New enzymes from directed protein evolution

By applying directed evolution on naturally occurring enzymes we produce new enzyme variants that exhibit predefined properties regarding substrate selectivities and catalytic efficiencies. This possbility to generate new enzyme based catalysts opens up for biocatalysis as a viable approach for a larger spectrum of useful reactions and enables more sustainable approach to chemical synthesis.

We are at present actively working on hydrolases, oxidoreductases, aldolases and amino transferases. A goal is to construct multi-step syntheses pathways involving reactants and intermediates with chiral centers (see figure below). Robust in vivo production of designed fine chemicals afforded by stepwise enzyme catalyzed synthesis is a long-term aim.

The Widersten Group is currently working on the following projects where the common theme shared between the projects is the study of structure/activity relationships in enzymes with the goal to produce new biocatalysts.

Do not hesitate to contact us if you are interested in conducting your exam project in our group. 

Key words: stereoselectivity, catalytic mechanism, kinetics, directed evolution

Epoxide hydrolase

Enzymology and directed evolution of epoxide hydrolases. The research aims for deeper understanding of mechanisms deciding catalytic efficiency and stereoselectivity.

Alcohol dehydrogenases

Enzymology and directed evolution of enzymes that catalyze the oxidation of vicinal diols. We are currently focusing on understanding of how regioselectivity in choice of alcohol that is oxidized and enantioselectivity is achieved.

Aldolases

Enzymology and in combination with directed evolution of E. coli 2'-deoxy-ribose-5-phosphate aldolase (DERA) and fructose-6-phosphate aldolase (FSA) is the current focus. We are especially interested in understanding the kinetic mechanisms and improvement in the acceptance of aryl substututed aldehyde acceptors in catalyzed condensations.

Amino transferases

Enzymology and directed evolution of amino transferases. At present, an enzyme from V. fluvialis is studied. Deeper understanding of kinetic mechanisms and tailored susbtrate preferences, primarily efficient amino transfer to acyloins, are focus areas.