Table 3.
Activity of PTE variants with racemic VXa.
| Variant | kcat (s−1) | Km (mM) | kcat/Km (M−1s−1) | Stereochemical Preferenceb |
|---|---|---|---|---|
| WT | 0.9 ± 0.1 | 2.9 ± 0.9 | 3 ± 1 × 102 | 1:1 |
| QF | 16 ± 1 | 0.5 ± 0.1 | 3.0 ± 0.6 × 104 | 12:1 (SP) |
| CVQFL | 45 ± 6 | 2.1 ± 0.7 | 2.2 ± 0.8 × 104 | 1:1 |
| VRN-VQFL | 44 ± 1 | 0.59 ± 0.09 | 7 ± 1 × 104 | 3:1 |
| L7ep-1 | 11 ± 1 | 0.8 ± 0.2 | 1.4 ± 0.3 × 104 | ND |
| L7ep-2 | 25 ± 2 | 1.3 ± 0.3 | 2.2 ± 0.3 × 104 | 5:1 |
| L7ep-3 | 31 ± 2 | 0.5 ± 0.2 | 6 ± 2 × 104 | 4:1 |
| L7ep-2a | 56 ± 4 | 3.4 ± 0.7 | 1.6 ± 0.4 × 104 | 4:1 |
| L7ep-2b | 56 ± 14 | 8 ± 3 | 7 ± 4 × 103 | 12:1 (RP) |
| L7ep-3a | 137 ± 22 | 5 ± 2 | 3 ± 1 × 104 | 4:1 |
a
Standard errors from fits of the data to equation 1.
b
Identity of preferred enantiomer was not determined for variants with less than a 10-fold preference.