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Fast and slow gating are inherent properties of the pore module of the K+ channel Kcv.

Abenavoli, Alessandra and DiFrancesco, Mattia Lorenzo and Schroeder, Indra and Epimashko, Svetlana and Gazzarrini, Sabrina and Hansen, Ulf Peter and Thiel, Gerhard and Moroni, Anna (2009):
Fast and slow gating are inherent properties of the pore module of the K+ channel Kcv.
In: The Journal of general physiology, pp. 219-29, 134, (3), ISSN 1540-7748,
[Article]

Abstract

Kcv from the chlorella virus PBCV-1 is a viral protein that forms a tetrameric, functional K+ channel in heterologous systems. Kcv can serve as a model system to study and manipulate basic properties of the K+ channel pore because its minimalistic structure (94 amino acids) produces basic features of ion channels, such as selectivity, gating, and sensitivity to blockers. We present a characterization of Kcv properties at the single-channel level. In symmetric 100 mM K+, single-channel conductance is 114+/-11 pS. Two different voltage-dependent mechanisms are responsible for the gating of Kcv. "Fast" gating, analyzed by beta distributions, is responsible for the negative slope conductance in the single-channel current-voltage curve at extreme potentials, like in MaxiK potassium channels, and can be explained by depletion-aggravated instability of the filter region. The presence of a "slow" gating is revealed by the very low (in the order of 1-4%) mean open probability that is voltage dependent and underlies the time-dependent component of the macroscopic current.

Item Type: Article
Erschienen: 2009
Creators: Abenavoli, Alessandra and DiFrancesco, Mattia Lorenzo and Schroeder, Indra and Epimashko, Svetlana and Gazzarrini, Sabrina and Hansen, Ulf Peter and Thiel, Gerhard and Moroni, Anna
Title: Fast and slow gating are inherent properties of the pore module of the K+ channel Kcv.
Language: English
Abstract:

Kcv from the chlorella virus PBCV-1 is a viral protein that forms a tetrameric, functional K+ channel in heterologous systems. Kcv can serve as a model system to study and manipulate basic properties of the K+ channel pore because its minimalistic structure (94 amino acids) produces basic features of ion channels, such as selectivity, gating, and sensitivity to blockers. We present a characterization of Kcv properties at the single-channel level. In symmetric 100 mM K+, single-channel conductance is 114+/-11 pS. Two different voltage-dependent mechanisms are responsible for the gating of Kcv. "Fast" gating, analyzed by beta distributions, is responsible for the negative slope conductance in the single-channel current-voltage curve at extreme potentials, like in MaxiK potassium channels, and can be explained by depletion-aggravated instability of the filter region. The presence of a "slow" gating is revealed by the very low (in the order of 1-4%) mean open probability that is voltage dependent and underlies the time-dependent component of the macroscopic current.

Journal or Publication Title: The Journal of general physiology
Volume: 134
Number: 3
Divisions: 10 Department of Biology > Plant Membrane Biophysics
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10 Department of Biology
Date Deposited: 21 Jun 2011 11:59
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