EVALUATION OF THE NA+ CHANNEL OUTER VESTIBULE

NA 通道外前庭的评估

• 批准号: 6390724
• 负责人: SAMUEL C DUDLEY
• 金额: $ 15.86万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-10 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6390724
• 关键词: chemical binding; chemical models; computer simulation; ligands; model design /development; protein structure function; sodium channel; structural biology; voltage gated channel

The voltage-gated Na+ channel is the central determinant of muscle excitability. There are seven human disorders associated with gene defects in the Na+ channel or its subunits including the Long QT Syndrome and idiopathic ventricular fibrillation. Drugs that act upon Na+ channels including anticonvulsants, local anesthetics, and antiarrhythmic agents. The aim of the proposed project is to test, refine, and expand a molecular model of the outer vestibule and selectivity filter of the Na+ channel as part of larger effort to understand the structural biology of this channel. Detailed structural information will be necessary to fully understand the function of the channel, to engage in rational drug design, and to consider the possibility of protein engineering in conjunction with gene therapy to ameliorate genetic diseases linked to the Na+ channel. The hypothesis being tested is that a detailed molecular model of a complementary binding surface can be constructed by determining sufficient ligand/substrate interaction points using several ligands of known structure. The experiments will evaluate, refine, and expand a previously described Na+ channel outer vestibule model by testing predictions about the points of interaction with high affinity ligands that bind in this area. The approach is general for ligand/receptor interactions, and an analogy for this approach would be a lock and key where the ligands are the keys and the Na+ channel is the lock. The structure of the lock is determined by looking at the shape of the keys. Specifically, points of interaction between channel amino acids and the ligands will be determined using mutant cycle analysis. The shape of the ligands and the points of interaction are used as constraints when refining computer-generated models of the binding surface. Multiple toxins will used to probe as much of the outer vestibule as possible, to serve as validation of results obtain with other ligands, and to develop sufficient interaction points to constrain adequately the model.

电压门控Na+通道是肌肉兴奋性的中心决定因素。 有七种人类疾病与Na+通道或其亚基中的基因缺陷相关，包括长QT综合征和特发性心室颤动。作用于Na+通道的药物，包括抗惊厥药、局部麻醉药和抗惊厥药。 该项目的目的是测试，完善和扩展Na+通道的外前庭和选择性过滤器的分子模型，作为更大努力的一部分，以了解该通道的结构生物学。 详细的结构信息将是必要的，以充分了解通道的功能，从事合理的药物设计，并考虑蛋白质工程的可能性与基因治疗相结合，以改善遗传疾病与Na+通道。正在测试的假设是，一个详细的互补结合表面的分子模型，可以通过使用几个已知结构的配体确定足够的配体/底物相互作用点。 实验将评估，完善，并扩大先前描述的Na+通道外前庭模型通过测试预测点的相互作用与高亲和力的配体，结合在这方面。该方法对于配体/受体相互作用是通用的，并且该方法的类比将是锁和钥匙，其中配体是钥匙，Na+通道是锁。 锁的结构是通过看钥匙的形状来确定的。 具体而言，将使用突变体循环分析来确定通道氨基酸与配体之间的相互作用点。 配体的形状和相互作用的点被用作约束条件时，细化计算机生成的模型的结合表面。 多种毒素将用于探测尽可能多的外前庭，以验证用其他配体获得的结果，并产生足够的相互作用点以充分约束模型。