Determination of the three-dimensional structure of proteins in solution is a stronghold of modern
bio-molecular NMR spectroscopy. Even more important for understanding processes in the living cell
is the characterization of interaction sites and surfaces of protein-protein and protein-ligand complexes.
NMR can provide not only structural but also dynamic information on this subject. Pseudo contact shift
(PCS) NMR spectroscopy has a unique property as it is a long-range method that can cover distances of
more than 50 Å, in combination with precise angle information. The very sensitive 2D-NMR experiments
can be performed even on larger proteins, provided a state of the art spectrometer is available. We have
recently presented a new lanthanide chelating tag "M8", based on a sterically overcrowded DOTA framework
that shows PCS of unprecedented size when linked to ubiquitin. This project is aimed at further improving
the properties of the new ligand by systematically optimizing the linker between the DOTA core
and the protein and by variation of the donor atom set of the chelator.