Fig. 4

The impacts of natural mutations at antigenic sites on binding and neutralizing activities of RBD-specific NAbs. a Binding activity of RBD natural mutants with a panel of NAbs was evaluated by ELISA. Degree of binding reduction was defined as percentage by OD₄₅₀ of each mutant relative to OD₄₅₀ of RBD wildtype is represented as a heatmap from white (reduction) to blue (no impact). The data are representative of at least two independent experiments. b Binding of 18 purified mammalian expressed RBD single-point mutants and two co-mutations with a panel of NAbs. Binding fold change was calculated as follows: EC₅₀ of RBD mutant/EC₅₀ of RBD wildtype. N.B., not binding. c Details of the structural interaction between CB6 and RBD (PDB ID: 7C01). d Details of the structural interaction between S309 and RBD (PDB ID: 6WPT). e Details of the structural interaction between CR3022 and RBD (PDB ID:7A5S). For c–e, polar interactions are indicated by yellow dashed lines. Cyan, heavy chain; light blue, light chain; gray, RBD. Key residues on RBD highlighted in orange sticks; key residues on heavy chain highlighted in cyan sticks. f Neutralization of 19 pseudotyped variants by a panel of RBD-specific NAbs. Neutralization fold change was calculated as follows: IC₅₀ of pseudotyped variants/IC₅₀ of the wildtype. IC₅₀ values were calculated from three independent experiments. The data represent one representative experiment of two independent experiments