Purification and Properties of Laccase from Basidiomycete

摘要

Laccase(p-diphenol:oxygen oxidoreductase,EC 1.10.3.2) is a member of the blue multi-copper family of enzymes,containing four copper atoms comprising one Type Ⅰ, one TypeⅡ and an antiferromagnetically-coupled Type Ⅲ pair of Cu~(2+) The enzyme was first discovered in the sap of the Japanese lacquer tree Rhus vernicifera. Subsequently it was also demonstrated to be a fungal enzyme.To date only one species of bacterium Azospirillum lipoferum has been shown to exhibit laccase-like phenol oxidase activity. Laccase can catalyze the oxidation of various compounds including o,p-diphenols,aminophenol, polyphenol,polyamines,lignin,some inorganic ions and acryl diamines.Industrial applications of laccase are foreseen in biobleaching of paper pulp,adhesive formation from lignin wastes,in the construction of bilosensors for industrial pollutants',in removal of phenolics from foodstuffs and in bioremediation. Fungal laccases usually are found in synthetic medium with addition of special inducer.We screened a constitutive-laccase-producing basidiomycete with plate method. Laccase activity reached 3U/ml.We purified isoenzyme Lacl of laccase and researched properties of it to give valuable data for basic research and application.