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)

We describe a bioluminescence method for measuring adenosine deaminase activity in serum. The method involves use of batchwise enzyme reaction containing adenosine, alpha-ketoglutarate, glutamic dehydrogenase and NADH. The resulting solution is injected to the continuous-flow bioluminescence system. In the system, a bacterial luciferase and NAD(P)H:FMN oxidoreductase are covalently co-immobilized on Sepharose 4B. Carrier solution (pH 6.8) for bioluminescence reaction contains FMN and decanal. The continuous-flow light-emitting system, in which the reactor (flow cell packed with immobilized enzyme) is placed in front of a photomultiplier tube inside a photon counter, is versatile and simple. Concentration and response are linearly related from 1.2 to 92.5 pmol per injection of ammonia. The precision of the method is satisfactory (coefficient of variation 3.9-6.8%). We validated the technique by comparing results with conventional assay method (UV method). Normal values for adenosine deaminase activity of serum ranged from 7.0 to 22.0 U/l in agreement with those obtained by other method. The Sepharose 4B-immobilized enzymes are stable for more than one year. This assay system could be used as a routine clinical laboratory test in the diagnosis of liver damage.
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PMID:Bioluminescent assay for serum adenosine deaminase with immobilized bacterial luciferase. 262 Apr 50

Effects of repeated administration of benthiocarb on the nitrogen metabolism of hepatic and neuronal systems have been studied. Repeated benthiocarb treatment was associated with significant decrease in proteins with a concomitant increase in free amino acids (FAA) and specific activity levels of proteases suggesting impaired protein synthesis or elevated proteolysis. The glycogenic aminotransferases showed a significant elevation in both the tissues indicating high feeding of ketoacids into oxidative pathway for efficient operation of TCA cycle to combat energy crisis during induced benthiocarb stress. However, the activity levels of branched-chain aminotransferases decreased suggesting their reduced contribution of intermediates to TCA cycle. A comparative evaluation of the activity levels of ammonogenic enzymes, AMP deaminase, adenosine deaminase and glutamate dehydrogenase (GDH) indicated that ammonia was mostly contributed by nucleotide deamination rather than by oxidative deamination. GDH exhibited reduced activity due to low availability of glutamate. In accordance with increased levels of urea, the activity levels of arginase, a terminal enzyme of urea cycle was increased suggesting increased urea cycle operation in order to combat the increased ammonia content. As the presence of urea cycle in the brain is rather doubtful, the conversion of ammonia to glutamine for the synthesis of GABA is envisaged in brain whereas in liver, excess ammonia was converted to urea through ornithine-arginine reacting system. The increased glutaminase activity observed during benthiocarb intoxication is accounted for counteracting acidosis or maintenance of metabolic homeostasis. Arginase, a terminal enzyme of ornithine cycle showed increased activity denoting the efficient potentiality of tissues to avert ammonia toxicity. The changes observed in tissues of rat administered with benthiocarb reflects a shift in nitrogen metabolism for efficient mobilization of end products of protein catabolism.
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PMID:Perturbations in nitrogen metabolism of brain and liver of rat following repeated benthiocarb administration. 266 46

185 isolates of Plasmodium vivax were collected from patients visiting the malaria clinic run by the National Malaria Eradication Programme, Delhi, India. Percoll gradient centrifugation was used to concentrate P. vivax parasites from 0.4 to 0.5 ml of blood collected by finger prick. The parasite concentrate from each isolate was electrophoretically analysed for lactate dehydrogenase (LDH), NADP-dependent glutamate dehydrogenase (GDH), glucose phosphate isomerase (GPI) and adenosine deaminase (ADA). Variations were observed in GPI, GDH and ADA systems. Four electrophoretic forms of GPI and 5 each of GDH and ADA were observed. Electrophoretic mobilities of the different isoenzymic forms in P. vivax were identical to those reported for P. falciparum, indicating that the 2 species cannot be differentiated on the basis of electrophoretic patterns of the 4 enzyme systems studied.
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PMID:Plasmodium vivax: enzyme polymorphism in isolates of Indian origin. 269 26

The activities of aspartate and alanine transaminase, serine dehydratase, arginase, glutamate dehydrogenase, adenylate deaminase and glutamine synthetase were determined in the stomach and small intestine of developing rats. Despite the common embryonic origin of the intestine and stomach, their enzymes showed quite different activity levels and patterns of development, depending on their roles. Most enzyme activities were low during late intrauterine life and after birth, attaining adult levels with the change of diet at weaning. No arginase activity was found in the stomach and no changes were detected in adenylate deaminase in the stomach or intestine throughout the period studied. Alanine transaminase, serine dehydratase and, to some extent, glutamine synthetase levels, significantly higher in late intrauterine life, decreased after birth, suggesting that the foetal stomach has a transient ability to handle amino acids.
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PMID:Activities of amino acid metabolizing enzymes in the stomach and small intestine of developing rats. 286 86

