Inhibiting fibrillation of Tau through changes in local intramolecular interactions

项目摘要/摘要 阿尔茨海默病等神经退行性疾病的特征是 大脑中的纤维状聚集体。微管相关蛋白tau可以形成这样的组件并定义 一组不同的疾病被称为tauopathy。Tau纤维的流行与疾病密切相关。 进展，突变增加聚集倾向，与疾病直接相关。即便如此，陶也是 耐高温，在体外或在没有特殊诱导剂的细胞中不形成纤维。本质上的无序 Tau蛋白的性质允许多价相互作用的采样，促进了tau蛋白的生物活性。 微管结合。然而，关于tau如何从聚集结构过渡的知识存在缺口。 抵抗易于聚集的构象。这项建议旨在通过学习当地知识来填补这一空白。 在tau的易于聚集的重复结构域中涉及淀粉样基序的相互作用。我会充分利用这些差异 在两种tau异构体的纤维毒性中，以创建定义纤化特性的序列特性图 陶氏家族的。我假设淀粉样蛋白基序与其周围序列之间的相互作用调节tau 聚集倾向；因此，稳定这些相互作用以形成局部结构可以防止纤维 队形。在这个提议中，我将确定tau中调节聚集倾向的原子相互作用 分子动力学模拟结合多肽聚集分析。然后我会设计改装的tau 预计将稳定当地结构的构造。最后，我将确定 用交联质谱法稳定了tau物种。然后我会测试稳定的结构是否 通过体外和细胞微管结合试验保持微管结合模体的灵活性。这 综合方法将创建一张稳定tau单体内部局部相互作用的地图以进行设计 保持生物微管结合活性的tau的抗聚集构象。通过理解 Tau早期错误折叠事件背后的生物物理基础，该项目可以为未来的诊断设计提供信息 以及稳定无毒tau物种的疗法，以治疗不同的tauopathy家族。

Project Summary/Abstract Neurodegenerative diseases such as Alzheimer's disease are characterized by the abnormal deposition of fibrillar aggregates in the brain. The microtubule-associated protein tau can form such assemblies and defines a diverse group of diseases termed tauopathies. The prevalence of tau fibrils strongly correlates with disease progression, with mutations that increase aggregation propensity directly linked to disease. Even so, tau is thermostable and does not form fibrils in vitro or in cells without specific inducers. The intrinsically disordered nature of tau protein allows the sampling of multivalent interactions, facilitating the biological activity of microtubule binding. However, there is a gap in knowledge of how tau structurally transitions from aggregation- resistant to an aggregation-prone conformation. This proposal aims to fill this gap in knowledge by studying local interactions involving amyloid motifs in the aggregation-prone repeat domain of tau. I will leverage the differences in fibril toxicity of two isoforms of tau to create a map of sequence properties that define the fibrillization properties of tau. I hypothesize that interactions between amyloid motifs and their surrounding sequence mediate tau aggregation propensity; therefore, stabilizing these interactions to form local structures can prevent fibril formation. In this proposal, I will identify atomic interactions in tau that modulate aggregation propensity using molecular dynamics simulations combined with peptide aggregation assay. Then I will engineer modified tau constructs that are predicted to stabilize the local structure. Lastly, I will determine the local structure of the stabilized tau species using cross-linking mass spectrometry. Then I will test whether the stabilized structure maintains flexibility in the microtubule-binding motifs through in vitro and in cell microtubule-binding assays. This integrative approach will create a map of stabilizing local interactions within a tau monomer to design aggregation-resistant conformations of tau that retain biological microtubule-binding activity. By understanding the biophysical basis behind early misfolding events in tau, this project can inform the future design of diagnostics and therapeutics that stabilize non-toxic tau species to treat the diverse family of tauopathies.