Titre du document / Document title
Focused electric field across the voltage sensor of potassium channels
Auteur(s) / Author(s)AHERN Christopher A.
Résumé / Abstract
Voltage-gated ion channels respond to changes in membrane potential by movement of their voltage sensors across the electric field between cytoplasmic and extracellular solutions. The principal voltage sensors in these proteins are positively charged S4 segments. The absolute magnitude of S4 movement discriminates two competing classes of gating models. In one class, the movement is <10 Å due to the fact that the electric field is focused by aqueous crevices in the channel protein. In an alternative model, based in part on the crystal structure of a potassium channel, the side chains of S4 arginines move their charges across the bilayer's electric field, a distance of >25 Å. Here, using tethered charges attached to an S4 segment, we provide evidence that the electric field falls across a distance of <4 Å, supporting a model in which the relative movement between S4 and the electric field is very small.
Revue / Journal TitleNeuron
Source / Source
2005, vol. 48, no
1, pp. 25-29 [5 page(s) (article)]
Langue / Language
Editeur / Publisher
Cell Press, Cambridge, MA, ETATS-UNIS
Localisation / Location
INIST-CNRS, Cote INIST : 22116, 35400013561502.0070
Nº notice refdoc (ud4) : 17197997