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Updated: Aug 19, 2026

Examining Monosynaptic Connections in Drosophila Using Tetrodotoxin Resistant Sodium Channels
Published on: February 14, 2018
The depressant scorpion neurotoxin LqqIT2 selectively modulates the insect voltage-gated sodium channel
Frank Bosmans1, Marie-France Martin-Eauclaire, Jan Tytgat
1Laboratory of Toxicology, Faculty of Pharmacy, University of Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium.
Abstract:
LqqIT2 is a depressant neurotoxin present in the venom of the Leiurus quinquestriatus quinquestriatus scorpion, one of the world's most dangerous scorpions endemic to dry habitats in Africa and Asia. In order to determine its efficacy, potency and selectivity, LqqIT2 was subjected for the first time to an electrophysiological and pharmacological comparison between two different cloned sodium channels expressed in Xenopus laevis oocytes. Aside from typical beta-toxin effects, LqqIT2 also affected the inactivation process and ion selectivity of the insect voltage-gated sodium channel. The most interesting feature of LqqIT2 is its total insect-selectivity. At a concentration of 1 microM, the insect-voltage-gated sodium channel, para, was profoundly modulated while its mammalian counterpart, the rat brain Na(v)1.2 channel, was not affected. This trait offers excellent prospects for the development of novel insecticides.
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