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Method for Identifying Small Molecule Inhibitors of the Protein-protein Interaction Between HCN1 and TRIP8b
Published on: November 11, 2016
Fragment mapping-guided virtual screening identifies a small-molecule modulator of NPM1 oligomerization
Shin-Ichiro Ozawa1, Taiyo Kikuchi2, Mitsuru Okuwaki2
1Laboratory of Physical Chemistry for Drug Design, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
Computational Biology and Chemistry
|August 1, 2026
Summary
Researchers identified a small molecule, STK947495, that disrupts the oligomeric assembly of Nucleophosmin 1 (NPM1), a protein implicated in acute myeloid leukemia. This study shows that targeting protein-protein interactions is feasible for drug discovery.
Area of Science:
- Biochemistry
- Molecular Biology
- Drug Discovery
Background:
- Nucleophosmin 1 (NPM1) is a key nucleolar protein essential for cellular functions.
- NPM1's oligomeric assembly is crucial for its function and implicated in acute myeloid leukemia.
- Targeting protein-protein interaction interfaces, like the NPM1 oligomerization surface, is challenging due to their structural characteristics.
Purpose of the Study:
- To identify small molecules that can modulate the NPM1 oligomerization interface.
- To demonstrate the feasibility of targeting shallow, extended protein-protein interaction surfaces with small molecules.
- To validate the fragment mapping-guided virtual screening strategy for identifying protein-protein interaction inhibitors.
Main Methods:
- Knowledge-based in silico fragment mapping to identify key features of the NPM1 oligomerization surface.
- Structure-based virtual screening using 3D pharmacophore models derived from fragment mapping.
- Multistep workflow including pharmacophore filtering and molecular docking for compound prioritization.
- Experimental validation using split Renilla luciferase complementation assay and non-boiled SDS-PAGE.
Main Results:
- Fragment mapping revealed aromatic and hydrogen-bonding features suitable for pharmacophore modeling.
- Virtual screening and docking prioritized candidate compounds targeting the NPM1 oligomerization interface.
- Compound STK947495 was identified as a modulator, reducing NPM1-dependent luminescence.
- Biochemical analysis confirmed STK947495 disrupts NPM1 oligomeric assembly, increasing monomeric species.
Conclusions:
- The NPM1 oligomerization interface is a druggable target for small-molecule intervention.
- Fragment mapping-guided virtual screening is an effective strategy for discovering ligands against challenging protein-protein interaction interfaces.
- This approach offers a promising avenue for developing therapeutics for NPM1-related malignancies.
