External ID: OPRM1-OPRD1_AG_LUMI_1536_1X%ACT PRUN

Protocol: Assay Overview:

The purpose of this assay is to identify compounds that activate heterodimer formation between the mu (OPRM1) and delta (OPRD1) opioid receptors, resulting in membrane recruitment of beta-arrestin. The assay monitors GPCR-beta-arrestin proximity using low affinity fragment complementation of beta-galactosidase (beta-gal). This assay employs U2OS cells which express OPRD1, OPRM1 fused to a beta-gal peptide fragment (enzyme donor), and beta-arrestin fused to the complementary beta-gal fragment (enzyme acceptor). Cells are incubated with test compound, followed by measurement of well luminescence. As designed, compounds that induce formation of OPRD1 homodimers or OPRM1-OPRD1 (Mu-Delta) heterodimers will cause beta-arrestin recruitment, resulting in reconstitution of the beta-gal holoenzyme. The reconstituted holoenzyme can then catalyze the hydrolysis of a substrate which yields a chemiluminescent signal, resulting in increased well luminescence. Deltorphin B will be used as the high (100% RLU) control for agonists, and wells containing cells treated with DMSO will be used as the low (0% RLU) control. Compounds were tested in singlicate at a final nominal concentration of 9.3 uM.

Protocol Summary:

The U2OS-OPRM1-OPRD1 (Mu-Delta) cell line was routinely cultured in T-175 sq cm flasks at 37 C and 95% relative humidity (RH). The growth media consisted of a 1:1 mixture of Ham's F-12 Nutrient Media (F-12) and Dulbecco's Modified Eagle Media (DMEM) supplemented with 10% v/v heat-inactivated certified fetal bovine serum, 25 mM HEPES, 250 ug/mL Geneticin, 250 ug/mL Hygromycin B, 0.25 ug/mL Puromycin and 1X antibiotic mix (penicillin, streptomycin, and neomycin).

The day before the assay 1000 cells in 3 uL of cell plating media were seeded into each well of 1536 well microtiter plates and allowed to incubate at 37 C, 5% CO2, and 95 % RH for 23 hours. Next, 28 nL of test compound in DMSO, Deltorphin B (0.9 uM final concentration) in DMSO, or DMSO alone were dispensed to the appropriate wells. The plates were then incubated for 3 hours at 37 C, 5% CO2, and 95 % RH. The assay was started by adding 2 uL of PathHuntertrade mark reagent (prepared according to the manufacturer's protocol); followed by 1 hour incubation at room temperature. Then, Well Luminescence was read on the ViewLux plate reader

The percent activation for each compound was calculated as follows:

% Activation = ( ( Ratio_Test_Compound - Median_Ratio_Low_Control ) / ( Median_Ratio_High_Control - Median_Ratio_Low_Control ) ) * 100

Where:

High_Control is defined as wells containing cells, Deltorphin B and DMSO.
Test_Compound is defined as wells containing cells, test compounds and DMSO.
Low_Control is defined as wells containing cells and DMSO.

A mathematical algorithm was used to determine nominally activating compounds in the primary screen. Two values were calculated: (1) the average percent activation of all compounds tested, and (2) three times their standard deviation. The sum of these two values was used as a cutoff parameter, i.e. any compound that exhibited greater % activation than the cutoff parameter was declared active.

PubChem Activity Outcome and Score:

The reported PubChem Activity Score has been normalized to 100% observed primary activation. Negative % activation values are reported as activity score zero.

The PubChem Activity Score range for active compounds is 100-2, and for inactive compounds 2-0.

