A Note Concerning Acetate Activation of Peroxidative Activity of Catalases Using 2,2′‐Azino‐bis(3‐ethylbenzthiazoline)‐6‐sulfonic Acid as a Substrate

Beef liver catalases showed peroxidative activity using 2,2′‐azino‐bis‐(3‐ethylbenzthiazoline)‐6‐sulfonic acid as the electron donor and hydrogen peroxide as the acceptor at a pH of 5. This activity was not observed at pH 7. The reaction depended on acetate concentration, although succinate and propionate could partly replace the acetate as a catalyst. Other haem proteins also catalyzed a peroxidative effect. The reaction using syringaldazine or the coupling between dimethylaminobenzoic acid and 3‐methyl‐2‐benzothiazolinone hydrazone was less effective and less sensitive. Evidence is presented that the reaction is associated with a conformational change of the catalase.