International Collaboration in Chemistry: Quantitative analysis of Hydrogen bonding in a membrane milieu

美国威斯康星大学麦迪逊分校的Alessandro Senes教授得到了化学系生命过程化学项目的支持，获得了国际化学合作奖（ICC），该奖项包括与以色列耶路撒冷希伯来大学的Isiah Arkin教授的国际合作，该项目的目的是研究膜蛋白形状的一种力量。整合膜蛋白包埋在细胞膜内，在细胞和外部环境之间的边界处，以及在称为细胞器的细胞内区室的膜内，这些蛋白质在其中执行各种各样的基本功能。 为了执行这些功能，膜蛋白需要折叠成确定的三维结构，并经常与其他膜蛋白结合。 使膜蛋白折叠成特定的三维结构并相互结合的力仍然没有很好的理解。 这项研究将阐明这些基本力之一-氢键-在膜蛋白折叠和缔合中所起的特定作用。 该提案的成果将用于更好地了解各种重要的生物系统。该项目将通过跨学科环境中的研究培训产生更广泛的影响。这项工作的跨学科性质将为研究生和博士后研究员以及早期职业学生提供在各种实验和计算方法中获得跨学科培训的机会。此外，通过为高中生提供计算技能和外展工作，使公众了解多学科研究在科学进步中的重要性，从而产生了更广泛的影响。该项目的研究定量地解决了氢键对膜蛋白稳定性和相互作用特异性的贡献这一重要问题，使用先进的实验和计算方法的独特组合。同位素编辑的FTIR光谱加上DFT计算将用于分析相互作用的跨膜α-螺旋中单个氢键的比能。同时，将通过使用FRET和分析超离心的组合来评估相同α-螺旋缔合的总体热力学稳定性。 这项研究将使用先进的计算建模提供的结构框架来完成，最初是在表征模型系统的背景下，后来使用预测的单通道膜蛋白寡聚螺旋，以及已知结构的膜蛋白。这种方法将允许探索单个氢键的强度和它们对复合物形成的有效贡献之间的关系。

Professor Alessandro Senes at the University of Wisconsin-Madison, USA, is supported by the Chemistry of Life Processes Program in the Division of Chemistry, for an International Collaboration in Chemistry (ICC) award that comprises an international collaboration with Professor Isiah Arkin, of The Hebrew University of Jerusalem in Israel, who is supported by The Israel Bi-national Science Foundation.The aim of this project is to investigate one of the forces responsible for the shapes of membrane proteins. Integral membrane proteins are embedded within cellular membranes, at the boundaries between the cell and the outside environments, as well as within the membrane of intracellular compartments called organelles, where these proteins perform a wide variety of essential functions. In order to perform these functions, membrane proteins are required to fold into a defined three-dimensional structure and often associate with other membrane proteins. The forces that allow membrane proteins to fold into a particular three-dimensional structure and associate with each other are still not well understood. This research will elucidate the specific role played by one of these fundamental forces - hydrogen bonding - in the folding and association of membrane proteins. The outcomes of this proposal will be used to better understand a wide variety of important biological systems. The project will have a broader impact through research training in an interdisciplinary environment. The interdisciplinary nature of the work will provide graduate students and postdoctoral fellows, as well as early career students, with opportunities to acquire inter-disciplinary training in a variety of experimental and computational methods. In addition, a broader impact is achieved through providing high school students with computational skills and outreach efforts to inform the public of the importance of multidisciplinary research in the advancement of science.The research in this project addresses quantitatively the important question of the contribution of hydrogen bonding to stability and interaction specificity in membrane proteins, with the use of a unique combination of advanced experimental and computational approaches. Isotope-edited FTIR spectroscopy coupled with DFT calculations will be used to analyze the specific energetics of individual hydrogen bonds in interacting transmembrane alpha-helices. In parallel, the overall thermodynamic stability of association of the same alpha-helices will be assessed by using a combination of FRET and analytical ultracentrifugation. This research will be accomplished using a structural framework provided by advanced computational modeling, initially in the context of characterized model systems, and later using predicted oligomerizing helices from single-pass membrane proteins, as well as membrane proteins of known structure. This approach will allow exploration of the relationship between the strength of individual hydrogen bonds and their effective contribution to complex formation.