Callon Morgane, Luder Dominique, Malär Alexander A, Wiegand Thomas, Římal Václav, Lecoq Lauriane, Böckmann Anja, Samoson Ago, Meier Beat H
Physical Chemistry, ETH Zürich 8093 Zürich Switzerland
Molecular Microbiology and Structural Biochemistry (MMSB) UMR 5086, CNRS, Université de Lyon, Labex Ecofect 7 passage du Vercors 69367 Lyon France.
Chem Sci. 2023 Sep 20;14(39):10824-10834. doi: 10.1039/d3sc03539e. eCollection 2023 Oct 11.
The NMR spectra of side-chain protons in proteins provide important information, not only about their structure and dynamics, but also about the mechanisms that regulate interactions between macromolecules. However, in the solid-state, these resonances are particularly difficult to resolve, even in relatively small proteins. We show that magic-angle-spinning (MAS) frequencies of 160 kHz, combined with a high magnetic field of 1200 MHz proton Larmor frequency, significantly improve their spectral resolution. We investigate in detail the gain for MAS frequencies between 110 and 160 kHz MAS for a model sample as well as for the hepatitis B viral capsid assembled from 120 core-protein (Cp) dimers. For both systems, we found a significantly improved spectral resolution of the side-chain region in the H-C 2D spectra. The combination of 160 kHz MAS frequency with a magnetic field of 1200 MHz, allowed us to assign 61% of the aliphatic protons of Cp. The side-chain proton assignment opens up new possibilities for structural studies and further characterization of protein-protein or protein-nucleic acid interactions.
蛋白质侧链质子的核磁共振谱不仅能提供有关其结构和动力学的重要信息，还能提供有关调节大分子间相互作用机制的重要信息。然而，在固态下，即使是相对较小的蛋白质，这些共振峰也特别难以分辨。我们表明，160千赫兹的魔角旋转（MAS）频率与1200兆赫质子拉莫尔频率的高磁场相结合，能显著提高其光谱分辨率。我们详细研究了模型样品以及由120个核心蛋白（Cp）二聚体组装而成的乙肝病毒衣壳在110至160千赫兹MAS频率之间的增益情况。对于这两个系统，我们在H-C二维谱中发现侧链区域的光谱分辨率有了显著提高。160千赫兹MAS频率与1200兆赫磁场的结合，使我们能够确定Cp中61%的脂肪族质子。侧链质子的确定为蛋白质结构研究以及蛋白质-蛋白质或蛋白质-核酸相互作用的进一步表征开辟了新的可能性。
