Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reactive analogs of substrates or allosteric regulators can be designed to bind reversibly to particular ligand sites of enzymes. Subsequently, these compounds can react covalently with amino acids accessible from the ligand site, thereby functioning as chemical arrows aimed at specific enzymatic target sites. The approach of affinity labeling can be used to identify amino acid participants in active or regulatory sites, to provide a rational choice of targets for site-directed mutagenesis experiments, or to monitor conformational changes in the region of a particular enzyme site. Illustrations of these approaches include: 1) the use of reactive nucleotide analogs directed to substrate sites in adenylosuccinate synthetase and adenylosuccinate lyase and to regulatory sites of glutamate dehydrogenase, 2) the use of affinity cleavage by Fe2(+)-isocitrate to locate the metal-substrate site of isocitrate dehydrogenase, and 3) the use of reactive peptides and aromatic compounds to target the glutathione and xenobiotic sites of glutathione S-transferases.
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PMID:Chemical arrows for enzymatic targets. 906 10

The pregnant rats were treated with formaldehyde (0.5 mg/kg daily per os) during whole period of pregnancy. The activity of cytochrome-c-oxidase, malate dehydrogenase, nucleotidase, glucose-6-phosphatase, beta-glucuronidase, N-acetyl-beta-glucosaminidase, beta-galactosidase, H(+)-ATPase, glutamate dehydrogenase, NAD- and NADP-isocitrate dehydrogenase, fructose-bisphosphate aldolase, glucose-6-phosphate dehydrogenase and content of protein in liver celts of offsprings (newborns, 2 weeks age and 2 months age) were studied. It was shown differences in development enzyme systems of control and experimental animals during ontogenesis.
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PMID:[Experimental study of the effect of formaldehyde during embryogenesis on the activity of rat liver enzyme systems in ontogenesis]. 913 53

The obligate methylotroph Methylobacillus flagellatum was grown in the presence of different ammonium concentrations and the regulation of the enzymes associated with ammonium assimilation was investigated in steady-state and transient growth regimes. As the medium changed from C-limitation to dual C/N- and finally to N-limitation, the culture passed through three definite growth phases. The NADP(+)-dependent glutamate dehydrogenase (GDH) was present under ammonium limitation of the culture growth (at 2 mmol 1(-1) of ammonium in the growth medium) and increased in response to an increase in nitrogen availability. Glutamine synthetase (GS) and glutamate synthase (GOGAT) activities were negligible during C- and C/N-limitation. In N-limited cells the GOGAT activity increased as the dilution rate increased up to 0.35 h-1, and then sharply dropped. In the N-sufficient cultures both NAD(+)-and NADP(+)-dependent isocitrate dehydrogenase (NAD-ICDH and NADP-ICDH) activities were up-regulated as dilution rate increased, but in the N-limited culture the NAD-ICDH activity was up-regulated whereas NADP-ICDH one was down-regulated. Pulse additions of ammonium and methanol demonstrated the coordinate regulation of the GDH and ICDHs activities. When pulses were added to the C/N-limited cultures, there was an immediate utilization of the nutrients, resulting in an increase in biomass; at the same time the GDH and ICDH activities increased and the GS and GOGAT activities decreased. When the same ammonium/methanol pulse was added into the N-limited culture, there was a 3 h delay in the culture response, after which the substrates were utilized at rates close to the ones shown by the C/N-limited culture after the analogous pulse.
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PMID:Regulation of ammonia assimilation in an obligate methylotroph Methylobacillus flagellatum under steady-state and transient growth conditions. 919 10

A developmental block is induced by phosphate in rat embryos at the late two-cell stage. The present study was designed to examine the energy metabolism of rat two-cell blocked and non-blocked embryos. Enzyme activity was measured in individual embryos by histochemical techniques. The activities of malate dehydrogenase, isocitrate dehydrogenase, lactate dehydrogenase, pyruvate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, and phosphorylase did not differ among non-blocked and blocked embryos. However, the activity of succinate dehydrogenase was significantly decreased in blocked embryos compared with non-blocked embryos. In blocked embryos, cytochrome oxidase activity was distributed homogeneously, but was located at the perinuclear region in non-blocked embryos. Active mitochondrial organization was visualized using the fluorescent probe rhodamine 123 and laser scanning confocal microscopy. In both non-blocked and blocked embryos, mitochondria were distributed homogeneously. The concentration of H2O2 measured fluorometrically in embryos cultured without phosphate did not change significantly during the culture period, but decreased in embryos cultured with phosphate. The timing corresponded to the occurrence of the two-cell block. In summary, these results suggest that the developmental block in rat two-cell embryos is induced by disturbance of mitochondrial energy metabolism.
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PMID:Microscopic analysis of enzyme activity, mitochondrial distribution and hydrogen peroxide in two-cell rat embryos. 986 Nov 63

