Labeling strategies for 13C-detected aligned-sample solid-state NMR of proteins.
(13)C-detected solid-state NMR experiments have substantially higher sensitivity than the corresponding (15)N-detected experiments on stationary, aligned samples of isotopically labeled proteins. Several methods for tailoring the isotopic labeling are described that result in spatially isolated (13)C sites so that dipole-dipole couplings among the (13)C are minimized, thus eliminating the need for homonuclear (13)C-(13)C decoupling in either indirect or direct dimensions of one- or multi-dimensional NMR experiments that employ (13)C detection. The optimal percentage for random fractional (13)C labeling is between 25% and 35%. Specifically labeled glycerol and glucose can be used at the carbon sources to tailor the isotopic labeling, and the choice depends on the resonances of interest for a particular study. For investigations of the protein backbone, growth of the bacteria on [2-(13)C]-glucose-containing media was found to be most effective.
Filipp
Fabian V
FV
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0307, USA.
Sinha
Neeraj
N
Jairam
Lena
L
Bradley
Joel
J
Opella
Stanley J
SJ
D001426:Bacterial Proteins / Q000032:analysis* / Q000737:chemistry*; D002247:Carbon Isotopes / Q000032:analysis / Q000737:chemistry; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D044367:Phase Transition; D011208:Powders
D001426:Bacterial Proteins; D002247:Carbon Isotopes; D011208:Powders