Kinetics of acetyl-CoA synthetase—II. Product inhibition studies

Abstract

Product inhibition studies with bovine heart mitochondrial acetyl-CoA synthetase yielded the following results: 1. 1. Uncompetitive inhibition by AMP, and noncompetitive inhibition by acetyl-CoA as product inhibitors, both with CoA as the variable substrate. 2. 2. Competitive inhibition by both AMP and acetyl-CoA as product inhibitors with either acetate or MgATP as the variable substrate. The uncompetitive inhibition by AMP with CoA as the variable substrate, and the competitive inhibitions by AMP and acetyl-CoA with either MgATP or acetate as variable substrate can perhaps be reconciled by a model in which AMP induces randomness in the addition of MgATP and acetate, but not the release of acetyl-CoA and AMP, while acetyl-CoA induces randomness in both the addition and release of these substrates and products.