Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Phys Chem Chem Phys. 2010 Jun 14;12(22):5911-9. doi: 10.1039/c003661g. Epub 2010 May 8.
Dynamic nuclear polarization (DNP) utilizes the inherently larger polarization of electrons to enhance the sensitivity of conventional solid-state NMR experiments at low temperature. Recent advances in instrumentation development and sample preparation have transformed this field and have opened up new opportunities for its application to biological systems. Here, we present DNP-enhanced (13)C-(13)C and (15)N-(13)C correlation experiments on GNNQQNY nanocrystals and amyloid fibrils acquired at 9.4 T and 100 K and demonstrate that DNP can be used to obtain assignments and site-specific structural information very efficiently. We investigate the influence of temperature on the resolution, molecular conformation, structural integrity and dynamics in these two systems. In addition, we assess the low-temperature performance of two commonly used solid-state NMR experiments, proton-driven spin diffusion (PDSD) and transferred echo double resonance (TEDOR), and discuss their potential as tools for measurement of structurally relevant distances at low temperature in combination with DNP.
动态核极化（DNP）利用电子固有的更大极化度来提高低温下常规固态 NMR 实验的灵敏度。仪器开发和样品制备方面的最新进展改变了这一领域，并为其在生物系统中的应用开辟了新的机会。在这里，我们展示了在 9.4 T 和 100 K 下对 GNNQQNY 纳米晶体和淀粉样纤维进行的 DNP 增强（13）C-（13）C 和（15）N-（13）C 相关实验，并证明 DNP 可用于非常有效地获得分配和特定于位置的结构信息。我们研究了温度对这两个系统的分辨率、分子构象、结构完整性和动力学的影响。此外，我们评估了两种常用的固态 NMR 实验——质子驱动的自旋扩散（PDSD）和转移回波双共振（TEDOR）——在低温下的性能，并讨论了它们与 DNP 结合作为低温下测量结构相关距离的工具的潜力。
