Acyl-CoA oxidase activity and peroxisomal fatty acid oxidation in rat tissues.
Acyl-CoA oxidase, the first enzyme of the peroxisomal beta-oxidation, was proved to be rate-limiting for this process in homogenates of rat liver, kidney, adrenal gland, heart and skeletal muscle. Acyl-CoA oxidase activity, based on H2O2-dependent leuko-dichlorofluorescein oxidation in tissue extract, was compared with radiochemically assayed peroxisomal beta-oxidation rates. Dichlorofluorescein production was a valid measure of peroxisomal fatty acid oxidation only in liver and kidney, but not in adrenal gland, heart or skeletal muscle. Production of 14C-labeled acid-soluble products from 1-14C-labeled fatty acids in the presence of antimycin-rotenone appears to be a more accurate and sensitive estimate of peroxisomal beta-oxidation than the acyl-CoA oxidase activity on base of H2O2 production. Chain-length specificity of acyl-CoA oxidase changed with the acyl-CoA concentrations used. Below 80 microM, palmitoyl-CoA showed the highest activity of the measured substrates in rat liver extract. No indications were obtained for the presence in rat liver of more forms of acyl-CoA oxidase with different chain-length specificity.
Reubsaet
F A
FA
Department of Pediatrics, University of Nijmegen, The Netherlands.
Veerkamp
J H
JH
Bukkens
S G
SG
Trijbels
J M
JM
Monnens
L A
LA
D042962:Acyl-CoA Oxidase; D000311:Adrenal Glands / Q000201:enzymology; D000818:Animals; D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism*; D005452:Fluoresceins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008297:Male; D008830:Microbodies / Q000201:enzymology*; D009132:Muscles / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012402:Rotenone / Q000494:pharmacology; D013379:Substrate Specificity
D005227:Fatty Acids; D005452:Fluoresceins; D012402:Rotenone; C032456:antimycin; D010171:Palmitoyl Coenzyme A; C029569:diacetyldichlorofluorescein; D000968:Antimycin A; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D042962:Acyl-CoA Oxidase