title: Novel nucleic acids with left-handed helicity.
abstract: Oligonucleotides containing a methylene bridge between Nl or N9 of the heterocyclic base and C1' of the pentofuranosyl ring (homo-N-oligonucleotides) were synthesized. Melting curves revealed that such homo-type oligomers could cross-pair with complementary homo-type or natural oligomers. Circular dichroism spectra provide evidence that the homo-type dimers have a left-handed stacked conformation and further suggest that single-stranded and double-stranded homo-type oligomers adopt a left-handed conformation, while duplexes with natural oligomers or nucleic acids form right-handed helices. NMR (NOESY) provides supporting evidence for a left-handed conformation of the homo-type dimer. Atomic force microscopy (AFM) indicates a left-handed helical conformation of homo-type dsDNA.
authors.affiliation: Discovery Research Laboratories, Nippon Shinyaku Co. Ltd., 3-14-1 Sakura, Tsukuba City, Ibaraki 305-0003, Japan.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Ishiyama
authors.forename: Gerald E
authors.initials: GE
authors.lastname: Smyth
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ueda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Masutomi
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Ohgi
authors.forename: Junichi
authors.initials: J
authors.lastname: Yano
mesh_terms: D002942:Circular Dichroism; D019281:Dimerization; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D009696:Nucleic Acids / Q000737:chemistry*
chemical_list: D009696:Nucleic Acids