The Chemical Sensitization of Pseudomonas Species to Ionizing Radiation

Publisher Website
Google Scholar
Abstract
The sensitization of Pseudomonas sp. to radiation by N-ethylmaleimide and various other compounds was studied. Of compounds chemically related to N-ethylmaleimide which were tested, maleic anhydride and m-phenylene-dimaleimide sensitized, and N-ethylmaleamic acid, maleic acid and succinimide were inactive. The double bond in a 5-membered hetero-cyclic ring (correlated with the ability to react with sulphydryl groups) is probably responsible for the sensitizing activity of this class of compound. Two other sulphydryl reagents, iodoacetic acid and phenylmercuric acetate, also sensitized Pseudomonas sp. No enhancement of radiation damage was observed when sensitizing agents were added within 1 minute after irradiation. A hypothesis has been formulated elsewhere in which the breaking and reforming of disulphide bonds is postulated to be a mechanism of energy dissipation in bacteria. It is suggested here that sensitizing agents might prevent this process by combining with the -SH groups or -S[degree] free radicals arising from bond breakage.