External ID: USP8 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of USP8: Primary Screen
1.#Compound, 20 nL of screening compounds (final concentration of 20 uM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076) (columns 45-46: DMSO control)
2.#Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
3.#Reagent, 2.5 uL of USP8 in assay buffer (final concentration of 1 nM) to columns 1-46
4.#Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 50 nM) to all wells
5.#Time, Incubate at room temperature for 30 minutes
6.#Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of USP8 (USP8_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914961

Protocol: N/A

Comment: Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

External ID: CHEMBL914962

Protocol: N/A

Comment: Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

External ID: USP17 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of USP17: Primary Screen
1. Compound, 50 nL of screening compounds (final concentration of 50 uM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076) (columns 45-46: DMSO control)
2. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
3. Reagent, 2.5 uL of USP17 in assay buffer (final concentration of 1 nM) to columns 1-46
4. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 40 nM) to all wells
5. Time, Incubate at room temperature for 3 hours
6. Reagent, 2.5 uL of stop buffer to all wells
7. Centrifuge plates (5s, 350 rpm)
8. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of USP17 (USP17_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914963

Protocol: N/A

Comment: Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

Target ChEMBL ID: CHEMBL387
ChEMBL Target Name: MCF7
ChEMBL Target Type: CELL-LINE - Target is a specific cell-line
Relationship Type: N - Non-molecular target assigned
Confidence: Target assigned is non-molecular

External ID: USP7 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of USP7: Primary Screen
1. Reagent, 2.5 uL of USP7 in assay buffer (final concentration of 4 nM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076)
2. Compound, 20 nL of screening compounds (final concentration of 20 uM) to columns 1-46 (columns 45-46: DMSO control)
3. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
4. Time, Incubate at room temperature for 60 minutes
5. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 40 nM) to all wells
6. Time, Incubate at room temperature for 10 minutes
7. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of USP7 (USP7_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914964

Protocol: N/A

Comment: Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

Target ChEMBL ID: CHEMBL614561
ChEMBL Target Name: COLO 205
ChEMBL Target Type: CELL-LINE - Target is a specific cell-line
Relationship Type: N - Non-molecular target assigned
Confidence: Target assigned is non-molecular

External ID: CHEMBL4135472

Protocol: N/A

Comment: Journal: J Nat Prod
Year: 2017
Volume: 80
Issue: 10
First Page: 2602
Last Page: 2608
DOI: 10.1021/acs.jnatprod.6b01052

Target ChEMBL ID: CHEMBL612594
ChEMBL Target Name: HL
ChEMBL Target Type: CELL-LINE - Target is a specific cell-line
Relationship Type: N - Non-molecular target assigned
Confidence: Target assigned is non-molecular

External ID: GPR151_PHUNTER_AG_LUMI_1536_1X%ACT

Protocol: Assay Overview:
TThe goal of this NIH sponsored research project was to identify GPR151 agonists via high-throughput screening (HTS) efforts. In brief, the McDonald Lab transferred the GPR151 AG 384wpf assay to Scripps for implementation and miniaturization to 1,536-well format followed by screening against the Scripps Drug Discovery Library (SDDL). A counterscreen assay, employing GPR119 cells, was also implemented by Scripps to identify compounds that non-specifically affect the PathHunter detection method. This project was aided by cheminformatic efforts to help identify compounds that demonstrated authentic agonist pharmacology and non-promiscuous activity profiles across other primary screens run against the SDDL. At completion of the project, several compounds demonstrated activity in the GPR151 AG PathHunter assay. All compounds selected for titration were also subjected to LC-MS analysis to confirm mass and sample purity

Protocol Summary:
Prior to the start of the assay, cells were resuspended in growth media at 2000cells/well in 1536 well plates. This was followed by an incubation of 18 hours at 37C+5%CO2. Then 1uL of Opti-Mem added to all wells except high controls to which 3X EA reagentwas added to each of those wells (0.2X final in lysis buffer). Compounds were pinned at 11.20uM final concentration in 1.0% DMSO followed by a 90 minute incubation at 37C+5%CO2. At this stage 3uL of Promega Beta-Glo detection Buffer was added to all wells followed by a 1 hour incubation at room temperature. Finally the assay end point read was taken using the ViewLux imaging reader from PerkinElemer Lifesciences with a 5 second exposure. Raw assay data was imported into Scripps# corporate database and ascetrained for Z' greater than 0.5 in order to be processed futher.

