title: A novel laccase from basidiomycete Cerrena sp.: Cloning, heterologous expression, and characterization.
abstract: A novel laccase gene Lac1 and its cDNA were cloned from a white-rot fungus Cerrena sp. and characterized. The 1554-bp cDNA of Lac1 encoded a mature protein with 497 amino acids, preceded by a signal peptide of 20 amino acids. An unconventional intron splice site and incomplete splicing variants of Lac1 were observed. Lac1 was heterologously expressed in the yeast host Pichia pastoris, and a maximal laccase activity of 6.3UmL(-1) in the fermentation broth was achieved after fermentation for 9 days. The recombinant protein rLac1 was purified, and its enzymatic properties and functional characteristics were investigated. When ABTS was used as the substrate, the enzyme was most active at pH 3.5 and 55°C, and stable at pH 4-10 and 20-60°C. The Km and kcat values of rLac1 toward ABTS were 28.9 μM and 332.4s(-1), respectively. Furthermore, rLac1 was tolerant to common metal ions up to 100mM concentration and capable of decolorizing structurally different dyes in the absence of a redox mediator. Hence, Lac1 may be useful for industrial applications, such as dye decolorization and bioremediation.
authors.affiliation: College of Biological Sciences and Technology, Fuzhou University, Fuzhou, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou, Fujian 350116, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: Tzi Bun
authors.initials: TB
authors.lastname: Ng
authors.affiliation: College of Biological Sciences and Technology, Fuzhou University, Fuzhou, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou, Fujian 350116, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Lin
authors.affiliation: College of Biological Sciences and Technology, Fuzhou University, Fuzhou, Fujian 350116, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou, Fujian 350116, China. Electronic address: xiuyunye@fzu.edu.cn.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Ye
mesh_terms: D001487:Basidiomycota / Q000201:enzymology* / Q000235:genetics*; D001709:Biotechnology; D003001:Cloning, Molecular; D003116:Color; D004396:Coloring Agents / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D042845:Laccase / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D008670:Metals / Q000494:pharmacology; D010843:Pichia / Q000235:genetics; D013501:Surface-Active Agents / Q000494:pharmacology; D013696:Temperature
chemical_list: D004396:Coloring Agents; D004791:Enzyme Inhibitors; D008670:Metals; D013501:Surface-Active Agents; D042845:Laccase
keywords: Cerrena sp.; Decolorization; Laccase; P. pastoris