List of Reagents:

PathHuntertrade mark B-arrestin recruitment assay, containing the U2OS OPRM1 OPRD1 Beta-arrestin cell line; PathHunter Detection Kit (DiscoveRx, part, 93-0558C3)
Ham's F-12 media (Invitrogen, part 11765-054)
DMEM media (Invitrogen, part 11995-073)
Detachin (Genlantis, part T100100)
Heat Inactivated Fetal Bovine Serum (Invitrogen, part 10082-147)
Puromycin (Invitrogen, part A11138-02)
Hygromycin B (Invitrogen, part 10687-010)
Geneticin (Invitrogen, part 10131-027)
100X Penicillin-Streptomycin-Neomycin mix (Invitrogen, part 15640-055)
T-175 tissue culture flasks (Nunc, part 159910)
Agonist: Deltorphin B (Anaspec, part 62683)
1536-well plates (Greiner, part 789173)

Comment: Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, and compounds that modulate well fluorescence. All test compound concentrations reported above and below are nominal; the specific test concentration(s) for a particular compound may vary based upon the actual sample provided by the MLSMR.

External ID: CHRM1_AG_FLUO8_1536_1X%ACT PRUN

Protocol: Assay Overview:

The purpose of this assay is to identify compounds that act as agonists of the human M1 muscarinic receptor (CHRM1; M1). In this assay, CHO-K1 cells stably expressing human M1 are loaded, intracellularly with the calcium indicator dye, Fluo-8, followed by treatment with agonist control or test compounds. As designed, compounds that act as CHRM1 agonists will increase intracellular calcium mobilization, resulting in increased relative fluorescence of the indicator dye and well fluorescence. Compounds are tested in singlicate at a final nominal concentration of 3 uM.

Protocol Summary:

The CHO-hM1 cell line was routinely cultured in T-175 sq cm flasks at 37 C and 95% relative humidity (RH). The growth media consisted of Ham's F-12 Nutrient Media (F-12) supplemented with 10% v/v heat-inactivated qualified fetal bovine serum, 20 mM HEPES, 50 ug/mL Geneticin, and 1X antibiotic mix (penicillin and streptomycin).

The day before the assay 3000 cells in 3 uL of growth media were seeded into each well of 1536 well microtiter plates and allowed to incubate at 37 C, 5% CO2, and 95 % RH for 17-24 hours. Next, 2 uL of the fluorogenic Fluo-8 intracellular calcium indicator mixture (prepared according to the manufacturer's protocol) was added to each well. Plates were then incubated for 1 hour at 37 C, 5% CO2, and 95 % RH, followed by 30 minute incubation at room temperature. Then, 15 nL of test compound in DMSO were dispensed to appropriate wells. The assay was started by performing a basal read of plate fluorescence (470-495 nm excitation and 515-575 nm emission) for 5 seconds on the FLIPR Tetra (Molecular Devices). Then a real time fluorescence measurement was immediately performed for the remaining 140 seconds of the assay. A ratio for each well was calculated to normalize assay data, according to the following mathematical expression:

Ratio = I_Max / I_Min

Where:

I_Max represents the maximum measured fluorescence emission intensity over the 140 second read.
I_Min represents the minimum (basal) measured fluorescence emission intensity before compound was added.

The percent activation was calculated from the median ratio as follows:

%_Activation = ( ( Ratio_Test_Compound - Median_Ratio_Low_Control ) / ( Median_Ratio_High_Control - Median_Ratio_Low_Control ) ) * 100

Where:

Test_Compound is defined as wells containing test compound.
Low_Control is defined as wells containing DMSO.
High_Control is defined as wells containing Acetylcholine (EC100) and DMSO.

PubChem Activity Outcome and Score:

A mathematical algorithm was used to determine nominally activating compounds in the primary screen. Two values were calculated for each assay plate: (1) the average percent activation of test compound wells and (2) three times their standard deviation. The sum of these two values was used as a cutoff parameter for the entire run, i.e. any compound that exhibited greater % activation than the entire screen's cutoff parameter was declared active.

The reported PubChem Activity Score has been normalized to 100% observed primary activation. Negative % activation values are reported as activity score zero.

The PubChem Activity Score range for active compounds is 100-1, and for inactive compounds 1-0.

