title: Nanoscale aggregation of cellular beta2-adrenergic receptors measured by plasmonic interactions of functionalized nanoparticles.
abstract: Adrenergic signaling that controls the contraction of cardiac myocyte cells and the beating of the mammalian heart is initiated by ligand binding to adrenergic receptors contained in nanoscale multiprotein complexes at the cellular membrane. Here we demonstrate that the surface-enhanced Raman scattering (SERS) of functionalized silver nanoparticles can be used to report on the receptor aggregation state of specifically label beta(2)-adrenergic receptors on mouse cardiac myocyte cells. Furthermore, multimodal imaging including Raman, Rayleigh scattering, scanning electron microscopy, and luminescence imaging was combined to fully characterize the beta(2)-adrenergic receptor-mediated aggregation of silver nanoparticles on the membrane of cardiac myocytes. Scanning electron microscopy analysis reveals distinct SERS active clusters of between 10 and 70 nanoparticles per signaling domain from ultra-high-resolution images of beta(2)-adrenergic receptor clusters on the cellular membrane. These techniques can be generally applied to study the aggregation of other cell surface receptors and explore their distribution on cell surfaces.
authors.affiliation: Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Canada.
authors.forename: David C
authors.initials: DC
authors.lastname: Kennedy
authors.forename: Li-Lin
authors.initials: LL
authors.lastname: Tay
authors.forename: Rodney K
authors.initials: RK
authors.lastname: Lyn
authors.forename: Yanouchka
authors.initials: Y
authors.lastname: Rouleau
authors.forename: John
authors.initials: J
authors.lastname: Hulse
authors.forename: John Paul
authors.initials: JP
authors.lastname: Pezacki
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry; D053768:Metal Nanoparticles / Q000032:analysis* / Q000737:chemistry / Q000648:ultrastructure; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D015394:Molecular Structure; D032342:Muscle Cells / Q000737:chemistry* / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D018343:Receptors, Adrenergic, beta-2; D012834:Silver