Long-Observation-Window Band-Selective Homonuclear Decoupling: Increased Sensitivity and Resolution in Solid-State NMR Spectroscopy of Proteins
Publication date: Available online 13 September 2013
Source:Journal of Magnetic Resonance
Author(s): Jochem O. Struppe , Chen Yang , Yachong Wang , Roy V. Hernandez , Lisa M. Shamansky , Leonard J. Mueller
Sensitivity and resolution are the two fundamental obstacles to extending solid-state nuclear magnetic resonance to even larger protein systems. Here, a novel long-observation-window band-selective homonuclear decoupling (LOW BASHD) scheme is introduced that increases resolution up to a factor of 3 and sensitivity up to 1.8 by decoupling backbone alpha-carbon (C?) and carbonyl (C’) nuclei in U-13C-labeled proteins during direct 13C acquisition. This approach introduces short (<200 ?s) pulse breaks into much longer (~8 ms) sampling windows to efficiently refocus the J-coupling interaction during detection while avoiding the deleterious effects on sensitivity inherent in rapid stroboscopic band-selective homonuclear decoupling techniques. A significant advantage of LOW BASHD detection is that it can be directly incorporated into existing correlation methods, as illustrated here for 2D CACO, NCO, and NCA correlation spectroscopy applied to the ?1 immunoglobulin binding domain of protein G and 3D CBCACO correlation spectroscopy applied to the ?-subunit of tryptophan synthase.
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