Research

The metalloproteins that are at the focus of our investigations, contain the so-called molybdenum and tungsten cofactors. These enzymes are ubiquitous and therefore found in every organism, including humans. The reactions which are catalysed by these enzymes are usually transfer reactions from O^2- from water to substrate or vice versa during a two-electron redox reaction: R + H₂O ⇆ RO + 2 H⁺ + 2 e^–. The reactions play an important role in the nitrogen, carbon and/or sulphur metabolism, therefore generally in the metabolism of all organisms. Although the enzymes are structurally diverse, their active sites can generally be summarised in a sketch, as shown in the above diagram.  The complex organic ligand that is shown is called molybdopterin and is one of the joint characteristics of all enzymes of this kind. The dithiolene function is a specific feature with which molybdopterin coordinates the metal, as it is non-innocent, i.e. it can actively take part in the redox reactions, which can generally be of considerable use for catalytic processes.