title: Formation of planar unilamellar phospholipid membranes on oxidized gold substrate.
abstract: Supported planar phospholipid membranes are used in a range of biophysical measurements, typically for characterizing protein-membrane interactions. Liposome deposition is the most common method to create such membranes. The ability of liposomes to fuse into a lamellar membrane during deposition is strongly dependent on the surface chemistry; some important substrate materials such as oxidized gold do not promote liposome fusion. Circumventing this determinism poses an enduring challenge to membrane biophysics. Here, the authors show that the effect of surface chemistry can be overcome by using osmotic stress. Reproducible single bilayer coverage was achieved on oxidized gold surface from liposomes of a variety of lipid compositions, as demonstrated by quartz crystal microbalance measurements and confirmed via fluorescence microscopy imaging. The continuity of the deposit was confirmed by fluorescence recovery after photobleaching. Using mixtures of di-myristoyl and di-palmitoyl lipids, it was also demonstrated that the formation of fused lamellar membranes upon osmotic stress is a sensitive function of the thermodynamic phase of the membrane.
authors: Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia.
authors: Imad Younus
authors: IY
authors: Hasan
authors: Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia.
authors: Adam
authors: A
authors: Mechler
mesh_terms: D006046:Gold / Q000737:chemistry*; D008051:Lipid Bilayers / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism*; D009997:Osmotic Pressure; D010743:Phospholipids / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids; D006046:Gold