Gating-modifier toxin that non-selectively inhibits voltage-gated sodium channel Nav by shifting the threshold for channel activation to more positive potentials. This toxin moderately inhibits human Nav1.2/SCN2A (IC(50)=404 nM), Nav1.5/SCN5A (IC(50)=218 nM) and Nav1.7/SCN9A (IC(50)=333 nM). Inhibition of Nav1.7 is voltage-dependent, with lower inhibition at more positive test pulses. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Monoisotopic mass. Belongs to the neurotoxin 30 (phrixotoxin) family.