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Conformations and dynamics of amyloid-induced membrane disruption

淀粉样蛋白诱导的膜破坏的构象和动力学

基本信息

批准号：
7618179
负责人：
ANDREW D. MIRANKER
金额：
$ 20.15万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-05-01 至 2011-01-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7618179
关键词：
Address Alzheimer&apos s Disease Amyloid Amyloid fibers Amyloidosis Area Behavior Beta Cell Binding Binding Proteins Biological Catalysis Cell Death Cell physiology Cells Characteristics Chemicals Complex Computer Systems Development Cytotoxic agent Deposition Diffuse Diffusion Disease Dyes Energy Transfer Experimental Designs Extravasation Fiber Filament Fluorescence Functional disorder Goals In Vitro Individual Investigation Ions Label Lipid Bilayers Lipids Liposomes Location Measurement Measures Membrane Membrane Proteins Methods Molecular Molecular Conformation Monitor Mutate Nanostructures Nature Non-Insulin-Dependent Diabetes Mellitus Normal Cell Pancreas Pathology Pathway interactions Patients Peptides Plasma Population Process Property Protein Conformation Proteins Reaction Research Resistance Sampling Solutions Structure System Testing Time Toxic effect Variant Vesicle Work amyloid formation base cytotoxicity experience fibrillogenesis fluorophore in vivo insight interest islet amyloid polypeptide molecular dynamics nanostructured new therapeutic target novel peptide hormone polypeptide prevent programs protein structure response single molecule skills therapeutic development tool

项目摘要

DESCRIPTION (provided by applicant): Amyloid fibers are remarkably stable, self-assembled filaments that can be formed from virtually any protein. As polypeptides are readily mutated and/or derivatized, these properties make amyloid an attractive system for the development of biological nano-structures. Fiber formation involves the sampling of heterogeneous intermediate species, both conformational and oligomeric, as a central part of the pathway for assembly. Importantly, it is these intermediates, not fibers themselves that are associated with cytotoxicity in diseases such as Alzheimer's. Promising insights into the molecular basis of fibrillization have been deduced from the interactions of amyloidogenic proteins with interfaces, particularly lipid bilayers. These stabilize and organize structural intermediates thereby catalyzing fiber formation. It is also these interactions that are implicated as causal to cell death in amyloid diseases. The mechanism of the latter involves disruption of membranes and elimination of the ion gradients required for normal cellular function. Despite great interest in membrane bound amyloid intermediates, and their obvious relevance to pathology, their molecular characterization has been elusive due to their heterogeneous and transient nature. Single molecule fluorescence measurements are uniquely capable of quantification of heterogeneous and dynamic molecular populations. These will be developed and applied to the study of interactions of islet amyloid polypeptide (IAPP) with synthetic lipid vesicles. Two areas are specifically addressed: (1) characterization of the mechanism of membrane integrity loss induced by IAPP and (2) determination of IAPP states and dynamics associated with membrane disruption. The results of these investigations will provide a description of the molecular species involved in membrane permeabilization, and give insight into the mechanism of fiber assembly. Such understanding is critical to developing processes for manipulation and control of fiber assembly, will provide new tools for studying the behavior of membrane proteins and amyloid intermediates both in vitro and in vivo, and finally, will provide a basis for identifying novel targets suitable for the development of therapeutics. Understanding the processes by which proteins form pathological amyloid fibers requires a detailed description of the heterogeneous molecular species populated during fibrillization. This includes the membrane-associated structures that are implicated as causal agents in cell death in amyloid diseases. The aim of this work is to develop single molecule methods for studying interactions between the amyloidogenic protein, islet amyloid polypeptide, and lipid bilayers with a view towards identifying novel targets suitable for the development of therapeutics.

描述（由申请人提供）：淀粉样蛋白纤维是非常稳定的自组装细丝，几乎可以由任何蛋白质形成。由于多肽容易突变和/或衍生化，这些特性使得淀粉样蛋白成为开发生物纳米结构的有吸引力的系统。纤维形成涉及对异构中间物质（包括构象物质和低聚物质）的采样，作为组装途径的核心部分。重要的是，正是这些中间体，而不是纤维本身，与阿尔茨海默氏症等疾病的细胞毒性有关。从淀粉样蛋白与界面，特别是脂质双层的相互作用中，已经推导出了对纤维化分子基础的有希望的见解。这些稳定和组织结构中间体，从而催化纤维形成。也正是这些相互作用被认为是淀粉样蛋白疾病中细胞死亡的原因。后者的机制涉及破坏膜和消除正常细胞功能所需的离子梯度。尽管对膜结合的淀粉样蛋白中间体及其与病理学的明显相关性有很大兴趣，但由于其异质性和瞬时性，其分子表征一直是难以捉摸的。单分子荧光测量是唯一能够定量的异质性和动态的分子群体。这些将被开发并应用于研究胰岛淀粉样多肽（IAPP）与合成脂质囊泡的相互作用。具体涉及两个领域：（1）表征由IAPP诱导的膜完整性损失的机制和（2）确定与膜破坏相关的IAPP状态和动力学。这些调查的结果将提供一个描述的分子物种参与膜透化，并深入了解纤维组装的机制。这样的理解是至关重要的开发过程中的操纵和控制的纤维组装，将提供新的工具，研究膜蛋白和淀粉样蛋白中间体的行为在体外和体内，并最终，将提供一个基础，确定新的目标，适用于发展的治疗。了解蛋白质形成病理性淀粉样纤维的过程需要详细描述纤维化过程中聚集的异质分子种类。这包括在淀粉样蛋白疾病中作为细胞死亡的致病因子的膜相关结构。这项工作的目的是开发单分子方法研究淀粉样蛋白，胰岛淀粉样多肽，脂质双层之间的相互作用，以期确定新的目标，适合发展的治疗。