Other · Inhibitor cystine-knot mechanosensitive-channel modulator
GsMTx4
Also known as GsMtx-4; Grammostola mechanotoxin 4
A membrane-active tarantula peptide used to probe mechanically activated cation currents and lipid-dependent channel gating.
- Length
- 34 amino acids
- Half-life
- Not well characterised
- Mechanism
- GsMTx4 partitions into the lipid bilayer and modifies the coupling of membrane tension to susceptible cation-permeable mechanosensitive channels, including PIEZO1. Its activity is better described as membrane-mediated gating modulation than as selective occupation of one receptor-binding site.
- Studied in
- Patch-clamp, membrane-stretch and mechanically stimulated cell assays use GsMTx4 to investigate PIEZO-associated currents and other cationic mechanosensitive conductances.
About GsMTx4
GsMTx4 was isolated from venom of the tarantula historically identified as Grammostola spatulata during screening for inhibitors of stretch-activated currents. The mature native peptide comprises 34 amino acids, three disulphide bonds and an amidated C-terminus. Its inhibitor cystine-knot fold presents hydrophobic and charged surfaces that support association with lipid membranes. Unlike many classical channel toxins, its defining experimental activity emerged from mechanically stimulated membrane recordings rather than screening against a single cloned receptor.
Research supports a mechanism in which GsMTx4 alters local bilayer mechanics and the energetic coupling between membrane tension and channel opening. PIEZO1 is a prominent target in recombinant systems, but GsMTx4 is not a PIEZO1-specific identification reagent. Both the natural L-peptide and its synthetic D-enantiomer can inhibit susceptible mechanosensitive currents, supporting a substantial lipid-mediated component. Mechanical stimulus geometry, membrane composition and recording configuration all influence the magnitude and interpretation of its effects.
Laboratory notes
- Specify whether material is the L- or D-enantiomer and confirm terminal chemistry before comparing datasets.
- Standardise mechanical stimulation, patch configuration and membrane conditions across experimental groups.
- Use genetic controls or orthogonal channel assays because GsMTx4 sensitivity alone does not identify PIEZO1.
Storage and reconstitution basics: storage guide.
Questions about GsMTx4
Is GsMTx4 selective for PIEZO1?
No. It can inhibit several susceptible cationic mechanosensitive conductances, so PIEZO1 assignment requires additional evidence.
Why is the D-enantiomer scientifically informative?
Activity of the mirror-image peptide supports a mechanism with a substantial membrane-mediated component rather than an exclusively stereospecific protein-binding interaction.
Does it inhibit all mechanically sensitive channels?
No. Mechanosensitive channels differ in their gating and membrane coupling, and some are insensitive or respond differently to the peptide.
Is GsMTx4 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.