Harnessing insulin- and leptin-induced oxidation of PTP1B for therapeutic development

Area of Science:

• Biochemistry
• Metabolic Diseases
• Drug Discovery

Background:

• Protein tyrosine phosphatase 1B (PTP1B) is a key regulator of glucose and energy metabolism.
• PTP1B is a validated therapeutic target for diabetes and obesity but challenging to inhibit.
• Previously, a recombinant antibody (scFv45) was developed to target the oxidized, inactive PTP1B conformation.

Purpose of the Study:

• To elucidate the molecular basis of scFv45 interaction with oxidized PTP1B.
• To identify small molecules that mimic scFv45's inhibitory effects.
• To establish a novel therapeutic paradigm for PTP1B inhibition.

Main Methods:

• X-ray crystallography to determine the structure of scFv45 bound to oxidized PTP1B.
• Biochemical assays to characterize small molecule inhibitors.
• Cell-based assays to assess insulin and leptin signaling.

Main Results:

• The molecular basis for scFv45 binding to reversibly oxidized PTP1B was elucidated.
• A small molecule inhibitor was identified that replicates the effects of scFv45.
• Stabilization of PTP1B in its inactive, oxidized state by small molecules was shown to enhance insulin and leptin signaling.

Conclusions:

• Small molecules can stabilize PTP1B in an inactive conformation, mimicking antibody-mediated inhibition.
• This approach offers a novel strategy for therapeutic intervention in diabetes and obesity.
• Targeting the oxidized conformation of PTP1B represents a promising new avenue for drug development.