Table 1.
SSNMR determined pKa values for nanocrystalline GB1 compared to values determined by solution NMR experiments and calculations from X-ray structure.
| 13C SSNMR | Hill coefficient (nH) | 1H NMR8 | Calculated (1PGB)41 | 13C NMR QQD-GB127 | 13C NMR QQD-GB1 (0.5 M salt)27 | |
|---|---|---|---|---|---|---|
| E15 | < 4.0 | 4.4 | 5.0 | 4.6 | 4.7 | |
| E19 | < 4.0 | 3.7 | 4.1 | 3.9 | 4.0 | |
| D22 | < 3.6 | 2.9 | 2.3 | 3.0 | 3.2 | |
| E27 | 4.1 ± 0.1 | 3.8 ± 0.6 | 4.5 | 4.9 | 4.8 | 4.9 |
| D36 | 4.3 ± 0.1 | 4.5 ± 0.7 | 3.8 | 4.9 | 4.2 | 4.1 |
| D40 | N.D. | 4.0 | 4.4 | 4.1 | 4.1 | |
| E42 | 4.2 ± 0.2 | 3.1 ± 0.6 | 4.4 | 4.0 | 4.9 | 4.6 |
| D46 | < 3.6 | 3.6 | 3.8 | 3.8 | 3.9 | |
| D47 | < 3.6 | 3.4 | 3.3 | 3.1 | 3.4 | |
| E56 | < 3.6 | 4.0 | 3.7 | 3.8 | 3.9 | |
| C terminus | < 3.6 | 3.1 | 3.2 |