Effect of gamma radiation on E. coli ribosomes. I. Inactivation by hydrogen atoms, hydroxyl radicals, hydrated electrons and secondary radicals.

E. coli ribosomes in aerated solutions were inactivated with a D37 dose of 144 Gy. In comparison, deaerated solutions bubbled with N2 or N2O showed a slight enhancement of the inactivation with D37 doses of 115 and 125 Gy, respectively. Isopropanol and tertiary-butanol provided partial protection. Results show that hydroxyl radicals, hydrated electrons and hydrogen atoms are involved in the inactivation process. Secondary radicals derived from the alcohols also inactivate ribosomes, with reduced efficiency.