Reversible inhibitor of voltage-gated sodium channels (Nav). Delays the fast inactivation kinetics of neuronal-type sodium channels. In vivo, it induces rat penile erection (PubMed:15246765). This effect may be due to the neuronal nitric oxide synthase (NOS1), since one of its selective inhibitor completely abolishes all the toxic effects of the toxin (PubMed:15246765). This toxin also causes scratching, lacrimation, hypersalivation, sweating and agitation followed by spastic paralysis of the anterior and posterior extremities and death at dose levels of 0.24 mg/mouse (PubMed:1397265, PubMed:16278100, PubMed:15246765). It is also insecticidal to the larval and adult forms of the house fly (PubMed:1397265). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the neurotoxin 03 (Tx2) family. 06 subfamily.