Purification and properties of an extremely thermostable NADP+-specific glutamate dehydrogenase from Archaeoglobus fulgidus.
NADP+-specific glutamate dehydrogenase (EC 1.4.1.4) was purified to homogeneity from the extremely thermophilic, strictly anaerobic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324. The native enzyme (263 kDa) is composed of subunits of mol. mass 46 kDa, suggesting a hexameric structure. The temperature optimum for enzyme activity was > 95 degrees C. The enzyme was highly thermostable, having a half-life of 140 min at 100 degrees C. Potassium phosphate, KCl, and NaCl enhanced the thermal stability and increased the rate of activity three- to fourfold. The N-terminal 26-amino-acid sequence showed a high degree of similarity to glutamate dehydrogenases from Pyrococcus spp. and Thermococcus spp.
Aalén
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N
Department of Microbiology, University of Bergen, Norway.
Steen
I H
IH
Birkeland
N K
NK
Lien
T
T
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D019611:Archaeoglobus fulgidus / Q000201:enzymology*; D004795:Enzyme Stability; D005969:Glutamate Dehydrogenase / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D006207:Half-Life; D007700:Kinetics; D008969:Molecular Sequence Data; D009249:NADP / Q000378:metabolism*; D013696:Temperature
D019843:Archaeal Proteins; D009249:NADP; D005969:Glutamate Dehydrogenase