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PMID: 1420923 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

Shaking stack model of ion conduction through the Ca(2+)-activated K+ channel.

Biophysical journal ·Vol. 63 ·No. 4 ·1992-10-00 ·Pages 1032-44

Schumaker MF

Abstract

Motivated by the results of Neyton and Miller (1988. J. Gen. Physiol. 92:549-586), suggesting that the Ca(2+)-activated K+ channel has four high affinity ion binding sites, we propose a physically attractive variant of the single-vacancy conduction mechanism for this channel. Simple analytical expressions for conductance, current, flux ratio exponent, and reversal potential under bi-ionic conditions are found. A set of conductance data are analyzed to determine a realistic range of parameter values. Using these, we find qualitative agreement with a variety of experimental results previously reported in the literature. The exquisite selectivity of the Ca(2+)-activated K+ channel may be explained as a consequence of the concerted motion of the "stack" in the proposed mechanism.

MeSH Terms

Animals Calcium/pharmacology Electric Conductivity Kinetics Lipid Bilayers Mathematics Membrane Potentials Models, Biological Muscles/physiology Phosphatidylcholines Phosphatidylethanolamines Potassium Channels/drug effects,physiology Rats

Chemicals

Lipid Bilayers Phosphatidylcholines Phosphatidylethanolamines Potassium Channels 1-palmitoyl-2-oleoylphosphatidylethanolamine Calcium 1-palmitoyl-2-oleoylphosphatidylcholine

Authors & Affiliations

1 authors, click to expand affiliations / ORCID

Schumaker M F

Department of Pure and Applied Mathematics, Washington State University, Pullman 99164-3113.

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26 references, click to expand

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Article Info

Journal

Biophysical journal

Abbr.

Biophys J

ISSN

0006-3495

DOI

10.1016/S0006-3495(92)81668-5

Published

1992-10-00

Pages

1032-44

Language

English

Region

United States

NLM ID

0370626

PMCID

PMC1262242

Subset

External Links

PubMed source DOI: 10.1016/S0006-3495(92)81668-5 PMC Full Text View journal details

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Shaking stack model of ion conduction through the Ca(2+)-activated K+ channel.

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