Selectively inhibits voltage-gated potassium channels rKv1.2/KCNA2 (IC(50)=331 nM) and hKv1.3/KCNA3 (IC(50)=503 nM). Partially inihibts rKv1.6/KCNA6 (IC(50)=9983 nM). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta). Contains 3 disulfide bonds. This toxin does not affect the following channels: rKv1.1/KCNA1, rKv1.4/KCNA4, rKv1.5/KCNA5, Shaker IR (with inactivation domain removed), rKv2.1/KCNB1, hKv3.1/KCNC1, rKv4.2/KCND2 and hKv11.1/KCNH2/ERG1. Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 08 subfamily.