Catalytic Mechanism of O2 Reduction by Cytochrome Oxidase
In the past it has been thought that the reduction of O2 to water catalysed by cytochrome oxidase would constitute an irreversible reaction step in the respiratiry chain. More recently it was shown that this is not the case, but that two consecutive one-electron steps of the catalytic cycle may be reversed at a high electrochemical proton gradient (1,2). This enabled identification of two spectrally distinct forms of the binuclear haem a3-copper centre, as probable intermediates of the catalytic process of O2 reduction. On the basis of such data a possible mechanism of catalysis has been proposed (1,2).
KeywordsCytochrome Oxidase Catalytic Cycle Forward Reaction Intramolecular Electron Transfer Reversed Electron Transfer
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- 2.Wikström, M. (1987) Chemica Scripta, in press.Google Scholar
- 3.Wikström, M., Krab, K. and Saraste, M. (1981) Cytochrome Oxidase - A Synthesis, Academic Press, London and New York.Google Scholar
- 4.Chance, B., Saronio, C. and Leigh, J.S., Jr. (1975) J. Biol. Chem. 250, 9226–9237.Google Scholar
- 5.Clore, G.M., Andreasson, L.-E., Karlsson, B., Aasa, R. and Malmström, B.C. (1980) Biochem. J. 185, 139–154.Google Scholar
- 6.Clore, G.M., Andreasson, L.-E., Karlsson, B., Aasa, R. and Malmström, B.C. (1980) Biochem. J. 185, 155–167.Google Scholar
- 9.Wilson, M.T., Jensen, P., Aasa, R., Malmström, B.C. and Vänngard, T. (1982) Biochem. J. 203, 483–492.Google Scholar
- 10.Blair, D.F., Martin, C.T., Gelles, J., Wang, H., Brudvig, G.W., Stevens, T.H. and Chan, S.I. (1983) Chemica Scripta 21, 43–53.Google Scholar
- 11.Fiamingo, F.G., Altschuld, R.A., Moh, P.P. and Alben, J.O. (1982) J. Biol. Chem. 257, 1639–1650.Google Scholar
- 13.Witt, S.N., Blair, D.F. and Chan, S.I. (1986) J. Biol. Chem. 261, 8104–8107.Google Scholar
- 14.Witt, S.N., and Chan, S.I. (1987) J Biol. Chem. 262, 1446–1448.Google Scholar
- 15.Wrigglesworth, J.M. (1984) Biochem. J. 217, 715–719.Google Scholar