help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 71: 632-647 (1996)
© 1996 the Biophysical Society

This Article
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 Related articles in Biophys. J.
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 Marrink, S J
Right arrow Articles by Berendsen, H J
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marrink, S J
Right arrow Articles by Berendsen, H J

Proton transport across transient single-file water pores in a lipid membrane studied by molecular dynamics simulations.

S J Marrink, F Jähnig and H J Berendsen

Abteilung Membranbiochemie, Max-Planck-Institut für Biologie, Tübingen, Germany. marrink@chem.rug.nl

ABSTRACT

To test the hypothesis that water pores in a lipid membrane mediate the proton transport, molecular dynamic simulations of a phospholipid membrane, in which the formation of a water pore is induced, are reported. The probability density of such a pore in the membrane was obtained from the free energy of formation of the pore, which was computed from the average force needed to constrain the pore in the membrane. It was found that the free energy of a single file of water molecules spanning the bilayer is 108(+/-10) kJ/mol. From unconstrained molecular dynamic simulations it was further deduced that the nature of the pore is very transient, with a mean lifetime of a few picoseconds. The orientations of water molecules within the pore were also studied, and the spontaneous translocation of a turning defect was observed. The combined data allowed a permeability coefficient for proton permeation across the membrane to be computed, assuming that a suitable orientation of the water molecules in the pore allows protons to permeate the membrane relatively fast by means of a wirelike conductance mechanism. The computed value fits the experimental data only if it is assumed that the entry of the proton into the pore is not rate limiting.


Related articles in Biophys. J.:

Water chains in lipid bilayers.
D W Deamer
Biophys. J. 1996 71: 543. [PDF]  



This article has been cited by other articles:


Home page
 Biophys. JHome page
J. L. MacCallum, W. F. D. Bennett, and D. P. Tieleman
Distribution of Amino Acids in a Lipid Bilayer from Computer Simulations
Biophys. J., May 1, 2008; 94(9): 3393 - 3404.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
H. L. Tepper and G. A. Voth
Protons May Leak through Pure Lipid Bilayers via a Concerted Mechanism
Biophys. J., May 1, 2005; 88(5): 3095 - 3108.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
S. Braun-Sand, M. Strajbl, and A. Warshel
Studies of Proton Translocations in Biological Systems: Simulating Proton Transport in Carbonic Anhydrase by EVB-Based Models
Biophys. J., October 1, 2004; 87(4): 2221 - 2239.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
A. Burykin and A. Warshel
What Really Prevents Proton Transport through Aquaporin? Charge Self-Energy versus Proton Wire Proposals
Biophys. J., December 1, 2003; 85(6): 3696 - 3706.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 by the Biophysical Society.