Lipid-dependent effects of halothane on gramicidin channel kinetics: a new role for lipid packing stress.
We find that the sensitivity of gramicidin A channels to the anesthetic halothane is highly lipid dependent. Specifically, exposure of membranes made of lamellar DOPC to halothane in concentrations close to clinically relevant reduces channel lifetimes by 1 order of magnitude. At the same time, gramicidin channels in membranes of nonlamellar DOPE are affected little, if at all, by halothane. We attribute this difference in channel behavior to a difference in the stress of lipid packing into a planar lipid bilayer, wherein the higher stress of DOPE packing reduces the degree of halothane partitioning into the hydrophobic interior.
Weinrich
Michael
M
National Center for Medical Rehabilitation Research, National Institutes of Health,Bethesda, Maryland 20892, USA. weinricm@mail.nih.gov
Rostovtseva
Tatiana K
TK
Bezrukov
Sergey M
SM
D018685:Anesthetics, Inhalation / Q000737:chemistry / Q000494:pharmacology*; D006096:Gramicidin / Q000737:chemistry* / Q000378:metabolism; D006221:Halothane / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry*; D008564:Membrane Potentials; D008567:Membranes, Artificial; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry
C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D018685:Anesthetics, Inhalation; D008051:Lipid Bilayers; D008055:Lipids; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D006096:Gramicidin; C017251:1,2-oleoylphosphatidylcholine; D006221:Halothane