Nuevos usos de las lacasas

Phytochemistry 60 (2002) 551–565 www.elsevier.com/locate/phytochem

Review

Laccase: new functions for an old enzyme
Alfred M. Mayera,*, Richard C. Staplesb
a

Department of Botany, The Hebrew University of Jerusalem, Jerusalem 91904, Israel b Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA Received 8 January 2002; received in revised form 2 May 2002

AbstractLaccases occur widely in fungi; they have been characterized less frequently in higher plants. Here we have focused on more recent reports on the occurrence of laccase and its functions in physiological development and industrial utility. The reports of molecular weights, pH optima, and substrate specificity are extremely diverse. Conclusive proof of the occurrence of laccase in a tissue mustdemonstrate that the enzyme be able to oxidize quinol with concomitant uptake of oxygen. Laccase is involved in the pigmentation process of fungal spores, the regeneration of tobacco protoplasts, as fungal virulence factors, and in lignification of cell walls and delignification during white rot of wood. Commercially, laccases have been used to delignify woody tissues, produce ethanol, and todistinguish between morphine and codeine. A very wide variety of bioremediation processes employ laccase in order to protect the environment from damage caused by industrial effluents. Research in recent years has been intense, much of it elicited by the wide diversity of laccases, their utility and their very interesting enzymology. # 2002 Published by Elsevier Science Ltd.
Keywords: Bioremediation;Delignification; Lignification; Virulence; Phytoalexin; Polyphenol oxidase; Semiquinone; Free radical; Multicopper enzymes

Contents 1. Introduction ............................................................................................................................................................................... 552 2. Occurrence and characterization of laccases..............................................................................................................................552 2.1. Higher plants ..................................................................................................................................................................... 552 2.2. Fungi................................................................................................................................................................................. 553 2.3. Laccase catalysis................................................................................................................................................................ 553 3. Cell biology................................................................................................................................................................................ 554 4. The role of laccases in lignification ............................................................................................................................................ 555 5. Pathogen virulence..................................................................................................................................................................... 556 5.1. Human pathogens ............................................................................................................................................................. 556 5.2. Phytoanticipins.................................................................................................................................................................. 556 5.3. Phytoalexins ...................................................................................................................................................................... 556 5.4. Effect of mycoviruses on laccase gene expression..............................................................................................................557 5.4.1....