title: Purification and characterization of a new laccase from the filamentous fungus Podospora anserina.
abstract: A new laccase from the filamentous fungus Podospora anserina has been isolated and identified. The 73 kDa protein containing 4 coppers, truncated from its first 31 amino acids, was successfully overexpressed in Pichia pastoris and purified in one step with a yield of 48% and a specific activity of 644Umg(-1). The kinetic parameters, k(cat) and K(M), determined at 37 °C and optimal pH are 1372 s(-1) and 307 μM for ABTS and, 1.29 s(-1) and 10.9 μM, for syringaldazine (SGZ). Unlike other laccases, the new protein displays a better thermostability, with a half life>400 min at 37 °C, is less sensitive to chloride and more stable at pH 7. Even though, the new 566 amino-acid enzyme displays a large homology with Bilirubin oxidase (BOD) from Myrothecium verrucaria (58%) and exhibits the four histidine rich domains consensus sequences of BODs, the new enzyme is not able to oxidize neither conjugated nor unconjugated bilirubin.
authors.affiliation: CNRS, CRPP, UPR 8641, F-33600 Pessac, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Durand
authors.forename: Sébastien
authors.initials: S
authors.lastname: Gounel
authors.forename: Nicolas
authors.initials: N
authors.lastname: Mano
mesh_terms: D004795:Enzyme Stability; D006835:Hydrazones / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D042845:Laccase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification*; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics; D010843:Pichia / Q000235:genetics; D048468:Podospora / Q000201:enzymology*; D013696:Temperature
chemical_list: D006835:Hydrazones; C009370:syringaldazine; D042845:Laccase; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase