PURIFICATION OF A BASIC PEROXIDASE ISOENZYME FROM CAPSICUM FRUITS AND THE IMMUNOINHIBITION OF ITS CAPSAICIN OXIDATION CAPACITY BY ANTIBODIES RAISED AGAINST HORSERADISH-PEROXIDASE

Pepper fruits contain a peroxidase isoenzyme of basic pI, the peroxidase isoenzyme B6, located in vacuoles and the principal component of peroxidase polymorphism in the whole fruit. This isoenzyme was purified by preparative isoelectric focusing in glycerol-stabilized 3.0-10.0 pH gradients and characterized for its ability to oxidize capsaicin (8-methyl-N-vanillyl-6-nonenamide). Spectrophotometric studies illustrated that the capsaicin oxidation by pepper peroxidase isoenzyme B6 was H2O2-dependent and was totally abolished by antibodies raised against horseradish peroxidase. From these studies, it can be concluded that capsaicin is oxidized by pepper peroxidase isoenzyme B6, thus confirming a role for this peroxidase isoenzyme in capsaicin turnover and degradation.