Linked Life Data

21038859

Source:http://linkedlifedata.com/resource/pubmed/id/21038859

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
50
pubmed:dateCreated
2010-12-14
pubmed:abstractText
In this work, we investigated the oxidative modification of histidine residues induced by peroxidase and thiol oxidase activities of bovine copper-zinc superoxide dismutase (Cu-ZnSOD) using NMR and pulse EPR spectroscopy. 1D NMR and 2D-NOESY were used to determine the oxidative damage at the Zn(II) and Cu(II) active sites as well as at distant histidines. Results indicate that during treatment of SOD with hydrogen peroxide (H(2)O(2)) or cysteine in the absence of bicarbonate anion (HCO(3)(-)), both exchangeable and nonexchangeable protons were affected. Both His-44 and His-46 in the Cu(II) active site were oxidized based on the disappearance of NOESY cross-peaks between CH and NH resonances of the imidazole rings. In the Zn(II) site, only His-69, which is closer to His-44, was oxidatively modified. However, addition of HCO(3)(-) protected the active site His residues. Instead, resonances assigned to the His-41 residue, 11 Å away from the Cu(II) site, were completely abolished during both HCO(3)(-)-stimulated peroxidase activity and thiol oxidase activity in the presence of HCO(3)(-) . Additionally, ESEEM/HYSCORE and ENDOR studies of SOD treated with peroxide/Cys in the absence of HCO(3)(-) revealed that hyperfine couplings to the distal and directly coordinated nitrogens of the His-44 and His-46 ligands at the Cu(II) active site were modified. In the presence of HCO(3)(-), these modifications were absent. HCO(3)(-)-mediated, selective oxidative modification of histidines in SOD may be relevant to understanding the molecular mechanism of SOD peroxidase and thiol oxidase activities.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1520-4995
pubmed:author
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10616-22
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Oxidation of histidine residues in copper-zinc superoxide dismutase by bicarbonate-stimulated peroxidase and thiol oxidase activities: pulse EPR and NMR studies.
pubmed:affiliation
Department of Biophysics, Free Radical Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural