Effect of cryosolvent on transient kinetics of the glutamate dehydrogenase reaction.
The transient and steady-state kinetics of the oxidative deamination of L-glutamate by glutamate dehydrogenase and NADP in both aqueous solution and 30% methanol are compared. Methanol causes an approximately 5-fold tightening of the enzyme--L-glutamate binary complex and an approximately 2-fold reduction of the interaction parameter for the ternary enzyme--NADP--L-glutamate complex. The most dramatic effect of methanol on the time course of the reaction is what appears to be a conversion of the enzyme at substoichiometric initial levels of reactant NADP to a form from which product alpha-ketoglutarate does not readily dissociate. This conversion appears only at NADP concentrations over one-third of the enzyme active site concentration.
D000818:Animals; D002417:Cattle; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D000432:Methanol / Q000494:pharmacology*; D009249:NADP / Q000378:metabolism; D012997:Solvents; D013997:Time Factors
D005971:Glutamates; D012997:Solvents; D018698:Glutamic Acid; D009249:NADP; D005969:Glutamate Dehydrogenase; D000432:Methanol