List of Reagents:

Cell line: Chinese Hamster Ovary (CHO) cells containing hM1 receptor; (Conn Lab)
Calcium sensitive dye: Fluo-8 No Wash Calcium Assay Kit; (AAT Bioquest, part 36316)
Growth media: Ham's F-12; 10% FBS, 20mM HEPES, 50 ug/mL G418
Assay media: Ham's F-12, 10% FBS, 20 mM HEPES
Assay plates: Aurora black/clear 1536well FLIPR plate; (Aurora, part 00019326)
Probenecid: 250 mM (pH 8.0); (Sigma P8761)
Agonist: Acetylcholine (50 mM stock in water); Sigma A9187

Comment: Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, and compounds that modulate well fluorescence. All test compound concentrations reported above and below are nominal; the specific test concentration(s) for a particular compound may vary based upon the actual sample provided by the MLSMR.

External ID: CYP273

Protocol: Tox21 Assay Protocol Summary:

Two ul of enzyme-substrate mix was dispensed into medium binding white/solid 1536-well plates (Greiner Bio-One North America Inc., Monroe, NC) using a BioRaptr Flying Reagent Dispenser (FRD, Beckman Coulter, Brea, CA). Compounds dissolved in DMSO and positive control (furafyllline) were transferred to the assay plates at 23 nl using a Pintool station (Wako, San Diego, CA). The assay plates were incubated at room temperature for 10 min. Then 2 ul of NADPH regeneration solution was added to each well of the assay plates using an FRD and incubated at room temperature for 1 h. The reaction was stopped by adding 4 ul of detection reagent using an FRD and after 20 min incubation at room temperature the luminescence signal was measured using a ViewLux plate reader (Perkin Elmer, Shelton, CT). Data were expressed as relative luminescence units.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (http://actor.epa.gov) and NTP (http://tools.niehs.nih.gov/cebs3/ui/).

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.

External ID: HMS1625

Protocol: The fix-reporter plasmid was conjugated into this strain which the stably integrates into the chromosome using the mini-Tn7 system (PMID: 15908923). This plasmid consists of the fixK promoter, which is a target of the fixLJ pathway driving expression of GFP.
The day before screen an overnight culture of B. multivorans strain VC7102, with fix reporter, is set up in tryptic soy broth (TSB) at 37 degrees C with shaking. The day of the screen the overnight culture is diluted 1:100 in fresh tryptic soy broth.
The day of the screen, 30 microL of tryptic soy broth (TSB) is pipetted into columns 1-22 of a 384-well plate (Corning 3764) using the Combi multidrop dispenser. To column 24, 30 microL of TSB containing 78 microM of Benserazide TSB is added for a positive control. To column 23, 30 microL of TSB containing with DMSO (0.078% v/v in TSB) is added for a negative control. 300 nL of each compound are pin-transferred to each plate. For every compound plate 2 replicate assay plates are set up. 30 microL of the 1:100 diluted-B. multivorans strain VC7102 is added to each well using the Combi. Initial OD600 and GFP are measured using the PerkinElmer EnVision. Plates are stacked 5 high, covered with lids and incubated at 37 degrees C overnight (~18 h).
The following day, assay plates are read using a PerkinElmer EnVision (600 nm filter and GFP).
Positive control: Benserazide 39 microM in column 24 (No positive control was used for plates 2089 & 2090; Plates 2091-2093: columns 1 & 24)
Negative control: DMSO 300 nL/well in column 23 (For plates 2089 & 2090 negative controls were located in columns 2 & 24; plates 2091-2093: columns 2 & 23)

Comment: Analysis method:
For each compound well, the initial GFP value was subtracted from overnight GFP value to calculate the deltaGFP. The mean and standard deviation of the negative control wells deltaGFP (column 23) on both replicate plates was calculated. Wells with replicate average deltaGFP at least 3 standard deviations above the plate negative control deltaGFP average were scored as potential positives.

