title: Activation of immobilized enzymes by acoustic wave resonance oscillation.
abstract: Acoustic wave resonance oscillation has been used successfully in the development of methods to activate immobilized enzyme catalysts. In this study, resonance oscillation effects were demonstrated for enzyme reactions on galactose oxidase (GAD), D-amino acid oxidase (DAAO), and L-amino acid oxidase (LAAO), all of which were immobilized covalently on a ferroelectric lead zirconate titanate (PZT) device that could generate thickness-extensional resonance oscillations (TERO) of acoustic waves. For galactose oxidation on immobilized GAD in a microreactor, TERO generation immediately increased enzyme activity 2- to 3-fold. Eliminating TERO caused a slight decrease in the activity, with ∼90% of the enhanced activity retained while the reaction proceeded. Contact of the enhanced enzyme with a galactose-free solution caused almost complete reversion of the activity to the original low level before TERO generation, indicating that, not only TERO-induced GAD activation, but also preservation of the increased activity, required a galactose substrate. Similar activity changes with TERO were observed for enzyme reactions on DAAO and LAAO. Kinetic analysis demonstrated that TERO helped strengthen the interactions of the immobilized enzyme with the reactant substrate and promoted formation of an activation complex.
authors.affiliation: Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188, Niigata, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishiyama
authors.affiliation: Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188, Niigata, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka 940-2188, Niigata, Japan. Electronic address: inoue@analysis.nagaokaut.ac.jp.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000818:Animals; D019149:Bioreactors; D002384:Catalysis; D003605:D-Amino-Acid Oxidase / Q000378:metabolism; D004789:Enzyme Activation; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005690:Galactose / Q000378:metabolism; D005692:Galactose Oxidase / Q000378:metabolism; D007700:Kinetics; D050830:L-Amino Acid Oxidase / Q000378:metabolism; D007854:Lead; D010084:Oxidation-Reduction; D013016:Sound; D014025:Titanium; D015040:Zirconium
chemical_list: D004800:Enzymes, Immobilized; C065536:lead titanate zirconate; D007854:Lead; D015040:Zirconium; D014025:Titanium; D005692:Galactose Oxidase; D050830:L-Amino Acid Oxidase; D003605:D-Amino-Acid Oxidase; D005690:Galactose
keywords: Acoustic waves; Amino acid oxidases; Enzyme activation; Galactose oxidase; Immobilized enzymes; Resonance oscillation