of aspartate aminotransferase (AST and alanine aminotransferase (ALT is prominent in acute dengue illness. The World Health Organization (WHO 2009 dengue guidelines defined AST or ALT ≥ 1000 units/liter (U/L as a criterion for severe dengue. We aimed to assess the clinical relevance and discriminatory value of AST or ALT for dengue hemorrhagic fever (DHF and severe dengue. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively studied and classified polymerase chain reaction positive dengue patients from 2006 to 2008 treated at Tan Tock Seng Hospital, Singapore according to WHO 1997 and 2009 criteria for dengue severity. Of 690 dengue patients, 31% had DHF and 24% severe dengue. Elevated AST and ALT occurred in 86% and 46%, respectively. Seven had AST or ALT ≥ 1000 U/L. None had acute liver failure but one patient died. Median AST and ALT values were significantly higher with increasing dengue severity by both WHO 1997 and 2009 criteria. However, they were poorly discriminatory between non-severe and severe dengue (e.g., AST area under the receiver operating characteristic [ROC] curve=0.62; 95% confidence interval [CI]: 0.57-0.67 and between dengue fever (DF and DHF (AST area under the ROC curve=0.56; 95% CI: 0.52-0.61. There was significant overlap in AST and ALT values among patients with dengue with or without warning signs and severe dengue, and between those with DF and DHF. CONCLUSIONS: Although aminotransferase levels increased in conjunction with dengue severity, AST or ALT values did not discriminate between DF and DHF or non-severe and severe dengue.

  14. Functional analysis of all aminotransferase proteins inferred from the genome sequence of Corynebacterium glutamicum.

    Science.gov (United States)

    Marienhagen, Jan; Kennerknecht, Nicole; Sahm, Hermann; Eggeling, Lothar

    2005-11-01

    Twenty putative aminotransferase (AT) proteins of Corynebacterium glutamicum, or rather pyridoxal-5'-phosphate (PLP)-dependent enzymes, were isolated and assayed among others with L-glutamate, L-aspartate, and L-alanine as amino donors and a number of 2-oxo-acids as amino acceptors. One outstanding AT identified is AlaT, which has a broad amino donor specificity utilizing (in the order of preference) L-glutamate > 2-aminobutyrate > L-aspartate with pyruvate as acceptor. Another AT is AvtA, which utilizes L-alanine to aminate 2-oxo-isovalerate, the L-valine precursor, and 2-oxo-butyrate. A second AT active with the L-valine precursor and that of the other two branched-chain amino acids, too, is IlvE, and both enzyme activities overlap partially in vivo, as demonstrated by the analysis of deletion mutants. Also identified was AroT, the aromatic AT, and this and IlvE were shown to have comparable activities with phenylpyruvate, thus demonstrating the relevance of both ATs for L-phenylalanine synthesis. We also assessed the activity of two PLP-containing cysteine desulfurases, supplying a persulfide intermediate. One of them is SufS, which assists in the sulfur transfer pathway for the Fe-S cluster assembly. Together with the identification of further ATs and the additional analysis of deletion mutants, this results in an overview of the ATs within an organism that may not have been achieved thus far.

  15. Níveis séricos de aminotransferases, bilirrubinas e gama-glutamil transpeptidase após a admininstração de óleo de copaíba em ratos

    Directory of Open Access Journals (Sweden)

    Noguchi Aki

    2002-01-01

    Full Text Available O óleo de copaíba é um óleo-resina empregado como fitoterápico na região Amazônica. Sua utilização se faz de forma empírica e pouco se conhece à respeito de seus efeitos sobre os sistemas orgânicos. Objetivo: Verificar os níveis séricos de aminotransferases, bilirrubinas e gama-glutamil transpeptidase após a administração do óleo. Métodos: Foram utilizados 20 ratos Wistar, machos, pesando entre 250 e 300g, distribuídos em 2 grupos: Grupo Cop (n=10 submetidos diariamente à gavagem com administração de 0,63ml/kg do óleo, por 5 dias; Grupo P (n=10, animais nos quais nenhuma substância foi administrada. Ao sexto dia, em ambos os grupos, procedeu-se anestesia inalatória e obtenção de 3ml de sangue da VCI para dosagem dos níveis séricos de ALT, AST, bilirrubinas e GGT. Resultados: Os resultados obtidos com o GCop foram comparados com os do GP e analisados estatisticamente pelo teste t -Student. O GCop apresentou níveis de ALT, AST e GGT significantemente mais baixos que o GP (p<0,01, enquanto os níveis de BT elevaram-se às custas da fração direta. Conclusão: O óleo de copaíba altera os níveis das aminotransferases, bilirrubinas e GGT, sem alterar os níveis da fração indireta.

  16. Kynurenine Aminotransferase Isozyme Inhibitors: A Review

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    Alireza Nematollahi

    2016-06-01

    Full Text Available Kynurenine aminotransferase isozymes (KATs 1–4 are members of the pyridoxal-5’-phosphate (PLP-dependent enzyme family, which catalyse the permanent conversion of l-kynurenine (l-KYN to kynurenic acid (KYNA, a known neuroactive agent. As KATs are found in the mammalian brain and have key roles in the kynurenine pathway, involved in different categories of central nervous system (CNS diseases, the KATs are prominent targets in the quest to treat neurodegenerative and cognitive impairment disorders. Recent studies suggest that inhibiting these enzymes would produce effects beneficial to patients with these conditions, as abnormally high levels of KYNA are observed. KAT-1 and KAT-3 share the highest sequence similarity of the isozymes in this family, and their active site pockets are also similar. Importantly, KAT-2 has the major role of kynurenic acid production (70% in the human brain, and it is considered therefore that suitable inhibition of this isozyme would be most effective in managing major aspects of CNS diseases. Human KAT-2 inhibitors have been developed, but the most potent of them, chosen for further investigations, did not proceed in clinical studies due to the cross toxicity caused by their irreversible interaction with PLP, the required cofactor of the KAT isozymes, and any other PLP-dependent enzymes. As a consequence of the possibility of extensive undesirable adverse effects, it is also important to pursue KAT inhibitors that reversibly inhibit KATs and to include a strategy that seeks compounds likely to achieve substantial interaction with regions of the active site other than the PLP. The main purpose of this treatise is to review the recent developments with the inhibitors of KAT isozymes. This treatise also includes analyses of their crystallographic structures in complex with this enzyme family, which provides further insight for researchers in this and related studies.

  17. Biochemical and structural characterization of mouse mitochondrial aspartate aminotransferase, a newly identified kynurenine aminotransferase-IV

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Robinson, H.; Cai, T.; Tagle, D. A.; Li, J.

    2011-10-01

    Mammalian mAspAT (mitochondrial aspartate aminotransferase) is recently reported to have KAT (kynurenine aminotransferase) activity and plays a role in the biosynthesis of KYNA (kynurenic acid) in rat, mouse and human brains. This study concerns the biochemical and structural characterization of mouse mAspAT. In this study, mouse mAspAT cDNA was amplified from mouse brain first stand cDNA and its recombinant protein was expressed in an Escherichia coli expression system. Sixteen oxo acids were tested for the co-substrate specificity of mouse mAspAT and 14 of them were shown to be capable of serving as co-substrates for the enzyme. Structural analysis of mAspAT by macromolecular crystallography revealed that the cofactor-binding residues of mAspAT are similar to those of other KATs. The substrate-binding residues of mAspAT are slightly different from those of other KATs. Our results provide a biochemical and structural basis towards understanding the overall physiological role of mAspAT in vivo and insight into controlling the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  18. Substrate specificity and structure of human aminoadipate aminotransferase/kynurenine aminotransferase II.

    Science.gov (United States)

    Han, Qian; Cai, Tao; Tagle, Danilo A; Robinson, Howard; Li, Jianyong

    2008-08-01

    KAT (kynurenine aminotransferase) II is a primary enzyme in the brain for catalysing the transamination of kynurenine to KYNA (kynurenic acid). KYNA is the only known endogenous antagonist of the N-methyl-D-aspartate receptor. The enzyme also catalyses the transamination of aminoadipate to alpha-oxoadipate; therefore it was initially named AADAT (aminoadipate aminotransferase). As an endotoxin, aminoadipate influences various elements of glutamatergic neurotransmission and kills primary astrocytes in the brain. A number of studies dealing with the biochemical and functional characteristics of this enzyme exist in the literature, but a systematic assessment of KAT II addressing its substrate profile and kinetic properties has not been performed. The present study examines the biochemical and structural characterization of a human KAT II/AADAT. Substrate screening of human KAT II revealed that the enzyme has a very broad substrate specificity, is capable of catalysing the transamination of 16 out of 24 tested amino acids and could utilize all 16 tested alpha-oxo acids as amino-group acceptors. Kinetic analysis of human KAT II demonstrated its catalytic efficiency for individual amino-group donors and acceptors, providing information as to its preferred substrate affinity. Structural analysis of the human KAT II complex with alpha-oxoglutaric acid revealed a conformational change of an N-terminal fraction, residues 15-33, that is able to adapt to different substrate sizes, which provides a structural basis for its broad substrate specificity.

  19. Biochemical and structural characterization of mouse mitochondrial aspartate aminotransferase, a newly identified kynurenine aminotransferase-IV.

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Cai, Tao; Tagle, Danilo A; Li, Jianyong

    2011-10-01

    Mammalian mAspAT (mitochondrial aspartate aminotransferase) is recently reported to have KAT (kynurenine aminotransferase) activity and plays a role in the biosynthesis of KYNA (kynurenic acid) in rat, mouse and human brains. This study concerns the biochemical and structural characterization of mouse mAspAT. In this study, mouse mAspAT cDNA was amplified from mouse brain first stand cDNA and its recombinant protein was expressed in an Escherichia coli expression system. Sixteen oxo acids were tested for the co-substrate specificity of mouse mAspAT and 14 of them were shown to be capable of serving as co-substrates for the enzyme. Structural analysis of mAspAT by macromolecular crystallography revealed that the cofactor-binding residues of mAspAT are similar to those of other KATs. The substrate-binding residues of mAspAT are slightly different from those of other KATs. Our results provide a biochemical and structural basis towards understanding the overall physiological role of mAspAT in vivo and insight into controlling the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  20. Substrate Specificity and Structure of Human Aminoadipate Aminotransferase/kynurenine Aminotransferase II

    Energy Technology Data Exchange (ETDEWEB)

    Han,Q.; Cai, T.; Tagle, D.; Robinson, H.; Li, J.

    2008-01-01

    KAT (kynurenine aminotransferase) II is a primary enzyme in the brain for catalysing the transamination of kynurenine to KYNA (kynurenic acid). KYNA is the only known endogenous antagonist of the N-methyl-D-aspartate receptor. The enzyme also catalyses the transamination of aminoadipate to a-oxoadipate; therefore it was initially named AADAT (aminoadipate aminotransferase). As an endotoxin, aminoadipate influences various elements of glutamatergic neurotransmission and kills primary astrocytes in the brain. A number of studies dealing with the biochemical and functional characteristics of this enzyme exist in the literature, but a systematic assessment of KAT II addressing its substrate profile and kinetic properties has not been performed. The present study examines the biochemical and structural characterization of a human KAT II/AADAT. Substrate screening of human KAT II revealed that the enzyme has a very broad substrate specificity, is capable of catalysing the transamination of 16 out of 24 tested amino acids and could utilize all 16 tested a-oxo acids as amino-group acceptors. Kinetic analysis of human KAT II demonstrated its catalytic efficiency for individual amino-group donors and acceptors, providing information as to its preferred substrate affinity. Structural analysis of the human KAT II complex with a-oxoglutaric acid revealed a conformational change of an N-terminal fraction, residues 15-33, that is able to adapt to different substrate sizes, which provides a structural basis for its broad substrate specificity.

  1. Substrate Specificity and Structure of Human aminoadipate aminotransferase/kynurenine aminotransferase II

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Cai, T; Tagle, D; Robinson, H; Li, J

    2009-01-01

    KAT (kynurenine aminotransferase) II is a primary enzyme in the brain for catalysing the transamination of kynurenine to KYNA (kynurenic acid). KYNA is the only known endogenous antagonist of the N-methyl-D-aspartate receptor. The enzyme also catalyses the transamination of aminoadipate to alpha-oxoadipate; therefore it was initially named AADAT (aminoadipate aminotransferase). As an endotoxin, aminoadipate influences various elements of glutamatergic neurotransmission and kills primary astrocytes in the brain. A number of studies dealing with the biochemical and functional characteristics of this enzyme exist in the literature, but a systematic assessment of KAT II addressing its substrate profile and kinetic properties has not been performed. The present study examines the biochemical and structural characterization of a human KAT II/AADAT. Substrate screening of human KAT II revealed that the enzyme has a very broad substrate specificity, is capable of catalysing the transamination of 16 out of 24 tested amino acids and could utilize all 16 tested alpha-oxo acids as amino-group acceptors. Kinetic analysis of human KAT II demonstrated its catalytic efficiency for individual amino-group donors and acceptors, providing information as to its preferred substrate affinity. Structural analysis of the human KAT II complex with alpha-oxoglutaric acid revealed a conformational change of an N-terminal fraction, residues 15-33, that is able to adapt to different substrate sizes, which provides a structural basis for its broad substrate specificity.

  2. Perfil da aspartato aminotransferase e alanina aminotransferase e biometria do fígado de codornas japonesas

    OpenAIRE

    Barbosa,Anderson de Almeida; Müller,Elisa Sialino; Moraes,George Henrique Kling de; Umigi,Regina Tie; Barreto,Sergio Luiz de Toledo; Ferreira,Ronaldo Martins

    2010-01-01

    Objetivou-se determinar o perfil da aspartato aminotransferase e alanina aminotransferase e a biometria do fígado de codornas poedeiras (Coturnix coturnix japonica) de 1 a 25 dias de idade. Avaliaram-se o peso vivo e o peso do fígado e as atividades das aspartato e alanina aminotransferases no fígado utilizando-se 90 codornas de 1 dia de idade. O delineamento experimental foi inteiramente casualizado com seis idades e cinco repetições, considerando cada animal uma unidade experimental. Aos 1,...

  3. Aminotransferase and glutamate dehydrogenase activities in lactobacilli and streptococci.

    Science.gov (United States)

    Peralta, Guillermo Hugo; Bergamini, Carina Viviana; Hynes, Erica Rut

    2016-01-01

    Aminotransferases and glutamate dehydrogenase are two main types of enzymes involved in the initial steps of amino acid catabolism, which plays a key role in the cheese flavor development. In the present work, glutamate dehydrogenase and aminotransferase activities were screened in twenty one strains of lactic acid bacteria of dairy interest, either cheese-isolated or commercial starters, including fifteen mesophilic lactobacilli, four thermophilic lactobacilli, and two streptococci. The strains of Streptococcus thermophilus showed the highest glutamate dehydrogenase activity, which was significantly elevated compared with the lactobacilli. Aspartate aminotransferase prevailed in most strains tested, while the levels and specificity of other aminotransferases were highly strain- and species-dependent. The knowledge of enzymatic profiles of these starter and cheese-isolated cultures is helpful in proposing appropriate combinations of strains for improved or increased cheese flavor.

  4. Allosteric inhibition of Staphylococcus aureus d-alanine:d-alanine ligase revealed by crystallographic studies

    OpenAIRE

    Liu, Shenping; Chang, Jeanne S.; Herberg, John T.; Horng, Miao-Miao; Tomich, Paul K.; Lin, Alice H.; Marotti, Keith R

    2006-01-01

    d-alanine:d-alanine ligase (DDl) is an essential enzyme in bacterial cell wall biosynthesis and an important target for developing new antibiotics. It catalyzes the formation of d-alanine:d-alanine dipeptide, sequentially by using one d-alanine and one ATP as substrates for the first-half reaction, and a second d-alanine substrate to complete the reaction. Some gain of function DDl mutants can use an alternate second substrate, causing resistance to vancomycin, one of the last lines of defens...

  5. Comparison of blood aminotransferase methods for assessment of myopathy and hepatopathy in Florida manatees (Trichechus manatus latirostris).

    Science.gov (United States)

    Harr, Kendal E; Allison, Kathryn; Bonde, Robert K; Murphy, David; Harvey, John W

    2008-06-01

    Muscle injury is common in Florida manatees (Trichechus manatus latirostris). Plasma aspartate aminotransferase (AST) is frequently used to assess muscular damage in capture myopathy and traumatic injury. Therefore, accurate measurement of AST and alanine aminotransferase (ALT) is important in managed, free-ranging animals, as well as in those rehabilitating from injury. Activities of these enzymes, however, are usually not increased in manatees with either acute or chronic muscle damage, despite marked increases in plasma creatine kinase activity. It is hypothesized that this absence of response is due to apoenzymes in the blood not detected by commonly used veterinary assays. Addition of coenzyme pyridoxal-5-phosphate (P5P or vitamin B6) should, therefore, result in higher measured enzyme activities. The objective of this study was to determine the most accurate, precise, and diagnostically useful method for aminotransferase measurement in manatees that can be used in veterinary practices and diagnostic laboratories. Additionally, appropriate collection and storage techniques were assessed. The use of an optimized commercial wet chemical assay with 100 micromol P5P resulted in a positive bias of measured enzyme activities in a healthy population of animals. However, AST and ALT were still much lower than that typically observed in domestic animals and should not be used alone in the assessment of capture myopathy and muscular trauma. Additionally, the dry chemistry analyzer, typically used in clinics, reported significantly higher and less precise AST and ALT activities with poor correlation to those measured with wet chemical methods found in diagnostic laboratories. Therefore, these results cannot be clinically compared. Overall, the optimized wet chemical method was the most precise and diagnostically useful measurement of aminotransferase in samples. Additionally, there was a statistically significant difference between paired serum and plasma measurement

  6. Antiretroviral Drugs and Risk of Chronic Alanine Aminotransferase Elevation in Human Immunodeficiency Virus (HIV)-Monoinfected Persons

    DEFF Research Database (Denmark)

    Kovari, Helen; Sabin, Caroline A; Ledergerber, Bruno;

    2016-01-01

    Background.  Although human immunodeficiency virus (HIV)-positive persons on antiretroviral therapy (ART) frequently have chronic liver enzyme elevation (cLEE), the underlying cause is often unclear. Methods.  Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) Study participants without...... a consistent association between tenofovir and cLEE emerging within the first 2 years after drug initiation. This novel tenofovir-cLEE signal should be further investigated....

  7. The role of elevated alanine aminotransferase (ALT), FasL and atherogenic dyslipidemia in type II diabetes mellitus

    OpenAIRE

    Howayda N. Mahran, PhD; Lobna M. Saber, MD; Abdullaziz A. Alghaithy, PhD; Azza A. Elareefy, PhD

    2017-01-01

    أهداف البحث: أظهرت العديد من الدراسات المقطعية والمستقبلية علاقة داء السكري من النوع الثاني كمسبب محتمل للإصابة بمرض الكبد الدهني غير الكحولي المصحوب بالتليف والتشمع. يهدف البحث إلى دراسة مستويات الترانساميناسات الأمينية في البلازما كمؤشرات حيوية في مرض الكبد الدهني غير الكحولي وعلاقتها بكل من مؤشرات موت الخلايا المبرمج ( فاس و فاس لجن ) ومستوى الدهون في الدم في مرضى داء السكري من النوع الثاني. طرق البحث: شملت هذه الدراسة المقطعية المقارنة ١٢٠ من مرضى داء السكري من النوع الثاني و١٠٠ مريض ل...

  8. The role of elevated alanine aminotransferase (ALT, FasL and atherogenic dyslipidemia in type II diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Howayda N. Mahran, PhD

    2017-02-01

    الاستنتاجات: أوضحت نتائج هذه الدراسة بأنه في مرضى داء السكري فإن ارتفاع مستويات ألانين أماينوترانسفريز والفاس لجن قد يلعبان دورا في خطورة الإصابة بأمراض الكبد ويمكن استخدامهما كمؤشر مستقل لمرض الكبد الدهني غير الكحولي مشيرا إلى إصابة الكبد. إضافة إلى ذلك فإن اضطراب دهون الدم المسببة لتصلب الشرايين هو خاصية بارزة في داء السكري من النوع الثاني. يرتبط انخفاض مستوى البروتين الدهني عالي الكثافة وارتفاع مستوى الدهون الثلاثية ارتباطا وثيقا بزيادة خطورة الإصابة بكل من أمراض القلب والأوعية الدموية ومرض الكبد الدهني غير الكحولي عند مرضى داء السكري.

  9. Late-onset primary hyperoxaluria type 1 in a Chinese individual with absent alanine:glyoxylate aminotransferase activity

    Institute of Scientific and Technical Information of China (English)

    黃炳南; 唐美華; 麥肇嘉; 盧建宜; 黃煜; 黃矩民

    2004-01-01

    @@ Nephrolithiasis is a common clinical problem, and its cause is often classified as idiopathic. Primary hyperoxaluria, mostly type 1, constitutes one of the rare causes of recurrent nephrolithiasis, but its diagnosis is often missed or delayed. The exact prevalence of primary hyperoxaluria type 1 (PH1), therefore, has been unclear. The reported prevalence varies in different countries. No Chinese PH1 has ever been reported in the literature. We report a rare case of late-onset primary hyperoxaluria, which was diagnosed only after the development of end-stage renal failure. To our knowledge, this case is the first confirmed Chinese PH1.

  10. Antiretroviral Drugs and Risk of Chronic Alanine Aminotransferase Elevation in Human Immunodeficiency Virus (HIV)-Monoinfected Persons

    DEFF Research Database (Denmark)

    Kovari, Helen; Sabin, Caroline A; Ledergerber, Bruno;

    2016-01-01

    elevation was not associated with use of lamivudine, abacavir, and other protease inhibitors. Mortality did not differ between participants with and without cLEE. Conclusions.  Although didanosine, stavudine, nevirapine, and efavirenz have been described to be hepatotoxic, we additionally observed...

  11. Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons

    DEFF Research Database (Denmark)

    Dadsetan, Sherry; Bak, Lasse Kristoffer; Sørensen, Michael

    2011-01-01

    It has been previously demonstrated that ammonia exposure of neurons and astrocytes in co-culture leads to net synthesis not only of glutamine but also of alanine. The latter process involves the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT). In the present...... study it was investigated if the glutamine synthetase (GS) inhibitor methionine sulfoximine (MSO) would enhance alanine synthesis by blocking the GS-dependent ammonia scavenging process. Hence, co-cultures of neurons and astrocytes were incubated for 2.5h with [U-(13)C]glucose to monitor de novo...... synthesis of alanine and glutamine in the absence and presence of 5.0 mM NH(4)Cl and 10 mM MSO. Ammonia exposure led to increased incorporation of label but not to a significant increase in the amount of these amino acids. However, in the presence of MSO, glutamine synthesis was blocked and synthesis...

  12. Elevated Serum Aminotransferases Secondary to Rippling Muscle Disease

    Directory of Open Access Journals (Sweden)

    Kumanan Nalankilli

    2013-05-01

    Full Text Available A 43-year-old man was referred by his general practitioner to the hepatology clinic with deranged serum aminotransferases, discovered as part of routine blood tests. The objective was to identify the cause of elevated serum aminotransferases in this patient in a systematic manner. Thorough history and physical examination revealed a background history of rippling muscle disease secondary to caveolin-3 protein deficiency, with typical clinical signs. There was a positive family history of musculoskeletal disease in the patient's father and brother. Previous diagnostic tests performed to investigate the patient's musculoskeletal symptoms, including muscle biopsies, were revisited. Subsequent systematic investigations such as blood tests, liver ultrasound scan and Fibroscan® were performed to exclude potential causes of the deranged serum aminotransferases. Liver biopsy was not performed. A consistent pattern of chronic low-grade elevations of serum aminotransferases, less than three times the upper limit of the normal range, was found. This was associated with a consistently elevated serum creatine kinase and normal renal function tests. Previous muscle biopsies had revealed chronic degenerative and regenerative changes suggestive of a focal necrotizing myopathy. Liver ultrasound scan and Fibroscan® were normal. With exclusion of other liver diseases and identification of profoundly elevated serum creatine kinase concentration, the deranged aminotransferases were attributed to rippling muscle disease.

  13. The retarded hair growth (rhg mutation in mice is an allele of ornithine aminotransferase (Oat

    Directory of Open Access Journals (Sweden)

    Jason J. Bisaillon

    2014-01-01

    Full Text Available Because of the similar phenotypes they generate and their proximate reported locations on Chromosome 7, we tested the recessive retarded hair growth (rhg and frizzy (fr mouse mutations for allelism, but found instead that these defects complement. To discover the molecular basis of rhg, we analyzed a large intraspecific backcross panel that segregated for rhg and restricted this locus to a 0.9 Mb region that includes fewer than ten genes, only five of which have been reported to be expressed in skin. Complementation testing between rhg and a recessive null allele of fibroblast growth factor receptor 2 eliminated Fgfr2 as the possible basis of the retarded hair growth phenotype, but DNA sequencing of another of these candidates, ornithine aminotransferase (Oat, revealed a G to C transversion specifically associated with the rhg allele that would result in a glycine to alanine substitution at residue 353 of the gene product. To test whether this missense mutation might cause the mutant phenotype, we crossed rhg/rhg mice with mice that carried a recessive, perinatal-lethal, null mutation in Oat (designated OatΔ herein. Hybrid offspring that inherited both rhg and OatΔ displayed markedly delayed postnatal growth and hair development, indicating that these two mutations are allelic, and suggesting strongly that the G to C mutation in Oat is responsible for the retarded hair growth phenotype. Comparisons among +/+, +/rhg, rhg/rhg and rhg/OatΔ mice showed plasma ornithine levels and ornithine aminotransferase activities (in liver lysates consistent with this assignment. Because histology of 7- and 12-month-old rhg/rhg and rhg/OatΔ retinas revealed chorioretinal degeneration similar to that described previously for OatΔ/OatΔ mice, we suggest that the rhg mutant may offer an ideal model for gyrate atrophy of the choroid and retina (GACR in humans, which is also caused by the substitution of glycine 353 in some families.

  14. Assessement of glycaemia and serum activities of aspartate aminotransferase, creatinekinase, gamma glutamyltransferase and lactate dehydrogenase in thoroughbred horses submitted to exercise of different intensities/ Avaliação da glicemia e da atividade sérica de aspartato aminotransferase, creatinoquinase, gama-glutamiltransferase e lactato desidrogenase em eqüinos puro sangue inglês (PSI submetidos a exercícios de diferentes intensidades

    Directory of Open Access Journals (Sweden)

    Joandes Henrique Fonteque

    2005-06-01

    Full Text Available In order to evaluate the influence of exercise of different intensities on biochemical parameters in Thoroughbred horses blood was collected from 60 animals, 30 males and 30 females.The animals were subdivided in two groups : 30 horses, 15 males and 15 females with 24 to 36 months of age and not in training, and after 12 months of training; 30 horses, 15 males and 15 females with 36 to 48 months of age in training. Blood samples were collected before and after trot and gallop. Plasmatic glucose was analyzed through a colorimetric method, while aspartate aminotransferase (AST, creatine kinase (CK, lactate dehydrogenase (LDH and gammaglutamyltransferase (GGT were analyzed through kinetic methods. Results show a statistically significant increase in plasmatic glucose after trot and gallop independent of gender, while the increases in CK and LDH were different for males and females. Variations for AST and GGT were not statistically significant.O objetivo do presente estudo foi avaliar as alterações na bioquímica sérica em eqüinos PSI submetidos a exercícios de diferentes intensidades. Foram colhidas amostras de sangue de 60 eqüinos PSI, distribuídos nos seguintes grupos: 30 animais sendo 15 machos e 15 fêmeas, com idade de 24 a 36 meses, não submetidos a treinamento e após um período de 12 meses de treinamento e 30 eqüinos de 36 a 48 meses, em fase de treinamento, antes e após o trote . Dos animais de 36 a 48 meses foram selecionados 20 machos e 10 fêmeas e colhido sangue antes e após o galope. Determinou-se, por métodos colorimétricos, os valores da glicose plasmática e, por métodos cinéticos, as enzimas aspartato aminotransferase (AST, creatinoquinase (CK, lactato desidrogenase (LDH e gama-glutamiltransferase (GGT. A análise estatística dos resultados comprovou a ocorrência de aumento significativo (p < 0,05 dos valores da glicose plasmática após o trote e galope para ambos os sexos. Para as enzimas CK e LDH ocorreram

  15. Radioimmunoassay of aspartate aminotransferase isoenzymes in human serum

    Energy Technology Data Exchange (ETDEWEB)

    Leung, F.Y.; Niblock, A.E.; Henderson, A.R.

    1984-08-01

    A description is given of the development of a sensitive, specific radioimmunoassay for the cytoplasmic and mitochondrial isoenzymes of human aspartate aminotransferase (L-aspartate:2-oxoglutarate aminotransferase; EC 2.6.1.1). Isoenzymes from human heart tissue were purified to homogeneity and used to raise high-titer antisera in rabbits. The antisera were partly purified by selective column chromatography. The Bolton-Hunter reagent was used to radioiodinate the isoenzymes. The assay requires 100 microL of serum, includes a solid-phase second-antibody separation, and can be completed in less than 3 h. There was no cross reactivity between the two isoenzymes. As little as 5 micrograms (50 pmol) of each aspartate aminotransferase can be measured per liter of serum.

  16. Structure of putrescine aminotransferase from Escherichia coli provides insights into the substrate specificity among class III aminotransferases.

    Science.gov (United States)

    Cha, Hyung Jin; Jeong, Jae-Hee; Rojviriya, Catleya; Kim, Yeon-Gil

    2014-01-01

    YgjG is a putrescine aminotransferase enzyme that transfers amino groups from compounds with terminal primary amines to compounds with an aldehyde group using pyridoxal-5'-phosphate (PLP) as a cofactor. Previous biochemical data show that the enzyme prefers primary diamines, such as putrescine, over ornithine as a substrate. To better understand the enzyme's substrate specificity, crystal structures of YgjG from Escherichia coli were determined at 2.3 and 2.1 Å resolutions for the free and putrescine-bound enzymes, respectively. Sequence and structural analyses revealed that YgjG forms a dimer that adopts a class III PLP-dependent aminotransferase fold. A structural comparison between YgjG and other class III aminotransferases revealed that their structures are similar. However, YgjG has an additional N-terminal helical structure that partially contributes to a dimeric interaction with the other subunit via a helix-helix interaction. Interestingly, the YgjG substrate-binding site entrance size and charge distribution are smaller and more hydrophobic than other class III aminotransferases, which suggest that YgjG has a unique substrate binding site that could accommodate primary aliphatic diamine substrates, including putrescine. The YgjG crystal structures provide structural clues to putrescine aminotransferase substrate specificity and binding.

  17. Structure of putrescine aminotransferase from Escherichia coli provides insights into the substrate specificity among class III aminotransferases.

    Directory of Open Access Journals (Sweden)

    Hyung Jin Cha

    Full Text Available YgjG is a putrescine aminotransferase enzyme that transfers amino groups from compounds with terminal primary amines to compounds with an aldehyde group using pyridoxal-5'-phosphate (PLP as a cofactor. Previous biochemical data show that the enzyme prefers primary diamines, such as putrescine, over ornithine as a substrate. To better understand the enzyme's substrate specificity, crystal structures of YgjG from Escherichia coli were determined at 2.3 and 2.1 Å resolutions for the free and putrescine-bound enzymes, respectively. Sequence and structural analyses revealed that YgjG forms a dimer that adopts a class III PLP-dependent aminotransferase fold. A structural comparison between YgjG and other class III aminotransferases revealed that their structures are similar. However, YgjG has an additional N-terminal helical structure that partially contributes to a dimeric interaction with the other subunit via a helix-helix interaction. Interestingly, the YgjG substrate-binding site entrance size and charge distribution are smaller and more hydrophobic than other class III aminotransferases, which suggest that YgjG has a unique substrate binding site that could accommodate primary aliphatic diamine substrates, including putrescine. The YgjG crystal structures provide structural clues to putrescine aminotransferase substrate specificity and binding.

  18. Aspartate Aminotransferase - Bridging Carbohydrate and Energy Metabolism in Plasmodium Falciparum

    NARCIS (Netherlands)

    Wrenger, Carsten; Mueller, Ingrid B.; Silber, Ariel M.; Jordanova, Rositsa; Lamzin, Victor S.; Groves, Matthew R.

    2012-01-01

    In this mini-review we briefly examine and summarize evidence on the role of the plasmodial aspartate aminotransferase (AspAT) of the malarial parasite. Recent data have provided information on the products of the purine salvage pathway as well as the glycolytic and oxidative phosphorylation pathway

  19. Response of Alanine Dosemeter to Heavy Ions

    Institute of Scientific and Technical Information of China (English)

    LiWenjian; SuXu; YangYingjie; YuanJianlei; DangBingrong; WangXiao; MaQiufeng; ZhouLibin; HaoJifang; MaoShuhong

    2003-01-01

    The amino acid L-α-alanine has been investigated for use as a radiation detector in low and high LET radiation fields[1]. The radiatioa detector is cheap and easy to handle. The radiation inducing free radicals are stable at normal laboratory conditions for doses below 104 Gy over a long period of time, which makes the detector useful for intercomparison and documentation purposes. The dosimetric features of alanine-based electron spin resonance (ESR) detectors in high energy electron beams used in radiotherapy were considered[2]. The 5 mm long alanine detectors were found to be the most suitable for carrying out in vivo dosimetry on patients undergoing electron beam radiotherapy. However, data concerning dosimetry of the alanine dosemeter to heavy charged particles are lacking, especially in China.

  20. Structural analysis and mutant growth properties reveal distinctive enzymatic and cellular roles for the three major L-alanine transaminases of Escherichia coli.

    Science.gov (United States)

    Peña-Soler, Esther; Fernandez, Francisco J; López-Estepa, Miguel; Garces, Fernando; Richardson, Andrew J; Quintana, Juan F; Rudd, Kenneth E; Coll, Miquel; Vega, M Cristina

    2014-01-01

    In order to maintain proper cellular function, the metabolism of the bacterial microbiota presents several mechanisms oriented to keep a correctly balanced amino acid pool. Central components of these mechanisms are enzymes with alanine transaminase activity, pyridoxal 5'-phosphate-dependent enzymes that interconvert alanine and pyruvate, thereby allowing the precise control of alanine and glutamate concentrations, two of the most abundant amino acids in the cellular amino acid pool. Here we report the 2.11-Å crystal structure of full-length AlaA from the model organism Escherichia coli, a major bacterial alanine aminotransferase, and compare its overall structure and active site composition with detailed atomic models of two other bacterial enzymes capable of catalyzing this reaction in vivo, AlaC and valine-pyruvate aminotransferase (AvtA). Apart from a narrow entry channel to the active site, a feature of this new crystal structure is the role of an active site loop that closes in upon binding of substrate-mimicking molecules, and which has only been previously reported in a plant enzyme. Comparison of the available structures indicates that beyond superficial differences, alanine aminotransferases of diverse phylogenetic origins share a universal reaction mechanism that depends on an array of highly conserved amino acid residues and is similarly regulated by various unrelated motifs. Despite this unifying mechanism and regulation, growth competition experiments demonstrate that AlaA, AlaC and AvtA are not freely exchangeable in vivo, suggesting that their functional repertoire is not completely redundant thus providing an explanation for their independent evolutionary conservation.

  1. Structural analysis and mutant growth properties reveal distinctive enzymatic and cellular roles for the three major L-alanine transaminases of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Esther Peña-Soler

    Full Text Available In order to maintain proper cellular function, the metabolism of the bacterial microbiota presents several mechanisms oriented to keep a correctly balanced amino acid pool. Central components of these mechanisms are enzymes with alanine transaminase activity, pyridoxal 5'-phosphate-dependent enzymes that interconvert alanine and pyruvate, thereby allowing the precise control of alanine and glutamate concentrations, two of the most abundant amino acids in the cellular amino acid pool. Here we report the 2.11-Å crystal structure of full-length AlaA from the model organism Escherichia coli, a major bacterial alanine aminotransferase, and compare its overall structure and active site composition with detailed atomic models of two other bacterial enzymes capable of catalyzing this reaction in vivo, AlaC and valine-pyruvate aminotransferase (AvtA. Apart from a narrow entry channel to the active site, a feature of this new crystal structure is the role of an active site loop that closes in upon binding of substrate-mimicking molecules, and which has only been previously reported in a plant enzyme. Comparison of the available structures indicates that beyond superficial differences, alanine aminotransferases of diverse phylogenetic origins share a universal reaction mechanism that depends on an array of highly conserved amino acid residues and is similarly regulated by various unrelated motifs. Despite this unifying mechanism and regulation, growth competition experiments demonstrate that AlaA, AlaC and AvtA are not freely exchangeable in vivo, suggesting that their functional repertoire is not completely redundant thus providing an explanation for their independent evolutionary conservation.

  2. Structural Analysis and Mutant Growth Properties Reveal Distinctive Enzymatic and Cellular Roles for the Three Major L-Alanine Transaminases of Escherichia coli

    Science.gov (United States)

    López-Estepa, Miguel; Garces, Fernando; Richardson, Andrew J.; Quintana, Juan F.; Rudd, Kenneth E.; Coll, Miquel; Vega, M. Cristina

    2014-01-01

    In order to maintain proper cellular function, the metabolism of the bacterial microbiota presents several mechanisms oriented to keep a correctly balanced amino acid pool. Central components of these mechanisms are enzymes with alanine transaminase activity, pyridoxal 5′-phosphate-dependent enzymes that interconvert alanine and pyruvate, thereby allowing the precise control of alanine and glutamate concentrations, two of the most abundant amino acids in the cellular amino acid pool. Here we report the 2.11-Å crystal structure of full-length AlaA from the model organism Escherichia coli, a major bacterial alanine aminotransferase, and compare its overall structure and active site composition with detailed atomic models of two other bacterial enzymes capable of catalyzing this reaction in vivo, AlaC and valine-pyruvate aminotransferase (AvtA). Apart from a narrow entry channel to the active site, a feature of this new crystal structure is the role of an active site loop that closes in upon binding of substrate-mimicking molecules, and which has only been previously reported in a plant enzyme. Comparison of the available structures indicates that beyond superficial differences, alanine aminotransferases of diverse phylogenetic origins share a universal reaction mechanism that depends on an array of highly conserved amino acid residues and is similarly regulated by various unrelated motifs. Despite this unifying mechanism and regulation, growth competition experiments demonstrate that AlaA, AlaC and AvtA are not freely exchangeable in vivo, suggesting that their functional repertoire is not completely redundant thus providing an explanation for their independent evolutionary conservation. PMID:25014014

  3. Aspartate aminotransferase-immunoglobulin complexes in patients with chronic liver disease

    Institute of Scientific and Technical Information of China (English)

    Masahiko Tameda; Katsuya Shiraki; Kinue Ooi; Koujirou Takase; Yoshitane Kosaka; Tsutomu Nobori; Yukihiko Tameda

    2005-01-01

    AIM: To determine the complex of AST and immunoglobulin and to investigate its clinical significance in patients with liver disease.METHODS: The complex of AST and immunoglobulin was determined by encounter immunoelectrophoresis and its clinical significance was investigated in 128 patients with liver disease.RESULTS: AST was bound to immunoglobulin of antiimmunoglobulin A (IgA) class, but any binding to antiimmunoglobulin G and anti-immunoglobulin M classes was not observed. Although the incidence of ASTimmunoglobulin complex was 41.8% in chronic hepatitis (CH), the incidences in liver cirrhosis and hepatocellular carcinoma were 62.2 and 90.0%, respectively. In alcoholic liver disease with high level of serum IgA, the incidence of the complex was 66.7%, which was higher than that in CH. The ratio of binding to lambda-chain of IgA was higher than that to kappa-chain of IgA. The serum level of IgA and the ratio of AST/alanine aminotransferase (ALT) were significantly higher in patients with AST-IgA complex than in those without complex.CONCLUSION: These results suggest that AST-IgA complex in patients with progressive liver diseases and alcoholic liver injury can lead to elevation of the ratio of AST/ALT.

  4. Effect of weak electromagnetic field on cardiac work, concentration of thyroid hormones and blood aminotransferase level in the chick embryo.

    Science.gov (United States)

    Pawlak, Krzysztof; Sechman, Andrzej; Nieckarz, Zenon; Wojtysiak, Dorota

    2013-09-01

    The aim of the study was to determine the effect of alternating electromagnetic field (EMF; 50 Hz frequency, 50 and 100 μT induction) on cardiac work of the chick embryo. Eggs from the experimental groups were exposed to EMF throughout incubation. During the experiment, heart rate (ballistocardiographic method), thyroxine (T4) and triiodothyronine (T3) concentrations, heart weight, ventricle wall thickness, and levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. The results show, for the first time, that the exposure of chick embryos to EMF augments the heart rate, especially from 17 days of incubation. The increased heart rate in the embryos exposed to EMF was associated with considerable increases in plasma T4 and T3 concentrations, which were recorded during the final stage of embryogenesis. The significant effect of the 100-μT field on heart weight and blood AST levels in the embryos suggests that EMF has a direct effect on the physiological function of cardiac muscle.

  5. Correlation between Aminotransferase Ratio (AST/ALT and Other Biochemical Parameters in Chronic Liver Disease of Viral Origin

    Directory of Open Access Journals (Sweden)

    Shah Md Fazlul Karim

    2015-03-01

    Full Text Available Background: In recent years the ratio of aspartate aminotransferase (AST to alanine aminotransferase (ALT in patients of chronic liver disease (CLD of various origins has gained much attention. This variable is readily available, easy to interpret, and inexpensive and the clinical utility of the AST/ALT ratio in the diagnostic workup of patients with CLD is quite promising. Objective: The present study was designed to find out the link between aminotransferase (AST/ALT ratio with commonly measured biochemical parameters of liver function tests in CLD of viral origin. Materials and method: This cross sectional study was carried out in the department of Biochemistry, Sir Salimullah Medical College, Dhaka, Bangladesh. Forty four biopsy proven diagnosed subjects of chronic viral hepatitis without cirrhosis of both sex were selected purposively. With aseptic precaution 5 mL venous blood was collected from each subject and common liver function tests (serum AST, ALT, AST/ALT ratio, alkaline phosphatase, total bilirubin, serum total protein, serum albumin, serum globulin, serum albumin/globulin ratio, prothrombin time and viral serology (HBsAg, Anti HDV antibody, Anti HCV antibody were performed. Data were analyzed by SPSS version 19 for Windows. Pearson’s correlation test was done to determine association between AST/ALT with other biochemical parameters. Results: Mean(±SD age of the study subjects was 32.55±10.55 years (range 20-50 years with 48 (77.7% male and 14 (22.6% female subjects. Pearson’s correlation test was done between AST to ALT ratio with other biochemical parameters and prothrombin time showed significant positive correlation (p <0.01. Conclusion: In our study we found significant positive correlation between AST/ALT with prothrombin time in CLD subjects without cirrhosis.

  6. Elevation of serum GGT and LDH levels, together with higher BCLC staging are associated with poor overall survival from hepatocellular carcinoma: a retrospective analysis.

    Science.gov (United States)

    Yang, Zongguo; Ye, Peiyan; Xu, Qingnian; Lu, Yunfei; Tang, Bozong; Wang, Qiang; Chen, Shishi; Chen, Xiaorong

    2015-06-01

    Serum biomarkers predicting prognosis have not been adequately explored in HCC patients. The aim of this study was to investigate prognostic significance of parameters of liver function, tumor markers, and other clinicopathological features in HCC patients. Medical records of HCC patients were retrospectively extracted and overall survival was evaluated with the Kaplan-Meier method. Significant difference was estimated with the Log rank method. Univariate and multivariate analyses were used for the study of significance of prognostic factor. A total of 273 HCC patients were included in this analysis. According to the Cox regression analysis and Kaplan-Meier event analysis, GGT and LDH levels of liver function tests were significantly associated with HCC overall survival. Elevated serum CEA level was a risk factor related to poor HCC overall survival. And advanced BCLC staging contributed to a lower overall survival in HCC patients. HCC could benefit from surgical resection, TACE, and radiotherapy. ROC curves demonstrated that different from CEA, elevated GGT and LDH could accurately predict HCC overall survival. In conclusion, serum GGT and LDH together with higher BCLC staging should be potential predictive factors for HCC overall survival.

  7. A systems biology approach to understanding elevated serum alanine transaminase levels in a clinical trial with ximelagatran.

    Science.gov (United States)

    Andersson, Ulf; Lindberg, Johan; Wang, Shunghuang; Balasubramanian, Raji; Marcusson-Ståhl, Maritha; Hannula, Mira; Zeng, Chenhui; Juhasz, Peter J; Kolmert, Johan; Bäckström, Jonas; Nord, Lars; Nilsson, Kerstin; Martin, Steve; Glinghammar, Björn; Cederbrant, Karin; Schuppe-Koistinen, Ina

    2009-12-01

    Ximelagatran was developed for the prevention and treatment of thromboembolic conditions. However, in long-term clinical trials with ximelagatran, the liver injury marker, alanine aminotransferase (ALT) increased in some patients. Analysis of plasma samples from 134 patients was carried out using proteomic and metabolomic platforms, with the aim of finding predictive biomarkers to explain the ALT elevation. Analytes that were changed after ximelagatran treatment included 3-hydroxybutyrate, pyruvic acid, CSF1R, Gc-globulin, L-glutamine, protein S and alanine, etc. Two of these analytes (pyruvic acid and CSF1R) were studied further in human cell cultures in vitro with ximelagatran. A systems biology approach applied in this study proved to be successful in generating new hypotheses for an unknown mechanism of toxicity.

  8. Inhibition of glutamine synthesis induces glutamate dehydrogenase-dependent ammonia fixation into alanine in co-cultures of astrocytes and neurons.

    Science.gov (United States)

    Dadsetan, Sherry; Bak, Lasse K; Sørensen, Michael; Keiding, Susanne; Vilstrup, Hendrik; Ott, Peter; Leke, Renata; Schousboe, Arne; Waagepetersen, Helle S

    2011-09-01

    It has been previously demonstrated that ammonia exposure of neurons and astrocytes in co-culture leads to net synthesis not only of glutamine but also of alanine. The latter process involves the concerted action of glutamate dehydrogenase (GDH) and alanine aminotransferase (ALAT). In the present study it was investigated if the glutamine synthetase (GS) inhibitor methionine sulfoximine (MSO) would enhance alanine synthesis by blocking the GS-dependent ammonia scavenging process. Hence, co-cultures of neurons and astrocytes were incubated for 2.5h with [U-(13)C]glucose to monitor de novo synthesis of alanine and glutamine in the absence and presence of 5.0 mM NH(4)Cl and 10 mM MSO. Ammonia exposure led to increased incorporation of label but not to a significant increase in the amount of these amino acids. However, in the presence of MSO, glutamine synthesis was blocked and synthesis of alanine increased leading to an elevated content intra- as well as extracellularly of this amino acid. Treatment with MSO led to a dramatic decrease in glutamine content and increased the intracellular contents of glutamate and aspartate. The large increase in alanine during exposure to MSO underlines the importance of the GDH and ALAT biosynthetic pathway for ammonia fixation, and it points to the use of a GS inhibitor to ameliorate the brain toxicity and edema induced by hyperammonemia, events likely related to glutamine synthesis.

  9. Comparison of blood aminotransferase methods for assessment of myopathy and hepatopathy in Florida manatees (Trichechus manatus latirostris)

    Science.gov (United States)

    Harr, K.E.; Allison, K.; Bonde, R.K.; Murphy, D.; Harvey, J.W.

    2008-01-01

    Muscle injury is common in Florida manatees (Trichechus manatus latirostris). Plasma aspartate amino-transferase (AST) is frequently used to assess muscular damage in capture myopathy and traumatic injury. Therefore, accurate measurement of AST and alanine aminotransferase (ALT) is important in managed, free-ranging animals, as well as in those rehabilitating from injury. Activities of these enzymes, however, are usually not increased in manatees with either acute or chronic muscle damage, despite marked increases in plasma creatine kinase activity. It is hypothesized that this absence of response is due to apoenzymes in the blood not detected by commonly used veterinary assays. Addition of coenzyme pyridoxal-5-phosphate (P5P or vitamin B6) should, therefore, result in higher measured enzyme activities. The objective of this study was to determine the most accurate, precise, and diagnostically useful method for aminotransferase measurement in manatees that can be used in veterinary practices and diagnostic laboratories. Additionally, appropriate collection and storage techniques were assessed. The use of an optimized commercial wet chemical assay with 100 ??mol P5P resulted in a positive bias of measured enzyme activities in a healthy population of animals. However, AST and ALT were still much lower than that typically observed in domestic animals and should not be used alone in the assessment of capture myopathy and muscular trauma. Additionally, the dry chemistry analyzer, typically used in clinics, reported significantly higher and less precise AST and ALT activities with poor correlation to those measured with wet chemical methods found in diagnostic laboratories. Therefore, these results cannot be clinically compared. Overall, the optimized wet chemical method was the most precise and diagnostically useful measurement of aminotransferase in samples. Additionally, there was a statistically significant difference between paired serum and plasma measurement

  10. Aspartate aminotransferase – key enzyme in the human systemic metabolism

    Directory of Open Access Journals (Sweden)

    Dagmara Otto-Ślusarczyk

    2016-03-01

    Full Text Available Aspartate aminotransferase is an organ - nonspecific enzyme located in many tissues of the human body where it catalyzes reversible reaction of transamination. There are two aspartate aminotransferase isoforms - cytoplasmic (AST1 and mitochondrial (AST2, that usually occur together and interact with each other metabolically. Both isoforms are homodimers containing highly conservative regions responsible for catalytic properties of enzyme. The common feature of all aspartate aminotransfeses is Lys – 259 residue covalent binding with prosthetic group - pyridoxal phosphate. The differences in the primary structure of AST isoforms determine their physico-chemical, kinetic and immunological properties. Because of the low concentration of L-aspartate (L-Asp in the blood, AST is the only enzyme, which supply of this amino acid as a substrate for many metabolic processes, such as urea cycle or purine and pyrimidine nucleotides in the liver, synthesis of L-arginine in the kidney and purine nucleotide cycle in the brain and the skeletal muscle. AST is also involved in D-aspartate production that regulates the metabolic activity at the auto-, para- and endocrine level. Aspartate aminotransferase is a part of the malate-aspartate shuttle in the myocardium, is involved in gluconeogenesis in the liver and kidney, glyceroneogenesis in the adipose tissue, and synthesis of neurotransmitters and neuro-glial pathway in the brain. Recently, the significant role of AST in glutaminolysis - normal metabolic pathway in tumor cells, was demonstrated. The article is devoted the role of AST, known primarily as a diagnostic liver enzyme, in metabolism of various human tissues and organs.

  11. Liver fibrosis progression in HIV/hepatitis C virus coinfected patients with normal aminotransferases levels

    Directory of Open Access Journals (Sweden)

    Fábio Heleno de Lima Pace

    2012-08-01

    Full Text Available INTRODUCTION: Approximately 30% of hepatitis C virus (HCV monoinfected patients present persistently normal alanine aminotransferase (ALT levels. Most of these patients have a slow progression of liver fibrosis. Studies have demonstrated the rate of liver fibrosis progression in hepatitis C virus-human immunodeficiency virus (HCV-HIV coinfected patients is faster than in patients infected only by HCV. Few studies have evaluated the histological features of chronic hepatitis C in HIV-infected patients with normal ALT levels. METHODS: HCV-HIV coinfected patients (HCV-RNA and anti-HIV positive with known time of HCV infection (intravenous drugs users were selected. Patients with hepatitis B surface antigen (HBsAg positive or hepatitis C treatment before liver biopsy were excluded. Patients were considered to have a normal ALT levels if they had at least 3 normal determinations in the previous 6 months prior to liver biopsy. All patients were submitted to liver biopsy and METAVIR scale was used. RESULTS: Of 50 studied patients 40 (80% were males. All patients were treated with antiretroviral therapy. The ALT levels were normal in 13 (26% patients. HCV-HIV co-infected patients with normal ALT levels had presented means of the liver fibrosis stages (0.77±0.44 versus 1.86±1.38; p<0.001 periportal inflammatory activity (0.62±0.77 versus 2.24±1.35; p<0.001 and liver fibrosis progression rate (0.058±0.043 fibrosis unit/year versus 0.118±0.102 fibrosis unit/year significantly lower as compared to those with elevated ALT. CONCLUSIONS: HCV-HIV coinfected patients with persistently normal ALTs showed slower progression of liver fibrosis. In these patients the development of liver cirrhosis is improbable.

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

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R.

    2013-12-01

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

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

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R

    2013-12-01

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

  14. Functional characterization of aromatic amino acid aminotransferase involved in 2-phenylethanol biosynthesis in isolated rose petal protoplasts.

    Science.gov (United States)

    Hirata, Hiroshi; Ohnishi, Toshiyuki; Ishida, Haruka; Tomida, Kensuke; Sakai, Miwa; Hara, Masakazu; Watanabe, Naoharu

    2012-03-15

    In rose flowers, 2-phenylethanol (2PE) is biosynthesized from l-phenylalanine (l-Phe) via phenylacetaldehyde (PAld) by the actions of two enzymes, pyridoxal-5'-phosphate (PLP)-dependent aromatic amino acid decarboxylase (AADC) and phenylacetaldehyde reductase (PAR). We here report that Rosa 'Yves Piaget' aromatic amino acid aminotransferase produced phenylpyruvic acid (PPA) from l-Phe in isolated petal protoplasts. We have cloned three full length cDNAs (RyAAAT1-3) of aromatic amino acid aminotransferase families based on rose EST database and homology regions. The RyAAATs enzymes were heterogeneously expressed in Escherichia coli and characterized biochemically. The recombinant RyAAAT3 showed the highest activity toward l-Phe in comparison with l-tryptophan, l-tyrosine, d-Phe, glycine, and l-alanine, and showed 9.7-fold higher activity with l-Phe rather than PPA as a substrate. RyAAAT3 had an optimal activity at pH 9 and at 45-55°C with α-ketoglutaric acid, and was found to be a PLP dependent enzyme based on the inhibition test using Carbidopa, an inhibitor of PLP-dependent enzymes. The transcript of RyAAAT3 was expressed in flowers as well as other organs of R. 'Yves Piaget'. RNAi suppression of RyAAAT3 decreased 2PE production, revealing the involvement of RyAAAT3 in 2PE biosynthesis in rose protoplasts and indicating that rose protoplasts have potentially two different 2PE biosynthetic pathways, the AADC route and the new route via PPA from l-Phe.

