Paramagnetic metal ions in ligand screening: The Co-II matrix metalloproteinase 12

Smaller amounts of proteins are now required to screen for weak binding interactions between ligands and the active site of metalloproteins as a result of the substitution of diamagnetic zinc(II) with paramagnetic cobalt(II) in the matrix metalloproteinase MMP-12. 1H NMR spectroscopy then provides qualitative information on the orientation of the ligand in the catalytic site targeted by drugs (see picture).