help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Biophys. J. BioFAST: First Published April 22, 2005. doi:10.1529/biophysj.104.054957
© 2005 by the Biophysical Society.

A more recent version of this article appeared on July 1, 2005.
This Article
Right arrow Full Text (Rapid PDF)
Right arrow Supplemental File
Right arrow All Versions of this Article:
biophysj.104.054957v1
89/1/321    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Suzuki, M.
Right arrow Articles by Ishiwata, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Suzuki, M.
Right arrow Articles by Ishiwata, S.

MUSCLE AND CONTRACTILITY

A new muscle contractile system composed of a thick filament lattice and a single actin filament

Madoka Suzuki 1, Hideaki Fujita 2 and Shin'ichi Ishiwata 1*

1 Waseda University
2 Tohoku University Biomedical Engineering Research Organization

* To whom correspondence should be addressed. E-mail: ishiwata{at}waseda.jp.

Submitted on October 22, 2004
Revised on November 22, 2004
Accepted on 14 January 2005


  Abstract
To bridge the gap between the contractile system in muscle and in vitro motility assay, we have devised an gA-band motility assay system. A glycerinated skeletal myofibril was treated with gelsolin to selectively remove the thin filaments and expose a single A-band. A single bead-tailed actin filament trapped by optical tweezers was interacted with the inside or the outer surface of the A-band, and the displacement of the bead-tailed filament was measured in a physiological ionic condition by phase-contrast and fluorescence microscopy. We observed large back and forth displacement of the filament accompanied by large change in developed force. In spite of this large tension fluctuation, we found that the average force was proportional to the overlap inside and outside the A-band up to about 150 nm and 300 nm from the end of the A-band, respectively. Consistent with the difference in the density of myosin molecules, the average force per unit length of the overlap inside the A-band (the time-averaged force / myosin head {approx} 1 pN) was approximately twice as large as that outside. Thus, we conclude that the "A-band motility assay system" devised here is suitable for studying force generation on a single actin filament, and its sliding movement within a regular three-dimensional thick filament lattice.

Key Words: A-band, Molecular motor, Muscle contraction, Myosin filament lattice, Optical tweezers, Sliding mechanism




This article has been cited by other articles:


Home page
 Biophys. JHome page
P. Bianco, A. Nagy, A. Kengyel, D. Szatmari, Z. Martonfalvi, T. Huber, and M. S. Z. Kellermayer
Interaction Forces between F-Actin and Titin PEVK Domain Measured with Optical Tweezers
Biophys. J., September 15, 2007; 93(6): 2102 - 2109.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2005 by the Biophysical Society.