Effects of radiations on catalase solutions. 2. The protecting action of complexing agents

Abstract

Catalase solutions are protected against X-ray inactivation when the iron centers in catalase are complexed with HCN. Some, but not all, of the evidence relating to protection by H2O2 can be explained on a similar basis. A 2d mechanism of protection by hydrogen must predominate over that due to its complexing action. Spectroscopic studies in the presence of HCN show that the protein portion of catalase may be damaged by radiation without loss of catalytic activity. It is concluded that the major inactivating effect of X-rays on catalase solutions is localized on the Fe centers.