Fig. 5
7D10-H partially inhibiting virus binding to its receptor DPP4. a Inhibition of the binding between recombinant soluble MERS-CoV spike trimer (S) and human DPP4 expressed on the Huh7 cell-surface. Soluble MERS-CoV spike trimer (S) with strep-tag (1 μg) was incubated with monoclonal antibodies (mAbs) in advance at a molar ratio 1:1, 1:3, 1:9, and 1:27 for 1 h. Huh7 cells were incubated with S or S and mAbs mixtures for 1 h. After washing the unbound S, Huh7 cells were stained with streptavidin APC and analyzed by fluorescence-activated cell sorting (FACS). The amounts of S-bound Huh-7 cells were measured and characterized as median fluorescence intensity. See also Supplementary Table 4 and Supplementary Fig. 6. b–e Top view and side view of the MERS-CoV spike trimer in receptor-binding activated states (PDB: 5 × 5c [https://doi.org/10.2210/pdb5X5C/pdb]) with two RBD in the up positions, on which the RBD/DPP4 and NTD/antibody structures are superimposed. The spike trimer (RBD in green, NTD in blue, and S2 subunit in gray) was shown as a cartoon. The DPP4 was shown as a semitransparent surface and colored in yellow. 7D10-scFv (b), 7D10-Fab (c), and 7D10-IgG (d, e) were all colored pink. 7D10-Fab and 7D10-IgG were modeled using homologous modeling in SWISS-MODEL
