BETA-OXIDATION OF FATTY-ACIDS BY THE UNSPECIALIZED PEROXISOMES FROM RICE COLEOPTILE

Rice coleoptiles grown under anaerobic conditions contain very low act ivities of beta-oxidation enzymes, whereas those grown in air contain unspecialized peroxisomes in which activities of the beta-oxidation en zymes have been well demonstrated. The ability of these peroxisomes to activate free fatty acids by an acyl-CoA synthetase (EC 6.2.1.3) is r eported here, The synthetase activity quantified as the production of [C-14]palmitoyl-CoA from [1-C-14]palmitic acid amounted to 0.8 nmol/mi n/mg protein, Overall beta-oxidation activity measured as NADH product ion was observed, using either palmitoyl-CoA or palmitic acid as subst rate. Inhibitors of the mitochondrial respiratory chain did not repres s the observed beta-oxidation activity.