A one-dimensional continuum elastic model for membrane-embedded gramicidin dimer dissociation Academic Article uri icon

Overview

MeSH Major

  • Cell Membrane
  • Gramicidin
  • Protein Multimerization

abstract

  • Membrane elastic properties, which are subject to alteration by compounds such as cholesterol, lipid metabolites and other amphiphiles, as well as pharmaceuticals, can have important effects on membrane proteins. A useful tool for measuring some of these effects is the gramicidin A channels, which are formed by transmembrane dimerization of non-conducting subunits that reside in each bilayer leaflet. The length of the conducting channels is less than the bilayer thickness, meaning that channel formation is associated with a local bilayer deformation. Electrophysiological studies have shown that the dimer becomes increasingly destabilized as the hydrophobic mismatch between the channel and the host bilayer increases. That is, the bilayer imposes a disjoining force on the channel, which grows larger with increasing hydrophobic mismatch. The energetic analysis of the channel-bilayer coupling is usually pursued assuming that each subunit, as well as the subunit-subunit interface, is rigid. Here we relax the latter assumption and explore how the bilayer junction responds to changes in this disjoining force using a simple one-dimensional energetic model, which reproduces key features of the bilayer regulation of gramicidin channel lifetimes.

publication date

  • February 17, 2011

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC3033891

Digital Object Identifier (DOI)

  • 10.1371/journal.pone.0015563

PubMed ID

  • 21326605

Additional Document Info

start page

  • e15563

volume

  • 6

number

  • 2