β‐oxidation of polyunsaturated fatty acids in peroxisomes Subcellular distribution of Δ3,Δ2‐enoyl‐CoA isomerase activity in rat liver

The metabolism of the double bonds at the delta 3 position in fatty acids was studied in rat liver. Infusion of delta 3-trans-dodecenoic acid into isolated perfused liver and subcellular fractionation studies showed the presence of both peroxisomal and mitochondrial delta 3,delta 2-enoyl-CoA isomerase activity (EC 5.3.3.8). These findings together with the previous demonstration of peroxisomal 2,4-dienoyl-CoA reductase (EC 1.3.1.34) [(1981) J. Biol. Chem. 256, 8259-8262] and D-3-OH-acyl-CoA epimerase (EC 5.1.2.3) [(1985) FEBS Lett. 185, 129-134] activities show that peroxisomes possess all the auxiliary enzymes required for the beta-oxidation of unsaturated fatty acids.