Table 1.
Kinetic and structural parameters obtained from the fit of 17O NMR and NMR dispersion (NMRD) data for the Gd2L1 complex in the absence and in the presence of Ca2+, compared with those of gadolinium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (GdDOTA)
| Parameters | Gd2L1 17O NMR + NMRD |
Gd2L1 + Ca2+ 17O NMR |
GdDOTA 17O NMR + NMRDa |
|---|---|---|---|
| k298ex (106 s−1) | 2.4 ± 0.2 | 7.5 ± 1.6 | 4.1 |
| ΔH‡ (kJ mol−1) | 43.6 ± 3.3 | 43.6 | 49.8 |
| ΔS‡ (J mol−1 K−1) | +23.5 | +33.0 | – |
| τ298RO (ps) | 350 ± 50 | 1,150 ± 250 | 77 |
| Er (kJ mol−1) | 24 ± 1 | 21 ± 6 | 16.1 |
| τ298v (ps) | 20.6 ± 2.7 | 0.13 ± 0.02 | 11 |
| Δ2 (1020 s−2) | 0.46 ± 0.10 | 0.50 ± 0.05 | 0.16 |
| q | 0.4 | 0.7 | 1 |
| q2 ns | 1 | 1 | – |
| r2981 (mM−1 s−1) 20 MHz | 5.74 | 6.13 | 4.74 |
Parameters in italics were fixed during the fitting
aReference [49]