Purification and properties of extremely thermostable glutamate dehydrogenases from two hyperthermophilic archaebacteria, Pyrococcus woesei and Pyrococcus furiosus.
Glutamate dehydrogenase (L-glutamate: NADP oxidoreductase, deaminating, EC 1.4.1.4) from the hyperthermophilic archaebacteria Pyrococcus woesei and P. furiosus were purified to homogeneity from crude extracts. The enzymes had similar enzymological properties: molecular mass, subunit structure, optimum pHs for the oxidative deamination and reductive amination, substrate specificity and coenzyme specificity as well as thermostability; the activity was not lost after incubation at 105 degrees C for 30 min. However, some differences were detected in resistance to urea denaturation and effects of salts on their activity and stability. The N-terminal 20 amino acid sequences of the two enzymes were identical.
Ohshima
T
T
Department of Chemistry, Kyoto University of Education, Japan.
Nishida
N
N
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D001105:Archaea / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005969:Glutamate Dehydrogenase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007651:Keto Acids / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
D000596:Amino Acids; D007651:Keto Acids; D009243:NAD; D009249:NADP; D005969:Glutamate Dehydrogenase