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)

Various flavins, FMN, FAD, and acriflavin, were immobilized to Sepharose using several different coupling methods. The only product stable enough to permit extended studies was acriflavin coupled to epoxy-substituted Sepharose. The nonenzymic oxidizing capacity towards NAD(P) H was investigated and a 25% specific activity, compared to that of free acriflavin, was observed. The reduced acriflavin was immediately auto-reoxidized in air and could thus be reused. It was shown that acriflavin-Sepharose preparations function as NAD(P)H oxidizing agents in a number of different dehydrogenase systems including lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH), malate dehydrogenase (MDH), alanine dehydrogenase (alaDH), and glutamate dehydrogenase (GDH). The amount of expensive coenzyme necessary for high product formation of such systems was thereby markedly reduced.
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PMID:Continuous regeneration of NAD(P)+ by flavins covalently bound to sepharose. 0 69

The activities of 12 enzymes, many related to ornithine metabolism, were measured in rat submaxillary gland, submaxillary gland tumors and pancreas. In submaxillary gland, the activities of arginase, ornithine aminotransferase, pyrroline-5-carboxylate reductase and glutamine synthetase were high, but no ornithine transcarbamylase or proline oxidase could be detected. In the fetal submaxillary gland, arginase was at almost adult levels while ornithine aminotransferase reached 50% of its adult value postnatally. Submaxillary tumors deviated from their cognate tissue by lower levels of amino acid metabolizing enzymes and by high concentrations of thymidine kinase. In pancreas, none of the pyrroline-5-carboxylate metabolizing enzymes were as high as in either liver or submaxillary gland. The outstanding activities were those of gamma-glutamyl transpeptidase and glutamate dehydrogenase. Although arginase activities in submaxillary gland and pancreas were quantitatively similar, they differed qualitatively: submaxillary gland contained the same variant as liver while the pancreatic isozymes resembled those of other nonhepatic tissues.
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PMID:Amino acid metabolizing enzymes in rat submaxillary gland, normal or neoplastic, and in pancreas. 0 9

The NADP-specific glutamate dehydrogenase (EC 1.4.1.4) of Neurospora crassa is inhibited by reaction with 1,2-cyclohexanedione which binds to arginine residues. With the 14C-labeled reagent, a peptide was isolated with the sequence: Gly-Gly-Leu-Arg-Leu-His-Pro-Ser-Val-Asn-Leu, corresponding to residues 78 through 88 in the protein. The arginine, residue 81, was present as N7,N8-(1,2-dihydroxycyclohex-1,2-ylene)-arginyl (or DHCH-arginine). Present evidence indicates that this arginine residue resides at or near the nicotinamide binding domain of the enzyme. Similar sequences are present in the bovine liver enzyme (EC 1.4.1.3) and the NAD-specific glutamate dehydrogenase of Neurospora (EC 1.4.1.2).
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PMID:Identification of a functional arginine residue involved in coenzyme binding by the NADP-specific glutamate dehydrogenase of Neurospora. 0 4

Transport properties of active enzyme species can be studied effectively by layering a small band of enzyme-containing sample on a gel chromatographic column previously saturated with substrate. The column is optically scanned at successive time intervals to yield profiles representing the appearance of chromophoric product or disappearnce of chromophoric substrate. These profiles permit determination of the specific activity and rate of transport of the active species. Initial studies on mechanic of the technique establish the feasibility of accurately determining transport properties of active enzyme species chromatographed on gel columns. Illustrative results are presented for L-glutamate dehydrogenase and for homoserine dehydrogenase studied in both forward and reverse reactions. It is shown that the partititon cross sections derived from the rates of motion of catalytic activity are the same as those determined by equilibrium saturation experiments which directly measure the degree of partitioning by the protein. These results establish the validity of the technique for a variety of future studies. Active enzyme gel chromatography appears comparable in precision to the active enzyme sedimentation technique at current stages of development.
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PMID:Active enzyme gel chromatography. I. Experimental aspects. 1 19

We have isolated mutant strains (nit) of Salmonella typhimurium that are defective in nitrogen metabolism. They have a reduced ability to use a variety of compounds including glutamate, proline, arginine, N-acetyl-glucosamine, alanine, and adenosine as sole nitrogen source. In addition, although they grow normally on high concentrations of ammonium chloride (greater than 1 mM) as nitrogen source, they grow substantially more slowly than wild type at low concentrations (less than 1 mM). We postulated that the inability of these strains to utilize low concentrations of ammonium chloride accounts for their poor growth on other nitrogen sources. The specific biochemical lesion in strains with a nit mutation is not known; however, mutant strains have no detectable alteration in the activities of glutamine synthetase, glutamate synthetase, or glutamate dehydrogenase, the enzymes known to be involved in assimilation of ammonia. A nit mutation is suppressed by second-site mutations in the structural gene for glutamine synthetase (glnA) that decrease glutamine synthetase activity.
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PMID:Mutant strains (nit) of Salmonella typhimurium with a pleiotropic defect in nitrogen metabolism. 1 Feb 75

