Conformational changes induced in DNA by the in vitro reaction with the mutagenic amine: 3-N,N-acetoxyacetylamino-4,6-dimethyldipyrido (1,2-a: 3', 2'-d) imidazole.
The conformation of synthetic or natural DNAs modified in vitro by covalent binding of N-AcO-A-Glu-P-3 was investigated by fluorescence and circular dichroism. In all cases, substitution occurs mainly on the C8 of guanine residues. In modified poly(dG-dC).poly(dG-dC) or poly(dA-dC).poly(dG-dT) in B conformation, A-Glu-P-3 residues interact strongly with the bases whereas in Z conformation these residues are largely exposed to the solvent and interact weakly with the bases. A-Glu-P-3 and N-acetyl-2-aminofluorene (AAF) residues are equally efficient to induce the B-Z transition of poly(dG-dC).poly(dG-dC) and of poly(dA-dC).poly(dG-dT). Modifications of poly(dG).poly(dC) and calf thymus DNA indicate strong interactions between A-Glu-P-3 and the bases.
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA; D007093:Imidazoles; D009153:Mutagens; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D013950:Thymus Gland
D007093:Imidazoles; D009153:Mutagens; D011089:Polydeoxyribonucleotides; D004247:DNA; C043663:3-(N-acetoxy-N-acetylamino)-4,6-dimethyldipyrido(1,2-a-3',2'-d)imidazole