Lipid Extraction from HeLa Cells, Quantification of Lipids, Formation of Large Unilamellar Vesicles (LUVs) by Extrusion and in vitro Protein-lipid Binding Assays, Analysis of the Incubation Product by Transmission Electron Microscopy (TEM) and by Flotation across a Discontinuous Sucrose Gradient

Abstract

Dissecting the interactions established between proteins and membranes in a given type of cells is not an easy task. Using a cell-free system of large unilamellar vesicles (LUVs) to analyze these interactions may help decipher these interactions and identify potential membrane deformations induced by the proteins incubated with these LUVs. This article describes the protocols for 1) extraction of total lipids from eukaryotic cells using the method developed by Bligh and Dyer (1959), 2) the quantification of glycerophospholipids by gas chromatography after methanolysis, followed by 3) the formation of LUVs by extrusion, 4) protein-lipid binding assay, 5) analysis of the incubation product by transmission electron microscopy (TEM) and by flotation across a discontinuous sucrose gradient and finally, 6) analysis of the proteins by immunoblot and revelation of the glycerophospholipids by iodin fumigation.