The complete bending energy function for nicked DNA
Department of Physics and Astronomy, University of California at Los Angeles - Los Angeles, CA 90095-1547, USA
Accepted: 25 February 2011
We derive an analytic expression for the bending elastic energy of short DNA molecules, valid in the entire range from low to high energies. The elastic energy depends on three parameters: the length of the molecule (2L), the bending modulus B, and a critical torque τc at which the molecule develops a kink. In the kinked state, the elastic energy is linear in the kink angle, i.e. the torque at the kink is constant (= τc). τc depends (weakly) on the sequence around the nick, but is about 27 pN×nm. We measure it for a specific sequence, through experiments where the elastic energy of constrained DNA molecules is directly measured.
PACS: 87.14.gk – DNA / 87.10.Pq – Elasticity theory / 87.15.La – Mechanical properties
© EPLA, 2011