Human myeloperoxidase catalyzes an oscillating peroxidase-oxidase reaction.
We have studied the peroxidase-oxidase reaction catalyzed by human myeloperoxidase in an open system where both substrates-molecular oxygen and NADH-are supplied continuously to the reaction mixture. The reaction shows oscillatory kinetics at pH values around 5, provided that the reaction medium in addition to the enzyme and the substrates also contains an aromatic electron mediator such as melatonin or 4-hydroxybenzoic acid and chloride ions at concentrations >1mM. The experimental findings can be simulated by a detailed model of the reaction. The results are important for our understanding of oxidant production in neutrophils.
CelCom, Institute of Biochemistry and Molecular Biology, Syddansk Universitet, Campusvej 55, DK-5230 Odense M, Denmark.
Jens Christian
JC
Brasen
Anita
A
Lunding
Lars Folke
LF
Olsen
D002712:Chlorides / Q000378:metabolism; D003198:Computer Simulation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008954:Models, Biological; D009243:NAD / Q000378:metabolism; D009504:Neutrophils / Q000201:enzymology / Q000378:metabolism; D016877:Oxidants / Q000096:biosynthesis; D010100:Oxygen / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism*; D013997:Time Factors
D002712:Chlorides; D016877:Oxidants; D009243:NAD; D009195:Peroxidase; D010100:Oxygen