Other · Peptide toxin
mu-Conotoxin GIIIA
Also known as μ-Conotoxin GIIIA
A 22-amino-acid peptide toxin from cone snail venom that selectively blocks skeletal muscle voltage-gated sodium channels (NaV1.4).
- Length
- 22 amino acids
- Half-life
- Not well characterised
- Mechanism
- A highly selective antagonist that physically occludes the pore of voltage-gated sodium channels, particularly the NaV1.4 subtype.
- Studied in
- Used as a specific pharmacological probe in electrophysiology to isolate and characterise skeletal muscle-type voltage-gated sodium channels (NaV1.4).
About mu-Conotoxin GIIIA
Mu-conotoxin GIIIA is a 22-amino-acid peptide originally isolated from the venom of the marine cone snail *Conus geographus*. Its compact structure is rigidly constrained by three disulfide bonds, which form a framework essential for its biological activity. This peptide belongs to the μ-conotoxin family, which is known for targeting voltage-gated sodium channels.
The toxin acts as a potent and highly selective blocker of the tetrodotoxin-sensitive, skeletal muscle subtype of the voltage-gated sodium channel, NaV1.4. It binds to receptor site 1 on the channel's extracellular face, physically occluding the ion-conducting pore and preventing sodium influx. This high specificity makes it an invaluable tool in neuroscience and pharmacology for discriminating NaV1.4 from other sodium channel isoforms in tissue preparations.
Laboratory notes
- The three disulfide bonds are crucial for the peptide's conformation and activity; avoid harsh reducing conditions during handling.
- Due to its high potency, it is typically effective at nanomolar concentrations in most electrophysiological and binding assays.
- Prepare solutions in buffers containing a carrier protein like 0.1% BSA to prevent non-specific binding and loss to labware surfaces.
Storage and reconstitution basics: storage guide.
Questions about mu-Conotoxin GIIIA
What is the source of this peptide?
It is a neurotoxin originally discovered in the venom of the marine cone snail *Conus geographus*. The research compound is a synthetic equivalent.
Which sodium channel subtype does μ-Conotoxin GIIIA block most selectively?
It is highly selective for the skeletal muscle sodium channel isoform, NaV1.4, with much lower affinity for neuronal or cardiac isoforms.
How does it block the channel?
It functions as a physical pore blocker, binding to the outer vestibule of the channel and obstructing the passage of sodium ions.
Is mu-Conotoxin GIIIA 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.