Table 1. Compounds selected for soaking into NK1 apo crystals. Piperazine-like compounds with a sulphonic acid group and their binding constants obtained using SPR and NMR.
| Piperazine-like compounds | Structure | K D in SPR a [mM] | K D in NMR a [mM] |
| HEPES |
|
2.4 ± 0.4 | 3.3 ± 0.4 |
| (H)EPPS |
|
7.0 ± 1.0 | 4.4 ± 1.8 |
| PIPES |
|
26.6 ± 0.6 | 45.9 ± 4.7 |
| MES |
|
24.3 ± 3.1 | 13.4 ± 5.7 |
| MOPS |
|
7.0 ± 1.0 | 4.7 ± 1.7 |
| CHES |
|
30.2 ± 3.1 | 15.7 ± 4.5 |
| CAPS |
|
1.2 ± 0.2 | 1.4 ± 0.5 |
aSteady-state binding constants.