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BioAssay: AID 488745

Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid, 96 hour incubation

The goal of this screen is to discover new antimalarial compounds that act by inhibiting the development of the apicoplast in the malarial parasite Plasmodium falciparum. The biochemical processes that make this organelle essential for erythrocytic stage parasites are not well understood. However, antibiotics such as azithromycin and tetracycline, which target the apicoplast translational more ..
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 Tested Compounds
 Tested Compounds
All(1273)
 
 
Active(165)
 
 
Inactive(798)
 
 
Inconclusive(311)
 
 
 Tested Substances
 Tested Substances
All(1280)
 
 
Active(165)
 
 
Inactive(803)
 
 
Inconclusive(312)
 
 
 Related BioAssays
 Related BioAssays
AID: 488745
Data Source: NCGC (DDV296)
BioAssay Type: Confirmatory, Concentration-Response Relationship Observed
Depositor Category: NIH Molecular Libraries Probe Production Network
BioAssay Version:
Deposit Date: 2010-10-08
Modify Date: 2010-10-14

Data Table ( Complete ):           View Active Data    View All Data
BioActive Compounds: 165
Related Experiments
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AIDNameTypeComment
488752Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid, 48 hour incubationConfirmatorydepositor-specified cross reference
488774Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: SummarySummarydepositor-specified cross reference
504834Primary qHTS for delayed death inhibitors of the malarial parasite plastid, 96 hour incubationConfirmatorydepositor-specified cross reference
504599Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid, 96 hour incubation.Confirmatorysame project related to Summary assay
504602Quantitative high throughput screen to test cell viability of anti-malarial compounds targeting the delayed death phenotypeConfirmatorysame project related to Summary assay
504604Quantitative high throughput screen to test activity of anti-malarial compounds in the Dd2 strain of Plasmodium FalciparumConfirmatorysame project related to Summary assay
504608Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid, 48 hour incubation.Confirmatorysame project related to Summary assay
504631A cell-based HTS for delayed death inhibitors of the malarial parasite plastid Measured in Microorganism System Using Plate Reader - 2126-02_Inhibitor_Dose_DryPowder_ActivityConfirmatorysame project related to Summary assay
504633A cell-based HTS for delayed death inhibitors of the malarial parasite plastid Measured in Microorganism System Using Plate Reader - 2126-01_Inhibitor_Dose_DryPowder_ActivityConfirmatorysame project related to Summary assay
504658FACS-based assay to assess parasite growth inhibition 48 hr Measured in Cell-Based System Using Flow Cytometry - 2126-03_Inhibitor_Dose_DryPowder_ActivityConfirmatorysame project related to Summary assay
504659FACS-based assay to assess parasite growth inhibition 96 hr Measured in Cell-Based System Using Flow Cytometry - 2126-05_Inhibitor_Dose_DryPowder_ActivityConfirmatorysame project related to Summary assay
504661Cell-based assay to measure Apicoplast Disruption using ImagingOthersame project related to Summary assay
504832Primary qHTS for delayed death inhibitors of the malarial parasite plastid, 48 hour incubationConfirmatorysame project related to Summary assay
624206Quantitative high throughput screen to test cell viability of anti-malarial compounds targeting the delayed death phenotype.Confirmatorysame project related to Summary assay
624328Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: Hit Validation at 48 hrConfirmatorysame project related to Summary assay
624329Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: Hit Validation with 3D7 at 48 hr using Flow CytometryConfirmatorysame project related to Summary assay
624332Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: Hit Validation at 96 hrConfirmatorysame project related to Summary assay
624335Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: Hit Validation with 3D7 at 96 hr using Flow CytometryConfirmatorysame project related to Summary assay
624336Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: Hit Validation with Dd2 at 48 hr using Flow CytometryConfirmatorysame project related to Summary assay
624337Quantitative high throughput screen for delayed death inhibitors of the malarial parasite plastid: Hit Validation with Dd2 at 96hr using Flow CytometryConfirmatorysame project related to Summary assay
Description:
NIH Molecular Libraries Probe Production Network [MLPCN]
NIH Chemical Genomics Center [NCGC]

MLPCN Grant: R21 NS059500
Assay Provider: David Fidock and Eric Ekland, Columbia University

