title: Immuno-spin trapping: detection of protein-centered radicals.
abstract: Protein-centered radicals are involved in biological oxidative damage induced by drugs, environmental hazards, and cellular reactive oxygen species. Presently, the technique most widely used to study protein-centered radicals is electron spin resonance (ESR; also known as electron paramagnetic resonance, EPR); used either directly or in combination with the spin-trapping technique. Protein-centered radicals may be trapped with the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) forming DMPO-radical adducts. However, after a few minutes these adducts decay, often by oxidation to DMPO-protein radical-derived nitrone adducts, which are ESR-silent species. Because nitrone adducts are not free radicals and their formation involves the creation of a covalent linkage, they are stable long after the ESR signal decays. In the new alternative technique of immuno-spin trapping, nitrone adducts are detected by using an antibody, i.e., anti-DMPO, that recognizes their nitrone moiety. Immuno-spin trapping is a simple, reliable, affordable, sensitive, and specific approach to detecting protein-centered radicals, and its development brings the power of immunoassays to bear on the field of toxicology of free radical-mediated biological damage.
authors.affiliation: National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina, USA.
authors.forename: Dario C
authors.initials: DC
authors.lastname: Ramirez
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Mason
mesh_terms: D000818:Animals; D003497:Cyclic N-Oxides / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods*; D005609:Free Radicals / Q000378:metabolism*; D006801:Humans; D008786:Metmyoglobin / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000032:analysis / Q000097:blood; D010108:Oxyhemoglobins / Q000378:metabolism*; D019097:Spin Trapping / Q000295:instrumentation / Q000379:methods*
chemical_list: D003497:Cyclic N-Oxides; D005609:Free Radicals; D009589:Nitrogen Oxides; D010108:Oxyhemoglobins; C015388:nitrones; D008786:Metmyoglobin; C017245:5,5-dimethyl-1-pyrroline-1-oxide