Exploring flavin-containing carbohydrate oxidases

Oxidases are enzymes capable of removing one or more electrons from their substrate and transfer them to molecular oxygen, forming hydrogen peroxide. Due to their high regio- and enantioselectivity, their use is preferred over traditional organic chemistry methods. Among the oxidases, flavoprotein oxidases employ a flavin cofactor to mediate the transfer of electrons. In flavoprotein oxidases the flavin cofactor is typically tightly bound and often involves one or two covalent flavin-protein linkages. Carbohydrate oxidases are a subset of flavoprotein oxidases. Glucose oxidase is a well-known example of a widely used flavoprotein carbohydrate oxidase. It is used for a wide array of applications ranging from glucose levels detection in the bloodstream to antiseptic in toothpaste formulations. Carbohydrate oxidases with a bicovalently bound flavin cofactor have been shown to act on relatively bulky substrates compared to the monocovalent flavoprotein oxidases. These substrates can be derived from plant biomass. In this thesis we aimed at discovering and engineering carbohydrate oxidases acting on plant-derived biomass