Cooperative transport in a potassium ion channel
- 28 July 2007
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 127 (4), 045103
- https://doi.org/10.1063/1.2756531
Abstract
Our current understanding of ion permeation through the selectivity filter of the KcsA potassium channel is based on the concept of a multi-ion transport mechanism. The details of this concerted movement, however, are not well understood. In the present paper we report on molecular dynamics simulations which provides new insights. It is shown that ion translocation is based on the collective hopping of ions and water molecules which is mediated by the flexible charged carbonyl groups lining the backbone of the pore. In particular, there is strong evidence for pairwise translocations where one ion and one water molecule form a bound state. We suggest a physical explanation of the observed phenomena employing a simple lattice model. It is argued that the water molecules can act as rectifiers during the hopping of ion-water pairsThis publication has 42 references indexed in Scilit:
- Ion permeation mechanism of the potassium channelNature, 2000
- Simulations of Ion Permeation Through a Potassium Channel: Molecular Dynamics of KcsA in a Phospholipid BilayerBiophysical Journal, 2000
- The Structure of the Potassium Channel: Molecular Basis of K + Conduction and SelectivityScience, 1998
- Ligand Binding: Molecular Mechanics Calculation of the Streptavidin-Biotin Rupture ForceScience, 1996
- Diffusion theory and discrete rate constants in ion permeationThe Journal of Membrane Biology, 1988
- Surmounting barriers in ionic channelsQuarterly Reviews of Biophysics, 1988
- Molecular dynamics with coupling to an external bathThe Journal of Chemical Physics, 1984
- Configurational model for a one-dimensional ionic conductorPhysical Review B, 1980
- Interacting Brownian particles and correlations in superionic conductorsPhysical Review B, 1979
- Theory of one-dimensional ionic and solitary-wave conduction in potassium hollanditePhysical Review B, 1978