Theoretical study of the sequence specificity in the covalent binding of the antitumor drug CC-1065 to DNA.

A theoretical modelling is presented of the covalent adducts of the antitumor agent CC-1065 with B-DNA. The optimal complexes are obtained by energy minimisation, taking into account full structure flexibility, including the flexible rings of the ligand and DNA. The binding preference of CC-1065 with respect to base sequence is studied. The results obtained elucidate the origin of the preference for two AT base pairs on the 5'side of the modified adenine. The modifications of the DNA structure upon ligand covalent binding are discussed.