Table 2.

Kinetic parameters of immunogens for binding to different S2-specific ligands in PBS pH 7.4 at 25 °C.

Ligand	Parameter	Immunogens
		RS2	S2R	Spike	S2
B6	ka (M−1s−1)	2.53 ± 0.05 × 105	1.24 ± 0.01 × 105	3.16 ± 0.07 × 104	2.04 ± 0.07 × 105
	kd (s−1)	7.32 ± 0.36 × 10−4	1.53 ± 0.8 × 10−3	3.48 ± 0.25 × 10−5	2.50 ± 0.25 × 10−4
	KD(M)	2.30 ± 0.12 × 10−9	1.24 ± 0.12 × 10−8	1.12 ± 0.08 × 10−9	1.22 ± 0.08 × 10−9
CC40.8	ka (M−1s−1)	1.62 ± 0.01 × 105	1.62 ± 0.02 × 105	1.19 ± 0.02 × 105	9.11 × 104
	kd (s−1)	6.77 ± 0.01 × 10−4	5.30 ± 1.6 × 10−4	ND	ND
	KD (M)	4.22 ± 0.08 × 10−9	3.23 ± 0.03 × 10−9	ND	ND

ND No dissociation.