Genetically modified rice seeds accumulating GLP‐1 analogue stimulate insulin secretion from a mouse pancreatic beta‐cell line

Abstract Glucagon-like peptide-1 (7-36) amide (GLP-1) is the most potent physiological insulinotropic hormone in humans. We produced large amounts of a GLP-1 analogue, [Ser 8 , Gln 26 , Asp 34 ]-GLP-1, which is resistant to trypsin-digestion, as part of a chimeric rice seed storage protein, a 26 kDa globulin, in genetically modified rice seeds. Junction sites between GLP-1 analogue and globulin were replaced by tryptic cleavage sites. The highest level of GLP-1 analogue accumulation was ≈20–50 μg per seed. We found that GLP-1 analogue derived from trypsin-digested genetically modified rice seeds stimulated insulin secretion from a mouse pancreatic beta-cell line, MIN6.