We created a chimeric laccase from two different laccases, Lcc1 and Lcc4, from Lentinula edodes. Lcc1 is a secretory lignin-degrading enzyme produced in liquid cultures of L. edodes. Lcc4 is a tissue-accumulating-type enzyme, which is thought to be involved in melanin synthesis in fruiting body after harvesting. Lcc1 and Lcc4 differ in their Km values for some substrates, especially beta-(3,4-dihydroxyphenyl) alanine (L-DOPA) and catechol. The novel chimeric laccase, Lcc4/1, has properties that are a hybrid of those of Lcc1 and Lcc4. Lcc4/1 acts upon both Lcc1 and Lcc4 substrates and most of its Km values are lower than those of Lcc1 and Lcc4. Homology modeling indicates that the deduced shape of the substrate-binding pocket of the chimeric laccase is larger than that of Lcc1 and similar to that of Lcc4. The other biochemical properties, such as temperature and pH dependency, are intermediate between those of Lcc1 and Lcc4.
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