Fig. 5.

Enhanced neutralization potency by Fc-fused biparatopic Nb. a Schematic representation of the construction of Nb1–Nb2–Fc. Homology modeling of Nb1–Nb2–Fc was performed with SWISS-MODEL server. The structure is depicted as surface mode. The CDR regions were colored as pink for Nb1 and blue for Nb2. b Coomassie Blue staining of the Fc vector (lane 1) and Nb1–Nb2–Fc plasmid transfected Expi293F supernatants. Lane 3 shows the affinity-purified Nb1–Nb2–Fc. Fc fusion to Nb1–Nb2 generates a heavy-chain antibody with an approximate molecular weight of 60 kDa in reduced condition. c Neutralization of multiple SARS-CoV-2 GFP/ΔN trVLP variants with Nb1–Nb2–Fc. d Summary of neutralization IC₅₀ value of Fc-fused Nb that was obtained in (c). IC₅₀ fold increases versus the corresponding non-Fc-fused bivalent Nb were calculated