Genetically Expanded Reactive Oxygen Tolerant Alcohol Dehydrogenase II

Herein we report a site-specific incorporation of L-3,4-dihydroxyphenylalanine as a promising method to engineer an oxygen-tolerant alcohol dehydrogenase II. The engineered mutant alcohol dehydrogenase II binds Zn2+ with high binding affinity and is functional under aerobic and oxidative conditions for a longer time than the wild type, Fe2+ binding Alcohol dehydrogenase II. Overall, the mutant enzyme demonstrated an electrochemical activity towards both acetaldehyde reduction and ethanol oxidation reactions. This enzyme could have a potential use in efficient biofuel production under aerobic conditions in photosynthetic organisms despite the inherent oxygen evolution reaction by photosystem II.