Table 3.
Changes in heat capacity and solvent-accessible surface area for eIF5B binding to GDP and GTP
| Construct | Ligand | ΔCp (cal/mol·K) | ΔASAmin (Å2) | ΔASAmax (Å2) | ΔASAcalc (Å2) |
|---|---|---|---|---|---|
| Ct-eIF5B(517C) | GDP+Mg | −140 ± 23 | −311 | −583 | −400 |
| GDP-Mg | −102 ± 5 | −227 | −425 | ||
| GTP+Mg | −155 ± 8 | −344 | −646 | ||
| Ct-eIF5B(517–858) | GTP+Mg | −553 ± 11 | −1229 | −2304 | −1800 |
ΔCp, heat capacity change; obtained from ΔH/dT.
ΔASAmin and ΔASAmax, changes in solvent-accessible surface areas assuming that all changes were conferred by either apolar or 70% apolar and 30% polar surfaces, respectively.
Calculated for 30°C from the first derivative of the second-order polynomial fit to ΔH measured at five different temperatures between 10 and 30°C.
Obtained from the slope of the linear fit to ΔH measured at different temperatures between 5 and 30°C.
Calculated from the crystal structures of GDP- and GTP-bound eIF5B relative to the apo state.