Abstract
We present a statistical physics model to describe the stochastic behaviorof ion transport and channel transitions under an applied membrane voltage.To get pertinent ideas we apply our general theoretical scheme to ananalytically tractable model of the channel with a deep binding site whichinteracts with the permeant ions electrostatically. It is found that theinteraction is modulated by the average ionic occupancy in the bindingsite, which is enhanced by the membrane voltage increases. Above acritical voltage, the interaction gives rise to a emergence of a newconducting state along with shift of S4 charge residues in the channel.This exploratory study calls for further investigations to correlate thecomplex transition behaviors with a variety of ion channels, withparameters in the model, potential energy parameters, voltage, and ionicconcentration.
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References
Alberts, B., Bray, D., Lewis, J., Raff, M., Roberts, K. and Watson, J.D.: Molecular Biology of the Cell, 3rd ed., Garland Publishing, New York, 1994.
Unwin, N.: The structure of ion channels in membranes of excitable cells, Neuron 3 (1989), 665–676.
Chancey, C.C. and George, S.A.: Physical model of voltage sensing in sodium channels based on the sliding helix complex, Phys.Rev. E 53 (1996), 5137–5145.
Mannuzzu, L.M., Moronne, M.M. and Isacoff, E.Y.: Direct physical measure of conformational rearrangement underlying potassium channel gating, Science 271 (1996), 213–216.
Larsson, H.P., Baker, O.S., Dhillon, D.S. and Isacoff, E.Y.: Transmembrane movement of the Shaker K+ channel S4, Neuron 16 (1996), 387–397.
Levitt, D.G.: Interpretation of biological flux data: reaction-rate theory versus continuum theory, Ann. Rev. Biophys. Biophys. Chem. 15 (1986), 29–57.
Honig, B.H., Hubbel, W.L. and Flewelling, R.F.: Electrostatic Interations in Membranes and Proteins, Ann. Rev. Biophys. Biophys. Chem. 15 (1986), 163–193.
Hille, B.: Ionic Channels of Excitable Membranes, 2nd ed., Sinauer, Massachusetts, 1992.
White, P.J., Smahel, M. and Thiel, G.: Characterization of ion channels from Acetabularia plasma membrane in planar lipid bilayers, J. Membrane Biol. 133 (1993), 145–160.
Haken, H.: Synergetics, 3rd ed., Springer-Verlag, Berlin, 1983.
Chinarov, V.A., Gaididei, Y.B., Kharkyanen, V.N. and Sit'ko, S.P.: Ion pores in biological membranes as self-organized bistable systems, Phys. Rev. A 46 (1992), 5232–5241.
Kharkyanen, V.N., Panchouk, A.S. and Weinreb, G.E.: Self-organization effects induced by ion-conformational interaction in biomembrane channels, J. Biol. Phys. 19, 259–272.
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Lee, K., Sung, W. A Stochastic Model of Conductance Transitions in Voltage-Gated IonChannels. Journal of Biological Physics 28, 279–288 (2002). https://doi.org/10.1023/A:1019987816498
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DOI: https://doi.org/10.1023/A:1019987816498