TY - JOUR
T1 - Label-Free Quantification of Small-Molecule Binding to Membrane Proteins on Single Cells by Tracking Nanometer-Scale Cellular Membrane Deformation
AU - Zhang, Fenni
AU - Jing, Wenwen
AU - Hunt, Ashley
AU - Yu, Hui
AU - Yang, Yunze
AU - Wang, Shaopeng
AU - Chen, Hong Yuan
AU - Tao, Nongjian
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/2/27
Y1 - 2018/2/27
N2 - Measuring molecular binding to membrane proteins is critical for understanding cellular functions, validating biomarkers, and screening drugs. Despite the importance, developing such a capability has been a difficult challenge, especially for small-molecule binding to membrane proteins in their native cellular environment. Here we show that the binding of both large and small molecules to membrane proteins can be quantified on single cells by trapping single cells with a microfluidic device and detecting binding-induced cellular membrane deformation on the nanometer scale with label-free optical imaging. We develop a thermodynamic model to describe the binding-induced membrane deformation, validate the model by examining the dependence of membrane deformation on cell stiffness, membrane protein expression level, and binding affinity, and study four major types of membrane proteins, including glycoproteins, ion channels, G-protein coupled receptors, and tyrosine kinase receptors. The single-cell detection capability reveals the importance of local membrane environment on molecular binding and variability in the binding kinetics of different cell lines and heterogeneity of different cells within the same cell line.
AB - Measuring molecular binding to membrane proteins is critical for understanding cellular functions, validating biomarkers, and screening drugs. Despite the importance, developing such a capability has been a difficult challenge, especially for small-molecule binding to membrane proteins in their native cellular environment. Here we show that the binding of both large and small molecules to membrane proteins can be quantified on single cells by trapping single cells with a microfluidic device and detecting binding-induced cellular membrane deformation on the nanometer scale with label-free optical imaging. We develop a thermodynamic model to describe the binding-induced membrane deformation, validate the model by examining the dependence of membrane deformation on cell stiffness, membrane protein expression level, and binding affinity, and study four major types of membrane proteins, including glycoproteins, ion channels, G-protein coupled receptors, and tyrosine kinase receptors. The single-cell detection capability reveals the importance of local membrane environment on molecular binding and variability in the binding kinetics of different cell lines and heterogeneity of different cells within the same cell line.
KW - binding kinetics
KW - label-free detection
KW - membrane proteins
KW - microfluidics
KW - single-cell analysis
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U2 - 10.1021/acsnano.8b00235
DO - 10.1021/acsnano.8b00235
M3 - Article
C2 - 29397682
AN - SCOPUS:85042714085
SN - 1936-0851
VL - 12
SP - 2056
EP - 2064
JO - ACS nano
JF - ACS nano
IS - 2
ER -