WorldWideScience

Sample records for ammonium-inducible glutamine synthetase

  1. Cytosolic glutamine synthetase

    DEFF Research Database (Denmark)

    Thomsen, Hanne Cecilie; Eriksson, Ulf Dennis; Møller, Inge Skrumsager;

    2014-01-01

    Overexpression of the cytosolic enzyme glutamine synthetase 1 (GS1) has been investigated in numerous cases with the goal of improving crop nitrogen use efficiency. However, the outcome has generally been inconsistent. Here, we review possible reasons underlying the lack of success and conclude...

  2. Cytosolic glutamine synthetase in barley

    DEFF Research Database (Denmark)

    Thomsen, Hanne Cecilie

    fertilizer requirement. The enzyme glutamine synthetase (GS) has been a major topic in plant nitrogen research for decades due to its central role in plant N metabolism. The cytosolic version of this enzyme (GS1) plays an important role in relation to primary N assimilation as well as in relation to N...

  3. Neural control of glutamine synthetase activity in rat skeletal muscles.

    Science.gov (United States)

    Feng, B; Konagaya, M; Konagaya, Y; Thomas, J W; Banner, C; Mill, J; Max, S R

    1990-05-01

    The mechanism of glutamine synthetase induction in rat skeletal muscle after denervation or limb immobilization was investigated. Adult male rats were subjected to midthigh section of the sciatic nerve. At 1, 2, and 5 h and 1, 2, and 7 days after denervation, rats were killed and denervated, and contralateral control soleus and plantaris muscles were excised, weighted, homogenized, and assayed for glutamine synthetase. Glutamine synthetase activity increased approximately twofold 1 h after denervation in both muscles. By 7 days postdenervation enzyme activity had increased to three times the control level in plantaris muscle and to four times the control level in soleus muscle. Increased enzyme activity after nerve section was associated with increased maximum velocity with no change in apparent Michaelis constant. Immunotitration with an antiglutamine synthetase antibody suggested that denervation caused an increase in the number of glutamine synthetase molecules in muscle. However, Northern-blot analysis revealed no increase in the steady-state level of glutamine synthetase mRNA after denervation. A mixing experiment failed to yield evidence for the presence of a soluble factor involved in regulating the activity of glutamine synthetase in denervated muscle. A combination of denervation and dexamethasone injections resulted in additive increases in glutamine synthetase. Thus the mechanism underlying increased glutamine synthetase after denervation appears to be posttranscriptional and is distinct from that of the glucocorticoid-mediated glutamine synthetase induction previously described by us. PMID:1970709

  4. The glutamine synthetase gene family in Populus

    Directory of Open Access Journals (Sweden)

    Cánovas Francisco M

    2011-08-01

    Full Text Available Abstract Background Glutamine synthetase (GS; EC: 6.3.1.2, L-glutamate: ammonia ligase ADP-forming is a key enzyme in ammonium assimilation and metabolism of higher plants. The current work was undertaken to develop a more comprehensive understanding of molecular and biochemical features of GS gene family in poplar, and to characterize the developmental regulation of GS expression in various tissues and at various times during the poplar perennial growth. Results The GS gene family consists of 8 different genes exhibiting all structural and regulatory elements consistent with their roles as functional genes. Our results indicate that the family members are organized in 4 groups of duplicated genes, 3 of which code for cytosolic GS isoforms (GS1 and 1 which codes for the choroplastic GS isoform (GS2. Our analysis shows that Populus trichocarpa is the first plant species in which it was observed the complete GS family duplicated. Detailed expression analyses have revealed specific spatial and seasonal patterns of GS expression in poplar. These data provide insights into the metabolic function of GS isoforms in poplar and pave the way for future functional studies. Conclusions Our data suggest that GS duplicates could have been retained in order to increase the amount of enzyme in a particular cell type. This possibility could contribute to the homeostasis of nitrogen metabolism in functions associated to changes in glutamine-derived metabolic products. The presence of duplicated GS genes in poplar could also contribute to diversification of the enzymatic properties for a particular GS isoform through the assembly of GS polypeptides into homo oligomeric and/or hetero oligomeric holoenzymes in specific cell types.

  5. Glutamine synthetase is a genetic determinant of cell type-specific glutamine independence in breast epithelia.

    Directory of Open Access Journals (Sweden)

    Hsiu-Ni Kung

    2011-08-01

    Full Text Available Although significant variations in the metabolic profiles exist among different cells, little is understood in terms of genetic regulations of such cell type-specific metabolic phenotypes and nutrient requirements. While many cancer cells depend on exogenous glutamine for survival to justify the therapeutic targeting of glutamine metabolism, the mechanisms of glutamine dependence and likely response and resistance of such glutamine-targeting strategies among cancers are largely unknown. In this study, we have found a systematic variation in the glutamine dependence among breast tumor subtypes associated with mammary differentiation: basal- but not luminal-type breast cells are more glutamine-dependent and may be susceptible to glutamine-targeting therapeutics. Glutamine independence of luminal-type cells is associated mechanistically with lineage-specific expression of glutamine synthetase (GS. Luminal cells can also rescue basal cells in co-culture without glutamine, indicating a potential for glutamine symbiosis within breast ducts. The luminal-specific expression of GS is directly induced by GATA3 and represses glutaminase expression. Such distinct glutamine dependency and metabolic symbiosis is coupled with the acquisition of the GS and glutamine independence during the mammary differentiation program. Understanding the genetic circuitry governing distinct metabolic patterns is relevant to many symbiotic relationships among different cells and organisms. In addition, the ability of GS to predict patterns of glutamine metabolism and dependency among tumors is also crucial in the rational design and application of glutamine and other metabolic pathway targeted therapies.

  6. The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, S.M.; Habash, D.Z.

    2009-07-02

    Glutamine synthetase assimilates ammonium into amino acids, thus it is a key enzyme for nitrogen metabolism. The cytosolic isoenzymes of glutamine synthetase assimilate ammonium derived from primary nitrogen uptake and from various internal nitrogen recycling pathways. In this way, cytosolic glutamine synthetase is crucial for the remobilization of protein-derived nitrogen. Cytosolic glutamine synthetase is encoded by a small family of genes that are well conserved across plant species. Members of the cytosolic glutamine synthetase gene family are regulated in response to plant nitrogen status, as well as to environmental cues, such as nitrogen availability and biotic/abiotic stresses. The complex regulation of cytosolic glutamine synthetase at the transcriptional to post-translational levels is key to the establishment of a specific physiological role for each isoenzyme. The diverse physiological roles of cytosolic glutamine synthetase isoenzymes are important in relation to current agricultural and ecological issues.

  7. Glutamine synthetase gene evolution: A good molecular clock

    International Nuclear Information System (INIS)

    Glutamine synthetase gene evolution in various animals, plants, and bacteria was evaluated by a general stationary Markov model. The evolutionary process proved to be unexpectedly regular even for a time span as long as that between the divergence of prokaryotes from eukaryotes. This enabled us to draw phylogenetic trees for species whose phylogeny cannot be easily reconstructed from the fossil record. The calculation of the times of divergence of the various organelle-specific enzymes led us to hypothesize that the pea and bean chloroplast genes for these enzymes originated from the duplication of nuclear genes as a result of the different metabolic needs of the various species. The data indicate that the duplication of plastid glutamine synthetase genes occurred long after the endosymbiotic events that produced the organelles themselves

  8. The glutamine synthetase gene family in Populus

    OpenAIRE

    Cánovas Francisco M; Kirby Edward G; Avila Concepción; Canales Javier; García-Gutiérrez Angel; Castro-Rodríguez Vanessa

    2011-01-01

    Abstract Background Glutamine synthetase (GS; EC: 6.3.1.2, L-glutamate: ammonia ligase ADP-forming) is a key enzyme in ammonium assimilation and metabolism of higher plants. The current work was undertaken to develop a more comprehensive understanding of molecular and biochemical features of GS gene family in poplar, and to characterize the developmental regulation of GS expression in various tissues and at various times during the poplar perennial growth. Results The GS gene family consists ...

  9. Glutamine metabolism in uricotelic species: variation in skeletal muscle glutamine synthetase, glutaminase, glutamine levels and rates of protein synthesis.

    Science.gov (United States)

    Watford, Malcolm; Wu, Guoyao

    2005-04-01

    High intracellular glutamine levels have been implicated in promoting net protein synthesis and accretion in mammalian skeletal muscle. Little is known regarding glutamine metabolism in uricotelic species but chicken breast muscle exhibits high rates of protein accretion and would be predicted to maintain high glutamine levels. However, chicken breast muscle expresses high glutaminase activity and here we report that chicken breast muscle also expresses low glutamine synthetase activity (0.07+/-0.01 U/g) when compared to leg muscle (0.50+/-0.04 U/g). Free glutamine levels were 1.38+/-0.09 and 9.69+/-0.12 nmol/mg wet weight in breast and leg muscles of fed chickens, respectively. Glutamine levels were also lower in dove breast muscle (4.82+/-0.35 nmol/mg wet weight) when compared to leg muscle (16.2+/-1.0 nmol/mg wet weight) and much lower (1.80+/-0.46 nmol/mg wet weight) in lizard leg muscle. In fed chickens, rates of fractional protein synthesis were higher in leg than in breast muscle, and starvation (48 h) resulted in a decrease in both glutamine content and rate of protein synthesis in leg muscle. Thus, although tissue-specific glutamine metabolism in uricotelic species differs markedly from that in ureotelic animals, differences in rates of skeletal muscle protein synthesis are associated with corresponding differences in intramuscular glutamine content. PMID:15763516

  10. Organisation and sequence determination of glutamine-dependent carbamoyl phosphate synthetase II in Toxoplasma gondii.

    Science.gov (United States)

    Fox, Barbara A; Bzik, David J

    2003-01-01

    Carbamoyl phosphate synthetase II encodes the first enzymic step of de novo pyrimidine biosynthesis. Carbamoyl phosphate synthetase II is essential for Toxoplasma gondii replication and virulence. In this study, we characterised the primary structure of a 28kb gene encoding Toxoplasma gondii carbamoyl phosphate synthetase II. The carbamoyl phosphate synthetase II gene was interrupted by 36 introns. The predicted protein encoded by the 37 carbamoyl phosphate synthetase II exons was a 1,687 amino acid polypeptide with an N-terminal glutamine amidotransferase domain fused with C-terminal carbamoyl phosphate synthetase domains. This bifunctional organisation of carbamoyl phosphate synthetase II is unique, so far, to protozoan parasites from the phylum Apicomplexa (Plasmodium, Babesia, Toxoplasma) or zoomastigina (Trypanosoma, Leishmania). Apicomplexan parasites possessed the largest carbamoyl phosphate synthetase II enzymes due to insertions in the glutamine amidotransferase and carbamoyl phosphate synthetase domains that were not present in the corresponding gene segments from bacteria, plants, fungi and mammals. The C-terminal allosteric regulatory domain, the carbamoyl phosphate synthetase linker domain and the oligomerisation domain were also distinct from the corresponding domains in other species. The novel C-terminal regulatory domain may explain the lack of activation of Toxoplasma gondii carbamoyl phosphate synthetase II by the allosteric effector 5-phosphoribosyl 1-pyrophosphate. Toxoplasma gondii growth in vitro was markedly inhibited by the glutamine antagonist acivicin, an inhibitor of glutamine amidotransferase activity typically associated with carbamoyl phosphate synthetase II, guanosine monophosphate synthetase, or CTP synthetase. PMID:12547350

  11. Response of transgenic poplar overexpressing cytosolic glutamine synthetase to phosphinothricin.

    Science.gov (United States)

    Pascual, María Belén; Jing, Zhong Ping; Kirby, Edward G; Cánovas, Francisco M; Gallardo, Fernando

    2008-01-01

    Glutamine synthetase (GS) is the main enzyme involved in ammonia assimilation in plants and is the target of phosphinothricin (PPT), an herbicide commonly used for weed control in agriculture. As a result of the inhibition of GS, PPT also blocks photorespiration, resulting in the depletion of leaf amino acid pools leading to the plant death. Hybrid transgenic poplar (Populus tremula x P. alba INRA clone 7171-B4) overexpressing cytosolic GS is characterized by enhanced vegetative growth [Gallardo, F., Fu, J., Cantón, F.R., García-Gutiérrez, A., Cánovas, F.M., Kirby, E.G., 1999. Expression of a conifer glutamine synthetase gene in transgenic poplar. Planta 210, 19-26; Fu, J., Sampalo, R., Gallardo, F., Cánovas, F.M., Kirby, E.G., 2003. Assembly of a cytosolic pine glutamine synthetase holoenzyme in leaves of transgenic poplar leads to enhanced vegetative growth in young plants. Plant Cell Environ. 26, 411-418; Jing, Z.P., Gallardo, F., Pascual, M.B., Sampalo, R., Romero, J., Torres de Navarra, A., Cánovas, F.M., 2004. Improved growth in a field trial of transgenic hybrid poplar overexpressing glutamine synthetase. New Phytol. 164, 137-145], increased photosynthetic and photorespiratory capacities [El-Khatib, R.T., Hamerlynck, E.P., Gallardo, F., Kirby, E.G., 2004. Transgenic poplar characterized by ectopic expression of a pine cytosolic glutamine synthetase gene exhibits enhanced tolerance to water stress. Tree Physiol. 24, 729-736], enhanced tolerance to water stress (El-Khatib et al., 2004), and enhanced nitrogen use efficiency [Man, H.-M., Boriel, R., El-Khatib, R.T., Kirby, E.G., 2005. Characterization of transgenic poplar with ectopic expression of pine cytosolic glutamine synthetase under conditions of varying nitrogen availability. New Phytol. 167, 31-39]. In vitro plantlets of GS transgenic poplar exhibited enhanced resistance to PPT when compared with non-transgenic controls. After 30 days exposure to PPT at an equivalent dose of 275 g ha(-1), growth

  12. Encapsulation of glutamine synthetase in mouse erythrocytes: a new procedure for ammonia detoxification.

    Science.gov (United States)

    Kosenko, Elena A; Venediktova, Natalia I; Kudryavtsev, Andrey A; Ataullakhanov, Fazoil I; Kaminsky, Yury G; Felipo, Vicente; Montoliu, Carmina

    2008-12-01

    There are a number of pathological situations in which ammonia levels increase leading to hyperammonemia, which may cause neurological alterations and can lead to coma and death. Currently, there are no efficient treatments allowing rapid and sustained decrease of ammonia levels in these situations. A way to increase ammonia detoxification would be to increase its incorporation in glutamine by glutamine synthetase. The aim of this work was to develop a procedure to encapsulate glutamine synthetase in mouse erythrocytes and to assess whether administration of these erythrocytes containing glutamine synthetase (GS) reduce ammonia levels in hyperammonemic mice. The procedure developed allowed the encapsulation of 3 +/- 0.25 IU of GS / mL of erythrocytes with a 70% cell recovery. Most metabolites, including ATP, remained unaltered in glutamine synthetase-loaded erythrocytes (named ammocytes by us) compared with native erythrocytes. The glutamine synthetase-loaded ammocytes injected in mice survived and retained essentially all of their glutamine synthetase activity for at least 48 h in vivo. Injection of these ammocytes into hyperammonemic mice reduced ammonia levels in the blood by about 50%. The results reported indicate that ammocytes are able to keep their integrity, normal energy metabolism, the inserted glutamine synthetase activity, and can be useful to reduce ammonia levels in hyperammonemic situations. PMID:19088795

  13. Regulation of Amidase Formation in Mutants from Pseudomonas aeruginosa PAO Lacking Glutamine Synthetase Activity

    NARCIS (Netherlands)

    Janssen, Dick B.; Herst, Patricia M.; Joosten, Han M.L.J.; Drift, Chris van der

    1982-01-01

    The formation of amidase was studied in mutants from Pseudomonas aeruginosa PAO lacking glutamine synthetase activity. It appeared that catabolite repression of amidase synthesis by succinate was partially relieved when cellular growth was limited by glutamine. Under these conditions, a correlation

  14. Isolation and characterization of glutamine synthetase genes in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Chen, Q; Silflow, C D

    1996-11-01

    To elucidate the role of glutamine synthetase (GS) in nitrogen assimilation in the green alga Chlamydomonas reinhardtii we used maize GS1 (the cytosolic form) and GS2 (the chloroplastic form) cDNAs as hybridization probes to isolate C. reinhardtii cDNA clones. The amino acid sequences derived from the C. reinhardtii clones have extensive homology with GS enzymes from higher plants. A putative amino-terminal transit peptide encoded by the GS2 cDNA suggests that the protein localizes to the chloroplast. Genomic DNA blot analysis indicated that GS1 is encoded by a single gene, whereas two genomic fragments hybridized to the GS2 cDNA probe. All GS2 cDNA clones corresponded to only one of the two GS2 genomic sequences. We provide evidence that ammonium, nitrate, and light regulate GS transcript accumulation in green algae. Our results indicate that the level of GS1 transcripts is repressed by ammonium but induced by nitrate. The level of GS2 transcripts is not affected by ammonium or nitrate. Expression of both GS1 and GS2 genes is regulated by light, but perhaps through different mechanisms. Unlike in higher plants, no decreased level of GS2 transcripts was detected when cells were grown under conditions that repress photorespiration. Analysis of GS transcript levels in mutants with defects in the nitrate assimilation pathway show that nitrate assimilation and ammonium assimilation are regulated independently. PMID:8938407

  15. Overexpression of glutamine synthetases confers transgenic rice herbicide resistance

    Institute of Scientific and Technical Information of China (English)

    Sun Hui; Huang Qiman; Su Jin

    2005-01-01

    Glutamine synthetase (GS, E.C.6.3.1.2) is a key enzyme involved in the assimilation of inorganic nitrogen in higher plants and gram-negative microorganisms. GS is the targeting enzyme of a herbicide phosphinothricin (PPT) or Basta. In order to generate PPT-resistant transgenic rice via overexpression of GS, we constructed a plant expression vector p2GS harboring two different isoenzymes GS1 and GS2 cDNAs under the control of constitutive promoters of rice Act1 and maize Ubiquitin(Ubi) genes. The p2GS was introduced into rice genome by Agrobacterium-mediated transformation and confirmed by PCR and Southern blot hybridization. GS-transgene expression was first detected by Northern blot analyses. Results from Basta test indicated that GS-transgenic plants can tolerate as high as 0.3% Basta solution. In addition, our results also demonstrated that GS overexpression conferred transformed rice calli PPT resistance. Thus, GS cassette can serve as a selective marker gene instead of bar cassette for selection of PPT transformants.

  16. Glutamine synthetase and glutamyltransferase in developing chick and rat tissues

    Energy Technology Data Exchange (ETDEWEB)

    Herzfeld, A.; Raper, S.M.

    1975-01-01

    Concomitant determination of ..gamma..-glutamine-hydroxylamine-glutamyltransferase (GT) and ..gamma..-glutamyl hydroxamate synthetase (GS) activities in chick retina, brain and liver between the 13th day of incubation and a day after hatching showed that while both activities increased late in incubation, in neural tissues their rises were not simultaneous throughout development; in liver both activities were already high on the 14th day of incubation and changed in parallel thereafter. GS and GT activities could be evoked prematurely in all three tissues by cortisol, but GT activity showed higher responses to the hormone. GT and GS were separable by differential solubilization in chick liver but not in retina of chick or rat. The wide spread of the ratios of GT : GS activities in homogenates of a number of chick and rat tissues (1 : 1 to 73 : 1) indicates that the GS reaction is not catalyzed by the same protein that catalyzes the GT reactions. Relative amounts of GT(T) (free of GS activity) and of variants of GS (with different competences to catalyze the GT reaction) may govern the changes between the two activities during development and their distribution among different adult tissues in chick and rat.

  17. Changes in the activity levels of glutamine synthetase, glutaminase and glycogen synthetase in rats subjected to hypoxic stress

    Science.gov (United States)

    Vats, P.; Mukherjee, A. K.; Kumria, M. M. L.; Singh, S. N.; Patil, S. K. B.; Rangnathan, S.; Sridharan, K.

    Exposure to high altitude causes loss of body mass and alterations in metabolic processes, especially carbohydrate and protein metabolism. The present study was conducted to elucidate the role of glutamine synthetase, glutaminase and glycogen synthetase under conditions of chronic intermittent hypoxia. Four groups, each consisting of 12 male albino rats (Wistar strain), were exposed to a simulated altitude of 7620 m in a hypobaric chamber for 6 h per day for 1, 7, 14 and 21 days, respectively. Blood haemoglobin, blood glucose, protein levels in the liver, muscle and plasma, glycogen content, and glutaminase, glutamine synthetase and glycogen synthetase activities in liver and muscle were determined in all groups of exposed and in a group of unexposed animals. Food intake and changes in body mass were also monitored. There was a significant reduction in body mass (28-30%) in hypoxia-exposed groups as compared to controls, with a corresponding decrease in food intake. There was rise in blood haemoglobin and plasma protein in response to acclimatisation. Over a three-fold increase in liver glycogen content was observed following 1 day of hypoxic exposure (4.76+/-0.78 mg.g-1 wet tissue in normal unexposed rats; 15.82+/-2.30 mg.g-1 wet tissue in rats exposed to hypoxia for 1 day). This returned to normal in later stages of exposure. However, there was no change in glycogen synthetase activity except for a decrease in the 21-days hypoxia-exposed group. There was a slight increase in muscle glycogen content in the 1-day exposed group which declined significantly by 56.5, 50.6 and 42% following 7, 14, and 21 days of exposure, respectively. Muscle glycogen synthetase activity was also decreased following 21 days of exposure. There was an increase in glutaminase activity in the liver and muscle in the 7-, 14- and 21-day exposed groups. Glutamine synthetase activity was higher in the liver in 7- and 14-day exposed groups; this returned to normal following 21 days of exposure

  18. Reduced density of glutamine synthetase immunoreactive astrocytes in different cortical areas in major depression but not in bipolar I disorder

    Directory of Open Access Journals (Sweden)

    Hans-Gert eBernstein

    2015-08-01

    Full Text Available There is increasing evidence for disturbances within the glutamate system in patients with affective disorders, which involve disruptions of the glutamate-glutamine- cycle. The mainly astroglia-located enzyme glutamine synthetase catalyzes the ATP-dependent condensation of ammonia and glutamate to form glutamine, thus playing a central role in glutamate and glutamine homoeostasis. However, glutamine synthetase is also expressed in numerous oligodendrocytes, another class of glial cells implicated in mood disorder pathology. To learn more about the role of glia-associated glutamine synthetase in mental illnesses, we decided to find out if numerical densities of glial cells immunostained for the enzyme protein differ between subjects with major depressive disorder, bipolar disorder and psychically healthy control cases. Counting of glutamine synthetase expressing astrocytes and oligodendrocytes in eight cortical and two subcortical brain regions of subjects with mood disorder (N=14, bipolar disorder (N=15 and controls (N=16 revealed that in major depression the densities of astrocytes were significantly reduced in some cortical but not subcortical gray matter areas, whereas no changes were found for oligodendrocytes. In bipolar disorder no alterations of glutamine synthetase-immunoreactive glia were found. From our findings we conclude that (1 glutamine synthetase expressing astrocytes are prominently involved in glutamate-related disturbances in major depression, but not in bipolar disorder and (2 glutamine synthetase expressing oligodendrocytes, though being present in significant numbers in prefrontal cortical areas, play a minor (if any role in mood disorder pathology. The latter assumption is supported by findings of others showing that - at least in the mouse brain cortex - glutamine synthetase immunoreactive oligodendroglial cells are unable to contribute to the glutamate-glutamine cycle due to the complete lack of amino acid transporters

  19. Effect of glutamine synthetase inhibition on brain and interorgan ammonia metabolism in bile duct ligated rats

    DEFF Research Database (Denmark)

    Fries, Andreas W; Dadsetan, Sherry; Keiding, Susanne;

    2014-01-01

    Ammonia has a key role in the development of hepatic encephalopathy (HE). In the brain, glutamine synthetase (GS) rapidly converts blood-borne ammonia into glutamine which in high concentrations may cause mitochondrial dysfunction and osmolytic brain edema. In astrocyte-neuron cocultures and brains...... of healthy rats, inhibition of GS by methionine sulfoximine (MSO) reduced glutamine synthesis and increased alanine synthesis. Here, we investigate effects of MSO on brain and interorgan ammonia metabolism in sham and bile duct ligated (BDL) rats. Concentrations of glutamine, glutamate, alanine, and...... aspartate and incorporation of (15)NH4(+) into these amino acids in brain, liver, muscle, kidney, and plasma were similar in sham and BDL rats treated with saline. Methionine sulfoximine reduced glutamine concentrations in liver, kidney, and plasma but not in brain and muscle; MSO reduced incorporation of...

  20. Glutamine Synthetase Is a Genetic Determinant of Cell Type–Specific Glutamine Independence in Breast Epithelia

    OpenAIRE

    Hsiu-Ni Kung; Marks, Jeffrey R.; Jen-Tsan Chi

    2011-01-01

    Although significant variations in the metabolic profiles exist among different cells, little is understood in terms of genetic regulations of such cell type-specific metabolic phenotypes and nutrient requirements. While many cancer cells depend on exogenous glutamine for survival to justify the therapeutic targeting of glutamine metabolism, the mechanisms of glutamine dependence and likely response and resistance of such glutamine-targeting strategies among cancers are largely unknown. In th...

  1. Changes in Activities of Glutamine Synthetase during Grain Filling and Their Relation to Rice Quality

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Four japonica rice varieties differed in cooking and eating qualities were used in a pot experiment to study the relationship between the activities of glutamine synthetase during grain filling and rice quality. The activities of glutamine synthetase gradually increased and then declined as a single peak curve in the course of grain filling. The 15th day after heading was a turning point, before which the enzymatic activities in the inferior rice varieties with high protein content were higher than those in the superior rice varietie with low protein content, and after which it was converse. The activity of glutamine synthetase in grain was correlated with the taste meter value, peak viscosity and breakdown negatively at the early stage of grain filling whereas positively at the middle and late stages. Moreover, it was correlated with the protein content of rice grain and setback positively at the early stage and negatively at the middle and late stages. The correlation degree varied with the course of grain filling. From 15 days to 20 days after heading was a critical stage, in which the direction of correlation between the activity of glutamine synthetase and taste meter value and RVA properties of rice changed.

  2. Bacterial Type I Glutamine Synthetase of the Rifamycin SV Producing Actinomycete, Amycolatopsis mediterranei U32, is the Only Enzyme Responsible for Glutamine Synthesis under Physiological Conditions

    Institute of Scientific and Technical Information of China (English)

    Wen-Tao PENG; Jin WANG; Ting WU; Jian-Qiang HUANG; Jui-Shen CHIAO; Guo-Ping ZHAO

    2006-01-01

    The structural gene for glutamine synthetase, glnA, from Amycolatopsis mediterranei U32 was cloned via screening a genomic library using the analog gene from Streptomyces coelicolor. The clone was functionally verified by complementing for glutamine requirement of an Escherichia coli glnA null mutant under the control of a lac promoter. Sequence analysis showed an open reading frame encoding a protein of466 amino acid residues. The deduced amino acid sequence bears significant homologies to other bacterial type I glutamine synthetases, specifically, 71% and 72% identical to the enzymes of S. coelicolor and Mycobacterium tuberculosis, respectively. Disruption of this glnA gene in A. mediterranei U32 led to glutamine auxotrophy with no detectable glutamine synthetase activity in vivo. In contrast, the cloned glnA+ gene can complement for both phenotypes in trans. It thus suggested that in A. mediterranei U32, the glnA gene encoding glutamine synthetase is uniquely responsible for in vivo glutamine synthesis under our laboratory defined physiological conditions.

  3. Glutamine synthetase immunor present in oligodendroglia of regions of the central nervous system

    Science.gov (United States)

    D'Amelio, Fernando; Eng, Lawrence F.; Gibbs, Michael A.

    1990-01-01

    Glutamine synthetase immunoreactive oligodendrocytes were identified in the cerebral cortex, cerebellum, brain stem, and spinal cord. They were mostly confined to the gray matter, particularly close to neurons and processes. The white matter showed few immunoreactive oligodendroglia. It was suggested that some type of oligodendrocytes, specially those in perineuronal location, might fulfill a functional role more akin to astrocytes than to the normally myelinating oligodendroglia.

  4. Coexpression of glutamine synthetase and carbamoylphosphate synthase I genes in pancreatic hepatocytes of rat.

    OpenAIRE

    Yeldandi, A. V.; X. D. Tan; Dwivedi, R S; Subbarao, V; Smith, D. D.; Scarpelli, D. G.; Rao, M S; Reddy, J K

    1990-01-01

    In the mammalian liver the distribution of ammonia-detoxifying enzymes, glutamine synthetase (GS) and carbamoylphosphate synthase I (ammonia) (CPS-I), is mutually exclusive in that these enzymes are expressed in two distinct populations of hepatocytes that are zonally demarcated in the liver acinus. In the present study we examined the distribution of GS and CPS-I in pancreatic hepatocytes to ascertain if the expression of these two genes in these hepatocytes is also mutually exclusive. Multi...

  5. Glutamine Synthetase in Legumes: Recent Advances in Enzyme Structure and Functional Genomics

    OpenAIRE

    Marco Betti; Margarita García-Calderón; Pérez-Delgado, Carmen M.; Alfredo Credali; Guillermo Estivill; Francisco Galván; Vega, José M.; Márquez, Antonio J.

    2012-01-01

    Glutamine synthetase (GS) is the key enzyme involved in the assimilation of ammonia derived either from nitrate reduction, N2 fixation, photorespiration or asparagine breakdown. A small gene family is encoding for different cytosolic (GS1) or plastidic (GS2) isoforms in legumes. We summarize here the recent advances carried out concerning the quaternary structure of GS, as well as the functional relationship existing between GS2 and processes such as nodulation, photore...

  6. Organization and expression of genes in the genomic region surrounding the glutamine synthetase gene Gln1 from Lotus japonicus

    DEFF Research Database (Denmark)

    Thykjaer, T; Danielsen, D; She, Q;

    1997-01-01

    within the 23326-bp genomic region analysed. The LjGln1 gene encodes a cytosolic glutamine synthetase and the LjKrm (Kinesin repeat motif) gene encodes a polypeptide with similarity to a repeated motif present in the microtubule-associated kinesin light chain protein. Transcripts of the glutamine...

  7. Glucosamine synthetase from Escherichia coli: purification, properties and glutamine-utilizing site location

    International Nuclear Information System (INIS)

    L-Glutamine: D-fructose-6-phosphate amidotransferase (glucosamine synthetase) has been purified to homogeneity from Escherichia coli. A subunit molecular weight of 70,800 was estimated by gel electrophoresis in sodium dodecyl sulfate. Pure glucosamine synthetase did not exhibit detectable NH3-dependent activity and did not catalyze the reverse reaction. The enzyme has a K/sub m/ of 2 mM for fructose 6-phosphate, a K/sub m/ of 0.4 mM for glutamine, and a turnover number of 1140 min-1. The amino-terminal sequence confirmed the identification of residues 2-26 of the translated E. coli glmS sequence. Methionine-1 is therefore removed by processing in vivo, leaving cysteine as the NH2-terminal residue. The enzyme was inactivated by the glutamine analog 6-diazo-5-oxo-L-norleucine (DON) and by iodoacetamide. Glucosamine synthetase exhibited half-of-the-sites reactivity when incubated with DON in the absence of fructose 6-phosphate. In its presence, inactivation with [6-14C]DON was accompanied by incorporation of 1 equiv of inhibitor per enzyme subunit. From this behavior, a dimeric structure was tentatively assigned to the native enzyme. The site of reaction with DON was the NH2-terminal cysteine residue as shown by Edman degradation

  8. Reaction Mechanism of Mycobacterium Tuberculosis Glutamine Synthetase Using Quantum Mechanics/Molecular Mechanics Calculations.

    Science.gov (United States)

    Moreira, Cátia; Ramos, Maria J; Fernandes, Pedro Alexandrino

    2016-06-27

    This paper is devoted to the understanding of the reaction mechanism of mycobacterium tuberculosis glutamine synthetase (mtGS) with atomic detail, using computational quantum mechanics/molecular mechanics (QM/MM) methods at the ONIOM M06-D3/6-311++G(2d,2p):ff99SB//B3LYP/6-31G(d):ff99SB level of theory. The complete reaction undergoes a three-step mechanism: the spontaneous transfer of phosphate from ATP to glutamate upon ammonium binding (ammonium quickly loses a proton to Asp54), the attack of ammonia on phosphorylated glutamate (yielding protonated glutamine), and the deprotonation of glutamine by the leaving phosphate. This exothermic reaction has an activation free energy of 21.5 kcal mol(-1) , which is consistent with that described for Escherichia coli glutamine synthetase (15-17 kcal mol(-1) ). The participating active site residues have been identified and their role and energy contributions clarified. This study provides an insightful atomic description of the biosynthetic reaction that takes place in this enzyme, opening doors for more accurate studies for developing new anti-tuberculosis therapies. PMID:27225077

  9. Reassimilation of Photorespiratory Ammonium in Lotus japonicus Plants Deficient in Plastidic Glutamine Synthetase.

    Directory of Open Access Journals (Sweden)

    Carmen M Pérez-Delgado

    Full Text Available It is well established that the plastidic isoform of glutamine synthetase (GS2 is the enzyme in charge of photorespiratory ammonium reassimilation in plants. The metabolic events associated to photorespiratory NH4(+ accumulation were analyzed in a Lotus japonicus photorespiratory mutant lacking GS2. The mutant plants accumulated high levels of NH4(+ when photorespiration was active, followed by a sudden drop in the levels of this compound. In this paper it was examined the possible existence of enzymatic pathways alternative to GS2 that could account for this decline in the photorespiratory ammonium. Induction of genes encoding for cytosolic glutamine synthetase (GS1, glutamate dehydrogenase (GDH and asparagine synthetase (ASN was observed in the mutant in correspondence with the diminishment of NH4(+. Measurements of gene expression, polypeptide levels, enzyme activity and metabolite levels were carried out in leaf samples from WT and mutant plants after different periods of time under active photorespiratory conditions. In the case of asparagine synthetase it was not possible to determine enzyme activity and polypeptide content; however, an increased asparagine content in parallel with the induction of ASN gene expression was detected in the mutant plants. This increase in asparagine levels took place concomitantly with an increase in glutamine due to the induction of cytosolic GS1 in the mutant, thus revealing a major role of cytosolic GS1 in the reassimilation and detoxification of photorespiratory NH4(+ when the plastidic GS2 isoform is lacking. Moreover, a diminishment in glutamate levels was observed, that may be explained by the induction of NAD(H-dependent GDH activity.

  10. Glial glutamate transporter and glutamine synthetase regulate GABAergic synaptic strength in the spinal dorsal horn.

    Science.gov (United States)

    Jiang, Enshe; Yan, Xisheng; Weng, Han-Rong

    2012-05-01

    Decreased GABAergic synaptic strength ('disinhibition') in the spinal dorsal horn is a crucial mechanism contributing to the development and maintenance of pathological pain. However, mechanisms leading to disinhibition in the spinal dorsal horn remain elusive. We investigated the role of glial glutamate transporters (GLT-1 and GLAST) and glutamine synthetase in maintaining GABAergic synaptic activity in the spinal dorsal horn. Electrically evoked GABAergic inhibitory post-synaptic currents (eIPSCs), spontaneous IPSCs (sIPSCs) and miniature IPSCs were recorded in superficial spinal dorsal horn neurons of spinal slices from young adult rats. We used (2S,3S)-3-[3-[4-(trifluoromethyl)benzoylamino]benzyloxy]aspartate (TFB-TBOA), to block both GLT-1 and GLAST and dihydrokainic acid to block only GLT-1. We found that blockade of both GLAST and GLT-1 and blockade of only GLT-1 in the spinal dorsal horn decreased the amplitude of GABAergic eIPSCs, as well as both the amplitude and frequency of GABAergic sIPSCs or miniature IPSCs. Pharmacological inhibition of glial glutamine synthetase had similar effects on both GABAergic eIPSCs and sIPSCs. We provided evidence demonstrating that the reduction in GABAergic strength induced by the inhibition of glial glutamate transporters is due to insufficient GABA synthesis through the glutamate-glutamine cycle between astrocytes and neurons. Thus, our results indicate that deficient glial glutamate transporters and glutamine synthetase significantly attenuate GABAergic synaptic strength in the spinal dorsal horn, which may be a crucial synaptic mechanism underlying glial-neuronal interactions caused by dysfunctional astrocytes in pathological pain conditions. PMID:22339645

  11. Regulation of the intersubunit ammonia tunnel in Mycobacterium tuberculosis glutamine-dependent NAD[superscript +] synthetase

    Energy Technology Data Exchange (ETDEWEB)

    Chuenchor, Watchalee; Doukov, Tzanko I.; Resto, Melissa; Chang, Andrew; Gerratana, Barbara (SSRL); (Maryland)

    2012-08-31

    Glutamine-dependent NAD{sup +} synthetase is an essential enzyme and a validated drug target in Mycobacterium tuberculosis (mtuNadE). It catalyses the ATP-dependent formation of NAD{sup +} from NaAD{sup +} (nicotinic acid-adenine dinucleotide) at the synthetase active site and glutamine hydrolysis at the glutaminase active site. An ammonia tunnel 40 {angstrom} (1 {angstrom} = 0.1 nm) long allows transfer of ammonia from one active site to the other. The enzyme displays stringent kinetic synergism; however, its regulatory mechanism is unclear. In the present paper, we report the structures of the inactive glutaminase C176A variant in an apo form and in three synthetase-ligand complexes with substrates (NaAD{sup +}/ATP), substrate analogue {l_brace}NaAD{sup +}/AMP-CPP (adenosine 5'-[{alpha},{beta}-methylene]triphosphate){r_brace} and intermediate analogues (NaAD{sup +}/AMP/PPi), as well as the structure of wild-type mtuNadE in a product complex (NAD{sup +}/AMP/PPi/glutamate). This series of structures provides snapshots of the ammonia tunnel during the catalytic cycle supported also by kinetics and mutagenesis studies. Three major constriction sites are observed in the tunnel: (i) at the entrance near the glutaminase active site; (ii) in the middle of the tunnel; and (iii) at the end near the synthetase active site. Variation in the number and radius of the tunnel constrictions is apparent in the crystal structures and is related to ligand binding at the synthetase domain. These results provide new insight into the regulation of ammonia transport in the intermolecular tunnel of mtuNadE.

  12. Crystallization and preliminary crystallographic characterization of glutamine synthetase from Medicago truncatula

    International Nuclear Information System (INIS)

    The enzyme glutamine synthetase from M. truncatula has been expressed, purified and crystallized. The crystals belonged to the monoclinic space group P21 and diffracted to 2.35 Å resolution. The condensation of ammonium and glutamate into glutamine catalyzed by glutamine synthetase (GS) is a fundamental step in nitrogen metabolism in all kingdoms of life. In plants, this is preceded by the reduction of inorganic nitrogen to an ammonium ion and therefore effectively articulates nitrogen fixation and metabolism. Although the three-dimensional structure of the dodecameric bacterial GS was determined quite some time ago, the quaternary architecture of the plant enzyme has long been assumed to be octameric, mostly on the basis of low-resolution electron-microscopy studies. Recently, the crystallographic structure of a monocotyledonous plant GS was reported that revealed a homodecameric organization. In order to unambiguously establish the quaternary architecture of GS from dicotyledonous plants, GS1a from the model legume Medicago truncatula was overexpressed, purified and crystallized. The collection of synchrotron diffraction data to 2.35 Å resolution allowed the determination of the three-dimensional structure of this enzyme by molecular replacement

  13. The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture

    Energy Technology Data Exchange (ETDEWEB)

    Torreira, Eva [Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Seabra, Ana Rita [IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); Marriott, Hazel; Zhou, Min [University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom); Llorca, Óscar [Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Robinson, Carol V. [University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom); Carvalho, Helena G. [IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); Fernández-Tornero, Carlos, E-mail: cftornero@cib.csic.es [Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Pereira, Pedro José Barbosa, E-mail: cftornero@cib.csic.es [IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto (Portugal); Centro de Investigaciones Biológicas – CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain)

    2014-04-01

    The experimental models of dicotyledonous cytoplasmic and plastid-located glutamine synthetases unveil a conserved eukaryotic-type decameric architecture, with subtle structural differences in M. truncatula isoenzymes that account for their distinct herbicide resistance. The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants.

  14. The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture

    International Nuclear Information System (INIS)

    The experimental models of dicotyledonous cytoplasmic and plastid-located glutamine synthetases unveil a conserved eukaryotic-type decameric architecture, with subtle structural differences in M. truncatula isoenzymes that account for their distinct herbicide resistance. The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants

  15. Cloning and expression of the Thiobacillus ferrooxidans glutamine synthetase gene in Escherichia coli

    International Nuclear Information System (INIS)

    The glutamine synthetase (GS) gene glnA of Thiobacillus ferrooxidans was cloned on recombinant plasmid pMEB100 which enabled Escherichia coli glnA deletion mutants to utilize (NH4)2SO4 as the sole source of nitrogen. High levels of GS-specific activity were obtained in the E. coli glnA deletion mutants containing the T. ferrooxidans GS gene. The cloned T. ferrooxidans DNA fragment containing the glnA gene activated histidase activity in an E. coli glnA glnL glnG deletion mutant containing the Klebsiella aerogenes hut operon. Plasmid pMEB100 also enabled the E. coli glnA glnL glnG deletion mutant to utilize arginine or low levels of glutamine as the sole source of nitrogen. There was no detectable DNA homology between the T. ferrooxidans glnA gene and the E. coli glnA gene

  16. Comparative properties of glutamine synthetases I and II in Rhizobium and Agrobacterium spp.

    OpenAIRE

    Fuchs, R L; Keister, D L

    1980-01-01

    Some properties of glutamine synthetase I (GSI) and GSII are described for a fast-growing Rhizobium sp. (Rhizobium trifolii T1), a slow-growing Rhizobium sp. (Rhizobium japonicum USDA 83), and Agrobacterium tumefaciens C58. GSII of the fast-growing Rhizobium sp. and GSII of the Agrobacterium sp. were considerably more heat labile than GSII of the slow-growing Rhizobium sp. As previously shown in R. japonicum 61A76, GSI became adenylylated rapidly in all species tested in response to ammonium....

  17. Dexamethasone enhances glutamine synthetase activity and reduces N-methyl-D-aspartate neurotoxicity in mixed cultures of neurons and astrocytes

    Directory of Open Access Journals (Sweden)

    Edith Debroas

    2015-05-01

    Full Text Available Astrocytes are claimed to protect neurons against excitotoxicity by clearing glutamate from the extracellular space and rapidly converting it into glutamine. Glutamine, is then released into the extracellular medium, taken up by neurons and transformed back into glutamate which is then stored into synaptic vesicles. Glutamine synthetase (GS, the key enzyme that governs this glutamate/glutamine cycle, is known to be upregulated by glucocorticoids. In the present work we have thus studied in parallel the effects of dexamethasone on glutamine synthetase activity and NMDA-induced neuronal death in cultures derived from the brain cortex of murine embryos. We showed that dexamethasone was able to markedly enhance GS activity in cultures of astrocytes but not in near pure neuronal cultures. The pharmacological characteristics of the dexamethasone action strongly suggest that it corresponds to a typical receptor-mediated effect. We also observed that long lasting incubation (72 h of mixed astrocyte-neuron cultures in the presence of 100 nM dexamethasone significantly reduced the toxicity of NMDA treatment. Furthermore we demonstrated that methionine sulfoximine, a selective inhibitor of GS, abolished the dexamethasone-induced increase in GS activity and also markedly potentiated NMDA toxicity. Altogether these results suggest that dexamethasone may promote neuroprotection through a stimulation of astrocyte glutamine synthetase.

  18. Sirtuin-dependent reversible lysine acetylation of glutamine synthetases reveals an autofeedback loop in nitrogen metabolism.

    Science.gov (United States)

    You, Di; Yin, Bin-Cheng; Li, Zhi-Hai; Zhou, Ying; Yu, Wen-Bang; Zuo, Peng; Ye, Bang-Ce

    2016-06-14

    In cells of all domains of life, reversible lysine acetylation modulates the function of proteins involved in central cellular processes such as metabolism. In this study, we demonstrate that the nitrogen regulator GlnR of the actinomycete Saccharopolyspora erythraea directly regulates transcription of the acuA gene (SACE_5148), which encodes a Gcn5-type lysine acetyltransferase. We found that AcuA acetylates two glutamine synthetases (GlnA1 and GlnA4) and that this lysine acetylation inactivated GlnA4 (GSII) but had no significant effect on GlnA1 (GSI-β) activity under the conditions tested. Instead, acetylation of GlnA1 led to a gain-of-function that modulated its interaction with the GlnR regulator and enhanced GlnR-DNA binding. It was observed that this regulatory function of acetylated GSI-β enzymes is highly conserved across actinomycetes. In turn, GlnR controls the catalytic and regulatory activities (intracellular acetylation levels) of glutamine synthetases at the transcriptional and posttranslational levels, indicating an autofeedback loop that regulates nitrogen metabolism in response to environmental change. Thus, this GlnR-mediated acetylation pathway provides a signaling cascade that acts from nutrient sensing to acetylation of proteins to feedback regulation. This work presents significant new insights at the molecular level into the mechanisms underlying the regulation of protein acetylation and nitrogen metabolism in actinomycetes. PMID:27247389

  19. Glutamine synthetase in Medicago truncatula, unveiling new secrets of a very old enzyme

    Directory of Open Access Journals (Sweden)

    Ana Rita Seabra

    2015-07-01

    Full Text Available Glutamine Synthetase (GS catalyses the first step at which nitrogen is brought into cellular metabolism and is also involved in the reassimilation of ammonium released by a number of metabolic pathways. Due to its unique position in plant nitrogen metabolism, GS plays essential roles in all aspects of plant development, from germination to senescence, and is a key component of nitrogen use efficiency (NUE and plant yield. Understanding the mechanisms regulating GS activity is therefore of utmost importance and a great effort has been dedicated to understand how GS is regulated in different plant species. The present review summarizes exciting recent developments concerning the structure and regulation of glutamine synthetase isoenzymes, using the model legume Medicago truncatula. These include the understanding of the structural determinants of both the cytosolic and plastid located isoenzymes, the existence of a seed-specific GS gene unique to M. truncatula and closely related species and the discovery that GS isoenzymes are regulated by nitric oxide at the post-translational level. The data is discussed and integrated with the potential roles of the distinct GS isoenzymes within the whole plant context.

  20. Antipeptide antibodies that can distinguish specific subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Cai, X.; Henry, R. L.; Takemoto, L. J.; Guikema, J. A.; Wong, P. P.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The amino acid sequences of the beta and gamma subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.) root nodules are very similar. However, there are small regions within the sequences that are significantly different between the two polypeptides. The sequences between amino acids 2 and 9 and between 264 and 274 are examples. Three peptides (gamma 2-9, gamma 264-274, and beta 264-274) corresponding to these sequences were synthesized. Antibodies against these peptides were raised in rabbits and purified with corresponding peptide-Sepharose affinity chromatography. Western blot analysis of polyacrylamide gel electrophoresis of bean nodule proteins demonstrated that the anti-beta 264-274 antibodies reacted specifically with the beta polypeptide and the anti-gamma 264-274 and anti-gamma 2-9 antibodies reacted specifically with the gamma polypeptide of the native and denatured glutamine synthetase. These results showed the feasibility of using synthetic peptides in developing antibodies that are capable of distinguishing proteins with similar primary structures.

  1. Purification and Properties of a Prokaryote Type Glutamine Synthetase from the Bialaphos Producer Streptomyces hygroscopicus SF1293

    NARCIS (Netherlands)

    Kumada, Yoichi; Takano, Eriko; Nagaoka, Kozo

    1990-01-01

    A prokaryote type glutamine synthetase (GS) was purified from a bialaphos (BA)-producing organism, Streptomyces hygroscopicus SF1293 (SF1293). The GS (GS I) consisted of a 55,000 dalton subunit, and its N-terminal amino acid sequence was similar to that of S. coelicolor GS. GS I was highly sensitive

  2. Phenotypic Changes Resulting from Distinct Point Mutations in the Azospirillum brasilense glnA Gene, Encoding Glutamine Synthetase

    OpenAIRE

    Van Dommelen, Anne; Keijers, Veerle; Wollebrants, An; Vanderleyden, Jozef

    2003-01-01

    Sequencing the glnA genes of two chemically induced Azospirillum brasilense glutamine synthetase mutants revealed an Arg→Cys mutation, corresponding to the glutamate binding site, in one mutant and an Asp→Asn mutation, corresponding to the ammonium binding site, in the second mutant. The phenotypic changes in these mutants are discussed in relation to their genotypes.

  3. Plant growth is influenced by glutamine synthetase-catalyzed nitrogen metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Langston-Unkefer, P.J.

    1991-06-11

    Ammonia assimilation has been implicated as participating in regulation of nitrogen fixation in free-living bacteria. In fact, these simple organisms utilize an integrated regulation of carbon and nitrogen metabolism; we except to observe an integration of nitrogen and carbon fixation in plants; how could these complex systems grow efficiently and compete in the ecosystem without coordinating these two crucial activities We have been investigating the role of ammonia assimilation regulating the complex symbiotic nitrogen fixation of legumes. Just as is observed in the simple bacterial systems, perturbation of ammonia assimilation in legumes results in increased overall nitrogen fixation. The perturbed plants have increased growth and total nitrogen fixation capability. Because we have targeted the first enyzme in ammonia assimilation, glutamine synthetase, this provides a marker that could be used to assist selection or screening for increased biomass yield. 45 refs., 4 tabs.

  4. Glutamine Synthetase in Legumes: Recent Advances in Enzyme Structure and Functional Genomics

    Directory of Open Access Journals (Sweden)

    Marco Betti

    2012-06-01

    Full Text Available Glutamine synthetase (GS is the key enzyme involved in the assimilation of ammonia derived either from nitrate reduction, N2 fixation, photorespiration or asparagine breakdown. A small gene family is encoding for different cytosolic (GS1 or plastidic (GS2 isoforms in legumes. We summarize here the recent advances carried out concerning the quaternary structure of GS, as well as the functional relationship existing between GS2 and processes such as nodulation, photorespiration and water stress, in this latter case by means of proline production. Functional genomic analysis using GS2-minus mutant reveals the key role of GS2 in the metabolic control of the plants and, more particularly, in carbon metabolism.

  5. Inhibition of Glutamine Synthetase: A Potential Drug Target in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Sherry L. Mowbray

    2014-08-01

    Full Text Available Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Globally, tuberculosis is second only to AIDS in mortality and the disease is responsible for over 1.3 million deaths each year. The impractically long treatment schedules (generally 6–9 months and unpleasant side effects of the current drugs often lead to poor patient compliance, which in turn has resulted in the emergence of multi-, extensively- and totally-drug resistant strains. The development of new classes of anti-tuberculosis drugs and new drug targets is of global importance, since attacking the bacterium using multiple strategies provides the best means to prevent resistance. This review presents an overview of the various strategies and compounds utilized to inhibit glutamine synthetase, a promising target for the development of drugs for TB therapy.

  6. The Populus Superoxide Dismutase Gene Family and Its Responses to Drought Stress in Transgenic Poplar Overexpressing a Pine Cytosolic Glutamine Synthetase (GS1a)

    OpenAIRE

    Molina-Rueda, Juan Jesús; Tsai, Chung Jui; Kirby, Edward G.

    2013-01-01

    Background Glutamine synthetase (GS) plays a central role in plant nitrogen assimilation, a process intimately linked to soil water availability. We previously showed that hybrid poplar (Populus tremula X alba, INRA 717-1B4) expressing ectopically a pine cytosolic glutamine synthetase gene (GS1a) display enhanced tolerance to drought. Preliminary transcriptome profiling revealed that during drought, members of the superoxide dismutase (SOD) family were reciprocally regulated in GS poplar when...

  7. Glutamine synthetase and Wnt-signaling%谷氨酰胺合成酶与Wnt信号转导通路

    Institute of Scientific and Technical Information of China (English)

    彭春伟; 燕敏

    2009-01-01

    GS(glutamine synthetase)或GLUL(glutamate-ammonia ligase),即谷氨酰胺合成酶,为人体内重要的功能酶,催化谷氨酸与氨生成谷氨酰胺.在体内氮的代谢中,尤其在维持氨离子和谷氨酰胺的稳定中发挥着重要的作用.GS表达和活性的异常常会导致人体很多疾病的发生.近年来研究发现GS表达和活性的异常与Wnt信号通路的异常密切相关.%GS is also called glutamine synthetase or glutamate-ammonia ligase, which is an important enzyme in human body. It can catalyze glutamine from glutamate and ammonia. Besides, it plays an important role in nitrogen metabolism, particularly in homeostasis of blood levels of ammonium ions and glutamine. The aberrant expression and activity will cause many human diseases. Recent studies show that the abnormality of its expression and activity has a close relationship with the aberrance of Wnt-signaling.

  8. On the assembly of dodecameric glutamine synthetase from stable chaperonin complexes.

    Science.gov (United States)

    Fisher, M T

    1993-07-01

    For many in vitro protein-folding reactions, the fraction of correctly folded product declines as the initial protein concentration increases due primarily to misfolding and aggregation reactions. Under optimal conditions and in the presence of ATP, chaperonins (groEL and groES) enhanced the renaturation of dodecameric glutamine synthetase (GS) with yields of active enzyme between 75 and 85% of the original activity (Fisher, M.T. (1992) Biochemistry 31, 3955-3963). In spite of this enhancement, a concentration-dependent decline in recoverable activity was observed when increasing concentrations of unfolded GS were rapidly mixed with renaturation buffer containing a 2-fold molar excess (GS subunits:groEL oligomer) of chaperonins. When a stable groEL-GS complex, formed under optimal conditions, was concentrated 4-fold by centrifugal ultrafiltration prior to ATP addition, the amount of total active GS (percent of the original activity) recovered remained at optimal levels and no longer showed a concentration-dependent decline. The GS subunits that are initially bound and then released from groEL by ATP are assembly-competent. It is proposed that the subunits are no longer able to kinetically equilibrate with folding intermediates that misfold or aggregate. If a stable groEL-protein substrate complex can be amassed without loss of activity, this will facilitate studies on molecular aspects of chaperonin release mechanisms and oligomeric protein assembly. PMID:8100224

  9. Modulation of phenolic metabolism under stress conditions in a Lotus japonicus mutant lacking plastidic glutamine synthetase.

    Science.gov (United States)

    García-Calderón, Margarita; Pons-Ferrer, Teresa; Mrázova, Anna; Pal'ove-Balang, Peter; Vilková, Mária; Pérez-Delgado, Carmen M; Vega, José M; Eliášová, Adriana; Repčák, Miroslav; Márquez, Antonio J; Betti, Marco

    2015-01-01

    This paper was aimed to investigate the possible implications of the lack of plastidic glutamine synthetase (GS2) in phenolic metabolism during stress responses in the model legume Lotus japonicus. Important changes in the transcriptome were detected in a GS2 mutant called Ljgln2-2, compared to the wild type, in response to two separate stress conditions, such as drought or the result of the impairment of the photorespiratory cycle. Detailed transcriptomic analysis showed that the biosynthesis of phenolic compounds was affected in the mutant plants in these two different types of stress situations. For this reason, the genes and metabolites related to this metabolic route were further investigated using a combined approach of gene expression analysis and metabolite profiling. A high induction of the expression of several genes for the biosynthesis of different branches of the phenolic biosynthetic pathway was detected by qRT-PCR. The extent of induction was always higher in Ljgln2-2, probably reflecting the higher stress levels present in this genotype. This was paralleled by accumulation of several kaempferol and quercetine glycosides, some of them described for the first time in L. japonicus, and of high levels of the isoflavonoid vestitol. The results obtained indicate that the absence of GS2 affects different aspects of phenolic metabolism in L. japonicus plants in response to stress. PMID:26442073

  10. Physiological Studies of Glutamine Synthetases I and III from Synechococcus sp. WH7803 Reveal Differential Regulation.

    Science.gov (United States)

    Domínguez-Martín, María Agustina; Díez, Jesús; García-Fernández, José M

    2016-01-01

    The marine picocyanobacterium Synechococcus sp. WH7803 possesses two glutamine synthetases (GSs; EC 6.3.1.2), GSI encoded by glnA and GSIII encoded by glnN. This is the first work addressing the physiological regulation of both enzymes in a marine cyanobacterial strain. The increase of GS activity upon nitrogen starvation was similar to that found in other model cyanobacteria. However, an unusual response was found when cells were grown under darkness: the GS activity was unaffected, reflecting adaptation to the environment where they thrive. On the other hand, we found that GSIII did not respond to nitrogen availability, in sharp contrast with the results observed for this enzyme in other cyanobacteria thus far studied. These features suggest that GS activities in Synechococcus sp. WH7803 represent an intermediate step in the evolution of cyanobacteria, in a process of regulatory streamlining where GSI lost the regulation by light, while GSIII lost its responsiveness to nitrogen. This is in good agreement with the phylogeny of Synechococcus sp. WH7803 in the context of the marine cyanobacterial radiation. PMID:27446010

  11. Glutamine synthetase in Durum Wheat: Genotypic Variation and Relationship with Grain Protein Content.

    Science.gov (United States)

    Nigro, Domenica; Fortunato, Stefania; Giove, Stefania L; Paradiso, Annalisa; Gu, Yong Q; Blanco, Antonio; de Pinto, Maria C; Gadaleta, Agata

    2016-01-01

    Grain protein content (GPC), is one of the most important trait in wheat and its characterized by a very complex genetic control. The identification of wheat varieties with high GPC (HGPC), as well as the characterization of central enzymes involved in these processes, are important for more sustainable agricultural practices. In this study, we focused on Glutamine synthetase (GS) as a candidate to study GPC in wheat. We analyzed GS expression and its enzymatic activity in different tissues and phenological stages in 10 durum wheat genotypes with different GPC. Although each genotype performed quite differently from the others, both because their genetic variability and their adaptability to specific environmental conditions, the highest GS activity and expression were found in genotypes with HGPC and vice versa the lowest ones in genotypes with low GPC (LGPC). Moreover, in genotypes contrasting in GPC bred at different nitrogen regimes (0, 60, 140 N Unit/ha) GS behaved differently in diverse organs. Nitrogen supplement increased GS expression and activity in roots of all genotypes, highlighting the key role of this enzyme in nitrogen assimilation and ammonium detoxification in roots. Otherwise, nitrogen treatments decreased GS expression and activity in the leaves of HGPC genotypes and did not affect GS in the leaves of LGPC genotypes. Finally, no changes in GS and soluble protein content occurred at the filling stage in the caryopses of all analyzed genotypes. PMID:27468287

  12. Physiological Studies of Glutamine Synthetases I and III from Synechococcus sp. WH7803 Reveal Differential Regulation

    Science.gov (United States)

    Domínguez-Martín, María Agustina; Díez, Jesús; García-Fernández, José M.

    2016-01-01

    The marine picocyanobacterium Synechococcus sp. WH7803 possesses two glutamine synthetases (GSs; EC 6.3.1.2), GSI encoded by glnA and GSIII encoded by glnN. This is the first work addressing the physiological regulation of both enzymes in a marine cyanobacterial strain. The increase of GS activity upon nitrogen starvation was similar to that found in other model cyanobacteria. However, an unusual response was found when cells were grown under darkness: the GS activity was unaffected, reflecting adaptation to the environment where they thrive. On the other hand, we found that GSIII did not respond to nitrogen availability, in sharp contrast with the results observed for this enzyme in other cyanobacteria thus far studied. These features suggest that GS activities in Synechococcus sp. WH7803 represent an intermediate step in the evolution of cyanobacteria, in a process of regulatory streamlining where GSI lost the regulation by light, while GSIII lost its responsiveness to nitrogen. This is in good agreement with the phylogeny of Synechococcus sp. WH7803 in the context of the marine cyanobacterial radiation. PMID:27446010

  13. Glutamine synthetase activity and glutamate uptake in hippocampus and frontal cortex in portal hypertensive rats

    Institute of Scientific and Technical Information of China (English)

    Gabriela Beatriz Acosta; María Alejandra Fernández; Diego Martín Roselló; María Luján Tomaro; Karina Balestrasse; Abraham Lemberg

    2009-01-01

    AIM: To study glutamine synthetase (GS) activity and glutamate uptake in the hippocampus and frontal cortex (FC) from rats with prehepatic portal vein hypertension. METHODS: Male Wistar rats were divided into shamoperated group and a portal hypertension (PH) group with a regulated stricture of the portal vein. Animals were sacrificed by decapitation 14 d after portal vein stricture. GS activity was determined in the hippocampus and FC. Specific uptake of radiolabeled L-glutamate was studied using synaptosome-enriched fractions that were freshly prepared from both brain areas. RESULTS: We observed that the activity of GS increased in the hippocampus of PH rats, as compared to control animals, and decreased in the FC. A significant decrease in glutamate uptake was found in both brain areas, and was more marked in the hippocampus. The decrease in glutamate uptake might have been caused by a deficient transport function, significantly and persistent increase in this excitatory neurotransmitter activity. CONCLUSION: The presence of moderate ammonia blood levels may add to the toxicity of excitotoxic glutamate in the brain, which causes alterations in brain function. Portal vein stricture that causes portal hypertension modifies the normal function in some brain regions.

  14. Metabolic indicators of drought stress tolerance in wheat: glutamine synthetase isoenzymes and Rubisco.

    Science.gov (United States)

    Nagy, Zoltán; Németh, Edit; Guóth, Adrienn; Bona, Lajos; Wodala, Barnabás; Pécsváradi, Attila

    2013-06-01

    Drought stress has a considerable impact on the ecosystem and agriculture. Continuous water deficit induces early leaf senescence in plants. During this process, chloroplasts are degraded and photosynthesis drastically drops. The objective of this investigation was to look into the regulation of nitrogen and carbon metabolism during water deficit. Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase; EC 4.1.1.39) and the total protein contents inform us of the sink-source relation in plants. Glutamine synthetase (GS, EC 6.3.1.2) isoenzymes are good markers of plastid status (GS2) and the nitrogen metabolism (GS1). Tolerant and sensitive wheat (Triticum aestivum L.) genotypes were tested, which are widely used in agriculture. The amount of protein, Rubisco and GS isoforms in leaves were measured during the grain filling period, as indicative traits that ultimately determine the onset and stage of senescence. The symptoms of senescence first appeared on the oldest and finally on the youngest leaves. Drought stress disrupted the sequentiality of senescence in the sensitive varieties. An untimely senescence appeared in flag leaves, earlier than in the older leaves. Total protein and Rubisco contents decreased and the GS2 isoenzyme declined considerably in the youngest leaves. In the tolerant varieties, however, these physiological parameters did not change under drought, only the sequential senescence of leaf levels accelerated in some cases compared to the control, well-watered plants. Our results revealed that GS is a good indicator of drought stress, which can be applied for the characterization of wheat cultivars in terms of drought stress tolerance. PMID:23542183

  15. The Synechococcus strain PCC 7942 glnN product (glutamine synthetase III) helps recovery from prolonged nitrogen chlorosis.

    Science.gov (United States)

    Sauer, J; Dirmeier, U; Forchhammer, K

    2000-10-01

    We report the cloning and sequencing of the glnN gene encoding a class III glutamine synthetase from the cyanobacterium Synechococcus strain PCC 7942. Mapping of the transcriptional start site revealed a DNA sequence in the promoter region that resembles an imperfect NtcA binding motif. Expression of glnN is impaired in NtcA- and P(II)-deficient mutants. The only parameter which was negatively affected in the glnN mutant compared to the wild type was the recovery rate of prolonged nitrogen-starved cells with low concentrations of combined nitrogen. PMID:10986271

  16. The Synechococcus Strain PCC 7942 glnN Product (Glutamine Synthetase III) Helps Recovery from Prolonged Nitrogen Chlorosis

    OpenAIRE

    Sauer, Jörg; Dirmeier, Ulrike; Forchhammer, Karl

    2000-01-01

    We report the cloning and sequencing of the glnN gene encoding a class III glutamine synthetase from the cyanobacterium Synechococcus strain PCC 7942. Mapping of the transcriptional start site revealed a DNA sequence in the promoter region that resembles an imperfect NtcA binding motif. Expression of glnN is impaired in NtcA- and PII-deficient mutants. The only parameter which was negatively affected in the glnN mutant compared to the wild type was the recovery rate of prolonged nitrogen-star...

  17. Glutamine availability as a target for the control of Glutamine-Synthetase negative human cancers: the case of oligodendroglioma

    OpenAIRE

    Ottaviani, Laura

    2015-01-01

    The amino acid Glutamine (Gln) is a nutrient of fundamental importance for cell metabolism. It is involved in many metabolic pathways, such as the synthesis of non essential amino acids, nucleotides and hexosamines, the regulation of cell volume, the response to oxidative stress (through the maintenance of intracellular glutathione). Moreover, it refuels the Krebs cycle with carbon moieties (anaplerosis) and activates mTOR, possibly through the energization of leucine influx. It has been k...

  18. Optimization of crude enzyme preparation methods for analysis of glutamine synthetase activity in phytoplankton and field samples

    Institute of Scientific and Technical Information of China (English)

    WANG Yujue; WANG Dazhi; HONG Huasheng

    2009-01-01

    Glutamine synthetase (GS) is an important enzyme involved in nitrogen assimilation and metabolism in marine phytoplankton. However, little work has been done in situ due to the limitation of crude enzyme preparation methods. In this study, three enzyme preparation methods, high-speed centrifugation (HC, <10 000 g), ultracentrifugation (UC, 70 000 g), and ultrafiltration (UF) with 100 kμ, molecular weight cutoff, were compared using two diatom species (Asterionellopsis glacialis and Thalassiosira weissflogii), and two dinoflagellate species (Alexandrium catenella and Prorocentrum donghaiense) as experimental materials together with field samples collected from Xiamen Harbor, China. The results showed that HC is the best method to prepare crude enzymes for glutamine synthetase activity (GSA) in diatom species and diatom-dominant samples, while UF is the best method to extract GS from dinoflagellate species and dinoflagellate-dominant samples. For the HC method, the optimal centrifugal speed and time were 10 000 g and 35 min, respectively, and under these conditions, the highest GSA was obtained in all samples. This study indicates that both methods (HC and UF) overcome the limitation of centrifugal speed and could be applied to in situ GSA analysis, especially at sea.

  19. Effect of post-silking drought on nitrogen partitioning and gene expression patterns of glutamine synthetase and asparagine synthetase in two maize (Zea mays L.) varieties.

    Science.gov (United States)

    Li, Yajun; Wang, Meiling; Zhang, Fengxia; Xu, Yadong; Chen, Xiaohong; Qin, Xiaoliang; Wen, Xiaoxia

    2016-05-01

    Glutamine synthetase (GS) and asparagine synthetase (AS) are proposed to have important function in plant nitrogen (N) remobilization, but their roles under drought stress are not well defined. In this study, the expression dynamics of GS and AS genes were analyzed in two maize varieties (ZD958 and NH101) in relation to post-silking drought stress induced nitrogen partitioning. ZD958 was a 'stay-green' variety with 5% nitrogen harvest index (NHI) lower than NH101. From silking to maturity, the amount of nitrogen remobilized from ear-leaves in ZD958 was evidently lower than NH101, and post-silking drought stress increased the nitrogen remobilization for both varieties. In ear-leaves, the expression of ZmGln1-3 was enhanced under drought stress. Three AS genes (ZmAS1, ZmAS2 and ZmAS3) were differentially regulated by post-silking drought treatment, of which the expression of ZmAS3 was stimulated at late stage of leaf senescence. In NH101, the expression level of ZmAS3 was markedly higher than that in ZD958. In developing grains, there were no significant differences in expression patterns of GS and AS genes between well water and drought treated plants. Drought stress altered maize N partitioning at the whole-plant level, and the up-regulation of GS and AS genes may contribute to the higher leaf nitrogen remobilization when exposed to drought treatments. PMID:26913793

  20. Characterization of Glutamine-Requiring Mutants of Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, Dick B.; Joosten, Han M.L.J.; Herst, Patricia M.; Drift, Chris van der

    1982-01-01

    Revertants were isolated from a glutamine-requiring mutant of Pseudomonas aeruginosa PAO. One strain showed thermosensitive glutamine requirement and formed thermolabile glutamine synthetase, suggesting the presence of a mutation in the structural gene for glutamine synthetase. The mutation conferri

  1. Medicago truncatula contains a second gene encoding a plastid located glutamine synthetase exclusively expressed in developing seeds

    Directory of Open Access Journals (Sweden)

    Seabra Ana R

    2010-08-01

    Full Text Available Abstract Background Nitrogen is a crucial nutrient that is both essential and rate limiting for plant growth and seed production. Glutamine synthetase (GS, occupies a central position in nitrogen assimilation and recycling, justifying the extensive number of studies that have been dedicated to this enzyme from several plant sources. All plants species studied to date have been reported as containing a single, nuclear gene encoding a plastid located GS isoenzyme per haploid genome. This study reports the existence of a second nuclear gene encoding a plastid located GS in Medicago truncatula. Results This study characterizes a new, second gene encoding a plastid located glutamine synthetase (GS2 in M. truncatula. The gene encodes a functional GS isoenzyme with unique kinetic properties, which is exclusively expressed in developing seeds. Based on molecular data and the assumption of a molecular clock, it is estimated that the gene arose from a duplication event that occurred about 10 My ago, after legume speciation and that duplicated sequences are also present in closely related species of the Vicioide subclade. Expression analysis by RT-PCR and western blot indicate that the gene is exclusively expressed in developing seeds and its expression is related to seed filling, suggesting a specific function of the enzyme associated to legume seed metabolism. Interestingly, the gene was found to be subjected to alternative splicing over the first intron, leading to the formation of two transcripts with similar open reading frames but varying 5' UTR lengths, due to retention of the first intron. To our knowledge, this is the first report of alternative splicing on a plant GS gene. Conclusions This study shows that Medicago truncatula contains an additional GS gene encoding a plastid located isoenzyme, which is functional and exclusively expressed during seed development. Legumes produce protein-rich seeds requiring high amounts of nitrogen, we postulate

  2. Ammonium assimilation in rice based on the occurrence of 15N and inhibition of glutamine synthetase activity

    International Nuclear Information System (INIS)

    Assimilation of ammonium (NH4) into free amino acids and total reduced nitrogen (N) was monitored in both roots and shoots of two-week old rice seedlings supplied with 5 mM 99% (15NH4)2SO4 in aerated hydroponic culture with or without a 2 h preincubation with 1 mM methionine sulfoximine (MSX) an inhibitor of glutamine synthetase (GS) activity. 15NH4 was not assimilated into amino acids when the GS/GOGAT (glutamate synthase) cycle was inhibited by MSX. Inhibition of glutamine synthetase (GS) activity in roots with MSX increased both the amount of NH4 and the abundance of 15N labeled NH4. In contrast, the amount of Gln and Glu, and their proportions as 15N, decreased in roots when GS activity was inhibited. This research confirms the importance of GS/GOGAT in NH4 assimilation in rice roots. 15N-labeled studies indicate that NH4 ions incorporated by roots of rice are transformed primarily into glutamine (Gin) and glutamic acid (Glu) before being converted to other amino acids through transamination. The formation of amino acids such as aspartic acid (Asp) and alanine (Ala) directly from free NH4 in roots also has been reported. Translocation of free NH4 to plant shoots, based on the concentration of free NH4 in xylem exudate, has been reported in tomato, although NH4 in shoots primarily originates from nitrate reduction in the shoot. Photorespiration also can contribute to the accumulation of NH4 in leaves. The GS/GOGAT cycle appears to be primarily responsible for the assimilation of exogenously supplied NH4 and NH4 derived from nitrate reduction in leaves, as well as NH4 derived from photorespiration. Genetic evidence cited to support this conclusion includes the lethal effect of photorespiratory conditions on plant mutants deficient in chloroplast-localized GS and GOGAT activities, and the rapid accumulation of free NH4 in GS-deficient mutants under photorespiratory conditions. The present study was initiated to quantify the in vivo amino acid synthesis in rice

  3. Repercussion of mesophyll-specific overexpression of a soybean cytosolic glutamine synthetase gene in alfalfa (Medicago sativa L.) and tobacco (Nicotiana tabaccum L.)

