title: A stopped-flow study of the reaction of reduced cytochrome oxidase with oxygen.
abstract: The reaction of a reduced cytochrome oxidase system consisting of beef heart cytochrome oxidase, cytochrome c, and ascorbate with molecular oxygen was kinetically and thermodynamically investigated using a stopped-flow, rapid wavelength-scanning technique. Processes for oxidation of ferrocytochrome a, bound ferrocytochrome c, and free ferrocytochrome c have been identified, and their rate constants have been determined. Values of the activation energy for these reactions indicate that the oxidation of bound ferrocytochrome c is a simple chemical electron-transfer process and that oxidations of ferrocytochrome a and free ferrocytochrome c are complex processes involving changes in protein conformation.
authors.forename: C
authors.initials: C
authors.lastname: Balny
authors.forename: H
authors.initials: H
authors.lastname: Anni
authors.forename: T
authors.initials: T
authors.lastname: Yonetani
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D002417:Cattle; D019826:Cholic Acid; D002793:Cholic Acids / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism*; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D011136:Polysorbates / Q000494:pharmacology; D011487:Protein Conformation; D013053:Spectrophotometry; D013696:Temperature; D013816:Thermodynamics
chemical_list: D002793:Cholic Acids; D003574:Cytochrome c Group; D011136:Polysorbates; D003576:Electron Transport Complex IV; D019826:Cholic Acid; D001205:Ascorbic Acid; D010100:Oxygen