Gene regulation by decoy approach (I): synthesis and properties of photo-crosslinked oligonucleotides.

To explore gene regulation by double stranded oligonucleotides as decoy molecules for transcriptional factors, oligodeoxyribonucleotides (ODN) and the complementary oligo(deoxyribonucleoside phosphorothioate)s (OPT) were photo-crosslinked by use of psoralen. UV melting curves showed that the thermal stability of crosslinked duplexes increased compared with that of non-crosslinked ones. CD spectra showed that the photo-crosslinked duplexes formed B-DNA structure. In addition, cross-linked duplexes were resistant against digestion by snake venom phosphodiesterase. These results suggest that the photo-crosslinked duplexes have desirable characteristics as decoy molecules.