Novel Intra- and Inter-molecular Sulfinamide Bonds in S100A8 Produced by Hypochlorite Oxidation

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Show simple item record Raftery, MJ Yang, Z Valenzuela, SM Geczy, CL 2010-05-28T09:49:26Z 2001-09-07
dc.identifier.citation Journal of Biological Chemistry, 2001, 276 (36), pp. 33393 - 33401
dc.identifier.issn 0021-9258
dc.identifier.other C1UNSUBMIT en_US
dc.description.abstract Hypochlorite is a major oxidant generated when neutrophils and macrophages are activated at inflammatory sites, such as in atherosclerotic lesions. Murine S100A8 (A8) is a major cytoplasmic protein in neutrophils and is secreted by macrophages in response to inflammatory stimuli. After incubation with reagent HOCl for 10 min, ∼85% of A8 was converted to 4 oxidation products, with electrospay ionization mass spectrometry masses of m/z 10354, 10388, 10354 ± 1, and 20707 ± 3. All were resistant to reduction by dithiothreitol. Initial formation of a reactive Cys sulfenic acid intermediate was demonstrated by the rapid conjugation of 5,5-dimethyl-1,3-cyclohexanedione (dimedone) to HOCl-treated A8 to form stable adducts. Matrix-assisted laser desorption-reflectron time of flight peptide mass fingerprinting of isolated oxidation products confirmed the mass additions observed in the full-length proteins. Both Met36/73 were converted to Met36/73 sulfoxides. An additional product with an unusual mass addition of m/z 14 (±0.2) was identified and corresponded to the addition of oxygen to Cys41, conjugation to various ε-amines of Lys6, Lys34/35, or Lys87 with loss of dihydrogen and formation of stable intra- or inter-molecular sulfinamide cross-links. Specific fragmentations identified in matrix-assisted laser desorption-post source decay spectra and low energy collisional-induced dissociation tandem mass spectroscopy spectra of sulfinamide-containing digest peptides confirmed Lys34/35 to Cys41 sulfinamide bonds. HOCl oxidation of mutants lacking Cys41 (Ala41S100A8) or specific Lys residues (e.g. Lys34/35, Ala34/35S100A8) did not form sulfinamide cross-links. HOCl generated by myeloperoxidase and H 2O2 and by phorbol 12-myristate 13-acetate-activated neutrophils also formed these products In contrast to the disulfide-linked dimer, oxidized monomer retained normal chemotactic activity for neutrophils. Sulfinamide bond formation represents a novel oxidative cross-linking process between thiols and amines and may be a general consequence of HOCl protein oxidation in inflammation not identified previously. Similar modifications in other proteins could potentially regulate normal and pathological processes during aging, atherogenesis, fibrosis, and neurogenerative diseases.
dc.language eng
dc.relation.isbasedon 10.1074/jbc.M101566200
dc.title Novel Intra- and Inter-molecular Sulfinamide Bonds in S100A8 Produced by Hypochlorite Oxidation
dc.type Journal Article
dc.parent Journal of Biological Chemistry
dc.journal.volume 36
dc.journal.volume 276
dc.journal.number 36 en_US
dc.publocation USA en_US
dc.identifier.startpage 33393 en_US
dc.identifier.endpage 33401 en_US SCI.Medical and Molecular Biosciences en_US
dc.conference Verified OK en_US
dc.for 0304 Medicinal and Biomolecular Chemistry
dc.for 0306 Physical Chemistry (Incl. Structural)
dc.for 1004 Medical Biotechnology
dc.personcode 010690
dc.percentage 50 en_US Medical Biotechnology en_US
dc.classification.type FOR-08 en_US
dc.edition en_US
dc.custom en_US en_US
dc.location.activity en_US
pubs.embargo.period Not known
pubs.organisational-group /University of Technology Sydney
pubs.organisational-group /University of Technology Sydney/Faculty of Science
pubs.organisational-group /University of Technology Sydney/Strength - Health Technologies
utslib.copyright.status Closed Access 2015-04-15 12:17:09.805752+10
pubs.consider-herdc false
utslib.collection.history Closed (ID: 3)

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