FIGURE 4.

Exploratory data. Test for selectivity among class B1 GPCRs (exploratory data). (a) Phylogenetic tree of the class B1 subfamily GPCRs consisting of the GLP‐2 receptor (R) and 14 sequence related GPCRs (modified from Gasbjerg et al., 2018). (b) Heterologous binding of [¹²⁵I]‐hGLP‐2(1–33,M10Y) (black) and [¹²⁵I]‐hGLP‐2(3–33,M10Y) (red) to the hGLP‐1 receptor (n = 3), hGIP receptor (n = 2), hglucagon receptor (n = 2), hSecretin receptor (n = 2), VPAC₁ receptor (n = 2) and VPAC₂ receptor (n = 2) displaced by increased concentrations of hGLP‐2(1–33). (c) Homologous competition binding of [¹²⁵I]‐GLP‐1(7–36) to the hGLP‐2 receptor (n = 3) and hGLP‐1 receptor (positive control) (n = 3) displaced by increasing concentration of GLP‐1(7–36). To compensate for inter‐assay variations, data were normalized to the specific binding of (b) hGLP‐2 receptor or (c) hGLP‐1 recepetor for each individual radioligand within each assay