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Acquisition of a specific and potent PTP1B inhibitor from a novel combinatorial library and screening procedure
1Department of Biochemistry, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA.
Abstract:
Protein-tyrosine phosphatases (PTPases) form a large family of enzymes that serve as key regulatory components in signal transduction pathways. Defective or inappropriate regulation of PTPase activity leads to aberrant tyrosine phosphorylation, which contributes to the development of many human diseases including cancers and diabetes. For example, recent gene knockout studies in mice identify PTP1B as a promising target for anti-diabetes/obesity drug discovery. Thus, there is intense interest in obtaining specific and potent PTPase inhibitors for biological studies and pharmacological development. However, given the highly conserved nature of the PTPase active site, it is unclear whether selectivity in PTPase inhibition can be achieved. We describe a combinatorial approach that is designed to target both the active site and a unique peripheral site in PTP1B. Compounds that can simultaneously associate with both sites are expected to exhibit enhanced affinity and specificity. We also describe a novel affinity-based high-throughput assay procedure that can be used for PTPase inhibitor screening. The combinatorial library/high-throughput screen protocols furnished a small molecule PTP1B inhibitor that is both potent (K(i) = 2.4 nm) and selective (little or no activity against a panel of phosphatases including Yersinia PTPase, SHP1, SHP2, LAR, HePTP, PTPalpha, CD45, VHR, MKP3, Cdc25A, Stp1, and PP2C). These results demonstrate that it is possible to acquire potent, yet highly selective inhibitors for individual members of the large PTPase family of enzymes.
Insights
Researchers developed a novel method to create specific inhibitors for protein-tyrosine phosphatases (PTPases), like PTP1B, which are crucial in diseases such as diabetes and cancer. This approach yields potent and selective small molecule inhibitors.
Area of Science:
- Biochemistry
- Enzymology
- Drug Discovery
Background:
- Protein-tyrosine phosphatases (PTPases) are key regulators in cell signaling.
- Dysregulated PTPase activity is implicated in diseases like cancer and diabetes.
- PTP1B is a significant target for anti-diabetic and anti-obesity drug development.
Purpose of the Study:
- To develop potent and selective inhibitors for PTPases, specifically PTP1B.
- To address the challenge of achieving selectivity due to conserved active sites in PTPases.
Main Methods:
- A combinatorial approach targeting both the active site and a peripheral site of PTP1B.
- Development of a novel affinity-based high-throughput assay for inhibitor screening.
Main Results:
- Identification of a potent PTP1B inhibitor with a K(i) of 2.4 nm.
- Demonstrated high selectivity of the inhibitor against a broad panel of other phosphatases.
Conclusions:
- It is feasible to achieve high potency and selectivity in PTPase inhibitors.
- The developed combinatorial strategy and screening assay are effective for discovering specific enzyme inhibitors.
