title: Investigating the Role of Conformational Effects on Laccase Stability and Hyperactivation under Stress Conditions.
abstract: Fungal laccase from Steccherinum ochraceum 1833 displays remarkable stability under different harsh conditions: organic/buffer mixtures, thermal treatment, and microwave radiation. The behavior is particularly significant in the light of the sharp inactivation observed for two different fungal laccases. Laccase from S. ochraceum 1833 also displays hyperactivation under mild thermal treatment (60 °C). Molecular dynamics simulations at 80 °C explained how this laccase retains the geometry of the electron transfer pathway, thereby assuring electron transfer through the copper ions and thus maintaining its catalytic activity at high temperature. Spectroscopic studies revealed that the thermal activation corresponds to specific conformational changes in the protein. The results indicate that this laccase is potentially applicable under denaturing conditions that might be beneficial for the biotransformation of recalcitrant substrates.
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Ferrario
authors.affiliation: G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 5 Prospekt Nauki, Pushchino, Moscow Region, 142290, Russia.
authors.forename: Alexey
authors.initials: A
authors.lastname: Chernykh
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Fiorindo
authors.affiliation: G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 5 Prospekt Nauki, Pushchino, Moscow Region, 142290, Russia.
authors.forename: Marina
authors.initials: M
authors.lastname: Kolomytseva
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.
authors.forename: Loris
authors.initials: L
authors.lastname: Sinigoi
authors.affiliation: G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 5 Prospekt Nauki, Pushchino, Moscow Region, 142290, Russia.
authors.forename: Nina
authors.initials: N
authors.lastname: Myasoedova
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Fattor
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Ebert
authors.affiliation: G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 5 Prospekt Nauki, Pushchino, Moscow Region, 142290, Russia.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Golovleva
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127, Trieste, Italy. gardossi@units.it.
authors.forename: Lucia
authors.initials: L
authors.lastname: Gardossi
mesh_terms: D001487:Basidiomycota / Q000201:enzymology; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D042845:Laccase / Q000737:chemistry / Q000378:metabolism*; D008872:Microwaves; D056004:Molecular Dynamics Simulation; D055550:Protein Stability / Q000528:radiation effects; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D005656:Fungal Proteins; D003300:Copper; D042845:Laccase
keywords: Steccherinum ochraceum; circular dichroism; electron transfer pathway; fluorescence; laccase stability; molecular dynamics