Rapid intracellular TEA block of the KcsA potassium channel

Biophys J. 2005 Feb;88(2):1018-29. doi: 10.1529/biophysj.104.052043. Epub 2004 Nov 19.

Abstract

Intracellular tetraethylammonium (TEA) inhibition was studied at the single-channel level in the KcsA potassium channel reconstituted in planar lipid bilayers. TEA acts as a fast blocker (resulting in decreased current amplitude) with an affinity in the 75 mM range even at high bandwidth. Studies over a wide voltage range reveal that TEA block has a complex voltage-dependence that also depends on the ionic conditions. These observations are examined in the context of permeation models to extend our understanding of the coupling between permeant ions and TEA blockade.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / antagonists & inhibitors
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / ultrastructure
  • Cell Membrane / chemistry*
  • Computer Simulation
  • Intracellular Fluid / chemistry*
  • Ion Channel Gating / drug effects*
  • Lipid Bilayers / chemistry*
  • Membranes, Artificial
  • Models, Chemical
  • Models, Molecular*
  • Permeability / drug effects
  • Porosity / drug effects
  • Potassium Channels / chemistry*
  • Potassium Channels / ultrastructure
  • Structure-Activity Relationship
  • Tetraethylammonium / chemistry*

Substances

  • Bacterial Proteins
  • Lipid Bilayers
  • Membranes, Artificial
  • Potassium Channels
  • prokaryotic potassium channel
  • Tetraethylammonium