Development /use of peptidic inhibitors for Kir channels

描述：我们研究的长期目标是开发有效的 内向整流性K+通道的抑制剂并将其用作分子探针 探索这些离子通道功能的分子机制。 我们最近发现了一种蜜蜂毒素Tertiapin，它是一种 纳摩尔亲和蛋白-某些内向整流性K+通道的抑制剂。 Tertiapin的结构已知，它通过与 K+传导小孔的外前庭。在目标1A中，我们将首先使用 以Tertiapin为探针探索细菌外孔的分子结构 内向整流钾通道。通过识别两个变量之间的配对关系 用热力学突变循环分析通道和毒素残留物，我们将 能够将与毒素残基配对的每个通道残基分配到位置 在相对于毒素结构的空间中，从而描绘出 外孔的结构。然后我们将在目标1B中研究该机制 通道-毒素相互作用的特异性。有了这些知识， 我们将设计具有更高通道特异性的抑制剂(目标2A)，并将 还使用了噬菌体展示，一种非常强大的组合肽 技术，从随机多肽中选择特定的通道抑制多肽 图书馆(目标2B)。 拟议的基础研究也具有重要的医学意义。 内向整流钾通道在生理和生理上都具有重要意义 具有病理生理学意义，是重要的药理靶点。这个 我们开发的抑制剂将成为研究 通道的生理学和/或病理生理学以及用于开发 特别针对这些渠道。

DESCRIPTION: The long term goal of our research is to develop effective inhibitors for inward-rectifier K+ channels and use them as molecular probes to explore the molecular mechanisms underlying the function of these ion channels. We have recently identified tertiapin, a honeybee toxin, as a nanomolar-affinity protein-inhibitor for some inward-rectifier K+ channels. Tertiapin, whose structure is known, inhibits the channels by binding to the external vestibule of the K+ conduction pore. In Aim 1A, we will first use tertiapin as a probe to explore the molecular architecture of the outer pore in inward-rectifier K+ channels. By identifying the pairing relation between channel and toxin residues with thermodynamic mutant cycle analysis, we will be able to assign each channel residue pairing with a toxin residue to a location in space with respect to the toxin structure, and thus to delineate the architecture of the outer pore. We will then in Aim 1B examine the mechanism underlying the specificity of channel-toxin interactions. With this knowledge we will design inhibitors with higher channel specificity (Aim 2A), and will also employ phage display, a type of very powerful combinatorial peptide technology, to select specific channel-inhibiting peptides from random peptide libraries (Aim 2B). The proposed fundamental studies also have important medical implications. Inward-rectifier K+ channels are significant both physiologically and pathophysiologically and represent important pharmacological targets. The inhibitors that we develop will be powerful tools both for investigating the physiology and/or pathophysiology of the channels and for developing drugs that specifically target these channels.