TABLE 2.

List of SARS-CoV, SARS-CoV-2 spike protein, and hACE2 constructs used in the study

Construct name	Supplier	Expression organism	Tag
SARS-CoV-2 RBD-His	In-house	High Five insect cells	6× His tag
SARS-CoV-2 S1-S2-His monomer	In-house	High Five insect cells	6× His tag
SARS-CoV (2002) S1-S2-His trimer	In-house	High Five insect cells	6× His tag
SARS-CoV-2 S1-S2-His-T4 trimer	In-house	High Five insect cells	6× His tag, T4-foldon
SARS-CoV-2 B.1.1.7 S1-S2 -His-T4 trimer	In-house	High Five insect cells	6× His tag, T4-foldon
hACE2-fc dimer	In-house	HEK293-6E cells	IgG1-Fc
hACE2-His biotin dimer	Acrobiosystems, USA (Cat. No. AC2-H82E6)a	HEK293 cells	Biotinylated Avitag, 6× His

^aUniProt KB Q9BYF1.