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...

Identification of regulatory mutations of glutamate dehydrogenase (GDH) in a form of congenital hyperinsulinism (GDH-HI) is providing a model for basal insulin secretion (IS) and amino acid (AA)-stimulated insulin secretion (AASIS) in which glutaminolysis plays a key role. Leucine and ADP are activators and GTP is an inhibitor of GDH. GDH-HI mutations impair GDH sensitivity to GTP inhibition, l...

PART from the TPN (triphosphopyridine nucleotide) -specific glutamate deA hydrogenase (T-GDH) first described by FINCHAM ( 1950, 195 l ), Neurospora crassa possesses a DPN (diphosphopyridine nucleotide) -specific glutamate dehydrogenase (D-GDH) which is present ( SANWAL and LATA 1961 a) both in wild-type strains (SANWAL and LATA 1961b) and in mutants lacking T-GDH (am-1 mutants). The presence o...

GDH* occupies a central role in the metabolism of many microorganisms because it provides a link betweeen carbohydrate and nitrogen metabolism (Smith et al., 1975; Brown et al., 1974). Many simple eukaryotic micro-organisms possess two genetically distinct forms of GDH with different nucleotide specificities, a catabolic role being assigned to the NAD-specific enzyme, whereas the NADP-specific ...

Following the discovery of glutamine synthetase/glutamate (Glu) synthase, the physiological roles of Glu dehydrogenase (GDH) in nitrogen metabolism in plants remain obscure and is the subject of considerable controversy. Recently, transgenics were used to overexpress the gene encoding for the beta-subunit polypeptide of GDH, resulting in the GDH-isoenzyme 1 deaminating in vivo Glu. In this work...

Insulin secretion by pancreatic beta-cells is stimulated by glucose, amino acids, and other metabolic fuels. Glutamate dehydrogenase (GDH) has been shown to play a regulatory role in this process. The importance of GDH was underscored by features of hyperinsulinemia/hyperammonemia syndrome, where a dominant mutation causes the loss of inhibition by GTP and ATP. Here we report the effects of gre...

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...

The nucleotide sequence for a surface-associated protein (A. Joe, A. Yamamoto, and B. C. McBride, Infect. Immun. 61:3294-3303, 1993) of Porphyromonas gingivalis was determined. The structural gene comprises 1,338 bp and codes for a protein of 445 amino acids. The deduced molecular weight of the protein is 49,243. A data base search for homologous proteins revealed significant sequence similarit...

It has been reported that the hyperinsulinism-hyperammonemia syndrome is caused by mutations in glutamate dehydrogenase (GDH) gene that affects enzyme sensitivity to GTP-induced inhibition. To identify the GTP binding site(s) within human GDH, mutant GDHs at Tyr-266 or Lys-450 position were constructed by cassette mutagenesis. More than 90% of the initial activities were remained at the concent...

Abstract Background Biosynthesis of l - tert -leucine ( -tle), a significant pharmaceutical intermediate, by cofactor regeneration system friendly and efficiently is worthful goal all the time. The leucine dehydrogenase (LeuDH) glucose (GDH) has showed great coupling catalytic efficiency in synthesis -tle, however multi-enzyme complex GDH LeuDH never been constructed successfully. Results In th...