Isotope exchange studies on liver alcohol dehydrogenase with cyclohexanol and cyclohexanone as reactants.

Isotope exchange studies at chemical equilibrium with cyclohexanol and cyclohexanone as reactants show that horse liver alcohol dehydrogenase has a partly random kinetic mechanism, in which the pathway involving nucleotides as first substrate and last product predominates. The exchange studies show clearly, however, that the nucleotides can dissociate from the central complexes at finite rates. Measurement of the apparent Michaelis constants for exchange as a function of the other reactant concentrations is suggested as a sensitive test for randomness in kinetic mechanisms of this type.