Faculty Collaboration Database

Characterization of sulfur-centered radical intermediates formed during the oxidation of thiols and sulfite by peroxynitrite. ESR-spin trapping and oxygen uptake studies. J Biol Chem 1996 Mar 15;271(11):6000-9

Date

03/15/1996

Pubmed ID

8626383

DOI

10.1074/jbc.271.11.6000

Scopus ID

2-s2.0-0029939154 (requires institutional sign-in at Scopus site)   220 Citations

Abstract

Using a novel phosphorylated spin trap, 5-diethoxy-phosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO), an analog of the commonly used trap 5,5'-dimethyl-1-pyrroline N-oxide (DMPO), we have investigated the reactions of sulfur-centered radicals produced from the oxidation of thiols and sulfite by peroxynitrite. The predominant species trapped in all cases are the corresponding sulfur-centered radicals, i.e. glutathionyl radical (GS) from glutathione (GSH), N-acetyl-DL-penicillamine thiyl radical (S-NAP) from N-acetyl-DL-penicillamine (NAP) and sulfate anion radical (SO3-) from sulfite. These radicals consume molecular oxygen forming either peroxyl or superoxide anion radicals. GS, S-NAP, and (SO3-)-derived radicals react with ammonium formate to form the carbon dioxide anion radical (CO2-). Further support of spin adduct assignments and radical reactions are obtained from photolysis of S-nitrosoglutathione and S-nitroso-N-acetyl-DL-penicillamine. We conclude that the direct reaction of peroxynitrite with thiols and sulfate forms thiyl and sulfate anion radicals, respectively, by a hydroxyl radical-independent mechanism. Pathological implications of thiyl radical formation and subsequent oxyradical-mediated chain reactions are discussed. Oxygen activation by thiyl radicals formed during peroxynitrite-mediated oxidation of glutathione may limit the effectiveness of GSH against peroxynitrite-mediated toxicity in cellular systems.

Author List

Karoui H, Hogg N, Fréjaville C, Tordo P, Kalyanaraman B

Authors

Neil Hogg PhD Associate Dean, Professor in the Biophysics department at Medical College of Wisconsin
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cyclic N-Oxides
Electron Spin Resonance Spectroscopy
Formates
Free Radicals
Glutathione
Hydroxyl Radical
In Vitro Techniques
Molecular Structure
Nitrates
Oxidation-Reduction
Penicillamine
Spin Labels
Sulfhydryl Compounds
Sulfites