TABLE 1.
Steady-state kinetic parameters of BphK for chlorinated HOPDAs and GSHa
| HOPDA | Km GSH (μM) | Km ClH (μM) | kcat (s−1) | kcat/Km ClH (103 M−1 s−1) | kcat/Km GSH (103 M−1 s−1) |
|---|---|---|---|---|---|
| 3-Cl | 110 (20) | 17 (5) | 0.16 (0.008) | 10 (2) | 1.5 (0.3) |
| 5-Cl | 370 (190) | 110 (40) | 0.24 (0.06) | 2 (1) | 0.6 (0.3) |
| 3,9,11-triCl | 390 (120) | 10 (3) | 0.010 (0.001) | 1.0 (0.2) | 0.03 (0.01) |
a
Values in parentheses represent standard errors. The kinetic parameters for 5-Cl HOPDA have higher standard errors as the enzyme could not be saturated with its substrates. Experiments were performed using potassium phosphate, pH 6.5 (I = 0.05 M), at 25°C.