TABLE 1.
Kinetic values of spike protein constructs with hACE2a
| Analyte | Expt | Fitting method | ka1 [1/M s] | kd1 [1/s] | KD1 [nM] | ka2 [1/M s] | kd2 [1/s] | KD-total [nM] | R2/Chi2 [-]b |
|---|---|---|---|---|---|---|---|---|---|
| SARS-Cov-2 S1-S2 monomer | BLI (cropped) | 1:1 Langmuir | 1.1E + 5 | 2.4E-3 | 22 | 0.98 | |||
| SARS-Cov-2 S1-S2 monomer | BLI (full) | 1:1 Langmuir | 1.7E + 5 | 1.9E-3 | 11 | 0.96 | |||
| SARS-Cov-2 S1-S2 monomer | SPR (cropped) | 1:1 Langmuir | 1.7E + 5 | 4.7E-3 | 28.5 | 0.28 RU2 | |||
| SARS-Cov-2 S1-S2 monomer | SPR (full) | 1:1 Langmuir | 5.4E + 7 | 0.7 | 12.15 | 6.63 RU2 | |||
| SARS-CoV-2 RBD | SPR | 1:1 Langmuir | 4.25E + 5 | 9.1E-3 | 21.3 | 0.05 RU2 | |||
| SARS-Cov-2 S1-S2 monomer | SPR | Secondary state | 1.8E + 5 | 6.6E-3 | 37.5 | 8.3E-4 | 8.5E-5 | 0.2 | 0.08 RU2 |
| SARS-CoV-2 RBD | SPR | 1:1 Langmuir | 4.3E + 5 | 9.1E-3 | 21.3 | 0.05 RU2 | |||
| SARS-CoV (2002) S1-S2 trimer | SPR | Secondary state | 6.7E + 5 | 4.7E-3 | 6.7 | 8.8E-3 | 2.1E-4 | 0.16 | 0.06 RU2 |
| SARS-CoV-2 wt S1-S2 trimer | SPR | Secondary state | 7.8E + 5 | 1.4E-3 | 1.8 | 1.1E-2 | 2.4E-4 | 0.04 | 0.08 RU2 |
| SARS-CoV B.1.1.7 S1-S2 trimer | SPR | Secondary state | 1.31 E + 6 | 2.5 E-2 | 192.7 | 5.3E-2 | 1.1E-4 | 0.04 | 0.07 RU2 |
a
Measurements were performed using the immobilized hACE2 dimer as the ligand and spike protein constructs as analytes.
b
[-] means that RU2 and Chi2 values have no SI unit.