Fig. 6.

Enhanced SARS-CoV S-RBD binding and increased virus entry-inhibition associated with the ACE2 mutations. a An SPR assay characterizing the real-time binding kinetics of the ACE2 proteins (wild-type and mutants) to SARS-CoV S-RBD. Three independent experiments are conducted and the recorded profiles from one representative experiment are shown. The calculated kinetic parameters are summarized. b Increased inhibitory efficacy of the indicated ACE2 mutants in blocking virus entry of SARS-CoV. The luciferase-incorporated SARS-CoV pseudovirus is pre-incubated with the indicated ACE2 proteins (wild-type and mutants) for 1 h at 37 °C and then used to infect the human ACE2-transfecting 293T cells. Luciferase activities in target are measured. Each point represents the mean ± SD from triplicate experiments