The percent activation for each compound was calculated as follows:

Percent Response of compound= 100 * ((Test Well-Median Data Wells)/(Median High Control # Median Data Wells))
Where:
Test_Well is defined as wells containing GPR151 cells in the presence of test compound
High_Control represents wells containing GPR151 cells stimulated with 0.2X EA reagent
Low_Control is defined as wells containing GPR151 cells and DMSO
PubChem Activity Outcome and Score:
Standard Cutoff
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 100-1, for inactive 1-0.
List of Reagents:
GPR151 cells (supplied by Patricia McDonald)
Pen Strep (Invtirogen 15140)
FBS (Invtirogen 16140)
Hygromycin (Invtirogen 10687010)
Lysis buffer (CisBio 62CL2FDF)
EA Reagent (DiscoverX 30-411)
G418 (Gemini Bio 400-113)
Opti-MEM (Invtirogen 31985)
Trypsin (Invtirogen 15400054)
Beta Glo (Promega E4780)
1536-well plates (Greiner Bio-One, part 789173)

Comment: Due to the size of the Scripps Molecular Screening Center compound library, this assay have been run as multiple 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 Scripps Molecular Screening Center.

A mathematical algorithm was used to determine what we call the standard hit cut-off to identify active compounds. Two values were calculated: (1) the average percent activation of all compounds tested in the screen, 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 percent activation than the cutoff parameter was declared active. Using this "Standard Cutoff" (= 4.91%) the primary assay yielded 6,756 active compounds ("hits")."

External ID: CHEMBL2166270

Protocol: N/A

Comment: Journal: Bioorg Med Chem
Year: 2012
Volume: 20
Issue: 22
First Page: 6669
Last Page: 6679
DOI: 10.1016/j.bmc.2012.09.040

Target ChEMBL ID: CHEMBL4078
ChEMBL Target Name: Acetylcholinesterase
ChEMBL Target Type: SINGLE PROTEIN - Target is a single protein chain
Relationship Type: D - Direct protein target assigned
Confidence: Direct single protein target assigned

External ID: CHEMBL2166271

Protocol: N/A

Comment: Journal: Bioorg Med Chem
Year: 2012
Volume: 20
Issue: 22
First Page: 6669
Last Page: 6679
DOI: 10.1016/j.bmc.2012.09.040

Target ChEMBL ID: CHEMBL5763
ChEMBL Target Name: Cholinesterase
ChEMBL Target Type: SINGLE PROTEIN - Target is a single protein chain
Relationship Type: D - Direct protein target assigned
Confidence: Direct single protein target assigned

External ID: USP28 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of USP28: Primary Screen
1. Compound, 25 nL of screening compounds (final concentration of 25 uM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076) (columns 45-46: DMSO control)
2. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
3. Reagent, 2.5 uL of USP28 in assay buffer (final concentration of 0.5 nM) to columns 1-46
4. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 12 nM) to all wells
5. Time, Incubate at room temperature for 30 minutes
6. Reagent, 2.5 uL of stop buffer to all wells
7. Centrifuge plates (5s, 350 rpm)
8. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of USP28 (USP28_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914957

Protocol: N/A

Comment: Compounds with activity <= 10uM or explicitly reported as active by ChEMBL are flagged as active in this PubChem assay presentation.

Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

Target ChEMBL ID: CHEMBL398
ChEMBL Target Name: KB
ChEMBL Target Type: CELL-LINE - Target is a specific cell-line
Relationship Type: N - Non-molecular target assigned
Confidence: Target assigned is non-molecular

External ID: USP10 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of USP10: Primary Screen
1. Compound, 20 nL of screening compounds (final concentration of 20 uM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076) (columns 45-46: DMSO control)
2. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
3. Reagent, 2.5 uL of USP10 in assay buffer (final concentration of 15 nM) to columns 1-46
4. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 15 nM) to all wells
5. Time, Incubate at room temperature for 60 minutes
6. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of USP10 (USP10_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914958

Protocol: N/A

Comment: Compounds with activity <= 10uM or explicitly reported as active by ChEMBL are flagged as active in this PubChem assay presentation.

Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

External ID: UCHL1 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of UCHL1: Primary Screen
1. Reagent, 2.5 uL of UCHL1 in assay buffer (final concentration of 1 nM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076)
2. Compound, 20 nL of screening compounds (final concentration of 20 uM) to columns 1-46 (columns 45-46: DMSO control)
3. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
4. Time, Incubate at room temperature for 60 minutes
5. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 7 nM) to all wells
6. Time, Incubate at room temperature for 10 minutes
7. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of UCHL1 (UCHL1_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914959

Protocol: N/A

Comment: Compounds with activity <= 10uM or explicitly reported as active by ChEMBL are flagged as active in this PubChem assay presentation.

Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

External ID: OTUD3 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of OTUD3: Primary Screen
1. Compound, 25 nL of screening compounds (final concentration of 25 uM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076) (columns 45-46: DMSO control)
2. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
3. Reagent, 2.5 uL of OTUD3 in assay buffer (final concentration of 12 nM) to columns 1-46
4. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 40 nM) to all wells
5. Time, Incubate at room temperature for 2 hours
6. Reagent, 2.5 uL of stop buffer to all wells
7. Centrifuge plates (5s, 350 rpm)
8. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of OTUD3 (OTUD3_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: CHEMBL914960

Protocol: N/A

Comment: Journal: J. Nat. Prod.
Year: 2007
Volume: 70
Issue: 4
First Page: 623
Last Page: 627
DOI: 10.1021/np060631s

Target ChEMBL ID: CHEMBL385
ChEMBL Target Name: K562
ChEMBL Target Type: CELL-LINE - Target is a specific cell-line
Relationship Type: N - Non-molecular target assigned
Confidence: Target assigned is non-molecular

External ID: USP30 FAST DUB HTS Primary

Protocol: Deubiquitinases were purified from E. Coli. Ub-Rho substrate was purchased from Boston BioChem (Cat #: U-555). Assay buffer consisted of 50 mM Tris pH 8, 50 mM NaCl, 0.002% Tween20, 5 mM DTT in MilliQ water. Stop buffer consisted of assay buffer + 0.2% trifluoroacetic acid.

Protocol for Inhibitors of USP30: Primary Screen
1. Compound, 25 nL of screening compounds (final concentration of 25 uM) to columns 1-46 of a Greiner 1536 well Black, flat bottom, polystyrene microplate (Griener 782076) (columns 45-46: DMSO control)
2. Reagent, 2.5 uL of assay buffer to columns 47-48 on all plates (No enzyme control)
3. Reagent, 2.5 uL of USP30 in assay buffer (final concentration of 1 nM) to columns 1-46
4. Reagent, 2.5 uL of Ub-Rho in assay buffer (final concentration of 12 nM) to all wells
5. Time, Incubate at room temperature for 2 hours
6. Reagent, 2.5 uL of stop buffer to all wells
7. Centrifuge plates (5s, 350 rpm)
8. Detection, Fluorescence, PheraStar, FITC Module

Comment: Normalization of raw data to positive and negative control wells were applied to the data using Helios, a high-throughput screening data analysis program developed at Novartis.(Gubler et al., 2018)

Compounds demonstrating greater than or equal to 30% inhibition of USP30 (USP30_EFFICACY >/= 30) were called as active, compounds demonstrating activity below this threshold were called as inactive.

External ID: FBW7_ACT_ALPHA_1536_1X%ACT PRUN

Protocol: Assay Overview:
FBW7 assay principle. In this assay, either mutant or wild type (w.t.) FBW7 interact with phosphorylated cyclin E peptide (cycE~P), which will bring donor and acceptor beads into close proximity. Laser excitation of the donor beads converts oxygen to an excited singlet state. Reaction of the singlet oxygen with the acceptor beads further activates a chemiluminescence/fluorescence reaction within the same bead resulting in emitted light at 520-620 nm. Small molecule activators that enhance the mutant FBW7 interaction with the cycE~P decrease the distance of the acceptor beads, thus leading to increased signal being emitted signal.
Protocol Summary:
There are six steps in this 1536 well assay format which are listed in order. First, 2.5uL/well of a 2X working solution containing RLFbw7 [12.5nM final], Cyclin E peptide [12.5nM final], and Ni beads [5ug/mL final], in assay buffer (25mM Tris-HCl pH 7.4 + 100mM NaCl, 0.1% Tween-20, 5mM ?-Mercaptoethanol and 0.05% BSA) was dispensed into columns 1-44. Then 2.5uL/well of a 2X working solution containing WTFbw7 [12.5nM final], Cyclin E peptide [12.5nM final], and Ni beads [5ug/mL final], in assay buffer was dispensed into columns 45-48. Using the pintool transfer device 134nL of compound or control was added to each well. This achieved a nominal screening concentration of 26.1uM and 2.6% DMSO concentration. This was followed by the addition of SA beads to all wells at 5ug/mL final concentration in assay buffer. The assay was then incubated for 20 hours in a temperature controlled 25C environment followed by Alphascreen detection using the PerkinElmer EnVision.

