Kinetic Properties of (+)‐Catechin Oxidation by a Basic Peroxidase Isoenzyme from Strawberries

Abstract

ABSTRACT The ability of a partially‐heat stable strawberry ( Fragaria × 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 H 2 O 2 [K 1 = 2.63 μM ‐1 s ‐1 ] and with (+)‐catechin [k 3 = 0.57 μM ‐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 H 2 O 2 concentrations.