This peptide, Exendin-4, has a biotin on the N-terminus. Exendin-4, an agonist of glucagon-like peptide 1 (GLP-1) receptor, induces release of insulin after food intake. Exendin-4 shares a 53% sequence homology with GLP-1. Derived from Gila monster, Heloderma suspectum, Exendin-4 has a longer half life than GLP-1 in the plasma, thus making it a more potent insulinotropic agent.