[Leu15]-Gastrin I (human) peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

[Leu15]-Gastrin I (human) is a peptide hormone primarily synthesized in the G cells of the stomach antrum. It plays a crucial role in stimulating gastric acid secretion from parietal cells via activation of the cholecystokinin-B (CCK-B) receptor, a G-protein-coupled receptor. This peptide also exhibits trophic effects on the gastrointestinal epithelium, influencing growth and maintenance of the digestive tract. In addition to its physiological functions, [Leu15]-Gastrin I (human) and its receptors are found to be overexpressed in certain malignancies, where it may contribute to cellular proliferation through autocrine signaling pathways.

The molecular actions of [Leu15]-Gastrin I (human) are mediated through the CCK-B receptor, triggering downstream signaling cascades involving phospholipase C, protein kinase C, and calcium mobilization. Beyond its role in acid regulation, this peptide has been implicated in activating pathways such as the Ras-ERK and EGFR transactivation, which are critical for cell proliferation and survival. Its expression is not limited to endocrine cells, as it is also detected in epithelial tumors, suggesting a potential role in neoplastic growth mechanisms.

• Smith JP, Nadella S, Osborne N. Gastrin and Gastric Cancer. Cell Mol Gastroenterol Hepatol. 2017 Mar 14;4(1):75-83. doi: 10.1016/j.jcmgh.2017.03.004. PMID: 28560291; PMCID: PMC5439238.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.