Sensitivity enhancement in solid state (15)N NMR by indirect detection with high-speed magic angle spinning.
Enhancement of sensitivity in solid state (15)N NMR by indirect detection through (1)H NMR signals under high-speed magic angle spinning and high-field conditions is demonstrated experimentally on two (15)N-labeled peptides, polycrystalline AlaGlyGly and the helix-forming, 17-residue peptide MB(i + 4)EK in lyophilized form. Sensitivity enhancement factors ranging from 2.0 to 3.2 are observed experimentally, depending on the (15)N and (1)H linewidths and polarization transfer efficiencies. The (1)H-detected two-dimensional (1)H/(15)N correlation spectrum of AlaGlyGly illustrates the possibility of increased spectral resolution and resonance assignments in indirectly detected experiments, in addition to the sensitivity enhancement.
Ishii
Y
Y
National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA.
Tycko
R
R
D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009587:Nitrogen Isotopes; D010455:Peptides / Q000737:chemistry
D009587:Nitrogen Isotopes; D010455:Peptides