Exendin-3 (9-39) fragment

An antagonist of the GLP-1 receptor.

Sequence: 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

Molecular Weight: 3367.69

Source: California Peptide Research, Inc., 918 Enterprise Way, Suite 1, Napa, California, 94558 USA, tel: 707.224.8675, Catalog No. 507-81, 1 mg at $240.00

Exendin-4

An agonist of the GLP-1 1R receptor. Produced by the salivary gland of the Gila Monster (Heloderma suspetum). See work by Christel and Denardo on salivary release of exendin-4 and (lack of) role in postingestive glucose regulation in the Gila PMID 16972064.

The N-terminal region of GLP-1 and exendin-4 are almost identical. The second amino acid, alanine in GLP-1 and glycine in exendin-4, gives exendin-4 its resistance to DPP IV digestion

Exenatide

Synthetic version of Exendin-4. Tradename Byetta. Marketed by Amylin Pharmaceuticals to improve glucose control in type 2 diabetes.