Efficiency of molecular motors at maximum power

TL;DR

This paper investigates the efficiency of molecular motors at maximum power using two generic models, revealing that the position of the transition state critically influences their performance and can lead to counter-intuitive efficiency increases.

Contribution

It introduces a theoretical analysis of molecular motor efficiency at maximum power, emphasizing the importance of transition state position and non-equilibrium effects.

Findings

Transition state near the initial state enhances power and efficiency.

Higher chemical potential differences can increase efficiency.

Qualitative behavior depends on transition state position.

Abstract

Molecular motors transduce chemical energy obtained from hydrolizing ATP into mechanical work exerted against an external force. We calculate their efficiency at maximum power output for two simple generic models and show that the qualitative behaviour depends crucially on the position of the transition state. Specifically, we find a transition state near the initial state (sometimes characterized as a "power stroke") to be most favorable with respect to both high power output and high efficiency at maximum power. In this regime, driving the motor further out of equilibrium by applying higher chemical potential differences can even, counter-intuitively, increase the efficiency.