Melittin, Honey Bee (Apis mellifera) – Catalog #B2026680

Melittin (Catalog #B2026680) is the major peptide component of honey bee (Apis mellifera) venom, comprising approximately 40–50% of the venom dry mass. It is a 26-amino-acid α-helical peptide (molecular weight 2847.5 Da) that adopts a highly hydrophobic structure at lipid interfaces. Melittin is one of the best-characterized antimicrobial peptides and is widely used to study the mechanisms by which amphipathic peptides permeabilize biological membranes. Unlike many ion-channel-forming peptides that require a membrane potential, melittin forms voltage-independent pores in lipid bilayers and has potent lytic activity at low concentrations. Supplied as 1 mg of lyophilized powder.

Scientific Overview

Melittin is an amphipathic peptide that combines hydrophobic and hydrophilic amino acids in a manner that allows it to insert into and disrupt lipid membranes. At the peptide concentration, melittin forms α-helical tetramers that oligomerize on the membrane surface and create large, non-selective ion channels or pores, leading to the collapse of the membrane potential and cell lysis. Unlike receptor-mediated ion channels, melittin's pore formation is voltage-independent, making it a powerful tool for studying the biophysics of membrane damage and the molecular basis of antimicrobial action. The peptide's hemolytic activity, cytotoxicity, and membrane-lytic capacity have made it a classic research compound in membrane biology, toxicology, and the study of anti-pathogenic peptide design.

Key applications include:

• Study of peptide-lipid interactions and membrane disruption mechanisms
• Formation and characterization of ion channels in planar lipid bilayers (electrophysiology)
• Cell lysis and permeabilization for cell biology and biochemistry applications
• Antimicrobial and antitumor activity screening
• Structure-function analysis of α-helical peptides and their membrane insertion
• Development of antimicrobial peptide analogs and derivatives

Usage & Handling Guidance

Reconstitute the lyophilized peptide in ultrapure water or your chosen buffer at the desired concentration. Melittin is soluble in aqueous and most physiological buffers. Start at low concentrations (e.g., 1–10 μM) and titrate as needed for your assay, since melittin is highly potent at lysis and cell permeabilization. Store reconstituted solutions at 2–8°C for immediate use, or at –20°C for longer storage; avoid repeated freeze-thaw cycles.

• Typical working range: 1–100 μM, depending on the cell type, membrane composition, and duration of exposure.
• Membrane lysis: Concentrations of 5–25 μM often cause rapid hemolysis of red blood cells and cell lysis within minutes.
• Ion channel formation (planar lipid bilayers): Use lower concentrations (0.1–1 μM) for single-channel recording.
• Solubility: Freely soluble in water and physiological buffers; insoluble in organic solvents.
• Stability: Lyophilized peptide is stable for years at –20°C; avoid light and moisture.

What You Get

• 1 mg of lyophilized melittin from Apis mellifera venom
• High-purity antimicrobial peptide (biotechnology grade)
• Molecular weight: 2847.5 Da
• Ready to reconstitute for membrane and cell biology research
• For research use only (RUO)

Why Researchers Choose It

• Well-characterized and extensively studied antimicrobial peptide
• Potent membrane-disrupting activity at low concentrations
• Voltage-independent pore formation, unlike many ion channels
• α-helical structure; classic model for amphipathic peptide research
• Suitable for biophysics, cell biology, and toxicology applications
• High purity and reliable batch-to-batch quality

Frequently Asked Questions (FAQ)

• How does melittin disrupt membranes?
  Melittin forms α-helical oligomers that insert into lipid membranes, creating large pores and ion channels. Unlike voltage-gated channels, melittin's pores are voltage-independent and non-selective, allowing passage of small molecules and ions, and ultimately leading to membrane rupture and cell lysis.
• What is a typical concentration for cell lysis?
  Red blood cells (RBCs) typically lyse at 5–25 μM melittin within a few minutes. Start with a low concentration and titrate upward to find the optimal concentration for your cell type and experimental time frame.
• Can I use melittin in living animal models?
  This product is Research Use Only (RUO) and is designed for in vitro mechanistic and research applications only.
• How should I prepare a stock solution?
  Dissolve the lyophilized peptide in ultrapure water or PBS at a desired concentration (e.g., 1 mM = 2.847 mg/mL). Store at –20°C. Aliquot to avoid repeated freeze-thaw cycles.
• Is melittin soluble in organic solvents?
  Melittin is poorly soluble in most organic solvents; use aqueous buffers. If you need to incorporate it into lipid systems, prepare it in a small volume of water or buffer and add it to pre-formed vesicles or bilayers.

References

• van den Bogaart G, Guzmán JV, Mika JT, Poolman B. On the mechanism of pore formation by melittin. J Biol Chem. 2008;283(49):33854-7.
• Singh PK, Ghosh D, Tewari D, Mohite GM, Carvalho E, Jha NN, Jacob RS, Sahay S, Banerjee R, Bera AK, Maji SK. Cytotoxic helix-rich oligomer formation by melittin and pancreatic polypeptide. PLoS One. 2015;10(3):e0120346.
• Huang HW. Free energies of molecular bound states in lipid bilayers: lethal concentrations of antimicrobial peptides. Biophys J. 2009;96(8):3263-72.