    OpenAIRE

    Seger, Mark; Ortega, Jose Luis; Bagga, Suman; Gopalan, Champa-Sengupta

    2009-01-01

    Glutamine synthetase (GS) plays a central role in plant nitrogen metabolism. Plant GS occurs as a number of isoenzymes present in either the cytosol (GS1) or chloroplast/plastid (GS2). There are several reports of improved performance in transgenic plants overexpressing GS1 transgenes driven by the constitutive CaMV35S promoter. Improvement has been attributed to the GS1 transgene product functioning to enhance re-assimilation of NH4+ released by photorespiration or protein degradation. In th...

  4. NITRIC OXIDE (NO, CITRULLINE - NO CYCLE ENZYMES, GLUTAMINE SYNTHETASE AND OXIDATIVE STRESS IN ANOXIA (HYPOBARIC HYPOXIA AND REPERFUSION IN RAT BRAIN

    Directory of Open Access Journals (Sweden)

    M. Swamy, Mohd Jamsani Mat Salleh, K. N .S. Sirajudeen, Wan Roslina Wan Yusof, G. Chandran

    2010-01-01

    Full Text Available Nitric oxide is postulated to be involved in the pathophysiology of neurological disorders due to hypoxia/ anoxia in brain due to increased release of glutamate and activation of N-methyl-D-aspartate receptors. Reactive oxygen species have been implicated in pathophysiology of many neurological disorders and in brain function. To understand their role in anoxia (hypobaric hypoxia and reperfusion (reoxygenation, the nitric oxide synthase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase and arginase activities along with the concentration of nitrate /nitrite, thiobarbituric acid reactive substances and total antioxidant status were estimated in cerebral cortex, cerebellum and brain stem of rats subjected to anoxia and reperfusion. The results of this study clearly demonstrated the increased production of nitric oxide by increased activity of nitric oxide synthase. The increased activities of argininosuccinate synthetase and argininosuccinate lyase suggest the increased and effective recycling of citrulline to arginine in anoxia, making nitric oxide production more effective and contributing to its toxic effects. The decreased activity of glutamine synthetase may favor the prolonged availability of glutamic acid causing excitotoxicity leading to neuronal damage in anoxia. The increased formation of thiobarbituric acid reactive substances and decreased total antioxidant status indicate the presence of oxidative stress in anoxia and reperfusion. The increased arginase and sustained decrease of GS activity in reperfusion group likely to be protective.

  5. Studies on Glutamine Synthetase Activity in Sugar Beet(Beta vulgaris L.) under Different Levels of Nitrogen

    Institute of Scientific and Technical Information of China (English)

    YanGuiping; YanHui; 等

    1995-01-01

    It was shown from the experiment that glutamine synthetase activity (GSA) in both leaf blades and roots under different nitrogen levels rose rapidly to reach its peak from seeding stage to foliage rapid growth stage and declined to its lowest level at the latter stage of root rapid growth,and then increased slightly,GSA in leaf blades had positive correlation with nitrogen level during the whole period of growth,GSA in roots showed the same tendency as it in leaf blades at the early middle stage of growth,but at the latter stage of growth,no positive correlation was established.GSA in leaf blades was the strongest compared with crowns,petioles and roots,and could represent the highest enzyme activity of the whole pant,GSA had quadratic curvilinear correlation with root yield and sugar production.GSA in leaf blades had significant positive correlation with α-NH2-N at the foliage rapid growth stage.

  6. Weak mitochondrial targeting sequence determines tissue-specific subcellular localization of glutamine synthetase in liver and brain cells.

    Science.gov (United States)

    Matthews, Gideon D; Gur, Noa; Koopman, Werner J H; Pines, Ophry; Vardimon, Lily

    2010-02-01

    Evolution of the uricotelic system for ammonia detoxification required a mechanism for tissue-specific subcellular localization of glutamine synthetase (GS). In uricotelic vertebrates, GS is mitochondrial in liver cells and cytoplasmic in brain. Because these species contain a single copy of the GS gene, it is not clear how tissue-specific subcellular localization is achieved. Here we show that in chicken, which utilizes the uricotelic system, the GS transcripts of liver and brain cells are identical and, consistently, there is no difference in the amino acid sequence of the protein. The N-terminus of GS, which constitutes a 'weak' mitochondrial targeting signal (MTS), is sufficient to direct a chimeric protein to the mitochondria in hepatocytes and to the cytoplasm in astrocytes. Considering that a weak MTS is dependent on a highly negative mitochondrial membrane potential (DeltaPsi) for import, we examined the magnitude of DeltaPsi in hepatocytes and astrocytes. Our results unexpectedly revealed that DeltaPsi in hepatocytes is considerably more negative than that of astrocytes and that converting the targeting signal into 'strong' MTS abolished the capability to confer tissue-specific subcellular localization. We suggest that evolutional selection of weak MTS provided a tool for differential targeting of an identical protein by taking advantage of tissue-specific differences in DeltaPsi. PMID:20053634

  7. Tissue-specific changes of glutamine synthetase activity in oats after rhizosphere infestation by Pseudomonas syringae pv. tabaci. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knight, T.J. [Univ. of Southern Maine, Portland, ME (United States); Temple, S.; Sengupta-Gopalan, C. [New Mexico State Univ., Las Curces, NM (United States)] [and others

    1996-05-15

    Oats (Avena sativa L. lodi) tolerant of rhizosphere infestation by Pseudomonas syringae pv. tabaci when challenged by the pathogen experience tissue-specific alterations of ammonia assimilatory capabilities. Altered ammonia assimilatory potentials between root and leaf tissue result from selective inactivation of glutamine synthetase (GS) by the toxin Tabtoxinine-B-lactam (TBL). Root GS is sensitive and leaf GSs are resistant to TBL inactivation. With prolonged challenge by the pathogen root GS activity decreases but leaf GS specific activity increase. Higher leaf GS activity is due to decreased rates of degradation rather than increased GS synthesis. Higher leaf GS activity and elevated levels of GS polypeptide appear to result from a limited interaction between GS and TBL leading to the accumulation of a less active but more stable GS holoenzyme. Tolerant challenged oats besides surviving rhizosphere infestation, experience enhanced growth. A strong correlation exists between leaf GS activity and whole plant fresh weight, suggesting that tissue-specific changes in ammonia assimilatory capability provides the plant a more efficient mechanism for uptake and utilization of nitrogen.

  8. TXNIP Suppresses Expression of Glutamine Synthetase by Inducing Oxidative Stress in Retinal Muller Glia Under Diabetic Conditions.

    Science.gov (United States)

    Zhou, Jia; Shen, Xi; Lu, Qiong; Zhang, Min

    2016-01-01

    BACKGROUND Diabetic retinopathy (DR) is a progressive neurodegenerative disease with early-stage symptoms such as dysfunction of Muller cells, which leads to ganglion cell death. Its pathogenesis is probably associated with oxidative stress and a recently discovered protein, thioredoxin-interacting protein (TXNIP). MATERIAL AND METHODS To explore the role of TXNIP in DR, we cultured Muller cells under diabetic conditions, and then used immunohistochemistry, Western blot, and RT-PCR to detect the expression level of TXNIP under diabetic conditions. We demonstrated the expression level of glutamine synthetase (GS) when TXNIP was inhibited. To explore the potential pathway of TXNIP-induced cell damage in DR, we confirmed the role of IL-1β under diabetic conditions. RESULTS Diabetes induces TXNIP expressions at mRNA levels, but shows the opposite effect on GS. IL-1β plays an important role in this pathway. Azaserine effectively increased the expression of GS via attenuating the expression of TXNIP. CONCLUSIONS This study demonstrates the role of TXNIP and its mechanism in DR, provides a possible treatment for DR, and lays a new theoretical foundation for the clinical treatment of DR and other diabetic microvascular changes. PMID:27131835

  9. Molecular evolution of glutamine synthetase II: Phylogenetic evidence of a non-endosymbiotic gene transfer event early in plant evolution

    Directory of Open Access Journals (Sweden)

    Tartar Aurélien

    2010-06-01

    Full Text Available Abstract Background Glutamine synthetase (GS is essential for ammonium assimilation and the biosynthesis of glutamine. The three GS gene families (GSI, GSII, and GSIII are represented in both prokaryotic and eukaryotic organisms. In this study, we examined the evolutionary relationship of GSII from eubacterial and eukaryotic lineages and present robust phylogenetic evidence that GSII was transferred from γ-Proteobacteria (Eubacteria to the Chloroplastida. Results GSII sequences were isolated from four species of green algae (Trebouxiophyceae, and additional green algal (Chlorophyceae and Prasinophytae and streptophyte (Charales, Desmidiales, Bryophyta, Marchantiophyta, Lycopodiophyta and Tracheophyta sequences were obtained from public databases. In Bayesian and maximum likelihood analyses, eubacterial (GSIIB and eukaryotic (GSIIE GSII sequences formed distinct clades. Both GSIIB and GSIIE were found in chlorophytes and early-diverging streptophytes. The GSIIB enzymes from these groups formed a well-supported sister clade with the γ-Proteobacteria, providing evidence that GSIIB in the Chloroplastida arose by horizontal gene transfer (HGT. Bayesian relaxed molecular clock analyses suggest that GSIIB and GSIIE coexisted for an extended period of time but it is unclear whether the proposed HGT happened prior to or after the divergence of the primary endosymbiotic lineages (the Archaeplastida. However, GSIIB genes have not been identified in glaucophytes or red algae, favoring the hypothesis that GSIIB was gained after the divergence of the primary endosymbiotic lineages. Duplicate copies of the GSIIB gene were present in Chlamydomonas reinhardtii, Volvox carteri f. nagariensis, and Physcomitrella patens. Both GSIIB proteins in C. reinhardtii and V. carteri f. nagariensis had N-terminal transit sequences, indicating they are targeted to the chloroplast or mitochondrion. In contrast, GSIIB proteins of P. patens lacked transit sequences, suggesting

  10. Changes in Activities of Key Enzymes for Starch Synthesis and Glutamine Synthetase in Grains of Progenies from a Rice Cross During Grain Filling

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-guang; LIU Hai-ying; JIN Zheng-xun; LIU Hong-liang; HUANG Xing; XU Mei-lan; ZHANG Feng-zhuan

    2010-01-01

    The progenies differed in amylose and protein contents in grains, which derived from a rice cross, Dongnong 423×Toukei 180, were used to study changes in the activities of ADP-glucose pyrophosphorylase (AGPP), soluble starch synthetase (SSS), starch branching enzyme (SBE) and glutamine synthetase (GS) in rice grains during grain filling. The activities of AGPP, SSS and SBE gradually increased and then declined as a single-peak curve with the process of grain filling in the progenies with high and low amylose contents in grains. The progenies with high amylose content peaked earlier in the AGPP, SSS and SBE activities and had higher AGPP, SSS and SBE activities at the early grain filling stage than those with low amylose content. The GS activity peaked earlier and was higher at the late stage of grain filling in the progenies with high protein content than in those with low protein content. It is suggested that the activities of key enzymes for starch synthesis and glutamine synthetase could be changed in oriented breeding for amylose and protein contents in grains.

  11. Downregulation of glutamine synthetase via GLAST suppression induces retinal axonal swelling in a rat ex vivo hydrostatic pressure model.

    Science.gov (United States)

    Ishikawa, Makoto; Yoshitomi, Takeshi; Zorumski, Charles F; Izumi, Yukitoshi

    2011-08-01

    PURPOSE. High levels of glutamate can be toxic to retinal GCs. Thus, effective buffering of extracellular glutamate is important in preserving retinal structure and function. GLAST, a major glutamate transporter in the retina, and glutamine synthetase (GS) regulate extracellular glutamate accumulation and prevent excitotoxicity. This study was an examination of changes in function and expression of GLAST and GS in ex vivo rat retinas exposed to acute increases in ambient pressure. METHODS. Ex vivo rat retinas were exposed to elevated hydrostatic pressure for 24 hours. The expression of GLAST and GS were examined using immunochemistry and real-time PCR analysis. Also examined were the effects of (2S,3S)-3-[3-[4-(trifluoromethyl) benzoylamino] benzyloxy] aspartate (TFB-TBOA), an inhibitor of glutamate transporters, and l-methionine-S-sulfoximine (MSO), an inhibitor of GS. RESULTS. In this acute model, Western blot and real-time RT-PCR analyses revealed that substantially (75 mm Hg), but not moderately (35 mm Hg), elevated pressure depressed GLAST expression, diminished GS activity, and induced axonal swelling between the GC layer and the inner limiting membrane. However, at the moderately elevated pressure (35 mm Hg), administration of either TFB-TBOA or MSO also induced axonal swelling and excitotoxic neuronal damage. MSO did not depress GLAST expression but TFB-TBOA significantly suppressed GS, suggesting that downregulation of GS during pressure loading may result from impaired GLAST expression. CONCLUSIONS. The retina is at risk during acute intraocular pressure elevation due to downregulation of GS activity resulting from depressed GLAST expression. PMID:21775659

  12. Inhibition of nitrogen-fixing activity of the cyanobiont affects the localization of glutamine synthetase in hair cells of Azolla.

    Science.gov (United States)

    Uheda, Eiji; Maejima, Kazuhiro

    2009-10-15

    In the Azolla-Anabaena association, the host plant Azolla efficiently incorporates and assimilates ammonium ions that are released from the nitrogen-fixing cyanobiont, probably via glutamine synthetase (GS; EC 6.3.1.2) in hair cells, which are specialized cells protruding into the leaf cavity. In order to clarify the regulatory mechanism underlying ammonium assimilation in the Azolla-Anabaena association, Azolla plants were grown under an argon environment (Ar), in which the nitrogen-fixing activity of the cyanobiont was inhibited specifically and completely. The localization of GS in hair cells was determined by immunoelectron microscopy and quantitative analysis of immunogold labeling. Azolla plants grew healthily under Ar when nitrogen sources, such as NO(3)(-) and NH(4)(+), were provided in the growth medium. Both the number of cyanobacterial cells per leaf and the heterocyst frequency of the plants under Ar were similar to those of plants in a nitrogen environment (N(2)). In hair cells of plants grown under Ar, regardless of the type of nitrogen source provided, only weak labeling of GS was observed in the cytoplasm and in chloroplasts. In contrast, in hair cells of plants grown under N(2), abundant labeling of GS was observed in both sites. These findings indicate that specific inhibition of the nitrogen-fixing activity of the cyanobiont affects the localization of GS isoenzymes. Ammonium fixed and released by the cyanobiont could stimulate GS synthesis in hair cells. Simultaneously, the abundant GS, probably GS1, in these cells, could assimilate ammonium rapidly. PMID:19464754

  13. Lethality of glnD null mutations in Azotobacter vinelandii is suppressible by prevention of glutamine synthetase adenylylation.

    Science.gov (United States)

    Colnaghi, R; Rudnick, P; He, L; Green, A; Yan, D; Larson, E; Kennedy, C

    2001-05-01

    GlnD is a pivotal protein in sensing intracellular levels of fixed nitrogen and has been best studied in enteric bacteria, where it reversibly uridylylates two related proteins, PII and GlnK. The uridylylation state of these proteins determines the activities of glutamine synthetase (GS) and NtrC. Results presented here demonstrate that glnD is an essential gene in Azotobacter vinelandii. Null glnD mutations were introduced into the A. vinelandii genome, but none could be stably maintained unless a second mutation was present that resulted in unregulated activity of GS. One mutation, gln-71, occurred spontaneously to give strain MV71, which failed to uridylylate the GlnK protein. The second, created by design, was glnAY407F (MV75), altering the adenylylation site of GS. The gln-71 mutation is probably located in glnE, encoding adenylyltransferase, because introducing the Escherichia coli glnE gene into MV72, a glnD(+) derivative of MV71, restored the regulation of GS activity. GlnK-UMP is therefore apparently required for GS to be sufficiently deadenylylated in A. vinelandii for growth to occur. The DeltaglnD GS(c) isolates were Nif(-), which could be corrected by introducing a nifL mutation, confirming a role for GlnD in mediating nif gene regulation via some aspect of the NifL/NifA interaction. MV71 was unexpectedly NtrC(+), suggesting that A. vinelandii NtrC activity might be regulated differently than in enteric organisms. PMID:11320130

  14. Possible role of glutamine synthetase in the NO signaling response in root nodules by contributing to the antioxidant defenses

    Directory of Open Access Journals (Sweden)

    Liliana Santos Silva

    2013-09-01

    Full Text Available Nitric oxide (NO is emerging as an important regulatory player in the Rhizobium-legume symbiosis. The occurrence of NO during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. The identification of the molecular targets of NO is key for the assembly of the signal transduction cascade that will ultimately help to unravel NO function. We have recently shown that the key nitrogen assimilatory enzyme Glutamine Synthetase (GS is a molecular target of NO in root nodules of Medicago truncatula, being post-translationally regulated by tyrosine nitration in relation to nitrogen fixation. In functional nodules of M. truncatula NO formation has been located in the bacteroid containing cells of the fixation zone, where the ammonium generated by bacterial nitrogenase is released to the plant cytosol and assimilated into the organic pools by plant GS. We propose that the NO-mediated GS post-translational inactivation is connected to nitrogenase inhibition induced by NO and is related to metabolite channeling to boost the nodule antioxidant defenses. Glutamate, a substrate for GS activity is also the precursor for the synthesis of glutathione (GSH, which is highly abundant in root nodules of several plant species and known to play a major role in the antioxidant defense participating in the ascorbate/GSH cycle. Existing evidence suggests that upon NO-mediated GS inhibition, glutamate could be channeled for the synthesis of GSH. According to this hypothesis, GS would be involved in the NO-signaling responses in root nodules and the NO-signaling events would meet the nodule metabolic pathways to provide an adaptive response to the inhibition of symbiotic nitrogen fixation by reactive nitrogen species (RNS.

  15. Cytosolic glutamine synthetase is important for photosynthetic efficiency and water use efficiency in potato as revealed by high-throughput sequencing QTL analysis

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sørensen, Kirsten Kørup; Andersen, Mathias Neumann;

    2015-01-01

    isoforms of cytosolic glutamine synthase were located in the QTL at chromosome 1 suggesting a major contribution of this enzyme to photosynthetic efficiency and thus WUE in potato. Indeed, Glutamine synthetase enzyme activity of leaf extracts was measured and found to be correlated with contrasting WUE......Potato (Solanum tuberosum L.) closes its stomata at relatively low soil water deficits frequently encountered in normal field conditions resulting in unnecessary annual yield losses and extensive use of artificial irrigation. Therefore, unraveling the genetics underpinning variation in water use...... efficiency (WUE) of potato is important, but has been limited by technical difficulties in assessing the trait on individual plants and thus is poorly understood. In this study, a mapping population of potatoes has been robustly phenotyped, and considerable variation in WUE under well-watered conditions was...

  16. Age-dependent decrease in glutamine synthetase expression in the hippocampal astroglia of the triple transgenic Alzheimer's disease mouse model: Mechanism for deficient glutamatergic transmission?

    Czech Academy of Sciences Publication Activity Database

    Olabarria, M.; Noristani, H. N.; Verkhratsky, Alexei; Rodríguez Arellano, Jose Julio

    2011-01-01

    Roč. 6, č. 1 (2011), s. 55-63. ISSN 1750-1326 R&D Projects: GA ČR GA309/09/1696; GA ČR(CZ) GAP304/11/0184; GA ČR GA305/08/1384; GA ČR GA309/08/1381 Institutional research plan: CEZ:AV0Z50390703 Keywords : astroglia * glutamine synthetase * Alzheimer?'?s disease Subject RIV: FH - Neurology Impact factor: 4.278, year: 2011

  17. Increased glutamine in leaves of poplar transgenic with pine GS1a caused greater anthranilate synthetase α-subunit (ASA1) transcript and protein abundances: an auxin-related mechanism for enhanced growth in GS transgenics?

    OpenAIRE

    Man, Huimin; Pollmann, Stephan; Weiler, Elmar W.; Kirby, Edward G.

    2011-01-01

    The initial reaction in the pathway leading to the production of indole-3-acetic acid (IAA) in plants is the reaction between chorismate and glutamine to produce anthranilate, catalysed by the enzyme anthranilate synthase (ASA; EC 4.1.3.27). Compared with non-transgenic controls, leaves of transgenic poplar with ectopic expression of the pine cytosolic glutamine synthetase (GS1a; EC 6.3.1.2) produced significantly greater glutamine and significantly enhanced ASA α-subunit (ASA1) transcript an...

  18. A Modified Bacillus Calmette-Guérin (BCG Vaccine with Reduced Activity of Antioxidants and Glutamine Synthetase Exhibits Enhanced Protection of Mice despite Diminished in Vivo Persistence

    Directory of Open Access Journals (Sweden)

    Douglas S. Kernodle

    2013-01-01

    Full Text Available Early attempts to improve BCG have focused on increasing the expression of prominent antigens and adding recombinant toxins or cytokines to influence antigen presentation. One such modified BCG vaccine candidate has been withdrawn from human clinical trials due to adverse effects. BCG was derived from virulent Mycobacterium bovis and retains much of its capacity for suppressing host immune responses. Accordingly, we have used a different strategy for improving BCG based on reducing its immune suppressive capacity. We made four modifications to BCG Tice to produce 4dBCG and compared it to the parent vaccine in C57Bl/6 mice. The modifications included elimination of the oxidative stress sigma factor SigH, elimination of the SecA2 secretion channel, and reductions in the activity of iron co-factored superoxide dismutase and glutamine synthetase. After IV inoculation of 4dBCG, 95% of vaccine bacilli were eradicated from the spleens of mice within 60 days whereas the titer of BCG Tice was not significantly reduced. Subcutaneous vaccination with 4dBCG produced greater protection than vaccination with BCG against dissemination of an aerosolized challenge of M. tuberculosis to the spleen at 8 weeks post-challenge. At this time, 4dBCG-vaccinated mice also exhibited altered lung histopathology compared to BCG-vaccinated mice and control mice with less well-developed lymphohistiocytic nodules in the lung parenchyma. At 26 weeks post-challenge, 4dBCG-vaccinated mice but not BCG-vaccinated mice had significantly fewer challenge bacilli in the lungs than control mice. In conclusion, despite reduced persistence in mice a modified BCG vaccine with diminished antioxidants and glutamine synthetase is superior to the parent vaccine in conferring protection against M. tuberculosis. The targeting of multiple immune suppressive factors produced by BCG is a promising strategy for simultaneously improving vaccine safety and effectiveness.

  19. Sixteen cytosolic glutamine synthetase genes identified in the Brassica napus L. genome are differentially regulated depending on nitrogen regimes and leaf senescence.

    Science.gov (United States)

    Orsel, Mathilde; Moison, Michaël; Clouet, Vanessa; Thomas, Justine; Leprince, Françoise; Canoy, Anne-Sophie; Just, Jérémy; Chalhoub, Boulos; Masclaux-Daubresse, Céline

    2014-07-01

    A total of 16 BnaGLN1 genes coding for cytosolic glutamine synthetase isoforms (EC 6.3.1.2.) were found in the Brassica napus genome. The total number of BnaGLN1 genes, their phylogenetic relationships, and genetic locations are in agreement with the evolutionary history of Brassica species. Two BnaGLN1.1, two BnaGLN1.2, six BnaGLN1.3, four BnaGLN1.4, and two BnaGLN1.5 genes were found and named according to the standardized nomenclature for the Brassica genus. Gene expression showed conserved responses to nitrogen availability and leaf senescence among the Brassiceae tribe. The BnaGLN1.1 and BnaGLN1.4 families are overexpressed during leaf senescence and in response to nitrogen limitation. The BnaGLN1.2 family is up-regulated under high nitrogen regimes. The members of the BnaGLN1.3 family are not affected by nitrogen availability and are more expressed in stems than in leaves. Expression of the two BnaGLN1.5 genes is almost undetectable in vegetative tissues. Regulations arising from plant interactions with their environment (such as nitrogen resources), final architecture, and therefore sink-source relations in planta, seem to be globally conserved between Arabidopsis and B. napus. Similarities of the coding sequence (CDS) and protein sequences, expression profiles, response to nitrogen availability, and ageing suggest that the roles of the different GLN1 families have been conserved among the Brassiceae tribe. These findings are encouraging the transfer of knowledge from the Arabidopsis model plant to the B. napus crop plant. They are of special interest when considering the role of glutamine synthetase in crop yield and grain quality in maize and wheat. PMID:24567494

  20. The Populus superoxide dismutase gene family and its responses to drought stress in transgenic poplar overexpressing a pine cytosolic glutamine synthetase (GS1a.

    Directory of Open Access Journals (Sweden)

    Juan Jesús Molina-Rueda

    Full Text Available BACKGROUND: Glutamine synthetase (GS plays a central role in plant nitrogen assimilation, a process intimately linked to soil water availability. We previously showed that hybrid poplar (Populus tremula X alba, INRA 717-1B4 expressing ectopically a pine cytosolic glutamine synthetase gene (GS1a display enhanced tolerance to drought. Preliminary transcriptome profiling revealed that during drought, members of the superoxide dismutase (SOD family were reciprocally regulated in GS poplar when compared with the wild-type control, in all tissues examined. SOD was the only gene family found to exhibit such patterns. RESULTS: In silico analysis of the Populus genome identified 12 SOD genes and two genes encoding copper chaperones for SOD (CCSs. The poplar SODs form three phylogenetic clusters in accordance with their distinct metal co-factor requirements and gene structure. Nearly all poplar SODs and CCSs are present in duplicate derived from whole genome duplication, in sharp contrast to their predominantly single-copy Arabidopsis orthologs. Drought stress triggered plant-wide down-regulation of the plastidic copper SODs (CSDs, with concomitant up-regulation of plastidic iron SODs (FSDs in GS poplar relative to the wild type; this was confirmed at the activity level. We also found evidence for coordinated down-regulation of other copper proteins, including plastidic CCSs and polyphenol oxidases, in GS poplar under drought conditions. CONCLUSIONS: Both gene duplication and expression divergence have contributed to the expansion and transcriptional diversity of the Populus SOD/CCS families. Coordinated down-regulation of major copper proteins in drought-tolerant GS poplars supports the copper cofactor economy model where copper supply is preferentially allocated for plastocyanins to sustain photosynthesis during drought. Our results also extend previous findings on the compensatory regulation between chloroplastic CSDs and FSDs, and suggest that this

  1. Age-dependent decrease in glutamine synthetase expression in the hippocampal astroglia of the triple transgenic Alzheimer's disease mouse model: mechanism for deficient glutamatergic transmission?

    Directory of Open Access Journals (Sweden)

    Verkhratsky Alexei

    2011-07-01

    Full Text Available Abstract Astrocytes are fundamental for brain homeostasis and the progression and outcome of many neuropathologies including Alzheimer's disease (AD. In the triple transgenic mouse model of AD (3xTg-AD generalised hippocampal astroglia atrophy precedes a restricted and specific β-amyloid (Aβ plaque-related astrogliosis. Astrocytes are critical for CNS glutamatergic transmission being the principal elements of glutamate homeostasis through maintaining its synthesis, uptake and turnover via glutamate-glutamine shuttle. Glutamine synthetase (GS, which is specifically expressed in astrocytes, forms glutamine by an ATP-dependent amination of glutamate. Here, we report changes in GS astrocytic expression in two major cognitive areas of the hippocampus (the dentate gyrus, DG and the CA1 in 3xTg-AD animals aged between 9 and 18 months. We found a significant reduction in Nv (number of cell/mm3 of GS immunoreactive (GS-IR astrocytes starting from 12 months (28.59% of age in the DG, and sustained at 18 months (31.65%. CA1 decrease of GS-positive astrocytes Nv (33.26% occurs at 18 months. This Nv reduction of GS-IR astrocytes is paralleled by a decrease in overall GS expression (determined by its optical density that becomes significant at 18 months (21.61% and 19.68% in DG and CA1, respectively. GS-IR Nv changes are directly associated with the presence of Aβ deposits showing a decrease of 47.92% as opposed to 23.47% in areas free of Aβ. These changes in GS containing astrocytes and GS-immunoreactivity indicate AD-related impairments of glutamate homeostatic system, at the advanced and late stages of the disease, which may affect the efficacy of glutamatergic transmission in the diseased brain that may contribute to the cognitive deficiency.

  2. Astrocytes and glutamate homoeostasis in Alzheimer's disease: a decrease in glutamine synthetase, but not in glutamate transporter-1, in the prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Alexei Verkhratsky

    2013-10-01

    Full Text Available Astrocytes control tissue equilibrium and hence define the homoeostasis and function of the CNS (central nervous system. Being principal homoeostatic cells, astroglia are fundamental for various forms of neuropathology, including AD (Alzheimer's disease. AD is a progressive neurodegenerative disorder characterized by the loss of cognitive functions due to specific lesions in mnesic-associated regions, including the mPFC (medial prefrontal cortex. Here, we analyzed the expression of GS (glutamine synthetase and GLT-1 (glutamate transporter-1 in astrocytes in the mPFC during the progression of AD in a triple-transgenic mouse model (3xTg-AD. GS is an astrocyte-specific enzyme, responsible for the intracellular conversion of glutamate into glutamine, whereas the removal of glutamate from the extracellular space is accomplished mainly by astroglia-specific GLT-1. We found a significant decrease in the numerical density (Nv, cells/mm3 of GS-positive astrocytes from early to middle ages (1–9 months; at the age of 1 month by 17%, 6 months by 27% and 9 months by 27% when compared with control animals in parallel with a reduced expression of GS (determined by Western blots, which started at the age of 6 months and was sustained up to 12 months of age. We did not, however, find any changes in the expression of GLT-1, which implies an intact glutamate uptake mechanism. Our results indicate that the decrease in GS expression may underlie a gradual decline in the vital astrocyte-dependent glutamate–glutamine conversion pathway, which in turn may compromise glutamate homoeostasis, leading towards failures in synaptic connectivity with deficient cognition and memory.

  3. Lengsin is a survivor of an ancient family of class I glutamine synthetases in eukaryotes that has undergone evolutionary re-engineering for a role in the vertebrate eye lens.

    OpenAIRE

    Wyatt, Keith; White, Helen E.; Wang, Luchun; Bateman, Orval A.; Slingsby, Christine; Orlova, Elena V.; Wistow, Graeme

    2006-01-01

    Lengsin is a member of the glutamine synthetase (GS) superfamily expressed in the vertebrate eye lens. While the GS homology domains of lengsin are well conserved in all species examined, the N-terminal domain shows evidence of dynamic evolutionary changes. Compared with zebrafish and chicken, most mammals have an additional exon in the lengsin gene corresponding to part of the N-terminal domain, however in human this is a non-functional pseudoexon. Lengsin belongs to the hitherto purely prok...

  4. Limitations to the development of recombinant human embryonic kidney 293E cells using glutamine synthetase-mediated gene amplification: Methionine sulfoximine resistance.

    Science.gov (United States)

    Yu, Da Young; Noh, Soo Min; Lee, Gyun Min

    2016-08-10

    To investigate the feasibility of glutamine synthetase (GS)-mediated gene amplification in HEK293 cells for the high-level stable production of therapeutic proteins, HEK293E cells were transfected by the GS expression vector containing antibody genes and were selected at various methionine sulfoximine (MSX) concentrations in 96-well plates. For a comparison, CHOK1 cells were transfected by the same GS expression vector and selected at various MSX concentrations. Unlike CHOK1 cells, HEK293E cells producing high levels of antibodies were not selected at all. For HEK293E cells, the number of wells with the cell pool did not decrease with an increase in the concentration of MSX up to 500μM MSX. A q-RT-PCR analysis confirmed that the antibody genes in the HEK293E cells, unlike the CHOK1 cells, were not amplified after increasing the MSX concentration. It was found that the GS activity in HEK293E cells was much higher than that in CHOK1 cells (P<0.05). In a glutamine-free medium, the GS activity of HEK293E cells was approximately 4.8 times higher than that in CHOK1 cells. Accordingly, it is inferred that high GS activity of HEK293E cells results in elevated resistance to MSX and therefore hampers GS-mediated gene amplification by MSX. Thus, in order to apply the GS-mediated gene amplification system to HEK293 cells, the endogenous GS expression level in HEK293 cells needs to be minimized by knock-out or down-regulation methods. PMID:27288593

  5. Enhanced expression of glutamine synthetase (GS1a) confers altered fibre and wood chemistry in field grown hybrid poplar (Populus tremula X alba) (717-1B4).

    Science.gov (United States)

    Coleman, Heather D; Cánovas, Francisco M; Man, Huimin; Kirby, Edward G; Mansfield, Shawn D

    2012-09-01

    Hybrid poplar (Populus tremula X P. alba) genetically engineered to express the pine cytosolic glutamine synthetase gene (GS1a) has been previously shown to display desirable field performance characteristics, including enhancements in growth and nitrogen use efficiency. Analysis of wood samples from a 3-year-old field trial of three independently transformed GS1a transgenic hybrid poplar lines revealed that, when compared with wild-type controls, ectopic expression of GS1a resulted in alterations in wood properties and wood chemistry. Included were significant enhancements in wood fibre length, wood density, microfibre angle, per cent syringyl lignin and elevated concentrations of wood sugars, specifically glucose, galactose, mannose and xylose. Total extractive content and acid-insoluble lignin were significantly reduced in wood of GS1a transgenics when compared with wild-type trees. Together, these cell wall characteristics resulted in improved wood pulping attributes, including improved lignin solubilization with no concurrent decrease in yield. Trees with increased GS1a expression have improved characteristics for pulp and paper production and hold potential as a feedstock for biofuels production. PMID:22672155

  6. Nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate synthase expression and activity in response to different nitrogen sources in nitrogen-starved wheat seedlings.

    Science.gov (United States)

    Balotf, Sadegh; Kavoosi, Gholamreza; Kholdebarin, Bahman

    2016-03-01

    The objective of this study was to examine the expression and activity of nitrate reductase (NR, EC 1.7.1.1), nitrite reductase (NiR, EC 1.7.2.2), glutamine synthetase (GS, EC 6.3.1.2), and glutamate synthase (GOGAT, EC 1.4.7.1) in response to potassium nitrate, ammonium chloride, and ammonium nitrate in nitrogen-starved wheat seedlings. Plants were grown in standard nutrient solution for 17 days and then subjected to nitrogen starvation for 7 days. The starved plants were supplied with potassium nitrate ammonium nitrate and ammonium chloride (50 mM) for 4 days and the leaves were harvested. The relative expression of NR, NiR, GS, and GOGAT as well as the enzyme activities were investigated. Nitrogen starvation caused a significant decrease both in transcript levels and in NR, NiR, GS, and GOGAT activities. Potassium nitrate and ammonium nitrate treatments restored NR, NiR, GS, and GOGAT expressions and activities. Ammonium chloride increased only the expressions and activities of GS and GOGAT in a dose-dependent manner. The results of our study highlight the differential effects between the type and the amount of nitrogen salts on NR, NiR, GS, and GOGAT activities in wheat seedlings while potassium nitrate being more effective. PMID:25676153

  7. Value and Limits of Routine Histology Alone or Combined with Glutamine Synthetase Immunostaining in the Diagnosis of Hepatocellular Adenoma Subtypes on Surgical Specimens

    Directory of Open Access Journals (Sweden)

    Paulette Bioulac-Sage

    2013-01-01

    Full Text Available Immunohistochemistry is a valid method to classify hepatocellular adenoma (HCA. The aim was to test the performance of routine histology combined to glutamine synthetase (GS staining to identify the 2 major HCA subtypes: HNF1α inactivated (H-HCA and inflammatory HCA (IHCA. 114 surgical cases, previously classified by immunohistochemistry, were analysed. Group A comprised 45 H-HCAs, 44 IHCAs, and 9 β-catenin-activated IHCAs (b-IHCA, and group B, 16 b-HCA and unclassified HCA (UHCA. Steatosis was the hallmark of H-HCA. IHCA and b-IHCA were mainly characterized by inflammation, thick arteries, and sinusoidal dilatation; b-IHCA could not be differentiated from IHCA by routine histology. Group B was identified by default. A control set (91 cases was analyzed using routine and GS stainings (without knowing immunohistochemical results. Among the 45 H-HCAs and 27 IHCAs, 40 and 24 were correctly classified, respectively. Among the 10 b-IHCAs, 4 were identified as such using additional GS. Eight of the 9 HCAs that were neither H-HCA nor IHCA were correctly classified. Conclusion. Routine histology allows to diagnose >85% of the 2 major HCA subtypes. GS is essential to identify b-HCA. This study demonstrates that a “palliative” diagnostic approach can be proposed, when the panel of specific antibodies is not available.

  8. FOXO1 activates glutamine synthetase gene in mouse skeletal muscles through a region downstream of 3'-UTR: possible contribution to ammonia detoxification.

    Science.gov (United States)

    Kamei, Yasutomi; Hattori, Maki; Hatazawa, Yukino; Kasahara, Tomomi; Kanou, Masanobu; Kanai, Sayaka; Yuan, Xunmei; Suganami, Takayoshi; Lamers, Wouter H; Kitamura, Tadahiro; Ogawa, Yoshihiro

    2014-09-15

    Skeletal muscle is a reservoir of energy in the form of protein, which is degraded under catabolic conditions, resulting in the formation of amino acids and ammonia as a byproduct. The expression of FOXO1, a forkhead-type transcription factor, increases during starvation and exercise. In agreement, transgenic FOXO1-Tg mice that overexpress FOXO1 in skeletal muscle exhibit muscle atrophy. The aim of this study was to examine the role of FOXO1 in amino acid metabolism. The mRNA and protein expressions of glutamine synthetase (GS) were increased in skeletal muscle of FOXO1-Tg mice. Fasting induced FOXO1 and GS expression in wild-type mice but hardly increased GS expression in muscle-specific FOXO1 knockout (FOXO1-KO) mice. Activation of FOXO1 also increased GS mRNA and protein expression in C2C12 myoblasts. Using a transient transfection reporter assay, we observed that FOXO1 activated the GS reporter construct. Mutation of a putative FOXO1-binding consensus sequence in the downstream genomic region of GS decreased basal and FOXO1-dependent reporter activity significantly. A chromatin immunoprecipitation assay showed that FOXO1 was recruited to the 3' region of GS in C2C12 myoblasts. These results suggest that FOXO1 directly upregulates GS expression. GS is considered to mediate ammonia clearance in skeletal muscle. In agreement, an intravenous ammonia challenge increased blood ammonia concentrations to a twofold higher level in FOXO1-KO than in wild-type mice, demonstrating that the capacity for ammonia disposal correlated inversely with the expression of GS in muscle. These data indicate that FOXO1 plays a role in amino acid metabolism during protein degradation in skeletal muscle. PMID:25074987

  9. Characterization of a glutamine synthetase gene DvGS2 from Dunaliella viridis and biochemical identification of DvGS2-transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Zhu, Chenguang; Fan, Qianlan; Wang, Wei; Shen, Chunlei; Meng, Xiangzong; Tang, Yuanping; Mei, Bing; Xu, Zhengkai; Song, Rentao

    2014-02-25

    The salt-tolerant green alga Dunaliella has remarkable capability to survive in some extreme environments such as nitrogen starvation, which makes Dunaliella be a proper model for mining novel genes on nitrogen uptake or assimilation. In this study, a glutamine synthetase (GS) gene DvGS2 with amino acid identity of 72% to other homologous GS proteins, was isolated and characterized from Dunaliella viridis. Phylogenetic comparison with other GSs revealed that DvGS2 occupied an independent phylogenetic position. Expressional analysis in D. viridis cells under nitrogen starvation confirmed that DvGS2 increased its mRNA level in 12h. Subcellular localization study and functional analysis in a GS-deficient Escherichia coli mutant proved that DvGS2 was a chloroplastic and functional GS enzyme. In order to investigate the potential application of DvGS2 in higher plants, the transgenic studies of DvGS2 in Arabidopsis thaliana were carried out. Results showed that the transgenic lines expressed the DvGS2 gene and demonstrated obviously enhanced root length (29%), fresh weight (40%-48% at two concentrations of nitrate supplies), stem length (21%), leaf size (39%) and silique number (44%) in contrast with the wild-type Arabidopsis. Furthermore, the transgenic lines had higher total nitrogen content (35%-43%), total GS activity (39%-45%) and soluble protein concentration (23%-24%) than the wild type. These results indicated that the overexpression of DvGS2 in A. thaliana resulted in higher biomass and the improvement of the host's nitrogen use efficiency. PMID:24334123

  10. High-affinity glutamate transporter and glutamine synthetase content in longissimus dorsi and adipose tissues of growing Angus steers differs among suckling, weanling, backgrounding, and finishing production stages.

    Science.gov (United States)

    Matthews, J C; Huang, J; Rentfrow, G

    2016-03-01

    Skeletal muscle and adipose tissues play important roles in maintaining whole-body Glu and N homeostasis by the uptake of Glu and release of Gln. To test the hypothesis that expression of high-affinity Glu transporters (GLAST1, EAAT4, EAAC1, GLT-1) and glutamine synthetase (GS) would increase in longissimus dorsi and adipose tissue of newborn Angus steers randomly assigned ( = 6) to develop through suckling (S; 32 d) and/or weanling (W; 184 d), backgrounding (B; 248 d), and finishing (F; 423 d) production stages. Carcass quality was determined at slaughter to verify shifts in adipose and lean deposition with development. Expression of mRNA (RT-PCR/Southern) and relative protein abundance (Western analysis) were determined in tissue homogenates isolated from longissimus dorsi, and kidney and subcutaneous adipose. The effect of production stage or tissue type on carcass and protein abundance was assessed by 1-way ANOVA using the GLM procedure of SAS, and Fisher's protected LSD procedure was used to separate data means. Neither GLAST1 nor EAAT4 mRNA or protein was detected. EAAC1, GLT-1, and GS mRNA were identified in all tissues, but GLT-1 and GS protein were not detected in kidney or subcutaneous adipose, and GS protein was not detected in longissimus dorsi. The EAAC1 content of subcutaneous ( = 0.06) and kidney ( = 0.02) adipose was 2 times greater in B and F than W steers, whereas GS was 5 times greater ( F). For longissimus dorsi, EAAC1 ( W > B = F, S = W > B = F, respectively). Within F steers, EAAC1 and GLT-1 mRNA was expressed by subcutaneous, kidney, omental, mesenchymal, and intramuscular adipose tissues, whereas GS mRNA was expressed by all except for intramuscular. Only EAAC1 protein was detected in any adipose tissue, with EAAC1 content being 104% and 112% greater ( 0.45) from omental or mesenchymal adipose. These data demonstrate (1) longissimus dorsi and adipose tissues of steers developing through typical production stages have different capacities for

  11. 大强度游泳抑制小鼠骨骼肌谷氨酰胺合成酶活性%Inhibition of Glutamine Synthetase by High Intensity Swimming in Skeleton Muscle of Mice

    Institute of Scientific and Technical Information of China (English)

    刘正冬; 李可基; 冯建英

    2001-01-01

    分析不同强度运动负荷对血浆和骨骼肌谷氨酰胺水平变化与骨骼肌谷氨酰胺合成酶活性变化,探讨运动影响血浆谷氨酰胺水平变化的机制。BAL/C小鼠不负重或2%负重不同强度游泳,每天2 h,持续8周。与对照组比较,大强度游泳组动物血浆(0.46±0.10、0.12±0.02 mmol/L,p<0.01)和肌肉(4.92±0.98、1.03±0.37 mmol/L,p<0.01)中的谷氨酰胺浓度降低,骨骼肌谷氨酰胺合成酶活性抑制(1874±191、1246±220 nmol/min/ g蛋白, p<0.01);而中等强度游泳升高血浆谷氨酰胺浓度(0.64±0.06 mmol/L,p<0.01)。小鼠在中等强度运动时,谷氨酰胺代谢表现了积极的代偿变化。但在大强度运动时,动物的体重增长减缓,血浆和肌肉谷氨酰胺水平均大幅度降低。结果提示,导致血浆谷氨酰胺水平降低的机制之一是骨骼肌中的谷氨酰胺合成酶抑制。%To analyze the effect of different intensity of exercise on glutamine levels in plasma and muscle and approach the mechanism of changes of plasma glutamine in exercise, BAL/C mice were randomly divided into middle intensity exercise (no extra load), high intensity exercise (2% bodyweight load) and control groups to swim for 2 hours/day and 8 weeks. Compared with the control group, high intensity exercise reduced glutamine levels in plasma (0.46±0.10, 0.12±0.02 mmol/L, p<0.01) and muscle (4.92±0.98, 1.03±0.37 mmol/L, p<0.01), and reduced the activity of glutamine synthetase in muscle (1874±191, 1246±220 mmol/min/mg, pglutamine levels in plasma (0.64±0.06 mmol/L, p<0.01). The results suggest that experimental animals showed a positive compensation in glutamine metabolism after middle intensity exercise, while they failed to maintain a balance in glutamine metabolism after high intensity exercise. The reduction of glutamine in plasma and muscle and the slowed growth rate of body weight, observed in this group

  12. 原位氮饥饿发酵工艺中梯度补氮对谷氨酰胺合成酶的调控%REGULATION OF GLUTAMINE SYNTHETASE IN GLUTAMINE PRODUCTION BY FERMENTATION OF Corynebacterium glutamicum WITH in-situ NITROGEN STARVATION AND GRADIENT FED NITROGEN

    Institute of Scientific and Technical Information of China (English)

    李春; 刘雨磊; 陈奎发; 杨艳; 曹竹安

    2004-01-01

    The effects of uniform and gradient fed nitrogen on glutamine synthetase (GS), glutamate dehydrogenase(GDH) and glutamate synthase ((K)GAT)were investigated in glutamine production by fermentation of Corynebacterium glutamicum NS611 after 3 h of in-situ nitrogen starvation. It was shown that the strain in the later growth phase entered naturally into in-situ nitrogen starvation by controlling the initial concentration of urea and the biomass was slightly decreased. The pH value reached 6.5 again in the culture system, which confirmed the beginning of nitrogen starvation in the culture system. After 3 h nitrogen starvation the activity of GS was increased over two folds and the time of high activity of GS persisted three folds longer in the gradient fed nitrogen system than that in the normal fed batch. The higher activity of GDH was also maintained. The glutamine production increased by 72 % than the original technology of nitrogen starvation and the time of fermentation was shortened by above 12 h.

  13. Light induces changes in activities of Na(+)/K(+)-ATPase, H(+)/K(+)-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam, Tridacna squamosa.

    Science.gov (United States)

    Ip, Yuen K; Ching, Biyun; Hiong, Kum C; Choo, Celine Y L; Boo, Mel V; Wong, Wai P; Chew, Shit F

    2015-01-01

    The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control), on enzymatic activities of transporters involved in the transport of NH(+) 4 or H(+), and activities of enzymes involved in converting NH(+) 4 to glutamate/glutamine in inner mantle, outer mantle, and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH(+) 4 in substitution for K(+) to activate Na(+)/K(+)-ATPase (NKA), manifested as a significant increase in the Na(+)/NH(+) 4-activated-NKA activity in the inner mantle. However, similar phenomena were not observed in the extensible outer mantle, which contained abundant symbiotic zooxanthellae. Hence, during light-enhanced calcification, H(+) released from CaCO3 deposition could react with NH3 to form NH(+) 4 in the extrapallial fluid, and NH(+) 4 could probably be transported into the shell-facing inner mantle epithelium through NKA. Light also induced an increase in the activity of glutamine synthetase, which converts NH(+) 4 and glutamate to glutamine, in the inner mantle. Taken together, these results explained observations reported elsewhere that light induced a significant increase in pH and a significant decrease in ammonia concentration in the extrapallial fluid, as well as a significant increase in the glutamine concentration in the inner mantle, of T. squamosa. Exposure of T. squamosa to light also led to a significant decrease in the N-ethylmaleimide (NEM)-sensitive-V-H(+)-ATPase (VATPase) in the inner mantle, and significant increases in the Na(+)/K(+)-activated-NKA, H(+)/NH(+) 4-activated-H(+)/K(+)-ATPase, and NEM-sensitive-VATPase activities in ctenidia, indicating that light-enhanced calcification might perturb Na(+) homeostasis and acid/base balance in the hemolymph, and might involve the active uptake of NH(+) 4 from the environment. This is the first report on light having direct

  14. Light induces changes in activities of Na+/K+(NH4+-ATPase, H+/K+(NH4+-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam Tridacna squamosa

    Directory of Open Access Journals (Sweden)

    Alex Y K Ip

    2015-03-01

    Full Text Available The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control, on enzymatic activities of transporters involved in the transport of NH4+ or H+, and activities of enzymes involved in converting NH4+ to glutamate/glutamine in inner mantle, outer mantle and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH4+ in substitution for K+ to activate Na+/K+-ATPase (NKA, manifested as a significant increase in the Na+/NH4+-activated-NKA activity in the inner mantle. However, similar phenomena were not observed in the extensible outer mantle, which contained abundant symbiotic zooxanthellae. Hence, during light-enhanced calcification, H+ released from CaCO3 deposition could react with NH3 to form NH4+ in the extrapallial fluid, and NH4+ could probably be transported into the shell-facing inner mantle epithelium through NKA. Light also induced an increase in the activity of glutamine synthetase, which converts NH4+ and glutamate to glutamine, in the inner mantle. Taken together, these results explained observations reported elsewhere that light induced a significant increase in pH and a significant decrease in ammonia concentration in the extrapallial fluid, as well as a significant increase in the glutamine concentration in the inner mantle, of T. squamosa. Exposure of T. squamosa to light also led to a significant decrease in the N-ethylmaleimide (NEM-sensitive-V-H+-ATPase (VATPase in the inner mantle, and significant increases in the Na+/K+-activated-NKA, H+/NH4+-activated-H+/K+-ATPase and NEM-sensitive-VATPase activities in ctenidia, indicating that light-enhanced calcification might perturb Na+ homeostasis and acid/base balance in the hemolymph, and might involve the active uptake of NH4+ from the environment. This is the first report on light having direct enhancing effects on activities of certain

  15. Glutamine supplementation.

    Science.gov (United States)

    Wernerman, Jan

    2011-01-01

    Intravenous glutamine supplementation is standard care when parenteral nutrition is given for critical illness. There are data of a reduced mortality when glutamine supplementation is given. In addition, standard commercial products for parenteral nutrition do not contain any glutamine due to glutamine instability in aqueous solutions. For the majority of critical ill patients who are fed enterally, the available evidence is insufficient to recommend glutamine supplementation. Standard formulation of enteral nutrition contains some glutamine: 2-4 g/L. However, this dose is insufficient to normalize glutamine plasma concentration.Plasma concentration of glutamine is low in many patients with critical illness and a low level is an independent risk factor for mortality. A low plasma glutamine concentration is the best indicator of glutamine depletion. Data are emerging about how the endogenous production of glutamine is regulated. We know that skeletal muscle is the major producer of glutamine and that a part of the profound depletion of skeletal muscle seen in critical illness is a reflection of the need to produce glutamine.Glutamine is utilized in rapidly dividing cells in the splanchnic area. Quantitatively most glutamine is oxidized, but the availability of glutamine in surplus is important for the de novo synthesis of nucleotides and necessary for cell division and protein synthesis. More knowledge about the regulation of the endogenous production of glutamine is needed to outline better guidelines for glutamine supplementation in the future. PMID:21906372

  16. NITRIC OXIDE (NO), CITRULLINE - NO CYCLE ENZYMES, GLUTAMINE SYNTHETASE AND OXIDATIVE STRESS IN ANOXIA (HYPOBARIC HYPOXIA) AND REPERFUSION IN RAT BRAIN

    OpenAIRE

    M. Swamy, Mohd Jamsani Mat Salleh, K. N .S. Sirajudeen, Wan Roslina Wan Yusof, G. Chandran

    2010-01-01

    Nitric oxide is postulated to be involved in the pathophysiology of neurological disorders due to hypoxia/ anoxia in brain due to increased release of glutamate and activation of N-methyl-D-aspartate receptors. Reactive oxygen species have been implicated in pathophysiology of many neurological disorders and in brain function. To understand their role in anoxia (hypobaric hypoxia) and reperfusion (reoxygenation), the nitric oxide synthase, argininosuccinate synthetase, argininosuccinate lyase...

  17. The Glutamine-Glutamate/GABA Cycle

    DEFF Research Database (Denmark)

    Walls, Anne B; Waagepetersen, Helle S; Bak, Lasse Kristoffer;

    2015-01-01

    The operation of a glutamine-glutamate/GABA cycle in the brain consisting of the transfer of glutamine from astrocytes to neurons and neurotransmitter glutamate or GABA from neurons to astrocytes is a well-known concept. In neurons, glutamine is not only used for energy production and protein...... synthesis, as in other cells, but is also an essential precursor for biosynthesis of amino acid neurotransmitters. An excellent tool for the study of glutamine transfer from astrocytes to neurons is [(14)C]acetate or [(13)C]acetate and the glial specific enzyme inhibitors, i.e. the glutamine synthetase...... information about glutamine transfer. The present review will give information about glutamine trafficking and the tools used to map it as exemplified by discussions of published work employing brain cell cultures as well as intact animals. It will be documented that considerably more glutamine is transferred...

  18. Glutamine supplementation

    OpenAIRE

    Wernerman, Jan

    2011-01-01

    Intravenous glutamine supplementation is standard care when parenteral nutrition is given for critical illness. There are data of a reduced mortality when glutamine supplementation is given. In addition, standard commercial products for parenteral nutrition do not contain any glutamine due to glutamine instability in aqueous solutions. For the majority of critical ill patients who are fed enterally, the available evidence is insufficient to recommend glutamine supplementation. Standard formul...

  19. Change in ATP-binding cassette B1/19, glutamine synthetase and alcohol dehydrogenase gene expression during root elongation in Betula pendula Roth and Alnus glutinosa L. Gaertn in response to leachate and leonardite humic substances.

    Science.gov (United States)

    Tahiri, Abdelghani; Delporte, Fabienne; Muhovski, Yordan; Ongena, Marc; Thonart, Philippe; Druart, Philippe

    2016-01-01

    Humic substances (HS) are complex and heterogeneous compounds of humified organic matter resulting from the chemical and microbiological decomposition of organic residues. HS have a positive effect on plant growth and development by improving soil structure and fertility. They have long been recognized as plant growth-promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture. The biochemical and molecular mechanisms through which HS influence plant physiology are not well understood. This study evaluated the bioactivity of landfill leachate and leonardite HS on alder (Alnus glutinosa L. Gaertn) and birch (Betula pendula Roth) during root elongation in vitro. Changes in root development were studied in relation to auxin, carbon and nitrogen metabolisms, as well as to the stress adaptive response. The cDNA fragments of putative genes encoding two ATP-binding cassette (ABC) transporters (ABCB1 and ABCB19) belonging to the B subfamily of plant ABC auxin transporters were cloned and sequenced. Molecular data indicate that HS and their humic acid (HA) fractions induce root growth by influencing polar auxin transport (PAT), as illustrated by the modulation of the ABCB transporter transcript levels (ABCB1 and ABCB19). There were also changes in alcohol dehydrogenase (ADH) and glutamine synthetase (GS) gene transcript levels in response to HS exposure. These findings confirmed that humic matter affects plant growth and development through various metabolic pathways, including hormonal, carbon and nitrogen metabolisms and stress response or signalization. PMID:26595095

  20. Characterization of a glutamine synthetase gene DvGS1 from Dunaliella viridis and investigation of the impact on expression of DvGS1 in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Zhu, Chenguang; Fan, Qianlan; Wang, Wei; Shen, Chunlei; Wang, Peipei; Meng, Xiangzong; Tang, Yuanping; Mei, Bing; Xu, Zhengkai; Song, Rentao

    2014-01-01

    A novel glutamine synthetase (GS) gene DvGS1 showing highest amino acid sequence identity of 78 % with the other homologous GS proteins from green algae, was isolated and characterized from Dunaliella viridis. Phylogenetic analysis revealed that DvGS1 occupied an independent phylogenetic position which was different with the GSs from higher plants, animals and microbes. Functional complement in E. coli mutant confirmed that the DvGS1 encoded functional GS enzyme. Real-time PCR analysis of DvGS1 in D. viridis cells under nitrogen starvation revealed that the mRNA level of DvGS1 was positively up-regulated in 12 h. The DvGS1 levels at the points of 12 and 24 h were separately twofold and fourfold of the level before nitrogen starvation. In order to investigate the potential application of DvGS1 in higher plants, the transgenic study of DvGS1 in Arabidopsis thaliana was carried out. Phenotype identification demonstrated that all three transgenic lines of T3 generation showed obviously enhanced root length (26 %), fresh weight (22-46 % at two concentrations of nitrate supplies), stem length (26 %), leaf size (29 %) and silique number (30 %) compared with the wild-type Arabidopsis. Biochemical analysis confirmed that all three transgenic lines had higher total nitrogen content, soluble protein concentration, total amino acid content and the leaf GS activity than the wild type plants. The free NH4 (+) and NO3 (-) concentration in fresh leaves of three transgenic lines were reduced by 17-26 % and 14-15 % separately (at two concentrations of nitrate supplies) compared with those of the wild types. All the results indicated that over-expression of DvGS1 in Arabidopsis significantly results in the improvement of growth phenotype and the host's nitrogen use efficiency. PMID:24307252

  1. Role of glutamine in cobinamide biosynthesis in Propionibacterium shermanii

    International Nuclear Information System (INIS)

    The role of glutamine as a possible donor of amide groups in the biosynthesis of vitamin B12 was investigated. In the incubation of P. shermanii cells preliminarily exhausted with respect to nitrogen on media containing ammonium sulfate or asparagine, the glutamine synthetase inhibitor methionine sulfoximine suppressed the formation of cobinamide (factor B) from the monoamide of cobiric acid (by 75 and 59%, respectively). At the same time, the inhibitor did not affect cobinamide synthesis on a medium with glutamine. The amide group of glutamine, labeled with 13N, was used for the amidation of corrinoids four times as efficiently as the amine group. It was concluded that a glutamine-dependent synthetase, which catalyzes the amidation of cobiric acids with the formation of cobinamide, functions in cells of propionic acid bacteria

  2. Substrate specificity of formylglycinamidine synthetase

    Energy Technology Data Exchange (ETDEWEB)

    Schendel, F.J.; Stubbe, J.

    1986-04-22

    Formylglycinamidine ribonucleotide (FGAM) synthetase, which catalyzes the conversion of formylglycinamide ribonucleotide (FGAR), glutamine, and ATP to FGAM, ADP, glutamate, and Pi, has been purified to homogeneity (sp act. 0.20 mumol min-1 mg-1) from chicken liver by an alternative procedure to that of Buchanan et al. (Buchanan, J. M., Ohnoki, S., and Hong, B. S. (1978) Methods Enzymol. 51, 193-201) (sp act. 0.12 mumol min-1 mg-1). A variety of new analogues of formylglycinamide ribonucleotide have been prepared in which the formylglycinamide arm (R = CH/sub 2/NHCHO) has been replaced by R = CH/sub 3/, CH/sub 2/OH, CH/sub 2/Cl, CH/sub 2/NH/sub 3/, CH/sub 2/NHCOCH/sub 3/, CH/sub 2/NHCOCH/sub 2/Cl, CH/sub 2/NHCO/sub 2/CH/sub 2/Ph, and L-CHC-H/sub 3/NHCHO. These compounds have been characterized by 1H and 13C NMR spectroscopy. With compounds R = CH/sub 3/, CH/sub 2/OH, and CH/sub 2/NHCOCH/sub 3/ and ATP, in the presence or absence of glutamine, FGAM synthetase catalyzes the production of Pi at 4.5, 48, and 20%, respectively, the rate of production of Pi from formylglycinamide ribonucleotide. Only R = CH/sub 2/NHCOCH/sub 3/ causes glutaminase activity as well as ATPase activity and has been shown to be converted to the amidine analogue. Both FGAR (R = CH/sub 2/NHCHO) and the FGAR analogue (R = CH/sub 2/NHCHOCH/sub 3/) in the presence of ATP and FGAM synthetase and in the absence of glutamine form a complex isolable by Sephadex G-50 chromatography. FGAM synthetase is thus highly specific for its formylglycine side chain. (18O)-beta-FGAR was prepared biosynthetically, and FGAM synthetase was shown by 31P NMR spectroscopy to catalyze the transfer of amide 18O to inorganic phosphate.

  3. Light induces changes in activities of Na+/K+-ATPase, H+/K+-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam, Tridacna squamosa

    OpenAIRE

    Ip, Yuen K.; Ching, Biyun; Kum C Hiong; Choo, Celine Y. L.; Boo, Mel V.; Wong, Wai P.; Chew, Shit F.

    2015-01-01

    The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control), on enzymatic activities of transporters involved in the transport of NH+ 4 or H+, and activities of enzymes involved in converting NH+ 4 to glutamate/glutamine in inner mantle, outer mantle, and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH+ 4 in substitution for K+ to ac...

  4. Light induces changes in activities of Na+/K+(NH4+)-ATPase, H+/K+(NH4+)-ATPase and glutamine synthetase in tissues involved directly or indirectly in light-enhanced calcification in the giant clam Tridacna squamosa

    OpenAIRE

    Alex Y K Ip; Biyun eChing; Kum C Hiong; Yen Ling eChoo; Mel Veen Boo; WaiP eWong; S F Chew

    2015-01-01

    The objective of this study was to determine the effects of 12 h of exposure to light, as compared with 12 h of exposure to darkness (control), on enzymatic activities of transporters involved in the transport of NH4+ or H+, and activities of enzymes involved in converting NH4+ to glutamate/glutamine in inner mantle, outer mantle and ctenidia of the giant clam, Tridacna squamosa. Exposure to light resulted in a significant increase in the effectiveness of NH4+ in substitution for K+ to activa...

  5. Glutamine Assimilation and Feedback Regulation of L-acetyl-N-glutamate Kinase Activity in Chlorella variabilis NC64A Results in Changes in Arginine Pools.

    Science.gov (United States)

    Minaeva, Ekaterina; Forchhammer, Karl; Ermilova, Elena

    2015-11-01

    Glutamine is a metabolite of central importance in nitrogen metabolism of microorganisms and plants. The Chlorella PII signaling protein controls, in a glutamine-dependent manner, the key enzyme of the ornithine/arginine biosynthesis pathway, N-acetyl-L-glutamate kinase (NAGK) that leads to arginine formation. We provide evidence that glutamine promotes effective growth of C. variabilis strain NC64A. The present study shows that externally supplied glutamine directly influences the internal pool of arginine in NC64A. Glutamine synthetase (GS) catalyzes the ATP-dependent conversion of glutamate and ammonium to glutamine. The results of this study demonstrate that glutamine acts as a negative effector of GS activity. These data emphasize the importance of glutamine-dependent coupling of metabolism and signaling as components of an efficient pathway allowing the maintenance of metabolic homeostasis and sustaining growth of Chlorella. PMID:26356535

  6. Effect of exercise on glutamine synthesis and transport in skeletal muscle from rats.

    Science.gov (United States)

    dos Santos, Ronaldo V T; Caperuto, Erico C; de Mello, Marco T; Batista, Miguel L; Rosa, Luis F B P C

    2009-08-01

    1. Reductions in plasma glutamine are observed after prolonged exercise. Three hypotheses can explain such a decrease: (i) high demand by the liver and kidney; (ii) impaired release from muscles; and (iii) decreased synthesis in skeletal muscle. The present study investigated the effects of exercise on glutamine synthesis and transport in rat skeletal muscle. 2. Rats were divided into three groups: (i) sedentary (SED; n = 12); (ii) rats killed 1 h after the last exercise bout (EX-1; n = 15); and (iii) rats killed 24 h after the last exercise bout (EX-24; n = 15). Rats in the trained groups swam 1 h/day, 5 days/week for 6 weeks with a load equivalent to 5.5% of their bodyweight. 3. Plasma glutamine and insulin were lower and corticosterone was higher in EX-1 compared with SED rats (P exercise (EX-24), plasma glutamine was restored to levels seen in SED rats, whereas insulin levels were higher (P glutamine, glutamate and ammonia levels were lower in EX-24 than in SED and EX-1 rats (P glutamine synthetase (GS) activity was increased in EX-1 and was decreased in EX-24 compared with SED rats (both P glutamine concentration in EX-1 is not mediated by GS or glutamine transport in skeletal muscle. However, 24 h after exercise, lower GS may contribute to the decrease in glutamine concentration in muscle. PMID:19207717

  7. Glutamine acts as a neuroprotectant against DNA damage, beta-amyloid and H2O2-induced stress.

    Directory of Open Access Journals (Sweden)

    Jianmin Chen

    Full Text Available Glutamine is the most abundant free amino acid in the human blood stream and is 'conditionally essential' to cells. Its intracellular levels are regulated both by the uptake of extracellular glutamine via specific transport systems and by its intracellular synthesis by glutamine synthetase (GS. Adding to the regulatory complexity, when extracellular glutamine is reduced GS protein levels rise. Unfortunately, this excess GS can be maladaptive. GS overexpression is neurotoxic especially if the cells are in a low-glutamine medium. Similarly, in low glutamine, the levels of multiple stress response proteins are reduced rendering cells hypersensitive to H(2O(2, zinc salts and DNA damage. These altered responses may have particular relevance to neurodegenerative diseases of aging. GS activity and glutamine levels are lower in the Alzheimer's disease (AD brain, and a fraction of AD hippocampal neurons have dramatically increased GS levels compared with control subjects. We validated the importance of these observations by showing that raising glutamine levels in the medium protects cultured neuronal cells against the amyloid peptide, Aβ. Further, a 10-day course of dietary glutamine supplementation reduced inflammation-induced neuronal cell cycle activation, tau phosphorylation and ATM-activation in two different mouse models of familial AD while raising the levels of two synaptic proteins, VAMP2 and synaptophysin. Together, our observations suggest that healthy neuronal cells require both intracellular and extracellular glutamine, and that the neuroprotective effects of glutamine supplementation may prove beneficial in the treatment of AD.

  8. Glutamine Modulates Macrophage Lipotoxicity

    Directory of Open Access Journals (Sweden)

    Li He

    2016-04-01

    Full Text Available Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs, activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli.

  9. Interrelationships between glutamine and citrulline metabolism

    Science.gov (United States)

    This article analyzes the contribution of glutamine to the synthesis of citrulline and reviews the evidence that glutamine supplementation increases citrulline production. Glutamine supplementation has been proposed in the treatment of critically ill patients; however, a recent large multicenter ran...

  10. The carbamate kinase-like carbamoyl phosphate synthetase of the hyperthermophilic archaeon Pyrococcus furiosus, a missing link in the evolution of carbamoyl phosphate biosynthesis

    OpenAIRE

    Durbecq, Virginie; Legrain, Christianne; Roovers, Martine; Piérard, André; Glansdorff, Nicolas

    1997-01-01

    Microbial carbamoyl phosphate synthetases (CPS) use glutamine as nitrogen donor and are composed of two subunits (or domains), one exhibiting glutaminase activity, the other able to synthesize carbamoyl phosphate (CP) from bicarbonate, ATP, and ammonia. The pseudodimeric organization of this synthetase suggested that it has evolved by duplication of a smaller kinase, possibly a carbamate kinase (CK). In contrast to other prokaryotes the hyperthermophilic archaeon Pyrococcus furiosus was found...

  11. Ammonium-induced calcium mobilization in 1321N1 astrocytoma cells

    International Nuclear Information System (INIS)

    High blood levels of ammonium/ammonia (NH4+/NH3) are associated with severe neurotoxicity as observed in hepatic encephalopathy (HE). Astrocytes are the main targets of ammonium toxicity, while neuronal cells are less vulnerable. In the present study, an astrocytoma cell line 1321N1 and a neuroblastoma glioma hybrid cell line NG108-15 were used as model systems for astrocytes and neuronal cells, respectively. Ammonium salts evoked a transient increase in intracellular calcium concentrations ([Ca2+]i) in astrocytoma (EC50 = 6.38 mM), but not in NG108-15 cells. The ammonium-induced increase in [Ca2+]i was due to an intracellular effect of NH4+/NH3 and was independent of extracellular calcium. Acetate completely inhibited the ammonium effect. Ammonium potently reduced calcium signaling by Gq protein-coupled receptors (H1 and M3) expressed on the cells. Ammonium (5 mM) also significantly inhibited the proliferation of 1321N1 astrocytoma cells. While mRNA for the mammalian ammonium transporters RhBG and RhCG could not be detected in 1321N1 astrocytoma cells, both transporters were expressed in NG108-15 cells. RhBG and RhBC in brain may promote the excretion of NH3/NH4+ from neuronal cells. Cellular uptake of NH4+/NH3 was mainly by passive diffusion of NH3. Human 1321N1 astrocytoma cells appear to be an excellent, easily accessible human model for studying HE, which can substitute animal studies, while NG108-15 cells may be useful for investigating the role of the recently discovered Rhesus family type ammonium transporters in neuronal cells. Our findings may contribute to the understanding of pathologic ammonium effects in different brain cells, and to the treatment of hyperammonemia

  12. Breathless cancer cells get fat on glutamine

    Institute of Scientific and Technical Information of China (English)

    Dimitrios Anastasiou; Lewis C Cantley

    2012-01-01

    Many cancer cells depend on glutamine as a fuel for proliferation,yet the mechanisms by which glutamine supports cancer metabolism are not fully understood.Two recent studies highlight an important role for glutamine in the synthesis of lipids and provide novel insights into how glutamine metabolism could be targeted for cancer therapy.

  13. Effect of growth temperature on folding of carbamoylphosphate synthetases of Salmonella typhimurium and a cold-sensitive derivative.

    OpenAIRE

    Han, B D; Nolan, W G; Hopkins, H P; Jones, R. T.; Ingraham, J L; Abdelal, A T

    1990-01-01

    The properties of homogeneous preparations of carbamoylphosphate synthetase (CPSase) from wild-type Salmonella typhimurium and a cold-sensitive derivative grown at different growth temperatures were examined. For the cold-sensitive mutant, the affinity for glutamine of the form of CPSase synthesized at 20 degrees C was lower than that of the form of the enzyme synthesized at 37 degrees C, regardless of the assay temperature. Thus, the cold sensitivity of the mutant reflects an effect of tempe...

  14. 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 of...

  15. Redox status affects the catalytic activity of glutamyl-tRNA synthetase

    DEFF Research Database (Denmark)

    Katz, Assaf; Banerjee, Rajat; de Armas, Merly;

    2010-01-01

    Glutamyl-tRNA synthetases (GluRS) provide Glu-tRNA for different processes including protein synthesis, glutamine transamidation and tetrapyrrole biosynthesis. Many organisms contain multiple GluRSs, but whether these duplications solely broaden tRNA specificity or also play additional roles in...... vitro, GluRS1 activity is reversibly inactivated upon oxidation by hemin and hydrogen peroxide. The targets for oxidation-based inhibition were found to be cysteines from a SWIM zinc-binding motif located in the tRNA acceptor helix-binding domain. tRNA(Glu) was able to protect GluRS1 against oxidative...

  16. Turnover of ammonium-inducible glutamate dehydrogenase during induction and its rapid inactivation after removal of inducer from Chlorella sorokiniana cells.

    OpenAIRE

    Bascomb, N F; Yeung, A T; Turner, K J; Schmidt, R R

    1981-01-01

    When ammonia was removed from Chlorella sorokiniana cells, which contain an ammonium-inducible nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH), the activity of this enzyme decayed with a half-life of approximately 8 min. By use of rocket immunoelectrophoresis, indirect immunoprecipitation, and indirect immunoadsorption (coupled with pulse-chase experiments with 35S-labeled sulfate), the rapid initial loss in activity was shown to be due to enzyme inacti...

