Table III.
Binding of BB ligands
| Addition | IC50, nM |
|---|---|
| BA1 | 1.1 ± 0.2 |
| BA2 | 21± 3 |
| BA3 | 15 ± 2 |
| BB | >2000 |
| BRS3 ant. | 750 ± 82 |
| BW2258U89 | >2000 |
| Gefitinib | >2000 |
| GRP | >2000 |
| NMB | >2000 |
| PD168368 | >2000 |
The ability of ligands to half maximally (IC50) inhibit specific 125I-BA1 binding to NCI-H1299-BRS-3 cells was determined at 37°C. The mean value ± S.E. of 4 determinations is shown.
The peptide structures are:
BB- Pyr-Gln-Arg-Leu-Gly-Asn-Leu-Trp-Ala-Val-Gly-His-Leu-Met-NH2
BA1- (DTyr6, βAla11, Phe13, Nle14)BB6-14
BA2- (DTyr6, R-Apa11, Phe13, Nle14)BB6-14
BA3- (DTyr6, R-Apa11, 4-Cl,Phe13, Nle14)BB6-14
BRS-3 ant. (DNal-Cys-Tyr-DTrp-Lys-Val-Cys-Nal)NH2.