Alpha toxins bind voltage-independently at site-3 of sodium channels and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission (By similarity). Shows analgesic activity (ED(50) is 1.42 mg/kg) and antitumor activity against Ehrlich ascites tumor and fibrosarcoma models in vivo. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.