Jaudzems Kristaps, Bertarello Andrea, Chaudhari Sachin R, Pica Andrea, Cala-De Paepe Diane, Barbet-Massin Emeline, Pell Andrew J, Akopjana Inara, Kotelovica Svetlana, Gajan David, Ouari Olivier, Tars Kaspars, Pintacuda Guido, Lesage Anne
Univ Lyon, CNRS, Université Claude Bernard Lyon 1, Ens Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100, VILLEURBANNE, France.
Department of Chemical Sciences, University of Naples Federico II, Via Cintia, I-80126, Naples, Italy.
Angew Chem Int Ed Engl. 2018 Jun 18;57(25):7458-7462. doi: 10.1002/anie.201801016. Epub 2018 Apr 27.
Dynamic nuclear polarization (DNP) is a powerful way to overcome the sensitivity limitation of magic-angle-spinning (MAS) NMR experiments. However, the resolution of the DNP NMR spectra of proteins is compromised by severe line broadening associated with the necessity to perform experiments at cryogenic temperatures and in the presence of paramagnetic radicals. High-quality DNP-enhanced NMR spectra of the Acinetobacter phage 205 (AP205) nucleocapsid can be obtained by combining high magnetic field (800 MHz) and fast MAS (40 kHz). These conditions yield enhanced resolution and long coherence lifetimes allowing the acquisition of resolved 2D correlation spectra and of previously unfeasible scalar-based experiments. This enables the assignment of aromatic resonances of the AP205 coat protein and its packaged RNA, as well as the detection of long-range contacts, which are not observed at room temperature, opening new possibilities for structure determination.
动态核极化（DNP）是克服魔角旋转（MAS）核磁共振实验灵敏度限制的一种有效方法。然而，蛋白质的DNP NMR谱分辨率会受到严重谱线展宽的影响，这与在低温下以及存在顺磁自由基的情况下进行实验的必要性有关。通过结合高磁场（800 MHz）和快速MAS（40 kHz），可以获得不动杆菌噬菌体205（AP205）核衣壳的高质量DNP增强NMR谱。这些条件可提高分辨率并延长相干寿命，从而能够采集分辨的二维相关谱以及之前无法实现的基于标量的实验。这使得能够对AP205外壳蛋白及其包装的RNA的芳香族共振进行归属，以及检测在室温下未观察到的长程接触，为结构测定开辟了新的可能性。
