Antimicrobial · Pore-forming Toxin
Pardaxin
Also known as Pardaxin P-1
A 33-amino-acid peptide toxin from flatfish that forms voltage-dependent pores in cell membranes, used in biophysical and antimicrobial research.
- Length
- 33 amino acids
- Half-life
- Not well characterised
- Mechanism
- Pardaxin self-assembles within lipid membranes to form voltage-gated ion channels or pores, causing rapid membrane depolarisation and lysis.
- Studied in
- Biophysical studies examine its mechanism of pore formation in artificial lipid bilayers, while microbiology research investigates its potent, broad-spectrum antimicrobial activities.
About Pardaxin
Pardaxin is a peptide toxin originally isolated from the gill secretions of the Red Sea Moses sole fish, *Pardachirus marmoratus*. Its primary sequence forms a unique 'gun-shaped' amphipathic helix-hinge-helix structure that is crucial for its pore-forming activity. It is known for its potent ichthyotoxic (shark-repellent) and antimicrobial properties.
The peptide's mechanism involves insertion into the cell membrane and subsequent aggregation to form voltage-dependent ion channels. This action disrupts the membrane's electrochemical gradient, leading to rapid depolarisation and cell lysis. In research, Pardaxin serves as a model for studying peptide-induced pore formation and is investigated for its broad-spectrum lytic activity against bacteria, protozoa, and certain vertebrate cells.
Laboratory notes
- Use electrophysiology techniques like patch-clamp on model membranes (e.g., black lipid membranes) to study its voltage-dependent channel formation.
- Due to its potent lytic activity, determine its hemolytic concentration (HC50) alongside its MIC to establish a therapeutic index in-vitro.
- Pardaxin's N-terminus is unblocked, and its C-terminus is a free carboxyl group, which are key structural features.
Storage and reconstitution basics: storage guide.
Questions about Pardaxin
What is meant by 'ichthyotoxic' activity?
Ichthyotoxic means it is toxic to fish. The natural function of Pardaxin is as a defensive secretion to repel predators like sharks.
How is Pardaxin's structure different from a simple alpha-helical AMP?
Unlike a single continuous alpha-helix, Pardaxin has a flexible hinge region that connects two helical segments. This allows it to adopt a specific conformation thought to be essential for its pore-forming function.
What are 'voltage-gated' ion channels?
These are channels or pores that open or close in response to changes in the electrical potential (voltage) across the membrane. Pardaxin-formed pores exhibit this property in experimental lipid bilayers.
Is Pardaxin for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.