Octadecaneuropeptide ODN

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

Batch to batch variation of the purity

Octadecaneuropeptide (ODN) is an endogenous neuropeptide consisting of 18 amino acids with the sequence Gln-Ala-Thr-Val-Gly-Asp-Val-Asn-Thr-Asp-Arg-Pro-Gly-Leu-Leu-Asp-Leu-Lys. It is derived from the tryptic digestion of diazepam binding inhibitor (DBI), a larger neuropeptide modulator of γ-aminobutyric acid (GABA) receptor function. ODN exhibits a higher potency than its parent compound in displacing specifically bound β-carboline-3-carboxylate methyl ester from recognition sites associated with GABA_A receptors.

Studies indicate that the biological activity of ODN resides in its carboxyl-terminal segment, as synthetic fragments containing the last six to eight residues retain displacing activity. The free carboxyl terminus of the terminal lysine is essential for this activity, since its amidation abolishes the peptide's effects. Immunological assays have detected ODN-like material in rat brain homogenates, suggesting it may be a natural product of DBI processing. In primary cultures of cerebellar granule cells, ODN and its active fragments preferentially displace β-carboline ligands over benzodiazepine ligands, indicating a specific interaction with regulatory sites on the GABA_A receptor complex.

• Ferrero P, Santi MR, Conti-Tronconi B, Costa E, Guidotti A. Study of an octadecaneuropeptide derived from diazepam binding inhibitor (DBI): biological activity and presence in rat brain. Proc Natl Acad Sci U S A. 1986 Feb;83(3):827-31. doi: 10.1073/pnas.83.3.827. Erratum in: Proc Natl Acad Sci U S A. 1986 Apr;83(8):2776. doi: 10.1073/pnas.83.8.2776. PMID: 3456171; PMCID: PMC322958.

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.