Gastrin-releasing peptide, GRP

• COA/MS/HPLC Report
• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

Gastrin-releasing peptide (GRP) is a mammalian neuropeptide that shares structural and functional similarities with the amphibian peptide bombesin. It is widely distributed in the gastrointestinal tract and pancreas, where it is primarily localized in neural structures. GRP exerts potent effects on the release of various gastroentero-pancreatic (GEP) hormones, including insulin, glucagon, and pancreatic polypeptide (PP). Studies in multiple species have demonstrated that GRP can stimulate basal hormone secretion and enhance glucose-induced insulin release, although its effects may vary depending on the experimental conditions and species examined.

GRP influences the endocrine pancreas through both direct and indirect mechanisms. In isolated pancreatic preparations, GRP has been shown to dose-dependently stimulate insulin and PP secretion while inhibiting somatostatin release. The peptide's actions are mediated through interactions with specific receptors on islet cells, though the precise signaling pathways remain under investigation. Anatomical studies reveal GRP-containing nerve fibers in close proximity to pancreatic islets, suggesting a role in local neural regulation of hormone secretion. Species differences exist in GRP's potency and spectrum of activity, as well as in the mechanisms governing its release, highlighting the complexity of its regulatory functions in the endocrine pancreas.

• Mcdonald TJ, Jörnvall H, Nilsson G, et al. Characterization of a gastrin releasing peptide from porcine non-antral gastric tissue. Biochem Biophys Res Commun. 1979;90(1):227-33.
• McDonald TJ, Houghton P, Challis JR, Hramiak IM. The effect of gastrin-releasing peptide on the endocrine pancreas. Ann N Y Acad Sci. 1988;547:242-54. doi: 10.1111/j.1749-6632.1988.tb23893.x. PMID: 3071222.

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.