Voltage-induced gating of the mechanosensitive MscL ion channel reconstituted in a tethered lipid bilayer membrane

Martin Andersson, George Okeyo, Danyell Wilson, Henk Keizer, Paul Moe, Paul Blount, Daniel Fine, Ananth Dodabalapur, Randolph S. Duran

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

The mechanosensitive (MS) ion channel is gated by changes in bilayer deformation. It is functional without the presence of any other proteins and gating of the channel has been successfully achieved using conventional patch clamping techniques where a voltage has been applied together with a pressure over the membrane. Here, we have for the first time analyzed the large conducting (MscL) channel in a supported membrane using only an external electrical field. This was made possible using a newly developed technique utilizing a tethered lipid bilayer membrane (tBLM), which is part of an engineered microelectronic array chip. Single ion channel activity characteristic for MscL was obtained, albeit with lower conductivity. The ion channel was gated using solely a transmembrane potential of 300 mV. Computations demonstrate that this amount of membrane potential induces a membrane tension of 12 dyn/cm, equivalent to that calculated to gate the channel in patch clamp from pressure-induced stretching of the bilayer. These results strengthen the supposition that the MscL ion channel gates in response to stress in the lipid membrane rather than pressure across it. Furthermore, these findings illustrate the possibility of using the MscL as a release valve for engineered membrane devices; one step closer to mimicking the true function of the living cell.

Original languageEnglish (US)
Pages (from-to)919-923
Number of pages5
JournalBiosensors and Bioelectronics
Volume23
Issue number6
DOIs
StatePublished - Jan 18 2008

Keywords

  • Ion channels
  • Mechanosensitive
  • MscL
  • Single channel activity
  • Tethered

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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