Optimal control based NCO and NCA experiments for spectral assignment in biological solid-state NMR spectroscopy.
We present novel pulse sequences for magic-angle-spinning solid-state NMR structural studies of (13)C,(15)N-isotope labeled proteins. The pulse sequences have been designed numerically using optimal control procedures and demonstrate superior performance relative to previous methods with respect to sensitivity, robustness to instrumental errors, and band-selective excitation profiles for typical biological solid-state NMR applications. Our study addresses specifically (15)N to (13)C coherence transfers being important elements in spectral assignment protocols for solid-state NMR structural characterization of uniformly (13)C,(15)N-labeled proteins. The pulse sequences are analyzed in detail and their robustness towards spin system and external experimental parameters are illustrated numerically for typical (15)N-(13)C spin systems under high-field solid-state NMR conditions. Experimentally the methods are demonstrated by 1D (15)N-->(13)C coherence transfer experiments, as well as 2D and 3D (15)N,(13)C and (15)N,(13)C,(13)C chemical shift correlation experiments on uniformly (13)C,(15)N-labeled ubiquitin.
Kehlet
Cindie
C
Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, Langelandsgade 140, DK-8000, Aarhus C, Denmark.
Bjerring
Morten
M
Sivertsen
Astrid C
AC
Kristensen
Torsten
T
Enghild
Jan J
JJ
Glaser
Steffen J
SJ
Khaneja
Navin
N
Nielsen
Niels Chr
NC
D000465:Algorithms; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D025801:Ubiquitin / Q000737:chemistry*
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D025801:Ubiquitin