Stretching single stranded DNA, a model polyelectrolyte

Publication Type:

Journal Article

Source:

PHYSICAL REVIEW LETTERS, AMERICAN PHYSICAL SOC, Volume 89, Number 24, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA (2002)

DOI:

10.1103/PhysRevLett.89.248102

Keywords:

ELASTICITY; MECHANICS; MOLECULES; TITIN; TRANSITIONS

Abstract:

The elastic properties of single stranded (ss)DNA, studied by pulling on an isolated molecule, are shown to agree with a recent model of ssDNA that takes into account base pairings and screened electrostatic repulsion of the phosphodiester backbone. By an appropriate physicochemical treatment, the pairing interactions were suppressed and ssDNA used as an experimental model for a generic polyelectrolyte. The elastic behavior of such an altered ssDNA deviates strongly from the behavior of an ideal polymer. This deviation is shown to result from the elasticity of the chain and its electrostatic self-avoiding interactions.