Structures of 2-Acetylaminofluorene Modified DNA Revisited: Insight into Conformational Heterogeneity

Abstract

Despite the extensive data on dG-AAF, the major DNA adduct derived from the model carcinogen 2-acetylaminofluorene, little is known with respect to its solution structures. Here, we provide NMR/CD evidence for three conformers of dG-AAF in duplex DNA: major groove B-type (B), base-displaced stacked (S), and minor groove wedge (W). The S/B/W-conformational heterogeneities were found to be sensitive to the nature of the flanking DNA sequence contexts and pH.