Single Molecule Studies of Protein Folding

本计画的目的是利用单分子研究来探讨蛋白质折叠的问题。蛋白质折叠是一种由氨基酸序列决定蛋白质能量分布（结构、能量和所有可接近构象的相互转化率）的机制，它仍然是现代分子生物学面临的一个重大挑战。如果没有更好地理解这些特征是如何在蛋白质序列中编码的，不断扩大的序列数据库将继续掩盖许多重要问题的答案。该项目旨在开发使用光学陷阱或磁镊等工具对单个蛋白质分子施加力或张力的方法，并通过跟踪蛋白质中特定位点之间的距离来监测蛋白质的构象。结果将产生可直接用于蛋白质折叠理论研究的观测值，实验设计将与该领域的理论家进行迭代合作。机械应力在蛋白质功能和生物学中起着无处不在的作用，因此，除了提供必要的蛋白质折叠问题的见解，这项工作还将提供急需的关于蛋白质机械稳定性的信息。除了它在蛋白质折叠和大分子生物物理学中的影响，本项目的研究需要物理学和生物学交叉的培训：这项工作是物理和生物化学实验室之间的合作成果。这项工作不仅是跨学科的;它实际上是相互依赖的，需要物理学和分子生物学方面的最先进的实验。这项工作需要具有不同背景的学生和博士后学员紧密合作。该项目还涉及大学生的帮助，特别是那些有工程和物理背景的大学生，让他们直接接触生物科学。总之，这项工作为参与该项目的学生和博士后研究员提供了独特的教育经验，并将有助于培养新一代精通生物和定量科学的科学家。

The objective of this project is to investigate the protein-folding problem using single molecule studies. Protein folding, the mechanism by which the amino acid sequence directs the energy landscape of a protein (the structures, energies, and rates of interconversion of all of the accessible conformations), remains a major challenge for modern molecular biology. Without a better understanding of how these features are encoded in a protein sequence, the expanding sequence databases continue to conceal the answers to many important questions. The project aims to develop methods for applying force or tension on a single protein molecule using tools such as an optical trap or magnetic tweezers and monitoring the conformation of the protein by following the distance between specific sites in the protein. The results will yield observables that can be used directly in theoretical studies of protein folding and the design of the experiments will be carried out in an iterative collaboration with theoreticians in the field. Mechanical stress plays a ubiquitous role in protein function and biology, and therefore, in addition to providing needed insight into the protein-folding problem this work will also provide much needed information about the mechanical stability of proteins.In addition to its impact in protein folding and macromolecular biophysics, the research in this project requires training at the intersection of physics and biology: the work is a collaborative effort between a physics and a biochemistry lab. The work is not just interdisciplinary; it is actually interdependent, requiring state-of-the-art experiments in both physics and molecular biology. The work requires a combination of students and postdoctoral trainees with diverse backgrounds to work closely together. The project also involves the help of undergraduates, particularly those with a background in engineering and physics, giving them direct exposure to the biological sciences. In sum, this work offers a unique educational experience for the students and post-doctoral fellows involved in the project, and will help to train a new generation of scientists fluent in both the biological and quantitative sciences.