Barrier crossing of semiflexible polymersP. Kraikivski, R. Lipowsky and J. Kierfeld
Max-Planck-Institut für Kolloid- und Grenzflächenforschung 14424 Potsdam, Germany
(Received 14 January 2004; accepted in final form 5 April 2004)
We consider the motion of semiflexible polymers in double-well potentials. We calculate shape, energy, and effective diffusion constant of kink excitations, and in particular their dependence on the bending rigidity of the semiflexible polymer. For symmetric potentials, the kink motion is purely diffusive, whereas kink motion becomes directed in the presence of a driving force on the polymer. We determine the average velocity of the semiflexible polymer based on the kink dynamics. The Kramers escape over the potential barriers proceeds by nucleation and diffusive motion of kink-antikink pairs, the relaxation to the straight configuration by annihilation of kink-antikink pairs. Our results apply to the activated motion of biopolymers such as DNA and actin filaments or synthetic polyelectrolytes on structured substrates.
87.15.-v - Biomolecules: structure and physical properties.
87.15.He - Dynamics and conformational changes.
87.15.Tt - Electrophoresis.
© EDP Sciences 2004