Small alcohols destabilize the KcsA tetramer via their effect on the membrane lateral pressure.
Previously, it was shown that the tetrameric potassium channel KcsA when present in a lipid bilayer can be dissociated by trifluoroethanol [van den Brink-van der Laan, E., et al. (2004) Biochemistry 43, 4240-4250]. Here, we demonstrate that this is a general property of small alcohols. We found that small alcohols dissociate the KcsA tetramer, at a concentration that depends on their membrane affinity. Importantly, the efficiency of the alcohol-induced tetramer dissociation was found to correlate with the efficiency of both alcohol-induced bilayer leakage and acyl chain disordering. Our data suggest that the ability of small alcohols to induce KcsA tetramer dissociation and to function as anesthetics depends on their effect on the membrane lateral pressure.
van den Brink-van der Laan
Els
E
Department of Biochemistry of Membranes, Centre for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. e.vandenbrink@chem.uu.nl
Chupin
Vladimir
V
Killian
J Antoinette
JA
de Kruijff
Ben
B
D000438:Alcohols / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D005452:Fluoresceins; D005456:Fluorescent Dyes / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry; D008958:Models, Molecular; D008970:Molecular Weight; D010713:Phosphatidylcholines / Q000737:chemistry; D015221:Potassium Channels / Q000737:chemistry* / Q000378:metabolism; D011312:Pressure; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D013223:Statistics as Topic
D000438:Alcohols; D001426:Bacterial Proteins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D015221:Potassium Channels; D021122:Protein Subunits; C107790:prokaryotic potassium channel; C024098:6-carboxyfluorescein; C017251:1,2-oleoylphosphatidylcholine