Assembly and Peptide Cross Talk in Amyloid Systems

通过这一奖项，化学系的生命过程化学项目资助了加州大学圣巴巴拉分校的迈克尔·T·鲍尔斯教授研究蛋白质和多肽是如何组装并相互“交谈”的。多肽或蛋白质聚集成团块或聚集体与许多人类疾病有关，包括神经退行性疾病肌萎缩侧索硬化症(ALS)、阿尔茨海默病(AD)和2型糖尿病(T2D)。该项目将通过一种名为离子迁移率的质谱学方法非常准确地确定这些聚集体的具体尺寸，并使用一种名为原子力显微镜的方法可视化它们的形状。当与计算机模拟相结合时，这些研究将提供关于这些肽如何组装成聚集体以及这些聚集体在分子水平上是什么样子的详细信息。此外，这些研究还将展示来自这些不同疾病的多肽如何相互作用或相互“交谈”。这项研究将为研究生和本科生，包括那些来自代表性不足的少数群体的学生提供实验和计算化学以及仪器开发方面的培训。此外，该项目将使研究生能够让高中生走上STEM职业道路。理解多肽在溶液和体内的组装是很困难的，因为传统的研究方法只能得到总体平均结果，而不能得到作为低聚体数量函数的低聚物结构和分布的结果。这里描述了允许进行这些测量的方法，包括离子迁移率光谱分析和原子力显微镜。先前的结果表明，这些方法是稳健的，当与高级分子动力学模拟相结合时，得到的低聚物结构是尺寸的函数，以及低聚物分布如何随着溶液参数的变化而变化。在这个提案中，这些方法针对的是与肌萎缩侧索硬化症有关的蛋白质的关键片段，特别是超氧化物歧化酶-1和反式反应DNA结合蛋白43。获得低聚物的结构和分布以及对关键的疾病导向突变的反应的变化。然后将这些关键的肌萎缩侧索硬化症多肽系统与主要导致AD的A-β-42的片段以及与胰岛淀粉样蛋白T2D相关的激素胰岛淀粉样多肽混合在一起。将监测这两个系统在混合物中的组装情况，以观察组装过程是否发生潜在的催化加速。目标是了解这些疾病相互作用的流行病学观察，并在分子水平上做到这一点。考虑到疾病相关集合之间的相互作用的可能性，可以为开发新的治疗方法来治疗这些集合依赖的疾病提供一种战略。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Professor Michael T. Bowers from the University of California at Santa Barbara to study how proteins and peptides assemble and “talk” to each other. The assembly of peptides or proteins into clumps or aggregates are associated with a number of human diseases, including the neurodegenerative disease amyotrophic lateral sclerosis (ALS), Alzheimer’s disease (AD), and type-2 diabetes (T2D). This project will very accurately determine the specific sizes of these aggregates by a method called ion mobility based mass spectrometry and visualize their shapes using a method call atomic force microscopy. When combined with computational simulations, these studies will provide detailed information on how these peptides assemble into aggregates and what these aggregates look like at the molecular level. In addition, the studies will show how the peptide aggregates from these different diseases interact or “talk” with each other. This study will provide graduate and undergraduate students, including those from underrepresented minority groups with training in experimental and computational chemistry, as well as instrument development. Furthermore, the project will allow graduate students to engage high school students on their pathway to STEM careers. Understanding peptide assembly in solution and in vivo is difficult because traditional methods of study only yield ensemble averaged results, not results on the structure and distribution of oligomers as a function of oligomer number. Here methods are described that allow these measurements to be made, including ion mobility spectrometry and atomic force microscopy. Prior results have demonstrated these methods are robust and when coupled with high level molecular dynamics simulations yield oligomer structures as a functions of size, and how oligomer distributions change with solution parameters. In this proposal these methods are directed to key fragments of proteins responsible for ALS, specifically superoxide dismutase-1 and transactive response DNA binding protein 43. Oligomer structures and distributions are obtained along with variations in response to key disease-oriented mutations. These key ALS peptide systems are then mixed with fragments of A-beta-42, the peptide primarily responsible for AD, as well as hormone islet amyloid polypeptide, the peptide responsible for islet amyloid T2D. The assembly of both systems in the mixtures will be monitored to observe whether potential catalytic acceleration of the assembly process occurs. The goal is to understand the epidemiological observation that these diseases interact and to do so at the molecular level. Taking the potential for cross-talk between the disease related aggregates into account could provide a strategy for the development of new therapeutics to treat these aggregate dependent diseases.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.