Purification and characterization of an extracellular laccase from the anthracene-degrading fungus Fusarium solani MAS2.
An extracellular laccase was purified from the culture medium of the non-white rot, anthracene-degrading fungal strain Fusarium solani MAS2. Both native PAGE and SDS-PAGE revealed one single band corresponding to a molecular weight of about 72 kDa. Treatment with endoglycosidase H reduced the molecular weight by 12%. The purified laccase maintained stable at pH 3-11 and up to 50 degrees C. The highest activity was detected at pH 3.0 and at 70 degrees C. The enzyme retained 46.2-97.2% of it activity in the presence of 20mM Pb(2+), Ni(2+), Cr(3+), and its activity was enhanced in the presence of 20mM Hg(2+). The laccase retained more than 50% of its activity in the presence of 5% acetone, acetonitrile, dimethyl sulphoxide (DMSO), ethanol and methanol. The kinetic constants (K(m) and k(cat)) showed that 2,6-dimethoxyphenol (DMOP) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) were the more effective substrates rather than catechol and guaiacol. The novel properties of this laccase suggest its potential for biotechnological and environmental applications.
Wu
Yi-Rui
YR
Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, PR China. oxwyr@tom.com
Luo
Zhu-Hua
ZH
Kwok-Kei Chow
R
R
Vrijmoed
L L P
LL
D000873:Anthracenes / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D005110:Extracellular Space / Q000187:drug effects / Q000201:enzymology*; D005670:Fusarium / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007477:Ions; D007700:Kinetics; D042845:Laccase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism*; D019216:Metals, Heavy / Q000494:pharmacology; D009930:Organic Chemicals / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology; D012997:Solvents / Q000494:pharmacology; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D013696:Temperature
D000873:Anthracenes; D004791:Enzyme Inhibitors; D007477:Ions; D019216:Metals, Heavy; D009930:Organic Chemicals; D010636:Phenols; D012997:Solvents; D042845:Laccase; C034020:anthracene