Kinetic parameters of 4-MU glucuronidation catalyzed by RLM pretreated either with Brij-58 or alamethicin: kinetics by varying the UDP-GlcUA concentration
RLM pretreated with Brij-58 (0.25 mg/mg protein) and alamethicin (0.05 mg/mg protein) were used as the enzyme source.
| Activator | Km | Vmax | Vmax/Km |
|---|---|---|---|
| μM | nmol · min−1 · mg protein−1 | ||
| Kinetics by varying 4-MUa | |||
| Brij-58 | 93.6 ± 0.3 | 26.3 ± 0.3 | 0.28 |
| Alamethicin | 163 ± 9 | 8.32 ± 0.15 | 0.05 |
| Kinetics by varying UDP-GlcUAb | |||
| Brij-58 | 348 ± 22 | 19.0 ± 0.3 | 0.05 |
| Alamethicin | 586 ± 49 | 4.73 ± 0.11 | 0.01 |
↵a 4-MU glucuronide formation was estimated at 10 concentrations of 4-MU (10–5000 μM). The concentration of UDP-GlcUA was set at 2 mM in this assay.
↵b 4-MU glucuronide formation was estimated at 10 concentrations of UDP-GlcUA (50–7500 μM). The concentration of 4-MU was set at 100 μM in this assay. Each value represents the optimized value ± S.E.