Figure 4.

12-16 and 12-19 inhibit ACE2-spike binding and ACE2-induced S1 shedding

(A) Human ACE2 and antibodies in complex with SARS-CoV-2 spike with one RBD in the up position (PDB: 7KRR). All of these antibodies can neutralize SARS-CoV-2 except 4-33.

(B) Competition assay of ACE2 binding to cell-surface-expressed SARS-CoV-2 D614G spike in the presence of competitors. The data are shown as the mean ± SEM.

(C) ACE2-induced S1 shedding from SARS-CoV-2 virions. D614G pseudovirus particles were incubated with hACE2-Fc at different doses for 1 h at 37°C before the retained S1 and S2 subunits were determined by western blot.

(D) Inhibition of ACE2-induced S1 shedding from the spike trimers on SARS-CoV-2 virions by the indicated antibodies. D614G pseudovirus particles were incubated with the indicated antibodies for 1 h prior to incubating with 5 μg/mL hACE2-Fc for another 1 h. The retained S1 and S2 subunits were determined by western blot.

(E) The intensities of the S1 and S2 glycoprotein bands in (D) were measured, and the S1/S2 ratios are shown. Numbers denote the concentration of each antibody that inhibited half of the shedding of S1.

The results in (B)–(E) are representative of those obtained in two independent experiments.

See also Figure S5.