Table 4.

Mapping of anti-RBD mAb epitopes with RBD mutants by ELISA^a

Group	MAb	Deletion of residues		Single-point mutation
		318–326	491–510	K390A	D429A	R441A	E452A	D454A	D463A
New mAbs
A	S6	0.00	0.02	2.33	0.04	0.02	0.03	0.01	0.35
	S9	0.00	0.04	2.27	0.06	0.06	0.68	0.01	0.39
	S37	0.00	0.03	2.39	0.06	0.05	0.06	0.02	0.40
	S40	0.00	0.06	2.62	0.14	0.02	0.94	0.01	1.08
	S50	0.00	0.02	2.30	0.05	0.01	0.04	0.01	0.40
B	S20	0.00	0.05	2.43	0.02	0.04	1.34	0.01	1.41
	S38	0.00	0.04	2.32	0.02	0.04	1.44	0.01	1.24
	S53	0.00	0.00	2.13	0.01	0.02	0.21	0.01	0.04
C	S44	0.02	0.18	2.71	0.19	0.04	1.99	0.06	2.38
D	S25	1.68	2.06	2.43	1.27	0.96	3.00	2.24	1.23
E	S29	2.12	2.57	1.79	1.87	2.23	2.93	0.02	3.34
	S33	1.48	2.19	1.96	1.18	1.05	2.59	1.73	1.30
Control mAbs
Conf I	10E 7	0.00	0.11	2.39	0.19	0.01	1.44	0.03	1.71
	12B11	0.00	0.03	2.40	0.09	0.03	0.19	0.00	0.45
Conf II	20E 7	−0.01	0.02	2.36	0.12	0.02	0.65	0.00	1.24
	26A4	0.00	0.02	2.42	0.14	0.02	0.65	0.00	1.08
Conf III	11E 12	0.00	0.01	2.05	0.01	0.02	0.25	0.01	0.05
	18D9	0.00	0.01	2.18	0.01	0.02	0.39	0.00	0.44
Conf IV	28D6	0.00	0.07	2.37	0.07	0.02	1.69	0.00	1.49
	30F9	0.00	0.06	2.43	0.05	0.02	1.59	0.00	1.37
Conf V	24F4	1.22	1.73	2.75	1.45	0.73	2.59	1.95	0.86
	33G4	1.56	2.03	2.50	1.71	1.05	2.56	2.06	2.02
	38D4	1.06	1.27	2.49	0.77	0.50	2.41	1.30	0.77
Conf VI	13B6	−0.01	0.00	2.32	0.15	0.02	1.40	0.00	1.28
	19B2	−0.01	0.04	2.36	0.00	0.01	1.15	0.00	0.86
Linear	4D5	2.20	2.70	1.75	0.89	0.83	3.03	2.44	0.82
	17H9	3.62	2.95	2.63	2.78	3.59	3.23	0.19	4.18

^aAntigens were coated to ELISA plates at 1 μg/ml and mAbs were tested at 10 μg/ml. OD450 value >0.2 was considered as positive reaction and highlighted in boldface.