Table 1. Kinetic Parameters of HEPD and Its Variants.
| HEPD | kcat (s–1) | Km,2-HEP (μM) | kcat/Km,2-HEP (M–1 s–1) | Km,O2 (μM) | kcat/Km,O2 (M–1s–1) |
|---|---|---|---|---|---|
| wild type | 0.35 ± 0.01 | 9.8 ± 1 | (3.6 ± 0.3) × 104 | 33 ± 1 | (11 ± 0.02) × 103 |
| R90A | N/Ab | 690 ± 140a | N/Ab | N/Ab | 100 ± 1 |
| R90K | 0.81 ± 0.01c | 60 ± 6 | (1.3 ± 0.1) × 104 | 100 ± 1 | (8.1 ± 0.04) × 103 |
| K16A | inactive | inactive | inactive | inactive | inactive |
| Y98F | N/Ab | 800 ± 110a | N/Ab | N/Ab | 740 ± 30 |
a
Apparent Km value.
b
Could not be obtained as these mutants could not be saturated in O2 (see the text).
c
See Figure S1C.