Figure 2.

Structural aspects obtained by molecular dynamics simulations of different SARS-CoV-2 RBD variants while interacting with hACE2. Backbone RMSD probability distributions are shown for (a) hACE2 and (b) RBD. Backbone RMSF are shown for (c) hACE2 and (d) RBD. The Panels (e–g) show different conformational changes of each RBD^variant/hACE2 complex in relation to the RBD^WT/hACE2 complex. Note that the main structural differences are localized in the loop 474–488 caused by the N501Y mutation in RBD^B.1.1.7 (e) that is partially recovered in RBD^P.1 (f) and RBD^B.1.351 (g). Residues 469−490 are colored in red in the RBD^WT/hACE2 complex. The structure models of RBD^WT/hACE2, RBD^B.1.1.7/hACE2, RBD^P.1/hACE2 and RBD^B.1.351/hACE2 were taken from a snapshot at 40 ns, 19 ns, 61 ns, and 42 ns, respectively, from each MD simulation trajectory. We observed in another independent calculation simulated for 300 ns for hACE2 in complex with RBD^WT, RBD^B.1.1.7, and RBD^P.1, showing the same structural behavior (Figures S15–S17).