Intraparticulate Localization of Some Peroxisomal Enzymes Related to Fatty Acid β‐Oxidation

Abstract

Male Wistar rats were given a diet containing 0.05% (wt/wt) LK-903 (.alpha.-methyl-p-myristyroxycinnamic acid 1-monoglyceride)for 2 wk. The activities of 4 hepatic peroxisomal enzymes involved in the fatty acyl-CoA .beta.-oxidizing system were determined. The activities of fatty acyl-CoA oxidase, crotonase, .beta.-hydroxybutyryl-CoA dehydrogenase and thiolase were all increased .apprx. 3 times by administration of LK-903. The intraparticulate localizations of the 4 enzymes were then investigated by treatment of the purified peroxisomes with Triton X-100, by sonication, and by sucrose-density-gradient centrifugation after Triton X-100 treatment. Thiolase is probably localized in the matrix of peroxisomes, crotonase and .beta.-hydroxybutyryl-CoA dehydrogenases are located in the core, and all or at least part of fatty acyl-CoA oxidase is associated with the core, though its association is weak.