title: 13C- and 31P-NMR studies of the conformation of carcinogen-modified nucleic acid dimers.
abstract: The effect of the carcinogen acetylaminofluorene (AAF) on nucleic acid structure was examined using 13C- and 31P-NMR spectroscopies. Conformational effects were compared in two AAF-modified dinucleoside monophosphates (ApG and GpA) and two AAF-modified deoxydinucleotides (dpApG and dpGpA). Changes in adenine 13C chemical shifts on formation of the AAF-adduct and as a function of temperature provided evidence of base stacking. Differences in fluorene 13C chemical shifts between the AAF-modified dimer and AAF-modified monomer provided evidence of fluorene stacking. The effect of forming the adduct on the phosphate backbone was examined using 31P-NMR. A correlation was demonstrated between the degree of adenine-fluorene stacking on one hand and the change in conformation of the backbone conformation on the other.
mesh_terms: D015073:2-Acetylaminofluorene / Q000031:analogs & derivatives; D000099:Acetoxyacetylaminofluorene; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009705:Nucleosides; D009841:Oligonucleotides; D013329:Structure-Activity Relationship
chemical_list: D009705:Nucleosides; D009841:Oligonucleotides; C028270:dinucleoside dimers; D000099:Acetoxyacetylaminofluorene; D015073:2-Acetylaminofluorene