Screening and Identification of a Targeting Peptide to nGLP-1R from Phage Display Peptide Library

In order to provide the structure information for designing new exendin-4 analogues, a phage display peptide library was screened by targeting the N-terminal extracellular domain of GLP-1R(nGLP-1R). After four rounds of selection, nine sequences were obtained, four of them have higher affinity for nGLP-1R than the others. We chose two of them named X and Y peptides. Islet beta-cell proliferation assay suggested that X and Y peptides didn't have any activity to increase islet beta-cell proliferation. In other words, X and Y peptides were not agonists to GLP-1R. However, the conservative motifs of X and Y peptides provided us useful information to design new exendin-4 analogues.