Table I.
Thermodynamic Parameters for IscU_wt as Obtained From the CD Data
| Tm (°C) | ΔHm (kcal/mol) | ΔCp (kcal/(mol K) | ΔSm (Kcal/mol K) | Ts (°C) | |
|---|---|---|---|---|---|
| As purified | 65.0 | 52.0 | 1.74 | 0.15 | 35 |
| Zn2+_free | 41.8 | 49.1 | 2.08 | 0.16 | 19 |
| Added Zn2+ | 72.6 | 69.6 | 1.59 | 0.20 | 29 |
| Zn2+/Salt free | 39.1 | 47.7 | 2.15 | 0.15 | 15 |
| Fe2+a | 67.5 | 53.8 | 1.70 | 0.16 | 35 |
| Fe3+a | 68.0 | 54.0 | 1.68 | 0.16 | 36 |
The midpoint of the thermal transition Tm and the temperature of maximal stability Ts are expressed in Celsius instead of Kelvin to make it easier to appreciate the values. The thermodynamic parameters were calculated as described in the Experimental Procedures.
a
The values refer to experiments in which 150 µM Fe(II or III) was added under anaerobic and aerobic conditions, respectively, to as purified IscU.