Table 1.

Antigenic Characterization of SARS-CoV-2 RBD-I53-50A Components

Antigen	Binder	kon (M–1 s–1)	koff (s–1)	KD (nM)
SARS-CoV-2 RBD	hACE2	7 × 104 ± 5 × 102	5 × 10−3 ± 1 × 10−5	69 ± 0.5
	CR3022 Fab	2 × 105 ± 2 × 103	9 × 10−3 ± 3 × 10−5	45 ± 0.5
RBD-8GS-I53-50A	hACE2	6 × 104 ± 4 × 102	4 × 10−3 ± 1 × 10−5	70 ± 0.5
	CR3022 Fab	2 × 105 ± 1 × 103	1 × 10−2 ± 3 × 10−5	57 ± 0.4
RBD-12GS-I53-50A	hACE2	6 × 104 ± 4 × 102	5 × 10−3 ± 1 × 10−5	78 ± 0.5
	CR3022 Fab	2 × 105 ± 2 × 103	9 × 10−3 ± 2 × 10−5	42 ± 0.4
RBD-16GS-I53-50A	hACE2	6 × 104 ± 4 × 102	4 × 10−2 ± 1 × 10−5	66 ± 0.4
	CR3022 Fab	2 × 105 ± 1 × 103	1 × 10−2 ± 2 × 10−5	56 ± 0.4

Each experiment was performed at least twice, and the values and fitting errors presented are derived from a representative experiment. The corresponding binding curves and fits are presented in Figure S2.