title: Electron transfer and conformation states in bovine cytochrome c oxidase.
abstract: The fluorophores 1,5-I-AEDANS and eosin maleimide bind to subunit III of bovine cytochrome c oxidase. Fluorescence lifetime measurements have been made of bound AEDANS under a number of conditions. It appears that the spatial relationship between this bound probe and metal centers is unaffected by the redox changes in the enzyme. Cyanide binding to CuA-modified cytochrome c oxidase during turnover suggests that reduction of cytochrome a leads to exposure of the cytochrome a3-CuB binuclear center to incoming ligands. These results are discussed in terms of a model describing the roles of cytochrome a and CuA in triggering the "closed" to "open" transition.
authors.affiliation: Department of Chemistry and Biological Chemistry, University of Essex, United Kingdom.
authors.forename: M T
authors.initials: MT
authors.lastname: Wilson
authors.forename: T
authors.initials: T
authors.lastname: Alleyne
authors.forename: M
authors.initials: M
authors.lastname: Clague
authors.forename: K
authors.initials: K
authors.lastname: Conroy
authors.forename: B
authors.initials: B
authors.lastname: el-Agez
mesh_terms: D000818:Animals; D002417:Cattle; D003486:Cyanides / Q000378:metabolism; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005456:Fluorescent Dyes; D007700:Kinetics; D009282:Naphthalenesulfonates; D010084:Oxidation-Reduction; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence
chemical_list: D003486:Cyanides; D005456:Fluorescent Dyes; D009282:Naphthalenesulfonates; C006421:1,5-I-AEDANS; D003576:Electron Transport Complex IV