FIG 2.
Affinity specificity and neutralizing abilities of the SARS-CoV-2 S protein MAbs. (A) ELISA analysis of 28 purified antibodies to S-ECD, S1, and S-RBD proteins. The concentration gradient of MAbs is the x axis, and the optical absorption values of OD450 are the y axis. The antibodies with five colored curves indicate that the antibodies have good combination ability with RBD. All samples were performed in triplicates, and the means are presented. (B to F) The binding affinity of five selected antibodies to the S-ECD protein was measured by SPR with a 1:1 binding model. KD values are shown above the individual plots. (G) The authentic virus neutralization ability of five selected antibodies. The neutralization activity curve of five monoclonal antibodies against Chinese endemic strains is shown. (H and I) Neutralization antibody nCoV617 and ACE2 competition for binding to RBD measured by SPR.