TABLE 5.
Enzyme activity and pomotrelvir susceptibility of mutant Mpro proteins containing nirmatrelvir resistance substitutions
| a Enzyme | K m (μM) | K cat (s-1) | k cat/K m × 106 (M-1 s-1) | b PBI-0451 | b GC376 | ||
|---|---|---|---|---|---|---|---|
| Mean IC50 (μM) | Mean fold | IC50 (μM) | Fold | ||||
| WT | 14 | 41 | 3 | 0.026 | – | 0.02 | – |
| A173V + T304I | 11 | 13 | 1.2 | 0.16 | 6.7 | 0.10 | 5.5 |
| A260V | 8 | 48 | 6 | 0.024 | 0.9 | 0.02 | 1.0 |
| D248E | 9 | 37 | 4.3 | 0.025 | 1 | 0.03 | 1.3 |
| E166A | 13 | 2.7 | 0.2 | 0.95 | 36 | 0.32 | 14 |
| E166V | 15 | 4.8 | 0.3 | 1.2 | 51 | 0.66 | 35 |
| F140A | 12 | 24 | 2 | 0.37 | 14 | 0.15 | 6.8 |
| F140L + A173V | 11 | 41 | 3.9 | 0.23 | 10 | 0.14 | 7.5 |
| G15S | 9 | 29 | 3.2 | 0.027 | 1 | 0.02 | 0.9 |
| H164N | 10 | 26 | 2.7 | 0.064 | 2.4 | 0.08 | 3.5 |
| H172Y | 25 | 4.5 | 0.2 | 1.94 | 71 | 0.41 | 18 |
| H172Y + P252L | 12 | 9.8 | 0.8 | 1.5 | 62 | 0.28 | 15 |
| K90R | 11 | 33 | 2.9 | 0.023 | 0.9 | 0.01 | 0.6 |
| L167F | 11 | 5.5 | 0.5 | 0.34 | 13 | 0.13 | 5.6 |
| L50F | 7 | 64 | 8.6 | 0.03 | 1.1 | 0.02 | 1.1 |
| L50F + A173V | 7 | 28 | 4.1 | 0.082 | 3.5 | 0.06 | 3.4 |
| L50F + E166A | 21 | 10 | 0.5 | 0.87 | 35 | 0.27 | 12 |
| L50F + E166A + L167F | 14 | 5.4 | 0.4 | 5.0 | 188 | 0.76 | 34 |
| L50F + E166V | 19 | 6.9 | 0.4 | 1.0 | 45 | 0.43 | 23 |
| L50F + F140L + L167F + T304I | 14 | 26 | 1.9 | 0.9 | 40 | 0.17 | 8.9 |
| L50F + T304I | 14 | 120 | 8.5 | 0.065 | 2.8 | 0.06 | 3.3 |
| Q189K | 13 | 14 | 1.1 | 0.071 | 2.7 | 0.05 | 2.1 |
| S144A | 9 | 26 | 2.9 | 0.18 | 6.7 | 0.12 | 5.2 |
| T135I | 12 | 51 | 4.3 | 0.047 | 1.8 | 0.02 | 0.8 |
| T135I + T304I | 7 | 44 | 6 | 0.087 | 3.7 | 0.07 | 3.8 |
| T21I | 10 | 82 | 8 | 0.027 | 1.0 | 0.02 | 1.0 |
| T21I + A173V | 8 | 37 | 4.7 | 0.11 | 4.7 | 0.08 | 4.2 |
| T21I + A173V + T304I | 15 | 35 | 2.3 | 0.14 | 6.1 | 0.09 | 5.0 |
| T21I + C160F + A173V+ V186A + T304I |
14 | 38 | 2.7 | 0.13 | 5.7 | 0.09 | 4.9 |
| T21I + E166V | 13 | 2.7 | 0.2 | 1.24 | 55 | 0.59 | 31 |
| T21I + L50F | 7 | 80 | 12.2 | 0.021 | 0.8 | 0.02 | 0.9 |
| T21I + L50F + A193P + S301P | 7 | 25 | 3.4 | 0.11 | 4.9 | 0.07 | 3.6 |
| T21I + S144A | 15 | 55 | 3.7 | 0.31 | 13 | 0.12 | 6.4 |
| T21I + S144A + T304I | 11 | 13 | 1.3 | 0.52 | 23 | 0.19 | 10 |
| T21I + T304I | 9 | 75 | 8.4 | 0.071 | 3.1 | 0.05 | 2.6 |
| Y54A | 11 | 2.3 | 0.2 | 0.15 | 5.6 | 0.16 | 7.0 |
a
Mutant enzymes are listed in alphabetic order.
b
IC50s of PBI-0451 are mean from n = 9 experiments for WT, n = 3 for mutant Mpro proteins; for GC376, only n = 1 experiment was performed (except for the WT enzyme, showing mean IC50 from n = 2 experiments).