The sequence of electron carriers in the reaction of cytochrome c oxidase with oxygen.
Kinetic studies of the electron transfer processes performed by cytochrome oxidase have assigned rates of electron transfer between the metal centers involved in the oxidation of ferrocytochrome c by molecular oxygen. Transient-state studies of the reaction with oxygen have led to the proposal of a sequence of carriers from cytochrome c, to CuA, to cytochrome a, and then to the binuclear (i.e., cytochrome a3-CuB) center. Electron exchange rates between these centers agree with relative center-to-center distances as follows; cytochrome c to CuA 5-7 A, cytochrome c to cytochrome a 20-25 A, CuA to cytochrome a 14-16 A and cytochrome a to cytochrome a3-CuB 8-10 A. It is proposed that the step from cytochrome a to the binuclear center is the key control point in the reaction and that this step is one of the major points of energy transduction in the reaction cycle.
Hill
B C
BC
Department of Biological Sciences, University of Calgary, AB, Canada.
D000818:Animals; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D046911:Macromolecular Substances; D008322:Mammals; D008928:Mitochondria / Q000201:enzymology; D008954:Models, Biological; D008961:Models, Structural; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption
D046911:Macromolecular Substances; D003576:Electron Transport Complex IV; D010100:Oxygen