New methods development for structure determination of multihelical membrane proteins in their native-like lipid bilayers by solid-state NMR with applications

在这个由化学学部化学测量和成像项目资助的项目中，Alexander Nevzorov教授正在用固态核磁共振（NMR）波谱技术研究类似天然条件下的膜蛋白（MPs）。膜蛋白执行过多的生物学功能，但其解决结构的数量仍然相对较少。固态核磁共振技术允许研究人员对MPs进行结构-功能研究，这些MPs在几乎生理条件下很难或不可能结晶。在本研究期间开发的核磁共振光谱方法将该技术的能力扩展到多螺旋MPs。本项目的主要目的是通过开发新的光谱工具，包括距离测量和拥挤光谱区域分配方法，来转换定向膜蛋白（MPs）的固态核磁共振。此外，基于纳米孔和定向大圆盘的柔性脂质组成的新型膜模拟物正在被创建，以监测脂质诱导的MPs构象变化。探讨了脂质双层的动态特性，包括膜内蛋白的旋转扩散和双层粘度。潜在的未来应用包括确定与阿尔茨海默病和其他神经系统疾病有关的人类乙酰胆碱受体的结构。由于该项目的广泛影响，这项研究的高度跨学科性质为参与其中的年轻科学家提供了全面的培训。作为拓展活动，通过Kenan Fellow的指导，Nevzorov博士将他的研究成果推广到高中教育和STEM项目。

In this Project funded by the Chemical Measurement and Imaging program of the Chemistry Division, Professor Alexander Nevzorov is studying membrane proteins (MPs) under their native-like conditions by solid-state Nuclear Magnetic Resonance (NMR) spectroscopy. Membrane proteins perform a plethora of biological functions, yet the number of their solved structures remains relatively small. The solid-state NMR technique allows researchers to perform structure-function studies of MPs that are difficult or impossible to crystallize at nearly physiological conditions. NMR spectroscopic methods developed during this research expand capabilities of this technique to multihelical MPs.The main purpose of this project is to transform solid-state NMR of oriented membrane proteins (MPs) by developing new spectroscopic tools including methods for distance measurements and assignment of crowded spectral regions. Moreover, new membrane mimetics of flexible lipid composition based on nanopores and oriented macrodisks are being created to monitor lipid-induced conformational changes of MPs. Dynamic properties of lipid bilayers are probed including rotational diffusion of membrane-embedded proteins and the bilayer viscosity. Potential future applications include structure determination of the human Acetylcholine receptor involved in the Alzheimer's disease and other neurological disorders. As broader impacts of this project, the highly interdisciplinary nature of this research provides versatile training for the young scientists involved. As outreach activities, via mentorship of a Kenan Fellow, Dr. Nevzorov promotes the results of his research to high-school education and STEM programs.