Table 1.
Binding and activation of cell signaling by CCK peptides
|
CCK-8 |
CCK-58
|
Bmax | |||
|---|---|---|---|---|---|
| Binding Kd, nM | Δ[Ca2+]i EC50, nM | Binding Ki, nM | Δ[Ca2+]i EC50, nM | ||
| rCCK1 | 1.1±0.1 | 0.23±0.1 | 5.4±0.4 | 1.2±0.1 | 4.2±0.2 |
| hCCK1 | 1.2±0.2 | 0.35±0.1 | 6.7±0.3 | 1.5±0.2 | 4.4±0.8 |
Receptor kinetic binding constants (Kd and Ki , nM) represent the means ± SE of data from 3 separate experiments. Maximum binding capacity (Bmax) values were calculated by Scatchard analysis of stably transfected cells and expressed as expressed as no. × 105 sites/cell. Concentrations of peptides stimulating half-maximal calcium responses (EC50, nM) were determined in duplicate from at least 2 separate experiments. rCCK1 and hCCK1, human and rat type 1 CCK, respectively; Δ[Ca2+]i, intracellular calcium increase.