Table 3.
Isothermal titration calorimetry data for P. aeruginosa RmlC with sugar nucleotides. The uncertainties are estimated from the fitting and underestimate the true error.
| Ka (× 103M) | ΔH (kJmol−1) | |
|---|---|---|
| dTDP-L-rhamnose | 11.6 ± 1.8 | −8.6 ± 0.9 |
| dTDPa | 13.2 ± 1.7 | −25 ± 2 |
| dTDP-xylose | 1.32 ± 0.05 | −11.8 ± 0.2 |
| dTDP-glucose | 0.96 ± 0.26 | −9.3 ± 6.2 |
The values for dTDP did vary depending on experiment and on the processing parameters. As is seen for dTDP-L-rhamnose (Fig 5) there is an endothermic event at the start of titration that we cannot interpret. If the endothermic points are omitted, N is set to 1 and the values recalculated the Ka drops to 4.5 × 103M. Our interpretation is that dTDP binds more tightly than dTDP-xylose/glucose, we do not think our data robust enough to compare dTDP and dTDP-L-rhamnose.