Glutamate dehydrogenase (GDH) catalyses the reversible conversion of glutamate into α-ketoglutarate with the concomitant reduction of NAD(P)(+) to NAD(P)H or vice versa. GDH activity is subject to complex allosteric regulation including substrate inhibition. To determine GDH kinetics in situ, we assessed the effects of various glutamate concentrations in combination with either the coenzyme NAD...

Glutamate dehydrogenase (GDH), encoded by GLUD1, participates in the breakdown and synthesis of glutamate, the main excitatory neurotransmitter. In the CNS, besides its primary signaling function, glutamate is also at the crossroad of metabolic and neurotransmitter pathways. Importance of brain GDH was questioned here by generation of CNS-specific GDH-null mice (CnsGlud1(-/-)); which were viabl...

NAD-specific glutamate dehydrogenase [L-glutamate: NAD+ oxidoreductase (deaminating) EC 1.4.1.2] from Medicago sativa constitutes organ-specific patterns of isoenzymes. The isoenzyme-patterns of seeds (GDH-I) and roots (GDH-II) were purified 1520-fold and 92-fold, respectively. All isoenzymes of both patterns remain stable throughout the purification procedures. Isoenzyme a7, the only isoenzyme...

Glutamate dehydrogenase (GDH) catalyzes reversible oxidative deamination of l-glutamate to alpha-ketoglutarate. Enzyme activity is regulated by several allosteric effectors. Recognition of a new form of hyperinsulinemic hypoglycemia, hyperinsulinism/hyperammonemia (HI/HA) syndrome, which is caused by gain-of-function mutations in GDH, highlighted the importance of GDH in glucose homeostasis. GD...

Quantitative fecal lactoferrin was measured in 112 patients tested for toxigenic Clostridium difficile using glutamate dehydrogenase (GDH) and toxin immunoassays combined with tcdB PCR. Lactoferrin levels were higher in the GDH-positive/toxin-positive group (79 μg/ml) than in the GDH-positive/toxin-negative/PCR-positive (21 μg/ml) and the GDH-negative groups (13 μg/ml). Differences in fecal lac...

In pancreatic β-cells, glutamate dehydrogenase (GDH) modulates insulin secretion, although its function regarding specific secretagogues is unclear. This study investigated the role of GDH using a β-cell-specific GDH knockout mouse model, called βGlud1(-/-). The absence of GDH in islets isolated from βGlud1(-/-) mice resulted in abrogation of insulin release evoked by glutamine combined with 2-...

The modulation of primary nitrogen metabolism by hypoxic stress was studied in young Medicago truncatula seedlings. Hypoxic seedlings were characterized by the up-regulation of glutamate dehydrogenase 1 (GDH1) and mitochondrial alanine aminotransferase (mAlaAT), and down-regulation of glutamine synthetase 1b (GS1b), NADH-glutamate synthase (NADH-GOGAT), glutamate dehydrogenase 3 (GDH3), and iso...

BACKGROUND Poly-γ-glutamic acid (γ-PGA) is a valuable polymer with glutamate as its sole precursor. Enhancement of the intracellular glutamate synthesis is a very important strategy for the improvement of γ-PGA production, especially for those glutamate-independent γ-PGA producing strains. Corynebacterium glutamicum has long been used for industrial glutamate production and it exhibits some uni...

l-Glutamate uptake, thiourea uptake, and methylammonium uptake and the intracellular ammonium concentration were measured in wild-type and mutant cells of Aspergillus nidulans held in various concentrations of ammonium and urea. The levels of l-glutamate uptake, thiourea uptake, nitrate reductase, and hypoxanthine dehydrogenase activity are determined by the extracellular ammonium concentration...

Brain glutamate dehydrogenase (GDH) activity was compared between streptozotocin induced diabetic rats and insulin treated diabetic rats using crude and purified preparations from rat brain. V. of GDH increased significantly (p<0.05) while Km remained same in diabetic state when compared to control. Insulin treatment restored Vmax to normal values. The observed changes in the present study indi...