This toxin activates voltage-gated sodium channels. It shifts the voltage-dependence of activation to more hyperpolarized potentials but has only little effect on channel inactivation. It is active on Nav1.3/SCN3A (EC(50)=3.98 nM), Nav1.4/SCN4A (EC(50)=4.99 nM), Nav1.6/SCN8A (EC(50)=1.27 nM) and Nav1.7/SCN9A (EC(50)=2.42 nM) voltage-gated sodium channels. In vivo, it induces nocifensive or pain-like behaviors in mice when injected intraplantarly. Expressed by the venom duct. The cysteine framework is VI/VII (C-C-CC-C-C). The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the conotoxin O1 superfamily.