Big LEN, Rat peptide

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

Batch to batch variation of the purity

BigLEN, a neuropeptide with the sequence LENSSPQAPARRLLPP, is derived from the proSAAS precursor protein. This peptide is abundantly expressed in the hypothalamus, particularly within the arcuate nucleus, and exhibits activity-dependent release from neurons. Biochemical studies demonstrate that BigLEN binds with high affinity and activates a specific G protein-coupled receptor, identified as GPR171. This receptor is a Gαi/o-coupled receptor, and its activation by BigLEN leads to downstream signaling events, including the inhibition of adenylate cyclase activity and the phosphorylation of ERK1/2.

The interaction between BigLEN and GPR171 is mediated by the C-terminal region of the peptide. The tetrapeptide Leu-Leu-Pro-Pro (L2P2), corresponding to the final four amino acids of BigLEN, is both necessary and sufficient for receptor binding and activation. The expression patterns of BigLEN and GPR171 are complementary in the hypothalamus, and receptor levels are modulated in the absence of the peptide, indicating a regulated ligand-receptor system. In cellular models such as Neuro2A cells, BigLEN signaling through GPR171 influences processes like neurite outgrowth.

• Gomes I, Aryal DK, Wardman JH, Gupta A, Gagnidze K, Rodriguiz RM, Kumar S, Wetsel WC, Pintar JE, Fricker LD, Devi LA. GPR171 is a hypothalamic G protein-coupled receptor for BigLEN, a neuropeptide involved in feeding. Proc Natl Acad Sci U S A. 2013 Oct 1;110(40):16211-6. doi: 10.1073/pnas.1312938110. Epub 2013 Sep 16. PMID: 24043826; PMCID: PMC3791715.

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.