title: The orientation of the ends of G-quadruplex structures investigated using end-extended oligonucleotides.
abstract: Human telomere DNA is of intense interest because of its role in the biology of both cancer and aging. The single-stranded telomere terminus can adopt the structure of a G-quadruplex, which is of particular important for anticancer drug discovery many researchers have reported various G-quadruplex structures in the human telomere. Although the human telomere consists of a number of tandem repeats, higher-order G-quadruplex structures are less discussed due to the complexity of the structures. Here we examined the orientation of the ends of the G-quadruplex structures with consideration given to higher-order structures. We prepared end-extended and (Br)G-substituted oligonucleotides. Native PAGE analysis, CD measurements and NMR spectroscopy showed that the ends of stable G-quadruplex structures point in opposite directions. Our results indicate that the human telomere DNA is likely to form rod-like higher-order structures. This may provide important information for understanding telomere structure and the development of telomere G-quadruplex-binding molecules as telomerase inhibitors.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Sannohe
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Sato
authors.forename: Akimasa
authors.initials: A
authors.lastname: Matsugami
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Shinohara
authors.forename: Tomoko
authors.initials: T
authors.lastname: Mashimo
authors.forename: Masato
authors.initials: M
authors.lastname: Katahira
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sugiyama
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism; D004587:Electrophoresis, Agar Gel; D054856:G-Quadruplexes; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009841:Oligonucleotides / Q000737:chemistry*; D016615:Telomere / Q000737:chemistry*
chemical_list: D009841:Oligonucleotides