Sanz-Hernández Máximo, Vostrikov Vitaly V, Veglia Gianluigi, De Simone Alfonso
Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK.
Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
Sci Rep. 2016 Mar 15;6:23063. doi: 10.1038/srep23063.
The structural dynamics governing collective motions in oligomeric membrane proteins play key roles in vital biomolecular processes at cellular membranes. In this study, we present a structural refinement approach that combines solid-state NMR experiments and molecular simulations to accurately describe concerted conformational transitions identifying the overall structural, dynamical, and topological states of oligomeric membrane proteins. The accuracy of the structural ensembles generated with this method is shown to reach the statistical error limit, and is further demonstrated by correctly reproducing orthogonal NMR data. We demonstrate the accuracy of this approach by characterising the pentameric state of phospholamban, a key player in the regulation of calcium uptake in the sarcoplasmic reticulum, and by probing its dynamical activation upon phosphorylation. Our results underline the importance of using an ensemble approach to characterise the conformational transitions that are often responsible for the biological function of oligomeric membrane protein states.
寡聚膜蛋白中控制集体运动的结构动力学在细胞膜的重要生物分子过程中起着关键作用。在本研究中，我们提出了一种结构优化方法，该方法结合了固态核磁共振实验和分子模拟，以准确描述协同构象转变，从而确定寡聚膜蛋白的整体结构、动力学和拓扑状态。用这种方法生成的结构集合的准确性被证明达到了统计误差极限，并通过正确再现正交核磁共振数据得到了进一步证明。我们通过表征受磷蛋白（肌浆网中钙摄取调节的关键因子）的五聚体状态，并探究其磷酸化后的动态激活，来证明这种方法的准确性。我们的结果强调了使用集合方法来表征构象转变的重要性，这些转变通常决定了寡聚膜蛋白状态的生物学功能。
