The hydrogen ion equilibria of horseradish peroxidase and apoperoxidase

The reaction of ferrous horseradish peroxidase with hydrogen peroxide.

Hydrogen peroxide reacts with ferrous horseradish peroxidase and converts it to oxyperoxidase in a sequence of two reactions. The first is the reaction of ferrous peroxidase with HzOz to form Compound II; the second is the reaction of Compound II with HzOz to form oxyperoxidase. Both reactions follow second order kinetics, being first order with respect to each of the reactants. They proceed wi...

Hydrogen Peroxide Biosensors Based on Horseradish Peroxidase and Hemoglobin

Hydrogen peroxide (H2O2) plays a pivotal role in various industrial applications [1]. It is an essential mediator in pharmaceutical, clinical, and environmental research. In addition, it is a byproduct of highly selective oxidases and an important contaminant in several industrial products and wastes [2]. Therefore, a reliable and economical method for the determination of H2O2 is of great sign...

Cobalt-substituted horseradish peroxidase.

Horseradish peroxidase can be reconstituted with cobalt porphyrin to give a cobaltic holoenzyme having physicochemical properties quite similar to those of the native ferric protein. The cobaltic protein (Co3+HRP) can be reduced to the cobaltous form (CoHRP), the analogue of ferroperoxidase and the reduced cobalt protein can bind O2 to form an analogue of oxyferroperoxidase (Compound III). Sinc...

The role of protein and porphyrin in the reactivity of horseradish peroxidase toward hydrogen donors.

Studies on Horseradish Peroxidase

The kinetics of the oxidation of p-cresol by Compound II of horseradish peroxidase has been studied by the stopped flow technique at an ionic strength of 0.11 from pH 2 to 11. In acid solution the reaction is kinetically first order in jcresol, but in the alkaline region a saturation effect attributable to complex formation is observed. At very high pH an additional second order reaction betwee...