title: Purification, biochemical characterization and dye decolorization capacity of an alkali-resistant and metal-tolerant laccase from Trametes pubescens.
abstract: Extracellular laccase (Tplac) from Trametes pubescens was purified to homogeneity by a three-step method, which resulted in a high specific activity of 18.543 Umg(-1), 16.016-fold greater than that of crude enzyme at the same level. Tplac is a monomeric protein that has a molecular mass of 68 kDa. The enzyme demonstrated high activity toward 1.0mM ABTS at an optimum pH of 5.0 and temperature of 50 °C, and under these conditions, the catalytic efficiency (k(cat)/K(m)) is 8.34 s(-1) μM(-1). Tplac is highly stable and resistant under alkaline conditions, with pH values ranging from 7.0 to 10.0. Interestingly, above 88% of initial enzyme activity was maintained in the presence of metal ions at 25.0mM, leading to an increase in substrate affinity, which indicated that the laccase is highly metal-tolerant. These unusual properties demonstrated that the new fungal laccase Tplac has potentials for the specific industrial or environmental applications.
authors.affiliation: Institute of Microbiology, Beijing Forestry University, Beijing 100083, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Si
authors.forename: Feng
authors.initials: F
authors.lastname: Peng
authors.forename: Baokai
authors.initials: B
authors.lastname: Cui
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D003116:Color; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification*; D004795:Enzyme Stability; D042845:Laccase / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D055454:Trametes / Q000201:enzymology* / Q000302:isolation & purification; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D000468:Alkalies; D004396:Coloring Agents; D042845:Laccase; D008670:Metals; D062065:Wastewater; D014874:Water Pollutants, Chemical