ENGINEERING OF ALCOHOL OXIDASE AND OXIDATION-AMINATION CASCADE: SYNTHESIS OF α-KETO ACIDS AND (R)- AND (S)-α-AMINO ACIDS FROM RACEMIC α-HYDROXY ACIDS

Abstract

Conversion of racemic alcohols to ketones via oxidation and to enantiopure amines via cascade reaction are the important processes in various industries. Alcohol oxidation is typically performed using chemical methods which tend to generate toxic chemical wastes. Alternatively, enzymatic oxidation can be performed under milder and environmentally benign conditions, while being more specific than the chemical methods. Alcohol oxidases catalyse irreversible alcohol oxidation using molecular oxygen as the electron acceptor. For the conversion of racemic alcohols to amines, one-pot enzymatic oxidation-amination cascades can replace the chemical methods which are generally atom inefficient and involve toxic chemicals. However, practical application of enzyme cascades depends on the selection of enzymes and engineering of the suitable cascades. In this work, we developed a new alcohol oxidase with enhanced activity via directed evolution as well as the enzyme cascades to produce the useful α-keto acids and (<i>R</i>)- and (<i>S</i>)-α-amino acids from racemic α-hydroxy acids.