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 inhibits inactivation of Nav1.6/SCN8A (EC(50)=790 nM) and drosophila DmNav1 (EC(50)=280 nM) (PubMed:21969612, Ref.2). The toxin (1 uM) does not significantly shift the midpoint of activation at the two channels, but induces a significant depolarizing shift in the V(1/2) of inactivation of the channels (PubMed:21969612). Has antimicrobial activity (Ref.2). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Shows no effect on Nav1.2/SCN2A and Nav1.8/SCN10A (PubMed:21969612). Shows a weak inhibition of inactivation on Nav1.3/SCN3A, Nav1.4/SCN4A, Nav1.5/SCN5A, and Nav1.7/SCN9A. Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily. Several genes are coding for this toxin for which the structure by NMR has been determined. The cross-references to PDB and additional information can be found in entry AC P86405.