Related Experiment Video
Updated: Aug 13, 2026
A Semi-High-Throughput Adaptation of the NADH-Coupled ATPase Assay for Screening Small Molecule Inhibitors
Published on: August 17, 2019
Engineering non-natural inhibitor sensitivity in protein tyrosine phosphatase H1
Elizabeth R Blair1, Hillary E Hoffman, Anthony C Bishop
1Department of Chemistry, Amherst College, Amherst, MA 01002, USA.
Abstract:
Protein tyrosine phosphatase H1, a member of the ubiquitous protein tyrosine phosphatase (PTP) superfamily of enzymes, is an important signaling molecule, mutant forms of which have been found in human colorectal cancers. Selective PTPH1 inhibitors would be valuable tools for investigating PTPH1's roles in cellular regulation. However, no PTPH1-specific inhibitors are known. To identify target-selective inhibitors of human PTPH1, we have redesigned a PTPH1/inhibitor interface. Structure-based protein design was used to identify two amino-acid residues, isoleucine 846 and methionine 883, that control PTPH1's sensitivity to oxalylaminoindole PTP inhibitors. Mutation of residues 846 and 883 to alanine and glycine, respectively, conferred novel inhibitor sensitivity onto PTPH1. From a small panel of putative inhibitors, compounds that potently and selectively target the inhibitor-sensitized PTPH1 mutants were identified.
Insights
Researchers engineered protein tyrosine phosphatase H1 (PTPH1) to be sensitive to new inhibitors. This breakthrough enables the development of selective PTPH1 inhibitors for cancer research.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Protein tyrosine phosphatase H1 (PTPH1) is a key enzyme in cellular signaling pathways.
- Mutations in PTPH1 are implicated in human colorectal cancers, highlighting its role in disease.
- Currently, no specific inhibitors exist for PTPH1, limiting research into its functions.
Purpose of the Study:
- To identify novel, target-selective inhibitors for human PTPH1.
- To overcome the lack of specificity in existing PTPH1 inhibitors.
- To develop tools for investigating PTPH1's roles in cellular regulation and cancer.
Main Methods:
- Utilized structure-based protein design to engineer the PTPH1 enzyme.
- Identified specific amino acid residues (isoleucine 846 and methionine 883) controlling inhibitor sensitivity.
- Mutated these residues to alter PTPH1's inhibitor response profile.
Main Results:
- Successfully engineered PTPH1 mutants with altered sensitivity to oxalylaminoindole PTP inhibitors.
- Identified specific mutations (I846A and M883G) conferring novel inhibitor sensitivity.
- Discovered potent and selective inhibitors targeting these engineered PTPH1 mutants.
Conclusions:
- Structure-based protein design is effective for creating enzyme variants with novel inhibitor specificities.
- The identified PTPH1 mutants and selective inhibitors provide valuable tools for PTPH1 research.
- This work paves the way for developing PTPH1-targeted therapies for colorectal cancer and other diseases.
Related Concept Videos
01:30Enzyme Inhibition
02:54Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...