Targeting a key protein-protein interaction surface on mitogen-activated protein kinases by a precision-guided...

Area of Science:

• Biochemistry
• Chemical Biology
• Molecular Pharmacology

Background:

• Mitogen-activated protein kinases (MAPKs) utilize a D-groove for protein binding, distinct from the substrate pocket.
• Targeting MAPK protein-protein interactions is crucial for modulating signaling pathways.

Purpose of the Study:

• To identify and characterize novel compounds that can inhibit MAPK protein-protein interactions.
• To explore the potential of chiral Michael acceptors as covalent inhibitors targeting the MAPK D-groove.

Main Methods:

• Screening of Michael acceptor compounds, focusing on cyclohexenone scaffolds.
• In vitro binding affinity assays to determine compound potency.
• Cell-based assays to assess the perturbation of MAPK signaling networks.

Main Results:

• A sterically crowded, chiral cyclohexenone moiety was identified as a promising scaffold.
• Compounds demonstrated reversible covalent modification of the conserved MAPK D-groove cysteine.
• Inversion of the chiral center altered target specificity, potentially engaging histidine.
• Low micromolar binding affinity was observed in vitro, with cellular pathway perturbation.

Conclusions:

• Chiral, cyclic Michael acceptors with enhanced 3D structures are effective in targeting the MAPK D-groove.
• These compounds offer a novel, non-ATP-competitive approach to modulating MAPK signaling.
• This scaffold presents a promising alternative for developing therapeutics against MAPK-driven diseases.