From the potential of the mean force to a quasiparticle’s effective potential in narrow ion channels

Barabash, Miraslau and Gibby, William Alexander Thomas and Guardiani, Carlo and Luchinsky, Dmitry and McClintock, Peter Vaughan Elsmere (2019) From the potential of the mean force to a quasiparticle’s effective potential in narrow ion channels. Fluctuation and Noise Letters, 18 (2). ISSN 0219-4775

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Abstract

We consider the selective permeation of ions through narrow water-filled channels in the presence of strong interaction between the ions. These interactions lead to highly correlated ionic motion, which can conveniently be described via the concept of a quasiparticle. Here, we connect the quasiparticle’s effective potential and the multi-ion potential of the mean force, found through molecular dynamics simulations, and we validate the method on an analytical toy model of the KcsA channel. Possible future applications of the method to the connection between molecular dynamical calculations and the experimentally measured current-voltage and current-concentration characteristics of the channel are discussed.