help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
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 Borovikov, Yu. S.
Right arrow Articles by Van Der Meer, B. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Borovikov, Yu. S.
Right arrow Articles by Van Der Meer, B. W.
Biophysical Journal 86:3020-3029 (2004)
© 2004 The Biophysical Society

Fluorescence Depolarization of Actin Filaments in Reconstructed Myofibers: The Effect of S1 or pPDM-S1 on Movements of Distinct Areas of Actin

Yu. S. Borovikov *, I. V. Dedova {dagger}, C. G. dos Remedios {dagger}, N. N. Vikhoreva *, P. G. Vikhorev *, S. V. Avrova *, T. L. Hazlett {ddagger} and B. W. Van Der Meer §

* Institute of Cytology, Russian Academy of Science, St. Petersburg 194064, Russia; {dagger} Institute for Biomedical Research, University of Sydney, Sydney NSW 2006, Australia; {ddagger} Laboratory for Fluorescence Dynamics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080 USA; and § Department of Physics and Astronomy, Western Kentucky University, Bowling Green, Kentucky 42101-3576 USA

Correspondence: Address reprint requests to Cristobal G. dos Remedios, Muscle Research Unit, Rm. 10, Institute for Biomedical Research, University of Sydney, Sydney NSW 2006, Australia. Tel.: 61-2-93513209; E-mail: crisdos{at}anatomy.usyd.edu.au.

Fluorescence polarization measurements were used to study changes in the orientation and order of different sites on actin monomers within muscle thin filaments during weak or strong binding states with myosin subfragment-1. Ghost muscle fibers were supplemented with actin monomers specifically labeled with different fluorescent probes at Cys-10, Gln-41, Lys-61, Lys-373, Cys-374, and the nucleotide binding site. We also used fluorescent phalloidin as a probe near the filament axis. Changes in the orientation of the fluorophores depend not only on the state of acto-myosin binding but also on the location of the fluorescent probes. We observed changes in polarization (i.e., orientation) for those fluorophores attached at the sites directly involved in myosin binding (and located at high radii from the filament axis) that were contrary to the fluorophores located at the sites close to the axis of thin filament. These altered probe orientations suggest that myosin binding alters the conformation of F-actin. Strong binding by myosin heads produces changes in probe orientation that are opposite to those observed during weak binding.




This article has been cited by other articles:


Home page
 Biophys. JHome page
A. K. Tsaturyan, N. Koubassova, M. A. Ferenczi, T. Narayanan, M. Roessle, and S. Y. Bershitsky
Strong Binding of Myosin Heads Stretches and Twists the Actin Helix
Biophys. J., March 1, 2005; 88(3): 1902 - 1910.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
A. Orlova, A. Shvetsov, V. E. Galkin, D. S. Kudryashov, P. A. Rubenstein, E. H. Egelman, and E. Reisler
Actin-destabilizing factors disrupt filaments by means of a time reversal of polymerization
PNAS, December 21, 2004; 101(51): 17664 - 17668.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2004 by the Biophysical Society.