Oxygenation and Oxygenases

Abstract Biological oxygenation reactions in which molecular oxygen is incorporated directly into organic subsrates are catalyzed by the enzymes known as oxygenases. These enzymes, first discovered in 1955, have since been found to be very widely distributed in nature. In dioxygenase‐catalyzed reactions, both atoms of the oxygen molecule are incorporated into the organic substrate, whereas monooxygenases incorporate only one of these oxygen atoms into the substrate. Currently, over 200 oxygenases enzymes are known, and these enzymes are all classified in EC groups 1.13 and 1.14. Among the reactions catalyzed by oxygenases are hydroxylations of methane and other alkanes, aromatics, flavonoids, menthol, and cholesterol; oxygenation of olefins, sulfur, and other heteroatoms; oxygenative cleavage of aromatic rings; and oxygenative decarboxylations. Oxygenases also catalyze the first step in the biosynthesis of prostaglandins; key steps in the biosynthesis and interconversion of antibiotics; and important bioremediation reactions critical to maintenance of the environment. A number of biotechnological applications for oxygenases have been emerging in recent years, and progress is also being made in the development of nonenzymatic model systems that might mimic the functional or structural properties of oxygenase enzymes.