Binds specifically to voltage-gated sodium channels (Nav) (site 3), thereby delaying their inactivation during signal transduction. Has a strong effect on crustaceans and insects and a weaker effect on mammals. It strongly inhibits D.melanogaster sodium channel (DmNav1). It strongly affects the heart sodium channels (Nav1.5/SCN5A) and weakly inhibits the brain sodium channel Nav1.2/SCN2A. In vivo, when released into the medium, this recombinant toxin induces impaired swimming, paralysis and death of the crustacean A.nauplii within several hours. Its effect on zebrafish (D.rerio) larvae is much faster, since it induces paralysis or strong convulsion and impaired swimming, within 10 minutes