title: Short-chain alcohols promote accelerated membrane distention in a dynamic liposome model of exocytosis.
abstract: We have used amperometric measurements in a model system consisting of two liposomes connected with a membrane nanotube to monitor catechol release during artificial exocytosis and thereby to elucidate the effect of small-chain alcohols on this dynamic membrane process. To determine the rate of membrane shape change, catechol release during membrane distention was monitored amperometrically, and the presence of alcohols in the buffer was shown to accelerate the membrane distention process in a concentration-dependent manner. Compression isotherms for the same lipid composition in the absence and presence of ethanol and 1-propanol were measured to determine how these short-chain alcohols affect the lipid packing in monolayers. The isotherms show a marked decrease in lipid packing density that is dependent on the particular alcohol and its concentration. Comparison of the electrochemical and isotherm results suggests a correlation between decreasing lipid packing density and increasing rates of membrane shape change.
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Wittenberg
authors.forename: Leiliang
authors.initials: L
authors.lastname: Zheng
authors.forename: Nicholas
authors.initials: N
authors.lastname: Winograd
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Ewing
mesh_terms: D000433:1-Propanol / Q000737:chemistry*; D002396:Catechols / Q000737:chemistry; D004563:Electrochemistry; D000431:Ethanol / Q000737:chemistry*; D005089:Exocytosis; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D008567:Membranes, Artificial; D008956:Models, Chemical
chemical_list: D002396:Catechols; D008051:Lipid Bilayers; D008081:Liposomes; D008567:Membranes, Artificial; D000431:Ethanol; D000433:1-Propanol; C034221:catechol