Two alpha-amylase-producing strains of Aspergillus oryzae, a wild-type strain and a recombinant containing additional copies of the alpha-amylase gene, were characterized with respect to enzyme activities, localization of enzymes to the mitochondria or cytosol, macromolecular composition, and metabolic fluxes through the central metabolism during glucose-limited chemostat cultivations. Citrate synthase and isocitrate dehydrogenase (NAD) activities were found only in the mitochondria, glucose-6-phosphate dehydrogenase and glutamate dehydrogenase (NADP) activities were found only in the cytosol, and isocitrate dehydrogenase (NADP), glutamate oxaloacetate transaminase, malate dehydrogenase, and glutamate dehydrogenase (NAD) activities were found in both the mitochondria and the cytosol. The measured biomass components and ash could account for 95% (wt/wt) of the biomass. The protein and RNA contents increased linearly with increasing specific growth rate, but the carbohydrate and chitin contents decreased. A metabolic model consisting of 69 fluxes and 59 intracellular metabolites was used to calculate the metabolic fluxes through the central metabolism at several specific growth rates, with ammonia or nitrate as the nitrogen source. The flux through the pentose phosphate pathway increased with increasing specific growth rate. The fluxes through the pentose phosphate pathway were 15 to 26% higher for the recombinant strain than for the wild-type strain.
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PMID:Identification of enzymes and quantification of metabolic fluxes in the wild type and in a recombinant aspergillus oryzae strain 987 53

Changes in the activity of enzymes involved in glutaminolysis and energy metabolism in the entire gastrointestinal (GI) tract of developing piglets are presented for the first time. The activities of glutaminase, glutamate dehydrogenase, oxoglutarate dehydrogenase, isocitrate dehydrogenase and alanine aminotransferase in the epithelium along the gastrointestinal tract from newborn, suckling (2-4 weeks old) and weaned (9 weeks old) piglets were investigated. The activity of glutaminase in the epithelium from the small intestine and colon was higher (p < 0.05) in weaned piglets than in newborn and suckling piglets. In addition, glutamate dehydrogenase and alanine aminotransferase activities in the small intestinal epithelium were higher (p < 0.05) for weaned piglets than for newborns. The activity of oxoglutarate dehydrogenase in the epithelium of the small intestine was significantly lower in newborn and suckling piglets compared with weaned individuals. The activity of isocitrate dehydrogenase in the epithelium along the gastrointestinal tract was higher (p < 0.05) for suckling and weaned piglets than for newborn piglets. The present data indicate that the utilization of substrates for energy production differs markedly between the stomach, small intestine and colon of growing piglets. Also, the capacity of enzymes in the epithelium of the GI tract to utilize acetyl-CoA as an energy substrate in the tricarboxylic acid cycle increased with piglet age. The epithelium of the GI tract of the newborn, suckling and weaned piglets showed a high capacity to metabolize alpha-ketoglutarate.
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PMID:Activities of enzymes involved in glutamine metabolism in connection with energy production in the gastrointestinal tract epithelium of newborn, suckling and weaned piglets. 1002 73

Changes in the activity of enzymes involved in oxidative metabolism of glutamine, and in protein content, in the epithelial tissue along the gastrointestinal (GI) tract of growing pigs exposed to nivalenol (NIV) in the diet were investigated. The epithelial tissue was taken from the stomach, small intestine and colon of three groups of animals fed diets without NIV (control), with inclusion of 2.5 mg NIV/kg diet (low dose) and with inclusion of 5.0 mg NIV/kg diet (high dose). The activities of glutaminase, glutamate dehydrogenase, oxoglutarate dehydrogenase, isocitrate dehydrogenase and alanine aminotransferase were determined. In the control pigs the activities of oxoglutarate dehydrogenase and alanine aminotransferase were higher (P < 0.05) in the epithelium of the small intestine as compared with the stomach and colon, while there were no differences in the activities of glutaminase, glutamate dehydrogenase and isocitrate dehydrogenase. With increasing inclusion of NIV in the diet the activity of oxoglutarate dehydrogenase decreased (P < 0.05) in the epithelium of the small intestine and colon, and the activity of alanine aminotransferase tended (P = 0.07) to increase in the epithelium of the small intestine. The activities of glutaminase, glutamate dehydrogenase and isocitrate dehydrogenase remained unaffected by the inclusion of NIV in the diet. In the control pigs the protein content in the epithelium of the small intestine was higher (P < 0.05) than in the stomach and colon, while there were no effects of NIV inclusion in the diet on the protein content. It can be concluded from the present study that the epithelial tissue of the small intestine and colon of pigs exposed to a diet containing NIV will have a reduced enzymatic capacity to utilise alpha-ketoglutarate in the tricarboxylic acid cycle (TCA-cycle), suggesting an impaired energy supply to these organs.
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PMID:Effect of exposure to dietary nivalenol on activity of enzymes involved in glutamine catabolism in the epithelium along the gastrointestinal tract of growing pigs. 1055 90

