Malonate
The malonate or propanedioate ion is CH2(COO)2 (malonic acid minus two hydrogen ions). Malonate compounds include salts and esters of malonic acid, such as
Malonate is a competitive inhibitor of the enzyme succinate dehydrogenase: malonate binds to the active site of the enzyme without reacting, and so competes with succinate, the usual substrate of the enzyme. The observation that malonate is a competitive inhibitor of succinate dehydrogenase was used to deduce the structure of the active site in that enzyme.The chemical malonate decreases cellular respiration. It resembles the substrate succinate, without a -CH2-CH2 group required for dehydrogenation.