Biochemistry 1994, 33, 6475-6482
6475
Intimate Relation between Cyclooxygenase and Peroxidase Acivities of Prostaglandin H Synthase. Peroxidase Reaction of Ferulic Acid and Its Influence on the Reaction of Arachidonic Acid Marica Bakovic and H. Brian Dunford' Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 Received November 1 1 , 1993; Revised Manuscript Received March 17, 1994"
ABSTRACT: The oxidation of ferulic acid by hydrogen peroxide catalyzed by prostaglandin H synthase follows a modified ping-pong irreversible mechanism, as is the case for classical peroxidases. The rate constant for the reaction of prostaglandin H synthase with hydrogen peroxide, determined from steady-state results, is (1.31 f 0.1) X lo6 M-l s-l, and for the reaction of prostaglandin H synthase