To determine activity scores, Z-scores were calculated for each replicate separately based on the replicate negative control deltaGFP plate average and standard deviation. The replicate average deltaGFP Z-scores were used for activity scores, with activity score of 100 set to Z-score = 4 and activity score = 0 (no activity) set to Z-score = 0. Z-scores > 4 were considered activity score = 100, and Z-scores < 0 were considered activity score = 0.

External ID: CHRM1_PAM_FLUO8_1536_1X%ACT PRUN

Protocol: Assay Overview:

The purpose of this assay is to identify compounds that act as positive allosteric modulators (PAMs) and increase activity of the human M1 muscarinic receptor (CHRM1; M1) in cells pre-treated with a known agonist. In this assay, CHO-K1 cells stably expressing human M1 are loaded with the Fluo-8 calcium indicator dye, followed by addition of test compounds and subsequent treatment with the activator acetylcholine at a concentration that results in 20% activation (EC20). As designed, compounds that act as CHRM1 PAMs will increase calcium mobilization, resulting in increased intracellular calcium and relative fluorescence of the indicator dye beyond that of the EC20 of acetylcholine. Compounds are tested in singlicate at a final nominal concentration of 3 micromolar.

Protocol Summary:

The CHO-hM1 cell line was routinely cultured in T-175 sq cm flasks at 37 degrees C and 95% relative humidity (RH). The growth media consisted of Ham's F-12 Nutrient Media (F-12) supplemented with 10% v/v heat-inactivated qualified fetal bovine serum, 20 mM HEPES, 50 micrograms/mL Geneticin, and 1X antibiotic mix (penicillin and streptomycin).

The day before the assay 3000 cells in 3 microliters of growth media were seeded into each well of 1536 well microtiter plates and allowed to incubate at 37 degrees C, 5% CO2, and 95 % RH for 17-24 hours. Next, 2 microliters of the fluorogenic Fluo-8 intracellular calcium indicator mixture (prepared according to the manufacturer's protocol) was added to each well. Plates were then incubated for 1 hour at 37 degrees C, 5% CO2, and 95 % RH, followed by 30 minute incubation at room temperature. Then, 15 nL of test compound in DMSO were transferred to appropriate wells. The assay was started by performing a basal read of plate fluorescence (470-495 nm excitation and 515-575 nm emission) for 5 seconds on the FLIPR Tetra (Molecular Devices) prior to all wells being treated with an EC20 concentration of acetylcholine. Then a real time fluorescence measurement was immediately performed for the remaining 140 seconds of the assay. A ratio for each well was calculated to normalize assay data, according to the following mathematical expression:

Ratio = I_Max / I_Min

Where:

I_Max represents the maximum measured fluorescence emission intensity over the 140 second read and;
I_Min represents the minimum (basal) measured fluorescence emission intensity before compound was added.

The percent activation was calculated from the median ratio as follows:

% Activation = ( ( Ratio_Test_Compound - Median_Ratio_Low_Control ) / ( Median_Ratio_High_Control - Median_Ratio_Low_Control ) ) * 100

Where:

Test_Compound is defined as wells containing test compound.
Low_Control is defined as wells containing Acetylcholine at EC20 and DMSO.
High_Control is defined as wells containing Acetylcholine (EC100) and DMSO.

A mathematical algorithm was used to determine nominally activating compounds in the primary screen. Two values were calculated for each assay plate: (1) the average percent activation of test compound wells and (2) three times their standard deviation. The sum of these two values was used as a cutoff parameter on an individual plate basis, i.e. any compound that exhibited greater % activation than the plate based cutoff parameter was declared active.

PubChem Activity Outcome and Score:

The inactive compounds of this assay have an activity score range of 0 to 78 and the active compounds have an activity score range of 50 to 100.

The reported PubChem Activity Score has been normalized to 100% observed primary activation. Negative % activation values are reported as activity score zero.

