Kinetic, structural and electrostatic aspects of the reduction of pentacyanoferrate(III) complexes by myoglobin.

The mechanism of the reduction of pentacyanoferrate(III) complexes by oxymyoglobin has been studied by conventional and high-pressure kinetic methods, and also by structural modelling. The results of this and an earlier study show that an outer-sphere mechanism is operating for electron transfer between oxymyoglobin and FeIII(CN)5Ln-, independent of the lability of the ligand L. The electron transfer process is preceded by precursor formation at a specific site on the protein close to the protein heme pocket.