  15. The efficacy of aspartate aminotransferase-toplatelet ratio index for assessing hepatic fibrosis in childhood nonalcoholic steatohepatitis for medical practice

    Directory of Open Access Journals (Sweden)

    Earl Kim

    2013-01-01

    Full Text Available Purpose: Childhood obesity is associated with nonalcoholic fatty liver disease (NAFLD, and it has become one of the most common causes of childhood chronic liver diseases which significant as a cause of liver related mortality and morbidity in children in the United States. The development of simpler and easier clinical indices for medical practice is needed to identify advanced hepatic fibrosis in childhood NAFLD instead of invasive method like liver biopsy. FibroScan and aspartate aminotransferase (AST-to-platelet ratio index (APRI have been proposed as a simple and noninvasive predictor to evaluate hepatic fibrosis in several liver diseases. APRI could be a good alternative to detect pathologic change in childhood NAFLD. The purpose of this study is to validate the efficacy of APRI for assessing hepatic fibrosis in childhood NAFLD based on FibroScan. Methods: This study included 23 children with NAFLD who underwent FibroScan. Clinical, laboratory and radiological evaluation including APRI was performed. To confirm the result of this study, 6 patients received liver biopsy. Results: Factors associated with hepatic fibrosis (stiffness measurement &gt;5.9 kPa Fibroscan were triglyceride, AST, alanine aminotransferase, platelet count, APRI and collagen IV. In multivariate analysis, APRI were correlated with hepatic fibrosis (&gt;5.9 kPa. In receiver operating characteristics curve, APRI of meaningful fibrosis (cutoff value, 0.4669; area under the receiver operating characteristics, 0.875 presented sensitivity of 94%, specificity of 66%, positive predictive value of 94%, and negative predictive value of 64%. Conclusion: APRI might be a noninvasive, simple, and readily available method for medical practice to predict hepatic fibrosis of childhood NAFLD.

  16. Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress.

    Science.gov (United States)

    Limami, Anis M; Glévarec, Gaëlle; Ricoult, Claudie; Cliquet, Jean-Bernard; Planchet, Elisabeth

    2008-01-01

    The modulation of primary nitrogen metabolism by hypoxic stress was studied in young Medicago truncatula seedlings. Hypoxic seedlings were characterized by the up-regulation of glutamate dehydrogenase 1 (GDH1) and mitochondrial alanine aminotransferase (mAlaAT), and down-regulation of glutamine synthetase 1b (GS1b), NADH-glutamate synthase (NADH-GOGAT), glutamate dehydrogenase 3 (GDH3), and isocitrate dehydrogenase (ICDH) gene expression. Hypoxic stress severely inhibited GS activity and stimulated NADH-GOGAT activity. GDH activity was lower in hypoxic seedlings than in the control, however, under either normoxia or hypoxia, the in vivo activity was directed towards glutamate deamination. (15)NH(4) labelling showed for the first time that the adaptive reaction of the plant to hypoxia consisted of a concerted modulation of nitrogen flux through the pathways of both alanine and glutamate synthesis. In hypoxic seedlings, newly synthesized (15)N-alanine increased and accumulated as the major amino acid, asparagine synthesis was inhibited, while (15)N-glutamate was synthesized at a similar rate to that in the control. A discrepancy between the up-regulation of GDH1 expression and the down-regulation of GDH activity by hypoxic stress highlighted for the first time the complex regulation of this enzyme by hypoxia. Higher rates of glycolysis and ethanol fermentation are known to cause the fast depletion of sugar stores and carbon stress. It is proposed that the expression of GDH1 was stimulated by hypoxia-induced carbon stress, while the enzyme protein might be involved during post-hypoxic stress contributing to the regeneration of 2-oxoglutarate via the GDH shunt.

  17. Glutamate oxidation in astrocytes: Roles of glutamate dehydrogenase and aminotransferases

    DEFF Research Database (Denmark)

    McKenna, Mary C; Stridh, Malin H; McNair, Laura Frendrup;

    2016-01-01

    The cellular distribution of transporters and enzymes related to glutamate metabolism led to the concept of the glutamate–glutamine cycle. Glutamate is released as a neurotransmitter and taken up primarily by astrocytes ensheathing the synapses. The glutamate carbon skeleton is transferred back...... oxidative degradation; thus, quantitative formation of glutamine from the glutamate taken up is not possible. Oxidation of glutamate is initiated by transamination catalyzed by an aminotransferase, or oxidative deamination catalyzed by glutamate dehydrogenase (GDH). We discuss methods available to elucidate...... the enzymes that mediate this conversion. Methods include pharmacological tools such as the transaminase inhibitor aminooxyacetic acid, studies using GDH knockout mice, and siRNA-mediated knockdown of GDH in astrocytes. Studies in brain slices incubated with [15N]glutamate demonstrated activity of GDH...

  18. Serum biochemical profile of laying hens in the region of Araçatuba, SP
    Perfil bioquímico das galinhas poedeiras na região de Araçatuba-SP.

    OpenAIRE

    Paulo César Ciarlini; Elisa Helena Giglio Ponsano; Lorrayne Bernegossi Polônio; Carolina Kimie Mori; Tatiana de Sousa Barbosa

    2011-01-01

    The establishment of reference values is extremely important for successful diagnosis and treatament. Considering that in most species the serum chemistry profile is influenced by race, climate and management, we decided to determine the values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), uric acid, creatinine, creatine kinase (CK), phosphatase alkaline (ALP), gamma-glutamyltransferase (GGT), total protein (TP) and albumin of Dekalb hens in the region of Araçatuba - SP...

  19. The effects of moderate drinking and abstinence on serum and urinary beta-hexosaminidase levels.

    Science.gov (United States)

    Kärkkäinen, P; Jokelainen, K; Roine, R; Suokas, A; Salaspuro, M

    1990-02-01

    The effects of moderate alcohol intake on serum (SHEX)- and urinary beta-hexosaminidase (UHEX) were studied in ten healthy volunteers, who ingested 60 g of 100% ethanol daily for 10 days. The drinking period was preceded and followed by an abstinence period. Moderate drinking and abstinence were rapidly and significantly reflected on SHEX, while UHEX levels did not change significantly during the study. Gramma-glutamyl transpeptidase (GGT), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) decreased during the first abstinence period (P less than 0.05), but stayed thereafter at a constant level. It is concluded that SHEX may better reflect recent alcohol consumption than UHEX, GGT, ASAT or ALAT.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yong-Zhi; Sheng, Yu [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Li, Lan-Fen [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Tang, De-Wei [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Liu, Xiang-Yu [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Zhao, Xiaojun, E-mail: zhaoxj@scu.edu.cn [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Liang, Yu-He, E-mail: zhaoxj@scu.edu.cn; Su, Xiao-Dong [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China)

    2007-09-01

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

  1. Dose Response of Alanine Detectors Irradiated with Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

    2011-01-01

    Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions....... Methods: Alanine detectors have been irradiated with carbon ions with an energy range of 89-400 MeV/u. The relative effectiveness of alanine has been measured in this regime. Pristine and spread out Bragg peak depth-dose curves have been measured with alanine dosimeters. The track-structure based alanine......-dose curves deviate from predictions in the peak region, most pronounced at the distal edge of the peak. Conclusions: The used model and its implementation show a good overall agreement for quasi mono energetic measurements. Deviations in depth-dose measurements are mainly attributed to uncertainties...

  2. Tyrosine aminotransferase from Leishmania infantum: A new drug target candidate

    Directory of Open Access Journals (Sweden)

    Miguel Angel Moreno

    2014-12-01

    Full Text Available Leishmania infantum is the etiological agent of zoonotic visceral leishmaniasis in the Mediterranean basin. The disease is fatal without treatment, which has been based on antimonial pentavalents for more than 60 years. Due to resistances, relapses and toxicity to current treatment, the development of new drugs is required. The structure of the L. infantum tyrosine aminotransferase (LiTAT has been recently solved showing important differences with the mammalian orthologue. The characterization of LiTAT is reported herein. This enzyme is cytoplasmic and is over-expressed in the more infective stages and nitric oxide resistant parasites. Unlike the mammalian TAT, LiTAT is able to use ketomethiobutyrate as co-substrate. The pharmacophore model of LiTAT with this specific co-substrate is described herein. This may allow the identification of new inhibitors present in the databases. All the data obtained support that LiTAT is a good target candidate for the development of new anti-leishmanial drugs.

  3. Dosimetry for the external radiation therapy. Dosimetry with alanine; Dosimetrie fuer die externe Strahlentherapie. Dosimetrie mit Alanin

    Energy Technology Data Exchange (ETDEWEB)

    Anton, Mathias [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe ' Alanin-Dosimetrie'

    2013-06-15

    The alanine-ESR dosimetry in the PTB is described. The response power of alanine related to the water energy dose for X-rays with average energy of 10-1000 keV is presented. Furthermore the application of alanine for the quality assurance in the radiation therapy is described by means of the prostate irradiation and the therapy of a tumor in the neck region as examples. (HSI)

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

    Science.gov (United States)

    Lu, Yongzhi; Xu, Hongyan; Zhao, Xiaojun

    2010-08-01

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

  5. Correlation of GGT with AFP and diagnostic value of GGT for hepatocellular carcinoma%γ-谷氨酰转肽酶和甲胎蛋白表达的相关性及其在肝细胞癌诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    高春; 房龙; 姚树坤

    2014-01-01

    Objective To analyze the correlation of gamma-glutamyl transpeptidase (GGT)level with alpha-fetoprotein (AFP)level and to re-evaluate the diagnostic value of GGT for hepatocellular carcinoma (HCC).Methods Four hundred and seventy-two patients with HCC or liver cirrhosis,who were hospitalized in China-Japan Friendship Hospital from January 2003 to June 2009,were included in the study.The correlation between GGT and AFP was analyzed by Spearman nonparametric test.The cut-off values for the two parameters were determined based on their receiver operating characteristics (ROC)curves,areas under the ROC curve (AUCs),sensitivity,and specifici-ty,and the diagnostic values were presented using their sensitivity,specificity,and correct index.Statistical analysis was performed using SPSS 17.0.Normally distributed continuous data were analyzed by independent-samples t test,while non-normally distributed continuous data were analyzed by Mann -Whitney U test.Categorical data were analyzed by Pearson chi -square test,continuity-corrected chi -square test,or Fisher’s exact test.Results Among 472 patients,224 were diagnosed with HCC,and 248 with liver cirrhosis.Compared with cirrhotic patients,HCC patients had a significantly higher GGT level (113 (58-254)U/L vs 38 (22-72)U/L,Z=-11.037,P<0.001)and a significantly higher AFP level (429.5 (15.7-1210.0)ng/ml vs 5.7 (3.4-18.2)ng/ml,Z=-10.157,P<0.001).A significant correlation was found between GGT and AFP (r=0.449,P<0.001).The AUC was 0.784 for GGT and 0.788 for AFP.The cut-off value was 60 U/L for GGT and 20 ng/ml for AFP.The sensitivity was 74.1%for GGT,71.8%for AFP,and 90.7%for a combina-tion of the two parameters,the specificity was 70.2%,77.6%,and 58.7%,respectively,and the correct index was 0.443,0.494,and 0.494,respectively.Conclusion GGT may be regarded as one biomarker for HCC,and its level is significantly correlated with AFP level. The diagnostic value of AFP may not be improved when used in combination with GGT.%目的

  6. Engineering of alanine dehydrogenase from Bacillus subtilis for novel cofactor specificity.

    Science.gov (United States)

    Lerchner, Alexandra; Jarasch, Alexander; Skerra, Arne

    2016-09-01

    The l-alanine dehydrogenase of Bacillus subtilis (BasAlaDH), which is strictly dependent on NADH as redox cofactor, efficiently catalyzes the reductive amination of pyruvate to l-alanine using ammonia as amino group donor. To enable application of BasAlaDH as regenerating enzyme in coupled reactions with NADPH-dependent alcohol dehydrogenases, we alterated its cofactor specificity from NADH to NADPH via protein engineering. By introducing two amino acid exchanges, D196A and L197R, high catalytic efficiency for NADPH was achieved, with kcat /KM  = 54.1 µM(-1)  Min(-1) (KM  = 32 ± 3 µM; kcat  = 1,730 ± 39 Min(-1) ), almost the same as the wild-type enzyme for NADH (kcat /KM  = 59.9 µM(-1)  Min(-1) ; KM  = 14 ± 2 µM; kcat  = 838 ± 21 Min(-1) ). Conversely, recognition of NADH was much diminished in the mutated enzyme (kcat /KM  = 3 µM(-1)  Min(-1) ). BasAlaDH(D196A/L197R) was applied in a coupled oxidation/transamination reaction of the chiral dicyclic dialcohol isosorbide to its diamines, catalyzed by Ralstonia sp. alcohol dehydrogenase and Paracoccus denitrificans ω-aminotransferase, thus allowing recycling of the two cosubstrates NADP(+) and l-Ala. An excellent cofactor regeneration with recycling factors of 33 for NADP(+) and 13 for l-Ala was observed with the engineered BasAlaDH in a small-scale biocatalysis experiment. This opens a biocatalytic route to novel building blocks for industrial high-performance polymers.

  7. Tyrosine aminotransferase: biochemical and structural properties and molecular dynamics simulations.

    Science.gov (United States)

    Mehere, Prajwalini; Han, Qian; Lemkul, Justin A; Vavricka, Christopher J; Robinson, Howard; Bevan, David R; Li, Jianyong

    2010-11-01

    Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using α-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 Å resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.

  8. Biochemical and structural properties of mouse kynurenine aminotransferase III.

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Cai, Tao; Tagle, Danilo A; Li, Jianyong

    2009-02-01

    Kynurenine aminotransferase III (KAT III) has been considered to be involved in the production of mammalian brain kynurenic acid (KYNA), which plays an important role in protecting neurons from overstimulation by excitatory neurotransmitters. The enzyme was identified based on its high sequence identity with mammalian KAT I, but its activity toward kynurenine and its structural characteristics have not been established. In this study, the biochemical and structural properties of mouse KAT III (mKAT III) were determined. Specifically, mKAT III cDNA was amplified from a mouse brain cDNA library, and its recombinant protein was expressed in an insect cell protein expression system. We established that mKAT III is able to efficiently catalyze the transamination of kynurenine to KYNA and has optimum activity at relatively basic conditions of around pH 9.0 and at relatively high temperatures of 50 to 60 degrees C. In addition, mKAT III is active toward a number of other amino acids. Its activity toward kynurenine is significantly decreased in the presence of methionine, histidine, glutamine, leucine, cysteine, and 3-hydroxykynurenine. Through macromolecular crystallography, we determined the mKAT III crystal structure and its structures in complex with kynurenine and glutamine. Structural analysis revealed the overall architecture of mKAT III and its cofactor binding site and active center residues. This is the first report concerning the biochemical characteristics and crystal structures of KAT III enzymes and provides a basis toward understanding the overall physiological role of mammalian KAT III in vivo and insight into regulating the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  9. Biochemical and Structural Properties of Mouse Kynurenine Aminotransferase III▿

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Cai, Tao; Tagle, Danilo A.; Li, Jianyong

    2009-01-01

    Kynurenine aminotransferase III (KAT III) has been considered to be involved in the production of mammalian brain kynurenic acid (KYNA), which plays an important role in protecting neurons from overstimulation by excitatory neurotransmitters. The enzyme was identified based on its high sequence identity with mammalian KAT I, but its activity toward kynurenine and its structural characteristics have not been established. In this study, the biochemical and structural properties of mouse KAT III (mKAT III) were determined. Specifically, mKAT III cDNA was amplified from a mouse brain cDNA library, and its recombinant protein was expressed in an insect cell protein expression system. We established that mKAT III is able to efficiently catalyze the transamination of kynurenine to KYNA and has optimum activity at relatively basic conditions of around pH 9.0 and at relatively high temperatures of 50 to 60°C. In addition, mKAT III is active toward a number of other amino acids. Its activity toward kynurenine is significantly decreased in the presence of methionine, histidine, glutamine, leucine, cysteine, and 3-hydroxykynurenine. Through macromolecular crystallography, we determined the mKAT III crystal structure and its structures in complex with kynurenine and glutamine. Structural analysis revealed the overall architecture of mKAT III and its cofactor binding site and active center residues. This is the first report concerning the biochemical characteristics and crystal structures of KAT III enzymes and provides a basis toward understanding the overall physiological role of mammalian KAT III in vivo and insight into regulating the levels of endogenous KYNA through modulation of the enzyme in the mouse brain. PMID:19029248

  10. Biochemical and Structural Properties of Mouse Kynurenine Aminotransferase III

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Robinson, H; Cai, T; Tagle, D; Li, J

    2009-01-01

    Kynurenine aminotransferase III (KAT III) has been considered to be involved in the production of mammalian brain kynurenic acid (KYNA), which plays an important role in protecting neurons from overstimulation by excitatory neurotransmitters. The enzyme was identified based on its high sequence identity with mammalian KAT I, but its activity toward kynurenine and its structural characteristics have not been established. In this study, the biochemical and structural properties of mouse KAT III (mKAT III) were determined. Specifically, mKAT III cDNA was amplified from a mouse brain cDNA library, and its recombinant protein was expressed in an insect cell protein expression system. We established that mKAT III is able to efficiently catalyze the transamination of kynurenine to KYNA and has optimum activity at relatively basic conditions of around pH 9.0 and at relatively high temperatures of 50 to 60C. In addition, mKAT III is active toward a number of other amino acids. Its activity toward kynurenine is significantly decreased in the presence of methionine, histidine, glutamine, leucine, cysteine, and 3-hydroxykynurenine. Through macromolecular crystallography, we determined the mKAT III crystal structure and its structures in complex with kynurenine and glutamine. Structural analysis revealed the overall architecture of mKAT III and its cofactor binding site and active center residues. This is the first report concerning the biochemical characteristics and crystal structures of KAT III enzymes and provides a basis toward understanding the overall physiological role of mammalian KAT III in vivo and insight into regulating the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  11. Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations

    Energy Technology Data Exchange (ETDEWEB)

    P Mehere; Q Han; J Lemkul; C Vavricka; H Robinson; D Bevan; J Li

    2011-12-31

    Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using {alpha}-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 {angstrom} resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.

  12. Tyrosine aminotransferase: biochemical and structural properties and molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Mehere, P.; Robinson, H.; Han, Q.; Lemkul, J. A.; Vavricka, C. J.; Bevan, D. R.; Li, J.

    2010-11-01

    Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using {alpha}-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 {angstrom} resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.

  13. The structure of alanine racemase from Acinetobacter baumannii.

    Science.gov (United States)

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

    2014-09-01

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

  14. Absolute quantification of serum microRNA-122 and its correlation with liver inflammation grade and serum alanine aminotransferase in chronic hepatitis C patients

    Directory of Open Access Journals (Sweden)

    Jiang-hua Wang

    2015-01-01

    Conclusions: The present study showed that serum microRNA-122 was elevated in acute and chronic hepatitis patients. However, this biomarker for acute liver injury did not reflect the liver inflammation activity in CHC patients.

  15. ELEVATED ALANINE AMINOTRANSFERASE (ALT IN BLOOD DONORS: AN ASSESSMENT OF THE MAIN ASSOCIATED CONDITIONS AND ITS RELATIONSHIP TO THE DEVELOPMENT OF HEPATITIS C

    Directory of Open Access Journals (Sweden)

    Fernando Lopes GONÇALES Jr.

    1998-07-01

    Full Text Available The determination of aminotranferases levels is very useful in the diagnosis of hepatopathies. In recent years, an elevated serum ALT level in blood donors has been associated with an increased risk of post-transfusion hepatitis (PTH. The purpose of the study was to research the factors associated with elevated ALT levels in a cohort of voluntary blood donors and to evaluate the relationship between increased ALT levels and the development of hepatitis C (HCV infection. 166 volunteer blood donors with elevated ALT at the time of their first donation were studied. All of the donors were questioned about previous hepatopathies, exposure to hepatitis, exposure to chemicals, use of medication or drugs, sexual behaviour, contact with blood or secretions and their intake of alcohol. Every three months, the serum levels of AST, ALT, alkaline phosphatase, gamma glutamyl transpeptidase, cholesterol, triglyceride and glycemia are assessed over a two year follow-up. The serum thyroid hormone levels as well as the presence of auto-antibodies were also measured. Abdominal ultrasound was performed in all patients with persistently elevated ALT or AST levels. A needle biopsy of liver was performed in 9 donors without definite diagnostic after medical investigation. The presence of anti-HCV antibodies in 116 donors were assayed again the first clinical evaluation. At the end of follow-up period (2 years later 71 donors were tested again for the presence of anti-HCV antibodies. None of donors resulted positive for hepatitis B or hepatitis C markers during the follow-up. Of the 116 donors, 101 (87% had persistently elevated ALT serum levels during the follow-up. Obesity and alcoholism were the principal conditions related to elevated ALT serum levels in 91/101 (90.1% donors. Hypertriglyceridemia, hypercholesterolemia, hypothyroidism and diabetes mellitus also were associated with increased ALT levels. Only 1/101 (0.9% had mild chronic active non A-G viral hepatitis and 3/101 (2.9% had liver biopsy with non-specific reactive hepatitis. The determination of ALT levels was not useful to detect donors infected with HCV at donation in Brazil, including the initial seronegative anti-HCV phase.A determinação dos níveis de alanina aminostransferase (ALT tem sido útil para o diagnóstico de hepatopatias. Ultimamente, a elevação dos níveis séricos de ALT em doadores de sangue, tem sido associada a um maior risco de hepatites pós-transfusionais. Este estudo busca identificar os fatores associados com elevados níveis de ALT entre doadores voluntários de sangue e avaliar as relações entre estes aumentos de ALT e o desenvolvimento de infecção pelo vírus da hepatite C. Assim, 116 doadores voluntários de sangue com níveis de ALT elevados, quando da primeira doação, foram estudados. Todos foram questionados sobre hepatopatias prévias, exposição a hepatites, exposição a produtos químicos, uso de drogas ou medicamentos, comportamento sexual, contacto com sangue ou secreções e consumo de álcool. A cada 3 meses foram medidos os níveis de AST, ALT, fosfatase alcalina, gama-glutamil transferase, colesterol, triglicérides e glicemia durante o período de 1-2 anos. Os níveis séricos de hormônios tireoidianos e a presença de auto-anticorpos também foram mensurados. Ultrassonografia abdominal foi realizada em todos os pacientes com elevação persistente dos níveis de AST ou ALT. Foi realizada biópsia hepática em 9 doadores sem diagnóstico definido após investigação clínica. A presença de anticorpos anti-HCV foi novamente pesquisada em 116 doadores no momento da primeira avaliação clínica. Ao final do follow-up (2 anos 71 doadores foram re-testados para a presença do anti-HCV. Nenhum doador se tornou reagente para os marcadores dos virus da hepatite B ou hepatite C, durante o seguimento. Dos 116 doadores, 101 (87% mantiveram níveis séricos de ALT persistentemente aumentados. Obesidade e alcoolismo foram as principais condições associadas à elevação dos níveis séricos de ALT em 91/101 (90,1% doadores. Hipertrigliceridemia, hipercolesterolemia, hipotireoidismo e diabetes mellitus também se associaram a níveis aumentados de ALT. Somente 1/101 (0,9% apresentou hepatite crônica ativa não A-G e 3/101 (2,9% apresentaram biópsia hepática com diagnóstico de hepatite reacional. A determinação rotineira dos níveis de ALT, em bancos de sangue não foi útil para detectar doadores infectados com o vírus da hepatite C no Brasil no período que antecede a soroconversão para anti-vhc.

  16. Elevated alanine aminotransferase activity is not associated with dyslipidemias, but related to insulin resistance and higher disease grades in non-diabetic non-alcoholic fatty liver disease

    Directory of Open Access Journals (Sweden)

    Mohammad Ebrahim Ghamar-Chehreh

    2012-09-01

    Conclusions: This study shows that the associations of increased ALT serum levels in NAFLD patients are different from what are supposed before. By excluding diabetic patients from our population, we find that increased ALT levels are not associated with dyslipidemias but are independently associated with insulin resistance and NAFLD grading on ultrasonographic evaluations. Further studies are needed to confirm our results.

  17. Plastidic aspartate aminotransferases and the biosynthesis of essential amino acids in plants.

    Science.gov (United States)

    de la Torre, Fernando; Cañas, Rafael A; Pascual, M Belén; Avila, Concepción; Cánovas, Francisco M

    2014-10-01

    In the chloroplasts and in non-green plastids of plants, aspartate is the precursor for the biosynthesis of different amino acids and derived metabolites that play distinct and important roles in plant growth, reproduction, development or defence. Aspartate biosynthesis is mediated by the enzyme aspartate aminotransferase (EC 2.6.1.1), which catalyses the reversible transamination between glutamate and oxaloacetate to generate aspartate and 2-oxoglutarate. Plastids contain two aspartate aminotransferases: a eukaryotic-type and a prokaryotic-type bifunctional enzyme displaying aspartate and prephenate aminotransferase activities. A general overview of the biochemistry, regulation, functional significance, and phylogenetic origin of both enzymes is presented. The roles of these plastidic aminotransferases in the biosynthesis of essential amino acids are discussed.

  18. Enzyme-Catalyzed Polymerization of Beta-alanine Esters, A Sustainable Route Towards the Formation of Poly-Beta-alanine

    NARCIS (Netherlands)

    Steunenberg, P.; Uiterweerd, M.; Sijm, M.; Scott, E.L.; Zuilhof, H.; Sanders, J.P.M.; Franssen, M.C.R.

    2013-01-01

    The synthesis of poly-ß-alanine by a lipase catalyzed polycondensation reaction between ß-alanine esters is reported. The effect of different solvents, reaction temperatures and substrate/enzyme concentrations on polymer yield and degree of polymerization (DP) was determined. Also the effect of meth

  19. β-Alanine supplementation for athletic performance: an update.

    Science.gov (United States)

    Bellinger, Phillip M

    2014-06-01

    β-alanine supplementation has become a common practice among competitive athletes participating in a range of different sports. Although the mechanism by which chronic β-alanine supplementation could have an ergogenic effect is widely debated, the popular view is that β-alanine supplementation augments intramuscular carnosine content, leading to an increase in muscle buffer capacity, a delay in the onset of muscular fatigue, and a facilitated recovery during repeated bouts of high-intensity exercise. β-alanine supplementation appears to be most effective for exercise tasks that rely heavily on ATP synthesis from anaerobic glycolysis. However, research investigating its efficacy as an ergogenic aid remains equivocal, making it difficult to draw conclusions as to its effectiveness for training and competition. The aim of this review was to update, summarize, and critically evaluate the findings associated with β-alanine supplementation and exercise performance with the most recent research available to allow the development of practical recommendations for coaches and athletes. A critical review of the literature reveals that when significant ergogenic effects have been found, they have been generally shown in untrained individuals performing exercise bouts under laboratory conditions. The body of scientific data available concerning highly trained athletes performing single competition-like exercise tasks indicates that this type of population receives modest but potentially worthwhile performance benefits from β-alanine supplementation. Recent data indicate that athletes may not only be using β-alanine supplementation to enhance sports performance but also as a training aid to augment bouts of high-intensity training. β-alanine supplementation has also been shown to increase resistance training performance and training volume in team-sport athletes, which may allow for greater overload and superior adaptations compared with training alone. The ergogenic

  20. The antiproton depth–dose curve measured with alanine detectors

    CERN Document Server

    Bassler, Niels; Palmans, Hugo; Holzscheiter, Michael H; Kovacevic, Sandra

    2008-01-01

    n this paper we report on the measurement of the antiproton depth–dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen and Olsen for conversion of calculated dose into response. A good agreement is observed between the measured and calculated relative effectiveness although an underestimation of the measured values beyond the Bragg-peak remains unexplained. The model prediction of response of alanine towards heavy charged particles encourages future use of the alanine detectors for dosimetry of mixed radiation fields.

  1. Colorimetry method for estimation of glycine, alanine and isoleucine

    Directory of Open Access Journals (Sweden)

    Shah S

    2007-01-01

    Full Text Available A simple and sensitive colorimetry method has been developed for estimation of amino acids glycine, alanine and isoleucine. Amino acids were derivatized with dichlone in presence of sodium bicarbonate. Amino acids showed maximum absorbance at 470 nm. The method was validated in terms of linearity (5-25 µg/ml for glycine, alanine and isoleucine, precision (intra-day variation 0.13-0.78, 0.22-1.29, 0.58-2.52% and inter-day variation 0.52-2.49, 0.43-3.12, 0.58- 4.48% for glycine, alanine and isoleucine respectively, accuracy (91.43-98.86, 96.26-105.99 and 95.73-104.82 for glycine, alanine and isoleucine respectively, limit of detection (0.6, 1 and 1 µg/ml for glycine, alanine and isoleucine respectively and limit of quantification (5 µg/ml for glycine, alanine and isoleucine. The method was found to be simple and sensitive.

  2. Selected Cytokines Serve as Potential Biomarkers for Predicting Liver Inflammation and Fibrosis in Chronic Hepatitis B Patients With Normal to Mildly Elevated Aminotransferases.

    Science.gov (United States)

    Deng, Yong-Qiong; Zhao, Hong; Ma, An-Lin; Zhou, Ji-Yuan; Xie, Shi-Bin; Zhang, Xu-Qing; Zhang, Da-Zhi; Xie, Qing; Zhang, Guo; Shang, Jia; Cheng, Jun; Zhao, Wei-Feng; Zou, Zhi-Qiang; Zhang, Ming-Xiang; Wang, Gui-Qiang

    2015-11-01

    Previous studies of small cohorts have implicated several circulating cytokines with progression of chronic hepatitis B (CHB). However, to date there have been no reliable biomarkers for assessing histological liver damage in CHB patients with normal or mildly elevated alanine aminotransferase (ALT). The aim of the present study was to investigate the association between circulating cytokines and histological liver damage in a large cohort. Also, this study was designed to assess the utility of circulating cytokines in diagnosing liver inflammation and fibrosis in CHB patients with ALT less than 2 times the upper limit of normal range (ULN). A total of 227 CHB patients were prospectively enrolled. All patients underwent liver biopsy and staging by Ishak system. Patients with at least moderate inflammation showed significantly higher levels of CXCL-11, CXCL-10, and interleukin (IL)-2 receptor (R) than patients with less than moderate inflammation (P inflammation and significant fibrosis, respectively. Multivariate analysis demonstrated that CXCL-11 was independently associated with at least moderate inflammation, and TGF-α and IL-2R independently correlated with significant fibrosis in patients with ALT inflammation-index and fib-index were developed, which showed areas under the receiver operating characteristics curve (AUROC) of 0.75 (95% CI 0.66-0.84) for at least moderate inflammation and 0.82 (95% CI 0.75-0.90) for significant fibrosis, correspondingly. Compared to existing scores, fib-index was significantly superior to aspartate aminotransferase (AST) to platelet ratio index (APRI) and FIB-4 score for significant fibrosis. In conclusion, CXCL-11 was independently associated with at least moderate inflammation, whereas IL-2R and TGF-α were independent indicators of significant fibrosis in both, total CHB patients and patients with normal or mildly elevated ALT. An IL-2R and TGF-α based score (fib-index) was superior to APRI and FIB-4 for the diagnosis

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Biochemical properties and crystal structure of a β-phenylalanine aminotransferase from Variovorax paradoxus.

    Science.gov (United States)

    Crismaru, Ciprian G; Wybenga, Gjalt G; Szymanski, Wiktor; Wijma, Hein J; Wu, Bian; Bartsch, Sebastian; de Wildeman, Stefaan; Poelarends, Gerrit J; Feringa, Ben L; Dijkstra, Bauke W; Janssen, Dick B

    2013-01-01

    By selective enrichment, we isolated a bacterium that can use β-phenylalanine as a sole nitrogen source. It was identified by 16S rRNA gene sequencing as a strain of Variovorax paradoxus. Enzyme assays revealed an aminotransferase activity. Partial genome sequencing and screening of a cosmid DNA library resulted in the identification of a 1,302-bp aminotransferase gene, which encodes a 46,416-Da protein. The gene was cloned and overexpressed in Escherichia coli. The recombinant enzyme was purified and showed a specific activity of 17.5 U mg(-1) for (S)-β-phenylalanine at 30°C and 33 U mg(-1) at the optimum temperature of 55°C. The β-specific aminotransferase exhibits a broad substrate range, accepting ortho-, meta-, and para-substituted β-phenylalanine derivatives as amino donors and 2-oxoglutarate and pyruvate as amino acceptors. The enzyme is highly enantioselective toward (S)-β-phenylalanine (enantioselectivity [E], >100) and derivatives thereof with different substituents on the phenyl ring, allowing the kinetic resolution of various racemic β-amino acids to yield (R)-β-amino acids with >95% enantiomeric excess (ee). The crystal structures of the holoenzyme and of the enzyme in complex with the inhibitor 2-aminooxyacetate revealed structural similarity to the β-phenylalanine aminotransferase from Mesorhizobium sp. strain LUK. The crystal structure was used to rationalize the stereo- and regioselectivity of V. paradoxus aminotransferase and to define a sequence motif with which new aromatic β-amino acid-converting aminotransferases may be identified.

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

    Science.gov (United States)

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

    2004-10-26

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

  6. Biochemical and Structural Characterization of a Ureidoglycine Aminotransferase in the Klebsiella pneumoniae Uric Acid Catabolic Pathway

    Energy Technology Data Exchange (ETDEWEB)

    French, Jarrod B.; Ealick, Steven E. (Cornell)

    2010-09-03

    Many plants, fungi, and bacteria catabolize allantoin as a mechanism for nitrogen assimilation. Recent reports have shown that in plants and some bacteria the product of hydrolysis of allantoin by allantoinase is the unstable intermediate ureidoglycine. While this molecule can spontaneously decay, genetic analysis of some bacterial genomes indicates that an aminotransferase may be present in the pathway. Here we present evidence that Klebsiella pneumoniae HpxJ is an aminotransferase that preferentially converts ureidoglycine and an {alpha}-keto acid into oxalurate and the corresponding amino acid. We determined the crystal structure of HpxJ, allowing us to present an explanation for substrate specificity.

  7. Serum hepatic enzyme activity in relation to semen quality and serum reproductive hormone levels among Estonian fertile Men.

    Science.gov (United States)

    Ehala-Aleksejev, K; Punab, M

    2016-01-01

    The aim of this study was to investigate the relations of basic semen parameters and reproductive hormones with alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT). In addition, to examine possible interaction between adiposity, alcohol consumption, and liver tests in relation to male reproductive health, standard semen analysis was performed and serum levels of reproductive hormones and liver tests were measured in 245 male partners of pregnant women at a University Hospital Andrology Centres in Estonia. Quartile analysis revealed that after adjustment for covariates GGT was negatively related to sperm concentration and total sperm count. These significant changes appeared from a GGT >35.5 U/L. Next to these changes ALT was not related to sperm parameters. Both enzymes, GGT and ALT, were not related to reproductive hormones. Alcohol consumption was positively related to GGT and in cases with elevated GGT alcohol use was negatively related to sperm concentration and total sperm count. Alcohol consumption was positively related to body mass index (BMI) and waist circumference (WC). Our findings also confirm results of previous studies that BMI and WC are associated positively with ALT and GGT. According to the study, increased GGT activity might represent a possible connection between adiposity, alcohol consumption, and semen quality.

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

    Science.gov (United States)

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

    2013-03-01

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

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

    Science.gov (United States)

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

    2016-05-01

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

  10. The Response of Alanine Dosimeters in Thermal Neutron Fields

    DEFF Research Database (Denmark)

    Schmitz, T.; Bassler, Niels; Sharpe, P.

    Purpose: Boron Neutron Capture Therapy (BNCT) is a special kind of particle therapy, based on the neutron induced fission of the boron isotope 10B [1]. We have performed dosimetry experiments on the mixed neutron and gamma fields at the TRIGA Mark II research reactor in Mainz. Commonly, dosimetry...... in such fields is realized by foil activation and ion chambers [2]. Here we investigate alanine as an easier and more robust alternative dosimeter. Methods: We have performed four phantom experiments at the TRIGA Mark II research reactor in Mainz [3], in a predominantly thermal neutron field with a strong gamma...... neutron capture of hydrogen. The primary gamma dose deposited originate from the reactor core itself. Conclusion: Alanine dosimeters are suitable of measurements in mixed neutron fields and the alanine response in thermal neutron fields can be fully understood by the used interpretation model. In further...

  11. Structure, expression, and function of kynurenine aminotransferases in human and rodent brains.

    Science.gov (United States)

    Han, Qian; Cai, Tao; Tagle, Danilo A; Li, Jianyong

    2010-02-01

    Kynurenine aminotransferases (KATs) catalyze the synthesis of kynurenic acid (KYNA), an endogenous antagonist of N-methyl-D: -aspartate and alpha 7-nicotinic acetylcholine receptors. Abnormal KYNA levels in human brains are implicated in the pathophysiology of schizophrenia, Alzheimer's disease, and other neurological disorders. Four KATs have been reported in mammalian brains, KAT I/glutamine transaminase K/cysteine conjugate beta-lyase 1, KAT II/aminoadipate aminotransferase, KAT III/cysteine conjugate beta-lyase 2, and KAT IV/glutamic-oxaloacetic transaminase 2/mitochondrial aspartate aminotransferase. KAT II has a striking tertiary structure in N-terminal part and forms a new subgroup in fold type I aminotransferases, which has been classified as subgroup Iepsilon. Knowledge regarding KATs is vast and complex; therefore, this review is focused on recent important progress of their gene characterization, physiological and biochemical function, and structural properties. The biochemical differences of four KATs, specific enzyme activity assays, and the structural insights into the mechanism of catalysis and inhibition of these enzymes are discussed.

  12. Structure Expression and Function of kynurenine Aminotransferases in Human and Rodent Brains

    Energy Technology Data Exchange (ETDEWEB)

    Q Han; T Cai; D Tagle; J Li

    2011-12-31

    Kynurenine aminotransferases (KATs) catalyze the synthesis of kynurenic acid (KYNA), an endogenous antagonist of N-methyl-D: -aspartate and alpha 7-nicotinic acetylcholine receptors. Abnormal KYNA levels in human brains are implicated in the pathophysiology of schizophrenia, Alzheimer's disease, and other neurological disorders. Four KATs have been reported in mammalian brains, KAT I/glutamine transaminase K/cysteine conjugate beta-lyase 1, KAT II/aminoadipate aminotransferase, KAT III/cysteine conjugate beta-lyase 2, and KAT IV/glutamic-oxaloacetic transaminase 2/mitochondrial aspartate aminotransferase. KAT II has a striking tertiary structure in N-terminal part and forms a new subgroup in fold type I aminotransferases, which has been classified as subgroup Iepsilon. Knowledge regarding KATs is vast and complex; therefore, this review is focused on recent important progress of their gene characterization, physiological and biochemical function, and structural properties. The biochemical differences of four KATs, specific enzyme activity assays, and the structural insights into the mechanism of catalysis and inhibition of these enzymes are discussed.

  13. Structural Determinants of the beta-Selectivity of a Bacterial Aminotransferase

    NARCIS (Netherlands)

    Wybenga, Gjalt G.; Crismaru, Ciprian G.; Janssen, Dick B.; Dijkstra, Bauke W.

    2012-01-01

    Chiral beta-amino acids occur as constituents of various natural and synthetic compounds with potentially useful bioactivities. The pyridoxal 5'-phosphate (PLP)-dependent S-selective transaminase from Mesorhizobium sp. strain LUK (MesAT) is a fold type I aminotransferase that can be used for the pre

  14. Biochemical Properties and Crystal Structure of a β-Phenylalanine Aminotransferase from Variovorax paradoxus

    NARCIS (Netherlands)

    Crismaru, Ciprian G.; Wybenga, Gjalt G.; Szymanski, Wiktor; Wijma, Hein J.; Wu, Bian; Bartsch, Sebastian; de Wildeman, Stefaan; Poelarends, Gerrit J.; Feringa, Ben L.; Dijkstra, Bauke; Janssen, Dick B.

    2013-01-01

    By selective enrichment, we isolated a bacterium that can use beta-phenylalanine as a sole nitrogen source. It was identified by 16S rRNA gene sequencing as a strain of Variovorax paradoxus. Enzyme assays revealed an aminotransferase activity. Partial genome sequencing and screening of a cosmid DNA

  15. Parvovirus B19-Induced Constellation of Acute Renal Failure, Elevated Aminotransferases and Congestive Heart Failure

    Directory of Open Access Journals (Sweden)

    Iain W McAuley

    1997-01-01

    Full Text Available This report details a case of acute renal failure and elevated aminotransferases with subsequent development of congestive heart failure in a patient with history of exposure to parvovirus B19 and serological evidence of acute infection with this agent. This constellation of organ involvement has not been previously reported in the literature.

  16. Characterization of the different spectral forms of glutamate 1-semialdehyde aminotransferase by mass spectrometry

    DEFF Research Database (Denmark)

    Brody, S; Andersen, Jens S.; Kannangara, C G

    1995-01-01

    Glutamate 1-semialdehyde aminotransferase produces delta-aminolevulinate for the synthesis of chlorophyll, heme, and other tetrapyrrole pigments. The native enzyme from Synechococcus is pale yellow and has absorption maxima at 338 and 418 nm from vitamin B6. Yellow, colorless, and pink forms...

  17. Identification and Partial Characterization of an L-Tyrosine Aminotransferase (TAT from Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Pranav R. Prabhu

    2010-01-01

    Full Text Available The aminotransferase gene family in the model plant Arabidopsis thaliana consists of 44 genes. Twenty six of these enzymes are classified as characterized meaning that the reaction(s that the enzyme catalyzes are documented using experimental means. The remaining 18 enzymes are uncharacterized and are therefore deemed putative. Our laboratory is interested in elucidating the function(s of the remaining putative aminotransferase enzymes. To this end, we have identified and partially characterized an aminotransferase (TAT enzyme from Arabidopsis annotated by the locus tag At5g36160. The full-length cDNA was cloned and the purified recombinant enzyme was characterized using in vitro and in vivo experiments. In vitro analysis showed that the enzyme is capable of interconverting L-Tyrosine and 4-hydroxyphenylpyruvate, and L-Phenylalanine and phenylpyruvate. In vivo analysis by functional complementation showed that the gene was able to complement an E. coli with a background of aminotransferase mutations that confers auxotrophy for L-Tyrosine and L-Phenylalanine.

  18. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo;

    of the depth dose curves. Solid state detectors, such as diamond detectors, radiochromic films, TLDs and the amino acid alanine are used due to there good spatial resolution. If used in particle beams their response often exhibits a dependence on particle energy and type, so the acquired signal is not always...... at energies below 20 MeV/u. We implemented this model in the Monte Carlo code FLUKA. At the GSI heavy ion facility in Darmstadt, Germany, alanine has been irradiated with carbon ions at energies between 88 an 400 MeV/u, which is the energy range used for therapy. The irradiation and the detector response have...

  19. Gamma-glutamyltransferase, aspartate aminotransferase and alkaline phosphatase as markers of alcohol consumption in out-patient alcoholics

    DEFF Research Database (Denmark)

    Gluud, C; Andersen, I; Dietrichson, O;

    1981-01-01

    Serum activity of gamma-glutamyltransferase, aspartate aminotransferase and alkaline phosphatase were determined in 316 patients attending an out-patients clinic for treatment of alcoholism. The activity of gamma-glutamyltransferase was raised in 34% and that of aspartate aminotransferase and alk...

  20. The narrow substrate specificity of human tyrosine aminotransferase--the enzyme deficient in tyrosinemia type II.

    Science.gov (United States)

    Sivaraman, Sharada; Kirsch, Jack F

    2006-05-01

    Human tyrosine aminotransferase (hTATase) is the pyridoxal phosphate-dependent enzyme that catalyzes the reversible transamination of tyrosine to p-hydrophenylpyruvate, an important step in tyrosine metabolism. hTATase deficiency is implicated in the rare metabolic disorder, tyrosinemia type II. This enzyme is a member of the poorly characterized Igamma subfamily of the family I aminotransferases. The full length and truncated forms of recombinant hTATase were expressed in Escherichia coli, and purified to homogeneity. The pH-dependent titration of wild-type reveals a spectrum characteristic of family I aminotransferases with an aldimine pK(a) of 7.22. I249A mutant hTATase exhibits an unusual spectrum with a similar aldimine pK(a) (6.85). hTATase has very narrow substrate specificity with the highest enzymatic activity for the Tyr/alpha-ketoglutarate substrate pair, which gives a steady state k(cat) value of 83 s(-1). In contrast there is no detectable transamination of aspartate or other cosubstrates. The present findings show that hTATase is the only known aminotransferase that discriminates significantly between Tyr and Phe: the k(cat)/K(m) value for Tyr is about four orders of magnitude greater than that for Phe. A comparison of substrate specificities of representative Ialpha and Igamma aminotransferases is described along with the physiological significance of the discrimination between Tyr and Phe by hTATase as applied to the understanding of the molecular basis of phenylketonuria.

  1. Intrahepatic and peripheral T-cell responses in genotype 1b hepatitis C virus-infected patients with persistently normal and elevated aminotransferase levels

    Institute of Scientific and Technical Information of China (English)

    Filiz Akyüz; Nuray Polat; Sabahattin Kaymakoglu; Nevzat Aksoy; Kadir Demir; Fatih Be(s)i(s)ik; Selim Badur; Yilmaz (C)akaloglu; Atilla (O)kten

    2005-01-01

    AIM: To evaluate whether the cytokine responses in liver and serum differ in chronic hepatitis C patients with normal and high alanine aminotransferase (ALT) levels.METHODS: Thirty-three (16 with normal ALT level as group 1 and 17 with elevated ALT level as group 2) patients infected with genotype 1b hepatitis C virus (HCV) were examined. Liver infiltrating lymphomononuclear cells (LILMCs) were isolated from liver biopsy by collagenase type 1 and stimulated with phytohemagglutinin and interleukin 2 (IL-2). IL-10, IL-12,interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) were determined in serum and LILMCs by ELISA.RESULTS: Serum cytokine levels were similar in both groups (P>0.05). Stimulated IFN-γ and TNF-α levels in LILMCs were increased in both groups. IL-12 and IL-10levels stimulated with IL-2 were higher in group 1 than in group 2 (P = 0.023). Histological activity index (HAI)and stage had a negative correlation with TNF-α and IFN-γ levels in group 2.CONCLUSION: Increased T-helper type 2 (Th2)cytokine response may regress inflammatory and biochemical activity. Progression of histological abnormalities in persons with elevated ALT probably depends on insufficient Th2 cytokine response, which does not balance Th1 cytokine response.

  2. Valores de referência da atividade enzimática da aspartato-aminotransferase e da gama-glutamiltransferase em bovinos da raça Jersey. Influência dos fatores etários, sexuais e da infecção pelo vírus da leucose dos bovinos

    Directory of Open Access Journals (Sweden)

    Gregory L.

    1999-01-01

    Full Text Available Com o objetivo de estabelecer os valores de referência de parâmetros bioquímicos que avaliem a função hepática, por meio da determinação da atividade enzimática da aspartato-aminotransferase (AST e da gama-glutamiltransferase (GGT, de bovinos da raça Jersey, criados no Estado de São Paulo, bem como avaliar a influência dos fatores etários, sexuais e da infecção pelo vírus da leucose dos bovinos sobre os referidos parâmetros bioquímicos, foram colhidas e examinadas amostras de soro sangüíneo de 170 animais, sendo 106 fêmeas e 17 machos, considerados clinicamente sadios e não reagentes ao antígeno glicoprotéico (gp51 da cápsula do vírus da leucose dos bovinos e 47 fêmeas soro-reagentes ao mencionado vírus. Os valores de referência obtidos para a AST foram iguais a 33,91±10,99U/l enquanto para a GGT obtiveram-se valores médios de 13,21±12,72U/l. A avaliação dos resultados demonstrou que as transaminases sofreram influência dos fatores etários, pois comprovou-se que os teores séricos da AST aumentaram significativamente com o evoluir da idade, sendo o valor mínimo observado nas bezerras com até 3 meses de idade (26,39±22,17U/l e valor máximo em vacas com idade entre 48 e 72 meses de idade (38,60±11,24U/l. Para os níveis séricos da GGT observou-se que nas bezerras com até 3 meses de idade os níveis séricos (31,15±38,70U/l foram maiores do que os observados nos animais mais velhos (entre 8,70±2,40U/l e 14,24±10,37U/l. Nesta pesquisa não foram observadas influências dos fatores sexuais e da infecção pelo vírus da leucose dos bovinos sobre a atividade enzimática das transaminases.

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

    Science.gov (United States)

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

    2010-08-01

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

  4. The Antiproton Depth Dose Curve Measured with Alanine Detectors

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, Johnny Witterseh; Palmans, Hugo;

    2008-01-01

    In this paper we report on the measurement of the antiproton depth dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen et Olsen for conversion of calculated dose...

  5. Pressure-induced phase transformations in L-alanine crystals

    DEFF Research Database (Denmark)

    Olsen, J. Staun; Gerward, Leif; Freire, P.T.C.

    2008-01-01

    Raman scattering and synchrotron X-ray diffraction have been used to investigate the high-pressure behavior of L-alanine. This study has confirmed a structural phase transition observed by Raman scattering at 2.3 GPa and identified it as a change from orthorhombic to tetragonal structure. Another...

  6. Branched-chain amino acid aminotransferase and methionine formation in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Radford Cynthia L

    2004-10-01

    Full Text Available Abstract Background Tuberculosis remains a major world-wide health threat which demands the discovery and characterisation of new drug targets in order to develop future antimycobacterials. The regeneration of methionine consumed during polyamine biosynthesis is an important pathway present in many microorganisms. The final step of this pathway, the conversion of ketomethiobutyrate to methionine, can be performed by aspartate, tyrosine, or branched-chain amino acid aminotransferases depending on the particular species examined. Results The gene encoding for branched-chain amino acid aminotransferase in Mycobacterium tuberculosis H37Rv has been cloned, expressed, and characterised. The enzyme was found to be a member of the aminotransferase IIIa subfamily, and closely related to the corresponding aminotransferase in Bacillus subtilis, but not to that found in B. anthracis or B. cereus. The amino donor preference for the formation of methionine from ketomethiobutyrate was for isoleucine, leucine, valine, glutamate, and phenylalanine. The enzyme catalysed branched-chain amino acid and ketomethiobutyrate transamination with a Km of 1.77 – 7.44 mM and a Vmax of 2.17 – 5.70 μmol/min/mg protein, and transamination of ketoglutarate with a Km of 5.79 – 6.95 mM and a Vmax of 11.82 – 14.35 μmol/min/mg protein. Aminooxy compounds were examined as potential enzyme inhibitors, with O-benzylhydroxylamine, O-t-butylhydroxylamine, carboxymethoxylamine, and O-allylhydroxylamine yielding mixed-type inhibition with Ki values of 8.20 – 21.61 μM. These same compounds were examined as antimycobacterial agents against M. tuberculosis and a lower biohazard M. marinum model system, and were found to completely prevent cell growth. O-Allylhydroxylamine was the most effective growth inhibitor with an MIC of 78 μM against M. marinum and one of 156 ��M against M. tuberculosis. Conclusion Methionine formation from ketomethiobutyrate is catalysed by a

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

    Science.gov (United States)

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

    2014-03-01

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

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

    Science.gov (United States)

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

    2013-12-01

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

  9. Branched-chain amino acid aminotransferase and methionine formation in Mycobacterium tuberculosis

    OpenAIRE

    Radford Cynthia L; Knodel Marvin H; Venos Erik S; Berger Bradley J

    2004-01-01

    Abstract Background Tuberculosis remains a major world-wide health threat which demands the discovery and characterisation of new drug targets in order to develop future antimycobacterials. The regeneration of methionine consumed during polyamine biosynthesis is an important pathway present in many microorganisms. The final step of this pathway, the conversion of ketomethiobutyrate to methionine, can be performed by aspartate, tyrosine, or branched-chain amino acid aminotransferases depending...

  10. 血清ALP、GGT、5’-NT与AFP联合检测在原发性肝癌诊断中的价值%Values of Combined Detection of Serum ALP, GGT, 5'-NT and AFP in the Diagnosis of Primary Hepatic Carcinoma

    Institute of Scientific and Technical Information of China (English)

    陈贞; 龙璐; 陶亚; 王堃; 易斌

    2012-01-01

    目的 探讨血清碱性磷酸酶(ALP)、谷氨酰转肽酶(GGT)、5核苷酸酶(5’-NT)以及AFP单独检测以及联合检测在原发性肝癌(PHC)诊断中的临床应用价值.方法 ALP、GGT、5’-NT检测采用酶速率法;AFP检测用电化学发光免疫分析法,分别检测原发性肝癌组(94例)、肝硬化组(60例)、慢性肝炎组(60例)、其他消化道肿瘤组(50例)和健康对照组(70例)血清ALP、GGT、5’-NT、AFP水平,应用ROC曲线对结果进行统计学分析.结果 AFP、ALP、GGT、5’-NT的ROC曲线下面积(AUCROC)分别为0.832、0.649、0.786、0.774; AFP、5’-NT血清含量PHC组与其他各组间差异有统计学意义(P<0.05).系列试验中,AFP+ GGT+5’-NT组合的各个特征参数指标较好;平行试验中,AFP/GGT/5’-NT的灵敏度超过了97%.结论 原发性肝癌诊断单项指标中以AFP的AUCROC最大,诊断价值最高;系列试验中以AFP+ GGT+5’-NT作为确诊PHC,平行试验中以AFP/GGT/5’-NT作为排除PHC较好的组合项目.%Objective To investigate the values of separate and combined detection of serum ALP, GGT, 5' - NT and AFP in the diagnosis of primary hepatic carcinoma (PHC). Methods Serum ALP, GGT and 5' — NT were detected by enzymatic rate method. Serum AFP was determined by electrochemical luminescence immunoassay. Sera from 94 patients with PHC, 60 patients with cirrhosis, 60 cases with chronic hepatitis, 50 with other gastrointestinal tumors and 70 healthy individuals were subject to AFP, ALP, GGT and 5' - NT detection. The results were analyzed with ROC curves. Results The areas under the ROC curve (AUCR0C)of AFP, ALP, GGT and 5' - NT were 0.832, 0.649, 0.786 and 0.774, respectively. Serum AFP and 5' — NT levels in the PHC group were statistically different from those in other groups (P<0.05). Ina series of tests, the combination of AFP , GGT and 5' - NT had fairly good characteristic parameters. In the parallel trial, the sensitivity of AFP/GGT/5' -NT exceeded

  11. Degradation of glycine and alanine on irradiated quartz.

    Science.gov (United States)

    Pawlikowski, Maciej; Benko, Aleksandra; Wróbel, Tomasz P

    2013-04-01

    Recent researches suggest participation of minerals in the formation of life under primordial conditions. Among all of the minerals, quartz seems to be one of the most probable to take part in such processes. However, an external source of energy is needed, e.g. electric discharge. A device simulating the proposed conditions was designed and was used to simulate prebiotic conditions. Investigation of processes occurring during the stimulation of quartz with electric discharge was studied by means of Ultraviolet-visible (UV-VIS) spectroscopy, in order to monitor the generation kinetics of free radicals. Additionally, infrared spectroscopy was applied to identify chemical reaction products created in a solution of alanine or glycine, in the presence of quartz treated with electric discharge. Formation of increased amounts of free radicals, compared to experiments performed without quartz and/or amino acid, is reported, along with identification of possible degradation products of alanine. No synthetic reactions were observed.

