Development and application of novel engineered transaminase panels assisted by in- silico rational design for the production of chiral amines
September 15-19, 2019
There is a high demand for the synthesis of chiral amines as building blocks for a large number of industrially valuable compounds. Transaminases (TAm) offer an enzymatic route for the synthesis of chiral amines that avoids complex chemical synthesis . However, their catalytic efficiency towards bulky ketone substrates is greatly limited by steric hinderance . This poster highlights a rational design strategy of combining in silico and in vitro methods to engineer the transaminase enzyme with a minimal number of mutations, achieving high catalytic activity and high enantioselectivity. The wildtype TAm showed no detectable activity towards the ketone 2-acetylbiphenyl but upon introduction of two mutations detectable enzyme activity was observed. The reaction rate was improved a further 1716-fold with the rationally designed variant, that contained a further 5 mutations, producing the corresponding enantiomeric pure (S)-amine (enantiomeric excess (ee) value of >99%).
In addition, screening of in silico designed (R)-TAm mutant panels in resolution mode offered an attractive and efficient route for the preparation of problematic (S)-amines. A mutant was identified from the panels that gave complete resolution of the racemic amine (high substrate loading) to leave the desired enantiomer at a low enzyme loading fit for process development towards an economically viable scale up process.
 R. C. Simon, et al, ACS Catal. 2014, 4(1)
 F. Steffen-Munsberg, et al, ChemCatChem 2013, 5, (1)
D.F.A.R.Dourado et al, ACS Catal. 2016, 6 (11)
Daniel F.A.R. Dourado, Stefan Pohle, Stefan Mix, Thomas S. Moody, Derek J. Quinn, Jill Caswell, Alexandra T. P. Carvalho, and Meilan Huang, "Development and application of novel engineered transaminase panels assisted by in- silico rational design for the production of chiral amines" in "Enzyme Engineering XXV", Huimin Zhao, University of Illinois at Urbana-Champaign, USA John Wong, Pfizer, USA Eds, ECI Symposium Series, (2019). https://dc.engconfintl.org/enzyme_xxv/6