  17. The glutamate/GABA-glutamine cycle

    DEFF Research Database (Denmark)

    Bak, Lasse K; Schousboe, Arne; Waagepetersen, Helle S

    2006-01-01

    Neurons are metabolically handicapped in the sense that they are not able to perform de novo synthesis of neurotransmitter glutamate and gamma-aminobutyric acid (GABA) from glucose. A metabolite shuttle known as the glutamate/GABA-glutamine cycle describes the release of neurotransmitter glutamate...... or GABA from neurons and subsequent uptake into astrocytes. In return, astrocytes release glutamine to be taken up into neurons for use as neurotransmitter precursor. In this review, the basic properties of the glutamate/GABA-glutamine cycle will be discussed, including aspects of transport and...... metabolism. Discussions of stoichiometry, the relative role of glutamate vs. GABA and pathological conditions affecting the glutamate/GABA-glutamine cycling are presented. Furthermore, a section is devoted to the accompanying ammonia homeostasis of the glutamate/GABA-glutamine cycle, examining the possible...

  18. Plasma Glutamine Concentrations in Liver Failure.

    Directory of Open Access Journals (Sweden)

    Gunnel Helling

    Full Text Available Higher than normal plasma glutamine concentration at admission to an intensive care unit is associated with an unfavorable outcome. Very high plasma glutamine levels are sometimes seen in both acute and chronic liver failure. We aimed to systematically explore the relation between different types of liver failure and plasma glutamine concentrations.Four different groups of patients were studies; chronic liver failure (n = 40, acute on chronic liver failure (n = 20, acute fulminant liver failure (n = 20, and post-hepatectomy liver failure (n = 20. Child-Pugh and Model for End-stage Liver Disease (MELD scores were assessed as indices of liver function. All groups except the chronic liver failure group were followed longitudinally during hospitalisation. Outcomes were recorded up to 48 months after study inclusion.All groups had individuals with very high plasma glutamine concentrations. In the total group of patients (n = 100, severity of liver failure correlated significantly with plasma glutamine concentration, but the correlation was not strong.Liver failure, regardless of severity and course of illness, may be associated with a high plasma glutamine concentration. Further studies are needed to understand whether high glutamine levels should be regarded as a biomarker or as a contributor to symptomatology in liver failure.

  19. In vitro characterization of the NAD(+) synthetase NadE1 from Herbaspirillum seropedicae.

    Science.gov (United States)

    Laskoski, Kerly; Santos, Adrian R S; Bonatto, Ana C; Pedrosa, Fábio O; Souza, Emanuel M; Huergo, Luciano F

    2016-05-01

    Nicotinamide adenine dinucleotide synthetase enzyme (NadE) catalyzes the amination of nicotinic acid adenine dinucleotide (NaAD) to form NAD(+). This reaction represents the last step in the majority of the NAD(+) biosynthetic routes described to date. NadE enzymes typically use either glutamine or ammonium as amine nitrogen donor, and the reaction is energetically driven by ATP hydrolysis. Given the key role of NAD(+) in bacterial metabolism, NadE has attracted considerable interest as a potential target for the development of novel antibiotics. The plant-associative nitrogen-fixing bacteria Herbaspirillum seropedicae encodes two putative NadE, namely nadE1 and nadE2. The nadE1 gene is linked to glnB encoding the signal transduction protein GlnB. Here we report the purification and in vitro characterization of H. seropedicae NadE1. Gel filtration chromatography analysis suggests that NadE1 is an octamer. The NadE1 activity was assayed in vitro, and the Michaelis-Menten constants for substrates NaAD, ATP, glutamine and ammonium were determined. Enzyme kinetic and in vitro substrate competition assays indicate that H. seropedicae NadE1 uses glutamine as a preferential nitrogen donor. PMID:26802007

  20. Functions of Glutamine Synthetase Isoforms in the Nitrogen Metabolism of Plants

    DEFF Research Database (Denmark)

    Guan, Miao

    Nitrogen is one of the major plant nutrients limiting crop production worldwide. In many parts of the world the availability of N fertilizers is limited, whereas in other parts of the world too much N fertilizer is applied, leading to serious negative environmental consequences. The use of N...... fertilizers accordingly needs to be optimized in order to make agriculture more sustainable. One pathway to achieve such optimization is to improve plant N use efficiency (NUE) by developing new crop genotypes with improved yield per unit of N fertilizer applied. For this purpose, more and better knowledge...... about bottlenecks in plant N assimilation is needed. Based on a reverse genetics strategy embracing characterization of knockout mutants in the model plant species Arabidopsis, the results obtained in this PhD study have provided new information about the specific roles of two genes Gln1;1 and Gln1...

  1. Glucosamine synthetase from Escherichia coli: kinetic mechanism and inhibition by N3-fumaroyl-L-2,3-diaminopropionic derivatives

    International Nuclear Information System (INIS)

    N3-(4-Methoxyfumaroyl)-L-2,3-diaminopropionic acid (FMDP; 1, R = OMe), a member of a new class of glutamine analogues, has been investigated as an inhibitor of pure Escherichia coli glucosamine synthetase. Product and dead-end inhibition studies indicate an ordered association to the enzyme with the sugar molecule binding prior to substrate or inhibitor. The inactivation exhibits pseudo-first-order kinetics, is irreversible, and occurs faster in the presence of fructose 6-phosphate, a behavior previously reported for the partially purified enzyme from Salmonella typhimurium. Inhibition occurs with partial covalent incorporation of L-FMDP into glucosamine synthetase. In the presence of fructose 6-phosphate, enzyme inactivation with [2-3H]-DL-FMDP is associated with the incorporation of 0.75 equiv of inhibitor and with the modification of 0.78 thiol residue per enzyme subunit. This result is the first evidence for covalent entrapment of the entire inhibitor molecule following FMDP-mediated glucosamine synthetase inactivation. Preliminary inactivation with 6-diazo-5-oxo-L-norleucine, known to alkylate selectively the NH2-terminal cysteine residue, completely prevents radioactivity incorporation. Therefore, this inhibitor is postulated to covalently modify glucosamine synthetase through direct addition of the thiol nucleophile from the terminal cysteine residue to the Michael acceptor 1, so acting as an affinity label rather than a mechanism-based inhibitor

  2. Radioimmune assay of human platelet prostaglandin synthetase

    International Nuclear Information System (INIS)

    Normal platelet function depends, in part, on platelet PG synthesis. PG synthetase (cyclo-oxygenase) catalyzes the first step in PG synthesis, the formation of PGH2 from arachidonic acid. Inhibition of the enzyme by ASA results in an abnormality in the platelet release reaction. Patients with pparent congenital abnormalities in the enzyme have been described, and the effects have been referred to as ''aspirin-like'' defects of the platelet function. These patients lack platelet PG synthetase activity, but the actual content of PG synthetase protein in these individuals' platelets is unknown. Therefore an RIA for human platelet PG synthetase would provide new information, useful in assessing the aspirin-like defects of platelet function. An RIA for human platelet PG synthetase is described. The assay utilizes a rabbit antibody directed against the enzyme and [125I]-labelled sheep PG synthetase as antigen. The human platelet enzyme is assayed by its ability to inhibit precipitation of the [125I]antigen. The assay is sensitive to 1 ng of enzyme. By the immune assay, human platelets contain approximately 1200 ng of PG synethetase protein per 1.5 mg of platelet protein (approximately 109 platelets). This content corresponds to 10,000 enzyme molecules per platelet. The assay provides a rapid and convenient assay for the human platelet enzyme, and it can be applied to the assessment of patients with apparent platelet PG synthetase (cyclo-oxygenase) deficiency

  3. Genetics Home Reference: glutathione synthetase deficiency

    Science.gov (United States)

    ... elevated acidity in the blood and tissues (metabolic acidosis). In addition to the features present in moderate ... Kaabachi N, Hachicha M. Hemolytic anemia and metabolic acidosis: think about glutathione synthetase deficiency. Fetal Pediatr Pathol. ...

  4. Genetics Home Reference: holocarboxylase synthetase deficiency

    Science.gov (United States)

    ... the body is unable to use the vitamin biotin effectively. This disorder is classified as a multiple ... impaired activity of certain enzymes that depend on biotin. The signs and symptoms of holocarboxylase synthetase deficiency ...

  5. Glutamine: the nonessential amino acid for performance enhancement.

    Science.gov (United States)

    Phillips, George C

    2007-07-01

    Glutamine is a popular dietary supplement consumed for purported ergogenic benefits of increased strength, quicker recovery, decreased frequency of respiratory infections, and prevention of overtraining. From a biochemical standpoint, glutamine does play a physiologic role in each of these areas, but it remains only one of a host of factors involved. This review examines the effects of glutamine on exercise and demonstrates a lack of evidence for definitive positive ergogenic benefits as a result of glutamine supplementation. PMID:17618004

  6. Low-frequency vibrational modes of glutamine

    Science.gov (United States)

    Wang, Wei-Ning; Wang, Guo; Zhang, Yan

    2011-12-01

    High-resolution terahertz absorption and Raman spectra of glutamine in the frequency region 0.2 THz-2.8 THz are obtained by using THz time domain spectroscopy and low-frequency Raman spectroscopy. Based on the experimental and the computational results, the vibration modes corresponding to the terahertz absorption and Raman scatting peaks are assigned and further verified by the theoretical calculations. Spectral investigation of the periodic structure of glutamine based on the sophisticated hybrid density functional B3LYP indicates that the vibrational modes come mainly from the inter-molecular hydrogen bond in this frequency region.

  7. Low-frequency vibrational modes of glutamine

    Institute of Scientific and Technical Information of China (English)

    Wang Wei-Ning; Wang Guo; Zhang Yan

    2011-01-01

    High-resolution terahertz absorption and Raman spectra of glutamine in the frequency region 0.2 THz-2.8 THz are obtained by using THz time domain spectroscopy and low-frequency Raman spectroscopy.Based on the experimental and the computational results,the vibration modes corresponding to the terahertz absorption and Raman scatting peaks are assigned and further verified by the theoretical calculations.Spectral investigation of the periodic structure of glutamine based on the sophisticated hybrid density functional B3LYP indicates that the vibrational modes come mainly from the inter-molecular hydrogen bond in this frequency region.

  8. Glutamine and glutamate as vital metabolites

    Directory of Open Access Journals (Sweden)

    Newsholme P.

    2003-01-01

    Full Text Available Glucose is widely accepted as the primary nutrient for the maintenance and promotion of cell function. This metabolite leads to production of ATP, NADPH and precursors for the synthesis of macromolecules such as nucleic acids and phospholipids. We propose that, in addition to glucose, the 5-carbon amino acids glutamine and glutamate should be considered to be equally important for maintenance and promotion of cell function. The functions of glutamine/glutamate are many, i.e., they are substrates for protein synthesis, anabolic precursors for muscle growth, they regulate acid-base balance in the kidney, they are substrates for ureagenesis in the liver and for hepatic and renal gluconeogenesis, they act as an oxidative fuel for the intestine and cells of the immune system, provide inter-organ nitrogen transport, and act as precursors of neurotransmitter synthesis, of nucleotide and nucleic acid synthesis and of glutathione production. Many of these functions are interrelated with glucose metabolism. The specialized aspects of glutamine/glutamate metabolism of different glutamine-utilizing cells are discussed in the context of glucose requirements and cell function.

  9. Effect of glutamine supplementation on neutrophil function in male judoists.

    Science.gov (United States)

    Sasaki, Eiji; Umeda, Takashi; Takahashi, Ippei; Arata, Kojima; Yamamoto, Yousuke; Tanabe, Masaru; Oyamada, Kazuyuki; Hashizume, Erika; Nakaji, Shigeyuki

    2013-01-01

    Glutamine is an important amino acid for immune function. Though high intensity and prolonged exercise decreases plasma glutamine concentration and causes immune suppression, the relationship between neutrophil functions and glutamine has not yet been found. The purpose of this study was to investigate the impacts of glutamine supplementation on neutrophil function. Twenty-six male university judoists were recruited. Subjects were classified into glutamine and control groups. The glutamine group ingested 3000 mg of glutamine per day and the control group ingested placebo for 2 weeks. Examinations were performed at the start of preunified loading exercise (pre-ULE), then 1 and 2 weeks after ULE (post-ULE). Reactive oxygen species (ROS) production, phagocytic activity, serum opsonic activity and serum myogenic enzymes were measured. Differences between the levels obtained in pre-ULE and post-ULE for the two groups were compared. In the glutamine group, ROS production activity increased 1 week after ULE, whereas it was not observed in the control group (P glutamine group remained unchanged by supplementation during ULE. Glutamine supplementation has prevented excessive muscle damage and suppression of neutrophil function, especially in ROS production activity, even during an intensive training period. PMID:23348981

  10. Biochemical characterization of recombinant guaA-encoded guanosine monophosphate synthetase (EC 6.3.5.2) from Mycobacterium tuberculosis H37Rv strain.

    Science.gov (United States)

    Franco, Tathyana Mar A; Rostirolla, Diana C; Ducati, Rodrigo G; Lorenzini, Daniel M; Basso, Luiz A; Santos, Diógenes S

    2012-01-01

    Administration of the current tuberculosis (TB) vaccine to newborns is not a reliable route for preventing TB in adults. The conversion of XMP to GMP is catalyzed by guaA-encoded GMP synthetase (GMPS), and deletions in the Shiguella flexneri guaBA operon led to an attenuated auxotrophic strain. Here we present the cloning, expression, and purification of recombinant guaA-encoded GMPS from Mycobacterium tuberculosis (MtGMPS). Mass spectrometry data, oligomeric state determination, steady-state kinetics, isothermal titration calorimetry (ITC), and multiple sequence alignment are also presented. The homodimeric MtGMPS catalyzes the conversion of XMP, MgATP, and glutamine into GMP, ADP, PP(i), and glutamate. XMP, NH(4)(+), and Mg(2+) displayed positive homotropic cooperativity, whereas ATP and glutamine displayed hyperbolic saturation curves. The activity of ATP pyrophosphatase domain is independent of glutamine amidotransferase domain, whereas the latter cannot catalyze hydrolysis of glutamine to NH(3) and glutamate in the absence of substrates. ITC data suggest random order of binding of substrates, and PP(i) is the last product released. Sequence comparison analysis showed conservation of both Cys-His-Glu catalytic triad of N-terminal Class I amidotransferase and of amino acid residues of the P-loop of the N-type ATP pyrophosphatase family. PMID:22119138

  11. Rotational Study of Natural Amino Acid Glutamine

    Science.gov (United States)

    Varela, Marcelino; Cabezas, Carlos; Alonso, José L.

    2014-06-01

    Recent improvements in laser ablation molecular beam Fourier transform microwave spectroscopy (LA-MB-FTMW) have allowed the investigation of glutamine (COOH-CH(NH2)-CH2-CH2-CONH2), a natural amino acid with a long polar side chain. One dominant structure has been detected in the rotational spectrum. The nuclear quadrupole hyperfine structure of two 14N nuclei has been totally resolved allowing the conclusive identification of the observed species.

  12. Carbamoyl-phosphate synthetase II of the mammalian CAD protein: kinetic mechanism and elucidation of reaction intermediates by positional isotope exchange

    International Nuclear Information System (INIS)

    The kinetic mechanism of carbamoyl-phosphate synthetase II from Syrian hamster kidney cells has been determined at pH 7.2 and 37 degrees C. Initial velocity, product inhibition, and dead-end inhibition studies of both the biosynthetic and bicarbonate-dependent adenosinetriphosphatase (ATPase) reactions are consistent with a partially random sequential mechanism in which the ordered addition of MgATP, HCO3-, and glutamine is followed by the ordered release of glutamate and Pi. Subsequently, the binding of a second MgATP is followed by the release of MgADP, which precedes the random release of carbamoyl phosphate and a second MgADP. Carbamoyl-phosphate synthetase II catalyzes beta gamma-bridge:beta-nonbridge positional oxygen exchange of [gamma-18O]ATP in both the ATPase and biosynthetic reactions. Negligible exchange is observed in the strict absence of HCO3- (and glutamine or NH4+). The ratio of moles of MgATP exchanged to moles of MgATP hydrolyzed (nu ex/nu cat) is 0.62 for the ATPase reaction, and it is 0.39 and 0.16 for the biosynthetic reaction in the presence of high levels of glutamine and NH4+, respectively. The observed positional isotope exchange is suppressed but not eliminated at nearly saturating concentrations of either glutamine or NH4+, suggesting that this residual exchange results from either the facile reversal of an E-MgADP-carboxyphosphate-Gln(NH4+) complex or exchange within an E-MgADP-carbamoyl phosphate-MgADP complex, or both. In the 31P NMR spectra of the exchanged [gamma-18O]ATP, the distribution patterns of 16O in the gamma-phosphorus resonances in all samples reflect an exchange mechanism in which a rotationally unhindered molecule of [18O, 16O]Pi does not readily participate

  13. Phosphorylation of eukaryotic aminoacyl-tRNA synthetases

    International Nuclear Information System (INIS)

    The phosphorylation of the highly purified aminoacyl-tRNA synthetase complex from rabbit reticulocytes was examined. The synthetase complex contained, in addition to eight aminoacyl-tRNA synthetases, three unidentified proteins and was free of endogenous protein kinase activity. Incubation of the complex with casein kinase I in the presence of ATP resulted in the phosphorylation of four synthetases, the glutamyl-, isoleucyl-, methionyl-, and lysyl-tRNA synthetases. Phosphorylation by casein kinase I altered binding to tRNA-Sepharose such that the phosphorylated complex eluted at 190 mM NaCl instead of the 275 mM salt observed for the nonphosphorylated form. Phosphorylation by casein kinase I resulted in a significant inhibition of aminoacylation with the four synthetases; the activities of the nonphosphorylated synthetases were unchanged. One of the unidentified proteins in the complex (M/sub r/ 37,000) was also an excellent substrate for casein kinase I. A comparison of the properties and two-dimensional phosphopeptide pattern of this protein with that of casein kinase I suggest that the 37,000 dalton protein in the synthetase complex is an inactive form of casein kinase I. Two other protein kinases were shown to phosphorylate aminoacyl-tRNA synthetases in the complex. The phosphorylation of threonyl-tRNA synthetase was also investigated. Five aminoacyl-tRNA synthetases in the high molecular weight complex were shown to be phosphorylated in rabbit reticulocytes following labeling with (32P)orthophosphate

  14. Phosphorylation of eukaryotic aminoacyl-tRNA synthetases

    Energy Technology Data Exchange (ETDEWEB)

    Pendergast, A.M.

    1986-01-01

    The phosphorylation of the highly purified aminoacyl-tRNA synthetase complex from rabbit reticulocytes was examined. The synthetase complex contained, in addition to eight aminoacyl-tRNA synthetases, three unidentified proteins and was free of endogenous protein kinase activity. Incubation of the complex with casein kinase I in the presence of ATP resulted in the phosphorylation of four synthetases, the glutamyl-, isoleucyl-, methionyl-, and lysyl-tRNA synthetases. Phosphorylation by casein kinase I altered binding to tRNA-Sepharose such that the phosphorylated complex eluted at 190 mM NaCl instead of the 275 mM salt observed for the nonphosphorylated form. Phosphorylation by casein kinase I resulted in a significant inhibition of aminoacylation with the four synthetases; the activities of the nonphosphorylated synthetases were unchanged. One of the unidentified proteins in the complex (M/sub r/ 37,000) was also an excellent substrate for casein kinase I. A comparison of the properties and two-dimensional phosphopeptide pattern of this protein with that of casein kinase I suggest that the 37,000 dalton protein in the synthetase complex is an inactive form of casein kinase I. Two other protein kinases were shown to phosphorylate aminoacyl-tRNA synthetases in the complex. The phosphorylation of threonyl-tRNA synthetase was also investigated. Five aminoacyl-tRNA synthetases in the high molecular weight complex were shown to be phosphorylated in rabbit reticulocytes following labeling with (/sup 32/P)orthophosphate.

  15. GLUTAMINE AND HYPERAMMONEMIC CRISES IN PATIENTS WITH UREA CYCLE DISORDERS

    Science.gov (United States)

    Lee, B.; Diaz, G.A.; Rhead, W.; Lichter-Konecki, U.; Feigenbaum, A.; Berry, S.A.; Le Mons, C.; Bartley, J.; Longo, N.; Nagamani, S.C.; Berquist, W.; Gallagher, R.C.; Harding, C.O.; McCandless, S.E.; Smith, W.; Schulze, A.; Marino, M.; Rowell, R.; Coakley, D.F.; Mokhtarani, M.; Scharschmidt, B.F.

    2016-01-01

    Blood ammonia and glutamine levels are used as biomarkers of control in patients with urea cycle disorders (UCDs). This study was undertaken to evaluate glutamine variability and utility as a predictor of hyperammonemic crises (HACs) in UCD patients. Methods The relationships between glutamine and ammonia levels and the incidence and timing of HACs were evaluated in over 100 adult and pediatric UCD patients who participated in clinical trials of glycerol phenylbutyrate. Results The median (range) intra-subject 24-hour coefficient of variation for glutamine was 15% (8–29%) as compared with 56% (28%–154%) for ammonia, and the correlation coefficient between glutamine and concurrent ammonia levels varied from 0.17 to 0.29. Patients with baseline (fasting) glutamine values >900 µmol/L had higher baseline ammonia levels (mean [SD]: 39.6 [26.2] µmol/L) than patients with baseline glutamine ≤900 µmol/L (26.6 [18.0] µmol/L). Glutamine values >900 µmol/L during the study were associated with an approximately 2-fold higher HAC risk (odds ratio [OR]=1.98; p=0.173). However, glutamine lost predictive significance (OR=1.47; p=0.439) when concomitant ammonia was taken into account, whereas the predictive value of baseline ammonia ≥ 1.0 upper limit of normal (ULN) was highly statistically significant (OR=4.96; p=0.013). There was no significant effect of glutamine >900 µmol/L on time to first HAC crisis (hazard ratio [HR]=1.14; p=0.813), but there was a significant effect of baseline ammonia ≥ 1.0 ULN (HR=4.62; p=0.0011). Conclusions The findings in this UCD population suggest that glutamine is a weaker predictor of HACs than ammonia and that the utility of the predictive value of glutamine will need to take into account concurrent ammonia levels. PMID:26586473

  16. A Novel Preparation Method of C-Terminal Glutamine Dipeptides

    Institute of Scientific and Technical Information of China (English)

    QIAN Shao-Song; LIU Yi; CHEN Ran; LI Jia-You; WU Xiao-Yan; JIAO Qing-Cai

    2006-01-01

    A novel synthesis method of dipeptides containing glutamine is reported. Protected L-amino acids were prepared by using inexpensive phthaloyl as the protecting group. Then the phthaloyl-L-amino acids were condensed with glutamine salts by the mixed anhydride method to afford phthaloyl dipeptides. Subsequently, the phthaloyl was removed from the dipeptides with hydrazine hydrate. As a result, optically pure glutamine-containing dipeptides were obtained in good yields.

  17. When Is It Appropriate to Use Glutamine in Critical Illness?

    Science.gov (United States)

    Mundi, Manpreet S; Shah, Meera; Hurt, Ryan T

    2016-08-01

    Glutamine is a nonessential amino acid, which under trauma or critical illness can become essential. A number of historic small single-center randomized controlled trials (RCTs) have demonstrated positive treatment effects on clinical outcomes with glutamine supplementation. Meta-analyses based on these trials demonstrated a significant reduction in hospital mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS with intravenous (IV) glutamine. Similar results were not noted in 2 large multicenter RCTs (REDOXS and MetaPlus) assessing the efficacy of glutamine supplementation in ventilated ICU patients. The REDOXS trial of 40 ICUs randomized 1223 ventilated ICU patients to glutamine (IV and enteral), antioxidants, both glutamine and antioxidants, or placebo. The main conclusions were a trend toward increased 28-day mortality and significant increased hospital and 6-month mortality in those who received glutamine. The MetaPlus trial of 14 ICUs, which randomized 301 ventilated ICU patients to glutamine-enriched enteral vs an isocaloric diet, noted increased 6-month mortality in the glutamine-supplemented group. Newer RCTs have focused on specific populations and have demonstrated benefits in burn and elective surgery patients with glutamine supplementation. Whether larger studies will confirm these findings is yet to be determined. Recent American Society for Parenteral and Enteral Nutrition guidelines recommend that IV and enteral glutamine should not be used in the critical care setting based on the moderate quality of evidence available. We agree with these recommendations and would encourage larger multicenter studies to evaluate the risks and benefits of glutamine in burn and elective surgery patients. PMID:27246308

  18. Alkali metal ion binding to glutamine and glutamine derivatives investigated by infrared action spectroscopy and theory

    NARCIS (Netherlands)

    Bush, M. F.; Oomens, J.; Saykally, R. J.; Williams, E. R.

    2008-01-01

    The gas-phase structures of alkali-metal cationized glutamine are investigated by using both infrared multiple photon dissociation (TRMPD) action spectroscopy, utilizing light generated by a free electron laser, and theory. The IRMPD spectra contain many similarities that are most consistent with gl

  19. Arginine deiminase resistance in melanoma cells is associated with metabolic reprogramming, glucose dependence, and glutamine addiction.

    Science.gov (United States)

    Long, Yan; Tsai, Wen-Bin; Wangpaichitr, Medhi; Tsukamoto, Takashi; Savaraj, Niramol; Feun, Lynn G; Kuo, Macus Tien

    2013-11-01

    Many malignant human tumors, including melanomas, are auxotrophic for arginine due to reduced expression of argininosuccinate synthetase-1 (ASS1), the rate-limiting enzyme for arginine biosynthesis. Pegylated arginine deiminase (ADI-PEG20), which degrades extracellular arginine, resulting in arginine deprivation, has shown favorable results in clinical trials for treating arginine-auxotrophic tumors. Drug resistance is the major obstacle for effective ADI-PEG20 usage. To elucidate mechanisms of resistance, we established several ADI-PEG20-resistant (ADI(R)) variants from A2058 and SK-Mel-2 melanoma cells. Compared with the parental lines, these ADI(R) variants showed the following characteristics: (i) all ADI(R) cell lines showed elevated ASS1 expression, resulting from the constitutive binding of the transcription factor c-Myc on the ASS1 promoter, suggesting that elevated ASS1 is the major mechanism of resistance; (ii) the ADI(R) cell lines exhibited enhanced AKT signaling and were preferentially sensitive to PI3K/AKT inhibitors, but reduced mTOR signaling, and were preferentially resistant to mTOR inhibitor; (iii) these variants showed enhanced expression of glucose transporter-1 and lactate dehydrogenase-A, reduced expression of pyruvate dehydrogenase, and elevated sensitivity to the glycolytic inhibitors 2-deoxy-glucose and 3-bromopyruvate, consistent with the enhanced glycolytic pathway (the Warburg effect); (iv) the resistant cells showed higher glutamine dehydrogenase and glutaminase expression and were preferentially vulnerable to glutamine inhibitors. We showed that c-Myc, not elevated ASS1 expression, is involved in upregulation of many of these enzymes because knockdown of c-Myc reduced their expression, whereas overexpressed ASS1 by transfection reduced their expression. This study identified multiple targets for overcoming ADI-PEG resistance in cancer chemotherapy using recombinant arginine-degrading enzymes. PMID:23979920

  20. Aromatase inhibitors and anti-synthetase syndrome.

    Science.gov (United States)

    Mascella, Fabio; Gianni, Lorenzo; Affatato, Alessandra; Fantini, Manuela

    2016-09-01

    Adjuvant therapy in postmenopausal women with endocrine-responsive breast cancer (BC) is actually centered on the use of anti-aromatase inhibitors (AI). Several reports, however, are emerging in literature associating the use of this drugs to rheumatic disorders. This case report describes the first case of anti-synthetase syndrome diagnosis after treatment with anti-estrogen agents in a patient with pre-existing rheumatoid arthritis. PMID:27225465

  1. Troglitazone suppresses glutamine metabolism through a PPAR-independent mechanism.

    Science.gov (United States)

    Reynolds, Miriam R; Clem, Brian F

    2015-08-01

    Enhanced glutamine metabolism is required for tumor cell growth and survival, which suggests that agents targeting glutaminolysis may have utility within anti-cancer therapies. Troglitazone, a PPARγ agonist, exhibits significant anti-tumor activity and can alter glutamine metabolism in multiple cell types. Therefore, we examined whether troglitazone would disrupt glutamine metabolism in tumor cells and whether its action was reliant on PPARγ activity. We found that troglitazone treatment suppressed glutamine uptake and the expression of the glutamine transporter, ASCT2, and glutaminase. In addition, troglitazone reduced 13C-glutamine incorporation into the TCA cycle, decreased [ATP], and resulted in an increase in reactive oxygen species (ROS). Further, troglitazone treatment decreased tumor cell growth, which was partially rescued with the addition of the TCA-intermediate, α-ketoglutarate, or the antioxidant N-acetylcysteine. Importantly, troglitazone's effects on glutamine uptake or viable cell number were found to be PPARγ-independent. In contrast, troglitazone caused a decrease in c-Myc levels, while the proteasomal inhibitor, MG132, rescued c-Myc, ASCT2 and GLS1 expression, as well as glutamine uptake and cell number. Lastly, combinatorial treatment of troglitazone and metformin resulted in a synergistic decrease in cell number. Therefore, characterizing new anti-tumor properties of previously approved FDA therapies supports the potential for repurposing of these agents. PMID:25872876

  2. Glutamine: A novel approach to chemotherapy-induced toxicity

    Directory of Open Access Journals (Sweden)

    Kumar Gaurav

    2012-01-01

    Full Text Available Treatment of cancer is associated with short- and long-term side-effects. Cancer produces a state of glutamine deficiency, which is further aggravated by toxic effects of chemotherapeutic agents leading to increased tolerance of tumor to chemotherapy as well as reduced tolerance of normal tissues to the side-effects of chemotherapy. This article reviews the possible role of glutamine supplementation in reducing the serious adverse events in patients treated with anticancer drugs. The literature related to the possible role of glutamine in humans with cancer and the supportive evidence from animal studies was reviewed. Searches were made and the literature was retrieved using PUBMED, MEDLINE, COCHRANE LIBRARY, CENAHL and EMBASE, with a greater emphasis on the recent advances and clinical trials. Glutamine supplementation was found to protect against radiation-induced mucositis, anthracycline-induced cardiotoxicity and paclitaxel-related myalgias/arthralgias. Glutamine may prevent neurotoxicity of paclitaxel, cisplatin, oxaplatin bortezomib and lenolidamide, and is beneficial in the reduction of the dose-limiting gastrointestinal toxic effects of irinotecan and 5-FU-induced mucositis and stomatitis. Dietary glutamine reduces the severity of the immunosuppressive effect induced by methotrexate and improves the immune status of rats recovering from chemotherapy. In patients with acute myeloid leukemia requiring parenteral nutrition, glycyl-glutamine supplementation could hasten neutrophil recovery after intensive myelosuppressive chemotherapy. Current data supports the usefulness of glutamine supplementation in reducing complications of chemotherapy; however, paucity of clinical trials weakens the clear interpretation of these findings.

  3. Exogenous Glutamine in Respiratory Diseases: Myth or Reality?

    Directory of Open Access Journals (Sweden)

    Gisele P. Oliveira

    2016-02-01

    Full Text Available Several respiratory diseases feature increased inflammatory response and catabolic activity, which are associated with glutamine depletion; thus, the benefits of exogenous glutamine administration have been evaluated in clinical trials and models of different respiratory diseases. Recent reviews and meta-analyses have focused on the effects and mechanisms of action of glutamine in a general population of critical care patients or in different models of injury. However, little information is available about the role of glutamine in respiratory diseases. The aim of the present review is to discuss the evidence of glutamine depletion in cystic fibrosis (CF, asthma, chronic obstructive pulmonary disease (COPD, acute respiratory distress syndrome (ARDS, and lung cancer, as well as the results of exogenous glutamine administration in experimental and clinical studies. Exogenous glutamine administration might be beneficial in ARDS, asthma, and during lung cancer treatment, thus representing a potential therapeutic tool in these conditions. Further experimental and large randomized clinical trials focusing on the development and progression of respiratory diseases are necessary to elucidate the effects and possible therapeutic role of glutamine in this setting.

  4. Complexation of asparagine and glutamine by dioxovanadium

    International Nuclear Information System (INIS)

    The complexation of pervanadyl ion (VO2+) with L-asparagine and L-glutamine has been investigated by spectrophotometric measurements in aqueous solution at 0.15 mol dm-3 ionic strength (NaCLO4) and 25 ± 0.1 Deg C in the pH 1.3 - 10.3 range. The stability constants of the formed complexes and their stoichiometries are given and interpreted. The logarithms of the cumulative stability constant, βxyz, of the complexes [(H)x(oxo metal)y(amino acid)z] are respectively: lgβ101 = 8.80 ± 0.08, lgβ011 = 9.47 ± 0.10, and lgβ012 = 14.57 ± 0.15 for asparagine and lgβ101 = 9.05 ± 0.10, lgβ011 9.54 ± 0.10, and lgβ012 = 14.81 ± 0.15 for glutamine. The mode coordination of the ligands in their protonated and deprotonated complexes is discussed on the basis of their parameters

  5. Leucyl-tRNA synthetase from the ancestral bacterium Aquifex aeolicus contains relics of synthetase evolution

    OpenAIRE

    Zhao, Ming-Wei; Zhu, Bin; Hao, Rui; Xu, Min-Gang; Eriani, Gilbert; Wang, En-Duo

    2005-01-01

    The editing reactions catalyzed by aminoacyl-tRNA synthetases are critical for the faithful protein synthesis by correcting misactivated amino acids and misaminoacylated tRNAs. We report that the isolated editing domain of leucyl-tRNA synthetase from the deep-rooted bacterium Aquifex aeolicus (αβ-LeuRS) catalyzes the hydrolytic editing of both mischarged tRNALeu and minihelixLeu. Within the domain, we have identified a crucial 20-amino-acid peptide that confers editing capacity when transplan...

  6. A widespread glutamine-sensing mechanism in the plant kingdom.

    Science.gov (United States)

    Chellamuthu, Vasuki-Ranjani; Ermilova, Elena; Lapina, Tatjana; Lüddecke, Jan; Minaeva, Ekaterina; Herrmann, Christina; Hartmann, Marcus D; Forchhammer, Karl

    2014-11-20

    Glutamine is the primary metabolite of nitrogen assimilation from inorganic nitrogen sources in microorganisms and plants. The ability to monitor cellular nitrogen status is pivotal for maintaining metabolic homeostasis and sustaining growth. The present study identifies a glutamine-sensing mechanism common in the entire plant kingdom except Brassicaceae. The plastid-localized PII signaling protein controls, in a glutamine-dependent manner, the key enzyme of the ornithine synthesis pathway, N-acetyl-l-glutamate kinase (NAGK), that leads to arginine and polyamine formation. Crystal structures reveal that the plant-specific C-terminal extension of PII, which we term the Q loop, forms a low-affinity glutamine-binding site. Glutamine binding alters PII conformation, promoting interaction and activation of NAGK. The binding motif is highly conserved in plants except Brassicaceae. A functional Q loop restores glutamine sensing in a recombinant Arabidopsis thaliana PII protein, demonstrating the modular concept of the glutamine-sensing mechanism adopted by PII proteins during the evolution of plant chloroplasts. PMID:25416954

  7. Preparation and characterization of electrospun nanofibers containing glutamine.

    Science.gov (United States)

    Tort, Serdar; Acartürk, Füsun

    2016-11-01

    Oral mucositis is a painful inflammation of mucous membranes commonly after chemotherapy or radiotherapy. The aim of this study was to develop mucoadhesive nanofibers containing glutamine via electrospinning and to characterize them for the treatment of oral mucositis. Different mucoadhesive polymers were tried for preparing nanofibers and sodium alginate nanofibers were chosen after the characterization studies. Glutamine-loaded nanofibers were produced and characterized. Glutamine loaded onto nanofibers was confirmed by differantial scanning calorimetry and fourier transform infrared spectroscopy analyses. As a result, scanning electron microscopy observations showed that the glutamine loaded nanofibers had average diameter of 160nm. Glutamine amount was found to be 0.452mg/cm(2). Work of mucoadhesion, tensile strength and elongation at break values of the glutamine loaded nanofibers were found to be 0.165mJ/cm(2), 2.61mPa and 6.62% respectively. In vitro dissolution tests showed that more than 85% of the drug was diffused from the nanofibers at the end of 4h. Stability studies showed that there was no significant changes at 4 and 25°C/65% relative humidity storage conditions. Therefore, these results demonstrate that glutamine loaded nanofibers could have potential as an oromucosal drug delivery system for the treatment oral mucositis. PMID:27516332

  8. Control of glutamine metabolism by the tumor suppressor Rb.

    Science.gov (United States)

    Reynolds, M R; Lane, A N; Robertson, B; Kemp, S; Liu, Y; Hill, B G; Dean, D C; Clem, B F

    2014-01-30

    Retinoblastoma (Rb) protein is a tumor suppressor that is dysregulated in a majority of human cancers. Rb functions to inhibit cell cycle progression in part by directly disabling the E2F family of cell cycle-promoting transcription factors. Because the de novo synthesis of multiple glutamine-derived anabolic precursors is required for cell cycle progression, we hypothesized that Rb also may directly regulate proteins involved in glutamine metabolism. We examined glutamine metabolism in mouse embryonic fibroblasts (MEFs) isolated from mice that have triple knock-outs (TKO) of all three Rb family members (Rb-1, Rbl1 and Rbl2) and found that loss of global Rb function caused a marked increase in (13)C-glutamine uptake and incorporation into glutamate and tricarboxylic acid cycle (TCA) intermediates in part via upregulated expression of the glutamine transporter ASCT2 and the activity of glutaminase 1 (GLS1). The Rb-controlled transcription factor E2F-3 altered glutamine uptake by direct regulation of ASCT2 mRNA and protein expression, and E2F-3 was observed to associate with the ASCT2 promoter. We next examined the functional consequences of the observed increase in glutamine uptake and utilization and found that glutamine exposure potently increased oxygen consumption, whereas glutamine deprivation selectively decreased ATP concentration in the Rb TKO MEFs but not the wild-type (WT) MEFs. In addition, TKO MEFs exhibited elevated production of glutathione from exogenous glutamine and had increased expression of gamma-glutamylcysteine ligase relative to WT MEFs. Importantly, this metabolic shift towards glutamine utilization was required for the proliferation of Rb TKO MEFs but not for the proliferation of the WT MEFs. Last, addition of the TCA cycle intermediate α-ketoglutarate to the Rb TKO MEFs reversed the inhibitory effects of glutamine deprivation on ATP, GSH levels and viability. Taken together, these studies demonstrate that the Rb/E2F cascade directly

  9. Spatial relationship of lectin-labelled extracellular matrix and glutamine synthetase-immunoreactive astrocytes in rat cortical forebrain regions.

    OpenAIRE

    Derouiche, A.; Härtig, W.; Brauer, K; Brückner, G.

    1996-01-01

    Extracellular matrix proteoglycans have previously been revealed by immunocytochemical and lectin-histochemical methods as distinct perineuronal nets in the microenvironment of different types of neurons, but also as a diffuse stain throughout the neuropil in region-dependent patterns. Ultrastructural investigations of perineuronal nets in subcortical regions have demonstrated glycan components in the close vicinity of astrocyte processes, suggesting that the extracellular matrix contributes ...

  10. Gene expression, cellular localisation and function of glutamine synthetase isozymes in wheat (Triticum aestivum L.)

    DEFF Research Database (Denmark)

    Bernard, Stéphanie M.; Møller, Anders Laurell Blom; Dionisio, Giuseppe;

    2008-01-01

    ). Phylogenetic analysis showed that the wheat GS sub-families together with the GS genes from other monocotyledonous species form four distinct clades. Immunolocalisation studies in leaves, stems and rachis in plants at flowering showed GS protein to be present in parenchyma, phloem companion and perifascicular...... sheath cells. In situ localisation confirmed that GS1 transcripts were present in the perifascicular sheath cells whilst those for GSr were confined to the vascular cells. Studies of the expression and protein profiles showed that all GS sub-families were differentially expressed in the leaves, peduncle...

  11. Downregulation of Glutamine Synthetase via GLAST Suppression Induces Retinal Axonal Swelling in a Rat Ex Vivo Hydrostatic Pressure Model

    OpenAIRE

    Ishikawa,Makoto; Yoshitomi, Takeshi; Zorumski, Charles F.; Izumi, Yukitoshi

    2011-01-01

    The present results suggest that downregulation of GS during pressure-loading may result from impaired GLAST expression. The authors conclude that the retina is at risk during acute intraocular pressure elevation due to downregulation of GS activity resulting from depressed GLAST expression.

  12. Effects of glutamine on performance and intestinal mucosa morphometry of broiler chickens vaccinated against coccidiosis

    OpenAIRE

    Brenda Carla Luquetti; Miguel Frederico Fernandez Alarcon; Raquel Lunedo; Daniel Mendes Borges Campos; Renato Luís Furlan; Marcos Macari

    2016-01-01

    ABSTRACT This study aimed to assess the effects of glutamine as feed additive on performance and intestinal mucosa morphometry of broiler chickens vaccinated against coccidiosis. A total of 400 day-old male chicks were randomly assigned to four treatments (NVNG – no vaccination, no glutamine supplementation; NVG – no vaccination, glutamine supplementation (10 g kg−1); VNG – vaccination, no glutamine supplementation; VG – vaccination, glutamine supplementation) replicated four times with 25 bi...

  13. Biosynthetic engineering of nonribosomal peptide synthetases.

    Science.gov (United States)

    Kries, Hajo

    2016-09-01

    From the evolutionary melting pot of natural product synthetase genes, microorganisms elicit antibiotics, communication tools, and iron scavengers. Chemical biologists manipulate these genes to recreate similarly diverse and potent biological activities not on evolutionary time scales but within months. Enzyme engineering has progressed considerably in recent years and offers new screening, modelling, and design tools for natural product designers. Here, recent advances in enzyme engineering and their application to nonribosomal peptide synthetases are reviewed. Among the nonribosomal peptides that have been subjected to biosynthetic engineering are the antibiotics daptomycin, calcium-dependent antibiotic, and gramicidin S. With these peptides, incorporation of unnatural building blocks and modulation of bioactivities via various structural modifications have been successfully demonstrated. Natural product engineering on the biosynthetic level is not a reliable method yet. However, progress in the understanding and manipulation of biosynthetic pathways may enable the routine production of optimized peptide drugs in the near future. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27465074

  14. Supplementation with L-Glutamine and L-Alanyl-L-Glutamine Changes Biochemical Parameters and Jejunum Morphophysiology in Type 1 Diabetic Wistar Rats

    OpenAIRE

    da Rosa, Carlos Vinicius D.; Azevedo, Silvia C. S. F.; Bazotte, Roberto B.; Peralta, Rosane M.; Buttow, Nilza C.; Maria Montserrat D Pedrosa; Vilma A F de Godoi; Maria Raquel M Natali

    2015-01-01

    We evaluated the effects of the supplementation with L-glutamine and glutamine dipeptide (GDP) on biochemical and morphophysiological parameters in streptozotocin-diabetic rats. For this purpose, thirty animals were distributed into six groups treated orally (gavage) during thirty days: non diabetic rats (Control) + saline, diabetic + saline; Control + L-glutamine (248 mg/kg), Diabetic + L-glutamine (248 mg/kg), Control + GDP (400 mg/kg), Diabetic + GDP (400 mg/kg). Diabetes was induced by an...

  15. Genetic identification of essential indels and domains in carbamoyl phosphate synthetase II of Toxoplasma gondii.

    Science.gov (United States)

    Fox, Barbara A; Ristuccia, Jessica G; Bzik, David J

    2009-04-01

    New treatments need to be developed for the significant human diseases of toxoplasmosis and malaria to circumvent problems with current treatments and drug resistance. Apicomplexan parasites causing these lethal diseases are deficient in pyrimidine salvage, suggesting that selective inhibition of de novo pyrimidine biosynthesis can lead to a severe loss of uridine 5'-monophosphate (UMP) and thymidine 5'-monophosphate (dTMP) pools, thereby inhibiting parasite RNA and DNA synthesis. Disruption of Toxoplasma gondii carbamoyl phosphate synthetase II (CPSII) induces a severe uracil auxotrophy with no detectable parasite replication in vitro and complete attenuation of virulence in mice. Here we show that a CPSII cDNA minigene efficiently complements the uracil auxotrophy of CPSII-deficient mutants, restoring parasite growth and virulence. Our complementation assays reveal that engineered mutations within, or proximal to, the catalytic triad of the N-terminal glutamine amidotransferase (GATase) domain inactivate the complementation activity of T. gondii CPSII and demonstrate a critical dependence on the apicomplexan CPSII GATase domain in vivo. Surprisingly, indels present within the T. gondii CPSII GATase domain as well as the C-terminal allosteric regulatory domain are found to be essential. In addition, several mutations directed at residues implicated in allosteric regulation in Escherichia coli CPS either abolish or markedly suppress complementation and further define the functional importance of the allosteric regulatory region. Collectively, these findings identify novel features of T. gondii CPSII as potential parasite-selective targets for drug development. PMID:18992249

  16. Effects of supplementation with free glutamine and the dipeptide alanyl-glutamine on parameters of muscle damage and inflammation in rats submitted to prolonged exercise.

    Science.gov (United States)

    Cruzat, Vinicius Fernandes; Rogero, Marcelo Macedo; Tirapegui, Julio

    2010-01-01

    In this study, we investigated the effect of the supplementation with the dipeptide L-alanyl-L-glutamine (DIP) and a solution containing L-glutamine and L-alanine on plasma levels markers of muscle damage and levels of pro-inflammatory cytokines and glutamine metabolism in rats submitted to prolonged exercise. Rats were submitted to sessions of swim training for 6 weeks. Twenty-one days prior to euthanasia, the animals were supplemented with DIP (n = 8) (1.5 g.kg(-1)), a solution of free L-glutamine (1 g.kg(-1)) and free L-alanine (0.61 g.kg(-1)) (G&A, n = 8) or water (control (CON), n = 8). Animals were killed at rest before (R), after prolonged exercise (PE-2 h of exercise). Plasma concentrations of glutamine, glutamate, tumour necrosis factor-alpha (TNF-alpha), prostaglandin E2 (PGE2) and activity of creatine kinase (CK), lactate dehydrogenase (LDH) and muscle concentrations of glutamine and glutamate were measured. The concentrations of plasma TNF-alpha, PGE2 and the activity of CK were lower in the G&A-R and DIP-R groups, compared to the CON-R. Glutamine in plasma (p glutamine and glutamate in soleus (p glutamine and the dipeptide LL-alanyl-LL-glutamine represents an effective source of glutamine, which may attenuate inflammation biomarkers after periods of training and plasma levels of CK and the inflammatory response induced by prolonged exercise. PMID:19885855

  17. Genetics Home Reference: carbamoyl phosphate synthetase I deficiency

    Science.gov (United States)

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions carbamoyl phosphate synthetase I deficiency ...

  18. Effect of parenteral glutamine supplementation in premature infants

    Institute of Scientific and Technical Information of China (English)

    LI Zheng-hong; WANG Dan-hua; DONG Mei

    2007-01-01

    Background Glutamine, proposed to be conditionally essential for critically ill patients, is not added routinely to parenteral amino acid formulations for premature infants and is provided in only small quantities by the enteral route when enteral feeding is Iow. Parenteral feeding is the basic way of nutrition in the first days of life of premature infants. In this study, we evaluated the effects of glutamine supplemented parenteral nutrition for premature infants on growth and development, feeding toleration, and infective episodes.Methods From December 2002 to July 2006, 53 premature infants were given either standard or glutamine supplemented parenteral nutrition for more than 2 weeks. Twenty-eight infants were in glutamine supplemented group, whose gestational age (31.4±2.0) weeks, birth weight range (1386±251) g; twenty-five infants were in control group, gestational age (31.1 ± 1.7) weeks, with birth weight range (1346± 199) g. There were no differences between the two groups. Various growth and biochemical indices were monitored throughout the duration of hospital stay. Data between groups were analyzed with Student's t test. Nonparametric data were analyzed using a Chi-square test. A two-tailed P value < 0.05 was considered statistically significant.Results The level of serum albumin was lower in the glutamine groups on the second week (3.0 vs 3.2 g/dl, P=0.028), and blood urea nitrogen was higher in glutamine groups on the fourth week (8.1 vs 4.9 mg/dl, P=0.014), but normal. Glutamine group infants took fewer days to regain birth weight (8.1 vs 10.4 days, P=0.017), required fewer days on parenteral nutrition (24.8 vs 30.8 days, P=0.035), with shorter stays in hospital (32.1 vs 38.6 days, P=0.047). Episodes of hospital acquired infection in glutamine supplemented infants were lower than that in control group (0.96 vs 1.84 times, P=0.000).Conclusion Parenteral glutamine supplementation in premature infants can shorten days on parenteral nutrition and

  19. Continuous spectrophotometric assay for aminoacyl-tRNA synthetases.

    Science.gov (United States)

    Chang, G G; Pan, F; Lin, Y H; Wang, H Y

    1984-11-01

    A simple, continuous assay for aminoacyl-tRNA synthetases utilizing a commercially available pyrophosphate assay reagent kit was demonstrated. The method coupled aminoacyl-tRNA synthetase activity with pyrophosphate-dependent fructose-6-phosphate kinase, aldolase, triosephosphate isomerase, and glycerophosphate dehydrogenase. PPi formation was correlated with the oxidation of NADH, and was monitored continuously by the decrease of absorbance at 340 nm. PMID:6099060

  20. Glutaminase enzyme biosensor for determination of glutamine in cerebrospinal fluid, human serum and l-glutamine capsule

    International Nuclear Information System (INIS)

    Ammonium-selective glutamine biosensor was prepared by immobilizing glutaminase on poly(vinylchloride) (PVC) ammonium membrane electrode containing palmitic acid prepared by using nonactine. The response of glutamine biosensor was linear over the concentration range of 1.0x10-11.0x10-4M and slope was Nernstian. We determined optimum working conditions of the biosensor such as buffer concentration, buffer pH, lifetime, response time, linear working range and other response characteristics. The optimum buffer concentration and pH of proposed glutamine biosensor were determined as 20mM and pH 7.5, respectively. The interference effects of some ions and amino acids that may be present in body fluids were also investigated. The Km and Vmax values of glutaminase were determined. Additionally, glutamine assay in several biological samples such as healthy human serum, cerebrospinal fluid (CSF) and commercial glutamine capsule were also successfully carried out by using the standard addition method. The results were good agreement with previously reported values. (author)

  1. The effect of glutamine infusion on the inflammatory response and HSP70 during human experimental endotoxaemia

    DEFF Research Database (Denmark)

    Andreasen, Anne Sofie; Pedersen-Skovsgaard, Theis; Mortensen, Ole Hartvig;

    2009-01-01

    INTRODUCTION: Glutamine supplementation has beneficial effects on morbidity and mortality in critically ill patients, possibly in part through an attenuation of the proinflammatory cytokine response and a stimulation of heat shock protein (HSP)70. We infused either alanine-glutamine or saline...... an infusion of alanine-glutamine at a rate of 0.025 g/(kg body weight x hour) or saline for 10 hours. After 2 hours, an intravenous bolus of Escherichia coli endotoxin (0.3 ng/kg) was administered. Blood samples were collected hourly for the following 8 hours. HSP70 protein content in isolated blood...... mononuclear cells (BMNCs) was measured by Western blotting. RESULTS: Plasma glutamine increased during alanine-glutamine infusion. Endotoxin reduced plasma glutamine during both trials, but plasma glutamine levels remained above baseline with alanine-glutamine supplementation. Endotoxin injection...

  2. Glutamine analogs promote cytoophidium assembly in human and Drosophila cells

    Institute of Scientific and Technical Information of China (English)

    Kangni Chen; Jing Zhang; (O)mür Yilmaz Tastan; Zillah Anne Deussen; Mayte Yu-Yin Siswick; Ji-Long Liu

    2011-01-01

    CTP synthase is compartmentalized within a subcellular structure,termed the cytoophidium,in a range of organisms including bacteria,yeast,fruit fly and rat.Here we show that CTP synthase is also compartmentalized into cytoophidia in human cells.Surprisingly,the occurrence of cyloophidia in human cells increases upon treatment with a glutamine analog 6-diazo-5-oxo-L-norleucine (DON),an inhibitor of glutaminedependent enzymes including CTP synthase.Experiments in flies confirmned that DON globally promotes cytoophidium assembly.Clonal analysis via CTP synthase RNA interference in somatic cells indicates that CTP synthase expression level is critical for the formation of cytoophidia.Moreover,DON facilitates cytoophidium assembly even when CTP synthase level is low.A second glutamine analog azaserine also promotes cytoophidum formation.Our data demonstrate that glutamine analogs serve as useful tools in the study of cytoophidia.

  3. Binge ethanol withdrawal: Effects on post-withdrawal ethanol intake, glutamate-glutamine cycle and monoamine tissue content in P rat model.

    Science.gov (United States)

    Das, Sujan C; Althobaiti, Yusuf S; Alshehri, Fahad S; Sari, Youssef

    2016-04-15

    Alcohol withdrawal syndrome (AWS) is a medical emergency situation which appears after abrupt cessation of ethanol intake. Decreased GABA-A function and increased glutamate function are known to exist in the AWS. However, the involvement of glutamate transporters in the context of AWS requires further investigation. In this study, we used a model of ethanol withdrawal involving abrupt cessation of binge ethanol administration (4g/kg/gavage three times a day for three days) using male alcohol-preferring (P) rats. After 48h of withdrawal, P rats were re-exposed to voluntary ethanol intake. The amount of ethanol consumed was measured during post-withdrawal phase. In addition, the expression of GLT-1, GLAST and xCT were determined in both medial prefrontal cortex (mPFC) and nucleus accumbens (NAc). We also measured glutamine synthetase (GS) activity, and the tissue content of glutamate, glutamine, dopamine and serotonin in both mPFC and NAc. We found that binge ethanol withdrawal escalated post-withdrawal ethanol intake, which was associated with downregulation of GLT-1 expression in both mPFC and NAc. The expression of GLAST and xCT were unchanged in the ethanol-withdrawal (EW) group compared to control group. Tissue content of glutamate was significantly lower in both mPFC and NAc, whereas tissue content of glutamine was higher in mPFC but unchanged in NAc in the EW group compared to control group. The GS activity was unchanged in both mPFC and NAc. The tissue content of DA was significantly lower in both mPFC and NAc, whereas tissue content of serotonin was unchanged in both mPFC and NAc. These findings provide important information of the critical role of GLT-1 in context of AWS. PMID:26821293

  4. Kinetics profiling of gramicidin S synthetase A, a member of nonribosomal peptide synthetases.

    Science.gov (United States)

    Sun, Xun; Li, Hao; Alfermann, Jonas; Mootz, Henning D; Yang, Haw

    2014-12-23

    Nonribosomal peptide synthetases (NRPS) incorporate assorted amino acid substrates into complex natural products. The substrate is activated via the formation of a reactive aminoacyl adenylate and is subsequently attached to the protein template via a thioester bond. The reactive nature of such intermediates, however, leads to side reactions that also break down the high-energy anhydride bond. The off-pathway kinetics or their relative weights compared to that of the on-pathway counterpart remains generally elusive. Here, we introduce multiplatform kinetics profiling to quantify the relative weights of on- and off-pathway reactions. Using the well-defined stoichiometry of thioester formation, we integrate a mass spectrometry (MS) kinetics assay, a high-performance liquid chromatography (HPLC) assay, and an ATP-pyrophosphate (PPi) exchange assay to map out a highly efficient on-pathway kinetics profile of the substrate activation and intermediate uploading (>98% relative weight) for wide-type gramicidin S synthetase A (GrsA) and a 87% rate profile for a cysteine-free GrsA mutant. Our kinetics profiling approach complements the existing enzyme-coupled byproduct-release assays, unraveling new mechanistic insights of substrate activation/channeling in NRPS enzymes. PMID:25437123

  5. SCREENING OF ANTIMICROBIAL ACTIVITY AND GENES CODING POLYKETIDE SYNTHETASE AND NONRIBOSOMAL PEPTIDE SYNTHETASE OF ACTINOMYCETE ISOLATES

    Directory of Open Access Journals (Sweden)

    Silvia Kovácsová

    2013-12-01

    Full Text Available The aim of this study was to observe antimicrobial activity using agar plate diffusion method and screening genes coding polyketide synthetase (PKS-I and nonribosomal peptide synthetase (NRPS from actinomycetes. A total of 105 actinomycete strains were isolated from arable soil. Antimicrobial activity was demonstrated at 54 strains against at least 1 of total 12 indicator organisms. Antifungal properties were recorded more often than antibacterial properties. The presence of PKS-I and NRPS genes were founded at 61 of total 105 strains. The number of strains with mentioned biosynthetic enzyme gene fragments matching the anticipated length were 19 (18% and 50 (47% respectively. Overall, five actinomycete strains carried all the biosynthetical genes, yet no antimicrobial activity was found against any of tested pathogens. On the other hand, twenty-one strains showed antimicrobial activity even though we were not able to amplify any of the PKS or NRPS genes from them. Combination of the two methods showed broad-spectrum antimicrobial activity of actinomycetes isolated from arable soil, which indicate that actinomycetes are valuable reservoirs of novel bioactive compounds.

  6. Effect of dexamethasone on fetal hepatic glutamine-glutamate exchange

    NARCIS (Netherlands)

    M. Timmerman (Michelle); C. Teng; R.B. Wilkening; P.V. Fennessey (Paul); F.C. Battaglia (Frederick); G. Meschia

    2000-01-01

    textabstractIntravenous infusion of dexamethasone (Dex) in the fetal lamb causes a two- to threefold increase in plasma glutamine and other glucogenic amino acids and a decrease of plasma glutamate to approximately one-third of normal. To explore the underlying mechanis

  7. Glutamine transport. From energy supply to sensing and beyond.

    Science.gov (United States)

    Scalise, Mariafrancesca; Pochini, Lorena; Galluccio, Michele; Indiveri, Cesare

    2016-08-01

    Glutamine is the most abundant amino acid in plasma and is actively involved in many biosynthetic and regulatory processes. It can be synthesized endogenously but becomes "conditionally essential" in physiological or pathological conditions of high proliferation rate. To accomplish its functions glutamine has to be absorbed and distributed in the whole body. This job is efficiently carried out by a network of membrane transporters that differ in transport mechanisms and energetics, belonging to families SLC1, 6, 7, 38, and possibly, 25. Some of the transporters are involved in glutamine traffic across different membranes for metabolic purposes; others are involved in specific signaling functions through mTOR. Structure/function relationships and regulatory aspects of glutamine transporters are still at infancy. In the while, insights in involvement of these transporters in cell redox control, cancer metabolism and drug interactions are arising, stimulating basic research to uncover molecular mechanisms of transport and regulation. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. PMID:26951943

  8. Glutamine: precursor or nitrogen donor for citrulline synthesis?

    Science.gov (United States)

    Glutamine (Gln) is considered the main precursor for citrulline (Cit) synthesis, but no attempts have been made to differentiate the contribution of Gln carbon (Gln-C) skeleton vs. the nonspecific contribution through NH3 and CO2. To study the contribution of dietary Gln-N to the synthesis of Cit, t...

  9. Intravenous glutamine enhances COX-2 activity giving cardioprotection.

    LENUS (Irish Health Repository)

    McGuinness, Jonathan

    2009-03-01

    Preconditioning, a highly evolutionary conserved endogenous protective response, provides the most powerful form of anti-infarct protection known. We investigated whether acute intravenous glutamine, through an effect on cyclooxygenase (COX)-2 and heat shock protein (HSP) 72, might induce preconditioning.

  10. Protective effect of glutamine pretreatment on ischemia-reperfusion injury of spinal cord in rabbits

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To investigate the effect of glutamine(Gln)on the content of reduced glutathione hormone(GSH)and aminoglutaminic acid(Glu)of spinal cord following ischemia-reperfusion injury.Methods Totally 40 healthy adult male rabbits were randomly divided into five groups:sham-operation group(S group),ischemia-reperfusion injury group(I/R group),low-dose glutamine group(L Gln group),median-dose glutamine group(M Gln group)and high-dose glutamine group(H Gln group).After glutamine preconditioning,the model of s...

  11. Evolutionary divergence of chloroplast FAD synthetase proteins

    Directory of Open Access Journals (Sweden)

    Arilla-Luna Sonia

    2010-10-01

    Full Text Available Abstract Background Flavin adenine dinucleotide synthetases (FADSs - a group of bifunctional enzymes that carry out the dual functions of riboflavin phosphorylation to produce flavin mononucleotide (FMN and its subsequent adenylation to generate FAD in most prokaryotes - were studied in plants in terms of sequence, structure and evolutionary history. Results Using a variety of bioinformatics methods we have found that FADS enzymes localized to the chloroplasts, which we term as plant-like FADS proteins, are distributed across a variety of green plant lineages and constitute a divergent protein family clearly of cyanobacterial origin. The C-terminal module of these enzymes does not contain the typical riboflavin kinase active site sequence, while the N-terminal module is broadly conserved. These results agree with a previous work reported by Sandoval et al. in 2008. Furthermore, our observations and preliminary experimental results indicate that the C-terminus of plant-like FADS proteins may contain a catalytic activity, but different to that of their prokaryotic counterparts. In fact, homology models predict that plant-specific conserved residues constitute a distinct active site in the C-terminus. Conclusions A structure-based sequence alignment and an in-depth evolutionary survey of FADS proteins, thought to be crucial in plant metabolism, are reported, which will be essential for the correct annotation of plant genomes and further structural and functional studies. This work is a contribution to our understanding of the evolutionary history of plant-like FADS enzymes, which constitute a new family of FADS proteins whose C-terminal module might be involved in a distinct catalytic activity.

  12. Dosing and efficacy of glutamine supplementation in human exercise and sport training.

    Science.gov (United States)

    Gleeson, Michael

    2008-10-01

    Some athletes can have high intakes of l-glutamine because of their high energy and protein intakes and also because they consume protein supplements, protein hydrolysates, and free amino acids. Prolonged exercise and periods of heavy training are associated with a decrease in the plasma glutamine concentration and this has been suggested to be a potential cause of the exercise-induced immune impairment and increased susceptibility to infection in athletes. However, several recent glutamine feeding intervention studies indicate that although the plasma glutamine concentration can be kept constant during and after prolonged strenuous exercise, the glutamine supplementation does not prevent the postexercise changes in several aspects of immune function. Although glutamine is essential for lymphocyte proliferation, the plasma glutamine concentration does not fall sufficiently low after exercise to compromise the rate of proliferation. Acute intakes of glutamine of approximately 20-30 g seem to be without ill effect in healthy adult humans and no harm was reported in 1 study in which athletes consumed 28 g glutamine every day for 14 d. Doses of up to 0.65 g/kg body mass of glutamine (in solution or as a suspension) have been reported to be tolerated by patients and did not result in abnormal plasma ammonia levels. However, the suggested reasons for taking glutamine supplements (support for immune system, increased glycogen synthesis, anticatabolic effect) have received little support from well-controlled scientific studies in healthy, well-nourished humans. PMID:18806122

  13. Recurrent Isolated Neonatal Hemolytic Anemia: Think About Glutathione Synthetase Deficiency.

    Science.gov (United States)

    Signolet, Isabelle; Chenouard, Rachel; Oca, Florine; Barth, Magalie; Reynier, Pascal; Denis, Marie-Christine; Simard, Gilles

    2016-09-01

    Hemolytic anemia (HA) of the newborn should be considered in cases of rapidly developing, severe, or persistent hyperbilirubinemia. Several causes of corpuscular hemolysis have been described, among which red blood cell enzyme defects are of particular concern. We report a rare case of red blood cell enzyme defect in a male infant, who presented during his first months of life with recurrent and isolated neonatal hemolysis. All main causes were ruled out. At 6.5 months of age, the patient presented with gastroenteritis requiring hospitalization; fortuitously, urine organic acid chromatography revealed a large peak of 5-oxoproline. Before the association between HA and 5-oxoprolinuria was noted, glutathione synthetase deficiency was suspected and confirmed by a low glutathione synthetase concentration and a collapse of glutathione synthetase activity in erythrocytes. Moreover, molecular diagnosis revealed 2 mutations in the glutathione synthetase gene: a previously reported missense mutation (c.[656A>G]; p.[Asp219Gly]) and a mutation not yet described in the binding site of the enzyme (c.[902T>C]; p.[Leu301Pro]). However, 15 days later, a control sample revealed no signs of 5-oxoprolinuria and the clinical history discovered administration of acetaminophen in the 48 hours before hospitalization. Thus, in this patient, acetaminophen exposure allowed the diagnosis of a mild form of glutathione synthetase deficiency, characterized by isolated HA. Early diagnosis is important because treatment with bicarbonate, vitamins C and E, and elimination of trigger factors are recommended to improve long-term outcomes. Glutathione synthetase deficiency should be screened for in cases of unexplained newborn HA. PMID:27581854

  14. Novel Insights into Regulation of Asparagine Synthetase in Conifers

    OpenAIRE

    Canales, Javier; Rueda-López, Marina; Craven-Bartle, Blanca; Avila, Concepción; Cánovas, Francisco M.

    2012-01-01

    Asparagine, a key amino acid for nitrogen storage and transport in plants, is synthesized via the ATP-dependent reaction catalyzed by the enzyme asparagine synthetase (AS; EC 6.3.5.4). In this work, we present the molecular analysis of two full-length cDNAs that encode asparagine synthetase in maritime pine (Pinus pinaster Ait.), PpAS1, and PpAS2. Phylogenetic analyses of the deduced amino acid sequences revealed that both genes are class II AS, suggesting an ancient origin of these genes in ...

  15. Serum glutamine, set-shifting ability and anorexia nervosa

    Directory of Open Access Journals (Sweden)

    Collier David A

    2010-06-01

    Full Text Available Abstract Background Set-shifting is impaired in people with anorexia nervosa (AN, but the underlying physiological and biochemical processes are unclear. Animal studies have established that glutamatergic pathways in the prefrontal cortex play an important role in set-shifting ability. However, it is not yet understood whether levels of serum glutamatergic amino acids are associated with set-shifting performance in humans. The aim of this study was to determine whether serum concentrations of amino acids related to glutamatergic neurotransmission (glutamine, glutamate, glycine, l-serine, d-serine are associated with set-shifting ability in people with acute AN and those after recovery. Methods Serum concentrations of glutamatergic amino acids were measured in 27 women with current AN (AN group, 18 women recovered from AN (ANRec group and 28 age-matched healthy controls (HC group. Set-shifting was measured using the Wisconsin Card Sorting Test (WCST and the Trail Making Task (TMT. Dimensional measures of psychopathology were used, including the Eating Disorder Examination Questionnaire (EDEQ, the Maudsley Obsessive-Compulsive Inventory (MOCI and the Hospital Anxiety and Depression Scale (HADS. Results Serum glutamine concentrations in the AN group (1,310.2 ± 265.6 μM, mean ± SD were significantly higher (by approximately 20% than those in the HC group (1,102.9 ± 152.7 μM, mean ± SD (F(2, 70 = 6.3, P = 0.003, 95% CI 61.2 to 353.4. Concentrations of serum glutamine were positively associated with markers of the illness severity: a negative correlation was present between serum glutamine concentrations and body mass index (BMI and lowest BMI and a positive correlation was found between duration of illness and EDEQ. The AN group showed significantly impaired set shifting in the WCST, both total errors, and perseverative errors. In the AN group, there were no correlations between serum glutamine concentrations and set shifting. Conclusions Serum

  16. Knockdown of asparagine synthetase by RNAi suppresses cell growth in human melanoma cells and epidermoid carcinoma cells.

    Science.gov (United States)

    Li, Hui; Zhou, Fusheng; Du, Wenhui; Dou, Jinfa; Xu, Yu; Gao, Wanwan; Chen, Gang; Zuo, Xianbo; Sun, Liangdan; Zhang, Xuejun; Yang, Sen

    2016-05-01

    Melanoma, the most aggressive form of skin cancer, causes more than 40,000 deaths each year worldwide. And epidermoid carcinoma is another major form of skin cancer, which could be studied together with melanoma in several aspects. Asparagine synthetase (ASNS) gene encodes an enzyme that catalyzes the glutamine- and ATP-dependent conversion of aspartic acid to asparagine, and its expression is associated with the chemotherapy resistance and prognosis in several human cancers. The present study aims to explore the potential role of ASNS in melanoma cells A375 and human epidermoid carcinoma cell line A431. We applied a lentivirus-mediated RNA interference (RNAi) system to study its function in cell growth of both cells. The results revealed that inhibition of ASNS expression by RNAi significantly suppressed the growth of melanoma cells and epidermoid carcinoma cells, and induced a G0/G1 cell cycle arrest in melanoma cells. Knockdown of ASNS in A375 cells remarkably downregulated the expression levels of CDK4, CDK6, and Cyclin D1, and upregulated the expression of p21. Therefore, our study provides evidence that ASNS may represent a potential therapeutic target for the treatment of melanoma. PMID:25858017

  17. Phosphorylation of five aminoacyl-tRNA synthetases in reticulocytes and identification of the protein kinases phosphorylating threonyl-tRNA synthetase from rat liver

    International Nuclear Information System (INIS)

    Five aminoacyl-tRNA synthetases in the high molecular weight complex were phosphorylated in rabbit reticulocytes following labeling with 32P. The five synthetases phosphorylated were the glutamyl-, glutaminyl-, lysyl-, aspartyl- and methionyl-tRNA synthetases. In addition, a 37,000 dalton protein, associated with the synthetase complex and tentatively identified as casein kinase I, was also phosphorylated in intact cells. Phosphoamino acid analysis of the proteins indicated all of the phosphate was on seryl residues. Incubation of reticulocytes with 32P in the presence of 8-bromo-cAMP and o, the 3-isobutyl-1-methylxanthine resulted in a six-fold increase in phosphorylation of the glutaminyl-tRNA synthetase, a two-fold increase in phosphorylation of the aspartyl-tRNA synthetase, and a 50 to 60% decrease in phosphorylation of the glutamyl-, methionyl- and lysyl-tRNA synthetases and the M/sub r/ 37,000 protein. When the site(s) on the glutaminyl-tRNA synthetase phosphorylated in response to 8-bromo-cAMP was analyzed by two-dimensional tryptic phosphopeptide mapping, a single phosphopeptide was observed which was identical to that obtained in vitro upon phosphorylation with the cAMP-dependent protein kinase. Also, the authors identify here, the protein kinases phosphorylating threonyl-tRNA synthetase from rat liver. They are protease activated kinase I, the cAMP-dependent protein kinase and protein kinase C

  18. Phosphorylation of five aminoacyl-tRNA synthetases in reticulocytes and identification of the protein kinases phosphorylating threonyl-tRNA synthetase from rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Pendergast, A.M.; Traugh, J.A.

    1986-05-01

    Five aminoacyl-tRNA synthetases in the high molecular weight complex were phosphorylated in rabbit reticulocytes following labeling with /sup 32/P. The five synthetases phosphorylated were the glutamyl-, glutaminyl-, lysyl-, aspartyl- and methionyl-tRNA synthetases. In addition, a 37,000 dalton protein, associated with the synthetase complex and tentatively identified as casein kinase I, was also phosphorylated in intact cells. Phosphoamino acid analysis of the proteins indicated all of the phosphate was on seryl residues. Incubation of reticulocytes with /sup 32/P in the presence of 8-bromo-cAMP and o, the 3-isobutyl-1-methylxanthine resulted in a six-fold increase in phosphorylation of the glutaminyl-tRNA synthetase, a two-fold increase in phosphorylation of the aspartyl-tRNA synthetase, and a 50 to 60% decrease in phosphorylation of the glutamyl-, methionyl- and lysyl-tRNA synthetases and the M/sub r/ 37,000 protein. When the site(s) on the glutaminyl-tRNA synthetase phosphorylated in response to 8-bromo-cAMP was analyzed by two-dimensional tryptic phosphopeptide mapping, a single phosphopeptide was observed which was identical to that obtained in vitro upon phosphorylation with the cAMP-dependent protein kinase. Also, the authors identify here, the protein kinases phosphorylating threonyl-tRNA synthetase from rat liver. They are protease activated kinase I, the cAMP-dependent protein kinase and protein kinase C.

