Fig. 5: Binding of NPY N-terminus to Y₁R.

a The sticks show the residues participating in van der Waals interactions between NPY helix and ECL2 of Y₁R. Unresolved regions of NPY and ECL2 of Y₁R are shown with dashed lines. b The results of Ca²⁺ assays performed with N-terminally truncated NPY peptides are shown. Removal of two N-terminal residues dramatically reduces NPY potency and efficacy. Symbol and error bar indicate the mean and S.E.M. (standard error of mean) of n = three (NPY(3–36), NPY(18–36), and NPY(AA-36)) or n = 17 (NPY) independent experiments, respectively. Calculated EC₅₀ values (pEC₅₀ ± SEM) are presented on each graph and are summarized in Supplementary Table 2. Source data are provided as a Source Data file. c Van der Waals interactions of Y1 and P2 of NPY with Y₁R are shown in two different orientations.