The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
Biochem Biophys Res Commun. 2020 Dec 17;533(4):958-964. doi: 10.1016/j.bbrc.2020.09.103. Epub 2020 Sep 29.
Voltage-gated sodium channels are critical for the generation and propagation of action potentials. Gating modifier toxins from spider venom can modulate the gating mechanism of sodium channels and thus have potential as drug leads. Here, we established expression of the gating modifier toxin PaurTx-3, a sodium channel inhibitor found in the venom of the spider Phrixotrichus auratus. Whole-cell voltage-clamp recordings indicated that recombinant PaurTx-3 (rPaurTx-3) inhibited Nav1.4, Nav1.5, and Nav1.7 currents with IC values of 61 nM, 72 nM, and 25 nM, respectively. Furthermore, rPaurTx-3 irreversibly inhibited Nav1.7 currents, but had 60-70% recovery in Nav1.4 and Nav1.5 after washing with a bath solution. rPaurTx-3 also hyperpolarized the voltage-dependent steady-state inactivation curve and significantly slowed recovery from fast inactivation of Nav1.7. Current-clamp recordings showed that rPaurTx-3 suppressed small DRG neuron activity. The biological activity assay findings for rPaurTx-3 support its potent pharmacological effect in Nav1.7 and small DRG neurons.
电压门控钠离子通道对于动作电位的产生和传播至关重要。来自蜘蛛毒液的门控修饰毒素可以调节钠离子通道的门控机制，因此具有作为药物先导的潜力。在这里，我们建立了门控修饰毒素 PaurTx-3 的表达，PaurTx-3 是在蜘蛛 Phrixotrichus auratus 的毒液中发现的一种钠离子通道抑制剂。全细胞电压钳记录表明，重组 PaurTx-3（rPaurTx-3）以 61 nM、72 nM 和 25 nM 的 IC 值分别抑制 Nav1.4、Nav1.5 和 Nav1.7 电流。此外，rPaurTx-3 不可逆地抑制 Nav1.7 电流，但在用浴液洗涤后，Nav1.4 和 Nav1.5 的恢复率为 60-70%。rPaurTx-3 还使电压依赖性稳态失活曲线超极化，并显著减慢 Nav1.7 的快速失活恢复。电流钳记录显示 rPaurTx-3 抑制了小 DRG 神经元的活动。rPaurTx-3 的生物活性测定结果支持其在 Nav1.7 和小 DRG 神经元中的强大药理学作用。
