[Catalytic cleavage of target DNA in a complementary complex by a bleomycin oligonucleotide derivative]

For the first time, reagents that are capable of catalytic site-specific cleavage of DNA were synthesized based on oligonucleotides. One molecule of reagent (Blm-R)pd(CCAAACA) containing bleomycin A5 residue (Blm-RH) could degrade three molecules of target DNA pd(TGTTTGGCGAAGGA). The reagent displayed maximum catalytic activity in a temperature range that was close to the melting temperature of the reagent-target DNA complex. The number of the target DNA molecules that could be degraded by the reagent was limited by the degradation of the antibiotic residue itself during the oxidative degradation of the target DNA. The reagent catalyzed the subsequent degradation of residues G7, T5, T4, and T3 of the target DNA at an equimolar reagent-target DNA ratio. When the tenfold excess of the target DNA was used, the reagent degraded primarily the single G7 residue of the target DNA by 30%.