Table 1. Calculated kinetic parameters for bacterial IspE orthologs.
| Source of IspE | Substrates |
Km (μM) |
Vmax (μmole/min) |
kcat (S-1) |
kcat/Km (S-1μM-1) |
|---|---|---|---|---|---|
| Wild type M. tuberculosis IspE | CDP-ME | 206.7 ± 12.5 | 2.4 | N.A. | N.A. |
| ATP | 20.7 ± 1.2 | 2.0 | N.A. | N.A. | |
| Rv1011 I (Δ301-305) | CDP-ME | 327.8 ± 21.4 | 2.8 | 480.1 | 1.5 |
| ATP | 75.2 ± 0.9 | 2.5 | 428.7 | 5.7 | |
| B. mallei IspE | CDP-ME | 31.3 ± 1.5 | 2.7 | 469.8 | 15.0 |
| ATP | 76.6 ± 1.1 | 2.4 | 417.6 | 5.5 | |
| S. Typhi IspE | CDP-ME | 25.4 ± 0.8 | 2.6 | 454.0 | 17.9 |
| ATP | 9.1 ± 0.2 | 2.1 | 366.7 | 40.2 | |
| V. cholerae IspE | CDP-ME | 52.9 ± 11.7 | 2.9 | 487.0 | 9.2 |
| ATP | 8.8 ± 1.3 | 2.1 | 352.7 | 40.1 |
The Km and Vmax values were calculated from averaged data from three independent experiments, using nonlinear regression analysis (SigmaPlot V.8.02A). In the reaction mixtures, 97.2 pmol of Rv1011 I, 95.5 pmol of B. mallei IspE, 99.2 pmol of S. Typhi IspE, and 95.8 pmol of V. cholerae IspE were used. N.A., not applicable.