Insecticidal neurotoxin with probable ion channel impairing activity. In vivo causes a rapid, irreversible flaccid paralysis that results in death. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. LD(50) is 0.02 ug/g by subcutaneous injection into moth (Manduca sexta). Belongs to the neurotoxin 21 family.