
Full text loading...
The NAD-dependent glutamate dehydrogenase from Phycomyces spores was purified more than 300-fold. Estimation of M r by gel filtration gave a value of 98000 whereas after SDS-PAGE one major band of M r 54000 was found, suggesting that the enzyme is a dimer. The enzyme was virtually dependent on the presence of AMP for activity and showed half-maximal activation at 9·5 and 43 μm-AMP in the direction of amination and deamination respectively. ADP was nearly as effective at 20-fold higher concentrations. Other nucleotide monophosphates were ineffective and nucleoside triphosphates were slightly inhibitory. Hyperbolic kinetics were found for all substrates yielding K m values of about 10 mm for ammonium, 1 mm for 2-oxoglutarate and 0·1 mm for NADH in the direction of amination, and 10 mm for glutamate and 0·7 mm for NAD in the direction of deamination.
Article metrics loading...
Full text loading...
References
Data & Media loading...