Binds to sodium channels (Nav) and inhibits the inactivation of the activated channels, thereby blocking neuronal transmission (By similarity). Tested on mice, has antitumor effect and strong inhibitory effect on pain. 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.