title: Rhodopsin reconstituted into a planar-supported lipid bilayer retains photoactivity after cross-linking polymerization of lipid monomers.
abstract: Transmembrane proteins (TMPs), particularly ion channels and receptors, play key roles in transport and signal transduction. Many of these proteins are pharmacologically important and therefore targets for drug discovery. TMPs can be reconstituted in planar-supported lipid bilayers (PSLBs), which has led to development of TMP-based biosensors and biochips. However, PSLBs composed of natural lipids lack the high stability desired for many technological applications. One strategy is to use synthetic lipid monomers that can be polymerized to form robust bilayers. A key question is how lipid polymerization affects TMP structure and activity. In this study, we have examined the effects of UV polymerization of bis-Sorbylphosphatidylcholine (bis-SorbPC) on the photoactivation of reconstituted bovine rhodopsin (Rho), a model G-protein-coupled receptor. Plasmon-waveguide resonance spectroscopy (PWR) was used to compare the degree of Rho incorporation and activation in fluid and poly(lipid) PSLBs. The results show that reconstitution of Rho into a supported lipid bilayer composed only of bis-SorbPC, followed by photoinduced lipid cross-linking, does not measurably diminish protein function.
authors.affiliation: Department of Chemistry, University of Arizona, Tucson, Arizona, 85721-0041, USA.
authors.forename: Varuni
authors.initials: V
authors.lastname: Subramaniam
authors.forename: Isabel D
authors.initials: ID
authors.lastname: Alves
authors.forename: Gilmar F J
authors.initials: GF
authors.lastname: Salgado
authors.forename: Pick-Wei
authors.initials: PW
authors.lastname: Lau
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wysocki
authors.forename: Zdzislaw
authors.initials: Z
authors.lastname: Salamon
authors.forename: Gordon
authors.initials: G
authors.lastname: Tollin
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Hruby
authors.forename: Michael F
authors.initials: MF
authors.lastname: Brown
authors.forename: S Scott
authors.initials: SS
authors.lastname: Saavedra
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D003432:Cross-Linking Reagents / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D010777:Photochemistry; D012243:Rhodopsin / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; C077390:1,2-bis(10(2',4'-hexadienoyloxy)decanoyl)-sn-glycero-3-phosphocholine; D012243:Rhodopsin