Few data are available on enzyme activity in amphibian plasma or erythrocytes. We measured the activity of several blood enzymes in the urodele amphibian Pleurodeles waltl reared under standard laboratory conditions. In subsequent experiments, we will estimate and compare the physiological and biochemical conditions of P. waltl when reared under extreme temperature or microgravity conditions. The enzymes selected were glutamate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, superoxide dismutase, catalase, isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase. In fresh plasma samples, enzyme activity in females was higher than in males, except for aspartate and alanine aminotransferases, which were equivalent in females and males. Glutamate dehydrogenase activity was higher in males than in females. In female erythrocytes, the activity of all enzymes was higher than in male erythrocytes. We have also studied the storage conditions of samples and observed that for most enzymes, the activity in freshly isolated plasma and erythrocyte preparations decreased after storage at -18 or +4 degrees C.
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PMID:Sex-linked differences in activity of enzymes in the blood of the urodele amphibian Pleurodeles waltl. 1169 17

The goal of the study was to evaluate the physiological and biochemical status of Pleurodeles waltli (urodele amphibian) by monitoring enzymatic activity in blood plasma and/or lood cell components. The following enzymes were chosen: glutamate dehydrogenase (GDH), aspartate and alanine aminotransferases (GOT and GPT), superoxide dismutase, catalase, isocitrate dehydrogenase, and glucose-6-phosphate dehydrogenase. With the exception of GDH, GOT and GPT, enzymatic activity was noticeably higher in blood of females as compared to males. Reflecting destructive processes in organism, under normal conditions levels of GOT and GPT activity in plasma are very much equal in females and males. Differences in activities of the other enzymes were proportional to levels of steroid hormones in blood plasma of animals.
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PMID:[Activities of certain enzymes in blood of the Pleurodeles waltl newt]. 1191 54

The metabolic cross-talk associated with re-assimilation of photorespiratory NH4+ was analysed in transformed tobacco (Nicotiana tabacum L.) plants with low activities of ferredoxin-dependent glutamine-alpha-ketoglutarate aminotransferase (Fd-GOGAT; EC 1.4.7.1). Amounts of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco; EC 4.1.1.39) protein and Rubisco transcripts were similar in all lines whether photorespiration rates were low (4,000 microl l(-1) CO2) or high (air). Leaf sucrose, hexose and starch contents were similar in all lines. In contrast, there was evidence that anaplerotic carbon flow was stimulated in the transformed lines with less than 60% Fd-GOGAT, since phospho enolpyruvate carboxylase (PEPc) activity and (PEPc) protein were increased. A strong positive correlation between leaf PEPc activity and glutamine accumulation was observed, suggesting that the increase in PEPc was related to the accumulation of glutamine. A modest stimulation of total NADP-isocitrate dehydrogenase (ICDH; EC 1.1.1.42) activity was also observed in the transformed lines with less than 60% Fd-GOGAT. This was accompanied by increases in both the cytosolic ICDH and mitochondrial NAD-isocitrate dehydrogenases (IDH; EC 1.1.1.41). IDH protein was also increased in the transformed plants with low Fd-GOGAT, suggesting that both IDH and ICDH are involved in the production of carbon skeletons (and ultimately alpha-ketoglutarate) necessary for the re-assimilation of NH4+. In contrast, PEPc, ICDH and IDH transcripts were similar in all lines. The aminating (but not the de-aminating) activity of NAD(H)-glutamate dehydrogenase (NAD(H)-GDH; EC 1.4.1.2) was greatly increased in plants with less than 60% of Fd-GOGAT after transfer to air. The data confirm that NH4+ or glutamine are involved in signalling, leading to modified gene expression and enzyme activity required for enhanced production of the C skeletons, to accommodate increases in the assimilation of photorespiratory NH4+. In addition, we provide the first demonstration of a compensatory role for NAD(H)-GDH in stabilising the leaf glutamic acid pool when Fd-GOGAT becomes limiting.
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PMID:Photorespiration-dependent increases in phospho enolpyruvate carboxylase, isocitrate dehydrogenase and glutamate dehydrogenase in transformed tobacco plants deficient in ferredoxin-dependent glutamine-alpha-ketoglutarate aminotransferase. 1194 64


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