title: Charge determination of membrane molecules in polymer-supported lipid layers.
abstract: A method for two-dimensional micro-electrophoresis and charge determination of fluorescence-labeled membrane molecules in lipid layers is presented. Therefore, the labeled molecules are dissolved in a lipid monolayer which acts as a fluid matrix. The essential part of the sample preparation is an aqueous polymer film composed of agarose onto which the layer is transferred by Langmuir-Blodgett technique. The induced force of an applied electric field leads to a drift of the charged fluorescent molecules. The mobility is determined by an analysis of the steady-state bleach profile which is produced by continuous fluorescence micro-photolysis of a rectangular area of the monolayer. Testing a variety of amphiphilic molecules, measurements yielded values of zero, plus or minus one elementary net charge within a margin of error. The experimental set-up described here can be used for lateral separation, enrichment and isoelectric focusing of membrane components.
authors.affiliation: Physik Department, Technische Universität München, Garching, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Dietrich
authors.forename: R
authors.initials: R
authors.lastname: Tampé
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D004586:Electrophoresis / Q000379:methods; D005456:Fluorescent Dyes; D008055:Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D008956:Models, Chemical; D010777:Photochemistry
chemical_list: D001704:Biopolymers; D005456:Fluorescent Dyes; D008055:Lipids; D008567:Membranes, Artificial