Time-optimized NMR spectroscopy for the investigation of challenging biological systems

该小组的主要重点是开发新型核磁共振（NMR）方法，重点是在要求苛刻的生物系统中的适用性。在这方面，我们的目标是提高现有的NMR资源的使用，同时检测不同的共振频率的几个实验。这可以显著减少记录相同数量的数据所需的昂贵的NMR测量时间（时间优化的NMR）。由于减少核磁共振测量时间是特别重要的大型生物系统的调查，核磁共振方法将开发重点放在这些系统。选择膜蛋白折叠和功能为新技术的应用提供非常合适的（即具有挑战性的）靶标。此外，选定的靶点本身代表了非常有趣的研究领域，该小组将利用这种可能性来研究例如，一个没有功能的蛋白质如何将自己插入细胞膜以执行其特定功能。这方面将首先使用蛋白质细菌视紫红质作为我们的第一个目标进行研究。对这一基本过程的深入了解将有助于开发靶向膜蛋白折叠的替代药物，或改善膜蛋白结构和功能的计算机预测。此外，我们还将研究第二个靶点黑皮质素-4受体（melanocortin-4 receptor，MC 4 R）的折叠和功能，MC 4 R属于G蛋白偶联受体（G-Protein coupled receptor，GPCRs）中非常重要的一类。虽然目前所有药物中约有一半估计直接作用于GPCR，但对这些系统的高分辨率见解非常有限。我们将结合联合收割机最有前途的传统和非传统的方法来研究结构和动力学的MC 4 R配体系统，以及配体诱导的变化的受体侧。配体本身由几种激素组成（如促肾上腺皮质激素和促黑素细胞激素）。MC 4 R信号通路参与体重和食欲的控制、血压的调节和炎症的抑制。预计，对该系统的任何高分辨率见解，特别是在受体和配体动力学方面，一方面可以帮助开发新的和改进的靶向MC 4 R信号通路的药物，另一方面可以提高我们对GPCR功能的理解。应用时间优化的NMR技术研究两种生物靶标不仅可以减少所需的NMR测量时间，而且还可以提供独特的可能性，例如同时检测蛋白质的不同折叠状态或动态不同区域。因此，预计该集团的不同方面之间将产生强大的协同作用。

The main focus of the proposed group lays on the development of novel nuclear magnetic resonance (NMR) methods with an emphasis on the applicability in demanding biological systems. In this context we aim to improve the use of existing NMR resources by simultaneous detection of several experiments on different resonance frequencies. This can significantly reduce the amount of expensive NMR measurement time required to record the same amount of data (time-optimized NMR). Since a reduction of NMR measurement time is in particular crucial for the investigation of larger biological systems, NMR methods will be developed with a strong emphasis on these systems. Membrane protein folding and function was selected to offer a well suited (i.e. challenging) target for the application of the new techniques. In addition the selected targets represent very interesting areas of research on its own and the group will use this possibility to investigate e.g. how a not functional protein can insert itself into a cell-membrane to carry out its specific function. This aspect will be initially investigated using the protein Bacteriorhodopsin as our first target. A more detailed insight into this fundamental process may help to develop alternate drugs targeting membrane protein folding or may improve computer predictions of membrane protein structure and function.Furthermore we will study folding and function of our second target, the melanocortin-4 receptor (MC4R), which belongs to the pharmacologically very important class of G-Protein coupled receptors (GPCRs). Although about half of all current drugs are estimated to directly act on GPCRs, high resolution insights into these systems are very limited. We will combine the most promising conventional and non-conventional approaches to investigate structure und dynamics of the MC4R ligand system as well as ligand induced changes on the receptor side. The ligands themselves consist of several hormones (e.g adrenocorticotropic and melanocyte-stimulating hormone). The MC4R signaling pathways are involved in the control of body weight and appetite, regulation of blood pressure and the inhibition of inflammation. It is anticipated, that any high resolution insights into this system in particular in respect to receptor and ligand dynamics may on the one hand help to develop new and improved drugs targeting the MC4R signaling pathway and on the other hand may improve our understanding of GPCR function in general. The application of time-optimized NMR techniques for the investigation of the two biological targets will not only reduce the required NMR measurement time, but will also provide unique possibilities, such as the simultaneous detection of different folding states or dynamically distinct regions of the protein. Hence a strong synergy between the different aspects of the group is expected.