TABLE 2.
Kinetic parameters for E. faecalis HMG-CoA reductase
| Reaction and substrate | Optimal pH | Vmax (eu/mg) | Km (μM) | Km values (μM) from literaturea |
|---|---|---|---|---|
| HMG-CoA→mevalonate (reaction 3) | 6.5 | 2.0 | ||
| HMG-CoA | 20 | 20-40 | ||
| NADPH | 30 | 80-160b | ||
| Mevaldehyde→mevalonate (reaction 4) | 7.0 | 13 | ||
| Mevaldehyde | 3,800 | 600-8,000 | ||
| NADPH | 250 | 30-1,800b | ||
| Mevaldehyde→HMG-CoA (reaction 5) | 8.0 | 2.4 | ||
| Mevaldehyde | 660 | 100-600 | ||
| CoASH | 220 | 20-500 | ||
| NADP+ | 670 | 40-900b | ||
| Mevalonate→HMG-CoA (reaction 6) | 9.3 | 1.2 | ||
| Mevalonate | 1,000 | 20-1,200 | ||
| CoASH | 230 | 10-1,700 | ||
| NADP+ | 250 | 90-580b |
a
The ranges of reported Km values for HMG-CoA reductases from different sources are given.
b
For either NADP(H) or NAD(H).