Integrative structural analysis of human insulin degrading enzyme

人胰岛素降解酶的整体结构分析

• 批准号: 10367488
• 负责人: WEI-JEN TANG
• 金额: $ 40.33万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10367488
• 关键词: Address; Affect; Agonist; Algorithms; Alzheimer' s Disease; Amyloid Fibrils; Amyloid beta-Protein; Animal Model; Binding; Biochemical; Biological Assay; Blood Glucose; C-terminal; Catalysis; Coupled; Cryoelectron Microscopy; Defect; Development; Diabetes Mellitus; Dimerization; Disease; Drug Targeting; Engineering; Enzyme Inhibitor Drugs; Enzyme Kinetics; Enzymes; Equilibrium; Exhibits; Family; Fluorescence Resonance Energy Transfer; Foundations; Genetic Screening; Glucagon; Glucose; Goals; Grain; Hormones; Human; Hyperactivity; Insulin; Insulinase; Knowledge; Link; Mechanics; Metalloproteases; Methods; Modeling; Molecular; Molecular Conformation; Monitor; Motion; Mus; Mutation; N-terminal; Non-Insulin-Dependent Diabetes Mellitus; Peptide Hydrolases; Peptides; Physiological; Play; Process; Proteome; Regulation; Research; Roentgen Rays; Role; Structure; Techniques; Time; Work; Yeasts; amyloid peptide; base; beta pleated sheet; combat; conformational conversion; cytotoxic; design; dimer; enzyme activity; enzyme mechanism; enzyme substrate; glucose tolerance; human disease; image processing; improved; innovation; insight; insulin regulation; islet amyloid polypeptide; member; millisecond; novel; screening; simulation; single molecule; small molecule; success; time use; unfoldase

Project Abstract/Summary: Aggregates of amyloid peptides, such as amyloid fibrils are highly cytotoxic, as exemplified by the role of amyloid b (Aβ) in Alzheimer's disease. To maintain a healthy proteome, a number of proteases target the monomeric form of amyloid peptides because this form fuels both seeding and elongation of amyloid fibrils. Insulin degrading enzyme (IDE) is a 110 kDa metalloprotease that degrades various amyloid peptides, including Aβ and three blood glucose-regulating hormones, namely insulin, amylin, and glucagon. Defects in IDE alter the progression of type 2 diabetes mellitus and Alzheimer’s disease in animal models and are linked to these diseases in humans. IDE inhibitors can control blood glucose level in mice and hold promise for treating diabetes. One of the key steps in the IDE catalytic cycle is the selective recognition and unfolding of amyloid peptides prior to degradation. Our premise is that the understudied conformational dynamics of IDE provide the mechanical basis for the unfolding of peptide substrates. Thus, we can leverage our understanding of these processes to selectively modulate the activity of IDE towards specific substrates. Our long-term goals are to elucidate the molecular details of how IDE selectively recognizes amyloid peptides and utilize this knowledge to develop novel IDE- based therapies to improve the human condition. Toward this goal, we have integrated ensemble structural determination and solution-based methods to show that IDE is a member of the chamber-containing protease, aka cryptidase, family that uses a sizable catalytic chamber to engulf monomeric amyloid peptides. We have also generated a working model that explains how IDE uses two key conformational switches to selectively degrade amyloid peptides. Our objectives for this application are to determine key unsolved conformational states and probe the conformational dynamics of IDE during the catalytic cycle by applying state-of-art integrative structural approaches. We will then combine MD simulation and screening to identify strategies to modulate the catalytic activity and selectivity of IDE. Our research rationale is that a deeper understanding of the regulation and functions of IDE will allow us to modulate its activity through engineering or novel small molecules and ultimately facilitate the design of IDE-based therapies to combat proteostatic imbalances. We will use time- resolved cryoEM and SAXS to understand the structural basis for substrate recognition during the key time window when IDE first encounters substrate in combination with advanced cryoEM image processing algorithms and MD simulation to address how IDE motions can unfold physiologically relevant substrates. We will apply the knowledge gained from the substrate recognition and unfolding studies to develop a screening strategy to identify methods to selectively modulate the degradation of Ab by IDE. This work will significantly enhance our understanding of the IDE catalytic cycle by defining key conformational states under physiologically relevant conditions and offer a platform to merge integrative structural analysis and MD simulation towards the discovery of innovative enzyme modulating strategies as the developmental foundation of novel IDE-based therapies.

项目摘要/摘要： 淀粉样蛋白肽的聚集体，例如淀粉样蛋白原纤维，具有高度细胞毒性，淀粉样蛋白的作用就证明了这一点 阿尔茨海默病中的 b (Aβ) 为了维持健康的蛋白质组，许多蛋白酶以单体为目标。 淀粉样肽的形式，因为这种形式促进淀粉样原纤维的播种和伸长。 酶 (IDE) 是一种 110 kDa 金属蛋白酶，可降解各种淀粉样肽，包括 Aβ 和三种淀粉样肽 血糖调节激素，即胰岛素、胰岛淀粉样多肽和胰高血糖素，IDE 的缺陷会改变进展。 动物模型中的 2 型糖尿病和阿尔茨海默氏病的发病率很高，并且与人类的这些疾病有关。 IDE抑制剂可以控制小鼠的血糖水平，有望成为治疗糖尿病的关键之一。 IDE 催化循环中的步骤是在降解之前选择性识别和解折叠淀粉样肽。 我们的前提是，IDE 中正在研究的构象动力学为 因此，我们可以利用我们对这些过程的理解来选择性地展开。 调节 IDE 对特定底物的活性我们的长期目标是阐明分子。 IDE 如何选择性识别淀粉样肽并利用这些知识开发新型 IDE 的详细信息 为了改善人类状况，我们整合了整体结构。 测定和基于溶液的方法表明 IDE 是含有蛋白酶的室的成员， 又名隐酶，使用相当大的催化室来吞噬单体淀粉样肽的家族。 还生成了一个工作模型，解释了 IDE 如何使用两个关键的构象开关来选择性地 降解淀粉样肽 我们此应用的目标是确定关键的未解决的构象。 通过应用最先进的综合技术，状态并探讨催化循环期间 IDE 的构象动力学 然后，我们将结合MD模拟和筛选来确定调节策略。 我们的研究理由是更深入地了解IDE的催化活性和选择性。 IDE 的功能和功能将使我们能够通过工程或新型小分子来调节其活性 最终促进基于 IDE 的疗法的设计，以对抗蛋白质稳态失衡。 解析cryoEM和SAXS，了解关键时间底物识别的结构基础 IDE 首次遇到基材时的窗口与先进的冷冻电镜图像处理算法相结合 我们将应用 MD 模拟来解决 IDE 运动如何展开生理相关底物的问题。 从底物识别和展开研究中获得的知识，以制定筛选策略来识别 通过 IDE 选择性调节抗体降解的方法这项工作将显着增强我们的能力。 通过定义生理相关下的关键构象状态来理解 IDE 催化循环 条件并提供一个平台，将综合结构分析和 MD 模拟结合起来以实现发现 创新酶调节策略作为新型 IDE 疗法的开发基础。