Methyl and Amino Acid Type Labelling
Methyl Labelling refers to methods which introduce either 13CH3 or 13CHD2 groups into otherwise a uniform deuterated protein. This can be achieved in both prokaryotic and eukaryotic expression systems by adding the amino acids(s) (in sufficient amounts) directly to the cell culture medium prior to protein induction. For E. coli cultures, selective protonation on methyl groups of ILV can be achieved by adding alpha-keto acid precursors to the D2O-based cell culture medium 1 hr prior to induction. Alpha-ketoisobutyrate becomes converted to isoleucine, and alpha-ketoisovaleric acid becomes converted to leucine and valine. This methodology has dramatically increased the useful molecular weight range of protein and protein complexes assessable by NMR when using methyl TROSY techniques.
Product Information and Resources
- Selective Isotope-Labelling Methods for Protein Structural Studies
- Stereospecific Leu/Val Methyl Labelling: An Important Technology for NMR Studies of High-Molecular-Weight Complexes (Application Note 48)
- Isotope Labelling of Alanine Methyl Groups on a Deuterated Background for NMR Studies of High-Molecular-Weight Proteins (Application Note 25)
- Production of U-[2H], Thy-γ2[13CH3] Labelled Proteins for methyl-TROSY NMR (Application Note 39)
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