Kinetics of oxidation of reduced cytochrome c by aquacopper(II) and chlorocopper(II) complexes in the presence of oxygen

Abstract

The rate constants for the oxidation of reduced cytochrome c by aquacopper(II) ion, aquachloro- copper(II) ion and aquadichlorocopper(II) were found to be 5.7±0.3 1. mol^-1 s^-1, 2.3×10² 1. mol^-1 s^-1 and 5.6xl0³1. mol^-1 s^-1 respectively at 25ºC, ionic strength 0.1 and pH 4.0. At low ratios of aquacopper(II) ion to ferrocytochrome c, when oxygen is required to completely oxidize the cytochrome, the reaction mechanism was found to be complex. No evidence for the involvement of copper bound to the cytochrome was found.