External ID: HMS1303

Protocol: Prior to screening, lyophilized FITC-GIV peptide (a.a. 1671-1701) is dissolved in 100% DMSO to a concentration of 0.5 mM, then further diluted with water to a final concentration of 50 microM. One stock was prepared in batch for the entire screen and aliquoted. All protein stocks were stored at -80C. Thawing of aliquots on the day of the assay was performed rapidly at room temperature.

Prior to transfer of screening compounds, experimental wells of 384-well assay plates were pre-filled with 37.8 nM of FITC-GIV peptide (for 25 nM final concentration) in a 10 microL volume of assay buffer (50 mM Tris [pH 7.4], 100 mM NaCl, 10 mM MgCl2, 5 mM EDTA, 0.4% NP-40, 30 microM GDP, 1 mM DTT). Control wells were pre-filled with 37.8 nM of FITC-GIV peptide in 10 microL of assay buffer containing either 1% DMSO (vehicle negative control) or 45.3 microM AlCl3+15.1 mM NaF (AlF4- positive control). Each plate contained 16 negative control and 16 positive control wells. Plates were centrifuged at 1000xg for 2 minutes to eliminate bubbling on the surface. Following, 100 nL of experimental compound was pin-transferred into individual wells for each of two replicate assay plates (A&B). After pin-transfer, 5 microL of 3 microM His-tagged rat Galphai3 purified from E. coli (for 1 microM final concentration) was added to each well, and assay plates were shaken at low speed for 5 seconds. Final assay volume was 15 microL. Plates were centrifuged at 1000xg for 2 minutes to eliminate bubbling on the surface and shaken for 10 seconds prior to an incubation of 90 minutes at room temperature. Plates were protected from prolonged light exposure. All manipulations were performed at room temperature.

Assay plates were read with a PerkinElmer Wallac EnVision Multilabel 2103 plate reader using the fluorescent polarization measurement technology with a D505fp/D535 dual mirror and a 480 nm excitation filter. 535 nm emission filters were used for P and S channel reads at 11 mm measurement height with 30 flashes and detector gains of 319 and 563. G-factor 0.96.

Negative control: DMSO
Positive control: Aluminum tetrafluoride (AlF4-, composite of NaF and AlCl3)

Comment: Calculated result values and scoring of active compounds:

Z-score: Indicates the number of standard deviations an experimental condition is from the mean. It is calculated based on plate average (u) and standard deviation (s) of experimental well fluorescence polarization (FP) measurements for each replicate. Z-score (z) is defined as the quotient of the mean of the experimental well population subtracted from an individual well's FP (x), divided by the standard deviation within the experimental wells; z = (x-u)/s.

Normalized percent control: calculated by subtracting plate average positive control FP from experimental well FP, dividing by the difference between plate average negative and positive control FP, and multiplying by 100.

STD: the number of standard deviations from the plate average negative control FP for each replicate experimental well

Compound wells with FP values exceeding +5 standard deviations from the negative control sample average were flagged as potential aggregators or fluorescence quenchers due to their high polarization signal (HighPol) and were excluded from further consideration. Activity scores were calculated by averaging the replicate normalized percent of control values and subtracting from 100 (score based on single replicate if data for other replicate was excluded for any reason). Result values < 0 were set to 0 (no activity) and > 100 were set to 100 (100% activity). Compounds with activity score >= 15 were considered active.

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: 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.