%0 Journal Article %A Nagai, Masaru %A Kawata, Maki %A Watanabe, Hisayuki %A Ogawa, Machiko %A Saito, Kumiko %A Takesawa, Toshikazu %A Kanda, Katsuhiro %A Sato, Toshitsugu %T Important role of fungal intracellular laccase for melanin synthesis: purification and characterization of an intracellular laccase from Lentinula edodes fruit bodies %D 2003 %J Microbiology, %V 149 %N 9 %P 2455-2462 %@ 1350-0872 %R https://doi.org/10.1099/mic.0.26414-0 %K GHB, γ-glutaminyl-4-hydroxybenzene %K ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt %K Lcc, laccase %K DHN, dihydroxynaphthalene %K PB, 10 mM sodium phosphate buffer %K Tyr, tyrosinase %K GDHB, γ-glutaminyl-3,4-dihydroxybenzene %K l-DOPA, β-(3,4-dihydroxyphenyl)alanine %I Microbiology Society, %X A laccase (EC was isolated from the fully browned gills of Lentinula edodes fruit bodies. The enzyme was purified to a homogeneous preparation using hydrophobic, cation-exchange and size-exclusion chromatography. SDS-PAGE analysis showed the purified laccase, Lcc 2, to be a monomeric protein of 58·0 kDa. The enzyme had an isoelectric point of around pH 6·9. The optimum pH for enzyme activity was around 3·0 against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS), and it was most active at 40 °C and stable up to 50 °C. The enzyme contained 8·6 % carbohydrate and some copper atoms. The enzyme oxidized ABTS, p-phenylenediamine, pyrogallol, guaiacol, 2,6-dimethoxyphenol, catechol and ferulic acid, but not veratryl alcohol and tyrosine. β-(3,4-Dihydroxyphenyl)alanine (l-DOPA), which was not oxidized by a laccase previously reported from the culture filtrate of L. edodes, was also oxidized by Lcc 2, and the oxidative product of l-dopa was identified as l-DOPA quinone by HPLC analysis. Lcc 2 was able to oxidize phenolic compounds extracted from fresh gills to brown-coloured products, suggesting a role for laccase in melanin synthesis in this strain. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.26414-0