title: Lipid-dependent effects of halothane on gramicidin channel kinetics: a new role for lipid packing stress.
abstract: 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.
authors.affiliation: National Center for Medical Rehabilitation Research, National Institutes of Health,Bethesda, Maryland 20892, USA. weinricm@mail.nih.gov
authors.forename: Michael
authors.initials: M
authors.lastname: Weinrich
authors.forename: Tatiana K
authors.initials: TK
authors.lastname: Rostovtseva
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Bezrukov
mesh_terms: 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
chemical_list: 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