Membrane thickness changes ion-selectivity of channel-proteins.
The plasma membrane is a highly dynamic cell-barrier if the nature and distribution of its constituents are considered. Ion channels are embedded in these double lipid bilayers, which modulate their 3D-structures. The structure modulations by the lipid bilayer can assume such a degree that channel activation depends on them, as was shown for the KcsA potassium channel. Here we show that the cation-over-anion selectivity of reconstituted ICln channels can be varied by the thickness of a bilayer build of phosphatidylcholines. The shorter the acyl-chains and therefore the thinner the bilayers of the membrane are, the more potassium selective the channels are. In contrast, the longer the acyl-chains and therefore the thicker the membranes are, the more chloride selective the channels become.
Department of Biomolecular Sciences and Biotechnology, Università degli Studi di Milano, Italy.
MariaLisa
M
Garavaglia
Silvia
S
Dopinto
Markus
M
Ritter
Johannes
J
Fürst
Stefano
S
Saino
Fabiana
F
Guizzardi
Martin
M
Jakab
Claudia
C
Bazzini
Valeria
V
Vezzoli
Silvia
S
Dossena
Simona
S
Rodighiero
Chiara
C
Sironi
Guido
G
Bottà
Giuliano
G
Meyer
Robert M
RM
Henderson
Markus
M
Paulmichl
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry* / Q000502:physiology* / Q000648:ultrastructure; D004285:Dogs; D006801:Humans; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D017136:Ion Transport; D008051:Lipid Bilayers / Q000737:chemistry*; D008564:Membrane Potentials; D018625:Microscopy, Atomic Force
C410035:CLNS1A protein, human; D007473:Ion Channels; D008051:Lipid Bilayers