Chapter 5: Heme Peroxidase Kinetics

One of the longest and most intensively studied enzymes is horseradish peroxidase. Its reactions are reviewed from historical, kinetic and mechanistic perspectives. Kinetics studies include steady state, transient state and relaxation kinetics. The methods and reasoning involved are applicable to other peroxidases and indeed to other enzymes. Accumulated evidence from several techniques indicate that distal His 42 plays a key role in its redox reactions. The possible implications of recent low temperature neutron diffraction experiments on oxidized yeast cytochrome c peroxidase are discussed.