title: Nanodiscs for immobilization of lipid bilayers and membrane receptors: kinetic analysis of cholera toxin binding to a glycolipid receptor.
abstract: Nanodiscs are self-assembled soluble discoidal phospholipids bilayers encirculated by an amphipathic protein that together provide a functional stabilized membrane disk for the incorporation of membrane-bound and membrane-associated molecules. The scope of the present work is to investigate how nanodiscs and their incorporated membrane receptors can be attached to surface plasmon resonance sensorchips and used to measure the kinetics of the interaction between soluble molecules and membrane receptors inserted in the bilayer of nanodiscs. Cholera toxin and its glycolipid receptor G(M1) constitute a system that can be considered a paradigm for interactions of soluble proteins with membrane receptors. In this work, we have investigated different technologies for capturing nanodiscs containing the glycolipid receptor G(M1) in lipid bilayers, enabling measurements of binding of its soluble interaction partner cholera toxin B subunit to the receptor with the sensorchip-based surface plasmon resonance (SPR) technology. The measured stoichiometric and kinetic values of the interaction are in agreement with those reported by previous studies, thus providing proof-of-principle that nanodiscs can be employed for kinetic SPR studies.
authors.affiliation: Protein Research Group, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark. jonasb@bmb.sdu.dk
authors.forename: Jonas
authors.initials: J
authors.lastname: Borch
authors.forename: Federico
authors.initials: F
authors.lastname: Torta
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Sligar
authors.forename: Peter
authors.initials: P
authors.lastname: Roepstorff
mesh_terms: D015374:Biosensing Techniques; D002462:Cell Membrane / Q000378:metabolism; D002772:Cholera Toxin / Q000737:chemistry* / Q000378:metabolism*; D005677:G(M1) Ganglioside / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism*; D049329:Nanostructures / Q000737:chemistry*; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism*; D020349:Surface Plasmon Resonance
chemical_list: D008051:Lipid Bilayers; D011956:Receptors, Cell Surface; C033639:glycolipid receptor; D005677:G(M1) Ganglioside; D002772:Cholera Toxin