Beta toxins bind voltage-independently at site-4 of sodium channels (Nav) and shift the voltage of activation toward more negative potentials thereby affecting sodium channel activation and promoting spontaneous and repetitive firing. This toxin shows moderate inhibition of Nav1.1/SCN1A, Nav1.2/SCN2A, and Nav1.4/SCN4A, and promotes a left voltage shift on these channels. It exhibits similar potency on Nav1.2/SCN2A and Nav1.4/SCN4A (40-50% peak current inhibition at 0.5 uM), and weaker inhibition on Nav1.2 (20-30% peak current inhibition at 0.5 uM). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Average mass. Shows weak inhibition on Nav1.3/SCN3A, Nav1.5/SCN5A, Nav1.8/SCN8A, and Nav1.7/SCN9A. Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Beta subfamily.