title: Supported lipopolymer membranes as nanoscale filters: simultaneous protein recognition and size-selection assays.
abstract: A technique for size-selective discrimination of protein analytes was developed by incorporating poly(ethylene glycol) (PEG) lipopolymers into supported lipid bilayers. The membranes also contained biotinylated lipids, which recognized both streptavidin and anti-biotin IgG. By employing various PEG lipopolymer concentrations, clear discrimination against anti-biotin (Mw = 150 000 Da) binding could be observed, which became more pronounced at higher polymer densities. On the other hand, streptavidin (Mw = 52 800) binding to the membrane remained unaffected even at PEG concentrations that were well into the mushroom-to-brush phase transition. These observations were exploited to create an on-chip ligand-receptor binding assay that favored streptavidin binding over anti-biotin by several orders of magnitude in the presence of the lipopolymer. Control experiments revealed that the two proteins are bound to similar extents from a multi-protein analyte solution in the absence of PEG.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Albertorio
authors.forename: Susan
authors.initials: S
authors.lastname: Daniel
authors.forename: Paul S
authors.initials: PS
authors.lastname: Cremer
mesh_terms: D001667:Binding, Competitive; D015374:Biosensing Techniques / Q000379:methods*; D005374:Filtration; D007074:Immunoglobulin G / Q000032:analysis; D008051:Lipid Bilayers / Q000737:chemistry*; D044085:Microfluidics; D049329:Nanostructures; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011506:Proteins / Q000032:analysis*; D019809:Streptavidin / Q000032:analysis
chemical_list: D007074:Immunoglobulin G; D008051:Lipid Bilayers; D010714:Phosphatidylethanolamines; D011506:Proteins; D011092:Polyethylene Glycols; D019809:Streptavidin