Tunable dynamics of microtubule based active isotropic gels

TL;DR

This study explores how the dynamics of microtubule-based active gels driven by kinesin motors can be precisely controlled by varying molecular and chemical parameters, revealing optimal conditions for maximal activity.

Contribution

It demonstrates the tunability of active gel dynamics through systematic variation of molecular and chemical parameters, highlighting an optimal motor concentration for peak activity.

Findings

Active gels exhibit turbulence-like states driven by kinesin motors.

Transport and flow depend on ATP, motor, and microtubule concentrations.

An optimal motor concentration maximizes activity.

Abstract

We investigate the dynamics of an active gel of bundled microtubules that is driven by clusters of kinesin molecular motors. Upon the addition of ATP, the coordinated action of thousands of molecular motors drives the gel to a highly dynamical turbulent-like state that persists for hours and is only limited by the stability of constituent proteins and the availability of the chemical fuel. We characterize how enhanced transport and emergent macroscopic flows of active gels depend on relevant molecular parameters, including ATP, kinesin motor, and depletant concentrations, microtubule volume fraction, as well as the stoichiometry of the constituent motor clusters. Our results show that the dynamical and structural properties of microtubule based active gels are highly tunable. They also indicate existence of an optimal concentration of molecular motors that maximize far-from-equilibrium activity of active isotropic MT gels.