Protein Engineering: Past, Present, and Future.

The last decade has seen a dramatic increase in the utilization of enzymes as green and sustainable (bio)catalysts in pharmaceutical and industrial applications. This trend has to a significant degree been fueled by advances in scientists' and engineers' ability to customize native enzymes by protein engineering. A review of the literature quickly reveals the tremendous success of this approach; protein engineering has generated enzyme variants with improved catalytic activity, broadened or altered substrate specificity, as well as raised or reversed stereoselectivity.

Truncated FAD synthetase for direct biocatalytic conversion of riboflavin and analogs to their corresponding flavin mononucleotides.

The preparation of flavin mononucleotide (FMN) and FMN analogs from their corresponding riboflavin precursors is traditionally performed in a two-step procedure. After initial enzymatic conversion of riboflavin to flavin adenine dinucleotide (FAD) by a bifunctional FAD synthetase, the adenyl moiety of FAD is hydrolyzed with snake venom phosphodiesterase to yield FMN. To simplify the protocol, we have engineered the FAD synthetase from Corynebacterium ammoniagenes by deleting its N-terminal adenylation domain.