CAREER: Interface-induced misfolding and aggregation of intrinsically disordered proteins

池，EvaCBET-1150855智力价值-非技术：尽管内在无序蛋白(IDPs)在一些人类疾病中存在，但IdP聚集导致疾病发展的机制仍然知之甚少。这项提议的目的是从根本上了解蜂窝环境中的接口如何影响国内流离失所者的错误折叠和聚集。PI将研究与阿尔茨海默病-S病(AD)有关的两个IDPs的聚集情况，即淀粉样蛋白GB(A GB)肽和tau蛋白。这项研究的成功完成不仅将促进当前对一类重要蛋白质结构动力学的界面效应的理解，还将促进对神经退行性疾病发病机制和热力学驱动力的理解。技术：PI提出了一种新的聚集机制，其中IDP首先形成具有聚集能力的中间体，该中间体部分折叠，然后通过结构收缩的过渡态进行。这一步骤之后是中间体的组装，以形成更大的聚集体。PI假设界面可以诱导IDP结构致密，降低聚集和模板成核的激活自由能。PI进一步假设，这些界面效应在模拟细胞环境的条件下被显著放大，即大分子拥挤和渗透分子的存在。PI假设，减弱A gb‘n肽和tau蛋白与生物界面的结合可以抑制它们的聚集和毒性。为了验证这些假设，她提出了以下三个目标，这些目标建立在她的研究小组-S在蛋白质聚集的热力学、蛋白质在溶液和界面上的生物物理分析以及生物化学方面的独特优势的基础上。PI建议完成以下三个研究目标：1)评估4个tau蛋白分配到两个界面，即空气/水界面和脂膜界面的可能性和亲和力，并表征伴随着蛋白质结合到两个界面上的tau结构和聚集动力学的变化；2)研究分子拥挤和渗透分子对A GB的NAND tau？S表面活性、膜相互作用和聚集的影响，以检验排除体积和优先排斥产生的界面力是否调节界面模板IDP聚集；3)探讨减弱A GB‘NAND tau与脂膜的结合是否可以改善其聚集和毒性。Broader的影响这项深植于分子热力学和界面科学的研究为研究IDPs的聚集提供了一种新的方法。对分子间相互作用和控制国内流离失所者组装的界面力的分析是一项基本的科学挑战，在生物学和医学中具有重要意义。从拟议的研究中获得的对IDP聚集的机制和热力学驱动力的理解对于促进当前对阿尔茨海默病-S病发病机制的分子机制的认识至关重要。确定国内流离失所者的聚集机制可能会导致治疗这种神经退行性疾病的治疗策略。在教育方面，她致力于通过新课程的开发和招生，为新墨西哥州首家生物医学工程本科和研究生课程S的建立做出更大的贡献。该协会还致力于将新墨西哥大学现有的外展工作扩大到美洲原住民农村小学，并向阿尔伯克基高中生推出了一个新的实践示范模块，重点是蛋白质结构和变性的分子方面。PI将继续努力指导西南印度理工学院的美国原住民学生，帮助他们成功过渡到新墨西哥大学。拟议的教育和外联努力的累积和长期影响将是增加生物工程专业的学生入学率和留校率，特别是代表人数不足的少数族裔和妇女，这将激发经济活力，满足新墨西哥州及其他地区未来的劳动力需求。

Chi, EvaCBET - 1150855 Intellectual MeritNON-TECHNICAL:Despite the implication of intrinsically disordered proteins (IDPs) in a number of human diseases, the aggregation mechanism of IDP by which the disease develops remains poorly understood. The objective of this proposal is to gain a fundamental understanding of how interfaces in the cellular environment can affect the misfolding and aggregation of IDPs. The PI will investigate the aggregation of two IDPs implicated in Alzheimer¡¦s disease (AD), the amyloid-£] (A£]) peptide and the tau protein. Successful completion of the proposed research will advance current understanding of not only the interfacial effects on the structural dynamics of an important class of proteins, but also of the mechanism and thermodynamic driving forces underlying the pathogenesis of neurodegenerative diseases.TECHNICAL:The PI proposes a novel aggregation mechanism in which an IDP first forms an aggregation-competent intermediate that is partially folded and proceeds through a structurally contracted transition state. This step is followed by the assembly of intermediates to form larger aggregates. The PI hypothesizes that interfaces can induce IDP structural compaction, lowering the activation free energy of aggregation and template nucleation. The PI further hypothesizes that these interfacial effects are significantly amplified under conditions that mimic the cell milieu, namely, macromolecular crowding and the presence of osmolytes. The PI hypothesizes that attenuating the binding of A£]'n peptide and tau protein to biological interfaces can inhibit their aggregation and toxicity. To test these hypotheses, the PI proposes the following three objectives that build on her research group¡¦s unique strengths in thermodynamics of protein aggregation, biophysical analysis of proteins in solution and at interfaces, and biochemistry. The PI proposes to accomplish the following three research objectives: 1) to evaluate the likelihood and affinity of four tau proteins to partition to two interfaces, the air/water interface and the lipid membrane interface, and characterize changes in tau structure and aggregation kinetics accompanying the binding of the proteins to the interfaces; 2) to study the effect of molecular crowding and osmolytes on A£]'nand tau¡¦s surface activity, membrane interaction, and aggregation to test if interfacial forces stemming from excluded volume and preferential exclusion can modulate interface-templated IDP aggregation; 3) to investigate whether attenuation of the binding of A£]'nand tau to lipid membranes can ameliorate their aggregation and toxicity.Broader Impacts The proposed research, deeply rooted in molecular thermodynamics and interface science, represents a novel approach to studying the aggregation of IDPs. The analysis of intermolecular interactions and interfacial forces that govern the assembly of IDPs represents a fundamental scientific challenge that is of great importance in biology and medicine. Understanding of the mechanism and thermodynamic driving forces of IDP aggregation gained from the proposed study is of paramount importance in advancing the current knowledge of the molecular mechanism underlying the pathogenesis of Alzheimer¡¦s disease. Determining the aggregation mechanism of IDPs could potentially lead to therapeutic strategies for treating such neurodegenerative diseases. In terms of education, the PI is committed to furthering her contribution to the establishment of New Mexico¡¦s first Biomedical Engineering undergraduate and graduate degree programs through new course development and student recruitment. The PI is also strongly dedicated to expanding and augmenting the existing outreach efforts at the University of New Mexico to rural Native American elementary schools and introducing a new hands-on demonstration module focusing on the molecular aspects of protein structure and denaturation to Albuquerque High School students. The PI will continue mentoring efforts to Native American students from the Southwest Indian Polytechnic Institute helping them make a successful transition to the University of New Mexico. The cumulative and long-term impact of the proposed educational and outreach efforts will be increased enrollment and retention of students in bioengineering, particularly underrepresented minorities and women, which will spark economic vitality and meet future work force demands in New Mexico and beyond.