PEROXIDASE ACTIVITY IN PEROXISOMES (MICROBODIES) OF ACATALASEMIC MICE

Abstract

Peroxisomes (microbodies) of a strain of acatalasemic mice (Cs^b) are, paradoxically, more rapidly and intensely stained than those of the wild type (Cs^a) when incubated in a diaminobenzidine medium that demonstrates the peroxidatic activity of catalase. Biochemical studies have shown that the mutant catalase is unstable and is rapidly inactivated by heat with loss of catalatic activity. Our results indicate that the inactivated catalase of the acatalasemic mutant is an active peroxidase that oxidizes both diaminobenzidine and benzidine at neutral and alkaline pH and at 15 and 37°C and is resistant to the catalase inhibitor, 3 amino-1,2,4-triazole.