Enzymes for Carboligation - 2-Ketoacid Decarboxylases and Hydroxynitrile Lyases

Enzymes for Carboligation - 2-Ketoacid Decarboxylases and Hydroxynitrile Lyases 

Martina Pohl, Holger Breithaupt, Bettina Frolich, Petra Heim, Hans Iding, 

Bettina Juchem, Petra Siegert, and Maria-Regina Kula 

Enantioselective C-C bond formation is gaining more and more importance in bioorganic synthesis. This reaction is efficiently catalyzed by 2-ketoacid decarboxylases (E.C. 4.1.l.X) as well as by hydroxynitrile lyases (E.C. 4.1.2.X). 

In order to increase the understanding of ThDP-dependent enzymes, the identification of amino acid side chains important for the catalysis of the carboligase reaction in pyruvate decarboxylase from Zymomonas mohilis (E.C. 4.1.1.1) and benzoylformate decarboxylase from Pseudomonasputida (E.C. 4.1.1.7) was a major task. Using site-directed mutagenesis and directed evolution, various enzyme variants were obtained, differing in substrate specificity and enantioselectivity. 

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