A co-expression system to shift the equilibrium of transamination reactions toward the synthesis of enantiomerically pure amines

Aline Telzerow, Markus Hobisch, Monika Müller, Martin Schürmann, Helmut Schwab, Kerstin Steiner*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The synthesis of chiral amines as important pharmaceutical and fine chemical building blocks can be carried out with amine transaminases. The reaction equilibrium is often unfavorable. There are several methods to shift the equilibrium by co-product removal. One strategy employs isopropylamine as co-substrate resulting in the co-product acetone which can easily be evaporated under reduced pressure. However, many amine transaminases do not accept isopropylamine without further protein engineering. A subtler and generally applicable method uses alanine as co-substrate. A lactate dehydrogenase and a glucose dehydrogenase are added to remove the co-product pyruvate. Drawbacks are high costs for enzyme production and the addition of high amounts of biomass to reaction mixtures. We overcame these drawbacks by co-expression of an amine transaminase with a lactate dehydrogenase and a glucose dehydrogenase in a recombinant Escherichia coli strain. We further demonstrated the applicability on preparative scale. We used the E. coli cell free extract in reactions with up to 74 g/L substrate load achieving yields of >95% in reaction volumes of 10 mL–200 mL.

Original languageEnglish
Pages (from-to)38-43
Number of pages6
JournalMolecular Catalysis
Publication statusPublished - 1 Jul 2019


  • Chiral amines
  • Co-expression
  • Co-factor recycling
  • Equilibrium shift
  • Transaminase

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology
  • Physical and Theoretical Chemistry

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