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Volume 120, Issue 11, 15 March 2004
120(2004); http://dx.doi.org/10.1063/1.1665656View Description Hide Description
We report molecular dynamics simulations of a generic hydrophobicnanopore connecting two reservoirs which are initially at different concentrations, as in a biological cell. The nanopore is impermeable to water under equilibrium conditions, but the strong electric field caused by the ionic concentration gradient drives water molecules in. The density and structure of water in the pore are highly field dependent. In a typical simulation run, we observe a succession of cation passages through the pore, characterized by approximately bulk mobility. These ion passages reduce the electric field, until the pore empties of water and closes to further ion transport, thus providing a possible mechanism for biological ion channel gating.