New limits for solid-state 17O NMR spectroscopy: complete resolution of multiple oxygen sites in a simple biomolecule.
A solid-state 17O NMR 1H-decoupled double angle rotation (DOR) study of monosodium l-glutamate monohydrate (l-MSG) is reported. It is shown that all eight inequivalent sites can be resolved with DOR line widths ( approximately 65 Hz) approximately 120 times narrower than those in the MAS spectrum. The lines are tentatively assigned on the basis of their behavior under proton decoupling and the isotropic chemical shift and the quadrupole interaction parameter for each extracted by a combination of DOR and 3Q MAS at variable magnetic fields. With a shift range of approximately 45 ppm for these similar oxygen sites and spectral resolution under DOR comparable to that for spin-1/2 nuclei, solid-state 17O NMR should have tremendous potential in the study of biomolecules.
Wong
Alan
A
Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
Howes
Andy P
AP
Pike
Kevin J
KJ
Lemaître
Vincent
V
Watts
Anthony
A
Anupõld
Tiit
T
Past
Jaan
J
Samoson
Ago
A
Dupree
Ray
R
Smith
Mark E
ME
D001665:Binding Sites; D003903:Deuterium / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010100:Oxygen / Q000737:chemistry*; D010103:Oxygen Isotopes / Q000737:chemistry*; D011506:Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
D010103:Oxygen Isotopes; D011506:Proteins; D003903:Deuterium; D010100:Oxygen