Naphthalene and diimide and platinum functionalized triplex-forming oligonucleotides

Triplex forming oligonucleotides (TFO) were functionalized with either naphthalene diimide intercalators (NDI) or platinum-containing ligands. NDls were tethered to one or both termini of an oligonucleotide while a cisplatin-like ligand was tethered only to the 5' terminus. Thermal denaturation studies were performed to determine the stability effects of the TFOs on the resulting triplexes. Results show that the NDI provides significant stability enhancements when tethered to either terminus of the strand, and even greater enhancement when tethered to both termini. When a TFO is functionalized with platinum, triplex stability may be enhanced by interaction of the platinum with the duplex or triplex formation may aid in the delivery of the platinum to a specific site. Results have revealed that the length and composition of the platinum functionalized TFO are important for the formation of a stable triplex.