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

Homogenates of insulin-producing tumoral cells catalyzed the phosphorylation of glucose, mannose, and fructose. The kinetics of phosphorylation at increasing glucose concentrations, the inhibitory effect of glucose 6-phosphate, and the comparison of results obtained with distinct hexoses indicated the presence of both low-Km hexokinase-like and high-Km enzymatic activities, the results being grossly comparable to those collected in normal pancreatic islets. Relative to protein content, the glucose-phosphorylating enzymatic activity was higher in tumoral than normal islet cells. The activity of other enzymes was either lower (glutamate dehydrogenase), moderately higher (phosphoglucomutase, lactate dehydrogenase) or considerably greater (ornithine decarboxylase) in tumoral than in normal islet cells. In intact tumoral cells, incubated under increasing glucose concentrations, the oxidation of D-[U-14C]glucose and the output of lactic and pyruvic acids reached a close-to-maximal value at 2.8 mM glucose. The ratios for glucose oxidation/utilization and lactate/pyruvate output were much lower in tumoral than in normal islet cells. Although glucose caused a modest increase in insulin output from the tumoral cells, this effect was saturated at a low glucose concentration (2.8 mM) and less marked than that of other secretagogues (e.g., L-leucine, L-ornithine, or forskolin). Thus, despite a close-to-normal enzymatic equipment for glucose phosphorylation, the tumoral cells displayed severe abnormalities in the metabolism and secretory response to this hexose. These findings point to regulatory mechanisms distal to glucose phosphorylation in the control of glucose metabolism in insulin-producing cells.
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PMID:Glucose metabolism in insulin-producing tumoral cells. 389 13

Fourteen stable mutants of Mucor bacilliformis which grew yeastlike under both aerobic and anaerobic conditions were isolated after treatment of growing mycelium with N-methyl-N'-nitro-N-nitrosoguanidine. Biochemical characterization of the mutants included determination of growth in different carbon and nitrogen sources, determination of sensitivity of respiration to cyanide and salicylhydroxamate, analysis of cytochrome spectra, determination of glutamate dehydrogenases, glutamine synthase, and ornithine decarboxylase activities, and measurement of cyclic AMP levels. Data showed that all mutants were defective in some aspect of oxidative metabolism and had low levels of ornithine decarboxylase, whereas other characters were variable. It was concluded that morphological transition in M. bacilliformis is probably associated with mitochondrial functions and expression of ornithine decarboxylase, but may be independent of cyclic AMP and glutamate dehydrogenase levels. The importance of genetic studies in the analysis of dimorphism is stressed.
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PMID:Isolation and biochemical analysis of Mucor bacilliformis monomorphic mutants. 613 77

Eleven rat genes have been assigned to rat chromosomes by use of mouse x rat somatic hybrids and/or use of linkage to known chromosome markers. Among them, the genes for the inducible nitric oxide synthase (Nos2) and for a vasoactive intestinal peptide receptor (Vipr) are potential candidates for genetic regulation of blood pressure and were localized to rat Chromosomes (Chrs) 10 and 8 respectively. Genes for gastric H,K-ATPase alpha subunit (Atp4a), Class I alcohol dehydrogenase (Adh), and aldolase C (Aldoc) were localized to Chrs 1, 2, and 10 respectively, and thus provide more DNA markers for genetic mapping of quantitative trait loci for blood pressure on those chromosomes. Genes for alkaline phosphatase (Alp1) and cardiac AE-3 Cl-/HCO3- exchanger (Ae3) were both localized to Chr 9. Genes for glutamate dehydrogenase (Glud) and gastric H,K-ATPase beta subunit (Atp4b) were localized to Chr 16. The ornithine decarboxylase (Odc) gene and ornithine decarboxylase pseudogene (Odcp) were localized to Chrs 6 and 11 respectively.
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PMID:Chromosomal assignment of 11 loci in the rat by mouse-rat somatic hybrids and linkage. 787 82

Ornithine decarboxylase (ODC) from Lactobacillus 30a catalyses the cleavage of alpha-methylornithine into ammonia and 2-methyl-1-pyrroline; glutamate decarboxylase (GAD) from Escherichia coli catalyses the cleavage of alpha-methylglutamate into ammonia and laevulinic acid. In our analyses, 2-methyl-1-pyrroline and laevulinic acid were identified by HPLC and mass spectroscopic analysis, and ammonia was identified by means of glutamate dehydrogenase. Molecular oxygen was consumed during these reactions in a 1:2 molar ratio with respect to the products. The catalytic efficiencies (k(cat)/K(m)) of the reactions catalysed by ODC and GAD were determined as 12500 and 9163 M(-1).min(-1) respectively. When the reactions were performed under anaerobic conditions, no ammonia, 2-methyl-1-pyrroline or laevulinic acid was produced to a significant extent. The formation of ammonia and O(2) consumption (in a 1:2 molar ratio with respect to ammonia) were also detected during the reaction of ODC and GAD with putrescine and gamma-aminobutyrate respectively. Taken together, these findings clearly indicate that ODC and GAD catalyse an oxidative deamination of their decarboxylation products, a reaction similar to that catalysed by dopa decarboxylase (DDC) with alpha-methyldopa [Bertoldi, Dominici, Moore, Maras and Borri Voltattorni (1998) Biochemistry 37, 6552-6561]. Furthermore, this reaction was accompanied by a decarboxylation-dependent transamination occurring for GAD, DDC and ODC with a frequency of approx. 0.24%, 1% and 9% respectively compared with that of oxidative deamination.
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PMID:Ornithine and glutamate decarboxylases catalyse an oxidative deamination of their alpha-methyl substrates. 1047 60