| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Biophys J, July 1998, p. 33-40, Vol. 75, No. 1
Groupe de Recherche en Transport Membranaire, Départements de Physique et de Chimie, Université de Montréal, Succursalle Centre-Ville, Montréal, Québec H3C 3J7, Canada
The molecular mechanism for proton conduction along
hydrogen-bonded chains, or "proton wires," is studied with free
energy simulations. The complete transport of a charge along a proton wire requires two complementary processes: 1) translocation of an
excess proton (propagation of an ionic defect), and 2) reorientation of
the hydrogen-bonded chain (propagation of a bonding defect). The
potential of mean force profile for these two steps is computed in
model systems comprising a single-file chain of nine dissociable and
polarizable water molecules represented by the PM6 model of Stillinger
and co-workers. Results of molecular dynamics simulations with umbrella
sampling indicate that the unprotonated chain is preferably polarized,
and that the inversion of its total dipole moment involves an
activation free energy of 8 kcal/mol. In contrast, the rapid
translocation of an excess H+ across a chain extending
between two spherical solvent droplets is an activationless process.
These results suggest that the propagation of a bonding defect
constitutes a limiting step for the passage of several protons along
single-file chains of water molecules, whereas the ionic translocation
may be fast enough to occur within the lifetime of transient
hydrogen-bonded water chains in biological membranes.
Biophys J, July 1998, p. 33-40, Vol. 75, No. 1
© 1998 by the Biophysical Society 0006-3495/98/07/33/08 $2.00
This article has been cited by other articles:
 |
|
 |
|
  R. Hagedorn, D. Gradmann, and P. Hegemann Dynamics of Voltage Profile in Enzymatic Ion Transporters, Demonstrated in Electrokinetics of Proton Pumping Rhodopsin Biophys. J., December 1, 2008; 95(11): 5005 - 5013. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Thomaeus, A. Naworyta, S. L. Mowbray, and M. Widersten Removal of distal protein-water hydrogen bonds in a plant epoxide hydrolase increases catalytic turnover but decreases thermostability Protein Sci., July 1, 2008; 17(7): 1275 - 1284. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. O. Jensen, U. Rothlisberger, and C. Rovira Hydroxide and Proton Migration in Aquaporins Biophys. J., September 1, 2005; 89(3): 1744 - 1759. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. B. Best and G. Hummer Chemical Theory and Computation Special Feature: Reaction coordinates and rates from transition paths PNAS, May 10, 2005; 102(19): 6732 - 6737. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Grudinin, G. Buldt, V. Gordeliy, and A. Baumgaertner Water Molecules and Hydrogen-Bonded Networks in Bacteriorhodopsin--Molecular Dynamics Simulations of the Ground State and the M-Intermediate Biophys. J., May 1, 2005; 88(5): 3252 - 3261. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
T. Chou Water Alignment, Dipolar Interactions, and Multiple Proton Occupancy during Water-Wire Proton Transport Biophys. J., May 1, 2004; 86(5): 2827 - 2836. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
Y. Wu and G. A. Voth A Computer Simulation Study of the Hydrated Proton in a Synthetic Proton Channel Biophys. J., August 1, 2003; 85(2): 864 - 875. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Zhu and K. Schulten Water and Proton Conduction through Carbon Nanotubes as Models for Biological Channels Biophys. J., July 1, 2003; 85(1): 236 - 244. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Amaro, E. Tajkhorshid, and Z. Luthey-Schulten Developing an energy landscape for the novel function of a ({beta}/{alpha})8 barrel: Ammonia conduction through HisF PNAS, June 24, 2003; 100(13): 7599 - 7604. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Takahashi and S. Kuyucak Functional Properties of Threefold and Fourfold Channels in Ferritin Deduced from Electrostatic Calculations Biophys. J., April 1, 2003; 84(4): 2256 - 2263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Chernyshev, K. M. Armstrong, and S. Cukierman Proton Transfer in Gramicidin Channels is Modulated by the Thickness of Monoglyceride Bilayers Biophys. J., January 1, 2003; 84(1): 238 - 250. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Gowen, J. C. Markham, S. E. Morrison, T. A. Cross, D. D. Busath, E. J. Mapes, and M. F. Schumaker The Role of Trp Side Chains in Tuning Single Proton Conduction through Gramicidin Channels Biophys. J., August 1, 2002; 83(2): 880 - 898. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. A. Gopta, D. A. Cherepanov, W. Junge, and A. Y. Mulkidjanian Proton transfer from the bulk to the bound ubiquinone QB of the reaction center in chromatophores of Rhodobacter sphaeroides: Retarded conveyance by neutral water PNAS, November 9, 1999; 96(23): 13159 - 13164. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
