Camilloni Carlo, Vendruscolo Michele
Department of Chemistry, University of Cambridge , Cambridge CB2 1EW, U.K.
J Phys Chem B. 2015 Jan 22;119(3):653-61. doi: 10.1021/jp5021824. Epub 2014 Jun 4.
Residual dipolar couplings (RDCs) are parameters measured in nuclear magnetic resonance spectroscopy that can provide exquisitely detailed information about the structure and dynamics of biological macromolecules. We describe here a method of using RDCs for the structural and dynamical refinement of proteins that is based on the observation that the RDC between two atomic nuclei depends directly on the angle ϑ between the internuclear vector and the external magnetic field. For every pair of nuclei for which an RDC is available experimentally, we introduce a structural restraint to minimize the deviation from the value of the angle ϑ derived from the measured RDC and that calculated in the refinement protocol. As each restraint involves only the calculation of the angle ϑ of the corresponding internuclear vector, the method does not require the definition of an overall alignment tensor to describe the preferred orientation of the protein with respect to the alignment medium. Application to the case of ubiquitin demonstrates that this method enables an accurate refinement of the structure and dynamics of this protein to be obtained.
剩余偶极耦合（RDCs）是在核磁共振光谱中测量的参数，它可以提供有关生物大分子结构和动力学的极其详细的信息。我们在此描述一种使用RDCs对蛋白质进行结构和动力学精修的方法，该方法基于这样的观察：两个原子核之间的RDC直接取决于核间矢量与外部磁场之间的夹角ϑ。对于每一对可通过实验获得RDC的原子核，我们引入一个结构约束，以最小化与从测量的RDC得出的以及在精修方案中计算的夹角ϑ值的偏差。由于每个约束仅涉及相应核间矢量夹角ϑ的计算，该方法不需要定义一个整体排列张量来描述蛋白质相对于排列介质的优选取向。应用于泛素的情况表明，该方法能够准确精修该蛋白质的结构和动力学。
