An NAD-specific glutamate dehydrogenase from cyanobacteria Identification and properties

• Published in: FEBS letters Vol. 285; no. 1; pp. 35 - 38
• Main Authors: Chávez, S., Candau, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 08-07-1991; Elsevier
• Subjects: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide; Ammonia - metabolism; Ammonium assimilation; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Chromatography, Gel; Cyanobacteria - enzymology; Cyanobacterium; Electrophoresis, Polyacrylamide Gel; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; GDH; glutamate dehydrogenase; Glutamate Dehydrogenase - chemistry; Glutamate Dehydrogenase - isolation & purification; Glutamate Dehydrogenase - metabolism; glutamate synthase; glutamine synthetase; GOGAT; Hydrogen-Ion Concentration; Isoelectric Point; Isoenzymes; Kinetics; MTT; NAD - metabolism; NAD-glutamate dehydrogenase; Oxidoreductases; phenazine methosulphate; phenylmethylsulfonyl fluoride; PMS; PMSF; Synechocystis sp. PCC 6803; Cyanobacterium; PMSF; PMS; Ammonium assimilation; GDH; NAD-glutamate dehydrogenase; Synechocystis sp. PCC 6803; GS; MTT; GOGAT; Glutamate dehydrogenase; Ammonium; Purification; Enzymatic activity; Cyanobacteria; Bacteria; Synechocystis; Kinetic parameter; Metabolism; Physicochemical properties
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(91)80719-J

The unicellular cyanobacterium
Synechocystis sp. PCC 6803 presents a hexameric NAD-specific glutamate dehydrogenase with a molecular mass of 295 kDa. The enzyme differs from the NADP-glutamate dehydrogenase found in the same strain and is coded by a different gene. NAD-glutamate dehydrogenase shows a high coenzyme specificity, catalyzes preferentially glutamate formation and presents
K
m
values for ammonium, NADH and 2-oxoglutarate of 4.5 mM, 50 μM and 1.8 mM respectively. An animating role for the enzyme is discussed.