Nonequilibrium Energetics of Molecular Motor Kinesin

TL;DR

This study investigates the nonequilibrium energetics of kinesin, revealing significant hidden dissipation primarily from internal processes, by measuring heat dissipation and analyzing Langevin dynamics with optical tweezers.

Contribution

It introduces a method to quantify hidden dissipation in kinesin by combining fluctuation-response violation measurements with Langevin dynamics analysis.

Findings

Large hidden dissipation exists in kinesin.

Internal dissipation dominates over external energy loss.

Heat dissipation measurements reveal energy inefficiencies.

Abstract

Nonequilibrium energetics of single molecule translational motor kinesin was investigated by measuring heat dissipation from the violation of the fluctuation-response relation of a probe attached to the motor using optical tweezers. The sum of the dissipation and work did not amount to the input free energy change, indicating large hidden dissipation exists. Possible sources of the hidden dissipation were explored by analyzing the Langevin dynamics of the probe, which incorporates the two-state Markov stepper as a kinesin model. We conclude that internal dissipation is dominant.