List of Reagents:

Cell line: Chinese Hamster Ovary (CHO) cells containing hM1 receptor; (Conn Lab)
Calcium sensitive dye: Fluo-8 No Wash Calcium Assay Kit; (AAT Bioquest, part 36316)
Growth media: Ham's F-12; 10% FBS, 20mM HEPES, 50?g/mL G418
Assay media: Ham's F-12, 10% FBS, 20 mM HEPES
Assay plates: Aurora black/clear 1536well FLIPR plate; (Aurora, part 00019326)
Probenecid: 250mM (pH 8.0); (Sigma P8761)
Potentiator: Acetylcholine (50mM stock in water); Sigma A9187

Comment: Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, and compounds that modulate well fluorescence. All test compound concentrations reported above and below are nominal; the specific test concentration(s) for a particular compound may vary based upon the actual sample provided by the MLSMR.

External ID: SIAE_INH_FP_1536_1X%INH PRUN

Protocol: Assay Overview:

The purpose of this biochemical assay is to identify compounds that act as inhibitors of sialic acid acetylesterase (SIAE). In this assay, SIAE protein is incubated with test compounds and fluorophosphonate-rhodamine (FP-Rh) activity-based probe. The reaction is excited with linear polarized light and the intensity of the emitted light is measured as the polarization value (mP). As designed, test compounds that act as SIAE inhibitors will prevent SIAE-probe interactions, thereby increasing the proportion of free (unbound) fluorescent probe in the well, leading to low fluorescence polarization. Compounds are tested in singlicate at a nominal test concentration of 9.66 micromolar.

Protocol Summary:

Prior to the start of the assay, 3 microliters of assay buffer (1X DPBS and 0.01% Pluronic F-127) were dispensed into column 1 thru column 3 of 1536 microtiter plates. Next, 3 microliters of assay buffer containing 0.73uM of SIAE protein were dispensed into columns 4 thru 48. Then, 39 nL of test compound in DMSO or DMSO alone (0.97% final concentration) were added to the appropriate wells and incubated for 45 minutes at 25 degrees Celsius.

The assay was started by dispensing 1.0 microliter of 300 nM FP-Rh in assay buffer to all wells. Plates were centrifuged and after 120 minutes of incubation at 25 degrees Celsius, fluorescence polarization was read on a Viewlux microplate reader (PerkinElmer, Turku, Finland) using a BODIPY TMR FP filter set and a BODIPY dichroic mirror (excitation = 525nm, emission = 598nm) for 25 seconds for each polarization plane (parallel and perpendicular).

Prior to further calculations, the following formula was used to calculate fluorescence polarization (FP):

FP = ( Raw1 - Raw2 ) / ( Raw1 + Raw2 )

Where:

Raw1 is defined as the S channel.
Raw2 is defined as the P channel.

The percent inhibition for each compound was calculated as follows:

100 *( ( Test_Compound - Median_Low_Control ) / ( Median_High_Control - Median_Low_Control ) )

Where:

Test_Compound is defined as wells containing SIAE protein in the presence of test compound and FP-Rh.
High_Control is defined as wells containing DMSO, FP-Rh but, no SIAE protein.
Low_Control is defined as the median of the wells containing test compounds.

PubChem Activity Outcome and Score:

A mathematical algorithm was used to determine nominally inhibiting compounds in the primary screen. Four values were calculated: (1) the average percent inhibition of all high controls tested plus three times the standard deviation of the high controls, (2) the average percent inhibition of all low controls tested minus three times the standard deviation of the low controls, (3) the average percent inhibition of all compounds tested between (1) and (2), and (4) three times their standard deviation. The sum of two of these values, (3) and (4), was used as a cutoff parameter, i.e. any compound that exhibited greater % inhibition/activity than the cutoff parameter was declared active.

The reported PubChem Activity Score has been normalized to 100% observed primary inhibition. Negative % inhibition values are reported as activity score zero.

The activity score range for active compounds is 100-2, for inactive 2-0.

