Differential effects of five 'classical' scorpion {beta}-toxins on rNa{sub v}1.2a and DmNav1 provide clues on species-selectivity
- Laboratory of Toxicology, University of Leuven, O and N 2, Postbus 922, Herestraat 49, 3000 Leuven (Belgium)
- CNRS FRE 2738, Biologie des Interactions Moleculaires et Cellulaires, Faculte de Medecine secteur Nord, Institut Jean Roche, Universite de la Mediterranee, Bd Pierre Dramard, 13916, Marseille, Cedex 20 (France)
In general, scorpion {beta}-toxins have been well examined. However, few in-depth studies have been devoted to species selectivity and affinity comparisons on the different voltage-activated Na{sup +} channels since they have become available as cloned channels that can be studied in heterologous expression systems. As a result, their classification is largely historical and dates from early in vivo experiments on mice and cockroach and fly larvae. In this study, we aimed to provide an updated overview of selectivity and affinity of scorpion {beta}-toxins towards voltage-activated Na{sup +} channels of vertebrates or invertebrates. As pharmacological tools, we used the classic {beta}-toxins AaHIT, Css II, Css IV, Css VI and Ts VII and tested them on the neuronal vertebrate voltage-activated Na{sup +} channel, rNa{sub v}1.2a. For comparison, its invertebrate counterpart, DmNav1, was also tested. Both these channels were expressed in Xenopus laevis oocytes and the currents measured with the two-electrode voltage-clamp technique. We supplemented this data with several binding displacement studies on rat brain synaptosomes. The results lead us to propose a general classification and a novel nomenclature of scorpion {beta}-toxins based on pharmacological activity.
- OSTI ID:
- 20976837
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 218, Issue 1; Other Information: DOI: 10.1016/j.taap.2006.10.009; PII: S0041-008X(06)00370-X; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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