CAREER: atomistic characterization of protein-polymer conjugates

非技术描述蛋白质基材料在工业和医疗应用中都具有独特的潜力，因为它们可以精确地针对特定任务进行定制。然而，微调蛋白质材料的能力也使它们容易迅速分解并变得无用。虽然蛋白质有望成为强大的生物传感器或治疗一系列疾病的强效药物，但它们往往无法在人体内存活。使蛋白质更坚固最有希望的方法是在蛋白质上附着一种聚合物。这就产生了连接在一起的蛋白质-聚合物分子，聚合物可以在不改变蛋白质有益特性的情况下保护蛋白质。这种方法已经产生了几种治疗炎症和癌症的重要药物。然而，释放由蛋白质-聚合物偶联物制造更多生物材料或药物的潜力一直非常困难。构建蛋白质-聚合物缀合物的方法有很多，有些有用，有些没用，而且没有指南说明它们应该如何组合在一起。这项研究的目标是促进对某些蛋白质-聚合物偶联物更加坚固的理解，并创建规则，以便可以有意地设计它们，这对于释放它们作为药物，生物传感器和新生物材料的全部潜力至关重要。拟议的研究与一个教育计划相结合，旨在提供用于在微观水平上可视化蛋白质的科学技术的介绍和培训，以及用于人体成像的密切相关的科学方法。首席研究员将与大学预科教育和培训中心合作，为高中生和本科生创建几个实践讲习班。技术描述虽然蛋白质-聚合物偶联物在材料研究中被广泛重视，但由于缺乏准确的分子水平描述，它们的发展主要是经验性的。本研究的目的是通过实验提供蛋白质-聚合物相互作用的原子描述，以增强生物材料中偶联蛋白质的稳定性。根据它们的整体构象和蛋白质与聚合物相互作用的程度，缀合物分为两种类型：松散连接的“哑铃”状结构或更紧密交织并显示更持久的蛋白质-聚合物相互作用的“寿衣”状结构。缀合蛋白的大分子性质，包括耐热性和化学变性，预计与缀合物的三维构象有关。假设这两种形式之间的平衡是由蛋白质侧链和共轭聚合物之间的特定相互作用决定的。共轭物具有衣壳状相互作用，具有独特和有利的性质。核磁共振的使用将有助于确定形成裹衣状相互作用的因素，并为设计具有可预测性质的蛋白质-聚合物偶联物建立一套定量原则。更深入地了解聚合物如何有效地稳定蛋白质免受热或化学变性的影响，将有助于探索新的现象，例如利用聚合物偶联来拯救部分错误折叠的蛋白质和稳定难处理的蛋白质。在原子水平上可视化蛋白质-聚合物相互作用对于释放新的聚合物合成方法和偶联策略的全部潜力至关重要，这对于在苛刻的环境中利用生物材料至关重要。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical descriptionProtein-based materials have unique potential in both industrial and medical applications because they can be precisely tailored for specific tasks. However, the ability to fine-tune protein materials also makes them vulnerable to quickly falling apart and becoming useless. While proteins hold the promise to be powerful biological sensors or potent drugs able to treat a range of diseases, they often do not survive in the human body. The most promising method for making proteins more robust is to attach a polymer to them. This creates protein-polymer molecules that are joined together, where the polymer can shield the protein without changing its beneficial properties. This approach has led to several important drugs for treating inflammation and cancer. However, unlocking the potential to create many more biological materials or drugs made from protein-polymer conjugates has been very difficult. There are many different ways to build protein-polymer conjugates, with some being useful while others are not, and there is no guide for how they should be put together. The goal of this research is to advance the understanding of what makes some protein-polymer conjugates more robust and create rules so that they can be intentionally designed, which is crucial to unleashing their full potential as medicines, biological sensors, and new biological materials. The proposed research is integrated with an educational program that aims to provide an introduction and training on scientific techniques used to visualize proteins at the microscopic level as well as closely related scientific methods used to image the human body. The principle investigator will lead several hands-on workshops created for visits of high school and undergraduate students in partnership with the university precollegiate education and training center.Technical descriptionWhile protein-polymer conjugates are widely valued in materials research, their development is mostly empirical due to the lack of accurate molecular-level depictions of conjugates. The goal of this research is to experimentally provide atomistic descriptions of protein-polymer interactions that enhance the stability of conjugated proteins in biological materials. Conjugates are classified between two types based on their overall conformation and the degree to which the protein and polymer interact: ‘dumbbell’-like structures that are loosely connected or ‘shroud’-like structures that are more interwoven and show more persistent protein-polymer interactions. Macromolecular properties of the conjugated protein, including resistance to thermal and chemical denaturation, are expected to correlate with the three-dimensional conformation of the conjugate. It is hypothesized that the equilibrium between these two forms is determined by specific interactions between protein side chains and conjugated polymer. Conjugates exhibiting shroud-like interactions appear to possess unique and advantageous properties. The use of NMR will enable determination of the factors contributing to formation of shroud-like interactions and establish a set of quantitative principles for the design of protein-polymer conjugates with predictable properties. A deeper understanding of how polymers effectively stabilize proteins against thermal or chemical denaturation, will enable exploration of novel phenomena, such as leveraging polymer conjugation to rescue partially misfolded proteins and stabilize intractable proteins. Visualizing protein-polymer interactions at the atomistic level is crucial in unlocking the full potential of new polymer synthesis approaches and conjugation strategies, which are essential for utilizing biological materials in demanding environments.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.