Fig. 3. Effect of spike binding on ACE2 dynamics.

a Regions of ACE2 manifesting a significant decrease in HDX upon spike binding are superimposed on the structure of ACE2 ectodomain bound to RBD (PDB: 2ajf), coloured in blue scale according to the magnitude of the HDX effect. The region coloured in red indicates increased HDX upon binding, in dark grey regions with no coverage. b ACE2 binding avidity. The cumulative difference in HDX (ΔHDX) between ACE2 alone and ACE2 bound to spikes and to the isolated ancestral RBD for selected peptides spanning binding sites and across time points 20 s on ice, 10 min at 23 °C and 360 min at 28 °C is plotted. A plot for all time points in Supplementary Fig. 28.