On the Mechanism of the Radiation-induced Inactivation of Lysozyme in Dilute Aqueous Solution

SummaryCombined pulse-radiolysis and enzyme-activity studies have shown that the radiation-induced inactivation of lysozyme in neutral aqueous solution is due principally to the reaction of hydroxyl radicals with tryptophan residues.Unlike some typical OH-radical scavengers which protect against inactivation, the thiocyanate ion (CNS)2− does not. This is due to a specific reaction between the thiocyanate radical and tryptophan residues. Part of this inactivating process involves tryptophan at position 108.