Antagonist of L-type calcium channels (Cav1/CACNA1). In vivo, causes paralysis in posterior limbs, and gradual decrease in movement and aggression during 24 hours after intracerebroventricular injection in mice at dose levels of 3 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 09 (Tx3-6) family.