THE EFFECT OF MEDIA PROPERTIES ON THE HOR SERADISH PEROXIDASE-CATALYZED FLUOROGENIC REACTION

The effect of the media properties on the horseradish preoxidase-catal yzed flourogenic reaction is investigated. There existed acid-base equ ilibrium in the dimer product. For p-hydroxylphenolpropionic acid, the pK(a) of the product is 8.3. The product fluorescence increases with higher pH, however, longer time is needed to reach the reaction equili brium due to the pH mismatch with the enzyme activity. Cationic micell es cetyltrimethyl ammonium bromide and cetyltrimithylammonium chloride have catalytic and enhancing effects on the reaction at the neutral p H. A more sensitive method for the determination of horseradish peroxi dase is thus suggested.