Stable, Ligand-Doped, Poly(bis-SorbPC) Lipid Bilayer Arrays for Protein Binding and Detection

A continuous-flow microspotter was used to generate, planar arrays of stabilized bilayers composed of the polymerizable lipid bis-SorbPC and dopant lipids bearing ligands for proteins. Fluorescence microscopy was used to determine the uniformity of the bilayers and to detect protein binding. After UV-initiated polymerization, poly(lipid) bilayer microarrays were air-stable. Cholera toxin subunit b (CTb) bound to an array of poly(lipid) bilayers doped with GM(1), and the extent of binding was correlated to the mote percentage of GM(1) in each spot. A poly(lipid) bilayer-array composed of spots doped with GM(1) and spots doped with biotin-DOPE specifically bound CTb and streptavidin to the respective, spots from a dissolved mixture of the two proteins. Poly (bis-SorbPC)/GM(1) arrays retained specific CTb binding capacity after multiple regenerations with a protein denaturing solution and also after exposure to air. In addition-these arrays are stable in vacuum, which allows the use of MALDI-TOF mass spectrometry to detect specifically, bound CTb. This work demonstrates the considerable potential of poly(lipid) bilayer arrays for high-throughput binding assays and lipidomics studies.