RUI: Learning the Rules that Govern the Folding and Stability of Coiled Coils

本研究的目的是探讨短肽聚合成α-螺旋聚合结构的调控因素。 对这种生物聚合物过程的更好理解将有助于许多不同研究领域的进步，包括：（1）阐明一般蛋白质折叠规则及其与聚合的关系;（2）理解这种过程如何导致错误折叠和聚集;（3）设计新型生物材料。 这些螺旋聚合物形成的能力取决于螺旋肽之间设计的交错相互作用，其结构基于众所周知的卷曲螺旋结构基序。 将突变肽序列以测试疏水相互作用在聚合物组装和结构中的作用。 还将进行突变以测试通过金属结合和能够诱导局部结构变化的新型光敏开关对聚合的调节。 为该项目制造的一种特定序列变体被发现形成含有a-螺旋或b-链构象的聚合物。 研究者将测试谷氨酰胺在影响形成这两种聚合物结构的倾向中的作用。 圆二色性和傅里叶变换红外光谱将用于定量聚合物的二级结构含量和稳定性。 聚合物的大小和形状将通过分析超离心、原子力显微镜和动态光散射来跟踪。虽然该项目集中在基础研究问题上，但它也将影响实验室中的一个不同项目，该项目的目标是创造生物电子材料，涉及哈弗福德和美国大学的教师。宾夕法尼亚 这里描述的工作将主要由本科生驱动，因为哈弗福德学院是一个本科院校。 学生通过撰写论文提案和最终论文论文，在小组会议和整个部门中展示他们的工作，同时进行实验来完成主要课程学分。 这项研究计划的元素已经开发了一个初级实验室课程的研究员教授化学和生物学专业，和相关的想法生物材料设计正在开发列入初级讲座课程化学生物学和生物化学。 该研究员长期致力于改善代表性不足的群体获得研究的机会。 除了长期致力于为费城K-12学生提供科学和写作的现有外展计划外，PI还在夏天定期在他的研究实验室为至少一名自认为属于代表性不足的学生保留空间。 在一个新的方向，研究人员还接待了来自费城的高中教师和学生在他的实验室工作，在过去的夏天，他们学会了合成和纯化对该项目的目标至关重要的肽。

The objective of this project is to explore factors that regulate the polymerization of short peptides into a-helical polymeric structures. An improved understanding of such biopolymer processes will contribute to the advancement of a number of different active fields of research, including: (1) elucidating general protein folding rules and how they relate to polymerization; (2) understanding how such processes can lead to misfolding and aggregation; and (3) designing novel biomaterials. The ability of these helical polymers to form depends on designed staggered interactions between helical peptides, whose structure is based on the well-known coiled-coil structural motif. The peptide sequence will be mutated to test the role of the hydrophobic interaction in polymer assembly and structure. Mutations will also be made to test regulation of polymerization by metal binding and a novel photosensitive switch capable of inducing local structural changes. One particular sequence variant made for this project was discovered to form polymers containing either a-helical or b-strand conformations. The investigator will test the role of glutamines in influencing the propensity to form these two polymer structures. Circular dichroism and Fourier transform infrared spectroscopy will be used to quantify secondary structure content and stability of the polymers. The size and shape of the polymers will be tracked by analytical ultracentrifugation, atomic force microscopy, and dynamic light scattering.Although focusing on basic research questions, this project will also impact a different project in the lab whose goal is to create bio-electronic materials, involving faculty at Haverford and at U. Pennsylvania. The work described here will be driven primarily by undergraduates, since Haverford College is an undergraduate institution. Students fulfill major course credit by writing a thesis proposal and a final thesis paper, presenting their work at group meetings and to the Department as a whole, while carrying out their experiments. Elements of this research program have been developed by the investigator for a junior laboratory course to be taught to chemistry and biology majors, and ideas relevant to biomaterial design are being developed for inclusion in a junior-level lecture course in chemical biology and biochemistry. The investigator has a long-standing commitment to improving access to research for under-represented groups. In addition to a long-term commitment to an existing outreach program for science and writing for K-12 students from Philadelphia, The PI regularly reserved space in his research lab over the summer for at least one student self-identified as belonging to an under-represented group. In a newer direction, the investigator has also hosted a high school teacher and student from Philadelphia to work in his lab this past summer, in which they learned to synthesize and purify peptides critical for the goals of this project.