Degradation of unsaturated fatty acids in peroxisomes. Existence of a 2,4-dienoyl-CoA reductase pathway.

1. There are two 2,4-dienoyl-CoA reductases (EC 1.3.1.-) (formerly called 4-enoyl-CoA reductase, Eur. J. Biochem. (1978) 91, 533-544) in rat liver, one in mitochondria and another one in peroxisomes. 2. Treatment of rats with clofibrate increases the activities of the 2,4-dienoyl-CoA reductases in both cell organelles. 3. Isolated peroxisomes metabolize 4-cis-decenoyl-CoA, a metabolite of linoleic acid, via the 2,4-dienoyl-CoA reductase pathway. 4. From these results it is concluded that peroxisomes have the enzymatic apparatus necessary for the degradation of unsaturated fatty acids.