Blocks Kv1.3/KCNA3 voltage-gated potassium channels of human T-lymphocytes (Kd=0.71 nM). 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 calcium-activated potassium channels (KCa3.1/KCNN4) of human T-lymphocytes. Does not inhibit voltage-gated Shaker potassium channels. Does not inhibit rKv2.1/KCNB1 potassium channels. Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 02 subfamily.