Thermodynamics of the glutamate dehydrogenase catalytic reaction

The enthalpy change for the oxidative deamination of glutamate by NADP+ catalyzed by bovine liver glutamate dehydrogenase has been determined calorimetrically. The deltaH0 values are 64.6 +/- 1.2 kJ/mol and 70.3 +/- 1.2 kJ/mol at 25 and 35 degrees C respectively. The equilibrium constants for the reaction at the two temperatures were determined spectrophotometrically. This enabled the determination of deltaG0 and deltaS0 of the reaction as well. deltaH0 values were also determined for the reaction using an alternative coenzyme and the deuterated substrate.