Characterization of an extracellular laccase, PbLac1, purified from Polyporus brumalis

Fungal Biol. 2010 Aug;114(8):609-18. doi: 10.1016/j.funbio.2010.05.002. Epub 2010 May 24.


Polyporus brumalis (strain ibrc05015) secreted high amounts of laccases (Lacs) in liquid medium. With 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) as a substrate, Lac activity was 7.72 U ml⁻¹ and this strain secreted a maximum 0.23 mg ml⁻¹ of total protein. The enzyme, PbLac1 was purified to homogeneity using hydrophobic and anion-exchange chromatography. The purified PbLac1 had a molecular mass of 63.4 kDa as determined by polyacrylamide-gel electrophoresis. PbLac1 oxidized a wide range of substrates such as 3,4-dihydroxy l-phenylalanine (l-DOPA) and catechol, but not tysorine. The activity of PbLac1 was increased by addition of 10.0 mM Cu(2+). PbLac1 could decolorize several industrial dyes, such as Remazol Brilliant Blue R known as model dyes of environmental xenobiotics. In addition, PbLac1 decolorized a wide range of substrates, such as the carcinogen, Poly R-478, in the presence of violuric acid as mediator. The E° value of PbLac1 was 0.80 V±0.01 versus normal hydrogen electrode, which is a very high redox potential compared to those of other basidiomycetous Lacs. These results suggest the potential utility of PbLac1 for industrial applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enzyme Stability
  • Extracellular Space / chemistry
  • Extracellular Space / enzymology*
  • Extracellular Space / genetics
  • Fungal Proteins / chemistry*
  • Fungal Proteins / genetics
  • Fungal Proteins / isolation & purification*
  • Fungal Proteins / metabolism
  • Hydrogen-Ion Concentration
  • Kinetics
  • Laccase / chemistry*
  • Laccase / genetics
  • Laccase / isolation & purification*
  • Laccase / metabolism
  • Molecular Weight
  • Polyporus / chemistry
  • Polyporus / enzymology*
  • Polyporus / genetics
  • Substrate Specificity


  • Fungal Proteins
  • Laccase