| Late stage assay provider results from the probe development effort to identify inhibitors of PME-1: fluorescence-based biochemical gel-based competitive Activity-Based Protein Profiling (ABPP) inhibition and selectivity among cysteine-reactive proteins - BioAssay Summary Late stage assay provider results from the probe development effort to identify inhibitors of PME-1: fluorescence-based biochemical gel-based competitive Activity-Based Protein Profiling (ABPP) inhibition and selectivity among cysteine-reactive proteins. ..more |
_ | |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tested Compound: Depositor Specified Assays
Description: Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center (SRIMSC) Center Affiliation: The Scripps Research Institute (TSRI) Assay Provider: Benjamin Cravatt, TSRI Network: Molecular Libraries Probe Production Centers Network (MLPCN) Grant Proposal Number: 1 R01 CA132630 Grant Proposal PI: Benjamin Cravatt, TSRI External Assay ID: ABHD10_INH_FLUO_GELBASEDABPP_SEL_SET2 Late stage assay provider results from the probe development effort to identify inhibitors of PME-1: fluorescence-based biochemical gel-based competitive Activity-Based Protein Profiling (ABPP) inhibition and selectivity among cysteine-reactive proteins. Description: Protein phosphatase methylesterase-1 (PME-1)-mediated methylesterification is thought to control the binding of different subunits to protein phosphatase 2A (PP2A) (1), which, along with protein phosphatase 1 (PP1), is responsible for > 90% of all serine/threonine phosphatase activity (2). PME-1 has also been identified as a protector of sustained ERK pathway activity in malignant gliomas (3), suggesting a link between cancer progression and PME-1-regulated methylesterification. A fluorescence-polarization activity-based protein profiling (fluopol-ABPP) HTS assay for PME-1 inhibitor discovery (AIDs 2130 and 2171) unveiled a phenomenal class of potent and selective inhibitors, the aza-beta lactams (ABLs). During medicinal chemistry campaign to refine ABL inhibitors for PME-1 (See Probe Report for ML174), we observed that one of the common anti-targets of several ABL members was the uncharacterized serine hydrolase abhydrolase domain containing protein 10 (ABHD10). We have preliminary evidence that ABHD10 functions as a lipase in situ (unpublished); however is physiological substrates and biological role(s) have not yet been explored. A principle goal of post-genomic research is to elucidate the molecular and cellular roles of uncharacterized enzymes like ABHD10, work that requires selective chemical tools to inactivate enzyme activity in a controlled manner. References: 1. Wu, J., Tolstykh, T., Lee, J., Boyd, K., Stock, J. B., Broach, J. R. (2000). Carboxyl methylation of the phosphoprotein phosphatase 2A catalytic subunit promotes its functional association with regulatory subunits in vivo. Embo J. 19, 5672-5681. 2. Oliver, C. J., Shenolikar, S. (1998). Physiologic importance of protein phosphatase inhibitors. Front. Biosci. 3, D961-972. 3. Puustinen, P., Junttila, M. R., Vanhatupa, S., Sablina, A. A., Hector, M. E., Teittinen, K., Raheem, O., Ketola, K., Lin, S., Kast, J., Haapasalo, H., Hahn, W. C., Westermarck, J. (2009). PME-1 protects extracellular signal-regulated kinase pathway activity from protein phosphatase 2A-mediated inactivation in human malignant glioma. Cancer Res. 69, 2870-2877. Keywords: late stage, late stage AID, assay provider, powders, abhdyrolase domain containing protein 10, ABHD10, uncharacterized, PME-1, protein phosphatase methylesterase 1, PPME-1, counterscreen, anti-targets, activity-based protein profiling, ABPP, gel-based, chloroacetamide-rhodamine, CA-Rh, in vitro, in situ, inhibitor, selectivity, Scripps, Scripps Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN Panel Information Protocol Assay Overview: The purpose of this assay is to assess selectivity among cysteine-containing proteins of powder samples of test compounds both in vitro (complex proteomic lysates) and in situ (cultured cells) using an activity-based proteomic profiling (ABPP) assay. In this assay, a complex proteome is incubated with test compound followed by reaction with a rhodamine-conjugated chloroacetamide (CA-Rh) activity-based probe. The reaction products are separated by SDS-PAGE and visualized in-gel using a flatbed fluorescence scanner. The percentage activity remaining is determined by measuring the integrated optical density (IOD) of the bands. As designed, test compounds that act as inhibitors will prevent enzyme-probe interactions, thereby decreasing the proportion of bound fluorescent probe, giving lower fluorescence intensity in the band in the gel. Percent inhibition is calculated relative to a DMSO (no compound) control. Protocol Summary: In vitro MBM Assay: Mouse brain membrane (MBM) and soluble proteome (1 mg/mL in DPBS; 50 uL reaction volume) was treated with 20, 10, 1, or 0.1 uM test compound (1 uL of a 50x stock in DMSO). Test compounds were incubated for 30 minutes at 37 C, and CA-Rh (1 uL of 50x stock in DMSO) was added to a final concentration of 5 uM. The reaction was incubated for 30 minutes at 25 C, quenched with 4x SDS-PAGE loading buffer, separated by SDS-PAGE and visualized by in-gel fluorescent scanning. The percentage activity remaining was determined by measuring the integrated optical density of anti-target bands relative to a DMSO-only (no compound) control. Only proteins for which at least 50% inhibition is observed at any test compound concentration are counted as anti-targets. In situ Neuro-2A Assay: Cultured Neuro-2A murine neuroblastoma cells in serum-free DMEM medium (1 mL total volume) were treated with DMSO or test compound (5 uL of a 200x stock in DMSO, 100 nM or 250 nM final concentration) for 2 hours at 37 C. Cells were washed with DPBS, harvested, and resuspended in DPBS (1 mL). Centrifugation (1000 x g, 5 minutes) provided a cell pellet that was resuspended in DPBS (200 uL) and homogenized by sonication. The membrane and soluble fractions were separated by centrifugation (100,000 x g, 45 minutes), and the protein concentrations were adjusted to 1 mg/mL with DPBS. CA-Rh (1 uL of 50x stock in DMSO) was added to a final concentration of 5 uM. The reaction was incubated for 30 minutes at 25 C, quenched with 4x SDS-PAGE loading buffer, separated by SDS-PAGE and visualized by in-gel fluorescent scanning. The percentage activity remaining was determined by measuring the integrated optical density of anti-target bands relative to a DMSO-only (no compound) control. Only proteins for which at least 50% inhibition is observed at any test compound concentration are counted as anti-targets. The % inhibition was then calculated as follows: %_Inhibition = ( 1 - ( IOD_Test_Compound - Median_IOD_Low_Control ) / ( Median_IOD_High_Control - Median_IOD_Low_Control ) ) * 100 Where: Test_Compound is defined as target or anti-target treated with test compound. High_Control is defined as target or anti-target treated with DMSO only (no compound). Low_Control is defined as background in a blank region of the gel. PubChem Activity Outcome and Score: The following applies to each panel: Compounds with anti-targets at any test compound concentration were considered active. Compounds with no observed anti-targets at all test compound concentrations were considered inactive. Overall Outcome and Score: Compounds active in either one or both assays were considered active. Compounds inactive in both assays were considered inactive. The PubChem Activity Score is assigned a value of 100 for active compounds, and 0 for inactive compounds. The PubChem Activity Score range for inactive compounds is 0-0. There are no active compounds. List of Reagents: Mouse brain membrane proteome (provided by Assay Provider) Neuro-2A cells (provided by Assay Provider) DMEM Medium (CellGro 10-017-CV) CA-Rh (provided by Assay Provider) DPBS (Cellgro 20-031-CV) Comment This assay was performed by the assay provider with powder samples of synthetic compounds. Categorized Comment BAO: version: 1.4b1090 BAO: bioassay specification: assay stage: secondary: selectivity BAO: bioassay specification: assay biosafety level: bsl1 BAO: assay format: biochemical format: protein format: protein complex format BAO: bioassay specification: assay measurement type: endpoint assay BAO: bioassay specification: assay readout content: assay readout method: regular screening BAO: bioassay specification: assay readout content: content readout type: single readout BAO: meta target: molecular target: protein target: enzyme: generic hydrolase BAO: meta target detail: binding reporter specification: interaction: protein-small molecule BAO: detection technology: fluorescence: fluorescence intensity Result Definitions
** Test Concentration. § Panel component ID. Additional Information Grant Number: 1 R01 CA132630 PageFrom: |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||