Antagonist of L-type calcium channels (Cav1/CACNA1). Causes paralysis in the posterior limbs and gradual decreases in movement and aggression during 24 hours at dose levels of 5 ug per mouse. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the neurotoxin 02 (plectoxin) family.