Measurements of carbon to amide-proton distances by C-H dipolar recoupling with 15N NMR detection.
A new magic-angle spinning NMR method for measuring internuclear distances between a 13C-labeled site and amide protons is described. The magnetization of the protons evolves under homonuclear decoupling and the recoupled 13C-1H dipolar interaction, which provides simple spin-pair REDOR curves if only one 13C-labeled site is present. The modulation of the amide proton HN is detected via short 1H-15N cross polarization followed by 15N detection. The method is demonstrated on two specifically 13C- and 15N-labeled peptides, with 13C-HN distances from 2.2 to ca. 6 A. This technique promises to be particularly useful for measuring distances between 13C=O and H-15N groups, to identify hydrogen bonds in peptides and proteins.
Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Klaus
K
Schmidt-Rohr
Mei
M
Hong
D000577:Amides / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry*; D006860:Hydrogen Bonding; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry
D000577:Amides; D009587:Nitrogen Isotopes; D011506:Proteins; C029052:BOC-glycine; D005998:Glycine