  19. Resistance to BRAF inhibitors induces glutamine dependency in melanoma cells

    Science.gov (United States)

    Baenke, Franziska; Chaneton, Barbara; Smith, Matthew; Van Den Broek, Niels; Hogan, Kate; Tang, Haoran; Viros, Amaya; Martin, Matthew; Galbraith, Laura; Girotti, Maria R.; Dhomen, Nathalie; Gottlieb, Eyal; Marais, Richard

    2016-01-01

    BRAF inhibitors can extend progression-free and overall survival in melanoma patients whose tumors harbor mutations in BRAF. However, the majority of patients eventually develop resistance to these drugs. Here we show that BRAF mutant melanoma cells that have developed acquired resistance to BRAF inhibitors display increased oxidative metabolism and increased dependency on mitochondria for survival. Intriguingly, the increased oxidative metabolism is associated with a switch from glucose to glutamine metabolism and an increased dependence on glutamine over glucose for proliferation. We show that the resistant cells are more sensitive to mitochondrial poisons and to inhibitors of glutaminolysis, suggesting that targeting specific metabolic pathways may offer exciting therapeutic opportunities to treat resistant tumors, or to delay emergence of resistance in the first-line setting. PMID:26365896

  20. Increased hepatic glycogen synthetase and decreased phosphorylase in trained rats

    DEFF Research Database (Denmark)

    Galbo, H; Saugmann, P; Richter, Erik

    1979-01-01

    Rats were either physically trained by a 12 wk swimming program or were freely eating or weight matched, sedentary controls. Trained rats had a higher relative liver weight and total hepatic glycogen synthetase (EC 2.4.1.11) activity and a lower phosphorylase (EC 2.4.1.1) activity than the other...

  1. Prostaglandin synthetase inhibitor in an infant with congenital chloride diarrhoea.

    OpenAIRE

    Minford, A M; Barr, D G

    1980-01-01

    Hyper-reninaemia, hypokaluria, and hypokalaemia in an infant with congenital chloride diarrhoea improved during treatment with a prostaglandin synthetase inhibitor, ketoprofen. There was evidence of increased activity of therenin-aldosterone system when ketoprofen was stopped. It is suggested that prostaglandins may be involved in stimulating the renin-aldosterone system in congenital chloride diarrhoea.

  2. Polyspecific pyrrolysyl-tRNA synthetases from directed evolution.

    Science.gov (United States)

    Guo, Li-Tao; Wang, Yane-Shih; Nakamura, Akiyoshi; Eiler, Daniel; Kavran, Jennifer M; Wong, Margaret; Kiessling, Laura L; Steitz, Thomas A; O'Donoghue, Patrick; Söll, Dieter

    2014-11-25

    Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA(Pyl) have emerged as ideal translation components for genetic code innovation. Variants of the enzyme facilitate the incorporation >100 noncanonical amino acids (ncAAs) into proteins. PylRS variants were previously selected to acylate N(ε)-acetyl-Lys (AcK) onto tRNA(Pyl). Here, we examine an N(ε)-acetyl-lysyl-tRNA synthetase (AcKRS), which is polyspecific (i.e., active with a broad range of ncAAs) and 30-fold more efficient with Phe derivatives than it is with AcK. Structural and biochemical data reveal the molecular basis of polyspecificity in AcKRS and in a PylRS variant [iodo-phenylalanyl-tRNA synthetase (IFRS)] that displays both enhanced activity and substrate promiscuity over a chemical library of 313 ncAAs. IFRS, a product of directed evolution, has distinct binding modes for different ncAAs. These data indicate that in vivo selections do not produce optimally specific tRNA synthetases and suggest that translation fidelity will become an increasingly dominant factor in expanding the genetic code far beyond 20 amino acids. PMID:25385624

  3. Binding of Divalent Magnesium by Escherichia coli Phosphoribosyl Diphosphate Synthetase

    DEFF Research Database (Denmark)

    Willemoës, Martin; Hove-Jensen, Bjarne

    1997-01-01

    The mechanism of binding of the substrates MgATP and ribose 5-phosphate as well as Mg2+ to the enzyme 5-phospho-d-ribosyl a-1-diphosphate synthetase from Escherichia coli has been analyzed. By use of the competive inhibitors of ATP and ribose 5-phosphate binding, a,ß-methylene ATP and (+)-1-a,2-a...

  4. Binding of divalent magnesium by Escherichia coli phosphoribosyl diphosphate synthetase

    DEFF Research Database (Denmark)

    Willemoës, Martin; Hove-Jensen, Bjarne

    1997-01-01

    The mechanism of binding of the substrates Mg x ATP and ribose 5-phosphate as well as Mg2+ to the enzyme 5-phospho-D-ribosyl (alpha-1-diphosphate synthetase from Escherichia coli has been analyzed. By use of the competive inhibitors of ATP and ribose 5-phosphate binding, alpha,beta-methylene ATP ...

  5. Variable Glutamine-Rich Repeats Modulate Transcription Factor Activity

    OpenAIRE

    Gemayel, Rita; Chavali, Sreenivas; Pougach, Ksenia; Legendre, Matthieu; Zhu, Bo; Boeynaems, Steven; van der Zande, Elisa; Gevaert, Kris; Rousseau, Frederic; Schymkowitz, Joost; Babu, M Madan; Verstrepen, Kevin J.

    2015-01-01

    Summary Excessive expansions of glutamine (Q)-rich repeats in various human proteins are known to result in severe neurodegenerative disorders such as Huntington’s disease and several ataxias. However, the physiological role of these repeats and the consequences of more moderate repeat variation remain unknown. Here, we demonstrate that Q-rich domains are highly enriched in eukaryotic transcription factors where they act as functional modulators. Incremental changes in the number of repeats i...

  6. Glutamine Supplementation in Sick Children: Is It Beneficial?

    OpenAIRE

    Elise Mok; Régis Hankard

    2011-01-01

    The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln) supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evide...

  7. Glutamine supplementation and immune function during heavy load training.

    Science.gov (United States)

    Song, Qing-Hua; Xu, Rong-Mei; Zhang, Quan-Hai; Shen, Guo-Qing; Ma, Ming; Zhao, Xin-Ping; Guo, Yan-Hua; Wang, Yi

    2015-05-01

    Athletes with heavy training loads are prone to infectious illnesses, suggesting that their training may suppress immune function. This study sought to determine whether supplementation with the amino acid glutamine, which supports immune health, alters immune function in athletes during heavy load training. 24 athletes were randomly assigned to either an experimental group (n = 12) or a control group (n = 12). Athletes exercised using heavy training loads for 6 weeks. Athletes in the experimental group took 10 g glutamine orally once a day beginning 3 weeks after initial testing, while athletes in the control group were given a placebo. Immune function was assessed by measuring the following immunity markers: CD4⁺ and CD8⁺ T cell counts, serum IgA, IgG, and IgM levels, and natural killer (NK) cell activity both before and after the completion of training. The percentages of circulating CD8⁺ T cells were significantly different before (39.13 ± 5.87%) and after (26.63 ± 3.95%) training in the experimental group (p glutamine supplementation may be able to restore immune function and reduce the immunosuppressive effects of heavy-load training. PMID:25740264

  8. Expression of glutamine transporter isoforms in cerebral cortex of rats with chronic hepatic encephalopathy

    DEFF Research Database (Denmark)

    Leke, Renata; Escobar, Thayssa D.C.; Rama Rao, Kakulavarapu V.;

    2015-01-01

    Hepatic encephalopathy (HE) is a neuropsychiatric disorder that occurs due to acute and chronic liver diseases, the hallmark of which is the increased levels of ammonia and subsequent alterations in glutamine synthesis, i.e. conditions associated with the pathophysiology of HE. Under physiological...... conditions, glutamine is fundamental for replenishment of the neurotransmitter pools of glutamate and GABA. The different isoforms of glutamine transporters play an important role in the transfer of this amino acid between astrocytes and neurons. A disturbance in the GABA biosynthetic pathways has been...... described in bile duct ligated (BDL) rats, a well characterized model of chronic HE. Considering that glutamine is important for GABA biosynthesis, altered glutamine transport and the subsequent glutamate/GABA–glutamine cycle efficacy might influence these pathways. Given this potential outcome, the aim of...

  9. Stimulation of glycogen synthesis and lipogenesis by glutamine in isolated rat hepatocytes.

    OpenAIRE

    Lavoinne, A; Baquet, A.; Hue, Louis

    1987-01-01

    Glutamine stimulated glycogen synthesis and lactate production in hepatocytes from overnight-fasted normal and diabetic rats. The effect, which was half-maximal with about 3 mM-glutamine, depended on glucose concentration and was maximal below 10 mM-glucose. beta-2-Aminobicyclo[2.2.1.]heptane-2-carboxylic acid, an analogue of leucine, stimulated glutaminase flux, but inhibited the stimulation of glycogen synthesis by glutamine. Various purine analogues and inhibitors of purine synthesis were ...

  10. L-glutamine supplementations enhance liver glutamine-glutathione axis and heat shock factor-1 expression in endurance-exercise trained rats.

    Science.gov (United States)

    Petry, Éder Ricardo; Cruzat, Vinicius Fernandes; Heck, Thiago Gomes; Homem de Bittencourt, Paulo Ivo; Tirapegui, Julio

    2015-04-01

    Liver L-glutamine is an important vehicle for the transport of ammonia and intermediary metabolism of amino acids between tissues, particularly under catabolic situations, such as high-intensity exercise. Hence, the aim of this study was to investigate the effects of oral supplementations with L-glutamine in its free or dipeptide forms (with L-alanine) on liver glutamine-glutathione (GSH) axis, and 70 kDa heat shock proteins (HSP70)/heat shock transcription factor 1 (HSF1) expressions. Adult male Wistar rats were 8-week trained (60 min/day, 5 days/week) on a treadmill. During the last 21 days, the animals were daily supplemented with 1 g of L-glutamine/kg body weight per day in either l-alanyl-L-glutamine dipeptide (DIP) form or a solution containing L-glutamine and l-alanine in their free forms (GLN+ALA) or water (controls). Exercise training increased cytosolic and nuclear HSF1 and HSP70 expression, as compared with sedentary animals. However, both DIP and GLN+ALA supplements enhanced HSF1 expression (in both cytosolic and nuclear fractions) in relation to exercised controls. Interestingly, HSF1 rises were not followed by enhanced HSP70 expression. DIP and GLN+ALA supplements increased plasma glutamine concentrations (by 62% and 59%, respectively) and glutamine to glutamate plasma ratio in relation to trained controls. This was in parallel with a decrease in plasma ammonium levels. Supplementations increased liver GSH (by 90%), attenuating the glutathione disulfide (GSSG) to GSH ratio, suggesting a redox state protection. In conclusion, oral administration with DIP and GLN+ALA supplements in endurance-trained rats improve liver glutamine-GSH axis and modulate HSF1 pathway. PMID:25202991

  11. New developments in glutamine delivery%谷氨酰胺给药的新进展

    Institute of Scientific and Technical Information of China (English)

    PeterFuerst,MD

    2001-01-01

    Free glutamine-a critical issueNumerous studies demonstrate that free glutamine can be added to commercially available crystalline amino acid based preparations prior to their administration.Instability during heat sterilization and prolonged storage and linited solubility (35 g/L at 20℃) hampers the use of free glutamine in routine clinical setting.Indeed,there are many well controlled and valuable trials with free glutamine,yet its use is restricted to clinical research.How to solve the problem?The obvious linitations of using free glutamine initiated an intensive search for alternative substrates.Indeed,glutamic acid is a poor precursor;its in vivo transformation to glutamine is restricted to yield only 5-6%.Similarly,the transformation of α-ketoglutarate or the salt ornthine-α-ketoglutarate to glutamine is confined since they are primarily precursors for glutamic acid.Parenterally supplied acetyl glutamine is poorly utilized in man;the large urinary excretion (45-50%) being associated with considerable accumulation of acetyl glutamine in body fluids.It can be concluded that N-acetylated glutamine is not suitable as alternative glutamine source in humans due to restricted acylase capacities.Synthetic glutamine dipeptides are stable under heat sterilization and highly soluble;these properties qualify the dipeptides as suitable constituents of nutritional preparations.Industrial production of these dipeptides at a reasonable price is an essential prerequisite for implications of dipeptide-containing solutions in clinical practice.Recent development of novel synthesis procedures allows increased capacity in industrial-scale production.Basic studies with synthetic glutamine-containing short-chain peptides provide convincing evidence that these new substrates are rqpidly cleared from plasma after parenteral administration,without being accumulated in tissues,and with negligible loss of urine.The presence of membrane-bound as well as tissue free extracellular

  12. The aminoacyl-tRNA synthetases of Drosophila melanogaster

    OpenAIRE

    Lu, Jiongming; Marygold, Steven J; Gharib, Walid H; Suter, Beat

    2015-01-01

    Aminoacyl-tRNA synthetases (aaRSs) ligate amino acids to their cognate tRNAs, allowing them to decode the triplet code during translation. Through different mechanisms aaRSs also perform several non-canonical functions in transcription, translation, apoptosis, angiogenesis and inflammation. Drosophila has become a preferred system to model human diseases caused by mutations in aaRS, to dissect effects of reduced translation or non-canonical activities, and to study aminoacylation and translat...

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

    International Nuclear Information System (INIS)

    Physiological elevations of plasma cortisol levels, as are encountered in stress and severe trauma, were produced in six normal subjects by infusing them with hydrocortisone for 64 h. Amino acid kinetics were measured in the postabsorptive state using three 4-h infusions of L-[1-13C]leucine, L-phenyl[2H5]phenylalanine, L-[2-15N]glutamine, and L-[1-13C]alanine tracers (1) before, (2) at 12 h, and (3) at 60 h of cortisol infusion. Before and throughout the study, the subjects ate a normal diet of adequate protein and energy intake. The cortisol infusion raised plasma cortisol levels significantly from 10 ± 1 to 32 ± 4 μg/dl, leucine flux from 83 ± 3 to 97 ± 3 μmol·kg-1·h-1, and phenylalanine flux from 34 ± 1 to 39 ± 1 (SE) μmol·kg-1·h-1 after 12 h of cortisol infusion. These increases were maintained until the cortisol infusion was terminated. These nearly identical 15% increases in two different essential amino acid appearance rates are reflective of increased whole body protein breakdown. Glutamine flux rose by 12 h of cortisol infusion and remained elevated at the same level at 64 h. The increase in flux was primarily due to a 55% increase in glutamine de novo synthesis. Alanine flux increased with acute hypercortisolemia and increased further at 60 h of cortisol infusion, a result primarily of increased alanine de novo synthesis. Insulin, alanine, and lactate plasma levels responded similarly with significant rises between the acute and chronic periods of cortisol infusion. Thus hypercortisolemia increases both protein breakdown and the turnover of important nonessential amino acids for periods of up to 64 h

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

    Energy Technology Data Exchange (ETDEWEB)

    Darmaun, D.; Matthews, D.E.; Bier, D.M. (Washington Univ. School of Medicine, St. Louis, MO (USA) Cornell Univ. Medical College, New York, NY (USA))

    1988-09-01

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

  15. Co-purification of dihydrofolate synthetase and N10formyltetrahydropteroyldiglutamate synthetase from E. coli

    International Nuclear Information System (INIS)

    The enzymatic activities which add a single glutamate to dihydropteroate (H2Pte) and to N10formyltetrahydropteroylglutamate (N10formylH4PteGlu) remained at a constant ratio when various purification techniques were used, including ammonium sulfate fractionation, isoelectric focusing, polyacrylamide gel electrophoresis, and column chromatography on Sephadex G-100, DEAE-Sephadex, CM-Sephadex, ADP-Sepharose, N10formylfolate-agarose or matrix Gel Red-A. The best combination of these methods yielded 900-fold purified enzyme. However, the kinetic properties were dependent upon the substrate used. H2Pte was a noncompetitive inhibitor (Kii . 1.1 microM) of the utilization of N10formylH4PteGlu, but no inhibition was detected in the reciprocal experiment. Aminopterin was a competitive inhibitor (Kis . 370 microM) of the reaction with N10formylH4PteGlu but was not inhibitory with H2Pte as substrate. In the dihydrofolate synthetase reaction, in Tris-HCl, pH 8.9 with 50 mM KCl, the apparent Km values for glutamate and MgATP were 3.5 mM and 8.1 microM respectively. With N10formylH4PteGlu as substrate, these Km values were 1.2 mM and 80 microM. Since the two activities were not separated by protein purification procedures but exhibited different kinetic properties (including lack of reciprocal inhibition), the data suggest these reactions are catalyzed on independent sites of a common protein

  16. Glutamate reduces experimental intestinal hyperpermeability and facilitates glutamine support of gut integrity

    Institute of Scientific and Technical Information of China (English)

    Mechteld AR Vermeulen; Jeffrey de Jong; Mathijs J Vaessen; Paul AM van Leeuwen; Alexander PJ Houdijk

    2011-01-01

    AIM: To assess whether glutamate plays a similar role to glutamine in preserving gut wall integrity. METHODS: The effects of glutamine and glutamate on induced hyperpermeability in intestinal cell lines were studied. Paracellular hyperpermeability was induced in Caco2.BBE and HT-29CL.19A cell lines by adding phorbol-12,13-dibutyrate (PDB) apically, after which the effects of glutamine and glutamate on horseradish peroxidase (HRP) diffusion were studied. An inhibitor of glutamate transport (L-trans-pyrrolidine-2,4-dicarboxylic acid: trans-PDC) and an irreversible blocker (acivicin) of the extracellular glutamine to glutamate converting enzyme, γ-glutamyltransferase, were used. RESULTS: Apical to basolateral HRP flux increased significantly compared to controls not exposed to PDB (n = 30, P < 0.001). Glutamine application reduced hyperpermeability by 19% and 39% in the respective cell lines. Glutamate application reduced hyperpermeability by 30% and 20%, respectively. Incubation of HT29CL.19A cells with acivicin and subsequent PDB and glutamine addition increased permeability levels. Incubation of Caco2.BBE cells with trans-PDC followed by PDB and glutamate addition also resulted in high permeability levels. CONCLUSION: Apical glutamate -similar to glutaminecan decrease induced paracellular hyperpermeability. Extracellular conversion of glutamine to glutamate and subsequent uptake of glutamate could be a pivotal step in the mechanism underlying the protective effect of glutamine.

  17. Cysteine digestive peptidases function as post-glutamine cleaving enzymes in tenebrionid stored product pests

    Science.gov (United States)

    Cereals have storage proteins with high amounts of the amino acids glutamine and proline. Therefore, storage pests need to have digestive enzymes that are efficient in hydrolyzing these types of proteins. Post-glutamine cleaving peptidases (PGP) were isolated from the midgut of the stored product pe...

  18. Reducing the serine availability complements the inhibition of the glutamine metabolism to block leukemia cell growth

    Science.gov (United States)

    Polet, Florence; Corbet, Cyril; Pinto, Adan; Rubio, Laila Illan; Martherus, Ruben; Bol, Vanesa; Drozak, Xavier; Grégoire, Vincent; Riant, Olivier; Feron, Olivier

    2016-01-01

    Leukemia cells are described as a prototype of glucose-consuming cells with a high turnover rate. The role of glutamine in fueling the tricarboxylic acid cycle of leukemia cells was however recently identified confirming its status of major anaplerotic precursor in solid tumors. Here we examined whether glutamine metabolism could represent a therapeutic target in leukemia cells and whether resistance to this strategy could arise. We found that glutamine deprivation inhibited leukemia cell growth but also led to a glucose-independent adaptation maintaining cell survival. A proteomic study revealed that glutamine withdrawal induced the upregulation of phosphoglycerate dehydrogenase (PHGDH) and phosphoserine aminotransferase (PSAT), two enzymes of the serine pathway. We further documented that both exogenous and endogenous serine were critical for leukemia cell growth and contributed to cell regrowth following glutamine deprivation. Increase in oxidative stress upon inhibition of glutamine metabolism was identified as the trigger of the upregulation of PHGDH. Finally, we showed that PHGDH silencing in vitro and the use of serine-free diet in vivo inhibited leukemia cell growth, an effect further increased when glutamine metabolism was blocked. In conclusion, this study identified serine as a key pro-survival actor that needs to be handled to sensitize leukemia cells to glutamine-targeting modalities. PMID:26625201

  19. Selective inhibition of type 2 fatty acid synthetase by the antibiotic thiolactomycin

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Ikuo; Kawaguchi, Akihiko; Yamada, Mitsuhiro (Tokyo Univ. (Japan). Faculty of Science)

    1984-03-01

    The antibiotic thiolactomycin inhibits the fatty acid synthesis from both (1-/sup 14/C)-acetate and (2/sup 14/C) malonyl-CoA of spinach leaves, developing castor bean endosperms and avocado mesocarp. On the other hand, fatty acid synthetases of Brevibacterium ammoniagenes and Corynebacterium glutamicum are much less sensitive to this antibiotic. As Hayashi et al. have indicated in their paper that thiolactomycin inhibits fatty acid synthetase of Escherichia coli but has little effect on the synthetases of yeast and rat liver, thiolactomycin is suggested to be a selective inhibitor of type 2 fatty acid synthetases.

  20. Selective inhibition of type 2 fatty acid synthetase by the antibiotic thiolactomycin

    International Nuclear Information System (INIS)

    The antibiotic thiolactomycin inhibits the fatty acid synthesis from both [1-14C]-acetate and [214C] malonyl-CoA of spinach leaves, developing castor bean endosperms and avocado mesocarp. On the other hand, fatty acid synthetases of Brevibacterium ammoniagenes and Corynebacterium glutamicum are much less sensitive to this antibiotic. As Hayashi et al. have indicated in their paper that thiolactomycin inhibits fatty acid synthetase of Escherichia coli but has little effect on the synthetases of yeast and rat liver, thiolactomycin is suggested to be a selective inhibitor of type 2 fatty acid synthetases. (author)

  1. SAT1, a glutamine transporter, is preferentially expressed in GABAergic neurons

    Directory of Open Access Journals (Sweden)

    Tom Tallak Solbu

    2010-02-01

    Full Text Available Subsets of GABAergic neurons are able to maintain high frequency discharge patterns, which requires efficient replenishment of the releasable pool of GABA. Although glutamine is considered a preferred precursor of GABA, the identity of transporters involved in glutamine uptake by GABAergic neurons remains elusive. Molecular analyses revealed that SAT1 (Slc38a1 features system A characteristics with a preferential affinity for glutamine, and that SAT1 mRNA expression is associated with GABAergic neurons. By generating specific antibodies against SAT1 we show that this glutamine carrier is particularly enriched in GABAergic neurons. Cellular SAT1 distribution resembles that of GAD67, an essential GABA synthesis enzyme, suggesting that SAT1 can be involved in translocating glutamine into GABAergic neurons to facilitate inhibitory neurotransmitter generation.

  2. Influence of glutamine on the effect of resistance exercise on cardiac ANP in rats

    Directory of Open Access Journals (Sweden)

    Romeu Rodrigues de Souza

    2015-03-01

    Full Text Available Various nutritional supplements (herbs, vitamins, and micronutrients improve responses and adaptations to resistance exercise. ANP is a heart hormone that contributes to fluid, electrolyte and blood pressure homeostasis through its natriuretic and vasodilative actions. In the present study, the adaptation of ANP in response to resistance exercise was investigated in rats supplemented with glutamine for five weeks. The results showed that supplementation with glutamine did not influence the number of ANP granules per atrial cardiocyte in sedentary animals. In exercised-trained rats, the number and diameter of the granules was significantly higher in comparison with the control group and in exercised animals supplemented with glutamine there was significant increase in the number and diameter of ANP granules compared with controls. Altogether, these data indicated that in resistance exercise rats, glutamine significantly enhances cardiac ANP thus implicating the beneficial effects of glutamine supplementation to the ANP system.

  3. Lack of cardioprotection from metabolic support with glutamine or glutamate in a porcine coronary occlusion model

    DEFF Research Database (Denmark)

    Kristensen, Jens; Mæng, Michael; Mortensen, Ulrik;

    2005-01-01

    OBJECTIVE: Previous experimental studies indicate that glutamine or glutamate may provide cardioprotection by improving the oxidative metabolism in myocardial ischemia. We investigated the effect of glutamine or glutamate, given during reperfusion, on resulting infarct size and hemodynamic recovery...... outcome measures were the hemodynamic variables. RESULTS: The infarct sizes as a proportion of the area at risk (mean+/-SD) were: control group, 0.64 +/- 0.19 (n = 9); glutamine group, 0.87 +/- 0.07 (p < 0.05 vs control group) (n = 8); glutamate group, 0.72 +/- 0.11 (n = 9). Glutamine increased systemic...... vascular resistance, while glutamate preserved cardiac output during infusion. CONCLUSION: Substrate supplementation with the anaplerotic precursors glutamine and glutamate is ineffective as adjunctive therapy for severe myocardial ischemia. Beneficial effects documented in less complex experimental...

  4. The effect of glutamine supplementation and physical exercise on neutrophil function.

    Science.gov (United States)

    Lagranha, C J; Levada-Pires, A C; Sellitti, D F; Procopio, J; Curi, R; Pithon-Curi, T C

    2008-04-01

    Glutamine is the most abundant free amino acid in the body. Its primary source is skeletal muscle, from where it is released into the bloodstream and transported to a variety of tissues. Several studies have shown that glutamine is important for rat and human neutrophil function and that these cells utilize glutamine at high rates. Physical exercise has also been shown to induce considerable changes in neutrophil metabolism and function. As neutrophils represent 50-60% of the total circulating leukocyte pool and play a key role in inflammation, both physical exercise and glutamine might be expected to regulate the inflammatory process. In this review, the changes in neutrophil function induced by physical exercise and glutamine supplementation are compared. PMID:17928941

  5. Key Roles of Glutamine Pathways in Reprogramming the Cancer Metabolism

    Science.gov (United States)

    Michalak, Krzysztof Piotr; Maćkowska-Kędziora, Agnieszka; Sobolewski, Bogusław; Woźniak, Piotr

    2015-01-01

    Glutamine (GLN) is commonly known as an important metabolite used for the growth of cancer cells but the effects of its intake in cancer patients are still not clear. However, GLN is the main substrate for DNA and fatty acid synthesis. On the other hand, it reduces the oxidative stress by glutathione synthesis stimulation, stops the process of cancer cachexia, and nourishes the immunological system and the intestine epithelium, as well. The current paper deals with possible positive effects of GLN supplementation and conditions that should be fulfilled to obtain these effects. The analysis of GLN metabolism suggests that the separation of GLN and carbohydrates in the diet can minimize simultaneous supply of ATP (from glucose) and NADPH2 (from glutamine) to cancer cells. It should support to a larger extent the organism to fight against the cancer rather than the cancer cells. GLN cannot be considered the effective source of ATP for cancers with the impaired oxidative phosphorylation and pyruvate dehydrogenase inhibition. GLN intake restores decreased levels of glutathione in the case of chemotherapy and radiotherapy; thus, it facilitates regeneration processes of the intestine epithelium and immunological system. PMID:26583064

  6. Prefrontal changes in the glutamate-glutamine cycle and neuronal/glial glutamate transporters in depression with and without suicide

    NARCIS (Netherlands)

    Zhao, J; Verwer, R W H; van Wamelen, D J; Qi, X-R; Gao, S-F; Lucassen, P J; Swaab, D F

    2016-01-01

    There are indications for changes in glutamate metabolism in relation to depression or suicide. The glutamate-glutamine cycle and neuronal/glial glutamate transporters mediate the uptake of the glutamate and glutamine. The expression of various components of the glutamate-glutamine cycle and the neu

  7. Glutamine transporters in mammalian cells and their functions in physiology and cancer.

    Science.gov (United States)

    Bhutia, Yangzom D; Ganapathy, Vadivel

    2016-10-01

    The SLC (solute carrier)-type transporters (~400 in number) in mammalian cells consist of 52 distinct gene families, grouped solely based on the amino acid sequence (primary structure) of the transporter proteins and not on their transport function. Among them are the transporters for amino acids. Fourteen of them, capable of transporting glutamine across the plasma membrane, are found in four families: SLC1, SLC6, SLC7, and SLC38. However, it is generally thought that the members of the SLC38 family are the principal transporters for glutamine. Some of the glutamine transporters are obligatory exchangers whereas some function as active transporters in one direction. While most glutamine transporters mediate the influx of the amino acid into cells, some actually mediate the efflux of the amino acid out of the cells. Glutamine transporters play important roles in a variety of tissues, including the liver, brain, kidney, and placenta, as clearly evident from the biological and biochemical phenotypes resulting from the deletion of specific glutamine transporters in mice. Owing to the obligatory role of glutamine in growth and proliferation of tumor cells, there is increasing attention on glutamine transporters in cancer biology as potential drug targets for cancer treatment. Selective blockers of certain glutamine transporters might be effective in preventing the entry of glutamine and other important amino acids into tumor cells, thus essentially starving these cells to death. This could represent the beginning of a new era in the discovery of novel anticancer drugs with a previously unexplored mode of action. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou. PMID:26724577

  8. Uroporphyrinogen-I-synthetase activity in red blood cells of lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    El-Waseef, A.

    1982-01-01

    Lead-exposed (n . 26) and control (n . 12) subjects were investigated for their blood lead concentration erythrocyte 5-amino-laevulinic acid dehydratase (5-ALAD) and erythrocyte uroporphyrinogen-I-synthetase (URO-I-S) activity; 5-amino-laevulinic acid (5-ALA) and porphobilinogen (PBG) were used as substrates in the synthetase assay. In the lead workers erythrocyte 5-ALA dehydratase was grossly inhibited but with PBG as substrate the synthetase activity was not significantly different from the control group. With 5-ALA as substrate the synthetase assay showed marked inhibition. Addition of zinc (0.1 mmol/l) and dithiotheritol (0.5 mmol/l) brought the activities of both the dehydratase and synthetase (using 5-ALA as substrate) back into the ranges seen in the control group. With porphobilinogen as substrate higher concentrations of zinc caused inhibition of the synthetase, whilst reduction of added zinc to 0.01 mmol/l resulted in stimulation of the synthetase. A good correlation (r . 0.87) was obtained in synthetase assay when PBG and 5-aminolaevulinate (with added zinc and dithiothreitol) were used as substrates. With these additions 5-ALA may be used as a substrate in the URO-I-S assay in the investigation of latent cases of acute intermittent porphyria.

  9. Proton-dependent glutamine uptake by aphid bacteriocyte amino acid transporter ApGLNT1.

    Science.gov (United States)

    Price, Daniel R G; Wilson, Alex C C; Luetje, Charles W

    2015-10-01

    Aphids house large populations of the gammaproteobacterial symbiont Buchnera aphidicola in specialized bacteriocyte cells. The combined biosynthetic capability of the holobiont (Acyrthosiphon pisum and Buchnera) is sufficient for biosynthesis of all twenty protein coding amino acids, including amino acids that animals alone cannot synthesize; and that are present at low concentrations in A. pisum's plant phloem sap diet. Collaborative holobiont amino acid biosynthesis depends on glutamine import into bacteriocytes, which serves as a nitrogen-rich amino donor for biosynthesis of other amino acids. Recently, we characterized A. pisum glutamine transporter 1 (ApGLNT1), a member of the amino acid/auxin permease family, as the dominant bacteriocyte plasma membrane glutamine transporter. Here we show ApGLNT1 to be structurally and functionally related to mammalian proton-dependent amino acid transporters (PATs 1-4). Using functional expression in Xenopus laevis oocytes, combined with two-electrode voltage clamp electrophysiology we demonstrate that ApGLNT1 is electrogenic and that glutamine induces large inward currents. ApGLNT1 glutamine induced currents are dependent on external glutamine concentration, proton (H+) gradient across the membrane, and membrane potential. Based on these transport properties, ApGLNT1-mediated glutamine uptake into A. pisum bacteriocytes can be regulated by changes in either proton gradients across the plasma membrane or membrane potential. PMID:26028424

  10. Reduced Hsp70 and Glutamine in Pediatric Severe Malaria Anemia

    DEFF Research Database (Denmark)

    Kempaiah, Prakasha; Dokladny, Karol; Karim, Zachary;

    2016-01-01

    decreased HSPA1A, a heat shock protein (Hsp) 70 coding gene. Hsp70 is a ubiquitous chaperone that regulates Nuclear Factor-kappa B (NF-κB) signaling and production of pro-inflammatory cytokines known to be important in malaria pathogenesis (e.g., IL-1β, IL-6 and TNF-α). Since the role of host Hsp70 in...... malaria pathogenesis is unexplored, we investigated Hsp70 and molecular pathways in children with SMA. Validation experiments revealed that leukocytic HSP70 transcripts were reduced in SMA relative to non-severe malaria, and that intraleukocytic hemozoin (PfHz) was associated with lower HSP70. HSP70 was...... correlated with reticulocyte production and Hb. Since glutamine (Gln) up-regulates Hsp70, modulates NF-κB activation, and attenuates over-expression of pro-inflammatory cytokines, circulating Gln was measured in children with malaria. Reduced Gln was associated with increased risk of developing SMA...

  11. Glutamine supplementation in sick children: is it beneficial?

    Science.gov (United States)

    Mok, Elise; Hankard, Régis

    2011-01-01

    The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln) supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evidence is available on the benefits of Gln supplementation in pediatric patients. This includes premature infants, infants with gastrointestinal disease, children with Crohn's disease, short bowel syndrome, malnutrition/diarrhea, cancer, severe burns/trauma, Duchenne muscular dystrophy, sickle cell anemia, cystic fibrosis, and type 1 diabetes. Moreover, methodological issues have been noted in some studies. Further mechanistic data is needed along with large randomized controlled trials in select populations of sick children, who may eventually benefit from supplemental Gln. PMID:22175008

  12. Glutamine Supplementation in Sick Children: Is It Beneficial?

    Directory of Open Access Journals (Sweden)

    Elise Mok

    2011-01-01

    Full Text Available The purpose of this review is to provide a critical appraisal of the literature on Glutamine (Gln supplementation in various conditions or illnesses that affect children, from neonates to adolescents. First, a general overview of the proposed mechanisms for the beneficial effects of Gln is provided, and subsequently clinical studies are discussed. Despite safety, studies are conflicting, partly due to different effects of enteral and parenteral Gln supplementation. Further insufficient evidence is available on the benefits of Gln supplementation in pediatric patients. This includes premature infants, infants with gastrointestinal disease, children with Crohn's disease, short bowel syndrome, malnutrition/diarrhea, cancer, severe burns/trauma, Duchenne muscular dystrophy, sickle cell anemia, cystic fibrosis, and type 1 diabetes. Moreover, methodological issues have been noted in some studies. Further mechanistic data is needed along with large randomized controlled trials in select populations of sick children, who may eventually benefit from supplemental Gln.

  13. Glutamine deprivation enhances antitumor activity of 3-bromopyruvate through the stabilization of monocarboxylate transporter-1.

    Science.gov (United States)

    Cardaci, Simone; Rizza, Salvatore; Filomeni, Giuseppe; Bernardini, Roberta; Bertocchi, Fabio; Mattei, Maurizio; Paci, Maurizio; Rotilio, Giuseppe; Ciriolo, Maria Rosa

    2012-09-01

    Anticancer drug efficacy might be leveraged by strategies to target certain biochemical adaptations of tumors. Here we show how depriving cancer cells of glutamine can enhance the anticancer properties of 3-bromopyruvate, a halogenated analog of pyruvic acid. Glutamine deprival potentiated 3-bromopyruvate chemotherapy by increasing the stability of the monocarboxylate transporter-1, an effect that sensitized cells to metabolic oxidative stress and autophagic cell death. We further elucidated mechanisms through which resistance to chemopotentiation by glutamine deprival could be circumvented. Overall, our findings offer a preclinical proof-of-concept for how to employ 3-bromopyruvate or other monocarboxylic-based drugs to sensitize tumors to chemotherapy. PMID:22773663

  14. End products of glutamine oxidation in MC-29 virus-induced chicken hepatoma mitochondria.

    Science.gov (United States)

    Matsuno, T

    1989-10-01

    Products of glutamine metabolism were examined in the MC-29 virus-induced chicken hepatoma mitochondria incubated in vitro. Glutamine oxidation proceeded in the tumor mitochondria exclusively via a pathway involving glutamic-oxalacetic transaminase. Malate stimulated aspartate production from glutamine, while pyruvate exerted suppressive effect on aspartate production with little alanine formation. The mitochondria of this hepatoma are unique in that the metabolic pattern and response to malate and pyruvate are essentially inconsistent with those reported in normal cells as well as those proposed by Moreadith and Lehninger in various tumor cells. PMID:2571353

  15. Curative effect of parenteral nutrition and glutamine on post-surgical patients

    Directory of Open Access Journals (Sweden)

    Bangash TA

    2012-03-01

    Full Text Available Background: To evaluate the influence of parenteral nutrition and glutamine on nutritional status and prognosis of surgical critically ill patients. Methods: 32 cases were treated by parenteral nutrition plus alanyl-glutamine injection. The differences in liver function, weight and nutritional status were compared between, before and after medication. Results: Patients were either cured or relieved, and no complication including infection appeared. Total protein. Albumin, ferrohemoglobin and weight increased after medication, respectively. Conclusions: The use of parenteral nutrition plus glutamine is beneficial for ameliorating malnutrition and negative nitrogen balance caused by hypermetabolism, inhibiting bacterial translocation, preventing the complication, and increasing healing rate of disease.

  16. Electron microscopy and image analysis of the GroEL-like protein and its complexes with glutamine synthetase from pea leaves

    NARCIS (Netherlands)

    Tsuprun, Vladimir L.; Boekema, Egbert J.; Pushkin, Alexander V.; Tagunova, Irina V.

    1992-01-01

    The molecular structure of groEL-like protein from pea leaves has been studied by electron microscopy and image analysis of negatively stained particles. Over 1500 molecular projections were selected and classified by multivariate statistical analysis. It was shown that the molecule consists of 14 s

  17. Adaptive Calcified Matrix Response of Dental Pulp to Bacterial Invasion Is Associated with Establishment of a Network of Glial Fibrillary Acidic Protein+/Glutamine Synthetase+ Cells

    OpenAIRE

    Farahani, Ramin M.; Nguyen, Ky-Anh; Simonian, Mary; Hunter, Neil

    2010-01-01

    We report evidence for anatomical and functional changes of dental pulp in response to bacterial invasion through dentin that parallel responses to noxious stimuli reported in neural crest-derived sensory tissues. Sections of resin-embedded carious adult molar teeth were prepared for immunohistochemistry, in situ hybridization, ultrastructural analysis, and microdissection to extract mRNA for quantitative analyses. In odontoblasts adjacent to the leading edge of bacterial invasion in carious ...

  18. A Modified Bacillus Calmette-Guérin (BCG) Vaccine with Reduced Activity of Antioxidants and Glutamine Synthetase Exhibits Enhanced Protection of Mice despite Diminished in Vivo Persistence

    OpenAIRE

    Kernodle, Douglas S.; Cynamon, Michael H.; Gates, Hiriam O.; Alexandria D. Allen; Miriam Braunstein; Kyi-Toe Tham; Shoen, Carolyn M.; Michelle S. DeStefano; Hager, Cynthia C.

    2013-01-01

    Early attempts to improve BCG have focused on increasing the expression of prominent antigens and adding recombinant toxins or cytokines to influence antigen presentation. One such modified BCG vaccine candidate has been withdrawn from human clinical trials due to adverse effects. BCG was derived from virulent Mycobacterium bovis and retains much of its capacity for suppressing host immune responses. Accordingly, we have used a different strategy for improving BCG based on reducing its immune...

  19. Glutamine Synthetases GLN1;2 and GLN2 in Relation to Arabidopsis Growth Response to Elevated Atmospheric Carbon Dioxide and Varying Nitrogen Forms

    DEFF Research Database (Denmark)

    Vurrakula, Swathi

    Carbon and nitrogen are the most abundant elements in plants, together making up around 40-50% and 2-6% of dry matter respectively. Elevated atmospheric CO2 levels are predicted to double by the end of this century, increasing carbon fixation by C3 plants like Arabidopsis and, hence, their carbon...... cues and adjusting it to the plant internal status. The two major types of GS include cytosolic GS1 (five isoforms in Arabidopsis, GLN1;1 to GLN1;5) and a single chloroplastic GS2. GS draws its substrates from carbon skeletons to synthesize amino acids. Thus, carbon and nitrogen metabolisms are closely...... nitrogen species (ammonium and nitrate) and availability. Arabidopsis gln1;2 knock-out and gln2 (reduced GS2 activity by 50%) mutants were studied in response to elevated CO2 (800 ppm) when provided with moderate and high levels of ammonium or nitrate alone, or in combination. Elevated CO2 promoted plant...

  20. Interaction of Cytosolic Glutamine Synthetase of Soybean Root Nodules with the C-terminal Domain of the Symbiosome Membrane Nodulin 26 Aquaglyceroporin*♦

    OpenAIRE

    Masalkar, Pintu; Wallace, Ian S.; Hwang, Jin Ha; Roberts, Daniel M.

    2010-01-01

    Nodulin 26 (nod26) is a major intrinsic protein that constitutes the major protein component on the symbiosome membrane (SM) of N2-fixing soybean nodules. Functionally, nod26 forms a low energy transport pathway for water, osmolytes, and NH3 across the SM. Besides their transport functions, emerging evidence suggests that high concentrations of major intrinsic proteins on membranes provide interaction and docking targets for various cytosolic proteins. Here it is shown that the C-terminal dom...

  1. Astrocytes and glutamate homeostasis in Alzheimer's disease: a decrease in glutamine synthetase but not in glutamate transporter-1 in the prefrontal cortex.

    Czech Academy of Sciences Publication Activity Database

    Kulijewicz-Nawrot, Magdaléna; Syková, Eva; Chvátal, Alexandr; Verkhratsky, A.; Rodríguez, J. J.

    2013-01-01

    Roč. 5, č. 4 (2013), s. 273-282. ISSN 1759-0914 R&D Projects: GA ČR(CZ) GAP304/11/0184; GA ČR(CZ) GBP304/12/G069; GA ČR GA309/09/1696; GA ČR GA305/08/1384 Institutional support: RVO:68378041 Keywords : Alzheimer's disease * astroglia * GLT-1 Subject RIV: FH - Neurology Impact factor: 4.436, year: 2013

  2. Holocarboxylase synthetase deficiency pre and post newborn screening

    Directory of Open Access Journals (Sweden)

    Taraka R. Donti

    2016-06-01

    Full Text Available Holocarboxylase synthetase deficiency is an autosomal recessive disorder of biotin metabolism resulting in multiple carboxylase deficiency. The typical presentation described in the medical literature is of neonatal onset within hours to weeks of birth with emesis, hypotonia, lethargy, seizures, metabolic ketolactic acidosis, hyperammonemia, developmental delay, skin rash and alopecia. The condition is screened for by newborn screening (NBS tandem mass spectroscopy by elevated hydroxypentanoylcarnitine on dried blood spots. Urine organic acid profile may demonstrate elevated lactic, 3-OH isovaleric, 3-OH propionic, 3-MCC, methylcitric acids, and tiglylglycine consistent with loss of function of the above carboxylases. Here we describe a cohort of patients, 2 diagnosed pre-NBS and 3 post-NBS with broad differences in initial presentation and phenotype. In addition, prior to the advent of NBS, there are isolated reports of late-onset holocarboxylase synthetase deficiency in the medical literature, which describe patients diagnosed between 1 and 8 years of life, however to our knowledge there are no reports of late-onset HCLS being missed by NBS. Also we report two cases, each with novel pathogenic variants HCLS, diagnosed at age 3 years and 21 months respectively. The first patient had a normal newborn screen whilst the second had an abnormal newborn screen but was misdiagnosed as 3-methylcrotonylcarboxylase (3-MCC deficiency and subsequently lost to follow-up until they presented again with severe metabolic acidosis.

  3. Holocarboxylase synthetase deficiency pre and post newborn screening.

    Science.gov (United States)

    Donti, Taraka R; Blackburn, Patrick R; Atwal, Paldeep S

    2016-06-01

    Holocarboxylase synthetase deficiency is an autosomal recessive disorder of biotin metabolism resulting in multiple carboxylase deficiency. The typical presentation described in the medical literature is of neonatal onset within hours to weeks of birth with emesis, hypotonia, lethargy, seizures, metabolic ketolactic acidosis, hyperammonemia, developmental delay, skin rash and alopecia. The condition is screened for by newborn screening (NBS) tandem mass spectroscopy by elevated hydroxypentanoylcarnitine on dried blood spots. Urine organic acid profile may demonstrate elevated lactic, 3-OH isovaleric, 3-OH propionic, 3-MCC, methylcitric acids, and tiglylglycine consistent with loss of function of the above carboxylases. Here we describe a cohort of patients, 2 diagnosed pre-NBS and 3 post-NBS with broad differences in initial presentation and phenotype. In addition, prior to the advent of NBS, there are isolated reports of late-onset holocarboxylase synthetase deficiency in the medical literature, which describe patients diagnosed between 1 and 8 years of life, however to our knowledge there are no reports of late-onset HCLS being missed by NBS. Also we report two cases, each with novel pathogenic variants HCLS, diagnosed at age 3 years and 21 months respectively. The first patient had a normal newborn screen whilst the second had an abnormal newborn screen but was misdiagnosed as 3-methylcrotonylcarboxylase (3-MCC) deficiency and subsequently lost to follow-up until they presented again with severe metabolic acidosis. PMID:27114915

  4. ß-Lysine discrimination by lysyl-tRNA synthetase

    DEFF Research Database (Denmark)

    Gilreath, Marla S; Roy, Hervé; Bullwinkle, Tammy J;

    2011-01-01

    Elongation factor P is modified with (R)-ß-lysine by the lysyl-tRNA synthetase (LysRS) paralog PoxA. PoxA specificity is orthogonal to LysRS, despite their high similarity. To investigate a- and ß-lysine recognition by LysRS and PoxA, amino acid replacements were made in the LysRS active site gui...... enantiomers of ß-lysine were substrates for tRNA aminoacylation by LysRS, which, together with the relaxed specificity of the A233S variant, suggest a possible means to develop systems for in vivo co-translational insertion of ß-amino acids.......Elongation factor P is modified with (R)-ß-lysine by the lysyl-tRNA synthetase (LysRS) paralog PoxA. PoxA specificity is orthogonal to LysRS, despite their high similarity. To investigate a- and ß-lysine recognition by LysRS and PoxA, amino acid replacements were made in the LysRS active site...

  5. Purification and properties of the dihydrofolate synthetase from Serratia indica

    International Nuclear Information System (INIS)

    The dihydrofolate synthetase (EC6.3.2.12) responsible for catalyzing the synthesis of dihydrofolic acid from dihydropteroic acid and L-glutamic acid was purified about 130-fold from extracts of Serratia indica IFO 3759 by ammonium sulfate fractionation, DEAE-Sephadex column chromatography, Sephadex G-200 gel filtration, and DEAE-cellulose column chromatography. The enzyme preparation obtained was shown to be homogeneous by DEAE-cellulose column chromatography and ultracentrifugal analysis. The sedimentation coefficient of this enzyme was 3.9 S, and the molecular weight was determined to be about 47,000 by Sephadex G-100. The optimum pH for the reaction was 9.0. The enzymatic reaction required dihydropteroate, L-glutamate and ATP as substrates, and Mg2+ and K+ as cofactors. γ-L-Glutamyl-L-glutamic acid cannot replace L-glutamic acid as the substrate. Neither pteroic acid nor tetrahydropteroic acid can be used as the substrate. ATP was partially replaced by ITP or GTP. The enzyme reaction was inhibited by the addition of ADP, but not by AMP. One mole of dihydrofolate, 1 mole of ADP and 1 mole of orthophosphate were produced from each 1 mole of dihydropteroic acid, L-glutamic acid, and ATP. These results suggest that the systematic name for the dihydrofolate synthetase is 7,8-dihydropteroate: L-glutamate ligase (ADP). (auth.)

  6. L-Arginine and L-Glutamine as Immunonutrients and Modulating Agents for Erysipelothrix rusiopathiae Infection

    Directory of Open Access Journals (Sweden)

    Haijun Wang

    2012-01-01

    Full Text Available L-arginine and L-glutamine were not only building blocks of proteins and polypeptides but also important regulators of key metabolic pathways that were necessary for maintenance, growth, reproduction and immunity in organisms. These compelling findings convinced us that L-arginine and L-glutamine play a vital role in virus and bacterium infection. However, scientific literature about its role on Erysipelothrix rhusiopathiae (E. rhusiopathiae infection was unavailable. Thus, this study was conduct to research the effect of dietary L-arginine and L-glutamine supplementation on E. rhusiopathiae infection. According to the exciting results, researchers concluded that dietary L-arginine and L-glutamine supplementation ameliorated the cytokines profile and blood parameters and delayed the development process of E. rhusiopathiae infection in mouse model.

  7. Effect of carbohydrate supplementation on plasma glutamine during prolonged exercise and recovery

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Saris, W H; Wagenmakers, A J

    1998-01-01

    Muscle glycogen and glucose have been suggested to be carbon-chain precursors for glutamine synthesis in skeletal muscle. Therefore, the aim of the present study is to investigate whether carbohydrate supplementation affects plasma glutamine and other amino acids during exercise and 7 h of recovery....... Eight well-trained subjects cycled at an alternating workload of 50 and 80% Wmax until exhaustion (59 to 140 min). During the exercise bout the subjects received either water (control) or a carbohydrate (CHO) drink (83 g CHO x l(-1), 2 ml x kg(-1) per kg body weight every 15 min). Plasma glutamine...... concentration appeared not to be affected by exercise, as a significant increase was only observed at some points in time during the control test. During recovery, however, plasma glutamine concentration decreased from 682+/-24 and 685+/-19 micromol x l(-1) at exhaustion to 552+/-19 and 534+/-12 micromol x l(-1...

  8. Effects of glutamine and curcumin on bacterial translocation in jaundiced rats

    OpenAIRE

    Karatepe, Oguzhan; Acet, Ersin; Battal, Muharrem; Adas, Gokhan; Kemik, Ahu; Altiok, Merih; Kamali, Gulcin; Koculu, Safiye; Catay, Atahan; Kamali, Sedat; Karahan, Servet

    2010-01-01

    AIM: To investigate the effect of curcumin on bacterial translocation and oxidative damage in an obstructive jaundice model and compare the results to glutamine, an agent known to be effective and clinically used.

  9. Glutamine-Loaded Liposomes: Preliminary Investigation, Characterization, and Evaluation of Neutrophil Viability.

    Science.gov (United States)

    Costa, Larissa Chaves; Souza, Bárbara Nayane Rosário Fernandes; Almeida, Fábio Fidélis; Lagranha, Cláudia Jacques; Cadena, Pabyton Gonçalves; Santos-Magalhães, Nereide Stela; Lira-Nogueira, Mariane Cajubá de Britto

    2016-04-01

    Glutamine has received attention due to its ability to ameliorate the immune system response. Once conventional liposomes are readily recognized and captured by immune system cells, the encapsulation of glutamine into those nanosystems could be an alternative to reduce glutamine dosage and target then to neutrophils. Our goals were to nanoencapsulate glutamine into conventional liposomes (Gln-L), develop an analytical high-performance liquid chromatography (HPLC) method for its quantification, and evaluate the viability of neutrophils treated with Gln-L. Liposomes were prepared using the thin-film hydration technique followed by sonication and characterized according to pH, mean size, zeta potential, and drug encapsulation efficiency (EE%). We also aimed to study the effect of liposomal constituent concentrations on liposomal characteristics. The viability of neutrophils was assessed using flow cytometry after intraperitoneal administration of free glutamine (Gln), Gln-L, unloaded-liposome (UL), and saline solution as control (C) in healthy Wistar rats. The selected liposomal formulation had a mean vesicle size of 114.65 ± 1.82 nm with a polydispersity index of 0.30 ± 0.00, a positive surface charge of 36.30 ± 1.38 mV, and an EE% of 39.49 ± 0.74%. The developed chromatographic method was efficient for the quantification of encapsulated glutamine, with a retention time at 3.8 min. A greater viability was observed in the group treated with glutamine encapsulated compared to the control group (17%), although neutrophils remain viable in all groups. Thus, glutamine encapsulated into liposomes was able to increase the number of viable neutrophils at low doses, thereby representing a promising strategy for the treatment of immunodeficiency conditions. PMID:26228746

  10. The effect of glutamine infusion on the inflammatory response and HSP70 during human experimental endotoxaemia

    OpenAIRE

    Andreasen, Anne Sofie; Pedersen-Skovsgaard, Theis; Mortensen, Ole Hartvig; van Hall, Gerrit; Moseley, Pope Lloyd; Pedersen, Bente Klarlund

    2009-01-01

    Introduction Glutamine supplementation has beneficial effects on morbidity and mortality in critically ill patients, possibly in part through an attenuation of the proinflammatory cytokine response and a stimulation of heat shock protein (HSP)70. We infused either alanine-glutamine or saline during endotoxin challenge and measured plasma cytokines and HSP70 protein expression. Methods This crossover study, conducted in eight healthy young men, was double-blind, randomized and placebo-controll...

  11. The effect of glutamine and synbiotics on the healing of colonic anastomosis

    OpenAIRE

    Nikolaos Sapidis; Chrysostomos Tziouvaras; Orestis Ioannidis; Ioanna Kalaitsidou; Dimitrios Botsios

    2014-01-01

    Introduction: Intestinal wound healing is an essential process for surgical reconstruction of the digestive tract. The purpose of this study is to evaluate the effect of perioperative administration of glutamine and synbiotics on the biological behavior of intestinal mucosal barrier and the healing of colonic anastomosis in rats. Material and methods: 80 Wistar rats were divided in five groups. A: Control. B: Mechanical bowel preparation and antibiotics. C: Glutamine. D: Synbiotics. E: Glutam...

  12. Influence of glutamine on the effect of resistance exercise on cardiac ANP in rats

    OpenAIRE

    Romeu Rodrigues de Souza; Cleomara Angélica Vieira Caldeira; Patrícia Oliva Carbone; Eduardo Victor Pianca

    2015-01-01

    Various nutritional supplements (herbs, vitamins, and micronutrients) improve responses and adaptations to resistance exercise. ANP is a heart hormone that contributes to fluid, electrolyte and blood pressure homeostasis through its natriuretic and vasodilative actions. In the present study, the adaptation of ANP in response to resistance exercise was investigated in rats supplemented with glutamine for five weeks. The results showed that supplementation with glutamine did not influence the n...

  13. Protection from radiation injury by elemental diet: does added glutamine change the effect?

    OpenAIRE

    McArdle, A. H.

    1994-01-01

    The feeding of a protein hydrolysate based 'elemental' diet supplemented with added glutamine did not provide superior protection to the small intestine of dogs subjected to therapeutic pelvic irradiation. Comparison of diets with and without the added glutamine showed significant protection of the intestine from radiation injury. Both histological examination and electron microscopy showed lack of tissue injury with both diets. The activity of the free radical generating enzymes, scavengers,...

  14. Glutamate/glutamine and neuronal integrity in adults with ADHD: a proton MRS study

    OpenAIRE

    Maltezos, S.; Horder, J; Coghlan, S; Skirrow, C; O'Gorman, R; Lavender, T J; Mendez, M A; Mehta, M.; Daly, E.; Xenitidis, K; Paliokosta, E; Spain, D; M. Pitts; Asherson, P.; Lythgoe, D J

    2014-01-01

    There is increasing evidence that abnormalities in glutamate signalling may contribute to the pathophysiology of attention-deficit hyperactivity disorder (ADHD). Proton magnetic resonance spectroscopy ([1H]MRS) can be used to measure glutamate, and also its metabolite glutamine, in vivo. However, few studies have investigated glutamate in the brain of adults with ADHD naive to stimulant medication. Therefore, we used [1H]MRS to measure the combined signal of glutamate and glutamine (Glu+Gln; ...

  15. Antenatal and postnatal radiologic diagnosis of holocarboxylase synthetase deficiency: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Bandaralage, Sahan P.S. [Gold Coast Hospital and Health Service, Southport, Queensland (Australia); Griffith University, School of Medicine, Southport, Queensland (Australia); Farnaghi, Soheil [Caboolture Hospital, Caboolture, Queensland (Australia); Dulhunty, Joel M.; Kothari, Alka [Redcliffe Hospital, Redcliffe, Queensland (Australia); The University of Queensland, School of Medicine, Herston, Queensland (Australia)

    2016-03-15

    Holocarboxylase synthetase deficiency results in impaired activation of enzymes implicated in glucose, fatty acid and amino acid metabolism. Antenatal imaging and postnatal imaging are useful in making the diagnosis. Untreated holocarboxylase synthetase deficiency is fatal, while antenatal and postnatal biotin supplementation is associated with good clinical outcomes. Although biochemical assays are required for definitive diagnosis, certain radiologic features assist in the diagnosis of holocarboxylase synthetase deficiency. To review evidence regarding radiologic diagnostic features of holocarboxylase synthetase deficiency in the antenatal and postnatal period. A systematic review of all published cases of holocarboxylase synthetase deficiency identified by a search of Pubmed, Scopus and Web of Science. A total of 75 patients with holocarboxylase synthetase deficiency were identified from the systematic review, which screened 687 manuscripts. Most patients with imaging (19/22, 86%) had abnormal findings, the most common being subependymal cysts, ventriculomegaly and intraventricular hemorrhage. Although the radiologic features of subependymal cysts, ventriculomegaly, intraventricular hemorrhage and intrauterine growth restriction may be found in the setting of other pathologies, these findings should prompt consideration of holocarboxylase synthetase deficiency in at-risk children. (orig.)

  16. Antenatal and postnatal radiologic diagnosis of holocarboxylase synthetase deficiency: a systematic review

    International Nuclear Information System (INIS)

    Holocarboxylase synthetase deficiency results in impaired activation of enzymes implicated in glucose, fatty acid and amino acid metabolism. Antenatal imaging and postnatal imaging are useful in making the diagnosis. Untreated holocarboxylase synthetase deficiency is fatal, while antenatal and postnatal biotin supplementation is associated with good clinical outcomes. Although biochemical assays are required for definitive diagnosis, certain radiologic features assist in the diagnosis of holocarboxylase synthetase deficiency. To review evidence regarding radiologic diagnostic features of holocarboxylase synthetase deficiency in the antenatal and postnatal period. A systematic review of all published cases of holocarboxylase synthetase deficiency identified by a search of Pubmed, Scopus and Web of Science. A total of 75 patients with holocarboxylase synthetase deficiency were identified from the systematic review, which screened 687 manuscripts. Most patients with imaging (19/22, 86%) had abnormal findings, the most common being subependymal cysts, ventriculomegaly and intraventricular hemorrhage. Although the radiologic features of subependymal cysts, ventriculomegaly, intraventricular hemorrhage and intrauterine growth restriction may be found in the setting of other pathologies, these findings should prompt consideration of holocarboxylase synthetase deficiency in at-risk children. (orig.)

  17. Understanding the mechanisms of glutamine action in critically ill patients

    Directory of Open Access Journals (Sweden)

    Gisele P. Oliveira

    2010-06-01

    Full Text Available Glutamine (Gln is an important energy source and has been used as a supplementary energy substrate. Furthermore, Gln is an essential component for numerous metabolic functions, including acid-base homeostasis, gluconeogenesis, nitrogen transport and synthesis of proteins and nucleic acids. Therefore, glutamine plays a significant role in cell homeostasis and organ metabolism. This article aims to review the mechanisms of glutamine action during severe illnesses. In critically ill patients, the increase in mortality was associated with a decreased plasma Gln concentration. During catabolic stress, Gln consumption rate exceeds the supply, and both plasma and skeletal muscle pools of free Gln are severely reduced. The dose and route of Gln administration clearly influence its effectiveness: high-dose parenteral appears to be more beneficial than low-dose enteral administration. Experimental studies reported that Gln may protect cells, tissues, and whole organisms from stress and injury through the following mechanisms: attenuation of NF (nuclear factor-kB activation, a balance between pro- and anti-inflammatory cytokines, reduction in neutrophil accumulation, improvement in intestinal integrity and immune cell function, and enhanced of heat shock protein expression. In conclusion, high-doses of parenteral Gln (>0.50 g/kg/day demonstrate a greater potential to benefit in critically ill patients, although Gln pathophysiological mechanisms requires elucidation.A glutamina (Gln é uma importante fonte de energia e tem sido usada como substrato energético suplementar. Além disso, a Gln é um componente essencial para numerosas funções metabólicas tais como: homeostase ácido-base, gliconeogênese, transporte de nitrogênio e síntese de proteínas e ácidos nucléicos. Portanto, a glutamina desempenha um papel importante na homeostase celular e no metabolismo dos órgãos. Esse artigo objetiva rever os mecanismos de ação da glutamina na doen

  18. Glutamine supplementation in cancer patients receiving chemotherapy: a double-blind randomized study.

    Science.gov (United States)

    Bozzetti, F; Biganzoli, L; Gavazzi, C; Cappuzzo, F; Carnaghi, C; Buzzoni, R; Dibartolomeo, M; Baietta, E

    1997-01-01

    The purpose of this study was to evaluate the efficacy of glutamine in preventing doxifluridine-induced diarrhea and the potential impact of glutamine on the tumor growth. We investigated 65 patients with advanced breast cancer receiving doxifluridine in a double-blind randomized fashion: 33 patients took glutamine (30 g/d, divided in 3 doses of 10 g each) for 8 consecutive days (5-12h) during each interval between chemotherapy, which was administered from day 1 to 4. Thirty-two patients took an equal dose of placebo (maltodextrine). The incidence of diarrhea was registered after each cycle of chemotherapy and severity was scored by the National Cancer Institute (NCI), Bethesda, Maryland, classification. The tumor response was evaluated by the World Health Organization (WHO) criteria. A total of 278 and 259 cycles (median 10 cycles), respectively, were delivered in glutamine and placebo groups. There were 34 and 32 episodes of diarrhea in glutamine and placebo groups, with no statistical difference overall, in the severity and duration of tumor growth, there was no difference in the response rate (21% and 28% of complete or partial response, respectively), in median time to response (2 mo), or in median duration of response. In conclusion, glutamine did not prevent the occurrence of the doxifluridine-induced diarrhea and did not have any impact on tumor response to chemotherapy. PMID:9263281

  19. Enhanced mitochondrial glutamine anaplerosis suppresses pancreatic cancer growth through autophagy inhibition.

    Science.gov (United States)

    Jeong, Seung Min; Hwang, Sunsook; Park, Kyungsoo; Yang, Seungyeon; Seong, Rho Hyun

    2016-01-01

    Cancer cells use precursors derived from tricarboxylic acid (TCA) cycle to support their unlimited growth. However, continuous export of TCA cycle intermediates results in the defect of mitochondrial integrity. Mitochondria glutamine metabolism plays an essential role for the maintenance of mitochondrial functions and its biosynthetic roles by refilling the mitochondrial carbon pool. Here we report that human pancreatic ductal adenocarcinoma (PDAC) cells have a distinct dependence on mitochondrial glutamine metabolism. Whereas glutamine flux into mitochondria contributes to proliferation of most cancer cells, enhanced glutamine anaplerosis results in a pronounced suppression of PDAC growth. A cell membrane permeable α-ketoglutarate analog or overexpression of glutamate dehydrogenase lead to decreased proliferation and increased apoptotic cell death in PDAC cells but not other cancer cells. We found that enhanced glutamine anaplerosis inhibits autophagy, required for tumorigenic growth of PDAC, by activating mammalian TORC1. Together, our results reveal that glutamine anaplerosis is a crucial regulator of growth and survival of PDAC cells, which may provide novel therapeutic approaches to treat these cancers. PMID:27477484

  20. Pilot study with a glutamine-supplemented enteral formula in critically ill infants

    Directory of Open Access Journals (Sweden)

    Barbosa Eliana

    1999-01-01

    Full Text Available Seriously ill infants often display protein-calorie malnutrition due to the metabolic demands of sepsis and respiratory failure. Glutamine has been classified as a conditionally essential amino acid, with special usefulness in critical patients. Immunomodulation, gut protection, and prevention of protein depletion are mentioned among its positive effects in such circumstances. With the intent of evaluating the tolerance and clinical impact of a glutamine supplement in seriously ill infants, a prospective randomized study was done with nine patients. Anthropometric and biochemical determinations were made, and length of stay in the intensive care unit (ICU, in the hospital, and under artificial ventilation, and septic morbidity and mortality were tabulated. Infants in the treatment group (n=5 were enterally administered 0.3 g/kg of glutamine, whereas controls received 0.3 g/kg of casein during a standard period of five days. Septic complications occurred in 75% of the controls (3/4 versus 20% of the glutamine-treated group (1/5, p<=0.10, and two patients in the control group died of bacterial infections (50% vs. 0%, p<=0.10. Days in the ICU, in the hospital, and with ventilation numerically favored glutamine therapy, although without statistical significance. The supplements were usually well tolerated, and no patient required discontinuation of the program. The conclusion was that glutamine supplementation was safe and tended to be associated with less infectious morbidity and mortality in this high-risk population.

  1. Thiol synthetases of legumes: Immunogold localization and differential gene regulation by phytohormones

    OpenAIRE

    Clemente, María Rebeca; Bustos-Sanmamed, Pilar; Loscos Aranda, Jorge; James, Euan Kevin; Pérez-Rontomé, Carmen; Navascués Ortega, Joaquín; Gay, Marina; Becana Ausejo, Manuel

    2012-01-01

    In plants and other organisms, glutathione (GSH) biosynthesis is catalysed sequentially by γ-glutamylcysteine synthetase (γECS) and glutathione synthetase (GSHS). In legumes, homoglutathione (hGSH) can replace GSH and is synthesized by γECS and a specific homoglutathione synthetase (hGSHS). The subcellular localization of the enzymes was examined by electron microscopy in several legumes and gene expression was analysed in Lotus japonicus plants treated for 1–48 h with 50 μM of hormones. Immu...

  2. Treatment of renal colic by prostaglandin synthetase inhibitors and avafortan (analgesic antispasmodic).

    Science.gov (United States)

    el-Sherif, A E; Foda, R; Norlen, L J; Yahia, H

    1990-12-01

    In a study of the pain-relieving effect of 3 drugs commonly used to treat acute renal colic in this hospital, intravenous indomethacin and intramuscular diclofenac (prostaglandin synthetase inhibitors) were compared with intravenous Avafortan (analgesic antispasmodic). As first-line analgesics, prostaglandin synthetase inhibitors, if given intravenously, offer an effective alternative to Avafortan. Of 145 patients studied, 32 required a second injection for complete relief of pain. Administering a second dose of prostaglandin synthetase inhibitors resulted in equally significant pain relief rate even though the route was intramuscular. PMID:2265331

  3. Effect of ionizing radiation on methylation of lysil-tRNA-synthetase from rat liver

    International Nuclear Information System (INIS)

    X-irradiation of animals with an absolutely lethal dose of 0.21 C/kg increases the incorporation of a methyl group into aminoacyl-tRNA-synthetases the radioactive label being traced in lysine, arginine, and histidine. The isolated protein methyltransferase methylated total preparaions of aminoacyl-tRNA-synthetases and lysil-tRNA-synthetase of rat liver in the in vitro experiments with the use of S-adenosylmethionine-14CH3 as a donor of methyl groups: the radioactive label was traced in arginine, lysine, histidine, aspartic and glytamic acids

  4. Rational design and directed evolution of a bacterial-type glutaminyl-tRNA synthetase precursor

    OpenAIRE

    Guo, Li-Tao; Helgadóttir, Sunna; Söll, Dieter; Ling, Jiqiang

    2012-01-01

    Protein biosynthesis requires aminoacyl-transfer RNA (tRNA) synthetases to provide aminoacyl-tRNA substrates for the ribosome. Most bacteria and all archaea lack a glutaminyl-tRNA synthetase (GlnRS); instead, Gln-tRNAGln is produced via an indirect pathway: a glutamyl-tRNA synthetase (GluRS) first attaches glutamate (Glu) to tRNAGln, and an amidotransferase converts Glu-tRNAGln to Gln-tRNAGln. The human pathogen Helicobacter pylori encodes two GluRS enzymes, with GluRS2 specifically aminoacyl...

  5. Activity of aminoacyl-tRNA synthetases in experimental hyperthyroidism in muscle tissue of the rabbit

    International Nuclear Information System (INIS)

    In cardial and femoral muscles of rabbits specific activities of aminoacyl-tRNA synthetases for twenty amino acids were generally similar, namely the activities towards amino acids and their amides, leucine, isoleucine, histidine, tyrosine, proline and serine were considerably lower than towards the remaining amino acids. Specific activities of most aminoacyl-tRNA synthetases were higher in hyperthyroidism than in euthyreosis, and were higher in femoral muscle than in heart. The response to thyroxine treatment of individual aminoacyl-tRNA synthetases in both kinds of muscles varied with respect to most of the amino acids. (author). 22 refs, 1 fig., 1 tab

  6. In Silico Discovery of Aminoacyl-tRNA Synthetase Inhibitors

    Directory of Open Access Journals (Sweden)

    Yaxue Zhao

    2014-01-01

    Full Text Available Aminoacyl-tRNA synthetases (aaRSs are enzymes that catalyze the transfer of amino acids to their cognate tRNA. They play a pivotal role in protein synthesis and are essential for cell growth and survival. The aaRSs are one of the leading targets for development of antibiotic agents. In this review, we mainly focused on aaRS inhibitor discovery and development using in silico methods including virtual screening and structure-based drug design. These computational methods are relatively fast and cheap, and are proving to be of great benefit for the rational development of more potent aaRS inhibitors and other pharmaceutical agents that may usher in a much needed generation of new antibiotics.

  7. Regulation of Angiogenesis by Aminoacyl-tRNA Synthetases

    Directory of Open Access Journals (Sweden)

    Adam C. Mirando

    2014-12-01

    Full Text Available In addition to their canonical roles in translation the aminoacyl-tRNA synthetases (ARSs have developed secondary functions over the course of evolution. Many of these activities are associated with cellular survival and nutritional stress responses essential for homeostatic processes in higher eukaryotes. In particular, six ARSs and one associated factor have documented functions in angiogenesis. However, despite their connection to this process, the ARSs are mechanistically distinct and exhibit a range of positive or negative effects on aspects of endothelial cell migration, proliferation, and survival. This variability is achieved through the appearance of appended domains and interplay with inflammatory pathways not found in prokaryotic systems. Complete knowledge of the non-canonical functions of ARSs is necessary to understand the mechanisms underlying the physiological regulation of angiogenesis.

  8. The effect of free glutamine and peptide ingestion on the rate of muscle glycogen resynthesis in man

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Saris, W H; van de Schoor, P A;

    2000-01-01

    The present study investigated previous claims that ingestion of glutamine and of protein-carbohydrate mixtures may increase the rate of glycogen resynthesis following intense exercise. Eight trained subjects were studied during 3 h of recovery while consuming one of four drinks in random order....... Drinks were ingested in three 500 ml boluses, immediately after exercise and then after 1 and 2 h of recovery. Each bolus of the control drink contained 0.8 g x kg(-1) body weight of glucose. The other drinks contained the same amount of glucose and 0.3 g x kg(-1) body weight of 1) glutamine, 2) a wheat...... hydrolysate (26% glutamine) and 3) a whey hydrolysate (6.6% glutamine). Plasma glutamine, decreased by approximately 20% during recovery with ingestion of the control drink, no changes with ingestion of the protein hydrolysates drinks, and a 2-fold increase with ingestion of the free glutamine drinks. The...

