What is "laccase"

n. (context enzyme English) Any of several copper-containing oxidase enzymes found in plants and microorganisms.

Laccases are copper-containing oxidase enzymes that are found in many plants, fungi, and microorganisms. Laccases act on phenols and similar molecules, performing a one-electron oxidations, which remain poorly defined. It is proposed that laccases play a role in the formation of lignin by promoting the oxidative coupling of monolignols, a family of naturally occurring phenols. Laccases can be polymeric, and the enzymatically active form can be a dimer or trimer. Other laccases, such as ones produced by the fungus Pleurotus ostreatus, play a role in the degradation of lignin, and can therefore be included in the broad category of ligninases.'''

Because laccase belongs to the oxidase enzyme family it requires oxygen as a second substrate for the enzymatic action.

Spectrophotometry can be used to detect laccases, using the substrates ABTS, syringaldazine, 2,6-dimethoxyphenol, and dimethyl-p-phenylenediamine. Activity can also be monitored with an oxygen sensor, as the oxidation of the substrate is paired with the reduction of oxygen to water.

Laccase was first studied by Gabriel Bertrand in 1894 in Chinese lacquer tree sap, where it serves in the formation of lacquer (hence the name "laccase").

Laccase is able to catalyze ring cleavage of aromatic compounds.