Coulomb blockade model of permeation and selectivity in biological ion channels

Kaufman, Igor Kh. and McClintock, Peter V. E. and Eisenberg, R. S. (2015) Coulomb blockade model of permeation and selectivity in biological ion channels. New Journal of Physics, 17 (8). ISSN 1367-2630

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Abstract

Biological ion channels are protein nanotubes embedded in, and passing through, the bilipid membranes of cells. Physiologically, they are of crucial importance in that they allow ions to pass into and out of cells, fast and efficiently, though in a highly selective way. Here we show that the conduction and selectivity of calcium/sodium ion channels can be described in terms of ionic Coulomb blockade in a simplified electrostatic and Brownian dynamics model of the channel. The Coulomb blockade phenomenon arises from the discreteness of electrical charge, the strong electrostatic interaction, and an electrostatic exclusion principle. The model predicts a periodic pattern of Ca2+ conduction versus the fixed charge Qf at the selectivity filter (conduction bands) with a period equal to the ionic charge. It thus provides provisional explanations of some observed and modelled conduction and valence selectivity phenomena, including the anomalous mole fraction effect and the calcium conduction bands. Ionic Coulomb blockade and resonant conduction are similar to electronic Coulomb blockade and resonant tunnelling in quantum dots. The same considerations may also be applicable to other kinds of channel, as well as to charged artificial nanopores.

Item Type:
Journal Article
Journal or Publication Title:
New Journal of Physics
Additional Information:
This is an author-created, un-copyedited version of an article accepted for publication/published in New Journal of Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/1367-2630/17/8/083021
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100
Subjects:
ID Code:
75371
Deposited By:
Deposited On:
09 Sep 2015 06:32
Refereed?:
Yes
Published?:
Published
Last Modified:
11 Jul 2020 05:21