This recombinant toxin selectively inhibits mouse voltage-gated potassium channel Kv1.3/KCNA3 (IC(50)=24.73 nM). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Shows only a weak inhibition on Kv1.1/KCNA1 (20.85% inhibition when tested with 1 uM of toxin) and Kv1.2/KCNA2 (7.23% inhibition, same conditions). Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 11 subfamily.