Depressant insect beta-toxins cause a transient contraction paralysis followed by a slow flaccid paralysis. They bind voltage-independently at site-4 of sodium channels and shift the voltage of activation toward more negative potentials thereby affecting sodium channel activation and promoting spontaneous and repetitive firing. Aside from typical beta-toxin effects, this toxin also affects the inactivation process and ion selectivity of the insect voltage-gated sodium channel. This toxin is active only on insects (PubMed:15733572). Is active on the insect voltage-gated sodium channel para (PubMed:15733572). In vivo, when injected intraperitoneally, it exhibits analgesic activity, increasing hot plate and tail flick withdrawal latencies in a dose-dependent fashion (PubMed:20619318). This phenomenon might be partly due to an inhibitory mechanism activated by noxious stimuli (PubMed:20619318). Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). Does not affect the rat brain Nav1.2/SCN2A sodium channel. Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Beta subfamily.