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(+) 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(+) 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(+) channel, rNa(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.

中文翻译：

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五个“经典”蝎子β毒素对rNav1.2a和DmNav1的不同作用提供了物种选择性的线索。

总的来说，蝎子的β-毒素已经被很好地检查过了。但是，很少有深入的研究致力于在不同电压激活的Na（+）通道上进行物种选择性和亲和力比较，因为它们已经可以作为克隆通道使用，可以在异源表达系统中进行研究。结果，它们的分类在很大程度上是历史性的，可以追溯到对小鼠，蟑螂和蝇类幼虫进行的早期体内实验。在这项研究中，我们旨在提供蝎子β毒素对脊椎动物或无脊椎动物的电压激活Na（+）通道的选择性和亲和力的更新概述。作为药理学工具，我们使用了经典的β-毒素AaHIT，Css II，Css IV，Css VI和Ts VII，并在神经元脊椎动物电压激活的Na（+）通道rNa（v）1.2a上对其进行了测试。为了比较，它的无脊椎动物 DmNav1，也经过了测试。这两个通道均在非洲爪蟾卵母细胞中表达，并用双电极电压钳技术测量电流。我们用对大鼠脑突触小体的一些结合置换研究来补充该数据。结果使我们提出了基于药理活性的蝎子β-毒素的一般分类和新颖的命名法。