Oral Presentation The 48th Lorne Conference on Protein Structure and Function 2023

Developing C-reactive protein modulators as new treatments for inflammation   (#11)

Karen S Cheung Tung Shing 1 2 , Tracy L Nero 1 2 , Johannes Zeller 3 4 , Guy Krippner 4 , Prerna Sharma 4 , Craig J Morton 1 2 , James D McFadyen 2 4 , Geoffrey Pietersz 2 4 , Karlheinz Peter 2 4 , Michael W Parker 1 2 5
  1. Department of Biochemistry and Pharmacology and ACRF Facility for Innovative Cancer Drug Discovery, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
  2. Baker Department of Cardiometabolic Health, The University of Melbourne, Parkville, VIC, Australia
  3. Department of Plastic and Hand Surgery, University of Freiburg Medical Centre, Medical Faculty of the University of Freiburg, Freiburg, Germany
  4. Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
  5. St. Vincent’s Institute of Medical Research, Melbourne, Victoria, Australia

C-reactive protein (CRP) is present in blood plasma as a homopentamer (pCRP), with its production regulated by cytokines such as interleukin-6. Upon tissue injury, bacterial stress or inflammation, the level of pCRP in blood increases a thousand fold. pCRP can bind to a wide variety of ligands, including bioactive lipids with phosphocholine, phosphoserine and phosphoethanolamine headgroups. These lipid headgroups are exposed on bacterial cell walls, fungi and yeast upon infection and on apoptotic cell membranes. Binding of pCRP to the lipid headgroups triggers the dissociation of the pentamer into an unfolded monomeric state (mCRP) 1, leading to inflammation involved in many pathologies such as atherosclerosis. We have designed a set of compounds mimicking the binding of phosphocholine to pCRP, thereby blocking lipid binding and preventing the dissociation of the pentamer. The direct interaction of the compounds with pCRP was verified using differential scanning fluorimetry, microscale thermophoresis and surface plasmon resonance. The binding mode of the compounds was determined using X-ray crystallography and electron microscopy. The best phosphocholine mimetic had micromolar affinity for pCRP and was subsequently tested in a variety of in vitro and in vivo models of inflammation. We applied this iterative discovery pipeline that includes a range of biophysical assays to identify pCRP ligands that serve as the basis for further drug development.

  1. 1 Braig, D. et al. Transitional changes in the CRP structure lead to the exposure of proinflammatory binding sites. Nat Commun 8, 14188, doi:10.1038/ncomms14188 (2017).