Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of L-glutamate dehydrogenase (GLUD) as a reagent in staining mixtures to detect the isozymes of enzymes which catalyze the production of ammonia has been investigated. Methods have been devised for the electrophoresis and detection, using GLUD, of seven enzymes: cytidine deaminase, adenosine deaminase, adenosine monophosphate deaminase, arginase, argininosuccinase, D-amino acid oxidase, and D-aspartate oxidase. GLUD-linked staining methods appear to be sensitive, specific, and of general application.
 ...
PMID:Detection after electrophoresis of enzymes involved in ammonia metabolism using L-glutamate dehydrogenase as a linking enzyme. 2 58

A simple, rapid (2 hours), fluorescent test for the activity of blood adenosine deaminase (ADA) is described. The test which can be performed on both heparinized and dried blood, is based on the conversion of adenosine to inosine and ammonium in the presence of ADA. The enzyme activity is visually estimated by the oxidation of NADH (fluorescent) to NAD+ (non-fluorescent) in a coupled reaction with glutamate dehydrogenase. The disappearance of fluorescence indicates ADA activity in the sample. The advantages are discussed of the use of this test for the study of the autosomal recessive severe combined immunodeficiency.
 ...
PMID:A simple rapid fluorescent assay for adenosine deaminase activity. 31 78

An assessment of the Gilford Automatic Enzyme Analyser was conducted over a period of one year. The optics of the instrument were satisfactory with regard to accuracy of wavelength selection and linearity of absorbance response. Excellent precision was obtained for both absorbance readings and operation of the dispenser pump. Carry-over within the microflow-cell was low. The method of operation recommended by the manufacturers for enzyme determinations failed to take account of endogenous blank reactions which could lead to significant error. When revised methods utilising a pre-incubation stage and initiation with a single substrate were employed, the results correlated well with those obtained with standard automatic (LKB 8600) and manual (Pye Unicam SP 800) kinetic systems for aspartate and alanine aminotransferase, creatine phosphokinase and alpha-hydroxybutyrate dehydrogenase, and the precision at all activity levels was satisfactory. Acceptable precision could not be obtained over the clinical range for enzyme assays requiring a blank determination on each sample (5'-nucleotidase and adenosine deaminase) and those with very low normal serum activities (isocitrate dehydrogenase and glutamate dehydrogenase). These limitations appeared to be due to relative insensitivity of the transducer response and liability to optical disturbance. This apart, the instrument has many advantages over alternative equipment.
 ...
PMID:An evaluation of the Gilford 3400 automatic enzyme analyser. 114 90

The present study deals with the effect of atrazine on nitrogen metabolism in the liver and brain of fish. Significant changes were seen in the levels of proteins, free amino acids, ammonia, urea, glutamine and the activity levels of proteases, glucogenic aminotransferases, branched-chain aminotransferases, glutamate dehydrogenase, glutaminase, arginase, AMP deaminase and adenosine deaminase in both the tissues of fish exposed to sublethal concentration of atrazine. The study reflects a shift in nitrogen concentration of atrazine. The study reflects a shift in nitrogen metabolism in the tissues of fish for efficient mobilization of end products of protein catabolism as a consequence of atrazine.
 ...
PMID:Modulations in nitrogen metabolism in the hepatic and neuronal tissues of fish, Tilapia mossambica exposed to atrazine. 185 31

Nineteen southern African isolates of Plasmodium falciparum were typed by polyacrylamide gel electrophoresis, using 5 enzymes (glucose phosphate isomerase, adenosine deaminase, lactate dehydrogenase, NADP-dependent glutamate dehydrogenase and 6-phosphogluconate dehydrogenase). Limited variation was found amongst the isolates and the frequencies of variants were similar to those of isolates from other parts of the world. Eight of the isolates contained 2 forms of glucose phosphate isomerase, indicating clonal heterogeneity. One of these 8 isolates also contained 2 forms of adenosine deaminase and another showed 2 forms of lactate dehydrogenase.
 ...
PMID:Enzyme typing of southern African isolates of Plasmodium falciparum by polyacrylamide gel electrophoresis. 209 43

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.
 ...
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.
 ...
PMID:Plasmodium vivax: enzyme polymorphism in isolates of Indian origin. 269 26

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.
 ...
PMID:A rapid assay method for ammonia using glutamine synthetase from glutamate-producing bacteria. 288 29

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.
 ...
PMID:A continuous method for the estimation of adenosine deaminase catalytic concentration in pleural effusions with a Hitachi 705 discrete analyser. 406 16

Changes in oxidative metabolism were studied in hepatopancreas, muscle, and hemolymph of the edible crab Scylla serrata, exposed to a sublethal concentration (2.5 ppm) of cadmium chloride. A significant decrease in glycogen, total carbohydrates, and pyruvate and an increase in lactate levels in hepatopancreas and muscle were observed. Hemolymph sugar levels were increased in experimental crabs. An increase in phosphorylase suggested increased glycogenolysis during cadmium toxicity. The decrease in lactate dehydrogenase activity and the increase in lactate content indicated reduced mobilization of pyruvate into the citric acid cycle. Krebs cycle enzymes such as succinate dehydrogenase and malate dehydrogenase were found to be decreased, suggesting impairment of mitochondrial oxidative metabolism as a consequence of cadmium toxicity. Glucose-6-phosphate dehydrogenase activity was increased, suggesting enhanced oxidation of glucose by the HMP pathway. Cytochrome-c oxidase and Mg2+ ATPase activity levels decreased, indicating impaired energy synthesis during cadmium stress. Acid and alkaline phosphatase activities increased, suggesting enhanced breakdown of phosphates to release energy in view of impaired ATPase system during cadmium exposure. A significant decrease in protein and free amino acid and an increase in ammonia, urea, and glutamine levels were observed in the tissues during exposure. An increase in protease, alanine aminotransaminase, and aspartate aminotransaminase suggested increased proteolysis and transamination of amino acids. The increase in glutamate dehydrogenase, AMP deaminase, and adenosine deaminase indicated increased ammonia production. The increased arginase and glutamine synthetase suggested the detoxification or mobilization of ammonia toward the production of urea and glutamine. These results suggest that cadmium affects oxidative metabolism and induces hyperammonemia, and crabs switch over their metabolic profiles toward compensatory mechanisms for the survivability in cadmium-polluted habitats.
 ...
PMID:Changes in oxidative metabolism in selected tissues of the crab (Scylla serrata) in response to cadmium toxicity. 753 86


1 2 Next >>