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 fol lowed the accepted model for peroxidase oxidations. Compound I (CoI) a nd compound II (CoII) were the main intermediates in the catalytic cyc le. 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 s trong cooperativity of this peroxidase isoenzyme indicates its great e fficacy in oxidation of (+)-catechin at low H2O2 concentrations.