Investigation of Molecular Motions by Lee-Goldburg Cross-Polarization NMR Spectroscopy

摘要: We demonstrate the use of Lee-Goldburg cross-polarization (LG-CP) NMR under fast magic-angle spinning (MAS) to investigate amplitude and geometry segmental motions in biomolecular polymeric solids. Motional information was previously available only from 2 H NMR, which, however, has limited site resolution requires site-specific isotopic labeling. Using a 2D LG-CP technique, we resolve 1 3 C- or 5 N- dipolar couplings according C N isotropic chemical shift. Applications systems undergoing 180° phenylene ring flips show spectral line shapes reflecting motion. this measured water-soluble membrane-bound states colicin la channel domain. The backbone scale both Ca-Ha N-H similarly, thus ruling out rotation α-helices around their axes as specific mechanism also that sensitivity spectra can be enhanced by addition phase-inverted H- step, indirect detection.