The rapid development of biomolecular NMR spectroscopy in the last decade(s) has paved the way for novel insights into the structure, dynamic properties, as well as the interaction of proteins. However, NMR data interpretation of large protein complexes is only feasible if the corresponding sample is selectively enriched in NMR active nuclei (13C and 15N) and/or 1H-depleted by 2H incorporation. One important strategy for selective protein isotope labeling is given by the addition of metabolic amino acid precursor compounds to the growth medium of a protein-overexpressing microorganism.

In our current projects, we investigate robust synthetic routes from cheap isotope sources to selectively labeled precursors. These compounds show an effective uptake into the metabolism of the overexpressing E. coli strains. Our techniques result in well defined 13C, 15N and 2H patterns in the corresponding target amino acids devoid of any cross labeling to other residues. Our proteins can be used for various biomolecular NMR experiments: They can provide additional restraints for structure calculation, simplify NMR spectra derived from large protein complexes, exhibit isolated spin systems for accurate interpretation of dynamic processes and offer well defined signals for straightforward chemical shift mapping.