Guanidinium Toxins as Molecular Probes for NaV Study

胍毒素作为 NaV 研究的分子探针

基本信息

批准号：
10848160
负责人：
Justin Du Bois
金额：
$ 4.62万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10848160
关键词：
Action Potentials Acute Address Affect Affinity Affinity Chromatography Antibodies Arrhythmia Binding Binding Proteins Biological Phenomena Biotin Biotinylation Cell Shape Cell membrane Cells Cellular Membrane Chemical Agents Chemicals Chemistry Collection Complex Cryoelectron Microscopy Cues Cysteine Development Digit structure Disease Drug Kinetics Electrophysiology (science)Engineering Epilepsy Epitopes Fluorescent Dyes Generations Genetic Genetic Variation Goals Human Human Pathology Image Individual Inflammation Mediators Inflammatory Injury Investigation Ions Kinetics Label Lead Literature Lysine Measures Medicine Membrane Membrane Proteins Methods Modeling Modification Molecular Molecular Probes Movement Mutagenesis Myopathy Natural Products Natural Source Nature Nerve Block Neuroglia Neurons Oral cavity Organism Penetration Physiology Population Post-Translational Protein Processing Process Property Protein Isoforms Proteins Proteomics Reagent Reporting Research Role Saxitoxin Shapes Signal Transduction Site Skeletal Muscle Sodium Channel Structure Study models Surface Tetrodotoxin Therapeutic Tissues Toxin Training Transfection Vestibule Work bioelectricity cell fixing cell type chemical synthesis experimental study extracellular genetic approach guanidinium human disease hydrophilicity imaging agent inhibitor insight interest live cell imaging mutant nanomolar nerve injury nervous system disorder neuronal excitability neurotransmission painful neuropathy programs protein complex protein degradation protein transport response small molecule sodium ion spatiotemporal success tool voltage

项目摘要

PROJECT SUMMARY Neuronal excitability relies on the tightly regulated expression and discrete subcellular localization of voltage-gated sodium ion channels (Navs). These large membrane protein complexes control the movement of sodium ions across cell membranes and are responsible for initiating and propagating action potentials. A desire to better understand the role of Nav subtypes in electrical signal conduction and the relationship between channel dysregulation and specific human pathologies (e.g., arrhythmia, epilepsy, skeletal muscle disorders, neuropathic pain} motivates the development of high precision reagents to facilitate Nav studies. Investigations of Nav physiology are currently limited by a lack of available methods with which to modulate the function of individual channel subtypes and to mark changes in cellular distributions, membrane expression levels, and structural modifications (i.e., protein posttranslational modification) in live cells and in response to external cues. We are developing small molecule probes for Nav studies based on naturally occurring bis-guanidinium toxins, among which saxitoxin (STX) is the archetype. These agents function as molecular 'corks' to occlude the extracellular mouth of the ion conductance pore, a desirable feature for the types of tool compounds we wish to access. De novo chemical synthesis has enabled the engineering of modified forms of STX, which we will use in combination with protein mutagenesis and electrophysiology to investigate Nav activity on action potential dynamics. Understanding how Nav expression is regulated and altered by extrinsic factors-glial cells, inflammatory mediators, pH, nerve injury-and how such changes modulate action potentials is a long-term goal of our research. To address these questions, we will develop and validate three classes of tool compounds. These reagents will enable 1) acute, spatiotemporal inhibition of individual Nav subtypes; 2) selective fluorescent labeling of membrane Navs; and 3) affinity purification of membrane Navs for proteomics analysis. With the success of our research program, we will deliver a unique set of high precision chemical probes to help illuminate the complex physiology of Navs that under1ies bioelectrical signaling.

项目概要神经元兴奋性依赖于严格调控的表达和离散的亚细胞电压门控钠离子通道（Navs）的定位。这些大膜蛋白复合物控制钠离子穿过细胞膜的运动，并负责启动和传播动作电位。渴望更好地理解导航的作用电信号传导的亚型以及通道失调与特定的人类病理（例如心律失常、癫痫、骨骼肌疾病、神经病 pain} 促进了高精度试剂的开发，以促进 Nav 研究。目前，由于缺乏可用的方法，导航生理学的研究受到限制。调节各个通道亚型的功能并标记细胞的变化分布、膜表达水平和结构修饰（即蛋白质翻译后修饰）在活细胞中并对外部线索做出反应。我们正在开发基于天然双胍的用于 Nav 研究的小分子探针毒素，其中石房蛤毒素（STX）是其原型。这些代理的作用是分子“软木塞”堵塞离子电导孔的细胞外口，这是一种理想的方法我们希望访问的工具化合物类型的功能。从头化学合成实现了 STX 修饰形式的工程化，我们将其与蛋白质结合使用诱变和电生理学研究 Nav 活动对动作电位动力学的影响。了解 Nav 表达如何受外在因素（神经胶质细胞）的调节和改变，炎症介质、pH、神经损伤——以及这些变化如何调节动作电位我们研究的一个长期目标。为了解决这些问题，我们将开发并验证三类工具化合物。这些试剂将实现 1) 急性时空抑制各个 Nav 亚型； 2）膜Navs的选择性荧光标记； 3）亲和力用于蛋白质组学分析的膜 Navs 的纯化。随着我们研究的成功计划中，我们将提供一套独特的高精度化学探针来帮助阐明 Navs 的复杂生理学是生物电信号传导的基础。