Metal Ion Redox Systems as Radiation Protective Agents

Abstract

IN investigations of the sensitivity of enzymes to ionizing radiations both in the solid state and in solution a marked variability has been observed between different batches of one enzyme¹. This has been ascribed to the presence of protective agents which are impurities even in samples of high enzymatic activity, and which are often difficult to remove. Little has been done to identify such natural agents although various substances, particularly sulphydryl compounds, have long been recognized as being especially effective as protective agents. It was suggested by Howard-Flanders² that these compounds act by donating hydrogen atoms to the radicals formed under the action of radiation, thus repairing the initial damage.