May inhibit voltage-gated potassium channels Kv1.1/KCNA1, hKv1.2/KCNA2, and Kv1.3/KCNA3 (By similarity). May also 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. KTX subfamily.