Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. The dissociation is voltage-dependent. This alpha-like toxin is highly toxic to insects and competes with LqhaIT on binding to insect sodium channels. Differs from classical anti-mammalian alpha-toxins as it inhibits sodium channel inactivation in cell bodies of hippocampus brain neurons, on which the anti-mammalian Lqh2 is inactive, and is unable to affect Nav1.2 in the rat brain, on which Lqh2 is highly active. Moreover, its pharmacological properties are unique in that its binding affinity for insect channels drops >30-fold at pH 8.5 versus pH 6.5, and its rate of association with receptor site-3 on both insect and mammalian sodium channels is 4-15-fold slower compared with LqhaIT and Lqh2. Monomer. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta). LD(50) is 50 mg/kg by intracerebroventricular injection into mice. Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.