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 抑制剂的内向整流钾离子通道，并使用它们作为分子探针， 探索这些离子通道功能的分子机制。 我们最近发现了特硫平，一种蜜蜂毒素， 纳摩尔亲和蛋白抑制剂，用于某些内向整流钾离子通道。 Tertiapin，其结构是已知的，通过结合到 K+传导孔的外前庭。在目标1A中，我们将首先使用 tertiapin作为探针探索外孔的分子结构， 内向整流钾离子通道。通过识别 通道和毒素残基与热力学突变循环分析，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 在空间上相对于毒素结构，从而描绘 外孔的结构。然后，我们将在目标1B中研究该机制 这是通道-毒素相互作用的特异性的基础。有了这些知识 我们将设计具有更高通道特异性的抑制剂（Aim 2A）， 也使用噬菌体展示，一种非常强大的组合肽 技术，从随机肽中选择特异性通道抑制肽 图书馆（目标2B）。 拟议的基础研究也具有重要的医学意义。 内向整流钾离子通道在生理和生理上都有重要意义， 在病理生理学上，并代表重要的药理学靶点。的 我们开发的抑制剂将是研究 用于研究通道的生理学和/或病理生理学以及用于开发 专门针对这些渠道。

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.