Structure and Function of CB2 Cannabinoid Receptor

这项研究计划的长期目标是确定以下功能的分子基础 CB 2大麻素受体为实现这一目标，将采取以下步骤。在目标1和2中， 将进行交互诱变，分子模拟和新化合物测试研究。 这种综合方法促进了我们的理解，并应继续揭示新的见解， 大麻素配体如何被其受体识别，受体亚型选择性的起源，以及 这些受体如何被激活/失活。大麻素受体有许多保守的 在其他研究充分的G蛋白偶联受体（GPCR）中看到的序列基序，如视紫红质和 生物胺受体然而，几个螺旋弯曲残基和基序以及一个关键的二硫键 存在于许多其他GPCR中的桥在大麻素受体中缺失。在目标3中，配体结合 CB 2大麻素受体的两个跨膜结构域的缝隙暴露将使用 取代半胱氨酸可及性方法。这种方法应阐明结构和功能 这是大麻素受体的这些跨膜结构域中序列差异的结果。在 目的4、利用现有技术直接测定CB 2受体的二硫键形成 质谱方法学。研究独特的二硫键或不存在二硫键 CB 2受体的螺旋折叠信息，这将具有重要意义。 关于配体结合裂缝和这种受体的激活机制的影响。最后，在Aim 5、将致力于大量过表达和纯化功能性CB 2受体。这 一项具有挑战性的任务，如果成功完成，应该通过提供糟糕的 需要纯受体蛋白用于未来的高分辨率生物物理研究。总的来说，这项研究应该 有助于我们更详细地了解CB 2受体的结构和功能。CB 2是 主要分布在免疫系统中。它对免疫调节作用非常重要， 大麻从长远来看，这项研究也应该帮助我们开发更好的大麻素模拟物， 治疗免疫系统疾病，如炎症和自身免疫性疾病。的药物 在CB 2中的所有目标都应该没有大麻的副作用。

The long-term goal of this research proposal is to identify the molecular basis underlying the functions of the CB2 cannabinoid receptor. To achieve this purpose, the following steps will be taken. In Aim 1 and 2, the interactive mutagenesis, molecular modeling and new compound testing studies will be carried out. This combined approach has advanced our understanding, and should continue to reveal new insights on how cannabinoid ligands are recognized by their receptors, the origin of receptor subtype-selectivity, and how _these receptors are activated/inactivated. Cannabinoid receptors share many of the conserved sequence motifs seen in other well-studied G protein-coupled receptors (GPCRs), such as rhodopsin and biogenic amine receptors. However, several helix-bending residues and motifs, and a key disulfide bridge present in many other GPCRs are missing in cannabinoid receptors. In Aim 3, Ligand binding crevice exposure of two transmembrane domains of CB2 cannabinoid receptor will be mapped using substituted-cysteine accessibility method. This approach should elucidate structural and functional consequences of the sequence divergence in these trasmembrane domains of cannabinoid receptors. In Aim 4, Disulfide bond formation of CB2 receptor will be determined directly by the state-of-art methodologies of mass spectrometry. Investigating the unique disulfide bond or absence of a disulfide bond should provide important helix folding information of CB2 receptor, and this will have important implications regarding ligand binding crevice and activation mechanisms of this receptor. Finally, in Aim 5, effort will be devoted to over-express and purify large amounts of functional CB2 receptor. This challenging task, if successfully completed, should have a significant impact by providing the badly needed pure receptor proteins for future high-resolution biophysical studies. Overall, This study should help us to understand in more molecular detail the structure and function of CB2 receptor. CB2 is primarily distributed in the immune system. It is very important for the immune-modulatory effects of marijuana. In the long run, this study should also help us to develop better cannabinoid mimetics for the treatment of immune system illnesses, such as inflammation and autoimmune diseases. The drugs that soecifi(;allv taroeted at CB2 should be devoid of [}svchoactive side effects of marijuana.