Table 1. Kinetic Parameters for S749 and Y317 SLO-1 Mutants Reported Here.
| enzyme | kcat(H)a (s–1) | Ea(H)b (kcal/mol) | Dkcatc | ΔEad (kcal/mol) |
|---|---|---|---|---|
| WTe | 359 (7) | 2.4 (0.2) | 57 (2) | 1.1 (0.1) |
| S749A | 289 (7) | 1.8 (0.2) | 59 (2) | 1.3 (0.2) |
| S749G | 296 (10) | 1.7 (0.2) | 63 (3) | 1.0 (0.1) |
| Y317S | 330 (8) | 2.3 (0.2) | 64 (2) | 1.2 (0.2) |
| Y317L | 368 (8) | 1.0 (0.1) | 68 (2) | 2.3 (0.2) |
| Y317F | 331 (10) | 2.5 (0.3) | 63 (2) | 0.2 (0.1) |
a
Parameters recorded at 30 °C. All kcat values have been corrected for iron content, determined by the ferrozine assay (see the Supporting Information for details).
b
Determined from kcat values across 7 to 8 (depending on mutant) temperatures (10–45 °C); see Table S7 for complete kcat data.
c
Dkcat is the kinetic isotope effect on kcat at 30 °C.
d
ΔEa = Ea(D) – Ea(H). This is the temperature dependence on the kinetic isotope effect.
e
The parameters reported for WT here are slightly different from previous reports (see Table S3) due to a modification in the protein purification procedure.