Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia; Moscow Institute of Physics and Technology, State University, Moscow Region, Russia.
J Biol Chem. 2022 Nov;298(11):102467. doi: 10.1016/j.jbc.2022.102467. Epub 2022 Sep 8.
Among voltage-gated potassium channel (K) isoforms, K1.6 is one of the most widespread in the nervous system. However, there are little data concerning its physiological significance, in part due to the scarcity of specific ligands. The known high-affinity ligands of K1.6 lack selectivity, and conversely, its selective ligands show low affinity. Here, we present a designer peptide with both high affinity and selectivity to K1.6. Previously, we have demonstrated that K isoform-selective peptides can be constructed based on the simplistic α-hairpinin scaffold, and we obtained a number of artificial Tk-hefu peptides showing selective blockage of K1.3 in the submicromolar range. We have now proposed amino acid substitutions to enhance their activity. As a result, we have been able to produce Tk-hefu-11 that shows an EC of ≈70 nM against K1.3. Quite surprisingly, Tk-hefu-11 turns out to block K1.6 with even higher potency, presenting an EC of ≈10 nM. Furthermore, we have solved the peptide structure and used molecular dynamics to investigate the determinants of selective interactions between artificial α-hairpinins and K channels to explain the dramatic increase in K1.6 affinity. Since K1.3 is not highly expressed in the nervous system, we hope that Tk-hefu-11 will be useful in studies of K1.6 and its functions.
在电压门控钾通道 (K) 异构体中，K1.6 是神经系统中分布最广泛的之一。然而，关于其生理意义的数据很少，部分原因是缺乏特异性配体。已知的高亲和力 K1.6 配体缺乏选择性，而具有选择性的配体则亲和力较低。在这里，我们提出了一种具有高亲和力和选择性的 K1.6 特异性肽。以前，我们已经证明可以基于简单的 α-发夹蛋白支架构建 K 同工型选择性肽，并且我们获得了一些人工 Tk-hefu 肽，它们在亚微摩尔范围内选择性阻断 K1.3。我们现在已经提出了氨基酸取代来增强它们的活性。结果，我们能够产生 Tk-hefu-11，其对 K1.3 的 EC 值约为 70 nM。令人惊讶的是，Tk-hefu-11 对 K1.6 的阻断作用甚至更强，EC 值约为 10 nM。此外，我们解决了肽结构，并使用分子动力学研究了人工 α-发夹蛋白与 K 通道之间选择性相互作用的决定因素，以解释对 K1.6 亲和力的显著增加。由于 K1.3 在神经系统中表达水平不高，我们希望 Tk-hefu-11 将有助于研究 K1.6 及其功能。
