Ligand binding studies for the single proline-to-alanine mutations
| Iloprost | Carbacyclin | PGE1 | Expression | |
|---|---|---|---|---|
| nM | nM | nM | pmol/mg protein | |
| hIP1D4PMT4 (WT) | 7 ± 3 | 121 ± 51 | 301 ± 90 | 2.1 ± 0.5 |
| P17A (I) | 52 ± 10 | 270 ± 52 | 896 ± 173 | 1.7 ± 0.3 |
| P69A (II) | 22 ± 6 | 128 ± 31 | 139 ± 28 | 0.9 ± 0.2 |
| P89A (III) | 3 ± 2 | 56 ± 22 | 149 ± 109 | 0.7 ± 0.4 |
| P141A (IV) | 14 ± 3 | 233 ± 56 | 697 ± 207 | 4.8 ± 2.7 |
| P154A (IV) | >5001-160 | N.D. | N.D. | 0.4 ± 0.1 |
| P179A (V) | 87 ± 91-150 | 660 ± 811-150 | 880 ± 83 | 1.0 ± 0.3 |
| P254A (VI) | >5001-160 | N.D. | N.D. | 0.4 ± 0.2 |
| P285A (VII) | 31 ± 5 | 243 ± 44 | 794 ± 161 | 4.2 ± 0.6 |
| P289A (VII) | 4 ± 1 | 354 ± 154 | 545 ± 307 | 0.8 ± 0.2 |
Shown are K i values (mean ± S.E.) from at least three separate experiments (duplicates of 12 different concentrations). Receptor expression was determined by saturation binding from membranes prepared from COS-1 cells transfected with 20 μg of DNA per plate.