Ultra-high resolution 17O solid-state NMR spectroscopy of biomolecules: a comprehensive spectral analysis of monosodium L-glutamate·monohydrate.

Journal article

Monosodium L-glutamate monohydrate, a multiple oxygen site (eight) compound, is used to demonstrate that a combination of high-resolution solid-state NMR spectroscopic techniques opens up new possibilities for (17)O as a nuclear probe of biomolecules. Eight oxygen sites have been resolved by double rotation (DOR) and multiple quantum (MQ) NMR experiments, despite the (17)O chemical shifts lying within a narrow shift range of <50 ppm. (17)O DOR NMR not only provides high sensitivity and spectral resolution, but also allows a complete set of the NMR parameters (chemical shift anisotropy and electric-field gradient) to be determined from the DOR spinning-sideband manifold. These (17)O NMR parameters provide an important multi-parameter comparison with the results from the quantum chemical NMR calculations, and enable unambiguous oxygen-site assignment and allow the hydrogen positions to be refined in the crystal lattice. The difference in sensitivity between DOR and MQ NMR experiments of oxygen in bio/organic molecules is also discussed. The data presented here clearly illustrates that a high resolution (17)O solid-state NMR methodology is now available for the study of biomolecules, offering new opportunities for resolving structural information and hence new molecular insights.

Authors: Wong, A; Howes, A; Yates, JR; Watts, A; Anupõld, T

• Publication status: Published
• Journal: Physical chemistry chemical physics : PCCP
• Volume: 13
• Issue: 26
• Pages: 12213-12224
• Publication date: 2011-07-01
• DOI: 10.1039/c1cp20629j
• EISSN: 1463-9084
• ISSN: 1463-9076
• Language: English
• Keywords: Models, Molecular; Quantum Theory; Sensitivity and Specificity; Magnetic Resonance Spectroscopy; Hydrogen Bonding; Sodium Glutamate; Oxygen Isotopes