Quantification of Receptor Association, Dissociation, and NA-Dependent Motility of Influenza A Particles by Biolayer Interferometry.

We describe a method for real-time analysis and quantification of influenza A virus (IAV)-receptor interactions by biolayer interferometry (BLI). Biotinylated synthetic sialoglycans or sialoglycoproteins (biotinylated or Fc-tagged) were immobilized on the tip of biosensors (coated with streptavidin or protein A) that were subsequently dipped into IAV particle solutions in 96-well plates. Association and/or dissociation of IAV particles was recorded in consecutive steps in buffers of choice. From the association and dissociation curves, parameters can be derived that describe IAV particle-receptor interactions in absence or presence of neuraminidase activity. Overall, the method provides a quantitative description of the hemagglutinin-neuraminidase balance that determines the interaction kinetics of IAV with specific sialoglycan receptors.