Understanding Molecular Recognition at the Rhodopsin/Transducin Interface

描述（由申请人提供）：G蛋白偶联受体（GPCR）参与许多病理过程并与许多疾病有关;超过50%的药物靶向GPCR。视紫红质，视网膜GPCR，被用作原型GPCR，因为它是唯一存在X射线结构的GPCR。在光暴露后，视紫红质改变构象（R->R*），允许其G蛋白，转导蛋白结合。转导素C-末端区域Gtalpha（340-350）与视紫红质的细胞内环的相互作用对于视觉级联中的GDP/GTP交换和随后的信号放大是至关重要的。视紫红质的一些先天性突变导致视紫红质停留在R* 状态，导致组成性信号放大。本研究的目的是了解视紫红质和转导素之间的分子识别，并开发一种分子治疗剂来阻断这种相互作用。使用实验和计算技术，我将确定Gtalpha（340-350）肽和肽模拟物与R* 的结合模式和残基-残基相互作用。我将使用平行的技术来获得一个小分子来抑制视紫红质/transducin相互作用。首先，我将使用建模软件和计算高通量筛选来设计抑制剂。其次，我将探索使用高效的反应来生成肽模拟化合物，使用视紫红质模板反应。相关性声明：尽管市场上有大量靶向G蛋白偶联受体（GPCR）的药物，但对GPCR如何与其他蛋白质相互作用和信号下游过程知之甚少。使用视紫红质，参与视觉的原型GPCR，我将确定视紫红质和transformin（视紫红质的G蛋白）如何使用实验和计算方法相互作用，我将设计和测试一个小分子来阻止这种相互作用。这项工作将提供有关GPCR如何与G蛋白相互作用的一般信息，并可能导致一些先天性视网膜疾病的小分子治疗。

DESCRIPTION (provided by applicant): G-protein coupled receptors (GPCRs) are involved in many pathological processes and implicated in many diseases; over 50% of the drugs target GPCRs. Rhodopsin, the retinal GPCR, is used as the prototypical GPCR because it is the only GPCR for which an X-ray structure exists. Following light exposure, rhodopsin changes conformation (R->R*), allowing its G-protein, transducin, to bind. The interaction of the transducin C-terminal region Gtalpha(340-350) with the intracellular loops of rhodopsin is critical for GDP/GTP exchange and subsequent signal amplification in the vision cascade. Some congenital mutations in rhodopsin cause rhodopsin to stay in the R* state, leading to constitutive signal amplification. The goal of my research is to learn about the molecular recognition between rhodopsin and transducin and develop a molecular therapeutic to block this interaction. Using both experimental and computational techniques, I will determine the binding mode and residue-residue interactions of Gtalpha(340-350) peptides and peptidomimetics with R*. I will use parallel techniques to derive a small molecule to inhibit the rhodopsin/transducin interaction. First, I will use modeling software and computational high-throughput screening to design an inhibitor. Secondly, I will explore the use of high-efficiency reactions to generate peptidomimetic compounds using rhodopsin to template the reaction. Statement of Relevance: Despite a large number of drugs on the market targeting G-protein coupled receptors (GPCRs), very little is known about how GPCRs interact with other proteins and signal downstream processes. Using rhodopsin, the prototypical GPCR involved in vision, I will determine how rhodopsin and transducin (rhodopsin's G-protein) interact using experimental and computational methods, and I will design and test a small molecule to block this interaction. This work will provide general information about how GPCRs interact with G-proteins and potentially lead to a small molecule therapeutic for some congenital retinal diseases.