A physico-chemical study of triple helix formation by an oligodeoxythymidylate with N3' -> P5' phosphoramidate linkages

Overview of Zhou-Sun B.W. et al.
AuthorsZhou-Sun B.W., Sun J.S., Gryaznov S.M., Liquier J., Garestier T., Hélène C., Taillandier E.
AffiliationLaboratoire de Spectroscopie Biomoléculaire, CNRS URA 1430, UFR Santé Médecine Biologie Humaine, Université Paris-Nord, 74, rue Marcel Cachin, 93017 Bobigny, France, Laboratoire de Biophysique, Muséum National d’Histoire Naturelle, INSERM U201, CNRS URA481, 43, rue Cuvier, 75231 Paris Cedex 05, France, Lynx therapeutics, Inc., 3832 Bay Center Place, Hayward, CA 94545, USA  
JournalNucleic Acids Research
Year 1997

Abstract

Non-denaturing gel retardation assay, DNA melting experiments and FTIR spectroscopy were used to characterize the triple helix formed by a 15mer 2′-deoxy-thymidylate with N3′->P5′ phosphoramidate linkages with its target sequence. The results indicate that: (i) the pentadecadeoxythymidylate with phosphoramidate linkages [dT15(np)] is highly potent to form a triple helix with a dT15•dA15 target duplex through Hoogsteen base-pairing; (ii) it forms a dT15(np)•dA15xdT15(np) triplex with the single-stranded oligo-2′-deoxyadenylate (dA15) without detectable double-helical intermediate; (iii) it does not only form a triple helix on the dT15•dA15 target duplex, but also partially displaces the dT15 strand from the dT15•dA15 duplex to form a dT15(np)•dA15xdT15(np) complex.