Table 4.
Competition-binding parameters of BODIPY®-labelled and native peptides of the NPY family in various NPY Y5-like receptor assays
| Y5 HEK293-transfected cells | Rat brain | |
|---|---|---|
| Competitors | Ki (nM) | Ki (nM) |
| NPY | 1.3±0.4 (3)a | 4.0±1.9 (5) |
| BODIPY®TMR-NPY | 2.0±0.8 (3) | 2.9±1.5 (4) |
| [Leu31, Pro34]NPY | 5.2±0.3 (3) | 7.7±2.8 (5) |
| BODIPY®TMR-[Leu31, Pro34]NPY | 1.3±0.4 (3)* | 2.7±0.3 (4) |
| [Leu31, Pro34]PYY | 3.2±0.8 (3) | 3.5±0.9 (5) |
| BODIPY®FL-[Leu31, Pro34]PYY | 3.0±0.7 (3) | 4.0±1.0 (4) |
| PYY(3–36) | 25±6 (3) | 14±2 (5) |
| BODIPY®FL-PYY(3–36) | 30±5 (3) | 12.0±1.0 (4) |
| hPP | 1.6±0.4 (3) | 2.0±0.7 (5) |
| BODIPY®FL-hPP | 15±3 (3)* | 26±10 (4)* |
| [hPP(1–17), Ala31, Aib32]NPY | 0.6±0.2 (3) | 0.7±0.2 (5) |
| BODIPY®TMR-[hPP(1–17), Ala31, Aib32]NPY | 0.4±0.1 (3) | 0.6±0.1 (4) |
| [cPP(1–7), NPY(19–23), Ala31, Aib32, Gln34]hPP | 0.1±0.04 (3) | 0.15±0.03 (5) |
| BODIPY®TMR-[cPP(1–7), NPY(19–23), Ala31, Aib32, Gln34]hPP | 0.1±0.03 (3) | 0.2±0.1 (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][Leu31, Pro34]PYY in the presence of BIBO3304 in order to mask Y1 receptors.
*
P<0.05, fluorescent vs nonfluorescent peptide.