CHARACTERIZATION OF A NOVEL ENZYME OF HUMAN FATTY-ACID BETA-OXIDATION - A MATRIX-ASSOCIATED, MITOCHONDRIAL 2-ENOYL-COA HYDRATASE

We present evidence for the existence of a previously unrecognised enzyme of mitochondrial beta-oxidation in man. This enzyme, which is situated in the mitochondrial matrix and has medium- and long-chain 2-enoyl-CoA hydratase activity, was identified by studying tissues from a patient with a severe deficiency of the trifunctional protein of mitochondrial beta-oxidation. The novel enzyme is present in all tissues studied - heart, liver and cultured skin fibroblasts- but is particularly active in liver. Together with other recently identified enzymes of mitochondrial beta-oxidation, the existence of this new enzyme suggests that two mitochondrial beta-oxidation enzyme systems exist in man: one associated with the mitochondrial membrane, responsible for the beta-oxidation of long-chain fatty acids and one in the mitochondrial matrix, responsible for the oxidation of medium- and short-chain fatty acids. (C) 1995 Academic Press, Inc.