The fidelity of spin trapping with DMPO in biological systems

Copyright © 2011 John Wiley & Sons, Ltd.

Bibliographische Detailangaben
Veröffentlicht in:Magnetic resonance in chemistry : MRC. - 1985. - 49(2011), 4 vom: 30. Apr., Seite 152-8
1. Verfasser: Ranguelova, Kalina (VerfasserIn)
Weitere Verfasser: Mason, Ronald P
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2011
Zugriff auf das übergeordnete Werk:Magnetic resonance in chemistry : MRC
Schlagworte:Journal Article Research Support, N.I.H., Intramural Cyclic N-Oxides Free Radicals Sulfur Oxides 5,5-dimethyl-1-pyrroline-1-oxide 7170JZ1QF3 Hydrogen Peroxide BBX060AN9V Horseradish Peroxidase mehr... EC 1.11.1.- sulfur trioxide HH2O7V4LYD Oxygen S88TT14065
Beschreibung
Zusammenfassung:Copyright © 2011 John Wiley & Sons, Ltd.
Unlike direct ESR, spin trap methodology depends on the absolute fidelity of the spin trap reaction. Two alternative reactions of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) leading to radical adduct artifacts have been discovered and investigated: inverted spin trapping and the Forrester-Hepburn nucleophilic mechanism. These two alternate pathways to radical adducts are a combination of one-electron oxidation and nucleophilic addition, in either order. In biological systems, serious artifacts have been reported due to the Forrester-Hepburn mechanism, which is initiated by the addition of a nucleophile to DMPO. It has recently been demonstrated that (bi)sulfite (hydrated sulfur dioxide) can react with DMPO via a nonradical, nucleophilic reaction, and it has been further proposed that DMPO/(•)SO(3)(-) formation in biological systems is an artifact and not the result of spin trapping of sulfur trioxide anion radical ((•)SO(3)(-)). The one-electron oxidation of (bi)sulfite catalyzed by horseradish peroxidase (HRP)/hydrogen peroxide (H(2)O(2)) has been reinvestigated by ESR spin trapping with DMPO and oxygen uptake studies to obtain further evidence for the radical reaction mechanism. In the absence of DMPO, the initial rate of (bi)sulfite-dependent oxygen and H(2)O(2) consumption was determined to be half of the initial rate of DMPO/(•)SO(3)(-) radical adduct formation as determined by ESR, demonstrating that, under our experimental conditions, DMPO exclusively forms the radical adduct by trapping the (•)SO(3)(-)
Beschreibung:Date Completed 01.08.2011
Date Revised 14.03.2024
published: Print-Electronic
Citation Status MEDLINE
ISSN:1097-458X
DOI:10.1002/mrc.2709