Development and study of specific Kir channel inhibitors

我们研究的长期目标是开发专门针对个别亚型的抑制剂。 离子通道，以确定抑制剂-通道相互作用机制，并使用抑制剂检查 引导生理学，并展示特定的治疗概念。由于内向整流K+(KIR)通道 发挥许多重要的生理作用，并代表着越来越重要的治疗靶点，亚型特定 KIR通道抑制剂具有实验和治疗价值。以下建议的研究将是 采用电生理学、生物化学和分子生物学相结合的方法进行。 此前，我们发现一种21个残基的蜜蜂毒素，Tertiapin(TPN)，抑制肾脏Kir1.1和 心肌Kir3.1/3.4通道具有纳摩尔亲和力。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允许选择性地 靶向不同的KIR亚型，也建立了这种亚型特异性抑制剂的原型。这个 由此产生的特定抑制剂可用于未来的研究，以帮助证明新的类别的概念 治疗某些心脏病的药物。 此外，我们发现哌嗪是一种非常安全和廉价的驱虫剂，已经被证明 在某些动物制剂中具有抗心律失常作用--选择性地抑制强整流性KIR通道 作为KIR 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物 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，通过结合 精力充沛和结构研究。此外，作为证明这一概念的第一步，我们将 证明可以利用哌嗪的某些阻断特性来治疗一种形式的短QT 由Kir2.1基因突变引起的综合征。 拟议的研究结果将显著提高我们破译生理学的能力 KIR通道在特定细胞类型或组织中的功能，并有助于开发有效的治疗方法 探员们。

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.