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Quantification of Multivalent Interactions between Sialic Acid and Influenza A Virus Spike Proteins by Single-Molecule Force Spectroscopy
journal contribution
posted on 2020-06-30, 00:03 authored by Jose Luis Cuellar-Camacho, Sumati Bhatia, Valentin Reiter-Scherer, Daniel Lauster, Susanne Liese, Jürgen P. Rabe, Andreas Herrmann, Rainer HaagMultivalency is a
key principle in reinforcing reversible molecular
interactions through the formation of multiple bonds. The influenza
A virus deploys this strategy to bind strongly to cell surface receptors.
We performed single-molecule force spectroscopy (SMFS) to investigate
the rupture force required to break individual and multiple bonds
formed between synthetic sialic acid (SA) receptors and the two principal
spike proteins of the influenza A virus (H3N2): hemagglutinin (H3)
and neuraminidase (N2). Kinetic parameters such as the rupture length
(χβ) and dissociation rate (koff) are extracted using the model by Friddle, De Yoreo,
and Noy. We found that a monovalent SA receptor binds to N2 with a
significantly higher bond lifetime (270 ms) compared to that for H3
(36 ms). By extending the single-bond rupture analysis to a multibond
system of n protein-receptor pairs, we provide an
unprecedented quantification of the mechanistic features of multivalency
between H3 and N2 with SA receptors and show that the stability of
the multivalent connection increases with the number of bonds from
tens to hundreds of milliseconds. Association rates (kon) are also provided, and an estimation of the dissociation
constants (KD) between the SA receptors
to both proteins indicate a 17-fold higher binding affinity for the
SA–N2 bond with respect to that of SA–H3. An optimal
designed multivalent SA receptor showed a higher binding stability
to the H3 protein of the influenza A virus than to the monovalent
SA receptor. Our study emphasizes the influence of the scaffold on
the presentation of receptors during multivalent binding.