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

    Science.gov (United States)

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

    2010-08-01

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

  13. Identification of ω-aminotransferase from Caulobacter crescentus and site-directed mutagenesis to broaden substrate specificity.

    Science.gov (United States)

    Hwang, Bum-Yeol; Ko, Seung-Hyun; Park, Hyung-Yeon; Seo, Joo-Hyun; Lee, Bon-Su; Kim, Byung-Gee

    2008-01-01

    A putative aminotransferase gene, cc3143 (aptA), from Caulobacter crescentus was screened by bioinformatical tools and overexpressed in E. coli, and the substrate specificity of the aminotransferase was investigated. AptA showed high activity for short-chain beta-amino acids. It showed the highest activity for 3-amino-n-butyric acid. It showed higher activity toward aromatic amines than aliphatic amines. The 3D model of the aminotransferase was constructed by homology modeling using a dialkylglycine decarboxylase PDB ID: 1DGE) as a template. Then, the aminotransferase was rationally redesigned to increase the activity for 3-amino- 3-phenylpropionic acid. The mutants N285A and V227G increased the relative activity for 3-amino-3-phenylpropionic acid to 3-amino-n-butyric acid by 11-fold and 3-fold, respectively, over that of wild type.

  14. Transport of the alpha-amino-mono-carboxylic acid L-alanine by the beta-alanine carrier of the rabbit ileum

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Munck, B G

    1987-01-01

    The proposal that the beta-alanine carrier of the rabbit ileum is a high affinity carrier of the neutral amino acids was examined by means of measurements of influx across the brush border membrane of the intact epithelium using L-alanine as a representative of the neutral amino acids. Confirming...... the proposal, evidence was provided for mutual competitive inhibition between beta-alanine and L-alanine; and it was also demonstrated that a process contributes to the influx of L-alanine, which is characterized by a maximum rate of transport equal to that of beta-alanine and a Kt, which is equal to the Ki...... of L-alanine against the influx of beta-alanine. In the concentration range 0.01 to 0.125 mM the influx of L-alanine was found to be linearly related to the concentration indicating a significant unstirred layer influence on present and previous estimates of the Kt values for influx of amino acids...

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

    Science.gov (United States)

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

    2017-05-01

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

  16. Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2014-01-01

    Full Text Available We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra.

  17. Thermal stability, pH dependence and inhibition of four murine kynurenine aminotransferases

    Directory of Open Access Journals (Sweden)

    Tagle Danilo A

    2010-05-01

    Full Text Available Abstract Background Kynurenine aminotransferase (KAT catalyzes the transamination of kynunrenine to kynurenic acid (KYNA. KYNA is a neuroactive compound and functions as an antagonist of alpha7-nicotinic acetylcholine receptors and is the only known endogenous antagonist of N-methyl-D-aspartate receptors. Four KAT enzymes, KAT I/glutamine transaminase K/cysteine conjugate beta-lyase 1, KAT II/aminoadipate aminotransferase, KAT III/cysteine conjugate beta-lyase 2, and KAT IV/glutamic-oxaloacetic transaminase 2/mitochondrial aspartate aminotransferase, have been reported in mammalian brains. Because of the substrate overlap of the four KAT enzymes, it is difficult to assay the specific activity of each KAT in animal brains. Results This study concerns the functional expression and comparative characterization of KAT I, II, III, and IV from mice. At the applied test conditions, equimolar tryptophan with kynurenine significantly inhibited only mouse KAT I and IV, equimolar methionine inhibited only mouse KAT III and equimolar aspartate inhibited only mouse KAT IV. The activity of mouse KAT II was not significantly inhibited by any proteinogenic amino acids at equimolar concentrations. pH optima, temperature preferences of four KATs were also tested in this study. Midpoint temperatures of the protein melting, half life values at 65°C, and pKa values of mouse KAT I, II, III, and IV were 69.8, 65.9, 64.8 and 66.5°C; 69.7, 27.4, 3.9 and 6.5 min; pH 7.6, 5.7, 8.7 and 6.9, respectively. Conclusion The characteristics reported here could be used to develop specific assay methods for each of the four murine KATs. These specific assays could be used to identify which KAT is affected in mouse models for research and to develop small molecule drugs for prevention and treatment of KAT-involved human diseases.

  18. Adrenal hormones and increase of liver tyrosine aminotransferase and tryptophan pyrrolase activity after immobilization in rats.

    Science.gov (United States)

    Németh, S; Vigas, M

    1975-06-01

    In adrenomedullectomized rats the postimmobilization increase of liver tyrosine aminotransferase and tryptophan pyrrolase activity was similar as in intact animals, wherease in adrenalectomized rats this response was completely absent. In intact animals a positive correlation between the magnitude of the response of both enzymes and the duration of immobilization and/or the extent of plasma corticosterone increase was observedmit is concluded that the postimmobilization hyperactivity of both enzymes arises exclusively as a consequence of hypercorticosteronaemia, catecholamines and other hormones being without any influence on this response.

  19. Structures of aspartate aminotransferases from Trypanosoma brucei, Leishmania major and Giardia lamblia.

    Science.gov (United States)

    Abendroth, Jan; Choi, Ryan; Wall, Abigail; Clifton, Matthew C; Lukacs, Christine M; Staker, Bart L; Van Voorhis, Wesley; Myler, Peter; Lorimer, Don D; Edwards, Thomas E

    2015-05-01

    The structures of three aspartate aminotransferases (AATs) from eukaryotic pathogens were solved within the Seattle Structural Genomics Center for Infectious Disease (SSGCID). Both the open and closed conformations of AAT were observed. Pyridoxal phosphate was bound to the active site via a Schiff base to a conserved lysine. An active-site mutant showed that Trypanosoma brucei AAT still binds pyridoxal phosphate even in the absence of the tethering lysine. The structures highlight the challenges for the structure-based design of inhibitors targeting the active site, while showing options for inhibitor design targeting the N-terminal arm.

  20. Ergogenic effects of β-alanine and carnosine: proposed future research to quantify their efficacy.

    Science.gov (United States)

    Caruso, John; Charles, Jessica; Unruh, Kayla; Giebel, Rachel; Learmonth, Lexis; Potter, William

    2012-07-01

    β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former's merits as a buffer. Carnosine normally makes a small contribution to a cell's total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle's ability to buffer protons. Numerous studies assessed the impact of oral β-alanine intake on muscle carnosine levels and exercise performance. β-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of β-alanine supplementation's ergogenic effect. Optimal β-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day(-1), for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral β-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest β-alanine. As for any supplement, caution should be exercised with β-alanine supplementation.

  1. Point mutations in the tyrosine aminotransferase gene in tyrosinemia type II.

    Science.gov (United States)

    Natt, E; Kida, K; Odievre, M; Di Rocco, M; Scherer, G

    1992-10-01

    Tyrosinemia type II (Richner-Hanhart syndrome, RHS) is a disease of autosomal recessive inheritance characterized by keratitis, palmoplantar hyperkeratosis, mental retardation, and elevated blood tyrosine levels. The disease results from deficiency in hepatic tyrosine aminotransferase (TAT; L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5), a 454-amino acid protein encoded by a gene with 12 exons. To identify the causative mutations in five TAT alleles cloned from three RHS patients, chimeric genes constructed from normal and mutant TAT alleles were tested in directing TAT activity in a transient expression assay. DNA sequence analysis of the regions identified as nonfunctional revealed six different point mutations. Three RHS alleles have nonsense mutations at codons 57, 223, and 417, respectively. One "complex" RHS allele carries a GT----GG splice donor mutation in intron 8 together with a Gly----Val substitution at amino acid 362. A new splice acceptor site in intron 2 of the fifth RHS allele leads to a shift in reading frame.

  2. Structural Insight into the Mechanism of Substrate Specificity of Aedes Kynurenine Aminotransferase

    Energy Technology Data Exchange (ETDEWEB)

    Han,Q.; Gao, Y.; Robinson, H.; Li, J.

    2008-01-01

    Aedes aegypti kynurenine aminotransferase (AeKAT) is a multifunctional aminotransferase. It catalyzes the transamination of a number of amino acids and uses many biologically relevant a-keto acids as amino group acceptors. AeKAT also is a cysteine S-conjugate {beta}-lyase. The most important function of AeKAT is the biosynthesis of kynurenic acid, a natural antagonist of NMDA and {alpha}7-nicotinic acetylcholine receptors. Here, we report the crystal structures of AeKAT in complex with its best amino acid substrates, glutamine and cysteine. Glutamine is found in both subunits of the biological dimer, and cysteine is found in one of the two subunits. Both substrates form external aldemines with pyridoxal 5-phosphate in the structures. This is the first instance in which one pyridoxal 5-phosphate enzyme has been crystallized with cysteine or glutamine forming external aldimine complexes, cysteinyl aldimine and glutaminyl aldimine. All the units with substrate are in the closed conformation form, and the unit without substrate is in the open form, which suggests that the binding of substrate induces the conformation change of AeKAT. By comparing the active site residues of the AeKAT-cysteine structure with those of the human KAT I-phenylalanine structure, we determined that Tyr286 in AeKAT is changed to Phe278 in human KAT I, which may explain why AeKAT transaminates hydrophilic amino acids more efficiently than human KAT I does.

  3. Longitudinal Changes in Liver Aminotransferases Predict Metabolic Syndrome in Chinese Patients with Nonviral Hepatitis

    Institute of Scientific and Technical Information of China (English)

    CHEN Qi Cai; XIAO Juan; ZHANG Peng Peng; CHEN Li Li; CHEN Xiao Xiao; WANG Shu Mei

    2016-01-01

    ObjectiveThis study exploredthe correlation of longitudinal changes in serumalanine aminotransferase (ALT) and aspartate aminotransferase (AST)levels with the incidence of metabolic syndrome (Mets)based on a dynamic health examination cohort. MethodsA Mets-free dynamic cohortinvolving 4541 participants who underwent at leastthree health examinations from 2006 to 2011 was included in the study. Mets was defined according to the Chinese Medical Association Diabetes Branch definitionthat included hypertension, obesity, hyperlipidemia, and hyperglycemia. Generalized estimating equation (GEE) model was used to analyze multivariate relative risk (RR) of repeated observations ofALT and AST in quartiles for Mets or its components according to gender. ResultsIn all, 826Mets cases were reported. Adjustmentof relevant parameters indicated that time-varyingchanges in ALT and ASTlevels were positively associated with the incidenceof Mets in a dose-response manner. Positive association between high ALT levels and fatty liver was much stronger than that between high AST levels and fatty liver, particularly in maleparticipants. These associations were consistently observed in the following subgroups: participants with ALT and ASTlevels of ConclusionThese results suggested that elevated serum ALT and AST levels wereearly biomarkers of Mets or its components.

  4. Mitochondrial aspartate aminotransferase: a third kynurenate-producing enzyme in the mammalian brain.

    Science.gov (United States)

    Guidetti, Paolo; Amori, Laura; Sapko, Michael T; Okuno, Etsuo; Schwarcz, Robert

    2007-07-01

    The tryptophan metabolite kynurenic acid (KYNA), which is produced enzymatically by the irreversible transamination of l-kynurenine, is an antagonist of alpha7 nicotinic and NMDA receptors and may thus modulate cholinergic and glutamatergic neurotransmission. Two kynurenine aminotransferases (KAT I and II) are currently considered the major biosynthetic enzymes of KYNA in the brain. In this study, we report the existence of a third enzyme displaying KAT activity in the mammalian brain. The novel KAT had a pH optimum of 8.0 and a low capacity to transaminate glutamine or alpha-aminoadipate (the classic substrates of KAT I and KAT II, respectively). The enzyme was inhibited by aspartate, glutamate, and quisqualate but was insensitive to blockade by glutamine or anti-KAT II antibodies. After purification to homogeneity, the protein was sequenced and the enzyme was identified as mitochondrial aspartate aminotransferase (mitAAT). Finally, the relative contributions of KAT I, KAT II, and mitAAT to total KAT activity were determined in mouse, rat, and human brain at physiological pH using anti-mitAAT antibodies. KAT II was most abundant in rat and human brain, while mitAAT played the major role in mouse brain. It remains to be seen if mitAAT participates in cerebral KYNA synthesis under physiological and/or pathological conditions in vivo.

  5. Sensitive non-radioactive determination of aminotransferase stereospecificity for C-4' hydrogen transfer on the coenzyme

    Energy Technology Data Exchange (ETDEWEB)

    Jomrit, Juntratip [Department of Biotechnology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400 (Thailand); Center of Excellence for Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok (Thailand); Summpunn, Pijug [Department of Biotechnology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400 (Thailand); Meevootisom, Vithaya [Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400 (Thailand); Center of Excellence for Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok (Thailand); Wiyakrutta, Suthep, E-mail: scsvy@mahidol.ac.th [Department of Microbiology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400 (Thailand); Center of Excellence for Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok (Thailand)

    2011-02-25

    Research highlights: {yields} Stereochemical mechanism of PLP enzymes is important but difficult to determine. {yields} This new method is significantly less complicated than the previous ones. {yields} This assay is as sensitive as the radioactive based method. {yields} LC-MS/MS positively identify the analyte coenzyme. {yields} The method can be used with enzyme whose apo form is unstable. -- Abstract: A sensitive non-radioactive method for determination of the stereospecificity of the C-4' hydrogen transfer on the coenzymes (pyridoxal phosphate, PLP; and pyridoxamine phosphate, PMP) of aminotransferases has been developed. Aminotransferase of unknown stereospecificity in its PLP form was incubated in {sup 2}H{sub 2}O with a substrate amino acid resulted in PMP labeled with deuterium at C-4' in the pro-S or pro-R configuration according to the stereospecificity of the aminotransferase tested. The [4'-{sup 2}H]PMP was isolated from the enzyme protein and divided into two portions. The first portion was incubated in aqueous buffer with apo-aspartate aminotransferase (a reference si-face specific enzyme), and the other was incubated with apo-branched-chain amino acid aminotransferase (a reference re-face specific enzyme) in the presence of a substrate 2-oxo acid. The {sup 2}H at C-4' is retained with the PLP if the aminotransferase in question transfers C-4' hydrogen on the opposite face of the coenzyme compared with the reference aminotransferase, but the {sup 2}H is removed if the test and reference aminotransferases catalyze hydrogen transfer on the same face. PLP formed in the final reactions was analyzed by LC-MS/MS for the presence or absence of {sup 2}H. The method was highly sensitive that for the aminotransferase with ca. 50 kDa subunit molecular weight, only 2 mg of the enzyme was sufficient for the whole test. With this method, the use of radioactive substances could be avoided without compromising the sensitivity of the assay.

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

    Directory of Open Access Journals (Sweden)

    Abdullah Küçükalp

    2014-11-01

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

  7. Caffeine–N-phthaloyl-β-alanine (1/1

    Directory of Open Access Journals (Sweden)

    Moazzam H. Bhatti

    2012-06-01

    Full Text Available The title co-crystal [systematic name: 3-(1,3-dioxoisoindolin-2-ylpropanoic acid–1,3,7-trimethyl-1H-purine-2,6(3H,7H-dione (1/1], C8H10N4O2·C11H9NO4, is the combination of 1:1 adduct of N-phthaloyl-β-alanine with caffeine. The phthalimide and purine rings in the N-phthaloyl-β-alanine and caffeine molecules are essentially planar, with r.m.s. deviations of the fitted atoms of 0.0078 and 0.0118 Å, respectively. In the crystal, the two molecules are linked via an O—H...N hydrogen bond involving the intact carboxylic acid (COOH group. The crystal structure is consolidated by C—H...O interactions. The H atoms of a methyl group of the caffeine molecule are disordered over two sets of sites of equal occupancy.

  8. Análise sérica das enzimas aspartato aminotransferase, alanina aminotransferase e gama glutamiltranspeptidase de coelhos adultos tratados com extrato bruto de própolis

    Directory of Open Access Journals (Sweden)

    J. N. Ribeiro

    2009-01-01

    Full Text Available

    Diversos trabalhos têm atribuído a própolis inúmeras propriedades farmacológicas, dentre elas podemos citar, como exemplo, efeitos antibacteriano, antiviral, antiinflamatório, regenerador do tecido cartilaginoso, inibidor da formação de radicais livres e redutor de níveis sangüíneo de glicose e triacilglicerol. Alguns efeitos colaterais são atribuídos à própolis principalmente em doses elevadas. Muitos efeitos tóxicos da própolis são atribuídos ao álcool etílico presente no extrato.Dentre alguns efeitos tóxicos citados em literatura como realmente da própolis temos a dermatite e o aumento da uréia sangüínea. O presente estudo teve como objetivo investigar se o extrato bruto de própolis ocasiona algum efeito adverso nos níveis séricos de alanina aminotransferase, aspartato aminotransferase e gama – glutamiltranspeptidase de coelhos saudáveis. O experimento teve 30 dias de duração, sendo as dosagens dos constituintes do sangue (alanina aminotransferase, aspartato aminotransferase e gama – glutamiltranspeptidase realizadas a 0, 15 e 30 dias. Os resultados indicaram que, de o extrato bruto de própolis na forma testadea, não ocasionou alteração relevante nos níveis séricos das enzimas marcadoras de metabolismo hepático. Palavras-chave: Própolis, alanina aminotransferase, aspartato aminotransferase, gama glutamiltranpeptidase, toxicologia.

  9. Eukaryotic beta-alanine synthases are functionally related but have a high degree of structural diversity

    DEFF Research Database (Denmark)

    Gojkovic, Zoran; Sandrini, Michael; Piskur, Jure

    2001-01-01

    beta -Alanine synthase (EC 3.5.1.6), which catalyzes the final step of pyrimidine catabolism, has only been characterized in mammals. A Saccharomyces kluyveri pyd3 mutant that is unable to grow on N-carbamy-beta -alanine as the sole nitrogen source and exhibits diminished beta -alanine synthase...... no pyrimidine catabolic pathway, it enabled growth on N-carbamyl- beta -alanine as the sole nitrogen source. The D. discoideum and D. melanogaster PYD3 gene products are similar to mammalian beta -alanine synthases. In contrast, the S. kluyveri protein is quite different from these and more similar to bacterial...... N- carbamyl amidohydrolases. All three beta -alanine synthases are to some degree related to various aspartate transcarbamylases, which catalyze the second step of the de novo pyrimidine biosynthetic pathway. PYD3 expression in yeast seems to be inducible by dihydrouracil and N-carbamyl-beta...

  10. Role of L-alanine for redox self-sufficient amination of alcohols

    OpenAIRE

    Klatte, Stephanie; Wendisch, Volker F

    2015-01-01

    Background In white biotechnology biocatalysis represents a key technology for chemical functionalization of non-natural compounds. The plasmid-born overproduction of an alcohol dehydrogenase, an L-alanine-dependent transaminase and an alanine dehydrogenase allows for redox self-sufficient amination of alcohols in whole cell biotransformation. Here, conditions to optimize the whole cell biocatalyst presented in (Bioorg Med Chem 22:5578–5585, 2014), and the role of L-alanine for efficient amin...

  11. Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

    OpenAIRE

    John Caruso; Jessica Charles; Kayla Unruh; Rachel Giebel; Lexis Learmonth; William Potter

    2012-01-01

    β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former’s merits as a buffer. Carnosine normally makes a small contribution to a cell’s total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that...

  12. 北京地区汉族人群ALT、AST、GGT和LDH的参考区间研究%Reference intervals for ALT, AST, GGT and LDH among the Han Chinese in Beijing area

    Institute of Scientific and Technical Information of China (English)

    曾洁; 闫颖; 张传宝; 朱玲; 潘洁; 赵艳燕; 高建平; 申子瑜

    2011-01-01

    Objective To establish the reference intervals for ALT,AST,GGT and LDH among the Han nationality in Beijing.Methods The document C28-P3 issued by CLSI was a guideline about how to define,establish,and verify reference intervals in the clinical laboratory.IFCC had established multicenter enzymes reference intervals based on the guideline.Exclusion criteria were designed for screening candidate reference individual according to the document C28-P3 and the multicenter study's experience.Blood specimens were collected from 315 healthy individuals aged 20 to 60 years old,including 132 males and 183 females.Reference materials were used to ensure the accuracy of the test results of the four liver enzymes.The methods which used to test the four liver enzymes could be traced to the IFCC enzymes reference measure procedure,the reagent of ALT and AST included pyridoxal phosphate.Results There was statistically difference between males and females of the reference ranges for ALT, AST and GGT.Therefore,gender-specific reference intervals were established as ALT:8.2 -50.8 U/L (F),12.7 -71.8 U/L (M) ; AST:15.0 -36.7 U/L ( F),16.6 -51.1 U/L (M) ;GGT:9.0 -37.3 U/L (F),12.0 -50.9 U/L (M).For LDH,the reference interval was 127 -224 U/L,as no significant gender difference was found.Conclusions The reference intervals for the four liver enzymes based on the population of the Han nationality in Beijing are established.The upper reference limit for ALT in Beijing Han population is higher than that from other similar studies.%目的 建立北京地区汉族人群的ALT、AST、GGT和LDH的参考区间.方法 按照CLSI文件C28-P3《医学实验室参考区间的定义、建立和确认》中的要求,借鉴IFCC多中心酶学参考区间研究模式及参考人群筛选标准,于2009年筛选卫生部北京医院20~60岁健康体检者315名,其中男132名,女183名,用于上述各种酶参考区间的研究.使用酶学参考物质保证本次研究结果的准确性.上述4种酶

  13. Beta-alanine and dopamine in the reddish brown scales of Papilio butterflies

    Energy Technology Data Exchange (ETDEWEB)

    Umebachi, Yoshishige; Ishizaki, Yumi (Kanazawa Univ. (Japan). Faculty of Science)

    1983-12-01

    (1) Reddish brown scales of the anal eye spot in the hind-wings of P. demoleus and P. machaon have been examined for ..beta..-alanine and dopamine. (2) The scales were fractionated into 70% ethanol-soluble fraction, 4% HCl-methanol-soluble fraction, and the residual scales, and the ..beta..-alanine content of each fraction was determined. Most of the ..beta..-alanine present in the scales has been found in the residual scales. On acid hydrolysis of the residual scales, the ..beta..-alanine has been rather rapidly released, and the hydrolysate has contained a large amount of ..beta..-alanine. (3) The protein-bound brown pigment (HCl-ppt fraction), which was extracted with 1 N NaOH and precipitated by being acidified with HCl, has contained a large amount of ..beta..-alanine. In most or at least some of the ..beta..-alanine, the NH/sub 2/-group has been proved to be free. (4) /sup 14/C-Labelled ..beta..-alanine and /sup 14/C-dopamine, which were injected at prepupal or pupal stage, have been incorporated in the highest degree into the residual scales. And the /sup 14/C has been confirmed to be present in the HCl-ppt fraction. (5) All these results indicate that the pigment of the reddish brown scales contains ..beta..-alanine and dopamine.

  14. Hepatitis A virus genotype IA-infected patient with marked elevation of aspartate aminotransferase levels.

    Science.gov (United States)

    Miura, Yoshifumi; Kanda, Tatsuo; Yasui, Shin; Takahashi, Koji; Haga, Yuki; Sasaki, Reina; Nakamura, Masato; Wu, Shuang; Nakamoto, Shingo; Arai, Makoto; Nishizawa, Tsutomu; Okamoto, Hiroaki; Yokosuka, Osamu

    2017-02-01

    We describe a case of acute liver failure (ALF) without hepatic encephalopathy with marked elevation of aminotransferase due to hepatitis A, according to the revised Japanese criteria of ALF. This liver biopsy of the patient showed compatible to acute viral hepatitis and she immediately recovered without intensive care. She had no comorbid disorders. Of interest, phylogenetic tree analysis using almost complete genomes of hepatitis A virus (HAV) demonstrated that the HAV isolate from her belonged to the HAV subgenotype IA strain and was similar to the HAJFF-Kan12 strain (99% nucleotide identity) or FH1 strain (98% nucleotide identity), which is associated with severe or fulminant hepatitis A. Careful interpretation of the association between HAV genome variations and severity of hepatitis A is needed and the mechanism of the severe hepatitis should be explored.

  15. Differential redox potential between the human cytosolic and mitochondrial branched-chain aminotransferase

    Institute of Scientific and Technical Information of China (English)

    Steven J. Coles; John T. Hancock; Myra E. Conway

    2012-01-01

    The human branched-chain aminotransferase (hBCAT) isoenzymes are CXXC motif redox sensitive homodimers central to glutamate metabolism in the central nervous system.These proteins respond differently to oxidation by H2O2,NO,and S-glutathionylation,suggesting that the redox potential is distinct between isoenzymes.Using various reduced to oxidized glutathione ratios (GSH:GSSG) to alter the redox environment,we demonstrate that hBCATc (cytosolic) has an overall redox potential that is 30 mV lower than hBCATm (mitochondrial).Furthermore,the CXXC motif of hBCATc was estimated to be 80 mV lower,suggesting that hBCATm is more oxidizing in nature.Western blot analysis revealed close correlations between hBCAT S-glutathionylation and the redox status of the assay environment,offering the hBCAT isoenzymes as novel biomarkers for cytosolic and mitochondrial oxidative stress.

  16. The role of glutamine oxoglutarate aminotransferase and glutamate dehydrogenase in nitrogen metabolism in Mycobacterium bovis BCG.

    Directory of Open Access Journals (Sweden)

    Albertus J Viljoen

    Full Text Available Recent evidence suggests that the regulation of intracellular glutamate levels could play an important role in the ability of pathogenic slow-growing mycobacteria to grow in vivo. However, little is known about the in vitro requirement for the enzymes which catalyse glutamate production and degradation in the slow-growing mycobacteria, namely; glutamine oxoglutarate aminotransferase (GOGAT and glutamate dehydrogenase (GDH, respectively. We report that allelic replacement of the Mycobacterium bovis BCG gltBD-operon encoding for the large (gltB and small (gltD subunits of GOGAT with a hygromycin resistance cassette resulted in glutamate auxotrophy and that deletion of the GDH encoding-gene (gdh led to a marked growth deficiency in the presence of L-glutamate as a sole nitrogen source as well as reduction in growth when cultured in an excess of L-asparagine.

  17. Pseudolinkage of the duplicate loci for supernatant aspartate aminotransferase in brook trout, Salvelinus fontinalis.

    Science.gov (United States)

    Wright, J E; May, B; Stoneking, M; Lee, G M

    1980-01-01

    Electrophoretic variation involving three alleles is described for the duplicated loci for supernatant aspartate aminotransferase (AAT-1,2), from muscle extracts of brook trout. Both loci exhibit largely disomic inheritance. Exceptional progeny types are proposed to be the result of a form of tetrasomic inheritance. Nonrandom segregation was found among the progeny of males doubly heterozygous for AAT markers; where so-called linkage phase was known, this nonrandom assortment was shown to be pseudolinkage (78.9 percent recombination). Analyses of joint segregation of triply heterozygous males for the AAT-(1,2) loci and for the single alpha glycerophosphate dehydrogenase locus (AGP-1) revealed true linkage of AGP-1 with one AAT locus (mean r = 11 percent), but pseudolinkage with the other AAT locus (r = 74 percent). Intraindividual variation for homoeologous multivalent pairing of two acrocentric with two metacentric chromosomes in males, but with bivalent pairing in females, is proposed to account for pseudolinkage and for the tetrasomically inherited types.

  18. An alternative pathway contributes to phenylalanine biosynthesis in plants via a cytosolic tyrosine:phenylpyruvate aminotransferase.

    Science.gov (United States)

    Yoo, Heejin; Widhalm, Joshua R; Qian, Yichun; Maeda, Hiroshi; Cooper, Bruce R; Jannasch, Amber S; Gonda, Itay; Lewinsohn, Efraim; Rhodes, David; Dudareva, Natalia

    2013-01-01

    Phenylalanine is a vital component of proteins in all living organisms, and in plants is a precursor for thousands of additional metabolites. Animals are incapable of synthesizing phenylalanine and must primarily obtain it directly or indirectly from plants. Although plants can synthesize phenylalanine in plastids through arogenate, the contribution of an alternative pathway via phenylpyruvate, as occurs in most microbes, has not been demonstrated. Here we show that plants also utilize a microbial-like phenylpyruvate pathway to produce phenylalanine, and flux through this route is increased when the entry point to the arogenate pathway is limiting. Unexpectedly, we find the plant phenylpyruvate pathway utilizes a cytosolic aminotransferase that links the coordinated catabolism of tyrosine to serve as the amino donor, thus interconnecting the extra-plastidial metabolism of these amino acids. This discovery uncovers another level of complexity in the plant aromatic amino acid regulatory network, unveiling new targets for metabolic engineering.

  19. Ab initio study of alanine polypeptide chains twisting

    CERN Document Server

    Solovyov, I A; Solovyov, A V; Yakubovitch, A V; Greiner, Walter; Solov'yov, Andrey V.; Solov'yov, Ilia A.; Yakubovitch, Alexander V.

    2005-01-01

    We have investigated the potential energy surfaces for alanine chains consisting of three and six amino acids. For these molecules we have calculated potential energy surfaces as a function of the Ramachandran angles Phi and Psi, which are widely used for the characterization of the polypeptide chains. These particular degrees of freedom are essential for the characterization of proteins folding process. Calculations have been carried out within ab initio theoretical framework based on the density functional theory and accounting for all the electrons in the system. We have determined stable conformations and calculated the energy barriers for transitions between them. Using a thermodynamic approach, we have estimated the times of characteristic transitions between these conformations. The results of our calculations have been compared with those obtained by other theoretical methods and with the available experimental data extracted from the Protein Data Base. This comparison demonstrates a reasonable corres...

  20. Microhardness studies on nonlinear optical -alanine single crystals

    Indian Academy of Sciences (India)

    R Hanumantharao; S Kalainathan

    2013-06-01

    Vickers and Knoop microhardness tests were carried out on grown -alanine single crystals by slow evaporation technique over a load range of 10–50 g on selected broad (2 0 3) plane. Vickers (v) and Knoop (k) microhardness for the above loads were found to be in the range of 60–71 kg/mm2 and 35–47 kg/mm2, respectively. Vickers microhardness number (v) and Knoop microhardness number (k) were found to increase with increasing load. Meyer’s index number () calculated from v shows that the material belongs to the soft material category. Using Wooster’s empirical relation, the elastic stiffness constant (11) was calculated from Vickers hardness values. Young’s modulus was calculated using Knoop hardness values. Hardness anisotropy has been observed in accordance with the orientation of the crystal.

  1. Histidine degradation via an aminotransferase increases the nutritional flexibility of Candida glabrata.

    Science.gov (United States)

    Brunke, Sascha; Seider, Katja; Richter, Martin Ernst; Bremer-Streck, Sibylle; Ramachandra, Shruthi; Kiehntopf, Michael; Brock, Matthias; Hube, Bernhard

    2014-06-01

    The ability to acquire nutrients during infections is an important attribute in microbial pathogenesis. Amino acids are a valuable source of nitrogen if they can be degraded by the infecting organism. In this work, we analyzed histidine utilization in the fungal pathogen of humans Candida glabrata. Hemiascomycete fungi, like C. glabrata or Saccharomyces cerevisiae, possess no gene coding for a histidine ammonia-lyase, which catalyzes the first step of a major histidine degradation pathway in most other organisms. We show that C. glabrata instead initializes histidine degradation via the aromatic amino acid aminotransferase Aro8. Although ARO8 is also present in S. cerevisiae and is induced by extracellular histidine, the yeast cannot use histidine as its sole nitrogen source, possibly due to growth inhibition by a downstream degradation product. Furthermore, C. glabrata relies only on Aro8 for phenylalanine and tryptophan utilization, since ARO8, but not its homologue ARO9, was transcriptionally activated in the presence of these amino acids. Accordingly, an ARO9 deletion had no effect on growth with aromatic amino acids. In contrast, in S. cerevisiae, ARO9 is strongly induced by tryptophan and is known to support growth on aromatic amino acids. Differences in the genomic structure of the ARO9 gene between C. glabrata and S. cerevisiae indicate a possible disruption in the regulatory upstream region. Thus, we show that, in contrast to S. cerevisiae, C. glabrata has adapted to use histidine as a sole source of nitrogen and that the aromatic amino acid aminotransferase Aro8, but not Aro9, is the enzyme required for this process.

  2. Efficient L-Alanine Production by a Thermo-Regulated Switch in Escherichia coli.

    Science.gov (United States)

    Zhou, Li; Deng, Can; Cui, Wen-Jing; Liu, Zhong-Mei; Zhou, Zhe-Min

    2016-01-01

    L-Alanine has important applications in food, pharmaceutical and veterinary and is used as a substrate for production of engineered thermoplastics. Microbial fermentation could reduce the production cost and promote the application of L-alanine. However, the presence of L-alanine significantly inhibit cell growth rate and cause a decrease in the ultimate L-alanine productivity. For efficient L-alanine production, a thermo-regulated genetic switch was designed to dynamically control the expression of L-alanine dehydrogenase (alaD) from Geobacillus stearothermophilus on the Escherichia coli B0016-060BC chromosome. The optimal cultivation conditions for the genetically switched alanine production using B0016-060BC were the following: an aerobic growth phase at 33 °C with a 1-h thermo-induction at 42 °C followed by an oxygen-limited phase at 42 °C. In a bioreactor experiment using the scaled-up conditions optimized in a shake flask, B0016-060BC accumulated 50.3 g biomass/100 g glucose during the aerobic growth phase and 96 g alanine/100 g glucose during the oxygen-limited phase, respectively. The L-alanine titer reached 120.8 g/l with higher overall and oxygen-limited volumetric productivities of 3.09 and 4.18 g/l h, respectively, using glucose as the sole carbon source. Efficient cell growth and L-alanine production were reached separately, by switching cultivation temperature. The results revealed the application of a thermo-regulated strategy for heterologous metabolic production and pointed to strategies for improving L-alanine production.

  3. Associations between γ-glutamyl transferase, metabolic abnormalities and inflammation in healthy subjects from a population-based cohort: A possible implication for oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Simona Bo; Roberto Gambino; Marilena Durazzo; Sabrina Guidi; Elisa Tiozzo; Federica Ghione; Luigi Gentile; Maurizio Cassader; Gian Franco Pagano

    2005-01-01

    AIM: To examine the relationships between γ -glutamyltransferase (GGT), alanine-aminotransferase (ALT),aspartate-aminotransferase (AST) and various metabolic parameters, C-reactive protein (CRP) and an oxidative stress marker (nitrotyrosine, NT) in subjects without any metabolic abnormalities from a population-based sample.METHODS: Two hundred and five subjects with normal body mass index (BMI), glucose tolerance, and without any metabolic abnormality were studied out of 1339subjects, without known liver diseases, alcohol abuse or use of hepatotoxic drugs, who are representative of the 45-64 aged population of Asti (north-western Italy).RESULTS: In all patients metabolic parameters and hs-CRP levels linearly increase from the lowest to the highest ALT and GGT tertiles, while in subjects without metabolic abnormalities, there is a significant association between fasting glucose, uric acid, waist circumference,hs-CRP, triglyceride values, and GGT levels. In these subjects, male sex, higher hs-CRP and glucose levels are associated with GGT levels in a multiple regression model, after adjustments for multiple confounders.In the same model, median NT levels are significantly associated with the increasing GGT tertile (β = 1.06;95%CI 0.67-1.45), but not with the AST and ALT tertiles.In a multiple regression model, after adjusting for age,sex, BMI, waist, smoking, and alcohol consumption, both NT (β = 0.05; 95%CI 0.02-0.08) and hs-CRP levels (β =0.09; 95%CI 0.03-0.15) are significantly associated with fasting glycemia.CONCLUSION: GGT, an easy, universally standardized and available measurement, could represent an early marker of sub-clinical inflammation and oxidative stress in otherwise healthy individuals. Prospective studies are needed to establish if GGT could predict future diabetes in these subjects.

  4. The effect of portacaval anastomosis on the expression of glutamine synthetase and ornithine aminotransferase in perivenous hepatocytes.

    Science.gov (United States)

    da Silva, Robin; Levillain, Oliver; Brosnan, John T; Araneda, Silvia; Brosnan, Margaret E

    2013-05-01

    There is functional zonation of metabolism across the liver acinus, with glutamine synthetase restricted to a narrow band of cells around the terminal hepatic venules. Portacaval anastomosis, where there is a major rerouting of portal blood flow from the portal vein directly to the vena cava bypassing the liver, has been reported to result in a marked decrease in the activity of glutamine synthetase. It is not known whether this represents a loss of perivenous hepatocytes or whether there is a specific loss of glutamine synthetase. To answer this question, we have determined the activity of glutamine synthetase and another enzyme from the perivenous compartment, ornithine aminotransferase, as well as the immunochemical localization of both glutamine synthetase and ornithine aminotransferase in rats with a portacaval shunt. The portacaval shunt caused a marked decrease in glutamine synthetase activity and an increase in ornithine aminotransferase activity. Immunohistochemical analysis showed that the glutamine synthetase and ornithine aminotransferase proteins maintained their location in the perivenous cells. These results indicate that there is no generalized loss of perivenous hepatocytes, but rather, there is a significant alteration in the expression of these proteins and hence metabolism in this cell population.

  5. Dependence of alanine gel dosimeter response as a function of photon clinical beams dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo, E-mail: cleber.feijo@famesp.com.br [Faculdade Metodo de Sao Paulo (FAMESP), SP (Brazil); Campos, Leticia Lucente, E-mail: Icrodri@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-11-01

    Gel dosimetry is a new area developed by Gore, it is ery useful for application in radiotherapy because using NMR imaging as evaluation technique is possible to evaluate three dimensional absorbed dose distribution. The measure technique is based on difference of ferrous (Fe{sup 2+}) and ferric (Fe{sup 3+}) ) ions concentration that can be measured also by spectrophotometry technique. The Alanine gel dosimeter was developed at IPEN. The alanine is an amino acid and tissue equivalent material that presents significant improvement on previous alanine dosimetry systems. The addition of Alanine increases the production of ferric ions in the solution. This work aims to study the dose rate dependence of photon clinical beams radiation on the alanine gel dosimeter optical response, as well as the response repeatability and gel production reproducibility, since this property is very important for characterization and standardization of any dosimeter. (author)

  6. Impact of charged amino acid substitution in the transmembrane domain of L-alanine exporter, AlaE, of Escherichia coli on the L-alanine export.

    Science.gov (United States)

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

    2017-01-01

    The Escherichia coli alaE gene encodes the L-alanine exporter, AlaE, that catalyzes active export of L-alanine using proton electrochemical potential. The transporter comprises only 149 amino acid residues and four predicted transmembrane domains (TMs), which contain three charged amino acid residues. The AlaE-deficient L-alanine non-metabolizing cells (ΔalaE cells) appeared hypersusceptible to L-alanyl-L-alanine showing a minimum inhibitory concentration (MIC) of 2.5 µg/ml for the dipeptide due to a toxic accumulation of L-alanine. To elucidate the mechanism by which AlaE exports L-alanine, we replaced charged amino acid residues in the TMs, glutamic acid-30 (TM-I), arginine-45 (TM-II), and aspartic acid-84 (TM-III) with their respective charge-conserved amino acid or a net neutral cysteine. The ΔalaE cells producing R45K or R45C appeared hypersusceptible to the dipeptide, indicating that arginine-45 is essential for AlaE activity. MIC of the dipeptide in the ΔalaE cells expressing E30D and E30C was 156 µg/ml and >10,000 µg/ml, respectively, thereby suggesting that a negative charge at this position is not essential. The ΔalaE cells expressing D84E or D84C showed an MIC >10,000 and 78 µg/ml, respectively, implying that a negative charge is required at this position. These results were generally consistent with that of the L-alanine accumulation experiments in intact cells. We therefore concluded that charged amino acid residues (R45 and D84) in the AlaE transmembrane domain play a pivotal role in L-alanine export. Replacement of three cysteine residues at C22, C28 (both in TM-I), and C135 (C-terminal region) with alanine showed only a marginal effect on L-alanine export.

  7. Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

    Directory of Open Access Journals (Sweden)

    John Caruso

    2012-06-01

    Full Text Available β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former’s merits as a buffer. Carnosine normally makes a small contribution to a cell’s total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle’s ability to buffer protons. Numerous studies assessed the impact of oral β-alanine intake on muscle carnosine levels and exercise performance. β-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of β-alanine supplementation’s ergogenic effect. Optimal β-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day−1, for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral β-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest β-alanine. As for any supplement, caution should be exercised with β-alanine supplementation.

  8. Thermochemical Study of Lanthanum Complex Crystal with β-Alanine

    Institute of Scientific and Technical Information of China (English)

    陈平初; 屈松生; 詹正坤; 吴新明

    2002-01-01

    Lanthanum complex crystal with β-alanine (1∶3) was synthesized. Through the DTA,TG,chemistry analysis and comparison with literature, it shows that its form is {[La2(β-ala)6* (H2O)4](ClO4)6*H2O}n, and its purity is 98.86%. The dissolution enthalpy of the reactants and products in 2 mol*L-1 HCl solution (298.15K) was measured by using the isoperibol reaction calorimetry. ΔrHm was calculated by a designed thermochemical cycle of the coordination reaction. From the results and other auxiliary quantities, the standard molar enthalpy of formation of [La2(β-ala)6*(H2O)4](ClO4)6*H2O is obtained to be ΔfHm°{[La2(β-ala)6*(H2O)4](ClO4)6*H2O} = - 7062.911 kJ*mol-1.

  9. Enzymatic characterization and crystal structure analysis of the D-alanine-D-alanine ligase from Helicobacter pylori.

    Science.gov (United States)

    Wu, Dalei; Zhang, Liang; Kong, Yunhua; Du, Jiamu; Chen, Shuai; Chen, Jing; Ding, Jianping; Jiang, Hualiang; Shen, Xu

    2008-09-01

    D-Alanine-D-alanine ligase is the second enzyme in the D-Ala branch of bacterial cell wall peptidoglycan assembly, and recognized as an attractive antimicrobial target. In this work, the D-Ala-D-Ala ligase of Helicobacter pylori strain SS1 (HpDdl) was kinetically and structurally characterized. The determined apparent K(m) of ATP (0.87 microM), the K(m1) (1.89 mM) and K(m2) of D-Ala (627 mM), and the k(cat) (115 min(-1)) at pH 8.0 indicated its relatively weak binding affinity and poor catalytic activity against the substrate D-Ala in vitro. However, by complementary assay of expressing HpDdl in Escherichia coli Delta ddl mutant, HpDdl was confirmed to be capable of D-Ala-D-Ala ligating in vivo. Through sequence alignment with other members of the D-Ala-D-X ligase superfamily, HpDdl keeps two conservatively substituted residues (Ile16 and Leu241) and two nonconserved residues (Leu308 and Tyr311) broadly located in the active region of the enzyme. Kinetic analyses against the corresponding HpDdl mutants (I16V, L241Y, L241F, L308T, and Y311S) suggested that these residues, especially Leu308 and Tyr311, might partly contribute to the unique catalytic properties of the enzyme. This was fairly proved by the crystal structure of HpDdl, which revealed that there is a 3(10)-helix (including residues from Gly306 to Leu312) near the D-Ala binding region in the C-terminal domain, where HpDdl has two sequence deletions compared with other homologs. Such 3(10)-helix may participate in D-Ala binding and conformational change of the enzyme. Our present work hopefully provides useful information for understanding the D-Ala-D-Ala ligase of Helicobacter pylori.

  10. β - Alanine protects mice from memory deficits induced by ageing, scopolamine, diazepam and ethanol

    Directory of Open Access Journals (Sweden)

    Dhingra D

    2006-01-01

    Full Text Available The present study was undertaken to investigate the effects of β-alanine (a glycine agonist, on learning and memory in mice. β-alanine (5, 10, 20 and 40 mg/kg i.p. was administered for 6 successive days, to young (3 months old and aged-mice (16 months old. The learning and memory parameters were assessed, using elevated plus-maze and passive-avoidance apparatus. The effect of β-alanine (20 mg/kg for 6 days on locomotor function of young and aged mice, was studied using photoactometer, to rule out the increase in locomotor performance of mice. β-alanine at both the doses (10 and 20 mg/kg, significantly improved learning and memory of young- and aged- mice. β-alanine also reversed scopolamine (0.4 mg/kg i.p., ethanol (1.0 g/kg i.p. and diazepam (1.0 mg/kg i.p. -induced amnesia in young mice. There was no significant effect of β-alanine on the locomotor activity of both young and aged mice. The probable underlying mechanism of the memory-enhancing effect of β-alanine appears to be related to its antioxidant, anti-amyloid and procholinergic activities.

  11. Growth and characterization of L-Alanine-doped Zinc Thiourea Chloride single crystal (ZTC)

    Science.gov (United States)

    Dhumane, N. R.; Hussaini, S. S.; Dongre, V. G.; Ghugare, P.; Shirsat, M. D.

    2009-06-01

    Single crystal of L-Alanine-doped Zinc Thiourea Chloride (ZTC) was grown by slow evaporation technique. L-Alanine was added in saturated ZTC solution by molar percent. The second-harmonic generation efficiency was studied by Kurtz and Perry powder SHG test for 1, 2, and 3 mole% L-Alanine-doped ZTC and compared with pure ZTC. We observed enhancement in the SHG efficiency of L-Alanine-doped ZTC. Higher enhancement was observed for 3 mole% L-Alanine-doped ZTC. Incorporation of L-Alanine in the crystal was confirmed by energy dispersive X-ray analysis (EDAX). The Fourier transform infrared spectroscopy (FTIR) qualitatively confirms the presence of all the functional groups. The unit cell parameters and crystal structure were determined by single crystal X-ray diffraction. The UV-visible absorption spectra of L-Alanine-doped ZTC show excellent transmittance from 300 nm to 1100 nm. The thermal stability of the grown crystal was also studied by thermo-gravimetric analysis (TGA).

  12. Structural Insight into the Inhibition of Human Kynurenine Aminotransferase I/Glutamine transaminase K∥

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Cai, Tao; Tagle, Danilo A.; Li, Jianyong

    2010-01-01

    Human kynurenine aminotransferase I (hKAT I) catalyzes the formation of kynurenic acid, a neuroactive compound. Here, we report three high-resolution crystal structures (1.50–1.55 Å) of hKAT I that are in complex with glycerol and each of two inhibitors of hKAT I: indole-3-acetic acid (IAC) and Tris. Because Tris is able to occupy the substrate binding position, we speculate that this may be the basis for hKAT I inhibition. Furthermore, the hKAT/IAC complex structure reveals that the binding moieties of the inhibitor are its indole ring and a carboxyl group. Six chemicals with both binding moieties were tested for their ability to inhibit hKAT I activity; 3-indolepropionic acid and DL-indole-3-lactic acid demonstrated the highest level of inhibition, and as they cannot be considered as substrates of the enzyme, these two inhibitors are promising candidates for future study. Perhaps even more significantly, we report the discovery of two different ligands located simultaneously in the hKAT I active center for the first time. PMID:19338303

  13. Structural insight into the inhibition of human kynurenine aminotransferase I/glutamine transaminase K.

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Cai, Tao; Tagle, Danilo A; Li, Jianyong

    2009-05-14

    Human kynurenine aminotransferase I (hKAT I) catalyzes the formation of kynurenic acid, a neuroactive compound. Here, we report three high-resolution crystal structures (1.50-1.55 A) of hKAT I that are in complex with glycerol and each of two inhibitors of hKAT I: indole-3-acetic acid (IAC) and Tris. Because Tris is able to occupy the substrate binding position, we speculate that this may be the basis for hKAT I inhibition. Furthermore, the hKAT/IAC complex structure reveals that the binding moieties of the inhibitor are its indole ring and a carboxyl group. Six chemicals with both binding moieties were tested for their ability to inhibit hKAT I activity; 3-indolepropionic acid and DL-indole-3-lactic acid demonstrated the highest level of inhibition, and as they cannot be considered as substrates of the enzyme, these two inhibitors are promising candidates for future study. Perhaps even more significantly, we report the discovery of two different ligands located simultaneously in the hKAT I active center for the first time.

  14. Structural Insight into the Inhibition of Human Kynurenine Aminotransferase I/Glutamine Transaminase K

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Robinson, H; Cai, T; Tagle, D; Li, J

    2009-01-01

    Human kynurenine aminotransferase I (hKAT I) catalyzes the formation of kynurenic acid, a neuroactive compound. Here, we report three high-resolution crystal structures (1.50-1.55 A) of hKAT I that are in complex with glycerol and each of two inhibitors of hKAT I: indole-3-acetic acid (IAC) and Tris. Because Tris is able to occupy the substrate binding position, we speculate that this may be the basis for hKAT I inhibition. Furthermore, the hKAT/IAC complex structure reveals that the binding moieties of the inhibitor are its indole ring and a carboxyl group. Six chemicals with both binding moieties were tested for their ability to inhibit hKAT I activity; 3-indolepropionic acid and dl-indole-3-lactic acid demonstrated the highest level of inhibition, and as they cannot be considered as substrates of the enzyme, these two inhibitors are promising candidates for future study. Perhaps even more significantly, we report the discovery of two different ligands located simultaneously in the hKAT I active center for the first time.

  15. Estimation of gingival crevicular fluid aspartate aminotransferase levels in periodontal health and disease

    Directory of Open Access Journals (Sweden)

    Priti B Patil

    2011-01-01

    Full Text Available Background: Various enzymes have been assessed as biochemical markers and aspartate aminotransferase (AST is one such marker that has received considerable attention recently. Analysis of gingival crevicular fluid (GCF has been pursued as a means of identifying the sites undergoing active disease. A problem central to periodontology today is the inability to detect actively deteriorating sites and highly susceptible patients other than by longitudinal observations of attachment. Hence, AST levels from samples of GCF can be taken as an indication for active periodontal tissue destruction. Aim: To estimate the levels of AST in the GCF in periodontal health and disease. Materials and Methods: This study was an in vivo, case control, and clinico-biochemical assay. Eighty samples were selected which were divided into four groups of 20 patients each based on Russell′s Periodontal Index. Statistical analysis: The values obtained for AST level in the different groups were subjected to Student′s " t" test. Results: The mean of AST level showed an increase from Group I to Group IV. These values ran parallel with the values of clinical index, i.e. more severe the inflammation, higher the index score and higher was the AST level. Conclusions: It was concluded that as the severity of inflammation increases, there is a significant increase in the AST levels suggesting that there is a direct relationship between the AST levels in the GCF and periodontal destruction.

  16. Characteristic features of kynurenine aminotransferase allosterically regulated by (alpha-ketoglutarate in cooperation with kynurenine.

    Directory of Open Access Journals (Sweden)

    Ken Okada

    Full Text Available Kynurenine aminotransferase from Pyrococcus horikoshii OT3 (PhKAT, which is a homodimeric protein, catalyzes the conversion of kynurenine (KYN to kynurenic acid (KYNA. We analyzed the transaminase reaction mechanisms of this protein with pyridoxal-5'-phosphate (PLP, KYN and α-ketoglutaric acid (2OG or oxaloacetic acid (OXA. 2OG significantly inhibited KAT activities in kinetic analyses, suggesting that a KYNA biosynthesis is allosterically regulated by 2OG. Its inhibitions evidently were unlocked by KYN. 2OG and KYN functioned as an inhibitor and activator in response to changes in the concentrations of KYN and 2OG, respectively. The affinities of one subunit for PLP or 2OG were different from that of the other subunit, as confirmed by spectrophotometry and isothermal titration calorimetry, suggesting that the difference of affinities between subunits might play a role in regulations of the KAT reaction. Moreover, we identified two active and allosteric sites in the crystal structure of PhKAT-2OG complexes. The crystal structure of PhKAT in complex with four 2OGs demonstrates that two 2OGs in allosteric sites are effector molecules which inhibit the KYNA productions. Thus, the combined data lead to the conclusion that PhKAT probably is regulated by allosteric control machineries, with 2OG as the allosteric inhibitor.

  17. Overexpression of phosphoserine aminotransferase PSAT1 stimulates cell growth and increases chemoresistance of colon cancer cells

    Directory of Open Access Journals (Sweden)

    Conseiller Emmanuel

    2008-01-01

    Full Text Available Abstract Background Colorectal cancer (CRC is one of the most common causes of cancer death throughout the world. In this work our aim was to study the role of the phosphoserine aminotransferase PSAT1 in colorectal cancer development. Results We first observed that PSAT1 is overexpressed in colon tumors. In addition, we showed that after drug treatment, PSAT1 expression level in hepatic metastases increased in non responder and decreased in responder patients. In experiments using human cell lines, we showed that ectopic PSAT1 overexpression in colon carcinoma SW480 cell line resulted in an increase in its growth rate and survival. In addition, SW480-PSAT1 cells presented a higher tumorigenic potential than SW480 control cells in xenografted mice. Moreover, the SW480-PSAT1 cell line was more resistant to oxaliplatin treatment than the non-transfected SW480 cell line. This resistance resulted from a decrease in the apoptotic response and in the mitotic catastrophes induced by the drug treatment. Conclusion These results show that an enzyme playing a role in the L-serine biosynthesis could be implicated in colon cancer progression and chemoresistance and indicate that PSAT1 represents a new interesting target for CRC therapy.

