Table 3.
Competition-binding parameters of BODIPY®-labelled and native peptides of the NPY family in various NPY Y4 receptor assays
| Y4 HEK293-transfected cells | Rat brain [125I]hPP | |
|---|---|---|
| Competitors | Ki (nM) | Ki (nM) |
| NPY | 140±30 (3)a | 10.0±1.5 (5) |
| BODIPY®TMR-NPY | 875±180 (3)* | 56.0±12.0 (4)* |
| [Leu31, Pro34]PYY | 5.0±1 (3) | 2.0±0.6 (5) |
| BODIPY®FL-[Leu31, Pro34]PYY | 10±3 (3) | 1.0±0.4 (4) |
| PYY(3–36) | 350±120 (3) | 2.0±0.5 (5) |
| BODIPY®FL-PYY(3–36) | >1000 (3) | 2.0±0.3 (4) |
| hPP | 5.0±1 (3) | 0.6±0.2 (5) |
| BODIPY®FL-hPP | 10±3 (3) | 3.0±0.6 (4)* |
Data are the mean±s.e.m. of three to five determinations, each performed in triplicate.
a
Number in parenthesis represents the number of determinations. Ki represents the concentration of competitor needed to inhibit 50% specifically bound [125I]hPP.
*
P<0.05, fluorescent vs nonfluorescent peptide.