  9. Glutamine: a precursor of glutathione and its effect on liver

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    AIM To investigate the relationship between alanyl-glutamine (ALA-GLN) and glutathione (GSH) biosynthesis in hepatic protection.METHODS Twenty male Wistar rats were randomly divided into two groups: one receiving standard parenteral nutrition (STD) and the other supplemented with or without ALA-GLN for 7 days. The blood and liver tissue samples were examined after 5-fluorouracil (5-FU) was injected peritoneally.RESULTS The concentration measurements were significantly higher in ALA-GLN group than in STD group in serum GLN (687 μmol/ L±50 μmol/ L vs 505 μmol/ L±39 μmol/ L, P<0.05), serum GSH (14 μmol/ L±5 μmol/ L vs 7 μmol/ L±3 μmol/ L, P<0.01) and in liver GSH content (6.9 μmol/ g±2.5 μmol/ g vs 4.4 μmol/ g±1.6 μmol/ g liver tissue, P<0.05). Rats in ALA-GLN group had lesser elevations in hepatic enzymes after 5-FU administration.CONCLUSION The supplemented nutrition ALA-GLN can protect the liver function through increasing the glutathione biosynthesis and preserving the glutathione stores in hepatic tissue.

  10. Glutamine Attenuates Acute Lung Injury Caused by Acid Aspiration

    Directory of Open Access Journals (Sweden)

    Chih-Cheng Lai

    2014-08-01

    Full Text Available Inadequate ventilator settings may cause overwhelming inflammatory responses associated with ventilator-induced lung injury (VILI in patients with acute respiratory distress syndrome (ARDS. Here, we examined potential benefits of glutamine (GLN on a two-hit model for VILI after acid aspiration-induced lung injury in rats. Rats were intratracheally challenged with hydrochloric acid as a first hit to induce lung inflammation, then randomly received intravenous GLN or lactated Ringer’s solution (vehicle control thirty min before different ventilator strategies. Rats were then randomized to receive mechanical ventilation as a second hit with a high tidal volume (TV of 15 mL/kg and zero positive end-expiratory pressure (PEEP or a low TV of 6 mL/kg with PEEP of 5 cm H2O. We evaluated lung oxygenation, inflammation, mechanics, and histology. After ventilator use for 4 h, high TV resulted in greater lung injury physiologic and biologic indices. Compared with vehicle treated rats, GLN administration attenuated lung injury, with improved oxygenation and static compliance, and decreased respiratory elastance, lung edema, extended lung destruction (lung injury scores and lung histology, neutrophil recruitment in the lung, and cytokine production. Thus, GLN administration improved the physiologic and biologic profiles of this experimental model of VILI based on the two-hit theory.

  11. Cavitation as a mechanism of substrate discrimination by adenylosuccinate synthetases.

    Science.gov (United States)

    Iancu, Cristina V; Zhou, Yang; Borza, Tudor; Fromm, Herbert J; Honzatko, Richard B

    2006-09-26

    Adenylosuccinate synthetase catalyzes the first committed step in the de novo biosynthesis of AMP, coupling L-aspartate and IMP to form adenylosuccinate. Km values of IMP and 2'-deoxy-IMP are nearly identical with each substrate supporting comparable maximal velocities. Nonetheless, the Km value for L-aspartate and the Ki value for hadacidin (a competitive inhibitor with respect to L-aspartate) are 29-57-fold lower in the presence of IMP than in the presence of 2'-deoxy-IMP. Crystal structures of the synthetase ligated with hadacidin, GDP, and either 6-phosphoryl-IMP or 2'-deoxy-6-phosphoryl-IMP are identical except for the presence of a cavity normally occupied by the 2'-hydroxyl group of IMP. In the presence of 6-phosphoryl-IMP and GDP (hadacidin absent), the L-aspartate pocket can retain its fully ligated conformation, forming hydrogen bonds between the 2'-hydroxyl group of IMP and sequence-invariant residues. In the presence of 2'-deoxy-6-phosphoryl-IMP and GDP, however, the L-aspartate pocket is poorly ordered. The absence of the 2'-hydroxyl group of the deoxyribonucleotide may destabilize binding of the ligand to the L-aspartate pocket by disrupting hydrogen bonds that maintain a favorable protein conformation and by the introduction of a cavity into the fully ligated active site. At an approximate energy cost of 2.2 kcal/mol, the unfavorable thermodynamics of cavity formation may be the major factor in destabilizing ligands at the L-aspartate pocket. PMID:16981730

  12. Transformation of Bacillus Subtilis with cloned thymidylate synthetases

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, Edward M.

    1980-01-01

    Bacillus subtilis carries two genes, thyA and thyB, each encoding different protein products, with thymidylate synthetase (TSase) activity. Either of these genes alone is sufficient for thymidine independence in B. subtilis. In addition there exist two B. subtilis temperate bacteriophages which upon infection of thymine requiring auxotrophs results in conversion of the organism to thymine independence. Chimeric plasmids selected for Thy/sup +/ transforming activity in E. coli were constructed and then used as a source of defined highly enriched DNA with which to transform competent B. subtilis. These plasmids were studied for their: (1) abiility to transform B. subtilis to thymine independence; (2) site of integration within the B. subtilis chromosome upon transformation; (3) phenotype of Thy/sup +/ plasmid generated transformants; and (4) nucleotide sequence homology among the cloned DNA fragments conferring thymine independence. Plasmids containing the two bacteriophage thy genes displayed the phenotype associated with thyA, whereas the plasmids containing the cloned B. subtilis chromosomal genes displayed the phenotype associated with thyB. Utilizing similar technology, the ability of an entirely foreign hybred bacterial plasmiid to transform B. subtilis was examined. In this case the gene from E. coli encoding thymidylate synthetase was cloned in the plasmid pBR322. The resulting chimeric plasmid was effective in transforming both E. coli and B. subtilis to thymine prototrophy. Uncloned linear E. coli chromosomal DNA was unable to transform thymine requiring strains of B. subtilis to thymine independence. Although the Thy/sup +/ transformants of E. coli contained plasmid DNA, the Thy/sup +/ transformants derived from the transformation of B. subtilis did not contain detectable extrachromosomal DNA. Instead the DNA from the chimeric plasmid was integrated into the chromosome of B. subtilis. (ERB)

  13. IMPROVEMENT OF INTESTINAL PERMEABILITY WITH ALANYL-GLUTAMINE IN HIV PATIENTS: a randomized, double blinded, placebo-controlled clinical trial

    OpenAIRE

    Roberio Dias LEITE; Noelia Leal LIMA; Christiane Araujo Chaves LEITE; Calil Kairalla FARHAT; Guerrant, Richard Littleton; Aldo Angelo Moreira LIMA

    2013-01-01

    Context Glutamine is the main source of energy of the enterocyte and diarrhea and weight loss are frequent in HIV infected patients. Objective To determine the effect of alanyl-glutamine supplementation on intestinal permeability and absorption in these patients. Methods Randomized double-blinded, placebo-controlled study using isonitrogenous doses of alanyl-glutamine (24 g/day) and placebo (glycine, 25 g/day) during 10 days. Before and after this nutritional supplementation l...

  14. IMPROVEMENT OF INTESTINAL PERMEABILITY WITH ALANYL-GLUTAMINE IN HIV PATIENTS: a randomized, double blinded, placebo-controlled clinical trial

    OpenAIRE

    Roberio Dias LEITE; Noelia Leal LIMA; Christiane Araujo Chaves LEITE; Calil Kairalla FARHAT; Guerrant, Richard Littleton; Aldo Angelo Moreira LIMA

    2013-01-01

    Context Glutamine is the main source of energy of the enterocyte and diarrhea and weight loss are frequent in HIV infected patients. Objective To determine the effect of alanyl-glutamine supplementation on intestinal permeability and absorption in these patients. Methods Randomized double-blinded, placebo-controlled study using isonitrogenous doses of alanyl-glutamine (24 g/day) and placebo (glycine, 25 g/day) during 10 days. Before and after this nutritional supplementation lactulose and...

  15. Lymphocyte Glucose and Glutamine Metabolism as Targets of the Anti-Inflammatory and Immunomodulatory Effects of Exercise

    OpenAIRE

    Frederick Wasinski; Gregnani, Marcos F.; Ornellas, Fábio H.; Aline V N Bacurau; Câmara, Niels O.; Ronaldo C Araujo; Reury F. Bacurau

    2014-01-01

    Glucose and glutamine are important energetic and biosynthetic nutrients for T and B lymphocytes. These cells consume both nutrients at high rates in a function-dependent manner. In other words, the pathways that control lymphocyte function and survival directly control the glucose and glutamine metabolic pathways. Therefore, lymphocytes in different functional states reprogram their glucose and glutamine metabolism to balance their requirement for ATP and macromolecule production. The tight ...

  16. Effects of L-glutamine supplementation on maternal and fetal hemodynamics in gestating ewes exposed to alcohol

    OpenAIRE

    Sawant, Onkar B.; Ramadoss, Jayanth; Hankins, Gary D.; Wu, Guoyao; Washburn, Shannon E.

    2014-01-01

    Not much is known about effects of gestational alcohol exposure on maternal and fetal cardiovascular adaptations. This study determined whether maternal binge alcohol exposure and L-glutamine supplementation could affect maternal-fetal hemodynamics and fetal regional brain blood flow during the brain growth spurt period. Pregnant sheep were randomly assigned to one of four groups: saline control, alcohol (1.75–2.5 g/kg body weight), glutamine (100 mg/kg body weight) or alcohol + glutamine. A ...

  17. High cerebral guanidinoacetate and variable creatine concentrations in argininosuccinate synthetase and lyase deficiency : Implications for treatment?

    NARCIS (Netherlands)

    van Spronsen, F. J.; Reijngoud, D. J.; Verhoeven, N. M.; Soorani-Lunsing, R. J.; Jakobs, C.; Sijens, P. E.

    2006-01-01

    Cerebral creatine and guanidinoacetate and blood and urine metabolites were studied in four patients with argininosuccinate synthetase (ASS) or argininosuccinate lyase (ASL) deficiency receiving large doses of arginine. Urine and blood metabolites varied largely. Cerebral guanidinoacetate was increa

  18. Mitochondrial phenylalanyl-tRNA synthetase mutations underlie fatal infantile Alpers encephalopathy

    DEFF Research Database (Denmark)

    Elo, Jenni M; Yadavalli, Srujana S; Euro, Liliya;

    2012-01-01

    Next-generation sequencing has turned out to be a powerful tool to uncover genetic basis of childhood mitochondrial disorders. We utilized whole-exome analysis and discovered novel compound heterozygous mutations in FARS2 (mitochondrial phenylalanyl transfer RNA synthetase), encoding the mitochon...... aminoacyl-tRNA synthetase as a cause of mitochondrial disease.......Next-generation sequencing has turned out to be a powerful tool to uncover genetic basis of childhood mitochondrial disorders. We utilized whole-exome analysis and discovered novel compound heterozygous mutations in FARS2 (mitochondrial phenylalanyl transfer RNA synthetase), encoding the...... mitochondrial phenylalanyl transfer RNA (tRNA) synthetase (mtPheRS) in two patients with fatal epileptic mitochondrial encephalopathy. The mutations affected highly conserved amino acids, p.I329T and p.D391V. Recently, a homozygous FARS2 variant p.Y144C was reported in a Saudi girl with mitochondrial...

  19. GLUTAMIN MEMPERCEPAT WAKTU PEMULIHAN JUMLAH SEL LIMFOSIT LIEN SETELAH AKTIVITAS FISIK MAKSIMAL PADA MENCIT (GLUTAMINE SHORTENS RECOVERY TIME OF LIEN LYMPHOCYTES AFTER EXCESSIVE PHYSICAL ACTIVITY IN MICE

    Directory of Open Access Journals (Sweden)

    I Made Jawi

    2007-06-01

    Full Text Available The immunologic? system? of the body requires? suitable recovery time after? excessive physical? activity. The recovery? time of spleen lymphocytes after? excessive? physical activity? in one? investigation was? 3? days. The? aim? of this? research is to identify?the role of? glutamine? in shortening? the recovery time of? spleen? lymphocytes? after?excessive physical activity. The? study? was conducted? on? 70? adults? Balb/c mice which? were? divided? into? 7? groups, with? a randomized control? group post-test? only design. In this? study? an observation? was made on? spleen? lymphocytes? of control, after? excessive? physical activity(in the the? form of swimming? until? near? drowning with glutamine,? without glutamine ?and? after? the? recovery time of 1 and 2 days? of? each of? the 10 mice. Spleen? lymphocytes? were? counted in spleen preparation by mikroskop. The data obtained were tested? by? one way Anova. The findings? showed? that the number of spleen? lymphocytes significantly decrease after? excessive? physical activity?? in the?glutamine? and? non glutamine groups ( p < 0,05.The number of spleen? lymphocytes? was? not different as compered to control group or returned? to normal after recovery? time? of 1? day? in? the? glutamine group (p > 0,05 .?In the nonglutamine group the number of spleen lymphocytes was different from control group until 2 days (p<0,05 . From this finding it can be concluded that glutamine? shortens the recovery time of spleen lymphocytes? after? excessive? physical activity in mice.

  20. No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise.

    Science.gov (United States)

    Marwood, Simon; Bowtell, Jo

    2008-08-01

    Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g kg body mass(-1) of glutamine in 5 ml kg body mass(-1) placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO(2) = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake (VO(2max)) immediately before completing a brief high-intensity time-trial (approximately 4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (DeltaVO(2max), P = 0.02) and exercise performance (control: 243 s, s(x) = 7; glutamine: 242 s, s(x) = 3; hyperoxia: 231 s, s(x) = 3; hyperoxia + glutamine: 228 s, s(x) = 5; P glutamine ingestion increased DeltaVO(2max) in normoxia, but not hyperoxia (interaction drink/FiO(2), P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise. PMID:18608833

  1. Proline and Glutamine Improvein vitro Callus Induction and Subsequent Shooting in Rice

    Institute of Scientific and Technical Information of China (English)

    Bhausaheb PAWAR; Prashant KALE; Jyoti BAHURUPE; Ashok JADHAV; Anil KALE; Sharad PAWAR

    2015-01-01

    This study was conducted to evaluate the effects of proline and glutamine onin vitro callus induction and subsequent regeneration and to develop a reproducible and highly efficient plant regeneration protocol in four ricegenotypes, viz. Pawana, Jaya, Indrayani and Ambemohar. Considerable variation in response to plant growth regulators and amino acid supplements used was observed in all the four genotypes. Medium supplemented with proline and glutamine was shown to be superior to medium without proline and glutamine. The best callusing from mature embryo was observed on Murashige and Skoog (MS) medium supplemented with 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), 500 mg/L proline and 500 mg/L glutamine. Shoot induction was higher in the callus obtained from medium supplemented with 500 mg/L proline and 500 mg/L glutamine. The highest shoot regeneration frequency (83.2%) was observed on MS medium with 2.0 mg/L benzylaminopurine, 0.5 mg/L 1-naphthaleneacetic acid, 500 mg/L proline, and 500 mg/L glutamine in the callus obtained from MS medium supplemented with 2.0 mg/L 2,4-D, 500 mg/L proline and 500 mg/L glutamine. Among the four genotypes, Pawana has the highest regeneration efficiency (83.2%), whereas the regeneration efficiency of the rest three rice genotypes was in the range of 32.0% to 72.3%. This optimized regeneration protocol can be efficiently used forAgrobacterium mediated genetic transformation in rice.

  2. Human tyrosyl-tRNA synthetase shares amino acid sequence homology with a putative cytokine.

    Science.gov (United States)

    Kleeman, T A; Wei, D; Simpson, K L; First, E A

    1997-05-30

    To test the hypothesis that tRNATyr recognition differs between bacterial and human tyrosyl-tRNA synthetases, we sequenced several clones identified as human tyrosyl-tRNA synthetase cDNAs by the Human Genome Project. We found that human tyrosyl-tRNA synthetase is composed of three domains: 1) an amino-terminal Rossmann fold domain that is responsible for formation of the activated E.Tyr-AMP intermediate and is conserved among bacteria, archeae, and eukaryotes; 2) a tRNA anticodon recognition domain that has not been conserved between bacteria and eukaryotes; and 3) a carboxyl-terminal domain that is unique to the human tyrosyl-tRNA synthetase and whose primary structure is 49% identical to the putative human cytokine endothelial monocyte-activating protein II, 50% identical to the carboxyl-terminal domain of methionyl-tRNA synthetase from Caenorhabditis elegans, and 43% identical to the carboxyl-terminal domain of Arc1p from Saccharomyces cerevisiae. The first two domains of the human tyrosyl-tRNA synthetase are 52, 36, and 16% identical to tyrosyl-tRNA synthetases from S. cerevisiae, Methanococcus jannaschii, and Bacillus stearothermophilus, respectively. Nine of fifteen amino acids known to be involved in the formation of the tyrosyl-adenylate complex in B. stearothermophilus are conserved across all of the organisms, whereas amino acids involved in the recognition of tRNATyr are not conserved. Kinetic analyses of recombinant human and B. stearothermophilus tyrosyl-tRNA synthetases expressed in Escherichia coli indicate that human tyrosyl-tRNA synthetase aminoacylates human but not B. stearothermophilus tRNATyr, and vice versa, supporting the original hypothesis. It is proposed that like endothelial monocyte-activating protein II and the carboxyl-terminal domain of Arc1p, the carboxyl-terminal domain of human tyrosyl-tRNA synthetase evolved from gene duplication of the carboxyl-terminal domain of methionyl-tRNA synthetase and may direct tRNA to the active site of

  3. Genetic validation of aminoacyl-tRNA synthetases as drug targets in Trypanosoma brucei.

    Science.gov (United States)

    Kalidas, Savitha; Cestari, Igor; Monnerat, Severine; Li, Qiong; Regmi, Sandesh; Hasle, Nicholas; Labaied, Mehdi; Parsons, Marilyn; Stuart, Kenneth; Phillips, Margaret A

    2014-04-01

    Human African trypanosomiasis (HAT) is an important public health threat in sub-Saharan Africa. Current drugs are unsatisfactory, and new drugs are being sought. Few validated enzyme targets are available to support drug discovery efforts, so our goal was to obtain essentiality data on genes with proven utility as drug targets. Aminoacyl-tRNA synthetases (aaRSs) are known drug targets for bacterial and fungal pathogens and are required for protein synthesis. Here we survey the essentiality of eight Trypanosoma brucei aaRSs by RNA interference (RNAi) gene expression knockdown, covering an enzyme from each major aaRS class: valyl-tRNA synthetase (ValRS) (class Ia), tryptophanyl-tRNA synthetase (TrpRS-1) (class Ib), arginyl-tRNA synthetase (ArgRS) (class Ic), glutamyl-tRNA synthetase (GluRS) (class 1c), threonyl-tRNA synthetase (ThrRS) (class IIa), asparaginyl-tRNA synthetase (AsnRS) (class IIb), and phenylalanyl-tRNA synthetase (α and β) (PheRS) (class IIc). Knockdown of mRNA encoding these enzymes in T. brucei mammalian stage parasites showed that all were essential for parasite growth and survival in vitro. The reduced expression resulted in growth, morphological, cell cycle, and DNA content abnormalities. ThrRS was characterized in greater detail, showing that the purified recombinant enzyme displayed ThrRS activity and that the protein localized to both the cytosol and mitochondrion. Borrelidin, a known inhibitor of ThrRS, was an inhibitor of T. brucei ThrRS and showed antitrypanosomal activity. The data show that aaRSs are essential for T. brucei survival and are likely to be excellent targets for drug discovery efforts. PMID:24562907

  4. Heterogeneity of holocarboxylase synthetase in patients with biotin-responsive multiple carboxylase deficiency.

    OpenAIRE

    Burri, B J; Sweetman, L.; Nyhan, W L

    1985-01-01

    Holocarboxylase synthetase activity has been determined in fibroblasts of seven patients with the neonatal form of biotin-responsive multiple carboxylase deficiency. The normal Km for biotin was 15 +/- 3 nmol/l, while in the patients the values ranged from 48 to 1,062 nmol/l. The mean maximum velocity was 27% of normal. Differences among the values obtained for the Km for biotin and the heat stability of holocarboxylase synthetase suggested that the patients studied represented at least four ...

  5. Oligo-2',5'-adenylate synthetase activity in peripheral blood mononuclear leukocytes in various diseases.

    OpenAIRE

    Fujii, N; Kotake, S.; Hirose, S; Ohno, S; Yasuda, I.; Sagawa, A; Ishikawa, K.; Minagawa, T

    1984-01-01

    Interferon induces oligo-2',5'-adenylate synthetase in cells. In various diseases, interferon was detectable in the circulation or was produced spontaneously from peripheral blood mononuclear leukocytes. The oligo-2',5'-adenylate synthetase activity in peripheral blood mononuclear leukocytes was examined in various diseases, including systemic lupus erythematosus, sarcoidosis, Vogt-Koyanagi-Harada disease, and Behcet's disease. The activity of this enzyme was significantly increased in system...

  6. Latent KSHV Infected Endothelial Cells Are Glutamine Addicted and Require Glutaminolysis for Survival.

    Directory of Open Access Journals (Sweden)

    Erica L Sanchez

    2015-07-01

    Full Text Available Kaposi's Sarcoma-associated Herpesvirus (KSHV is the etiologic agent of Kaposi's Sarcoma (KS. KSHV establishes a predominantly latent infection in the main KS tumor cell type, the spindle cell, which is of endothelial cell origin. KSHV requires the induction of multiple metabolic pathways, including glycolysis and fatty acid synthesis, for the survival of latently infected endothelial cells. Here we demonstrate that latent KSHV infection leads to increased levels of intracellular glutamine and enhanced glutamine uptake. Depletion of glutamine from the culture media leads to a significant increase in apoptotic cell death in latently infected endothelial cells, but not in their mock-infected counterparts. In cancer cells, glutamine is often required for glutaminolysis to provide intermediates for the tri-carboxylic acid (TCA cycle and support for the production of biosynthetic and bioenergetic precursors. In the absence of glutamine, the TCA cycle intermediates alpha-ketoglutarate (αKG and pyruvate prevent the death of latently infected cells. Targeted drug inhibition of glutaminolysis also induces increased cell death in latently infected cells. KSHV infection of endothelial cells induces protein expression of the glutamine transporter, SLC1A5. Chemical inhibition of SLC1A5, or knockdown by siRNA, leads to similar cell death rates as glutamine deprivation and, similarly, can be rescued by αKG. KSHV also induces expression of the heterodimeric transcription factors c-Myc-Max and related heterodimer MondoA-Mlx. Knockdown of MondoA inhibits expression of both Mlx and SLC1A5 and induces a significant increase in cell death of only cells latently infected with KSHV, again, fully rescued by the supplementation of αKG. Therefore, during latent infection of endothelial cells, KSHV activates and requires the Myc/MondoA-network to upregulate the glutamine transporter, SLC1A5, leading to increased glutamine uptake for glutaminolysis. These findings

  7. Effects of acute exhaustive physical exercise upon glutamine metabolism of lymphocytes from trained rats.

    Science.gov (United States)

    Santos, Ronaldo Vagner Thomatieli; Caperuto, Erico Chagas; Costa Rosa, Luis Fernando Bicudo Pereira

    2007-01-16

    Transitory immunosupression is reported after intense exercise, especially after an increase in training overload and in overtraining. The influence of intense exercise on plasma hormones and glutamine concentration may contribute to this effect. However, the effect of such exercise-induced changes upon lymphocyte and glutamine metabolism is not known. We compared glutamine metabolism in lymphocytes in sedentary (SED) and trained rats. Rats from the moderate group (MOD) swam for 6 weeks, 1 h/day, in water at 32+/-1 degrees C, with a load of 5.5% body weight attached to the tail. Animals from the exhaustive group (EXT) trained like MOD, with training increasing to 3 times 1 h a day during the last week, with 150 min rest between each bout. Animals were killed immediately after the last training bout. We observed reduced concentrations of plasma glucose (pglutamine (pglutamine (pglutamine consumption (pglutamine consumption (pexercise promoted decreased glutamine plasma concentration and changes in glutamine metabolism that did not impair lymphocyte proliferation in exhaustive trained rats. PMID:17123550

  8. The effect of glutamine supplementation on the function of neutrophils from exercised rats.

    Science.gov (United States)

    Lagranha, Claudia Jacques; de Lima, Thais Martins; Senna, Sueli Moreno; Doi, Sonia Quatelli; Curi, Rui; Pithon-Curi, Tania Cristina

    2005-01-01

    In a recent publication, we showed the protective effect of glutamine on neutrophil apoptosis induced by acute exercise. The purpose of the present study was to examine the effect of a single bout of intensive exercise on rat neutrophil function and the possible effect of glutamine supplementation. An aqueous solution of glutamine was given by gavage (1 g per kg b.w.), 1 h before the exercise session. The exercise was carried out on a treadmill for 1 h at 85% VO2máx.. Neutrophils were obtained by intraperitoneal lavage with PBS. The following parameters were evaluated: phagocytosis capacity, production of nitric oxide and reactive oxygen metabolites, expression of iNOS, and expression of NADPH-oxidase components (p22phox, p47phox and gp91phox). One hour of exercise at 85% VO2max. induced no change in the phagocytosis capacity and reactive oxygen species production but decreased nitric oxide production. When rats received oral glutamine supplementation, the phagocytosis capacity was significantly increased, the decrease in nitric oxide production induced by exercise was abolished and production of reactive oxygen species was raised. Glutamine supplementation presents a significant effect on neutrophil function including changes induced by exercise. PMID:15617036

  9. Effect of total parenteral nutrition, systemic sepsis, and glutamine on gut mucosa in rats

    Science.gov (United States)

    Yoshida, S.; Leskiw, M. J.; Schluter, M. D.; Bush, K. T.; Nagele, R. G.; Lanza-Jacoby, S.; Stein, T. P.

    1992-01-01

    The effect of the combination of total parenteral nutrition (TPN) and systemic sepsis on mucosal morphology and protein synthesis was investigated. Rats were given a standard TPN mixture consisting of glucose (216 kcal.kg-1.day-1), lipid (24 kcal.kg-1.day-1), and amino acids (1.5 g N.kg-1.day-1) for 5 days. On the 5th day the rats (n = 37) were randomized into four groups according to diet as follows: 1) control nonseptic on standard TPN, 2) control nonseptic on TPN with glutamine, 3) septic on standard TPN, and 4) septic with the TPN supplemented with glutamine. Twenty hours after the injection of Escherichia coli, the rats were given a 4-h constant infusion of [U-14C]leucine to determine the mucosal fractional protein synthesis rates. The following results were obtained. 1) Histological examination showed that systemic sepsis caused tissue damage to the ileum and jejunum. 2) Glutamine supplementation attenuated these changes. 3) There were no visible changes to the colon either from glutamine supplementation or sepsis. 4) Sepsis was associated with an increase in mucosal protein synthesis and decreased muscle synthesis. 5) Addition of glutamine to the TPN mix further increased protein synthesis in the intestinal mucosa of septic rats.

  10. Glucose-independent glutamine metabolism via TCA cycling for proliferation and survival in B-cells

    Science.gov (United States)

    Le, Anne; Lane, Andrew N.; Hamaker, Max; Bose, Sminu; Gouw, Arvin; Barbi, Joseph; Tsukamoto, Takashi; Rojas, Camilio J.; Slusher, Barbara S.; Zhang, Haixia; Zimmerman, Lisa J.; Liebler, Daniel C.; Slebos, Robbert J.C.; Lorkiewicz, Pawel K.; Higashi, Richard M.; Fan, Teresa W. M.; Dang, Chi V.

    2012-01-01

    Summary Because MYC plays a causal role in many human cancers, including those with hypoxic and nutrient-poor tumor microenvironments, we have determined the metabolic responses of a MYC-inducible human Burkitt lymphoma model P493 cell line to aerobic and hypoxic conditions, and to glucose deprivation, using Stable Isotope Resolved Metabolomics. Using [U-13C]-glucose as the tracer, both glucose consumption and lactate production were increased by MYC expression and hypoxia. Using [U-13C,15N]-glutamine as the tracer, glutamine import and metabolism through the TCA cycle persisted under hypoxia, and glutamine contributed significantly to citrate carbons. Under glucose deprivation, glutamine-derived fumarate, malate, and citrate were significantly increased. Their 13C labeling patterns demonstrate an alternative energy-generating glutaminolysis pathway involving a glucose-independent TCA cycle. The essential role of glutamine metabolism in cell survival and proliferation under hypoxia and glucose deficiency, makes them susceptible to the glutaminase inhibitor BPTES, and hence could be targeted for cancer therapy. PMID:22225880

  11. Prevention of Radiochemotherapy-Induced Esophagitis With Glutamine: Results of a Pilot Study

    International Nuclear Information System (INIS)

    Purpose: To assess the usefulness of oral glutamine to prevent radiochemotherapy-induced esophagitis in patients with lung cancer, and to determine the dosimetric parameter predictive of esophagitis. Methods and Materials: Seventy-five patients were enrolled; 34.7% received sequential radiochemotherapy, and 65.3% received concomitant radiochemotherapy. Every patient received prophylactic glutamine powder in doses of 10 g/8 h. Prescribed radiation doses were 45-50 Gy to planning target volume (PTV)1 (gross tumor volume plus wide margins) and 65-70 Gy to PTV2 (reduced margins). The primary endpoint was the incidence of Grade 2 or greater acute esophagitis. Results: No patient experienced glutamine intolerance or glutamine-related toxicity. Seventy-three percent of patients who received sequential chemotherapy and 49% of those who received concomitant chemotherapy did not present any form of esophagitis. V50 was the dosimetric parameter with better correlation between esophagitis and its duration. A V50 of ≤30% had a 22% risk of esophagitis Grade ≥2, which increased to 71% with a V50 of >30% (p = 0.0009). Conclusions: The use of oral glutamine may have an important role in the prevention of esophageal complications of concomitant radiochemotherapy in lung cancer patients. However, randomized trials are needed to corroborate that effect. V50 is the dosimetric parameter with better correlation with esophagitis grade and duration

  12. Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment

    Science.gov (United States)

    Hu, Hong; Bai, Xi; Shah, Assar Ali; Dai, Sifa; Wang, Like; Hua, Jinling; Che, Chuanyan; He, Shaojun; Wen, Aiyou; Jiang, Jinpeng

    2016-06-01

    The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased ( P glutamine synthetase (GS) and gamma-aminobutyric acid transaminase (GABA-T) at 28, 35, and 42 days. Dietary Gln and GABA improved ( P < 0.05) DWG and DFC of broilers under cyclic HS during 28-42 days. In breast muscle, the Gln supplementation increased ( P < 0.05) the concentrations of Gln (28, 35, and 42 days), Glu (28, 35, and 42 days), and GABA (42 days) and the activities of glutaminase (28, 35, and 42 days) and GAD (28, 35, and 42 days) but decreased ( P < 0.05) GS activities at 28, 35, and 42 days and GABA-T activities at 28 days. The addition of GABA increased ( P < 0.05) the concentrations of Gln and Glu and activities of glutaminase and GAD, while it decreased ( P < 0.05) GABA-T activities at 28, 35, and 42 days. Significant interactions ( P < 0.05) between Gln and GABA were found on breast skeletal muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA metabolism of broilers.

  13. Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment

    Science.gov (United States)

    Hu, Hong; Bai, Xi; Shah, Assar Ali; Dai, Sifa; Wang, Like; Hua, Jinling; Che, Chuanyan; He, Shaojun; Wen, Aiyou; Jiang, Jinpeng

    2015-10-01

    The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased (P glutamine synthetase (GS) and gamma-aminobutyric acid transaminase (GABA-T) at 28, 35, and 42 days. Dietary Gln and GABA improved (P < 0.05) DWG and DFC of broilers under cyclic HS during 28-42 days. In breast muscle, the Gln supplementation increased (P < 0.05) the concentrations of Gln (28, 35, and 42 days), Glu (28, 35, and 42 days), and GABA (42 days) and the activities of glutaminase (28, 35, and 42 days) and GAD (28, 35, and 42 days) but decreased (P < 0.05) GS activities at 28, 35, and 42 days and GABA-T activities at 28 days. The addition of GABA increased (P < 0.05) the concentrations of Gln and Glu and activities of glutaminase and GAD, while it decreased (P < 0.05) GABA-T activities at 28, 35, and 42 days. Significant interactions (P < 0.05) between Gln and GABA were found on breast skeletal muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA metabolism of broilers.

  14. Activity of the lactate-alanine shuttle is independent of glutamate-glutamine cycle activity in cerebellar neuronal-astrocytic cultures

    DEFF Research Database (Denmark)

    Bak, Lasse K; Sickmann, Helle M; Schousboe, Arne;

    2004-01-01

    The glutamate-glutamine cycle describes the neuronal release of glutamate into the synaptic cleft, astrocytic uptake, and conversion into glutamine, followed by release for use as a neuronal glutamate precursor. This only explains the fate of the carbon atoms, however, and not that of the ammonia......]/[5-(15)N]glutamine (0.25 mM), and [(15)N]ammonia (0.3 mM) were used as precursors and cell extracts were analyzed by mass spectrometry. Labeling from [(15)N]alanine in glutamine, aspartate, and glutamate in cerebellar cocultures was independent of depolarization of the neurons. Employing glutamine...... with the amino group labeled ([2-(15)N]glutamine) as the precursor, an activity-dependent increase in the labeling of both glutamate and aspartate (but not alanine) was observed in the cerebellar neurons. When the amide group of glutamine was labeled ([5-(15)N]glutamine), no labeling could be detected...

  15. Deprive to kill: glutamine closes the gate to anticancer monocarboxylic drugs.

    Science.gov (United States)

    Cardaci, Simone; Ciriolo, Maria Rosa

    2012-12-01

    Killing properties of antitumor drugs can be enhanced by strategies targeting biochemical adaptations of cancer cells. Recently, we reported that depriving cancer cells of glutamine is a feasible approach to enhance antitumor effects of the alkylating analog of pyruvic acid, 3-bromopyruvate, which rely on the induction of autophagic cell death by metabolic-oxidative stress. 3-bromopyruvate chemopotentiation is the result of its increased intracellular uptake mediated by the monocarboxylate transporter 1, whose expression is post-transcriptionally increased upon glutamine withdrawal. Overall, our results identified the metabolic condition able to increase the selectivity of 3-bromopyruvate targets in neoplastic tissues, thereby providing a stage for its use in clinical settings for targeting malignancies and represent a proof of principle that modulation of glutamine availability can influence the delivery of monocarboxylic drugs into tumors. PMID:22932475

  16. Cerebral glutamine concentration and lactate-pyruvate ratio in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, P.N.; Hauerberg, J.; Frederiksen, Hans-Jørgen;

    2008-01-01

    pressure (CPP). RESULTS: The cerebral glutamine concentration was 4,396 (1,011-9,712) microM, lactate 2.15 (1.1-4.45) mM, and pyruvate 101 (43-255) microM. The lactate-pyruvate ratio was 21 (16-40), ICP 20 (2-28) mmHg, and CPP 72 (56-115) mmHg. Cerebral glutamine concentration correlated with the lactate......-pyruvate ratio (r = 0.89, P < 0.05). Also the ICP, but not CPP, correlated to the lactate-pyruvate ratio (r = 0.64, P < 0.05). CONCLUSION: ICP and the cerebral glutamine concentration in patients with ALF correlate to the lactate-pyruvate ratio. Since CPP was sufficient in all patients the rise in lactate...

  17. Reduced parietooccipital white matter glutamine measured by proton magnetic resonance spectroscopy in treated graves' disease patients

    DEFF Research Database (Denmark)

    Danielsen, Else Rubæk; Elberling, T.V.; Rasmussen, Åse Krogh;

    2008-01-01

    battery of biochemical, affective, and cognitive tests were used. RESULTS: Previously reported findings of reduced choline and myo-inositol in acute Graves' disease were confirmed and reversibility was demonstrated. Parieto-occipital white matter glutamine was and remained significantly reduced (P < 0.......01). Acute phase parieto-occipital white matter total choline correlated significantly (r = -0.57; P < 0.01) with impaired thyroid function. Pretreatment total T(3) predicted posttreatment occipital gray matter glutamine (r = -0.52; P < 0.01). Occipital gray matter total choline (r = -0.53; P < 0.01) and...... parietooccipital white matter glutamate (r = -0.54; P < 0.01) correlated with initial values of selected attention and concentration cognitive scores and predicted them at follow-up. CONCLUSIONS: The persistent reduction of glutamine in white matter, the decreasing glutamate in occipital gray matter, and the...

  18. Knockout of GAD65 has major impact on synaptic GABA synthesized from astrocyte-derived glutamine

    DEFF Research Database (Denmark)

    Walls, Anne Byriel; Eyjolfsson, Elvar M.; Smeland, Olav B.;

    2011-01-01

    65 for maintenance of the highly compartmentalized intracellular and intercellular GABA homeostasis, GAD65 knockout and corresponding wild-type mice were injected with [1-(13)C]glucose and the astrocyte-specific substrate [1,2-(13)C]acetate. Synthesis of GABA from glutamine in the GABAergic synapses...... cortex and hippocampus. The GABA content in both brain regions was reduced by ∼20%. Moreover, it was revealed that GAD65 is crucial for maintenance of biosynthesis of synaptic GABA particularly by direct synthesis from astrocytic glutamine via glutamate. The GAD67 was found to be important for synthesis...... of GABA from glutamine both via direct synthesis and via a pathway involving mitochondrial metabolism. Furthermore, a severe neuronal hypometabolism, involving glycolysis and tricarboxylic acid (TCA) cycle activity, was observed in cerebral cortex of GAD65 knockout mice....

  19. Glutamine methylation in histone H2A is an RNA-polymerase-I-dedicated modification

    DEFF Research Database (Denmark)

    Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C;

    2014-01-01

    Nucleosomes are decorated with numerous post-translational modifications capable of influencing many DNA processes. Here we describe a new class of histone modification, methylation of glutamine, occurring on yeast histone H2A at position 105 (Q105) and human H2A at Q104. We identify Nop1 as the...... methyltransferase in yeast and demonstrate that fibrillarin is the orthologue enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using an H2AQ105me-specific antibody, shows that this modification is exclusively enriched over the 35S ribosomal DNA...... and increased transcription at the ribosomal DNA locus. These features are phenocopied by mutations in FACT complex components. Together these data identify glutamine methylation of H2A as the first histone epigenetic mark dedicated to a specific RNA polymerase and define its function as a regulator...

  20. The utilization of glutamine by the retina: an autoradiographic and metabolic study

    International Nuclear Information System (INIS)

    The cells able to accumulate exogenously applied [3H] glutamine in rat, cat, frog, pigeon and guinea pig retinas have been located by autoradiography, and the fate of the labelled glutamine, as regards its incorporation into aspartic, glutamic and γ-amino-butyric acids, followed for 60 min. The results support the notion of glutamine as a precursor of transmitter amino acids in some neurones. In particular, it would appear to be a source of a relatively stable pool of GABA which may be located, with species variation, in amacrine or ganglion cells. In the pigeon retina glutamate pool incorporates and retains a major percentage of the label, and perikarya in the middle of the inner nuclear layer of the tissue are predominantly labelled. (author)

  1. The gene encoding human glutathione synthetase (GSS) maps to the long arm of chromosome 20 at band 11.2

    Energy Technology Data Exchange (ETDEWEB)

    Webb, G.C.; Vaska, V.L.; Ford, J.H. [Queen Elizabeth Hospital, Woodville (Australia)] [and others

    1995-12-10

    Two forms of glutathione synthetase deficiency have been described. While one form is mild, causing hemolytic anemia, the other more severe form causes 5-oxoprolinuria with secondary neurological involvement. Despite the existence of two deficiency phenotypes, Southern blots hybridized with a glutathione synthetase cDNA suggest that there is a single glutathione synthetase gene in the human genome. Analysis of somatic cell hybrids showed the human glutathione synthetase gene (GSS) to be located on chromosome 20, and this assignment has been refined to subband 20q11.2 using in situ hybridization. 16 refs., 2 figs.

  2. Dose intercomparison for 400–500 keV electrons using FWT-60 film and glutamine (spectrophotometric readout) dosimeters

    DEFF Research Database (Denmark)

    Gupta, B. L.; Nilekani, S. R.; Gehringer, P.;

    1986-01-01

    This paper describes the dose and the depth dose measurements with FWT-60 film and glutamine (Spectrophotometric readout) dosimeters for 400–500 keV electrons. The glutamine powder was spread uniformly in polyethylene bags and the powder thickness in each bag was 5 mg cm−2. Both techniques show a...

  3. Repression of nitrogen catabolic genes by ammonia and glutamine in nitrogen-limited continuous cultures of Saccharomyces cerevisiae

    NARCIS (Netherlands)

    ter Schure, E G; Silljé, H H; Vermeulen, E E; Kalhorn, J W; Verkleij, A J; Boonstra, J; Verrips, C T

    1998-01-01

    Growth of Saccharomyces cerevisiae on ammonia and glutamine decreases the expression of many nitrogen catabolic genes to low levels. To discriminate between ammonia- and glutamine-driven repression of GAP1, PUT4, GDH1 and GLN1, a gln1-37 mutant was used. This mutant is not able to convert ammonia in

  4. Standard enthalpy of formation of L-glutamine and the products of its dissociation in aqueous solutions

    Science.gov (United States)

    Kochergina, L. A.; Lytkin, A. I.; Krutova, O. N.; Damrina, K. V.

    2014-03-01

    Heat effects of the dissolution of crystalline L-glutamine in water and lithium hydroxide solutions were determined by direct calorimetry at 298.15 K. Standard enthalpies of formation of L-glutamine and the products of its dissociation in aqueous solution were calculated.

  5. Acute liver failure in rats activates glutamine-glutamate cycle but declines antioxidant enzymes to induce oxidative stress in cerebral cortex and cerebellum.

    Directory of Open Access Journals (Sweden)

    Santosh Singh

    Full Text Available BACKGROUND AND PURPOSE: Liver dysfunction led hyperammonemia (HA causes a nervous system disorder; hepatic encephalopathy (HE. In the brain, ammonia induced glutamate-excitotoxicity and oxidative stress are considered to play important roles in the pathogenesis of HE. The brain ammonia metabolism and antioxidant enzymes constitute the main components of this mechanism; however, need to be defined in a suitable animal model. This study was aimed to examine this aspect in the rats with acute liver failure (ALF. METHODS: ALF in the rats was induced by intraperitoneal administration of 300 mg thioacetamide/Kg. b.w up to 2 days. Glutamine synthetase (GS and glutaminase (GA, the two brain ammonia metabolizing enzymes vis a vis ammonia and glutamate levels and profiles of all the antioxidant enzymes vis a vis oxidative stress markers were measured in the cerebral cortex and cerebellum of the control and the ALF rats. RESULTS: The ALF rats showed significantly increased levels of ammonia in the blood (HA but little changes in the cortex and cerebellum. This was consistent with the activation of the GS-GA cycle and static levels of glutamate in these brain regions. However, significantly increased levels of lipid peroxidation and protein carbonyl contents were consistent with the reduced levels of all the antioxidant enzymes in both the brain regions of these ALF rats. CONCLUSION: ALF activates the GS-GA cycle to metabolize excess ammonia and thereby, maintains static levels of ammonia and glutamate in the cerebral cortex and cerebellum. Moreover, ALF induces oxidative stress by reducing the levels of all the antioxidant enzymes which is likely to play important role, independent of glutamate levels, in the pathogenesis of acute HE.

  6. Protective effect of glutamine pretreatment on ischemia-reperfusion injury of spinal cord in rabbits

    Institute of Scientific and Technical Information of China (English)

    Shou-ping Gong; Da-lin Zhong; Jian Lü; Wen-tao Wang; Gang Xu; Qian Song; Feng Wu; Jin Che; Zhi-yuan Seng; Xi-jing He

    2009-01-01

    Objective To investigate the effect of glutamine (Gln) on the content of reduced glutathione hormone (GSH) and aminoglutaminic acid (Glu) of spinal cord following ischemia-reperfusion injury. Methods Totally 40 healthy adult male rabbits were randomly divided into five groups: sham-operation group (S group), ischemia-reperfusion injury group (I/R group), low-dose glutamine group (L Gln group), median-dose glutamine group (M Gln group) and high-dose glutamine group (H Gln group). After glutamine preconditioning, the model of spinal cord ischemia-reporfasion injury was established according to Zivin's method. The general status of animals was observed and the changes of Jacobs scoring were recorded in each group. Malondialdehydes (MDA), GSH, Glu and superoxide dismutase (SOD) activity in lumbar spinal cord tissues were determined using chemical colorimetry. The neuron number and deviation rate in spinal cord anterior horn were observed histopathologically. Results There was no significant difference between L Gin group and I/R group in behavior scoring, SOD activity, content of MDA and Glu, neuron number and deviation rate of spinal cord (P>0.05); however, there was a significant difference in GSH content of spinal cord (P0.05), whereas there was a significant difference in SOD activity and Giu content (P<0.05). Conclusion Pretreatment with medium-dose glutamine has a protective effect on spinal cord ischemia-reporfasion injury in rabbits, which may be related to the maintenance of GSH content, increase of SOD activity and reduction of MDA.

  7. Effect of exercise on glutamine metabolism in macrophages of trained rats.

    Science.gov (United States)

    dos Santos, Ronaldo Vagner Thomatieli; Caperuto, Erico Chagas; de Mello, Marco Túlio; Costa Rosa, Luis Fernando Bicudo Pereira

    2009-10-01

    This study investigated the effect of exercise on glutamine metabolism in macrophages of trained rats. Rats were divided into three groups: sedentary (SED); moderately trained (MOD) rats that were swim trained 1 h/day, 5 days/week for 6 weeks; and exhaustively trained (EXT) rats that were similarly trained as MOD for 5 weeks and, in the 6th week, trained in three 1-h sessions/day with 150 min of rest between sessions. The animals swam with a load equivalent to 5.5% of their body weight and were killed 1 h after the last exercise session. Cells were collected, and glutamine metabolism in macrophage and function were assayed. Exercise increased phagocytosis in MOD when compared to SED (34.48 +/- 1.79 vs 15.21 +/- 2.91%, P Glutamine consumption increased in MOD and EXT (26.53 +/- 3.62 and 19.82 +/- 2.62 nmol h x 10(5) cell(-1), respectively) relative to SED (6.72 +/- 0.57 nmol h x 10(5) cell(-1), P Glutamine decarboxylation was increased in MOD (12.10 +/- 0.27 nmol h x 10(5) cell(-1)) and EXT (16.40 +/- 2.17 nmol h x 10(5) cell(-1)) relative to SED (1.10 +/- 0.06 nmol h x 10(5) cell(-1), P exercise, which was supported by enhanced glutamine consumption and metabolism, and highlights the importance for glutamine after exercise. PMID:19609552

  8. L-Arginine but not L-glutamine likely increases exogenous carbohydrate oxidation during endurance exercise.

    Science.gov (United States)

    Rowlands, David S; Clarke, Jim; Green, Jackson G; Shi, Xiaocai

    2012-07-01

    The addition of L-arginine or L-glutamine to glucose-electrolyte solutions can increase intestinal water, glucose, and sodium absorption in rats and humans. We evaluated the utility of L-arginine and L-glutamine in energy-rehydration beverages through assessment of exogenous glucose oxidation and perceptions of exertion and gastrointestinal distress during endurance exercise. Eight cyclists rode 150 min at 50% of peak power on four occasions while ingesting solutions at a rate of 150 mL 15 min(-1) that contained (13)C-enriched glucose (266 mmol L(-1)) and sodium citrate ([Na(+)] 60 mmol L(-1)), and either: 4.25 mmol L(-1) L-arginine or 45 mmol L(-1) L-glutamine, and as controls glucose only or no glucose. Relative to glucose only, L-arginine invoked a likely 12% increase in exogenous glucose oxidation (90% confidence limits: ± 8%); however, the effect of L-glutamine was possibly trivial (4.5 ± 7.3%). L-Arginine also led to very likely small reductions in endogenous fat oxidation rate relative to glucose (12 ± 4%) and L-glutamine (14 ± 4%), and relative to no glucose, likely reductions in exercise oxygen consumption (2.6 ± 1.5%) and plasma lactate concentration (0.20 ± 0.16 mmol L(-1)). Effects on endogenous and total carbohydrate oxidation were inconsequential. Compared with glucose only, L-arginine and L-glutamine caused likely small-moderate effect size increases in perceptions of stomach fullness, abdominal cramp, exertion, and muscle tiredness during exercise. Addition of L-arginine to a glucose and electrolyte solution increases the oxidation of exogenous glucose and decreases the oxygen cost of exercise, although the mechanisms responsible and impact on endurance performance require further investigation. However, L-arginine also increases subjective feelings of gastrointestinal distress, which may attenuate its other benefits. PMID:22048324

  9. Dual-emitting biosensors for glucose and glutamine from genertically engineered E. coli binding proteins

    Science.gov (United States)

    Tolosa, Leah; Ge, Xudong; Kostov, Yordan; Lakowicz, Joseph R.; Rao, Govind

    2003-07-01

    Glucose is the major source of carbon, and glutamine is the major source of nitrogen in cell culture media. Thus, glucose and glutamine monitoring are important in maintaining optimal conditions in industrial bioprocesses. Here we report reagentless glucose and glutamine sensors using the E. coli glucose binding protein (GBP) and the glutamine binding protein (GlnBP). Both of these proteins are derived from the permease system of the gram-negative bacteria. The Q26C variant of GBP was labeled at the 26-position with anilino-naphthalene sulfonate (ANS), while the S179C variant of GlnBP was labeled at the 179-position with acrylodan. The ANS and acrylodan emissions are quenched in the presence of glucose and glutamine, respectively. The acrylodan-labeled GlnBP was labeled at the N-terminal with ruthenium bis-(2,2"-bipyridyl)-1,10-phenanthroline-9-isothiocyanate. The ruthenium acts as a non-responsive long-lived reference. The apparent binding constant, Kd", of 8.0 μM glucose was obtained from the decrease in intensity of ANS in GBP. The reliability of the method in monitoring glucose during yeast fermentation was determined by comparison with the YSI Biochemistry Analyzer. The apparent binding constant, Kd", of 0.72 μM glutamine was calculated from the ratio of emission intensities of acrylodan and ruthenium (I515/I610) in GlnBP. The presence of the long-lived ruthenium allowed for modulation sensing at lower frequencies (1-10 MHz) approaching an accuracy of +/- 0.02 μM. The conversion of the GBP into a similar ratiometric sensor was described.

  10. Effect of dietary glutamine supplementation on Salmonella colonization in the ceca of young broiler chicks.

    Science.gov (United States)

    Fasina, Y O; Bowers, J B; Hess, J B; McKee, S R

    2010-05-01

    Live poultry is an important vehicle for transmitting Salmonella Typhimurium to humans that have salmonellosis. It is therefore imperative to reduce Salmonella Typhimurium levels in the gastrointestinal tract of live chickens. Glutamine is an established immunonutrient that is capable of alleviating disease conditions in humans and rats. Thus, 2 experiments that used Ross broiler chicks were conducted to evaluate the effect of glutamine supplementation at 1% level of the diet on cecal Salmonella Typhimurium levels in young broiler chicks. Experiment 1 consisted of i) treatment 1 (control, CN), in which chicks were given an unmedicated corn-soybean meal basal starter diet without glutamine supplementation or Salmonella Typhimurium challenge; ii) treatment 2 (CST), in which chicks were given the same diet as CN but challenged with 3.6 x 10(6) cfu Salmonella Typhimurium/mL at 3 d of age; and iii) treatment 3 (GST), in which chicks were given the unmedicated corn-soybean meal basal starter diet supplemented with glutamine at 1% level, and challenged with 3.6 x 10(6) cfu at 3 d of age. Experiment 2 used similar treatments (CN, CST, and GST), except that chicks in CST and GST were challenged with 7.4 x 10(7) cfu Salmonella Typhimurium/mL, and a fourth treatment was added. The fourth treatment consisted of chicks that were not challenged with Salmonella Typhimurium but given the same diet as in GST. Duration of each experiment was 14 d. Growth performance of chicks was monitored weekly, and cecal Salmonella Typhimurium concentration was microbiologically enumerated on d 4, 10, or 11 postchallenge. Results showed that glutamine supplementation improved BW and BW gain in experiment 2 (P 0.05). The optimum supplemental level of glutamine that will enhance intestinal resistance to Salmonella Typhimurium colonization should be determined. PMID:20371858

  11. Protective effects of l-glutamine against toxicity of deltamethrin in the cerebral tissue

    Science.gov (United States)

    Varol, Sefer; Özdemir, Hasan Hüseyin; Çevik, Mehmet Uğur; Altun, Yaşar; Ibiloğlu, Ibrahim; Ekinci, Aysun; Ibiloğlu, Aslıhan Okan; Balduz, Metin; Arslan, Demet; Tekin, Recep; Aktar, Fesih; Aluçlu, Mehmet Ufuk

    2016-01-01

    Background Deltamethrin (DLM) is a broad-spectrum synthetic dibromo-pyrethroid pesticide that is widely used for agricultural and veterinary purposes. However, human exposure to the pesticide leads to neurotoxicity. Glutamine is one of the principal, free intracellular amino acids and may also be an antioxidant. This study was undertaken in order to examine the neuroprotective and antioxidant potential of l-glutamine against DLM toxicity in female Wistar albino rats. Materials and methods The rats were divided into the following groups (n=10): Group I: control (distilled water; 10 mL/kg, po one dose), Group II: l-glutamine (1.5 g/kg, po one dose), Group III: DLM (35 mg/kg, po one dose), and Group IV: DLM (35 mg/kg, po one dose) and l-glutamine (1.5 g/kg, po one dose after 4 hours). Total oxidant status (TOS), total antioxidant status (TAS), tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 levels and apoptosis were evaluated in brain tissue. Results DLM-treated animals had a significant increase in brain biochemical parameters, as well as TOS and TAS. Furthermore, the histopathological examination showed neuronal cell degeneration in the cerebral tissue. l-Glutamine treatment decreased the elevated brain levels of TOS and neuronal cell degeneration. There was no difference in tumor necrosis factor-α, IL-1β, and IL-6 levels between the groups. Conclusion l-Glutamine may reduce the toxic effects of DLM in the cerebral tissue through antioxidant properties. PMID:27143900

  12. Oral glutamine to alleviate radiation-induced oral mucositis: a pilot randomized trial

    International Nuclear Information System (INIS)

    Purpose: To evaluate the influence of oral glutamine on radiation-induced oral mucositis in the radiotherapy of head and neck cancer. Methods and Materials: From July 1997 through June 1998, 17 patients with head and neck cancer receiving primary or adjuvant irradiation were randomized to either glutamine suspension (16 g in 240 ml normal saline) (n = 8) or placebo (normal saline) (n = 9) arm. Patients were instructed to swish the test solutions (30 ml) four times per day. All patients received half-mouth irradiation at least. Patients were treated 1.8 Gy per fraction daily, 5 days a week. We evaluated the grading of oral mucositis daily fraction at each day of treatment until 45 Gy/25 fractions. World Health Organization (WHO) step analgesic medication and body weight change were compared between the two arms. Results: The duration of objective oral mucositis ≥ Grade 1 (p 0.0097), Grade 2 (p = 0.0232), and Grade 3 (p = 0.0168) was shorter in the glutamine arm. Mean maximum grade of objective oral mucositis was less severe in the glutamine arm (1.6 vs. 2.6) (p = 0.0058). Glutamine did not reduce the duration and severity of subjective oral mucositis except for duration ≥ Grade 3 (p = 0.0386). In the analysis of mean maximum WHO step of analgesic medication, there was no statistical difference (p = 0.5374) between the two arms. Mean body weight change was also not significantly different (p 0.8070). Conclusions: Oral glutamine may significantly reduce the duration and severity of objective oral mucositis during radiotherapy. It may shorten the duration of ≥ Grade 3 subjective mucositis

  13. Chitin synthetase in encysting Giardia lamblia and Entamoeba invadens

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.; Gillin, F.D.

    1987-05-01

    Giardia lamblia (Gl) and Entamoeba invadens (Ei) are protozoan parasites with two morphologic stages in their life cycles. Motile trophozoites colonize the intestine of humans and reptiles respectively. Water resistant cysts, which can survive outside the host, transmit infection. In vitro cyst formation of Ei from trophozoites has been reported, and the authors have recently induced in vitro encystation of Gl. Although the cyst walls of both parasites contain chitin, it synthesis by encysting trophozoites has not been reported. The authors now show that encystation conditions greatly increase chitin synthetase (CS) specific activity (incorporation of /sup 3/H GlcNAc from UDP-GlcNAc into TCA-or alcohol-precipitable material). Extracts of encysting Gl incorporated 3.6 nmol/mg protein in 5 hr compared to < 0.005 in controls. Extracts of encysting Fi incorporated 4.8 n mol/mg protein, compared to 1.7 in the control. CS activity of both parasites requires preformed chitin. The Gl enzyme requires a reducing agent, is inhibited by digitonin and the CS inhibitors, polyoxin D and Nikkomycin, but not by tunicamycin. The product is digested by chitinase. Ei enzyme does not require a reducing agent and is stimulated by 1 mg/ml digitonin, but inhibited by higher concentrations. These studies demonstrate CS enzymes which may play important roles in encystation of Gl and Ei.

  14. Chitin synthetase in encysting Giardia lamblia and Entamoeba invadens

    International Nuclear Information System (INIS)

    Giardia lamblia (Gl) and Entamoeba invadens (Ei) are protozoan parasites with two morphologic stages in their life cycles. Motile trophozoites colonize the intestine of humans and reptiles respectively. Water resistant cysts, which can survive outside the host, transmit infection. In vitro cyst formation of Ei from trophozoites has been reported, and the authors have recently induced in vitro encystation of Gl. Although the cyst walls of both parasites contain chitin, it synthesis by encysting trophozoites has not been reported. The authors now show that encystation conditions greatly increase chitin synthetase (CS) specific activity (incorporation of 3H GlcNAc from UDP-GlcNAc into TCA-or alcohol-precipitable material). Extracts of encysting Gl incorporated 3.6 nmol/mg protein in 5 hr compared to < 0.005 in controls. Extracts of encysting Fi incorporated 4.8 n mol/mg protein, compared to 1.7 in the control. CS activity of both parasites requires preformed chitin. The Gl enzyme requires a reducing agent, is inhibited by digitonin and the CS inhibitors, polyoxin D and Nikkomycin, but not by tunicamycin. The product is digested by chitinase. Ei enzyme does not require a reducing agent and is stimulated by 1 mg/ml digitonin, but inhibited by higher concentrations. These studies demonstrate CS enzymes which may play important roles in encystation of Gl and Ei

  15. The aminoacyl-tRNA synthetases of Drosophila melanogaster.

    Science.gov (United States)

    Lu, Jiongming; Marygold, Steven J; Gharib, Walid H; Suter, Beat

    2015-01-01

    Aminoacyl-tRNA synthetases (aaRSs) ligate amino acids to their cognate tRNAs, allowing them to decode the triplet code during translation. Through different mechanisms aaRSs also perform several non-canonical functions in transcription, translation, apoptosis, angiogenesis and inflammation. Drosophila has become a preferred system to model human diseases caused by mutations in aaRS genes, to dissect effects of reduced translation or non-canonical activities, and to study aminoacylation and translational fidelity. However, the lack of a systematic annotation of this gene family has hampered such studies. Here, we report the identification of the entire set of aaRS genes in the fly genome and we predict their roles based on experimental evidence and/or orthology. Further, we propose a new, systematic and logical nomenclature for aaRSs. We also review the research conducted on Drosophila aaRSs to date. Together, our work provides the foundation for further research in the fly aaRS field. PMID:26761199

  16. Nitric oxide synthetase and Helicobacter pylori in patients undergoing appendicectomy.

    LENUS (Irish Health Repository)

    Kell, M R

    2012-02-03

    BACKGROUND: This study was designed to determine whether Helicobacter pylori forms part of the normal microenvironment of the appendix, whether it plays a role in the pathogenesis of acute appendicitis, and whether it is associated with increased expression of inducible nitric oxide synthetase (iNOS) in appendicular macrophages. METHODS: Serology for H. pylori was performed on 51 consecutive patients undergoing emergency appendicectomy. Appendix samples were tested for urease activity, cultured and stained for H. pylori, graded according to the degree of inflammatory infiltrate, and probed immunohistochemically for iNOS expression. RESULTS: The mean age of the patients was 21 (range 7-51) years. Seventeen patients (33 per cent) were seropositive for H. pylori but no evidence of H. pylori was found in any appendix specimen. However, an enhanced inflammatory cell infiltration was observed in seropositive patients (P < 0.04) and the expression of macrophage iNOS in the mucosa of normal and inflamed appendix specimens was increased (P < 0.01). CONCLUSION: H. pylori does not colonize the appendix and is unlikely to be a pathogenic stimulus for appendicitis. Priming effects on mucosal immunology downstream from the foregut may occur after infection with H. pylori.

  17. Is there a role for glutamine supplementation in the management of acute pancreatitis?

    Science.gov (United States)

    Castro-Gutiérrez, Victoria; Rada, Gabriel

    2016-01-01

    There is no consensus about the effects of glutamine supplementation for acute pancreatitis. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified 15 systematic reviews including 31 randomized controlled trials addressing the question of this article. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded glutamine supplementation might decrease infectious complications in acute pancreatitis, but it is not clear if it affects mortality or length of hospital stay because the certainty of the evidence is very low. PMID:27580296

  18. Effects of glutamine and curcumin on bacterial translocation in jaundiced rats

    Institute of Scientific and Technical Information of China (English)

    Oguzhan; Karatepe; Ersin; Acet; Muharrem; Battal; Gokhan; Adas; Ahu; Kemik; Merih; Altiok; Gulcin; Kamali; Safiye; Koculu; Atahan; Catay; Sedat; Kamali; Servet; Karahan

    2010-01-01

    AIM: To investigate the effect of curcumin on bacterial translocation and oxidative damage in an obstructive jaundice model and compare the results to glutamine, an agent known to be effective and clinically used. METHODS: Twenty-four female Wistar-Albino rats, weighing 200-250 g, were randomly divided into three groups (8 in each group). After ligation of the common bile duct in all animals, GroupⅠ received oral normal saline, Group Ⅱ received oral glutamine and Group Ⅲ received oral curcumin for seven day...

  19. Effects of Glutamine on Glycemic Control During and After Exercise in Adolescents With Type 1 Diabetes

    OpenAIRE

    Mauras, Nelly; Xing, Dongyuan; Fox, Larry A.; Englert, Kim; Darmaun, Dominique

    2010-01-01

    OBJECTIVE To investigate if oral glutamine ameliorates exercise and postexercise nighttime hypoglycemia in type 1 diabetic adolescents. RESEARCH DESIGN AND METHODS Ten adolescents (15.2 ± 1.4 years [SD], A1C 6.9 ± 0.9%) on insulin pumps were studied. The subjects were randomized to receive a glutamine or placebo drink pre-exercise and at bedtime (0.25 g/kg/dose). A 3:00 p.m. exercise session consisted of four 15-min treadmill/5-min rest cycles. Pre-exercise blood glucose was 140–150 mg/dl and...

  20. Effects of glutamine and curcumin on bacterial translocation in jaundiced rats

    OpenAIRE

    Oguzhan Karatepe, Ersin Acet, Muharrem Battal, Gokhan Adas, Ahu Kemik, Merih Altiok, Gulcin Kamali, Safiye Koculu, Atahan Cagatay, Sedat Kamali, Servet Karahan

    2010-01-01

    AIM: To investigate the effect of curcumin on bacterial translocation and oxidative damage in an obstructive jaundice model and compare the results to glutamine, an agent known to be effective and clinically used.METHODS: Twenty-four female Wistar-Albino rats, weighing 200-250 g, were randomly divided into three groups (8 in each group). After ligation of the common bile duct in all animals, Group I received oral normal saline, Group II received oral glutamine and Group III received oral curc...

  1. Hypoosmotic swelling modifies glutamate-glutamine cycle in the cerebral cortex and in astrocyte cultures

    OpenAIRE

    Hyzinski-García, María C.; Vincent, Melanie Y.; Haskew-Layton, Renée E.; Dohare, Preeti; Keller, Richard W.; Mongin, Alexander A.

    2011-01-01

    In our previous work, we found that perfusion of the rat cerebral cortex with hypoosmotic medium triggers massive release of the excitatory amino acid L-glutamate but decreases extracellular levels of L-glutamine (R.E. Haskew-Layton et al., PLoS ONE, 3: e3543). The release of glutamate was linked to activation of volume-regulated anion channels (VRAC), while mechanism(s) responsible for alterations in extracellular glutamine remained unclear. When mannitol was added to the hypoosmotic medium ...

  2. Effects of Glutamine Supplementation on Patients Undergoing Abdominal Surgery

    Institute of Scientific and Technical Information of China (English)

    Yue-ping Fan; Jian-chun Yu; Wei-ming Kang; Qun Zhang

    2009-01-01

    Objective To evaluate the effects of supplementation of glutamine (GLN) on maintaining glutathione (GSH) level, immune system function, liver function, and clinical outcome of patients receiving abdominal operation. Methods Forty patients undergoing elective abdominal surgical treatment were randomly divided into 2 groups: study group (n = 20) and control group (n = 20). All patients received total parenteral nutrition (TPN) for up to 7 days during perioperative period. The study group received TPN supplemented with GLN dipeptide while the control group received TPN without GLN dipeptide. Patients in both groups received equivalent nitrogen and caloric intake. Blood sample was taken on preoperative day, and the 1st, 3rd, 6th postoperative day to measure GSH level, immune indexes, and liver function indexes. Results The decrease of GSH level in plasma and red blood cell (RBC) in study group was less than that in control group during postoperative period. Ratio of GSH/glutathione disulfide (GSSG) in plasma in study group was higher than that in control group on the 3rd postoperative day (52.53 ± 11.46 vs. 31.43 ± 7.27, P = 0.001). Albumin level in study group was higher than that in control group on the 3rd postoperative day (37.7 ± 3.8 g/L vs. 33.8 ± 4.2 g/L, P = 0.02). There was no significant difference in the levels of immunoglobin (IgG, IgM, IgA) or T lymphocyte subgroup (CD4, CD8, CD4/CD8) in both groups during postoperative period. There was one case with infectious complication in control group, while none in study group. A trend of shortened hospital stay was observed in study group compared with control group (22.3 ± 2.1 d vs. 24.9 ± 1.7 d, P = 0.32). Conclusions Supplementation of GLN-enriched TPN has beneficial effects on maintaining GSH levels in plasma and RBC, sustaining GSH/GSSG ratio and albumin level, and keeping antioxidant abilities during postoperative period in patients with abdominal operation, with the trends of decreasing incidence of

  3. Urinary Metabolomic Approach Provides New Insights into Distinct Metabolic Profiles of Glutamine and N-Carbamylglutamate Supplementation in Rats.

    Science.gov (United States)

    Liu, Guangmang; Cao, Wei; Fang, Tingting; Jia, Gang; Zhao, Hua; Chen, Xiaoling; Wu, Caimei; Wang, Jing

    2016-01-01

    Glutamine and N-carbamylglutamate can enhance growth performance and health in animals, but the underlying mechanisms are not yet elucidated. This study aimed to investigate the effect of glutamine and N-carbamylglutamate supplementation in rat metabolism. Thirty rats were fed a control, glutamine, or N-carbamylglutamate diet for four weeks. Urine samples were analyzed by nuclear magnetic resonance (NMR)-based metabolomics, specifically high-resolution ¹H NMR metabolic profiling combined with multivariate data analysis. Glutamine significantly increased the urine levels of acetamide, acetate, citrulline, creatinine, and methymalonate, and decreased the urine levels of ethanol and formate (p glutamine and N-carbamylglutamate could modify urinary metabolome related to nitrogen metabolism and gut microbiota metabolism. Moreover, N-carbamylglutamate could alter energy and lipid metabolism. These findings indicate that different arginine precursors may lead to differences in the biofluid profile in rats. PMID:27527211

  4. Electron paramagnetic resonance study of free radicals in γ-irradiated L-glutamine and L-glutamine-t-butyl ester hydrochloride

    Science.gov (United States)

    Yeşim Dicle, Işık; Osmanğolu, Şemsettin; İpek, Nazenin

    2015-01-01

    Electron paramagnetic resonance (EPR) spectra of γ-irradiated single crystals of l-glutamine (LG) and l-glutamine-t-butyl ester hydrochloride (LGBESHCI) powders were studied and analyzed for different orientations of the crystals in the magnetic field, after γ-irradiation. The spectra were observed to be independent of temperature down to 130 K. The hyperfine interaction tensors for one α proton and two β protons of radical have been determined at 295 K. An analysis of the EPR of γ-irradiated single crystals of LG and LGBESHCI powders shows that the paramagnetic species produced by the radiation damage is CH2ĊH. The g values of the radical and the hyperfine structure constants of the free electron with nearby protons and 14N nucleus were determined. The results were found to be in good agreement with the existing literature data.

  5. Effects of acetylsalicylic acid (ASA), ASA plus L-glutamine and L-glutamine on healing of chronic gastric ulcer in the rat.

    Science.gov (United States)

    Okabe, S; Takeuchi, K; Honda, K; Takagi, K

    1976-01-01

    A chronic gastric ulcer model was produced in rats by the subserosal injection of 20% acetic acid solution (0.015 ml) in order to examine whether (1) acetylsalicylic acid (ASA) irritates the chronic gastric ulcer in active or healed or diminished stage, (2) L-glutamine, given together with ASA, inhibits the adverse effect of ASA. Oral ASA 200 mg/kg/day, given in two divided doses for 10 consecutive days, apparently delayed the healing of the gastric ulcer and irritated the healed ulcer to reulcerate. L-Glutamine, 1,500 mg/kg/day, which was given together with ASA in two divided doses, markedly protected the gastric ulcer both in active and healed stages from the deleterious activity of ASA. PMID:955326

  6. Quantitative analysis of 15N labeled positional isomers of glutamine and citrulline via electrospray ionization tandem mass spectrometry of their dansyl derivatives

    Science.gov (United States)

    The enteral metabolism of glutamine and citrulline are intertwined because, while glutamine is one of the main fuel sources for the enterocyte, citrulline is one of its products. It has been shown that the administration of 15N labeled glutamine results in the incorporation of the 15N label into cit...

  7. Glutamine depletion induces murine neonatal melena with increased apoptosis of the intestinal epithelium

    Institute of Scientific and Technical Information of China (English)

    Takayuki Motoki; Hiroshi Tsuchita; Mehmet Gunduz; Hitoshi Nagatsuka; Noriaki Tanaka; Toshiyoshi Fujiwara; Yoshio Naomoto; Junji Hoshiba; Yasuhiro Shirakawa; Tomoki Yamatsuji; Junji Matsuoka; Munenori Takaoka; Yasuko Tomono; Yasuhiro Fujiwara

    2011-01-01

    AIM: To investigate the possible biological outcome and effect of glutamine depletion in neonatal mice and rodent intestinal epithelial cells.METHODS: We developed three kinds of artificial milk with different amounts of glutamine; Complete amino acid milk (CAM), which is based on maternal mouse milk, glutamine-depleted milk (GDM), and glutaminerich milk (GRM). GRM contains three-fold more glutamine than CAM. Eighty-seven newborn mice were divided into three groups and were fed with either of CAM, GDM, or GRM via a recently improved nipple-bottle system for seven days. After the feeding period, the mice were subjected to macroscopic and microscopic observations by immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU) and Ki-67 as markers of cell proliferation,and for cleaved-caspase-3 as a marker of apoptosis.Moreover, IEC6 rat intestinal epithelial cells were cultured in different concentrations of glutamine and were subject to a 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate cell proliferation assay, flow cytometry, and western blotting to examine the biological effect of glutamine on cell growth and apoptosis.RESULTS: During the feeding period, we found colonic hemorrhage in six of 28 GDM-fed mice (21.4%), but not in the GRM-fed mice, with no differences in body weight gain between each group. Microscopic examination showed destruction of microvilli and the disappearance of glycocalyx of the intestinal wall in the colon epithelial tissues taken from GDM-fed mice. Intake of GDM reduced BrdU incorporation (the average percentage of BrdU-positive staining; GRM: 13.8%, CAM: 10.7%, GDM:1.14%, GRM vs GDM: P < 0.001, CAM vs GDM: P < 0.001)and Ki-67 labeling index (the average percentage of Ki-67-positive staining; GRM: 24.5%, CAM: 22.4% GDM:19.4%, GRM vs GDM: P = 0.001, CAM vs GDM: P =0.049), suggesting that glutamine depletion inhibited cell proliferation of intestinal epithelial cells. Glutamine deprivation further caused the

  8. Synthesis and Radiolabelling of DOTA-Linked Glutamine Analogues with 67,68Ga as Markers for Increased Glutamine Metabolism in Tumour Cells

    Directory of Open Access Journals (Sweden)

    Ivan Greguric

    2013-06-01

    Full Text Available DOTA-linked glutamine analogues with a C6- alkyl and polyethyleneglycol (PEG chain between the chelating group and the L-glutamine moiety were synthesised and labelled with 67,68Ga using established methods. High yields were achieved for the radiolabelling of the molecules with both radionuclides (>90%, although conversion of the commercially available 67Ga-citrate to the chloride species was a requirement for consistent high radiochemical yields. The generator produced 68Ga was in the [68Ga(OH4]− form. The 67Ga complexes and the 67Ga complexes were demonstrated to be stable in PBS buffer for a week. Uptake studies were performed with longer lived 67Ga analogues against four tumour cell lines, as well as uptake inhibition studies against L-glutamine, and two known amino acid transporter inhibitors. Marginal uptake was exhibited in the PEG variant radio-complex, and inhibition studies indicate this uptake is via a non-targeted amino acid pathway.

