title: Label-free measuring and mapping of binding kinetics of membrane proteins in single living cells.
abstract: Membrane proteins mediate a variety of cellular responses to extracellular signals. Although membrane proteins are studied intensively for their values as disease biomarkers and therapeutic targets, in situ investigation of the binding kinetics of membrane proteins with their ligands has been a challenge. Traditional approaches isolate membrane proteins and then study them ex situ, which does not reflect accurately their native structures and functions. We present a label-free plasmonic microscopy method to map the local binding kinetics of membrane proteins in their native environment. This analytical method can perform simultaneous plasmonic and fluorescence imaging, and thus make it possible to combine the strengths of both label-based and label-free techniques in one system. Using this method, we determined the distribution of membrane proteins on the surface of single cells and the local binding kinetic constants of different membrane proteins. Furthermore, we studied the polarization of the membrane proteins on the cell surface during chemotaxis.
authors.affiliation: Center for Bioelectronics and Biosensors, Biodesign Institute, Arizona State University, Tempe, Arizona                 85287, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Yunze
authors.initials: Y
authors.lastname: Yang
authors.forename: Shaopeng
authors.initials: S
authors.lastname: Wang
authors.forename: Vinay J
authors.initials: VJ
authors.lastname: Nagaraj
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.forename: Nongjian
authors.initials: N
authors.lastname: Tao
mesh_terms: D002460:Cell Line; D002465:Cell Movement; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D037102:Lectins / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020349:Surface Plasmon Resonance
chemical_list: D006023:Glycoproteins; D037102:Lectins; D008565:Membrane Proteins