Inhibition of restriction endonuclease cleavage by triple helix formation with RNA and 2'-O-methyl RNA oligonucleotides containing 8-oxo-adenosine in place of cytidine

A study was conducted to determine whether homopyrimidine oligo-RNA and oligo-2'-O-methyl-RNA containing 8-oxo-adenosine (AOH) and 8-oxo-O-methyl (AmOH) adenosine instead of cytidine can inhibit the sequence-specific cleavage of DNA binding proteins by the restriction endonuclease Ksp632-I. The simian virus 40 (SV40) DNA was used in the study. Results showed that the cleavage of SV40 DNA was inhibited by the AmOH-substituted 2'-O-mthyl RNA oligonucleotides but not by the homopyrimidine oligo-RNA and oligo-2'-O-methyl-RNA containing AOH moieties.