Pexiganan peptide

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

Batch to batch variation of the purity

Pexiganan is a 22-amino-acid antimicrobial peptide, chemically synthesized as an analog of the magainin peptides originally isolated from the skin of the African clawed frog Xenopus laevis. Its primary structure is Gly-Ile-Gly-Lys-Phe-Leu-Lys-Lys-Ala-Lys-Lys-Phe-Gly-Lys-Ala-Phe-Val-Lys-Ile-Leu-Lys-Lys-NH₂, with a molecular weight of 2478 Da for the free peptide base. This cationic peptide exhibits broad-spectrum in vitro antibacterial activity against a wide range of gram-positive and gram-negative bacteria, including aerobic and anaerobic species.

The peptide demonstrates rapid bactericidal activity, which is attributed to a membrane-disruptive mechanism. Studies indicate that for the majority of bacterial isolates tested, the minimum bactericidal concentrations (MBCs) are identical to or within a narrow range of the minimum inhibitory concentrations (MICs), confirming its bactericidal mode of action. The antimicrobial activity of pexiganan is largely unaffected by variations in pH within a physiological range. Furthermore, attempts to generate bacterial resistance to pexiganan through repeated in vitro passage with subinhibitory concentrations or through mutagenesis were unsuccessful, and no cross-resistance with several conventional antibiotic classes has been observed.

• Ge Y, MacDonald DL, Holroyd KJ, Thornsberry C, Wexler H, Zasloff M. In vitro antibacterial properties of pexiganan, an analog of magainin. Antimicrob Agents Chemother. 1999 Apr;43(4):782-8. doi: 10.1128/AAC.43.4.782. PMID: 10103181; PMCID: PMC89207.

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.