Fatty acid oxidation in rat brain is limited by the low activity of 3-ketoacyl-coenzyme A thiolase.

摘要: In an attempt to clarify why the brain oxidizes fatty acids poorly or not at all, activities of beta-oxidation enzymes present in rat and heart mitochondria were measured compared with each other. Although apparent Km values chain-length specificities are similar, specific all but one enzyme between 4 50% those observed mitochondria. The exception is 3-ketoacyl-CoA thiolase (EC 2.3.1.16) whose activity 125 times lower than partially purified was shown be catalytically immunologically identical enzyme. low rate acid oxidation mitochondria, estimated on basis palmitoylcarnitine-supported respiration [1-14C]palmitoylcarnitine degradation less 0.5 nmol/min/mg protein, may consequence thiolase. Inhibition by 4-bromocrotonic proves dependent thus occur via beta-oxidation. Since reactions catalyzed carnitine palmitoyltransferase 2.3.1.21) acyl-CoA synthetase 6.2.1.3) do seem restrict brain, it concluded that limited mitochondrial 3-keto-acyl-CoA