Single Molecule Studies of Protein Folding

这个项目的目的是利用单分子研究来研究蛋白质折叠问题。蛋白质折叠，即氨基酸序列指导蛋白质能量格局的机制（结构、能量和所有可接近构象的相互转换速率），仍然是现代分子生物学的主要挑战。如果不能更好地理解这些特征是如何在蛋白质序列中编码的，那么不断扩大的序列数据库将继续隐藏许多重要问题的答案。该项目旨在开发使用诸如光学陷阱或磁性镊子之类的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察结果，实验设计将与该领域的理论家进行反复合作。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，除了提供蛋白质折叠问题所需的见解外，这项工作还将提供关于蛋白质机械稳定性的急需信息。除了在蛋白质折叠和大分子生物物理学方面的影响外，本项目的研究还需要在物理学和生物学的交叉领域进行培训：这项工作是物理学和生物化学实验室之间的合作努力。这项工作不仅仅是跨学科的；它实际上是相互依赖的，需要最先进的物理和分子生物学实验。这项工作需要不同背景的学生和博士后实习生紧密合作。该项目还需要本科生的帮助，特别是那些有工程和物理背景的本科生，让他们直接接触到生物科学。总之，这项工作为参与该项目的学生和博士后提供了独特的教育经验，并将有助于培养精通生物科学和定量科学的新一代科学家。

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.