Selective inhibitor of voltage-gated potassium channels, blocks the Kv1.2/KCNA2 (Kd=1.3 nM) and Kv1.3/KCNA3 (Kd=7.2 nM) channels. Association and dissociation rates of the toxin are slower for Kv1.2/KCNA2 than for Kv1.3/KCNA3. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta). Does not inhibit the potassium channels Kv1.1/KCNA1, Kv1.4/KCNA4, Kv1.5/KCNA5, Kv2.1/KCNB1, Kv11.1/KCNH2, KCa3.1/KCNN4, KCa1.1/KCNMA1 and the sodium channel Nav1.5/SCN5A. Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 02 subfamily.