J-deconvolution using maximum entropy reconstruction applied to 13C-13C solid-state cross-polarization magic-angle-spinning NMR of proteins.
Scalar couplings between 13C spins can impair both resolution and sensitivity in 13C-labeled preparations. It is demonstrated that deconvolution of magic-angle-spinning NMR data with maximum entropy (MaxEnt) reconstruction allows the removal of splittings due to J-couplings without expenses in sensitivity. A combination of MaxEnt reconstruction in t2 with selective pulses in t1 produces fully J-resolved data in both dimensions. The possibility to obtain J-resolved 13C-13C data without compromising the sensitivity is particularly important for solid-state NMR of "difficult" biological samples, like membrane proteins, where sacrifices in signal-to-noise are fatal. The method is demonstrated using preparations of alpha-spectrin SH3 domain (62 residues) as small test system and of outermembrane protein G as example of a membrane protein with higher molecular weight (281 residues). Both preparations were obtained using [2-13C]-glycerol as the carbon source during the bacterial growth.
Scholz
Ingo
I
Leibnizinstitut für Molekulare Pharmakologie, Berlin, Germany.
Jehle
Stefan
S
Schmieder
Peter
P
Hiller
Matthias
M
Eisenmenger
Frank
F
Oschkinat
Hartmut
H
van Rossum
Barth-Jan
BJ
D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry; D002247:Carbon Isotopes; D019277:Entropy; D029968:Escherichia coli Proteins / Q000737:chemistry; D005583:Fourier Analysis; D005990:Glycerol / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D018272:Porins / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D014633:Valine / Q000737:chemistry
D001425:Bacterial Outer Membrane Proteins; D002247:Carbon Isotopes; D029968:Escherichia coli Proteins; C114347:OmpG protein, E coli; D018272:Porins; D011506:Proteins; D014633:Valine; D005990:Glycerol