Fig. 8
Contribution of amino acid positions in hαCGRP8-37N25K-C20DA-γGlu for antagonism against the hCGRP-R expressed in the CHO-K1 cell line. Cells were incubated with 24 pM hαCGRP (EC90) and increasing concentrations of antagonist. Antagonist potency was evaluated with five-point antagonist concentration response curves ranging from 30 nM to 3 µM. Each position was mutated to five different amino acids, either alone or in combination, resulting in a total data set consisting of 950 peptides. Lysine (K), glutamic acid (E), phenylalanine (F), serine (S), and alanine (A) were applied as substitutions. When one of these amino acids was already present in the backbone, a glycine (G) was induced as alternative. A random forest model was computed based on the relationship between the pIC50 values and the amino acid sequences. SHAP values were computed to determine the potency contribution of each mutation, where a positive SHAP value correspond to a positive contribution and a negative SHAP value corresponds to a negative contribution.
