Effect of Some Metabolites and Antimetabolites on the Breakdown of Deoxyribonucleic Acid and on the Colony-Forming Ability of Escherichia coli B after Gamma Irradiation: III. Effect of Uncoupling Agents and the Fate of Ribonucleic Acid and Protein during the Breakdown of Deoxyribonucleic Acid and Its Inhibition

Abstract

The effect of the uncoupling agents 2,4-dinitro-phenol, sodium azide, and salicylate on the gamma-ray-induced breakdown of DNA and lethality in E. coli B, incubated after irradiation in acetate buffer was studied. These agents caused nearly a complete inhibition of gamma-ray-induced DNA breakdown in E. coli B, and suppressed also the biosynthesis of this macromolecule in the control. They had no effect on the viability of the unirradiated cells, and there was not a great change in the survival of irradiated cells, as compared with the results obtained in acetate buffer alone. Also a breakdown of RNA was observed in the irradiated starving bacteria, which was, however, of a different kinetics and smaller than the breakdown of DNA. RNA breakdown was also inhibited by some of the agents that inhibited DNA breakdown. The protein content of the irradiated starving bacteria did not change during incubation after irradiation.