The Effects of γ-irradiation on Solutions of Catalase, Apocatalase and Haematin

Abstract

SummaryDilute aqueous solutions of catalase, apocatalase and haematin were irradiated; the hydroxyl radical was the major inactivating species. The initial destruction of the haem group in the enzyme was related to the loss of catalytic activity. Cysteyl, histidyl and tyrosyl residues were destroyed during the radiolysis of the apocatalase and catalase and protection of the haematin was afforded by the apoenzyme.