Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The activities of 6 dehydrogenases, lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PDH), isocitrate dehydrogenase (ICDH), glycerol-3-phosphate dehydrogenase (GDH), succinate dehydrogenase (SDH) and glutamate dehydrogenase (GLDH), determined by means of flow cytometry in 13 primary human gastrointestinal tumour cell lines, including 10 esophageal carcinomas, one gastric cancer, and 2 pancreatic cancers. Two-parametric measurements of specific dehydrogenase activities in single cells were performed with DAPI as fluorochrome for the nuclear DNA and with the fluorescent redox system of 5-cyano-2,3-ditolyl-tetrazolium chloride (CTC) which forms brilliant red formazan crystals upon reduction by cellular redox enzymes. Furthermore, with the aid of the calibration procedure reported previously [18] the enzyme activities were expressed as biochemical units. This application of tetrazolium salt technique for demonstrating dehydrogenase activities in human tumour cells by flow cytometry offers an alternative tool to characterize malignant tumors.
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PMID:Flow-cytometric determination of dehydrogenase activities in primary human gastrointestinal tumor cell lines. 816

We describe an improved enzymatic ultraviolet absorbance method for assaying creatinine in serum, plasma, and urine. Creatinine is hydrolyzed by creatinine iminohydrolase (EC 3.5.4.21) to ammonia and N-methylhydantoin. The ammonia produced combines with 2-oxoglutarate and NADPH in the presence of glutamate dehydrogenase to yield glutamate and NADP+. The consumption of NADPH, measured by a two-point fixed-time assay, is proportional to the amount of creatinine in the sample. The assay is carried out in two steps: The first step eliminates background absorbance in hyperlipemic samples and endogenous ammonia through a "clearing system" and an isocitrate dehydrogenase-based "ammonia scavenger system"; the second step starts creatinine measurement. The method affords a simple, rapid, and sensitive assay with good precision and extended linearity; it employs working solutions stable at least 4 months. Test results compare closely with those of the isotope dilution-mass spectrometry Definitive Method, the HPLC procedure, and the fuller's earth method. The proposed method is not subject to interference from several metabolites or from the 72 drugs tested. Because it is easily automated, the method is suitable for routine work in clinical laboratories.
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PMID:A step forward in enzymatic measurement of creatinine. 828 20

Flow cytometric measurements of the activities of lactate dehydrogenase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, glycerol-3-phosphate dehydrogenase, succinate dehydrogenase and glutamate dehydrogenase in single Ehrlich ascites tumour cells are described using a tetrazolium salt/fluorescent formazan reaction. Applying cyano-ditolyl-tetrazolium chloride (CTC) as redox dye indicating enzyme reaction, and DAPI as a fluorochrome for nuclear DNA staining, the bivariate flow cytometric assay of enzyme activity and cell cycle analysis was established. Furthermore, adopting the calibration procedure reported formerly, consisting of biochemical determination and flow cytometry of the same sample performed parallelly, the enzyme activities were expressed in biochemical units. The dehydrogenase activities found in Ehrlich ascites cells were 97.5 fmol H2 per average positive cell during 5 min for lactate dehydrogenase, 69.0, 10.6, 25.3, 29.7, and 19.0 fmol H2 per average positive cell during 20 min for glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, glycerol-3-phosphate dehydrogenase, succinate dehydrogenase and glutamate dehydrogenase, respectively. This quantitative procedure can offer an alternative analytic tool for enzyme cytology.
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PMID:Enzyme activities of six different dehydrogenases in Ehrlich ascites cells measured by flow cytometry. 835 66

A two-step method for assaying creatinine in serum and urine samples, suitable with automated analyzers, is reported. Reagent 1, for the first step, contains a blanking system [creatine amidinohydrolase (CRTase), urease, glutamate dehydrogenase, NADPH, and 2-oxoglutarate] and a NADPH-regenerating system [Mg(2+)-dependent isocitrate dehydrogenase (ICD), MgCl2, and excess isocitrate]. Reagent 2, for the second step, contains the metal-chelating reagent trans-1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid (CyDTA) and a trigger system [creatinine amidohydrolase (CRNase)]. When a specimen is mixed with reagent 1, all the creatine, urea, and NH3 present are removed by the blanking and NADPH systems. On adding reagent 2, CyDTA inactivates ICD to inhibit the NADPH system. Simultaneously, the creatinine (1 mol) in the specimen is hydrolyzed into creatine by CRNase, and then releases NADP+ (2 mol) through the blanking system. Our optimized method can determine creatinine linearly up to 500 mg/L, with within-day CVs < 1.2% and day-to-day CVs < 2.7%.
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PMID:Enzymatic rate assay of creatinine in serum and urine. 840 98

