Characterization of Receptor Binding Profiles of Influenza A Viruses Using An Ellipsometry-Based Label-Free Glycan Microarray Assay Platform
Yiyan Fei,
Yung-Shin Sun,
Yanhong Li,
Hai Yu,
Kam Lau,
James P. Landry,
Zeng Luo,
Nicole Baumgarth,
Xi Chen,
Xiangdong Zhu
Affiliations
Yiyan Fei
Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, 220 Handan Road, Shanghai 200433, China
Yung-Shin Sun
Department of Physics, University of California, Davis, CA 95616, USA
Yanhong Li
Department of Chemistry, University of California, Davis, CA 95616, USA
Hai Yu
Department of Chemistry, University of California, Davis, CA 95616, USA
Kam Lau
Department of Chemistry, University of California, Davis, CA 95616, USA
James P. Landry
Department of Physics, University of California, Davis, CA 95616, USA
Zeng Luo
Center for Comparative Medicine, University of California, Davis, CA 95616, USA
Nicole Baumgarth
Center for Comparative Medicine, University of California, Davis, CA 95616, USA
Xi Chen
Department of Chemistry, University of California, Davis, CA 95616, USA
Xiangdong Zhu
Department of Physics, University of California, Davis, CA 95616, USA
A key step leading to influenza viral infection is the highly specific binding of a viral spike protein, hemagglutinin (HA), with an extracellular glycan receptor of a host cell. Detailed and timely characterization of virus-receptor binding profiles may be used to evaluate and track the pandemic potential of an influenza virus strain. We demonstrate a label-free glycan microarray assay platform for acquiring influenza virus binding profiles against a wide variety of glycan receptors. By immobilizing biotinylated receptors on a streptavidin-functionalized solid surface, we measured binding curves of five influenza A virus strains with 24 glycans of diverse structures and used the apparent equilibrium dissociation constants (avidity constants, 10–100 pM) as characterizing parameters of viral receptor profiles. Furthermore by measuring binding kinetic constants of solution-phase glycans to immobilized viruses, we confirmed that the glycan-HA affinity constant is in the range of 10 mM and the reaction is enthalpy-driven.
