Table 2.

The HDOCK energy score, ligand RMSD (Å), binding affinity (ΔG) and dissociation constant (Kd) predicted values of Delta-hACE2, Omicron BA.1-hACE2 and Omicron BA.2-hACE2 protein–protein complex.

	Protein–Protein Complex of SARS-CoV-2 RBDs and hACE2
Parameters	Delta-hACE2	Omicron BA.1-hACE2	Omicron BA.2-hACE2
Docking energy score	−339.88	−360.96	−369.70
Ligand RMSD (Å)	0.39	0.50	0.47
ΔG (kcal/mol)	−12.5	−11.1	−12.6
Kd (M) at 37.0 ℃	1.5 × 10−9	1.5 × 10−8	1.4 × 10−9