Fig. 2. Binding affinity of SARS-CoV-2 RBDs to ACE2, characterized by SPR.
a–k Mouse Fc (mFc)-fused hACE2 or miACE2 in the supernatant was captured in the CM5 chip via its interaction with the pre-immobilized anti-mFc antibody. Various concentrations of SARS-CoV-2 WT RBD (a), Alpha RBD (b), Beta RBD (c), Gamma RBD (d), Mink-Y453F RBD (e), Mink-N501T RBD (f), and Mink-F486L RBD (g) protein were used to evaluate their binding affinity for hACE2. Serially diluted WT RBD (h), Mink-Y453F RBD (i), Mink-N501T RBD (j), and Mink-F486L RBD (k) protein were measured the binding to miACE2. KD, ka, and kd values are all recorded and the representative results from three experiments are shown. The data are presented as the mean ± SEM of three independent replicates (n = 3).