title: Enhanced ordering of interacting filaments by molecular motors.
abstract: We theoretically study the cooperative behavior of cytoskeletal filaments in motility assays in which immobilized motor proteins bind the filaments to substrate surfaces and actively pull them along these surfaces. Because of the mutual exclusion of the filaments, the coupled dynamics of filaments, motor heads, and motor tails leads to a nonequilibrium phase transition which generalizes the isotropic-nematic phase transition of the corresponding equilibrium system, the hard-rod fluid. Langevin dynamics simulations show that the motor activity enhances the tendency for nematic ordering. We develop a quantitative theory for the location of the phase boundary as a function of motor density. At high detachment forces of motors, we also observe filament clusters arising from blocking effects.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany.
authors.forename: Pavel
authors.initials: P
authors.lastname: Kraikivski
authors.forename: Reinhard
authors.initials: R
authors.lastname: Lipowsky
authors.forename: Jan
authors.initials: J
authors.lastname: Kierfeld
mesh_terms: D003198:Computer Simulation; D003599:Cytoskeleton / Q000502:physiology*; D007700:Kinetics; D008954:Models, Biological; D020409:Molecular Motor Proteins / Q000502:physiology*; D013269:Stochastic Processes
chemical_list: D020409:Molecular Motor Proteins