Cooperation and competition in the collective drive by motor proteins: Mean active force, fluctuations, and self-load

TL;DR

This paper models the collective behavior of motor proteins driving a bio-filament, analyzing force generation, fluctuations, and self-load effects through analytical and numerical methods.

Contribution

It introduces an analytical framework for understanding how motor protein parameters influence force and fluctuations, including the concept of self-load via effective temperature.

Findings

Mean directed force depends on motor parameters

Force fluctuations are characterized analytically and numerically

Self-load impacts filament motion through effective temperature

Abstract

We consider the dynamics of a bio-filament under the collective drive of motor proteins. They are attached irreversibly to a substrate and undergo stochastic attachment-detachment with the filament to produce a directed force on it. We establish the dependence of the mean directed force and force correlations on the parameters describing the individual motor proteins using analytical theory and direct numerical simulations. The effective Langevin description for the filament motion gives mean-squared displacement, asymptotic diffusion constant, and mobility leading to an effective temperature. Finally, we show how competition between motor protein extensions generates a self-load, describable in terms of the effective temperature, affecting the filament motion.