Influence of non-esterified fatty acids on respiratory control of reconstituted cytochrome-c oxidase.
Bovine heart cytochrome-c oxidase was reconstituted in liposomes (asolectin) and the activity measured in the presence and absence of uncoupler at increasing concentrations of non-esterified fatty acids. Palmitic and stearic acids resulted in a decrease of about 40% in the respiratory control ratio at a concentration of 1 microM, when measured using a spectrophotometric procedure but not with a polarographic assay method. At higher fatty acid concentrations no further change was found. A 50% decrease in respiratory control was determined when the enzyme was reconstituted in pure phosphatidylcholine containing 2% cardiolipin. The respiratory control of reconstituted cytochrome-c oxidase from bovine liver was not influenced by fatty acids.
Thiel
C
C
Fachbereich Chemie, Philipps-Universität, Marburg, FRG.
Kadenbach
B
B
D000818:Animals; D002308:Cardiolipins; D002417:Cattle; D003574:Cytochrome c Group / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D008081:Liposomes / Q000378:metabolism; D008929:Mitochondria, Heart / Q000201:enzymology; D008930:Mitochondria, Liver / Q000201:enzymology; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000494:pharmacology; D010713:Phosphatidylcholines; D013053:Spectrophotometry; D013229:Stearic Acids / Q000494:pharmacology
D002308:Cardiolipins; D003574:Cytochrome c Group; D005230:Fatty Acids, Nonesterified; D008081:Liposomes; D010169:Palmitic Acids; D010713:Phosphatidylcholines; D013229:Stearic Acids; D019308:Palmitic Acid; C031183:stearic acid; D003576:Electron Transport Complex IV