Above-Filter Digestion Proteomics Reveals Drug Targets and Localizes Ligand Binding Site

Area of Science:

• Chemical proteomics
• Molecular dynamics
• Structural biology

Background:

• Identifying drug-protein interactions is crucial for understanding drug efficacy and toxicity.
• Existing chemical proteomics methods have limitations and
• blind spots
• necessitating complementary techniques.

Purpose of the Study:

• Introduce Above-Filter Digestion Proteomics (AFDIP) as a novel method to identify drug-protein interactions.
• Address the limitations of current chemical proteomics approaches.
• Provide structural insights into drug-binding sites.

Main Methods:

• Monitor trypsin digestion rates, which decrease at ligand-binding sites.
• Utilize molecular dynamics simulations to correlate digestion changes with backbone flexibility.
• Perform two-dimensional analysis with drug concentration as a variable.

Main Results:

• AFDIP identified drug and metabolite targets by detecting altered trypsin digestion.
• The method determined binding sites within ≤10 Å of crystallographic locations, with improved resolution (≤5 Å) for larger proteins.
• Demonstrated simpler sample preparation, deeper proteome coverage, and broader sequence analysis compared to existing methods.

Conclusions:

• AFDIP effectively identifies drug targets and binding sites, complementing existing chemical proteomics tools.
• The method offers advantages in sample preparation, proteome depth, and sequence coverage.
• AFDIP enhances the chemical proteomics toolkit by addressing blind spots and providing structural insights.