Table 1.

Apparent thermodynamic parameters of binding of the HR2 peptides to CoVS-HR1 proteins measured by ITC at 25 °C. The parameters correspond to the best fittings of the binding isotherms using a binding model of n identical and independent sites.

Protein	Peptide	Kd (μM)	ΔHb (kJ·mol−1)	n
CoVS-HR1-L1	V39E (a)	1.03 ± 0.24 (c)	−33.5 ± 2.3	0.74
CoVS-HR1-L2	V39E	0.13 ± 0.04	−43.6 ± 1.8	0.66
CoVS-HR1-L1	V27E (b)	4.1 ± 0.7	−37 ± 8	0.25
CoVS-HR1-N	V27E	28 ± 3	−7.7 ± 0.6	0.5 (d)

^(a) HR2-derived peptide V39E encompassing residues Val1164-Glu1202. ^(b) HR2-derived peptide V27E encompassing residues Val1176-Glu1202. ^(c) Uncertainties in the parameters correspond to 95% confidence intervals of the parameters. ^(d) Parameter fixed in the fittings.