The goal of this screen is to discover new antimalarial compounds that act by inhibiting the development of the apicoplast in the malarial parasite Plasmodium falciparum. The biochemical processes that make this organelle essential for erythrocytic stage parasites are not well understood. However, antibiotics such as azithromycin and tetracycline, which target the apicoplast translational machinery, have a potent antimalarial effect. The killing caused by these drugs is unusual in that it does not appear to affect the first generation of parasites that are exposed to the drug, but rather manifests itself in their progeny.
We have developed a cell-based assay that measures parasite growth based on the expression of an integrated copy of a firefly luciferase reporter. To detect small molecules that cause this 'delayed death' phenotype, erythrocytes infected with the luciferase-expressing parasites were incubated with compounds for either one or two generations, corresponding to 48 and 96 hours, respectively. Compounds that inhibit parasite growth in the second generation, but not the first, should be enriched in antimalarials that target the apicoplast. Growth inhibition is detected by a decrease in luciferase activity
Protocol
Four microliters of culture medium (RPMI 1640 with 0.5% w/v Albumax (GIBCO), 24 mM sodium bicarbonate and 10 ug/mL gentamycin) were dispensed by a Multi-drop Combi into white solid 1536-well plates (Grenier) and 23 nL compound was added by a pin tool. Four microliters of infected erythrocytes (2% hematocrit, 0.1% parasitemia final concentration) in culture medium were dispensed and the plates incubated for 96 hours at 37 C in 5% CO2. Two microliters of luciferase detection reagent was added and luminescence was detected by a ViewLux (PerkinElmer) reader
Comment
Compound Ranking:

1. Compounds are first classified as having full titration curves, partial modulation, partial curve (weaker actives), single point activity (at highest concentration only), or inactive. See data field "Curve Description". For this assay, apparent inhibitors are ranked higher than compounds that showed apparent activation.
2. For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. For all active compounds, a score range was given for each curve class type given above. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 1 and 39. Fit_LogAC50 was used for determining relative score and was scaled to each curve class' score range.
Result Definitions
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TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
ScoreThe BioAssay activity ranking scoreInteger
1PhenotypeIndicates type of activity observed: inhibitor, activator, fluorescent, cytotoxic, inactive, or inconclusive.String
2Potency*Concentration at which compound exhibits half-maximal efficacy, AC50. Extrapolated AC50s also include the highest efficacy observed and the concentration of compound at which it was observed.FloatμM
3EfficacyMaximal efficacy of compound, reported as a percentage of control. These values are estimated based on fits of the Hill equation to the dose-response curves.Float%
4Analysis CommentAnnotation/notes on a particular compound's data or its analysis.String
5Curve_DescriptionA description of dose-response curve quality. A complete curve has two observed asymptotes; a partial curve may not have attained its second asymptote at the highest concentration tested. High efficacy curves exhibit efficacy greater than 80% of control. Partial efficacies are statistically significant, but below 80% of control.String
6Fit_LogAC50The logarithm of the AC50 from a fit of the data to the Hill equation (calculated based on Molar Units).Float
7Fit_HillSlopeThe Hill slope from a fit of the data to the Hill equation.Float
8Fit_R2R^2 fit value of the curve. Closer to 1.0 equates to better Hill equation fit.Float
9Fit_InfiniteActivityThe asymptotic efficacy from a fit of the data to the Hill equation.Float%
10Fit_ZeroActivityEfficacy at zero concentration of compound from a fit of the data to the Hill equation.Float%
11Fit_CurveClassNumerical encoding of curve description for the fitted Hill equation.Float
12Excluded_PointsWhich dose-response titration points were excluded from analysis based on outlier analysis. Each number represents whether a titration point was (1) or was not (0) excluded, for the titration series going from smallest to highest compound concentrations.String
13Max_ResponseMaximum activity observed for compound (usually at highest concentration tested).Float%
14Activity at 0.00184 uM (0.00184μM**)% Activity at given concentration.Float%
15Activity at 0.00920 uM (0.0092μM**)% Activity at given concentration.Float%
16Activity at 0.046 uM (0.046μM**)% Activity at given concentration.Float%
17Activity at 0.230 uM (0.23μM**)% Activity at given concentration.Float%
18Activity at 1.150 uM (1.15μM**)% Activity at given concentration.Float%
19Activity at 5.750 uM (5.75μM**)% Activity at given concentration.Float%
20Activity at 28.70 uM (28.7μM**)% Activity at given concentration.Float%
21Compound QCNCGC designation for data stage: 'qHTS', 'qHTS Verification', 'Secondary Profiling'String

* Activity Concentration. ** Test Concentration.
Additional Information
Grant Number: R21 NS059500

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