  18. Targeting kynurenine aminotransferase II in psychiatric diseases: promising effects of an orally active enzyme inhibitor.

    Science.gov (United States)

    Wu, Hui-Qiu; Okuyama, Masahiro; Kajii, Yasushi; Pocivavsek, Ana; Bruno, John P; Schwarcz, Robert

    2014-03-01

    Increased brain levels of the tryptophan metabolite kynurenic acid (KYNA) have been linked to cognitive dysfunctions in schizophrenia and other psychiatric diseases. In the rat, local inhibition of kynurenine aminotransferase II (KAT II), the enzyme responsible for the neosynthesis of readily mobilizable KYNA in the brain, leads to a prompt reduction in extracellular KYNA levels, and secondarily induces an increase in extracellular glutamate, dopamine, and acetylcholine levels in several brain areas. Using microdialysis in unanesthetized, adult rats, we now show that the novel, systemically active KAT II inhibitor BFF-816, applied orally at 30 mg/kg in all experiments, mimics the effects of local enzyme inhibition. No tolerance was seen when animals were treated daily for 5 consecutive days. Behaviorally, daily injections of BFF-816 significantly decreased escape latency in the Morris water maze, indicating improved performance in spatial and contextual memory. Thus, systemically applied BFF-816 constitutes an excellent tool for studying the neurobiology of KYNA and, in particular, for investigating the mechanisms linking KAT II inhibition to changes in glutamatergic, dopaminergic, and cholinergic function in brain physiology and pathology.

  19. Structural Basis for the Stereochemical Control of Amine Installation in Nucleotide Sugar Aminotransferases.

    Science.gov (United States)

    Wang, Fengbin; Singh, Shanteri; Xu, Weijun; Helmich, Kate E; Miller, Mitchell D; Cao, Hongnan; Bingman, Craig A; Thorson, Jon S; Phillips, George N

    2015-09-18

    Sugar aminotransferases (SATs) are an important class of tailoring enzymes that catalyze the 5'-pyridoxal phosphate (PLP)-dependent stereo- and regiospecific installation of an amino group from an amino acid donor (typically L-Glu or L-Gln) to a corresponding ketosugar nucleotide acceptor. Herein we report the strategic structural study of two homologous C4 SATs (Micromonospora echinospora CalS13 and Escherichia coli WecE) that utilize identical substrates but differ in their stereochemistry of aminotransfer. This study reveals for the first time a new mode of SAT sugar nucleotide binding and, in conjunction with previously reported SAT structural studies, provides the basis from which to propose a universal model for SAT stereo- and regiochemical control of amine installation. Specifically, the universal model put forth highlights catalytic divergence to derive solely from distinctions within nucleotide sugar orientation upon binding within a relatively fixed SAT active site where the available ligand bound structures of the three out of four representative C3 and C4 SAT examples provide a basis for the overall model. Importantly, this study presents a new predictive model to support SAT functional annotation, biochemical study and rational engineering.

  20. The rice FISH BONE gene encodes a tryptophan aminotransferase, which affects pleiotropic auxin-related processes.

    Science.gov (United States)

    Yoshikawa, Takanori; Ito, Momoyo; Sumikura, Tsuyoshi; Nakayama, Akira; Nishimura, Takeshi; Kitano, Hidemi; Yamaguchi, Isomaro; Koshiba, Tomokazu; Hibara, Ken-Ichiro; Nagato, Yasuo; Itoh, Jun-Ichi

    2014-06-01

    Auxin is a fundamental plant hormone and its localization within organs plays pivotal roles in plant growth and development. Analysis of many Arabidopsis mutants that were defective in auxin biosynthesis revealed that the indole-3-pyruvic acid (IPA) pathway, catalyzed by the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) and YUCCA (YUC) families, is the major biosynthetic pathway of indole-3-acetic acid (IAA). In contrast, little information is known about the molecular mechanisms of auxin biosynthesis in rice. In this study, we identified a auxin-related rice mutant, fish bone (fib). FIB encodes an orthologue of TAA genes and loss of FIB function resulted in pleiotropic abnormal phenotypes, such as small leaves with large lamina joint angles, abnormal vascular development, small panicles, abnormal organ identity and defects in root development, together with a reduction in internal IAA levels. Moreover, we found that auxin sensitivity and polar transport activity were altered in the fib mutant. From these results, we suggest that FIB plays a pivotal role in IAA biosynthesis in rice and that auxin biosynthesis, transport and sensitivity are closely interrelated.

  1. Infrared spectroscopic study of a phosphoryl-containing enzyme: cytosolic aspartate aminotransferase

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Ruiz, J.M.; Martinez-Carrion, M.

    1986-05-01

    A Fourier Transform Infrared spectroscopic study of cytosolic aspartate aminotransferase has been carried out in order to determine the ionization state of the phosphate group of the bound pyridoxal phosphate. The band arising from the symmetric stretching of the dianionic phosphate monoester has been identified in holoenzyme spectra in solution. Its integrated intensity does not change with pH in the range 5.3-8.6, the value being close to the integrated intensity of the same band in free pyridoxal phosphate in solution at pH 8-9. On the other hand, for free cofactor, the integrated intensity changes with pH according to the pK expected for a 5'-phosphate group in solution. It appears, therefore, that the 5'-phosphate group of the bound cofactor remains mostly dianionic in the pH range 5.3-8.6, and a small /sup 31/P-NMR chemiCal shift/pH titration dependent curve observed in holoenzyme solutions seems due to the phosphate group in the protein, likely the Lys 258-pyridoxal phosphate Schiff's base. These results also show Fourier Transform Infrared Spectroscopy as a valuable technique in the study of phosphoryl-containing proteins.

  2. Longitudinal increase in gamma-glutamyltransferase within the reference interval predicts metabolic syndrome in middle-aged Korean men.

    Science.gov (United States)

    Ryu, Seungho; Chang, Yoosoo; Woo, Hee-Yeon; Yoo, Sang-Ho; Choi, Nam-Kyong; Lee, Won-Young; Kim, Inah; Song, Jaechul

    2010-05-01

    In the absence of existing research, we examined the association between longitudinal changes in serum gamma-glutamyltransferase (GGT) levels and the risk for metabolic syndrome (MetS). A MetS-free cohort of 9148 healthy male workers, who had participated in a health checkup program in 2002, was followed until September 2007. Metabolic syndrome was defined according to the modified National Cholesterol Education Program, using body mass index instead of waist circumference. Standard Cox proportional hazards and time-dependent Cox models were performed. During 37 663.4 person-years of follow-up, 1056 men developed MetS. The risk of incident MetS increased across the baseline GGT quartiles, even after further updating GGT values during the follow-up. A longitudinal increase in GGT as a time-dependent variable as well as a non-time-dependent variable was significantly related to MetS after adjusting for age plus the elapsed time from visit 1 to visit 2, baseline MetS traits, uric acid, regular exercise, alcohol consumption, and smoking. Even within the GGT reference interval (interval, 1.26-2.07). Furthermore, these associations were consistently observed within the subgroups-those with body mass index less than 23 kg/m(2), C-reactive protein less than 3.0 mg/L, homeostasis model assessment of insulin resistance less than 2.04, alcohol intake not exceeding 20 g/d, alanine aminotransferase less than 35 U/L, an absence of ultrasonographically detected fatty liver, and an absence of any MetS traits. A longitudinal increase in the GGT level, even within the GGT reference interval, may be an independent predictor for MetS, regardless of the baseline GGT.

  3. Spectroscopic Evidence for an Oxazolone Structure of the b(2) Fragment Ion from Protonated Tri-Alanine

    NARCIS (Netherlands)

    Oomens, J.; Young, S.; Molesworth, S.; Van Stipdonk, M.

    2009-01-01

    Infrared multiple photon dissociation (IRMPD) spectroscopy is used to identify the structure of the b(2)(+) ion generated from protonated tri-alanine by collision induced dissociation (CID). The IRMPD spectrum of b(2)(+) differs markedly from that of protonated cyclo-alanine-alanine, demonstrating t

  4. Characterization of the l-alanine exporter AlaE of Escherichia coli and its potential role in protecting cells from a toxic-level accumulation of l-alanine and its derivatives.

    Science.gov (United States)

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

    2015-08-01

    We previously reported that the alaE gene of Escherichia coli encodes the l-alanine exporter AlaE. The objective of this study was to elucidate the mechanism of the AlaE exporter. The minimum inhibitory concentration of l-alanine and l-alanyl-l-alanine in alaE-deficient l-alanine-nonmetabolizing cells MLA301ΔalaE was 4- and >4000-fold lower, respectively, than in the alaE-positive parent cells MLA301, suggesting that AlaE functions as an efflux pump to avoid a toxic-level accumulation of intracellular l-alanine and its derivatives. Furthermore, the growth of the alaE-deficient mutant derived from the l-alanine-metabolizing strain was strongly inhibited in the presence of a physiological level of l-alanyl-l-alanine. Intact MLA301ΔalaE and MLA301ΔalaE/pAlaE cells producing plasmid-borne AlaE, accumulated approximately 200% and 50%, respectively, of the [(3) H]l-alanine detected in MLA301 cells, suggesting that AlaE exports l-alanine. When 200 mmol/L l-alanine-loaded inverted membrane vesicles prepared from MLA301ΔalaE/pAlaE were placed in a solution containing 200 mmol/L or 0.34 μmol/L l-alanine, energy-dependent [(3) H]l-alanine accumulation occurred under either condition. This energy-dependent uphill accumulation of [(3) H]l-alanine was strongly inhibited in the presence of carbonyl cyanide m-chlorophenylhydrazone but not by dicyclohexylcarbodiimide, suggesting that the AlaE-mediated l-alanine extrusion was driven by proton motive force. Based on these results, physiological roles of the l-alanine exporter are discussed.

  5. Temperature dependences of piezoelectric, elastic and dielectric constants of L-alanine crystal

    Science.gov (United States)

    Tylczyński, Z.; Sterczyńska, A.; Wiesner, M.

    2011-09-01

    Temperature changes in the components of piezoelectric, elastic and dielectric tensors were studied in L-alanine crystals in the range 100-300 K. A jumpwise increase in the c55 component of the elastic stiffness accompanied by maxima in damping of all face-shear modes observed at 199 K in L-alanine crystal were interpreted as a result of changes in the NH3+ vibrations occurring through electron-phonon coupling. All components of the piezoelectric tensor show small anomalies in this temperature range. The components of the electromechanical coupling coefficient determined indicate that L-alanine is a weak piezoelectric.

  6. Interactions of L-alanine with alumina as studied by vibrational spectroscopy.

    Science.gov (United States)

    Garcia, Ana R; de Barros, Ricardo Brito; Fidalgo, Alexandra; Ilharco, Laura M

    2007-09-25

    The interactions of L-alanine with gamma- and alpha-alumina have been investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). L-alanine/alumina samples were dried from aqueous suspensions, at 36.5 degrees C, with two amino acid concentrations (0.4 and 0.8 mmol g-1) and at different pH values (1, 6, and 13). The vibrational spectra proved that the nature of L-alanine interactions with both aluminas is the same (hydrogen bonding), although the groups involved depend on the L-alanine form and on alumina surface groups, both controlled by the pH. For samples prepared at pH 1, cationic L-alanine [CH3CH(NH3+)COOH] displaces physisorbed water from alumina, and strong hydrogen bonds are established between the carbonyl groups of alanine, as electron donors, and the surface Al-OH2+ groups of alumina. This occurs at the expense of alanine dimer dissociation and breaking of intramolecular bonds. When samples are prepared at pH 6, the interacting groups are Al-OH2+ and the carboxylate groups of zwitterionic L-alanine [CH3CH(NH3+)COO-]. The affinity of L-alanine toward alumina decreases, as the strong NH3+...-OOC intermolecular hydrogen bonds prevail over the interactions with alumina. Thus, for a load of 0.8 mmol g-1, phase segregation is observed. On alpha-alumina, crystal deposition is even observed for a load of 0.4 mmol g-1. At pH 13, the carboxylate groups of anionic L-alanine [CH3CH(NH2)COO-] are not affected by alumina. Instead, hydrogen bond interactions occur between NH2 and the Al-OH surface groups of the substrate. Complementary N2 adsorption-desorption isotherms showed that adsorption of L-alanine occurs onto the alumina pore network for samples prepared at pH 1 and 13, whereas at pH 6 the amino acid/alumina interactions are not strong enough to promote adsorption. The mesoporous structure and the high specific surface area of gamma-alumina make it a more efficient substrate for adsorption of L-alanine. For each alumina, however, it is

  7. Optical and Spectral Studies on β Alanine Metal Halide Hybrid Crystals

    Science.gov (United States)

    Sweetlin, M. Daniel; Selvarajan, P.; Perumal, S.; Ramalingom, S.

    2011-10-01

    We have synthesized and grown β alanine metal halide hybrid crystals viz. β alanine cadmium chloride (BACC), an amino acid transition metal halide complex crystal and β alanine potassium chloride (BAPC), an amino acid alkali metal halide complex crystal by slow evaporation method. The grown crystals were found to be transparent and have well defined morphology. The optical characteristics of the grown crystals were carried out with the help of UV-Vis Spectroscopy. The optical transmittances of the spectrums show that BAPC is more transparent than BACC. The Photoluminescence of the materials were determined by the Photoluminescent Spectroscopy

  8. 西安地区高ALT值献血者HEV亚临床感染情况调查%Study on Hepatitis E Virus Subclinical Infection in High Alanine Aminotransferase Donors in Xi'an area

    Institute of Scientific and Technical Information of China (English)

    廖红; 陈海珊; 穆士杰; 张献清

    2013-01-01

    目的 探讨西安地区无偿献血者中戊型肝炎病毒的亚临床感染情况及其与ALT水平的相关性.方法 收集西安地区2009年1月~2010年12月ALT水平升高的1 874名无偿献血者血样,根据ALT检测结果分组后进行抗-HEVIgM和IgG、HEV RNA检测,比较各项指标间的相关性,并对HEV RNA阳性标本进行测序和基因分型.结果 1 874名无偿献血者中有7例抗-HEV IgM阳性,占0.37%;21例抗-HEV IgG阳性,占1.12%;8例HEV RNA阳性,占0.43%.其中7例抗-HEV IgM阳性者其RNA均为阳性.抗-HEV IgG的阳性率随年龄升高而增加.扩增8例HEV RNA阳性血样的保守序列ORF2分析发现5例基因型为Ⅰ型,另外3例基因型为Ⅳ型.结论 西安地区戊型肝炎病毒的亚临床感染率为0.37%,HEV流行株主要为Ⅰ型和Ⅳ型病毒株.%Objective To study the subciinical infection of hepatitis E virus of blood donors in Xi'an area, and its correlation with ALT levels. Methods To collect 1 874 blood donors samples with high ALT levels in Xi'an area from January 2009 to December 2010 and to test ALT. They were grouped according to the level of ALT. And they were detected on anti-HEV IgM and IgG, HEV RNA,then the relationships were analyzed among different indicators. The age of the donors, sequence and genotype were analyzed on the positive samples with HEV RNA. Results Among 1 874 blood donors, 7 were positive with HEV-IgM, accounting for 0. 37%, all of the seven were positive with HEV RNA. 21 were positive with HEV-IgG, accounting for 1.12%. Anti-HEV IgG positive rate increased with the age of the dolors. 8 were positive with HEV RNA, accounting for 0. 43%. HEV RNA ORF2 was amplified in 8 samples, 5 belonged to genotype I and the other 3 belonged to genotype IV. Conclusion The rate of subclinical infection of hepatitis E virus in Xi'an was 0. 37%, the genotypes of hepatitis E belonged to genotype 1 and 4.

  9. In vivo dosimetry with L-alpha-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Boey, R.; Van Der Velden, K. [Industriele Hogeschool van het Gemeenschapsonderwijs Limburg, Hasselt (Belgium); Schaeken, B. [Algemeen Ziekenhuis Middelheim, Antwerp (Belgium). Dept. of Radiotherapy

    1995-12-01

    When organic substances are irradiated, stable electrons can be formed. The concentration of these electrons is detected via electron paramagnetic resonance (EPR), a non-destructive form of dosimetry. L-alpha-alanine is extremely suited as a detector because of its high stability and high yield of unpaired electrons. With an EMS 104 spectrometer, we measure the peak-to-peak value of the first derivate of the resonance-spectrum. This value is proportional to the concentration of unpaired electrons and therefore with the absorbed dose. Prior to the in vivo measurements in teletherapy, a calibration curve had to be established. This clearly showed a linear relationship between the EPR-signal and the absorbed dose, except for very low dose where precision was low (20% 1 sd). This indicates that the background signal of the dosimeter is strongly orientation dependent. For this reason it was decided to use pre-irradiated detectors. A number of in vivo measurements has been performed. It was found that the error propagation plays a major role in the calculation of the measured absorbed dose, in the range 1 Gy-6 Gy. Contrary to in vivo measurements in brachytherapy, where higher doses are measured, large uncertainties (30% 1 sd) on the entry dose calculations were observed. For this reason, it is recommended to use a statistical method of reducing this standard deviation to an acceptable level. The proposed method, consisting of 2 detectors and the usage of weight coefficients on our standard deviations, gave promising results. However, theoretical calculations and in vivo measurements show that this method is still not satisfactory to reduce the uncertainty to an acceptable standard in clinical situations.

  10. Exercise training and beta-alanine-induced muscle carnosine loading.

    Directory of Open Access Journals (Sweden)

    Tine eBex

    2015-05-01

    Full Text Available Purpose. Beta-alanine (BA supplementation has been shown to augment muscle carnosine concentration, thereby promoting high-intensity exercise performance. Trained muscles of athletes have a higher increase in carnosine concentration after BA supplementation compared to untrained muscles, but it remains to be determined whether this is due to an accumulation of acute exercise effects or to chronic adaptations from prior training. The aim of the present study was to investigate whether high-volume (HV and/or high-intensity (HI exercise can improve BA-induced carnosine loading in untrained subjects.Methods. All participants (n=28 were supplemented with 6.4 g/day of BA for 23 days. The subjects were allocated to a control group, HV or HI training group. During the BA supplementation period, the training groups performed 9 exercise sessions consisting of either 75–90 min continuous cycling at 35–45% Wmax (HV or 3 to 5 repeats of 30s cycling at 165% Wmax with 4 min recovery (HI. Carnosine content was measured in soleus and gastrocnemius medialis by proton magnetic resonance spectroscopy.Results. There was no difference in absolute increase in carnosine content between the groups in soleus and gastrocnemius muscle. For the average muscle carnosine content, a higher absolute increase was found in HV (+ 2.95 mM; P = 0.046 and HI (+ 3.26 mM; P = 0.028 group compared to the control group (+ 1.91 mM. However, there was no additional difference between the HV and HI training group.Conclusions. HV and HI exercise training showed no significant difference on BA-induced muscle carnosine loading in soleus and gastrocnemius muscle. It can be suggested that there can be a small cumulative effect of exercise on BA supplementation efficiency, although differences did not reach significance on individual muscle level.

  11. Purification, crystallization and preliminary X-ray crystallographic analysis of branched-chain aminotransferase from Deinococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chung-Der; Huang, Tien-Feng [Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Lin, Chih-Hao [Institute of Biological Chemistry, National Taiwan University, Taipei 110,Taiwan (China); Guan, Hong-Hsiang; Hsieh, Yin-Cheng [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Lin, Yi-Hung; Huang, Yen-Chieh; Liu, Ming-Yih [Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China); Chang, Wen-Chang, E-mail: wchang@ntu.edu.tw [Institute of Biological Chemistry, National Taiwan University, Taipei 110,Taiwan (China); Chen, Chun-Jung, E-mail: wchang@ntu.edu.tw [Department of Physics, National Tsing-Hua University, Hsinchu 30013,Taiwan (China); Life Science Group, Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076,Taiwan (China)

    2007-06-01

    The crystallization of branched-chain aminotransferase from D. radiodurans is described. The branched-chain amino-acid aminotransferase (BCAT), which requires pyridoxal 5′-phosphate (PLP) as a cofactor, is a key enzyme in the biosynthetic pathway of the hydrophobic amino acids leucine, isoleucine and valine. DrBCAT from Deinococcus radiodurans, which has a molecular weight of 40.9 kDa, was crystallized using the hanging-drop vapour-diffusion method. According to X-ray diffraction data to 2.50 Å resolution from a DrBCAT crystal, the crystal belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 56.37, b = 90.70, c = 155.47 Å. Preliminary analysis indicates the presence of two DrBCAT molecules in the asymmetric unit, with a solvent content of 47.52%.

  12. A comparative study on the growth and characterization of nonlinear optical amino acid crystals: L-alanine (LA) and L-alanine alaninium nitrate (LAAN).

    Science.gov (United States)

    Aravindan, A; Srinivasan, P; Vijayan, N; Gopalakrishnan, R; Ramasamy, P

    2008-11-15

    A comparative study on the properties of L-alanine and LAAN crystals has been made and discussed. It may be concluded that the protonation of the amino group in the L-alanine molecule is the key factor in increasing the relative SHG efficiency of LAAN. The protonation is justified by the crystal structure analysis, FTIR and photoluminescence studies. The factor group vibrations are compared and found that there is an increase in vibrational modes of LA when reacted with nitric acid forming LAAN.

  13. Determination of the carbon, hydrogen and nitrogen contents of alanine and their uncertainties using the certified reference material L-alanine (NMIJ CRM 6011-a).

    Science.gov (United States)

    Itoh, Nobuyasu; Sato, Ayako; Yamazaki, Taichi; Numata, Masahiko; Takatsu, Akiko

    2013-01-01

    The carbon, hydrogen, and nitrogen (CHN) contents of alanine and their uncertainties were estimated using a CHN analyzer and the certified reference material (CRM) L-alanine. The CHN contents and their uncertainties, as measured using the single-point calibration method, were 40.36 ± 0.20% for C, 7.86 ± 0.13% for H, and 15.66 ± 0.09% for N; the results obtained using the bracket calibration method were also comparable. The method described in this study is reasonable, convenient, and meets the general requirement of having uncertainties ≤ 0.4%.

  14. Branched-chain fatty acid biosynthesis in a branched-chain amino acid aminotransferase mutant of Staphylococcus carnosus

    DEFF Research Database (Denmark)

    Beck, Hans Christian

    2005-01-01

    Fatty acid biosynthesis by a mutant strain of Staphylococcus carnosus deficient in branched-chain amino acid aminotransferase (IlvE) activity was analysed. This mutant was unable to produce the appropriate branched-chain alpha-ketoacid precursors for branched-chain fatty acid biosynthesis from...... for 2-methylpropanoic acid production, revealing that the IlvE protein plays an important, but not essential role in the biosynthesis of branched-chain fatty acids and secondary metabolites in S. carnosus....

  15. Substrate Specificity of the Aspartate:Alanine Antiporter (AspT) of Tetragenococcus halophilus in Reconstituted Liposomes*

    OpenAIRE

    Sasahara, Ayako; Nanatani, Kei; Enomoto, Masaru; Kuwahara, Shigefumi; Abe, Keietsu

    2011-01-01

    The aspartate:alanine antiporter (AspT) of the lactic acid bacterium Tetragenococcus halophilus is a member of the aspartate:alanine exchanger (AAEx) transporter family. T. halophilus AspT catalyzes the electrogenic exchange of l-aspartate1− with l-alanine0. Although physiological functions of AspT were well studied, l-aspartate1−:l-alanine0 antiport mechanisms are still unsolved. Here we report that the binding sites of l-aspartate and l-alanine are independently present in AspT by means of ...

  16. Second harmonic generation studies in L-alanine single crystals grown from solution

    Science.gov (United States)

    Boomadevi, Shanmugam; Pandiyan, Krishnamoorthy

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm3 were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV-vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  17. Second harmonic generation studies in L-alanine single crystals grown from solution

    Energy Technology Data Exchange (ETDEWEB)

    Boomadevi, Shanmugam, E-mail: sboomi@gmail.com [Department of Physics, Periyar Maniammai University, Thanjavur-613 403, Tamil Nadu (India); Pandiyan, Krishnamoorthy [School of Electrical and Electronics Engineering, SASTRA University, Thanjavur-613 401, Tamil Nadu (India)

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm{sup 3} were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV–vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  18. Implementation of an alanine dosimetry service; Puesta en marcha de un servicio de dosimetria de alanima

    Energy Technology Data Exchange (ETDEWEB)

    Gago Arias, A.; Nunez Pelaez, N.; Peteiro Vilaseco, E.; Gomez Rodriguez, F.; Gonzalez Castano, D. M.

    2011-07-01

    This work facing the implementation of an alanine dosimetry service, linked to the installation of Co{sub 6}0 Radio physics Laboratory (LP) and Paramagnetic Resonance Service of the University of Santiago de Compostela (USC).

  19. SYNTHESIS OF D-AND L-β-(4-CHLOROPHENYL)-α-ALANINE

    Institute of Scientific and Technical Information of China (English)

    沈宗璇; 张雅文; 顾德本; 滕洪流; 杨冰

    1991-01-01

    N-acetyl-β-(4-chloropheayl)-DL-α-alanine ethyl ester was synthesized from p-chlorobenzyl chloride via diethyl malonate method. The ethyl ester was effectively resofued by enzymatic hydrolysis with using of subtilisin carlsberg.

  20. Overexpression, purification and crystallization of lysine ∊-aminotransferase (Rv3290c) from Mycobacterium tuberculosis H37Rv

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Sarvind Mani; Ramachandran, Ravishankar, E-mail: ravi-anitha@yahoo.com [Molecular and Structural Biology Division, Central Drug Research Institute, PO Box 173, Chattar Manzil, Mahatma Gandhi Marg, Lucknow 226001 (India)

    2006-06-01

    Lysine ∊-aminotransferase from M. tuberculosis has been crystallized. Preliminary crystallographic analysis shows that there is one monomer in the asymmetric unit of the crystal. Lysine ∊-aminotransferase (LAT) is a protein involved in lysine catabolism; it belongs to the aminotransferase family of enzymes, which use pyridoxal 5′-phosphate (PLP) as a cofactor. LAT probably plays a significant role during the persistent/latent phase of Mycobacterium tuberculosis, as observed by its up-regulation by ∼40-fold during this stage. Crystals of recombinant LAT have been grown in 0.1 M trisodium citrate dihydrate solution containing 0.2 M ammonium acetate and 25% PEG 4000 in the pH range 5.4–6.0. Diffraction data extending to 1.98 Å were collected at room temperature from a single crystal. Crystals are trigonal in shape and belong to space group P3{sub 1}21, with unit-cell parameters a = 103.26, b = 103.26, c = 98.22 Å. The crystals contain a monomer in the asymmetric unit, which corresponds to a Matthews coefficient (V{sub M}) of 3.1 Å{sup 3} Da{sup −1}.

  1. Novel and recurrent tyrosine aminotransferase gene mutations in tyrosinemia type II.

    Science.gov (United States)

    Hühn, R; Stoermer, H; Klingele, B; Bausch, E; Fois, A; Farnetani, M; Di Rocco, M; Boué, J; Kirk, J M; Coleman, R; Scherer, G

    1998-03-01

    Tyrosinemia type II (Richner-Hanhart syndrome, RHS) is a disorder of autosomal recessive inheritance characterized by keratitis, palmoplantar hyperkeratosis, mental retardation, and elevated blood tyrosine levels. The disease results from deficiency in hepatic tyrosine aminotransferase (TAT). We have previously described one deletion and six different point mutations in four RHS patients. We have now analyzed the TAT genes in a further seven unrelated RHS families from Italy, France, the United Kingdom, and the United States. We have established PCR conditions for the amplification of all twelve TAT exons and have screened the products for mutations by direct sequence analysis or by first performing single-strand conformation polymorphism analysis. We have thus identified the presumably pathological mutations in eight RHS alleles, including two nonsense mutations (R57X, E411X) and four amino acid substitutions (R119W, L201R, R433Q, R433W). Only the R57X mutation, which was found in one Scottish and two Italian families, has been previously reported in another Italian family. Haplotype analysis indicates that this mutation, which involves a CpG dinucleotide hot spot, has a common origin in the three Italian families but arose independently in the Scottish family. Two polymorphisms have also been detected, viz., a protein polymorphism, P15S, and a silent substitution S103S (TCG-->TCA). Expression of R433Q and R433W demonstrate reduced activity of the mutant proteins. In all, twelve different TAT gene mutations have now been identified in tyrosinemia type II.

  2. Biochemical and phenotypic abnormalities in kynurenine aminotransferase II-deficient mice.

    Science.gov (United States)

    Yu, Ping; Di Prospero, Nicholas A; Sapko, Michael T; Cai, Tao; Chen, Amy; Melendez-Ferro, Miguel; Du, Fu; Whetsell, William O; Guidetti, Paolo; Schwarcz, Robert; Tagle, Danilo A

    2004-08-01

    Kynurenic acid (KYNA) can act as an endogenous modulator of excitatory neurotransmission and has been implicated in the pathogenesis of several neurological and psychiatric diseases. To evaluate its role in the brain, we disrupted the murine gene for kynurenine aminotransferase II (KAT II), the principal enzyme responsible for the synthesis of KYNA in the rat brain. mKat-2(-/-) mice showed no detectable KAT II mRNA or protein. Total brain KAT activity and KYNA levels were reduced during the first month but returned to normal levels thereafter. In contrast, liver KAT activity and KYNA levels in mKat-2(-/-) mice were decreased by >90% throughout life, though no hepatic abnormalities were observed histologically. KYNA-associated metabolites kynurenine, 3-hydroxykynurenine, and quinolinic acid were unchanged in the brain and liver of knockout mice. mKat-2(-/-) mice began to manifest hyperactivity and abnormal motor coordination at 2 weeks of age but were indistinguishable from wild type after 1 month of age. Golgi staining of cortical and striatal neurons revealed enlarged dendritic spines and a significant increase in spine density in 3-week-old mKat-2(-/-) mice but not in 2-month-old animals. Our results show that gene targeting of mKat-2 in mice leads to early and transitory decreases in brain KAT activity and KYNA levels with commensurate behavioral and neuropathological changes and suggest that compensatory changes or ontogenic expression of another isoform may account for the normalization of KYNA levels in the adult mKat-2(-/-) brain.

  3. Characterization of kynurenine aminotransferase III, a novel member of a phylogenetically conserved KAT family.

    Science.gov (United States)

    Yu, Ping; Li, Zhengsheng; Zhang, Ling; Tagle, Danilo A; Cai, Tao

    2006-01-03

    Kynurenine aminotransferase (KAT) is an enzyme responsible for synthesis of kynurenic acid (KYNA), a well established neuroprotective and anticonvulsant agent, involved in synaptic transmission and implicated in the pathophysiology of schizophrenia, Huntington's disease and other neurological disorders. We have shown previously that kat2-/- mice had lower hippocampal KYNA levels and were more hyperactive than wild-type mice. However, these abnormalities occur early and are transitory coinciding with restoration of KYNA levels, suggesting that compensatory changes or ontogenetic expression of another unknown homolog may account for the normalization of KYNA levels in the adult kat2-/- mice brain. Here, we report the isolation of a novel KAT molecule, kat3, from mouse and human brain cDNA libraries. The encoded 454 amino acids of human KAT III share 64.8% similarity to that of KAT I and 30.1% to KAT II. Northern blot analysis demonstrated that kat3 mRNA is widely expressed but with higher expression levels in liver, kidney, heart, and neuroendocrine tissues. RT-PCR and Northern analysis showed that kat3 expression starts as early as postnatal day (PND) 7 and peaks in adult. The mRNA level of kat3 and kat1 when measured together is significantly higher at PND 60 in kat2-/- mice than those of wild-type mice indicating possible co-regulation of expression levels. RNA-interference (RNAi) directed towards transcripts for either R03A10.4 or F28H6.3 in Caenorhabditis elegans which are kat1 and kat3 orthologs, respectively, did not result in any gross abnormalities. Our results show that upregulation of kat3 and kat1 may be responsible for the phenotypic rescue on kat2-/- mice.

  4. Relaxed evolution in the tyrosine aminotransferase gene tat in old world fruit bats (Chiroptera: Pteropodidae).

    Science.gov (United States)

    Shen, Bin; Fang, Tao; Yang, Tianxiao; Jones, Gareth; Irwin, David M; Zhang, Shuyi

    2014-01-01

    Frugivorous and nectarivorous bats fuel their metabolism mostly by using carbohydrates and allocate the restricted amounts of ingested proteins mainly for anabolic protein syntheses rather than for catabolic energy production. Thus, it is possible that genes involved in protein (amino acid) catabolism may have undergone relaxed evolution in these fruit- and nectar-eating bats. The tyrosine aminotransferase (TAT, encoded by the Tat gene) is the rate-limiting enzyme in the tyrosine catabolic pathway. To test whether the Tat gene has undergone relaxed evolution in the fruit- and nectar-eating bats, we obtained the Tat coding region from 20 bat species including four Old World fruit bats (Pteropodidae) and two New World fruit bats (Phyllostomidae). Phylogenetic reconstructions revealed a gene tree in which all echolocating bats (including the New World fruit bats) formed a monophyletic group. The phylogenetic conflict appears to stem from accelerated TAT protein sequence evolution in the Old World fruit bats. Our molecular evolutionary analyses confirmed a change in the selection pressure acting on Tat, which was likely caused by a relaxation of the evolutionary constraints on the Tat gene in the Old World fruit bats. Hepatic TAT activity assays showed that TAT activities in species of the Old World fruit bats are significantly lower than those of insectivorous bats and omnivorous mice, which was not caused by a change in TAT protein levels in the liver. Our study provides unambiguous evidence that the Tat gene has undergone relaxed evolution in the Old World fruit bats in response to changes in their metabolism due to the evolution of their special diet.

  5. Relaxed evolution in the tyrosine aminotransferase gene tat in old world fruit bats (Chiroptera: Pteropodidae.

    Directory of Open Access Journals (Sweden)

    Bin Shen

    Full Text Available Frugivorous and nectarivorous bats fuel their metabolism mostly by using carbohydrates and allocate the restricted amounts of ingested proteins mainly for anabolic protein syntheses rather than for catabolic energy production. Thus, it is possible that genes involved in protein (amino acid catabolism may have undergone relaxed evolution in these fruit- and nectar-eating bats. The tyrosine aminotransferase (TAT, encoded by the Tat gene is the rate-limiting enzyme in the tyrosine catabolic pathway. To test whether the Tat gene has undergone relaxed evolution in the fruit- and nectar-eating bats, we obtained the Tat coding region from 20 bat species including four Old World fruit bats (Pteropodidae and two New World fruit bats (Phyllostomidae. Phylogenetic reconstructions revealed a gene tree in which all echolocating bats (including the New World fruit bats formed a monophyletic group. The phylogenetic conflict appears to stem from accelerated TAT protein sequence evolution in the Old World fruit bats. Our molecular evolutionary analyses confirmed a change in the selection pressure acting on Tat, which was likely caused by a relaxation of the evolutionary constraints on the Tat gene in the Old World fruit bats. Hepatic TAT activity assays showed that TAT activities in species of the Old World fruit bats are significantly lower than those of insectivorous bats and omnivorous mice, which was not caused by a change in TAT protein levels in the liver. Our study provides unambiguous evidence that the Tat gene has undergone relaxed evolution in the Old World fruit bats in response to changes in their metabolism due to the evolution of their special diet.

  6. L,L-diaminopimelate aminotransferase from Chlamydomonas reinhardtii: a target for algaecide development.

    Directory of Open Access Journals (Sweden)

    Renwick C J Dobson

    Full Text Available In some bacterial species and photosynthetic cohorts, including algae, the enzyme L,L-diaminopimelate aminotransferase (DapL (E.C. 2.6.1.83 is involved in the anabolism of the essential amino acid L-lysine. DapL catalyzes the conversion of tetrahydrodipicolinate (THDPA to L,L-diaminopimelate (L,L-DAP, in one step bypassing the DapD, DapC and DapE enzymatic reactions present in the acyl DAP pathways. Here we present an in vivo and in vitro characterization of the DapL ortholog from the alga Chlamydomonas reinhardtii (Cr-DapL. The in vivo analysis illustrated that the enzyme is able to functionally complement the E. coli dap auxotrophs and was essential for plant development in Arabidopsis. In vitro, the enzyme was able to inter-convert THDPA and L,L-DAP, showing strong substrate specificity. Cr-DapL was dimeric in both solution and when crystallized. The structure of Cr-DapL was solved in its apo form, showing an overall architecture of a α/β protein with each monomer in the dimer adopting a pyridoxal phosphate-dependent transferase-like fold in a V-shaped conformation. The active site comprises residues from both monomers in the dimer and shows some rearrangement when compared to the apo-DapL structure from Arabidopsis. Since animals do not possess the enzymatic machinery necessary for the de novo synthesis of the amino acid L-lysine, enzymes involved in this pathway are attractive targets for the development of antibiotics, herbicides and algaecides.

  7. Inhibition of kynurenine aminotransferase II reduces activity of midbrain dopamine neurons.

    Science.gov (United States)

    Linderholm, Klas R; Alm, Maximilian Tufvesson; Larsson, Markus K; Olsson, Sara K; Goiny, Michel; Hajos, Mihaly; Erhardt, Sophie; Engberg, Göran

    2016-03-01

    Kynurenic acid (KYNA), a neuroactive metabolite of tryptophan, is elevated in the brain of patients with psychotic disorders. Therefore, lowering brain KYNA levels might be a novel approach in the treatment of psychotic disorders. The present in vivo electrophysiological study aimed to investigate the effect of an inhibitor of kynurenine aminotransferase (KAT) II, the primary enzyme for KYNA synthesis, on dopamine (DA) neurons in the ventral tegmental area (VTA). Acute administration of the KAT II inhibitor PF-04859989 (5 or 10 mg/kg) was associated with a short-onset, time-dependent decrease in firing rate and burst activity of DA neurons, both parameters reaching a 50% reduction within 45 min. Furthermore, PF-04859989 reduced the number of spontaneously active DA cells as measured 4-6 after administration. Pretreatment with d-cycloserine (30 mg/kg) or CGP-52432 (10 mg/kg) prevented the inhibitory action of PF-04859989 (5 mg/kg) on firing rate and burst firing activity. In contrast, pretreatment with methyllycaconitine (MLA, 4 mg/kg) did not change the response, whereas picrotoxin (4.5 mg/kg) partially prevented the inhibitory effects of PF-04859989 (5 mg/kg, i.v.). Our results show that a specific inhibition of KAT II is associated with a marked reduction in VTA DA firing activity. This effect appears to be specifically executed by NMDA-receptors and mediated indirectly via a GABA(B)-receptor-induced disinhibition of DA neurons. Our findings are in line with the view that endogenous KYNA, by modulation of the NMDA-receptor, exerts important physiological roles in the brain.

  8. Altered Expression of Human Mitochondrial Branched Chain Aminotransferase in Dementia with Lewy Bodies and Vascular Dementia.

    Science.gov (United States)

    Ashby, Emma L; Kierzkowska, Marta; Hull, Jonathon; Kehoe, Patrick G; Hutson, Susan M; Conway, Myra E

    2017-01-01

    Cytosolic and mitochondrial human branched chain aminotransferase (hBCATc and hBCATm, respectively) play an integral role in brain glutamate metabolism. Regional increased levels of hBCATc in the CA1 and CA4 region of Alzheimer's disease (AD) brain together with increased levels of hBCATm in frontal and temporal cortex of AD brains, suggest a role for these proteins in glutamate excitotoxicity. Glutamate toxicity is a key pathogenic feature of several neurological disorders including epilepsy associated dementia, AD, vascular dementia (VaD) and dementia with Lewy bodies (DLB). To further understand if these increases are specific to AD, the expression profiles of hBCATc and hBCATm were examined in other forms of dementia including DLB and VaD. Similar to AD, levels of hBCATm were significantly increased in the frontal and temporal cortex of VaD cases and in frontal cortex of DLB cases compared to controls, however there were no observed differences in hBCATc between groups in these areas. Moreover, multiple forms of hBCATm were observed that were particular to the disease state relative to matched controls. Real-time PCR revealed similar expression of hBCATm mRNA in frontal and temporal cortex for all cohort comparisons, whereas hBCATc mRNA expression was significantly increased in VaD cases compared to controls. Collectively our results suggest that hBCATm protein expression is significantly increased in the brains of DLB and VaD cases, similar to those reported in AD brain. These findings indicate a more global response to altered glutamate metabolism and suggest common metabolic responses that might reflect shared neurodegenerative mechanisms across several forms of dementia.

  9. SU-E-T-643: Pure Alanine Dosimeter for Verification Dosimetry in IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Al-Karmi, Anan M.; Zraiqat, Fadi [Physics Department, King Fahd University of Petroleum & Minerals, Dhahran 31261 (Saudi Arabia)

    2015-06-15

    Purpose: The objective of this study was evaluation of accuracy of pure alanine dosimeters measuring intensity-modulated radiation therapy (IMRT) dose distributions in a thorax phantom. Methods: Alanine dosimeters were prepared in the form of 110 mg pure L-α-alanine powder filled into clear tissue-equivalent polymethylmethacrylate (PMMA) plastic tubes with the dimensions 25 mm length, 3 mm inner diameter, and 1 mm wall thickness. A dose-response calibration curve was established for the alanine by placing the dosimeters at 1.5 cm depth in a 30×30×30 cm{sup 3} solid water phantom and then irradiating on a linac with 6 MV photon beam at 10×10 cm{sup 2} field size to doses ranging from 1 to 5 Gy. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the absorbed dose in alanine. An IMRT treatment plan was designed for a commercial heterogeneous CIRS thorax phantom and the dose values were calculated at three different points located in tissue, lung, and bone equivalent materials. A set of dose measurements was carried out to compare measured and calculated dose values by placing the alanine dosimeters at those selected locations inside the thorax phantom and delivering the IMRT to the phantom. Results: The alanine dose measurements and the IMRT plan dose calculations were found to be in agreement within ±2%. Specifically, the deviations were −0.5%, 1.3%, and −1.7% for tissue, lung, and bone; respectively. The slightly large deviations observed for lung and bone may be attributed to tissue inhomogeneity, steep dose gradients in these regions, and uncontrollable changes in spectrometer conditions. Conclusion: The results described herein confirmed that pure alanine dosimeter was suitable for in-phantom dosimetry of IMRT beams because of its high sensitivity and acceptable accuracy. This makes the dosimeter a promising option for quality control of the therapeutic beams, complementing the commonly used ionization chambers, TLDs, and films.

  10. L-alanine supplementation in late infantile glycogen storage disease type II.

    Science.gov (United States)

    Bodamer, Olaf A; Haas, Dorothea; Hermans, Monique M; Reuser, Arnold J; Hoffmann, Georg F

    2002-08-01

    We report a male with late infantile glycogen storage disease type II (Pompe's disease) who presented at 12 months of age with muscular hypotonia and developmental delay. Oral supplementation with L-alanine has been administered for 5 years. Progression of skeletal myopathy was slow, and cardiomyopathy resolved almost completely. L-alanine may be a valuable supplement for infants with glycogen storage disease type II.

  11. Effect of abomasal glucose infusion on alanine metabolism and urea production in sheep.

    Science.gov (United States)

    Obitsu, T; Bremner, D; Milne, E; Lobley, G E

    2000-08-01

    The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0.75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0.75), based on hay and grass pellets. Glucose provision reduced urinary N (P = 0.040) and urea (P = 0.009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822 v. 619 mmol/d, P = 0.024) by glucose while plasma alanine-N flux rate was elevated (295 v. 342 mmol/d, P = 0.011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127 v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15%). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.

  12. Expression, crystallization and preliminary X-ray crystallographic analysis of D-alanine-D-alanine ligase from OXA-23-producing Acinetobacter baumannii K0420859.

    Science.gov (United States)

    Huynh, Kim-Hung; Tran, Huyen-Thi; Pham, Tan-Viet; Ngo, Ho-Phuong-Thuy; Cha, Sun-Shin; Chung, Kyung Min; Lee, Sang Hee; Kang, Lin-Woo

    2014-04-01

    Acinetobacter baumannii causes bacteraemia, pneumonia, other respiratory-tract and urinary-tract infections in humans. OXA-23 carbapenemase-producing A. baumannii K0420859 (A. baumannii OXA-23) is resistant to carbapenem, a common antibacterial drug. To develop an efficient and novel antibacterial drug against A. baumannii OXA-23, D-alanine-D-alanine ligase, which is essential in bacterial cell-wall synthesis, is of interest. Here, the D-alanine-D-alanine ligase (AbDdl) gene from A. baumannii OXA-23 was cloned and expressed, and the AbDdl protein was purified and crystallized; this enzyme can be used as a novel target for an antibacterial drug against A. baumannii OXA-23. The AbDdl crystal diffracted to a resolution of 2.8 Å and belonged to the orthorhombic space group P212121, with unit-cell parameters a = 113.4, b = 116.7, c = 176.5 Å, a corresponding VM of 2.8 Å(3) Da(-1) and a solvent content of 56.3%, and six protomers in the asymmetric unit.

  13. Alanine and TLD coupled detectors for fast neutron dose measurements in neutron capture therapy (NCT).

    Science.gov (United States)

    Cecilia, A; Baccaro, S; Cemmi, A; Colli, V; Gambarini, G; Rosi, G; Scolari, L

    2004-01-01

    A method was investigated to measure gamma and fast neutron doses in phantoms exposed to an epithermal neutron beam designed for neutron capture therapy (NCT). The gamma dose component was measured by TLD-300 [CaF2:Tm] and the fast neutron dose, mainly due to elastic scattering with hydrogen nuclei, was measured by alanine dosemeters [CH3CH(NH2)COOH]. The gamma and fast neutron doses deposited in alanine dosemeters are very near to those released in tissue, because of the alanine tissue equivalence. Couples of TLD-300 and alanine dosemeters were irradiated in phantoms positioned in the epithermal column of the Tapiro reactor (ENEA-Casaccia RC). The dosemeter response depends on the linear energy transfer (LET) of radiation, hence the precision and reliability of the fast neutron dose values obtained with the proposed method have been investigated. Results showed that the combination of alanine and TLD detectors is a promising method to separate gamma dose and fast neutron dose in NCT.

  14. Effect of 10 week beta-alanine supplementation on competition and training performance in elite swimmers.

    Science.gov (United States)

    Chung, Weiliang; Shaw, Greg; Anderson, Megan E; Pyne, David B; Saunders, Philo U; Bishop, David J; Burke, Louise M

    2012-10-09

    Although some laboratory-based studies show an ergogenic effect with beta-alanine supplementation, there is a lack of field-based research in training and competition settings. Elite/Sub-elite swimmers (n = 23 males and 18 females, age = 21.7 ± 2.8 years; mean ± SD) were supplemented with either beta-alanine (4 weeks loading phase of 4.8 g/day and 3.2 g/day thereafter) or placebo for 10 weeks. Competition performance times were log-transformed, then evaluated before (National Championships) and after (international or national selection meet) supplementation. Swimmers also completed three standardized training sets at baseline, 4 and 10 weeks of supplementation. Capillary blood was analyzed for pH, bicarbonate and lactate concentration in both competition and training. There was an unclear effect (0.4%; ± 0.8%, mean, ± 90% confidence limits) of beta-alanine on competition performance compared to placebo with no meaningful changes in blood chemistry. While there was a transient improvement on training performance after 4 weeks with beta-alanine (-1.3%; ± 1.0%), there was an unclear effect at ten weeks (-0.2%; ± 1.5%) and no meaningful changes in blood chemistry. Beta-alanine supplementation appears to have minimal effect on swimming performance in non-laboratory controlled real-world training and competition settings.

  15. Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans

    Institute of Scientific and Technical Information of China (English)

    Yuan Wei; Xin Xu; Ming-Yun Li; Wei Qiu; Xue-Dong Zhou; Xin Zheng; Ke-Ke Zhang; Shi-Da Wang; Yu-Qing Li; Lei Cheng; Ji-Yao Li

    2016-01-01

    D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S. mutans. We constructed alr mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that alr deletion was lethal to S. mutans. A minimal supplement of D-Ala (150μg·mL−1) was required for the optimal growth of the alr mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the alr mutant strain. We also determined the compromised competitiveness of the alr mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonii), demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of alr to the growth and competitiveness of S. mutans, Alr may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.

  16. Effect of 10 Week Beta-Alanine Supplementation on Competition and Training Performance in Elite Swimmers

    Directory of Open Access Journals (Sweden)

    Louise M. Burke

    2012-10-01

    Full Text Available Although some laboratory-based studies show an ergogenic effect with beta-alanine supplementation, there is a lack of field-based research in training and competition settings. Elite/Sub-elite swimmers (n = 23 males and 18 females, age = 21.7 ± 2.8 years; mean ± SD were supplemented with either beta-alanine (4 weeks loading phase of 4.8 g/day and 3.2 g/day thereafter or placebo for 10 weeks. Competition performance times were log-transformed, then evaluated before (National Championships and after (international or national selection meet supplementation. Swimmers also completed three standardized training sets at baseline, 4 and 10 weeks of supplementation. Capillary blood was analyzed for pH, bicarbonate and lactate concentration in both competition and training. There was an unclear effect (0.4%; ±0.8%, mean, ±90% confidence limits of beta-alanine on competition performance compared to placebo with no meaningful changes in blood chemistry. While there was a transient improvement on training performance after 4 weeks with beta-alanine (−1.3%; ±1.0%, there was an unclear effect at ten weeks (−0.2%; ±1.5% and no meaningful changes in blood chemistry. Beta-alanine supplementation appears to have minimal effect on swimming performance in non-laboratory controlled real-world training and competition settings.

  17. Effects of Nordic Walking and Pilates training programs on aminotransferase activity in overweight and obese elderly women

    OpenAIRE

    Hagner-Derengowska, Magdalena; Kałużny, Krystian; Budzyński, Jacek

    2015-01-01

    Hagner-Derengowska Magdalena, Kałużny Krystian, Budzyński Jacek. Effects of Nordic Walking and Pilates training programs on aminotransferase activity in overweight and obese elderly women. Journal of Education, Health and Sport. 2015;5(12):563-580. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.44248 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%2812%29%3A563-580 http://pbn.nauka.gov.pl/works/687148 Formerly Journal of Health Sciences. ISSN 1429-9623 / 2300-665...

  18. Branched-chain Amino Acid Metabolon: INTERACTION OF GLUTAMATE DEHYDROGENASE WITH THE MITOCHONDRIAL BRANCHED-CHAIN AMINOTRANSFERASE (BCATm)*

    OpenAIRE

    Islam, Mohammad Mainul; Nautiyal, Manisha; Wynn, R. Max; Mobley, James A.; Chuang, David T.; Hutson, Susan M.

    2009-01-01

    The catabolic pathway for branched-chain amino acids includes deamination followed by oxidative decarboxylation of the deaminated product branched-chain α-keto acids, catalyzed by the mitochondrial branched-chain aminotransferase (BCATm) and branched-chain α-keto acid dehydrogenase enzyme complex (BCKDC). We found that BCATm binds to the E1 decarboxylase of BCKDC, forming a metabolon that allows channeling of branched-chain α-keto acids from BCATm to E1. The protein complex also contains glut...

  19. Ultradian rhythmicity of tyrosine aminotransferase activity in Euglena gracillis: Analysis by cosine and non-sinusoidal fitting procedures

    Science.gov (United States)

    Neuhaus-Steinmetz, Ulrich; Balzer, Ivonne; Hardeland, Rüdiger

    1990-03-01

    Although the geophysical periodicity of the earth's rotation corresponds to a biological cyclicity of ca. 24 h, cellular temporal organization comprises a multifrequency time structure, in which ultradian rhythms may be regarded as subelements of the circadian oscillator. In Euglena gracilis kept under conditons in which various cellular functions oscillate with a circadian period, tyrosine aminotransferase activity exhibited predominantly an ultradian cycle, whereas its circadian frequency was only weakly expressed. Ultradian period lengths were in the range of 4 5 h, as demonstrated by least squares fitting of cosines and of a non-sinusoidal regression function.

  20. Purification and characterization of a branched-chain amino acid aminotransferase from Lactobacillus paracasei subsp paracasei CHCC 2115

    DEFF Research Database (Denmark)

    Thage, B.V.; Rattray, F.P.; Laustsen, M.W.;

    2004-01-01

    Purification and characterization of an aminotransferase (AT) specific for the degradation of branched-chain amino acids from Lactobacillus paracasei subsp. paracasei CHCC 2115. Methods and Results: The purification protocol consisted of anion exchange chromatography, affinity chromatography...... of other metal ions, thiol- and carbonyl-binding agents. The N-terminal sequence of the enzyme was SVNIDWNNLGFDYMQLPYRYVAHXKDGVXD, and had at the amino acid level, 60 and 53% identity to a branched-chain amino acid AT of Lact. plantarum and Lactococcus lactis, respectively. Conclusions: The results suggest...

  1. Substrate Specificity of the Aspartate:Alanine Antiporter (AspT) of Tetragenococcus halophilus in Reconstituted Liposomes*

    Science.gov (United States)

    Sasahara, Ayako; Nanatani, Kei; Enomoto, Masaru; Kuwahara, Shigefumi; Abe, Keietsu

    2011-01-01

    The aspartate:alanine antiporter (AspT) of the lactic acid bacterium Tetragenococcus halophilus is a member of the aspartate:alanine exchanger (AAEx) transporter family. T. halophilus AspT catalyzes the electrogenic exchange of l-aspartate1− with l-alanine0. Although physiological functions of AspT were well studied, l-aspartate1−:l-alanine0 antiport mechanisms are still unsolved. Here we report that the binding sites of l-aspartate and l-alanine are independently present in AspT by means of the kinetic studies. We purified His6-tagged T. halophilus AspT and characterized its kinetic properties when reconstituted in liposomes (Km = 0.35 ± 0.03 mm for l-aspartate, Km = 0.098 ± 0 mm for d-aspartate, Km = 26 ± 2 mm for l-alanine, Km = 3.3 ± 0.2 mm for d-alanine). Competitive inhibition by various amino acids of l-aspartate or l-alanine in self-exchange reactions revealed that l-cysteine selectively inhibited l-aspartate self-exchange but only weakly inhibited l-alanine self-exchange. Additionally, l-serine selectively inhibited l-alanine self-exchange but barely inhibited l-aspartate self-exchange. The aspartate analogs l-cysteine sulfinic acid, l-cysteic acid, and d-cysteic acid competitively and strongly inhibited l-aspartate self-exchange compared with l-alanine self-exchange. Taken together, these kinetic data suggest that the putative binding sites of l-aspartate and l-alanine are independently located in the substrate translocation pathway of AspT. PMID:21719707

  2. Substrate specificity of the aspartate:alanine antiporter (AspT) of Tetragenococcus halophilus in reconstituted liposomes.

