Resolution enhancement by homonuclear J-decoupling: application to three-dimensional solid-state magic angle spinning NMR spectroscopy.
We describe a simple protocol to achieve homonuclear J-decoupling in the indirect dimensions of multidimensional experiments, and to enhance spectral resolution of the backbone Calpha carbons in the 3D NCACX experiment. In the proposed protocol, the refocusing of the Calpha-CO homonuclear J-couplings is achieved by applying an off-resonance selective pi pulse to the CO spectral region in the middle of Calpha chemical shift evolution. As is commonly used in solution NMR, a compensatory echo period is used to refocus the unwanted chemical shift evolution of Calpha spins, which takes place during the off-resonance selective pulse. The experiments were carried out on the beta1 immunoglobulin binding domain of protein G (GB1). In GB1, such implementation results in significantly reduced line widths, and leads to an overall sensitivity enhancement.
Shi
Lichi
L
Department of Physics and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G 2W1.
Peng
Xiaohu
X
Ahmed
Mumdooh A M
MA
Edwards
Dale
D
Brown
Leonid S
LS
Ladizhansky
Vladimir
V
D001426:Bacterial Proteins / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*
D001426:Bacterial Proteins; C034284:IgG Fc-binding protein, Streptococcus; D011506:Proteins; D002244:Carbon