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BioAssay: AID 648268

Binding affinity to recombinant GST-tagged human hnRNP A1 expressed in Escherichia coli using QCM biosensor by Scatchard plot analysis

Camptothecin (CPT) is an anti-tumor natural product that forms a ternary complex with topoisomerase I (top I) and DNA (CPT-top I-DNA). In this study, we identified the direct interaction between CPT and human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) using the T7 phage display technology. On an avidin-agarose bead pull down assay, hnRNP A1 protein was selectively pulled down in the more ..
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 Tested Compounds
 Tested Compounds
All(1)
 
 
Active(1)
 
 
 Tested Substances
 Tested Substances
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Active(1)
 
 
AID: 648268
Data Source: ChEMBL (805716)
BioAssay Type: Confirmatory, Concentration-Response Relationship Observed
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2012-09-09
Modify Date: 2014-08-24

Data Table ( Complete ):           View Active Data    View All Data
Target
Sequence: RecName: Full=Heterogeneous nuclear ribonucleoprotein A1; Short=hnRNP A1; AltName: Full=Helix-destabilizing protein; AltName: Full=Single-strand RNA-binding protein; AltName: Full=hnRNP core protein A1; Contains: RecName: Full=Heterogeneous nuclear ribonucleoprotein A1, N-terminally processed
Description ..   
Protein Family: RNA recognition motif 1 in heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) and similar proteins
Comment ..   

Gene:HNRNPA1     Related Protein 3D Structures     More BioActivity Data..
BioActive Compound: 1
Description:
Title: Camptothecin (CPT) directly binds to human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) and inhibits the hnRNP A1/topoisomerase I interaction.

Abstract: Camptothecin (CPT) is an anti-tumor natural product that forms a ternary complex with topoisomerase I (top I) and DNA (CPT-top I-DNA). In this study, we identified the direct interaction between CPT and human heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) using the T7 phage display technology. On an avidin-agarose bead pull down assay, hnRNP A1 protein was selectively pulled down in the presence of C20-biotinylated CPT derivative (CPT-20-B) both in vitro and in vivo. The interaction was also confirmed by an analysis on a quartz-crystal microbalance (QCM) device, yielding a K(D) value of 82.7 nM. A surface plasmon resonance (SPR) analysis revealed that CPT inhibits the binding of hnRNP A1 to top I (K(D): 260 nM) in a non-competitive manner. Moreover, an in vivo drug evaluation assay using Drosophila melanogaster showed that the knockout of the hnRNP A1 homolog Hrb87F gene showed high susceptibility against 5-50 muM of CPT as compared to a wild-type strain. Such susceptibility was specific for CPT and not observed after treatment with other cytotoxic drugs. Collectively, our data suggests that CPT directly binds to hnRNP A1 and non-competitively inhibits the hnRNP A1/top I interaction in vivo. The knockout strain loses the hnRNP A1 homolog as a both CPT-binding partner and naive brakes of top I, which enhances the formation of the CPT-top I-DNA ternary complexes and subsequently sensitizes the growth inhibitory effect of CPT in D. melanogaster.
(PMID: 22071521)
Comment
Compounds with activity <= 50uM or explicitly reported as active by ChEMBL are flagged as active in this PubChem assay presentation.

Categorized Comment - additional comments and annotations
From BioAssay Depositor:
Assay Type: Binding
Target Type: Target is a single protein chain
Assay Data Source: Scientific Literature
Result Definitions
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TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Kd*Kd PubChem standard valueFloatμM
3BEIBinding Efficiency Index(nM)Float
2SEISurface Efficiency Index(nM)Float
4LELigand EfficiencyFloat
5LLELipophilic Ligand EfficiencyFloat
6Bmax activity commentBmax activity commentString
7Bmax standard flagBmax standard flagInteger
8Bmax qualifierBmax qualifierString
9Bmax published valueBmax published valueFloatpg/mm2
10Bmax standard valueBmax standard valueFloatpg/mm2
11Bmax binding domainsBmax binding domainsString
12Kd activity commentKd activity commentString
13Kd standard flagKd standard flagInteger
14Kd qualifierKd qualifierString
15Kd published valueKd published valueFloatnM
16Kd standard valueKd standard valueFloatnM
17Kd binding domainsKd binding domainsString

* Activity Concentration.

Data Table (Concise)
Data Table ( Complete ):     View Active Data    View All Data
Classification
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