Exendin-3

H-His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2

Exendin-3, a member of the glucagon superfamily, was originally isolated from the venom of the lizard, Heloderma horridum. At low concentrations, the 39-amino acid peptide interacts with putative exendin receptors causing an increase in pancreatic acinar cAMP, whereas at higher concentrations it interacts with VIP receptors to stimulate an increase in cellular cAMP and amylase release.