Voltage-gated potassium channel (Kv) inhibitor (Ref.2). In addition it may increase intracellular calcium release through the activation of nuclear inositol 1,4,5-trisphosphate receptors (ITPR) of cardiomyocytes, thereby causing an increase in the contraction frequency of these cells (By similarity). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the scorpion calcin-like family.