Motional Modeling by NMR Relaxation

对蛋白质功能的理解只有在详细了解结构、相互作用和局部动力学的情况下才能接近于完整性。在过去的资助期，为蛋白质模块中快速局部动力学的实验推导运动模型奠定了基础。其目的不仅是检测局部动力学的存在，而且还描述运动的实际情况。这是通过测量与单个运动单元相关的几个原子核的核磁共振弛豫行为来实现的。根据与弛豫有关的不同磁相互作用矢量的动力学参数来解释这些数据，由此可以建立运动模型。在目前的工作中，这一新的范例将用新的核磁共振技术来扩展和完善，以描述蛋白质骨架的局部各向异性动力学。蛋白质侧链动力学建模将通过测量几个不同侧链相互作用向量的动力学参数来以类似的方式进行。完善土壤构象变化动力学的测定方法。这些动力学通常与配体/底物相互作用有关。通过几种结构方法和动力学方法的结合，可以得到慢运动的模型。这些方法将开发并应用于小核糖核酸酶和黄素蛋白的活性部位动力学。在有利的情况下，新方法可以区分相关和不相关的局部运动。蛋白质、DNA和RNA等生物分子是生命所必需的。为了了解它们的功能，近几十年来，人们从静态结构的角度对其中许多分子进行了分析。虽然这使人们从定性的角度对功能有了更多的了解，但定量的解释仍然难以捉摸。大多数生物分子可以被视为引擎或工厂。就像工厂的真正发动机只有在运动时才能工作一样，生物分子也必须移动才能发挥它们的功能。因此，只有在研究了生物分子的动态方面和静态图像之后，才能完整地了解生物分子的实际工作原理。本项目将研究分子的小范围运动，并将重点放在酶活性部位的动力学上。由此产生的知识将有助于对生命过程的基本理解。在这项研究中，将使用尽可能高磁场强度的核磁共振技术。

Understanding of protein function can only approach completeness if structure, interactions and local dynamics are understood in detail. In the past funding period, the foundation to experimentally derived motional models for fast local dynamics in protein modules has been established. The goal was to not only detect the existence of local dynamics but also describe what the motions actually are. this is achieved by measuring the NMR relaxation behavior for several nuclei associated with a single motion unit. This data is interpreted in terms of dynamical parameters for the different magnetic interaction vectors associated with the relaxation, from which a motional model can be developed. In the present work this new paradigm will be extended and refined with new NMR techniques for the description of local anisotropic dynamics of the protein backbone. Protein sidechains dynamics modeling will be approached in a similar way by measuring dynamical parameters for several different sidechain interaction vectors. The methods for the measurements of sloe conformational change dynamics will be improved. These dynamics are often associated with ligand/substrate interaction. By combination of several methods, structural as well dynamical, one can obtain models for the slow motions. The methods will be developed with and applied to the active site dynamics of a small ribonuclease and of a flavoprotein. In favorable cases the new methods can differentiate between correlated and uncorrelated local motions.Biological molecules such as proteins, DNA and RNA are essential to life. In order to understand how they function, many of these molecules have been analyzed in terms to their static structures in the recent decades. While this has yeilded much insight into function in qualitative terms, explanations in quantitative terms have remained elusive. Most biological molecules can be seen as engines or factories. Just as real engines ot factories only work when they are in motion, biobolecules have to move to carry out their functions. Thus, knowledge of how biomolecules actually work can only be complete when their dynamical aspects are studied in addition to static pictures. This porject will study the molecules in terms of their small-scale motions and will focus especially on dynamics of the active sites of enzymes. The resulting knowledge will contribute to the basic understanding of life-processes. For this research the technique of nuclear magnetic resonance at the highest possible magnetic field strengths will be used.