Forced desorption of semiflexible polymers, adsorbed and driven by molecular motors

Abstract

We formulate and characterize a model to describe the dynamics of semiflexible polymers in the presence of activity due to motor proteins attached irreversibly to a substrate, and a transverse pulling force acting on one end of the filament. The stochastic binding-unbinding of the motor proteins and their ability to move along the polymer, generates active forces. As the pulling force reaches a threshold value, the polymer eventually desorbs from the substrate. Performing molecular dynamics simulations of the polymer in presence of a Langevin heat bath, and stochastic motor activity, we obtain desorption phase diagrams. The correlation time for fluctuations in desorbed fraction increases as one approaches complete desorption, captured quantitatively by a power law spectral density. We present theoretical analysis of the phase diagram using mean field approximations in the weakly bending limit of the polymer and performing linear stability analysis. This predicts increase in the desorption force with the polymer bending rigidity, active velocity and processivity of the motor proteins to capture the main features of the simulation results.

9 pages, 7 figures

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Cited by in corpus (7)

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• Morphological and dynamical properties of semiflexible filaments driven by molecular motors
• Bidirectional motion of filaments: Role of motor proteins and passive cross linkers
• Strength and stability of active ligand-receptor bonds: a microtubule attached to a wall by molecular motor tethers
• Cooperation and competition in the collective drive by motor proteins: Mean active force, fluctuations, and self-load
• Stabilization of overlapping biofilaments by passive crosslinkers
• Filament-motor protein system under loading: instability and limit cycle oscillations