Table 1.
Binding properties and functional activities of CRF-family ligands
| Peptide | Binding* hCRF-R1 (Ki, nM) | Binding* rCRF-R2α (Ki, nM) | Binding* mCRF-R2β (Ki, nM) | cAMP† hCRF-R1 (EC50, nM) | cAMP† rCRF-R2α (EC50, nM) | cAMP† mCRF-R2β (EC50, nM) |
|---|---|---|---|---|---|---|
| Ucn (rat) | 0.32 (0.14–0.77) | 2.2 (0.91–5.4) | 0.62 (0.14–2.8) | 0.15 (0.03–0.64) | 0.063 (0.014–0.28) | 0.087 (0.017–0.43) |
| Ucn II (human) | >100 | 1.7 (0.73–4.1) | 0.50 (0.22–1.16) | >100 | 0.26 (0.11–0.61) | 0.42 (0.16–1.1) |
| Ucn II (mouse) | >100 | 2.1 (0.78–5.4) | 0.66 (0.13–3.3) | >100 | 0.14 (0.04–0.43) | 0.05 (0.02–0.12) |
| Ucn III (human) | >100 | 21.7 (8.2–57) | 13.5 (9.2–19.7) | >100 | 0.16 (0.09–0.28) | 0.12 (0.06–0.20) |
| Ucn III (mouse) | >100 | 5.0 (4.0–6.3) | 1.8 (0.77–4.1) | >100 | 0.073 (0.052–0.10) | 0.081 (0.08–0.80) |
The values were determined from three to six independent experiments using stably transfected Chinese hamster ovary cells (†) or their membranes (*) for each test peptide. EC50 and Ki values were determined by using prism software. Their log10 values were averaged (γ). The average EC50 or Ki was taken to be 10γ. The standard deviation of the log10 values was calculated (δ). The ranges given were taken to be [(10γ)10δ or 10γ/10δ]. Ucn, urocortin.