Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. This toxin expressed with the pET-14b vector has low inhibitory activity on sodium channels (11.33% on rNav1.2/SCN2A, 15.96% on mNav1.4/SCN4A and 5.04% on hNav1.5/SCN5A). When expressed with the pET-28a vector, this toxin has higher inhibitory activities (44.12% on rNav1.2/SCN2A, 25.40% on mNav1.4/SCN4A and 65.34% on hNav1.5/SCN5A). 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.