Catalysis of in situ Click - Chemistry by Hybrid Metalloenzymes

Lisa Englert1, Dong Sun2, Johannes Schulze Wischeler1, Andreas Heine1, Ulrich Koert2, and Gerhard Klebe1

1Institute of Pharmaceutical Chemistry, Philipps-University, Marbacher Weg 6, 35032 Marburg, Germany, and

2Institute of Organic Chemistry, Philipps-University, Hans-Meerwein-Straße, 35032 Marburg, Germany




Both, dynamic combinatorial chemistry as well as click-chemistry are novel innovative tools for modern drug discovery. Combining the two strategies offers a very promising approach to achieve target selective inhibitor synthesis.[1,2]

The overall goal of our project is to introduce a Cu+ into the metalloenzymes thermolysin and carbonic anhydrase II transforming these into selective catalysts for in situ click-chemistry. For the enzyme thermolysin this will be achieved by replacing the Zn2+ ion in the active site against Cu+, while for the enzyme carbonic anhydrase II the mutation of selected amino acids will result in novel Cu+ coordinating residues. The modified hybrid-enzymes will then select, optimise and synthesise their own inhibitor.

We designed a combinatorial library of triazoles and tetrazoles which can be synthesised via 1,3 - cycloaddition of alkines/nitriles and azides.[3] Furthermore, we were already able to generate Zn2+-free crystals by soaking native thermolysin crystals in a solution of 1,10-phenanthroline. The second metallo enzyme, carbonic anhydrase II, has been modified by site-directed mutagenesis, introducing sulphur containing residues to form a Cu+-binding site.