Table of Contents
Journal of Biophysics
Volume 2015, Article ID 465693, 9 pages
Research Article

Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion

1Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA
2Department of Mechanical & Aeronautical Engineering, Clarkson University, Potsdam, NY 13699, USA

Received 25 August 2015; Revised 29 October 2015; Accepted 8 November 2015

Academic Editor: Andrei B. Rubin

Copyright © 2015 Arthur J. Michalek et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Supplementary Material

Supplemental material contains additional validation tests for the tethered particle motion technique. Measurement of quantum dot image size as a function of focus distance confirmed that tether length itself did not bias size measurements. Size parameters for single and paired Qdots were compared in order to verify that pairs of Qdots appear much larger than either stationary Qdots or Qdots moving as a result of tether deformation. Stationary Qdots were also used to confirm that measured image size is independent of the location of a Qdot on our microscope’s field of view. Additionally, processivity of MyoVa motors on actin filaments was used to confirm (by way of run length measurement in the presence or absence of excess calmodulin) that in our S1 experiment (without added calcium), calmodulin occupancy was at saturation.

  1. Supplementary Material