Effect of ionic liquid on the kinetics of peroxidase catalysis.
The effect of a water-miscible ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), on the horseradish peroxidase (HRP)-catalyzed oxidation of 2-methoxyphenol (guaiacol) with hydrogen peroxide (H2O2) was investigated. HRP maintains its high activity in the aqueous mixtures containing various concentrations of the ionic liquid and even in 90% (v/v) ionic liquid. In order to minimize the effect of solution viscosity on the kinetic constants of HRP catalysis, the enzymatic reactions in the subsequent kinetic study were performed in water-ionic liquid mixtures containing 25% (v/v) ionic liquid at maximum. As the concentration of [BMIM][BF4] increased for the oxidation of guaiacol by HRP, the K(m) value increased with a slight decrease in the k(cat) value: The K(m) value increased from 2.8 mM in 100% (v/v) water to 22.5 mM in 25% (v/v) ionic liquid, indicating that ionic liquid significantly weakens the binding affinity of guaiacol to HRP.
Department of Chemical Engineering and Bioengineering, University of Ulsan, Ulsan 680-749, Korea.
Yoon-Mi
YM
Lee
O-Yul
OY
Kwon
Ik-Keun
IK
Yoo
Keun-Garp
KG
Ryu
D002384:Catalysis; D006139:Guaiacol / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000378:metabolism*; D052578:Ionic Liquids / Q000494:pharmacology*; D007700:Kinetics; D010084:Oxidation-Reduction; D014783:Viscosity
D052578:Ionic Liquids; D006139:Guaiacol; D006735:Horseradish Peroxidase