title: Ion-selective formation of a guanine quadruplex on DNA origami structures.
abstract: DNA origami nanostructures are a versatile tool that can be used to arrange functionalities with high local control to study molecular processes at a single-molecule level. Here, we demonstrate that DNA origami substrates can be used to suppress the formation of specific guanine (G) quadruplex structures from telomeric DNA. The folding of telomeres into G-quadruplex structures in the presence of monovalent cations (e.g. Na(+) and K(+)) is currently used for the detection of K(+) ions, however, with insufficient selectivity towards Na(+). By means of FRET between two suitable dyes attached to the 3'- and 5'-ends of telomeric DNA we demonstrate that the formation of G-quadruplexes on DNA origami templates in the presence of sodium ions is suppressed due to steric hindrance. Hence, telomeric DNA attached to DNA origami structures represents a highly sensitive and selective detection tool for potassium ions even in the presence of high concentrations of sodium ions.
authors.affiliation: Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam (Germany); School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin (Germany).
authors.forename: Lydia
authors.initials: L
authors.lastname: Olejko
authors.forename: Piotr J
authors.initials: PJ
authors.lastname: Cywinski
authors.forename: Ilko
authors.initials: I
authors.lastname: Bald
mesh_terms: D004247:DNA / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry*; D007477:Ions; D009690:Nucleic Acid Conformation
chemical_list: D007477:Ions; D006147:Guanine; D004247:DNA
keywords: DNA nanotechnology; FRET; G-quadruplexes; nanostructures; self-assembly