title: The effect of active fluctuations on the dynamics of particles, motors and DNA-hairpins.
abstract: Inspired by recent experiments on the dynamics of particles and polymers in artificial cytoskeletons and in cells, we introduce a modified Langevin equation for a particle in an environment that is a viscoelastic medium and that is brought out of equilibrium by the action of active fluctuations caused by molecular motors. We show that within such a model, the motion of a free particle crosses over from superdiffusive to subdiffusive as observed for tracer particles in an in vitro cytoskeleton or in a cell. We investigate the dynamics of a particle confined by a harmonic potential as a simple model for the motion of the tethered head of kinesin-1. We find that the probability that the head is close to its binding site on the microtubule can be enhanced by a factor of two due to active forces. Finally, we study the dynamics of a particle in a double well potential as a model for the dynamics of DNA-hairpins. We show that the active forces effectively lower the potential barrier between the two minima and study the impact of this phenomenon on the zipping/unzipping rate.
authors.affiliation: Faculty of Sciences, Hasselt University, 3590 Diepenbeek, Belgium. hans.vandebroek@uhasselt.be carlo.vanderzande@uhasselt.be.
authors.forename: Hans
authors.initials: H
authors.lastname: Vandebroek
authors.affiliation: Faculty of Sciences, Hasselt University, 3590 Diepenbeek, Belgium. hans.vandebroek@uhasselt.be carlo.vanderzande@uhasselt.be and Instituut Theoretische Fysica, Katholieke Universiteit Leuven, 3001 Heverlee, Belgium.
authors.forename: Carlo
authors.identifier: http://orcid.org/0000-0002-1596-8183
authors.initials: C
authors.lastname: Vanderzande
mesh_terms: D003599:Cytoskeleton / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D055029:Inverted Repeat Sequences; D008958:Models, Molecular
chemical_list: D004247:DNA