  9. Interdomain and Intermodule Organization in Epimerization Domain Containing Nonribosomal Peptide Synthetases.

    Science.gov (United States)

    Chen, Wei-Hung; Li, Kunhua; Guntaka, Naga Sandhya; Bruner, Steven D

    2016-08-19

    Nonribosomal peptide synthetases are large, complex multidomain enzymes responsible for the biosynthesis of a wide range of peptidic natural products. Inherent to synthetase chemistry is the thioester templated mechanism that relies on protein/protein interactions and interdomain dynamics. Several questions related to structure and mechanism remain to be addressed, including the incorporation of accessory domains and intermodule interactions. The inclusion of nonproteinogenic d-amino acids into peptide frameworks is a common and important modification for bioactive nonribosomal peptides. Epimerization domains, embedded in nonribosomal peptide synthetases assembly lines, catalyze the l- to d-amino acid conversion. Here we report the structure of the epimerization domain/peptidyl carrier protein didomain construct from the first module of the cyclic peptide antibiotic gramicidin synthetase. Both holo (phosphopantethiene post-translationally modified) and apo structures were determined, each representing catalytically relevant conformations of the two domains. The structures provide insight into domain-domain recognition, substrate delivery during the assembly line process, in addition to the structural organization of homologous condensation domains, canonical players in all synthetase modules. PMID:27294598

  10. Structure of the prolyl-tRNA synthetase from the eukaryotic pathogen Giardia lamblia

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Eric T.; Kim, Jessica E.; Napuli, Alberto J.; Verlinde, Christophe L. M. J.; Fan, Erkang; Zucker, Frank H.; Van Voorhis, Wesley C.; Buckner, Frederick S.; Hol, Wim G. J.; Merritt, Ethan A., E-mail: merritt@u.washington.edu [Medical Structural Genomics of Pathogenic Protozoa, (United States); University of Washington, Seattle, WA 98195 (United States)

    2012-09-01

    The structure of Giardia prolyl-tRNA synthetase cocrystallized with proline and ATP shows evidence for half-of-the-sites activity, leading to a corresponding mixture of reaction substrates and product (prolyl-AMP) in the two active sites of the dimer. The genome of the human intestinal parasite Giardia lamblia contains only a single aminoacyl-tRNA synthetase gene for each amino acid. The Giardia prolyl-tRNA synthetase gene product was originally misidentified as a dual-specificity Pro/Cys enzyme, in part owing to its unexpectedly high off-target activation of cysteine, but is now believed to be a normal representative of the class of archaeal/eukaryotic prolyl-tRNA synthetases. The 2.2 Å resolution crystal structure of the G. lamblia enzyme presented here is thus the first structure determination of a prolyl-tRNA synthetase from a eukaryote. The relative occupancies of substrate (proline) and product (prolyl-AMP) in the active site are consistent with half-of-the-sites reactivity, as is the observed biphasic thermal denaturation curve for the protein in the presence of proline and MgATP. However, no corresponding induced asymmetry is evident in the structure of the protein. No thermal stabilization is observed in the presence of cysteine and ATP. The implied low affinity for the off-target activation product cysteinyl-AMP suggests that translational fidelity in Giardia is aided by the rapid release of misactivated cysteine.

  11. Structure of the prolyl-tRNA synthetase from the eukaryotic pathogen Giardia lamblia

    International Nuclear Information System (INIS)

    The structure of Giardia prolyl-tRNA synthetase cocrystallized with proline and ATP shows evidence for half-of-the-sites activity, leading to a corresponding mixture of reaction substrates and product (prolyl-AMP) in the two active sites of the dimer. The genome of the human intestinal parasite Giardia lamblia contains only a single aminoacyl-tRNA synthetase gene for each amino acid. The Giardia prolyl-tRNA synthetase gene product was originally misidentified as a dual-specificity Pro/Cys enzyme, in part owing to its unexpectedly high off-target activation of cysteine, but is now believed to be a normal representative of the class of archaeal/eukaryotic prolyl-tRNA synthetases. The 2.2 Å resolution crystal structure of the G. lamblia enzyme presented here is thus the first structure determination of a prolyl-tRNA synthetase from a eukaryote. The relative occupancies of substrate (proline) and product (prolyl-AMP) in the active site are consistent with half-of-the-sites reactivity, as is the observed biphasic thermal denaturation curve for the protein in the presence of proline and MgATP. However, no corresponding induced asymmetry is evident in the structure of the protein. No thermal stabilization is observed in the presence of cysteine and ATP. The implied low affinity for the off-target activation product cysteinyl-AMP suggests that translational fidelity in Giardia is aided by the rapid release of misactivated cysteine

  12. Characterization of arachidonate 5-lipoxygenase and leukotriene A4 synthetase from RBL-1 cells

    International Nuclear Information System (INIS)

    5-lipoxygenase (LO) and leukotriene (LT) A4 synthetase from RBL-1 high speed (105,000 x g for 60 min) supernatants were partially purified by protein-high performance liquid chromatography (HPLC) and characterized in detail. The partially purified preparation contained only 5-LO and LTA4 synthetase and was isolated from 12-LO, peroxidase and LTA4 hydrolase activities. Reaction products were separated by reversed phase HPLC and quantitated by absorption spectrophotometry and radiochemical detection. The enzyme preparation rapidly converted [14C]arachidonate to [14C]5-hydroperoxyeicosatetraenoic acid (HPETE) and [14C]5,12-dihydroperoxyeicosatetraenoic acids (diHETEs). The 5,12-diHETEs were primarily non-enzymatic breakdown products of LTA4 (e.g., 6-trans-LTB4 and 6-trans-12-epi-LTB4). Both the 5-LO and LTA4 synthetase activities were Ca2+- and ATP-dependent. For both enzyme activities, the CA2+ stimulation required the presence of ATP. The fatty acid hydroperoxides, 5-,12-, and 15-HPETE, both stimulated ([ 3 μM]) 5-LO and LTA4 synthetase activities. The rapid isolation and subsequent characterization of 5-LO and LTA4 synthetase provide the bases for the further understanding of the role of the LO pathway in biological processes

  13. Calcium regulates the expression of a Dictyostelium discoideum asparaginyl tRNA synthetase gene

    Indian Academy of Sciences (India)

    Jyoti K Jaiswal; Vidyanand Nanjundiah

    2003-12-01

    In a screen for calcium-regulated gene expression during growth and development of Dictyostelium discoideum we have identified an asparaginyl tRNA synthetase (ddAsnRS) gene, the second tRNA synthetase gene identified in this organism. The ddAsnRS gene shows many unique features. One, it is repressed by lowering cellular calcium, making it the first known calcium-regulated tRNA synthetase. Two, despite the calcium-dependence, its expression is unaltered during the cell cycle, making this the first D. discoideum gene to show a calcium-dependent but cell cycle phase-independent expression. Finally, the N-terminal domain of the predicted ddAsnRS protein shows higher sequence similarity to Glutaminyl tRNA synthetases than to other Asn tRNA synthetases. These unique features of the AsnRS from this primitive eukaryote not only point to a novel mechanism regulating the components of translation machinery and gene expression by calcium, but also hint at a link between the evolution of GlnRS and AsnRS in eukaryotes.

  14. Regulation of the Glutamate-Glutamine Transport System by Intracellular pH in Streptococcus lactis

    NARCIS (Netherlands)

    POOLMAN, B; HELLINGWERF, KJ; KONINGS, WN

    1987-01-01

    Various methods of manipulation of the intracellular pH in Streptococcus lactis result in a unique relationship between the rate of glutamate and glutamine transport and the cytoplasmic pH. The initial rate of glutamate uptake by S. lactis cells increases more than 30-fold when the intracellular pH

  15. Astroglial glutamate-glutamine cycle is involved in the modulation of inflammatory nociception in rats

    Institute of Scientific and Technical Information of China (English)

    Tiancheng Wang; Jing Wang; Bin Geng; Hongyu Guo; Haili Shen; Yayi Xia

    2011-01-01

    Our previous behavioral studies have indicated that the astroglial glutamate-glutamine cycle is involved in the process of formalin-induced spinal cord central sensitization, but there was little morphological evidence. In this study, double-labeling immunofluorescence techniques showed that after rats were intrathecally injected with PBS and plantarly injected with formalin, glial fibrillary acidic protein (GFAP) and glutamine synthesase (GS) expression were increased and GFAP/GS coexpression was changed to include layers III and IV. After intrathecal injection of methionine sulfoximine, a GS specific inhibitor, the formalin-induced change in expression and coexpression of GFAP and GS in spinal cord dorsal horns was inhibited. The morphology, distribution and quantity of astrocytes recovered to normal levels. An intrathecal glutamine injection reversed the inhibitory effect of methionine sulfoximine. Astrocytes showed significant activation and distribution extended to layers V and VI. The present study provides morphological evidence that the astroglial glutamate-glutamine cycle is involved in the process of formalin-induced spinal cord central sensitization.

  16. Evidence for Tautomerisation of Glutamine in BLUF Blue Light Receptors by Vibrational Spectroscopy and Computational Chemistry

    Science.gov (United States)

    Domratcheva, Tatiana; Hartmann, Elisabeth; Schlichting, Ilme; Kottke, Tilman

    2016-03-01

    BLUF (blue light sensor using flavin) domains regulate the activity of various enzymatic effector domains in bacteria and euglenids. BLUF features a unique photoactivation through restructuring of the hydrogen-bonding network as opposed to a redox reaction or an isomerization of the chromophore. A conserved glutamine residue close to the flavin chromophore plays a central role in the light response, but the underlying modification is still unclear. We labelled this glutamine with 15N in two representative BLUF domains and performed time-resolved infrared double difference spectroscopy. The assignment of the signals was conducted by extensive quantum chemical calculations on large models with 187 atoms reproducing the UV-vis and infrared signatures of BLUF photoactivation. In the dark state, the comparatively low frequency of 1,667 cm‑1 is assigned to the glutamine C=O accepting a hydrogen bond from tyrosine. In the light state, the signature of a tautomerised glutamine was extracted with the C=N stretch at ~1,691 cm‑1 exhibiting the characteristic strong downshift by 15N labelling. Moreover, an indirect isotope effect on the flavin C4=O stretch was found. We conclude that photoactivation of the BLUF receptor does not only involve a rearrangement of hydrogen bonds but includes a change in covalent bonds of the protein.

  17. Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center

    DEFF Research Database (Denmark)

    Hejgaard, Jørn

    2005-01-01

    Serpins appear to be ubiquitous in eukaryotes, except fungi, and are also present in some bacteria, archaea and viruses. Inhibitory serpins with a glutamine as the reactive-center P1 residue have been identified exclusively in a few plant species. Unique serpins with a reactive center sequence of...

  18. Protective effects of glutamine preconditioning on ischemia-reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Wan-XingZhang; Li-FangZhou; LeiZhang; LeiBao; Chun-ChengWang; Hui-YanMeng; WenYin

    2011-01-01

    BACKGROUND: Hepatic ischemia-reperfusion injury is a common phenomenon in hepatic surgical procedures and can result in further severe damage. This study aimed to investigate the protective effects of glutamine preconditioning on hepatic ischemia-reperfusion injury in rats and its dose-dependency. METHODS: Thirty-twohealthymaleWistar ratswererandomly divided into four groups (n=8 per group). One group received 0.9% NaCl (control) and the other three received glutamine (Gln groups) 4 hours before ischemia. The Gln groups were named GL, GM, and GH according to the glutamine dose. The liver was subjected to 1 hour of ischemia and 2 hours of reperfusion. Two hours later, the levels of alanine aminotransferase (ALT), intracellular free calcium (Ca2+), and activity of Na+/K+adenosine triphosphatase (ATPase) and superoxide dismutase (SOD) were assessed, and liver tissue sections were examined under a microscope. RESULTS: The Gln and control groups differed in the concentration of intracellular free calcium (P CONCLUSIONS: Glutaminepreconditioningprotectedeffectively against hepatic ischemia-reperfusion injury. These protective effects were related to the dose of glutamine and due to the reduction of intracellular calcium overload and the improvements in the activity of Na+/K+ ATPase and SOD.

  19. Glutamine is highly effective in preventing in vivo cobalt-induced oxidative stress in rat liver

    Institute of Scientific and Technical Information of China (English)

    Soledad Gonzales; Ariel H. Polizio; María A. Erario; María L. Tomaro

    2005-01-01

    AIM: To evaluate the in vivo effect of glutamine on cobaltgenerated oxidative stress and (HO-1) induction in rat liver.METHODS: Fasted female Wistar rats received a single injection of cobalt chloride (375 μmol/kg body weight) and then were killed at different times. Lipid peroxidation and soluble and enzymatic antioxidant defense system (reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD)) were measured in liver homogenates. Ferritin and ferritin iron contents as well as heme oxygenase-1 (HO-1) activity and expression were also determined. The antioxidant properties of glutamine (Gin) were also evaluated. RESULTS: Cobalt chloride increased lipid peroxidation (50% over control values) 1 h after treatment. GSH reached a minimum at 3 h (40%) increasing thereafter. Twelve hours after CoCl2 injection, the antioxidant enzymes CAT, GSH-Px and SOD also diminished by about 30%. Heme oxygenase-1 induction was observed 6 h after treatment reaching a maximum value of 14-fold over the controls, 12 h after cobalt treatment. A 1.7-fold increase in ferritin and ferritin-bound iron 24 h after treatment were also obtained. Administration of glutamine (300 mg/kg body weight) by gavage 24 h before CoCl2 treatment entirely prevented the increase in thiobarbituric acid reactive substances (TBARS) content, the decrease in GSH levels, and partially reverted heme oxygenase-1 induction. CONCLUSION: These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.

  20. Glutamine supplementation, citrulline production, and de novo arginine synthesis: Is there a relation?

    Science.gov (United States)

    We would like to comment on the recent publications by Buijs et al. The authors hypothesized that a parenteral supplement of glutamine stimulates citrulline formation and enhances de novo arginine synthesis. To test this hypothesis, they conducted an experiment with stable isotopes in patients under...

  1. In vitro enzyme degradation of crosslinked films of poly hydroxyalkyl glutamine

    Institute of Scientific and Technical Information of China (English)

    PAN Shi-rong; WANG Qin-mei; Yi Wu

    2001-01-01

    @@ Polybenzyl glutamate as one of polyα-amino acids displaying excellent biocompatibility and biodegradabi-lity is capable of reacting with hydroxyalkyl-amine byaminolysis and changing the benzyl glutamate to hydro-xyalkyl glutamine, whichproperties can obviously be improved.

  2. No effect of glutamine ingestion on indices of oxidative metabolism in stable COPD.

    Science.gov (United States)

    Marwood, Simon; Jack, Sandy; Patel, Mukhtar; Walker, Paul; Bowtell, Joanna; Calverley, Peter

    2011-06-30

    COPD patients have reduced muscle glutamate which may contribute to an impaired response of oxidative metabolism to exercise. We hypothesised that prior glutamine supplementation would enhance V(O2) peak, V(O2) at lactate threshold and speed pulmonary oxygen uptake kinetics in COPD. 13 patients (9 males, age 66±5 years, mean±SD) with severe COPD (mean FEV(1) 0.88±0.23l, 33±7% predicted) performed on separate days ramp cycle-ergometry (5-10 W min(-1)) to volitional exhaustion and subsequently square-wave transitions to 80% estimated lactate threshold (LT) following consumption of either placebo (CON) or 0.125 g kg bm(-1) of glutamine (GLN) in 5 ml kg bm(-1) placebo. Oral glutamine had no effect on peak or V(O2) at LT, {V(O2) peak: CON=0.70±0.1 l min(-1) vs. GLN=0.73±0.2 l min(-1); LT: CON=0.57±0.1 l min(-1) vs. GLN=0.54±0.1 lmin(-1)} or V(O2) kinetics {tau: CON=68±22 s vs. GLN=68±16 s}. Ingestion of glutamine before exercise did not improve indices of oxidative metabolism in this patient group. PMID:21419239

  3. Evidence for Tautomerisation of Glutamine in BLUF Blue Light Receptors by Vibrational Spectroscopy and Computational Chemistry

    Science.gov (United States)

    Domratcheva, Tatiana; Hartmann, Elisabeth; Schlichting, Ilme; Kottke, Tilman

    2016-01-01

    BLUF (blue light sensor using flavin) domains regulate the activity of various enzymatic effector domains in bacteria and euglenids. BLUF features a unique photoactivation through restructuring of the hydrogen-bonding network as opposed to a redox reaction or an isomerization of the chromophore. A conserved glutamine residue close to the flavin chromophore plays a central role in the light response, but the underlying modification is still unclear. We labelled this glutamine with 15N in two representative BLUF domains and performed time-resolved infrared double difference spectroscopy. The assignment of the signals was conducted by extensive quantum chemical calculations on large models with 187 atoms reproducing the UV-vis and infrared signatures of BLUF photoactivation. In the dark state, the comparatively low frequency of 1,667 cm−1 is assigned to the glutamine C=O accepting a hydrogen bond from tyrosine. In the light state, the signature of a tautomerised glutamine was extracted with the C=N stretch at ~1,691 cm−1 exhibiting the characteristic strong downshift by 15N labelling. Moreover, an indirect isotope effect on the flavin C4=O stretch was found. We conclude that photoactivation of the BLUF receptor does not only involve a rearrangement of hydrogen bonds but includes a change in covalent bonds of the protein. PMID:26947391

  4. Combined Effects of Tauroursodeoxycholic Acid and Glutamine on Bacterial Translocation in Obstructive Jaundiced Rats:

    OpenAIRE

    Hatipoğlu, Ahmet Rahmi; Gürcan, Şaban; Yalta, Tülin; ALBAYRAK, Doğan; Erenoğlu, Cengiz; Sağıroğlu, Tamer; SEZER, Yavuz Atakan

    2013-01-01

    Background: Bacterial Translocation is believed to be an important factor on mortality and morbidity in Obstructive Jaundiced. Aims: We investigated the probable or estimated positive effects of tauroursodeoxycholic acid, which has antibacterial and regulatory effects on intestinal flora, together with glutamine on BT in an experimental obstructive jaundiced rat model. Study Design: Animal experimentation. Methods: Forty adult, male, Sprague Dawley rats were used...

  5. The protection of glutamine on radiation-induced intestinal mucosa injury in rats

    International Nuclear Information System (INIS)

    Objective: To observe the protection of glutamine on radiation-induced intestinal mucosa injury. Methods: Thirty rats were randomly divided into normal control group (group A), radiation control group (group B) and glutamine protection group (group C). The rats were received abdominal radiation of 1000 cGy. Feeding glutamine began since the day before radiation in group C. Four days later, the rats were killed, and the intestinal bacterial translocation, the concentration of endotoxin in blood and pathological changes of intestinal mucosa were measured or observed. Results: Bacteria translocation was not found in group A, but evident in group B, and much lighter in group C than in group B. The concentration of endotoxin in blood was very low in group A, very high in group B, but much lower in group C than in group B. The villus edema, mucosa infiltrated with informative cells and epithelial exuviation were found in group B, but these pathological changes were much lighter in group C, and not found in group A. Conclusion: Whole abdomen radiation will evidently cause intestinal mucosa injury in rats, and bacteria translocation and endotoxemia would occur. Glutamine can prevent those changes

  6. Nonribosomal Peptide Synthetase Genes pesL and pes1 Are Essential for Fumigaclavine C Production in Aspergillus fumigatus

    DEFF Research Database (Denmark)

    O'Hanlon, Karen A.; Gallagher, Lorna; Schrettl, Markus;

    2012-01-01

    The identity of metabolites encoded by the majority of nonribosomal peptide synthetases in the opportunistic pathogen, Aspergillus fumigatus, remains outstanding. We found that the nonribosomal peptide (NRP) synthetases PesL and Pes1 were essential for fumigaclavine C biosynthesis, the end produc...

  7. Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

    DEFF Research Database (Denmark)

    Demant, Erland J.F.; Nystrøm, Birthe T.

    2001-01-01

    acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

  8. Methods and compositions for the production of orthogonal tRNA-aminoacyl tRNA synthetase pairs

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter G.; Wang, Lei; Anderson, John Christopher; Chin, Jason W.; Liu, David R.; Magliery, Thomas J.; Meggers, Eric L.; Mehl, Ryan Aaron; Pastrnak, Miro; Santoro, Stephen William; Zhang, Zhiwen

    2015-10-20

    This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.

  9. Advances in the research of intestinal glutamine transporters%肠道谷氨酰胺转运载体研究进展

    Institute of Scientific and Technical Information of China (English)

    吴炜; 彭曦

    2014-01-01

    Glutamine,the most abundant amino acid in bloodstream,is the preferred fuel source for enterocytes.Glutamine exerts its functions through the activity of its transporters,which are located in cytomembrane,to transport it into or out of intestinal epithelial cells.Intestine is the primary center for glutamine metabolism in the body.As ASCT2 and B0AT1 are the most important glutamine transporters in the intestine,it wound be helpful to gain the knowledge of the structure,function,and pathologic changes and control strategy of the two transporters in order to have a better understanding of the metabolism and function of glutamine.

  10. Protective effects of L-glutamine against toxicity of deltamethrin in the cerebral tissue

    Directory of Open Access Journals (Sweden)

    Varol S

    2016-04-01

    Full Text Available Sefer Varol, Hasan Hüseyin Özdemir, Mehmet Uğur Çevik, Yaşar Altun, Ibrahim Ibiloğlu, Aysun Ekinci, Aslıhan Okan Ibiloğlu, Metin Balduz, Demet Arslan, Recep Tekin, Fesih Aktar, Mehmet Ufuk Aluçlu Department of Neurology, Faculty of Medicine, Dicle University, Diyarbakir, Turkey Background: Deltamethrin (DLM is a broad-spectrum synthetic dibromo-pyrethroid pesticide that is widely used for agricultural and veterinary purposes. However, human exposure to the pesticide leads to neurotoxicity. Glutamine is one of the principal, free intracellular amino acids and may also be an antioxidant. This study was undertaken in order to examine the neuroprotective and antioxidant potential of L-glutamine against DLM toxicity in female Wistar albino rats. Materials and methods: The rats were divided into the following groups (n=10: Group I: control (distilled water; 10 mL/kg, po one dose, Group II: L-glutamine (1.5 g/kg, po one dose, Group III: DLM (35 mg/kg, po one dose, and Group IV: DLM (35 mg/kg, po one dose and L-glutamine (1.5 g/kg, po one dose after 4 hours. Total oxidant status (TOS, total antioxidant status (TAS, tumor necrosis factor-α, interleukin (IL-1β, and IL-6 levels and apoptosis were evaluated in brain tissue. Results: DLM-treated animals had a significant increase in brain biochemical parameters, as well as TOS and TAS. Furthermore, the histopathological examination showed neuronal cell degeneration in the cerebral tissue. L-Glutamine treatment decreased the elevated brain levels of TOS and neuronal cell degeneration. There was no difference in tumor necrosis factor-α, IL-1β, and IL-6 levels between the groups. Conclusion: L-Glutamine may reduce the toxic effects of DLM in the cerebral tissue through antioxidant properties. Keywords: deltamethrin, L-glutamine, rat

  11. An archaeal tRNA-synthetase complex that enhances aminoacylation under extreme conditions

    DEFF Research Database (Denmark)

    Godinic-Mikulcic, Vlatka; Jaric, Jelena; Hausmann, Corinne D;

    2011-01-01

    Aminoacyl-tRNA synthetases (aaRSs) play an integral role in protein synthesis, functioning to attach the correct amino acid with its cognate tRNA molecule. AaRSs are known to associate into higher-order multi-aminoacyl-tRNA synthetase complexes (MSC) involved in archaeal and eukaryotic translation...... the catalytic efficiency of serine attachment to tRNA, but had no effect on the activity of MtArgRS. Further, the most pronounced improvements in the aminoacylation activity of MtSerRS induced by MtArgRS were observed under conditions of elevated temperature and osmolarity. These data indicate that......, although the precise biological role remains largely unknown. To gain further insights into archaeal MSCs, possible protein-protein interactions with the atypical Methanothermobacter thermautotrophicus seryl-tRNA synthetase (MtSerRS) were investigated. Yeast two-hybrid analysis revealed arginyl-tRNA...

  12. Association of a multi-synthetase complex with translating ribosomes in the archaeon Thermococcus kodakarensis

    DEFF Research Database (Denmark)

    Raina, Medha; Elgamal, Sara; Santangelo, Thomas J; Ibba, Michael

    2012-01-01

    In archaea and eukaryotes aminoacyl-tRNA synthetases (aaRSs) associate in multi-synthetase complexes (MSCs), however the role of such MSCs in translation is unknown. MSC function was investigated in vivo in the archaeon Thermococcus kodakarensis, wherein six aaRSs were affinity co-purified together...... with several other factors involved in protein synthesis, suggesting that MSCs may interact directly with translating ribosomes. In support of this hypothesis, the aminoacyl-tRNA synthetase (aaRS) activities of the MSC were enriched in isolated T. kodakarensis polysome fractions. These data indicate...... that components of the archaeal protein synthesis machinery associate into macromolecular assemblies in vivo and provide the potential to increase translation efficiency by limiting substrate diffusion away from the ribosome, thus facilitating rapid recycling of tRNAs. STRUCTURED SUMMARY OF PROTEIN...

  13. Quantitative proteomics analysis reveals glutamine deprivation activates fatty acid β-oxidation pathway in HepG2 cells.

    Science.gov (United States)

    Long, Baisheng; Muhamad, Rodiallah; Yan, Guokai; Yu, Jie; Fan, Qiwen; Wang, Zhichang; Li, Xiuzhi; Purnomoadi, Agung; Achmadi, Joelal; Yan, Xianghua

    2016-05-01

    Glutamine, a multifunctional amino acid, functions in nutrient metabolism, energy balance, apoptosis, and cell proliferation. Lipid is an important nutrient and controls a broad range of physiological processes. Previous studies have demonstrated that glutamine can affect lipolysis and lipogenesis, but the effect of glutamine on the detailed lipid metabolism remains incompletely understood. Here, we applied the quantitative proteomics approach to estimate the relative abundance of proteins in HepG2 cells treated by glutamine deprivation. The results showed that there were 212 differentially abundant proteins in response to glutamine deprivation, including 150 significantly increased proteins and 62 significantly decreased proteins. Interestingly, functional classification showed that 43 differentially abundant proteins were related to lipid metabolism. Further bioinformatics analysis and western blotting validation revealed that lipid accumulation may be affected by β-oxidation of fatty acid induced by glutamine deprivation in HepG2 cells. Together, our results may provide the potential for regulating lipid metabolism by glutamine in animal production and human nutrition. The MS data have been deposited to the ProteomeXchange Consortium with identifier PXD003387. PMID:26837383

  14. In vivo and in vitro liver cancer metabolism observed with hyperpolarized [5-13C]glutamine

    Science.gov (United States)

    Cabella, C.; Karlsson, M.; Canapè, C.; Catanzaro, G.; Colombo Serra, S.; Miragoli, L.; Poggi, L.; Uggeri, F.; Venturi, L.; Jensen, P. R.; Lerche, M. H.; Tedoldi, F.

    2013-07-01

    Glutamine metabolism is, with its many links to oncogene expression, considered a crucial step in cancer metabolism and it is thereby a key target for alteration in cancer development. In particular, strong correlations have been reported between oncogene expression and expression and activity of the enzyme glutaminase. This mitochondrial enzyme, which is responsible for the deamidation of glutamine to form glutamate, is overexpressed in many tumour tissues. In animal models, glutaminase expression is correlated with tumour growth rate and it is readily possible to limit tumour growth by suppression of glutaminase activity. In principle, hyperpolarized 13C MR spectroscopy can provide insight to glutamine metabolism and should hence be a valuable tool to study changes in glutaminase activity as tumours progress. However, no such successful in vivo studies have been reported, even though several good biological models have been tested. This may, at least partly, be due to problems in preparing glutamine for hyperpolarization. This paper reports a new and improved preparation of hyperpolarized [5-13C]glutamine, which provides a highly sensitive 13C MR marker. With this preparation of hyperpolarized [5-13C]glutamine, glutaminase activity in vivo in a rat liver tumour was investigated. Moreover, this marker was also used to measure response to drug treatment in vitro in cancer cells. These examples of [5-13C]glutamine used in tumour models warrant the new preparation to allow metabolic studies with this conditionally essential amino acid.

  15. Lid L11 of the glutamine amidotransferase domain of CTP synthase mediates allosteric GTP activation of glutaminase activity

    DEFF Research Database (Denmark)

    Willemoës, Martin; Mølgaard, Anne; Johansson, Eva;

    2005-01-01

    GTP is an allosteric activator of CTP synthase and acts to increase the k(cat) for the glutamine-dependent CTP synthesis reaction. GTP is suggested, in part, to optimally orient the oxy-anion hole for hydrolysis of glutamine that takes place in the glutamine amidotransferase class I (GATase) domain...... position depending on the presence or absence of glutamine in the glutamine binding site. Displacement or rearrangement of this loop may provide a means for the suggested role of allosteric activation by GTP to optimize the oxy-anion hole for glutamine hydrolysis. Arg359, Gly360 and Glu362 of the...... enzyme behaved like wild-type enzyme. Apart from the G360A enzyme, the results from kinetic analysis of the enzymes altered at position 359 and 360 showed a 10- to 50-fold decrease in GTP activation of glutamine dependent CTP synthesis and concomitant four- to 10-fold increases in K(A) for GTP. The R359M...

  16. Impact of Glutamine in Drinking Water on Performance and Intestinal Morphology of Broiler Chickens under High Stocking Density

    Directory of Open Access Journals (Sweden)

    Majid SHAKERI

    2016-01-01

    Full Text Available This work sought to look into the impacts of glutamine in drinking water on performance, intestinal morphology and corticosterone level of chickens under different stocking densities. A total 300 male chicks randomly were divided to battery cages as 10 birds/(normal stocking density and 15 birds/(high stocking density. The chicks received feed as (i control diet and (ii control diet + 5g glutamine/ liter in drinking water under normal and high stocking density for the whole experiment. On d 42, 3 chicks from each cage were randomly selected and slaughtered to collect blood and duodenal samples. The results showed significant improvement in growth performance and longer villi when chicken were supplemented with glutamine via drinking water. High stocking density impaired performance of chicks in the control diet, but not in chicken supplemented with glutamine under high stocking density condition. Moreover, high stocking density increased the level of corticosterone in the both groups. More interestingly, the rate of mortality significantly decreased in chickens fed with glutamine supplemented diet (2% when supplemented with glutamine and 5.33% without supplementation. In conclusion, glutamine supplementation via drinking water resulted in better growth performance of birds subjected to high stocking density.

  17. End products of glucose and glutamine metabolism by L929 cells.

    Science.gov (United States)

    Lanks, K W

    1987-07-25

    Products of glucose and glutamine metabolism by L929 cells were detected and quantitated by gas chromatography and mass spectrometry of the oxime-trimethylsilyl derivatives. This method allowed detection and identification of all major carboxylic and amino acids produced in the system. Although lactic acid was expected to be the major product, alanine, citric, glutamic, aspartic, and pyruvic acids were also released into the culture medium at significant rates. Incorporation of labeled carbon from D-[U-13C]glucose showed that the alanine, lactic, and pyruvic acids were derived from glucose as was one-third of the citric acid carbon. The rate of glucose utilization for production of these end products was 29-fold greater than the rate of glucose oxidation to CO2, and calculated ATP production from alanine and pyruvate synthesis exceeded that from lactate synthesis by nearly 2-fold. Utilization of glutamine for synthesis of aspartic, glutamic, and citric acids also exceeded the rate of glutamine oxidation, thereby making end-product synthesis from glucose and glutamine the dominant cellular metabolic activity. In the absence of glucose, synthesis and intracellular levels of aspartic and glutamic acids increased, whereas synthesis and cell content of the other acids decreased markedly. This response is consistent with the metabolic pattern proposed by Moreadith and Lehninger (Moreadith, R.W., and Lehninger, A.L. (1984) J. Biol. Chem. 259, 6215-6221) in which much of the glutamine used by these cells is converted to aspartate in the absence of a pyruvate source and to aspartate or citrate in the presence of pyruvate. PMID:3611053

  18. Use of butyrate or glutamine in enema solution reduces inflammation and fibrosis in experimental diversion colitis

    Institute of Scientific and Technical Information of China (English)

    Rodrigo Goulart Pacheco; Christiano Costa Esposito; Lucas CM Müller; Morgana TL Castelo-Branco; Leonardo Pereira Quintella; Vera Lucia A Chagas; Heitor Siffert P de Souza

    2012-01-01

    AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing glutamine,butyrate,or saline.Enemas were administered twice a week in the excluded segment of the colon from 4 to 12 wk after the surgical procedure.Follow-up colonoscopy was performed every 4 wk for 12 wk.The effect of treatment was evaluated using video-endoscopic and histologic scores and measuring interleukin-1β,tumor necrosis factor-alpha,and transforming growth factor beta production in organ cultures by enzyme linked immunosorbent assay.RESULTS:Colonoscopies of the diverted segment showed mucosa with hyperemia,increased number of vessels,bleeding and mucus discharge.Treatment with either glutamine or butyrate induced significant reductions in both colonoscopic (P < 0.02) and histological scores (P < 0.01) and restored the densities of collagen fibers in tissue (P =0.015; P =0.001),the number of goblet cells (P =0.021; P =0.029),and the rate of apoptosis within the epithelium (P =0.043; P =0.011) to normal values.The high levels of cytokines in colon explants from rats with diversion colitis significantly decreased to normal values after treatment with butyrate or glutamine.CONCLUSION:The improvement of experimental diversion colitis following glutamine or butyrate enemas highlights the importance of specific luminal nutrients in the homeostasis of the colonic mucosa and supports their utilization for the treatment of human diversion colitis.

  19. Dietary glutamine supplementation partly reverses impaired macrophage function resulting from overload training in rats.

    Science.gov (United States)

    Xiao, Weihua; Chen, Peijie; Dong, Jingmei; Wang, Ru; Luo, Beibei

    2015-04-01

    The aim of this study was to evaluate the effect of overload training on the function of peritoneal macrophages in rats, and to test the hypothesis that glutamine in vivo supplementation would partly reverse the eventual functional alterations induced by overload training in these cells. Forty male Wistar rats were randomly divided into 5 groups: control group (C), overload training group (E1), overload training and restore one week group (E2), glutamine-supplementation group (EG1), and glutamine-supplementation and restore 1-week group (EG2). All rats, except those placed on sedentary control were subjected to 11 weeks of overload training protocol. Blood hemoglobin, serum testosterone, and corticosterone of rats were measured. Moreover, the functions (chemotaxis, phagocytosis, cytokines synthesis, reactive oxygen species generation) of peritoneal macrophages were determined. Data showed that blood hemoglobin, serum testosterone, corticosterone and body weight in the overload training group decreased significantly as compared with the control group. Meanwhile, the chemotaxis capacity (decreased by 31%, p = .003), the phagocytosis capacity (decreased by 27%, p = .005), the reactive oxygen species (ROS) generation (decreased by 35%, p = .003) and the cytokines response capability of macrophages were inhibited by overload training. However, the hindering of phagocytosis and the cytokines response capability of macrophages induced by overload training could be ameliorated and reversed respectively, by dietary glutamine supplementation. These results suggest that overload training impairs the function of peritoneal macrophages, which is essential for the microbicidal actions of macrophages. This may represent a novel mechanism of immunodepression induced by overload training. Nonetheless, dietary glutamine supplementation could partly reverse the impaired macrophage function resulting from overload training. PMID:25028814

  20. Glutamine, glutamate, and arginine-based acid resistance in Lactobacillus reuteri.

    Science.gov (United States)

    Teixeira, Januana S; Seeras, Arisha; Sanchez-Maldonado, Alma Fernanda; Zhang, Chonggang; Su, Marcia Shu-Wei; Gänzle, Michael G

    2014-09-01

    This study aimed to determine whether glutamine deamidation improves acid resistance of Lactobacillus reuteri, and to assess whether arginine, glutamine, and glutamate-mediated acid resistance are redundant or complementary mechanisms of acid resistance. Three putative glutaminase genes, gls1, gls2, and gls3, were identified in L. reuteri 100-23. All three genes were expressed during growth in mMRS and wheat sourdough. L. reuteri consistently over-expressed gls3 and the glutamate decarboxylase gadB. L. reuteri 100-23ΔgadB over-expressed gls3 and the arginine deiminase gene adi. Analysis of the survival of L. reuteri in acidic conditions revealed that arginine conversion is effective at pH of 3.5 while glutamine or glutamate conversion were effective at pH of 2.5. Arginine conversion increased the pHin but not ΔΨ; glutamate decarboxylation had only a minor effect on the pHin but increased the ΔΨ. This study demonstrates that glutamine deamidation increases the acid resistance of L. reuteri independent of glutamate decarboxylase activity. Arginine and glutamine/glutamate conversions confer resistance to lactate at pH of 3.5 and phosphate at pH of 2.5, respectively. Knowledge of L. reuteri's acid resistance improves the understanding of the adaptation of L. reuteri to intestinal ecosystems, and facilitates the selection of probiotic and starter cultures. PMID:24929734

  1. Membrane transporters for the special amino acid glutamine: Structure/function relationships and relevance to human health.

    Science.gov (United States)

    Pochini, Lorena; Scalise, Mariafrancesca; Galluccio, Michele; Indiveri, Cesare

    2014-08-01

    Glutamine together with glucose is essential for body’s homeostasis. It is the most abundant amino acid and is involved in many biosynthetic, regulatory and energy production processes. Several membrane transporters which differ in transport modes, ensure glutamine homeostasis by coordinating its absorption, reabsorption and delivery to tissues. These transporters belong to different protein families, are redundant and ubiquitous. Their classification, originally based on functional properties, has recently been associated with the SLC nomenclature. Function of glutamine transporters is studied in cells over-expressing the transporters or, more recently in proteoliposomes harboring the proteins extracted from animal tissues or over-expressed in microorganisms. The role of the glutamine transporters is linked to their transport modes and coupling with Na+ and H+. Most transporters share specificity for other neutral or cationic amino acids. Na+-dependent co-transporters efficiently accumulate glutamine while antiporters regulate the pools of glutamine and other amino acids. The most acknowledged glutamine transporters belong to the SLC1, 6, 7 and 38 families. The members involved in the homeostasis are the co-transporters B0AT1 and the SNAT members 1, 2, 3, 5 and 7; the antiporters ASCT2, LAT1 and 2. The last two are associated to the ancillary CD98 protein. Some information on regulation of the glutamine transporters exist, which, however, need to be deepened. No information at all is available on structures, besides some homology models obtained using similar bacterial transporters as templates. Some models of rat and human glutamine transporters highlight very similar structures between the orthologues. Moreover the presence of glycosylation and/or phosphorylation sites located at the extracellular or intracellular faces has been predicted. ASCT2 and LAT1 are over-expressed in several cancers, thus representing potential targets for pharmacological intervention.

  2. The Influence of Oral L-Glutamine Supplementation on Muscle Strength Recovery and Soreness Following Unilateral Knee Extension Eccentric Exercise.

    Science.gov (United States)

    Legault, Zachary; Bagnall, Nicholas; Kimmerly, Derek S

    2015-10-01

    The study aimed to examine the effects that L-glutamine supplementation has on quadriceps muscle strength and soreness ratings following eccentric exercise. It was hypothesized that glutamine ingestion would quicken the recovery rate of peak force production and decrease muscle soreness ratings over a 72-hr recovery period. Sixteen healthy participants (8♀/8♂; 22 ± 4 years) volunteered in a double-blind, randomized, placebo-controlled crossover study. Supplement conditions consisted of isoenergetic placebo (maltodextrin, 0.6 g·kg-1·day-1) and L-glutamine (0.3 g·kg-1·day-1 + 0.3 g·kg-1·day-1 maltodextrin) ingestion once per day over 72 hr. Knee extensor peak torque at 0°, 30°, and 180° per second and muscle soreness were measured before, immediately following, 24, 48, and 72 hr posteccentric exercise. Eccentric exercise consisted of 8 sets (10 repetitions/set) of unilateral knee extension at 125% maximum concentric force with 2-min rest intervals. L-glutamine resulted in greater relative peak torque at 180°/sec both immediately after (71 ± 8% vs. 66 ± 9%), and 72 hr (91 ± 8% vs. 86 ± 7%) postexercise (all, p glutamine produced greater (p glutamine condition than women (all, p glutamine resulted in lower soreness ratings at 24 (2.8 ± 1.2 vs. 3.4 ± 1.2), 48 (2.6 ± 1.4 vs. 3.9 ± 1.2), and 72 (1.7 ± 1.2 vs. 2.9 ± 1.3) hr postexercise (p glutamine supplementation resulted in faster recovery of peak torque and diminished muscle soreness following eccentric exercise. The effect of L-glutamine on muscle force recovery may be greater in men than women. PMID:25811544

  3. Various mechanisms in cyclopeptide production from precursors synthesized independently of non-ribosomal peptide synthetases

    Institute of Scientific and Technical Information of China (English)

    Wenyan Xu; Liling Li; Liangcheng Du; Ninghua Tan

    2011-01-01

    An increasing number of cyclopeptides have been discovered as products of ribosomal synthetic pathway.The biosynthetic study of these cyclopeptides has revealed interesting new mechanisms for cyclization.This review highlighted the recent discoveries in cyclization mechanisms for cyclopeptides synthesized independently of non-ribosomal peptide synthetases,including endopeptidase-catalyzed cyclization,intein-mediated cyclization,and peptide synthetase-catalyzed cyclization.This information may help to design hybrid ribosomal and non-ribosomal biosynthetic systems to produce novel cyclopeptides with various bioactivities.

  4. A cDNA clone from Zea mays endosperm sucrose synthetase mRNA.

    OpenAIRE

    Geiser, M.; Döring, H P; Wöstemeyer, J; Behrens, U.; Tillmann, E; Starlinger, P.

    1980-01-01

    A cDNA clone for maize endosperm sucrose synthetase of 62o nucleotide pairs length was obtained by cloning double stranded DNA obtained from the total maize endosperm poly(A) RNA in pBR322, and identifying the appropriate clone by hybrid-promoter translation. In Southern blotting to genomic BamHI-digested DNA, a single band only of approximately 20 Kb lights up, indicating that the sucrose synthetase gene is unique, or that closely linked copies are located on this DNA fragment.

  5. Reversible lysine acetylation controls the activity of the mitochondrial enzyme acetyl-CoA synthetase 2

    DEFF Research Database (Denmark)

    Schwer, Bjoern; Bunkenborg, Jakob; Verdin, Regis O; Andersen, Jens S; Verdin, Eric

    2006-01-01

    We report that human acetyl-CoA synthetase 2 (AceCS2) is a mitochondrial matrix protein. AceCS2 is reversibly acetylated at Lys-642 in the active site of the enzyme. The mitochondrial sirtuin SIRT3 interacts with AceCS2 and deacetylates Lys-642 both in vitro and in vivo. Deacetylation of AceCS2 b...

  6. 2'-phosphodiesterase and 2',5'-oligoadenylate synthetase activities in the lowest metazoans, sponge [porifera

    DEFF Research Database (Denmark)

    Saby, Emilie; Poulsen, Jesper Buchhave; Justesen, Just;

    2009-01-01

    Sponges [porifera], the most ancient metazoans, contain modules related to the vertebrate immune system, including the 2′,5′-oligoadenylate synthetase (OAS). The components of the antiviral 2′,5′-oligoadenylate (2–5A) system (OAS, 2′-Phosphodiesterase (2′-PDE) and RNAse L) of vertebrates have not...

  7. The PRPP Synthetase Spectrum: What Does it Demonstrate About Nucleotide Syndromes?

    NARCIS (Netherlands)

    Duley, J.A.; Christodoulou, J.; Brouwer, A.P.M. de

    2011-01-01

    Defects in X-linked phosphoribosylpyrophosphate synthetase 1 (PRPS1) manifest as follows: (1) PRS-I enzyme "superactivity" (gain-of-function mutations affecting allosteric regions); (2) PRS-I overexpression (which may be linked to miRNA mutation); (3) severe PRS-I deficiency/Arts syndrome (missense

  8. Characterization of a Salmonella typhimurium mutant defective in phosphoribosylpyrophosphate synthetase

    DEFF Research Database (Denmark)

    Jochimsen, Bjarne U.; Hove-Jensen, Bjarne; Garber, Bruce B.;

    1985-01-01

    This study describes the isolation and characterization of a mutant (strain GP122) of Salmonella typhimurium with a partial deficiency of phosphoribosylpyrophosphate (PRPP) synthetase activity. This strain was isolated in a purE deoD gpt purine auxotroph by a procedure designed to select guanosin...

  9. Purification and properties of phosphoribosyl-diphosphate synthetase from Bacillus subtilis

    DEFF Research Database (Denmark)

    Arnvig, Kirsten; Hove-Jensen, Bjarne; Switzer, Robert L.

    1990-01-01

    Phosphoribosyl-diphosphate (PPRibP) synthetase from Bacillus subtiliis has been purified to near homogeneity from an Escherichia coli Δprs strain bearing the cloned B. subtilis prs gene, encoding PPRibP synthentase, on a plasmid. The Mr of the subunit (34,000) and its amino-terminal amino acid...

  10. Acyl-CoA synthetase 1 deficiency alters cardiolipin species and impairs mitochondrial function

    DEFF Research Database (Denmark)

    Grevengoed, Trisha J; Martin, Sarah A; Katunga, Lalage; Cooper, Daniel E; Anderson, Ethan J; Murphy, Robert C; Coleman, Rosalind A

    2015-01-01

    Long-chain acyl-CoA synthetase 1 (ACSL1) contributes more than 90% of total cardiac ACSL activity, but its role in phospholipid synthesis has not been determined. Mice with an inducible knockout of ACSL1 (Acsl1(T-/-)) have impaired cardiac fatty acid oxidation and rely on glucose for ATP producti...

  11. Tandem heterocyclization domains in a nonribosomal peptide synthetase essential for siderophore biosynthesis in Vibrio anguillarum

    NARCIS (Netherlands)

    Di Lorenzo, M.; Stork, M.; Naka, H.; Tolmasky, M.E.; Crosa, J.H.

    2008-01-01

    Anguibactin, the siderophore produced by Vibrio anguillarum 775, is synthesized via a nonribosomal peptide synthetase (NRPS) mechanism. Most of the genes required for anguibactin biosynthesis are harbored by the pJM1 plasmid. Complete sequencing of this plasmid identified an orf encoding a 108 kDa p

  12. Phosphoribosyl pyrophosphate synthetase activity affects growth and riboflavin production in Ashbya gossypii

    Directory of Open Access Journals (Sweden)

    Revuelta José L

    2008-09-01

    Full Text Available Abstract Background Phosphoribosyl pyrophosphate (PRPP is a central compound for cellular metabolism and may be considered as a link between carbon and nitrogen metabolism. PRPP is directly involved in the de novo and salvage biosynthesis of GTP, which is the immediate precursor of riboflavin. The industrial production of this vitamin using the fungus Ashbya gossypii is an important biotechnological process that is strongly influenced by substrate availability. Results Here we describe the characterization and manipulation of two genes of A. gossypii encoding PRPP synthetase (AGR371C and AGL080C. We show that the AGR371C and AGL080C gene products participate in PRPP synthesis and exhibit inhibition by ADP. We also observed a major contribution of AGL080C to total PRPP synthetase activity, which was confirmed by an evident growth defect of the Δagl080c strain. Moreover, we report the overexpression of wild-type and mutant deregulated isoforms of Agr371cp and Agl080cp that significantly enhanced the production of riboflavin in the engineered A. gossypii strains. Conclusion It is shown that alterations in PRPP synthetase activity have pleiotropic effects on the fungal growth pattern and that an increase in PRPP synthetase enzymatic activity can be used to enhance riboflavin production in A. gossypii.

  13. A novel therapeutic target for peripheral nerve injury-related diseases: aminoacyl-tRNA synthetases

    Directory of Open Access Journals (Sweden)

    Byung Sun Park

    2015-01-01

    Full Text Available Aminoacyl-tRNA synthetases (AminoARSs are essential enzymes that perform the first step of protein synthesis. Beyond their original roles, AminoARSs possess non-canonical functions, such as cell cycle regulation and signal transduction. Therefore, AminoARSs represent a powerful pharmaceutical target if their non-canonical functions can be controlled. Using AminoARSs-specific primers, we screened mRNA expression in the spinal cord dorsal horn of rats with peripheral nerve injury created by sciatic nerve axotomy. Of 20 AminoARSs, we found that phenylalanyl-tRNA synthetase beta chain (FARSB, isoleucyl-tRNA synthetase (IARS and methionyl-tRNA synthetase (MARS mRNA expression was increased in spinal dorsal horn neurons on the injured side, but not in glial cells. These findings suggest the possibility that FARSB, IARS and MARS, as a neurotransmitter, may transfer abnormal sensory signals after peripheral nerve damage and become a new target for drug treatment.

  14. Absence of acetohydroxy acid synthetase in a clinical isolate of Neisseria gonorrhoeae requiring isoleucine and valine.

    OpenAIRE

    Lerner, S A; Friedman, E L; Dudek, E J; Kominski, G; Bohnhoff, M.; Morello, J A

    1980-01-01

    A clinical isolate of Neisseria gonorrhoeae with an unusual growth requirement for isoleucine and valine lacked the activity of acetohydroxy acid synthetase, one of the enzymes required for the biosynthesis of these amino acids. A spontaneous mutant which no longer required isoleucine and valine had acquired this enzymatic activity.

  15. Structures of two distinct conformations of holo-non-ribosomal peptide synthetases.

    Science.gov (United States)

    Drake, Eric J; Miller, Bradley R; Shi, Ce; Tarrasch, Jeffrey T; Sundlov, Jesse A; Allen, C Leigh; Skiniotis, Georgios; Aldrich, Courtney C; Gulick, Andrew M

    2016-01-14

    Many important natural products are produced by multidomain non-ribosomal peptide synthetases (NRPSs). During synthesis, intermediates are covalently bound to integrated carrier domains and transported to neighbouring catalytic domains in an assembly line fashion. Understanding the structural basis for catalysis with non-ribosomal peptide synthetases will facilitate bioengineering to create novel products. Here we describe the structures of two different holo-non-ribosomal peptide synthetase modules, each revealing a distinct step in the catalytic cycle. One structure depicts the carrier domain cofactor bound to the peptide bond-forming condensation domain, whereas a second structure captures the installation of the amino acid onto the cofactor within the adenylation domain. These structures demonstrate that a conformational change within the adenylation domain guides transfer of intermediates between domains. Furthermore, one structure shows that the condensation and adenylation domains simultaneously adopt their catalytic conformations, increasing the overall efficiency in a revised structural cycle. These structures and the single-particle electron microscopy analysis demonstrate a highly dynamic domain architecture and provide the foundation for understanding the structural mechanisms that could enable engineering of novel non-ribosomal peptide synthetases. PMID:26762461

  16. Association of IDDM and attenuated response of 2',5'-oligoadenylate synthetase to yellow fever vaccine

    DEFF Research Database (Denmark)

    Bonnevie-Nielsen, V; Larsen, M L; Frifelt, J J;

    1989-01-01

    Basal and yellow fever vaccination-induced 2',5'-oligoadenylate synthetase (2',5'A) activity was determined in blood mononuclear cells (peripheral blood lymphocytes [PBLs]) from insulin-dependent diabetes mellitus (IDDM) and matched control subjects. The live attenuated yellow fever vaccine repre...

  17. Exogenous glutamine increases lipid accumulation in developing seeds of castor bean (Ricinus communis L. cultured in vitro

    Directory of Open Access Journals (Sweden)

    Zhang Yang

    2015-01-01

    Full Text Available This report describes biomass production and compositional changes of developing castor seeds in response to change in the nitrogen resource (glutamine of the medium. During the early developmental period (24-36 days after pollination, oil was found to initially accumulate in the developing seeds. Carbohydrates and oil were inversely related after glutamine provision (35 mM, in the culture medium. [U-14C] sucrose labeling was used to investigate the effect of metabolic fluxes among different storage materials. Addition of glutamine led to a 7% increase of labeling in lipids and an inverse decrease of labeling in carbohydrates. It was postulated that changes in the glutamine concentration in the medium are likely to influence the partitioning of resources between the various storage products, especially carbohydrates and oil. These observations will contribute to a better understanding of assimilate partitioning in developing castor seeds and the development of molecular strategies to improve castor bean seed quality and plant breeding studies.

  18. An example of non-conservation of oligomeric structure in prokaryotic aminoacyl-tRNA synthetases. Biochemical and structural properties of glycyl-tRNA synthetase from Thermus thermophilus.

    Science.gov (United States)

    Mazauric, M H; Reinbolt, J; Lorber, B; Ebel, C; Keith, G; Giegé, R; Kern, D

    1996-11-01

    Glycyl-tRNA synthetase (Gly-tRNA synthetase) from Thermus thermophilus was purified to homogeneity and with high yield using a five-step purification procedure in amounts sufficient to solve its crystallographic structure [Logan, D.T., Mazauric, M.-H., Kern, D. & Moras, D. (1995) EMBO J. 14, 4156-4167]. Molecular-mass determinations of the native and denatured protein indicate an oligomeric structure of the alpha 2 type consistent with that found for eukaryotic Gly-tRNA synthetases (yeast and Bombyx mori), but different from that of Gly-tRNA synthetases from mesophilic prokaryotes (Escherichia coli and Bacillus brevis) which are alpha 2 beta 2 tetramers. N-terminal sequencing of the polypeptide chain reveals significant identity, reaching 50% with those of the eukaryotic enzymes (B. mori, Homo sapiens, yeast and Caenorhabditis elegans) but no significant identity was found with both alpha and beta chains of the prokaryotic enzymes (E. coli, Haemophilus influenzae and Coxiella burnetii) albeit the enzyme is deprived of the N-terminal extension characterizing eukaryotic synthetases. Thus, the thermophilic Gly-tRNA synthetase combines strong structural homologies of eukaryotic Gly-tRNA synthetases with a feature of prokaryotic synthetases. Heat-stability measurements show that this synthetase keeps its ATP-PPi exchange and aminoacylation activities up to 70 degrees C. Glycyladenylate strongly protects the enzyme against thermal inactivation at higher temperatures. Unexpectedly, tRNA(Gly) does not induce protection. Cross-aminoacylations reveal that the thermophilic Gly-tRNA synthetase charges heterologous E. coli tRNA(gly(GCC)) and tRNA(Gly(GCC)) and yeast tRNA(Gly(GCC)) as efficiently as T. thermophilus tRNA(Gly). All these aminoacylation reactions are characterized by similar activation energies as deduced from Arrhenius plots. Therefore, contrary to the E. coli and H. sapiens Gly-tRNA synthetases, the prokaryotic thermophilic enzyme does not possess a strict

  19. Glycyl-L-glutamine opposes the fall in choline acetyltransferase in the denervated superior cervical ganglion of the cat.

    OpenAIRE

    Koelle, G B; O'Neill, J J; Thampi, N S; Han, M S; Caccese, R

    1989-01-01

    Intracarotid infusion of 3 microM glycyl-L-glutamine was found to oppose the fall in the choline acetyl-transferase content of the preganglionically denervated cat superior cervical ganglion; this same effect has been demonstrated previously for acetylcholinesterase content. Because choline acetyltransferase, in contrast to acetylcholinesterase, occurs exclusively in the preganglionic axons and their terminals, this finding raises the possibility that glycyl-L-glutamine opposes postsectional ...

  20. Role of oral glutamine in alleviation and prevention of radiation-induced oral mucositis: A prospective randomized study

    OpenAIRE

    Subrata Chattopadhyay; Aramita Saha; Mohammad Azam; Anindya Mukherjee; Prabir Kumar Sur

    2014-01-01

    Background: Oral mucositis is the most frequently occurring painful and dose-limiting side-effect of radiation of the head and neck region. Few studies demonstrated that oral glutamine suspension may significantly reduce the duration and severity of objective oral mucositis during radiotherapy. Materials and Methods: A randomized, prospective single institutional case control study was performed between April 2012 and November 2012 comparing the influence of oral glutamine on radiation induce...

  1. Inhibitory serpins from rye grain with glutamine as P-1 and P-2 residues in the reactive center

    DEFF Research Database (Denmark)

    Hejgaard, Jørn

    2001-01-01

    (k(a)'similar to 10(6) M-1 s(-1)). Similar but differently organized glutamine-rich reactive centers were recently found in grain serpins cloned from wheat [Ostergaard et al. (2000) J. Biol. Chem. 275, 33272] but not from barley. The prolamin storage proteins of cereal grains contain similar...... sequences in their glutamine-rich repeats. A possible adaption of hypervariable serpin reactive centers late in Triticeae cereal evolution as defence against insects feeding on cereal grains is discussed....

  2. Exogenous glutamine increases lipid accumulation in developing seeds of castor bean (Ricinus communis L.) cultured in vitro

    OpenAIRE

    Zhang Yang; Mulpuri Sujatha; Liu Aizhong

    2015-01-01

    This report describes biomass production and compositional changes of developing castor seeds in response to change in the nitrogen resource (glutamine) of the medium. During the early developmental period (24-36 days after pollination), oil was found to initially accumulate in the developing seeds. Carbohydrates and oil were inversely related after glutamine provision (35 mM, in the culture medium). [U-14C] sucrose labeling was used to investigate the effe...

  3. Neutrophil fatty acid composition: effect of a single session of exercise and glutamine supplementation.

    Science.gov (United States)

    Lagranha, C J; Alba-Loureiro, T C; Martins, E F; Pithon-Curi, T C; Curi, R

    2008-06-01

    The fatty acid composition of immune cells appears to contribute to variations of cell function. The independent and combined effects of a single session of exercise (SSE) and glutamine supplementation (GS) on neutrophil fatty acid composition were investigated. Compared to control (no treatment given--i.e. neither SSE or GS), single session of exercise decreased myristic, palmitic and eicosapentaenoic (EPA) acids, and increased lauric, oleic, linoleic, arachidonic (AA) and docosahexaenoic (DHA) acids whereas glutamine supplementation combined with SSE (GS+SSE) increased oleic acid. Polyunsaturated/saturated fatty acid ratio and Unsaturation index were higher in neutrophils from the SSE and GS groups as compared with control. These findings support the proposition that SSE and GS may modulate neutrophil function through alterations in fatty acid composition. PMID:17721676

  4. Effects of glutamine supplementation on gut barrier,glutathione content and acute phase response in malnourished rats during inflammatory shock

    Institute of Scientific and Technical Information of China (English)

    Liliana Belmonte; Philippe Ducrotté; Pierre Déchelotte; Mo(i)se Co(e)ffier; Florence Le Pessot; Olga Miralles-Barrachina; Martine Hiron; Antony Leplingard; Jean-Fran(c)ois Lemeland; Bernadette Hecketsweiler; Maryvonne Daveau

    2007-01-01

    AIM:To evaluate the effect of glutamine on intestinal mucosa integrity, glutathione stores and acute phase response in protein-depleted rats during an inflammatory shock.METHODS: Plasma acute phase proteins (APP),jejunal APP mRNA levels, liver and jejunal glutathione concentrations were measured before and one, three and seven days after turpentine injection in 4 groups of control, protein-restricted, protein-restricted rats supplemented with glutamine or protein powder.Bacterial translocation in mesenteric lymph nodes and intestinal morphology were also assessed.RESULTS: Protein deprivation and turpentine injection significantly reduced jejunal villus height, and crypt depths. Mucosal glutathione concentration significantly decreased in protein-restricted rats. Before turpentine oil, glutamine supplementation restored villus heights and glutathione concentration (3.24 ± 1.05 vs 1.72 ±0.46 μmol/g tissue, P < 0.05) in the jejunum, whereas in the liver glutathione remained low. Glutamine markedly increased jejunal α1-acid glycoprotein mRNA level after turpentine oil but did not affect its plasma concentration. Bacterial translocation in protein-restricted rats was not prevented by glutamine or protein powder supplementation.CONCLUSION: Glutamine restored gut glutathione stores and villus heights in malnourished rats but had no preventive effect on bacterial translocation in our model.

  5. Self-assembled multi-ring formations of glutamine and a possible link to erythema gyratum repens.

    Science.gov (United States)

    Forrester, Derek Michael

    2015-07-01

    In the body L-glutamine is abundant and required for the proliferation of cells. Indeed human physiology is dependent upon having and maintaining the correct glutamine levels for a range of functions including neurological signalling and a healthy immune system. However, during tumourigenesis cell proliferation demands elevated levels of glutamine, which can ultimately lead to muscle atrophy. In some cases the skin provides the first indications of the underlying disease and erupts in a wave of complicated pattern formations. One such skin marker is erythema gyratum repens. We investigated the pattern formations associated with concentrations of glutamine in aqueous solutions at levels higher than that of a normal biological functionality. We find remarkable similarities between the patterns of erythema gyratum repens and the unusual self-assembled patterns of glutamine. The findings may lead to new therapeutics and understanding for those working in oncology and toxicology. Utilising the formations associated with glutamine could also assist in bio-functionalising micro and nanoparticles for high efficacy. PMID:25804239

  6. The impact of use of Glutamine on patients with head and neck tumors in radiotherapy and chemotherapy treatment

    International Nuclear Information System (INIS)

    Introduction: patients with head and neck neoplasia usually show malnutrition or a nutritional risk, because of common symptoms like: dysphagia, odynophagia and xerostomia. Objective: this study aimed to verify the impact of using amino glutamine in patients with head and neck neoplasia and under radiotherapy and chemotherapy treatment concomitantly. Methods: the research was quantitative, cross-sectional, descriptive and exploratory. The data was collected from nutritional evaluation, and patients chart consultation. The patients were divided in a control group (without use of glutamine) and a test group (with use of glutamine). 16 patients, 13 of which were men and three were women, participated in the research. Results: The control group presented mucositis grades I to IV while patients who used the amino glutamine showed mucositis grades I to II only. It could be observed that the Nutritional Risk Index decreased, which represents higher nutritional risk in patients from the control group only. In patients who used glutamine, this decrease was not significant. Conclusion: these results suggest that the use of glutamine in patients with head and neck tumors and under antineoplastic therapy helps to maintain their nutritional stage and to prevent mucositis throughout their treatment, mainly grades III and IV, which prevents adequate and regular eating and nourishment. (author)

  7. Arginine Deiminase Resistance in Melanoma Cells Is Associated with Metabolic Reprogramming, Glucose Dependence and Glutamine Addiction

    OpenAIRE

    Long, Yan; Tsai, Wen-Bin; Wangpaichitr, Medhi; Tsukamoto, Takashi; Savaraj, Niramol; Feun, Lynn G.; Kuo, Macus Tien

    2013-01-01

    Many malignant human tumors, including melanomas are auxotrophic for arginine due to reduced expression of argininosuccinate synthetase1 (ASS1), the rate-limiting enzyme for arginine biosynthesis. Pegylated arginine deiminase (ADI-PEG20), which degrades extracellular arginine resulting in arginine deprivation, has shown favorable results in clinical trials for treating arginine-auxotrophic tumors. Drug resistance is the major obstacle for effective ADI-PEG20 usage. To elucidate mechanisms of ...

  8. Activation of 2'-5' oligoadenylate synthetase by single-stranded and double-stranded RNA aptamers

    DEFF Research Database (Denmark)

    Hartmann, R; Norby, P L; Martensen, P M;

    1998-01-01

    . Competition experiments indicate that the binding site for the small RNAs on the 2'-5' oligoadenylate synthetase molecule at least partially overlaps that for the synthetic double-stranded RNA, poly(I).poly(C). Several of the RNAs function as potent activators of 2'-5' oligoadenylate synthetase in vitro......, although there is no correlation between binding affinity and ability to activate. The RNA aptamers having the strongest activation potential appear to have few base-paired regions. This suggests that 2'-5' oligoadenylate synthetase, which has previously been believed to be activated only by double-stranded...

  9. Deprive to kill: Glutamine closes the gate to anticancer monocarboxylic drugs

    OpenAIRE

    Cardaci, Simone; Ciriolo, Maria Rosa

    2012-01-01

    Killing properties of antitumor drugs can be enhanced by strategies targeting biochemical adaptations of cancer cells. Recently, we reported that depriving cancer cells of glutamine is a feasible approach to enhance antitumor effects of the alkylating analog of pyruvic acid, 3-bromopyruvate, which rely on the induction of autophagic cell death by metabolic-oxidative stress. 3-bromopyruvate chemopotentiation is the result of its increased intracellular uptake mediated by the monocarboxylate tr...

  10. Glutamine uptake contributes to central sensitization in the medullary dorsal horn

    OpenAIRE

    Chiang, Chen Yu; Li, Zhaohui; Dostrovsky, Jonathan O.; Hu, James W.; Sessle, Barry J.

    2008-01-01

    Mustard oil application to tooth pulp produces central sensitization in rat medullary dorsal horn (MDH) nociceptive neurons, which has been implicated in persistent pain mechanisms. We found that superfusion onto MDH of methylaminoisobutyric acid, a competitive inhibitor of the neuronal system A transporter for presynaptic uptake of glutamine (a glutamate precursor released from astroglia), significantly depressed development of mustard oil-induced central sensitization in rat MDH nociceptive...

  11. Adipocytes Cause Leukemia Cell Resistance to L-Asparaginase via Release of Glutamine

    OpenAIRE

    Ehsanipour, Ehsan A.; SHENG, Xia; Behan, James W.; Wang, Xingchao; Butturini, Anna; Avramis, Vassilios I; Mittelman, Steven D.

    2013-01-01

    Obesity is a significant risk factor for cancer. A link between obesity and a childhood cancer has been identified: obese children diagnosed with high-risk acute lymphoblastic leukemia (ALL) had a 50% greater risk of relapse than their lean counterparts. L-asparaginase (ASNase) is a first-line therapy for ALL that breaks down asparagine and glutamine, exploiting the fact that ALL cells are more dependent on these amino acids than other cells. In the present study, we investigated whether adip...

  12. Role of NifS in maturation of glutamine phosphoribosylpyrophosphate amidotransferase.

    OpenAIRE

    Chen, S.; Zheng, L; Dean, D R; Zalkin, H.

    1997-01-01

    Glutamine phosphoribosylpyrophosphate amidotransferase from Bacillus subtilis is synthesized as an inactive precursor that requires two maturation steps: incorporation of a [4Fe-4S] center and cleavage of an 11-residue NH2-terminal propeptide. Overproduction from a multicopy plasmid in Escherichia coli leads to the formation of soluble proenzyme and mature enzyme forms as well as a small fraction of insoluble proenzyme. Heterologous expression of Azotobacter vinelandii nifS from a compatible ...

  13. The effect of glutamine and synbiotics on the healing of colonic anastomosis

    Directory of Open Access Journals (Sweden)

    Nikolaos Sapidis

    2014-04-01

    Full Text Available Introduction: Intestinal wound healing is an essential process for surgical reconstruction of the digestive tract. The purpose of this study is to evaluate the effect of perioperative administration of glutamine and synbiotics on the biological behavior of intestinal mucosal barrier and the healing of colonic anastomosis in rats. Material and methods: 80 Wistar rats were divided in five groups. A: Control. B: Mechanical bowel preparation and antibiotics. C: Glutamine. D: Synbiotics. E: Glutamine and synbiotics. The animals were sacrificed on 3rd and 7th postoperative day. Results: Zero mortality and no septic complications were noted. On 3rd postoperative days, a significant weight loss was observed in all groups in comparison with the preoperative weights, but on the 7th day in groups C and E, in contrast with the other groups, weight loss was not significant. On the 3rd postoperative day, neoangiogenesis, inflammatory infiltration and fibroblast activity were significantly enhanced in group E compared to control. On the 7th postoperative day in group E fibroblast activity was significantly enhanced and inflammatory infiltration was significantly limited compared to control. The bursting pressures as well as the hydroxyproline tissue content were significantly higher in the group E on 3rd and 7th postoperative days. The percentage of positive mesenteric lymph node cultures were significantly limited in group E compared to control. Conclusions: The administration of synbiotics in conjunction with glutamine resulted in increasing the mechanical strength of the anastomosis, thus increasing the bursting pressure and decreasing or effacing of anastomotic dehiscence and limiting bacterial translocation.

  14. Glutamine dipeptide for parenteral nutrition in abdominal surgery: A meta-analysis of randomized controlled trials

    Institute of Scientific and Technical Information of China (English)

    Ya-Min Zheng; Fei Li; Ming-Ming Zhang; Xiao-Ting Wu

    2006-01-01

    AIM: To assess the clinical and economical validity of glutamine dipeptide supplemented to parenteral nutrition(PN) in patients undergoing abdominal surgery.METHODS: A meta-analysis of all the relevant randomized controlled trials (RCTs) was performed. The trials compared the standard PN and PN supplemented with glutamine dipeptide in abdominal surgery. RCTs were identified from the following electronic databases:the Cochrane Library, MEDLINE, EMBASE and ISI web of knowledge (SCI). The search was undertaken in April 2006. Literature references were checked by computer or hand at the same time. Clinical trials were extracted and evaluated by two reviewers independently. Statistical analysis was performed by RevMan4.2 software from Cochrane Collaboration. A P value of <0.05 was considered statistically significant.RESULTS: Nine RCTs involving 373 patients were included. The combined results showed that glutamine dipeptide has a positive effect in improving postoperative cumulative nitrogen balance (weighted mean difference (WMD = 8.35, 95% CI [2.98, 13.71], P = 0.002),decreasing postoperative infectious morbidity (OR = 0.24,95% CI [0.06, 0.93], P = 0.04), shortening the length of hospital stay (WMD= -3.55, 95% CI [-5.26, -1.84], P<0.00001). No serious adverse effects were found.CONCLUSION: Postoperative PN supplemented with glutamine dipeptide is effective and safe to decrease the infectious rate, reduce the length of hospital stay and improve nitrogen balance in patients undergoing abdominal surgery. Further high quality trials in children and severe patients are required, and mortality and hospital cost should be considered in future RCTs with sufficient size and rigorous design.

