Molecular enzyme evolution

Molecular enzyme evolution

Many enzymes are superior catalysts with high regio-, chemo- and stereoselectivity and are able to catalyse a great variety of chemical transformations. Unfortunately, enzymes are optimised for natural processes and conditions during evolution and not for specific, non-natural biotransformations in a harsh industrial environment.

In order to tune enzymes towards specific reactions we use knowledge from nature on different levels. First of all we use the Directed Evolution technique in which we mimic natural evolution processes in a test tube by introducing mutations in a random or site directed way and recombining different mutations afterwards. This evolution process can be directed towards the desired enzyme by applying selective pressure (survival of the fittest) or by screening all mutant enzymes in order to find the desired properties. Setting-up robust and cost-effective screening methods is one of the research lines in this area. A fully equipped screening lab including pipetting and picking robots is available.

Since it is impossible to probe all potential mutations in an enzyme we use bio-informatics tools to visualise and calculate the most promising mutations for an envisaged reaction.  These tools use existing enzyme structures and known mutations to compute new activities, which can be tested in the lab. This in silico pre-selection reduces the screening effort and improves the chance of finding the best biocatalyst. Finding the right mix of calculation and randomness in preparing a library is crucial to a successful outcome.

© 2017 TU Delft