Premium
Kinetics of inhibition of peroxidase activity of myeloperoxidase by quercetin
Author(s) -
Momić Tatjana,
Vujčić Zoran,
Vasić Vesna
Publication year - 2008
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20319
Subject(s) - chemistry , quercetin , myeloperoxidase , kinetics , peroxidase , substrate (aquarium) , enzyme kinetics , enzyme , reaction rate , non competitive inhibition , chemical kinetics , stereochemistry , biochemistry , catalysis , active site , medicine , physics , oceanography , quantum mechanics , inflammation , antioxidant , geology
The inhibition of myeloperoxidase (MPO), isolated from human neutrophils, by quercetin was investigated by following peroxidase activity of the enzyme using o ‐dianisidine as the substrate. The inhibition parameters (IC 50 ) were obtained by graphical analysis of the inhibition curves. A reaction mechanism, which involved the enzyme inhibition by quercetin and H 2 O 2 in excess, was proposed. The rate and equilibrium constants for the proposed reaction path were calculated from experimental data. Kinetic analysis in noninhibiting H 2 O 2 concentration range in the absence and the presence of quercetin revealed that the reaction mechanism underwent Michaelis–Menten kinetics. K app,H 2 O 2mand V app max values indicated that quercetin was a mixed inhibitor of MPO activity. The initial reaction rates were recalculated using the obtained results. Calculated curves fitted the experimental results within the range of experimental error. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 384–394, 2008
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom