title: Supported lipopolysaccharide bilayers.
abstract: In this report, the formation of supported lipopolysaccharide bilayers (LPS-SLBs) is studied with extracted native and glycoengineered LPS from  Escherichia coli  ( E. coli ) and  Salmonella enterica sv typhimurium  ( S. typhimurium ) to assemble a platform that allows measurement of LPS membrane structure and the detection of membrane tethered saccharide-protein interactions. We present quartz crystal microbalance with dissipation monitoring (QCM-D) and fluorescence recovery after photobleaching (FRAP) characterization of LPS-SLBs with different LPS species, having, for example, different molecular weights, that show successful formation of SLBs through vesicle fusion on SiO(2) surfaces with LPS fractions up to 50 wt %. The thickness of the LPS bilayers were investigated with AFM force-distance measurements which showed only a slight thickness increase compared to pure POPC SLBs. The  E. coli  LPS were chosen to study the saccharide-protein interaction between the Htype II glycan epitope and the  Ralstonia solanacearum  lectin (RSL). RSL specifically recognizes fucose sugars, which are present in the used Htype II glycan epitope and absent in the epitopes LPS1 and EY2. We show via fluorescence microscopy that the specific, but weak and multivalent interaction can be detected and discriminated on the LPS-SLB platform.
authors: Laboratory for Surface Science and Technology, Department for Materials Science, ETH Zurich, Zurich, Switzerland.
authors: Stefan
authors: S
authors: Kaufmann
authors: Karin
authors: K
authors: Ilg
authors: Alireza
authors: A
authors: Mashaghi
authors: Marcus
authors: M
authors: Textor
authors: Bernard
authors: B
authors: Priem
authors: Markus
authors: M
authors: Aebi
authors: Erik
authors: E
authors: Reimhult
mesh_terms: D000939:Epitopes / Q000276:immunology; D048168:Escherichia coli K12 / Q000737:chemistry; D037102:Lectins / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D043368:Ralstonia solanacearum / Q000737:chemistry; D012486:Salmonella typhimurium / Q000737:chemistry
chemical_list: D000939:Epitopes; D037102:Lectins; D008051:Lipid Bilayers; D008070:Lipopolysaccharides