Selective stabilization of AT-rich DNA duplexes by oligodeoxyribonucleotide conjugates with distamycin analogues

Oligodeoxyribonucleotide conjugates with distamycin analogues containing up to five pyrrolecarboxamide moieties were synthesized. The stability of duplexes formed by these conjugates was shown to depend directly upon the number of pyrrolecarboxamide moieties in the ligand molecule. For the duplexes formed by octaadenylate and octathymidilate conjugates with the distamycin pentapyrrole analogue, stability was demonstrated to be achieved by either one or two ligand molecules; however, duplexes containing two ligand molecules are more stable.