A steady-state random-order mechanism for the oxidative deamination of norvaline by glutamate dehydrogenase.
The kinetic mechanism of glutamate dehydrogenase with the monocarboxylic substrate norvaline was examined by using initial-rate steady-state kinetics and inhibition kinetics. To a first approximation the reaction mechanism can be described as a rapid-equilibrium random-order one. Binding synergism between the monocarboxylic substrate and coenzyme is not observed. Dissociation constants for NAD+ and 2-oxoglutarate calculated from the kinetic data assuming a rapid-equilibrium random-order model are in good agreement with independently obtained estimates. Lineweaver-Burk plots with varied norvaline concentration are not strictly linear, and it is concluded that a steady-state random-order model more accurately reflects the observed kinetics with norvaline as substrate.
D000818:Animals; D002417:Cattle; D003641:Deamination; D005969:Glutamate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005977:Glutarates / Q000494:pharmacology; D007656:Ketoglutaric Acids / Q000494:pharmacology; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D014631:Valerates / Q000494:pharmacology; D014633:Valine / Q000378:metabolism* / Q000031:analogs & derivatives
D005977:Glutarates; D007656:Ketoglutaric Acids; D014631:Valerates; D009243:NAD; C005313:norvaline; D005969:Glutamate Dehydrogenase; D014633:Valine