title: Probing the dioxygen route in Melanocarpus albomyces laccase with pressurized xenon gas.
abstract: Laccases catalyze the oxidation of phenolic substrates and the concominant reduction of dioxygen to water. We used xenon as an oxygen probe in search of routes for the entry of dioxygen into the catalytic center. Two xenon-pressurized crystal structures of recombinant Melanocarpus albomyces laccase were determined, showing three hydrophobic Xe-binding sites located in domain C. The analysis of hydrophobic cavities in other laccase structures further suggested the preference of domain C for binding of hydrophobic species such as dioxygen, thus suggesting that the hydrophobic core of domain C could function as a channel through which dioxygen can enter the trinuclear copper center.
authors.affiliation: Department of Chemistry, University of Eastern Finland, Joensuu, Finland.
authors.forename: Juha P
authors.initials: JP
authors.lastname: Kallio
authors.forename: Juha
authors.initials: J
authors.lastname: Rouvinen
authors.forename: Kristiina
authors.initials: K
authors.lastname: Kruus
authors.forename: Nina
authors.initials: N
authors.lastname: Hakulinen
mesh_terms: D001203:Ascomycota / Q000201:enzymology*; D001665:Binding Sites; D020134:Catalytic Domain; D005740:Gases; D042845:Laccase / Q000378:metabolism*; D008958:Models, Molecular; D015335:Molecular Probes; D010100:Oxygen / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D014978:Xenon
chemical_list: D005740:Gases; D015335:Molecular Probes; D011994:Recombinant Proteins; D014978:Xenon; D042845:Laccase; D010100:Oxygen