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

该小组的主要重点是发展新型核磁共振（NMR）方法，重点是在要求苛刻的生物系统中的适用性。在这种情况下，我们的目标是通过同时检测不同共振频率的几个实验来改善现有核磁共振资源的使用。这可以显著减少记录相同数量的数据（时间优化的NMR）所需的昂贵的NMR测量时间。由于减少核磁共振测量时间对于大型生物系统的研究尤为重要，因此核磁共振方法将在这些系统上得到大力发展。选择膜蛋白折叠和功能为新技术的应用提供了一个非常合适的（即具有挑战性的）目标。此外，所选择的目标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，无功能蛋白质如何将自身插入细胞膜以执行其特定功能。这方面的初步研究将以蛋白细菌视紫红质作为我们的第一个目标。对这一基本过程的更详细的了解可能有助于开发针对膜蛋白折叠的替代药物，或者可能改善膜蛋白结构和功能的计算机预测。此外，我们将研究我们的第二个目标，黑素皮质素-4受体（MC4R）的折叠和功能，它属于药理学上非常重要的一类g蛋白偶联受体（gpcr）。虽然目前估计约有一半的药物直接作用于gpcr，但对这些系统的高分辨率了解非常有限。我们将结合最有前途的常规和非常规方法来研究MC4R配体系统的结构和动力学以及配体诱导受体侧的变化。配体本身由几种激素（如促肾上腺皮质激素和促黑素细胞激素）组成。MC4R信号通路参与控制体重和食欲，调节血压和抑制炎症。可以预见的是，对该系统的任何高分辨率的见解，特别是在受体和配体动力学方面，一方面可能有助于开发新的和改进的靶向MC4R信号通路的药物，另一方面可能提高我们对GPCR功能的总体理解。应用时间优化的核磁共振技术来研究这两种生物靶点不仅减少了所需的核磁共振测量时间，而且还提供了独特的可能性，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，期望集团的不同方面之间有强大的协同作用。

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.