KINETICS AND DISSOCIATION CONSTANTS OF LIVER ALCOHOL DEHYDROGENASE WITH 3-ACETYL PYRIDINE NAD+ AND NADH

Binary complex dissociation constants and kinetic values of liver alcohol dehydrogenase were determined for 3-acetyl pyridine NAD+ and NADH. The reduced analog was bound 24 times less tightly than NADH to liver alcohol dehydrogenase whereas no significant difference was found between the binding of 3-acetyl pyridine NAD+ and NAD+ to liver alcohol dehydrogenate. The rates of interaction of substrates with binary complexes were 1/10 as fast when the acetyl pyridine analogs were used. These results were interpreted with reference to the significance of the pyridine ring amide group in binding, and the interaction of binary complexes with substrates.