Amine oxidase (copper-containing) (AOC) is a family of amine oxidase enzymes which includes both primary-amine oxidase and diamine oxidase; belongs to oxidoreductases. Copper Amine Oxidases act as a disulphide-linked homodimer. They catalyse the oxidation of primary amines to aldehydes, with the subsequent release of ammonia and hydrogen peroxide, which requires one copper ion per subunit and topaquinone as cofactor.
Monooxygenases are enzymes that incorporate one hydroxyl group into substrates in many metabolic pathways. In order to carry out this type of reaction, these enzymes need to activate molecular oxygen to overcome its spin-forbidden reaction with the organic substrate. In most cases, monooxygenases utilize (in)organic cofactors to transfer electrons to molecular oxygen for its activation. Monooxygenases typically are highly chemo-, regio-, and/or enantioselective, making them attractive biocatalysts. In this review, an exclusive overview of known monooxygenases is presented, based on the type of cofactor that these enzymes require. This includes not only the cytochrome P450 and flavin-dependent monooxygenases, but also enzymes that utilize pterin, metal ions (copper or iron) or no cofactor at all. As most of these monooxygenases require nicotinamide coenzymes as electron donors, also an overview of current methods for coenzyme regeneration is given. This latter overview is of relevance for the biotechnological applications of these oxidative enzymes.