Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-1-30
pubmed:abstractText
The reaction of nitrite with hemoglobin has become of increasing interest due to the realization that plasma nitrite may act as an NO congener that is activated by interaction with red blood cells. Using a combination of spectrophotometry, immuno-spin trapping, and EPR, we have examined the formation of radicals during the oxidation of oxyhemoglobin (oxyHb) and oxymyoglobin (oxyMb) by inorganic nitrite. The proposed intermediacy of ferryl species during this oxidation was confirmed by spectrophotometry using multiple linear regression analysis of kinetic data. Using EPR/spin trapping, a protein radical was observed in the case of oxyMb, but not oxyHb, and was inhibited by catalase. When DMPO spin trapping was combined with Western blot analysis using an anti-DMPO-nitrone antibody, globin/DMPO adducts of both oxyHb and oxyMb were detected, and their formation was inhibited by catalase. Catalase effects confirm the intermediacy of hydrogen peroxide as a heme oxidant in this system. Spectrophotometric kinetic studies revealed that the presence of DMPO elongated the lag phase and decreased the maximal rate of oxidation of both oxyHb and oxyMb, which suggests that the globin radical plays an active role in the mechanism of autocatalysis. Interestingly, the oxidation of oxyHb or oxyMb by nitrite, but not by hydrogen peroxide, produced a diffusible radical that was able to generate spin adducts on a bystander protein. This indicates that the oxidation of oxyhemeproteins by nitrite may cause more widespread oxidative damage than the corresponding oxidation by hydrogen peroxide. The immuno-spin trapping technique represents an important new development for the study of the range and extent of protein oxidation by free radicals and oxidants.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
507-15
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Immuno-spin trapping of hemoglobin and myoglobin radicals derived from nitrite-mediated oxidation.
pubmed:affiliation
Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural