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Important role of peroxynitrite‐nitric oxide interaction for S‐, N‐ and C‐nitrosation reactions
Author(s) -
Daiber Andreas,
Schildknecht Stefan,
Müller Johanna,
Frein Daniel,
Ullrich Volker
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.835.7
Subject(s) - peroxynitrite , nitrosation , chemistry , nitric oxide , superoxide , superoxide dismutase , nitrosylation , redox , biochemistry , photochemistry , antioxidant , biophysics , organic chemistry , enzyme , biology
Biological nitrosations belong to a set of redox based chemical posttranslational modifications of proteins that are involved in cellular regulation. Peroxynitrite is a central player in redox signaling and is expected to play a role in nitrosation. In earlier work we and others have suggested that nitrosation is mediated by intermediates that arise by cellular fluxes of nitric oxide and superoxide but the nature of such intermediates remained elusive. In the present study we have investigated model systems for cellular nitrosation using phenol, diaminonaphthaline and isocitrate dehydrogenase as substrates for C‐, N‐, and S‐nitrosation. The thermal aerobic decay of Sin‐1 into equal amounts of NO and superoxide was used and NONOate was added as a NO source which lead to a nitrosation maximum at a NO:superoxide ratio of 3:1. When Cu, Zn‐SOD was present during the decay of Sin‐1 a gradual shift to NO formation was indicated by use of an NO‐sensitive electrode and a SOD dependent maximum of nitrosations was obtained also in this system. Qualitatively similar results were obtained when the SOD mimetic osmium tetroxide was used. We conclude from the various systems investigated that biological nitrosations can arise from fluxes of NO and superoxide at ratios of about 3:1. It is too early to speculate on the mechanism involved but the systems presented seem to be valid models to elucidate biological nitrosation reactions.