Investigating Membrane Proteins with Magnetic Resonance Spectroscopy

在生命过程化学项目的支持下，加里A.来自迈阿密大学的Lorigan正在研究两种膜蛋白，即pinholin和gp 28，它们参与细胞溶解/细胞死亡。膜蛋白约占所有已知蛋白质的三分之一，并负责生物系统的许多重要性质和功能。尽管它们丰富而重要，但关于膜相关分子的信息很少。该项目将应用电子顺磁共振（EPR）光谱技术来收集有关膜蛋白pinholin和gp 28的结构和动力学特性的信息。在本项目的实施中，研究生和本科生将获得膜蛋白样品制备和最先进的EPR光谱技术的知识和经验。本科生将获得生物物理化学的宝贵经验，研究生参与DUOS，迈阿密大学的一个STEM（科学，技术，工程和数学）项目，是一个机会，让他们成为优秀的导师。Pinholin是一种具有生物学意义的膜结合holin蛋白，直接参与细胞死亡，通过溶解的内膜在E。杆菌这些研究的另一个主要目标是gp 28，一种破坏噬菌体phiKT外膜（OM）的新型蛋白质。目前，关于pinholin和gp 28的结构信息非常有限。 嵌入脂质双层的突变的针洞蛋白的二级和三级结构将通过使用EPR光谱测量策略性放置的氮氧自旋标记之间的距离来阐明。 最先进的EPR技术，如双电子电子共振（DEER）将被应用于研究的结构，拓扑结构，寡聚化状态，和动态特性的膜结合蛋白质pinholin和gp 28。 将研究不同的构象形式。EPR数据将用于开发结构模型，以帮助阐明孔形成的机制。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With the support of the Chemistry of Life Processes Program, Professor Gary A. Lorigan from the Miami University is studying two membrane proteins, namely pinholin and gp28, which are involved in cell lysis/cell death. Membrane proteins make up approximately one-third of all known proteins and are responsible for many important properties and functions of biological systems. Despite their abundance and importance, there is very little information about membrane-associated molecules. This project will apply electron paramagnetic resonance (EPR) spectroscopic techniques to gather information about the structural and dynamic properties of the membrane proteins pinholin and gp28. In the implementation of this project, graduate students and undergraduate student will acquire knowledge and experience in the preparation of membrane protein samples and in state-of-the-art EPR spectroscopic techniques. Undergraduate students will obtain valuable experience in biophysical chemistry and graduate students participation in DUOS, a STEM (science, technology, engineering and mathematics) project at Miami University, is an opportunity for them to become outstanding mentors.Pinholin is a biologically significant membrane-bound holin protein that is directly involved in cell death through lysis of the inner membrane in E. coli. The other prinicipal target of these studies is gp28, a new type of protein that disrupts the outer membrane (OM) in phage phiKT. Currently, there is very limited structural information on both pinholin and gp28. The secondary and tertiary structure of mutated pinholin embedded in a lipid bilayer will be elucidated by measuring distances between strategically placed nitroxide spin labels using EPR spectroscopy. State-of-the-art EPR techniques such as double electron electron resonance (DEER) will be applied to study the structure, topology, oligomerization state, and dynamic properties of the membrane-bound proteins pinholin and gp28. Different conformational forms will be investigated. The EPR data will be used in the development of a structural model to help elucidate the mechanism of hole formation.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.