Structure and Function of CB2 Cannabinoid Receptor

CB2 大麻素受体的结构和功能

• 批准号: 7061327
• 负责人: ZHAO-HUI SONG
• 金额: $ 25.12万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7061327
• 关键词: active sites; cannabinoid receptor; chemical models; computer simulation; disulfide bond; ligands; mass spectrometry; molecular dynamics; protein purification; protein reconstitution; protein structure function; receptor expression; site directed mutagenesis

DESCRIPTION (provided by applicant): 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 specifically targeted at CB2 should be devoid of psvchoactive side effects of marijuana.

描述（由申请人提供）：该研究建议的长期目标是确定CB2大麻素受体功能的分子基础。为了实现此目的，将采取以下步骤。在AIM 1和2中，将进行互动诱变，分子建模和新的化合物测试研究。这种结合的方法已经提高了我们的理解，并应继续揭示有关大麻素配体如何被其受体，受体亚型 - 选择性的起源以及如何激活/灭活这些受体认识的新见解。大麻素受体共享许多在其他良好研究的G蛋白偶联受体（GPCR）中看到的许多保守序列基序，例如Rhodopsin和生物胺受体。但是，大麻素受体中缺少了许多其他GPCR中存在的几个螺旋弯曲残基和基序以及一个关键的二硫键。在AIM 3中，将使用取代的半胱氨酸可及性法映射CB2大麻素受体的两个跨膜结构域的配体结合缝隙暴露。这种方法应阐明大麻素受体这些trasmemmbrane结构域中序列差异的结构和功能后果。 在AIM 4中，CB2受体的二硫键形成将直接通过质谱的最新方法来确定。研究独特的二硫键或不存在二硫键应提供CB2受体的重要螺旋折叠信息，这将对该受体的配体结合缝隙和激活机制具有重要意义。最后，在AIM 5中，努力将用于过表达和净化大量功能CB2受体。如果成功完成，这项具有挑战性的任务应该通过为未来的高分辨率生物物理研究提供急需的纯受体蛋白质产生重大影响。总体而言，这项研究应帮助我们以更分子的细节了解CB2受体的结构和功能。 CB2主要分布在免疫系统中。这对于大麻的免疫调节作用非常重要。从长远来看，这项研究还应帮助我们开发更好的大麻素模拟物来治疗免疫系统疾病，例如炎症和自身免疫性疾病。专门针对CB2的药物应没有大麻的PSVCHOACTIVE副作用。