Blocks voltage-gated potassium channels. At 2 uM, blocks rat Kv1.1/KCNA1 and Kv1.3/KCNA3, has a strong effect on rat Kv1.2/KCNA2 and Kv1.6/KCNA6 as well as a moderate effect on Shaker IR. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta). LD(50) is 2.0 ug/kg by intracerebroventricular injection into mice. Has no effect on rat Kv1.4/KCNA4, Kv1.5/KCNA5, Kv4.1/KCND1 or human Kv11.1/KCNH2 and Kv3.1/KCNC1 (PubMed:20713119). Has no effect on bovine KCa1.1 (PubMed:9354615, PubMed:20713119). Does not inhibit the growth of Gram-positive and Gram-negative bacteria (PubMed:26817841). The primary structure of this mature peptide is identical to that of toxin alpha-KTx 3.19 from Mesobuthus eupeus (AC C0HJQ6). Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 03 subfamily.