title: Unprecedented right- and left-handed quadruplex structures formed by heterochiral oligodeoxyribonucleotides.
abstract: CD and NMR studies on heterochiral oligodeoxynucleotides (d/l-ODNs) forming quadruplex structures are reported. Heterochiral ODNs, based on sequence TGGGGT, are able to form stable either right- or left-handed quadruplexes depending on d/l ratio and residues position. Results suggest that the 3'-end and the core of the G-run are more important than the 5'-end in determining the quadruplex handness. Particularly, oligonucleotide T(D)G(D)G(L)G(L)G(D)T(D) (L34) at low temperatures forms a well-defined left-handed quadruplex, notwithstanding it is mostly composed by natural d residues. This structure is characterized by three all-anti G-tetrads and one all-syn G-tetrad.
authors.affiliation: Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, Via D. Montesano 49, Naples, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Virgilio
authors.forename: Veronica
authors.initials: V
authors.lastname: Esposito
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Citarella
authors.forename: Alfonso
authors.initials: A
authors.lastname: Mangoni
authors.forename: Luciano
authors.initials: L
authors.lastname: Mayol
authors.forename: Aldo
authors.initials: A
authors.lastname: Galeone
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D013237:Stereoisomerism; D044366:Transition Temperature
chemical_list: D009838:Oligodeoxyribonucleotides; D004247:DNA