Polymer-Lipid Particles investigated by Magnetic Resonance Spectroscopy

项目概要/摘要 膜蛋白约占所有已知蛋白质的30%， 大约1%的蛋白质结构。尽管最近的方法取得了进展， 膜蛋白结构生物学，关于这类重要蛋白质的知识落后于 它们的可溶性对应物膜蛋白对健康的许多方面至关重要， 从调节细胞功能和进出细胞的运输，到病毒感染 它们利用膜蛋白作为感染循环的一部分。了解的结构 膜蛋白对于破坏这种病毒感染可能是至关重要的，并且也可能导致病毒感染。 开发有效的抗病毒疗法。在近90%的新开发和批准的 治疗学，蛋白质结构信息用于指导治疗剂的开发。 分子。由于膜结合蛋白的结构信息有限且不完整， 靶向膜结合蛋白质的治疗剂和治疗方法的发展受到限制。 一个重要的贡献，在阐明膜蛋白结构的挑战是缺乏 稳健和适当的脂质膜模拟物。现有的膜模拟物引入 限制膜蛋白结构测定的显著挑战。这些挑战包括 从可能不代表基本上平坦的脂质双层的高度弯曲的胶束，缺乏 与用于双胞的许多脂质的相容性、引入各向异性的大尺寸囊泡、成本 和来自膜支架蛋白的潜在背景信号，以及缺乏对 聚合物结构和在几种现有的纳米盘上存在芳族基团 聚合物这突出了迫切需要开发脂质膜模拟物，其既提供 在结构和曲率方面与天然脂质双层有很好的近似，而 也有利于嵌入模拟物中的膜蛋白的结构分析。Yet聚合物 对于与脂质相互作用的聚合物， 膜蛋白 该项目将使用现代可控聚合物化学工具，创造一类新的聚合物 能够与脂质进行自我组装这些自组装的聚合物-脂质系统将很好地形成 在10纳米的数量级上限定的盘，给出适合于脂质膜的脂质膜模拟物。 许多膜蛋白的分析。先进的高分子化学技术将使 聚合物的长度、电荷和疏水性的微调。聚合物也将被改性， 电子顺磁共振光谱的自旋标记，一种磁共振方法。 磁共振光谱法将用于聚合物、脂质和膜 用适当的自旋标签修饰的蛋白质，提供对局部动力学的见解， 自组装的聚合物-脂质和聚合物-脂质-膜蛋白复合物的接近性。 关于自组装复合物的结构和动力学的信息， 所使用的聚合物官能度和结构的不同范围将提供重要的见解， 聚合物结构影响其与生物分子的相互作用和组装。这些见解 可用于指导用于稳健脂质膜模拟物的聚合物的设计。 培训和指导本科生以及研究生助理将是一个核心 建议项目的特点。一个多元化的学生团队将致力于项目的各个方面， 从基本的聚合物化学，磁共振光谱学， 膜蛋白生物物理学本科生将完全融入项目， 沿着研究生，在材料科学的界面上获得这一领域的技能， 生物物理学除了核心科学培训，学生将获得书面和口头沟通技巧 传播研究成果。

Project Summary/Abstract Membrane proteins represent approximately 30% of all known proteins but only approximately 1% of all solved protein structures. Despite recent advances in methods for membrane protein structural biology, knowledge about this important class of proteins lags behind their soluble counterparts. Membrane proteins are critical to numerous aspects of health, ranging from regulation cellular function and transport into and out of the cell, through to viral infections which use membrane proteins as part of the infection cycle. Understanding the structure of membrane proteins can be critical to disrupting such viral infections, and can also lead to the development of effective antiviral therapies. In almost 90% of newly developed and approved therapeutics, protein structural information was used to guide the development of the therapeutic molecules. Due to the limited and incomplete structural information on membrane bound proteins, the development of therapeutics and treatments that target membrane bound proteins is limited. A significant contribution to the challenges in elucidating membrane protein structures is the lack of robust and appropriate lipid membrane mimetics. Existing membrane mimetics introduce notable challenges that limit membrane protein structural determination. These challenges range from highly curved micelles which may not represent the essentially flat lipid bilayer, lack of compatibility with many lipids for bicelles, large sizes of vesicles which introduces anisotropy, cost and potential background signal from membrane scaffold proteins, and lack of control over polymer structure and the presence of aromatic groups on several existing nanodisc forming polymers. This highlights an urgent need to develop lipid membrane mimetics which both provide a good approximation to the native lipid bilayer in terms of both structure and curvature, while also facilitating structural analysis of the membrane protein embedded in the mimetic. Yet polymer structure-function relationships are not well established for polymers that interact with lipids and membrane proteins. This project will use modern controlled polymer chemistry tools, to create a new class of polymers that will self-assemble with lipids. These self assembled polymer-lipid systems will form well defined discs on the order of 10s of nanometers, giving lipid membrane mimetics suitable for the analysis of many membrane proteins. The advanced polymer chemistry techniques will enable fine tuning of polymer’s length, charges, and hydrophobicity. Polymers will also be modified with spin-labels for electron paramagnetic resonance spectroscopy, a magnetic resonance method. The magnetic resonance spectroscopic methods will be used on polymers, lipids and membrane proteins modified with appropriate spin labels, providing insights into the local dynamics and proximities of the self assembled polymer-lipid and polymer-lipid-membrane protein complexes. The information regarding the structure and dynamics of the self-assembled complexes across the diverse range of polymer functionality and structures used will give important insights into how polymer structure impacts its interactions and assembly with biological molecules. These insights can be used to guide the design of polymers for robust lipid membrane mimetics. Training and mentoring of undergraduate students as well as a graduate assistant will be a core feature of the proposed project. A diverse team of students will work on all aspects of the project, gaining skills from the fundamental polymer chemistry, magnetic resonance spectroscopy to membrane protein biophysics. Undergraduate students will be integrated fully into the projects, along with the graduate student, gaining skills in this field at the interface of materials science and biophysics. Beyond core scientific training, students will gain written and oral communication skills disseminating the results of the research.