Gn. Grimm et al., Design and simple routes of synthesis of oligonucleotide conjugates for studies of dna triple helix formation, NUCLEOS NUC, 20(4-7), 2001, pp. 909-914
A series of oligonucleotides conjugated to intercalators, as well as fluore
scent and lipophilic substances, minor groove binders and photoactive molec
ules were synthesized for studies of their ability to form a stable triple
helix. Purine-rich short double stranded DNA fragments from HIV-1 genome an
d pyrimidine 16-mer oligodeoxyribonucleotide were used as models. A conjuga
te of a dipyrido[3,2-a:2',3'-c]phenazine-ruthenium (II) complex and a tripl
e helix-forming oligonucleotide was constructed. Upon sequence-specific dup
lex and triplex formation of the conjugate, the ruthenium complex becomes h
ighly fluorescent. The attached ruthenium complex induces a stabilization o
f the DNA triple helix and a significant increase of the time of residence
of the third strand on the duplex.