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A laccase from the medicinal mushroom Ganoderma lucidum

Wang, H. X., Ng, T. B.
Applied microbiology and biotechnology 2006 v.72 no.3 pp. 508-513
Ganoderma lucidum, Human immunodeficiency virus, RNA-directed DNA polymerase, adsorption, chromatography, fruiting bodies, gels, inhibitory concentration 50, laccase, molecular weight, mushrooms, pH, temperature
A protein demonstrating laccase activity and potent inhibitory activity towards human immunodeficiency virus (HIV)-1 reverse transcriptase (IC₅₀ 1.2 μM) was isolated from fresh fruiting bodies of the medicinal mushroom Ganoderma lucidum. The laccase had a novel N-terminal sequence and a molecular mass of 75 kDa, which is higher than the range (55-56 kDa) reported for most other mushroom laccases. It was isolated by sequential chromatography on DEAE-cellulose and Affi-gel blue gel and adsorption on Con A-Sepharose. Unlike some of the previously isolated laccases, it was adsorbed only on Con A-Sepharose. The enzyme required a pH of 3-5 and a temperature of 70°C to exhibit maximal activity. Minimal activity was detected at pH 6 and 7. Activity was undetectable at pH 8 and 9 and after exposure to 100°C for 10 min.