Alpha toxins bind voltage-independently at site-3 of sodium channels and inhibit the inactivation of the activated channels. The toxin affect mammalian sodium channels Nav1.7/SCN9A (EC(50)=4.5 nM), Nav1.4/SCN4A (EC(50)=9.6 nM), Nav1.6/SCN8A (EC(50)=30 nM), Nav1.5/SCN5A (only at micromolar concentrations), and insect sodium channel para/tipE (EC(50)=80 nM) (PubMed:16038905, PubMed:16641312, PubMed:23527544). In vivo, intraplantar administration of this toxin elicits pain behaviors, including licking and flinching of the hind paw (PubMed:26999206). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). With amidation. Intraplantal administration of this protein is used as a pharmacological tool to establish a Nav1.7/SCN9A-mediated mouse model of pain. Has no effect on mammalian sodium channels Nav1.2/SCN2A, Nav1.3/SCN3A, and Nav1.8/SCN10A (PubMed:16038905, PubMed:16641312). Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.