Orthosteric inhibition of MutSβ ATPase function: First disclosure of MSH3-bound small molecule inhibitors

Bioorg Med Chem Lett. 2025 Dec 1:128:130326. doi: 10.1016/j.bmcl.2025.130326. Epub 2025 Jul 3.

Abstract

Orthosteric inhibitors of the human heterodimeric DNA mismatch repair complex MutSβ were identified by high-throughput screening. Following extensive hit confirmation to remove false positives, two series were found to give consistent activity free of likely artefactual effects. Extensive hit profiling confirmed an ATP-competitive mode of action and resulted in our obtaining the first reported X-ray and cryo-EM structures of small molecule inhibitors of MutSβ occupying the ATP-binding site of MSH3.

Keywords: ATPase; DNA mismatch repair; High-throughput screening; Huntington's disease; MSH3; MutSβ; Screening cascade.

MeSH terms

  • Adenosine Triphosphatases* / antagonists & inhibitors
  • Adenosine Triphosphatases* / metabolism
  • Adenosine Triphosphate / metabolism
  • Binding Sites
  • Cryoelectron Microscopy
  • Crystallography, X-Ray
  • DNA-Binding Proteins* / antagonists & inhibitors
  • DNA-Binding Proteins* / chemistry
  • DNA-Binding Proteins* / metabolism
  • Enzyme Inhibitors* / chemical synthesis
  • Enzyme Inhibitors* / chemistry
  • Enzyme Inhibitors* / pharmacology
  • High-Throughput Screening Assays
  • Humans
  • Models, Molecular
  • Molecular Structure
  • MutS Homolog 3 Protein / antagonists & inhibitors
  • MutS Homolog 3 Protein / metabolism
  • Small Molecule Libraries* / chemical synthesis
  • Small Molecule Libraries* / chemistry
  • Small Molecule Libraries* / pharmacology
  • Steroids / chemistry
  • Structure-Activity Relationship

Substances

  • Adenosine Triphosphatases
  • Adenosine Triphosphate
  • DNA-Binding Proteins
  • Enzyme Inhibitors
  • MSH3 protein, human
  • MutS Homolog 3 Protein
  • Small Molecule Libraries
  • Steroids