  15. Glucose-independent glutamine metabolism via TCA cycling for proliferation and survival in B-cells

    OpenAIRE

    Le, Anne; Lane, Andrew N.; Hamaker, Max; Bose, Sminu; Gouw, Arvin; Barbi, Joseph; Tsukamoto, Takashi; Rojas, Camilio J.; Slusher, Barbara S.; Zhang, Haixia; Zimmerman, Lisa J.; Liebler, Daniel C.; Slebos, Robbert J. C.; Lorkiewicz, Pawel K.; Higashi, Richard M

    2012-01-01

    Because MYC plays a causal role in many human cancers, including those with hypoxic and nutrient-poor tumor microenvironments, we have determined the metabolic responses of a MYC-inducible human Burkitt lymphoma model P493 cell line to aerobic and hypoxic conditions, and to glucose deprivation, using Stable Isotope Resolved Metabolomics. Using [U-13C]-glucose as the tracer, both glucose consumption and lactate production were increased by MYC expression and hypoxia. Using [U-13C,15N]-glutamin...

  16. Influence of different ammonium, lactate and glutamine concentrations on CCO cell growth

    OpenAIRE

    Slivac, Igor; Blajić, Višnja; Radošević, Kristina; Kniewald, Zlatko; Gaurina Srček, Višnja

    2010-01-01

    In this study the effects of ammonium and lactate on a culture of channel catfish ovary (CCO) cells were examined. We also made investigation on the influence of glutamine, since our previous research revealed that this amino acid stimulated CCO cell growth more than glucose in a concentration-dependent manner. The effect of ammonium in cell culture included the considerable decrease in cell growth rate with eventual growth arrest as well as the retardation of glucose consumption. At ammonium...

  17. Distribution of glutamine and asparagine residues and their near neighbors in peptides and proteins.

    OpenAIRE

    Robinson, A. B.; Robinson, L. R.

    1991-01-01

    In a statistical study of neighboring residues in 1465 peptides and proteins comprising 450,431 residues, it was found that the preferences for residues neighboring to glutamine and asparagine residues are consistent with the hypothesis that the rates of deamidation of these residues are of biological significance. Some dipeptide and tripeptide structures have special usefulness and some are especially undesirable. More such structures exist for amide residues than for other residues, and the...

  18. 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.

  19. Glutamine methylation in histone H2A is an RNA-polymerase-I-dedicated modification

    Science.gov (United States)

    Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C.; Sylvestersen, Kathrine B.; Nelson, Christopher J.; Nielsen, Michael L.; Kouzarides, Tony

    2014-01-01

    Nucleosomes are decorated with numerous post-translational modifications capable of influencing many DNA processes. Here we describe a new class of histone modification, methylation of glutamine, occurring on yeast histone H2A at position 105 (Q105) and human H2A at Q104. We identify Nop1 as the methyltransferase in yeast and demonstrate that fibrillarin is the orthologue enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using an H2AQ105me-specific antibody, shows that this modification is exclusively enriched over the 35S ribosomal DNA transcriptional unit. We show that the Q105 residue is part of the binding site for the histone chaperone FACT (facilitator of chromatin transcription) complex. Methylation of Q105 or its substitution to alanine disrupts binding to FACT in vitro. A yeast strain mutated at Q105 shows reduced histone incorporation and increased transcription at the ribosomal DNA locus. These features are phenocopied by mutations in FACT complex components. Together these data identify glutamine methylation of H2A as the first histone epigenetic mark dedicated to a specific RNA polymerase and define its function as a regulator of FACT interaction with nucleosomes.

  20. Is Long Term Creatine and Glutamine Supplementation Effective in Enhancing Physical Performance of Military Police Officers?

    Directory of Open Access Journals (Sweden)

    Lázaro da Silveira Celismar

    2014-12-01

    Full Text Available The objective of this study was to analyze the effect of supplementation with creatine and glutamine on physical fitness of military police officers. Therefore, an experimental double blind study was developed, with the final sample composed by 32 men randomly distributed into three groups: a group supplemented with creatine (n=10, glutamine (n=10 and a placebo group (n=12 and evaluated in three distinct moments, in an interval of three months (T1, T2 and T3. The physical training had a weekly frequency of 5 sessions x 90 min, including strength exercises, local muscular resistance, flexibility and both aerobic and anaerobic capacity. After analyzing the effect of time, group and interaction (group x time for measures that indicated the physical capabilities of the subjects, a significant effect of time for the entire variable was identified (p0,05. In face of the results it was concluded that supplementation with creatine and glutamine showed no ergogenic effect on physical performance in military police officers.

  1. Glutamine, Exercise and Immunity%谷氨酰胺,运动与免疫

    Institute of Scientific and Technical Information of China (English)

    彭莉

    2002-01-01

    This paper reviewed the relations among glutamine, exercise and immunity.Glutamine is utilized at a high rate by some cells of the immune system and is essential for the normal functions of these cells. Prolonged exercise can decrease muscle and plasma glutamine level, therefore resulting in an impairment of the functions of the immune system.%论述了有关谷氨酰胺,运动与免疫之间的关系及其变化机制.认为免疫细胞对谷氨酰胺有很高的利用率,而且谷氨酰胺对免疫细胞正常功能的维持也有非常重要的作用.长时间耐力运动可能降低骨骼肌和血浆谷氨酰胺的含量,进而损害免疫系统的功能.

  2. Is long term creatine and glutamine supplementation effective in enhancing physical performance of military police officers?

    Science.gov (United States)

    da Silveira, Celismar Lázaro; de Souza, Thiago Siqueira Paiva; Batista, Gilmário Ricarte; de Araújo, Adenilson Targino; da Silva, Júlio César Gomes; de Sousa, Maria do Socorro Cirilo; Marta, Carlos; Garrido, Nuno Domingo

    2014-09-29

    The objective of this study was to analyze the effect of supplementation with creatine and glutamine on physical fitness of military police officers. Therefore, an experimental double blind study was developed, with the final sample composed by 32 men randomly distributed into three groups: a group supplemented with creatine (n=10), glutamine (n=10) and a placebo group (n=12) and evaluated in three distinct moments, in an interval of three months (T1, T2 and T3). The physical training had a weekly frequency of 5 sessions × 90 min, including strength exercises, local muscular resistance, flexibility and both aerobic and anaerobic capacity. After analyzing the effect of time, group and interaction (group × time) for measures that indicated the physical capabilities of the subjects, a significant effect of time for the entire variable was identified (p0,05). In face of the results it was concluded that supplementation with creatine and glutamine showed no ergogenic effect on physical performance in military police officers. PMID:25713653

  3. Glutamine Reduces the Apoptosis of H9C2 Cells Treated with High-Glucose and Reperfusion through an Oxidation-Related Mechanism

    OpenAIRE

    Kai Li; Yong-Chun Cui; Hong Zhang; Xiao-Peng Liu; Dong Zhang; Ai-Li Wu; Jian-Jun Li; Yue Tang

    2015-01-01

    Mitochondrial overproduction of reactive oxygen species (ROS) in diabetic hearts during ischemia/reperfusion injury and the anti-oxidative role of glutamine have been demonstrated. However, in diabetes mellitus the role of glutamine in cardiomyocytes during ischemia/reperfusion injury has not been explored. To examine the effects of glutamine and potential mechanisms, in the present study, rat cardiomyoblast H9C2 cells were exposed to high glucose (33 mM) and hypoxia-reoxygenation. Cell viabi...

  4. Nonribosomal Peptide Synthetase Genes pesL and pes1 Are Essential for Fumigaclavine C Production in Aspergillus fumigatus

    OpenAIRE

    O'Hanlon, Karen A.; Gallagher, Lorna; Schrettl, Markus; Jöchl, Christoph; Kavanagh, Kevin; Larsen, Thomas O.; Doyle, Sean

    2012-01-01

    The identity of metabolites encoded by the majority of nonribosomal peptide synthetases in the opportunistic pathogen, Aspergillus fumigatus, remains outstanding. We found that the nonribosomal peptide (NRP) synthetases PesL and Pes1 were essential for fumigaclavine C biosynthesis, the end product of the complex ergot alkaloid (EA) pathway in A. fumigatus. Deletion of either pesL (ΔpesL) or pes1 (Δpes1) resulted in complete loss of fumigaclavine C biosynthesis, relatively increased production...

  5. Properties of asparagine synthetase in asparagine-independent variants of Jensen rat sarcoma cells induced by 5-azacytidine.

    OpenAIRE

    Sugiyama, R H; Arfin, S M; Harris, M.

    1983-01-01

    Jensen rat sarcoma cells in culture require L-asparagine for growth and lack detectable levels of asparagine synthetase. Cultures exposed for 24 h to graded concentrations of 5-azacytidine give rise to asparagine-independent variants in high frequency. These prototrophs are stable phenotypically whether maintained in the presence or absence of L-asparagine. Asparagine synthetase activity in several variant clones was uniform in thermolability and several kinetic parameters, as well as in immu...

  6. Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J. Christopher; Wu, Ning; Santoro, Stephen; Schultz, Peter G

    2014-03-11

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.

  7. Impaired protein translation in Drosophila models for Charcot–Marie–Tooth neuropathy caused by mutant tRNA synthetases

    OpenAIRE

    Niehues, Sven; Bussmann, Julia; Steffes, Georg; Erdmann, Ines; Sun, Litao; Wagner, Marina; Wang, Guangxia; Koerdt, Sophia N.; Stum, Morgane; Rajbhandary, Uttam L.; Thomas, Ulrich; Aberle, Hermann; Burgess, Robert W.; Yang, Xiang-Lei; Dieterich, Daniela

    2014-01-01

    Dominant mutations in five tRNA synthetases cause Charcot–Marie–Tooth (CMT) neuropathy, suggesting that altered aminoacylation function underlies the disease. However, previous studies showed that loss of aminoacylation activity is not required to cause CMT. Here we present a Drosophila model for CMT with mutations in glycyl-tRNA synthetase (GARS). Expression of three CMT-mutant GARS proteins induces defects in motor performance and motor and sensory neuron morphology, and shortens lifespan. ...

  8. Evidence that the mitochondrial leucyl tRNA synthetase (LARS2) gene represents a novel type 2 diabetes susceptibility gene

    DEFF Research Database (Denmark)

    hart, Leen M; Hansen, Torben; Rietveld, Ingrid;

    2005-01-01

    Previously, we have shown that a mutation in the mitochondrial DNA-encoded tRNA(Leu(UUR)) gene is associated with type 2 diabetes. One of the consequences of this mutation is a reduced aminoacylation of tRNA(Leu(UUR)). In this study, we have examined whether variants in the leucyl tRNA synthetase...... first report of association between an aminoacyl tRNA synthetase gene and disease. Our results further highlight the important role of mitochondria in glucose homeostasis....

  9. Ranking reactive glutamines in the fibrinogen αC region that are targeted by blood coagulant factor XIII.

    Science.gov (United States)

    Mouapi, Kelly Njine; Bell, Jacob D; Smith, Kerrie A; Ariëns, Robert A S; Philippou, Helen; Maurer, Muriel C

    2016-05-01

    Factor XIIIa (FXIIIa) introduces covalent γ-glutamyl-ε-lysyl crosslinks into the blood clot network. These crosslinks involve both the γ and α chains of fibrin. The C-terminal portion of the fibrin α chain extends into the αC region (210-610). Crosslinks within this region help generate a stiffer clot, which is more resistant to fibrinolysis. Fibrinogen αC (233-425) contains a binding site for FXIIIa and three glutamines Q237, Q328, and Q366 that each participate in physiological crosslinking reactions. Although these glutamines were previously identified, their reactivities toward FXIIIa have not been ranked. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and nuclear magnetic resonance (NMR) methods were thus used to directly characterize these three glutamines and probe for sources of FXIIIa substrate specificity. Glycine ethyl ester (GEE) and ammonium chloride served as replacements for lysine. Mass spectrometry and 2D heteronuclear single quantum coherence NMR revealed that Q237 is rapidly crosslinked first by FXIIIa followed by Q366 and Q328. Both (15)NH4Cl and (15)N-GEE could be crosslinked to the three glutamines in αC (233-425) with a similar order of reactivity as observed with the MALDI-TOF mass spectrometry assay. NMR studies using the single αC mutants Q237N, Q328N, and Q366N demonstrated that no glutamine is dependent on another to react first in the series. Moreover, the remaining two glutamines of each mutant were both still reactive. Further characterization of Q237, Q328, and Q366 is important because they are located in a fibrinogen region susceptible to physiological truncations and mutation. The current results suggest that these glutamines play distinct roles in fibrin crosslinking and clot architecture. PMID:26951791

  10. The Metabolic Responses to L-Glutamine of Livers from Rats with Diabetes Types 1 and 2.

    Science.gov (United States)

    Comar, Jurandir Fernando; de Oliveira, Denise Silva; Bracht, Livia; Kemmelmeier, Fumie Suzuki; Peralta, Rosane Marina; Bracht, Adelar

    2016-01-01

    There are several claims about the beneficial effects of supplementing L-glutamine to both type 1 and type 2 diabetes. The purpose of the present study was to provide detailed knowledge about the fate of this amino acid in the liver, the first organ that receives the compound when ingested orally. The study was done using the isolated perfused rat liver, an experimental system that preserves the microcirculation of the organ and that allows to measured several parameters during steady-state and pre steady-state conditions. L-Glutamine was infused in the portal vein (5 mM) and several parameters were monitored. Livers from type 1 diabetic rats showed an accelerated response to L-glutamine infusion. In consequence of this accelerated response livers from type 1 diabetic rats presented higher rates of ammonia, urea, glucose and lactate output during the first 25-30 minutes following L-glutamine infusion. As steady-state conditions approached, however, the difference between type 1 diabetes and control livers tended to disappear. Measurement of the glycogen content over a period of 100 minutes revealed that, excepting the initial phase of the L-glutamine infusion, the increased glucose output in livers from type 1 diabetic rats was mainly due to accelerated glycogenolysis. Livers from type 2 diabetic rats behaved similarly to control livers with no accelerated glucose output but with increased L-alanine production. L-Alanine is important for the pancreatic β-cells and from this point of view the oral intake of L-glutamine can be regarded as beneficial. Furthermore, the lack of increased glucose output in livers from type 2 diabetic rats is consistent with observations that even daily L-glutamine doses of 30 g do not increase the glycemic levels in well controlled type 2 diabetes patients. PMID:27490892

  11. eth-1, the Neurospora crassa locus encoding S-adenosylmethionine synthetase: Molecular cloning, sequence analysis and in vivo overexpression

    Energy Technology Data Exchange (ETDEWEB)

    Mautino, M.R.; Barra, J.L.; Rosa, A.L. [Universidad Nacional de Cordoba (Argentina)

    1996-03-01

    Intense biochemical and genetic research on the eth-1 mutant of Neurospora crassa suggested that this locus might encode S-adenosylmethionine synthetase (S-Adomet synthetase). We have used protoplast transformation and phenotypic rescue of a thermosensitive phenotype associated with the eth-1 mutation to clone the locus. Nucleotide sequence analysis demonstrated that it encodes S-Adomet synthetase. Homology analyses of prokaryotic, fungal and higher eukaryotic S-Adomet synthetase polypeptide sequences show a remarkable evolutionary conservation of the enzyme. N. crassa strains carrying S-Adomet synthetase coding sequences fused to a strong heterologous promoter were constructed to assess the phenotypic consequences of in vivo S-Adomet synthetase overexpression. Studies of growth rates and microscopic examination of vegetative development revealed that normal growth and morphogenesis take place in N. crassa even at abnormally high levels of cellular S-Adomet. The degree of cytosine methylation of a naturally methylated genomic region was dependent on the cellular levels of S-Adomet. We conclude that variation in S-Adomet levels in N. crassa cells, which in addition to the status of genomic DNA methylation could modify the flux of other S-Adomet-dependent metabolic pathways, does not affect growth rate or morphogenesis. 90 refs., 5 figs., 1 tab.

  12. Effects of aeration on formation and localization of the acetyl coenzyme A synthetases of Saccharomyces cerevisiae

    Science.gov (United States)

    Klein, H. P.; Jahnke, L.

    1979-01-01

    Previous studies on the yeast Saccharomyces cerevisiae have shown that two different forms of the enzyme acetyl coenzyme A synthetase (ACS) are present, depending on the conditions under which the cells are grown. The paper evaluates the usefulness of a method designed to assay both synthetases simultaneously in yeast homogenates. The data presented confirm the possibility of simultaneous detection and estimation of the amount of both ACSs of S. cerevisiae in crude homogenates of this strain, making possible the study of physiological factors involved in the formation of these isoenzymes. One important factor for specifying which of the two enzymes is found in these yeast cells is the presence or absence of oxygen in their environment. Aeration not only affects the ratio of the two ACSs but also appears to affect the cellular distribution of these enzymes. Most of the data presented suggest the possibility that the nonaerobic ACS may serve as a precursor to the aerobic form.

  13. Multistep modeling of protein structure: application towards refinement of tyr-tRNA synthetase

    Science.gov (United States)

    Srinivasan, S.; Shibata, M.; Roychoudhury, M.; Rein, R.

    1987-01-01

    The scope of multistep modeling (MSM) is expanding by adding a least-squares minimization step in the procedure to fit backbone reconstruction consistent with a set of C-alpha coordinates. The analytical solution of Phi and Psi angles, that fits a C-alpha x-ray coordinate is used for tyr-tRNA synthetase. Phi and Psi angles for the region where the above mentioned method fails, are obtained by minimizing the difference in C-alpha distances between the computed model and the crystal structure in a least-squares sense. We present a stepwise application of this part of MSM to the determination of the complete backbone geometry of the 321 N terminal residues of tyrosine tRNA synthetase to a root mean square deviation of 0.47 angstroms from the crystallographic C-alpha coordinates.

  14. let-65 is cytoplasmic methionyl tRNA synthetase in C. elegans

    Directory of Open Access Journals (Sweden)

    Maha Z. Alriyami

    2014-12-01

    Full Text Available Cytoplasmic methionyl tRNA synthetase (MetRS is one of more than 20 cytoplasmic aminoacyl tRNA synthetase enzymes (ARS. This family of enzymes catalyzes a process fundamental for protein translation. Using a combination of genetic mapping, oligonucleotide array comparative genomic hybridization, and phenotypic correlation, we show that mutations in the essential gene, let-65, reside within the predicted Caenorhabditis elegans homologue of MetRS, which we have named mars-1. We demonstrate that the lethality associated with alleles of let-65 is fully rescued by a transgenic array that spans the mars-1 genomic region. Furthermore, sequence analysis reveals that six let-65 alleles lead to the alteration of highly conserved amino acids.

  15. Molecular analysis of intragenic recombination at the tryptophan synthetase locus in Neurospora crassa

    Indian Academy of Sciences (India)

    A. Wiest; D. Barchers; M. Eaton; R. Henderson; R. Schnittker; K. Mccluskey

    2013-12-01

    Fifteen different classically generated and mapped mutations at the tryptophan synthetase locus in Neurospora crassa have been characterized to the level of the primary sequence of the gene. This sequence analysis has demonstrated that intragenic recombination is accurate to order mutations within one open reading frame. While classic genetic analysis correctly ordered the mutations, the position of mutations characterized by gene sequence analysis was more accurate. A leaky mutation was found to have a wild-type primary sequence. The presence of unique polymorphisms in the primary sequence of the trp-3 gene from strain 861 confirms that it has a unique history relative to the other strains studied. Most strains that were previously shown to be immunologically nonreactive with antibody preparations raised against tryptophan synthetase protein were shown to have nonsense mutations. This work defines 14 alleles of the N. crassa trp-3 gene.

  16. Structure of an unusual S-adenosylmethionine synthetase from Campylobacter jejuni.

    Science.gov (United States)

    Zano, Stephen P; Pavlovsky, Alexander G; Viola, Ronald E

    2014-02-01

    S-Adenosylmethionine (AdoMet) participates in a wide range of methylation and other group-transfer reactions and also serves as the precursor for two groups of quorum-sensing molecules that function as regulators of the production of virulence factors in Gram-negative bacteria. The synthesis of AdoMet is catalyzed by AdoMet synthetases (MATs), a ubiquitous family of enzymes found in species ranging from microorganisms to mammals. The AdoMet synthetase from the bacterium Campylobacter jejuni (cjMAT) is an outlier among this homologous enzyme family, with lower sequence identity, numerous insertions and substitutions, and higher catalytic activity compared with other bacterial MATs. Alterations in the structure of this enzyme provide an explanation for its unusual dimeric quaternary structure relative to the other MATs. Taken together with several active-site substitutions, this new structure provides insights into its improved kinetic properties with alternative substrates. PMID:24531478

  17. Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment.

    Science.gov (United States)

    Hu, Hong; Bai, Xi; Shah, Assar Ali; Dai, Sifa; Wang, Like; Hua, Jinling; Che, Chuanyan; He, Shaojun; Wen, Aiyou; Jiang, Jinpeng

    2016-06-01

    The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased (P consumption (DFC), the concentrations of Gln, glutamate (Glu), and GABA, and the activities of glutaminase and glutamic acid decarboxylase (GAD) in breast muscle at 28, 35, and 42 days, while it increased (P < 0.05) the activities of glutamine synthetase (GS) and gamma-aminobutyric acid transaminase (GABA-T) at 28, 35, and 42 days. Dietary Gln and GABA improved (P < 0.05) DWG and DFC of broilers under cyclic HS during 28-42 days. In breast muscle, the Gln supplementation increased (P < 0.05) the concentrations of Gln (28, 35, and 42 days), Glu (28, 35, and 42 days), and GABA (42 days) and the activities of glutaminase (28, 35, and 42 days) and GAD (28, 35, and 42 days) but decreased (P < 0.05) GS activities at 28, 35, and 42 days and GABA-T activities at 28 days. The addition of GABA increased (P < 0.05) the concentrations of Gln and Glu and activities of glutaminase and GAD, while it decreased (P < 0.05) GABA-T activities at 28, 35, and 42 days. Significant interactions (P < 0.05) between Gln and GABA were found on breast skeletal muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA

  18. Targeted Disruption of Nonribosomal Peptide Synthetase pes3 Augments the Virulence of Aspergillus fumigatus

    OpenAIRE

    O'Hanlon, Karen; Cairns, Timothy; Stack, Deirdre; Schrettl, Markus; Bignell, Elaine; Kavanagh, Kevin; Miggin, Sinead; O'Keeffe, Grainne; Larsen, Thomas; Doyle, Sean

    2011-01-01

    Nonribosomal peptide synthesis (NRPS) is a documented virulence factor for the opportunistic pathogen Aspergillus fumigatus and other fungi. Secreted or intracellularly located NRP products include the toxic molecule gliotoxin and the iron-chelating siderophores triacetylfusarinine C and ferricrocin. No structural or immunologically relevant NRP products have been identified in the organism. We investigated the function of the largest gene in A. fumigatus, which encodes the NRP synthetase Pes...

  19. Diversity of Nonribosomal Peptide Synthetase Genes in the Microbial Metagenomes of Marine Sponges

    OpenAIRE

    Ute Hentschel; Sheila Marie Pimentel-Elardo; Sebastian Proksch; Lubomir Grozdanov

    2012-01-01

    Genomic mining revealed one major nonribosomal peptide synthetase (NRPS) phylogenetic cluster in 12 marine sponge species, one ascidian, an actinobacterial isolate and seawater. Phylogenetic analysis predicts its taxonomic affiliation to the actinomycetes and hydroxy-phenyl-glycine as a likely substrate. Additionally, a phylogenetically distinct NRPS gene cluster was discovered in the microbial metagenome of the sponge Aplysina aerophoba, which shows ...

  20. Bimodular Peptide Synthetase SidE Produces Fumarylalanine in the Human Pathogen Aspergillus fumigatus

    OpenAIRE

    Steinchen, Wieland; Lackner, Gerald; Yasmin, Sabiha; Schrettl, Markus; Dahse, Hans-Martin; Haas, Hubertus; Hoffmeister, Dirk

    2013-01-01

    The filamentous mold Aspergillus fumigatus causes invasive aspergillosis, a potentially life-threatening infectious disease, in humans. The sidE gene encodes a bimodular peptide synthetase and was shown previously to be strongly upregulated during initiation of murine lung infection. In this study, we characterized the two adenylation domains of SidE with the ATP-[32P]pyrophosphate exchange assay in vitro, which identified fumarate and l-alanine, respectively, as the preferred substrates. Usi...

  1. Genetic identification of essential indels and domains in carbamoyl phosphate synthetase II of Toxoplasma gondii

    OpenAIRE

    Fox, Barbara A.; Ristuccia, Jessica G.; Bzik, David J.

    2008-01-01

    New treatments need to be developed for the significant human diseases of toxoplasmosis and malaria to circumvent problems with current treatments and drug resistance. Apicomplexan parasites causing these lethal diseases are deficient in pyrimidine salvage suggesting that selective inhibition of de novo pyrimidine biosynthesis can lead to a severe loss of UMP and dTMP pools thereby inhibiting parasite RNA and DNA synthesis. Disruption of Toxoplasma gondii carbamoyl phosphate synthetase II (CP...

  2. Genetic Validation of Aminoacyl-tRNA Synthetases as Drug Targets in Trypanosoma brucei

    OpenAIRE

    Kalidas, Savitha; Cestari, Igor; Monnerat, Severine; Li, Qiong; Regmi, Sandesh; Hasle, Nicholas; Labaied, Mehdi; Parsons, Marilyn; Stuart, Kenneth; Phillips, Margaret A.

    2014-01-01

    Human African trypanosomiasis (HAT) is an important public health threat in sub-Saharan Africa. Current drugs are unsatisfactory, and new drugs are being sought. Few validated enzyme targets are available to support drug discovery efforts, so our goal was to obtain essentiality data on genes with proven utility as drug targets. Aminoacyl-tRNA synthetases (aaRSs) are known drug targets for bacterial and fungal pathogens and are required for protein synthesis. Here we survey the essentiality of...

  3. Aminoacyl-tRNA Synthetases, the Genetic Code, and the Evolutionary Process

    OpenAIRE

    Woese, Carl R.; Olsen, Gary J; Ibba, Michael; Söll, Dieter

    2000-01-01

    The aminoacyl-tRNA synthetases (AARSs) and their relationship to the genetic code are examined from the evolutionary perspective. Despite a loose correlation between codon assignments and AARS evolutionary relationships, the code is far too highly structured to have been ordered merely through the evolutionary wanderings of these enzymes. Nevertheless, the AARSs are very informative about the evolutionary process. Examination of the phylogenetic trees for each of the AARSs reveals the followi...

  4. Effect of detergents on membrane-associated glucan synthetase from Paracoccidioides brasiliensis.

    OpenAIRE

    San-Blas, G; San-Blas, F

    1982-01-01

    Yeast and mycelial particulate preparations of Paracoccidioides brasiliensis were subjected to the action of several detergents in an attempt to solubilize the glucan synthetase present in these preparations. This was achieved more successfully in the yeast membranes than in the mycelial ones. The enzymatic activity was greatly stimulated in the insoluble fractions upon treatment with some of the detergents used. The results suggest that the yeast and mycelial phases of P. brasiliensis may di...

  5. Virtual Screening to Identify Lead Inhibitors for Bacterial NAD Synthetase (NADs)

    OpenAIRE

    Moro, Whitney Beysselance; Yang, Zhengrong; Kane, Tasha; Brouillette, Christie G; Brouillette, Wayne J.

    2009-01-01

    Virtual screening was employed to identify new drug-like inhibitors of NAD synthetase (NADs) as antibacterial agents. Four databases of commercially available compounds were docked against three subsites of the NADs active site using FlexX in conjunction with CScore. Over 200 commercial compounds were purchased and evaluated in enzyme inhibition and antibacterial assays. 18 compounds inhibited NADs at or below 100 μM (7.6% hit rate), and two were selected for future SAR studies.

  6. Virtual Screening to Identify Lead Inhibitors for Bacterial NAD Synthetase (NADs)

    Science.gov (United States)

    Moro, Whitney Beysselance; Yang, Zhengrong; Kane, Tasha; Brouillette, Christie G.; Brouillette, Wayne J.

    2009-01-01

    Virtual screening was employed to identify new drug-like inhibitors of NAD synthetase (NADs) as antibacterial agents. Four databases of commercially available compounds were docked against three subsites of the NADs active site using FlexX in conjunction with CScore. Over 200 commercial compounds were purchased and evaluated in enzyme inhibition and antibacterial assays. 18 compounds inhibited NADs at or below 100 μM (7.6% hit rate), and two were selected for future SAR studies. PMID:19249205

  7. Holocarboxylase synthetase regulates expression of biotin transporters by chromatin remodeling events at the SMVT locus⋆

    OpenAIRE

    Gralla, Michael; Camporeale, Gabriela; Zempleni, Janos

    2007-01-01

    The sodium-dependent multivitamin transporter (SMVT) is essential for mediating and regulating biotin entry into mammalian cells. In cells, biotin is covalently linked to histones in a reaction catalyzed by holocarboxylase synthetase (HCS); biotinylation of lysine 12-biotinylated histone H4 (K12Bio H4) causes gene silencing. Here, we propose a novel role for HCS in sensing and regulating levels of biotin in eukaryotic cells. We hypothesized that nuclear translocation of HCS increases in respo...

  8. Nucleotide synthetase ribozymes may have emerged first in the RNA world

    OpenAIRE

    Ma, Wentao; Yu, Chunwu; Zhang, Wentao; Hu, Jiming

    2007-01-01

    Though the “RNA world” hypothesis has gained a central role in ideas concerning the origin of life, the scenario concerning its emergence remains uncertain. It has been speculated that the first scene may have been the emergence of a template-dependent RNA synthetase ribozyme, which catalyzed its own replication: thus, “RNA replicase.” However, the speculation remains uncertain, primarily because of the large sequence length requirement of such a replicase and the lack of a convincing mechani...

  9. Comparative inhibition of bacterial and microsomal 3-ketodihydrosphingosine synthetases by L-cycloserine and other inhibitors.

    OpenAIRE

    Sundaram, K S; Lev, M

    1984-01-01

    Eleven compounds were examined for their capacity to inhibit the first enzyme of the sphingolipid pathway, 3-ketodihydrosphingosine synthetase. Of these, L-cycloserine was the most potent, affecting both bacterial and brain microsomal enzymes to a significant degree at 0.04 mM. D- and L-cycloserine irreversibly inactivated the enzyme, indicating a suicide substrate mode of action. L-Cycloserine was a more potent inhibitor of the growth of Bacteroides levii than was D-cycloserine, indicating t...

  10. On the active site thiol of gamma-glutamylcysteine synthetase: relationships to catalysis, inhibition, and regulation.

    OpenAIRE

    C. S. Huang; Moore, W. R.; Meister, A.

    1988-01-01

    gamma-Glutamylcysteine synthetase (glutamate-cysteine ligase; EC 6.3.2.2) was isolated from an Escherichia coli strain enriched in the gene for this enzyme by recombinant DNA techniques. The purified enzyme has a specific activity of 1860 units/mg and a molecular weight of 56,000. Comparison of the E. coli enzyme with the well-characterized rat kidney enzyme showed that these enzymes have similar catalytic properties (apparent Km values, substrate specificities, turnover numbers). Both enzyme...

  11. Effect of Glutamine Supplementation on Intestinal Mucosal Protein,DNA and Mucosal Morphology of Early-Weaned Piglets

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-min; GAO Zhen-chuan

    2002-01-01

    Forty piglets weaned at 21 days age were randomly assigned to one of two groups. The treatmentgroup contained 1.2 % glutamine. The diets were calculated to be isonitrogenous and isoenergetic, each treat-ment contained five replicates of four piglets. Five piglets from each dietary treatment were killed at 35 daysand 49 days age. The results showed that dietary glutamine supplementation increased jejunal DNA content ofpiglets in the treatment group at 35 days and 49 days age. There was no significant change of ileum DNA con-tent and intestinal protein content between the treatment and control ones. Dietary glutamine supplementationincreased mucosal thickness of piglets in treatment group markedly at 35 days age. The intestinal villus heightswere significantly higher in treatment than that in control. The results of electron micrograph showed that di-etary glutamine supplementation prevented deterioration of intestinal epithelium, and maintained normal in-testinal microvillus structure. The results suggested that glutamine supplementation prevented villus atrophy,and had protective effect on intestinal structure.

  12. mTORC2 Responds to Glutamine Catabolite Levels to Modulate the Hexosamine Biosynthesis Enzyme GFAT1.

    Science.gov (United States)

    Moloughney, Joseph G; Kim, Peter K; Vega-Cotto, Nicole M; Wu, Chang-Chih; Zhang, Sisi; Adlam, Matthew; Lynch, Thomas; Chou, Po-Chien; Rabinowitz, Joshua D; Werlen, Guy; Jacinto, Estela

    2016-09-01

    Highly proliferating cells are particularly dependent on glucose and glutamine for bioenergetics and macromolecule biosynthesis. The signals that respond to nutrient fluctuations to maintain metabolic homeostasis remain poorly understood. Here, we found that mTORC2 is activated by nutrient deprivation due to decreasing glutamine catabolites. We elucidate how mTORC2 modulates a glutamine-requiring biosynthetic pathway, the hexosamine biosynthesis pathway (HBP) via regulation of expression of glutamine:fructose-6-phosphate amidotransferase 1 (GFAT1), the rate-limiting enzyme of the HBP. GFAT1 expression is dependent on sufficient amounts of glutaminolysis catabolites particularly α-ketoglutarate, which are generated in an mTORC2-dependent manner. Additionally, mTORC2 is essential for proper expression and nuclear accumulation of the GFAT1 transcriptional regulator, Xbp1s. Thus, while mTORC1 senses amino acid abundance to promote anabolism, mTORC2 responds to declining glutamine catabolites in order to restore metabolic homeostasis. Our findings uncover the role of mTORC2 in metabolic reprogramming and have implications for understanding insulin resistance and tumorigenesis. PMID:27570073

  13. Enteral glutamine pretreatment does not decrease plasma endotoxin level induced by ischemia-reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Arda Demirkan; Erkin Orazakunov; Berna Savas; M Ayhan Kuzu; Mehmet Melli

    2008-01-01

    AIM: To investigate whether oral glutamine pretreatment prevents impairment of intestinal mucosal integrity during ischemia-reperfusion (I/R) in rats. METHODS: The study was performed as two series with 40 rats in each. Each series of animals was divided into four groups. The first group was used as a control. Animals in the second group were only pretreated with oral glutamine, 1 g/kg for 4 d. The third group received a normal diet, and underwent intestinal I/R, while the fourth group was pretreated with oral glutamine in the same way, and underwent intestinal I/R. Intestinal mucosal permeability to 51Cr-labeled EDTA was measured in urine in the first series of animals. In the second series, histopathological changes in intestinal tissue and plasma endotoxin levels were evaluated. RESULTS: Intestinal I/R produced a significant increase in intestinal permeability, plasma endotoxin level and worsened histopathological alterations. After intestinal I/R, permeability was significantly lower in glutamine- treated rats compared to those which received a normal diet. However, no significant change was observed in plasma endotoxin levels or histopathological findings. CONCLUSION: Although glutamine pretreatment seems to be protective of intestinal integrity, upon I/R injury, such an effect was not observable in the histopathological changes or plasma endotoxin level.

  14. L-glutamine supplementation prevents the development of experimental diabetic cardiomyopathy in streptozotocin-nicotinamide induced diabetic rats.

    Directory of Open Access Journals (Sweden)

    Sachin L Badole

    Full Text Available The objective of the present investigation was to evaluate the effect of L-glutamine on cardiac myopathy in streptozotocin-nicotinamide induced diabetic rats. Diabetes was induced in overnight fasted Sprague Dawely rats by using intraperitonial injection of streptozotocin (55 mg/kg. Nicotinamide (100 mg/kg, i.p. was administered 20 min before administration of streptozotocin. Experimental rats were divided into Group I: non-diabetic control (distilled water; 10 ml/kg, p.o., II: diabetic control (distilled water, 10 ml/kg, p.o., III: L-glutamine (500 mg/kg, p.o. and IV: L-glutamine (1000 mg/kg, p.o.. All groups were diabetic except group I. The plasma glucose level, body weight, electrocardiographic abnormalities, hemodynamic changes and left ventricular contractile function, biological markers of cardiotoxicity, antioxidant markers were determined after 4 months after STZ with nicotinamide injection. Histopathological changes of heart tissue were carried out by using H and E stain. L-glutamine treatment improved the electrocardiographic, hemodynamic changes; LV contractile function; biological markers; oxidative stress parameters and histological changes in STZ induced diabetic rats. Results from the present investigation demonstrated that L-glutamine has seemed a cardioprotective activity.

  15. Glutamine reduces postprandial glycemia and augments the glucagon-like peptide-1 response in type 2 diabetes patients

    DEFF Research Database (Denmark)

    Samocha-Bonet, Dorit; Wong, Olivia; Synnott, Emma-Leigh;

    2011-01-01

    Impaired glucagon-like peptide (GLP-1) secretion or response may contribute to ineffective insulin release in type 2 diabetes. The conditionally essential amino acid glutamine stimulates GLP-1 secretion in vitro and in vivo. In a randomized, crossover study, we evaluated the effect of oral...... glutamine, with or without sitagliptin (SIT), on postprandial glycemia and GLP-1 concentration in 15 type 2 diabetes patients (glycated hemoglobin 6.5 ± 0.6%). Participants ingested a low-fat meal (5% fat) after receiving either water (control), 30 g l-glutamine (Gln-30), 15 g L-glutamine (Gln-15), 100 mg...... SIT, or 100 mg SIT and 15 g L-glutamine (SIT+Gln-15). Studies were conducted 1-2 wk apart. Blood was collected at baseline and postprandially for 180 min for measurement of circulating glucose, insulin, C-peptide, glucagon, and total and active GLP-1. Gln-30 and SIT+Gln-15 reduced the early (t = 0...

  16. Interactions of glutamine dipeptides with sodium dodecyl sulfate in aqueous solution measured by volume, conductivity, and fluorescence spectra

    International Nuclear Information System (INIS)

    Highlights: → Ion-ion and ion-polar group interactions are dominant interactions. → The SDS addition and temperature increase cause a dehydration effect on dipeptides. → The addition of dipeptide in water decreases the ccmc of SDS. → Enthalpy-entropy compensation takes place during micellization. → Micelle aggregation number was decreased by addition of glutamine dipeptides. - Abstract: Densities, conductivities, and fluorescence spectra of {sodium dodecyl sulfate (SDS) + glutamine dipeptide + water} mixtures were measured as a function of temperature. The density data have been utilized to calculate apparent molar volumes, standard partial molar volumes (V2,φo), standard partial molar volumes of transfer from water to aqueous SDS solutions (ΔtVo), the hydration number, partial molar expansibility (Eφo), and Hepler's constant of glutamine dipeptides. The critical micellar concentration (ccmc) and the degree of counterion dissociation of SDS micelles obtained from electrical conductivity data have been estimated at various concentrations of glutamine dipeptide. Thermodynamic parameters of micellization of SDS in aqueous dipeptide solutions have been determined from ccmc values and an enthalpy-entropy compensation effect was observed for the ternary systems. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of SDS with glutamine dipeptide, and the aggregation behavior of SDS. The results have been interpreted in terms of solute-solvent interactions and structural changes in the mixed solutions.

  17. Effects of L-glutamine on acetylsalycylic acid induced gastric lesions and acid back diffusion in dogs.

    Science.gov (United States)

    Hung, C R; Takeuchi, K; Okabe, S; Murata, T; Takagi, K

    1976-12-01

    Effects of L-glutamine on acetylsalicylic acid (ASA)-induced gastric mucosal lesions were studied in mongrel dogs. It was confirmed that when oral ASA at 1.0 or 2.0 g per dog is given in two divided doses, there is severe and consistent dose-dependent mucosal damage in the glandular portion of the stomach in fasted dogs. However, when L-glutamine 2.0 or 4.0 g per dog in two divided doses is given concomitantly with ASA 2.0 g per dog orally, the gastric irritation is significantly inhibited. Instillation of 20 mM of ASA in 100 mM HCl solution into the Heidenhain pouch of Beagle dogs produced a significant loss of H+ from the pouch and a gain of Na+ in the lumen compared with ASA-free controls. When L-glutamine (100 mM) was given concomitantly with ASA (20 mM) into the pouch, changes of electrolyte fluxes in response to ASA alone were significantly suppressed. However, 50 mM of L-glutamine had no appreciable effect on acid back diffusion caused by ASA 20 mM. The amino acid itself had little effect on the ionic movement in the pouch. Gross bleeding from the pouch treated with ASA was never observed with the concomitant dosing of ASA and L-glutamine 50 or 100 mM. PMID:15154

  18. Crystallization and preliminary X-ray diffraction studies of FAD synthetase from Corynebacterium ammoniagenes

    International Nuclear Information System (INIS)

    Native and selenomethionine-labelled FAD synthetase from C. ammoniagenes have been crystallized by the hanging-drop vapour-diffusion method. A MAD data set for SeMet-labelled FAD synthetase was collected to 2.42 Å resolution, while data sets were collected to 1.95 Å resolution for the native crystals. FAD synthetase from Corynebacterium ammoniagenes (CaFADS), a prokaryotic bifunctional enzyme that catalyses the phosphorylation of riboflavin as well as the adenylylation of FMN, has been crystallized using the hanging-drop vapour-diffusion method at 277 K. Diffraction-quality cubic crystals of native and selenomethionine-labelled (SeMet-CaFADS) protein belonged to the cubic space group P213, with unit-cell parameters a = b = c = 133.47 Å and a = b = c = 133.40 Å, respectively. Data sets for native and SeMet-containing crystals were collected to 1.95 and 2.42 Å resolution, respectively

  19. Purification and characterization of fatty acyl-acyl carrier protein synthetase from Vibrio harveyi.

    Science.gov (United States)

    Fice, D; Shen, Z; Byers, D M

    1993-01-01

    A Vibrio harveyi enzyme which catalyzes the ATP-dependent ligation of fatty acids to acyl carrier protein (ACP) has been purified 6,000-fold to apparent homogeneity by anion-exchange, gel filtration, and ACP-Sepharose affinity chromatography. Purified acyl-ACP synthetase migrated as a single 62-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as an 80-kDa protein by gel filtration under reducing conditions. Activity of the purified enzyme was lost within hours in the absence of glycerol and low concentrations of Triton X-100. Acyl-ACP synthetase exhibited Kms for myristic acid, ACP, and ATP of 7 microM, 18 microM, and 0.3 mM, respectively. The enzyme was specific for adenine-containing nucleotides, and AMP was the product of the reaction. No covalent acyl-enzyme intermediate was observed. Enzyme activity was stimulated up to 50% by iodoacetamide but inhibited > 80% by N-ethylmaleimide: inhibition by the latter was prevented by ATP and ACP but not myristic acid. Dithiothreitol and sulfhydryl-directed reagents also influenced enzyme size, activity, and elution pattern on anion-exchange resins. The function of acyl-ACP synthetase has not been established, but it may be related to the capacity of V. harveyi to elongate exogenous fatty acids by an ACP-dependent mechanism. Images PMID:8384617

  20. Directed evolution of adenylosuccinate synthetase from Bacillus subtilis and its application in metabolic engineering.

    Science.gov (United States)

    Wang, Xiaoyue; Wang, Guanglu; Li, Xinli; Fu, Jing; Chen, Tao; Wang, Zhiwen; Zhao, Xueming

    2016-08-10

    Adenylosuccinate synthetase (EC. 6.3.4.4) encoded by purA in Bacillus subtilis, catalyzing the first step of the conversion of IMP to AMP, plays an important role in flux distribution in the purine biosynthetic pathway. In this study, we described the use of site saturation mutagenesis to obtain a desired enzyme activity of adenylosuccinate synthetase and its application in flux regulation. Based on sequence alignment and structural modeling, a library of enzyme variants was created by a semi-rational evolution strategy in position Thr238 and Pro242. Other than purA deletion, the leaky mutation purA(P242N) partially reduced the flux towards AMP derived from IMP and increased the riboflavin synthesis precursor GTP, while also kept the requirement of ATP synthesis for cell growth. PurA(P242N) was introduced into an inosine-producing strain and resulted in an approximately 4.66-fold increase in inosine production, from 0.088±0.009g/L to 0.41±0.051g/L, in minimal medium without hypoxanthine accumulation. These results underline that the directed evolution of adenylosuccinate synthetase could tailor its activities and adjust metabolic flux. This mutation may provide a promising application in purine-based product accumulation, like inosine, guanosine and folate which are directly stemming from purine pathway in B. subtilis. PMID:27234879

  1. Structural studies of lysyl-tRNA synthetase: conformational changes induced by substrate binding.

    Science.gov (United States)

    Onesti, S; Desogus, G; Brevet, A; Chen, J; Plateau, P; Blanquet, S; Brick, P

    2000-10-24

    Lysyl-tRNA synthetase is a member of the class II aminoacyl-tRNA synthetases and catalyses the specific aminoacylation of tRNA(Lys). The crystal structure of the constitutive lysyl-tRNA synthetase (LysS) from Escherichia coli has been determined to 2.7 A resolution in the unliganded form and in a complex with the lysine substrate. A comparison between the unliganded and lysine-bound structures reveals major conformational changes upon lysine binding. The lysine substrate is involved in a network of hydrogen bonds. Two of these interactions, one between the alpha-amino group and the carbonyl oxygen of Gly 216 and the other between the carboxylate group and the side chain of Arg 262, trigger a subtle and complicated reorganization of the active site, involving the ordering of two loops (residues 215-217 and 444-455), a change in conformation of residues 393-409, and a rotation of a 4-helix bundle domain (located between motif 2 and 3) by 10 degrees. The result of these changes is a closing up of the active site upon lysine binding. PMID:11041850

  2. Structural basis for the binding of succinate to succinyl-CoA synthetase.

    Science.gov (United States)

    Huang, Ji; Fraser, Marie E

    2016-08-01

    Succinyl-CoA synthetase catalyzes the only step in the citric acid cycle that provides substrate-level phosphorylation. Although the binding sites for the substrates CoA, phosphate, and the nucleotides ADP and ATP or GDP and GTP have been identified, the binding site for succinate has not. To determine this binding site, pig GTP-specific succinyl-CoA synthetase was crystallized in the presence of succinate, magnesium ions and CoA, and the structure of the complex was determined by X-ray crystallography to 2.2 Å resolution. Succinate binds in the carboxy-terminal domain of the β-subunit. The succinate-binding site is near both the active-site histidine residue that is phosphorylated in the reaction and the free thiol of CoA. The carboxy-terminal domain rearranges when succinate binds, burying this active site. However, succinate is not in position for transfer of the phosphoryl group from phosphohistidine. Here, it is proposed that when the active-site histidine residue has been phosphorylated by GTP, the phosphohistidine displaces phosphate and triggers the movement of the carboxylate of succinate into position to be phosphorylated. The structure shows why succinyl-CoA synthetase is specific for succinate and does not react appreciably with citrate nor with the other C4-dicarboxylic acids of the citric acid cycle, fumarate and oxaloacetate, but shows some activity with L-malate. PMID:27487822

  3. (p)ppGpp synthetases regulate the pathogenesis of zoonotic Streptococcus suis.

    Science.gov (United States)

    Zhu, Jiawen; Zhang, Tengfei; Su, Zhipeng; Li, Lu; Wang, Dong; Xiao, Ran; Teng, Muye; Tan, Meifang; Zhou, Rui

    2016-10-01

    (p)ppGpp-mediated stringent response is one of the main adaption mechanism in bacteria, and the ability to adapt to environment is linked to the pathogenesis of bacterial pathogens. In the zoonotic pathogen Streptococcus suis, there are two (p)ppGpp synthetases, RelA and RelQ. To investigate the regulatory functions of (p)ppGpp/(p)ppGpp synthetases on the pathogenesis of S. suis, the phenotypes of the [(p)ppGpp(0)] mutant ΔrelAΔrelQ and its parental strain were compared. Light and electron microscopy observation showed that the mutant strain had a longer chain-length than its parental strain. Disruption of relA and relQ led to decreased adhesive and invasive ability to HEp-2 cells, and increased sensitivity to the blood killing and phagocytosis. Mouse infection experiments showed that the mutant strain was attenuated and easier to be cleaned up in vivo. Quantitative reverse transcription PCR (qRT-PCR) analysis indicated that the expressions of virulence related genes involving in morphology and virulence were down-regulated in the mutant strain. Our study demonstrated that the (p)ppGpp synthetases or (p)ppGpp can regulate the pathogenesis of this important zoonotic pathogen. PMID:27524648

  4. Interferon titer and the 2',5'-oligoadenylate-synthetase activity in rat thymus lymphocytes in conditions of Omeprazol-caused hypergastrinemia

    OpenAIRE

    Kompanets I. V.; Korotkiy О. G.; Karpovets T. P.; Pilipenko S. V.; Nikolska V. V.; Ostapchenko L. I.; Yankovsky D. S.

    2013-01-01

    The aim of this work was the determination of rat thymocytes response to hypergastrinemia evoked by hypoacidity and multiprobiotic «Symbiter® acidophilic concentrated» (symbiter) treatment via the estimation of the interferon (IFN) titer and 2', 5'-oligoadenylate (OA)-synthetase activity in lymphocytes. 2', 5'-OA-synthetase is the IFN-induced enzyme. Methods. The micromethod of IFN titer determination by antiviral activity, spectrophotometrical method of 2', 5'-OA-synthetase activity determin...

  5. Glutamine supplemented parenteral nutrition prevents intestinal ischemia- reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Guo-Hao Wu; Hao Wang; Yan-Wei Zhang; Zhao-Han Wu; Zhao-Guang Wu

    2004-01-01

    AIM: To examine whether glutamine prevents the injury to the intestinal mucosa after intestinal ischemia-reperfusion (I/R) in rats.METHODS: Thirty male Sprague-Dawley rats were randomly divided into 3 groups: a standard parenteral nutrition (PN)group (n = 10); an I/R-PN group (n = 10); an I/R-glutamine enriched PN (I/R-Gln) group (n = 10). The superior mesenteric artery (SMA) was clamped. After 60 min of ischemia, reperfusion was initiated and infusion was started. All rats received isocaloric and isonitrogenous nutritional support for 48 h. Spleen, liver, mesenteric lymph nodes (MLN), and intestinal segments were removed for morphological and biochemical analyses, and blood samples were collected for bacterial culture and measurement of endotoxin levels.The permeability of intestinnal mucosa was assayed by measurement of D-(-)-lactate levels in plasma.RESULTS: In I/R-PN group, extensive epithelial atrophy was observed, mucosal thickness, villous height, crypt depth and villous surface area were decreased significantly compared with PN group, whereas these findings did not occur in the I/R-Gln group. The incidence of intestinal bacterial translocation to spleen, liver, MLN, and blood was significantly higher in I/R-PN group than that in other groups.Plasma endotoxin levels significantly increased in the I/R-PN group compared with the I/R-Gln group. Remarkably higher values of D-(-)-lactate were also detected in PN group compared with that in I/R-Gln group.CONCLUSION: Glutamine protects the morphology and function of intestinal mucosa from injury after I/R in rats.

  6. Study on L-Glutamine Fermentation%谷氨酰胺发酵的研究

    Institute of Scientific and Technical Information of China (English)

    杨燕凌

    2005-01-01

    本文对磺胺胍(SG)抗性株谷氨酸棒杆菌S9114发酵生成谷氨酰胺条件作了研究,确立了所试因素的最佳组合:碳源为6%淀粉水解糖,氮源为4%氯化铵,锌离子为20mg/L,碳酸钙为5%装量为30ml/500ml三角瓶,初始pH为7.0,接种量为10%.在最适条件下发酵72h生成谷氨酰胺的最高量为52.6mg/ml,平均为49.5mg/ml.%The L-glutamine fermentation was carried out with a SG resistant strain Carynebacterium Glutamicum S9114,and the optimum conditions for producing glutamine were listed as follows: the carbon source was 18% hydrolysed starch and the nitrogen source was 4% NH4Cl, Zn2+ concentration was 20mg/L and CaCO3 concentration was 5%. The 500ml flask were filled 30ml media with pH7.0 to incubate 72h, with inoculation amount 10%. Under optimum condions, Carynebacterium Glutamicum S9114 was able to accumulate the maximum quantity of 52.6mg/ml with the average of 49.5mg/ml of L-glutamine.

  7. The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine.

    Science.gov (United States)

    Cribb, Paul J; Williams, Andrew D; Carey, Michael F; Hayes, Alan

    2006-10-01

    Different dietary proteins affect whole body protein anabolism and accretion and therefore, have the potential to influence results obtained from resistance training. This study examined the effects of supplementation with two proteins, hydrolyzed whey isolate (WI) and casein (C), on strength, body composition, and plasma glutamine levels during a 10 wk, supervised resistance training program. In a double-blind protocol, 13 male, recreational bodybuilders supplemented their normal diet with either WI or C (1.5 gm/kg body wt/d) for the duration of the program. Strength was assessed by 1-RM in three exercises (barbell bench press, squat, and cable pull-down). Body composition was assessed by dual energy X-ray absorptiometry. Plasma glutamine levels were determined by the enzymatic method with spectrophotometric detection. All assessments occurred in the week before and the week following 10 wk of training. Plasma glutamine levels did not change in either supplement group following the intervention. The WI group achieved a significantly greater gain (P < 0.01) in lean mass than the C group (5.0 +/- 0.3 vs. 0.8 +/- 0.4 kg for WI and C, respectively) and a significant (P < 0.05) change in fat mass (-1.5 +/- 0.5 kg) compared to the C group (+0.2 +/- 0.3 kg). The WI group also achieved significantly greater (P < 0.05) improvements in strength compared to the C group in each assessment of strength. When the strength changes were expressed relative to body weight, the WI group still achieved significantly greater (P < 0.05) improvements in strength compared to the C group. PMID:17240782

  8. 谷氨酰胺代谢与运动%Glutamine Metabolism and Exercise

    Institute of Scientific and Technical Information of China (English)

    彭莉

    2001-01-01

    谷氨酰胺是人体内重要的氨基酸,与运动能力有密切的联系。机体运动对谷氨酰胺代谢的影响与运动持续时间、运动强度、运动方式等因素有关,短时间运动能使血浆谷氨酰胺浓度升高,长时间耐力运动则使之含量下降。长时间耐力性运动导致的血浆谷氨酰胺含量的降低可能引起耐力运动中蛋白质分解代谢失常、氨转运清除率下降以及运动后机体免疫功能下降等。本文综述了谷氨酰胺的代谢过程与作用;分析了运动尤其是长时间耐力性运动与谷氨酰胺代谢之间相互影响的关系及其机制;提出谷氨酰胺代谢的改变可能是长时间耐力性运动中疲劳产生的原因之一。%This article makes analysis on the metabolism and function of glutamine, put forwards the relationship between exercise and glutamine metabolism. The change of glutamine metabolism might be one of the reasons of fatigue during prolonged exercise.

  9. Peptide glutamine supplementation for tolerance of intermittent exercise in soccer players

    Directory of Open Access Journals (Sweden)

    Alessandra Favano

    2008-01-01

    Full Text Available OBJECTIVE: To investigate whether supplementation of carbohydrate together with peptide glutamine would increase exercise tolerance in soccer players. METHODS: Nine male soccer players (mean age: 18.4 ± 1.1 years; body mass: 69.2 ± 4.6 kg; height: 175.5 ± 7.3 cm; and maximum oxygen consumption of 57.7 ± 4.8 ml.kg-1.min-1 were evaluated. All of them underwent a cardiopulmonary exercise test and followed a protocol that simulated the movements of a soccer game in order to evaluate their tolerance to intermittent exercise. By means of a draw, either carbohydrate with peptide glutamine (CARBOGLUT: 50g of maltodextrin + 3.5g of peptide glutamine in 250 ml of water or carbohydrate alone (CARBO: 50g of maltodextrin in 250 ml of water was administered in order to investigate the enhancement of the soccer players' performances. The solution was given thirty minutes before beginning the test, which was performed twice with a one-week interval between tests. RESULTS: A great improvement in the time and distance covered was observed when the athletes consumed the CARBOGLUT mixture. Total distance covered was 12750 ± 4037m when using CARBO, and 15571 ± 4184m when using CARBOGLUT (p<0.01; total duration of tolerance was 73 ± 23 min when using CARBO and 88 ± 24 min when using CARBOGLUT (p<0.01. CONCLUSION: The CARBOGLUT mixture was more efficient in increasing the distance covered and the length of time for which intermittent exercise was tolerated. CARBOGLUT also reduced feelings of fatigue in the players compared with the use of the CARBO mixture alone.

  10. Glutamate, GABA, and glutamine are synchronously upregulated in the mouse lateral septum during the postpartum period.

    Science.gov (United States)

    Zhao, Changjiu; Gammie, Stephen C

    2014-12-01

    Dramatic structural and functional remodeling occurs in the postpartum brain for the establishment of maternal care, which is essential for the growth and development of young offspring. Glutamate and GABA signaling are critically important in modulating multiple behavioral performances. Large scale signaling changes occur in the postpartum brain, but it is still not clear to what extent the neurotransmitters glutamate and GABA change and whether the ratio of glutamate/GABA remains balanced. In this study, we examined the glutamate/GABA-glutamine cycle in the lateral septum (LS) of postpartum female mice. In postpartum females (relative to virgins), tissue levels of glutamate and GABA were elevated in LS and increased mRNA was found for the respective enzymes producing glutamate and GABA, glutaminase (Gls) and glutamate decarboxylase 1 and 2 (Gad1 and Gad2). The common precursor, glutamine, was elevated as was the enzyme that produces it, glutamate-ammonia ligase (Glul). Additionally, glutamate, GABA, and glutamine were positively correlated and the glutamate/GABA ratio was almost identical in the postpartum and virgin females. Collectively, these findings indicate that glutamate and GABA signaling are increased and that the ratio of glutamate/GABA is well balanced in the maternal LS. The postpartum brain may provide a useful model system for understanding how glutamate and GABA are linked despite large signaling changes. Given that some mental health disorders, including depression and schizophrenia display dysregulated glutamate/GABA ratio, and there is increased vulnerability to mental disorders in mothers, it is possible that these postpartum disorders emerge when glutamate and GABA changes are not properly coordinated. PMID:25451092

  11. Effects of glutamine and hyperoxia on pulmonary oxygen uptake and muscle deoxygenation kinetics.

    Science.gov (United States)

    Marwood, Simon; Bowtell, Joanna L

    2007-01-01

    The aim of the present study was to determine whether glutamine ingestion, which has been shown to enhance the exercise-induced increase in the tricarboxylic acid intermediate (TCAi) pool size, resulted in augmentation of the rate of increase in oxidative metabolism at the onset of exercise. In addition, the potential interaction with oxygen availability was investigated by completing exercise in both normoxic and hyperoxic conditions. Eight male cyclists cycled for 6 min at 70% VO2max following consumption of a drink (5 ml kg body mass(-1)) containing a placebo or 0.125 g kg body mass(-1) of glutamine in normoxic (CON and GLN respectively) and hyperoxic (HYP and HPG respectively) conditions. Breath-by-breath pulmonary oxygen uptake and continuous, non-invasive muscle deoxygenation (via near infrared spectroscopy: NIRS) data were collected throughout exercise. The time constant of the phase II component of pulmonary oxygen uptake kinetics was unchanged between trials (CON: 21.5 +/- 3.0 vs. GLN: 18.2 +/- 1.3 vs. HYP: 18.9 +/- 2.0 vs. HPG: 18.6 +/- 1.2 s). There was also no alteration of the kinetics of relative muscle deoxygenation as measured via NIRS (CON: 5.9 +/- 0.7 vs. GLN: 7.3 +/- 0.8 vs. HYP: 6.5 +/- 0.9 vs. HPG: 5.2 +/- 0.4 s). Conversely, the mean response time of pulmonary oxygen uptake kinetics was faster (CON: 33.4 +/- 1.2 vs. GLN: 29.8 +/- 2.3 vs. HYP: 33.2 +/- 2.6 vs. HPG: 31.6 +/- 2.6 s) and the time at which muscle deoxygenation increased above pre-exercise values was earlier (CON: 9.6 +/- 0.9 vs. GLN: 8.7 +/- 1.1 vs. HYP: 8.5 +/- 0.8 vs. HPG: 8.4 +/- 0.7 s) following glutamine ingestion. In normoxic conditions, plasma lactate concentration was lower following glutamine ingestion compared to placebo. Whilst the results of the present study provide some support for the present hypothesis, the lack of any alteration in the time constant of pulmonary oxygen uptake and muscle deoxygenation kinetics suggest that the normal exercise induced expansion of

  12. Synthesis, characterization, and biological evaluation of poly(L-γ-glutamyl-glutamine)-paclitaxel nanoconjugate

    OpenAIRE

    Van, Sang

    2010-01-01

    Sang Van1, Sanjib K Das1, Xinghe Wang1, Zhongling Feng1, Yi Jin1, Zheng Hou1, Fu Chen1, Annie Pham1, Nan Jiang1, Stephen B Howell2, Lei Yu11Nitto Denko Technical Corporation, Oceanside, CA, USA; 2Moores Cancer Center, University of California, La Jolla, San Diego, CA, USAAbstract: The purpose of this study was to develop a novel, highly water-soluble poly(L-γ-glutamyl-glutamine)-paclitaxel nanoconjugate (PGG-PTX) that would improve the therapeutic index of paclitaxel (PTX). PGG-PTX ...

  13. Clinical use of growth hormone and glutamine in short bowel syndrome

    OpenAIRE

    Cukier Celso; Waitzberg Dan L.; Borges Viviane Chaer; Silva Maria de Lourdes T.; Gama-Rodrigues Joaquim; Pinotti Henrique Walter

    1999-01-01

    Growth hormone (GH) and glutamine (GLN) are considered bowel trophic factors and are used experimentally after bowel resection. Their clinical uses in short bowel syndrome (SBS) are still not standardized. It is of interest to verify metabolic, nutritional and side effects of the association of GH and GLN in SBS. Three patients, 39 (A), 33 (B), and 01 years old (C) underwent bowel resection with jejunum anastomosis 15 cm (A) and 60 cm (B) distant from the Treitz angle, and 40 cm (C) preservin...

  14. Nucleic acids encoding plant glutamine phenylpyruvate transaminase (GPT) and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-03-29

    Glutamine phenylpyruvate transaminase (GPT) proteins, nucleic acid molecules encoding GPT proteins, and uses thereof are disclosed. Provided herein are various GPT proteins and GPT gene coding sequences isolated from a number of plant species. As disclosed herein, GPT proteins share remarkable structural similarity within plant species, and are active in catalyzing the synthesis of 2-hydroxy-5-oxoproline (2-oxoglutaramate), a powerful signal metabolite which regulates the function of a large number of genes involved in the photosynthesis apparatus, carbon fixation and nitrogen metabolism.

  15. 大别山野生油茶中茶氨酸检测与茶氨酸合成酶基因克隆%Determination of theanine and cloning of theanine synthetase gene in Dabieshan wild Camellia oleifera

    Institute of Scientific and Technical Information of China (English)

    马林龙; 顾辰辰; 邓威威; 金阳; 宛晓春

    2015-01-01

    茶氨酸是茶树叶片中最丰富的游离氨基酸,具有重要的生理药理功能,但迄今仅在蘑菇、蕈和一些山茶科(属)植物中检测到茶氨酸.茶氨酸因有一种独特的风味特色“umami鲜爽味”而被人类营养学广泛研究,并发现合成茶氨酸的植物不仅在植物分类上具有积极意义,而且对于植物资源的有效发掘有巨大经济价值;同时还可以间接去研究茶树中茶氨酸的代谢机理以及茶氨酸合成酶的分离纯化和 TS基因的克隆表达.该文运用 HPLC、LC-TOF/MS对大别山地区野生幼年与成年油茶根、叶中茶氨酸进行检测,并结合分子生物学手段对油茶中茶氨酸合成酶(theanine synthetase,TS)基因进行克隆与生物信息学分析.结果表明:在幼年的油茶根中检测到茶氨酸,含量为0.08 mg·g-1(鲜重),而在幼年的油茶叶片和成年油茶根、叶中均未检测到茶氨酸;在幼年油茶根中克隆出一条长为1071 bp油茶 TS 基因开放阅读框,其基因序列与茶树谷氨酰胺合成酶(glutamine synthetase,GS,AB117934)基因和TS(DD410896)序列的同源性达到98%,氨基酸序列与茶树中GS(AB117934)和TS(DD410896)的相似性高达99%.经生物信息学分析,该序列编码的TS蛋白具有20个磷酸化位点,不存在信号肽序列与跨膜结构,含有卷曲螺旋结构的亲水性细胞质蛋白.该研究将为油茶新经济价值的发掘,为茶氨酸在油茶中合成代谢途径的研究提供一定的理论基础,同时也为进一步研究茶氨酸在茶树中代谢机理提供了新的研究思路.%Theanine was discovered as the most abundant free amino acid in Camellia sinensis leaves with many physi-ological and pharmacological function.However,only limited reports have subsequently been published about theanine in the plant kingdom,for instance,mushroom,Xerocomus badius,and some theaceae plants.Theanine has been ex-tensively studied about human nutrition for tea unique taste

  16. Thermochemical study of processes of complex formation of Cu2+ ions with L-glutamine in aqueous solutions

    Science.gov (United States)

    Gorboletova, G. G.; Gridchin, S. N.; Lutsenko, A. A.

    2010-11-01

    Heats of the interaction of Cu(NO3)2 solutions with L-glutamine solutions were measured directly by calorimetry at a temperature of 298.15 K and ionic strength values of 0.5, 1.0, and 1.5 (KNO3). Using RRSU universal software, the experimental data were subjected to rigorous mathematical treatment with allowances made for several concurrent processes in the system. The heats of formation of the CuL+ and CuL2 complexes were calculated from the calorimetric measurements. The standard heats of the complex formation of Cu2+ with L-glutamine were obtained by extrapolation to zero ionic strength. The complete thermodynamic characteristic (Δr H o, Δr G o, Δr S o) of the complex formation processes in a Cu2+—L-glutamine system was obtained.

  17. Biosynthesis of Polymyxins B, E, and P Using Genetically Engineered Polymyxin Synthetases in the Surrogate Host Bacillus subtilis.

    Science.gov (United States)

    Kim, Se-Yu; Park, Soo-Young; Choi, Soo-Keun; Park, Seung-Hwan

    2015-07-01

    The development of diverse polymyxin derivatives is needed to solve the toxicity and resistance problems of polymyxins. However, no platform has generated polymyxin derivatives by genetically engineering a polymyxin synthetase, which is a nonribosomal peptide synthetase. In this study, we present a two-step approach for the construction of engineered polymyxin synthetases by substituting the adenylation (A) domains of polymyxin A synthetase, which is encoded by the pmxABCDE gene cluster of Paenibacillus polymyxa E681. First, the seventh L-threonine-specific A-domain region in pmxA was substituted with the Lleucine- specific A-domain region obtained from P. polymyxa ATCC21830 to make polymyxin E synthetase, and then the sixth D-leucine-specific A-domain region (A6-D-Leu-domain) was substituted with the D-phenylalanine-specific A-domain region (A6-D-Phe-domain) obtained from P. polymyxa F4 to make polymyxin B synthetase. This step was performed in Escherichia coli on a pmxA-containing fosmid, using the lambda Red recombination system and the sacB gene as a counter-selectable marker. Next, the modified pmxA gene was fused to pmxBCDE on the chromosome of Bacillus subtilis BSK4dA, and the resulting recombinant strains BSK4-PB and BSK4-PE were confirmed to produce polymyxins B and E, respectively. We also succeeded in constructing the B. subtilis BSK4-PP strain, which produces polymyxin P, by singly substituting the A6-D-Leu-domain with the A6-D-Phe-domain. This is the first report in which polymyxin derivatives were generated by genetically engineering polymyxin synthetases. The two recombinant B. subtilis strains will be useful for improving the commercial production of polymyxins B and E, and they will facilitate the generation of novel polymyxin derivatives. PMID:26059516

  18. Glutamine inhibits CCl4 induced liver fibrosis in mice and TGF-β1 mediated epithelial-mesenchymal transition in mouse hepatocytes.

    Science.gov (United States)

    Shrestha, Nirajan; Chand, Lokendra; Han, Myung Kwan; Lee, Seung Ok; Kim, Chan Young; Jeong, Yeon Jun

    2016-07-01

    Glutamine, traditionally a non-essential amino acid, now has been considered as essential in serious illness and injury. It is a major precursor for glutathione synthesis. However, the anti-fibrotic effect of glutamine and its molecular mechanism in experimental liver fibrosis have not been explored. In the present study we aimed to examine the potential role of glutamine in carbon tetrachloride (CCl4) induced liver fibrosis and TGF-β1 mediated epithelial mesenchymal transition (EMT) and apoptosis in mouse hepatocytes. Liver fibrosis was induced by intraperitoneal injection of CCl4 three times a week for 10 weeks. Glutamine treatment effectively attenuated liver injury and oxidative stress. Collagen content was significantly decreased in liver sections of glutamine treated mice compared to CCl4 model mice. Furthermore, glutamine decreased expression level of α-SMA and TGF-β in liver tissue. Our in vitro study showed that TGF-β1 treatment in hepatocytes resulted in loss of E-cadherin and increased expression of mesenchymal markers and EMT related transcription factor. In addition, TGF-β1 increased the expression of apoptotic markers. However, glutamine interestingly suppressed TGF-β1 mediated EMT and apoptosis. In conclusion, our results suggest that glutamine ameliorates CCl4 induced liver fibrosis and suppresses TGF-β1 induced EMT progression and apoptosis. PMID:27137983

  19. L-glutamine and whole protein restore first-phase insulin response and increase glucagon-like Peptide-1 in type 2 diabetes patients

    DEFF Research Database (Denmark)

    Samocha-Bonet, Dorit; Chisholm, Don J; Holst, Jens Juul;

    2015-01-01

    l-glutamine triggers glucagon-like peptide-1 (GLP-1) release from L cells in vitro and when ingested pre-meal, decreases postprandial glycaemia and increases circulating insulin and GLP-1 in type 2 diabetes (T2D) patients. We aimed to evaluate the effect of oral l-glutamine, compared with whole...... protein low in glutamine, on insulin response in well-controlled T2D patients. In a randomized study with a crossover design, T2D patients (n = 10, 6 men) aged 65.1 ± 5.8, with glycosylated hemoglobin (HbA1c) 6.6% ± 0.7% (48 ± 8 mmol/mol), received oral l-glutamine (25 g), protein (25 g) or water...... tested 1–2 weeks apart. Both l-glutamine and protein increased first-phase insulin response (p ≤ 0.02). Protein (p = 0.05), but not l-glutamine (p = 0.2), increased second-phase insulin response. Total GLP-1 was increased by both l-glutamine and protein (p ≤ 0.02). We conclude that oral l-glutamine and...

  20. The metabolism of L-arginine and its significance for the biosynthesis of endothelium-derived relaxing factor: L-glutamine inhibits the generation of L-arginine by cultured endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Sessa, W.C.; Hecker, M.; Mitchell, J.A. Vane, J.R. (William Harvey Research Inst., London (England))

    1990-11-01

    The mechanism by which L-glutamine (L-Gln) inhibits the release of endothelium-derived factor from bovine aortic cultured endothelial cells was investigated. The intracellular concentration of L-arginine (L-Arg) in Arg-depleted endothelial cells was inversely related to the level of L-Gln. Removal of L-Gln from the culture medium (usually containing L-Gln at 2 mM) abolished the inhibitory effect of the culture medium on L-Arg generation. L-Gln (0.2 and 2 mM) but not D-Gln inhibited the generation of L-Arg by both Arg-depleted and nondepleted endothelial cells. L-Gln did not interfere with the uptake of L-Arg or the metabolism of L-Arg-L-Phe to L-Arg but inhibited the formation of L-Arg from L-citrulline (L-Cit), L-Cit-L-Phe, and N{sup G}-monomethyl-L-arginine. L-Gln also inhibited the conversion of L-({sup 14}C)Cit to L-({sup 14}C)Arg by Arg-depleted endothelial cells. However, L-Gln did not inhibit the conversion of L-argininosuccinic acid to L-Arg by endothelial cell homogenates. Thus, L-Gln interferes with the conversion of L-Cit to L-Arg probably by acting on argininosuccinate synthetase rather than argininosuccinate lyase. L-Gln also inhibited the generation of L-Arg by the monocyte-macrophage cell line J774 but had no effect on the conversion of L-Cit to L-Arg by these cells. As the release of endothelium-derived relaxing factor from cultured and non-cultured endothelial cells is limited by the availability of L-Arg, endogenous L-Gln may play a regulatory role in the biosynthesis of endothelium-derived relaxing factor.

