Understanding Microbial Rhodopsins by linking Solid-State NMR with computational Approaches

蛋白视紫红质(PR)家族的膜蛋白是地球上最丰富的视网膜光感受器。它们作为光驱动质子泵的功能为海洋生态系统的生物能量学做出了重大贡献。此外，他们还可以完成一系列额外的传感和监管活动。在这个项目中，我们将在原子分辨率下解决绿色和蓝色PR以及红色吸收突变体之间颜色调节的分子细节，阐明光循环中的结构和电子变化，并剖析特定的交叉异构体相互作用在天然五聚体中的功能作用。该项目将法兰克福Glaubitz实验室的固体核磁共振(包括动态核极化和光诱导低温捕获)与上海He实验室的基于QM/MM的核磁共振参数计算、吸收光谱和MD模拟相结合。通过这种方式，我们将能够将光学性质与结构和电子参数联系起来。这种实验和理论方法的协同应用还将产生方案和程序，这些方案和程序可能在未来应用于其他膜蛋白。

Membrane proteins of the proteorhodopsin (PR) family are the most abundant retinal-based photoreceptors on this planet. Their function as light-driven proton pump creates a significant contribution to the bioenergetics in marine ecosystems. In addition, they could fulfill an array of additional sensing and regulatory activities. In this project, we will resolve the molecular details of color tuning between green and blue PR as well as red-absorbing mutants at atomic resolution, elucidate structural and electronic changes during the photocycle and dissect the functional role of specific cross-protomer interactions within the native pentamers. This project combines solid-state NMR including dynamic nuclear polarization and light-induced cryo-trapping in the Glaubitz lab, Frankfurt, with QM/MM-based calculations of NMR parameters, absorption spectra and MD simulations in the He lab, Shanghai. In this way, we will be able to connect optical properties with structural and electronic parameters. Such a concerted application of experimental and theoretical approaches will also result in protocols and procedures, which could be applied to other membrane proteins in the future.