Table 3.

Standard Gibbs energies, Δ_BG⁰(25 °C), enthalpies, Δ_BH⁰(25 °C), and entropies, Δ_BS⁰(25 °C), of binding at 25 °C of spike protein to the ACE2 receptor, for various SARS-CoV-2 strains. Enthalpies of binding were calculated using the Van ‘t Hoff equation (19) from the experimental K_B data (Table 1). Δ_BG⁰(25 °C) values were calculated from K_B values in Table 1, using equation (18). Δ_BH⁰(25 °C) and Δ_BG⁰(25 °C) values were combined to find Δ_BS⁰(25 °C) values, using equation (20). The “Reference” column contains sources from which the K_B data were taken to find Δ_BG⁰(25 °C) values. All the data are at 25 °C.

Mutation	Reference	ΔBG⁰(25 °C) (kJ/mol)	ΔBH⁰(25 °C) (kJ/mol)	ΔBS⁰(25 °C) (J/mol K)
Wild type (Hu-1)	Laffeber et al., 2021	−44.35	−73.31	−97.16
Wild type (Hu-1)	Augusto et al. (2021)	−43.79	−73.31	−99.04
E484K	Laffeber et al., 2021	−45.01	−73.31	−94.93
E484K	Augusto et al. (2021)	−43.98	−73.31	−98.39
N501Y	Laffeber et al., 2021	−49.20	−51.07	−6.29
E484K/N501Y	Laffeber et al., 2021	−50.54	−59.86	−31.26
K417 N/E484K/N501Y	Laffeber et al., 2021	−47.01	−67.66	−69.26
K417 N	Laffeber et al., 2021	−40.67	−94.70	−181.22