    Science.gov (United States)

    Sasahara, Ayako; Nanatani, Kei; Enomoto, Masaru; Kuwahara, Shigefumi; Abe, Keietsu

    2011-08-19

    The aspartate:alanine antiporter (AspT) of the lactic acid bacterium Tetragenococcus halophilus is a member of the aspartate:alanine exchanger (AAEx) transporter family. T. halophilus AspT catalyzes the electrogenic exchange of L-aspartate(1-) with L-alanine(0). Although physiological functions of AspT were well studied, L-aspartate(1-):L-alanine(0) antiport mechanisms are still unsolved. Here we report that the binding sites of L-aspartate and L-alanine are independently present in AspT by means of the kinetic studies. We purified His(6)-tagged T. halophilus AspT and characterized its kinetic properties when reconstituted in liposomes (K(m) = 0.35 ± 0.03 mm for L-aspartate, K(m) = 0.098 ± 0 mm for D-aspartate, K(m) = 26 ± 2 mm for L-alanine, K(m) = 3.3 ± 0.2 mm for D-alanine). Competitive inhibition by various amino acids of L-aspartate or L-alanine in self-exchange reactions revealed that L-cysteine selectively inhibited L-aspartate self-exchange but only weakly inhibited L-alanine self-exchange. Additionally, L-serine selectively inhibited L-alanine self-exchange but barely inhibited L-aspartate self-exchange. The aspartate analogs L-cysteine sulfinic acid, L-cysteic acid, and D-cysteic acid competitively and strongly inhibited L-aspartate self-exchange compared with L-alanine self-exchange. Taken together, these kinetic data suggest that the putative binding sites of L-aspartate and L-alanine are independently located in the substrate translocation pathway of AspT.

  3. 熊去氧胆酸纳米混悬剂治疗乙型肝炎肝硬化GGT升高的临床疗效%Effect of ursodeoxycholic acid nanosuspension on elevated GGT level in patients with HBV-related liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    何卫平; 丁晋彪; 袁海龙; 张文瑾

    2012-01-01

    Objective. To investigate the effect of ursodeoxycholic acid nanosuspension on lowering the elevated serum GGT levels in patients with HBV-related liver cirrhosis. Methods Eighty patients with HBV--related liver cirrhosis were randomly divided into two groups, a treatment group and a control group. The patients in the control group received conventional liver-protecting therapy and those in the treatment group were given oral intake of ursodeoxycholic acid nanosuspension in addition to the conventional therapy. The serum GGT levels of the two groups were detected at week 2 and 4 of treatment. Results The differences in serum GGT levels were significant between the two groups at different time points. The serum CCT levels decreased more rapidly at week 2 and 4 of treatment in the treatment group than in the control group. Conclusion Ursodeoxycholic acid nanosuspension can lower the elevated serum GGT levels in patients with HBV-related liver cirrhosis rapidly and effectively.%目的 观察熊去氧胆酸纳米混悬剂治疗GGT持续升高的乙型肝炎肝硬化患者的疗效.方法 80例乙型肝炎肝硬化患者随机分为治疗组和对照组,对照组给予常规保肝治疗,治疗组在对照组的基础上加用熊去氧胆酸纳米混悬剂口服治疗,分别检测2组治疗后第2周和第4周时血清GGT水平.结果 2组不同时间点血清GGT水平差异有统计学意义,治疗组在治疗第2周和第4周时,血清GGT下降速度更快.结论 熊去氧胆酸纳米混悬剂能快速、有效地降低乙型肝炎肝硬化患者持续升高的血清GGT水平.

  4. Nucleation kinetics, growth and studies of β-alanine single crystals

    Science.gov (United States)

    Shanthi, D.; Selvarajan, P.; HemaDurga, K. K.; Lincy Mary Ponmani, S.

    2013-06-01

    Solubility and metastable zone width for the re-crystallized salt of β-alanine was determined. Induction period measurement for the selected supersaturation ratios at room temperature (31 °C) was carried out for supersaturated aqueous solutions of β-alanine and it is noticed that induction period decreases with increase of supersaturation ratio. The nucleation parameters such as Gibbs free energy change, radius and number of molecules of the critical nucleus, interfacial tension and the nucleation rate have been evaluated by classical nucleation theory. Single crystals of β-alanine were grown using the optimized nucleation parameters by solution method and grown crystals have been subjected to various studies like XRD studies, FTIR, optical, thermal and SHG studies.

  5. Adsorption of L-Alanine on Cu(111) Studied by Scanning Tunnelling Microscopy

    Institute of Scientific and Technical Information of China (English)

    GE Si-Ping; L(U) Chao; ZHAO Ru-Guang

    2006-01-01

    The adsorption of L-alanine on Cu(111)surface is studied by means of scanning tunnelling microscopy under ultra-high Vacuum conditions.The results show that the adsorbates are chemisorbed on the surface,and can form a two-dimensional gas phase,chain phase and solid phase,depending on deposition rate and amount.The adsorbed molecules can be imaged as individual protrusions and parallel chains in gas and chain phases respectively.It is also found that alanine can form(2×2)superstructure on Cu(111)and copper step facet to directions in solid phase.On the basis of our scanning tunnelling microscopic images,a model js proposed for the Cu(111)(2×2)-alanine superstructure.In the model,we point out the close link between -direction hydrogen bond chains with the same direction copper step faceting.

  6. Sensitivity of alanine dosimeters with gadolinium exposed to 6 MV photons at clinical doses.

    Science.gov (United States)

    Marrale, M; Longo, A; Spanò, M; Bartolotta, A; D'Oca, M C; Brai, M

    2011-12-01

    In this study we analyzed the ESR signal of alanine dosimeters with gadolinium exposed to 6 MV linear accelerator photons. We observed that the addition of gadolinium brings about an improvement in the sensitivity to photons because of its high atomic number. The experimental data indicated that the addition of gadolinium increases the sensitivity of the alanine to 6 MV photons. This enhancement was better observed at high gadolinium concentrations for which the tissue equivalence is heavily reduced. However, information about the irradiation setup and of the radiation beam features allows one to correct for this difference. Monte Carlo simulations were carried out to obtain information on the expected effect of the addition of gadolinium on the dose absorbed by the alanine molecules inside the pellets. These results are compared with the experimental values, and the agreement is discussed.

  7. Radiation chemistry of L-Alanine: application to EPR dosimetry (1)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. J.; Jeo, Y. H.; Ha, Y. K.; Park, Y. S.; Choi, I. G. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    High energy ionizing radiation leaves stable radicals to certain organic materials, such as alanine and tartrate. Electron Paramagnetic Resonance (EPR) spectroscopy is a powerful tool for the identification and quantification of these radiation-induced radicals. An EPR method has been applied to study the radical characteristics of L-alanine after gamma radiation dose in the range of {approx}mGy to 60 kGy. The free radicals induced by gamma radiation were fairly stable, and EPR intensity, radical concentration, was proportional to the absorbed dose up to 60 kGy. From the results of our EPR measurements, it can be concluded that an alanine/EPR method is a useful technique for gamma radiation dosimetry from very low to high dose range.

  8. The background of the total synthesis of yeast alanine transfer RNA

    Institute of Scientific and Technical Information of China (English)

    QI GuoRong

    2010-01-01

    @@ The research findings concerning the total synthesis of yeast alanine transfer RNA (yeast alanine tRNA) were successively published in Chinese Science Bulletin (1982) and Science in China (1983) [1].The research work started in 1968 and was finished in November 1981.It was the first artificial synthesis of a nucleic acid molecule, which followed the first artificial synthesis of protein, crystalline bovine insulin, in China in 1965, both scientific milestones occurring in China.The composition, sequence and biological functions of the synthesized nucleic acid were identical to those of the natural yeast alanine tRNA.The research lasted for 13 years.From 1982 to 1984, one of the investigators in charge of the research Prof.

  9. Probing the Catalytic Charge-Relay System in Alanine Racemase with Genetically Encoded Histidine Mimetics.

    Science.gov (United States)

    Sharma, Vangmayee; Wang, Yane-Shih; Liu, Wenshe R

    2016-12-16

    Histidine is a unique amino acid with an imidazole side chain in which both of the nitrogen atoms are capable of serving as a proton donor and proton acceptor in hydrogen bonding interactions. In order to probe the functional role of histidine involved in hydrogen bonding networks, fine-tuning the hydrogen bonding potential of the imidazole side chain is required but not feasible through traditional mutagenesis methods. Here, we show that two close mimetics of histidine, 3-methyl-histidine and thiazole alanine, can be genetically encoded using engineered pyrrolysine incorporation machinery. Replacement of the three histidine residues predicted to be involved in an extended charge-relay system in alanine racemase with 3-methyl-histidine or thiazole alanine shows a dramatic loss in the enzyme's catalytic efficiency, implying the role of this extended charge-relay system in activating the active site residue Y265, a general acid/base catalyst in the enzyme.

  10. The effect of β-alanine supplementation on cycling time trials of different length.

    Science.gov (United States)

    Bellinger, Phillip M; Minahan, Clare L

    2016-10-01

    The varying results reported in response to β-alanine supplementation may be related to the duration and nature of the exercise protocol employed. We investigated the effects of β-alanine supplementation on a wide range of cycling performance tests in order to produce a clear concise set of criteria for its efficacy. Fourteen trained cyclists (Age = 24.8 ± 6.7 years; VO2max = 65.4 ± 10.2 mL·kg·min(-1)) participated in this placebo-controlled, double-blind study. Prior to supplementation, subjects completed two (familiarization and baseline) supramaximal cycling bouts until exhaustion (120% pre-supplementation VO2max) and two 1-, 4- and 10-km cycling time trial (TT). Subjects then supplemented orally for 4 weeks with 6.4 g/d placebo or β-alanine and repeated the battery of performance tests. Blood lactate was measured pre-exercise, post-exercise and 5  min post-exercise. β-alanine supplementation elicited significant increases in time to exhaustion (TTE) (17.6 ± 11.5 s; p = 0.013, effect compared with placebo) and was likely to be beneficial to 4-km TT performance time (-7.8 ± 8.1 s; 94% likelihood), despite not being statistically different (p = 0.060). Performance times in the 1- and 10-km TT were not affected by treatment. For the highly trained cyclists in the current study, β-alanine supplementation significantly extended supramaximal cycling TTE and may have provided a worthwhile improvement to 4-km TT performance. However, 1- and 10-km cycling TT performance appears to be unaffected by β-alanine supplementation.

  11. Exchange of aspartate and alanine. Mechanism for development of a proton-motive force in bacteria.

    Science.gov (United States)

    Abe, K; Hayashi, H; Maloney, P C; Malone, P C

    1996-02-09

    We examined the idea that aspartate metabolism by Lactobacillus subsp. M3 is organized as a proton-motive metabolic cycle by using reconstitution to monitor the activity of the carrier, termed AspT, expected to carry out the electrogenic exchange of precursor (aspartate) and product (alanine). Membranes of Lactobacillus subsp. M3 were extracted with 1.25% octyl glucoside in the presence of 0. 4% Escherichia coli phospholipid and 20% glycerol. The extracts were then used to prepare proteoliposomes loaded with either aspartate or alanine. Aspartate-loaded proteoliposomes accumulated external [3H]aspartate by exchange with internal substrate; this homologous self-exchange (Kt = 0.4 mm) was insensitive to potassium or proton ionophores and was unaffected by the presence or absence of Na+, K+, or Mg2+. Alanine-loaded proteoliposomes also took up [3H]aspartate in a heterologous antiport reaction that was stimulated or inhibited by an inside-positive or inside-negative membrane potential, respectively. Several lines of evidence suggest that these homologous and heterologous exchange reactions were catalyzed by the same functional unit. Thus, [3H]aspartate taken up by AspT during self-exchange was released by a delayed addition of alanine. In addition, the spontaneous loss of AspT activity that occurs when a detergent extract is held at 37 degrees C prior to reconstitution was prevented by the presence of either aspartate (KD(aspartate) = 0.3 mm) or alanine (KD(alanine) > or = 10 mm), indicating that both substrates interact directly with AspT. These findings are consistent with operation of a proton-motive metabolic cycle during aspartate metabolism by Lactobacillus subsp. M3.

  12. Relative response of the alanine dosimeter to medium energy x-rays.

    Science.gov (United States)

    Anton, M; Büermann, L

    2015-08-01

    The response of the alanine dosimeter to kilovoltage x-rays with respect to the dose to water was measured, relative to the response to Co-60 radiation.Two series of x-ray qualities were investigated, one ranging from 30 kV to 100 kV tube voltage (TW series), the other one ranging from 70 kV to 280 kV (TH series). Due to the use of the water calorimeter as a primary standard, the uncertainty of the delivered dose is significantly lower than for other published data. The alanine response was measured as described in a previous publication (Anton et al 2013 Phys. Med. Biol. 58 3259-82). The uncertainty component due to the alanine measurement and analysis is ⩽0.4%, the major part of the combined uncertainty of the relative response originates from the uncertainty of the delivered dose. The relative uncertainties of the relative response vary from ⩽2% for the TW series to ⩽1.1% for the TH series.Different from the behaviour of the alanine dosimeter for megavoltage x-rays or electrons, the relative response drops significantly from unity for Co-60 radiation to less than 64% for the TW quality with a tube voltage of 30 kV. In order to reproduce this behaviour through Monte Carlo simulations, not only the ratio of the absorbed dose to alanine to the absorbed dose to water has to be known, but also the intrinsic efficiency, i.e. the dependence of the number of free radicals generated per unit of absorbed dose on the photon energy. This quantity is not yet accessible for the TW series.For a possible use of the alanine dosimeter for kilovoltage x-rays, for example in electronic brachytherapy, users should rely on the measured data for the relative response which have become available with this publication.

  13. The crystal structure of the D-alanine-D-alanine ligase from Acinetobacter baumannii suggests a flexible conformational change in the central domain before nucleotide binding.

    Science.gov (United States)

    Huynh, Kim-Hung; Hong, Myoung-ki; Lee, Clarice; Tran, Huyen-Thi; Lee, Sang Hee; Ahn, Yeh-Jin; Cha, Sun-Shin; Kang, Lin-Woo

    2015-11-01

    Acinetobacter baumannii, which is emerging as a multidrug-resistant nosocomial pathogen, causes a number of diseases, including pneumonia, bacteremia, meningitis, and skin infections. With ATP hydrolysis, the D-alanine-D-alanine ligase (DDL) catalyzes the synthesis of D-alanyl-D-alanine, which is an essential component of bacterial peptidoglycan. In this study, we determined the crystal structure of DDL from A. baumannii (AbDDL) at a resolution of 2.2 Å. The asymmetric unit contained six protomers of AbDDL. Five protomers had a closed conformation in the central domain, while one protomer had an open conformation in the central domain. The central domain with an open conformation did not interact with crystallographic symmetry-related protomers and the conformational change of the central domain was not due to crystal packing. The central domain of AbDDL can have an ensemble of the open and closed conformations before the binding of substrate ATP. The conformational change of the central domain is important for the catalytic activity and the detail information will be useful for the development of inhibitors against AbDDL and putative antibacterial agents against A. baumannii. The AbDDL structure was compared with that of other DDLs that were in complex with potent inhibitors and the catalytic activity of AbDDL was confirmed using enzyme kinetics assays.

  14. Poly[μ3-β-alanine-aqua-μ4-sulfato-dilithium

    OpenAIRE

    M. Daniel Sweetlin; Eapen, Shibu M.; Perumal, S.; S. Ramalingom

    2012-01-01

    The title compound, [Li2(SO4)(C3H7NO2)(H2O)]n, is a coordination polymer in which the β-alanine residues remain in the zwitterionic form. The crystal structure consists of corrugated sheets of [LiO4] and [SO4] tetrahedra parallel to (010) with the β-alanine molecules located between the sheets. The two independent Li+ cations are four-coordinated by O atoms in a distorted tetrahedral geometry. The crystal structure is formed by stacking of alternate organic and inorganic lay...

  15. Poly[μ3-β-alanine-aqua-μ4-sulfato-dilithium

    Directory of Open Access Journals (Sweden)

    M. Daniel Sweetlin

    2012-02-01

    Full Text Available The title compound, [Li2(SO4(C3H7NO2(H2O]n, is a coordination polymer in which the β-alanine residues remain in the zwitterionic form. The crystal structure consists of corrugated sheets of [LiO4] and [SO4] tetrahedra parallel to (010 with the β-alanine molecules located between the sheets. The two independent Li+ cations are four-coordinated by O atoms in a distorted tetrahedral geometry. The crystal structure is formed by stacking of alternate organic and inorganic layers along the a axis. The crystal structure is further stabilized by N—H...O hydrogen bonds.

  16. Poly[μ3-β-alanine-aqua-μ4-sulfato-dilithium

    OpenAIRE

    Sweetlin, M. Daniel; Eapen, Shibu M.; Perumal, S.; S. Ramalingom

    2012-01-01

    The title compound, [Li2(SO4)(C3H7NO2)(H2O)] n , is a coordination polymer in which the β-alanine residues remain in the zwitterionic form. The crystal structure consists of corrugated sheets of [LiO4] and [SO4] tetra­hedra parallel to (010) with the β-alanine mol­ecules located between the sheets. The two independent Li+ cations are four-coordinated by O atoms in a distorted tetra­hedral geometry. The crystal structure is formed by stacking of alternate organic and inorganic layers along the...

  17. Oxidation of phenyl alanine by pyridinium chlorochromate in acidic DMF–water medium: A kinetic study

    Directory of Open Access Journals (Sweden)

    B.L. Hiran

    2016-11-01

    Full Text Available The kinetics of oxidation of phenyl alanine by pyridinium chlorochromate in DMF–water (70:30% mixture in presence of perchloric acid leads to the formation of corresponding aldehyde. The reaction is of first order each in [PCC], [HClO4] and [AA]. Michaelis–Menten type kinetics was observed with phenyl alanine. The reaction rates were determined at different temperatures [25, 30, 35, 40, 45, 50 °C] and the activation parameters were calculated. The reaction does not induce polymerization of acrylonitrile. With an increase in the amount of DMF in its aqueous mixture, the rate increases. A suitable mechanism for the reaction was postulated.

  18. Active Oxygen Radical Scavenging Ability of Water-Soluble β-Alanine C60 Adducts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water-soluble β-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2-and hydroxyl radicalOH were studied by autoxidation ofpyrogallol and chemiluminescence, respectively. It was found that β-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.

  19. Standard Enthalpies of Formation of Solid Complexes of Lanthanide Nitrates with Alanine

    Institute of Scientific and Technical Information of China (English)

    杨旭武; 陈三平; 高胜利; 刘晓华; 史启祯

    2002-01-01

    The combustion energies of fourteen solid complexes of lanthanide nitrate with alanine were determined. The standard enthalpies of combustion, Δc,coor(s)H°, and standard enthalpies of formation, Δf,coor(s)H°, were calculated for these complexes. The relationship of Δc,coor(s)H° and Δf,coor(s)H° with the atomic numbers of the elements in the lanthanide series were examined. The results show that a certain amount of covalence is present in the chemical bond between the lanthanide cations and alanine.

  20. Synthesis, Characterization and Metal Ion Detection of Novel Fluoroionophores Based on Heterocyclic Substituted Alanines

    Directory of Open Access Journals (Sweden)

    M. Manuela M Raposo

    2007-10-01

    Full Text Available The synthesis of new fluorescent probes containing the thiophene andbenzoxazole moieties combined with an alanine residue is described. The resulting highlyfluorescent heterocyclic alanine derivatives respond via a quenching effect, withparamagnetic Cu(II and Ni(II metal ions and with diamagnetic Hg(II, as shown by theabsorption and steady-state fluorescence spectroscopy studies. The formation ofmononuclear or dinuclear metal complexes was postulated based on the presence of thefree carboxylic acid as binding site and also with the interaction with the donor atoms inthe chromophore. Interaction with other important biological metal ions such as Zn(II,Ca(II and Na(I was also explored.

  1. The effect of isotretinoin on triglycerides and liver aminotransferases Influência da isotretinoína nas transaminases hepáticas e triglicerídeos

    Directory of Open Access Journals (Sweden)

    Andreia Salezze Vieira

    2012-06-01

    Full Text Available BACKGROUND: Isotretinoin has been used to treat the most severe cases of acne; however, it may provoke adverse events in mucocutaneous and hepatic tissues, lead to alterations in lipid levels and cause teratogenicity. OBJECTIVE: The objective of this study was to evaluate the profile of changes in alanine aminotransferase (ALT, aspartate aminotransferase (AST and triglyceride levels in patients who had been treated with oral isotretinoin dispensed by the São Mateus/ES pharmacy for special drugs. METHODS: A retrospective, observational, longitudinal study was conducted by carrying out a secondary analysis of each patient's data. RESULTS: Of the 130 patients who received isotretinoin between January and December 2009, only 70 were actually treated for 3 months or more and handed in the results of their laboratory tests. Of these 70 patients, 39 (55.7% were female. The mean age of the women (23.9 years was higher than the mean age of the men (20.1 years. There was a statistically significant increase in the levels of triglycerides (87.01 ± 48.25 versus 105.32 ± 48.76 mg/dL, AST (20.44 ± 6.26 versus 24.38 ± 11.92 U/L and ALT (18.24 ± 8.31 versus 23.34 ± 20.03 U/L performed prior to and 3 months or more after oral isotretinoin treatment. After treatment with oral isotretinoin, triglyceride levels had increased beyond the normal range in 11% of the patients, while 8.6% had elevated AST levels and 7.3% had increased ALT levels. CONCLUSION: The results in this population show that the use of oral isotretinoin for the treatment of acne may result in altered triglyceride, AST and ALT levels. These findings are in accordance with data published previously in the scientific literature, confirming the need to monitor these patients.FUNDAMENTOS: A isotretinoína tem sido usada no tratamento dos casos mais graves de acne, embora possa induzir reações adversas nos tecidos mucocutâneos e hepáticos, alterações nos níveis lipídicos e

  2. Comparison of the tyrosine aminotransferase cDNA and genomic DNA sequences of normal mink and mink affected with tyrosinemia type II.

    Science.gov (United States)

    Leib, S R; McGuire, T C; Prieur, D J

    2005-01-01

    Type II tyrosinemia, designated Richner-Hanhart syndrome in humans, is a hereditary metabolic disorder with autosomal recessive inheritance characterized by a deficiency of tyrosine aminotransferase activity. Mutations occur in the human tyrosine aminotransferase gene, resulting in high levels of tyrosine and disease. Type II tyrosinemia occurs in mink, and our hypothesis was that it would also be associated with mutation(s) in the tyrosine aminotransferase gene. Therefore, the transcribed cDNA and the genomic tyrosine aminotransferase gene were sequenced from normal and affected mink. The gene extended over 11.9 kb and had 12 exons coding for a predicted 454-amino-acid protein with 93% homology with human tyrosine aminotransferase. FISH analysis mapped the gene to chromosome 8 using the Mandahl and Fredga (1975) nomenclature and chromosome 5 using the Christensen et al. (1996) nomenclature. The hypothesis was rejected because sequence analysis disclosed no mutations in either cDNA or introns that were associated with affected mink. This suggests that an unlinked gene regulatory mutation may be the cause of tyrosinemia in mink.

  3. Spectral characterization of a non-centrosymmetric organic compound: D-(-)-alanine

    Science.gov (United States)

    Moovendaran, K.; Martin Britto Dhas, S. A.; Natarajan, S.

    2013-08-01

    The crystal growth of D-(-)-alanine (1), a non-centrosymmetric solid is reported. It was characterized by NMR, infrared, Raman, UV-Vis-NIR and CD spectra. Experimental vibrational frequencies are compared with theoretically calculated values. Second harmonic generation (SHG) and first hyperpolarizability measurements are reported.

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

    Science.gov (United States)

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

    2013-04-01

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

  5. [Temperature-dependent optical activity and birefringence study of D-alanine single crystal].

    Science.gov (United States)

    Li, Zong-Sheng; Gong, Yan; Wang, Wen-Qing; Du, Wei-Min

    2006-02-01

    The measurement of the anisotropy of optical acitivity and birefringence is one of the most important clues to studying physical properties of a biaxial crystal of D-alanine. In order to investigate a second-order phase transition predicted by A. Salam between two states of D-alanine, the behavior of birefringence and optical activity is useful for the phenomenological approach to the transition mechanism. The optical activity as a peculiar quantity can respond to the modulation of the crystal lattice and to the change in the bonding nature of constituent atoms. In the present paper, the authors use the PEM-90 photoelastic modulator to study the conformation change of D-alanine at the temperature ranging from 220 to 290 K. The temperature dependence of I(2f)/I(dc) showed that the conformation of D-alanine molecule in single crystal changed around 250 K. The obtained results provide an obvious evidence of optical rotation phase transition predicted by Salam.

  6. Probing the interaction of the amino acid alanine with the surface of ZnO(1010).

    Science.gov (United States)

    Gao, Y K; Traeger, F; Shekhah, O; Idriss, H; Wöll, C

    2009-10-01

    The adsorption modes and stability of the amino acid alanine (NH(2)-CH(CH(3))-COOH) have been studied on the nonpolar single crystal surface of zinc oxide, ZnO(1010), experimentally by X-ray photoelectron spectroscopy (XPS) and computationally using density functional theory (DFT). Deposition at 200 K was found to lead to the formation of multilayers identified by an XPS N1s peak at 401.7 eV assigned to the NH(3)(+) group, a fingerprint of the zwitterionic structure of alanine in the solid state. Heating to 300 K resulted in the removal of most of the multilayers with the remaining surface coverage estimated to 0.4 with respect to Zn cations. At this temperature most of the alanine molecules are found to be deprotonated (dissociated), yielding a carboxylate species (NH(2)-CH(CH(3))-COO(-) (a) + OH (s); where O is surface oxygen, (a) for adsorbed and (s) for surface species). Further heating of the surface resulted in a gradual decrease of the surface coverage and by 500 K a large fraction of adsorbed alanine molecules have desorbed from the surface. Total energy DFT computations of different adsorbate species identified two stable dissociative adsorption modes: bidentate and monodentate. The bidentate species with adsorption energy of 1.75 eV was found to be more stable than the monodentate species by about 0.7 eV.

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

    Science.gov (United States)

    Contreras, E; Tamayo, L

    1980-05-01

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

  8. Small-Field Dosimetry in A 6 MV Photon Beam Using Alanine and Liquid Ionisation Chamber

    DEFF Research Database (Denmark)

    Zimmermann, S.; Riis, H. L.; Hjelm-Hansen, M.

    2012-01-01

    Purpose/Objective: Dosimetry of small field sizes in MV photon beams is an increasingly important subject, and a generally accepted guideline for clinical measurements is still lacking. The present comparative study was carried out to further investigate the use of alanine and the PTW microLion i......, and this may explain part of the measured deviations. A practical difference between the two systems was that the alanine measurements were much more time consuming than the liquid ionization chamber measurements.......Lion ionisation chamber for small-field dosimetry in liquid water. Materials and Methods: The measurements were carried out on a Siemens Primus 58 leaves MLC. The alanine dosimeters were cylindric Ø4.9 mm × 3.0 mm and density of 1.2 g/cm3. The alanine dosimeters were placed on the top of a solid water stick of Ø4...... of each field and depth. This dose maximum was measured for each field using a Scanditronix Wellhöfer photon field diode. The same measurements were carried out using a liquid ionchamber, PTW microLion, irradiated by 500 MU. The output of the accelerator was controlled by a PTW semiflex ion chamber...

  9. High-pressure X-ray diffraction of L-ALANINE crystal

    DEFF Research Database (Denmark)

    Olsen, J.S.; Gerward, Leif; Souza, A.G.

    2006-01-01

    L-ALANINE has been studied by X-ray diffraction at ambient temperature and pressure up to 10.3 GPa. The material is found to transform to a tetragonal structure between 2 and 3 GPa. and to a monoclinic structure between 8 and 10 GPa. The experimental bulk modulus is 25(5) GPa for the orthorhombic...

  10. On the fragmentation of biomolecules: fragmentation of alanine dipeptide along the polypeptide chain

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander; Solov'yov, Andrey;

    2006-01-01

    The interaction potential between amino acids in alanine dipeptide has been studied for the first time taking into account exact molecular geometry. Ab initio calculation has been performed in the framework of density functional theory taking into account all electrons in the system. The fragment...

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

    Science.gov (United States)

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

    2016-12-01

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

  12. Investigation on physical properties of L-alanine: An effect of Methylene blue dye

    Science.gov (United States)

    Shkir, Mohd.; Yahia, I. S.; Al-Qahtani, A. M. A.; Ganesh, V.; AlFaify, S.

    2017-03-01

    In the present investigation, a bulk size (35 mm × 25 mm × 15 mm) single crystal of 0.1 wt% Methylene blue dye (MLB) added L-alanine is grown at room temperature using solution technique for the first time. The L-alanine crystals with higher concentrations of dye (0.5 and 1 wt%) were also grown. Solubility study was performed at different temperatures. Structural, vibrational and good quality was inveterate by powder XRD, FT-Raman and SEM analyses. High transmittance in dyed crystals was confirmed. The presence of MLB dye was confirmed by an absorption band centered at 650 nm. Optical band gap was calculated for pure and dyed L-alanine crystals and found to be 5.45 and 4.49 eV respectively. Photoluminescence intensity of UV-A emission band centered at 332 nm was found to be enhanced due to the presence of dye. The dielectric measurement was done in the wide frequency range. Furthermore, the third order nonlinear optical parameters are enhanced in dyed L-alanine crystals determined by Z-scan technique.

  13. Fragmentation of alpha- and beta-alanine molecules by ions at Bragg-peak energies

    NARCIS (Netherlands)

    Bari, S.; Sobocinski, P.; Postma, J.; Alvarado, F.; Hoekstra, R.; Bernigaud, V.; Manil, B.; Rangama, J.; Huber, B.; Schlathoelter, T.

    2008-01-01

    The interaction of keV He(+), He(2+), and O(5+) ions with isolated alpha and beta isomers of the amino acid alanine was studied by means of high resolution coincidence time-of-flight mass spectrometry. We observed a strong isomer dependence of characteristic fragmentation channels which manifests in

  14. Polymerisation of Beta-alanine through catalytic ester-amide exchange

    NARCIS (Netherlands)

    Steunenberg, P.; Könst, P.M.; Scott, E.L.; Franssen, M.C.R.; Zuilhof, H.; Sanders, J.P.M.

    2013-01-01

    Herein we present the use of group (IV) metal alkoxides as catalysts for the polymerisation of esters of p-alanine and its derivatives. The influence of different group (IV) metal alkoxides, different esters, temperature and solvents on the polymerisation are investigated. The order in which the gro

  15. Isomeric effects in ion-induced fragmentation of alpha- and beta-alanine

    NARCIS (Netherlands)

    Sobocinski, P.; Bari, S.; Postma, J.; Alvarado, F.; Hoekstra, R.; Manil, B.; Rangama, J.; Bernigaud, V.; Huber, B. A.; Schlatholter, T.; McGuigan, KG; Tokesi, K; Sulik, B

    2008-01-01

    We have investigated the dissociation of alpha- and beta- alanine following impact of slow multicharged ions, namely He(+), He(2+), O(5+) and Xe(20+) at 10 keV per charge unit. The collision products were analyzed using a reflectron-type time-of-flight mass spectrometer. In general, for a given proj

  16. Verification of GGT Detection Results with Two Measurement Systems by IFCC Reference Method%IFCC参考方法对两种测量系统GGT结果正确性的验证

    Institute of Scientific and Technical Information of China (English)

    陈宝荣; 孙慧颖; 邵燕; 胡滨; 陈琦

    2011-01-01

    采用IFCC参考方法和A、B两厂家测量系统(以下简称方法),同时测量20份不同浓度的新鲜单人份血清、ERM-AD452(有证酶参考物质)、RELA(Ring-trial,国际参考实验室室间质量评价活动)样本,有效数据采用MVSl.380软件按EP9-A2文件评价两厂家方法测量结果的正确性,并用Bland-Altman图形分析法进行验证.采用Matlab软件根据EP14-A2文件评价A、B两厂家校准品的互通性.通过采用不同方法对此两个GGT厂家测量系统进行的正确性验证和比对,可见A、B两个厂家不同方法所得的测量结果也明显不同:A方法与IFCC参考方法的回归方程为Y = 0.995X+0.443,预测偏倚值为0.359,按EP9-A2文件方法评价,A方法与IFCC参考方法正确度性能一致;B方法与IFCC参考方法的回归方程为Y=0.827X-0.566,预测偏倚值为17.258,按EP9-A2文件方法评价,B方法与IFCC参考方法正确度性能不一致.对两种不同来源的样本ERM(114.1±2.4U/L)和RELA-A(111.0±2.2U/L)、RELA-B(203.6±3.3U/L)样本使用IFCC参考方法、A方法、B方法同时测量,测量结果各样本均值分别为114.8U/L、115.5U/L、88.1U/L;110.9U/L、109.5U/L、93.4U/L;203.8U/L、201.OU/L、173.4U/L,即A方法与IFCC参考方法正确度性能一致,而B方法与IFCC参考方法正确度性能不一致.鉴于各厂家测量结果的明显差异,实验室应建立常规测量方法,以评价测量结果的正确性.%20 fresh, single human serum samples with different concentrations, ERM-AD4S2 and RELA samples were simultaneously measured by using A, B two factories measurement systems and IFCC reference method. The results measured with two methods were evaluated by software MVS and Matlab. The results showed that the GGT concentration in serum samples measured with A and B methods were obviously different. The measured results with method A was consistent with IFCC reference method, and the regression equation between method A and IFCC reference method was Y = 0

  17. Inhibiting Inosine Hydrolase and Alanine Racemase to Enhance the Germination of Bacillus anthracis Sterne Spores: Potential Spore Decontamination Strategies

    Science.gov (United States)

    2015-06-19

    2015): << Inhibiting inosine hydrolase and alanine racemase to enhance the germination of Bacillus anthracis Sterne spores: potential spore...inosine hydrolase and alanine racemase to enhance the germination of Bacillus anthracis Sterne spores potential spore decontamination strategies 5a...EASIER, SAFER, and CHEAPER Inducing spore germination should make resulting bacteria much more susceptible to decontamination methods and will be

  18. Effects of endogenous D-alanine synthesis and autoinhibition of Bacillus anthracis germination on in vitro and in vivo infections.

    Science.gov (United States)

    McKevitt, Matthew T; Bryant, Katie M; Shakir, Salika M; Larabee, Jason L; Blanke, Steven R; Lovchik, Julie; Lyons, C Rick; Ballard, Jimmy D

    2007-12-01

    Bacillus anthracis transitions from a dormant spore to a vegetative bacillus through a series of structural and biochemical changes collectively referred to as germination. The timing of germination is important during early steps in infection and may determine if B. anthracis survives or succumbs to responsive macrophages. In the current study experiments determined the contribution of endogenous D-alanine production to the efficiency and timing of B. anthracis spore germination under in vitro and in vivo conditions. Racemase-mediated production of endogenous D-alanine by B. anthracis altered the kinetics for initiation of germination over a range of spore densities and exhibited a threshold effect wherein small changes in spore number resulted in major changes in germination efficiency. This threshold effect correlated with D-alanine production, was prevented by an alanine racemase inhibitor, and required L-alanine. Interestingly, endogenous production of inhibitory levels of D-alanine was detected under experimental conditions that did not support germination and in a germination-deficient mutant of B. anthracis. Racemase-dependent production of D-alanine enhanced survival of B. anthracis during interaction with murine macrophages, suggesting a role for inhibition of germination during interaction with these cells. Finally, in vivo experiments revealed an approximately twofold decrease in the 50% lethal dose of B. anthracis spores administered in the presence of D-alanine, indicating that rates of germination may be directly influenced by the levels of this amino acid during early stages of disease.

  19. Biochemical and structural characterization of alanine racemase from Bacillus anthracis (Ames

    Directory of Open Access Journals (Sweden)

    Hill Ryan E

    2009-08-01

    Full Text Available Abstract Background Bacillus anthracis is the causative agent of anthrax and a potential bioterrorism threat. Here we report the biochemical and structural characterization of B. anthracis (Ames alanine racemase (AlrBax, an essential enzyme in prokaryotes and a target for antimicrobial drug development. We also compare the native AlrBax structure to a recently reported structure of the same enzyme obtained through reductive lysine methylation. Results B. anthracis has two open reading frames encoding for putative alanine racemases. We show that only one, dal1, is able to complement a D-alanine auxotrophic strain of E. coli. Purified Dal1, which we term AlrBax, is shown to be a dimer in solution by dynamic light scattering and has a Vmax for racemization (L- to D-alanine of 101 U/mg. The crystal structure of unmodified AlrBax is reported here to 1.95 Å resolution. Despite the overall similarity of the fold to other alanine racemases, AlrBax makes use of a chloride ion to position key active site residues for catalysis, a feature not yet observed for this enzyme in other species. Crystal contacts are more extensive in the methylated structure compared to the unmethylated structure. Conclusion The chloride ion in AlrBax is functioning effectively as a carbamylated lysine making it an integral and unique part of this structure. Despite differences in space group and crystal form, the two AlrBax structures are very similar, supporting the case that reductive methylation is a valid rescue strategy for proteins recalcitrant to crystallization, and does not, in this case, result in artifacts in the tertiary structure.

  20. Structural and functional characterization of the alanine racemase from Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Tassoni, Raffaella; van der Aart, Lizah T; Ubbink, Marcellus; van Wezel, Gilles P; Pannu, Navraj S

    2017-01-29

    The conversion of l-alanine (L-Ala) into d-alanine (D-Ala) in bacteria is performed by pyridoxal phosphate-dependent enzymes called alanine racemases. D-Ala is an essential component of the bacterial peptidoglycan and hence required for survival. The Gram-positive bacterium Streptomyces coelicolor has at least one alanine racemase encoded by alr. Here, we describe an alr deletion mutant of S. coelicolor which depends on D-Ala for growth and shows increased sensitivity to the antibiotic d-cycloserine (DCS). The crystal structure of the alanine racemase (Alr) was solved with and without the inhibitors DCS or propionate, at 1.64 Å and 1.51 Å resolution, respectively. The crystal structures revealed that Alr is a homodimer with residues from both monomers contributing to the active site. The dimeric state of the enzyme in solution was confirmed by gel filtration chromatography, with and without L-Ala or d-cycloserine. The activity of the enzyme was 66 ± 3 U mg(-1) for the racemization of L- to D-Ala, and 104 ± 7 U mg(-1) for the opposite direction. Comparison of Alr from S. coelicolor with orthologous enzymes from other bacteria, including the closely related d-cycloserine-resistant Alr from S. lavendulae, strongly suggests that structural features such as the hinge angle or the surface area between the monomers do not contribute to d-cycloserine resistance, and the molecular basis for resistance therefore remains elusive.

  1. Structural features and kinetic characterization of alanine racemase from Staphylococcus aureus (Mu50).

    Science.gov (United States)

    Scaletti, Emma R; Luckner, Sylvia R; Krause, Kurt L

    2012-01-01

    Staphylococcus aureus is an opportunistic Gram-positive bacterium which causes a wide variety of diseases ranging from minor skin infections to potentially fatal conditions such as pneumonia, meningitis and septicaemia. The pathogen is a leading cause of nosocomial acquired infections, a problem that is exacerbated by the existence of methicillin- and glycopeptide antibiotic-resistant strains which can be challenging to treat. Alanine racemase (Alr) is a pyridoxal-5'-phosphate-dependent enzyme which catalyzes reversible racemization between enantiomers of alanine. As D-alanine is an essential component of the bacterial cell-wall peptidoglycan, inhibition of Alr is lethal to prokaryotes. Additionally, while ubiquitous amongst bacteria, this enzyme is absent in humans and most eukaryotes, making it an excellent antibiotic drug target. The crystal structure of S. aureus alanine racemase (Alr(Sas)), the sequence of which corresponds to that from the highly antibiotic-resistant Mu50 strain, has been solved to 2.15 Å resolution. Comparison of the Alr(Sas) structure with those of various alanine racemases demonstrates a conserved overall fold, with the enzyme sharing most similarity to those from other Gram-positive bacteria. Structural examination indicates that the active-site binding pocket, dimer interface and active-site entryway of the enzyme are potential targets for structure-aided inhibitor design. Kinetic constants were calculated in this study and are reported here. The potential for a disulfide bond in this structure is noted. This structural and biochemical information provides a template for future structure-based drug-development efforts targeting Alr(Sas).

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

    Directory of Open Access Journals (Sweden)

    Michelle M Giffin

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

  3. Glutamate Racemase Is the Primary Target of β-Chloro-d-Alanine in Mycobacterium tuberculosis

    Science.gov (United States)

    Rodenburg, Anne; Khoury, Hania; de Chiara, Cesira; Howell, Steve; Snijders, Ambrosius P.

    2016-01-01

    The increasing global prevalence of drug resistance among many leading human pathogens necessitates both the development of antibiotics with novel mechanisms of action and a better understanding of the physiological activities of preexisting clinically effective drugs. Inhibition of peptidoglycan (PG) biosynthesis and cross-linking has traditionally enjoyed immense success as an antibiotic target in multiple bacterial pathogens, except in Mycobacterium tuberculosis, where it has so far been underexploited. d-Cycloserine, a clinically approved antituberculosis therapeutic, inhibits enzymes within the d-alanine subbranch of the PG-biosynthetic pathway and has been a focus in our laboratory for understanding peptidoglycan biosynthesis inhibition and for drug development in studies of M. tuberculosis. During our studies on alternative inhibitors of the d-alanine pathway, we discovered that the canonical alanine racemase (Alr) inhibitor β-chloro–d-alanine (BCDA) is a very poor inhibitor of recombinant M. tuberculosis Alr, despite having potent antituberculosis activity. Through a combination of enzymology, microbiology, metabolomics, and proteomics, we show here that BCDA does not inhibit the d-alanine pathway in intact cells, consistent with its poor in vitro activity, and that it is instead a mechanism-based inactivator of glutamate racemase (MurI), an upstream enzyme in the same early stage of PG biosynthesis. This is the first report to our knowledge of inhibition of MurI in M. tuberculosis and thus provides a valuable tool for studying this essential and enigmatic enzyme and a starting point for future MurI-targeted antibacterial development. PMID:27480853

  4. K-band EPR dosimetry: small-field beam profile determination with miniature alanine dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Felipe [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Department of Radiological Health, Caja de Seguro Social, Panama City (Panama); Department of Physics, Faculty of Natural and Exact Sciences and Technology, University of Panama, Panama City (Panama); Graeff, Carlos F.O. [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Baffa, Oswaldo [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil)

    2005-02-01

    The use of small-size alanine dosimeters presents a challenge because the signal intensity is less than the spectrometer sensitivity. K-band (24 GHz) EPR spectrometer seems to be a good compromise between size and sensitivity of the sample. Miniature alanine pellets were evaluated for small-field radiation dosimetry. Dosimeters of DL-alanine/PVC with dimensions of 1.5 mm diameter and 2.5 mm length with 5 mg mass were developed. These dosimeters were irradiated with 10 MV X-rays in the dose range 0.05-60 Gy and the first harmonic (1 h) spectra were recorded. Microwave power, frequency and amplitude of modulation were optimized to obtain the best signal-to-noise ratio (S/N). For beam profile determination, a group of 25 dosimeters were placed in an acrylic device with dimensions of (7.5x2.5x1) cm{sup 3} and irradiated with a (3x3) cm{sup 2} 10 MV X-rays beam field size. The dose at the central region of the beam was 20 Gy at a depth of 2.2 cm (build up for acrylic). The acrylic device was oriented perpendicular to the beam axis and to the gantry rotation axis. For the purposes of comparison of the spatial resolution, the beam profile was also determined with a radiographic film and 2 mm aperture optical densitometer; in this case the dose was 1 cGy. The results showed a similar spatial resolution for both types of dosimeters. The dispersion in dose reading was larger for alanine in comparison with the film, but alanine dosimeters can be read faster and more directly than film over a wide dose range.

  5. Enhancement of solubility in Escherichia coli and purification of an aminotransferase from Sphingopyxis sp. MTA144 for deamination of hydrolyzed fumonisin B1

    Directory of Open Access Journals (Sweden)

    Hartinger Doris

    2010-08-01

    Full Text Available Abstract Background Fumonisin B1 is a cancerogenic mycotoxin produced by Fusarium verticillioides and other fungi. Sphingopyxis sp. MTA144 can degrade fumonisin B1, and a key enzyme in the catabolic pathway is an aminotransferase which removes the C2-amino group from hydrolyzed fumonisin B1. In order to study this aminotransferase with respect to a possible future application in enzymatic fumonisin detoxification, we attempted expression of the corresponding fumI gene in E. coli and purification of the enzyme. Since the aminotransferase initially accumulated in inclusion bodies, we compared the effects of induction level, host strain, expression temperature, solubility enhancers and a fusion partner on enzyme solubility and activity. Results When expressed from a T7 promoter at 30°C, the aminotransferase accumulated invariably in inclusion bodies in DE3 lysogens of the E. coli strains BL21, HMS174, Rosetta 2, Origami 2, or Rosetta-gami. Omission of the isopropyl-beta-D-thiogalactopyranoside (IPTG used for induction caused a reduction of expression level, but no enhancement of solubility. Likewise, protein production but not solubility correlated with the IPTG concentration in E. coli Tuner(DE3. Addition of the solubility enhancers betaine and sorbitol or the co-enzyme pyridoxal phosphate showed no effect. Maltose-binding protein, used as an N-terminal fusion partner, promoted solubility at 30°C or less, but not at 37°C. Low enzyme activity and subsequent aggregation in the course of purification and cleavage indicated that the soluble fusion protein contained incorrectly folded aminotransferase. Expression in E. coli ArcticExpress(DE3, which co-expresses two cold-adapted chaperonins, at 11°C finally resulted in production of appreciable amounts of active enzyme. Since His tag-mediated affinity purification from this strain was hindered by co-elution of chaperonin, two steps of chromatography with optimized imidazole concentration in the

  6. Comparative study of dynamic structure of pig and chicken aspartate aminotransferases by measuring the rotational correlation time.

    Science.gov (United States)

    Timofeev, V P; Dudich, I V; Volkenstein, M V

    1980-01-01

    The rotational correlation time of two homologous cytoplasmic aspartate aminotransferase molecules isolated from pig and chicken hearts was obtained by spin-labeling technique. The maleimide and iodoacetamide spin-labels modifying external SH-groups of a protein were used. In the interpretation of ESR spectra a rotational motion of nitroxide group relative to the protein molecule was taken into account. To determine the macromolecule rotational correlation time two methods of the immobilization of a protein molecule were used: 1) by means of increasing protein solution viscosity and 2) by fixation of the protein molecule on adsorbent. From comparison of experimental and theoretical values of rotational correlation time it was conclude that the both enzymes exhibits an intramolecular flexibility.

  7. Cloning and inactivation of a branched-chain-amino-acid aminotransferase gene from Staphylococcus carnosus and characterization of the enzyme

    DEFF Research Database (Denmark)

    Madsen, Søren M; Beck, Hans Christian; Ravn, Peter

    2002-01-01

    Staphylococcus carnosus and Staphylococcus xylosus are widely used as aroma producers in the manufacture of dried fermented sausages. Catabolism of branched-chain amino acids (BCAAs) by these strains contributes to aroma formation by production of methyl-branched aldehydes and carboxy acids....... The first step in the catabolism is most likely a transamination reaction catalyzed by BCAA aminotransferases (IlvE proteins). In this study, we cloned the ilvE gene from S. carnosus by using degenerate oligonucleotides and PCR. We found that the deduced amino acid sequence was 80% identical...... to that of the corresponding enzyme in Staphylococcus aureus and that the ilvE gene was constitutively expressed as a monocistronic transcript. To study the influence of ilvE on BCAA catabolism, we constructed an ilvE deletion mutant by gene replacement. The IlvE protein from S. carnosus was shown mainly to catalyze...

  8. Effects of Omega-3 Fatty Acid in Nonalcoholic Fatty Liver Disease: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Wenxia Lu

    2016-01-01

    Full Text Available A meta-analysis was conducted to assess the effect of omega-3 fatty acid supplementation (n-3 PUFAs in lowering liver fat, liver enzyme (alanine aminotransferase (ALT, aspartate aminotransferase (AST, and gamma-glutamyltransferase (GGT levels, and blood lipids (triglyceride (TG, total cholesterol (TC, high density lipoprotein (HDL, and low density lipoprotein (LDL in patients with nonalcoholic fatty liver disease (NAFLD or nonalcoholic steatohepatitis (NASH. Methods. MEDLINE/PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, CINAHL, Science Citation Index (ISI Web of Science, Chinese Biomedical Literature Database (CBM, and Chinese National Knowledge Infrastructure (CNKI were searched for relevant randomized controlled trials on the effects of n-3 polyunsaturated fatty acids (PUFAs in patients with NAFLD from inception to May 2015. Ten studies were included in this meta-analysis. Results. 577 cases of NAFLD/NASH in ten randomized controlled trials (RCTs were included. The results of the meta-analysis showed that benefit changes in liver fat favored PUFA treatment, and it was also beneficial for GGT, but it was not significant on ALT, AST, TC, and LDL. Conclusions. In this meta-analysis, omega-3 PUFAs improved liver fat, GGT, TG, and HDL in patients with NAFLD/NASH. Therefore, n-3 PUFAs may be a new treatment option for NAFLD.

  9. Effects of Omega-3 Fatty Acid in Nonalcoholic Fatty Liver Disease: A Meta-Analysis

    Science.gov (United States)

    Lu, Wenxia; Li, Sainan; Li, Jingjing; Wang, Jianrong; Zhang, Rong; Zhou, Yuqing; Yin, Qin; Wang, Fan; Xia, Yujing; Liu, Tong; Lu, Jie; Zhou, Yingqun

    2016-01-01

    A meta-analysis was conducted to assess the effect of omega-3 fatty acid supplementation (n-3 PUFAs) in lowering liver fat, liver enzyme (alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) levels), and blood lipids (triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL), and low density lipoprotein (LDL)) in patients with nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH). Methods. MEDLINE/PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, CINAHL, Science Citation Index (ISI Web of Science), Chinese Biomedical Literature Database (CBM), and Chinese National Knowledge Infrastructure (CNKI) were searched for relevant randomized controlled trials on the effects of n-3 polyunsaturated fatty acids (PUFAs) in patients with NAFLD from inception to May 2015. Ten studies were included in this meta-analysis. Results. 577 cases of NAFLD/NASH in ten randomized controlled trials (RCTs) were included. The results of the meta-analysis showed that benefit changes in liver fat favored PUFA treatment, and it was also beneficial for GGT, but it was not significant on ALT, AST, TC, and LDL. Conclusions. In this meta-analysis, omega-3 PUFAs improved liver fat, GGT, TG, and HDL in patients with NAFLD/NASH. Therefore, n-3 PUFAs may be a new treatment option for NAFLD. PMID:27651787

  10. The alanine detector in BNCT dosimetry: Dose response in thermal and epithermal neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, T., E-mail: schmito@uni-mainz.de [Institute for nuclear chemistry, Johannes Gutenberg-University, Mainz D-55128 (Germany); Bassler, N. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus C, Aarhus 8000 (Denmark); Blaickner, M. [AIT Austrian Institute of Technology GmbH, Vienna A-1220 (Austria); Ziegner, M. [AIT Austrian Institute of Technology GmbH, Vienna A-1220, Austria and TU Wien, Vienna University of Technology, Vienna A-1020 (Austria); Hsiao, M. C. [Insitute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Liu, Y. H. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Koivunoro, H. [Department of Physics, University of Helsinki, POB 64, FI-00014, Finland and HUS Medical Imaging Center, Helsinki University Central Hospital, FI-00029 HUS (Finland); Auterinen, I.; Serén, T.; Kotiluoto, P. [VTT Technical Research Centre of Finland, Espoo (Finland); Palmans, H. [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW, United Kingdom and Medical Physics Group, EBG MedAustron GmbH, Wiener Neustadt A-2700 (Austria); Sharpe, P. [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW (United Kingdom); Langguth, P. [Department of Pharmacy and Toxicology, University of Mainz, Mainz D-55128 (Germany); Hampel, G. [Institut für Kernchemie, Johannes Gutenberg-Universität, Mainz D-55128 (Germany)

    2015-01-15

    Purpose: The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different neutron beams to explore the alanine dose response behavior and to validate model predictions. Additionally, application in medical neutron fields for boron neutron capture therapy is discussed. Methods: Alanine detectors have been irradiated in the thermal neutron field of the research reactor TRIGA Mainz, Germany, in five experimental conditions, generating different secondary particle spectra. Further irradiations have been made in the epithermal neutron beams at the research reactors FiR 1 in Helsinki, Finland, and Tsing Hua open pool reactor in HsinChu, Taiwan ROC. Readout has been performed with electron spin resonance spectrometry with reference to an absorbed dose standard in a {sup 60}Co gamma ray beam. Absorbed doses and dose components have been calculated using the Monte Carlo codes FLUKA and MCNP. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using the Hansen and Olsen alanine response model. Results: The measured dose response of the alanine detector in the different experiments has been evaluated and compared to model predictions. Therefore, a relative effectiveness has been calculated for each dose component, accounting for its dependence on particle type and energy. Agreement within 5% between model and measurement has been achieved for most irradiated detectors. Significant differences have been observed in response behavior between thermal and epithermal neutron fields, especially regarding dose composition and depth dose curves. The calculated dose components could be verified with the experimental results in the different primary and secondary particle fields. Conclusions: The

  11. Mutation in a D-alanine-D-alanine ligase of Azospirillum brasilense Cd results in an overproduction of exopolysaccharides and a decreased tolerance to saline stress.

