help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Biophys. J. BioFAST: First Published June 15, 2007. doi:10.1529/biophysj.107.108910
© 2007 by the Biophysical Society.

A more recent version of this article appeared on October 15, 2007.
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
biophysj.107.108910v1
93/8/2805    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 Nesmelov, Y. E.
Right arrow Articles by Thomas, D. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nesmelov, Y. E.
Right arrow Articles by Thomas, D. D.

PROTEINS

Rotational Dynamics of Phospholamban Determined by Multifrequency Electron Paramagnetic Resonance

Yuri E. Nesmelov 1*, Christine Karim 1, Likai Song 2, Piotr G. Fajer 2 and David D. Thomas 3

1 University of Minnesota
2 Florida State Univ.
3 University of Minnesota Medical School

* To whom correspondence should be addressed. E-mail: nesme004{at}umn.edu.

Submitted on March 15, 2007
Revised on May 4, 2007
Accepted on 8 June 2007


  Abstract
We have used multifrequency electron paramagnetic resonance (EPR) to define the multi-state structural dynamics of an integral membrane protein, phospholamban (PLB), in a lipid bilayer. PLB is a key regulator of cardiac calcium transport, and its function requires transitions between distinct states of intramolecular dynamics. Monomeric PLB was synthesized with the TOAC spin label at positions 11 (in the cytoplasmic domain) and 46 (in the transmembrane domain) and reconstituted into lipid bilayers. Unlike other protein spin labels, TOAC reports directly the motion of the peptide backbone, so quantitative analysis of its dynamics is worthwhile. EPR spectra at 9.4 GHz (X-band) and 94 GHz (W-band) were analyzed in terms of anisotropic rotational diffusion of the two domains. Motion of the transmembrane domain is highly restricted, while the cytoplasmic domain exhibits two distinct conformations, a major one with moderately restricted nanosecond dynamics (T) and another with nearly unrestricted subnanosecond motion (R). The global analysis of spectra at two frequencies yielded values for the rotational correlation times and order parameters that were much more precisely determined than at either frequency alone. Multifrequency EPR is a powerful approach for analysis of complex rotational dynamics of proteins.

Key Words: EPR, ESR, TOAC, lipid, multifrequency, phospholamban




This article has been cited by other articles:


Home page
 Biophys. JHome page
Y. E. Nesmelov, R. V. Agafonov, A. R. Burr, R. T. Weber, and D. D. Thomas
Structure and Dynamics of the Force-Generating Domain of Myosin Probed by Multifrequency Electron Paramagnetic Resonance
Biophys. J., July 1, 2008; 95(1): 247 - 256.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
E. M. Kelly, Z. Hou, J. Bossuyt, D. M. Bers, and S. L. Robia
Phospholamban Oligomerization, Quaternary Structure, and Sarco(endo)plasmic Reticulum Calcium ATPase Binding Measured by Fluorescence Resonance Energy Transfer in Living Cells
J. Biol. Chem., May 2, 2008; 283(18): 12202 - 12211.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2007 by the Biophysical Society.