Extended Data Table 2 Inositol phosphate accumulation assays of wild-type and mutant Y1 receptors for NPY and antagonists

From: Structural basis of ligand binding modes at the neuropeptide Y Y1 receptor

  1. nd, not determined; /, not tested.
  2. *Antagonist concentrations were chosen based on their antagonistic activity on Y1R.
  3. †EC50 values were determined after 1 h stimulation by increasing the concentration of NPY or NPY together with different antagonists. Data are shown as mean values from at least three independent experiments or the results of two individual experiments each performed in technical duplicate.
  4. ‡Sample size; the number of independent experiments performed in technical duplicate.
  5. §The EC50 ratio represents the shift between the NPY and NPY + antagonist curve (EC50(NPY + antagonist)/EC50(NPY)) and characterizes the antagonistic effect on the wild-type receptor or receptor mutants. By comparison of EC50 ratios between wild-type and mutant receptor, influences of all tested residues on antagonist activity were determined. A higher ratio indicates higher antagonist activity. A reduced EC50 ratio of mutant compared to the wild-type receptor was interpreted as important for the respective antagonist.
  6. ||Kb values were determined using the Gaddum transformation (Kb = [antagonist]/(EC50 ratio 1)).
  7. #These data were obtained at a reduced concentration of UR-HU404 (10−8 M) as concentration response curves did not reach saturation (EC50 > 10,000 nM) when a higher concentration was used (10−7 M).