Activity-based chemical proteomics accelerates inhibitor development for deubiquitylating enzymes

Area of Science:

• Biochemistry
• Proteomics
• Drug Discovery

Background:

• Drug development requires early assessment of compound potency, selectivity, and off-target effects.
• Deubiquitylating enzymes (DUBs) are critical targets in various diseases, including cancer.

Purpose of the Study:

• To determine the potency and selectivity of DUB inhibitors using activity-based chemical proteomics.
• To characterize PR-619 as a broad-range DUB inhibitor and P22077 as a USP7 inhibitor for potential therapeutic applications.

Main Methods:

• Activity-based chemical proteomics in cell culture models.
• Characterization of small molecule inhibitors PR-619 and P22077.
• Analysis of ubiquitylated proteins using tandem mass spectrometry.

Main Results:

• PR-619 was identified as a broad-range DUB inhibitor.
• P22077 was identified as a selective USP7 inhibitor with potential for cancer therapy.
• Inhibition of DUBs led to polyubiquitylated protein accumulation without impairing proteasomal activity.
• Distinct ubiquitylated substrate profiles were observed for general versus specific DUB inhibition.

Conclusions:

• Chemical proteomics is effective for evaluating DUB inhibitors.
• P22077 shows promise as a chemotherapeutic agent targeting USP7.
• DUB inhibition reveals novel functional links between USP7 and DNA repair pathways.