title: Strong substrate-stabilizing effect of a water-miscible ionic liquid [BMIM][BF(4)] in the catalysis of horseradish peroxidase.
abstract: The effects of a water-miscible ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF(4)]), on both thermodynamics and kinetic mechanism of the horseradish peroxidase (HRP)-catalyzed oxidation of guaiacol (2-methoxyphenol) by H(2)O(2) were investigated. The ionic liquid stabilized the ground state of guaiacol by causing an 8-fold increase of K(m) from 3 to 23 mM upon the addition of 25% (v/v) [BMIM][BF(4)]. In addition, the effect of [BMIM][BF(4)] in decreasing the k(cat) value of HRP catalysis was described by a non-competitive inhibition mechanism. The value of the inhibition constant of [BMIM][BF(4)] was 2.9 M indicating that the ionic liquid plays the role of a weak non-competitive inhibitor for HRP catalysis.
authors.affiliation: School of Chemical Engineering and Bioengineering, College of Engineering, University of Ulsan, Ulsan, Korea.
authors.forename: Eun Sik
authors.initials: ES
authors.lastname: Hong
authors.forename: O Yul
authors.initials: OY
authors.lastname: Kwon
authors.forename: Keungarp
authors.initials: K
authors.lastname: Ryu
mesh_terms: D002384:Catalysis; D006139:Guaiacol / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D052578:Ionic Liquids / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D013816:Thermodynamics
chemical_list: D052578:Ionic Liquids; D006139:Guaiacol; D006735:Horseradish Peroxidase