    Science.gov (United States)

    Jofré, Edgardo; Fischer, Sonia; Príncipe, Analía; Castro, Marina; Ferrari, Walter; Lagares, Antonio; Mori, Gladys

    2009-01-01

    Bacteria of the genus Azospirillum are free-living nitrogen-fixing, rhizobacteria that are found in close association with plant roots, where they exert beneficial effects on plant growth and yield in many crops of agronomic importance. Unlike other bacteria, little is known about the genetics and biochemistry of exopolysaccharides in Azospirillum brasilense. In an attempt to characterize genes associated with exopolysaccharides production, we generated an A. brasilense Cd Tn5 mutant that showed exopolysaccharides overproduction, decreased tolerance to saline conditions, altered cell morphology, and increased sensitivity to detergents. Genetic characterization showed that the Tn5 was inserted within a ddlB gene encoding for a d-alanine-d-alanine ligase, and located upstream of the ftsQAZ gene cluster responsible for cell division in different bacteria. Heterologous complementation of the ddlB Tn5 mutant restored the exopolysaccharides production to wild-type levels and the ability to grow in the presence of detergents, but not the morphology and growth characteristics of the wild-type bacteria, suggesting a polar effect of Tn5 on the fts genes. This result and the construction of a nonpolar ddlB mutant provide solid evidence of the presence of transcriptional coupling between a gene associated with peptidoglycan biosynthesis and the fts genes required to control cell division.

  12. 血清γ谷氨酰转肽酶与BMI的相关性研究%Correlation research on gamma-glutamyltransferase and body mass index

    Institute of Scientific and Technical Information of China (English)

    王晶莹; 傅晓英

    2014-01-01

    Objective To explore the relationship between serum gamma-glutamyltransferase (GGT)and body mass index (BMI). Methods All subjects of this cross-sectional study engaged in light manual labor. The study was conducted by questionnaire survey,anthropometric measurements and biochemical examination. And then 172 subjects with complete data were enrolled and divided into different sub-groups ac-cording to BMI,gender and GGT. The association between serum GGT and BMI was analyzed by one-way anal-ysis of variance,Pearson correlation analysis and multiple stepwise regression analysis. Results GGT levels in 4 BMI sub-groups were significantly different (P<0.05). In male,from GGT quartile 1 to quartile 4,the differences of BMI,waist circumference,heart rate,diastolic blood pressure,alanine aminotransferase,aspar-tate aminotransferase,alkaline phosphatase were significant,while in female,the differences of alanine amin-otransferase,aspartate aminotransferase,alkaline phosphatase,high density lipoprotein cholesterol,triglyceride were significant (P<0.05 ). Pearson correlation analysis showed that GGT in male was positively related with BMI,waist circumference,heart rate,the oblique diameter of right lobe of liver measured by ultrasound,ala-nine aminotransferase,aspartate aminotransferase,alkaline phosphatase. In female,GGT was positively related with BMI,waist circumference,systolic blood pressure,diastolic blood pressure,alanine aminotransferase,as-partate aminotransferase,alkaline phosphatase,serum creatinine,triglyceride,but negatively related with high density lipoprotein cholesterol. Multiple stepwise regression analysis revealed that increased serum GGT level had a significant association with BMI and waist circumference. After adjusting for age,gender,waist circum-ference,heart rate,blood pressure,the oblique diameter of right lobe of liver,blood lipid,fasting glucose lev-el,alanine aminotransferase,aspartate aminotransferase,alkaline phosphatase and serum creatinine,GGT

  13. New classes of alanine racemase inhibitors identified by high-throughput screening show antimicrobial activity against Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Karen G Anthony

    Full Text Available BACKGROUND: In an effort to discover new drugs to treat tuberculosis (TB we chose alanine racemase as the target of our drug discovery efforts. In Mycobacterium tuberculosis, the causative agent of TB, alanine racemase plays an essential role in cell wall synthesis as it racemizes L-alanine into D-alanine, a key building block in the biosynthesis of peptidoglycan. Good antimicrobial effects have been achieved by inhibition of this enzyme with suicide substrates, but the clinical utility of this class of inhibitors is limited due to their lack of target specificity and toxicity. Therefore, inhibitors that are not substrate analogs and that act through different mechanisms of enzyme inhibition are necessary for therapeutic development for this drug target. METHODOLOGY/PRINCIPAL FINDINGS: To obtain non-substrate alanine racemase inhibitors, we developed a high-throughput screening platform and screened 53,000 small molecule compounds for enzyme-specific inhibitors. We examined the 'hits' for structural novelty, antimicrobial activity against M. tuberculosis, general cellular cytotoxicity, and mechanism of enzyme inhibition. We identified seventeen novel non-substrate alanine racemase inhibitors that are structurally different than any currently known enzyme inhibitors. Seven of these are active against M. tuberculosis and minimally cytotoxic against mammalian cells. CONCLUSIONS/SIGNIFICANCE: This study highlights the feasibility of obtaining novel alanine racemase inhibitor lead compounds by high-throughput screening for development of new anti-TB agents.

  14. Lactococcal aminotransferases AraT and BcaT are key enzymes for the formation of aroma compounds from amino acids in cheese

    NARCIS (Netherlands)

    Rijnen, L.; Yvon, M.; Kranenburg, van R.; Courtin, P.; Verheul, A.; Chambellon, E.; Smit, G.

    2003-01-01

    Amino acid catabolism plays a major role in cheese aroma development. Previously, we showed that the lactococcal aminotransferases AraT and BcaT initiate the conversion of aromatic amino acids, branched-chain amino acids and methionine to aroma compounds. In this study, we evaluated the importance o

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

    Science.gov (United States)

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

    2015-10-28

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

  16. An Optical Overview of Poly[-L-alanine--nitrato-sodium(I] Crystals

    Directory of Open Access Journals (Sweden)

    E. Gallegos-Loya

    2012-01-01

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

  17. Membrane topology of the electrogenic aspartate-alanine antiporter AspT of Tetragenococcus halophilus.

    Science.gov (United States)

    Nanatani, Kei; Ohonishi, Fumito; Yoneyama, Hiroshi; Nakajima, Tasuku; Abe, Keietsu

    2005-03-04

    AspT is an electrogenic aspartate:alanine exchange protein that represents the vectorial component of a proton-motive metabolic cycle found in some strains of Tetragenococcus halophilus. AspT is the sole member of a new family, the Aspartate: Alanine Exchanger (AAE) family, in secondary transporters, according to the computational classification proposed by Saier et al. (http://www.biology.ucsd.edu/~msaier/transport/). We analyzed the topology of AspT biochemically, by using fusion methods in combination with alkaline phosphatase or beta-lactamase. These results suggested that AspT has a unique topology; 8 TMS, a large cytoplasmic loop (183 amino acids) between TMS5 and TMS6, and N- and C-termini that both face the periplasm. These results demonstrated a unique 2D-structure of AspT as the novel AAE family.

  18. Unusual hydroxyl migration in the fragmentation of β-alanine dication in the gas phase.

    Science.gov (United States)

    Piekarski, Dariusz Grzegorz; Delaunay, Rudy; Maclot, Sylvain; Adoui, Lamri; Martín, Fernando; Alcamí, Manuel; Huber, Bernd A; Rousseau, Patrick; Domaracka, Alicja; Díaz-Tendero, Sergio

    2015-07-14

    We present a combined experimental and theoretical study of the fragmentation of doubly positively charged β-alanine molecules in the gas phase. The dissociation of the produced dicationic molecules, induced by low-energy ion collisions, is analysed by coincidence mass spectrometric techniques; the coupling with ab initio molecular dynamics simulations allows rationalisation of the experimental observations. The present strategy gives deeper insights into the chemical mechanisms of multiply charged amino acids in the gas phase. In the case of the β-alanine dication, in addition to the expected Coulomb explosion and hydrogen migration processes, we have found evidence of hydroxyl-group migration, which leads to unusual fragmentation products, such as hydroxymethyl cation, and is necessary to explain some of the observed dominant channels.

  19. The behaviour of alanine dosimeters at temperatures between 100 and 300 K

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, P.H.G. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom)], E-mail: peter.sharpe@npl.co.uk; Sephton, J.P.; Gouldstone, C.A. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom)

    2009-07-15

    A cryostat has been constructed to enable irradiations in a MDS Nordion Gammacell 220 irradiator to be carried out at selected temperatures between 100 and 300 K. The principle of operation and the performance of this cryostat are described and results are given of a study into the behaviour of alanine dosimeters at cryogenic temperatures. This work extends previously published data to the region between solid CO{sub 2} and liquid N{sub 2} temperatures and has demonstrated complex dose-dependent behaviour. A sharp discontinuity in the effect of temperature on alanine dosimeter response has been found in the region between 150 and 180 K, with no further influence of irradiation temperature on response observed below this point.

  20. The behaviour of alanine dosimeters at temperatures between 100 and 300 K

    Science.gov (United States)

    Sharpe, P. H. G.; Sephton, J. P.; Gouldstone, C. A.

    2009-07-01

    A cryostat has been constructed to enable irradiations in a MDS Nordion Gammacell 220 irradiator to be carried out at selected temperatures between 100 and 300 K. The principle of operation and the performance of this cryostat are described and results are given of a study into the behaviour of alanine dosimeters at cryogenic temperatures. This work extends previously published data to the region between solid CO 2 and liquid N 2 temperatures and has demonstrated complex dose-dependent behaviour. A sharp discontinuity in the effect of temperature on alanine dosimeter response has been found in the region between 150 and 180 K, with no further influence of irradiation temperature on response observed below this point.

  1. SERUM ACTIVITIES OF ASPARTATE AMINOTRANSFERASE, CREATINE KINASE AND LACTATE DEHYDROGENASE IN HORSES WITH COLIC ATIVIDADE SÉRICA DAS ENZIMAS ASPARTATO AMINOTRANSFERASE, CREATINA QUINASE E LACTATO DESIDROGENASE EM EQÜINOS COM CÓLICA

    Directory of Open Access Journals (Sweden)

    Aureo Evangelista Santana

    2008-12-01

    Full Text Available Seventy equines distributed in two experimental groups were used, G1 (20 healthy equines, and G2 (50 equines with colic. Blood samples were obtained by jugular vein puncture in ten different moments. The variables aspartate aminotransferase (AST, creatine kinase (CK, and lactate dehydrogenase (LDH were determined by spectrophotometric assay using specific reagents. The average values presented by the animals of the G2 for variables CK, AST, and LDH were higher (P<0.05 than the values presented by the animals of the G1 in all the evaluation moments. The results showed for G2 animals suggest the existence of acute muscle injury. The muscle injuries in equines with colic were attributed to the tissue hypoperfusion, and the muscular damage.

    KEY WORDS: Acute abdomen, horses, muscles enzyme. De setenta eqüinos, distribuídos em dois grupos experimentais – G1 (vinte eqüinos hígidos e G2 (cinqüenta eqüinos com cólica –, colheram-se amostras de sangue em dez diferentes momentos, mediante punção da jugular, para a determinação da atividade sérica das enzimas aspartato aminotransferase (AST, creatina quinase (CK e lactato desidrogenase (LDH. Os valores médios apresentados pelos animais do G2, para as variáveis CK, AST e LDH, foram superiores (P<0,05 aos valores médios apresentados pelos animais do G1 em todos os momentos de avaliação. Os resultados apresentados pelos animais com cólica (G2 sugerem a existência de lesão muscular aguda, porém com tendência a cura, e foram atribuídos a hipoperfusão tecidual e a traumas musculares. A análise seriada das enzimas CK, AST e LDH auxilia tanto no diagnóstico de lesões musculares em eqüinos com cólica como no acompanhamento da evolução do processo de cura.

    PALAVRAS-CHAVES: Abdômen agudo, cavalos, enzimas musculares.

  2. The effect of irradiation temperatures between ambient and 80 deg. C on the response of alanine dosimeters

    DEFF Research Database (Denmark)

    Sharpe, P.H.G.; Miller, Arne; Sephton, J.P.;

    2009-01-01

    Published data on the effect of irradiation temperature on the response of alanine dosimeters does not extend to the temperatures that may be experienced in high-dose industrial irradiations, particularly in the case of electron beams. We describe here results of the irradiation of alanine...... begins to deviate significantly from linearity and shows marked dose dependence. The effect of this behaviour under conditions typically experienced in industrial processing is evaluated and recommendations made concerning the use of alanine dosimeters at high doses and temperatures....

  3. Structure and vibrational spectra of L-alanine L-alaninium picrate monohydrate

    Science.gov (United States)

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

    2012-05-01

    Preparation, crystal and molecular structure as well as vibrational spectra of the crystal L-alanine L-alaninium picrate monohydrate are described. The title crystal is monoclinic, space group P21. The asymmetric unit contains one dimeric (L-Ala⋯L-Ala+) cation, one picrate anion and a water molecule. The O⋯O distance in the dimeric cation is equal to 2.553(2) Å. The IR and Raman spectra are interpreted based on the structure.

  4. [Alanine dehydrogenase of the cyanobacterium Plectonema boryanum in the early period of cyanophage LPP-3 development].

    Science.gov (United States)

    Perepelitsa, S I; Koltukova, N V; Mendzhul, M I

    1995-01-01

    It has been studied how reproduction of LPP-3 in Plectonema boryanum cells influences the alanine dehydrogenase activity. It has been found that immediately after the virus adsorption the enzyme activity falls by 50% and the anabolic reaction is blocked. Physicochemical properties of the enzyme vary as well. An infected cell has one isoenzyme-octamer with pl 9.1-9.2, pH-optimum by action 9-10, molecular weight about 27 kDa.

  5. Electronic structure and first hyperpolarizability of poly(2-L-alanine-3-sodium nitrate (I)) crystals

    Indian Academy of Sciences (India)

    A Duarte Moller

    2014-10-01

    Poly(2-L-alanine-3-sodium nitrate (I)), -LASN, crystals have been grown by slow evaporation at room temperature. The nominal size of the crystals obtained by the method was of 500 nm. The UV–Vis spectrum shows a wide range, where absorption is lacking around 532 nm, which is required in order to have the second harmonic emission, when an incident radiation of 1064 nm strikes on the crystal. This guarantees the possible use of the crystal in visible light applications. The transparent nature of the crystal in the visible and infrared regions within the transmission spectrum confirms the nonlinear optical properties of the crystal. Additionally, Fourier transform infrared spectroscopy displays its functional groups which correspond to the poly(2-L-alanine-3-sodium nitrate (I)), where the presence of nitrates in the lattice generally can be identified by their characteristic signature within the 1660–1625, 1300–1255, 870–833 and 763–690 cm-1 range. Single crystal diffraction was carried out in order to determine atomic structure and lattice parameter. Structural parameters were = 5.388(9) Å, = 9.315(15) Å and = 13.63(2) Å. The structure of poly(2-Lalanine-3-sodium nitrate (I)) shown by single crystal diffraction shows an asymmetric unit consisting of one sodium and one nitrate ion and one L-alanine molecule. The coordination geometry around the sodium atom was trigonal bipyramidal, with three bidentate nitrate anions coordinating through their oxygen atoms and two L-alanine molecules, each coordinating through one carboxyl oxygen atom. Electronic structure was obtained by using the Becke–Lee–Yang–Part and Hartree–Fock approximations with hybrid exchangecorrelation three-parameter functional and G-311**G() basis set. Theoretical and experimental results were compared and discussed as having an excellent agreement among them.

  6. Densities and solubilities of Glycylglycine and Glycyl-L-Alanine in Aqueous Electrolyte Solutions

    DEFF Research Database (Denmark)

    Breil, Martin Peter; Mollerup, Jørgen; Rudolph, E. Susanne J.

    2004-01-01

    is 1.74 and 4.78 mol/kg of water, respectively. The solubility of glycylglycine in salt solutions of NaCl, Na2SO4, and (NH4)(2)SO4 show a moderate salting-in effect. The solubility of glycyl-L-alanine show a minor or no salting-in effect at low salt concentrations and a moderate salting-out effect...

  7. Uracil and beta-alanine degradation in Saccharomyces Kluyveri - discovery of a novel catabolic pathway

    DEFF Research Database (Denmark)

    Andersen, Gorm

    2006-01-01

    ’en i gær og de genetiske forudsætninger for uracil og beta-alanine (BAL) katabolisme i S. kluyveri undersøgt. Evnen til at bruge uracil, dihydrouracil (DHU), beta-ureidopropionate (BUP) og BAL som nitrogenkilde blev studeret i 38 gær arter. Disse var udvalgt, så de dækkede “Saccharomyces komplekset...

  8. β-alanine supplementation improves isometric endurance of the knee extensor muscles

    Directory of Open Access Journals (Sweden)

    Sale Craig

    2012-06-01

    Full Text Available Abstract Background We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC. Methods Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg, matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6 or β-alanine (n = 7; 6.4 g·d-1 over 4 weeks supplementation group. Participants completed an isometric knee extension test (IKET to fatigue, at an intensity of 45% MVIC, before and after supplementation. In addition, two habituation tests were completed in the week prior to the pre-supplementation test and a further practice test was completed in the week prior to the post-supplementation test. MVIC force, IKET hold-time, and impulse generated were recorded. Results IKET hold-time increased by 9.7 ± 9.4 s (13.2% and impulse by 3.7 ± 1.3 kN·s-1 (13.9% following β-alanine supplementation. These changes were significantly greater than those in the placebo group (IKET: t(11 = 2.9, p ≤0.05; impulse: t(11 = 3.1, p ≤ 0.05. There were no significant changes in MVIC force in either group. Conclusion Four weeks of β-alanine supplementation at 6.4 g·d-1 improved endurance capacity of the knee extensors at 45% MVIC, which most likely results from improved pH regulation within the muscle cell as a result of elevated muscle carnosine levels.

  9. Surface chemistry of alanine on Cu{111}: Adsorption geometry and temperature dependence

    Science.gov (United States)

    Baldanza, Silvia; Cornish, Alix; Nicklin, Richard E. J.; Zheleva, Zhasmina V.; Held, Georg

    2014-11-01

    Adsorption of L-alanine on the Cu{111} single crystal surface was investigated as a model system for interactions between small chiral modifier molecules and close-packed metal surfaces. Synchrotron-based X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy are used to determine the chemical state, bond coordination and out-of-plane orientation of the molecule on the surface. Alanine adsorbs in its anionic form at room temperature, whilst at low temperature the overlayer consists of anionic and zwitterionic molecules. NEXAFS spectra exhibit a strong angular dependence of the π* resonance associated with the carboxylate group, which allows determining the tilt angle of this group with respect to the surface plane (48° ± 2°) at room temperature. Low-energy electron diffraction (LEED) shows a p(2√{ 13} × 2√{ 13}) R 13 ° superstructure with only one domain, which breaks the mirror symmetry of the substrate and, thus, induces global chirality to the surface. Temperature-programmed XPS (TP-XPS) and temperature-programmed desorption (TPD) experiments indicate that the zwitterionic form converts into the anionic species (alaninate) at 293 K. The latter desorbs/decomposes between 435 K and 445 K.

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

    Science.gov (United States)

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

    2009-12-10

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

  11. Qualitative analysis of collective mode frequency shifts in L-alanine using terahertz spectroscopy.

    Science.gov (United States)

    Taulbee, Anita R; Heuser, Justin A; Spendel, Wolfgang U; Pacey, Gilbert E

    2009-04-01

    We have observed collective mode frequency shifts in deuterium-substituted L-alanine, three of which have previously only been calculated. Terahertz (THz) absorbance spectra were acquired at room temperature in the spectral range of 66-90 cm(-1), or 2.0-2.7 THz, for L-alanine (L-Ala) and four L-Ala compounds in which hydrogen atoms (atomic mass = 1 amu) were substituted with deuterium atoms (atomic mass = 2 amu): L-Ala-2-d, L-Ala-3,3,3-d(3), L-Ala-2,3,3,3-d(4), and L-Ala-d(7). The absorbance maxima of two L-Ala collective modes in this spectral range were recorded for multiple spectral measurements of each compound, and the magnitude of each collective mode frequency shift due to increased mass of these specific atoms was evaluated for statistical significance. Calculations were performed which predict the THz absorbance frequencies based on the estimated reduced mass of the modes. The shifts in absorbance maxima were correlated with the location(s) of the substituted deuterium atom(s) in the L-alanine molecule, and the atoms contributing to the absorbing delocalized mode in the crystal structure were deduced using statistics described herein. The statistical analyses presented also indicate that the precision of the method allows reproducible frequency shifts as small as 1 cm(-1) or 0.03 THz to be observed and that these shifts are not random error in the measurement.

  12. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

    Science.gov (United States)

    Umeda, Yuhei; Fukunaga, Nao; Sekine, Toshimori; Furukawa, Yoshihiro; Kakegawa, Takeshi; Kobayashi, Takamichi; Nakazawa, Hiromoto

    2016-01-01

    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

  13. Structural, spectral, thermal, dielectric, mechanical and optical properties of urea L-alanine acetate single crystals

    Science.gov (United States)

    Jaikumar, D.; Kalainathan, S.; Bhagavannarayana, G.

    2010-05-01

    A new organic nonlinear optical crystal, urea L-alanine acetate (ULAA) has been grown by solution growth using slow cooling technique with the vision to improve the properties of the L-alanine crystals. Urea and L-alanine material were mixed in the molar ratio 1:4. Solubility and metastable zone width were determined. Single crystal XRD analyses revealed that the crystal lattice of ULAA is orthorhombic system, primitive lattice with cell parameters a=5.7971 Å, b=6.0391 Å, c=12.3276 Å with space group P2 12 12 1 (D 24). High-resolution X-ray diffraction (HR-XRD) analysis was carried out to study their crystalline perfection. FTIR spectrum was recorded to identify the presence of functional groups and molecular structure was confirmed by 1H NMR spectrum. From the mass spectrum, the ratio of compound formation of ULAA was analyzed. Thermal strength of the grown crystal has been studied using thermo-gravimetric (TG) and differential thermal analysis (DTA). Dielectric measurements reveal that the grown crystals have very low dielectric loss. The mechanical behavior was studied by Vickers microhardness test. The grown crystals were found to be transparent in the entire visible region. Preliminary measurement using Kurtz powder technique with Nd-YAG laser light of wavelength 1064 nm indicates that their second harmonic generation (SHG) efficiency is roughly equal to that of pure KDP.

  14. Effect of dipeptide of glutamine and alanine on severe traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    YANG De-lin; XU Jun-fa

    2007-01-01

    Objective: To determine the effect of dipeptide of glutamine and alanine on patients with severe traumatic brain injury. Methods: A total of 46 patients (31 males and 15 females, aged 7-68 years, (47±9.6) years on average) with severe traumatic brain injury were randomized into two groups: Group G (n=23) and Group C (n=23). The patients in Group G received nutritional remedy with the dipeptide of glutamine and alanine, whereas the patients in Group C received routine nutritional therapy only. GCS changes, the length of stay in the neurosurgical intensive care unit (NICU), the mortality,the count of lymphocytes, related complications including lung infection and hemorrhage of alimentary tracts, etc, were examined and recorded. Results: The fatality rate and the length of stay in NICU in Group G was lower than these in Group C (P<0.05), but no obvious difference was found in GCS changes of the patients between the two groups (P>0.05). The patients with lung infection and alimentary tract hemorrhage in Group G were less than those in Group C (P<0.05). The count of lymphocytes in Group G was more than that in Group C (P<0.05), but no difference was found in other nutritional data. Conclusions: Dipeptide of glutamine and alanine can increase the resisting stress and anti-infection ability of patients with severe traumatic brain injury, which can also lower the mortality and shorten the NICU stay.

  15. Beta-alanine-hydrochloride (2:1) crystal: structure, 13C NMR and vibrational properties, protonation character.

    Science.gov (United States)

    Godzisz, D; Ilczyszyn, M; Ciunik, Z

    2003-01-15

    The crystal structure of beta-alanine-hydrochloride (2:1) complex (2A-HCl) has been determined by X-ray diffraction method at 298 and 100 K as monoclinic, space group C2/c, Z=4. The crystal comprises chloride anions and protonated beta-alanine dimers: two beta-alanine zwitterions are joined by strong, symmetric (Ci) hydrogen bond with the O...O distance of 2.473 A at room temperature. Powder FT-IR and FT-Raman as well as solid state 13C NMR spectra provide insights into the solid structure of this complex, character of its hydrogen bonds and the beta-alanine protonation.

  16. Feasibility on using composite gel-alanine dosimetry on the validation of a multiple brain metastasis radiosurgery VMAT technique

    Science.gov (United States)

    Pavoni, J. F.; Neves-Junior, W. F. P.; Silveira, M. A.; Ramos, P. A. M. M.; Haddad, C. M. K.; Baffa, O.

    2015-01-01

    This work presents an end-to-end test using a composite Gel-Alanine phantom, in order to validate 3-dimensionally the dose distribution delivered by a single isocenter VMAT technique on the simultaneous treatment of multiple brain metastases. The results obtained with the gel and alanine dosimeters are consistent with the expected by the treatment planning system, showing the potential of this multidosimetric approach and validating dosimetrically the multiple brain metastases treatment using VMAT.

  17. Assessment of Metabolic Changes in Mycobacterium smegmatis Wild-Type and alr Mutant Strains: Evidence of a New Pathway of d-Alanine Biosynthesis.

    Science.gov (United States)

    Marshall, Darrell D; Halouska, Steven; Zinniel, Denise K; Fenton, Robert J; Kenealy, Katie; Chahal, Harpreet K; Rathnaiah, Govardhan; Barletta, Raúl G; Powers, Robert

    2017-03-03

    In mycobacteria, d-alanine is an essential precursor for peptidoglycan biosynthesis. The only confirmed enzymatic pathway to form d-alanine is through the racemization of l-alanine by alanine racemase (Alr, EC 5.1.1.1). Nevertheless, the essentiality of Alr in Mycobacterium tuberculosis and Mycobacterium smegmatis for cell survivability in the absence of d-alanine has been a point of controversy with contradictory results reported in the literature. To address this issue, we examined the effects of alr inactivation on the cellular metabolism of M. smegmatis. The M. smegmatis alr insertion mutant TAM23 exhibited essentially identical growth to wild-type mc(2)155 in the absence of d-alanine. NMR metabolomics revealed drastically distinct phenotypes between mc(2)155 and TAM23. A metabolic switch was observed for TAM23 as a function of supplemented d-alanine. In the absence of d-alanine, the metabolic response directed carbon through an unidentified transaminase to provide the essential d-alanine required for survival. The process is reversed when d-alanine is available, in which the d-alanine is directed to peptidoglycan biosynthesis. Our results provide further support for the hypothesis that Alr is not an essential function of M. smegmatis and that specific Alr inhibitors will have no bactericidal action.

  18. Relationship of creatine kinase, aspartate aminotransferase, lactate dehydrogenase, and proteinuria to cardiomyopathy in the owl monkey (Aotus vociferans)

    Energy Technology Data Exchange (ETDEWEB)

    Gozalo, Alfonso S.; Chavera, Alfonso; Montoya, Enrique J.; Takano, Juan; Weller, Richard E.

    2008-02-01

    The purpose of this study was to determine serum reference values for crea- tine kinase (CK), aspartate aminotransferase (AST), and lactate dehydroge- nase (LDH) in captive-born and wild-caught owl monkeys to assess their usefulness for diagnosing myocardial disease. Urine samples were also collected and semi-quantitative tests performed. There was no statistically significant difference between CK, AST, and LDH when comparing both groups. However, when comparing monkeys with proteinuria to those without proteinuria, a statistically significant difference in CK value was observed (P = 0.021). In addition, the CK/AST ratio revealed that 29% of the animals included in this study had values suggesting cardiac infarction. Grossly, cardiac concentric hypertrophy of the left ventricle and small, pitted kidneys were the most common findings. Microscopically, myocardial fibrosis, contraction band necrosis, hypertrophy and hyperplasia of coronary arteries, medium-sized renal arteries, and afferent glomerular arteriolae were the most significant lesions, along with increased mesangial matrix and hypercellularity of glomeruli, Bowman’s capsule, and peritubular space fibroplasia. These findings suggest that CK, AST, and LDH along with urinalysis provide a reliable method for diagnosing cardiomyopathies in the owl monkey. In addition, CK/AST ratio, proteinuria, and the observed histological and ultrastructural changes suggest that Aotus vociferans suffer from arterial hypertension and chronic myocardial infarction.

  19. The tryptophan aminotransferase Tam1 catalyses the single biosynthetic step for tryptophan-dependent pigment synthesis in Ustilago maydis.

    Science.gov (United States)

    Zuther, Katja; Mayser, Peter; Hettwer, Ursula; Wu, Wenying; Spiteller, Peter; Kindler, Bernhard L J; Karlovsky, Petr; Basse, Christoph W; Schirawski, Jan

    2008-04-01

    Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the tryptophan aminotransferase Tam1 catalyses pigment biosynthesis by conversion of tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.

  20. Aspartate aminotransferase-to-platelet ratio index for fibrosis and cirrhosis prediction in chronic hepatitis C patients

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    Roberto Gomes da Silva Junior

    2008-02-01

    Full Text Available In chronic hepatitis C (CHC, liver biopsy is the gold standard method for assessing liver histology, however it is invasive and can have complications. Non-invasive markers have been proposed and aspartate aminotransferase (AST-to-platelet ratio index (APRI has been shown as an easy and inexpensive marker of liver fibrosis. This study evaluated the diagnostic performance of APRI for significant fibrosis and cirrhosis prediction in CHC patients. This study included treatment-naive CHC patients who had undergone liver biopsy from January 2000 to August 2006. All histological slides were reviewed according to the METAVIR system. APRI was calculated based on laboratory results performed within four months from the biopsy. Twenty-eight (56% patients had significant fibrosis (F2-F4 and 13 (26% had cirrhosis (F4. The area under ROC curves of APRI for predicting significant fibrosis and cirrhosis were 0.92 (0.83-1.00 and 0.92 (0.85-1.00, respectively. Using cut-off values recommended by prior studies, significant fibrosis could be identified, in accordance with liver biopsy, in 44% and cirrhosis in 66% of patients. APRI could identify significant fibrosis and cirrhosis at a high degree of accuracy in studied patients.

  1. Aspartic acid aminotransferase activity is increased in actively spiking compared with non-spiking human epileptic cortex.

    Science.gov (United States)

    Kish, S J; Dixon, L M; Sherwin, A L

    1988-01-01

    Increased concentration of the excitatory neurotransmitter aspartic acid in actively spiking human epileptic cerebral cortex was recently described. In order to further characterise changes in the aspartergic system in epileptic brain, the behaviour of aspartic acid aminotransferase (AAT), a key enzyme involved in aspartic acid metabolism has now been examined. Electrocorticography performed during surgery was employed to identify cortical epileptic spike foci in 16 patients undergoing temporal lobectomy for intractable seizures. Patients with spontaneously spiking lateral temporal cortex (n = 8) were compared with a non-spiking control group (n = 8) of patients in whom the epileptic lesions were confined to the hippocampus sparing the temporal convexity. Mean activity of AAT in spiking cortex was significantly elevated by 16-18%, with aspartic acid concentration increased by 28%. Possible explanations for the enhanced AAT activity include increased proliferation of cortical AAT-containing astrocytes at the spiking focus and/or a generalised increase in neuronal or extraneuronal metabolism consequent to the ongoing epileptic discharge. It is suggested that the data provide additional support for a disturbance of central excitatory aspartic acid mechanisms in human epileptic brain. PMID:2898010

  2. Molecular cloning and expression of phosphoglycerate dehydrogenase and phosphoserine aminotransferase in the serine biosynthetic pathway from Acanthamoeba castellanii.

    Science.gov (United States)

    Deng, Yihong; Wu, Duo; Tachibana, Hiroshi; Cheng, Xunjia

    2015-04-01

    Free-living amoebae of the genus Acanthamoeba are widespread protozoans that can cause serious infectious diseases. This study characterised phosphoglycerate dehydrogenase (PGDH) and phosphoserine aminotransferase (PSAT) in the phosphorylated serine biosynthetic pathway of Acanthamoeba castellanii. The PGDH gene encodes a protein of 442 amino acids with a calculated molecular weight of 47.7 kDa and an isoelectric point (pI) of 7.64. Meanwhile, the PSAT gene encodes a protein of 394 amino acids with a calculated molecular weight of 43.8 kDa and a pI of 5.80. Confocal microscopy suggests that PGDH is mainly diffused in the cytoplasm, whereas PSAT is located in the inner part of the cell membrane. The messenger RNA (mRNA) expression levels of PGDH and PSAT vary depending on growth state under consecutive culture conditions. No significant changes in the mRNA expression levels of both PGDH and PSAT occur after the incubation of L-serine with Acanthamoeba. This result indicates that exogenous serine exerts no influence on the expression of these genes and that the so-called feedback inhibition of both PGDH and PSAT in Acanthamoeba differs from that in bacteria or other organisms. We propose that the enzymes in the phosphorylated serine biosynthetic pathway function in amoeba growth and proliferation.

  3. [Isolation and properties of cortisol inducible and cortisol non-inducible isoenzymes of rat liver tyrosine aminotransferase].

    Science.gov (United States)

    Mertvetsov, N P; Chesnokov, V N; Sakhno, L V; Salganik, R I

    1976-08-01

    Rat liver contains two groups of tyrosine aminotransferase (TAT) isoenzymes; during electrophoresis in agar gel one of the groups moves to the anode and the other--to the catode. Cortisol is shown to induce only the anode isoenzymes of TAT, which were isolated, purified and thoroughly analyzed. The inducible anode isoenzyme of TAT spearated from other proteins is more sensitive to the effect of proteases (trypsin and chymotrypsin) than the catode isoenzyme. Some kinetic parameters of the purified TAT isoenzymes were studied. Both isoenzymes have pH optimum around 7.5; their apparent Km values for tyrosine are also similar. However, the catode isoenzyme of TAT possesses a higher affinity for alpha-ketoglutarate than does the anode isoenzyme. Unlike the latter, the former isoenzyme may use oxaloacetate as an amino group acceptor. Pyridoxal phosphate is firmly bound to the catode isoenzyme and can be readily spearated from the anode isoenzyme during dyalisis. An increased sensitivity of the inducible isoenzyme to proteases is due not only to the possibility of coenzyme dissociation, but also to some specific properties of the apoenzyme. The results obtained support the assumption that a high sensitivity of the inducible isoenzymes to proteases provides for a removal of excessive amounts of the enzymes from the cells under cessation of hormonal induction, thus maintaining enzymatic homostasis in the cell.

  4. Branched-chain amino acid metabolon: interaction of glutamate dehydrogenase with the mitochondrial branched-chain aminotransferase (BCATm).

    Science.gov (United States)

    Islam, Mohammad Mainul; Nautiyal, Manisha; Wynn, R Max; Mobley, James A; Chuang, David T; Hutson, Susan M

    2010-01-01

    The catabolic pathway for branched-chain amino acids includes deamination followed by oxidative decarboxylation of the deaminated product branched-chain alpha-keto acids, catalyzed by the mitochondrial branched-chain aminotransferase (BCATm) and branched-chain alpha-keto acid dehydrogenase enzyme complex (BCKDC). We found that BCATm binds to the E1 decarboxylase of BCKDC, forming a metabolon that allows channeling of branched-chain alpha-keto acids from BCATm to E1. The protein complex also contains glutamate dehydrogenase (GDH1), 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1, pyruvate carboxylase, and BCKDC kinase. GDH1 binds to the pyridoxamine 5'-phosphate (PMP) form of BCATm (PMP-BCATm) but not to the pyridoxal 5'-phosphate-BCATm and other metabolon proteins. Leucine activates GDH1, and oxidative deamination of glutamate is increased further by addition of PMP-BCATm. Isoleucine and valine are not allosteric activators of GDH1, but in the presence of 5'-phosphate-BCATm, they convert BCATm to PMP-BCATm, stimulating GDH1 activity. Sensitivity to ADP activation of GDH1 was unaffected by PMP-BCATm; however, addition of a 3 or higher molar ratio of PMP-BCATm to GDH1 protected GDH1 from GTP inhibition by 50%. Kinetic results suggest that GDH1 facilitates regeneration of the form of BCATm that binds to E1 decarboxylase of the BCKDC, promotes metabolon formation, branched-chain amino acid oxidation, and cycling of nitrogen through glutamate.

  5. In situ detection of myocardial infarction in pig by measurements of aspartate aminotransferase (ASAT) activity in the interstitial fluid.

    Science.gov (United States)

    Kennergren, C; Nyström, B; Nyström, U; Berglin, E; Larsson, G; Mantovani, V; Lönnroth, P; Hamberger, A

    1997-01-01

    Microdialysis probes permeable to large molecules (m.w. cut-off > 200 kD) were introduced into the myocardium of anaesthetized pigs in order to evaluate their potential for early detection of myocardial ischaemia and enzyme markers for infarction. The left anterior descending coronary artery was occluded for 30 min and the myocardium was reperfused for 3 h. The concentrations of aspartate aminotransferase (ASAT), lactate, glucose and selected free amino acids were measured. The levels in the interstitium of ischaemic and non-ischaemic myocardium were compared with those in plasma from the coronary sinus as well as from a peripheral vein. Twelve probes were inserted in six pigs and withdrawn after 8-72 hours of sampling. No complications occurred. Simultaneous 100% increase of ASAT and lactate was found in myocardial dialysates after 30 min of ischaemia. ASAT activity remained at that level until the end of reperfusion. The plasma peak ASAT level was not attained until after 3 h. Glutamate was the only amino acid which increased significantly in the myocardial interstitium during ischaemia, peaking after 30 min of reperfusion. Dialysates from the unaffected myocardium showed no effects on lactate, ASAT or glutamate. The use of myocardial microdialysis for pre- and postoperative recordings in man is discussed.

  6. Distribution of messenger RNAs encoding the enzymes glutaminase, aspartate aminotransferase and glutamic acid decarboxylase in rat brain.

    Science.gov (United States)

    Najlerahim, A; Harrison, P J; Barton, A J; Heffernan, J; Pearson, R C

    1990-05-01

    In situ hybridization histochemistry (ISHH) using synthetic oligonucleotide probes has been used to identify cells containing the mRNAs coding for glutaminase (GluT), aspartate aminotransferase (AspT) and glutamic acid decarboxylase (GAD). The distribution of GAD mRNA confirms previous descriptions and matches the distribution of GAD detected using specific antibodies. AspT mRNA is widely distributed in the brain, but is present at high levels in GABAergic neuronal populations, some that may be glutamatergic, and in a subset of neurons which do not contain significant levels of either GAD or GluT mRNA. Particularly prominent are the neurons of the magnocellular division of the red nucleus, the large cells in the deep cerebellar nuclei and the vestibular nuclei and neurons of the lateral superior olivary nucleus. GluT mRNA does not appear to be present at high levels in all GAD-containing neurons, but is seen prominently in many neuronal populations that may use glutamate as a neurotransmitter, such as neocortical and hippocampal pyramidal cells, the granule cells of the cerebellum and neurons of the dentate gyrus of the hippocampus. The heaviest labelling of GluT mRNA is seen in the lateral reticular nucleus of the medulla. ISHH using probes directed against the mRNAs encoding these enzymes may be an important technique for identifying glutamate and aspartate using neuronal populations and for examining their regulation in a variety of experimental and pathological circumstances.

  7. The crystal structure of alanine racemase from Streptococcus pneumoniae, a target for structure-based drug design

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    Davlieva Milya

    2011-05-01

    Full Text Available Abstract Background Streptococcus pneumoniae is a globally important pathogen. The Gram-positive diplococcus is a leading cause of pneumonia, otitis media, bacteremia, and meningitis, and antibiotic resistant strains have become increasingly common over recent years.Alanine racemase is a ubiquitous enzyme among bacteria and provides the essential cell wall precursor, D-alanine. Since it is absent in humans, this enzyme is an attractive target for the development of drugs against S. pneumoniae and other bacterial pathogens. Results Here we report the crystal structure of alanine racemase from S. pneumoniae (AlrSP. Crystals diffracted to a resolution of 2.0 Å and belong to the space group P3121 with the unit cell parameters a = b = 119.97 Å, c = 118.10 Å, α = β = 90° and γ = 120°. Structural comparisons show that AlrSP shares both an overall fold and key active site residues with other bacterial alanine racemases. The active site cavity is similar to other Gram positive alanine racemases, featuring a restricted but conserved entryway. Conclusions We have solved the structure of AlrSP, an essential step towards the development of an accurate pharmacophore model of the enzyme, and an important contribution towards our on-going alanine racemase structure-based drug design project. We have identified three regions on the enzyme that could be targeted for inhibitor design, the active site, the dimer interface, and the active site entryway.

  8. Microhydration of Alanine in Gas Phase Studied by Quantum Chemical Method and ABEEMσπ/MM Fluctuating Charge Model

    Institute of Scientific and Technical Information of China (English)

    LU Li-nan; LIU Cui; GONG Li-dong

    2013-01-01

    A fluctuating charge interaction potential function for alanine-water was constructed in the spirit of newly developed ABEEMσπ/MM(atom-bond electronegativity equalization method at the σπ level fused into molecular mechanics).The properties of gaseous neutral alanine-(H2O)n(n=1-7) clusters were systematically investigated by quantum mechanics(QM) and the constructed ABEEMσπ/MM potential,such as conformations,hydrogen bonds (H-bonds),interaction energies,charge distributions,and so on.The results of ABEEMσπ/MM model are in fair agreement with those of QM and available experimental data.For isolated alanine,compared with those of experi-mental structure,the average absolute deviations(AAD) of bond length and bond angle are 0.002 nm and 1.4°,respectively.For alanine-water clusters,the AAD of interaction energies and H-bond lengths are only 3.77 kJ/mol and 0.012 nm,respectively,compared to the results of MP2/aug-cc-pVDZ//MP2/6-311+G** method.The ABEEMσπ charges fluctuate with the changing conformation of the system,and can accurately and reasonably reflect the interpolarization between water and alanine.The presented alanine-water potential function may provide a basis for further simulations on related aqueous solutions of biomolecules.

  9. Combined effect of amino and carboxyl group in α-alanine on seeded precipitation of sodium aluminate solution

    Institute of Scientific and Technical Information of China (English)

    L(U) Bao-lin; CHEN Qi-yuan; YIN Zhou-lan; HU Hui-ping

    2009-01-01

    α-alanine was adopted as a new additive to elucidate the seeded precipitation mechanism of sodium aluminate solution. α-alanine has the inhibitory effect at the initial period of reaction, but the favorable effect in subsequent reaction. The combined effect of amino and carboxyl group in α-alanine was confirmed by investigating the effect of propionic acid, ethamine and the mixture of propionic acid and ethamine (mole ratio 1:1) on the precipitation of sodium aluminate solution, respectively. The inhibitory effect derives from the adsorption of amino or carboxyl group in α-alanine on the active surface sites of gibbsite, which was confirmed by the alleviating inhibitory effects of propionic acid, ethamine and α-alanine due to the double crystal seed mass. The semi-quantitative IR spectrum analysis of the relative concentrations of Al2O(OH)62- with the band at about 550 cm-1 and polynuclear aluminate ion with the bands at about 880 cm-1 and 635 cm-1, indicates that the dynamic balance among some aluminate species present in sodium aluminate solution is broken due to the addition of α-alanine, thus resulting in the change of the seeded precipitation ratio of sodium aluminate solution.

  10. Effect of copper on liver and bone metabolism in malnutrition.

    Science.gov (United States)

    Güler, A H; Sapan, N; Ediz, B; Genç, Z; Ozkan, K

    1994-01-01

    This study was planned to investigate the effects of copper (Cu) deficiency on liver and bone metabolism in malnourished children. Serum total calcium (Ca), inorganic phosphorus (P), Ca/P, Cu/Ca, Cu/P ratios and alkaline phosphatase (ALP) activity values were analyzed. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (GGT) enzyme activities and the ALT/AST (De Ritis) ratio as well as their correlations with Cu were tested to determine liver function. The results of the study showed that Cu deficiency directly affects the organic matrix formation, and by the suppression of ALP activity, indirectly causes decalcification. In the liver, however, no direct effect of Cu deficiency was seen. Deterioration in liver function and Cu deficiency increased parallel with the severity of malnutrition. Thus we concluded that a correlation exists between Cu and the parameters that indicate liver function.

  11. Alanine scan of core positions in ubiquitin reveals links between dynamics, stability, and function.

    Science.gov (United States)

    Lee, Shirley Y; Pullen, Lester; Virgil, Daniel J; Castañeda, Carlos A; Abeykoon, Dulith; Bolon, Daniel N A; Fushman, David

    2014-04-03

    Mutations at solvent-inaccessible core positions in proteins can impact function through many biophysical mechanisms including alterations to thermodynamic stability and protein dynamics. As these properties of proteins are difficult to investigate, the impacts of core mutations on protein function are poorly understood for most systems. Here, we determined the effects of alanine mutations at all 15 core positions in ubiquitin on function in yeast. The majority (13 of 15) of alanine substitutions supported yeast growth as the sole ubiquitin. Both the two null mutants (I30A and L43A) were less stable to temperature-induced unfolding in vitro than wild type (WT) but were well folded at physiological temperatures. Heteronuclear NMR studies indicated that the L43A mutation reduces temperature stability while retaining a ground-state structure similar to WT. This structure enables L43A to bind to common ubiquitin receptors in vitro. Many of the core alanine ubiquitin mutants, including one of the null variants (I30A), exhibited an increased accumulation of high-molecular-weight species, suggesting that these mutants caused a defect in the processing of ubiquitin-substrate conjugates. In contrast, L43A exhibited a unique accumulation pattern with reduced levels of high-molecular-weight species and undetectable levels of free ubiquitin. When conjugation to other proteins was blocked, L43A ubiquitin accumulated as free ubiquitin in yeast. Based on these findings, we speculate that ubiquitin's stability to unfolding may be required for efficient recycling during proteasome-mediated substrate degradation.

  12. Structural and biochemical analyses of alanine racemase from the multidrug-resistant Clostridium difficile strain 630.

    Science.gov (United States)

    Asojo, Oluwatoyin A; Nelson, Sarah K; Mootien, Sara; Lee, Yashang; Rezende, Wanderson C; Hyman, Daniel A; Matsumoto, Monica M; Reiling, Scott; Kelleher, Alan; Ledizet, Michel; Koski, Raymond A; Anthony, Karen G

    2014-07-01

    Clostridium difficile, a Gram-positive, spore-forming anaerobic bacterium, is the leading cause of infectious diarrhea among hospitalized patients. C. difficile is frequently associated with antibiotic treatment, and causes diseases ranging from antibiotic-associated diarrhea to life-threatening pseudomembranous colitis. The severity of C. difficile infections is exacerbated by the emergence of hypervirulent and multidrug-resistant strains, which are difficult to treat and are often associated with increased mortality rates. Alanine racemase (Alr) is a pyridoxal-5'-phosphate (PLP)-dependent enzyme that catalyzes the reversible racemization of L- and D-alanine. Since D-alanine is an essential component of the bacterial cell-wall peptidoglycan, and there are no known Alr homologs in humans, this enzyme is being tested as an antibiotic target. Cycloserine is an antibiotic that inhibits Alr. In this study, the catalytic properties and crystal structures of recombinant Alr from the virulent and multidrug-resistant C. difficile strain 630 are presented. Three crystal structures of C. difficile Alr (CdAlr), corresponding to the complex with PLP, the complex with cycloserine and a K271T mutant form of the enzyme with bound PLP, are presented. The structures are prototypical Alr homodimers with two active sites in which the cofactor PLP and cycloserine are localized. Kinetic analyses reveal that the K271T mutant CdAlr has the highest catalytic constants reported to date for any Alr. Additional studies are needed to identify the basis for the high catalytic activity. The structural and activity data presented are first steps towards using CdAlr for the development of structure-based therapeutics for C. difficile infections.

  13. Study of pyruvate kinase activity in human astrocytomas - Alanine-inhibition test revisted

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    Javalkar V

    2009-01-01

    Full Text Available Background: Recent studies have confirmed that alterations in the isoenzyme of pyruvate kinase (PK provide tumor cells with selective growth advantage. Aims: Our aim was to establish the mean activity of the enzyme PK in human astrocytomas and to look for any trends in the activity with relation to histological grade. Materials and Methods: The PK (EC 2.7.1.40 activity was measured in the tumor homogenate by spectrophotometric rate determination. ΔAbsorbance at 340 nm (A 340nm per minute was obtained using the maximal linear rate for both the test and the blank. Enzyme activity was estimated in the presence and absence of amino acid alanine. Results: The mean PK level in astrocytomas was 3.5 ± 2.0 mmol/min/mg protein, which was significantly higher (24%; P < 0.001 when compared to 2.8 ± 0.3 mmol/min/mg protein in control brain. Highest PK activity was noted in grade 2 astrocytomas. In controls there was no change in PK activity in the presence of alanine. In grade 2 astrocytomas there was 7% decrease in mean PK activity in the presence of alanine, this difference in grade 3 astrocytomas was 33% and in grade 4 astrocytomas it was 61%. As the tumors were becoming malignant there was a graded increase in the levels of PK inhibition. Conclusions: Mean PK activity was significantly higher in astrocytomas. There was a graded increase in level of PK inhibition as the tumors were becoming more malignant.

  14. Tetrakis-μ-l-alanine-κ8O:O′-bis[tetraaquaterbium(III] hexaperchlorate

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    Musa E. Mohamed

    2010-02-01

    Full Text Available The asymmetric unit of the title compound, [Tb2(C3H7NO24(H2O8](ClO46, contains a dinuclear cation and six perchlorate anions, one of which is disordered. In the cation, the four l-alanine molecules are present in their zwitterionic form and bridge two Tb3+ ions through their carboxylate O atoms. Each Tb atom is also coordinated by four water molecules in a square-antiprismatic geometry. In the crystal structure, the cations and anions are held together via intermolecular O—H...O and N—H...O hydrogen bonds.

  15. Growth and Characterization of Pure and Doped L-Alanine Tartrate Single Crystals

    OpenAIRE

    K. Rajesh; B. Milton Boaz; P. Praveen Kumar

    2013-01-01

    Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were a...

  16. Conserved aspartic acid 233 and alanine 231 are not required for poliovirus polymerase function in replicons

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    Freistadt Marion S

    2007-03-01

    Full Text Available Abstract Nucleic acid polymerases have similar structures and motifs. The function of an aspartic acid (conserved in all classes of nucleic acid polymerases in motif A remains poorly understood in RNA-dependent RNA polymerases. We mutated this residue to alanine in a poliovirus replicon. The resulting mutant could still replicate, although at a reduced level. In addition, mutation A231C (also in motif A yielded high levels of replication. Taken together these results show that poliovirus polymerase conserved residues D233 and A231 are not essential to poliovirus replicon function.

  17. Conserved aspartic acid 233 and alanine 231 are not required for poliovirus polymerase function in replicons

    Science.gov (United States)

    Freistadt, Marion S; Eberle, Karen E

    2007-01-01

    Nucleic acid polymerases have similar structures and motifs. The function of an aspartic acid (conserved in all classes of nucleic acid polymerases) in motif A remains poorly understood in RNA-dependent RNA polymerases. We mutated this residue to alanine in a poliovirus replicon. The resulting mutant could still replicate, although at a reduced level. In addition, mutation A231C (also in motif A) yielded high levels of replication. Taken together these results show that poliovirus polymerase conserved residues D233 and A231 are not essential to poliovirus replicon function. PMID:17352827

  18. Kynurenine aminotransferase III and glutamine transaminase L are identical enzymes that have cysteine S-conjugate β-lyase activity and can transaminate L-selenomethionine.

    Science.gov (United States)

    Pinto, John T; Krasnikov, Boris F; Alcutt, Steven; Jones, Melanie E; Dorai, Thambi; Villar, Maria T; Artigues, Antonio; Li, Jianyong; Cooper, Arthur J L

    2014-11-01

    Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase activity, as does mouse KAT II. Thus, depending on the nature of the substrate, all four KATs possess cysteine S-conjugate β-lyase activity. These present studies show that KAT III and glutamine transaminase L are identical enzymes. This report also shows that KAT I, II, and III differ in their ability to transaminate methyl-L-selenocysteine (MSC) and L-selenomethionine (SM) to β-methylselenopyruvate (MSP) and α-ketomethylselenobutyrate, respectively. Previous studies have identified these seleno-α-keto acids as potent histone deacetylase inhibitors. Methylselenol (CH3SeH), also purported to have chemopreventive properties, is the γ-elimination product of SM and the β-elimination product of MSC catalyzed by cystathionine γ-lyase (γ-cystathionase). KAT I, II, and III, in part, can catalyze β-elimination reactions with MSC generating CH3SeH. Thus, the anticancer efficacy of MSC and SM will depend, in part, on the endogenous expression of various KAT enzymes and cystathionine γ-lyase present in target tissue coupled with the ability of cells to synthesize in situ either CH3SeH and/or seleno-keto acid metabolites.

  19. Crystal structures of the PLP- and PMP-bound forms of BtrR, a dual functional aminotransferase involved in butirosin biosynthesis.

    Science.gov (United States)

    Popovic, Bojana; Tang, Xiao; Chirgadze, Dimitri Y; Huang, Fanglu; Blundell, Tom L; Spencer, Jonathan B

    2006-10-01

    The aminotransferase (BtrR), which is involved in the biosynthesis of butirosin, a 2-deoxystreptamine (2-DOS)-containing aminoglycoside antibiotic produced by Bacillus circulans, catalyses the pyridoxal phosphate (PLP)-dependent transamination reaction both of 2-deoxy-scyllo-inosose to 2-deoxy-scyllo-inosamine and of amino-dideoxy-scyllo-inosose to 2-DOS. The high-resolution crystal structures of the PLP- and PMP-bound forms of BtrR aminotransferase from B. circulans were solved at resolutions of 2.1 A and 1.7 A with R(factor)/R(free) values of 17.4/20.6 and 19.9/21.9, respectively. BtrR has a fold characteristic of the aspartate aminotransferase family, and sequence and structure analysis categorises it as a member of SMAT (secondary metabolite aminotransferases) subfamily. It exists as a homodimer with two active sites per dimer. The active site of the BtrR protomer is located in a cleft between an alpha helical N-terminus, a central alphabetaalpha sandwich domain and an alphabeta C-terminal domain. The structures of the PLP- and PMP-bound enzymes are very similar; however BtrR-PMP lacks the covalent bond to Lys192. Furthermore, the two forms differ in the side-chain conformations of Trp92, Asp163, and Tyr342 that are likely to be important in substrate selectivity and substrate binding. This is the first three-dimensional structure of an enzyme from the butirosin biosynthesis gene cluster.

