Table 2.
Effects of superoxide dismutase on the pH effects on the steady-state kinetic parameters of the PaDADH E246L variant enzyme with D-arginine as substratea
|
kcat/Km | ||||
|---|---|---|---|---|
| Condition | CH | pKa | Slope | R2 |
| 25 oC | 665,000 ± 78,000 | 8.2 ± 0.1 | 1.5 ± 0.1 | 0.997 |
| 25 oC + superoxide dismutase | 263,000 ± 80,000 | 8.8 ± 0.2 | 1.1 ± 0.1 | 0.983 |
| 12 oC | 531,000 ± 64,000 | 8.5 ± 0.1 | 1.4 ± 0.1 | 0.997 |
a
Enzymatic activities were measured at varying concentrations of D-arginine and fixed 1 mM PMS. Reactions were carried out in 20 mM sodium pyrophosphate. The kcat/Km parameter values were obtained after fitting the kinetic data with Equation 3.