Folding time dependence of the motions of a molecular motor diluted inside an amorphous medium

TL;DR

This study explores how the folding time of a molecular motor in an amorphous medium affects its motion, revealing two regimes with distinct physical mechanisms and efficiency behaviors linked to entropy production.

Contribution

It introduces a detailed analysis of folding time dependence on molecular motor motion in glassy materials, highlighting two distinct regimes and their underlying physical principles.

Findings

Slow foldings lead to balanced displacement during folding and unfolding.

Fast foldings result in more efficient motion due to weaker counteraction.

Motor efficiency increases with entropy production, aligning with fluctuation theorems.

Abstract

We investigate the dependence of the displacements of a molecular motor embedded inside a glassy material on its folding characteristic time. We observe two different time regimes. For slow foldings (regime I) the diffusion evolves very slowly with the folding time, while for rapid foldings (regime II) the diffusion increases strongly with the folding time suggesting two different physical mechanisms. We find that in regime I the motor displacement during the folding process is counteracted by a reverse displacement during the unfolding, while in regime II this counteraction is much weaker. We notice that regime I behavior is reminiscent of the scallop theorem that holds for larger motors in a continuous medium. We find that the difference in the efficiency of the motor motion explains most of the observed difference between the two regimes. For fast foldings the motor trajectories differ significantly from the opposite trajectories induced by the following unfolding process, resulting in a more efficient global motion than for slow foldings. This result agrees with the fluctuation theorems expectation for time reversal mechanisms. In agreement with the fluctuation theorems we find that the motors are unexpectedly more efficient when they are generating more entropy, a result that can be used to increase dramatically the motor motion.