Focused electric field across the voltage sensor of potassium channels

Christopher A Ahern; Richard Horn

doi:10.1016/j.neuron.2005.08.020

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Focused electric field across the voltage sensor of potassium channels

Journal article

Open access

Peer reviewed

Focused electric field across the voltage sensor of potassium channels

Christopher A Ahern and Richard Horn

Neuron (Cambridge, Mass.), Vol.48(1), pp.25-29

10/06/2005

DOI: 10.1016/j.neuron.2005.08.020

PMID: 16202706

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Abstract

Voltage-gated ion channels respond to changes in membrane potential by movement of their voltage sensors across the electric field between cytoplasmic and extracellular solutions. The principal voltage sensors in these proteins are positively charged S4 segments. The absolute magnitude of S4 movement discriminates two competing classes of gating models. In one class, the movement is <10 Angstrom due to the fact that the electric field is focused by aqueous crevices in the channel protein. In an alternative model, based in part on the crystal structure of a potassium channel, the side chains of S4 arginines move their charges across the bilayer's electric field, a distance of >25 Angstrom. Here, using tethered charges attached to an S4 segment, we provide evidence that the electric field falls across a distance of <4 Angstrom, supporting a model in which the relative movement between S4 and the electric field is very small.

Xenopus

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Potassium Channels, Voltage-Gated - physiology

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Models, Biological

Arginine - genetics

Cloning, Molecular - methods

Protein Conformation

Potassium Channels, Voltage-Gated - genetics

Details

Title: Subtitle: Focused electric field across the voltage sensor of potassium channels
Creators: Christopher A Ahern - Department of Physiology, Institute of Hyperexcitability, Jefferson Medical College, 1020 Locust Street, Philadelphia, Pennsylvania 19107, USA
Richard Horn
Resource Type: Journal article
Publication Details: Neuron (Cambridge, Mass.), Vol.48(1), pp.25-29
Publisher: United States
DOI: 10.1016/j.neuron.2005.08.020
PMID: 16202706
ISSN: 0896-6273
eISSN: 1097-4199
Grant note: AR41691 / NIAMS NIH HHS
Language: English
Date published: 10/06/2005
Academic Unit: Molecular Physiology and Biophysics; Iowa Neuroscience Institute
Record Identifier: 9984070627802771

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