Acyl-CoA oxidase (ACO) is the key enzyme that catalyzes the rate-determining step in the peroxisomal beta-oxidation of fatty acids. ACO catalyzes the oxidation of acyl-CoA with molecular oxygen to produce trans-2,3-dehydroacyl-CoA and H2O2. Given the participation of H2O2 in an enhanced chemiluminescent reaction with luminol, we have developed a novel "two-step" procedure for the quantitation of ACO activity by recording light emission using a chemiluminescence detector. A number of recommendations on standardizing the reaction conditions for the quantitative measurement of ACO-catalyzed reactions are offered. The proposed method is simple and reliable and has been successfully applied in the rat liver assay. The results indicate that ACO activities increased in the liver of type-2 diabetic rats but showed no significant change in the liver of insulin-resistant rat.
acyl-CoA oxidase; chemiluminescence; luminol; peroxisomal oxidation
