Brownian molecular motors driven by rotation-translation coupling

TL;DR

This paper explores three models of Brownian motors that convert rotational diffusion into directed translation through potential switching, highlighting mechanisms like asymmetry, diffusion, drift, and combined states, with biological relevance.

Contribution

It introduces and analyzes three novel models of Brownian motors utilizing rotation-translation coupling, expanding understanding of motor mechanisms and their biological implications.

Findings

Model 1 acts like a flashing ratchet with asymmetric potential.

Model 2 generates translation via diffusion and drift without spatial asymmetry.

Model 3 combines Brownian and powerstroke mechanisms by switching states.

Abstract

We investigated three models of Brownian motors which convert rotational diffusion into directed translational motion by switching on and off a potential. In the first model a spatially asymmetric potential generates directed translational motion by rectifying rotational diffusion. It behaves much like a conventional flashing ratchet. The second model utilizes both rotational diffusion and drift to generate translational motion without spatial asymmetry in the potential. This second model can be driven by a combination of a Brownian motor mechanism (diffusion driven) or by powerstroke (drift driven) depending on the chosen parameters. In the third model, elements of both the Brownian motor and powerstroke mechanisms are combined by switching between three distinct states. Relevance of the model to biological motor proteins is discussed.