Table 2.
IC50 values (with the 95% confidence interval in parenthesis) of [Lys40(natIn-DTPA)]exendin-3, [Lys40(natIn-DTPA)]exendin-4 and [Lys40(natIn-DTPA)]exendin(9-39) determined in a competition binding assay in INS-1 cells. The dissociation constant (Kd) and the Bmax (with the 95% confidence interval in parenthesis) of [Lys40(111In-DTPA)]exendin-3, [Lys40(111In-DTPA)]exendin-4 and [Lys40(111In-DTPA)]exendin(9-39) determined by a binding saturation experiment in INS-1 cells.
Compound | IC50 (nM) | Kd (nM) | Bmax (receptors/cell) |
---|---|---|---|
[Lys40(DTPA)]exendin-3 | 13.5 (9.9 – 18.5) | 8.7 (7.6 – 10.1) | 26,000 (24 × 103 – 29 × 103) |
[Lys40(DTPA)]exendin-4 | 13.4 (10.5 – 17.0) | 17.6 (14.2 – 23.3) | 41,000 (35 × 103 – 50 × 103) |
[Lys40(DTPA)]exendin(9-39) | 14.4 (4.8 – 43.2) | 15.1 (6.9 – 80.7) | 37,000 (13 × 103 – 60 × 103) |