Issue
EPL
Volume 82, Number 2, April 2008
Article Number 28011
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/82/28011
Published online 11 April 2008
EPL, 82 (2008) 28011
DOI: 10.1209/0295-5075/82/28011

Dwell time distributions for kinesin's mechanical steps

A. Valleriani, S. Liepelt and R. Lipowsky

Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems - 14424 Potsdam, Germany, EU

valleriani@mpikg.mpg.de

received 14 January 2008; accepted in final form 5 March 2008; published April 2008
published online 11 April 2008

Abstract
The mechanical steps of molecular motors that walk processively along filaments are governed by four distinct dwell time distributions corresponding to the four possible pairs of subsequent forward and backward steps. These distributions can be calculated from the master equation for the network of motor states if one extends this network by two absorbing states and determines the corresponding absorption times. This procedure is illustrated for the kinesin motor for which the four dwell time distributions are explicitly calculated. The tails of these distributions are governed by a single decay rate $\Omega _{1}$, which corresponds to the smallest nonzero eigenvalue of the master equation. For kinesin, this theoretical decay rate is found to be in good agreement with the experimental rate $\Omega _{{\rm ex}}$ as deduced from recent measurements.

PACS
87.16.Nn - Motor proteins (myosin, kinesin dynein).
82.39.-k - Chemical kinetics in biological systems.
87.16.Uv - Active transport processes.

© EPLA 2008