Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. Is active on mammals and bind with high affinity to rat brain synaptosome. Does not display phospholipid-binding activity. 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 125 ng/kg (2.5 ng/mouse) by intracerebroventricular injection into mice, 3.4 pmol/g by subcutaneous injection in mouse and 2317 pmol/g in Blattella germanica. Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.