List of Reagents:

SIAE protein (supplied by Assay Provider)
FP-Rh probe (supplied by Assay Provider)
DPBS (Mediatech, part 20-031-CV)
Pluronic F-127 (Invitrogen, part P6866)
1536-well plates (Greiner, part 789176)

Comment: Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, compounds that modulate well fluorescence. All test compound concentrations reported above and below are nominal; the specific test concentration(s) for a particular compound may vary based upon the actual sample provided by the MLSMR.

External ID: P53600

Protocol: Tox21 Assay Protocol Summary:

The p53RE-bla cells were dispensed at 4,000 cells/5 ul/well in 1536-well black wall/clear bottom plates using a Multidrop dispenser. After the assay plates were incubated at a 37 C/5% CO2 incubator for 5 hours, 23 nL of compounds dissolved in DMSO, positive controls or DMSO only was transferred to the assay plate by a pin tool. The plates were incubated at 37 C for 16 hours. After 1 uL of LiveBLAzerTM B/G FRET substrate was added using a Flying Reagent Dispenser, the plates were incubated at room temperature for 2 hours, and fluorescence intensity was measured by an Envision plate reader. For cell viability readout that measures cytotoxicity, 4 ul/well of CellTiter-Glo reagent was added into the assay plates using a Flying Reagent Dispenser. After 30 min incubation at room temperature, the luminescence intensity in the plates was measured using a ViewLux plate reader.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).
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.

External ID: P53MS958

Protocol: Tox21 Assay Protocol Summary:

The p53RE-bla cells were dispensed at 4,000cells/3ul/well in 1536-well black-clear bottom plates. After the assay plates were incubated at 37 C, 5% CO2 incubator for 5 hours, 23 nL of compounds dissolved in DMSO, positive controls or DMSO only was transferred to the assay plate. Following compound addition, 3 uL of rat liver microsomes (Molecular Toxicology, Boone, NC) at final concentration of 0.5 mg/mL and 1uL of B-Nicotinamide adenine dinucleotide 2'-phosphate (NADPH) at final concentration of 0.5 mg/mL were transferred to the assay plate. The plates were incubated at 37 C for 16 hours. 1 uL of LiveBLAzer detection mixture was added to each well and the plates were incubated at room temperature in the dark for 2 h. Fluorescence intensity at 460 and 530 nm emission and 405 nm excitation were measured by an Envision plate reader. For cell viability readout that measures cytotoxicity, 4 ul/well of CellTiter-Glo reagent was added into the assay plates using a Flying Reagent Dispenser. After 30 min incubation at room temperature, the luminescence intensity in the plates was measured using a ViewLux plate reader.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).

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.

External ID: P53MS482

Protocol: Please refer to other AIDs 1963578, 1963580, 720687, 720685, 720678 and 720681 for detailed assay protocols.

Comment: This summary is written for the purposes of summarizing the compound activities from the project combining the results from both the p53 with rat microsomes agonist mode assay (AID 1963578), cell viability counter screen (AID 1963580), and auto fluorescence counter screens (AID 720687, 720685, 720678, and 720681). For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Potency and efficacy were used for determining relative score. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 5 and 30 determined by phenotype.

Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).

External ID: P53344

Protocol: Tox21 Assay Protocol Summary:

The p53RE-bla cells were dispensed at 4,000 cells/5 ul/well in 1536-well black wall/clear bottom plates using a Multidrop dispenser. After the assay plates were incubated at a 37 C/5% CO2 incubator for 5 hours, 23 nL of compounds dissolved in DMSO, positive controls or DMSO only was transferred to the assay plate by a pin tool. The plates were incubated at 37 C for 16 hours. After 1 uL of LiveBLAzerTM B/G FRET substrate was added using a Flying Reagent Dispenser, the plates were incubated at room temperature for 2 hours, and fluorescence intensity was measured by an Envision plate reader.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).

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 activators are ranked higher than compounds that showed apparent inhibition.
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.

