Cardiovascular · Venom-derived ETB-preferring receptor agonist
Sarafotoxin S6c
Also known as SRTX-c; S6c
An ETB-preferring sarafotoxin used to distinguish endothelin receptor subtype signalling in cells and isolated tissues.
- Length
- 21 amino acids
- Half-life
- Not well characterised
- Mechanism
- Sarafotoxin S6c preferentially activates ETB receptors over ETA receptors. ETB-dependent signalling can produce calcium mobilisation and, in endothelial preparations, engage nitric oxide-linked pathways.
- Studied in
- ETB-expressing cell lines, isolated vessel preparations and receptor-deficient animal models use S6c to dissect ETB-dependent signalling and cellular responses.
About Sarafotoxin S6c
Sarafotoxin S6c is a 21-residue peptide from the sarafotoxin family identified in Atractaspis engaddensis venom. Like S6b and the endothelins, it contains four cysteines arranged into two disulphide bonds, linking positions 1–15 and 3–11. Sequence differences within this shared scaffold substantially alter receptor preference. S6c consequently became a useful experimental ligand for distinguishing ETB-mediated activity from responses involving ETA, rather than serving as a general substitute for every endothelin agonist.
The significance of ETB activation depends on which cells express the receptor. Endothelial ETB signalling can engage nitric oxide production, whereas ETB on vascular smooth muscle can support contractile responses. S6c is therefore particularly informative in preparations with defined cell composition or paired intact and endothelium-denuded vessels. Its selectivity is relative rather than absolute, and receptor abundance, assay conditions and species differences should be considered when interpreting functional potency or efficacy.
Laboratory notes
- For research use only; apply appropriate containment and handling procedures for a potent venom-derived receptor agonist.
- Document endothelial integrity in vessel assays, since endothelial and smooth-muscle ETB signalling can yield different readouts.
- Include an ETB antagonist or receptor-null control; do not infer subtype specificity from the ligand name alone.
Storage and reconstitution basics: storage guide.
Questions about Sarafotoxin S6c
Why is S6c used as an ETB probe?
Its strong preference for ETB over ETA makes it useful for isolating ETB-associated responses in appropriately controlled assays.
Why compare intact and endothelium-denuded vessels?
This comparison helps distinguish endothelial ETB-dependent signalling from responses arising in the underlying vascular smooth muscle.
Does S6c selectivity eliminate the need for controls?
No. Selectivity is assay-dependent, and receptor antagonists or genetic controls remain important for assigning mechanism.
Is Sarafotoxin S6c 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.