Ce(IV)-catalyzed site-selective DNA hydrolysis using tris- and tetrakismethylenephosphonate-modified oligonucleotides.

To improve the recruitment of the catalytically active Ce(IV) ion to the DNA cleavage site in the ARCUT (Artificial Restriction DNA Cutter) system, two phosphonate ligands, nitrilotris(methylenephosphonic acid) (NTP) and N,N,N',N'-ethylenediaminetetra-(methylenephosphonic acid) (EDTP), have been linked to the 5'- or 3'-end of oligonucleotides complementary to the target DNA. Compared to their counterparts bearing a terminal monophosphate, these new modified oligonucleotides exhibit a modest to significant increase in the cleavage activity, depending on the target.