title: Inosine substitutions demonstrate that intramolecular DNA quadruplexes adopt different conformations in the presence of sodium and potassium.
abstract: We have examined the stability of fluorescently-labelled oligonucleotides that are based on the human telomeric repeat [(GGGTTA)(3)GGG], in which one of the guanines in turn is substituted with inosine. We show that the relative stability of the substitutions is different in the presence of sodium and potassium. The data for potassium suggest a parallel arrangement of the strands, while the sodium form is mixed parallel and antiparallel.
authors.affiliation: School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK.
authors.forename: Antonina
authors.initials: A
authors.lastname: Risitano
authors.forename: Keith R
authors.initials: KR
authors.lastname: Fox
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D054856:G-Quadruplexes; D006801:Humans; D007288:Inosine / Q000737:chemistry* / Q000235:genetics; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry; D011188:Potassium / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*; D013768:Tetrahymena / Q000235:genetics
chemical_list: D009841:Oligonucleotides; D007288:Inosine; D004247:DNA; D012964:Sodium; D011188:Potassium