  1. The metabolism of L-arginine and its significance for the biosynthesis of endothelium-derived relaxing factor: L-glutamine inhibits the generation of L-arginine by cultured endothelial cells

    International Nuclear Information System (INIS)

    The mechanism by which L-glutamine (L-Gln) inhibits the release of endothelium-derived factor from bovine aortic cultured endothelial cells was investigated. The intracellular concentration of L-arginine (L-Arg) in Arg-depleted endothelial cells was inversely related to the level of L-Gln. Removal of L-Gln from the culture medium (usually containing L-Gln at 2 mM) abolished the inhibitory effect of the culture medium on L-Arg generation. L-Gln (0.2 and 2 mM) but not D-Gln inhibited the generation of L-Arg by both Arg-depleted and nondepleted endothelial cells. L-Gln did not interfere with the uptake of L-Arg or the metabolism of L-Arg-L-Phe to L-Arg but inhibited the formation of L-Arg from L-citrulline (L-Cit), L-Cit-L-Phe, and NG-monomethyl-L-arginine. L-Gln also inhibited the conversion of L-[14C]Cit to L-[14C]Arg by Arg-depleted endothelial cells. However, L-Gln did not inhibit the conversion of L-argininosuccinic acid to L-Arg by endothelial cell homogenates. Thus, L-Gln interferes with the conversion of L-Cit to L-Arg probably by acting on argininosuccinate synthetase rather than argininosuccinate lyase. L-Gln also inhibited the generation of L-Arg by the monocyte-macrophage cell line J774 but had no effect on the conversion of L-Cit to L-Arg by these cells. As the release of endothelium-derived relaxing factor from cultured and non-cultured endothelial cells is limited by the availability of L-Arg, endogenous L-Gln may play a regulatory role in the biosynthesis of endothelium-derived relaxing factor

  2. IMPROVEMENT OF INTESTINAL PERMEABILITY WITH ALANYL-GLUTAMINE IN HIV PATIENTS: a randomized, double blinded, placebo-controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Roberio Dias LEITE

    2013-03-01

    Full Text Available Context Glutamine is the main source of energy of the enterocyte and diarrhea and weight loss are frequent in HIV infected patients. Objective To determine the effect of alanyl-glutamine supplementation on intestinal permeability and absorption in these patients. Methods Randomized double-blinded, placebo-controlled study using isonitrogenous doses of alanyl-glutamine (24 g/day and placebo (glycine, 25 g/day during 10 days. Before and after this nutritional supplementation lactulose and mannitol urinary excretion were determined by high performance liquid chromatography. Results Forty six patients with HIV/AIDS, 36 of whom were male, with 37.28 ± 3 (mean ± standard error years were enrolled. Twenty two and 24 subjects were treated with alanyl-glutamine and with glycine respectively. In nine patients among all in the study protocol that reported diarrhea in the 14 days preceding the beginning of the study, mannitol urinary excretion was significantly lower than patients who did not report this symptom [median (range: 10.51 (3.01–19.75 vs. 15.37 (3.93–46.73; P = 0.0281] and lactulose/mannitol ratio was significantly higher [median (range: 0.04 (0.00–2.89 vs. 0.02 (0.00–0.19; P = 0.0317]. There was also a significant increase in mannitol urinary excretion in the group treated with alanyl-glutamine [median (range: 14.38 (8.25–23.98 before vs 21.24 (6.27–32.99 after treatment; n = 14, P = 0.0382]. Conclusion Our results suggest that the integrity and intestinal absorption are more intensely affected in patients with HIV/AIDS who recently have had diarrhea. Additionally, nutritional supplementation with alanyl-glutamine was associated with an improvement in intestinal absorption.

  3. Targeting glutamine metabolism in multiple myeloma enhances BIM binding to BCL-2 eliciting synthetic lethality to venetoclax.

    Science.gov (United States)

    Bajpai, R; Matulis, S M; Wei, C; Nooka, A K; Von Hollen, H E; Lonial, S; Boise, L H; Shanmugam, M

    2016-07-28

    Multiple myeloma (MM) is a plasma cell malignancy that is largely incurable due to development of resistance to therapy-elicited cell death. Nutrients are intricately connected to maintenance of cellular viability in part by inhibition of apoptosis. We were interested to determine if examination of metabolic regulation of BCL-2 proteins may provide insight on alternative routes to engage apoptosis. MM cells are reliant on glucose and glutamine and withdrawal of either nutrient is associated with varying levels of apoptosis. We and others have demonstrated that glucose maintains levels of key resistance-promoting BCL-2 family member, myeloid cell leukemic factor 1 (MCL-1). Cells continuing to survive in the absence of glucose or glutamine were found to maintain expression of MCL-1 but importantly induce pro-apoptotic BIM expression. One potential mechanism for continued survival despite induction of BIM could be due to binding and sequestration of BIM to alternate pro-survival BCL-2 members. Our investigation revealed that cells surviving glutamine withdrawal in particular, enhance expression and binding of BIM to BCL-2, consequently sensitizing these cells to the BH3 mimetic venetoclax. Glutamine deprivation-driven sensitization to venetoclax can be reversed by metabolic supplementation with TCA cycle intermediate α-ketoglutarate. Inhibition of glucose metabolism with the GLUT4 inhibitor ritonavir elicits variable cytotoxicity in MM that is marginally enhanced with venetoclax treatment, however, targeting glutamine metabolism with 6-diazo-5-oxo-l-norleucine uniformly sensitized MM cell lines and relapse/refractory patient samples to venetoclax. Our studies reveal a potent therapeutic strategy of metabolically driven synthetic lethality involving targeting glutamine metabolism for sensitization to venetoclax in MM. PMID:26640142

  4. Luminal leptin inhibits L-glutamine transport in rat small intestine: involvement of ASCT2 and B0AT1

    OpenAIRE

    Ducroc, R. (Robert); Sakar, Y. (Yassine); Fanjul, C. (Carmen); Barber, A. (Ana); Bado, A.; Lostao, M.P. (María Pilar)

    2010-01-01

    International audience l-glutamine is the primary metabolic fuel for enterocytes. Glutamine from the diet is transported into the absorptive cells by two sodium-dependent neutral amino acid transporters present at the apical membrane: ASCT2/SLC1A5 and B(0)AT1/SLC6A19. We have demonstrated that leptin is secreted into the stomach lumen after a meal and modulates the transport of sugars after binding to its receptors located at the brush border of the enterocytes. The present study was desig...

  5. 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...... repression (NCR) may be responsible for this regulation. Ninety-one genes had transcript levels on both L-glutamine and ammonium that were decreased compared to those on L-alanine, independent of the concentration. The GATAAG element in these genes suggests two groups of NCR-responsive genes, those that...

  6. Effect of L-Glutamine Supplementation on Electromyographic Activity of the Quadriceps Muscle Injured By Eccentric Exercise

    OpenAIRE

    Farhad Rahmani Nia; Esmail Farzaneh; Arsalan Damirchi; Ali Shamsi Majlan

    2013-01-01

      Objective(s): The purpose of the present study was to examine the effects of L-glutamine on electromyographic (EMG) activity of the quadriceps muscle injured by eccentric exercise (EE).   Materials and Methods: Seventeen healthy men (age: 22.35±2.27 yr; body mass: 69.91±9.78 kg; height: 177.08±4.32 cm) were randomly and double-blind study with subjects assigned to either an L-glutamine supplementation (n=9) or placebo (n=8) group. The subjects in two groups were asked to take three times du...

  7. 7T Proton Magnetic Resonance Spectroscopy of Gamma-Aminobutyric Acid, Glutamate, and Glutamine Reveals Altered Concentrations in Patients With Schizophrenia and Healthy Siblings

    DEFF Research Database (Denmark)

    Thakkar, Katharine N; Rösler, Lara; Wijnen, Jannie P;

    2016-01-01

    BACKGROUND: The N-methyl-D-aspartate receptor hypofunction model of schizophrenia predicts dysfunction in both glutamatergic and gamma-aminobutyric acidergic (GABAergic) transmission. We addressed this hypothesis by measuring GABA, glutamate, glutamine, and the sum of glutamine plus glutamate...... concentrations in vivo in patients with schizophrenia using proton magnetic resonance spectroscopy at 7T, which allows separation of metabolites that would otherwise overlap at lower field strengths. In addition, we investigated whether altered levels of GABA, glutamate, glutamine, and the sum of glutamine plus......, and 24 healthy nonrelatives. Glutamate, glutamine, and GABA were measured cortically and subcortically in bilateral basal ganglia and occipital cortex. RESULTS: Patients with schizophrenia had reduced cortical GABA compared with healthy relatives and the combined sample of healthy relatives and...

  8. Nano-nutrition of chicken embryos. The effect of silver nanoparticles and glutamine on molecular responses, and the morphology of pectoral muscle

    DEFF Research Database (Denmark)

    Sawosz, Filip; Pineda, Lane Manalili; Hotowy, Anna Malgorzata;

    2012-01-01

    vascular endothelial growth factor. We have therefore tested if silver nanoparticles can affect muscle development of chicken embryos and, furthermore, if they can be used in in ovo nutrition as carriers of nutrients e.g. glutamine into muscle cells. Methods: 160 broiler eggs were randomly divided into the...... control group (Control) without injection and injected groups with hydrocolloids of nanoparticles of silver (Nano-Ag), glutamine (Glu) and the complex of nanoparticles of silver and glutamine (Nano-Ag/Glu). The embryos were evaluated on day 20 of incubation. Samples of the breast muscles were collected...... for gene expression analysis or fixed for electron microscopy preparation. Results: Results indicate a significant role of silver nanoparticles and the complex Nano-Ag/Glu in muscle development. Conclusion: Nanoparticles of Ag, glutamine and the complexes of Ag and glutamine were without negative...

  9. Ammonia toxicity induces glutamine accumulation, oxidative stress and immunosuppression in juvenile yellow catfish Pelteobagrus fulvidraco.

    Science.gov (United States)

    Li, Ming; Gong, Shiyan; Li, Qing; Yuan, Lixia; Meng, Fanxing; Wang, Rixin

    2016-01-01

    A study was carried to test the response of yellow catfish for 28days under two ammonia concentrations. Weight gain of fish exposure to high and low ammonia abruptly increased at day 3. There were no significant changes in fish physiological indexes and immune responses at different times during 28-day exposure to low ammonia. Fish physiological indexes and immune responses in the treatment of high ammonia were lower than those of fish in the treatment of low ammonia. When fish were exposed to high ammonia, the ammonia concentration in the brain increased by 19-fold on day 1. By comparison, liver ammonia concentration reached its highest level much earlier at hour 12. In spite of a significant increase in brain and liver glutamine concentration, there was no significant change in glutamate level throughout the 28-day period. The total superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione reductase (GR) activities in the brain gradually decreased from hour 0 to day 28. Liver SOD, GPX and GR activities reached the highest levels at hour 12, and then gradually decreased. Thiobarbituric acid reactive substance brain and liver content gradually increased throughout the 28-day period. Lysozyme, acid phosphatase and alkaline phosphatase activities in the liver reached exceptionally low levels after day 14. This study indicated that glutamine accumulation in the brain was not the major cause of ammonia poisoning, the toxic reactive oxygen species is not fully counter acted by the antioxidant enzymes and immunosuppression is a process of gradual accumulation of immunosuppressive factors. PMID:26811908

  10. Supramolecular Probes for Assessing Glutamine Uptake Enable Semi-Quantitative Metabolic Models in Single Cells.

    Science.gov (United States)

    Xue, Min; Wei, Wei; Su, Yapeng; Johnson, Dazy; Heath, James R

    2016-03-01

    We describe a supramolecular surface competition assay for quantifying glutamine uptake from single cells. Cy3-labeled cyclodextrins were immobilized on a glass surface as a supramolecular host/FRET donor, and adamantane-BHQ2 conjugates were employed as the guest/quencher. An adamantane-labeled glutamine analog was selected through screening a library of compounds and validated by cell uptake experiments. When integrated onto a single cell barcode chip with a multiplex panel of 15 other metabolites, associated metabolic enzymes, and phosphoproteins, the resultant data provided input for a steady-state model that describes energy potential in single cells and correlates that potential with receptor tyrosine kinase signaling. We utilize this integrated assay to interrogate a dose-dependent response of model brain cancer cells to EGFR inhibition. We find that low-dose (1 μM erlotinib) drugging actually increases cellular energy potential even as glucose uptake and phosphoprotein signaling is repressed. We also identify new interactions between phosphoprotein signaling and cellular energy processes that may help explain the facile resistance exhibited by certain cancer patients to EGFR inhibitors. PMID:26916347

  11. Mitochondrial Sirt3 supports cell proliferation by regulating glutamine-dependent oxidation in renal cell carcinoma.

    Science.gov (United States)

    Choi, Jieun; Koh, Eunjin; Lee, Yu Shin; Lee, Hyun-Woo; Kang, Hyeok Gu; Yoon, Young Eun; Han, Woong Kyu; Choi, Kyung Hwa; Kim, Kyung-Sup

    2016-06-01

    Clear cell renal carcinoma (RCC), the most common malignancy arising in the adult kidney, exhibits increased aerobic glycolysis and low mitochondrial respiration due to von Hippel-Lindau gene defects and constitutive hypoxia-inducible factor-α expression. Sirt3 is a major mitochondrial deacetylase that mediates various types of energy metabolism. However, the role of Sirt3 as a tumor suppressor or oncogene in cancer depends on cell types. We show increased Sirt3 expression in the mitochondrial fraction of human RCC tissues. Sirt3 depletion by lentiviral short-hairpin RNA, as well as the stable expression of the inactive mutant of Sirt3, inhibited cell proliferation and tumor growth in xenograft nude mice, respectively. Furthermore, mitochondrial pyruvate, which was used for oxidation in RCC, might be derived from glutamine, but not from glucose and cytosolic pyruvate, due to depletion of mitochondrial pyruvate carrier and the relatively high expression of malic enzyme 2. Depletion of Sirt3 suppressed glutamate dehydrogenase activity, leading to impaired mitochondrial oxygen consumption. Our findings suggest that Sirt3 plays a tumor-progressive role in human RCC by regulating glutamine-derived mitochondrial respiration, particularly in cells where mitochondrial usage of cytosolic pyruvate is severely compromised. PMID:27114304

  12. Exchange facilitated indirect detection of hyperpolarized 15ND 2-amido-glutamine

    Science.gov (United States)

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

    2011-10-01

    Hyperpolarization greatly enhances opportunities to observe in vivo metabolic processes in real time. Accessible timescales are, however, limited by nuclear spin relaxation times, and sensitivity is limited by magnetogyric ratios of observed nuclei. The majority of applications to date have involved direct 13C observation of metabolites with non-protonated carbons at sites of interest ( 13C enriched carbonyls, for example), a choice that extends relaxation times and yields moderate sensitivity. Interest in 15N containing metabolites is equally high but non-protonated sites are rare and direct 15N observation insensitive. Here an approach is demonstrated that extends applications to protonated 15N sites with high sensitivity. The normally short relaxation times are lengthened by initially replacing protons (H) with deuterons (D) and low sensitivity detection of 15N is avoided by indirect detection through protons reintroduced by H/D exchange. A pulse sequence is presented that periodically samples 15N polarization at newly protonated sites by INEPT transfer to protons while returning 15N magnetization of deuterated sites to the + Z axis to preserve polarization for subsequent samplings. Applications to 15ND 2-amido-glutamine are chosen for illustration. Glutamine is an important regulator and a direct donor of nitrogen in cellular metabolism. Potential application to in vivo observation is discussed.

  13. Glutamine and carbohydrate supplements reduce ammonemia increase during endurance field exercise.

    Science.gov (United States)

    Carvalho-Peixoto, Jacqueline; Alves, Robson Cardilo; Cameron, Luiz-Claudio

    2007-12-01

    Blood ammonia concentration increases during endurance exercise and has been proposed as a cause for both peripheral and central fatigue. We examined the impact of glutamine and (or) carbohydrate supplementation on ammonemia in high-level runners. Fifteen men in pre-competitive training ran 120 min (approximately 34 km) outdoors on 4 occasions. On the first day, the 15 athletes ran without the use of supplements and blood samples were taken every 30 min. After that, each day for 4 d before the next 3 exercise trials, we supplemented the athletes' normal diets in bolus with carbohydrate (1 g.kg(-1).d(-1)), glutamine (70 mg.kg(-1).d(-1)), or a combination of both in a double-blind study. Blood ammonia level was determined before the run and every 30 min during the run. During the control trial ammonia increased progressively to approximately 70% above rest concentration. Following supplementation, independent of treatment, ammonia was not different (p>0.05) for the first 60 min, but for the second hour it was lower than in the control (pexercise in a field situation. PMID:18059593

  14. Effects of exercise on leukocyte death: prevention by hydrolyzed whey protein enriched with glutamine dipeptide.

    Science.gov (United States)

    Cury-Boaventura, Maria Fernanda; Levada-Pires, Adriana C; Folador, Alessandra; Gorjão, Renata; Alba-Loureiro, Tatiana C; Hirabara, Sandro M; Peres, Fabiano P; Silva, Paulo R S; Curi, Rui; Pithon-Curi, Tania C

    2008-06-01

    Lymphocyte and neutrophil death induced by exercise and the role of hydrolyzed whey protein enriched with glutamine dipeptide (Gln) supplementation was investigated. Nine triathletes performed two exhaustive exercise trials with a 1-week interval in a randomized, double blind, crossover protocol. Thirty minutes before treadmill exhaustive exercise at variable speeds in an inclination of 1% the subjects ingested 50 g of maltodextrin (placebo) or 50 g of maltodextrin plus 4 tablets of 700 mg of hydrolyzed whey protein enriched with 175 mg of glutamine dipeptide dissolved in 250 mL water. Cell viability, DNA fragmentation, mitochondrial transmembrane potential and production of reactive oxygen species (ROS) were determined in lymphocytes and neutrophils. Exhaustive exercise decreased viable lymphocytes but had no effect on neutrophils. A 2.2-fold increase in the proportion of lymphocytes and neutrophils with depolarized mitochondria was observed after exhaustive exercise. Supplementation of maltodextrin plus Gln (MGln) prevented the loss of lymphocyte membrane integrity and the mitochondrial membrane depolarization induced by exercise. Exercise caused an increase in ROS production by neutrophils, whereas supplementation of MGln had no additional effect. MGln supplementation partially prevented lymphocyte apoptosis induced by exhaustive exercise possibly by a protective effect on mitochondrial function. PMID:18320208

  15. Time-resolved transcriptome analysis of Bacillus subtilis responding to valine, glutamate, and glutamine.

    Directory of Open Access Journals (Sweden)

    Bang-Ce Ye

    Full Text Available Microorganisms can restructure their transcriptional output to adapt to environmental conditions by sensing endogenous metabolite pools. In this paper, an Agilent customized microarray representing 4,106 genes was used to study temporal transcript profiles of Bacillus subtilis in response to valine, glutamate and glutamine pulses over 24 h. A total of 673, 835, and 1135 amino-acid-regulated genes were identified having significantly changed expression at one or more time points in response to valine, glutamate, and glutamine, respectively, including genes involved in cell wall, cellular import, metabolism of amino-acids and nucleotides, transcriptional regulation, flagellar motility, chemotaxis, phage proteins, sporulation, and many genes of unknown function. Different amino acid treatments were compared in terms of both the global temporal profiles and the 5-minute quick regulations, and between-experiment differential genes were identified. The highlighted genes were analyzed based on diverse sources of gene functions using a variety of computational tools, including T-profiler analysis, and hierarchical clustering. The results revealed the common and distinct modes of action of these three amino acids, and should help to elucidate the specific signaling mechanism of each amino acid as an effector.

  16. Properties of 5-aminolaevulinate synthetase and its relationship to microsomal mixed-function oxidation in the southern armyworm (Spodoptera eridania).

    Science.gov (United States)

    Brattsten, L B; Wilkinson, C F

    1975-07-01

    1. Activity of 5-aminolaevulinate synthetase was measured in the midgut and other tissues of the last larval instar of the southern armyworm (Spodoptera eridania Cramer, formerly Prodenia eridania Cramer). 2. Optimum conditions for measuring the activity were established with respect to all variables involved and considerable differences from those reported for mammalian enzyme preparations were found. 3. Maximum activity (20 nmol/h per mg of protein) occurs 18-24 h after the fifth moult and thereafter decreases to trace amounts as the larvae age and approach pupation. 4. Synthetase activity was rapidly induced by oral administration (in the diet) of pentamethylbenzene, phenobarbital, diethyl 1,4-dihydro-2,4,6-trimethylpyridine-3, 5-dicarboxylate, and 2-allyl-2-isopropylacetamide. 5. Puromycin inhibited the induction of synthetase by pentamethylbenzene. 6. Induction of 5-aminolaevulinate synthetase correlated well with the induction of microsomal N-demethylation of p-chloro-N-methylaniline, except for phenobarbital, which induced the microsomal oxidase relatively more than the synthetase. PMID:1004

  17. Phosphoribosylpyrophosphate synthetase of Escherichia coli. Properties of the purified enzyme and primary structure of the prs gene

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Harlow, Kenneth W.; King, Cheryl J.;

    1986-01-01

    Phosphoribosylpyrophosphate (P-Rib-PP) synthetase of Escherichia coli has been purified to near homogeneity from a strain harboring the prs gene, encoding P-Rib-PP synthetase, on a multicopy plasmid. Analysis of the enzyme showed that it required inorganic phosphate for activity and for stability...

  18. REGULATION OF RAT HEPATIC DELTA-AMINOLEVULINIC ACID SYNTHETASE AND HEME OXYGENASE ACTIVITIES: EVIDENCE FOR CONTROL BY HEME AND AGAINST MEDIATION BY PROSTHETIC IRON

    Science.gov (United States)

    The effects of in vivo administration of 6 compounds on the activity of delta-aminolevulinic acid (ALA) synthetase and heme oxygenase were determined. The order of decreasing potency in reducing ALA synthetase activity was heme, bilirubin, protoporphyrin IX, bilirubin dimethyl es...

  19. δ-(L-α-Aminoadipyl)-L-cysteinyl-D-valine synthetase, that mediates the first committed step in penicillin biosynthesis, is a cytosolic enzyme

    NARCIS (Netherlands)

    Lende, Ted R. van der; Kamp, Mart van de; Berg, Marco van den; Sjollema, Klaas; Bovenberg, Roel A.L.; Veenhuis, Marten; Konings, Wil N.; Driessen, Arnold J.M.

    2002-01-01

    Penicillin biosynthesis by Penicillium chrysogenum is a compartmentalized process. The first catalytic step is mediated by δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACV synthetase), a high molecular mass enzyme that condenses the amino acids L-α-aminoadipate, L-cysteine, and L-valine into

  20. delta-(L-alpha-Aminoadipyl)-L-cysteinyl-D-valine synthetase, that mediates the first committed step in penicillin biosynthesis, is a cytosolic enzyme

    NARCIS (Netherlands)

    van der Lende, T.R.; de Kamp, M.; den Berg, M.van; Sjollema, K.; Bovenberg, R.A.L.; Veenhuis, M; Konings, W.N; Driessen, A.J.M.

    2002-01-01

    Penicillin biosynthesis by Penicillium chrysogenum is a compartmentalized process. The first catalytic step is mediated by delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACV synthetase), a high molecular mass enzyme that condenses the amino acids L-alpha-aminoadipate, L-cysteme, and L-

  1. Structural Insights into the Polyphyletic Origins of Glycyl tRNA Synthetases*♦

    Science.gov (United States)

    Valencia-Sánchez, Marco Igor; Rodríguez-Hernández, Annia; Ferreira, Ruben; Santamaría-Suárez, Hugo Aníbal; Arciniega, Marcelino; Dock-Bregeon, Anne-Catherine; Moras, Dino; Beinsteiner, Brice; Brieba, Luis G.; Grøtli, Morten

    2016-01-01

    Glycyl tRNA synthetase (GlyRS) provides a unique case among class II aminoacyl tRNA synthetases, with two clearly widespread types of enzymes: a dimeric (α2) species present in some bacteria, archaea, and eukaryotes; and a heterotetrameric form (α2β2) present in most bacteria. Although the differences between both types of GlyRS at the anticodon binding domain level are evident, the extent and implications of the variations in the catalytic domain have not been described, and it is unclear whether the mechanism of amino acid recognition is also dissimilar. Here, we show that the α-subunit of the α2β2 GlyRS from the bacterium Aquifex aeolicus is able to perform the first step of the aminoacylation reaction, which involves the activation of the amino acid with ATP. The crystal structure of the α-subunit in the complex with an analog of glycyl adenylate at 2.8 Å resolution presents a conformational arrangement that properly positions the cognate amino acid. This work shows that glycine is recognized by a subset of different residues in the two types of GlyRS. A structural and sequence analysis of class II catalytic domains shows that bacterial GlyRS is closely related to alanyl tRNA synthetase, which led us to define a new subclassification of these ancient enzymes and to propose an evolutionary path of α2β2 GlyRS, convergent with α2 GlyRS and divergent from AlaRS, thus providing a possible explanation for the puzzling existence of two proteins sharing the same fold and function but not a common ancestor. PMID:27226617

  2. Structural Insights into the Polyphyletic Origins of Glycyl tRNA Synthetases.

    Science.gov (United States)

    Valencia-Sánchez, Marco Igor; Rodríguez-Hernández, Annia; Ferreira, Ruben; Santamaría-Suárez, Hugo Aníbal; Arciniega, Marcelino; Dock-Bregeon, Anne-Catherine; Moras, Dino; Beinsteiner, Brice; Mertens, Haydyn; Svergun, Dmitri; Brieba, Luis G; Grøtli, Morten; Torres-Larios, Alfredo

    2016-07-01

    Glycyl tRNA synthetase (GlyRS) provides a unique case among class II aminoacyl tRNA synthetases, with two clearly widespread types of enzymes: a dimeric (α2) species present in some bacteria, archaea, and eukaryotes; and a heterotetrameric form (α2β2) present in most bacteria. Although the differences between both types of GlyRS at the anticodon binding domain level are evident, the extent and implications of the variations in the catalytic domain have not been described, and it is unclear whether the mechanism of amino acid recognition is also dissimilar. Here, we show that the α-subunit of the α2β2 GlyRS from the bacterium Aquifex aeolicus is able to perform the first step of the aminoacylation reaction, which involves the activation of the amino acid with ATP. The crystal structure of the α-subunit in the complex with an analog of glycyl adenylate at 2.8 Å resolution presents a conformational arrangement that properly positions the cognate amino acid. This work shows that glycine is recognized by a subset of different residues in the two types of GlyRS. A structural and sequence analysis of class II catalytic domains shows that bacterial GlyRS is closely related to alanyl tRNA synthetase, which led us to define a new subclassification of these ancient enzymes and to propose an evolutionary path of α2β2 GlyRS, convergent with α2 GlyRS and divergent from AlaRS, thus providing a possible explanation for the puzzling existence of two proteins sharing the same fold and function but not a common ancestor. PMID:27226617

  3. Molecular cloning and characterization of an S-adenosylmethionine synthetase gene from Chorispora bungeana.

    Science.gov (United States)

    Ding, Chenchen; Chen, Tao; Yang, Yu; Liu, Sha; Yan, Kan; Yue, Xiule; Zhang, Hua; Xiang, Yun; An, Lizhe; Chen, Shuyan

    2015-11-10

    S-adenosylmethionine synthetase (SAMS) catalyzes the formation of S-adenosylmethionine (SAM) which is a molecule essential for polyamines and ethylene biosynthesis, methylation modifications of protein, DNA and lipids. SAMS also plays an important role in abiotic stress response. Chorispora bungeana (C. bungeana) is an alpine subnival plant species which possesses strong tolerance to cold stress. Here, we cloned and characterized an S-adenosylmethionine synthetase gene, CbSAMS (C. bungeana S-adenosylmethionine synthetase), from C. bungeana, which encodes a protein of 393 amino acids containing a methionine binding motif GHPDK, an ATP binding motif GAGDQG and a phosphate binding motif GGGAFSGDK. Furthermore, an NES (nuclear export signal) peptide was identified through bioinformatics analysis. To explore the CbSAMS gene expression regulation, we isolated the promoter region of CbSAMS gene 1919bp upstream the ATG start codon, CbSAMSp, and analyzed its cis-acting elements by bioinformatics method. It was revealed that a transcription start site located at 320 bp upstream the ATG start codon and cis-acting elements related to light, ABA, auxin, ethylene, MeJA, low temperature and drought had been found in the CbSAMSp sequence. The gene expression pattern of CbSAMS was then analyzed by TR-qPCR and GUS assay method. The result showed that CbSAMS is expressed in all examined tissues including callus, roots, petioles, leaves, and flowers with a significant higher expression level in roots and flowers. Furthermore, the expression level of CbSAMS was induced by low temperature, ethylene and NaCl. Subcellular localization revealed that CbSAMS was located in the cytoplasm and nucleus but has a significant higher level in the nucleus. These results indicated a potential role of CbSAMS in abiotic stresses and plant growth in C. bungeana. PMID:26205258

  4. Cloning, expression, purification, crystallization and preliminary X-ray crystallographic study of DHNA synthetase from Geobacillus kaustophilus

    International Nuclear Information System (INIS)

    DHNA synthetase from G. kaustophilus has been cloned, expressed, purified and crystallized. The aerobic Gram-positive bacterium Geobacillus kaustophilus is a bacillus species that was isolated from deep-sea sediment from the Mariana Trench. 1,4-Dihydroxy-2-naphthoate (DHNA) synthetase plays a vital role in the biosynthesis of menaquinone (vitamin K2) in this bacterium. DHNA synthetase from Geobacillus kaustophilus was crystallized in the orthorhombic space group C2221, with unit-cell parameters a = 77.01, b = 130.66, c = 131.69 Å. The crystal diffracted to a resolution of 2.2 Å. Preliminary studies and molecular-replacement calculations reveal the presence of three monomers in the asymmetric unit

  5. Purification, gene cloning, and characterization of γ-butyrobetainyl CoA synthetase from Agrobacterium sp. 525a.

    Science.gov (United States)

    Fujimitsu, Hiroshi; Matsumoto, Akira; Takubo, Sayaka; Fukui, Akiko; Okada, Kazuma; Mohamed Ahmed, Isam A; Arima, Jiro; Mori, Nobuhiro

    2016-08-01

    The report is the first of purification, overproduction, and characterization of a unique γ-butyrobetainyl CoA synthetase from soil-isolated Agrobacterium sp. 525a. The primary structure of the enzyme shares 70-95% identity with those of ATP-dependent microbial acyl-CoA synthetases of the Rhizobiaceae family. As distinctive characteristics of the enzyme of this study, ADP was released in the catalytic reaction process, whereas many acyl CoA synthetases are annotated as an AMP-forming enzyme. The apparent Km values for γ-butyrobetaine, CoA, and ATP were, respectively, 0.69, 0.02, and 0.24 mM. PMID:27125317

  6. Glucose and glutamine fuel protein O-GlcNAcylation to control T cell self-renewal and malignancy.

    Science.gov (United States)

    Swamy, Mahima; Pathak, Shalini; Grzes, Katarzyna M; Damerow, Sebastian; Sinclair, Linda V; van Aalten, Daan M F; Cantrell, Doreen A

    2016-06-01

    Sustained glucose and glutamine transport are essential for activated T lymphocytes to support ATP and macromolecule biosynthesis. We found that glutamine and glucose also fuel an indispensable dynamic regulation of intracellular protein O-GlcNAcylation at key stages of T cell development, transformation and differentiation. Glucose and glutamine are precursors of uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), a substrate for cellular glycosyltransferases. Immune-activated T cells contained higher concentrations of UDP-GlcNAc and increased intracellular protein O-GlcNAcylation controlled by the enzyme O-linked-β-N-acetylglucosamine (O-GlcNAc) glycosyltransferase as compared with naive cells. We identified Notch, the T cell antigen receptor and c-Myc as key controllers of T cell protein O-GlcNAcylation via regulation of glucose and glutamine transport. Loss of O-GlcNAc transferase blocked T cell progenitor renewal, malignant transformation and peripheral T cell clonal expansion. Nutrient-dependent signaling pathways regulated by O-GlcNAc glycosyltransferase are thus fundamental for T cell biology. PMID:27111141

  7. EFFECT OF PREOPERATIVE GLUTAMINE ADMINISTRATION ON ICAM-1 EXPRESSION IN RAT LUNG INDUCED BY INTESTINAL ISCHEMIA-REPERFUSION

    Institute of Scientific and Technical Information of China (English)

    GENG Gui-qi; JIANG Hong; ZHU Ye-sen

    2008-01-01

    Objective To evaluate the effect of preoperative glutamine administration on intracellular adhesion molecule-1 (ICAM-1) expression in rat lung induced by intestinal ischemia-reperfusion( I/R ). Methods Sprague-Dawley rats (n = 25) were randomly divided into 5 groups: sham group ( sham surgery), glutamine groups (three different doses) and control group. All groups except sham were subjected to intestinal I/R injury, and superior mesenteric artery (SMA) occluded for 60 min followed by 90 min of reperfusion. Lung injury was evaluated with Evans blue dye concentration and histopathologic examination. The immunohistochemical expression and mRNA expression of ICAM-1 were measured with immunohistochemical staining and RT-PCR method respectively. The level of myeloperoxidase (MPO) was also measured with biochemistry method. Results Intestinal I/R resulted in lung injury characterized by an increase in Evans blue dye concentration, neutrophil sequestration, and obvious staining for expression of pulmonary ICAM-1, compared with sham group. The expression of ICAM-1 and the level of MPO in rat lung were lower in glutamine groups compared with control group. Conclusion I-R injury increases the expression of ICAM-1 within the lung. This may contribute to the migration, accumulation and activation of polymorphanuclear neutrophils (PMNs) after such injury. Preoperative glutamine administration attenuates rat lung injury induced by intestinal I-R, and inhibiting ICAM-1 expression maybe one of the potential mechanisms.

  8. Residue 259 in protein-tyrosine phosphatase PTP1B and PTPα determines the flexibility of glutamine 262

    DEFF Research Database (Denmark)

    Peters, Günther H.j.; Iversen, L.F.; Andersen, H.S.;

    2004-01-01

    (cat). Additionally, in the simulation with the Michaelis-Menten complexes, we found that a glutamine in position 259 induces steric hindrance by pushing the Gln262 side chain further toward the substrate and thereby negatively affecting K-m as indicated by kinetic studies. Detailed analysis of the water structure...

  9. The influence of glutamine on the changes of lactate and cortisole levels in the elite wrestlers blood

    OpenAIRE

    Minassian

    2012-01-01

    Wrestling is weight classification sport and due to the time of competition various energy systems are involved in it. Nutrition is very effective in the performance of an athlete during exercise, competition and weight loss period. Therefore, most of athletes have attended to take nutritional supplements such as creatine and glutamine to improve their athletic performance.

  10. Effect of L-Glutamine Supplementation on Electromyographic Activity of the Quadriceps Muscle Injured By Eccentric Exercise

    Directory of Open Access Journals (Sweden)

    Farhad Rahmani Nia

    2013-06-01

    Full Text Available   Objective(s: The purpose of the present study was to examine the effects of L-glutamine on electromyographic (EMG activity of the quadriceps muscle injured by eccentric exercise (EE.   Materials and Methods: Seventeen healthy men (age: 22.35±2.27 yr; body mass: 69.91±9.78 kg; height: 177.08±4.32 cm were randomly and double-blind study with subjects assigned to either an L-glutamine supplementation (n=9 or placebo (n=8 group. The subjects in two groups were asked to take three times during a week for 4 weeks. Each subject was screened for dietary habits before inclusion into the study. Participants performed 6 set to exhaustion eccentric leg extensions at 75% of 1RM and rest intervals were 3 min among sets. Pain Assessment Scale (PAS, EMG activity and range of motion (ROM measurements were taken before exercise protocol and 24 and 48 hr afterwards. Results: There was no statistically significant difference between groups in perceived muscle soreness (SOR, ROM and EMG activity (P < 0.05. Conclusion: The results indicate that L-glutamine supplementation has no significant effect on muscle injury markers in between groups, although glutamine supplementation attenuated delayed onset muscle soreness (DOMS effects in sup group.

  11. Lymphocyte glucose and glutamine metabolism as targets of the anti-inflammatory and immunomodulatory effects of exercise.

    Science.gov (United States)

    Wasinski, Frederick; Gregnani, Marcos F; Ornellas, Fábio H; Bacurau, Aline V N; Câmara, Niels O; Araujo, Ronaldo C; Bacurau, Reury F

    2014-01-01

    Glucose and glutamine are important energetic and biosynthetic nutrients for T and B lymphocytes. These cells consume both nutrients at high rates in a function-dependent manner. In other words, the pathways that control lymphocyte function and survival directly control the glucose and glutamine metabolic pathways. Therefore, lymphocytes in different functional states reprogram their glucose and glutamine metabolism to balance their requirement for ATP and macromolecule production. The tight association between metabolism and function in these cells was suggested to introduce the possibility of several pathologies resulting from the inability of lymphocytes to meet their nutrient demands under a given condition. In fact, disruptions in lymphocyte metabolism and function have been observed in different inflammatory, metabolic, and autoimmune pathologies. Regular physical exercise and physical activity offer protection against several chronic pathologies, and this benefit has been associated with the anti-inflammatory and immunomodulatory effects of exercise/physical activity. Chronic exercise induces changes in lymphocyte functionality and substrate metabolism. In the present review, we discuss whether the beneficial effects of exercise on lymphocyte function in health and disease are associated with modulation of the glucose and glutamine metabolic pathways. PMID:24987195

  12. Lymphocyte Glucose and Glutamine Metabolism as Targets of the Anti-Inflammatory and Immunomodulatory Effects of Exercise

    Directory of Open Access Journals (Sweden)

    Frederick Wasinski

    2014-01-01

    Full Text Available Glucose and glutamine are important energetic and biosynthetic nutrients for T and B lymphocytes. These cells consume both nutrients at high rates in a function-dependent manner. In other words, the pathways that control lymphocyte function and survival directly control the glucose and glutamine metabolic pathways. Therefore, lymphocytes in different functional states reprogram their glucose and glutamine metabolism to balance their requirement for ATP and macromolecule production. The tight association between metabolism and function in these cells was suggested to introduce the possibility of several pathologies resulting from the inability of lymphocytes to meet their nutrient demands under a given condition. In fact, disruptions in lymphocyte metabolism and function have been observed in different inflammatory, metabolic, and autoimmune pathologies. Regular physical exercise and physical activity offer protection against several chronic pathologies, and this benefit has been associated with the anti-inflammatory and immunomodulatory effects of exercise/physical activity. Chronic exercise induces changes in lymphocyte functionality and substrate metabolism. In the present review, we discuss whether the beneficial effects of exercise on lymphocyte function in health and disease are associated with modulation of the glucose and glutamine metabolic pathways.

  13. Npr2 inhibits TORC1 to prevent inappropriate utilization of glutamine for biosynthesis of nitrogen-containing metabolites.

    Science.gov (United States)

    Laxman, Sunil; Sutter, Benjamin M; Shi, Lei; Tu, Benjamin P

    2014-12-16

    Cells must be capable of switching between growth and autophagy in unpredictable nutrient environments. The conserved Npr2 protein complex (comprising Iml1, Npr2, and Npr3; also called SEACIT) inhibits target of rapamycin complex 1 (TORC1) kinase signaling, which inhibits autophagy in nutrient-rich conditions. In yeast cultured in media with nutrient limitations that promote autophagy and inhibit growth, loss of Npr2 enables cells to bypass autophagy and proliferate. We determined that Npr2-deficient yeast had a metabolic state distinct from that of wild-type yeast when grown in minimal media containing ammonium as a nitrogen source and a nonfermentable carbon source (lactate). Unlike wild-type yeast, which accumulated glutamine, Npr2-deficient yeast metabolized glutamine into nitrogen-containing metabolites and maintained a high concentration of S-adenosyl methionine (SAM). Moreover, in wild-type yeast grown in these nutrient-limited conditions, supplementation with methionine stimulated glutamine consumption for synthesis of nitrogenous metabolites, demonstrating integration of a sulfur-containing amino acid cue and nitrogen utilization. These data revealed the metabolic basis by which the Npr2 complex regulates cellular homeostasis and demonstrated a key function for TORC1 in regulating the synthesis and utilization of glutamine as a nitrogen source. PMID:25515537

  14. Systematic replacement of lysine with glutamine and alanine in Escherichia coli malate synthase G: effect on crystallization

    International Nuclear Information System (INIS)

    Alanine and glutamine mutations were made to the same 15 lysine positions on the surface of E. coli malate synthase G and the impact on crystallization observed. The results support lysine replacement for improvement of crystallization and provide insight into site selection and type of amino-acid replacement. Two proposals recommend substitution of surface lysine residues as a means to improve the quality of protein crystals. In proposal I, substitution of lysine by alanine has been suggested to improve crystallization by reducing the entropic cost of ordering flexible side chains at crystal contacts. In proposal II, substitution of lysine by residues more commonly found in crystal contacts, such as glutamine, has been proposed to improve crystallization. 15 lysine residues on the surface of Escherichia coli malate synthase G, distributed over a variety of secondary structures, were individually mutated to both alanine and glutamine. For 28 variants, detailed studies of the effect on enzymatic activity and crystallization were conducted. This has permitted direct comparison of the relative effects of the two types of mutations. While none of the variants produced crystals suitable for X-ray structural determination, small crystals were obtained in a wide variety of conditions, in support of the general approach. Glutamine substitutions were found to be more effective than alanine in producing crystals, in support of proposal II. Secondary structure at the site of mutation does not appear to play a major role in determining the rate of success

  15. Purification and characterization of fatty acyl-acyl carrier protein synthetase from Vibrio harveyi.

    OpenAIRE

    Fice, D; Z. Shen; Byers, D M

    1993-01-01

    A Vibrio harveyi enzyme which catalyzes the ATP-dependent ligation of fatty acids to acyl carrier protein (ACP) has been purified 6,000-fold to apparent homogeneity by anion-exchange, gel filtration, and ACP-Sepharose affinity chromatography. Purified acyl-ACP synthetase migrated as a single 62-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as an 80-kDa protein by gel filtration under reducing conditions. Activity of the purified enzyme was lost within hours in the ...

  16. Purification and characterization of 3-deoxy-D-manno-octulosonate 8-phosphate synthetase from Escherichia coli.

    OpenAIRE

    Ray, P H

    1980-01-01

    3-Deoxy-D-manno-octulosonate (KDO)-8-phosphate synthetase has been purified 450-fold from frozen Escherichia coli B cells. The purified enzyme catalyzed the stoichiometric formation of KDO-8-phosphate and Pi from phosphoenolpyruvate (PEP) and D-arabinose-5-phosphate. The enzyme showed no metal requirement for activity and was inhibited by 1 mM Cd2+, Cu2+, Zn2+, and Hg2+. The inhibition by Hg2+ could be reversed by dithiothreitol. The optimum temperature for enzyme activity was determined to b...

  17. A radiochemical method for carbamoyl-phosphate synthetase I: application to rats fed a hyperproteic diet

    OpenAIRE

    Arriarán, Sofía; Agnelli, Silvia; Fernández López, José Antonio; Remesar Betlloch, Xavier; Alemany, Marià

    2012-01-01

    A method for the measurement of carbamoyl-phosphate synthetase I activity in animal tissues has been developed using the livers of rats under normal and hyperproteic diets. The method is based on the incorporation of 14C-ammonium bicarbonate to carbamoyl-phosphate in the presence of ATP-Mg and N-acetyl-glutamate. The reaction is stopped by chilling, lowering the pH and adding ethanol. Excess bicarbonate is flushed out under a gentle stream of cold CO2. The only label remaining in the medium w...

  18. Determinant nucleotides of yeast tRNA(Asp) interact directly with aspartyl-tRNA synthetase.

    OpenAIRE

    Rudinger, J; Puglisi, J D; Pütz, J.; Schatz, D; Eckstein, F; Florentz, C; Giegé, R

    1992-01-01

    The interaction of wild-type and mutant yeast tRNA(Asp) transcripts with yeast aspartyl-tRNA synthetase (AspRS; EC 6.1.1.12) has been probed by using iodine cleavage of phosphorothioate-substituted transcripts. AspRS protects phosphates in the anticodon (G34, U35), D-stem (U25), and acceptor end (G73) that correspond to determinant nucleotides for aspartylation. This protection, as well as that in anticodon stem (C29, U40, G41) and D-stem (U11 to U13), is consistent with direct interaction of...

  19. Heme ligand identification and redox properties of the cytochrome c synthetase, CcmF†

    OpenAIRE

    Francisco, Brian San; Bretsnyder, Eric C.; Rodgers, Kenton R.; Kranz, Robert G.

    2011-01-01

    Cytochrome c maturation in many bacteria, archaea, and plant mitochondria involves the integral membrane protein CcmF, which is thought to function as a cytochrome c synthetase by facilitating the final covalent attachment of heme to the apocytochrome c. We previously reported that the E. coli CcmF protein contains a b-type heme that is stably and stoichiometrically associated with the protein and is not the heme attached to apocytochrome c. Here, we show that mutation of either of two conser...

  20. Effects of glutamine on intestinal permeability and bacterial translocation in TPN-rats with endotoxemia

    Institute of Scientific and Technical Information of China (English)

    Lian-An Ding; Jie-Show Li

    2003-01-01

    AIM: To evaluate the protective effect and mechanism ofglutamine on the intestinal barrier function in totalparenteral nutrition (TPN) rats with trauma or endotoxemia. METHODS: To perform prospective, randomized andcontrolled animal experimentation of rats with surgicaltrauma, TPN and endotoxemia, thirty-four male, adultSprague Dawley rats were divided into four groups: control group (n=8), TPN group (n=9), trauma and endotoxemia group (LPS, n=8) and trauma plus endotoxemia supplemented with glutamine in TPN solution group (Gin.group, n=9). All groups except the control group were given TPN solutions in 7-day experimental period. For Gin group, 1 000 mg/kg/d of glutamine was added to TPN solution during day 1-6. On the 7th day all the animals were gavaged with lactulose (66 mg) and mannitol (50 mg)in 2 mi of normal saline. Then 24 h urine with preservative was collected and kept at -20 ℃. On day 8, under intraperitoneal anesthesia using 100 mg/kg ketamin, the intestine, liver, mesenteric lymph nodes and blood were taken for examination. RESULTS: The body weight of LPS group decreased most among the four groups. The structure of small intestinal mucosa in TPN group, LPS group and Gln group showed impairments of different degrees, and the damage of small intestinal mucosa in Gln group was remarkably alleviated.The concentrations of interleukins in small intestine mucosa were lower (for IL-4 and IL-6) or the lowest (IL-10) in Gln group. The IgA level in the blood plasma and the mucosa of Gln group was the highest among all of the groups. The urine lactulose/mannitol test showed that the intestinal permeability in LPS group was lower than that in TPN group (P<0.001), but there was no difference between LPS group and Gln group. The rate of bacterial translocation in Gln group was lower than that in LPS group (P<0.02). CONCLUSION: Prophylactic treatment with glutamine could minimize the increments of intestinal permeability and bacterial translocation caused by

  1. Alanyl-glutamine dipeptide inhibits hepatic ischemia-reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Chang-Jun Jia; Chao-Liu Dai; Xu Zhang; Kai Cui; Feng Xu; Yong-Qing Xu

    2006-01-01

    AIM: To investigate the protective effect and mechanism of alanyl-glutamine dipeptide (Ala-Gln) against hepatic ischemia-reperfusion injury in rats.METHODS: Rats were divided into group C as normal control Group (n=16) and group G as alanyl-glutamine pretreatment (n=16). Rats were intravenously infused with 0.9% saline solution in group C and Ala-Gln -enriched (2% glutamine) 0.9% saline solution in group G via central venous catheter for three days. Then all rats underwent hepatic warm ischemia for 30 min followed by different periods of reperfusion. Changes in biochemical parameters, the content of glutathione (GSH) and the activity of superoxide dismutase (SOD) in liver tissue, Bcl-2and Bax protein expression and morphological changes of liver tissue were compared between both groups.RESULTS: One hour after reperfusion, the levels of liver enzymes in group G were significantly lower than those in group C (P<0.05). Twenty-four hours after reperfusion, the levels of liver enzymes in both groups were markedly recovered and the levels of liver enzyme in group G were also significantly lower than those in group C (P<0.01). One and 24 h after reperfusion, GSH content in group G was significantly higher than that in group C (P <0.05). There was no statistical difference in activities of SOD between the two groups. One and 24 h after reperfusion, the positive expression rate of Bcl-2 protein was higher in group G than in group C (P<0.05)and the positive expression rate of Bax protein was lower in group G than in group C (P<0.05). Histological and ultrastructural changes of liver tissue were inhibited in group C compared to group G.CONCLUSION: Our results suggest that Ala-Gln pretreatment provides the rat liver with significant tolerance to warm ischemia-reperfusion injury, which may be mediated partially by enhancing GSH content and regulating the expression of Bcl-2 and Bax proteins in the liver tissue.

  2. Effect of the association l-glutamine – ethylene glycol In equine semen cryopreservation

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Neira

    2007-12-01

    Full Text Available In order to improve the effectiveness in the cryopreservation of horse sperm, the effect of association L-glutamine with Ethylenglicole and Glycerol in the freezing media spermatozoa was evaluated. 4 Colombian native stallions were used to complete a total of 21 samples which were frozen in two different media: INRA 97 and cryoprotectant. The following study was done: L-glutamine 80mM + Etilenglicol 2.5% (protocol 1, L-glutamine 80 mM + Glycerol 2.5% (protocol 2, Etilenglicol 2.5% (protocol 3 and glycerol 2.5% (protocol 4. The freezing methodology was: 60 minutes to descend the temperature from 38°C to 5°C (0.55°C/min during the transport. The samples were centrifuged at 600G/10min., and the semen was diluted with the four protocols in straws of 0.5 ml. Then, 60 minutes of equilibrium in refrigeration; 20 minutes in liquid nitrogen vapors and then immersed. In the progressive motility evaluation there was not any significant difference between protocols at 0 time (p ≤ 0.6383, at 30 minutes (p ≤ 0.511, and at 60 minutes (p ≤ 0.1659. The motility averages for the 4 protocols at 0 time were (1 29,6 ± 15,1; (2 28,1 ± 13,5; (3 28,4 ± 12,3 and (4 30,8 ± 11,1; at the 30 minutes: (1 25,1 ± 13,6; (2 22,3 ± 13,0; (3 24,9 ± 12,4 and (4 25,5 ± 11,6, and at 60 minutes (1 17,1 ± 10,2; (2 15,4 ± 11,7; (3 19,9 ± 11,5 and (4 17,6 ± 10,4. The spermatic survival was evaluated with eosine-nigrosine coloration, after thawing and there was not any significant difference among the protocols (p≤ 0.6336, the average measures were (1 30,7; (2 28,8; (3 28,7 and (4 31,7. As a conclusion, although significant difference was not demonstrated among the protocols; the tendency to the highest average was presented by the protocol 4 (glycerol 2.5%.

  3. Expression of acyl-CoA synthetase 5 reflects the state of villus architecture in human small intestine

    DEFF Research Database (Denmark)

    Gassler, Nikolaus; Kopitz, Jürgen; Tehrani, Arman;

    2004-01-01

    -CoA synthetase 5 pattern correlate with conversion of intestinal epithelial cells to a gastric phenotype. These results suggest that deranged acyl-CoA synthetase 5 expression, synthesis, and activity are closely related to the state of villus architecture and epithelial homeostasis in human small intestine.......Several disorders of the small intestine are associated with disturbances in villus architecture. Thus, an understanding of the molecular mechanisms associated with the differentiation of villi represents an important step in the improvement of the understanding of small intestinal pathology...

  4. Recognition of tRNALeu by Aquifex aeolicus leucyl-tRNA synthetase during the aminoacylation and editing steps

    OpenAIRE

    Yao, Peng; Zhu, Bin; Jaeger, Sophie; Eriani, Gilbert; Wang, En-Duo

    2008-01-01

    Recognition of tRNA by the cognate aminoacyl-tRNA synthetase during translation is crucial to ensure the correct expression of the genetic code. To understand tRNALeu recognition sets and their evolution, the recognition of tRNALeu by the leucyl-tRNA synthetase (LeuRS) from the primitive hyperthermophilic bacterium Aquifex aeolicus was studied by RNA probing and mutagenesis. The results show that the base A73; the core structure of tRNA formed by the tertiary interactions U8–A14, G18–U55 and ...

  5. Functional Analysis of Long-chain Acyl-CoA Synthetase 1 in 3T3-L1 Adipocytes*

    OpenAIRE

    Lobo, Sandra; Wiczer, Brian M.; Bernlohr, David A

    2009-01-01

    ACSL1 (acyl-CoA synthetase 1), the major acyl-CoA synthetase of adipocytes, has been proposed to function in adipocytes as mediating free fatty acid influx, esterification, and storage as triglyceride. To test this hypothesis, ACSL1 was stably silenced (knockdown (kd)) in 3T3-L1 cells, differentiated into adipocytes, and evaluated for changes in lipid metabolism. Surprisingly, ACSL1-silenced adipocytes exhibited no significant changes in basal or insulin-stimulated long-chain fatty acid uptak...

  6. The tRNA synthetase paralog PoxA modifies elongation factor-P with (R)-ß-lysine

    DEFF Research Database (Denmark)

    Roy, Hervé; Zou, S Betty; Bullwinkle, Tammy J;

    2011-01-01

    The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with a-lysine at low efficiency. Cell-free extracts containing non-a-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of ß-lysine, a substrate also predicted by genomic analyses. EF......-P was efficiently functionally modified with (R)-ß-lysine but not (S)-ß-lysine or genetically encoded a-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases....

  7. Activity of interferon-dependent 2',5'-oligoadenylate synthetase in rat lymphoid cells under transformed environment conditions

    Science.gov (United States)

    Ostapchenko, L. I.; Mikhailik, I. V.; Prokopova, K. V.

    It is detected that interferon-dependent 2',5'-oligoadenylate synthetase is a sensitive index of immunocompetent cells functional state under transformed environment conditions. Microgravitation and ionising radiation induce increase of investigated enzyme activity in rat lymphocytes, which can be a result of lymphoid cells compensatory mechanisms starting in response to stress factors action. Administration of interferon inductors permits to stimulate the 2',5'-oligoadenylate synthetase, which enables one to correct pathological changes in the cells and to intensify adaptive reactions of immune systems.

  8. Influence of Serum and Hypoxia on Incorporation of [(14)C]-D-Glucose or [(14)C]-L-Glutamine into Lipids and Lactate in Murine Glioblastoma Cells.

    Science.gov (United States)

    Ta, Nathan L; Seyfried, Thomas N

    2015-12-01

    Glucose and glutamine are essential energy metabolites for brain tumor growth and survival under both normoxic and hypoxic conditions. Both metabolites can contribute their carbons to lipid biosynthesis. We used uniformly labeled [(14)C]-U-D-glucose and [(14)C]-U-L-glutamine to examine the profile of de novo lipid biosynthesis in the VM-M3 murine glioblastoma cells. The major lipids synthesized included phosphatidylcholine (PtdCho), phosphatidylethanolamine (EtnGpl), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer), sphingomyelin (CerPCho), bis(monoacylglycero)phosphate (BMP)/phosphatidic acid (PtdOH), cholesterol (C), cardiolipin (Ptd2Gro), and gangliosides. Endogenous lipid synthesis, using either glucose or glutamine, was greater in media without fetal bovine serum (FBS) than in media containing 10 % FBS under normoxia. De novo lipid synthesis was greater using glucose carbons than glutamine carbons under normoxia. The reverse was observed for most lipids under hypoxia suggesting an attenuation of glucose entering the TCA cycle. Lactate was produced largely from glucose carbons with minimal lactate derived from glutamine under either normoxia or hypoxia. Accumulation of triacylglycerols (TAG), containing mostly saturated and mono-unsaturated fatty acids, was observed under hypoxia using carbons from either glucose or glutamine. The data show that the incorporation of labeled glucose and glutamine into most synthesized lipids was dependent on the type of growth environment, and that the VM-M3 glioblastoma cells could acquire lipids, especially cholesterol, from the external environment for growth and proliferation. PMID:26537505

  9. Anticodon recognition in evolution: switching tRNA specificity of an aminoacyl-tRNA synthetase by site-directed peptide transplantation.

    Science.gov (United States)

    Brevet, Annie; Chen, Josiane; Commans, Stéphane; Lazennec, Christine; Blanquet, Sylvain; Plateau, Pierre

    2003-08-15

    The highly conserved aspartyl-, asparaginyl-, and lysyl-tRNA synthetases compose one subclass of aminoacyl-tRNA synthetases, called IIb. The three enzymes possess an OB-folded extension at their N terminus. The function of this extension is to specifically recognize the anticodon triplet of the tRNA. Three-dimensional models of bacterial aspartyl- and lysyl-tRNA synthetases complexed to tRNA indicate that a rigid scaffold of amino acid residues along the five beta-strands of the OB-fold accommodates the base U at the center of the anticodon. The binding of the adjacent anticodon bases occurs through interactions with a flexible loop joining strands 4 and 5 (L45). As a result, a switching of the specificity of lysyl-tRNA synthetase from tRNALys (anticodon UUU) toward tRNAAsp (GUC) could be attempted by transplanting the small loop L45 of aspartyl-tRNA synthetase inside lysyl-tRNA synthetase. Upon this transplantation, lysyl-tRNA synthetase loses its capacity to aminoacylate tRNALys. In exchange, the chimeric enzyme acquires the capacity to charge tRNAAsp with lysine. Upon giving the tRNAAsp substrate the discriminator base of tRNALys, the specificity shift is improved. The change of specificity was also established in vivo. Indeed, the transplanted lysyl-tRNA synthetase succeeds in suppressing a missense Lys --> Asp mutation inserted into the beta-lactamase gene. These results functionally establish that sequence variation in a small peptide region of subclass IIb aminoacyl-tRNA synthetases contributes to specification of nucleic acid recognition. Because this peptide element is not part of the core catalytic structure, it may have evolved independently of the active sites of these synthetases. PMID:12766171

  10. Glutamine Reduces the Apoptosis of H9C2 Cells Treated with High-Glucose and Reperfusion through an Oxidation-Related Mechanism.

    Directory of Open Access Journals (Sweden)

    Kai Li

    Full Text Available Mitochondrial overproduction of reactive oxygen species (ROS in diabetic hearts during ischemia/reperfusion injury and the anti-oxidative role of glutamine have been demonstrated. However, in diabetes mellitus the role of glutamine in cardiomyocytes during ischemia/reperfusion injury has not been explored. To examine the effects of glutamine and potential mechanisms, in the present study, rat cardiomyoblast H9C2 cells were exposed to high glucose (33 mM and hypoxia-reoxygenation. Cell viability, apoptosis, intracellular glutamine, and mitochondrial and intracellular glutathione were determined. Moreover, ROS formation, complex I activity, membrane potential and adenosine triphosphate (ATP content were also investigated. The levels of S-glutathionylated complex I and mitochondrial apoptosis-related proteins, including cytochrome c and caspase-3, were analyzed by western blot. Data indicated that high glucose and hypoxia-reoxygenation were associated with a dramatic decline of intercellular glutamine and increase in apoptosis. Glutamine supplementation correlated with a reduction in apoptosis and increase of glutathione and glutathione reduced/oxidized ratio in both cytoplasm and mitochondria, but a reduction of intracellular ROS. Glutamine supplementation was also associated with less S-glutathionylation and increased the activity of complex I, leading to less mitochondrial ROS formation. Furthermore, glutamine supplementation prevented from mitochondrial dysfunction presented as mitochondrial membrane potential and ATP levels and attenuated cytochrome c release into the cytosol and caspase-3 activation. We conclude that apoptosis induced by high glucose and hypoxia-reoxygenation was reduced by glutamine supplementation, via decreased oxidative stress and inactivation of the intrinsic apoptotic pathway.

  11. Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center

    DEFF Research Database (Denmark)

    Hejgaard, Jørn

    2005-01-01

    Serpins appear to be ubiquitous in eukaryotes, except fungi, and are also present in some bacteria, archaea and viruses. Inhibitory serpins with a glutamine as the reactive-center P1 residue have been identified exclusively in a few plant species. Unique serpins with a reactive center sequence of...... proteinases that specifically degrade storage prolamins containing Gln-rich repetitive sequences, most likely for digestive proteinases of insect pests or fungal pathogens that infect cereals. An assembled full-length amino acid sequence of a serpin expressed in cotton boll fiber (GaZ1) included conserved...... regions essential for serpin-proteinase interaction, suggesting inhibitory capacity at a putative reactive center P2-P2' with a sequence of four Gln residues....

  12. Ionic strength dependence of formation constants and complexation of glutamine with dioxovanadium(V)

    International Nuclear Information System (INIS)

    The dependence of L-glutamine protonation and its complexation with dioxovanadium(V) on ionic strength (I) is reported in sodium perchlorate solutions as a background salt. The measurements have been performed at 25 ±0.1 Deg C and various ionic strengths in the range 0.1 to 1.0 mol/l, using a combination of potentiometric and spectrophotometric techniques. The overall analysis of the present and the previous data dealing with the determination of stability constants at different ionic strengths allowed to obtain a general equation, by which a formation constant determined at a fixed ionic strength can be calculated, with a good approximation, at another ionic strength, if 0.1≤I≤1.0 mol/l

  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. Effects of oral glutamine supplementation on exercise-induced gastrointestinal permeability and tight junction protein expression.

    Science.gov (United States)

    Zuhl, Micah N; Lanphere, Kathryn R; Kravitz, Len; Mermier, Christine M; Schneider, Suzanne; Dokladny, Karol; Moseley, Pope L

    2014-01-15

    The objectives of this study are threefold: 1) to assess whether 7 days of oral glutamine (GLN) supplementation reduces exercise-induced intestinal permeability; 2) whether supplementation prevents the proinflammatory response; and 3) whether these changes are associated with upregulation of the heat shock response. On separate occasions, eight human subjects participated in baseline testing and in GLN and placebo (PLA) supplementation trials, followed by a 60-min treadmill run. Intestinal permeability was higher in the PLA trial compared with baseline and GLN trials (0.0604 ± 0.047 vs. 0.0218 ± 0.008 and 0.0272 ± 0.007, respectively; P exercise in the GLN trial compared with the PLA trial (1.411 ± 0.523 vs. 0.9839 ± 0.343, respectively; P exercise-induced permeability, possibly through HSF-1 activation. PMID:24285149

  15. A Glutamine-Rich Factor Affects Stem Cell Genesis in Leech

    Directory of Open Access Journals (Sweden)

    Kristi A. Hohenstein

    2010-01-01

    Full Text Available Leech embryogenesis is a model for investigating cellular and molecular processes of development. Due to the unusually large size of embryonic stem cells (teloblasts: 50–300 μm in the glossiphoniid leech, Theromyzon tessulatum, and the presence of identifiable stem cell precursors (proteloblasts, we previously isolated a group of genes upregulated upon stem cell birth. In the current study, we show that one of these genes, designated Theromyzon proliferation (Tpr, is required for normal stem cell genesis; specifically, transient Tpr knockdown experiments conducted with antisense oligonucleotides and monitored by semiquantitative RT-PCR, caused abnormal proteloblast proliferation leading to embryonic death, but did not overtly affect neuroectodermal or mesodermal stem cell development once these cells were born. Tpr encodes a large glutamine-rich (∼34% domain that shares compositional similarity with strong transcriptional enhancers many of which have been linked with trinucleotide repeat disorders (e.g., Huntington's.

  16. Possible links between intestinal permeablity and food processing: a potential therapeutic niche for glutamine

    Directory of Open Access Journals (Sweden)

    Jean Robert Rapin

    2010-01-01

    Full Text Available Increased intestinal permeability is a likely cause of various pathologies, such as allergies and metabolic or even cardiovascular disturbances. Intestinal permeability is found in many severe clinical situations and in common disorders such as irritable bowel syndrome. In these conditions, substances that are normally unable to cross the epithelial barrier gain access to the systemic circulation. To illustrate the potential harmfulness of leaky gut, we present an argument based on examples linked to protein or lipid glycation induced by modern food processing. Increased intestinal permeability should be largely improved by dietary addition of compounds, such as glutamine or curcumin, which both have the mechanistic potential to inhibit the inflammation and oxidative stress linked to tight junction opening. This brief review aims to increase physician awareness of this common, albeit largely unrecognized, pathology, which may be easily prevented or improved by means of simple nutritional changes.

  17. Preventive effect of glutamine on intestinal barrier dysfunction induced by severe trauma

    Institute of Scientific and Technical Information of China (English)

    Jun-You Li; Yi Lu; Sen Hu; Dan Sun; Yong-Ming Yao

    2002-01-01

    AIM: To investigate the mechanism underlying intestinalbarrier function damage after severe trauma and thetherapeutic effect of glutamine.METHODS: Burned patients, and animal models of severstrauma replicated by hemorrhagic shock combined withendotoxin infusion and burn injury, were included in a serialexperiment. Effects of oral glutamine on intestinal barrierfunction were observed in scalded rets. Parametersmeasured in these experiments were as follows: plasmalevels of diamine oxidase (DAO), tumor necrosis factor(TNFα), endotoxin (LPS), and lactate as well as D-lactateby biochemical methods, lactose/mannitol (L/M) ratio inurine by SP-3400, and pathological examination of intestinalmucosa under light microscopy.RESULTS: Plasma DAO activity was significantly increasedafter injury. There was a negative correlation betweenplasma DAO and intestinal mucosal DAO or pHi ( r= -0.93,plasma 0.80 ± 0.93,2.83 ± 1.71, 1.14 ± 0.64,2.36 ± 2.06 and2.49± 1.67 vs intestinal 0.52± 0.12,0.34 ± 0.03,0.45 ± 0.18,0.37± 0.26 and 0.41 ± 0.07; r = - 0.533, plasma 0.87 ± 0.75,1.89± 1.13, 1.21 ± 0.23,3.03 ± 2.61 and 4.70 ± 1.22 Vs pHi7.03± 0.05,7.05 ± 0.06,7.14 ± 0.096,7.20 ± 0.08 and 7.05 ±0.07; P < 0.01-0.05). Positive correlations were foundbetween DAO activity and plasma TNFα, LPS, lactate, L/Mand D-lactate ( r = 0.817, 0.842, 0.872, and 0.951; plasmaDAO 0.87 ± 0.75,1.89 ± 1.13, 1.21 ± 0.23,3.03 ± 2.61 and 4.70± 1.22 vs TNF 0.08 ± 0.02,0.03 ± 0.25,0.17 ± 0.09,0.34 ± 0.15and 0.33 ± 0.18; vs LPS 0.14 ± 0.03,0.16 ± 0.04,0.21 ± 0.02,0.18± 0.16 and 0.37 ± 0.10; vs lactate 9.03 ± 2.19, 18.30 ±2.56,9.81 ± 2.83,12.01 ± 6.83, 12.01 ± 6.84 and 43.61 ± 11.27;vs L/M 0.03 ± 0.01,0.41 ± 0.27,0.62 ± 0.20, 1.70 ± 0.60; r =0.774, plasma DAO 1.25 ± 0.41,2.17 ± 0.71,2.29 ± 0.87, 1.23± 0.55 and 1.11 ± 0.47 vs D-lactate 8.37 ± 2.48, 18.25 ± 6.18,13.96 ± 4.94, 8.93 ± 3.00 and 12.39 ± 4.94; all P < 0.01),repestively. Damage of intestinal mucosa was

  18. Feasibility of biohydrogen production from tofu wastewater with glutamine auxotrophic mutant of Rhodobacter sphaeroides

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, G.H.; Wang, L.; Kang, Z.H. [School of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping road, Shanghai 200092 (China)

    2010-12-15

    NH{sub 4}{sup +}, which is normally the integrant in organic wastewater, such as Tofu wastewater, is an inhibitor to hydrogen production by anoxygenic phototrophic bacterium. In order to release inhibition of NH{sub 4}{sup +} to biohydrogen generation by Rhodobacter sphaeroides, a glutamine auxotrophic mutant R. sphaeroides TJ-0803 was obtained by mutagenizing with ethyl methane sulfonate. The mutant could generate biohydrogen efficiently in the medium with high NH{sub 4}{sup +} concentration, because the inhibition of NH{sub 4}{sup +} to nitrogenase was released. Under suitable conditions, TJ-0803 could effectively produce biohydrogen from tofu wastewater, which commonly containing 50-60 mg L{sup -1} NH{sub 4}{sup +}, and the generation rate was increased by more than 100% compared with that from wild-type R. sphaeroides. (author)

  19. Glutamine Synthetase Gene Amplification by 3'RACE and Bioinformatics Analysis%3'RACE法扩增谷氨酰胺合成酶基因及其生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    张志灯; 罗土炎; 饶秋华; 曹治云; 郑腾

    2012-01-01

    以抽提得到的黑曲霉mRNA为模板,根据GenBank上检索的谷氨酰胺合成酶基因mRNA序列,设计特异性引物,进行3 ' RACE PCR扩增,并在NCBI网站进行生物信息学分析.结果扩增得到长约1 kb的DNA片段,测序结果表明,所获得的DNA序列与gene bank上检索到黑曲霉产谷氨酰胺合成酶基因的同源性大于97%,与其他曲霉产谷氨酰胺合成酶的基因同源性大于50%.经开放阅读框软件分析发现其具有2个外显子,其中1个外显子的氨基酸序列与黑曲霉产GS同源性为100%.%On the basis of GS mRNA and specific primer, Using 3'RACE PCR amplified the gene sequence and analyzed some bioinformatics information of the sequence in NCBI web. GS DNA fragment was about 1. 0 kb. The sequence blast showed that the homology of fragment with GS gene of Asp. niger in GenbBank was more than 97 % and with other Asp were more than 50%. Open reading frame analyzed that it included 2 exon, one of which had 100% homology with GS of Asp. niger.

  20. Enhanced shoot multiplication in Ficus religiosa L. in the presence of adenine sulphate, glutamine and phloroglucinol.

    Science.gov (United States)

    Siwach, Priyanka; Gill, Anita Rani

    2011-07-01

    Ficus religiosa (Pipal) is a long-lived valuable multipurpose forest tree. The tree is exploited because of its religious, ornamental and medicinal value and the regeneration rate in natural habitat is low. An in vitro propagation protocol has been developed from nodal segments obtained from a 45-50-year old tree. The highest bud break frequency (100 %) followed by maximum number of multiple shoots (13.9) as well as length (2.47 cm) were obtained on Woody Plant medium (WPM) supplemented with 1.0 mg/l BAP along with 0.5 mg/l IAA. Two modifications in this medium resulted in enhanced shoot regeneration-one with 200 mg/l glutamine + 150 mg/l ADS (called as MM-1) giving 32.5 shoots per nodal explant while another modification-with 200 mg/l glutamine + 150 mg/l ADS + 100 mg/l phloroglucinol (called as MM-2) giving 35.65 shoots per explant. These two media were used for sub-culturing of shoots for 4 months. The rate of shoot multiplication was same during the first three sub-cultures on MM-1 and the shoots regenerated were healthy, afterwards shoot multiplication declined. While on MM-2, shoot multiplication declined after first sub-culture and shoots underwent the problem of early leaf fall. Rooting was best induced in micro-shoots excised from proliferated shoot cultures on semi-solid as well as liquid WPM modified with 2.0 mg/l IBA and 0.5 mg/l IAA. The in vitro-raised plantlets were potted and acclimatized under culture room conditions for 25-30 days before transfer to soil conditions, where the established plants showed more than 90 % survival. PMID:23573019