Pseudomonas cytochrome c peroxidase. XII. Product inhibition studies.

Kinetic studies of the reaction mechanism of Pseudomonas cytochrome c peroxidase (PaCCP) were made by the method of product inhibition using oxidized cytochrome C (551 P.aeruginosa) and oxidized Pseudomonas azurin as products. Inhibition by the two oxidized substrates was linearly non-competitive towards the respective reduced electron donor and towards hydrogen peroxide. Although a full kinetic analysis is experimentally impossible in a peroxidase-type reaction, the results do provide some evidence in favour of an ordered reaction mechanism in which hydrogen peroxide is the first to add to PaCCP and electron donor the second.