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BioAssay: AID 390218

Induction of ascorbic acid oxidation preincubated for 60 mins in presence of Cu2++

The present study investigated the redox-consequences of the interaction between various endogenous thiols (RSH)-glutathione, cysteine, homocysteine, gamma-glutamyl-cysteine, and cysteinyl-glycine- and Cu(2+) ions, in terms of their free radical-scavenging, ascorbate-oxidizing and O2(*-)-generating properties of the resulting mixtures. Upon a brief incubation (3-30 min) with Cu(2+), the free more ..
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 Tested Compounds
 Tested Compounds
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Unspecified(5)
 
 
 Tested Substances
 Tested Substances
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Unspecified(5)
 
 
 Related BioAssays
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AID: 390218
Data Source: ChEMBL (538247)
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2010-05-26
Modify Date: 2013-05-08

Data Table ( Complete ):           All
Tested Compounds:
Description:
Title: Double edge redox-implications for the interaction between endogenous thiols and copper ions: In vitro studies.

Abstract: The present study investigated the redox-consequences of the interaction between various endogenous thiols (RSH)-glutathione, cysteine, homocysteine, gamma-glutamyl-cysteine, and cysteinyl-glycine- and Cu(2+) ions, in terms of their free radical-scavenging, ascorbate-oxidizing and O2(*-)-generating properties of the resulting mixtures. Upon a brief incubation (3-30 min) with Cu(2+), the free radical-scavenging properties (towards ABTS(*)(+) and DPPH(*)) and thiol-titratable groups of the RSH added to the mixtures decreased significantly. Remarkably, both effects were only partial, even in the presence of a large molar Cu(2+)-excess, and were unaffected despite increasing the incubation time. At equimolar concentrations, the RSH/Cu(2+) mixtures led to the formation of (EPR paramagnetic) Cu(II)-complexes that were time-stable and ascorbate-reducible, but redox-inactive towards oxygen. In turn, at a slight molar thiol-excess (3:1), the mixtures resulted in the formation of time-stable Cu(I)-complexes (EPR silent) that were unreactive towards ascorbate and oxygen. The only exception was seen for the thiol, glutathione, whose mixture with Cu(2+) mixture displayed a O2(*-)-generating capacity (cytochrome c- and lucigenin-reduction). The data indicate that, depending on their molar ratio, the interaction between Cu(2+) and the tested thiols would give place to mixtures containing either: (i) time-stable and ascorbate-reducible Cu(II)-complexes which display free radical-scavenging properties, or (ii) time-stable but redox-inactive towards oxygen Cu(I)-complexes. Among the latter, the only exception was that of glutathione.
(PMID: 18926709)
Comment
Putative Target:

ChEMBL Target ID: 22226
Target Type: UNCHECKED
Pref Name: Unchecked
Confidence: Default value - Target unknown or has yet to be assigned
Relationship Type: Default value - Target has yet to be curated
Categorized Comment
ChEMBL Assay Type: Unassigned

ChEMBL Assay Data Source: Scientific Literature

Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Activity activity commentActivity activity commentString
2Activity standard flagActivity standard flagInteger
3Activity qualifierActivity qualifierString
4Activity published valueActivity published valueFloat%
5Activity standard valueActivity standard valueFloat%

Data Table (Concise)
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