title: Imaging G protein-coupled receptors while quantifying their ligand-binding free-energy landscape.
abstract: Imaging native membrane receptors and testing how they interact with ligands is of fundamental interest in the life sciences but has proven remarkably difficult to accomplish. Here, we introduce an approach that uses force-distance curve-based atomic force microscopy to simultaneously image single native G protein-coupled receptors in membranes and quantify their dynamic binding strength to native and synthetic ligands. We measured kinetic and thermodynamic parameters for individual protease-activated receptor-1 (PAR1) molecules in the absence and presence of antagonists, and these measurements enabled us to describe PAR1's ligand-binding free-energy landscape with high accuracy. Our nanoscopic method opens an avenue to directly image and characterize ligand binding of native membrane receptors.
authors.affiliation: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Alsteens
authors.affiliation: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland.
authors.forename: Moritz
authors.initials: M
authors.lastname: Pfreundschuh
authors.affiliation: Department of Cellular Physiology and Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland.
authors.forename: Patrizia M
authors.initials: PM
authors.lastname: Spoerri
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA.
authors.forename: Shaun R
authors.initials: SR
authors.lastname: Coughlin
authors.affiliation: Department of Cellular Physiology and Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Kobilka
authors.affiliation: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zurich, Basel, Switzerland.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Müller
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D004735:Energy Transfer; D006801:Humans; D007700:Kinetics; D008024:Ligands; D008051:Lipid Bilayers / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008956:Models, Chemical; D057054:Molecular Imaging / Q000379:methods*; D011485:Protein Binding; D044463:Receptor, PAR-1 / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: D008024:Ligands; D008051:Lipid Bilayers; D044463:Receptor, PAR-1