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Physiologically relevant orthogonal assays for the discovery of small-molecule modulators of WIP1 phosphatase in high-throughput screens
- Source :
- The Journal of Biological Chemistry
- Publication Year :
- 2019
- Publisher :
- American Society for Biochemistry and Molecular Biology, 2019.
-
Abstract
- Wildtype P53-induced phosphatase 1 (WIP1) is a member of the magnesium-dependent serine/threonine protein phosphatase (PPM) family and is induced by P53 in response to DNA damage. In several human cancers, the WIP1 protein is overexpressed, which is generally associated with a worse prognosis. Although WIP1 is an attractive therapeutic target, no potent, selective, and bioactive small-molecule modulator with favorable pharmacokinetics has been reported. Phosphatase enzymes are among the most challenging targets for small molecules because of the difficulty of achieving both modulator selectivity and bioavailability. Another major obstacle has been the availability of robust and physiologically relevant phosphatase assays that are suitable for high-throughput screening. Here, we describe orthogonal biochemical WIP1 activity assays that utilize phosphopeptides from native WIP1 substrates. We optimized an MS assay to quantify the enzymatically dephosphorylated peptide reaction product in a 384-well format. Additionally, a red-shifted fluorescence assay was optimized in a 1,536-well format to enable real-time WIP1 activity measurements through the detection of the orthogonal reaction product, inorganic phosphate. We validated these two optimized assays by quantitative high-throughput screening against the National Center for Advancing Translational Sciences (NCATS) Pharmaceutical Collection and used secondary assays to confirm and evaluate inhibitors identified in the primary screen. Five inhibitors were further tested with an orthogonal WIP1 activity assay and surface plasmon resonance binding studies. Our results validate the application of miniaturized physiologically relevant and orthogonal WIP1 activity assays to discover small-molecule modulators from high-throughput screens.
- Subjects :
- 0301 basic medicine
Phosphopeptides
Phosphatase
Wip1
Enzyme Activators
Peptide
Biochemistry & Proteomics
Biochemistry
phosphatase
Substrate Specificity
Serine
Small Molecule Libraries
03 medical and health sciences
high-throughput screening (HTS)
oncogene
enzyme kinetics
therapeutics
cancer
Humans
mass spectrometry (MS)
Enzyme kinetics
Surface plasmon resonance
Molecular Biology
chemistry.chemical_classification
030102 biochemistry & molecular biology
phosphorylation
Methods and Resources
Cell Biology
assay
Small molecule
High-Throughput Screening Assays
Protein Phosphatase 2C
030104 developmental biology
Enzyme
chemistry
RapidFire
kinetics
Phosphorylation
cancer therapy
fluorescence
Tumor Suppressor Protein p53
Structural Biology & Biophysics
Subjects
Details
- Language :
- English
- ISSN :
- 1083351X and 00219258
- Volume :
- 294
- Issue :
- 46
- Database :
- OpenAIRE
- Journal :
- The Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....195e41fcef7b640fd2b44107385f675a