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. The toxin induces a leftward shift, on all channels tested (including Blattella germanica and Varroa destructor Nav1), displacing a change in voltage dependence activation to more hyperpolarized potentials (PubMed:30131471). In addition, the toxin mostly inhibits peak current of hNav1.4/SCN4A (53% inhibition of peak current at 100 nM) and hNav1.5/SCN5A (71% inhibition) (PubMed:30131471). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). The toxin shows a weak peak current inhibition of Nav1.1/SCN1A, Nav1.2/SCN2A, Nav1.3/SCN3A, Nav1.6/SCN8A, Nav1.7/SCN9A (17-30% inhibition of peak current at 100 nM). It does not inhibit peak current on insect (BgNaV1 from Blattella germanica) and arachnidan (VdNaV1 from Varroa destructor) sodium channel subtypes (tested at 100 nM) (PubMed:30131471). Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Beta subfamily.