Chip electrophoretic characterization of liposomes with biological lipid composition: Coming closer to a model for viral infection

In first attempts at elucidating the transfer of the RNA genome of a human Rhinovirus through lipid membranes in vitro we made use of liposomes decorated with recombinant receptors. This model system was characterized previously by CE but suffered from the requirement for inclusion of polyethylene glycol-modified lipids for reliable separations [Weiss, V. U., Bilek, G., Pickl-Herk, A., Blaas, D., Kenndler, E., Electrophoresis 2009, 30, 2123-2128.]. We here report the analysis of liposomes with a lipid composition much more similar to that of biological lipid bilayers. We found that vesicles containing and lacking this non-physiologic lipid differ significantly in their electrophoretic mobility (by factor 2) although the concentration of charge-bearing lipids in their bilayers is the same. We demonstrate that binding of a human Rhinovirus to the latter liposomes decorated with a cognate receptor can be analysed via electrophoresis on microchips; we support our results with transmission electron microscopy.