TABLE 2.
Binding parameters of CCK2 receptor-based chimeric constructs expressed in CHO cells
| CCK2R-based chimeric receptors | Receptor abbreviations | 125I-BDZ-2 vs GI181771X Ki | 125I-BDZ-2 vs GI181771X Bmax | 125I-BDZ-1 vs GI181771X Ki | 125I-BDZ-1 vs GI181771X Bmax |
|---|---|---|---|---|---|
| nm | pmol/mg protein | nm | pmol/mg protein | ||
| CCK2R WT | CCK2R | 5.1 ± 1.6 | 6 ± 2 | NDBa | NDB |
| T2.61N | CCK2R TM2 | NDB | NDB | NDB | NDB |
| V3.28T, S3.29T | CCK2R TM3 | 15.4 ± 4.3b | 5 ± 1 | NDB | NDB |
| V6.51I, Y6.52F | CCK2R TM6 | 4.6 ± 2.5 | 16 ± 7 | NDB | NDB |
| H7.39L | CCK2R TM7 | 51.5 ± 21.2b | 4 ± 1 | NDB | NDB |
| T2.61N, V3.28T, S3.29T | CCK2R TM (2,3) | NDB | NDB | NDB | NDB |
| T2.61N, V6.51I, Y6.52F | CCK2R TM (2,6) | NDB | NDB | NDB | NDB |
| T2.61N, H7.39L | CCK2R TM (2,7) | 71.4 ± 29.2b | 3 ± 1 | NDB | NDB |
| V3.28T, S3.29T, V6.51I, Y6.52F | CCK2R TM (3,6) | 11.7 ± 3.6 | 5 ± 1 | NDB | NDB |
| V3.28T, S3.29T, H7.39L | CCK2R TM (3,7) | 12.9 ± 6.6 | 4 ± 2 | 8.0 ± 3.3c | 53 ± 13 |
| V6.51I, Y6.52F, H7.39L | CCK2R TM (6,7) | NDB | NDB | 47.4 ± 12.9c | 113 ± 47 |
| T2.61N, V3.28T, S3.29T, V6.51I, Y6.52F | CCK2R TM (2,3,6) | NDB | NDB | NDB | NDB |
| T2.61N, V3.28T, S3.29T, H7.39L | CCK2R TM (2,3,7) | NDB | NDB | NDB | NDB |
| T2.61N, V6.51I, Y6.52F, H7.39L | CCK2R TM (2,6,7) | NDB | NDB | NDB | NDB |
| V3.28T, S3.29T, V6.51I, Y6.52F, H7.39L | CCK2R TM (3,6,7) | NDB | NDB | 150.3 ± 17.8 | 42 ± 10 |
| T2.61N, V3.28T, S3.29T, V6.51I, Y6.52F, H7.39L | CCK2R TM (2,3,6,7) | NDB | NDB | NDB | NDB |
| CCK1R WT | CCK1R | 104.7 ± 19.6 | 41 ± 7 |
a NDB, no detectable binding.
b p < 0.05 compared to values for wild-type CCK2R.
c p < 0.05 compared to values for wild-type CCK1R.