Development and study of specific Kir channel inhibitors

我们研究的长期目标是开发特异性针对单个亚型的抑制剂， 离子通道，以确定通道-通道相互作用机制，并使用抑制剂来检查 引导生理学并展示某些治疗概念。由于内向整流钾离子（Kir）通道 发挥许多重要的生理作用，并代表越来越重要的治疗靶点，亚型特异性 Kir通道抑制剂具有实验和治疗价值。下文提议的研究将 通过电生理学、生物化学和分子生物学的组合方法进行。 以前，我们发现21个残基的蜜蜂毒素，特硫平（TPN），抑制肾Kir1.1和 具有纳摩尔亲和力的心脏Kir3.1/3.4通道。在目标#1中，我们将创建针对Kir1.1或 Kir3.1/3.4。我们的初步研究不仅确定了通道序列， 靶向各种Kir亚型，而且还建立了这种亚型特异性抑制剂的原型。的 由此产生的特异性抑制剂可用于未来的研究，以帮助证明新类别的概念， 治疗某些心脏病的药物。 此外，我们发现哌嗪-一种非常安全和廉价的驱虫剂， 在某些动物制剂中具有抗组胺作用-选择性地抑制强烈的整流Kir通道， 作为基尔2.1。哌嗪的选择性和安全性使其（或其衍生物）成为一种很有前途的候选药剂 用于治疗某些心律失常。由于这种潜在的治疗价值，我们将在目标2中， 研究哌嗪与通道相互作用的机制， 能量和结构研究。此外，作为证明概念的第一步，我们将 证明了哌嗪的某些封闭特性可以用于治疗短QT形式 由Kir2.1突变引起的综合征。 拟议研究的结果将大大提高我们破译生理学的能力。 Kir通道在给定细胞类型或组织中的功能，并帮助开发有效的治疗药物。 剂.

The long-term goals of our research are to develop inhibitors specifically targeting individual subtypes of ion channels, to determine inhibitor-channel interaction mechanisms, and to use the inhibitors to examine channel physiology and demonstrate certain therapeutic concepts. Since inward-rectifier K+ (Kir) channels play many vital physiological roles and represent increasingly important therapeutic targets, subtype-specific Kir channel inhibitors are experimentally and therapeutically valuable. The studies proposed below will be carried out with a combined approach of electrophysiology, biochemistry, and molecular biology. Previously, we discovered that a 21-residue honey bee toxin, tertiapin (TPN), inhibits renal Kir1.1 and cardiac Kir3.1/3.4 channels with nanomolar affinity. In Aim#1, we will create inhibitors specific for Kir1.1 or Kir3.1/3.4. Our preliminary studies have not only identified the channel sequence that will allow the selective targeting of various Kir subtypes but also established the prototype for such a subtype-specific inhibitor. The resulting specific inhibitors can be used in future studies to help prove the concept of new classes of medicine for treating certain cardiac diseases. Additionally, we found that piperazine - a very safe and inexpensive anthelmintic which has been shown to be anti-arrhythmic in some animal preparations - selectively inhibits strongly rectifying Kir channels such as Kir 2.1. The selectivity and safety of piperazine make it (or its derivatives) a promising candidate agent for treating certain cardiac arrhythmias. Because of this potential therapeutic value we will, in Aim#2, investigate the mechanisms by which piperazine interacts with the channel through a combination of energetic and structural studies. Furthermore, as the first step toward proving the concept, we will demonstrate that certain blocking properties of piperazine can be exploited for treating a form of short QT syndrome caused by a mutation in Kir2.1. The outcome of the proposed studies will significantly enhance our ability to decipher the physiological functions of Kir channels in a given cell type or tissue, and help in the development of effective therapeutic agents.