Voltage-dependent gating of an asymmetric gramicidin channel Academic Article Article uri icon


MeSH Major

  • Gramicidin
  • Lipid Bilayers
  • Membrane Transport Proteins


  • In an effort to understand the molecular mechanisms of voltage activation of ion channels, we have chosen a system of known structure and examined the properties of heterodimeric channels formed between [Val1]gramicidin A ([Val1]gA) and [F6Val1]gramicidin A ([F6Val1]gA). Gramicidin channels are usually not voltage-dependent; but the introduction of a single symmetry-breaking dipolar F6Val1 residue into a ([Val1]gA)2 dimer to form the [F6Val1]gA/[Val1]gA heterodimer induces voltage-dependent transitions between two conducting states: a high-conductance state and a zero conductance (closed) state. The distribution between these states varies as a function of the applied potential but is not dependent on the nature of the permeant ion (H+ or Cs+). The permeating ions do not seem to contribute to the apparent gating charge.

publication date

  • March 14, 1995



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1073/pnas.92.6.2121

PubMed ID

  • 7534411

Additional Document Info

start page

  • 2121

end page

  • 5


  • 92


  • 6