Anticancer peptide A2

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

Batch to batch variation of the purity

Anticancer peptide A2 is a designed cationic peptide derived from the N-terminal sequence of the Escherichia coli enzyme IIAGlc membrane anchor. It adopts a disordered conformation in aqueous solution but forms an amphipathic α-helical structure in membrane-mimetic environments such as SDS micelles, as demonstrated by circular dichroism spectroscopy. The three-dimensional NMR structure reveals a distinct hydrophobic surface, enabling deeper membrane penetration compared to the nontoxic parental peptide. Key structural features include a broader hydrophobic face and interfacial basic residues, which contribute to its membrane-interactive properties.

The peptide's sequence (GLFDKLKSLVSDF) incorporates a Phe13 substitution and C-terminal truncation relative to the original membrane anchor. NMR-derived structural analysis indicates that A2 lacks strong salt bridges but possesses a well-defined helical segment spanning residues Leu2-Ser11. Its membrane activity is linked to the presence of hydrophobic patches bordered by cationic residues, a characteristic shared with other bioactive peptides in the GLFD family. The structural attributes of A2 provide insights into the role of sequence modifications in modulating membrane interactions.

• Wang G, Li Y, Li X. Correlation of three-dimensional structures with the antibacterial activity of a group of peptides designed based on a nontoxic bacterial membrane anchor. J Biol Chem. 2005 Feb 18;280(7):5803-11. doi: 10.1074/jbc.M410116200. Epub 2004 Nov 30. PMID: 15572363.

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.