PPARγ Corepression Involves Alternate Ligand Conformation and Inflation of H12 Ensembles

ACS Chem Biol. 2023 May 19;18(5):1115-1123. doi: 10.1021/acschembio.2c00917. Epub 2023 May 5.


Inverse agonists of peroxisome proliferator activated receptor γ (PPARγ) have emerged as safer alternatives to full agonists for their reduced side effects while still maintaining impressive insulin-sensitizing properties. To shed light on their molecular mechanism, we characterized the interaction of the PPARγ ligand binding domain with SR10221. X-ray crystallography revealed a novel binding mode of SR10221 in the presence of a transcriptionally repressing corepressor peptide, resulting in much greater destabilization of the activation helix, H12, than without corepressor peptide. Electron paramagnetic resonance provided in-solution complementary protein dynamic data, which revealed that for SR10221-bound PPARγ, H12 adopts a plethora of conformations in the presence of corepressor peptide. Together, this provides the first direct evidence for corepressor-driven ligand conformation for PPARγ and will allow the development of safer and more effective insulin sensitizers suitable for clinical use.

MeSH terms

  • Co-Repressor Proteins / metabolism
  • Drug Inverse Agonism
  • Insulins*
  • Ligands
  • PPAR gamma* / metabolism
  • Protein Conformation


  • Co-Repressor Proteins
  • Insulins
  • Ligands
  • PPAR gamma
  • SR10221