Binding of citrate synthase and malate dehydrogenase to mitochondrial inner membranes: tissue distribution and metabolite effects.

Citrate synthase and malate dehydrogenase bind to mitochondrial membrane preparations obtained from various species of animals and lemon fruit. The amount of enzyme bound per mg mitochondrial protein was comparable in all tissues studied. The effect of various substrates, products, and substrate analogs on citrate synthase binding to rat liver mitochondrial inner membrane was examined. OAA was the most effective inhibitor of binding followed by AcCoA , CoA, citrate, ATP, and MgATP. Neither D- nor L- malate were effective in blocking binding. The wide distribution of binding of citrate synthase and malate dehydrogenase to the inner membrane and specificity of substrate effects on the binding of citrate synthase are discussed in relation to the possible physiologic nature of these phenomena.