Discovery of Protease-Activated Receptor 4 (PAR4)-Tethered Ligand Antagonists Using Ultralarge Virtual Screening

  • ACS Pharmacol Transl Sci. 2024 Mar 21;7(4):1086-1100. doi: 10.1021/acsptsci.3c00378.
Shannon T Smith  1 ,  Jackson B Cassada  2 ,  Lukas Von Bredow  3  4 ,  Kevin Erreger  2 ,  Emma M Webb  2 ,  Trevor A Trombley  3 ,  Jacob J Kalbfleisch  1  3 ,  Brian J Bender  5 ,  Irene Zagol-Ikapitte  3 ,  Valerie M Kramlinger  2  3 ,  Jacob L Bouchard  3 ,  Sidnee G Mitchell  2 ,  Maik Tretbar  4 ,  Brian K Shoichet  5 ,  Craig W Lindsley  2  1  3 ,  Jens Meiler  2  1  4 ,  Heidi E Hamm  2
Affiliations
  • 1. Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States.
  • 2. Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States.
  • 3. Warren Center for Neuroscience Drug Discovery, Nashville, Tennessee 37067, United States.
  • 4. Institute for Drug Discovery, Leipzig University Medical School, Leipzig 04109, Germany.
  • 5. Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94158, United States.
PMID: 38633591 DOI: 10.1021/acsptsci.3c00378
Abstract

Here, we demonstrate a structure-based small molecule virtual screening and lead optimization pipeline using a homology model of a difficult-to-drug G-protein-coupled receptor (GPCR) target. Protease-activated Receptor 4 (PAR4) is activated by Thrombin cleavage, revealing a tethered ligand that activates the receptor, making PAR4 a challenging target. A virtual screen of a make-on-demand chemical library yielded a one-hit compound. From the single-hit compound, we developed a novel series of PAR4 antagonists. Subsequent lead optimization via simultaneous virtual library searches and structure-based rational design efforts led to potent antagonists of thrombin-induced activation. Interestingly, this series of antagonists was active against PAR4 activation by the native protease Thrombin cleavage but not the synthetic PAR4 Agonist peptide AYPGKF.

Products