title: Reaction potentials of the constituent bases of DNA and the effects of base stacking.
abstract: Reaction potential maps (RPM's) around the constituent bases of DNA have been plotted using the CNDO/2 method. The maps were drawn to evaluate site selectivity in electrophilic attack on the bases of DNA as a function of two considerations: base sequence and the nature of the attacking reagent. It was found that base sequence does have a substantial effect on a site's reactivity and that a change in the nature of the attacking reagent can alter site selectivity of the electrophile. The former result was applied in a specific case to offer a plausible explanation for some results of a recent study of the mutagenic effects of arylating metabolites of nitrofluorenes in the Salmonella tester strains TA98 and TA97. These strains differ in the arrangement of guanine and cytosine residues at the mutational target ("hot spot"). The results also suggest that the "hot spot" for TA98, which consists of a run of alternating guanine and cytosine base pairs, does not exist in the Z-configuration.
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000032:analysis*; D005449:Fluorenes / Q000494:pharmacology; D008433:Mathematics; D008957:Models, Genetic; D009152:Mutagenicity Tests; D009690:Nucleic Acid Conformation
chemical_list: D005449:Fluorenes; D004247:DNA