Bookmark and Share
BioAssay: AID 263782

Selectivity for Plasmodium falciparum TrxR over human TrxR

Plasmodium falciparum thioredoxin reductase (PfTrxR: NADPH+Trx(S)2+H+<-->NADP++Trx(SH)2) is a high Mr flavin-dependent TrxR that reduces thioredoxin (Trx) via a CysXXXXCys pair located penultimately to the C-terminal Gly. In this respect, PfTrxR differs significantly from its human counterpart which bears a Cys-Sec redox pair at the same position. PfTrxR is essentially involved in more ..
_
   
 Tested Compounds
 Tested Compounds
All(10)
 
 
Unspecified(10)
 
 
 Tested Substances
 Tested Substances
All(10)
 
 
Unspecified(10)
 
 
 Related BioAssays
 Related BioAssays
AID: 263782
Data Source: ChEMBL (347985)
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2010-05-24
Modify Date: 2014-05-21

Data Table ( Complete ):           View All Data
Tested Compounds:
Description:
Title: Specific inhibitors of Plasmodium falciparum thioredoxin reductase as potential antimalarial agents.

Abstract: Plasmodium falciparum thioredoxin reductase (PfTrxR: NADPH+Trx(S)2+H+<-->NADP++Trx(SH)2) is a high Mr flavin-dependent TrxR that reduces thioredoxin (Trx) via a CysXXXXCys pair located penultimately to the C-terminal Gly. In this respect, PfTrxR differs significantly from its human counterpart which bears a Cys-Sec redox pair at the same position. PfTrxR is essentially involved in antioxidant defense and redox regulation of the parasite and has been previously validated by knock-out studies as a potential drug target for malaria chemotherapy. Moreover, human TrxR is present in most cancer cells at levels tenfold higher than in normal cells. Here we report the discovery of a series of potent inhibitors of PfTrxR. The three most promising inhibitors, 3(IC50(PfTrxR)=2 microM and IC50(hTrxR)=50 microM), 7(IC50(PfTrxR)=2 microM and IC50(hTrxR)=140 microM), and 11(IC50(PfTrxR)=0.5 microM and IC50(hTrxR)=4 microM) were selective for the parasite enzyme. Detailed mechanistic characterization of the effects of these compounds on the PfTrxR-catalyzed reaction showed clear uncompetitive inhibition with respect to both substrate and cofactor. For the most specific PfTrxR inhibitor 7, an alkylation mechanism study based on a thiol conjugation model was performed. Furthermore, all three compounds were active in the lower micromolar range on the chloroquine-resistant P. falciparum strain K1 in vitro.
(PMID: 16458512)
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 - additional comments and annotations
From ChEMBL:
Assay Type: Binding
Assay Data Source: Scientific Literature
Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Ratio IC50 activity commentRatio IC50 activity commentString
2Ratio IC50 standard flagRatio IC50 standard flagInteger
3Ratio IC50 qualifierRatio IC50 qualifierString
4Ratio IC50 published valueRatio IC50 published valueFloat
5Ratio IC50 standard valueRatio IC50 standard valueFloat

Data Table (Concise)
Data Table ( Complete ):     View All Data
PageFrom: