This lethal (towards mammals) heterodimer induces hemolytic activities due to its ability to form pores in the cell membrane (PubMed:1790672, PubMed:9271089, PubMed:12177053, PubMed:26627714). The pore may be composed of 10 SNTX-alpha/beta heterodimers (PubMed:26627714). The toxin elicits potent hypotension which is endothelium-dependent and appears to be mediated by the nitric oxide pathway and activation of potassium channels (PubMed:8310447, PubMed:11931843). In addition, it displays edema-inducing activities, increases vascular permeability. It also shows myotoxic activities and interferes irreversibly with neuromuscular function (PubMed:8079369). It also induces irreversible platelet aggregation in rabbit or rat but not in human or mouse whole blood (PubMed:8533137). In addition, it has been observed to increase spontaneous quantal acetylcholine release from isolated frog cutaneous pectoris motor endings (PubMed:8921306). Heterodimer of alpha and beta subunits (PubMed:1790672, PubMed:8921306); non-covalently linked. Secreted into the venom gland lumen (PubMed:8810331). The secretion is proved by the fact that the complete sequence shown in this entry is found in the venom gland's lumen, although no signal peptide has been found (PubMed:8810331). This protein may follow a novel secretion pathway (PubMed:8810331). It has been reported that venom-secreting cells of stonefishes do not possess Golgi apparatus and rough endoplasmic reticulum (PubMed:8810331). Expressed by the venom gland. The first domain (residues 2-265) is structurally homologous to the membrane attack complex-ferforin/cholesterol-dependent cytolysin (MACPF/CDC) pore-forming domain. It makes numerous contacts with the FAT domain and comprise essentially the core pore-forming machinery. The second domain is structurally homologous to the focal adhesion-targeting (FAT) domain (266-385). It makes numerous in cis contacts with the MACPF/CDC domain (first domain) and the thioredoxin (THX) domain (third domain) as well as extensive in trans interactions at the SNTX-alpha/beta interface. The third domain corresponds to the thioredoxin (THX) domain. It makes numerous contacts with the second domain (FAT domain). Since it lacks the canonical catalytic residues, it may only play a purely structural role. The fourth domain corresponds to the B30.2/SPRY domain. This domain would be responsible for initial interaction with the cell surface through either lipid- or protein-mediated interactions. Intrachain disulfide bonds may be present in the heterodimer (PubMed:8810331). Not glycosylated. LD(50) of stonustoxin is 0.017 mg/kg by intravenous injection. Belongs to the SNTX/VTX toxin family. The toxin name trachynilysin was given according to the species S.trachynis. This species has finally been reclassified as a synonym of S.horrida.