External ID: P53MS233

Protocol: Tox21 Assay Protocol Summary:

The p53RE-bla cells were dispensed at 4,000cells/3ul/well in 1536-well black-clear bottom plates. After the assay plates were incubated at 37 C, 5% CO2 incubator for 5 hours, 23 nL of compounds dissolved in DMSO, positive controls or DMSO only was transferred to the assay plate. Following compound addition, 3 uL of human liver microsomes (XenoTech, Kansas City, KS) at final concentration of 0.5 mg/mL and 1uL of Beta-Nicotinamide adenine dinucleotide 2-phosphate (NADPH) at final concentration of 0.5 mg/mL were transferred to the assay plate. The plates were incubated at 37 C for 16 hours. 1 uL of LiveBLAzer detection mixture was added to each well and the plates were incubated at room temperature in the dark for 2 h. Fluorescence intensity at 460 and 530 nm emission and 405 nm excitation were measured by an Envision plate reader.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).

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 activators are ranked higher than compounds that showed apparent inhibition.
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.

External ID: P53MS837

Protocol: Tox21 Assay Protocol Summary:

The p53RE-bla cells were dispensed at 4,000cells/3ul/well in 1536-well black-clear bottom plates. After the assay plates were incubated at 37 C, 5% CO2 incubator for 5 hours, 23 nL of compounds dissolved in DMSO, positive controls or DMSO only was transferred to the assay plate. Following compound addition, 3 uL of human liver microsomes (XenoTech, Kansas City, KS) at final concentration of 0.5 mg/mL and 1uL of B-Nicotinamide adenine dinucleotide 2'-phosphate (NADPH) at final concentration of 0.5 mg/mL were transferred to the assay plate. The plates were incubated at 37 C for 16 hours. 1 uL of LiveBLAzer detection mixture was added to each well and the plates were incubated at room temperature in the dark for 2 h. Fluorescence intensity at 460 and 530 nm emission and 405 nm excitation were measured by an Envision plate reader. For cell viability readout that measures cytotoxicity, 4 ul/well of CellTiter-Glo reagent was added into the assay plates using a Flying Reagent Dispenser. After 30 min incubation at room temperature, the luminescence intensity in the plates was measured using a ViewLux plate reader.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).
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.

External ID: GDH-TPI_INH_ABS_1536_1X%INH CSRUN

Protocol: Assay Overview:

The purpose of this biochemical counterscreen is to determine whether compounds act as absorbance assay artifacts or are non-selective. This assay also serves as a counterscreen for a set of ongoing high throughput primary experiments entitled, "Absorbance-based biochemical primary high throughput screening assay to identify inhibitors of the aldolase of M. tuberculosis."

This counterscreen is similar in format to the aforementioned assay with the only two following differences: (i) the fructose-1,6-bisphosphate substrate is replaced with glyceraldehyde 3 phosphate, a product of its conversion by FBA and (ii) no (FBA) is used. The counterscreen hence recapitulates the two steps involved in the monitoring of FBA activity through the conversion of FB into the triose product glyceraldehyde 3 phosphate (G3P), which would be converted to dihydroxyacetone phosphate (DHAP) by the helper enzyme triose phosphate isomerase (TPI). A second helper enzyme, glycerophosphate dehydrogenase (GDH), converts the dihydroxyacetone phosphate to glycerol-3-phosphate with the concomitant oxidation of NADH to NAD, which is monitored by measuring the absorbance at 340 nm. In this new assay format, the A340 is independent of FBA activity, hence compounds that reduce absorbance at 340 nm are either absorbance artifacts or helper enzyme inhibitors that will not be pursued. Compounds are tested in singlicate at a final nominal concentration of 4.78 uM.

