Detection, characterization, and decay kinetics of ROS and thiyl adducts of mito-DEPMPO spin trap. Chem Res Toxicol 2007 Jul;20(7):1053-60
Date
06/15/2007Pubmed ID
17559235Pubmed Central ID
PMC4455887DOI
10.1021/tx700101dScopus ID
2-s2.0-34547615931 (requires institutional sign-in at Scopus site) 59 CitationsAbstract
We report here the detection and characterization of spin adducts formed from the trapping of reactive oxygen species (superoxide and hydroxyl radicals) and glutathiyl and carbon-centered radicals by a newly synthesized nitrone, Mito-DEPMPO. This is a cationic nitrone spin trap with a triphenyl phosphonium cation conjugated to the DEPMPO analogue. The Mito-DEPMPO-OOH adduct, formed from the trapping of superoxide by Mito-DEPMPO, was enzymatically generated using xanthine/xanthine oxidase and neuronal nitric oxide synthase, and chemically generated by KO2 in 18-crown-6. The Mito-DEPMPO-OOH adduct exhibits an eight-line EPR spectrum with partial asymmetry arising from the alternate line-width effect. The half-life of the Mito-DEPMPO-OOH adduct is 2-2.5-times greater than that of the DEPMPO-OOH. The Mito-DEPMPO-SG adduct, formed from the trapping of glutathiyl radicals by Mito-DEPMPO, is 3-times more persistent than the analogue DEPMPO-SG adduct. In this study, we describe the EPR characterization of spin adducts formed from Mito-DEPMPO. The EPR parameters of Mito-DEPMPO adducts are distinctly different and highly characteristic. The detection of superoxide from an intact mitochondrion was feasible with Mito-DEPMPO but not with DEPMPO. We conclude that Mito-DEPMPO nitrone and its analogues are more effective than most nitrone spin traps for trapping superoxide, hydroxyl, and thiyl radicals formed in biological systems, including mitochondria.
Author List
Hardy M, Rockenbauer A, Vásquez-Vivar J, Felix C, Lopez M, Srinivasan S, Avadhani N, Tordo P, Kalyanaraman BAuthors
Micael Joel Hardy PhD Visiting Assistant Professor in the Biophysics department at Medical College of WisconsinBalaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin
Jeannette M. Vasquez-Vivar PhD Professor in the Biophysics department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsCell Line
Electron Spin Resonance Spectroscopy
Hydroxyl Radical
Kinetics
Mice
Mitochondria
Molecular Structure
Pyrroles
Reactive Oxygen Species
Spin Trapping
Sulfhydryl Compounds
Superoxide Dismutase
Superoxides