help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Originally published as Biophys J. BioFAST on February 4, 2005.
doi:10.1529/biophysj.104.056184
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
biophysj.104.056184v1
88/5/3095    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 Tepper, H. L.
Right arrow Articles by Voth, G. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tepper, H. L.
Right arrow Articles by Voth, G. A.
Biophysical Journal 88:3095-3108 (2005)
© 2005 The Biophysical Society

Protons May Leak through Pure Lipid Bilayers via a Concerted Mechanism

Harald L. Tepper and Gregory A. Voth

Center for Biophysical Modeling and Simulation, and Department of Chemistry, University of Utah, Salt Lake City, Utah

Correspondence: Address reprint requests to Gregory A. Voth, Dept. of Chemistry, University of Utah, 315 S. 1400 E., Rm. 2020, Salt Lake City, UT 84112-0850. E-mail: voth{at}chem.utah.edu.

Protons are known to permeate pure lipid bilayers at a rate that is anomalous compared to those of other small monovalent cations. The prevailing mechanism via which they cross the membrane is still unclear, and it is unknown how to probe the mechanism directly by experiment. One of the more popular theories assumes the formation of membrane-spanning single-file water wires providing a matrix along which the protons can "hop" over the barrier. However, free energy calculations on such structures (without the presence of an excess proton) suggest that this mechanism alone cannot account for the observed permeation rates. We use the multistate empirical valence bond method to directly study water structures surrounding a (delocalized) excess proton on its way through the membrane. We find that membrane-spanning networks, rather than single-file chains, are formed around the proton. We also find that such structures are considerably stabilized in the presence of the proton, with lifetimes of several hundreds of picoseconds. The observed structures are suggestive of a new, concerted, mechanism and provide some direction for further investigation.




This article has been cited by other articles:


Home page
 Biophys. JHome page
R. Notman, J. Anwar, W. J. Briels, M. G. Noro, and W. K. den Otter
Simulations of Skin Barrier Function: Free Energies of Hydrophobic and Hydrophilic Transmembrane Pores in Ceramide Bilayers
Biophys. J., November 15, 2008; 95(10): 4763 - 4771.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
S. Schulmeister, M. Ruttorf, S. Thiem, D. Kentner, D. Lebiedz, and V. Sourjik
Protein exchange dynamics at chemoreceptor clusters in Escherichia coli
PNAS, April 29, 2008; 105(17): 6403 - 6408.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
H. Leontiadou, A. E. Mark, and S.-J. Marrink
Ion Transport across Transmembrane Pores
Biophys. J., June 15, 2007; 92(12): 4209 - 4215.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
H. Chen, B. Ilan, Y. Wu, F. Zhu, K. Schulten, and G. A. Voth
Charge Delocalization in Proton Channels, I: The Aquaporin Channels and Proton Blockage
Biophys. J., January 1, 2007; 92(1): 46 - 60.
[Abstract] [Full Text] [PDF]


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