Chemical modification of DNA with muta-carcinogens. II. Base sequence-specific binding to DNA of 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1).

2-Amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) binds covalently to DNA after metabolic activation to give 2-(C8-guanyl)amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Gua-Glu-P-1). The importance of the intercalative ability of the Glu-P-1 skeleton into DNA base pairs for this reaction is emphasized. The reactive form of Glu-P-1, N-acetoxy-Glu-P-1 (N-OAc-Glu-P-1), reacts preferentially at the C8 position of guanine residues in G-C-rich regions of DNA.