  20. Cloning, purification, crystallization and preliminary X-ray crystallographic analysis of the biosynthetic N-acetylornithine aminotransferases from Salmonella typhimurium and Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Rajaram, V.; Prasad, K.; Ratna Prasuna, P.; Ramachandra, N.; Bharath, S. R. [Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012 (India); Savithri, H. S. [Department of Biochemistry, Indian Institute of Science, Bangalore 560 012 (India); Murthy, M. R. N., E-mail: mrn@mbu.iisc.ernet.in [Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012 (India)

    2006-10-01

    Acetylornithine aminotransferases, members of the type I subgroup II family of PLP-dependent enzymes, from S. typhimurium and E. coli have been cloned, overexpressed, purified and crystallized. Acetylornithine aminotransferase (AcOAT) is a type I pyridoxal 5′-phosphate-dependent enzyme catalyzing the conversion of N-acetylglutamic semialdehyde to N-acetylornithine in the presence of α-ketoglutarate, a step involved in arginine metabolism. In Escherichia coli, the biosynthetic AcOAT also catalyzes the conversion of N-succinyl-l-2-amino-6-oxopimelate to N-succinyl-l,l-diaminopimelate, one of the steps in lysine biosynthesis. It is closely related to ornithine aminotransferase. AcOAT was cloned from Salmonella typhimurium and E. coli, overexpressed in E. coli and purified using Ni–NTA affinity column chromatography. The enzymes crystallized in the presence of gabaculine. Crystals of E. coli AcOAT (eAcOAT) only diffracted X-rays to 3.5 Å and were twinned. The crystals of S. typhimurium AcOAT (sAcOAT) diffracted to 1.9 Å and had a dimer in the asymmetric unit. The structure of sAcOAT was solved by the molecular-replacement method.

  1. Cloning of a novel phosphateserine aminotransferase gene from a Triticum aestivum-Elytrigia elongatum alien substitution line with resistance to powdery mildew

    Institute of Scientific and Technical Information of China (English)

    HE Daoyi; WANG Honggang

    2005-01-01

    Shannong 551, a T. aestivum-E. elongatum alien substitution line with resistance to powdery mildew, was inoculated with pathogenic spores of powdery mildew. The leaf samples were prepared 48 h after inoculation for scanning electron microscopy. The result showed that germination of spores and growth of young mycelia on leaves of Shannong 551 were suppressed at the early stage of infection. At the same time, RNAs were prepared from the leaves for the cloning of WRP1 and RPW2 by cDNA RDA and RACE technology. BLAST analysis of the sequences indicated that both WRP1 and RPW2 were novel genes. WRP1 contains no complete ORF. RPW2 contains the conserved structure domain of aminotransferase, and its DNA sequence shares high homology with genes of phosphateserine aminotransferase in many organisms. Therefore, it is speculated as a novel phosphateserine aminotransferase gene. The results of Northern blot suggested that expression of RPW2 occurred at the early stage of infection by powdery mildew. Southern blot using the probe of RPW2, in which there was strong hybridizing signals in both genome of Shannong 551 and E. elongatum, but not in those of Jinan 13 and Lumai No.5, indicated that RPW2 derived from the genome of E. elongatum.

  2. Two mechanisms for putrescine-dependent transcriptional expression of the putrescine aminotransferase gene, ygjG, in Escherichia coli.

    Science.gov (United States)

    Kim, Young-Sik; Shin, Hyun-Chul; Lee, Jong-Ho

    2014-09-01

    In this study, on evaluating the physiological function and mechanism of putrescine, we found that putrescine supplementation (1 mM) increases transcription of the putrescine aminotransferase gene, ygjG. Putrescine-dependent expression was confirmed by measuring β-galactosidase activity and with reverse transcription-polymerase chain reaction. To understand the role of putrescine in ygjG expression, we genetically characterized and found that a knockout mutation in an alternative sigma factor, rpoS, abolished putrescine-dependent ygjG-lacZ expression. In the rpoS mutant, RpoS overexpression complemented the mutant phenotype. However, RpoS overexpression induced ygjG-lacZ expression with putrescine supplementation but not without supplementation. We also found that the loss of putrescine-dependent ygjG-lacZ expression induced by rpoS was completely restored under nitrogen-starvation conditions. The putrescine-dependent expression of ygjG-lacZ under this condition was clearly dependent on another alternative sigma factor, rpoN, and its cognate activator ntrC. These results show that rpoS is required for putrescine-dependent ygjG-lacZ expression, but the effect of putrescine on this expression is not caused by simple modulation of RpoS synthesis. Putrescine-dependent expression of ygjG-lacZ was controlled by at least two sigma factors: rpoS under excess nitrogen conditions and rpoN under nitrogen-starvation conditions. These results suggest that putrescine plays an important role in the nitrogen regulation system.

  3. Characterization of five putative aspartate aminotransferase genes in the N2-fixing heterocystous cyanobacterium Anabaena sp. strain PCC 7120.

    Science.gov (United States)

    Xu, Xinyi; Gu, Liping; He, Ping; Zhou, Ruanbao

    2015-06-01

    Aspartate and glutamate are two key amino acids used in biosynthesis of many amino acids that play vital role in cellular metabolism. Aspartate aminotransferases (AspATs) are required for channelling nitrogen (N(2)) between Glu and Asp in all life forms. Biochemical and genetic characterization of AspATs have been lacking in N(2)-fixing cyanobacteria. In this report, five putative AspAT genes (alr1039, all2340, alr2765, all4327 and alr4853) were identified in the N(2)-fixing heterocystous cyanobacterium Anabaena sp. PCC 7120. Five recombinant C-terminal hexahistidine-tagged AspATs (AspAT-H(6)) were overexpressed in Escherichia coli and purified to homogeneity. Biochemical analysis demonstrated that these five putative AspATs have authentic AspAT activity in vitro using aspartate as an amino donor. However, the enzymic activities of the five AspATs differed in vitro. Alr4853-H(6) showed the highest AspAT activity, while the enzymic activity for the other four AspATs ranged from 6.5 to 53.7 % activity compared to Alr4853 (100 %). Genetic characterization of the five AspAT genes was also performed by inactivating each individual gene. All of the five AspAT knockout mutants exhibited reduced diazotrophic growth, and alr4853 was further identified to be a Fox gene (requiring fixed N(2) for growth in the presence of oxygen). Four out of five P(aspAT)-gfp transcriptional fusions were constitutively expressed in both diazotrophic and nitrate-dependent growth conditions. Quantitative reverse transcriptase PCR showed that alr4853 expression was increased by 2.3-fold after 24 h of N(2) deprivation. Taken together, these findings add to our understanding of the role of AspATs in N(2)-fixing within heterocystous cyanobacteria.

  4. Saccharomyces cerevisiae Bat1 and Bat2 aminotransferases have functionally diverged from the ancestral-like Kluyveromyces lactis orthologous enzyme.

    Directory of Open Access Journals (Sweden)

    Maritrini Colón

    Full Text Available BACKGROUND: Gene duplication is a key evolutionary mechanism providing material for the generation of genes with new or modified functions. The fate of duplicated gene copies has been amply discussed and several models have been put forward to account for duplicate conservation. The specialization model considers that duplication of a bifunctional ancestral gene could result in the preservation of both copies through subfunctionalization, resulting in the distribution of the two ancestral functions between the gene duplicates. Here we investigate whether the presumed bifunctional character displayed by the single branched chain amino acid aminotransferase present in K. lactis has been distributed in the two paralogous genes present in S. cerevisiae, and whether this conservation has impacted S. cerevisiae metabolism. PRINCIPAL FINDINGS: Our results show that the KlBat1 orthologous BCAT is a bifunctional enzyme, which participates in the biosynthesis and catabolism of branched chain aminoacids (BCAAs. This dual role has been distributed in S. cerevisiae Bat1 and Bat2 paralogous proteins, supporting the specialization model posed to explain the evolution of gene duplications. BAT1 is highly expressed under biosynthetic conditions, while BAT2 expression is highest under catabolic conditions. Bat1 and Bat2 differential relocalization has favored their physiological function, since biosynthetic precursors are generated in the mitochondria (Bat1, while catabolic substrates are accumulated in the cytosol (Bat2. Under respiratory conditions, in the presence of ammonium and BCAAs the bat1Δ bat2Δ double mutant shows impaired growth, indicating that Bat1 and Bat2 could play redundant roles. In K. lactis wild type growth is independent of BCAA degradation, since a Klbat1Δ mutant grows under this condition. CONCLUSIONS: Our study shows that BAT1 and BAT2 differential expression and subcellular relocalization has resulted in the distribution of the

  5. Expression of Mitochondrial Branched-Chain Aminotransferase and α-Keto-Acid Dehydrogenase in Rat Brain: Implications for Neurotransmitter Metabolism

    Directory of Open Access Journals (Sweden)

    Jeffrey Thomas Cole

    2012-05-01

    Full Text Available In the brain, metabolism of the essential branched chain amino acids (BCAAs leucine, isoleucine and valine, is regulated in part by protein synthesis requirements. Excess BCAAs are catabolized or excreted. The first step in BCAA catabolism is catalyzed by the branched chain aminotransferase (BCAT isozymes, mitochondrial BCATm and cytosolic BCATc. A product of this reaction, glutamate, is the major excitatory neurotransmitter and precursor of the major inhibitory neurotransmitter -aminobutyric acid (GABA. The BCATs are thought to participate in an α-keto-acid nitrogen shuttle that provides nitrogen for synthesis of glutamate from -ketoglutarate. The branched-chain α-keto acid dehydrogenase enzyme complex (BCKDC catalyzes the second and first irreversible step in BCAA metabolism, which is oxidative decarboxylation of the branched-chain α-keto acid (BCKA products of the BCAT reaction. Maple Syrup Urine Disease (MSUD results from genetic defects in BCKDC, which leads to accumulation of toxic levels of BCAAs and BCKAs that result in brain swelling. Immunolocalization of BCATm and BCKDC in rats revealed that BCATm is present in astrocytes in white matter and in neuropil, while BCKDC is expressed only in neurons. BCATm appears uniformly distributed in astrocyte cell bodies throughout the brain. The segregation of BCATm to astrocytes and BCKDC to neurons provides further support for the existence of a BCAA-dependent glial-neuronal nitrogen shuttle since the data show that BCKAs produced by glial BCATm must be exported to neurons. Additionally, the neuronal localization of BCKDC suggests that MSUD is a neuronal defect involving insufficient oxidation of BCKAs, with secondary effects extending beyond the neuron.

  6. Design of Deinococcus radiodurans thioredoxin reductase with altered thioredoxin specificity using computational alanine mutagenesis.

    Science.gov (United States)

    Obiero, Josiah; Sanders, David A R

    2011-06-01

    In this study, the X-ray crystal structure of the complex between Escherichia coli thioredoxin reductase (EC TrxR) and its substrate thioredoxin (Trx) was used as a guide to design a Deinococcus radiodurans TrxR (DR TrxR) mutant with altered Trx specificity. Previous studies have shown that TrxRs have higher affinity for cognate Trxs (same species) than that for Trxs from different species. Computational alanine scanning mutagenesis and visual inspection of the EC TrxR-Trx interface suggested that only four residues (F81, R130, F141, and F142) account for the majority of the EC TrxR-Trx interface stability. Individual replacement of equivalent residues in DR TrxR (M84, K137, F148, and F149) with alanine resulted in drastic changes in binding affinity, confirming that the four residues account for most of TrxR-Trx interface stability. When M84 and K137 were changed to match equivalent EC TrxR residues (K137R and M84F), the DR TrxR substrate specificity was altered from its own Trx to that of EC Trx. The results suggest that a small subset of the TrxR-Trx interface residues is responsible for the majority of Trx binding affinity and species-specific recognition.

  7. Role of tRNAPro in pretransfer editing of alanine by prolyl-tRNA synthetase

    Directory of Open Access Journals (Sweden)

    Boyarshin K. S.

    2013-09-01

    Full Text Available Aim. To characterize the process of tRNA-dependent pretransfer edi- ting of alanine by prolyl-tRNA synthetase of bacteria Enterococcus faecalis (ProRSEf. Methods. Velocity of the editing processes in vitro was determined by ATP hydrolysis by ProRSEf. Pretransfer and posttransfer editing were experimentally separated by site-directed mutagenesis. Results. tRNA-dependent pretransfer editing is characterized by three-fold larger velocity then tRNA-independent editing. Effectivity of the process depends on the presence of 2'-hydroxyle group of A76 tRNAPro. In the absence of tRNAPro selective release of alanyl-AMP occurs simultaneously with tRNA-independent pretransfer editing. Released alanyl-AMP can be re-bound and hydrolyzed. Conclusions. tRNA-dependent pretransfer editing of alanine by ProRSEf is the catalytic mechanism, mediated by 2'-hydroxyl group of A76 tRNAPro. In the absence of tRNAPro tRNA-independent pretransfer editing and selective release of alanyl-AMP occur.

  8. Advancements in accuracy of the alanine dosimetry system. Part 2. The influence of the irradiation temperature

    Science.gov (United States)

    Nagy, Vitaly; Puhl, James M.; Desrosiers, Marc F.

    2000-01-01

    Systematic measurements of the temperature coefficient for alanine electron paramagnetic resonance (EPR) response have been performed for irradiation in the temperature range (10-50)°C and in the absorbed dose range (1-100) kGy at the dose rate 9.5 kGy/h. During the 60Co rad -ray irradiation, rad - L-alanine dosimeters were kept in a sealed aluminum holder that provided an effective heat exchange with the temperature-controlled environment. The time between the irradiation and signal measurements was standardized, and a reference sample fixed in the resonant cavity was used to correct the signals for small variations in the spectrometer sensitivity. The temperature coefficient for each dose was determined from approximately 30 experimental points processed by the weighted least-squares technique after the necessary statistical tests were done. The temperature coefficients thus determined were considerably lower than previously reported. The dose dependence of the temperature coefficient features a minimum at (20-30) kGy (about 0.135%/K) with higher values at 1 kGy (0.17%/K) and at 100 kGy ((0.175-0.19) %/K). With the exception of very high doses, no significant distinction was found between the temperature coefficients of Bruker and NIST dosimeters, which differ in shape and binder content.

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

    Directory of Open Access Journals (Sweden)

    Michael Wierer

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

  10. Ibalizumab-human CD4 receptor interaction: computational alanine scanning molecular dynamics studies.

    Science.gov (United States)

    Su, Zhi-Yuan

    2014-01-01

    Antibody drugs are used in the treatment of many chronic diseases. Recently, however, patients and doctors have encountered problems with drug resistance, and improving the affinity of antibody drugs has therefore become a pressing issue. Ibalizumab is a humanized monoclonal antibody that binds human CD4, the primary receptor for human immunodeficiency virus type 1 (HIV-1). In this study, we sought to identify the key residues of the complementaritydetermining regions (CDRs) of ibalizumab. Virtual alanine mutations (complementarity-determining regions of ibalizumab) were also studied using solvated interaction energies derived from molecular dynamics and the explicit water model. Using 1,000 nanosecond molecular dynamic simulations, we identified six residues: Tyr50 [HCDR2], Tyr53 [HCDR3], Asp58 [HCDR2], Glu95 [HCDR2], and Arg95 [LCDR3]. The Robetta alanine-scanning mutagenesis method and crystallographic information were used to verify our simulations. Our simulated binding affinity of -17.33 kcal/mol is close to the experimentally determined value of -16.48 kcal/mol. Our findings may be useful for protein engineering the structure of the ibalizumab-human CD4 receptor complex. Moreover, the six residues that we identified may play a significant role in the development of bioactive antibody analogues.

  11. Characterization and biocompatibility of organogels based on L-alanine for parenteral drug delivery implants.

    Science.gov (United States)

    Motulsky, Aude; Lafleur, Michel; Couffin-Hoarau, Anne-Claude; Hoarau, Didier; Boury, Frank; Benoit, Jean-Pierre; Leroux, Jean-Christophe

    2005-11-01

    The development of simple and efficient drug delivery systems for the sustained release of peptides/proteins and low molecular weight hydrophilic molecules is an ongoing challenge. The purpose of this work was to prepare and characterize novel biodegradable in situ-forming implants obtained via the self-assembly of L-alanine derivatives in pharmaceutical oils. Six different amphiphilic organogelators based on L-alanine were synthesized. These derivatives could successfully gel various vegetable and synthetic oils approved for parenteral administration. Gelation was thermoreversible, and phase transition temperatures depended on gelator structure, concentration and solvent. Hydrogen bonds and van der Waals interactions were shown to be the main forces implicated in network formation. Selected formulations were then injected subcutaneously in rats for preliminary assessment of biocompatibility. Histopathological analysis of the surrounding tissues revealed mild, chronic inflammation and an overall good biocompatibility profile of the implants over the 8 wk evaluation period. This study demonstrates that in situ-forming organogels represent a potentially promising platform for sustained drug delivery.

  12. Polarizable Simulations with Second order Interaction Model (POSSIM) force field: Developing parameters for alanine peptides and protein backbone

    Science.gov (United States)

    Ponomarev, Sergei Y.; Kaminski, George A.

    2011-01-01

    A previously introduced POSSIM (POlarizable Simulations with Second order Interaction Model) force field has been extended to include parameters for alanine peptides and protein backbones. New features were introduced into the fitting protocol, as compared to the previous generation of the polarizable force field for proteins. A reduced amount of quantum mechanical data was employed in fitting the electrostatic parameters. Transferability of the electrostatics between our recently developed NMA model and the protein backbone was confirmed. Binding energy and geometry for complexes of alanine dipeptide with a water molecule were estimated and found in a good agreement with high-level quantum mechanical results (for example, the intermolecular distances agreeing within ca. 0.06Å). Following the previously devised procedure, we calculated average errors in alanine di- and tetra-peptide conformational energies and backbone angles and found the agreement to be adequate (for example, the alanine tetrapeptide extended-globular conformational energy gap was calculated to be 3.09 kcal/mol quantim mechanically and 3.14 kcal/mol with the POSSIM force field). However, we have now also included simulation of a simple alpha-helix in both gas-phase and water as the ultimate test of the backbone conformational behavior. The resulting alanine and protein backbone force field is currently being employed in further development of the POSSIM fast polarizable force field for proteins. PMID:21743799

  13. Topology of AspT, the Aspartate:Alanine Antiporter of Tetragenococcus halophilus, Determined by Site-Directed Fluorescence Labeling▿ †

    OpenAIRE

    Nanatani, Kei; Fujiki, Takashi; Kanou, Kazuhiko; Takeda-Shitaka, Mayuko; Umeyama, Hideaki; Ye, Liwen; Wang, Xicheng; Nakajima, Tasuku; Uchida, Takafumi; Maloney, Peter C.; Abe, Keietsu

    2007-01-01

    The gram-positive lactic acid bacterium Tetragenococcus halophilus catalyzes the decarboxylation of l-aspartate (Asp) with release of l-alanine (Ala) and CO2. The decarboxylation reaction consists of two steps: electrogenic exchange of Asp for Ala catalyzed by an aspartate:alanine antiporter (AspT) and intracellular decarboxylation of the transported Asp catalyzed by an l-aspartate-β-decarboxylase (AspD). AspT belongs to the newly classified aspartate:alanine exchanger family (transporter cla...

  14. Beta-alanine-oxalic acid (1:1) hemihydrate crystal: structure, 13C NMR and vibrational properties, protonation character.

    Science.gov (United States)

    Godzisz, D; Ilczyszyn, M; Ilczyszyn, M M

    2003-03-01

    The crystal structure of beta-alanine-oxalic acid (1:1) hemihydrate complex has been reinvestigated by X-ray diffraction method at 293 K. Formation of monoclinic crystal system belonging to C2/c space group and consisting of semi-oxalate chains, diprotonated beta-alanine dimers and water molecules bonded to both these units is confirmed. New results are obtained for distances in the carboxylic groups and hydrogen bonds. These structural observations are used for protonation degree monitoring on the carboxylic oxygen atoms. They are in accordance with our vibrational study. The 13C NMR spectra provide insights into the solid structure of this complex, character of its hydrogen bonds and the beta-alanine protonation.

  15. Global Transcriptional and Physiological Responses of Saccharomyces cerevisiae to Ammonium, L-Alanine, or L-Glutamine Limitation

    DEFF Research Database (Denmark)

    Usaite, Renata; Patil, Kiran Raosaheb; Grotkjær, Thomas;

    2006-01-01

    The yeast Saccharomyces cerevisiae encounters a range of nitrogen sources at various concentrations in its environment. The impact of these two parameters on transcription and metabolism was studied by growing S. cerevisiae in chemostat cultures with L-glutamine, L-alanine, or L-ammonium in limit......The yeast Saccharomyces cerevisiae encounters a range of nitrogen sources at various concentrations in its environment. The impact of these two parameters on transcription and metabolism was studied by growing S. cerevisiae in chemostat cultures with L-glutamine, L-alanine, or L...... activity in L-alanine-limited cells. The changes in these cells were found to be focused around pyruvate, acetyl coenzyme A, glyoxylate, and alpha-ketoglutarate via increased levels of ALT1, DAL7, PYC1, GDH2, and ADH5 and decreased levels of GDH3, CIT2, and ACS1 transcripts. The transcript profiles were...

  16. Adaptive regulation of taurine and beta-alanine uptake in a human kidney cell line from the proximal tubule

    DEFF Research Database (Denmark)

    Jessen, H; Jacobsen, Christian

    1997-01-01

    homeostasis occurs predominantly via changes in the activity of the high-affinity taurine transport system by alterations in the uptake capacity and with an unaffected half-saturation constant. An adaptive response was not observed for the structurally related beta-alanine. 3. Only colchicine, which......), mimicking the effects of diacylglycerol, induced inhibition of both beta-alanine and taurine uptake. By contrast, the Ca2(+)-ionophore A23187, mimicking the effects of IP3, only stimulated the uptake of taurine but not the influx of beta-alanine. However, the effect of PMA down-regulation and A23187 up......1. The underlying mechanisms involved in the adaptive regulation of beta-amino acid uptake in the human proximal tubule were examined by use of an immortalized human embryonic kidney epithelial cell line (IHKE). 2. The results indicated that the adaptive response to maintain whole-body taurine...

  17. Effect of mammals’ excretory function on aspartate aminotransferase activity in Glechoma hederacea leaves in conditions of Cd pollution

    Directory of Open Access Journals (Sweden)

    O. M. Vasilyuk

    2014-07-01

    Full Text Available The paper includes analysis of research of Cd impact on the activity of the enzyme of aspartate aminotransferase (AST nitrogen metabolism and the content of water-soluble protein fraction (albumin in Glechoma hederacea L. leaves, which dominated in the research area (in natural floodplain oak forest with Stellaria holostea L.. Cd was introduced in the form of salts of Cd(NO32 in the range of concentrations of: 0.25, 1.25, 2.5 g/m2, equivalent to the inclusion of Cd in 1, 5, 10 doses of MAC. Increase (P < 0.05 in the activity of AST 2.6–3.0 times (with adding Cd salts at a dose of 1 and 5 МAС and albumin content by 37% (with adding Cd salts at a dose of 10 МAС compared to control (the area without Cd pollution and excretory activity of mammals was shown. Using of excreta of some representatives of mammals (for example, Capreolus capreolus L. contributed to reduction of Cd toxic effects and restoring of the functional metabolic activity of AST by 23% (with Cd 1 МAС and by 34% (Cd 5 МAС. It is the evidence of protective function of mammals and their normalization effect at the above concentrations of Cd. Whereas the adding of Cd salts at a dose of 10 МAС led to 3 times’ inhibition of AST activity, the toxic effect of metal by excretory function of mammals was not reduced. Observations revealed the albumin content normalization by 22% in the presence of Cd 1MAC respectively (with the introduction of C. capreolus excreta and to the control level (the area without Cd pollution and excretory activity of mammals with the excreta of Sus scrofa L. in the setting of Cd 10 MAC. It proves the need to use the different mammal species for integrated and comprehensive normalization of ecosystems under conditions of uncontrolled anthropogenic pollution.

  18. Mechanism of Substrate Recognition And PLP-Induced Conformational Changes in II-Diaminopimelate Aminotransferase From Arabidopsis Thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, N.; Clay, M.D.; Belkum, M.J.van; Cherney, M.M.; Vederas, J.C.; James, M.N.G.

    2009-05-26

    LL-Diaminopimelate aminotransferase (LL-DAP-AT), a pyridoxal phosphate (PLP)-dependent enzyme in the lysine biosynthetic pathways of plants and Chlamydia, is a potential target for the development of herbicides or antibiotics. This homodimeric enzyme converts L-tetrahydrodipicolinic acid (THDP) directly to LL-DAP using L-glutamate as the source of the amino group. Earlier, we described the 3D structures of native and malate-bound LL-DAP-AT from Arabidopsis thaliana (AtDAP-AT). Seven additional crystal structures of AtDAP-AT and its variants are reported here as part of an investigation into the mechanism of substrate recognition and catalysis. Two structures are of AtDAP-AT with reduced external aldimine analogues: N-(5'-phosphopyridoxyl)-L-glutamate (PLP-Glu) and N-(5'-phosphopyridoxyl)- LL-Diaminopimelate (PLP-DAP) bound in the active site. Surprisingly, they reveal that both L-glutamate and LL-DAP are recognized in a very similar fashion by the same sets of amino acid residues; both molecules adopt twisted V-shaped conformations. With both substrates, the {alpha}-carboxylates are bound in a salt bridge with Arg404, whereas the distal carboxylates are recognized via hydrogen bonds to the well-conserved side chains of Tyr37, Tyr125 and Lys129. The distal C{sup {var_epsilon}} amino group of LL-DAP is specifically recognized by several non-covalent interactions with residues from the other subunit (Asn309*, Tyr94*, Gly95*, and Glu97* (Amino acid designators followed by an asterisk (*) indicate that the residues originate in the other subunit of the dimer)) and by three bound water molecules. Two catalytically inactive variants of AtDAP-AT were created via site-directed mutagenesis of the active site lysine (K270N and K270Q). The structures of these variants permitted the observation of the unreduced external aldimines of PLP with L-glutamate and with LL-DAP in the active site, and revealed differences in the torsion angle about the PLP-substrate bond

  19. 血清a-L-岩藻糖苷酶、γ-谷氨酰转移酶、碱性磷酸酶和同型半胱氨酸联合检测对原发性肝癌的诊断价值%Clinical value of combination of AFU, GGT, ALP and Hcy for diagnosis in patients with primary hepatocarcinoma

    Institute of Scientific and Technical Information of China (English)

    黄义强; 刘斌; 张永辉

    2011-01-01

    目的 探讨血清a-L-岩藻糖苷酶(a-L-fucosidase,AFU)、γ-谷氨酰转移酶(r-utamyl transferase,GGT)、碱性磷酸酶(alkaline phosphatase,ALP)和同型半胱氨酸(homocysteine,Hcy)对原发性肝癌(primary hepatocarcinoma,PHC)的诊断价值.方法 联合检测96例原发性肝癌、65例良性肝病和50例健康人血清A-FU、GGT、ALP和Hcy,并分析水平差异.结果 原发性肝癌患者血清AFU、GGT、ALP和Hcy水平及阳性率均明显高于良性肝病组及正常对照组(P<0.05);联合检测的敏感性和诊断准确性均比单项检测高.结论 联合检测AFU、GGT、ALP和Hcy对原发性肝癌的诊断有重要价值.

  20. Significance of Combineddetecting Serum α-L-fucosidase (AFU), alpha-fetoprotein (AFP) andγ-glutamyl peptidase (GGT) for Earlydiagnosis ofhepatocellular Carcinoma (PHC)%AFP、AFU、GGT联合检测在原发性肝癌诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    安哲; 李伟; 屈梦

    2011-01-01

    目的 探讨血清α-L-岩藻糖苷酶(AFU)、甲胎蛋白(AFP)和γ-谷氨酰转肽酶(GGT)联合检测对提高原发性肝癌(PHC)阳性检出率的意义.方法 对50例原发性肝癌患者、30例肝硬化(LC)患者及30例健康人以AFP的检测为主体,配合GGT、AFU进行检测,优化组合,分析联检的结果.结果 AFP、AFU、GGT三项指标对PHC的阳性检出率分别为74%,82%,70%,AFP+AFU+GGT检测总阳性率达到98.85%,PHC组AFU、AFP与LC组和正常对照组均差异有显著性(P<0.05),LC组AFU、AFP、GGT与正常对照组比较差异有显著性(P<0.05).结论 应用AFU、AFP、GGT联合检测与AFP单项检测相比,PHC的诊断率明显提高.

  1. Plasmid-encoded asp operon confers a proton motive metabolic cycle catalyzed by an aspartate-alanine exchange reaction.

    Science.gov (United States)

    Abe, Keietsu; Ohnishi, Fumito; Yagi, Kyoko; Nakajima, Tasuku; Higuchi, Takeshi; Sano, Motoaki; Machida, Masayuki; Sarker, Rafiquel I; Maloney, Peter C

    2002-06-01

    Tetragenococcus halophila D10 catalyzes the decarboxylation of L-aspartate with nearly stoichiometric release of L-alanine and CO(2). This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an L-aspartate-beta-decarboxylase (AspD) and an aspartate-alanine antiporter (AspT), respectively, and determined the nucleotide sequences. The sequence analysis revealed that the genes of the asp operon in pD1 were in the following order: promoter --> aspD --> aspT. The deduced amino acid sequence of AspD showed similarity to the sequences of two known L-aspartate-beta-decarboxylases from Pseudomonas dacunhae and Alcaligenes faecalis. Hydropathy analyses suggested that the aspT gene product encodes a hydrophobic protein with multiple membrane-spanning regions. The operon was subcloned into the Escherichia coli expression vector pTrc99A, and the two genes were cotranscribed in the resulting plasmid, pTrcAsp. Expression of the asp operon in E. coli coincided with appearance of the capacity to catalyze the decarboxylation of aspartate to alanine. Histidine-tagged AspD (AspDHis) was also expressed in E. coli and purified from cell extracts. The purified AspDHis clearly exhibited activity of L-aspartate-beta-decarboxylase. Recombinant AspT was solubilized from E. coli membranes and reconstituted in proteoliposomes. The reconstituted AspT catalyzed self-exchange of aspartate and electrogenic heterologous exchange of aspartate with alanine. Thus, the asp operon confers a proton motive metabolic cycle consisting of the electrogenic aspartate-alanine antiporter and the aspartate decarboxylase, which keeps intracellular levels of alanine, the countersubstrate for aspartate, high.

  2. Kinetics and Mechanism of Oxidation of Leucine and Alanine by Ag(III Complex in Alkaline Medium

    Directory of Open Access Journals (Sweden)

    Changying Song

    2008-01-01

    Full Text Available Kinetics and mechanism of oxidation of leucine and alanine by Ag(III complex were studied spectrophotometrically in alkaline medium at constant ion strength. The reaction was in first order with respect to Ag(III complex and amino acids (leucine, alanine. The second-order rate constant, k−, decreased with the increasing in [OH−] and [IO4−]. A plausible mechanism was proposed from the kinetics study, and the rate equations derived from mechanism can explain all experimental phenomena. The activation parameters were calculated at 298.2 K.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cavaignac, A.L.O. [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Lima, R.J.C., E-mail: ricardo.lima.ufma@gmail.com [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Façanha Filho, P.F. [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Moreno, A.J.D. [Coordenação de Ciências Naturais, Universidade Federal do Maranhão, Bacabal, MA 65700-000 (Brazil); Freire, P.T.C. [Departamento de Física, Universidade Federal do Ceará, Fortaleza, CE 60455-760 (Brazil)

    2016-03-01

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

  4. Plasmid-Encoded asp Operon Confers a Proton Motive Metabolic Cycle Catalyzed by an Aspartate-Alanine Exchange Reaction

    OpenAIRE

    Abe, Keietsu; Ohnishi, Fumito; Yagi, Kyoko; Nakajima, Tasuku; Higuchi, Takeshi; Sano, Motoaki; Machida, Masayuki; Sarker, Rafiquel I.; Maloney, Peter C.

    2002-01-01

    Tetragenococcus halophila D10 catalyzes the decarboxylation of l-aspartate with nearly stoichiometric release of l-alanine and CO2. This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an l-aspartate-β-decarboxylase (AspD) and an aspartate-alanine antiporter (AspT), respectively, and determined the nucleotide sequences. The sequence analysis revealed that the genes of the asp operon i...

  5. A Thermochemical Study of the Reaction of Lanthanum Nitrate with Alanine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The standard molar reaction enthalpy of the solid-solid coordination reaction La(NO3)3 ·6H2O (s) +4Ala(s) (Ala is Alanine)=La(NO3)3 · (Ala)4 · H2O(s) + 5H2O(1) was studied byusing classical solution calorimetry. The molar dissolution enthalpies of the reactants and theproduct of the solid-solid coordination reaction in 2 mol/L HCl were measured by using anisoperibol calorimeter. From the results and other auxiliary quantities, the standard molar formation enthalpy of [La (NO3)3 · (Ala)4 · H2O, s, 298. 15 K] has been determined to be△fHm [La(NO3)3 · (Ala)4 · H2O, s, 298. 15 K]=-3 864. 248 kJ/mol.

  6. Growth and Characterization of Pure and Doped L-Alanine Tartrate Single Crystals

    Directory of Open Access Journals (Sweden)

    K. Rajesh

    2013-01-01

    Full Text Available Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were analyzed by FT-IR spectroscopy. Using Vickers microhardness tester, mechanical strength of the material was found. Dielectric studies of pure and doped LAT single crystals were carried out. The doped LAT crystal is found to have efficiency higher than that of pure LAT crystal.

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

    Science.gov (United States)

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

    2011-10-01

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

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

    Science.gov (United States)

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

    2016-05-01

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

  9. Dosimetry auditing procedure with alanine dosimeters for light ion beam therapy

    DEFF Research Database (Denmark)

    Ableitinger, Alexander; Vatnitsky, Stanislav; Herrmann, Rochus

    2013-01-01

    verification aimed at measuring a dose of 10 Gy homogeneously delivered to a virtual-target volume of 8 × 8 × 12 cm3. In order to interpret the readout of the irradiated alanine dosimeters additional Monte Carlo simulations were performed to calculate the energy dependent detector response of the particle......Background and purpose In the next few years the number of facilities providing ion beam therapy with scanning beams will increase. An auditing process based on an end-to-end test (including CT imaging, planning and dose delivery) could help new ion therapy centres to validate their entire logistic...... chain of radiation delivery. An end-to-end procedure was designed and tested in both scanned proton and carbon ion beams, which may also serve as a dosimetric credentialing procedure for clinical trials in the future. The developed procedure is focused only on physical dose delivery and the validation...

  10. Assessment of an alanine EPR dosimetry technique with enhanced precision and accuracy

    CERN Document Server

    Hayes, R B; Wieser, A; Romanyukha, A A; Hardy, B L; Barrus, J K

    2000-01-01

    Dose reconstruction in the course of a series of blind tests demonstrated that an accuracy of 10 mGy for low doses and 1% for high doses can be achieved using EPR spectroscopy. This was accomplished using a combination of methodologies including polynomial filtration of the EPR spectrum, dosimeter rotation during scanning, use of an EPR standard fixed into the resonator and subtraction of all nonradiogenic signals. Doses were reconstructed over the range of 0.01-1000 Gy using this compound spectral EPR analysis. This EPR technique, being equally applicable to fractionated doses (such as those delivered during multiple radiotherapy treatments), was verified to exhibit dose reciprocity. Irradiated alanine dosimeters which were stored exhibited compound spectral EPR signal fading of ca 3% over 9 months. All error estimates given in this paper are given at the 1 standard deviation level and unless otherwise specified do not account for uncertainties in source calibration.

  11. Excitatory amino acid b-N-methylamino-L-alanine is a putative environmental neurotoxin

    Directory of Open Access Journals (Sweden)

    VLADIMIR NEDELJKOV

    2011-04-01

    Full Text Available The amino acid b-N-methylamino-L-alanine (L-BMAA has been associated with the amyotrophic lateral sclerosis/parkinsonism-dementia complex in three distinct western Pacific populations. The putative neurotoxin is produced by cyanobacteria, which live symbiotically in the roots of cycad trees. L-BMAA was thought to be a threat only to those few populations whose diet and medicines rely heavily on cycad seeds. However, the recent discovery that cyanobacteria from diverse terrestrial, freshwater, and saltwater ecosystems around the world produce the toxin requires a reassessment of whether it poses a larger health threat. Therefore, it is proposed that monitoring L-BMAA levels in cyanobacteria-contaminated water supplies might be prudent.

  12. Ste20-related proline/alanine-rich kinase: A novel regulator of intestinal inflammation

    Institute of Scientific and Technical Information of China (English)

    Yutao Yan; Didier Merlin

    2008-01-01

    Recently, inflammatory bowel disease (IBD) has been the subject of considerable research, with increasing attention being paid to the loss of intestinal epithelial cell barrier function as a mechanism of pathogenesis. Ste20-related proline/alanine-rich kinase (SPAK) is involved in regulating barrier function. SPAK is known to interact with inflammation-related kinases (such as p38, JNK, NKCC1, PKCθ, WNK and MLCK), and with transcription factor AP-1, resulting in diverse biological phenomena, including cell differentiation, cell transformation and proliferation, cytoskeleton rearrangement, and regulation of chloride transport. This review examines the involvement of Ste20-like kinases and downstream mitogen-activated protein kinases (MAPKs) pathways in the pathogenesis and control of intestinal inflammation. The primary focus will be on the molecular features of intestinal inflammation, with an emphasis on the interaction between SPAK and other molecules, and the effect of these interactions on homeostatic maintenance, cell volume regulation and increased cell permeability in intestinal inflammation.

  13. Formation Equilibria of Ternary Metal Complexes with Citric Acid and Glutamine (Alanine) in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    王进平; 牛春吉; 杨魁跃; 倪嘉缵

    2004-01-01

    The species and their formation constants in the ternary systems were obtained by the Scogs2 software from potentiometric titration data. The Comics software was used to calculate the distribution of species in the ternary systems. MLXH, MLXH2 and MLXH3 are the common species in these systems. The coordination behaviors of the rare earths are very similar and their stability is closely matched. The ternary rare earth complexes are more stable than the corresponding ternary complexes of calcium. The ternary zinc complex with glutamine as the secondary ligand is more stable than the corresponding complexes of rare earths, but the ternary complex with alanine as the secondary ligand shows an inverse trend. The distributions of species in the ternary systems vary with pH changing. A prediction can be made that exogenous rare earths can affect the species of Ca and Zn in human body.

  14. Eight-alanine duplication in homeobox D13 in a Chinese family with synpolydactyly.

    Science.gov (United States)

    Xin, Qian; Li, Lin; Li, Jiangxia; Qiu, Rongfang; Guo, Chenhong; Gong, Yaoqin; Liu, Qiji

    2012-05-10

    Human synpolydactyly (SPD), belonging to syndactyly (SD) II, is an inherited autosomal-dominant limb malformation characterized by SD of finger 3 or 4 or toe 4 or 5, usually with digit duplication. Previous studies have demonstrated that homeobox protein D13 (HOXD13) is responsible for this Mendelian disorder. In this paper, we report on a family with SPD - 7 members show typical SPD malformations. We used PCR and Sanger sequencing of DNA from peripheral blood samples and found an 8-Ala expansion in exon 1 of HOXD13 by mutation detection; this variant was absent in unaffected members and in 50 unaffected non-related subjects. This study further confirmed the correlation between SPD and alanine expansion in HOXD13.

  15. Yeast beta-alanine synthase shares a structural scaffold and origin with dizinc-dependent exopeptidases

    DEFF Research Database (Denmark)

    Lundgren, S.; Gojkovic, Zoran; Piskur, Jure

    2003-01-01

    beta-Alanine synthase (betaAS) is the final enzyme of the reductive pyrimidine catabolic pathway, which is responsible for the breakdown of pyrimidine bases, including several anticancer drugs. In eukaryotes, betaASs belong to two subfamilies, which exhibit a low degree of sequence similarity. We...... determined the structure of betaAS from Saccharomyces kluyveri to a resolution of 2.7 Angstrom. The subunit of the homodimeric enzyme consists of two domains: a larger catalytic domain with a dizinc metal center, which represents the active site of betaAS, and a smaller domain mediating the majority...... of the intersubunit contacts. Both domains exhibit a mixed alpha/beta-topology. Surprisingly, the observed high structural homology to a family of dizinc-dependent exopeptidases suggests that these two enzyme groups have a common origin. Alterations in the ligand composition of the metal-binding site can be explained...

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

    Science.gov (United States)

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

    2014-12-01

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

  17. Synthesis of {sup 15}N isotope labeled alanine; Sintese da alanina enriquecida com {sup 15}N

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Claudineia R. de; Bendassolli, Jose Albertino; Sant' Ana, Carlos Roberto; Tagliassachi, Romulo Barbieri; Maximo, Everaldo; Prestes, Clelber Vieira [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Dept. de Isotopos Estaveis]. E-mail: crolivei@cena.usp.br

    2005-07-01

    The application of light chemical elements and their stable isotopes in biological studies have been increased over the last years. The use of {sup 15}N labeled amino acids is an important tool for elucidation of peptides structures. This paper describe a method for the synthesis of {sup 15}N isotope labeled alanine at lower costs than international ones, as well as the details of the recovery system of the nitrogen residues. In the present work an amination of {alpha}-haloacids, with the bromopropionic carboxylic acid and labeled aqua ammonia ({sup 15}NH{sub 3} aq) was carried out. In order to avoid eventually losses of {sup 15}NH{sub 3}, special cares were adopted, since the production cost is high. Although the acquisition cost of the {sup 13}N (radioactive) labeled compounds is lower, the obtained stable tracer will allow the accomplishment of important studies of the nitrogen cycling in living things, less occupational and environment hazards, and the time limitation problems in field studies. The tests took place in triplicates with NH{sub 3} (aq) being employed. With the establishment of the system for {sup 15}NH{sub 3} recovery, an average of 94 % of the ammonia employed in the synthesis process was recovered. The purity of the amino acid was state determined by TLC (Thin Layer Chromatography) and HPLC (High-Performance Liquid Chromatography) with a fluorescence detector. The Rf and the retention time of the synthesized sample were similar the sigma standard. Finally, regarding the established conditions, it was possible to obtain the alanine with a production cost about 40 % lower than the international price. (author)

  18. Alanine mutagenesis of the primary antigenic escape residue cluster, c1, of apical membrane antigen 1.

    Science.gov (United States)

    Dutta, Sheetij; Dlugosz, Lisa S; Clayton, Joshua W; Pool, Christopher D; Haynes, J David; Gasser, Robert A; Batchelor, Adrian H

    2010-02-01

    Antibodies against apical membrane antigen 1 (AMA1) inhibit invasion of Plasmodium merozoites into red cells, and a large number of single nucleotide polymorphisms on AMA1 allow the parasite to escape inhibitory antibodies. The availability of a crystal structure makes it possible to test protein engineering strategies to develop a monovalent broadly reactive vaccine. Previously, we showed that a linear stretch of polymorphic residues (amino acids 187 to 207), localized within the C1 cluster on domain 1, conferred the highest level of escape from inhibitory antibodies, and these were termed antigenic escape residues (AER). Here we test the hypothesis that immunodampening the C1 AER will divert the immune system toward more conserved regions. We substituted seven C1 AER of the FVO strain Plasmodium falciparum AMA1 with alanine residues (ALA). The resulting ALA protein was less immunogenic than the native protein in rabbits. Anti-ALA antibodies contained a higher proportion of cross-reactive domain 2 and domain 3 antibodies and had higher avidity than anti-FVO. No overall enhancement of cross-reactive inhibitory activity was observed when anti-FVO and anti-ALA sera were compared for their ability to inhibit invasion. Alanine mutations at the C1 AER had shifted the immune response toward cross-strain-reactive epitopes that were noninhibitory, refuting the hypothesis but confirming the importance of the C1 cluster as an inhibitory epitope. We further demonstrate that naturally occurring polymorphisms that fall within the C1 cluster can predict escape from cross-strain invasion inhibition, reinforcing the importance of the C1 cluster genotype for antigenic categorization and allelic shift analyses in future phase 2b trials.

  19. Chiral selectivity of amino acid adsorption on chiral surfaces—The case of alanine on Pt

    Energy Technology Data Exchange (ETDEWEB)

    Franke, J.-H.; Kosov, D. S. [Department of Physics, Campus Plaine - CP 231, Université Libre de Bruxelles, 1050 Brussels (Belgium)

    2015-02-07

    We study the binding pattern of the amino acid alanine on the naturally chiral Pt surfaces Pt(531), Pt(321), and Pt(643). These surfaces are all vicinal to the (111) direction but have different local environments of their kink sites and are thus a model for realistic roughened Pt surfaces. Alanine has only a single methyl group attached to its chiral center, which makes the number of possible binding conformations computationally tractable. Additionally, only the amine and carboxyl group are expected to interact strongly with the Pt substrate. On Pt(531), we study the molecule in its pristine as well as its deprotonated form and find that the deprotonated one is more stable by 0.47 eV. Therefore, we study the molecule in its deprotonated form on Pt(321) and Pt(643). As expected, the oxygen and nitrogen atoms of the deprotonated molecule provide a local binding “tripod” and the most stable adsorption configurations optimize the interaction of this “tripod” with undercoordinated surface atoms. However, the interaction of the methyl group plays an important role: it induces significant chiral selectivity of about 60 meV on all surfaces. Hereby, the L-enantiomer adsorbs preferentially to the Pt(321){sup S} and Pt(643){sup S} surfaces, while the D-enantiomer is more stable on Pt(531){sup S}. The binding energies increase with increasing surface density of kink sites, i.e., they are largest for Pt(531){sup S} and smallest for Pt(643){sup S}.

  20. GMXPBSA 2.0: A GROMACS tool to perform MM/PBSA and computational alanine scanning

    Science.gov (United States)

    Paissoni, C.; Spiliotopoulos, D.; Musco, G.; Spitaleri, A.

    2014-11-01

    GMXPBSA 2.0 is a user-friendly suite of Bash/Perl scripts for streamlining MM/PBSA calculations on structural ensembles derived from GROMACS trajectories, to automatically calculate binding free energies for protein-protein or ligand-protein complexes. GMXPBSA 2.0 is flexible and can easily be customized to specific needs. Additionally, it performs computational alanine scanning (CAS) to study the effects of ligand and/or receptor alanine mutations on the free energy of binding. Calculations require only for protein-protein or protein-ligand MD simulations. GMXPBSA 2.0 performs different comparative analysis, including a posteriori generation of alanine mutants of the wild-type complex, calculation of the binding free energy values of the mutant complexes and comparison of the results with the wild-type system. Moreover, it compares the binding free energy of different complexes trajectories, allowing the study the effects of non-alanine mutations, post-translational modifications or unnatural amino acids on the binding free energy of the system under investigation. Finally, it can calculate and rank relative affinity to the same receptor utilizing MD simulations of proteins in complex with different ligands. In order to dissect the different MM/PBSA energy contributions, including molecular mechanic (MM), electrostatic contribution to solvation (PB) and nonpolar contribution to solvation (SA), the tool combines two freely available programs: the MD simulations software GROMACS and the Poisson-Boltzmann equation solver APBS. All the calculations can be performed in single or distributed automatic fashion on a cluster facility in order to increase the calculation by dividing frames across the available processors. The program is freely available under the GPL license. Catalogue identifier: AETQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETQ_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing

  1. Structural and Functional Characterization of PseC, an Aminotransferase Involved in the Biosynthesis of Pseudaminic Acid, an Essential Flagellar Modification in Helicobacter Pylori

    Energy Technology Data Exchange (ETDEWEB)

    Schoenhofen,I.; Lunin, V.; Julien, J.; Li, Y.; Ajamian, E.; Matte, A.; Cygler, M.; Brisson, J.; Aubry, A.; et al.

    2006-01-01

    Helicobacter pylori flagellin is heavily glycosylated with the novel sialic acid-like nonulosonate, pseudaminic acid (Pse). The glycosylation process is essential for assembly of functional flagellar filaments and consequent bacterial motility. As motility is a key virulence factor for this and other important pathogens, the Pse biosynthetic pathway offers potential for novel therapeutic targets. From recent NMR analyses, we determined that the conversion of UDP-a-D-GlcNAc to the central intermediate in the pathway, UDP-4-amino-4,6-dideoxy-{beta}-L-AltNAc, proceeds by formation of UDP-2-acetamido-2,6-dideoxy-{beta}-L-arabino-4-hexulose by the dehydratase/epimerase PseB (HP0840) followed with amino transfer by the aminotransferase, PseC (HP0366). The central role of PseC in the H. pylori Pse biosynthetic pathway prompted us to determine crystal structures of the native protein, its complexes with pyridoxal phosphate alone and in combination with the UDP-4-amino-4,6-dideoxy-{beta}-L-AltNAc product, the latter being converted to the external aldimine form in the enzyme's active site. In the binding site, the AltNAc sugar ring adopts a 4C1 chair conformation which is different from the predominant 1C4 form found in solution. The enzyme forms a homodimer where each monomer contributes to the active site, and these structures have permitted the identification of key residues involved in stabilization, and possibly catalysis, of the {beta}-L-arabino intermediate during the amino transfer reaction. The essential role of Lys183 in the catalytic event was confirmed by site-directed mutagenesis. This work presents for the first time a nucleotide-sugar aminotransferase co-crystallized with its natural ligand, and in conjunction with the recent functional characterization of this enzyme, will assist in elucidating the aminotransferase reaction mechanism within the Pse biosynthetic pathway.

  2. 3T3 fibroblasts transfected with a cDNA for mitochondrial aspartate aminotransferase express plasma membrane fatty acid-binding protein and saturable fatty acid uptake.

    OpenAIRE

    1995-01-01

    To explore the relationship between mitochondrial aspartate aminotransferase (mAspAT; EC 2.6.1.1) and plasma membrane fatty acid-binding protein (FABPpm) and their role in cellular fatty acid uptake, 3T3 fibroblasts were cotransfected with plasmid pMAAT2, containing a full-length mAspAT cDNA downstream of a Zn(2+)-inducible metallothionein promoter, and pFR400, which conveys methotrexate resistance. Transfectants were selected in methotrexate, cloned, and exposed to increasing methotrexate co...

  3. Synthesis and characterization of gold/alanine nanocomposites with potential properties for medical application as radiation sensors.

    Science.gov (United States)

    Guidelli, Eder José; Ramos, Ana Paula; Zaniquelli, Maria Elisabete D; Nicolucci, Patricia; Baffa, Oswaldo

    2012-11-01

    Radiation dose assessment is essential for several medical treatments and diagnostic procedures. In this context, nanotechnology has been used in the development of improved radiation sensors, with higher sensitivity as well as smaller sizes and energy dependence. This paper deals with the synthesis and characterization of gold/alanine nanocomposites with varying mass percentage of gold, for application as radiation sensors. Alanine is an excellent stabilizing agent for gold nanoparticles because the size of the nanoparticles does not augment with increasing mass percentage of gold, as evidenced by UV-vis spectroscopy, dynamic light scattering, and transmission electron microscopy. X-ray diffraction patterns suggest that the alanine crystalline orientation undergoes alterations upon the addition of gold nanoparticles. Fourier transform infrared spectroscopy indicates that there is interaction between the gold nanoparticles and the amine group of the alanine molecules, which may be the reason for the enhanced stability of the nanocomposite. The application of the nanocomposites as radiation detectors was evaluated by the electron spin resonance technique. The sensitivity is improved almost 3 times in the case of the nanocomposite containing 3% (w/w) gold, so it can be easily tuned by changing the amount of gold nanoparticles in the nanocomposites, without the size of the nanoparticles influencing the radiation absorption. In conclusion, the featured properties, such as homogeneity, nanoparticle size stability, and enhanced sensitivity, make these nanocomposites potential candidates for the construction of small-sized radiation sensors with tunable sensitivity for application in several medical procedures.

  4. Crystal and molecular structure of N-(4-nitrophenyl)-β-alanine--its vibrational spectra and theoretical calculations.

    Science.gov (United States)

    Marchewka, M K; Drozd, M; Janczak, J

    2011-08-15

    The N-(4-nitrophenyl)-β-alanine in crystalline form directly by the addition of 4-nitroaniline to the acrylic acid in aqueous solution has been obtained. The title β-alanine derivative crystallizes in the P2(1)/c space group of monoclinic system with four molecules per unit cell. The X-ray geometry of β-alanine derivative molecule has been compared with those obtained by molecular orbital calculations corresponding to the gas phase. In the crystal the molecules related by an inversion center interact via symmetrically equivalent O-H···O hydrogen bonds with O···O distance of 2.656(2) Å forming a dimeric structure. The dimers of β-alanine derivative weakly interact via N-H···O hydrogen bonds between the H atom of β-amine groups and one of O atom of nitro groups. The room temperature powder vibrational (infrared and Raman) measurements are in accordance with the X-ray analysis. In aqueous solution of 4-nitroaniline and acrylic acid, the double CC bond of vinyl group of acrylic acid breaks as result of 4-nitroaniline addition.

  5. Expression, crystallization and preliminary X-ray crystallographic analysis of alanine racemase from Acinetobacter baumannii OXA-23.

    Science.gov (United States)

    Nguyen, Dinh-Duc; Ngo, Ho-Phuong-Thuy; Hong, Myoung-ki; Pham, Tan-Viet; Lee, Jung Hun; Lee, Jae Jin; Kwon, Dae Beom; Lee, Sang Hee; Kang, Lin-Woo

    2013-09-01

    Acinetobacter baumannii has received much attention owing to its exceptional ability to develop resistance to currently available antibiotics. Alanine racemase (ALR) catalyzes the racemization of L-alanine to D-alanine with pyridoxal 5'-phosphate (PLP) as a cofactor. The D-alanine product is an essential component of the bacterial cell wall and ALR is a potential target for the development of novel antibacterial drugs. The alr gene from A. baumannii was cloned and the protein (AbALR) was expressed, purified and crystallized. The AbALR crystal diffracted to 2.3 Å resolution and belonged to the primitive orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 55.1, b = 85.0, c = 167.7 Å. Two protomers were present in the asymmetric unit, with a corresponding V(M) value of 2.3 Å(3) Da(-1) and a solvent content of 47.5%.

