Motor properties from persistence: a linear molecular walker lacking spatial and temporal asymmetry

Zuckermann, M.J.; Angstmann, C.N.; Schmitt, R.; Blab, G.A.; Bromley, E.H.C.; Forde, N.R.; Linke, H.; Curmi, P.M.G.

Abstract

The stepping direction of linear molecular motors is usually defined by a spatial asymmetry of the motor, its track, or both. Here we present a model for a molecular walker that undergoes biased directional motion along a symmetric track in the presence of a temporally symmetric chemical cycle. Instead of using asymmetry, directionality is achieved by persistence. At small load force the walker can take on average thousands of steps in a given direction until it stochastically reverses direction. We discuss a specific experimental implementation of a synthetic motor based on this design and find, using Langevin and Monte Carlo simulations, that a realistic walker can work against load forces on the order of picoNewtons with an efficiency of ~18%, comparable to that of kinesin. In principle, the walker can be turned into a permanent motor by externally monitoring the walker's momentary direction of motion, and using feedback to adjust the direction of a load force. We calculate the thermodynamic cost of using feedback to enhance motor performance in terms of the Shannon entropy, and find that it reduces the efficiency of a realistic motor only marginally. We discuss the implications for natural protein motor performance in the context of the strong performance of this design based only on a thermal ratchet.

Citation

Zuckermann, M., Angstmann, C., Schmitt, R., Blab, G., Bromley, E., Forde, N., …Curmi, P. (2015). Motor properties from persistence: a linear molecular walker lacking spatial and temporal asymmetry. New Journal of Physics, 17(5), Article 055017. https://doi.org/10.1088/1367-2630/17/5/055017

• Journal Article Type: Article
• Acceptance Date: Apr 13, 2015
• Online Publication Date: May 15, 2015
• Publication Date: May 15, 2015
• Deposit Date: Mar 1, 2016
• Publicly Available Date: Mar 2, 2016
• Journal: New Journal of Physics
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 17
• Issue: 5
• Article Number: 055017
• DOI: https://doi.org/10.1088/1367-2630/17/5/055017
• Public URL: https://durham-repository.worktribe.com/output/1411260