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

职业：界面诱导的本质无序蛋白质的错误折叠和聚集

• 批准号: 1150855
• 负责人: Eva Chi
• 金额: $ 40万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1150855&HistoricalAwards=false
• 关键词: CAREER; Interface; induced; misfolding; aggregation

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.

Chi，EvaCBET - 1150855知识产权非技术性：尽管在许多人类疾病中存在固有无序蛋白（IDP），但对疾病发展的IDP聚集机制仍知之甚少。 这个建议的目的是获得一个基本的理解如何在细胞环境中的接口可以影响错误折叠和聚合的IDP。 PI将研究与阿尔茨海默病（AD）有关的两种IDP的聚集，即淀粉样蛋白（A β）肽和tau蛋白。 成功完成拟议的研究将推进目前的理解，不仅是一个重要的一类蛋白质的结构动力学的界面效应，而且机制和热力学驱动力的神经退行性疾病的发病机制。技术：PI提出了一种新的聚集机制，其中IDP首先形成一个聚集能力的中间体，是部分折叠和收益通过结构收缩过渡态。 该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结构压实，降低聚集和模板成核的活化自由能。 PI进一步假设这些界面效应在模拟细胞环境的条件下显著放大，即大分子拥挤和渗透剂的存在。 PI假设，减弱A β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，PI提出了以下三个目标，这些目标建立在她的研究小组在蛋白质聚集热力学，蛋白质在溶液和界面中的生物物理分析以及生物化学方面的独特优势之上。 本项目拟完成以下三个研究目标：1）评估四种tau蛋白分配到两个界面（空气/水界面和脂膜界面）的可能性和亲和力，并表征tau蛋白与界面结合时的结构变化和聚集动力学特征; 2）研究分子拥挤和渗透剂对A-tau蛋白的影响。β的表面活性，膜相互作用和聚集，以测试是否源于排斥体积和优先排斥的界面力可以调节界面模板IDP聚集; 3）研究减弱A β-tau与脂膜的结合是否可以改善其聚集和毒性。更广泛的影响拟议的研究，深深植根于分子热力学和界面科学，是研究国内流离失所者聚集的一种新方法。 分析分子间的相互作用和界面力，支配组装的IDP代表了一个基本的科学挑战，是非常重要的生物学和医学。 从这项研究中获得的IDP聚集的机制和热力学驱动力的理解是至关重要的，在推进目前的知识的分子机制的基础上阿尔茨海默病的发病机制。 确定IDP的聚集机制可能会导致治疗此类神经退行性疾病的治疗策略。 在教育方面，PI致力于通过新的课程开发和学生招聘，进一步为建立新墨西哥州的第一个生物医学工程本科和研究生学位课程做出贡献。 PI还大力致力于扩大和增强新墨西哥州的农村美国原住民小学的大学现有的推广工作，并介绍了一个新的动手示范模块，侧重于蛋白质结构和变性的分子方面的阿尔伯克基高中学生。 PI将继续指导来自西南印第安理工学院的美洲原住民学生，帮助他们成功过渡到新墨西哥州大学。 拟议的教育和推广工作的累积和长期影响将增加生物工程学生的入学率和保留率，特别是代表性不足的少数民族和妇女，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。