Directed evolution of enantioselective enzymes: An unceasing catalyst source for organic chemistry

Directed evolution has emerged as a powerful method for engineering essentially any catalytic parameter of enzymes for application in synthetic organic chemistry and biotechnology, including thermostability, substrate scope, and enantioselectivity. Enantioselectivity is especially crucial when applying biocatalysts to synthetic organic chemistry. This contribution focuses on recent methodology developments in laboratory evolution of stereoselective enzymes, hydrolases, and monooxygenases serving as the enzymes. Specifically, iterative saturation mutagenesis (ISM) has been developed as an unusually effective method to evolve enhanced or reversed enantioselectivity, broader substrate scope, and/or higher thermostability of enzymes.