Random bursts determine dynamics of active filaments.
Constituents of living or synthetic active matter have access to a local energy supply that serves to keep the system out of thermal equilibrium. The statistical properties of such fluctuating active systems differ from those of their equilibrium counterparts. Using the actin filament gliding assay as a model, we studied how nonthermal distributions emerge in active matter. We found that the basic mechanism involves the interplay between local and random injection of energy, acting as an analog of a thermal heat bath, and nonequilibrium energy dissipation processes associated with sudden jump-like changes in the system's dynamic variables. We show here how such a mechanism leads to a nonthermal distribution of filament curvatures with a non-Gaussian shape. The experimental curvature statistics and filament relaxation dynamics are reproduced quantitatively by stochastic computer simulations and a simple kinetic model.
Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, 80333 Munich, Germany; Department of Biological Physics, Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany;
Christoph A
CA
Weber
Lehrstuhl für Biophysik (E27), Technische Universität München, 85748 Garching, Germany;
Ryo
R
Suzuki
Lehrstuhl für Biophysik (E27), Technische Universität München, 85748 Garching, Germany;
Volker
V
Schaller
Argonne National Laboratory, Argonne, IL 60439.
Igor S
IS
Aranson
Lehrstuhl für Biophysik (E27), Technische Universität München, 85748 Garching, Germany; abausch@mytum.de frey@lmu.de.
Andreas R
AR
Bausch
Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, 80333 Munich, Germany; abausch@mytum.de frey@lmu.de.
Erwin
E
Frey
D008841:Actin Cytoskeleton / Q000502:physiology* / Q000648:ultrastructure; D000818:Animals; D003198:Computer Simulation; D004548:Elasticity; D004735:Energy Transfer; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008962:Models, Theoretical; D009038:Motion; D015879:Myosin Subfragments / Q000502:physiology; D016008:Statistical Distributions; D013269:Stochastic Processes; D055471:Thermal Diffusion
D015879:Myosin Subfragments
active filaments; gliding assay; kinetic model; molecular motors; nonthermal statistics