Oxygenase

Oxygenases are enzymes that transfer one or more oxygen atoms to its substrate, which often take place on the aromatic ring openings molecule. Most NADP / NADPH is consumed.

Monooxygenases

Monooxygenases are almost always NADPH - consuming, and often depend on FAD and / or Fe2 ( exception is, for example, the dopamine -beta- hydroxylase, the use is as an electron donor ascorbate. ) In the catalyzed reaction is exactly an oxygen atom of an oxygen molecule (O2) to the substrate transmitted. Monooxygenases are also classified as mixed function oxygenases, as they reduce in addition to the transfer of an oxygen atom, a second oxygen atom to form water ( H2O).

Catalyzed reactions:

• Monohydroxylierungen aromatic rings
• Epoxidation of carbon -carbon double bonds
• Insertion of an oxygen ( Baeyer- Villiger monooxygenases )

Dioxygenases

Dioxygenase enzymes are referred to as the transmit both atoms of an oxygen molecule (O2) to a substrate. Dioxygenases often consume NADH or NADPH, and are often dependent on FAD and / or Fe2 .

Catalyzed reactions:

• Dihydroxylation of aromatic rings (aromatic cis- diols )
• Ring cleavage ( the aromatic cis- diols between the hydroxyl groups or hydroxyl groups adjacent )

Examples:

• Homogentisate dioxygenase
• Tryptophan -2 ,3- dioxygenase
• 3 Hydroxyanthranilat -3 ,4- dioxygenase