Oxygenase

An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O2 (as in air) to it. The oxygenases form a class of oxidoreductases; their EC number is EC 1.13 or EC 1.14.

Oxygenases were discovered in 1955 simultaneously by two groups, Osamu Hayaishi from Japan  and Howard Mason from the US.

There are two types of oxygenases:
 * Monooxygenases, or mixed function oxidase, transfer one oxygen atom to the substrate, and reduce the other oxygen atom to water.
 * Dioxygenases, or oxygen transferases, transfer both atoms of molecular oxygen (O2) onto the substrate.

Among the most important monooxygenases are the cytochrome P450 oxidases, responsible for breaking down numerous chemicals in the body.