Table 2.
Average best fits of ITC experimental data for ligand → Cu+ titrations at 25 °Ca
| Ligand | Model | n 1 | ΔH1 kJ mol–1 (kcal mol–1) | K1 (×106) | ΔH2 kJ mol–1 (kcal mol–1) | K2 (×106) |
|---|---|---|---|---|---|---|
| 25 mM Tris pH 8.0 | ||||||
| BCS | One site | 2.11 ± 0.05 | –37 ± 1 (–8.84 ± 0.02) | 22 ± 2 | ||
| BCS | Sequential | — | –33 ± 1 (–7.9 ± 0.2) | 150 ± 60 | –42 ± 2 (–10.0 ± 0.5) | 40 ± 1 |
| GSH | One site | 1.03 ± 0.3 | –118.9 ± 0.7 (–28.4 ± 0.2) | 1.3 ± 0.1 | ||
| 25 mM HEPES pH 7.5 | ||||||
| GSH | One site | 0.99 ± 0.01 | –104 ± 4 (–24.9 ± 0.9) | 0.32 ± 0.08 | ||
| GSH | Sequential | — | –98 ± 2 (–23 ± 1) | 0.3 ± 0.2 | –6±20(–1 ± 5) | 0.001 ± 0.001 |
a
All data collected in 100 mM NaCl and 25 mM MeCN. Fit parameters represent the average of at least two independent titrations. Error is calculated by propagation of individual fits; see Experimental for explanation.