J-deconvolution using maximum entropy reconstruction applied to 13C-13C solid-state cross-polarization magic-angle-spinning NMR of proteins

J Am Chem Soc. 2007 May 30;129(21):6682-3. doi: 10.1021/ja070849g. Epub 2007 May 9.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry
  • Carbon Isotopes
  • Entropy
  • Escherichia coli Proteins / chemistry
  • Fourier Analysis
  • Glycerol / chemistry
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Porins / chemistry
  • Proteins / chemistry*
  • Valine / chemistry

Substances

  • Bacterial Outer Membrane Proteins
  • Carbon Isotopes
  • Escherichia coli Proteins
  • OmpG protein, E coli
  • Porins
  • Proteins
  • Valine
  • Glycerol