title: Solution structure of the duplexes between phosphorothioate DNA and target DNA/RNA.
abstract: Duplex stability measured by the melting temperature (Tm) of the duplex between oligodeoxynucleotide whose one phosphate linkage is replaced by thiophosphate and its complementary DNA/RNA. The resultant Tm values were higher for Sp isomer than Rp isomer when DNA was a target. When RNA was a target, however, Rp isomers of 5'-dGCTsTCG-3' and 5'-dGCAsTCG-3' had higher stability than Sp isomers. NMR and CD spectra obtained for the duplexes of such isomers exhibited only small difference for the base protons around the phosphorothioate linkage and could not account for the difference in Tm. Temperature dependent NMR spectra showed broadening for the AH8 proton signal of Rp and for the TH6 proton resonance of Sp. This characteristic broadening may be indicative of the different melting behavior of the duplexes of the isomers.
authors.affiliation: Department of Polymer Science and Engineering, Kyoto Institute of Technology, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kanehara
authors.forename: M
authors.initials: M
authors.lastname: Nishi
authors.forename: K
authors.initials: K
authors.lastname: Makino
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012313:RNA / Q000737:chemistry*; D012996:Solutions; D013696:Temperature; D013873:Thionucleotides / Q000737:chemistry*
chemical_list: D009838:Oligodeoxyribonucleotides; D012996:Solutions; D013873:Thionucleotides; D012313:RNA; D004247:DNA