Crowding-Induced Hybridization of Single DNA Hairpins

TY - JOUR

T1 - Crowding-Induced Hybridization of Single DNA Hairpins

AU - Baltierra-Jasso, Laura E

AU - Morten, Michael J

AU - Laflör, Linda

AU - Quinn, Steven D.

AU - Magennis, Steven W.

PY - 2015/12/11

Y1 - 2015/12/11

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=84953426311&partnerID=8YFLogxK

U2 - 10.1021/jacs.5b11829

DO - 10.1021/jacs.5b11829

M3 - Article

C2 - 26654490

AN - SCOPUS:84953426311

SN - 0002-7863

VL - 137

SP - 16020

EP - 16023

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 51

ER -