Evolution in the test tube as a means to create enantioselective enzymes for use in organic synthesis.

A novel method for the creation of mutant enzymes showing increased levels of enantioselectivity in a given synthetic organic reaction is reviewed. It makes use of directed evolution and is therefore independent of structural or mechanistic aspects. Accordingly, known molecular biological methods for random mutagenesis coupled with the proper expression system and high-throughput screening methods for enantioselectivity form the basis of this new approach. An example is the lipase-catalyzed hydrolytic kinetic resolution of a chiral ester in which the original enantioselectivity of 2% ee is increased to > 90% ee in just a few rounds of mutagenesis.