Mutations induced in the supF gene of pSP189 by @entity3787 radical and singlet @entity26 : relevance to XXXX mutagenesis.

@entity1 @entity26 @entity2767 @entity2774 @entity3787 @entity29101 @entity6710 @entity2145 @entity526
We previously showed that the oxidant @entity6710 ( @entity29101 -) was strongly mutagenic in the supF shuttle vector pSP189 replicated in bacteria or @entity1 cells. Qualitative characteristics of the mutational spectra induced by @entity29101 - differed significantly from those reportedly caused by @entity3787 radical ( @entity2145 .) in other experimental systems but showed similarities to spectra reportedly produced by singlet @entity26 ( @entity2767 ). The molecular mechanisms of @entity29101 --mediated DNA damage are unknown. The objective of the present set of experiments was to characterize mutational effects induced in the supF gene of pSP189 by @entity2145 * and @entity2767 to permit direct comparison with mutational spectra induced by @entity29101 - in this system. Base substitutions were the major form of mutation induced in plasmids replicated in @entity1 (AD293) cells by @entity29101 - (84%) and @entity2767 (71%), whereas @entity2145 * induced fewer of them (49%). In plasmids replicated in bacteria ( @entity526 MBL50), frequencies of base substitutions induced by the three treatments were similar. G:C-to-T:A transversions were the most common form of base substitution induced by @entity29101 - (75% and 67%, respectively, in AD293- and MBL50-replicated plasmids) and @entity2767 (68% and 71%); they were induced at lower frequencies by @entity2145 . (51% and 47%). G:C-to-C:G transversions or G:C-to-A:T transitions were induced at almost equal frequencies by both @entity29101 - and @entity2767 , whereas @entity2145 * induced these mutations at different frequencies in the AD293 system. Collectively, our results confirm that in several important respects mutational spectra induced by @entity29101 - have greater similarity to spectra induced by @entity2767 than to those induced by @entity2145 * and suggest that genotoxic derivatives of @entity29101 - are likely to include species that have DNA-damaging properties resembling those of @entity2767 in selectivity for @entity2774 but not identical in sequence specificity.
