Antagonist of L-type calcium channels (Cav1/CACNA1) (PubMed:10098851). In GH3 neuroendocrinal cell line, it reversibly inhibits the A-type potassium current but does not block other potassium currents or calcium channels (PubMed:10098851). Shows an important acetylcholine-mediated antiarrhythmogenic effect in isolated hearts (PubMed:21115025). In vivo, causes paralysis in the posterior limbs and gradual decreases in movement and aggression during 24 hours at dose levels of 5 ug per mouse (PubMed:10098851). 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.