title: Analytical description of extension, torque, and supercoiling radius of a stretched twisted DNA.
abstract: We study the mixture of extended and supercoiled DNA that occurs in a twisted DNA molecule under tension. Closed-form asymptotic solutions for the supercoiling radius, extension, and torque of the molecule are obtained in the high-force limit where electrostatic and elastic effects dominate. We demonstrate that experimental data obey the extension and torque scaling laws apparent in our formulas, in the regime where thermal fluctuation effects are quenched by applied force.
authors.affiliation: CNRS, UMR 7190, Institut Jean Le Rond d'Alembert, F-75005 Paris, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Neukirch
authors.forename: John F
authors.initials: JF
authors.lastname: Marko
mesh_terms: D004278:DNA, Superhelical / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D013816:Thermodynamics; D019415:Torque
chemical_list: D004278:DNA, Superhelical