Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission (By similarity). This protein is weakly toxic against insects (ED(50)>2 ug per 100 mg of blowfly larvae), but is inactive against mammalian sodium channels (rNav1.2a, and rNav1.4) (PubMed:20018978). 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.