title: The activity of 3-hydroxyacyl-CoA epimerase is insufficient to account for the rate of linoleate oxidation in rat heart mitochondria. Evidence for a modified pathway of linoleate degradation.
abstract: The activities of cis-delta 3-trans-delta 2-enoyl-CoA isomerase (EC 5.3.3.8), 3-hydroxyacyl-CoA epimerase (EC 5.1.2.3), and 2,4-dienoyl-CoA reductase, all of which have been proposed to function as auxiliary enzymes in the beta-oxidation of polyunsaturated fatty acids, have been determined in mitochondria from rat heart and rat liver. In heart mitochondria the activity of 3-hydroxyacyl-CoA epimerase was lower, whereas that of 2,4-dineoyl-CoA reductase was higher than the observed rate of linoleate degration. This observation suggests that 2,4-dienoyl-CoA reductase and not 3-hydroxyacyl-CoA epimerase functions as an auxiliary enzyme in the metabolism of polyunsaturated fatty acids in heart. A modified pathway of linoleate degradation is presented.
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D000818:Animals; D019748:Carbon-Carbon Double Bond Isomerases; D064006:Dodecenoyl-CoA Isomerase; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D007535:Isomerases / Q000378:metabolism*; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000378:metabolism*; D010101:Oxygen Consumption; D019998:Racemases and Epimerases / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity
chemical_list: D000214:Acyl Coenzyme A; D008041:Linoleic Acids; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; D007535:Isomerases; D019998:Racemases and Epimerases; C029601:3-hydroxybutyryl-CoA epimerase; D019748:Carbon-Carbon Double Bond Isomerases; D064006:Dodecenoyl-CoA Isomerase