Gating-modifier toxin that inhibits both sodium (Nav) and calcium (Cav3) channels by inducing hyperpolarizing shift in voltage-dependence of activation and steady state inactivation. Inhibits Nav1.1/SCN1A, Nav1.2/SCN2A, Nav1.6/SCN6A, Nav1.7/SCN9A and Cav3.1/CACNA1G sodium and calcium channels at nanomolar concentrations (IC(50)=169-621 nM). Surprisingly, selectively slows fast inactivation of Nav1.3/SCN3A. Also shows moderate inhibition of Nav1.3/SCN3A sodium channels (IC(50)=1216 nM). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Monoisotopic mass. Shows no or weak activity on Nav1.4/SCN4A and Nav1.5/SCN5A sodium channels, as well as on Cav3.2/CACNA1H and Cav3.3/CACNA1I calcium channels. Belongs to the neurotoxin 10 (Hwtx-1) family. 59 (Tltx) subfamily.