Giant Lipid Membranes Supported By Glass Beads For Membrane-Protein Interaction Studies

Artificial membrane systems are essential elements for investigating fundamental biophysical features such as biomolecular interactions between membrane components and exogenous molecules that target them. While planar bilayer lipid membranes and liposomes have been extensively used for decades for such studies, their poor stability and small size may seriously limit their applicability. To overcome these roadblocks, we examined the use of large glass beads as support for the formation of stable membranes. Membrane formation and stability was assessed in fluorescence microscopy studies that used lipophilic dyes for membrane imaging. The same technique was utilized to indicate biomolecular interactions between fluorescent cholera toxin B subunit and GM1 gangliosides embedded in the membrane as target for the toxin. In addition, we succeeded to reconstitute membrane systems by using glass beads as support and intact red blood cell membranes as precursors. The lipid partition of the resulted membrane was identified by lipophilic staining, while the presence of proteins was confirmed by specific antibody staining. Membranes of either artificial or natural origin showed an outstanding stability, which recommends the supported membranes for investigations on biomolecular interactions in which membrane stability is an essential factor.