Melittin (Apis mellifera) peptide

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

Batch to batch variation of the purity

Melittin is a cationic linear peptide-amide consisting of 26 amino acid residues (GIGAVLKVLTTGLPALISWIKRKRQQ-NH₂) and serves as the principal component of European honeybee (Apis mellifera) venom. This peptide exhibits strong partitioning into lipid bilayer membranes due to its hydrophobic and amphipathic nature. Upon membrane binding, melittin folds into an amphipathic α-helical secondary structure characterized by a continuous hydrophobic face and a distinct polar face. The peptide adopts a bent rod or helix-hinge-helix motif, with a central glycine-X-proline hinge region separating a more hydrophobic N-terminal helix from a more hydrophilic C-terminal helix. In aqueous solution, melittin α-helices can form tetramers where hydrophobic surfaces are buried and polar surfaces are exposed, conferring high water solubility.

Melittin disrupts the permeability barrier properties of membranes, leading to membrane permeabilization. While the precise mechanism is context-dependent, the insertion of amphipathic melittin into bilayers typically causes transient permeabilization, often resulting in rapid leakage of contents. Under certain conditions, melittin may assemble into stable transmembrane bundles to form pores. The peptide's membrane-active properties make it a model system for studying peptide and protein structure, folding, and function in membranes, and it has been utilized as a template for evolving new membrane activities.

• Guha S, Ferrie RP, Ghimire J, Ventura CR, Wu E, Sun L, Kim SY, Wiedman GR, Hristova K, Wimley WC. Applications and evolution of melittin, the quintessential membrane active peptide. Biochem Pharmacol. 2021 Nov;193:114769. doi: 10.1016/j.bcp.2021.114769. Epub 2021 Sep 17. PMID: 34543656; PMCID: PMC9235364.
• Zhang HQ, Sun C, Xu N, Liu W. The current landscape of the antimicrobial peptide melittin and its therapeutic potential. Front Immunol. 2024 Jan 22;15:1326033. doi: 10.3389/fimmu.2024.1326033. PMID: 38318188; PMCID: PMC10838977.

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.