Glutamate dehydrogenase from the extremely thermophilic archaebacterial isolate AN1
- PMID: 8399386
- DOI: 10.1016/0167-4838(93)90011-f
Glutamate dehydrogenase from the extremely thermophilic archaebacterial isolate AN1
Abstract
Glutamate dehydrogenase (L-glutamate:NADP+ oxidoreductase, deaminating and transaminating, EC 1.4.1.4) was purified to homogeneity from the extremely thermophilic archaebacterial isolate AN1 (a member of the Thermococcales). The enzyme comprised a large proportion of the soluble cell protein (11%) and was purified in high yield. The molecular mass of the native enzyme was 204 kDa, while the subunit molecular mass was 47 kDa, indicating a tetrameric structure. The enzyme is specific for NADP(H) rather than NAD(H) by a factor of greater than 1000, as judged by Vmax/Km. Glutamate synthase activity was about 50% of the glutamate dehydrogenase activity. Activity was markedly enhanced by calcium, magnesium and manganese ions. The enzyme was highly thermostable with t1/2 values of 12.5 h and 47 min at 90 degrees C and 103 degrees C, respectively.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources