Understanding Molecular Recognition at the Rhodopsin/Transducin Interface

说明书(申请人提供)：G蛋白偶联受体(GPCRs)参与许多病理过程，并与许多疾病有关；超过50%的药物针对GPCRs。视紫红质，视网膜gpr，被用作原型gpr，因为它是唯一存在X射线结构的gpr。光照后，视紫红质改变构象(R-&gt；R*)，使其G蛋白、转导蛋白结合。转导蛋白C-末端区域Gtalpha(340-350)与视紫红质细胞内环的相互作用对GDP/GTP交换和随后的视觉级联信号放大至关重要。视紫红质的一些先天突变导致视紫红质停留在R*状态，导致结构性信号放大。我的研究目标是了解视紫红质和转导蛋白之间的分子识别，并开发一种分子疗法来阻断这种相互作用。利用实验和计算技术，我将确定Gtalpha(340-350)多肽和多肽模拟物与R*的结合模式和残基-残基相互作用。我将使用平行技术衍生出一个小分子来抑制视紫红质/转导蛋白的相互作用。首先，我将使用建模软件和计算高通量筛选来设计一种抑制剂。其次，我将探索使用高效反应来产生模拟肽化合物，使用视紫红质作为反应模板。相关声明：尽管市场上有大量针对G蛋白偶联受体(GPCRs)的药物，但人们对GPCRs如何与其他蛋白质相互作用并向下游过程发出信号知之甚少。利用视紫红质，这是参与视觉的典型GPCR，我将使用实验和计算方法确定视紫红质和转导蛋白(视紫红质的G蛋白)是如何相互作用的，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GPCRs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.