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Changes in Single K+ Channel Behavior Induced by a Lipid Phase Transition

Authors :
Andrea Alessandrini
Laura Aldrovandi
Paolo Facci
Heiko M. Seeger
Source :
Biophysical journal, (2010)., info:cnr-pdr/source/autori:Seeger H.M., L. Aldrovandi, A. Alessandrini, and P. Facci/titolo:Changes in Single K+ Channel Behavior Induced by a Lipid Phase Transition/doi:/rivista:Biophysical journal (Print)/anno:2010/pagina_da:/pagina_a:/intervallo_pagine:/volume
Publication Year :
2010
Publisher :
Elsevier BV, 2010.

Abstract

We show that the activity of an ion channel is correlated with the phase state of the lipid bilayer hosting the channel. By measuring unitary conductance, dwell times, and open probability of the K+ channel KcsA as a function of temperature in lipid bilayers composed of POPE and POPG in different relative proportions, we obtain that all those properties show a trend inversion when the bilayer is in the transition region between the liquid-disordered and the solid-ordered phase. These data suggest that the physical properties of the lipid bilayer influence ion channel activity likely via a fine-tuning of its conformations. In a more general interpretative framework, we suggest that other parameters such as pH, ionic strength, and the action of amphiphilic drugs can affect the physical behavior of the lipid bilayer in a fashion similar to temperature changes resulting in functional changes of transmembrane proteins.

Details

ISSN :
00063495
Volume :
99
Issue :
11
Database :
OpenAIRE
Journal :
Biophysical Journal
Accession number :
edsair.doi.dedup.....271acdf941b5c6766d20a7690123f62c
Full Text :
https://doi.org/10.1016/j.bpj.2010.10.042