help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Biophys. J. BioFAST: First Published February 24, 2006. doi:10.1529/biophysj.105.076224
© 2006 by the Biophysical Society.

A more recent version of this article appeared on May 15, 2006.
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
biophysj.105.076224v1
90/10/3806    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 Walther, K. A.
Right arrow Articles by Fernandez, J. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Walther, K. A.
Right arrow Articles by Fernandez, J. M.

OTHER

Sub-Ångstrom conformational changes of a single molecule captured by AFM variance analysis

Kirstin Annika Walther 1, Jasna Brujic 1, Hongbin Li 2 and Julio M. Fernandez 1*

1 Columbia University
2 University of British Columbia

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

Submitted on October 18, 2005
Revised on December 8, 2005
Accepted on 12 January 2006


  Abstract
A system's equilibrium variance can be analyzed to probe its underlying dynamics at higher resolution. Here, using single molecule atomic force microscope (AFM) techniques, we show how the variance in the length of a single dextran molecule can be used to establish thermodynamic equilibrium and to detect conformational changes not directly observable with other methods. Dextran is comprised of a chain of pyranose rings that each undergo an Ångstrom-scale transition from a chair to boat conformation under a stretching force. Our analysis of the variance of the molecule's fluctuations verifies equilibrium throughout the force-extension curve, consistent with the expected thermodynamic ensemble. This validates further analysis of the variance in the transition region, which reveals an intermediate conformation between the chair and the boat on the sub-Ångstrom scale. Our test of thermal equilibrium as well as our variance analysis can be readily extended to a wide variety of molecules, including proteins.

Key Words: AFM, dextran, single-molecule, thermal equilibrium, variance




This article has been cited by other articles:


Home page
 Biophys. JHome page
D. B. Staple, F. Hanke, and H. J. Kreuzer
Comment on "Sub-Angstrom Conformational Changes of a Single Molecule Captured by AFM Variance Analysis"
Biophys. J., July 15, 2008; 95(2): 1001 - 1002.
[Full Text] [PDF]

Home page
 Biophys. JHome page
S. Garcia-Manyes, J. Brujic, C. L. Badilla, and J. M. Fernandez
Force-Clamp Spectroscopy of Single-Protein Monomers Reveals the Individual Unfolding and Folding Pathways of I27 and Ubiquitin
Biophys. J., October 1, 2007; 93(7): 2436 - 2446.
[Abstract] [Full Text] [PDF]

Home page
 ScienceHome page
M. T. Woodside, P. C. Anthony, W. M. Behnke-Parks, K. Larizadeh, D. Herschlag, and S. M. Block
Direct measurement of the full, sequence-dependent folding landscape of a nucleic Acid.
Science, November 10, 2006; 314(5801): 1001 - 1004.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
Z. Lu, H. Hu, W. Yang, and P. E. Marszalek
Simulating Force-Induced Conformational Transitions in Polysaccharides with the SMD Replica Exchange Method
Biophys. J., September 15, 2006; 91(6): L57 - L59.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2006 by the Biophysical Society.