There was a nil arginase and serine dehydratase activities in interscapular brown adipose tissue, but the activity of adenylate deaminase, glutamine synthetase, glutamate dehydrogenase and the aspartate, alanine and branched chain amino acid transaminases was higher than those of white adipose tissue; the differences were diminished when expressed per unit of protein weight. Brown adipose tissue enzyme activities were in a range between those of liver and muscle. The high amino acid handling capabilities, together with its physiological role, suggest that brown adipose tissue can metabolize significant amounts of amino acids, its enzyme pattern being different both from white adipose tissue, as well as of liver and muscle.
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PMID:Activities of enzymes of amino acid metabolism in rat brown adipose tissue. 287 38

The effect of 24-hr starvation on the amino acid pool composition and its concentration ratios with respect to blood and plasma as well as the activities of alanine, aspartate and branched chain amino acid transaminases, glutamate dehydrogenase, glutamine synthetase and adenylate deaminase have been studied in rat brown adipose tissue. Starvation induced a considerable decrease of pool amino acid concentration. Alanine and taurine were the amino acids in which the decrease was more marked. Small changes were observed in the activities of the enzymes studied, with decreases only in glutamate dehydrogenase and adenylate deaminase. These changes agree with a decrease in amino acid utilization in this tissue induced by starvation.
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PMID:Effect of 24-hour starvation on amino acid pool composition and enzyme activities of rat brown adipose tissue. 288 93

A rapid enzymatic assay method for ammonia was developed by using glutamine synthetase from glutamate-producing bacteria together with pyruvate kinase, lactate dehydrogenase, and NADH. The time required for determination of 25 nmol of ammonia was 5 min with 1 unit of glutamine synthetase, as opposed to 14-30 min with 1 unit of glutamate dehydrogenases from various sources. The present method was used to determine ammonia in serum, microbiol-culture broth, and waste water. The method can be modified for spectrophotometry in the visible region by substituting pyruvate oxidase, peroxidase, and appropriate chromogens for lactate dehydrogenase and NADH. With 4-aminoantipyrine (4AA) and phenol, and with 4AA and N-ethyl-N-2-hydroxyethyl-m-toluidine as chromogens, the sensitivity of ammonia determination was 0.65 and 1.7 times that with glutamate dehydrogenase, respectively. The present method was also applicable to the continuous detection of the activity of some ammonia-forming enzymes such as guanase, adenosine deaminase, and urease and to the determination of 0.5-30 microM ATP-ADP after some modification of the mixture.
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PMID:A rapid assay method for ammonia using glutamine synthetase from glutamate-producing bacteria. 288 29

The amino acid pool composition and its concentration ratios with respect to blood and plasma, as well as the activities of alanine, aspartate and branched chain amino acid transaminases, glutamine synthetase, adenylate deaminase and glutamate dehydrogenase have been studied in the interscapular brown adipose tissue of control, 12-h cold-exposed and 15-day cold-acclimated rats. Cold temperature affected the amino acid metabolism and pool composition more intensely after 15 days than after 12-h cold-exposure, even though the patterns of change were very similar in both groups. Cold temperatures induced a decrease in glutamine and an increase in glutamate concentration in the tissue. This probably increased the metabolism of branched chain amino acids and caused a decrease in adenylate deaminase activity. It also seemed to increase alanine utilization. We concluded that amino acid metabolism in brown adipose tissue is enhanced by cold temperature acclimation.
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PMID:Effect of cold-temperature exposure and acclimation on amino acid pool changes and enzyme activities of rat brown adipose tissue. 288 9

The activities of alanine, aspartate and branched-chain amino acid transaminases, glutamate dehydrogenase, glutamine synthetase and adenylate deaminase have been studied in liver of male rats exposed [12 hours at 4 degrees C] or acclimated [15 days at 4 degrees C] to cold temperature. Cold temperature induced an increase of the activities of glutamate dehydrogenase and alanine and aspartate transaminases both in cold-exposed and cold-acclimated animals; adenylate deaminase activity diminished after 15-day cold acclimation. There were not significant changes induced by cold temperature in the activities of the other two enzymes studied. These results agree with a possible direct implication of amino acid utilization by the liver in the context of the overall thermogenic response to cold temperature.
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PMID:Influence of cold exposure on liver amino acid metabolism enzymes of the rat. 290 59

An assay of adenosine deaminase activity in pleural effusions is described. For the continuous determination of adenosine deaminase, the liberated ammonia is estimated by coupling the liberated NH3 with 2-oxoglutarate. The reaction is followed by the decrease of NADH absorbance at 340 nm. The assay was optimized for a Hitachi 705 analyser, with respect to pH, adenosine concentration and glutamate dehydrogenase activity. The assay is linear to an adenosine deaminase catalytic concentration of 110 U/l. Elevated adenosine deaminase activities are found in pleural effusions of patients with tuberculosis, empyema and mesothelioma. Although elevated adenosine deaminase activity in pleural effusion is not pathognomonic for tuberculosis, it may be valuable as a first screening parameter.
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PMID:A continuous method for the estimation of adenosine deaminase catalytic concentration in pleural effusions with a Hitachi 705 discrete analyser. 406 16


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