Investigating the impact of lipid-protein interactions in membrane protein structure and conformational dynamics

膜是细胞周围的壁，膜蛋白是允许信息和分子穿过壁的门和窗。细胞壁（膜）和窗口（膜蛋白）是如何相互作用的？膜是直接与膜蛋白相互作用的脂质的复杂混合物。这些相互作用的一般原理以及这些相互作用如何调节膜蛋白的结构和功能在很大程度上是未知的。在过去的十年中，有一个激增的膜蛋白结构，提供了这些蛋白质看起来像什么快照，并提供了一个平台，假设这些蛋白质如何执行其功能。在这些假设中经常被忽视的是脂质双层的作用，因为缺乏描述脂质-蛋白质相互作用的一般原则和确定这些相互作用的直接实验方法。需要系统分析脂质对结构和构象动力学的影响，并在本项目中提供。这项研究的结果将影响分子生物物理学以外的许多领域，如细胞信号传导和调控，分子组装，脂质代谢和稳态。通过该项目的研究和教育目标，PI将通过关注以下举措影响更广泛的社区：（i）增加本科STEM研究中代表性不足的群体的参与;（ii）促进本科STEM教育中有效和包容性实践的使用。为了研究一般原理，研究了两种非常不同的膜蛋白（结构和功能）。已经建立了使用膜环境的物理方面的系统变化来设计解决与脂质分离和膜模拟性质相关的特定问题的实验。结合起来，这些方法，利用本项目中描述的各种生物物理方法将确定脂质边界是否对膜蛋白的结构和功能至关重要。这项研究的结果将提供一个基本的理解，并建立一般原则的作用，脂质-蛋白质相互作用（i）稳定膜蛋白质折叠和（ii）促进构象动力学参与催化。这些结果将影响膜蛋白的体外制备、膜错误折叠突变的解释、膜中生物分子复合物的组装、膜中的聚集等。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响评审标准进行评估，被认为值得支持。

Membranes are the walls around cells and membrane proteins are the doors and the windows that allow passage of information and molecules across the wall. How do the walls (membrane) and windows (membrane protein) interact? Membranes are a complex mixture of lipids that interact directly with membrane proteins. The general principles of these interactions and how these interactions modulate membrane protein structure and function is largely unknown. In the last decade, there has been a surge of membrane protein structures that provide snapshots of what these proteins look like and provide a platform to hypothesize how these proteins carryout their functions. Often neglected in these hypotheses is the role of the lipid bilayer because of the lack of general principles describing lipid-protein interactions and straightforward experimental methods for determining these interactions. A systematic analysis of the impact of lipids on structure and conformational dynamics is needed and is provided in this project. The results of this research will impact many fields beyond molecular biophysics such as cell signaling and regulation, molecular assembly, and lipid metabolism and homeostasis. Through the research and educational goals of the project, the PI will impact the broader community by focusing on initiatives that (i) increase the participation of underrepresented groups in undergraduate STEM research and (ii) catalyze the use of effective and inclusive practices in undergraduate STEM education.To investigate general principles, two very different membrane proteins (both in structure and function) are investigated. The use of systematic variation of physical aspects of the membrane environment have been established to design experiments which address specific questions associated with lipid segregation and membrane mimic properties. Combined, the approaches, which utilize a variety of biophysical methods described in this project will determine if the lipid boundary is critical to membrane protein structure and function. The results of this research will provide a fundamental understanding and establish general principles for the role of lipid - protein interactions in (i) stabilizing membrane protein folds and (ii) facilitating conformational dynamics involved in catalysis. These results will impact the in vitro preparation of membrane proteins, the interpretation of membrane misfolding mutations, the assemblies of biomolecular complexes in the context of membranes, clustering in the membrane, and much more.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.