Structure-Function of Opioid Receptors

描述（由申请人提供）：处理阿片类药物系统的物质是广泛使用的药物；治疗慢性疼痛的激动剂（麻醉性镇痛药）；拮抗剂通常用于治疗成瘾性疾病，包括物质滥用（阿片、酒精、安非他明）和非物质成瘾，即行为成瘾。鉴于阿片类激动剂治疗的困难、过量使用导致死亡的高风险（2008年报告的受害者人数超过海洛因和可卡因过量使用人数的总和）以及耐受性和成瘾性的发展，需要更安全的麻醉镇痛药。该研究计划采用结构、计算、生物物理、生化和药理学方法：(1)对阿片受体| j、6、K和痛感肽受体的作用有了新的认识，定义了分子识别和激活的结构基础；(2)设计新的结合配体。目的是：(1)利用x射线晶体学和核磁共振了解阿片受体的分子识别和功能选择性；(2)利用计算方法了解这四种受体的功能和药理选择性的分子机制；(3)了解配体定向信号（g蛋白，阻滞蛋白，jnk依赖）及其在介导阿片受体作用中的相关性。由四个核心小组通过项目间合作支持的三个项目将以今年之前无法想象的规模解决重要但困难的问题。项目1将对配体结合的配合物进行结构测定。项目2将进行计算研究，定义阿片受体的结合口袋，并进行计算机辅助的SBDD，设计一系列新的优化化合物，包括变构、功能选择性和双位配体。项目3将进行体外和体内研究，以表征配体的药理学特性，并产生新的受体偏倚突变体，以测试与功能选择性和阿片受体作用相关的假设。核心小组支持所有3个项目的目标，并将负责(1)纯化阿片受体的大规模生产；(2)阿片配体的合成，包括新设计的工具化合物，用于结构和功能研究；(3)分子分析和新小分子的筛选；(4)整个项目的管理和管理。设施资源将由NIGMS GPCR网络的大规模蛋白质生产和结构解决方案的结构测定管道和NIMH精神活性药物筛选计划的资源提供，用于新型小分子的选择性分析。

DESCRIPTION (provided by applicant): Substances addressing the opioid system are widely used pharmaceuticals; agonists (narcotic analgesics) for the treatment of chronic pain; antagonists generally for the treatment of addictive disorders, including substance abuse (opiate, alcohol, amphetamine) and non-substance, i.e. behavioral addictions. Given the difficulties associated with opioid agonist therapy, high risk of death due to overdose (more victims were reported in 2008, than overdose of heroin and cocaine combined) and the development of tolerance and addiction, there is a need for safer narcotic analgesics. The proposed research program uses structural, computational, biophysical, biochemical, and pharmacological approaches: (1) to develop a new level of understanding of the action the opioid receptors, | j , 6, K, and the nociceptin receptor, defining the structural basis for molecuar recognition and activation, and (2) to design new binding ligands. Aims are to (1) understand opioid receptor molecular recognition and functional selectivity using X-ray crystallography and NMR; (2) understand the molecular mechanisms for functional and pharmacological selectivity for the four receptors using computational approaches; and (3) understand ligand-directed signaling (G-protein-, arrestin-, JNK-dependent) and its relevance in mediating opioid receptor action. Three projects supported by four core groups via inter-project collaborations will address important but difficult questions at a scale not imagined prior to this year. Project 1 will carry ut structural determination on ligand bound complexes. Project 2 will carry out computational studies to define the binding pockets of opioid receptors and perform computer-assisted SBDD to design a new series of optimized compounds including allosteric, functionally selective and bitopic ligands. Project 3, will carry out in vitro and in vivo studies to characterize pharmacological properties of ligands and generate new receptor biased mutants to test hypotheses related to functional selectivity and opioid receptor actions. Core groups support the aims of all 3 projects and will be responsible for (1) large-scale production of purified opioid receptors; (2) synthesis of opiate ligands including newly designed tool compounds for structural and functional studies; (3) molecular profiling and screening of new small molecules, and (4) management and administration of the overall program. Facility resources will be provided by the NIGMS GPCR Networks' Structural Determination Pipeline for large-scale protein production and structure solution and the NIMH Psychoactive Drug Screening Program resources for selectivity profiling of novel small molecules.