Binding and functional parameters of WT/RAMP1 and mutant receptors Values are presented as mean ± S.E.M.; the number of determinations is shown in parentheses. Emax is the maximum response expressed as a percentage of the response to the WT receptor.
| Mutation | CGRP binding (pIC50) | Stimulation of cAMP | |||
|---|---|---|---|---|---|
| WT/RAMP1 pEC50 | Mutant/RAMP1 | ||||
| WT/RAMP1 | Mutant/RAMP1 | pEC50 | Emax | ||
| % | |||||
| P241A | 8.66 ± 0.20 (6) | 8.80 ± 0.13 (6) | 9.15 ± 0.37 (3) | 8.79 ± 0.54 (3) | 97 ± 7 (3) |
| P244A | 8.31 ± 0.37 (4) | 8.64 ± 0.36 (4) | 9.05 ± 0.16 (4) | 9.01 ± 0.2 (4) | 112 ± 7 (3) |
| P275A | 8.86 ± 0.31 (6) | 8.91 ± 0.17 (3) | 9.8 ± 0.18 (3) | 9.56 ± 0.37 (3) | 97 ± 2 (3) |
| P321A | 8.84 ± 0.31 (5) | 7.69 ± 0.21* | 9.18 ± 0.46 (3) | 6.86 ± 0.2 (3)** | 59 ± 12 (3) |
| P331A | 9.18 ± 0.33 (7) | 8.65 ± 0.24 (7)† | 9.57 ± 0.22 (4) | 8.54 ± 0.25 (4)* | 121 ± 11 (3) |