Preprocaerulein I precursor [34-43] peptide

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

Batch to batch variation of the purity

The Preprocaerulein I precursor [34-43] is a decapeptide derived from the skin secretion of Xenopus laevis. It is part of a small family of precursor polypeptides that contain one, three, or four copies of the final caerulein product. The caerulein sequences within these precursors are flanked by complex processing signals, including Arg-Arg-Phe-Ala-Asp-Gly or Arg-Arg-Asp-Gly at the amino-terminal side and Gly-Arg-Arg at the carboxyl-terminal end. The precursors exhibit high internal homology, with repeated segments that are conserved both within a given precursor and across different types of precursors.

The nucleotide sequences of the preprocaerulein cDNAs reveal a high degree of conservation, with differences primarily arising from deletions or insertions of segments containing one or two caerulein sequences. The processing of these precursors involves cleavage at pairs of basic residues, followed by further modifications to yield the mature caerulein peptide. The presence of multiple copies of caerulein and homologous segments in the precursors suggests a complex evolutionary history involving gene duplication and deletion events.

• Richter K, Egger R, Kreil G. Sequence of preprocaerulein cDNAs cloned from skin of Xenopus laevis. A small family of precursors containing one, three, or four copies of the final product. J Biol Chem. 1986 Mar 15;261(8):3676-80. PMID: 3753978.
• Anastasi A, Bertaccini G, Cei JM, De Caro G, Erspamer V, Impicciatore M, Roseghini M. Presence of caerulein in extracts of the skin of Leptodactylus pentadactylus labyrinthicus and of Xenopus laevis. Br J Pharmacol. 1970 Jan;38(1):221-8. doi: 10.1111/j.1476-5381.1970.tb10351.x. PMID: 5413288; PMCID: PMC1702644.

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.