Employing RNA gel mobility shift assays we detected specific binding events between several dehydrogenases and various regions of the GLUT1 mRNA 3'-untranslated region. In particular, the enzymes glyceraldehyde 3-phosphate dehydrogenase (G3PDH), lactate dehydrogenase (LDH), and glucose 6-phosphate dehydrogenase (G6PDH) bound to the GLUT1 3'-UTR while isocitrate dehydrogenase (IDH) and glutamate dehydrogenase (GluDH) did not. Comparison of shifts obtained with purified dehydrogenases to those obtained using authentic cell extracts indicate that G3PDH and G6PDH may play a role in the intact cell.
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PMID:Dehydrogenase binding to the 3'-untranslated region of GLUT1 mRNA. 866 Mar 40

Efficient energy utilization is essential for cell growth; in an attempt to improve the growth conditions of the rat T-lymphocyte culture model for potential use in studying the mutagenic activity of carcinogens in vitro, we have investigated the effects of phytohemagglutinin (PHA), interleukin-2 (IL-2) and 2-mercaptoethanol (2-ME) on the activities of intermediary metabolism enzymes and cell proliferation. Isolated lymphocytes were cultured in the presence and absence of PHA, IL-2, or 2-ME. The intermediary metabolism enzymes investigated were glutamate dehydrogenase, glutamate-pyruvate transaminase, malate dehydrogenase, isocitrate dehydrogenase, lactate dehydrogenase, pyruvate kinase, and fatty acid synthetase (FAS). Measurable activity of all enzymes investigated, except for FAS, was detected in PHA-stimulated cells cultured with IL-2 or 2-ME. The unstimulated lymphocytes had significantly lower enzyme activity than stimulated cells. The combination of all three agents showed increased enzyme activity. This increase in activity brought about by the combination of the three agents was not reproduced by either agent acting alone. In general, the increase in enzyme activity correlated with cell proliferation as measured by [3H]thymidine uptake in PHA-stimulated cultures containing IL-2 and/or 2-ME. The results suggest that the addition of exogenous IL-2 and 2-ME enhances metabolic function and may be beneficial in in vitro culture of rat lymphocytes.
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PMID:Characterization of rat lymphocyte primary culture for the development of an in-vitro mutagenesis assay: effect of interleukin-2 and 2-mercaptoethanol on the activities of intermediary metabolism enzymes and cell proliferation. 873 77

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

Severe iron deficiency results in complex systemic disorders e.g., including metabolism of energy and minerals. To investigate whether also moderate iron depletion may alter the activities of citric cycle enzymes and the cytochrome oxidase, the trace element status, and serum enzymes indicative of cell damage, this experiment was carried out with rats supplied with sub-optimal iron (9, 13 and 18 mg iron per kg diet) over a total of 5 weeks. The study included 3 pair-fed groups and an ad libitum group, fed with 50 mg iron/kg diet. All iron-restricted rats were classified as iron-deficient on the basis of reduced iron concentrations in body and iron-depending blood parameters. Body weight gain and catalase activity in kidney were lowered in rats receiving the lowest dietary iron level, exclusively. Rats fed 9 and 13 mg iron per kg diet had nearly 6- and 3-fold, respectively higher platelet counts in blood than their corresponding pair-fed controls. The activities of transaminases ASAT and ALAT, alkaline phosphatase, glutamate dehydrogenase and lactate dehydrogenase in serum which are indicative of cell damage were also markedly influenced by moderate dietary iron restriction, in which the enzyme levels in serum increased with intensifying iron depletion. Although, moderate iron restriction to young male rats was associated with marked alterations in iron status and serum enzymes, the activities of tricarboxylic acid cycle enzymes including malic dehydrogenase, fumarase, and isocitric dehydrogenase as well as cytochrome oxidase in liver remained largely unaffected. Only hepatic aconitase showed a somewhat reduction with iron depletion. Moreover, iron restriction was also accompanied with an accumulation of copper in liver which was significant for rats fed 9 and 13 mg iron per kg diet, whereas zinc status remained completely unaffected by moderate iron deficiency. It can be concluded, that a short-term moderate iron deficiency with ranging hemoglobin concentrations from 66 and 121 g/L, was accompanied with altered platelet counts, serum enzyme activities indicative of cell damage, and hepatic copper concentrations, but the activities of the tricarboxylic acid cycle enzymes and cytochrome oxidase in liver remained largely unaffected.
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PMID:Effect of different degrees of moderate iron deficiency on the activities of tricarboxylic acid cycle enzymes, and the cytochrome oxidase, and the iron, copper, and zinc concentrations in rat tissues. 980 Mar 17


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