Calcitonin (salmon I) peptide

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

Batch to batch variation of the purity

Calcitonin (salmon I) is a 32-amino acid peptide hormone. Its primary structure features an N-terminal disulfide bond between cysteine residues at positions 1 and 7, forming a characteristic ring structure. The peptide exhibits a propensity to adopt an α-helical conformation, which is associated with its biological activity. The amino acid sequence of salmon calcitonin shares approximately 50% homology with human calcitonin, with the most divergent region located in the central to C-terminal portion of the peptide.

In silico analysis of the linearized sequence identifies several putative T-cell epitopes. A prominent feature is a promiscuous 9-mer binding frame within the C-terminal region, predicted to bind to multiple human leukocyte antigen (HLA) DR alleles. This region contains minimal sequence homology with the human proteome. The peptide is amidated at its C-terminus, a common post-translational modification for this class of hormones.

• M.Munoz-Torres et al., Treat. Endocrinol., 3, 117 (2004)
• R.A.Davey and H.A.Morris, J. Bone Miner. Res,, 23, 359 (2005)
• P.Y.Wielinga et al., Physiol. Behav., 91, 212 (2007)
• P.K.Chelikani et al., Am. J. Physiol. Regul. Integr. Comp. Physiol., 293, R1798 (2007)
• S.Liao et al., Pharmazie, 63, 743 (2008)
• N.T.Bello et al., Am. J. Physiol. Regul. Integr. Comp. Physiol., 295, R76 (2008)
• Roberts BJ, Mattei AE, Howard KE, Weaver JL, Liu H, Lelias S, Martin WD, Verthelyi D, Pang E, Edwards KJ, De Groot AS. Assessing the immunogenicity risk of salmon calcitonin peptide impurities using in silico and in vitro methods. Front Pharmacol. 2024 Aug 9;15:1363139. doi: 10.3389/fphar.2024.1363139. PMID: 39185315; PMCID: PMC11341359.

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.