title: Crowding-Induced Hybridization of Single DNA Hairpins.
abstract: It is clear that a crowded environment influences the structure, dynamics, and interactions of biological molecules, but the complexity of this phenomenon demands the development of new experimental and theoretical approaches. Here we use two complementary single-molecule FRET techniques to show that the kinetics of DNA base pairing and unpairing, which are fundamental to both the biological role of DNA and its technological applications, are strongly modulated by a crowded environment. We directly observed single DNA hairpins, which are excellent model systems for studying hybridization, either freely diffusing in solution or immobilized on a surface under crowding conditions. The hairpins followed two-state folding dynamics with a closing rate increasing by 4-fold and the opening rate decreasing 2-fold, for only modest concentrations of crowder [10% (w/w) polyethylene glycol (PEG)]. These experiments serve both to unambiguously highlight the impact of a crowded environment on a fundamental biological process, DNA base pairing, and to illustrate the benefits of single-molecule approaches to probing the structure and dynamics of complex biomolecular systems.
authors.affiliation: The School of Chemistry and The Photon Science Institute, The University of Manchester , Oxford Road, Manchester, M13 9PL, U.K.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Baltierra-Jasso
authors.affiliation: WestCHEM, School of Chemistry, University of Glasgow , Joseph Black Building, University Avenue, Glasgow, G12 8QQ, U.K.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Morten
authors.affiliation: WestCHEM, School of Chemistry, University of Glasgow , Joseph Black Building, University Avenue, Glasgow, G12 8QQ, U.K.
authors.forename: Linda
authors.initials: L
authors.lastname: Laflör
authors.affiliation: WestCHEM, School of Chemistry, University of Glasgow , Joseph Black Building, University Avenue, Glasgow, G12 8QQ, U.K.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Quinn
authors.affiliation: WestCHEM, School of Chemistry, University of Glasgow , Joseph Black Building, University Avenue, Glasgow, G12 8QQ, U.K.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Magennis
mesh_terms: D004247:DNA / Q000737:chemistry*; D009693:Nucleic Acid Hybridization
chemical_list: D004247:DNA