Kinetic properties of (+)-catechin oxidation by a basic peroxidase isoenzyme from strawberries

The ability of a partially-heat stable strawberry (Fragaria X ananassa) peroxidase to oxidize (+)-catechin was studied and its oxidation followed the accepted model for peroxidase oxidations. Compound I (CoI) and compound II (CoII) were the main intermediates in the catalytic cycle. The reactivity of strawberry peroxidase with H2O2 [k(1) = 2.63 mu M-1 s(-1)] and with (+)-catechin [k(3) = 0.57 mu M-1 s(-1)] suggested that (+)-catechin is an excellent o-diphenol for CoII reduction. The strong cooperativity of this peroxidase isoenzyme indicates its great efficacy in oxidation of (+)-catechin at low H2O2 concentrations.