Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. Electrophysiological studies of this were performed using sodium-channels expressed in F11 cell culture, by patch-clamp recordings. Affinity of this toxin toward sodium channels in F11 cell line is in the order of 1 uM concentration. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). LD(50) is 2.5 ug/kg when intracranially injected into mice. Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.