The β‐Oxidative Cleavage of Long‐Chain Fatty Acids in Rat‐Liver Cytoplasm

A β‐oxidative cleavage of oleyl‐ and stearyl‐CoA has been obtained with soluble enzymes of rat‐liver homogenate. The transformation requires NAD+ as an oxido‐reductive cofactor and is enhanced by ATP and CoA. Under the reported conditions 2,9‐octadecadienoic, 3,9‐octadecadienoic, 3‐hydroxy‐9‐octadecenoic, 7‐hexadecenoic, 3‐hydroxy‐7‐hexadecenoic and 5‐tetradecenoic acids are present after incubation of oleyl‐CoA, while no detectable amounts of shorter fatty acids are formed. A similar oxidation pattern is obtained with stearyl‐CoA when Mg2+ ions are also added to the system. The cytoplasmic origin of these enzymes is established by comparing their activity with that of the mitochondrial β‐oxidation enzymes.