title: Purification and characterization of the extracellular laccase produced by Trametes polyzona WR710-1 under solid-state fermentation.
abstract: Laccase from Trametes polyzona WR710-1 was produced under solid-state fermentation using the peel from the Tangerine orange (Citrus reticulata Blanco) as substrate, and purified to homogeneity. This laccase was found to be a monomeric protein with a molecular mass of about 71 kDa estimated by SDS-PAGE. The optimum pH was 2.0 for ABTS, 4.0 for L-DOPA, guaiacol, and catechol, and 5.0 for 2,6-DMP. The K(m) value of the enzyme for the substrate ABTS was 0.15 mM, its corresponding V(max) value was 1.84 mM min(-1), and the k(cat)/K(m) value was about 3960 s(-1)  mM(-1). The enzyme activity was stable between pH 6.0 and 8.0, at temperatures of up to 40 °C. The laccase was inhibited by more than 50% in the presence of 20 mM NaCl, by 95% at 5 mM of Fe(2+), and it was completely inhibited by 0.1 mM NaN(3). The N-terminal amino acid sequence of this laccase is AVTPVADLQISNAGISPDTF, which is highly similar to those of laccases from other white-rot basidiomycetes.
authors.affiliation: Biotechnology Program, Graduate School, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Thanunchanok
authors.initials: T
authors.lastname: Chairin
authors.forename: Thitinard
authors.initials: T
authors.lastname: Nitheranont
authors.forename: Akira
authors.initials: A
authors.lastname: Watanabe
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Asada
authors.forename: Chartchai
authors.initials: C
authors.lastname: Khanongnuch
authors.forename: Saisamorn
authors.initials: S
authors.lastname: Lumyong
mesh_terms: D000595:Amino Acid Sequence; D002957:Citrus / Q000378:metabolism; D005285:Fermentation; D007700:Kinetics; D042845:Laccase / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D055454:Trametes / Q000201:enzymology*
chemical_list: D042845:Laccase
keywords: Enzyme characterization; Laccase; Purification; Trametes polyzona; White-rot fungus