Intact cells and extracts from Spirillum lipoferum rapidly oxidized malate, succinate, lactate, and pyruvate. Glucose, galactose, fructose, acetate, and citrate did not increase the rate of O2 uptake by cells above the endogenous rate. Cells grown on NH+/4 oxidized the various substrates at about the same rate as did cells grown on N2. Added oxidized nicotinamide adenine dinucleotide generally enhanced O2 uptake by extracts supplied organic acids, whereas oxidized nicotinamide adenine dinucleotide phosphate had little effect. Nitrogenase synthesis repressed by growth of cells in the presence of NH+/4 was derepressed by methionine sulfoximine or methionine sulfone. The total glutamine synthetase activity from N2-grown cells was about eight times that from NH+/4-grown S. lipoferum; the response of glutamate dehydrogenase was the opposite. The total glutamate synthetase activity from N2-grown S. lipoferum was 1.4 to 2.6 times that from NH+/4-grown cells. The levels of poly-beta-hydroxybutyrate and beta-hydroxybutyrate dehydrogenase were elevated in cells grown on N2 as compared with those grown on NH+/4. Cell-free extracts capable of reducing C2H2 have been prepared; both Mg2+ and Mn2+ are required for good activity.
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PMID:Carbon and ammonia metabolism of Spirillum lipoferum. 1 Feb 78

The photosynthetic bacterium Rhodopseudomonas capsulata lacks glutamate dehydrogenase and normally uses the glutamine synthetase/glutamate synthase sequence of reactions for assimilation of N2 and ammonia. The glutamine synthetase in cell-free extracts of the organism is completely sedimented by centrifugation at 140,000 X g for 2 h, is inhibited by L-alanine but not by adenosine 5'-monophosphate, and exhibits two apparent Km values for ammonia (ca. 13 muM and 1 mM).
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PMID:Inorganic nitrogen assimilation by the photosynthetic bacterium Rhodopseudomonas capsulata. 1 Feb 81

A method for the preparation of D- and L-glutamyl alpha-chloromethyl ketones (4-amino-6-chloro-5-oxohexanoic acid) is described. These chloromethyl ketones irreversibly inactivated bovine glutamate dehydrogenase, whereas several other related compounds had no adverse effect on the activity of the enzyme. The inactivation process was shown to be due to the modification of lysine-126. The time-courses for the inactivation and the incorporation of radioactivity from tritiated L-glutamyl alpha-chloromethyl ketone into the glutamate dehydrogenase were biphasic. The results were interpreted to suggest the involvement of 'negative co-operative' interactions in the reactivity of lysine-126. From the cumulative evidence it is argued that the first subunit of the enzyme, which takes part in catalysis, makes the largest, and the last the smallest, contribution to the overall catalysis. It is emphasized that three of the six subunits of the enzyme may possess as much as 80% of the total activity of bovine glutamate dehydrogenase.
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PMID:The asymmetric distribution of enzymic activity between the six subunits of bovine liver glutamate dehydrogenase. Use of D- and L-glutamyl alpha-chloromethyl ketones (4-amino-6-chloro-5-oxohexanoic acid. 1 Aug 89

Inhibition of bovine liver glutamate dehydrogenase by pyridoxal-5'-phosphate was studied by measuring the full time course of the oxidation of NADPH. Progress curves were determined before and after incubation of the enzyme with PLP in the presence of saturating concentrations of alpha-ketoglutarate and ammonium ion, at pH 7.4 and 25 degrees C. The data were fitted to the integrated Michaelis-Menten equation and an inhibition model derived. According to the model, PLP inhibits the enzyme non-competitively, by reversible formation of the complexes E--PLP and E--PLP--NADPH; the oxidation of NADPH is also inhibited by NADP+. After incubation with PLP, the dissociation constants of E--NADPH and E--NADP+ (Km and Kp) show a very definite decrease, while the maximum rate of oxidation (Vm) is increased. The inhibition constants for PLP were also computed.
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PMID:Full-time course studies of bovine liver glutamate dehydrogenase. Simulation of inhibition by pyridoxal-5'-phosphate. 1 Nov 96

The total values were determined for the activity of glutamate dehydrogenase, glutamine synthetase, and dehydrogenase with pyruvate in broilers fed a diet with a 0, 2 and 4% content of urea for three weeks. A statistically significant increase of glutamate dehydrogenase activity was ascertained in the liver and kidney of broilers. The increase of the activity of glutamine synthetase in liver was close to the threshold of statistical significance. Dehydrogenase activity with pyruvate increased in liver.
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PMID:[Effect of a urea diet on glutamate dehydrogenase and glutamine synthetase activity in various organs of chickens]. 1 5


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