TABLE 7.
Ki, IC50, and dose ratio values for antagonist binding to strains expressing truncated Ste2p
| STE2 allele | Ligand type | Ki (for binding) | IC50 (for binding) | EC50 | Expected dose ratioa | Measured dose ratiob | Expected/observed dose ratio |
|---|---|---|---|---|---|---|---|
| nm | nm | nm | |||||
| CEN-STE2 (Δ305–431) (A4649) | Agonist | 0.7 ± 0.2 | |||||
| +5 μm d-Tyr3 | 9 ± 0.6 | 21 ± 1 | 3.5 ± 0.5 | 565 ± 40 | 6 ± 2 | 101 | |
| + 5 μm dTA | 8 ± 4 | 18 ± 8 | 1.1 ± 0.3 | 664 ± 306 | 2 ± 0.7 | 373 | |
| +5 μm dTH | 13 ± 2 | 30 ± 6 | 2.6 ± 0.6 | 391 ± 74 | 4 ± 1.8 | 95 | |
| Multicopy STE2 (Δ305–431) (A4651) | Agonist | 1.3 ± 0.3 | |||||
| +5 μm d-Tyr3 | 22 ± 11 | 42 ± 21 | 4 ± 0.8 | 237 ± 122 | 3 ± 1 | 78 | |
| +5 μm dTA | 31 ± 7 | 60 ± 13 | 5 ± 1 | 163 ± 36 | 4 ± 1 | 47 | |
| +5 μm dTH | 28 ± 3 | 53 ± 4 | 7 ± 1 | 183 ± 18 | 5 ± 1 | 35 |
a The expected dose ratio = DRbind = 1 + [antagonist]/Ki.
b The measured dose ratio = DRsig = EC50 in the presence of antagonist/EC50 in the absence of antagonist.