Reversibly blocks N-type calcium channels (Cav2.2/CACNA1B) in rat dorsal root ganglion cells (IC(50)=40 nM). Elicits no toxic symptoms in either vertebrates or invertebrates during a period of 48 hours post-injection, when it was assayed in vivo by direct injection into mice and cockroaches. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the neurotoxin 36 family. 02 subfamily.