Linked Life Data

3049442

Source:http://linkedlifedata.com/resource/pubmed/id/3049442

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-11-21
pubmed:abstractText
Human erythrocytes have been treated with different agents producing oxidative stress. Diamide, tetrathionate, chromate, cystamine and iodate preferentially influenced the cellular redox state by oxidation of free and protein thiol groups leaving the redox state of hemoglobin virtually unaffected. None of these compounds was able to stimulate the proteolysis. By contrast, phenylhydrazine, nitrite, hydrogen peroxide, ter-butylhydroperoxide, cumene hydroperoxide and copper-ascorbate caused a noticeable oxidation of hemoglobin to methemoglobin. These latter agents, except nitrite and copper-ascorbate, triggered proteolysis. Identical results have been obtained in a ghost-free hemolysate. The fraction containing the proteolytic activity was isolated from hemolysate and tested on native or oxidant-treated hemoglobin. The proteolysis was stimulated by all agents able to produce methemoglobin. It is concluded that proteolysis correlated to an unbalance of cellular redox state. The results obtained with isolated and recombined fractions suggests that increased proteolysis does not depend on the removal of the effect of protease(s) inhibitor(s). Since all agents stimulating proteolysis are able to generate free radicals, it seems that protein breakdown is triggered by the direct effect of these intermediates on proteins (mostly hemoglobin) without the involvement of radical species produced in the membranes by action of organic hydroperoxides. In addition, since nitrite and copper-ascorbate, which also oxidize hemoglobin by radical generation, are unable to stimulate proteolysis, it should be concluded that protein degradation induced by oxidative stress is a complex event induced only by specific agents.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0021-2938
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
129-38
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Proteolysis in human erythrocytes is triggered only by selected oxidative stressing agents.
pubmed:affiliation
Istituto di Scienze Biochimiche, Università, Chieti.
pubmed:publicationType
Journal Article, In Vitro