Inhibiting fibrillation of Tau through changes in local intramolecular interactions

项目概要/摘要 神经退行性疾病如阿尔茨海默氏病的特征在于， 大脑中的纤维状聚集体微管相关蛋白tau可以形成这样的组装体，并定义 一组不同的疾病称为tau蛋白病。tau纤维的流行与疾病密切相关 进展，其中增加聚集倾向的突变与疾病直接相关。即便如此，Tau 热稳定的，并且在体外或在没有特异性诱导剂的细胞中不形成原纤维。内在无序的 tau蛋白的性质允许多价相互作用的取样，促进了 微管结合然而，关于tau蛋白如何从聚集体结构上转变的知识还存在空白- 抵抗易于聚集的构象。这项建议旨在填补这方面的知识空白，通过研究当地 涉及tau的聚集倾向重复结构域中的淀粉样蛋白基序的相互作用。我会利用 在tau的两种同种型的原纤维毒性中， 关于Tau我假设淀粉样蛋白基序和它们周围序列之间的相互作用介导了tau蛋白 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化。 阵在这个建议中，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肽聚集测定。然后我会设计改造过的tau 预计将稳定局部结构的结构。最后，我将确定本地的结构， 使用交联质谱法稳定化tau种类。然后我将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基序的灵活性。这 整合方法将创建tau单体内稳定局部相互作用的图谱，以设计 保留生物微管结合活性的tau的抗聚集构象。通过了解 tau蛋白早期错误折叠事件背后的生物物理学基础，该项目可以为未来的诊断设计提供信息。 以及稳定无毒tau种类以治疗不同家族的tau蛋白病的治疗剂。

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.