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

    Science.gov (United States)

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

    2016-01-01

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

  7. Selection and characterization of conditionally active promotors in Lactobacillus plantarum, using alanine racemase as a promotor probe

    NARCIS (Netherlands)

    Bron, P.A.; Hoffer, S.M.; Swam, van I.I.; Vos, de W.M.; Kleerebezem, M.

    2004-01-01

    This paper describes the use of the alr gene, encoding alanine racemase, as a promoter-screening tool for the identification of conditional promoters in Lactobacillus plantarum. Random fragments of the L. plantarum WCFS1 genome were cloned upstream of the promoterless alr gene of Lactococcus lactis

  8. Effects of β-alanine administration on selected parameters of oxidative stress and phosphoryltransfer network in cerebral cortex and cerebellum of rats

    NARCIS (Netherlands)

    Gemelli, Tanise; de Andrade, Rodrigo Binkowski; Rojas, Denise Bertin; Bonorino, Nariélle Ferner; Mazzola, Priscila Nicolao; Tortorelli, Lucas Silva; Funchal, Cláudia; Filho, Carlos Severo Dutra; Wannmacher, Clovis Milton Duval

    2013-01-01

    β-Alanine is a β-amino acid derivative of the degradation of pyrimidine uracil and precursor of the oxidative substrate acetyl-coenzyme A (acetyl-CoA). The accumulation of β-alanine occurs in β-alaninemia, an inborn error of metabolism. Patients with β-alaninemia may develop neurological abnormaliti

  9. Developing a dosimetry system with alanine at University of Santiago de Compostela; Desarrollo de un sistema de dosimetria con alamina en la Universidad de Santiago de Compostela

    Energy Technology Data Exchange (ETDEWEB)

    Gago Arias, M. A.; Gomez Rodriguez, F.; Gonzalez Castano, D. M.; Peteiro Vilaseco, E.; Lodeiro Remesar, C.

    2013-07-01

    This paper presents the studies realized for the calibration, absorbed dose in water, the signal of Electron Paramagnetic Resonance of dosimeters of alanine, necessary step for the implementation of a service of dosimetry with alanine, traced to the secondary pattern of the Radio physics laboratory (RPL), and linked to the service of resonance Para Magnetic of the University of Santiago de Compostela. (Author)

  10. De Novo Alanine Synthesis by Bacteroids of Mesorhizobium loti Is Not Required for Nitrogen Transfer in the Determinate Nodules of Lotus corniculatus

    OpenAIRE

    Kumar, Shalini; Bourdès, Alexandre; Poole, Philip

    2005-01-01

    Deletion of both alanine dehydrogenase genes (aldA) in Mesorhizobium loti resulted in the loss of AldA enzyme activity from cultured bacteria and bacteroids but had no effect on the symbiotic performance of Lotus corniculatus plants. Thus, neither indeterminate pea nodules nor determinate L. corniculatus nodules export alanine as the sole nitrogen secretion product.

  11. De novo alanine synthesis by bacteroids of Mesorhizobium loti is not required for nitrogen transfer in the determinate nodules of Lotus corniculatus.

    Science.gov (United States)

    Kumar, Shalini; Bourdès, Alexandre; Poole, Philip

    2005-08-01

    Deletion of both alanine dehydrogenase genes (aldA) in Mesorhizobium loti resulted in the loss of AldA enzyme activity from cultured bacteria and bacteroids but had no effect on the symbiotic performance of Lotus corniculatus plants. Thus, neither indeterminate pea nodules nor determinate L. corniculatus nodules export alanine as the sole nitrogen secretion product.

  12. Proliferation and function of microbodies in the nematophagous fungus Arthrobotrys oligospora during growth on oleic acid or D-alanine as the sole carbon source

    NARCIS (Netherlands)

    Dijksterhuis, Jan; Harder, Willem; Veenhuis, Marten

    1993-01-01

    The nematophagous fungus Arthrobotrys oligospora is able to grow on oleic acid or D-alanine as the sole carbon source. During growth on oleic acid, activities of enzymes of the beta-oxidation pathway, but not catalase, were induced. In the presence of D-alanine, both D-amino acid oxidase and catalas

  13. Study of serum LDH and GGT levels in carcinoma breast

    OpenAIRE

    Rajeswari, Guddanti; Srinivas, P Satya; Krishna Sai, K. Siva Rama; Suresh, Eadala

    2016-01-01

    Background: Breast cancer is the second most common cancer in women next only to cervical cancer. Multiple factors are associated with an increased risk of developing breast cancer. For the early detection of carcinoma of breast, a number of biochemical markers have been studied to evaluate the malignancy.Aim: To analyse serum Lactate Dehydrogenase, Gamma Glutamyl Transpeptidase, liver enzymes (SGOT, SGPT, & ALP) and total proteins in diagnosis of carcinoma breast patients and compared wi...

  14. Experimental determination of the energy response of alanine pellets in the high dose rate 192Ir spectrum

    Science.gov (United States)

    Schaeken, B.; Cuypers, R.; Goossens, J.; Van den Weyngaert, D.; Verellen, D.

    2011-10-01

    An experimental determination of the energy correction factor for alanine/paraffin pellets in the 192Ir spectrum at varying distances from the source is presented. Alanine dosimeters were irradiated in water under full scatter conditions with a high dose rate (HDR) 192Ir source (Flexisource), using a dedicated holder. Up to six line sources (catheters) fit in a regular pattern at fixed radial distances from the holder axis, the alanine detector being placed at the centre of the holder. The HDR source was stepping every 0.5 cm within a trocar needle within ± 3.0 cm around the medial plane through the detector in order to achieve dose homogeneity within the detector volume. The energy correction factor of alanine/paraffin pellets in 192Ir relative to 60Co was experimentally determined as the inverse ratio of the dose to water measured in water around the 192Ir source to the dose to water calculated in water using the TG-43 formalism. The pellets were read out with a Bruker EMXmicro spectrometer (X-band). The amplitude of the central line in the alanine absorption spectrum from pellets irradiated within the 192Ir spectrum was directly compared with the amplitude from 60Co-irradiated pellets. The energy correction factors of Harwell pellets irradiated in the 192Ir spectrum are 1.029 ± 0.02, 1.027 ± 0.02 and 1.045 ± 0.02 at a mean weighted source-detector distance of 2.0, 2.9 and 5.3 cm, respectively. The experimentally obtained values for the energy response are 1.3% lower compared to the theoretical values for radial distances smaller than 3 cm.

  15. Metabolic consequences of β-alanine supplementation during exhaustive supramaximal cycling and 4000-m time-trial performance.

    Science.gov (United States)

    Bellinger, Phillip M; Minahan, Clare L

    2016-08-01

    The present study investigated the effects of β-alanine supplementation on the resultant blood acidosis, lactate accumulation, and energy provision during supramaximal-intensity cycling, as well as the aerobic and anaerobic contribution to power output during a 4000-m cycling time trial (TT). Seventeen trained cyclists (maximal oxygen uptake = 4.47 ± 0.55 L·min(-1)) were administered 6.4 g of β-alanine (n = 9) or placebo (n = 8) daily for 4 weeks. Participants performed a supramaximal cycling test to exhaustion (equivalent to 120% maximal oxygen uptake) before (PreExh) and after (PostExh) the 4-week supplementation period, as well as an additional postsupplementation supramaximal cycling test identical in duration and power output to PreExh (PostMatch). Anaerobic capacity was quantified and blood pH, lactate, and bicarbonate concentrations were measured pre-, immediately post-, and 5 min postexercise. Subjects also performed a 4000-m cycling TT before and after supplementation while the aerobic and anaerobic contributions to power output were quantified. β-Alanine supplementation increased time to exhaustion (+12.8 ± 8.2 s; P = 0.041) and anaerobic capacity (+1.1 ± 0.7 kJ; P = 0.048) in PostExh compared with PreExh. Performance time in the 4000-m TT was reduced following β-alanine supplementation (-6.3 ± 4.6 s; P = 0.034) and the mean anaerobic power output was likely to be greater (+6.2 ± 4.5 W; P = 0.035). β-Alanine supplementation increased time to exhaustion concomitant with an augmented anaerobic capacity during supramaximal intensity cycling, which was also mirrored by a meaningful increase in the anaerobic contribution to power output during a 4000-m cycling TT, resulting in an enhanced overall performance.

  16. Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study.

    Directory of Open Access Journals (Sweden)

    Marina Yazigi Solis

    Full Text Available Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d(-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1 and on cognitive function before and after exercise in trained cyclists (Study 2.In Study 1, seven healthy vegetarians (3 women and 4 men and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation, with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task being performed before and after exercise on each occasion.In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99 or omnivores (p = 0.27; nor was there any effect when data from both groups were pooled (p = 0.19. Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27. In study 2, exercise improved cognitive function across all tests (P 0.05 of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise.28 d of beta-alanine supplementation at 6.4 g d(-1 appeared not to influence brain homocarnosine/carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists.

  17. Dependence of the enthalpies of alanyl-alanine dissolution on the composition of mixed water + acetone and water + DMSO solvents at 298.15 K

    Science.gov (United States)

    Smirnov, V. I.; Badelin, V. G.

    2015-08-01

    The enthalpies of dissolution of two dipeptides, DL-α-alanyl-β-alanine and β-alanyl-β-alanine, in mixed solvents H2O + acetone (AC) and H2O + dimethyl sulfoxide (DMSO) are measured via calorimetry at an organic component concentration of x 2 = 0-0.25 mole fraction at 298.15 K. The standard enthalpies of dissolution (Δsol H po) and the transfer (Δtr H po) of dipeptides from water to the mixed solvent and the enthalpic coefficients of pairwise interactions ( h xy ) with AC and DMSO molecules are calculated from these data. The effect the composition of aqueous organic mixtures has on the enthalpy characteristics of the dissolution of DL-α-alanyl-β-alanine and β-alanyl-β-alanine is considered. A comparative analysis of h xy values is performed for alanine dipeptides in the investigated mixed solvents.

  18. root uv-b sensitive Mutants Are Suppressed by Specific Mutations in ASPARTATE AMINOTRANSFERASE2 and by Exogenous Vitamin B6

    Institute of Scientific and Technical Information of China (English)

    Colin D. Leasure; Hong-Yun Tong; Xue-Wen Hou; Amy Shelton; Mike Minton; Raymond Esquerra; Sanja Roje; Hanjo Hellmann; Zheng-Hui He

    2011-01-01

    Vitamin B6 (vitB6)serves as an essential cofactor for more than 140 enzymes. Pyridoxal 5'-phosphate (PLP),active cofactor form of vitB6, can be photolytically destroyed by trace amounts of ultraviolet-B (UV-B). How sun-exposed organisms cope with PLP photosensitivity and modulate vitB6 homeostasis is currently unknown. We previously reported on two Arabidopsis mutants, rusl and rus2, that are hypersensitive to trace amounts of UV-B light. We performed mu-tagenesis screens for second-site suppressors of the rus mutant phenotype and identified mutations in the ASPARTATE AMINOTRANSFERASE2 (ASP2)gene. ASP2 encodes for cytosolic aspartate aminotransferase (AAT), a PLP-dependent en-zyme that plays a key role in carbon and nitrogen metabolism. Genetic analyses have shown that specific amino acid substitutions in ASP2 override the phenotypes of rusl and rus2 single mutants as well as rusl rus2 double mutant. These substitutions, all shown to reside at specific positions in the PLP-binding pocket, resulted in no PLP binding. Additional asp2 mutants that abolish AAT enzymatic activity, but which alter amino acids outside of the PLP-binding pocket, fail to suppress the rus phenotype. Furthermore, exogenously adding vitB6 in growth media can rescue both rusl and rus2. Our data suggest that AAT plays a role in vitB6 homeostasis in Arabidopsis.

  19. Corticosterone, cortisol, triglycerides, aspartate aminotransferase and uric acid plasma concentrations during foie gras production in male mule ducks (Anas platyrhynchos × Cairina moschata).

    Science.gov (United States)

    Flament, A; Delleur, V; Poulipoulis, A; Marlier, D

    2012-01-01

    1. Corticosterone, cortisol, triglycerides, aspartate aminotransferase (AST) and uric acid (UA) plasma concentration were measured at 8 (7 days after group housing), 12 (after 7 days of force feeding) and 13 weeks of age (at slaughter after 12 days of force feeding), and 45 min after an adrenocorticotrophic hormone (ACTH) stimulation test at 8 weeks of age in 12 male mule ducks in an on-farm experiment. 2. No significant increase of corticosterone was found during the force-feeding period compared with the concentration after housing. 3. Comparison of corticosterone and cortisol values indicates that cortisol can be considered as a reliable acute stress indicator in future routine examinations. 4. Plasma concentrations of triglycerides and aspartate aminotransferase increased progressively from pre-force feeding period to slaughtering. 5. Plasma concentrations of uric acid increased from the start at 8 weeks of age to the mid-force feeding period but no difference was noticed between the mid-force feeding period and slaughtering. 6. It is concluded that acute stress induced by force-feeding is similar at the beginning and end of the commercial production of foie gras.

  20. Synthesis and characterization of new polyamides derived from alanine and valine derivatives

    Directory of Open Access Journals (Sweden)

    El-Faham Ayman

    2012-11-01

    Full Text Available Abstract Background Many efforts have been recently devoted to design, investigate and synthesize biocompatible, biodegradable polymers for applications in medicine for either the fabrication of biodegradable devices or as drug delivery systems. Many of them consist of condensation of polymers having incorporated peptide linkages susceptible to enzymatic cleavage. Polyamides (PAs containing α-amino acid residues such as L-leucine, L-alanine and L-phenylalanine have been reported as biodegradable materials. Furthermore, polyamides (PAs derived from C10 and C14 dicarboxylic acids and amide-diamines derived from 1,6-hexanediamine or 1,12-dodecanediamine and L-phenylalanine, L-valyl-L-phenylalanine or L-phenylalanyl-L-valine residues have been reported as biocompatible polymers. We have previously described the synthesis and thermal properties of a new type of polyamides-containing amino acids based on eight new symmetric meta-oriented protected diamines derived from coupling of amino acids namely; Fomc-glycine, Fmoc-alanine, Fomc-valine and Fomc-leucine with m-phenylene diamine or 2,6-diaminopyridine. Results revealed that incorporation of pyridine onto the polymeric backbone of all series decreases the thermal stability. Here we describe another family of polyamides based on benzene dicarboxylic acid, pyridine dicarboxylic acid, and α-amino acid linked to benzidine and 4,4′-oxydianiline to study the effect of the dicarboxylic acid as well as the amino acids on the nature and thermal stability of the polymers. Results We report here the preparation of a new type of polyamides based on benzene dicarboxylic acid, pyridine dicarboxylic acid, and α-amino acid linked to benzidine and 4,4′-oxydianiline to study the effect of the dicarboxylic acid as well as the amino acids on the nature and thermal stability of polymers. The thermal properties of the polymers were evaluated by different techniques. Results revealed that structure-thermal property

  1. GGT、AFU和AFP联检在原发性肝癌中的诊断价值%Clinical value of tumor marker r- glutamyle transpeptidase(GGT) ,alpha - fucosidase (AFU) and alphafetoprotein (AFP) in the diagnose of primary hepatocellular carcinoma (PHC)

    Institute of Scientific and Technical Information of China (English)

    王怡明

    2006-01-01

    目的 探讨肿瘤标志物谷氨酰转肽酶(GGT)、a-L岩藻糖苷酶(AFU)和甲胎蛋白(AFP)在原发性肝癌(PHC)诊断中的价值.方法 对PHC组84例、转移性肝癌(MC)组48例、肝炎组57例和正常对照组79例,检测血清GGT、AFU和AFP水平(前三组患者在接受治疗前检测).结果 PHC组血清GGT、AFU和AFP水平均明显高于肝炎组及正常对照组,差异有非常显著性(P<0.01).PHC组血清GGT、AFU和AFP阳性率分别为91.7%、80.9%、69.0%,AFU、AFP联检阳性率92.4%,GGT与AFU、AFP联检阳性率97.1%;AFP阴性的PHC26例中,血清GGT、AFU阳性率分别为92.3%(24/26)、76.9%(20/26),表明二者对AFP阴性的PHC患者具有较高的诊断互补作用.结论 血清GGT、AFU和AFP联合检测可提高PHC的诊断率,特别是对AFP阴性、低浓度的PHC更具有诊断价值.

  2. Homology of pyridoxal-5'-phosphate-dependent aminotransferases with the cobC (cobalamin synthesis), nifS (nitrogen fixation), pabC (p-aminobenzoate synthesis) and malY (abolishing endogenous induction of the maltose system) gene products.

    Science.gov (United States)

    Mehta, P K; Christen, P

    1993-01-15

    Bacterial deletion mutants have indicated that the gene products of cobC, nifS, pabC and malY participate in important metabolic pathways, i.e. cobalamin synthesis, nitrogen fixation, synthesis of p-aminobenzoate and the regulation of the maltose system, respectively. However, the proteins themselves and their specific functions have not yet been identified. In the course of our studies on the evolutionary relationships among aminotransferases, we have found that the above gene products are homologous to aminotransferases. Profile analysis [Gribskov, M., Lüthy, R. & Eisenberg, D. (1990) Methods Enzymol. 183, 146-159] based on the amino acid sequences of certain subgroups of aminotransferases as probes attributed significant Z scores in the range 5-20 SD to the deduced amino acid sequences of the above gene products as included in the protein data base. Reciprocal profile analyses confirmed the homologies. All known aminotransferases are pyridoxal-5'-phosphate-dependent enzymes and catalyze the reversible transfer of amino groups from amino acids to oxo acids. The sequence homologies suggest that the above gene products are aminotransferases or other closely related pyridoxal-5'-phosphate-dependent enzymes probably catalyzing transformations of amino acids involving cleavage of a bond at C alpha.

  3. Serum biochemical profile of laying hens in the region of Araçatuba, SPPerfil bioquímico das galinhas poedeiras na região de Araçatuba-SP.

    Directory of Open Access Journals (Sweden)

    Paulo César Ciarlini

    2011-10-01

    Full Text Available The establishment of reference values is extremely important for successful diagnosis and treatament. Considering that in most species the serum chemistry profile is influenced by race, climate and management, we decided to determine the values of aspartate aminotransferase (AST, alanine aminotransferase (ALT, uric acid, creatinine, creatine kinase (CK, phosphatase alkaline (ALP, gamma-glutamyltransferase (GGT, total protein (TP and albumin of Dekalb hens in the region of Araçatuba - SP. All samples were processed soon after harvesting in an automatic biochemical analyzer calibrated and monitored with control serum levels I and II. The following confidence intervals were obtained: 44-65,5 U / L (AST; 18,4-21,2 U / L (ALT, 2.1-2.5 mg / dL (uric acid; 1.7 to 5.7 U / L (CK; CI 1.2-2.2 mg / dL (creatinine, 1276-1506 U / L (FA; 18-23,4 U / L (GGT; 27.12 to 29 g / L (PT, from 11.4 to 12.16 g / L (albumin.O estabelecimento de valores bioquímicos de referência é de extrema importância para o sucesso do diagnóstico e do tratamento. Considerando que na maioria das espécies o perfil bioquímico sérico sofre influência de raça, clima e manejo, decidiu-se determinar os valores de aspartato aminotransferase (AST, alanina aminotransferase (ALT, ácido úrico, creatinina, creatina quinase (CK, fostatase alcalina (FA, gama-glutamiltransferase (GGT, proteína total (PT e albumina de galinhas poedeiras da linhagem Dekalb da região de Araçatuba – SP. Todas as amostras foram processadas logo após a colheita em um analisador bioquímico automatizado previamente calibrado e monitorado com soros controles nível I e II. Obtiveram-se os seguintes intervalos de confiança: 44-65,5 U/L (AST; 18,4-21,2 U/L (ALT; 2,1–2,5 mg/dL (ácido úrico ; 1,7– 5,7 U/L (CK ; 1,2–2,2 mg/dL (creatinina; 1276–1506 U/L (FA; 18-23,4 U/L (GGT; 27,12– 29 g/L (PT; 11,4 – 12,16 g/L (albumina.

  4. Treatment of non-alcoholic fatty liver disease with metformin versus lifestyle intervention in insulin-resistant adolescents.

    Science.gov (United States)

    Nadeau, Kristen J; Ehlers, Lindsay B; Zeitler, Philip S; Love-Osborne, Kathy

    2009-02-01

    The presence of fatty liver per ultrasound and liver-associated enzymes were measured in a select cohort of youth with both obesity and insulin resistance, and the effect of metformin on these parameters evaluated. Fifty obese, multiethnic, insulin-resistant adolescents (mean age 15.1 yr, mean body mass index 39.8 kg/m2) were randomized to receive lifestyle recommendations plus either twice per day doses of 850 mg of metformin or placebo. Fasting and post-glucose challenge biochemistries and liver ultrasounds were compared at baseline and 6 months. The prevalence of fatty liver was 74%, elevated alanine aminotransferase (ALT) 14%, aspartate aminotransferase (AST) 14%, and gamma-glutamyl transferase (GGT) 17%. Fatty liver was mild in 23%, moderate in 31%, and severe in 46%. Fatty liver was more common in male and Hispanic subjects and elevated ALT more common in Hispanic subjects. Subjects with fatty liver appeared more insulin resistant (higher fasting insulin and triglycerides, lower high-density lipoprotein cholesterol) and had higher ALT and AST. At 6 months, mean ALT, GGT, and fasting insulin improved significantly in all subjects. Fatty liver prevalence (p metformin compared to placebo. Non-alcoholic fatty liver disease (NAFLD) occurs with a high prevalence and severity in obese, insulin-resistant adolescents. While metformin plus lifestyle intervention appears promising, defining NAFLD therapies capable of preventing fibrosis and cirrhosis requires further study.

  5. Changes in selected hematology and serum biochemistry in Turkish Angora cats (Felis catus during growth period

    Directory of Open Access Journals (Sweden)

    Ozkan Simsek

    2015-03-01

    Full Text Available The purpose of the present study was to determine the changes in selected hematology and serum biochemistry of Angora cats (Felis catus during growth period. A total of 32 Angora cats (16 adults and 16 kittens were used in this study. Blood samples were collected from the animals, and were analyzed for white blood cells, red blood cells, hemoglobin, packed cell volume, mean corpuscular volume (MCV, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, granulocytes, monocytes and lymphocytes numbers. In the serum, alanine aminotransferase, aspartate aminotransferase (AST, alkaline phosphatase (ALP, gamma glutamyl transferase (GGT, lactate dehydrogenase (LDH, creatinine kinase (CK, total cholesterol, glucose, triglyceride, urea, creatinine, total protein, albumin, Ca, Mg, Pi levels were determined. Monocyte level was found higher, and ALP, LDH, CK activities and Pi levels were lower in adult cats as compared to the kittens. MCV was lower and GGT and AST activities, and glucose level were higher in kittens of 1.5-3 months old than in kittens of >3 months. Concentrations of total cholesterol and Mg were higher in kitten (1.5-3 months old than in adult cats. In conclusion, age related effects on hematological and biochemical blood parameters have been determined for the first time in Angora cats.

  6. Toll-like receptor 3 gene polymorphisms are not associated with the risk of hepatitis B and hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    Keyla Santos Guedes de Sá

    2015-04-01

    Full Text Available INTRODUCTION: The present study investigated the prevalence of two single-nucleotide polymorphisms (SNPs in the Toll-like receptor 3 (TLR3 gene in patients infected with hepatitis B virus (HBV and hepatitis C virus (HCV. METHODS: Samples collected from HCV (n = 74 and HBV (n = 35 carriers were subjected to quantitative real-time PCR (qPCR to detect the presence of the SNPs rs5743305 and rs3775291 in TLR3 and to measure the following biomarkers: alanine aminotransferase (ALT, aspartate aminotransferase (AST, gamma-glutamyl transpeptidase (GGT, and prothrombin time (PT. A healthy control group was investigated and consisted of 299 HCV- and HBV-seronegative individuals. RESULTS: No significant differences in allele, genotype and haplotype frequencies were observed between the investigated groups, and no association was observed between the polymorphisms and histopathological results. Nevertheless, genotypes TA/AA (rs5743305 and GG (rs3775291 appear to be associated with higher levels of ALT (p<0.01, AST (p<0.05 and PT (p<0.05. In addition, genotypes TT (rs5743305; p<0.05 and GG (rs3775291; p<0.05 were associated with higher GGT levels. CONCLUSIONS: This genetic analysis revealed the absence of an association between the polymorphisms investigated and susceptibility to HBV and HCV infection; however, these polymorphisms might be associated with a greater degree of biliary damage during the course of HCV infection.

  7. Investigations on Blood Activities of Some Enzymes in Dogs After Acute Intoxication with the Carbamate Insecticide Carbofuran

    Directory of Open Access Journals (Sweden)

    Rumen Binev

    2016-10-01

    Full Text Available Experiments for monitoring of changes in blood enzyme activities were carried out in dogs after acute intoxication with the carbamate insecticide carbofuran (Carbosan 35 СТ. The studies involved one control and 6 experimental groups of dogs (total n=42, treated once orally with increasing doses of the preparation via oesophageal probe: 0.525 mg/kg (experimental group I, 1.05 mg/kg (experimental group II, 2.1 mg/kg (experimental group III, 3.5 mg/kg (experimental group IV, 5.25 mg/kg (experimental group V and 10.5 mg/kg (LD50, (experimental group VI, corresponding to 1/20, 1/10, 1/5, 1/3, 1/2 and LD50, oral doses for albino rats. Blood samples were obtained from v. antebrachi cephalica or v. jugularis in the course of 3 consecutive days prior to the treatment (hours -48, -24 and 0 and on post treatment hours 1, 3, 5, 7, 24 and 48 from all groups for analysis of acetylcholinesterase (AChE, aspartate aminotransferase (ASAT, alanine aminotransferase (ALAT, amylase (AMY, gamma-glutamyltransferase (g-GT, alkaline phosphatase (ALP and lactate dehydrogenase (LDH. It was established that the tested carbamate insecticide provoked lower blood activity of AChE and increased the levels of ASAT, ALAT, AMY, g-GT, AP and LDH between post treatment hours 1 and 7; afterwards, the studied parameters regained the respective control values.

  8. Effects of fumonisin B1 on selected biological responses and performance of broiler chickens

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    Ricardo H. Rauber

    2013-09-01

    Full Text Available The objective of this study was to determine the effects of three doses of fumonisin B1 (0, 100, and 200mg/kg of feed on biological variables (relative weight of liver [RWL], total plasma protein [TPP], albumin [Alb], calcium [Ca], phosphorus [P], uric acid [UA], alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma glutamyltransferase [GGT], alkaline phosphatase [AP], total cholesterol [Chol], triglycerides [Tri], sphinganine-to-sphingosine ratio [SA:SO], and C-reactive protein [CRP], morphological evaluation of the small intestine (villus height [VH], crypt depth [CD], and villus-to-crypt ratio [V:C], histological evaluation, and on performance (body weight [BW], feed intake [FI], and feed conversion rate [FCR] of broiler chickens. Significant effects of FB were observed on BW and FI (reduced, on RWL, TPP, Ca, ALT, AST, GGT, Chol, and Tri (increased at both 14 and 28 days evaluations. In addition, significant increase was observed on FCR, Alb, P, SA:SO, and CRP and significant reduction in UA, VH, and V:C only at the 28 days evaluation. Significant histological lesions were observed on liver and kidney of FB inoculated broilers at 14 and 28 days. Those results show that FB has a significant effect on biological and histological variables and on performance of broiler chickens.

  9. Peroxisome proliferators-activated alpha agonist treatment ameliorates hepatic damage in rats with obstructive jaundice: an experimental study

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    Alper Murat

    2007-11-01

    Full Text Available Abstract Background Peroxisome proliferators-activated receptor alpha (PPARα activation modulates cholesterol metabolism and suppresses bile acid synthesis. This study aims to evaluate the effect of short-term administration of fenofibrate, a PPARα agonist, on proinflammatory cytokines, apoptosis, and hepatocellular damage in cholestasis. Methods Forty male Wistar rats were randomly divided into four groups: I = sham operated, II = bile duct ligation (BDL, III = BDL + vehicle (gum Arabic, IV = BDL + fenofibrate (100 mg/kg/day. All rats were sacrificed on 7th day after obtaining blood samples and liver tissue. Total bilirubin, aminotransferase (AST, alanine aminotransferase (ALT and alkaline phosphatase (ALP, gamma-glutamyl transferase, (GGT, tumor necrosis factor alpha (TNF-α, interleukin 1 beta (IL-1 β, and total bile acid (TBA in serum, and liver damage scores; portal inflammation, necrosis, bile duct number, in liver tissue were evaluated. Apoptosis in liver was also assessed by immunohistochemical staining. Results Fenofibrate administration significantly reduced serum total bilirubin, AST, ALT, ALP, and GGT, TNF-α, IL-1 β levels, and TBA (P P P P Conclusion Short-term administration of fenofibrate to the BDL rats exerts beneficial effects on hepatocellular damage and apoptosis.

  10. Routine testing of liver function before and after elective laparoscopic cholecystectomy: is it necessary?

    LENUS (Irish Health Repository)

    Ahmad, Nasir Zaheer

    2012-01-31

    BACKGROUND AND OBJECTIVES: Liver function tests (LFTs) include alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and bilirubin. The role of routine testing before and after laparoscopic cholecystectomy was evaluated in this study. PATIENTS AND METHODS: A total of 355 patients were retrospectively analyzed by examining the LFTs the day before, the day after, and 3 weeks after the surgery. The Wilcoxon signed-rank test and Student t test were performed to determine statistical significance. RESULTS: Alterations in the serum AST, ALT, and GGT were seen on the first postoperative day. Minor changes were seen in bilirubin and ALP. An overall disturbance in the LFTs was seen in more than two-thirds of the cases. Repeat LFTs performed after 3 weeks on follow-up were found to be within normal limits. CONCLUSION: Mild-to-moderate elevation in preoperative LFTs may not be associated with any deleterious effect, and, in the absence of clinical indications, routine preoperative or postoperative liver function testing is unnecessary.

  11. Changes in white blood pictures and some biochemical parameters of dairy cows in peripartum period and early lactation

    Directory of Open Access Journals (Sweden)

    Mirjana Joksimović Todorović

    2012-06-01

    Full Text Available The objective of this research was to determine the changes in the number of cells of white blood line and some biochemical parameters: concentration of glucose, concentration of non-esterified fatty acids (NEFA, activity of enzymes of aspartat aminotransferase (AST, alanin aminotransferase (ALT and gamma glutamyltranferase (GGT, in 17 Holstein-Friesian breed dairy cows in peripartum period and early lactation (on d 15 prepartum, on the day of parturition and on d 15, 30, and 45 postpartum. The highest values of total leukocytes count, neutrophiles, monocytes and basophiles count were recorded on the day of parturition, and then decreased, so that the minimum value established on d 45 of lactation. The lymphocytes count was the lowest on the day of parturation, while the eosinophils and basophiles counts were significantly different in observed time intervals. The concentration of glucose ranged from 3.07 mmol/L on d 15 prepartum to 2.71 mmol/L on d 15 postpartum. A high concentration of non-esterified fatty acids (NEFA in the postpartum period is a consequence of changes in energy balance and more intensive process of lypolisis in fat tissue, due to energy disbalance at the beginning of lactation. Established activity of enzymes AST, ALT and GGT was approximately the same in studied time intervals and was within physiological limits. The results of hematological and biochemical analysis in this paper do not indicate the development of postpartum ailments, because the investigated parameters were within physiological limits.

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

    Science.gov (United States)

    Yi, Hankuil; Jez, Joseph M

    2012-11-01

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

  13. Effect of radiation quality on radical formation in ion-irradiated solid alanine

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Hitoshi; Ichikawa, Tsuneki; Yoshida, Hiroshi [Hokkaido Univ., Sapporo (Japan); Namba, Hideki; Taguchi, Mitsumasa; Kojima, Takuji

    1997-03-01

    Radical formation in solid alanine irradiated with H{sup +} and He{sup +} ions of 0.5-3.0 MeV and with heavy ions of hundreds of MeV was examined by the ESR method. Radical yield is constant below a critical fluence, and the yield decreases above the fluence. The critical fluence for the H{sup +} and He{sup +} ions is about 10{sup 12} ions cm{sup -2}, while the critical fluence for the heavy ions is 10{sup 10}-10{sup 11} ions cm{sup -2}. G-value of the radical formation (radicals per 100 eV absorbed dose) is obtained from the constant yield at the low fluences. The G-value depends on the radiation quality. This dependence is ascribed to the difference of local dose in the ion tracks. The fluence-yield curves were simulated with a model assuming cylindrical shape of ion tracks and dose-yield relationship for {gamma}-irradiation. This model well explains the fluence-yield curves for the ion irradiations. (author)

  14. Alanine scanning mutagenesis of anti-TRAP (AT) reveals residues involved in binding to TRAP.

    Science.gov (United States)

    Chen, Yanling; Gollnick, Paul

    2008-04-11

    The trp RNA-binding attenuation protein (TRAP) regulates expression of the tryptophan biosynthetic (trp) genes in response to changes in intracellular levels of free l-tryptophan in many Gram-positive bacteria. When activated by binding tryptophan, TRAP binds to the mRNAs of several genes involved in tryptophan metabolism, and down-regulates transcription or translation of these genes. Anti-TRAP (AT) is an antagonist of TRAP that binds to tryptophan-activated TRAP and prevents it from binding to its RNA targets, and thereby up-regulates trp gene expression. The crystal structure shows that AT is a cone-shaped trimer (AT(3)) with the N-terminal residues of the three subunits assembled at the apex of the cone and that these trimers can further assemble into a dodecameric (AT(12)) structure. Using alanine-scanning mutagenesis we found four residues, all located on the "top" region of AT(3), that are essential for binding to TRAP. Fluorescent labeling experiments further suggest that the top region of AT is in close juxtaposition to TRAP in the AT-TRAP complex. In vivo studies confirmed the importance of these residues on the top of AT in regulating TRAP mediated gene regulation.

  15. Laser trapping dynamics of L-alanine depending on the laser polarization

    Science.gov (United States)

    Yuyama, Ken-ichi; Ishiguro, Kei; Sugiyama, Teruki; Masuhara, Hiroshi

    2012-10-01

    We successfully demonstrate crystallization and crystal rotation of L-alanine in D2O solution using a focused laser beam of 1064 nm with right- or left-handed circularly polarization. Upon focusing each laser beam into a solution/air interface of the solution thin film, one single crystal is generally formed from the focal spot. The necessary time for the crystallization is systematically examined against polarization and power of the trapping laser. The significant difference in the average time is observed between two polarization directions at a relatively high laser power, where the left-handed circularly polarized laser takes 3 times longer than the right-handed one. On the other hand, the prepared crystal is stably trapped and rotated at the focal point by circularly polarized lasers after the crystallization, and the rotation direction is completely controlled by the polarization of the trapping laser. The mechanisms for the crystallization and the crystal rotation are discussed in terms of trapping force and rotation torque of circularly polarized lasers acting on the liquid-like clusters and its bulk crystal, respectively.

  16. Growth, structural, vibrational, optical, laser and dielectric aspects of L-alanine alaninium nitrate single crystal

    Science.gov (United States)

    Caroline, M. Lydia; Prakash, M.; Geetha, D.; Vasudevan, S.

    2011-09-01

    Bulk single crystals of L-alanine alaninium nitrate [abbreviated as LAAN], an intriguing material for frequency conversion has been grown from its aqueous solution by both slow solvent evaporation and by slow cooling techniques. The optimized pH value to grow good quality LAAN single crystal was found to be 2.5. The grown crystals were subjected to single crystal X-ray diffraction studies to determine the unit cell dimensions and morphology. Vibrational frequencies of the grown crystals by Fourier transform infrared spectroscopic technique were investigated. Also, the presence of hydrogen and carbon atoms in the grown sample was confirmed using proton and carbon NMR analyses. The dielectric constant and dielectric loss measurements of the as grown crystal at different temperatures and frequencies of the applied field are measured and reported. LAAN has good optical transmission in the entire visible region with cutoff wavelength within the UV region confirms its suitability for device fabrications. The existence of second harmonic generation signals was observed using Nd:YAG laser with fundamental wavelength of 1064 nm. Its Laser Damage Threshold (LDT) was measured and also tested by using a Q-switched Nd:YAG laser and the value of LDT of LAAN is 17.76 GW/cm 2 respectively, is found to be better than certain organic and semiorganic materials.

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

    Science.gov (United States)

    Oda, Akifumi; Fukuyoshi, Shuichi

    2015-06-01

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

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

    Science.gov (United States)

    Oda, Akifumi; Fukuyoshi, Shuichi

    2015-06-01

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

  19. Thermodynamic and spectroscopic studies of alanine and phenylalanine in aqueous β-cyclodextrin solutions

    Directory of Open Access Journals (Sweden)

    Anwar Ali

    2017-01-01

    Full Text Available Ultrasonic speed, u and density, ρ have been measured for dl-alanine (Ala and l-phenylalanine (Phe in aqueous β-cyclodextrin (β-CD at 298.15, 303.15, 308.15, and 313.15 K. The complexation of Ala and Phe with β-CD has been studied by means of UV–vis and thermodynamic (ultrasonic speed and density studies. Using the measured ultrasonic speed and density data the apparent molar compressibility (κS,φ, apparent molar volume (Vφ, limiting apparent molar compressibility (κS,φ0, limiting apparent molar volume (Vφ0, their constants (SK and Sv, and hydration number (nH have been obtained. The positive values of transfer properties at infinite dilution for Ala and Phe in β-CD is the outcome of the balance between released water molecules from β-CD cavity and hydrophobic groups of Ala and Phe that enter into the macrocycle β-CD cavity. The experimental results have also been discussed on the basis of UV–vis absorbance. The results indicate the formation of a more stable host–guest complex between Phe-β-CD than between Ala-β-CD.

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

    Science.gov (United States)

    Ilayabarathi, P.; Chandrasekaran, J.

    2012-10-01

    A new semiorganic nonlinear optical crystal, L-alanine cadmium bromide (LACB) was grown from aqueous solution by slow solvent evaporation method at room temperature. As grown crystals were characterized for its spectral, thermal, linear and second order nonlinear optical properties. LACB crystallizes in orthorhombic system and unit cell parameters a = 5.771(2) Å, b = 6.014(4) Å, c = 12.298(2) Å, α = β = γ = 90° and volume = 426.8(3) Å3. The mode of vibrations of different molecular groups present in the crystal was identified by FTIR study. The grown crystals were found to be transparent in the entire visible region. The thermal strength and the decomposition of the grown crystals were studied using TG/DTA and DSC analysis. Dielectric measurement revealed that the crystals had very low dielectric constant at higher frequency in room temperature. The mechanical behavior was studied by Vicker's microhardness tester. The grown crystal has negative photoconductivity nature. The fluorescence spectrum of the crystal was recorded and its optical band gap is about 3.356 eV. The NLO property of crystal using modified Kurtz-Perry powder technique with Nd:YAG laser light of wavelength 1064 nm indicated that their second harmonic generation (SHG) efficiency was half that of pure KDP.

  1. Optical, thermal and magnetic studies of pure and cobalt chloride doped L-alanine cadmium chloride

    Science.gov (United States)

    Benila, B. S.; Bright, K. C.; Delphine, S. Mary; Shabu, R.

    2017-03-01

    Single crystals of L-alanine cadmium chloride (LACC) and cobalt chloride (Co2+) doped LACC have been grown by the slow evaporation solution growth technique. The grown crystals were subjected to various characterizations such as powder XRD, SXRD, FTIR, UV-vis, EDAX, TG/DTA, VSM, Dielectric and Second Harmonic Generation (SHG) measurements. The lattice parameters of the grown crystals were determined by single crystal X-ray analysis. EDAX analysis confirms the presence of Co2+ ion in the host material. The functional group and optical behavior of the crystals were identified from FTIR and UV-vis spectrum analysis. Electrical parameters such as dielectric constant, dielectric loss have been studied. The thermal stability of the compound was found out using TGA/DTA analysis. Second Harmonic Generation of the samples was confirmed by Kurtz-Perry powder technique. Magnetic properties of the crystals studied by VSM were also reported. The encouraging results show that the cobalt chloride doped LACC crystals have greater potential applications in optical devices.

  2. Cycas micronesica (Cycadales) plants devoid of endophytic cyanobacteria increase in beta-methylamino-L-alanine.

    Science.gov (United States)

    Marler, Thomas E; Snyder, Laura R; Shaw, Christopher A

    2010-09-15

    Cycads are among the most ancient of extant Spermatophytes, and are known for their pharmacologically active compounds. beta-methylamino-l-alanine (BMAA) is one metabolite that been implicated as causal of human neurodegenerative diseases in Guam. We grew Cycas micronesica seedlings without endophytic cyanobacteria symbiosis, and quantified initial and ending BMAA in various plant tissues. BMAA increased 79% during nine months of seedling growth, and root tissue contained 75% of the ultimate BMAA pool. Endophytic cyanobacteria symbionts were not the source of BMAA increase in these seedlings, which contradicts previously reported claims that biosynthesis of this toxin by cyanobacteria initiates its accumulation in the Guam environment. The preferential loading of root tissue with BMAA does not support earlier reports that this toxin serves a defensive role against herbivory of leaf or seed tissues. The long history of conflicting results in Guam's cycad toxin research continues, and recent developments underscore the sense of urgency in continued research as this endangered cycad population approaches extirpation from the island.

  3. The cyanobacteria derived toxin Beta-N-methylamino-L-alanine and amyotrophic lateral sclerosis.

    Science.gov (United States)

    Banack, Sandra Anne; Caller, Tracie A; Stommel, Elijah W

    2010-12-01

    There is mounting evidence to suggest that environmental factors play a major role in the development of neurodegenerative diseases like ALS (Amyotrophic Lateral Sclerosis). The non-protein amino acid beta-N-methylamino-L-alanine (BMAA) was first associated with the high incidence of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia Complex (ALS/PDC) in Guam, and has been implicated as a potential environmental factor in ALS, Alzheimer's disease, and other neurodegenerative diseases. BMAA has a number of toxic effects on motor neurons including direct agonist action on NMDA and AMPA receptors, induction of oxidative stress, and depletion of glutathione. As a non-protein amino acid, there is also the strong possibility that BMAA could cause intraneuronal protein misfolding, the hallmark of neurodegeneration. While an animal model for BMAA-induced ALS is lacking, there is substantial evidence to support a link between this toxin and ALS. The ramifications of discovering an environmental trigger for ALS are enormous. In this article, we discuss the history, ecology, pharmacology and clinical ramifications of this ubiquitous, cyanobacteria-derived toxin.

  4. Membrane topology of aspartate:alanine antiporter AspT from Comamonas testosteroni.

    Science.gov (United States)

    Fujiki, Takashi; Nanatani, Kei; Nishitani, Kei; Yagi, Kyoko; Ohnishi, Fumito; Yoneyama, Hiroshi; Uchida, Takafumi; Nakajima, Tasuku; Abea, Keietsu

    2007-01-01

    We cloned the aspT gene encoding the L-aspartate:L-alanine antiporter AspTCt in Comamonas testosteroni genomic DNA. Analysis of the nucleotide sequence revealed that C. testosteroni has an asp operon containing aspT upstream of the l-aspartate 4-decarboxylase gene, and that the gene order of the asp operon of C. testosteroni is the inverse of that of Tetragenococcus halophilus. We used proteoliposomes to confirm the transport processes of AspTCt. To elucidate the two-dimensional structure of AspTCt, we analysed its membrane topology by means of alkaline phosphatase (PhoA) and beta-lactamase (BlaM) fusion methods. The fusion analyses revealed that AspTCt has seven transmembrane segments (TMs), a large cytoplasmic loop containing approximately 200 amino acid residues between TM4 and TM5, a cytoplasmic N-terminus, and a periplasmic C-terminus. These results suggest that the orientation of the N-terminus of AspTCt differs from that of tetragenococcal AspT, even though these two AspT orthologues catalyse the same transport reactions.

  5. Sequential micellar electrokinetic chromatography analysis of racemization reaction of alanine enantiomers.

    Science.gov (United States)

    Fu, Rao; Liu, Lina; Guo, Yingna; Guo, Liping; Yang, Li

    2014-02-28

    A novel method for online monitoring racemization reaction of alanine (Ala) enantiomers was developed, by combining sequential sample injection and micellar electrokinetic chromatography (MEKC) technique. Various conditions were investigated to optimize the sequential injection, Ala derivatization and MEKC chiral separation of d-/l-Ala. High reproducibility of the sequential MEKC analysis was demonstrated by analyzing the standard Ala samples, with relative standard deviation values (n=20) of 1.35%, 1.98%, and 1.09% for peak height, peak area and migration time, respectively. Ala racemization was automatically monitored every 40s from the beginning to the end of the reaction, by simultaneous detection of the consumption of the substrate enantiomer and the formation of the product enantiomer. The Michaelis constants of the racemization reaction were obtained by the sequential MEKC method, and were in good agreement with those obtained by traditional off-line enzyme assay. Our study indicated that the present sequential MEKC method can perform fast, efficient, accurate and reproducible analysis of racemization reaction of amino acids, which is of great importance for the determination of the activity of racemase and thus understanding its metabolic functions.

  6. The non-protein amino acid β-N-methylamino-L-alanine in Portuguese cyanobacterial isolates.

    Science.gov (United States)

    Cervantes Cianca, Rosa C; Baptista, Mafalda S; Lopes, Viviana R; Vasconcelos, Vitor M

    2012-06-01

    The tailor made amino acid β-N-methyl-amino-L-alanine (BMAA) is a neurotoxin produced by cyanobacteria. It has been associated with certain forms of progressive neurodegenerative disease, including sporadic Amyotrophic Lateral Sclerosis and Alzheimer's disease. Some different reports of BMAA in cyanobacterial blooms from lakes, reservoirs, and other water resources have been made by different investigators. We here report the detection of BMAA of both free and protein-bound produced by cyanobacteria, belonging to the Chroococcales, Oscillatoriales and Nostocales ordered. We use a rapid and sensitive HPLC-FD method that utilizes methanol elution and the Waters AQC Tag chemistry. On other hand, we have used three different assay procedures for BMAA extraction from cyanobacteria: Trichloroacetic acid (TCA), Methanol/Acetone and hydrochloric acid (HCl). All assays let successfully detect BMAA in all cyanobacteria samples analyzed. Nevertheless, with TCA and HCl extraction procedures the highest BMAA values, for free as well as protein-bound BMAA were detected. BMAA content could not be related to the taxonomy of the isolates or to their geographical origin, and no correlation between free and protein-bound BMAA concentrations were observed within or between taxonomic groups. These data offer confirmation of the taxonomic and geographic ubiquity of BMAA from naturally occurring populations of cyanobacteria, for the first time reported for estuaries.

  7. The Cyanobacteria Derived Toxin Beta-N-Methylamino-L-Alanine and Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Elijah W. Stommel

    2010-12-01

    Full Text Available There is mounting evidence to suggest that environmental factors play a major role in the development of neurodegenerative diseases like ALS (Amyotrophic Lateral Sclerosis. The non-protein amino acid beta-N-methylamino-L-alanine (BMAA was first associated with the high incidence of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia Complex (ALS/PDC in Guam, and has been implicated as a potential environmental factor in ALS, Alzheimer’s disease, and other neurodegenerative diseases. BMAA has a number of toxic effects on motor neurons including direct agonist action on NMDA and AMPA receptors, induction of oxidative stress, and depletion of glutathione. As a non-protein amino acid, there is also the strong possibility that BMAA could cause intraneuronal protein misfolding, the hallmark of neurodegeneration. While an animal model for BMAA-induced ALS is lacking, there is substantial evidence to support a link between this toxin and ALS. The ramifications of discovering an environmental trigger for ALS are enormous. In this article, we discuss the history, ecology, pharmacology and clinical ramifications of this ubiquitous, cyanobacteria-derived toxin.

  8. Chiral recognition of alanine across modified carbon electrodes with 3,4-dihydroxyphenylalanine

    Energy Technology Data Exchange (ETDEWEB)

    Bustos, E. [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., P.O. Box 064, C.P. 76700 Pedro Escobedo, Queretaro (Mexico); Chemistry Department, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, P.O. Box 14-740, C.P. 07360 Mexico, D.F. (Mexico)], E-mail: ebustos@cideteq.mx; Godinez, Luis A. [Electrochemistry Department, Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., P.O. Box 064, C.P. 76700 Pedro Escobedo, Queretaro (Mexico); Rangel-Reyes, G.; Juaristi, E. [Chemistry Department, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, P.O. Box 14-740, C.P. 07360 Mexico, D.F. (Mexico)

    2009-11-01

    3,4-Dihydroxyphenylalanine (DOPA) was covalently grafted onto a glassy carbon electrode (GCE) by the formation of an amine cation radical in the electro-oxidation of the amino-containing compound. Cyclic voltammetric experiments proved that the DOPA was formed on the GCE as a monolayer. Its electron transfer over the GCE surface at different pH values was studied by cyclic voltammetry. Changes in solution pH resulted in the variation of the charge state of the terminal group and the surface pK{sub a} was estimated on the basis of these results. Because of electrostatic interactions between the negatively charged groups on the electrode surface and the alanine (Ala) in solution, the modified electrode was used as an enantioselective sensor. The peak current for D(+) or L(-)DOPA over the modified electrode decreased as a result of the chiral recognition across the blocking interaction with the respective enantiomer of L(-) or D(+)Ala. The recognition was verified with the protection of L(-)DOPA with a Fmoc group.

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

    Science.gov (United States)

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

    2012-02-01

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

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

    Science.gov (United States)

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

    2012-02-01

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

  11. Effects of Four Weeks of β-Alanine Supplementation on Repeated Sprint Ability in Water Polo Players

    Science.gov (United States)

    Brisola, Gabriel Motta Pinheiro; Artioli, Guilherme Giannini; Papoti, Marcelo; Zagatto, Alessandro Moura

    2016-01-01

    The purpose of this study was to investigate the effect of four weeks of β-alanine supplementation on repeated sprint ability in water polo players. Twenty-two male water polo players participated in the study, divided randomly into two homogeneous groups (placebo and β-alanine groups). The study design was double-blind, parallel and placebo controlled. Before and after the supplementation period (28 days), the athletes performed two specific repeated sprint ability tests interspaced by a 30-minute swimming test. Participants received 4.8g∙day-1 of the supplement (dextrose or β-alanine) on the first 10 days and 6.4g∙day-1 on the final 18 days. There was no significant group-time interaction for any variable. The qualitative inference for substantial changes demonstrated a likely beneficial effect in the β-alanine group (β-alanine vs placebo) for mean time (6.6±0.4s vs 6.7±0.4s; 81% likely beneficial), worst time (6.9±0.5s vs 7.1±0.5s; 78% likely beneficial) and total time (39.3±2.5s vs 40.4±2.5s; 81% likely beneficial) in the first repeated sprint ability set and for worst time (7.2±0.6s vs 7.5±0.6s; 57% possible beneficial) in the second repeated sprint ability set. Further, was found substantial change for total time for both repeated sprint ability tests (80.8±5.7s vs 83.4±5.6s; 52% possible beneficial). To conclude, four weeks of β-alanine supplementation had a likely beneficial effect in the first set of repeated sprint ability tests and a possible beneficial effect for worst time in the second set performed in a specific protocol in water polo players. PMID:27930743

  12. Alterações na bioquímica hepática em cães com leptospirose aguda determinada por amostras do sorogrupo Icterohaemorrhagiae Hepatic biochemistry alterations in dogs with naturally occurring acute leptospirosis determined by Icterohaemorrhagiae serogroup

    Directory of Open Access Journals (Sweden)

    Isabel Maria Alexandre Freire

    2008-12-01

    Full Text Available Foram testadas 120 amostras séricas de cães com títulos (³100 perante Leptospira spp. serovar Icterohaemorrhagiae para a determinação da atividade sérica de alanina aminotransferase (ALT, aspartato aminotransferase (AST, fosfatase alcalina (FA, gamaglutamiltransferase (GGT e dos níveis séricos de colesterol total, triglicerídeos, proteína total, albumina, globulinas e bilirrubinas total, direta e indireta. Um grupo de 34 animais sem qualquer sintomatologia clínica e idade semelhante ao grupo testado foi utilizado como controle, tendo sido submetido às mesmas dosagens bioquímicas. Os animais com títulos ³200 apresentaram dosagens de FA e bilirubina direta superiores ao grupo controle e também aos animais com títulos menores que 200 (POne hundred and twenty serum samples obtained from dogs with specific titres (³100 against Leptospira spp. serovar Icterohaemorrhagiae were tested in order to determine the enzymatic activities of alanine aminotransferase (ALT, aspartate aminotransferase (AST, alkaline phosphatase (ALP, gamaglutamyltransferase (GGT, as well as of the total cholesterol, triglycerides, total protein, albumin, globulins and total, direct and indirect bilirubins serum concentrations. Thirty four animals free from clinical signs with the same age of the tested group were used as control group and submitted to the same biochemical tests. The animals with titres ³200 showed increased ALP activity and greater direct bilirubin concentration when compared to the control group and also to the group of dogs with titres <200 (P<0.05. A clear correlation was observed between hepatic damage, without hepatocellular necrosis, and specific seroreactivity for leptospirosis caused by serogroup Icterohaemorrhagiae.

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

    Science.gov (United States)

    Mojibola, Adeolu; Dongmo-Momo, Gilles; Mohammed, Muzaffer; Aslan, Kadir

    2014-05-07

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

  14. An optical overview of poly[μ(2)-L-alanine-μ(3)-nitrato-sodium(I)] crystals.

    Science.gov (United States)

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

    2012-01-01

    Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN) and D-alanine sodium nitrate (DASN), were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD) studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-Vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR) spectrum of single