Efficient Cleavage of DS DNA by Bleomycin Conjugated via Hexaethylene Glycol Linker to Triplex-Forming Oligonucleotides

New conjugates of bleomycin A5 with oligonucleotides are synthesized. The bleomycin residue was attached to the 3'- or 5'- terminus of hexadecathymidilate via a hexaethylene glycol phosphate linker. Newly designed conjugates were shown to cleave site-specifically both strands of a dsDNA fragment within a triplex. The maximum extent of cleavage for individual strand amounts to 61%.