Affinity of STa Analogs for GC-C
| Compound | Ki (nmol/L) | No. of observations | Comments |
|---|---|---|---|
| STa (1–17) | 0.7 ± 0.2 | 6 | Native GC-C ligand |
| STa (5–18) | 0.4 ± 0.1 | 20 | Selected core vector |
| NC100586 | 0.8 ± 0.2 | 4 | EOE-N3S-adipate STa (5–18) |
| NC100588 | Below detection | 3 | Negative control; no specific binding up to 500 μmol/L |
Ki values are mean ± SEM and represent concentration of peptide required to displace 50% of radiolabeled STa as defined by competitive binding analysis (32). Nonspecific binding accounted for <0.1% in all cases, and total binding (no competing peptide) was not >20% in any case.