This review focuses on the role of acute pH changes in the regulation of Gln/Glu metabolism in the kidney, liver, and brain. Alterations of proton concentration ([H+]) profoundly affect flux through phosphate-dependent glutaminase (PDG) or glutamate dehydrogenase (GDH), the primary enzymes responsible for mitochondrial metabolism of glutamine and glutamate, respectively. In the kidney, acute ac...

Thirty-one strains characterized initially as Prevotella inter-media were subjected to: DNADNA hybridization, against reference DNA probes from strains ATCC 25611T and ATCC 33563; physiological tests; peptidase and lipase activities; and multilocus enzyme analysis using malate dehydrogenase (MDH) and glutamate dehydrogenase (GDH). In keeping with the properties of Pr. intermedia, all strains fe...

The ammonium induction of the chloroplast-localized NADP-specific glutamate dehydrogenase (NADP-GDH) was shown not to be a light-dependent process per se in Chlorella sorokiniana. In the dark without exogenous organic substrates, the cells synthesized low levels of fully active NADP-GDH, provided endogenous starch reserves had not been depleted. When cells were supplied with exogenous acetate, ...

Prevotella ruminicola B(1)4 possesses both NADPH- and NADH-linked glutamate dehydrogenase (GDH) activities, with the greatest specific activity being measured from ammonia-limited cultures. Relative to cells grown in the presence of 1 mM ammonium chloride, the NADPH-dependent activity was decreased approximately 10-fold when peptides were provided as a nitrogen source. Nondenaturing polyacrylam...

Urea-induced effects in clostridial glutamate dehydrogenase (GDH, EC 1.4.1.2) were studied by spectrophotometry, circular dichroism, FPLC, affinity chromatography and PAGE. Denaturation of enzyme occurred over a narrow range of urea concentrations (2.5-3.5 M), accompanied by inactivation of enzyme with a similar rate constant. The contribution of instantaneous inhibition by urea was also ascert...

To investigate the role of stress in nitrogen management in plants, the effect of pathogen attack, elicitors, and phytohormone application on the expression of the two senescence-related markers GS1 (cytosolic glutamine synthetase EC 6.3.1.2) and GDH (glutamate dehydrogenase, EC 1.4.1.2) involved in nitrogen mobilization in senescing leaves of tobacco (Nicotiana tabacum L.) plants, was studied....

The swamp eel, Monopterus albus, is an obligatory air-breathing teleost which can undergo long period of emersion, has high environmental and tissue ammonia tolerance, and can survive in brackish water. We obtained a cDNA sequence of glutamate dehydrogenase (gdh), which consisted of a 133-bp 5' UTR, a complete coding sequence region spanning 1629 bp and a 3' UTR of approximately 717 bp, from th...

BACKGROUND Glutamate dehydrogenase (GDH) is a key enzyme for the synthesis and catabolism of glutamic acid, proline and alanine, which are important osmolytes in aquatic animals. However, the response of GDH gene expression to salinity alterations has not yet been determined in macro-crustacean species. METHODOLOGY/PRINCIPAL FINDINGS GDH cDNA was isolated from Eriocheir sinensis. Then, GDH ge...

A glycine-resistant Neurospora crassa mutant (am-132;glyr), derived from the am-132 mutant, was isolated and characterized. [am-132 itself has a deletion in the structural gene for NADP-dependent glutamate dehydrogenase (GDH).] This new mutation also conferred resistance to serine and methionine sulphoximine (MS), which are inhibitors of glutamine synthetase (GS). In addition, the mutant obtain...

Oncogenes influence nutrient metabolism and nutrient dependence. The oncogene c-Myc stimulates glutamine metabolism and renders cells dependent on glutamine to sustain viability ("glutamine addiction"), suggesting that treatments targeting glutamine metabolism might selectively kill c-Myc-transformed tumor cells. However, many current or proposed cancer therapies interfere with the metabolism o...