Ranatuerin-2CSa peptide

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

Batch to batch variation of the purity

Ranatuerin-2CSa is a cationic antimicrobial peptide originally isolated from the skin secretions of the Cascades frog, Rana cascadae. Its primary structure is GILSSFKGVAKGVAKDLAGKLLETLKCKITGC. Structural analysis via NMR spectroscopy in a membrane-mimetic solvent (50% aqueous 2,2,2-trifluoroethanol) reveals that the peptide adopts a well-defined full-length helix-turn-helix conformation. This motif consists of an N-terminal α-helix spanning residues I2 to L21, a turn region between residues L22 and L25, and a C-terminal α-helix from K26 to T30, stabilized by a disulfide bridge between C27 and C32.

The peptide exhibits amphipathic character, particularly in its N-terminal helical domain, where polar lysine residues segregate on one face and hydrophobic residues on the opposite face. In purely aqueous solution, ranatuerin-2CSa lacks stable secondary structure, adopting a random coil conformation. The transition to a structured state in less polar solvents is associated with the promotion of intramolecular hydrogen bonding, mimicking interactions with hydrophobic microbial cell membranes.

• Conlon JM, Al-dhaheri A, Al-mutawa E, et al. Peptide defenses of the Cascades frog Rana cascadae: implications for the evolutionary history of frogs of the Amerana species group. Peptides. 2007;28(6):1268-74.
• Subasinghage AP, Conlon JM, Hewage CM. Conformational analysis of the broad-spectrum antibacterial peptide, ranatuerin-2CSa: identification of a full length helix-turn-helix motif. Biochim Biophys Acta. 2008 Jun;1784(6):924-9. doi: 10.1016/j.bbapap.2008.02.019. Epub 2008 Mar 14. PMID: 18387372.

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.