title: The role of naturally occurring phenols in inducing oscillations in the peroxidase-oxidase reaction.
abstract: The influence of a series of naturally occurring phenolic compounds on the dynamics of the horseradish peroxidase-catalyzed oxidation of NADH by oxygen (the peroxidase-oxidase reaction) was investigated. Various types of dynamic behaviors are induced in the peroxidase-oxidase reaction upon addition of low concentrations of different phenols. The identity of the particular phenol determines the type of dynamics shown (inhibition of the reaction, monotonic reaction, damped oscillations, sustained oscillations, and complex oscillations). The kind of behavior that a given phenolic compound is able to induce is governed by the reduction potentials for the formation of the phenoxyl radical. The phenolic compounds are shown not to be consumed during the reaction. Mechanistic considerations are made on the basis of the reduction potentials of the different reactants present in the peroxidase-oxidase system. We interpret the role of the phenols as electron mediators of the electron transfer between some enzyme intermediates or O2- and NADH.
authors.affiliation: Physical Biochemistry Group, Odense University, Forskerparken 10, DK-5230 Odense M, Denmark.
authors.forename: M J
authors.initials: MJ
authors.lastname: Hauser
authors.forename: L F
authors.initials: LF
authors.lastname: Olsen
mesh_terms: D004563:Electrochemistry; D005609:Free Radicals / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D009243:NAD / Q000378:metabolism; D009991:Oscillometry; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D005609:Free Radicals; D010636:Phenols; D009243:NAD; C042329:phenoxy radical; D006735:Horseradish Peroxidase