title: Study of the alkyl chain length on laccase stability and enzymatic kinetic with imidazolium ionic liquids.
abstract: The activity and stability of laccase and their kinetic mechanisms in water soluble ionic liquids (ILs): 1-butyl-3-methyl imidazolium chloride [C(4)mim][Cl], 1-octyl-3-methyl imidazolium chloride [C(8)mim][Cl], and 1-decyl-3-methyl imidazolium chloride [C(10)mim][Cl] were investigated. The results show that an IL concentration up to 10% is satisfactory for initial laccase activity at pH 9.0. The laccase stability was well maintained in [C(4)mim][Cl] IL when compared to the control. The inactivation of laccase increases with the length of the alkyl chain in the IL: [C(10)mim][Cl] > [C(8)mim][Cl] > [C(4)mim][Cl]. The kinetic studies in the presence of ABTS as substrate allowed calculating the Michaelis-Menten parameters. Among the ILs, [C(4)mim][Cl] was the suitable choice attending to laccase activity and stability. Alkyl chains in the ions of ILs have a deactivating effect on laccase, which increases strongly with the length of the alkyl chain.
authors.affiliation: LSRE-Laboratory of Separation and Reaction Engineering, Associate Laboratory LSRE/LCM, Department of Chemical Engineering, University of Porto, Rua, Portugal.
authors.forename: Oscar
authors.initials: O
authors.lastname: Rodríguez
authors.forename: Raquel O
authors.initials: RO
authors.lastname: Cristóvão
authors.forename: Ana P M
authors.initials: AP
authors.lastname: Tavares
authors.forename: Eugénia A
authors.initials: EA
authors.lastname: Macedo
mesh_terms: D001881:Borates / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D007700:Kinetics; D042845:Laccase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: C528768:1-octyl-3-methylimidazolium; D001881:Borates; D007093:Imidazoles; D052578:Ionic Liquids; C502841:1-butyl-3-methylimidazolium chloride; C029899:imidazole; D042845:Laccase