Proton-detected separated local field spectroscopy.
PISEMO, a separated local field experiment that can be performed with either direct (15)N (or (13)C) detection or indirect (1)H detection, is demonstrated on a single crystal of a model peptide. The (1)H signals modulated by (1)H-(15)N heteronuclear dipole-dipole couplings are observed stroboscopically in the windows of the multiple-pulse sequence used to attenuate (1)H-(1)H homonuclear dipole-dipole couplings. (1)H-detection yields spectra with about 2.5 times the signal to noise ratio observed with (15)N-detection under equivalent conditions. Resolution in both the (15)N chemical shift and (1)H-(15)N heteronuclear dipole-dipole coupling dimensions is similar to that observed with PISEMA, however, since only on-resonance pulses are utilized, the bandwidth is better.
Wu
Chin H
CH
Department of Chemistry and Biochemistry, 9500 Gilman Drive, University of California, San Diego, La Jolla, CA 92093-0307, USA.
Opella
Stanley J
SJ
D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009587:Nitrogen Isotopes; D010455:Peptides / Q000737:chemistry*; D011522:Protons
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010455:Peptides; D011522:Protons