The percent activation 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 RLFbw7 (mutant), cyclin E peptide and Nickel acceptor beads in the presence of test compound
High_Control is defined as wells containing WTFbw7 (wild type), cyclin E peptide and Nickel acceptor beads
Low_Control is defined as the median of the wells containing DMSO, RLFbw7 (mutant), cyclin E peptide and Nickel acceptor beads
PubChem Activity Outcome and Score:

A mathematical algorithm was used to determine active compounds. Two values were calculated: (1) the average percent activation of all compounds tested for the screen, 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 percent activation than the cutoff parameter (1.85% in the case here) 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 100-1, for inactive 1-0.
List of Reagents:
Ni Beads- PerkinEmer Lifesciences Cat#6760619R
RLFbw7-Assay Provider
WTFbw7-Assay Provider
Cyclin E peptide-Assay Provider
5M NaCl- Sigma Cat# S6546-1L
Tween20- Fisher Cat# BP337
Tris 1M pH7.4 Research Organics Cat# 9686T
BSA-Sigma Cat#A7030
?-Mercaptoethanol-SigmaM6250
1536-well plates (Corning, part 7254)

Comment: Due to the size of the Scripps Molecular Screening Center 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 Scripps Molecular Screening Center.

External ID: MITF_INH_Alpha_1536_1X%INH PRUN

Protocol: Assay Overview:

The purpose of this biochemical assay is to identify MITF dimerization inhibitors that disrupt or prevent its homodimerization. This assay is a bead-based proximity assay, which employs acceptor beads and donor beads to generate a chemiluminescence signal. In this assay, Biotin-labelled MITF and His- tagged MITF homodimerization will bring donor and acceptor beads into close proximity. Laser excitation of the donor beads converts oxygen to an excited singlet state. Reaction of the singlet oxygen with the acceptor beads further activates a chemiluminescence reaction within the same bead resulting in emitted light at 520-620 nm. As designed, small molecule inhibitors that interfere with this interaction will increase the distance of the acceptor beads, thus leading to decreased signal. Compounds were tested in singlicate at a nominal test concentration of 2.6 micromolar.

Protocol Summary:
Prior to the start of the assay, 1.25#L of assay buffer (50mM HEPEs pH7.5, 250mM Sodium chloride, 0.1% Tween, 0.1% BSA) containing 10nM His-MITF_r259stop were dispensed into columns 1 thru column 2, and 1.25#L of assay buffer containing 10nM of His MBP MITF were dispensed into columns 3 thru column 48 of 1536 microtiter plates. Next, 10nL of test compounds in DMSO, 7,8-Dihydroxycoumarin (200#M final highest concentration) in DMSO, or DMSO alone (0.15% final concentration) were added to the appropriate wells before dispensing 1.25#L of 10#g/mL Acceptor beads into column 1 to 46 and 1.25#L of assay buffer into column 47 and 48. Plates were incubated in dark for 2hrs at room temperature. Then, dispenses of 1.25#L of 10nM Biotin-MITF into all columns, and 10#g/mL Donor beads into column 1 to 46 and 1.25#L of assay buffer into column 47 to 48 followed by 3hrs incubation in dark at RT, was done. Alphascreen signal was determined using an EnVision microplate reader (PerkinElmer, Waltham, MA) at 680nm excitation and 570nm emission.

The percent inhibition for each compound was calculated as follows:

100 *( ( Median_Low Control-Test Compound) / ( Median_Low Control - Median_High Control ) )

Where:

Test_Compound is defined as wells containing His-MITF + Biotin-MITF in the presence of test compound
High_Control is defined as wells containing His-MITF_r259stop + Biotin-MITF and DMSO.
Low_Control is defined as wells containing His-MITF + Biotin-MITF and DMSO

PubChem Activity Outcome and Score:

Standard Cutoff

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 100-1, for inactive 1-0.

List of Reagents:

His-tagged MITF protein (supplied by Min Guo)
His-tagged MITF_r259stop protein (supplied by Min Guo)
Biotinylated-MITF protein (supplied by Min Guo)
7,8-Dihydroxycoumarin (Sigma, part D5564)
HEPEs (Sigma, part H3375, H3784)
Sodium chloride (Fisher, part BP358-212)
Tween-20 (Fisher, part 50146671)
DMSO (Fisher, part D159)
BSA (Fisher, part BP1600-100)
AlphaScreen Beads Kit (Perkin Elmer, part 6760619L)
1536-well plates (Greiner Bio-One, part 789175)

Comment: Due to the size of the Scripps Molecular Screening Center compound library, this assay have been run as multiple 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 Scripps Molecular Screening Center.