What is "catechol oxidase"

n. An enzyme, similar to tyrosinase, that catalyses the oxidation of phenols such as catechol.

Catechol oxidase is a copper oxidase that contains a type 3 di-copper cofactor and catalyzes the oxidation of ortho- diphenols into ortho- quinones coupled with the reduction of molecular oxygen to water. It is present in a variety of species of plants and fungi including Ipomoea batatas ( sweet potato) and Camellia sinensis (Indian tea leaf). Metalloenzymes with type 3 copper centers are characterized by their ability to reversibly bind dioxygen at ambient conditions. In plants, catechol oxidase plays a key role in enzymatic browning by catalyzing the oxidation of catechol to o-quinone in the presence of oxygen, which can rapidly polymerize to form the melanin that grants damaged fruits their dark brown coloration.

In enzymology, a catechol oxidase (dimerizing) is an enzyme that catalyzes the chemical reaction

4 catechol + 3 O$\rightleftharpoons$ 2 dibenzo[1,4]dioxin-2,3-dione + 6 HO

Thus, the two substrates of this enzyme are catechol and O, whereas its two products are [[dibenzo[1,4]dioxin-2,3-dione]] and HO.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with oxygen as acceptor. The systematic name of this enzyme class is catechol:oxygen oxidoreductase (dimerizing).