Discovery of Pentacyclic Triterpenoid PROTACs as a Class of Effective Hemagglutinin Protein Degraders

J Med Chem. 2022 May 26;65(10):7154-7169. doi: 10.1021/acs.jmedchem.1c02013. Epub 2022 May 17.

Abstract

Influenza hemagglutinin that drives viral entry into cells via the membrane fusion process is an up-and-coming antiviral drug target. Herein, we described for the first time the design, synthesis, and biological characteristics of a new class of pentacyclic triterpenoid-based proteolysis targeting chimeras (PROTACs) to enhance the degradation of hemagglutinin target. Among these PROTACs, V3 showed the best degradation effect on the hemagglutinin with a median degradation concentration of 1.44 μM in a ubiquitin and proteasome-dependent manner and broad-spectrum anti-influenza A virus activity but not affected the entry of influenza virus. Moreover, intravenous injection of V3 protected mice against influenza A virus-induced toxic effects. Further diazirine-containing photo-crosslinking mass spectrometric analysis of hemagglutinin complexes indicated crosslinking to Asn15, Thr31, and Asn27, a novel target of hemagglutinin. Taken together, our data revealed that oleanolic acid-based PROTACs could degrade hemagglutinin protein, providing a new direction toward the discovery of potential anti-influenza drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chimera / metabolism
  • Hemagglutinins
  • Humans
  • Influenza, Human* / drug therapy
  • Intercellular Signaling Peptides and Proteins
  • Mice
  • Proteins / metabolism
  • Proteolysis
  • Triterpenes* / chemistry

Substances

  • Hemagglutinins
  • Intercellular Signaling Peptides and Proteins
  • Proteins
  • Triterpenes
  • snake venom protein C activator