title: Effect of three trifluoromethanesulfonate ionic liquids on the activity, stability and conformation of laccase.
abstract: The activity, stability and conformation of laccase were first investigated in an aqueous solution of ionic liquids 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim]TfO), 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([Bmpyr]TfO) or tetramethylammonium trifluoromethanesulfonate ([TMA]TfO). Compared with control system, high level of [Bmim]TfO or [Bmpyr]TfO destabilizes laccase while [TMA]TfO stabilizes laccase. These effects are more pronounced with the extension of the incubation time. The activity variations are well correlated with the changes of the conformation of laccase evidenced by fluorescence and circular dichroism spectra under specified conditions. The effects of the three ionic liquids on laccase are associated with the chaotropicity of the cations in Hofmeister series. For laccase, [TMA]TfO is not a good activating agent but it greatly enhances the stability of laccase in addition to maintaining the catalytic efficiency of laccase, showing its great potential in real application.
authors: Key Laboratory of Colloid & Interface Chemistry of the Education Ministry of China, Shandong University, Jinan 250100, PR China.
authors: Xinxin
authors: X
authors: Yu
authors: Feixue
authors: F
authors: Zou
authors: Ying
authors: Y
authors: Li
authors: Lu
authors: L
authors: Lu
authors: Xirong
authors: X
authors: Huang
authors: Yinbo
authors: Y
authors: Qu
mesh_terms: D002942:Circular Dichroism; D004795:Enzyme Stability / Q000187:drug effects; D019791:Guanidine / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000494:pharmacology; D052578:Ionic Liquids / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D042845:Laccase / Q000737:chemistry* / Q000378:metabolism*; D016018:Least-Squares Analysis; D008698:Mesylates / Q000737:chemistry / Q000494:pharmacology*; D017711:Nonlinear Dynamics; D011487:Protein Conformation / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D012044:Regression Analysis; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D055454:Trametes / Q000201:enzymology*
chemical_list: C532403:1-butyl-3-methylimidazolium trifluoromethanesulfonate; D007093:Imidazoles; D052578:Ionic Liquids; D008698:Mesylates; D042845:Laccase; C012077:trifluoromethanesulfonic acid; D019791:Guanidine