Blocks small conductance calcium-activated potassium channels (PubMed:12239213). Shows activity on KCa2.2/KCNN2 (IC(50)=0.0243 nM), KCa2.3/KCNN3 (IC(50)=1.7 nM), and KCa2.1/KCNN1 (IC(50)=42 nM) (PubMed:12239213). Induces cell death when tested on Jurkat E6-1 and human mammary breast cancer MDA-MB-231 which constituvely express KCa2.2/KCNN2, but not on human peripheral blood lymphocytes (which do not express KCa2.2/KCNN2) (PubMed:24821061). 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 show inhibition on KCa3.1/KCNN4 at concentrations up to 50 nM. Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 05 subfamily.