Inhibits mammalian and insect voltage-gated sodium and potassium voltage-gated channels. Inhibits the mammalian sodium channels rNav1.2/SCN2A, rNav1.3/SCN3A, rNav1.4/SCN4A, hNav1.5/SCN5A, mNav1.6/SCN8A (IC(50)=156.39 nM), hNav1.8/SCN10A, the arachnid sodium channel VdNav (IC(50)=124.05 nM), as well as the potassium channels Kv11.1/KCNH2/ERG1 (IC(50)=3.7 uM) and rKv4.3/KCND3. In vivo, is lethal on insects (tested on flies M.domestica). When tested on mice, it shows very low toxicity, causing reversible paralyzes at the first hour after intracerebroventricular injection. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. LD(50) is 20.9 mg/kg by intrathoracic injections into adult house flies (Musca domestica). This toxin does not inhibit the potassium channels Shaker-IR (with inactivation domain removed) and the rat Kv2.1/KCNB1. Belongs to the phrixotoxin family.