Linked Life Data

11811518

Source:http://linkedlifedata.com/resource/pubmed/id/11811518

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2002-1-28
pubmed:abstractText
Although considerably more oxidation-resistant than other P-type ATPases, the yeast PMA1 H+-ATPase of Saccharomyces cerevisiae SY4 secretory vesicles was inactivated by H2O2, Fe2+, Fe- and Cu-Fenton reagents. Inactivation by Fe2+ required the presence of oxygen and hence involved auto-oxidation of Fe2+ to Fe3+. The highest Fe2- (100 microM) and H2O2 (100 mM) concentrations used produced about the same effect. Inactivation by the Fenton reagent depended more on Fe2+ content than on H2O2 concentration, occurred only when Fe2+ was added to the vesicles first and was only slightly reduced by scavengers (mannitol, Tris, NaN3, DMSO) and by chelators (EDTA, EGTA, DTPA, BPDS, bipyridine, 1,10-phenanthroline). Inactivation by Fe- and Cu-Fenton reagent was the same; the identical inactivation pattern found for both reagents under anaerobic conditions showed that both reagents act via OH*. The lipid peroxidation blocker BHT prevented Fenton-induced rise in lipid peroxidation in both whole cells and in isolated membrane lipids but did not protect the H+-ATPase in secretory vesicles against inactivation. ATP partially protected the enzyme against peroxide and the Fenton reagent in a way resembling the protection it afforded against SH-specific agents. The results indicate that Fe2+ and the Fenton reagent act via metal-catalyzed oxidation at specific metal-binding sites, very probably SH-containing amino acid residues. Deferrioxamine, which prevents the redox cycling of Fe2+, blocked H+-ATPase inactivation by Fe2+ and the Fenton reagent but not that caused by H2O2, which therefore seems to involve a direct non-radical attack. Fe-Fenton reagent caused fragmentation of the H+-ATPase molecule, which, in Western blots, did not give rise to defined fragments bands but merely to smears.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1071-5762
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
643-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Mechanisms of Saccharomyces cerevisiae PMA1 H+-ATPase inactivation by Fe2+, H2O2 and Fenton reagents.
pubmed:affiliation
Institute of Botany, University of Bonn, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't