Mechanism of interaction of citrate synthase with citryl-CoA

Arguments are presented which indicate that the low steady-state rates of citrate production governing the catalytic interaction of citrate synthase from pig heart with citryl-CoA reflect the formation of a non-productive enzyme.citryl-CoA complex. The kinetic predictions of such an extended reaction mechanism are examined and are shown to account in satisfactory detail for the complex multiphasic rate behaviour exhibited by the enzyme under a variety of conditions in reactions involving citryl-CoA as a substrate.