GLP-1

GLP-1 is short for glucagon-like peptide 1, a 30- or 31-amino-acid peptide hormone produced primarily by enteroendocrine L cells of the distal small intestine and colon. It is cleaved post-translationally from the preproglucagon precursor - the same precursor that gives rise to glucagon in pancreatic alpha cells, but processed differently in the gut - and it circulates as two biologically active forms, GLP-1(7-37) and GLP-1(7-36) amide. Its principal studied activity is the glucose-dependent potentiation of insulin secretion from pancreatic beta cells, an effect that is part of a broader family of gut-derived signals collectively termed the incretin effect. Foundational biology is reviewed in Drucker, Cell Metab. 2006 (NLM 16459310).

Receptor biology and why GLP-1 analogs exist

GLP-1 acts through the glucagon-like peptide 1 receptor (GLP-1R), a class B G-protein-coupled receptor expressed on pancreatic beta cells, neurons in the area postrema and hypothalamus, and a number of peripheral tissues. The native peptide is rapidly inactivated in circulation by the serine protease dipeptidyl peptidase-4 (DPP-4), which cleaves the N-terminal dipeptide and yields a metabolite with much reduced receptor activity. The measured circulating half-life of intact native GLP-1 is on the order of one to two minutes, which is why native GLP-1 itself has limited utility as a long-acting research probe. Synthetic GLP-1 receptor agonist analogs - exenatide, liraglutide, semaglutide, and others - are engineered to resist DPP-4 cleavage or to bind albumin, producing measured half-lives that are orders of magnitude longer than the native peptide. The half-life biology is detailed in Deacon et al., Diabetes 1995 (NLM 7789648).

GLP-1 in research contexts

In RUO research, GLP-1 and its analogs are used as reference ligands to study GLP-1R pharmacology in recombinant cell lines, to characterize receptor-mediated signaling in beta-cell and neuronal models, and as tool compounds in in vitro screens. Characterization of a GLP-1-family research peptide should include intact-mass confirmation by LC-MS, HPLC purity, and a disclosed net-peptide content because the commercial forms vary in salt form and in the presence of modifications (e.g., amidation, acylation, fatty-acid conjugation) that substantially affect measured receptor binding and in vitro potency. A review of GLP-1R pharmacology relevant to assay design is Baggio & Drucker, Gastroenterology 2007 (NLM 17498508).

How Open Assay handles GLP-1-family listings

Listings for GLP-1 and its analogs are indexed by peptide identity (sequence, modification state, salt form) rather than by trade name, and the COA fields discussed above are surfaced alongside the vendor's claimed identity. Open Assay does not make claims about clinical use or compare research materials to approved medicines; it indexes RUO reference peptides used in receptor-level and cell-based research.