Purification and Characterization of Fungal Laccase from Mycena purpureofusca
Shujing Sun1, Yonghui Zhang1, Youxiong Que2, Bixian Liu1, Kaihui Hu1, and Liping Xu2** Author for corresponding; e-mail address: xlpmail@yahoo.com.cn; shjsun2004@126.com
Volume: Vol.40 No.2 (APRIL 2013)
Research Article
DOI:
Received: 17 May 2012, Revised: -, Accepted: 10 September 2012, Published: -
Citation: Sun1 S., Zhang1 Y., Que2 Y., Liu1 B., Hu1 K. and Xu2 L., Purification and Characterization of Fungal Laccase from Mycena purpureofusca, Chiang Mai Journal of Science, 2013; 40(2): 151-160.
Abstract
The extracellular laccase produced by Mycena purpureofusca was purified and characterized biochemically and biologically. The molecular mass of the laccase was determined from the analysis of SDS-PAGE following purification with anion exchange chromatography. The purified laccase showed a relative molecular mass of 61.7 kDa. Laccase activity was detected in culture filtrate of M. purpureofusca with ABTS as substrate, optimum pH being 2.2 and optimum temperature at 50°C. The enzymatic activity was stable at neutral pH and temperatures between 10 and 30°C. The laccase activity decreased rapidly when the temperature was above 30°C for 1h. The values of kinetic parameters Km and Vmax for purified laccase were 0.296 (mM) and 0.0645 (mM/min), respectively. Among the metal ions used, Fe3+, Mn2+ , Cu2+, Ag+, Ca2+, Ba2+ and Zn2+ were found to have a slightly stimulating effect on the enzyme activity at the concentrations of 0.05 mM. The enzyme activity can be enhanced by 18.7% and 130.5% when Ag+ was added to the medium at the concentration of 0.05 and 0.5 respectively. On the contrary, Fe2+ strongly inhibited enzyme activity up to 98% at a concentration of 0.05 and 0.5 mM.