Methyl groups as probes for proteins and complexes in in-cell NMR experiments

J Am Chem Soc. 2004 Jun 9;126(22):7119-25. doi: 10.1021/ja049977k.


Studying protein components of large intracellular complexes by in-cell NMR has so far been impossible because the backbone resonances are unobservable due to their slow tumbling rates. We describe a methodology that overcomes this difficulty through selective labeling of methyl groups, which possess more favorable relaxation behavior. Comparison of different in-cell labeling schemes with three different proteins, calmodulin, NmerA, and FKBP, shows that selective labeling with [(13)C]methyl groups on methionine and alanine provides excellent sensitivity with low background levels at very low costs.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Carbon Isotopes / chemistry
  • Cells / chemistry*
  • Escherichia coli / chemistry*
  • Methionine / chemistry
  • Methylation
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Pharmaceutical Preparations / chemistry
  • Pharmaceutical Preparations / metabolism
  • Proteins / chemistry*
  • Pyruvic Acid / chemistry
  • Tacrolimus Binding Proteins / chemistry


  • Carbon Isotopes
  • Pharmaceutical Preparations
  • Proteins
  • Pyruvic Acid
  • Methionine
  • Tacrolimus Binding Proteins