Spontaneous lipid vesicle fusion with electropermeabilized cells.
Fusion is obtained between electropermeabilized mammalian cells and intact large unilamellar lipid vesicles. This is monitored by a fluorescence assay. Prepulse contact is obtained by Ca2+ when negatively charged lipids are present in the liposomes. The mixing of the liposome content in the cell cytoplasm is observed under conditions preserving cell viability. Electric conditions are such that free liposomes are not affected by the external field. Therefore destabilization of only one of the two membranes of the partners is sufficient for fusion. The comparison between the efficiency of dye delivery for different liposome preparations (multilamellar vesicles, large unilamellar vesicles, small unilamellar vesicles) is indicative that more metastable liposomes are more fusable with electropulsated cells. This observation is discussed within the framework of the recent hypothesis that occurrence of a contact induced electrostatic destabilization of the plasma membrane is a key step in the exocytosis process.
Ramos
Corinne
C
Institut de Pharmacologie et de Biologie Structurale du CNRS, UMR 5089, 205, route de Narbonne, 31077 Cedex 4, Toulouse, France.
Bonato
David
D
Winterhalter
Mathias
M
Stegmann
Toon
T
Teissié
Justin
J
D018274:Electroporation / Q000379:methods*; D005089:Exocytosis; D005456:Fluorescent Dyes / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism*; D008561:Membrane Fusion; D010539:Permeability; D055672:Static Electricity
D005456:Fluorescent Dyes; D008081:Liposomes