Mechanistic studies of the GYKI Compounds

描述(由申请人提供)：离子型谷氨酸受体的1-氨基-3-羟基-5-甲基-4-异恶唑丙酸酯(AMPA)亚型的过度激活被认为是许多神经系统疾病的主要因素，如癫痫、中风和肌萎缩侧索硬化症(ALS)。使用抑制剂作为神经保护药物来抑制过度的受体活性一直是人们追求的治疗策略。2，3-苯二氮卓类化合物，也称为GYKI化合物，是AMPA受体的抑制剂，代表了迄今为止开发的一类最有前途的候选药物。然而，这些化合物在AMPA受体上的定量和功能活性仍然不清楚。这是因为AMPA受体在微秒的时间范围内打开它们的通道，即使在毫秒的时间范围内也会脱敏。然而，目前的动力学技术没有足够的时间分辨率来表征通道开放的动力学机制和抑制剂/药物-受体相互作用的机制。在这个方案中，我们将系统地阐明一系列19个GYKI化合物的作用机制，测量它们对特定AMPA受体亚基的效力，并表征结构-活性关系，包括受体上抑制部位的数量以及任何两个部位是否相互作用(即，两个抑制剂与其结合部位的结合可能独立于第一个结合，也可能受到第一个结合的负面影响)。为了达到特定的目的，我们将进行一些实验，包括利用S时间分辨率的激光脉冲光解研究，以考察GYKI化合物对AMPA受体通道开放速率过程的影响。这些化合物的动力学研究与所有受体形式仍然起作用的时间尺度有关，以前是不可能的。我们对这些化合物的受体性质和构效关系的研究结果将对合理设计和合成具有较高效价的亚基和构象选择性GYKI化合物，以便更定量地控制AMPA受体活性具有重要意义。公共卫生相关性：我们建议系统地表征一组GYKI化合物，它们是AMPA谷氨酸离子通道受体的抑制剂。这些化合物是开发治疗涉及AMPA受体的一些神经疾病的潜在药物的候选药物。

DESCRIPTION (provided by applicant): Excessive activation of the 1-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) subtype of ionotropic glutamate receptors has been implicated as a leading contributor to a number of neurological diseases, such as epilepsy, stroke and amyotrophic lateral sclerosis (ALS). Using inhibitors as neuroprotective drugs to dampen the excessive receptor activity has been a long pursued therapeutic strategy. 2,3-Benzodiazepine derivatives, also known as GYKI compounds, are inhibitors of AMPA receptors, and they represent a class of the most promising drug candidates developed to date. However, the quantitative, functional activities of these compounds on AMPA receptors remain poorly defined. This is because AMPA receptors open their channels in the microsecond time domain and desensitize even in the millisecond time region. Yet, current kinetic techniques do not have sufficient time resolutions required to characterize the kinetic mechanism of channel opening and the mechanism of inhibitor/drug- receptor interaction. In this proposal, we will systematically elucidate the mechanism of action for a series of 19 GYKI compounds, measure their potency on specific AMPA receptor subunits, and characterize the structure-activity relationship, including the number of inhibitory sites on a receptor and whether any two sites interact with each other (i.e., the binding of two inhibitors to their sites can be independent or negatively affected by binding of either one first). To achieve the specific aims, we will carry out a number of experiments, including a laser- pulse photolysis study with the ?s time resolution to investigate the effect of a GYKI compound on the channel-opening rate process of an AMPA receptor. The kinetic investigation of these compounds, relevant to the time scale within which all receptor forms are still functional, has not been previously possible. Our results on the receptor properties and the structure-activity relationship of these compounds will be valuable for rational design and synthesis of subunit- and conformation-selective GYKI compounds with higher potency so that AMPA receptor activities can be controlled more quantitatively. PUBLIC HEALTH RELEVANCE: We propose to systematically characterize a group of GYKI compounds, which are inhibitors on AMPA glutamate ion channel receptors. These compounds are candidates for developing potential drugs to treat a number of neurological diseases involving AMPA receptors.