title: Electrochemical discrimination between G-quadruplex and duplex DNA.
abstract: Analytical tools enabling the discrimination between duplex DNA and G-quadruplex DNA are necessary to unravel the biological function(s) of G-quadruplexes. A methodology relying on the electrochemical response of the electroactive hexaammineruthenium(III) cation at DNA-modified surfaces is presented. A characteristic voltammetric peak is evidenced for all the investigated G-quadruplex sequences, encompassing various types of folding and numbers of quartets. In contrast, no such peak is detected for dsDNA sequences. The occurrence of the voltammetric peak is the consequence of a strong association between the hexaammineruthenium ligand and the surface-immobilized G-quadruplexes. The peak potential points to a significant contribution of nonelectrostatic interactions between the electroactive ligand and G-quadruplexes. The very good efficiency of the discrimination methodology is demonstrated by comparing a G-quadruplex and its corresponding duplex.
authors.affiliation: Chimie Analytique et Chimie des Interfaces, Faculté des Sciences, Université Libre de Bruxelles , CP 255, Boulevard du Triomphe 2, B-1050 Bruxelles, Belgium.
authors.forename: Aurore
authors.initials: A
authors.lastname: De Rache
authors.forename: Thomas
authors.initials: T
authors.lastname: Doneux
authors.forename: Claudine
authors.initials: C
authors.lastname: Buess-Herman
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D054856:G-Quadruplexes; D006801:Humans; D008024:Ligands; D017975:Ruthenium Compounds / Q000737:chemistry; D055672:Static Electricity
chemical_list: D008024:Ligands; D017975:Ruthenium Compounds; C031584:hexammineruthenium; D004247:DNA