title: Partition of horseradish peroxidase with maintained activity in aqueous biphasic system based on ionic liquid.
abstract: Enzyme activity and partition behavior in aqueous biphasic systems (ABSs) consisting of ionic liquid (IL) and salt (IL-ABSs) were investigated to increase our understanding of IL-ABSs and shed light on their application potential as enzyme extraction system. With horseradish peroxidase (HRP) as the model enzyme, several effects of alkylimidazolium chloride-K(2)HPO(4) ABSs on activity and partition behavior of enzyme were studied including alkyl chain length of ILs and concentrations of each component. High lyotropic ILs (1-butyl-3-methylimidazolium and 1-ethyl-3-methylimidazolium chloride) and adequate water content (>40%) were both essential for the activity maintenance of HRP in IL-ABS. 1-Butyl-3-methylimidazolium chloride ([C(4)mim]Cl) was found to be an appropriate IL for phase forming and HRP activity retaining. After optimization of phase condition, about 80% HRP amount was distributed in the IL-rich upper phase, and greater than 90% enzyme activity was obtained. Moreover, compared with the commonly used polymer-based ABSs, this [C(4)mim]Cl-ABS has a much lower viscosity, which is very beneficial to the experimental operation. Therefore, the tested IL-ABS could be considered as a potential enzyme extraction system.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, The Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, College of Chemistry, Peking University, Chengfu Road, Beijing 100871, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Cao
authors.forename: Li
authors.initials: L
authors.lastname: Quan
authors.forename: Chiyang
authors.initials: C
authors.lastname: He
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Kean
authors.initials: K
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
mesh_terms: D000478:Alkylation; D017606:Chlorine Compounds / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000378:metabolism*; D048288:Imidazolines / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D012996:Solutions; D014783:Viscosity
chemical_list: D017606:Chlorine Compounds; D048288:Imidazolines; D052578:Ionic Liquids; D012996:Solutions; D006735:Horseradish Peroxidase