title: Redox state of the partially reduced cytochrome aa3- cyanide complex.
abstract: The low-spin ferric cyanide complex of beef heart cytochrome aa3 can be partially reduced by stoichiometric additions of ferrous cytochrome c or by similar additions of N,N,N',N'-tetramethyl-p-phenylene diamine. In both cases the initial ratio of cytochrome c oxidized: cytochrome a reduced or Wurster's Blue: cytochrome a reduced approximates the value 2. It is concluded that the binding of a single HCN prevents the reduction of both cytochrome a3 and its associated EPR-invisible Cu atom.
mesh_terms: D001665:Binding Sites; D003300:Copper / Q000378:metabolism; D003486:Cyanides / Q000378:metabolism*; D003580:Cytochromes / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D003486:Cyanides; D003580:Cytochromes; D003300:Copper; D007501:Iron