1. Motor properties from persistence: a linear molecular walker lacking spatial and temporal asymmetry.
- Author
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Martin J Zuckermann, Christopher N Angstmann, Regina Schmitt, Gerhard A Blab, Elizabeth HC Bromley, Nancy R Forde, Heiner Linke, and Paul MG Curmi
- Subjects
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STEREOCHEMISTRY , *MOLECULAR motor proteins , *BROWNIAN motion , *MONTE Carlo method , *LANGEVIN equations , *KINESIN , *SYNTHETIC proteins , *FEEDBACK control systems - 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. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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