Large Unilamellar Vesicle Preparation

Liposomes were prepared using the lipid film technique²⁸ from stock solutions of lipid and sterol in chloroform. For the ITC and CD experiments, the lipid films were hydrated with a phosphate buffer [10 mM PO₄ (pH 6.5)], and for the laurdan experiments, the lipid films were hydrated with a liposome buffer [150 mM NaCl, 5 mM CaCl₂, 5 mM HEPES, and 3 mM NaN₃ (pH 7.4)] to produce multilamellar vesicles (MLVs). The MLVs were then extruded through a 100 nm polycarbonate Whatman membrane (GE Healthcare BioSciences, Pittsburgh, PA) with a LiposoFast extruder (AVESTIN Inc., Ottawa, ON) to create large unilamellar vesicles (LUVs).²⁹