Effects of oxygen and sulphydryl-containing compounds on irradiated transforming DNA. III. Reaction rates.
The absolute rate for the repair reaction of radiation-induced, oxygen-dependent lesions in bacterial transforming DNA with the sulphydryl (SH)-containing compound dithiothreitol (DTT) has been determined using a fast response method, the gas explosion technique, to be 1.6 X 10(6) mol-1 s-1. Glutathione reacts ten times slower than DTT with the irradiated transforming DNA. It can also be calculated that transforming DNA radicals react with O2 in a damage-fixing reaction with a rate of about 3 X 10(8) dm3 mol-1 s-1. These rates are compared with values in the literature for reaction rates of SH, compounds and O2 with irradiated DNA constituents and with bacterial cells.
D001412:Bacillus subtilis / Q000235:genetics*; D004269:DNA, Bacterial / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D010100:Oxygen; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D013997:Time Factors; D014169:Transformation, Bacterial
D004269:DNA, Bacterial; D011837:Radiation-Protective Agents; D013438:Sulfhydryl Compounds; D010100:Oxygen