Laccases: blue enzymes for green chemistry.

Laccases are oxidoreductases belonging to the multinuclear copper-containing oxidases; they catalyse the monoelectronic oxidation of substrates at the expense of molecular oxygen. Interest in these essentially "eco-friendly" enzymes--they work with air and produce water as the only by-product--has grown significantly in recent years: their uses span from the textile to the pulp and paper industries, and from food applications to bioremediation processes. Laccases also have uses in organic synthesis, where their typical substrates are phenols and amines, and the reaction products are dimers and oligomers derived from the coupling of reactive radical intermediates. Here, we provide a brief discussion of this interesting group of enzymes, increased knowledge of which will promote laccase-based industrial processes in the future.