Identification of Bidentate Salicylic Acid Inhibitors of PTP1B

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Molecular Biology

Background:

• Protein Tyrosine Phosphatase 1B (PTP1B) is a key regulator of insulin and leptin signaling pathways.
• Dysregulation of PTP1B activity is implicated in metabolic disorders like type II diabetes and obesity.
• PTP1B inhibition has demonstrated anti-cancer effects by suppressing tumor cell growth.

Purpose of the Study:

• To computationally optimize a salicylic acid-based PTP1B inhibitor (compound 6).
• To identify novel, more potent bidentate PTP1B inhibitors.
• To evaluate the efficacy and selectivity of newly developed inhibitors.

Main Methods:

• Computational guided optimization of inhibitor 6.
• Synthesis of novel bidentate PTP1B inhibitors.
• In vitro assays using CHO-IR cells to measure PTP1B activity and insulin receptor phosphorylation.
• Selectivity profiling against related protein tyrosine phosphatases (PTPσ, PTP-LAR, PRL2 A/S, MKPX) and papain.

Main Results:

• Identified new bidentate PTP1B inhibitors with significantly improved potency (e.g., compound 20h showed >4-fold activity increase).
• Compounds 20f, 20h, and 20j effectively suppressed PTP1B activity and restored insulin receptor phosphorylation in CHO-IR cells.
• Compound 20f exhibited 5-fold selectivity for PTP1B over PTPσ and showed no significant inhibition against other tested phosphatases.
• Compounds 20i and 20j demonstrated nanomolar inhibition against PTPσ.

Conclusions:

• The optimized salicylic acid-based inhibitors represent a promising new class of PTP1B modulators.
• These compounds hold potential for therapeutic development against type II diabetes, obesity, and cancer.
• Further investigation of PTPσ inhibitors (20i, 20j) is warranted for potential applications.