Research Repository

Theoretical Prediction of Run Speed Distribution for a Molecular Motor

Walcott, Sam and Kad, Neil M (2008) 'Theoretical Prediction of Run Speed Distribution for a Molecular Motor.' In: UNSPECIFIED, (ed.) ASME Conference Proceedings. Biomedical and Biotechnology Engineering, Vol 2 (2). ASME, Boston, Massachusetts, USA, pp. 437-446. ISBN 978-0-7918-4863-0

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Processive molecular motors are large proteins that “walk” along filaments in a cell, transforming chemical energy into mechanical work. These microscopic motors behave, at least qualitatively, like macroscopic walking machines. The dynamics and stability of macroscopic walkers are understood by analysis of “stride functions” (Poincaré maps from one step to the next). We show that molecular motors have linear, probabilistic stride functions. Using these functions, we derive expressions for three measurable distributions: step period, run length and average run speed. The former two distributions are well known, the latter is new. We validate our calculation with simulations of a realistic model for Myosin Va (a molecular motor). The parameters of the run speed distribution specify both the run-length and step period distributions. As step-period distributions are difficult to measure under physiologically relevant conditions, this technique provides new information. Finally, we discuss the effects of variable step size and experimental error.

Item Type: Book Section
Additional Information: ASME 2008 International Mechanical Engineering Congress and Exposition (IMECE2008) October 31–November 6, 2008 , Boston, Massachusetts, USA Paper no. IMECE2008-68761 pp. 437-446
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Science and Health > Biological Sciences, School of
Depositing User: Jim Jamieson
Date Deposited: 11 Oct 2011 15:54
Last Modified: 11 Oct 2011 15:54

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