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

Pepper fruits contain a peroxidase isoenzyme of basic pI, the peroxida se isoenzyme B6, located in vacuoles and the principal component of pe roxidase 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-m ethyl-N-vanillyl-6-nonenamide). Spectrophotometric studies illustrated that the capsaicin oxidation by pepper peroxidase isoenzyme B6 was H2 O2-dependent and was totally abolished by antibodies raised against ho rseradish peroxidase. From these studies, it can be concluded that cap saicin is oxidized by pepper peroxidase isoenzyme B6, thus confirming a role for this peroxidase isoenzyme in capsaicin turnover and degrada tion.