Protocol Summary:

Prior to the start of the assay, 5 uL /well of Buffer A (50 mM HEPES, 0.01% Triton X-100, 10% Glycerol, pH8.0) supplemented with 400 nM ZnCl2,240 uM NADH and the helper enzymes GDH-TPI (4 U/mL) was dispensed into all wells of a 1536-well plate except the "No enzyme" wells that contained the same supplemented buffer but no GDH-TPI enzymes. Next, 48 nL of test compounds were then delivered in each well using a PinTool. The assay was then initiated by dispensing 5 uL of Buffer A supplemented with 240 uM of the substrate glyceraldehyde-3-phosphate (G3P). Plates were incubated at room temperature for 20 minutes before A340 was measured using the EnVision plate reader (Perkin Elmer).

The percent inhibition for each compound was calculated as follows:

%Inhibition = 100 * ( ( Test_Compound - Median_Low_Control ) / ( Median_High_Control - Median_Low_Control ) )

Where:

Test_Compound is defined as wells treated with test compounds.
Low_Control is defined as wells treated with DMSO.
High_Control is defined as wells with no GDH-TPI enzyme.

A mathematical algorithm was used to determine nominally inhibiting compounds in the primary screen. Two values were calculated for each assay plate: (1) the average percent inhibition of test compound wells and (2) three times their standard deviation. The sum of these two values was used as a cutoff parameter for each plate, i.e. any compound that exhibited greater % inhibition than the cutoff parameter was declared active.

PubChem Activity Outcome and Score:

The reported PubChem Activity Score has been normalized to 100% observed inhibition. Negative % inhibition values are reported as activity score zero.

The PubChem Activity Score range for active compounds is 100-13, and for inactive compounds 13-0.

List of Reagents:

ZnCl2 (Fisher Scientific, part Z33-500)
NADH (EMD Biosciences, part 481913)
GDH-TPI (Sigma, part G1881)
HEPES (EMD Biosciences, part EM-5310)
Triton X-100 (Sigma, part T8787)
Glycerol (Fisher, part AC327255000)
Glyceraldehyde-3-phosphate (Sigma, part D7137)
1536-well plates (Aurora, part 1091-11020-S)

Comment: Due to the increasing size of the MLPCN compound library, this assay may have been run as two or more separate campaigns, each campaign testing a unique set of compounds. In this case the results of each separate campaign were assigned "Active/Inactive" status based upon that campaign's specific compound activity cutoff value. All data reported were normalized on a per-plate basis. Possible artifacts of this assay can include, but are not limited to: dust or lint located in or on wells of the microtiter plate, and compounds that quench or emit absorbance within the well. All test compound concentrations reported are nominal; the specific concentration for a particular test compound may vary based upon the actual sample provided by the MLSMR

External ID: P53MS898

Protocol: Tox21 Assay Protocol Summary:

The p53RE-bla cells were dispensed at 4,000cells/3ul/well in 1536-well black-clear bottom plates. After the assay plates were incubated at 37 C, 5% CO2 incubator for 5 hours, 23 nL of compounds dissolved in DMSO, positive controls or DMSO only was transferred to the assay plate. Following compound addition, 3 uL of rat liver microsomes (Molecular Toxicology, Boone, NC) at final concentration of 0.5 mg/mL and 1uL of Beta-Nicotinamide adenine dinucleotide 2-phosphate (NADPH) at final concentration of 0.5 mg/mL were transferred to the assay plate. The plates were incubated at 37 C for 16 hours. 1 uL of LiveBLAzer detection mixture was added to each well and the plates were incubated at room temperature in the dark for 2 h. Fluorescence intensity at 460 and 530 nm emission and 405 nm excitation were measured by an Envision plate reader.

Comment: Disclaimer:

Although all reasonable efforts have been made to ensure the accuracy and reliability of the data, caution should be exercised when interpreting the results as artifacts are possible from nonspecific effects such as assay signal interference. The curve fitting and activity calls presented here are based on the NCATS analysis methods. Alternative analysis methods and interpretations of the data are available at EPA (https://www.epa.gov/comptox-tools/comptox-chemicals-dashboard) and NTP (https://cebs.niehs.nih.gov/cebs/).

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 activators are ranked higher than compounds that showed apparent inhibition.
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.