Fragment-Based Discovery of a Qualified Hit Targeting the Latency-Associated Nuclear Antigen of the Oncogenic Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8

J Med Chem. 2019 Apr 25;62(8):3924-3939. doi: 10.1021/acs.jmedchem.8b01827. Epub 2019 Apr 12.

Abstract

The latency-associated nuclear antigen (LANA) is required for latent replication and persistence of Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8. It acts via replicating and tethering the virus episome to the host chromatin and exerts other functions. We conceived a new approach for the discovery of antiviral drugs to inhibit the interaction between LANA and the viral genome. We applied a biophysical screening cascade and identified the first LANA binders from small, structurally diverse compound libraries. Starting from a fragment-sized scaffold, we generated optimized hits via fragment growing using a dedicated fluorescence-polarization-based assay as the structure-activity-relationship driver. We improved compound potency to the double-digit micromolar range. Importantly, we qualified the resulting hit through orthogonal methods employing EMSA, STD-NMR, and MST methodologies. This optimized hit provides an ideal starting point for subsequent hit-to-lead campaigns providing evident target-binding, suitable ligand efficiencies, and favorable physicochemical properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Viral / metabolism*
  • Antiviral Agents / chemical synthesis
  • Antiviral Agents / chemistry*
  • Antiviral Agents / metabolism
  • Binding Sites
  • Herpesvirus 8, Human / isolation & purification
  • Herpesvirus 8, Human / metabolism*
  • Humans
  • Imidazoles / chemical synthesis
  • Imidazoles / chemistry
  • Imidazoles / metabolism
  • Molecular Docking Simulation
  • Nuclear Proteins / antagonists & inhibitors
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Sarcoma, Kaposi / pathology*
  • Sarcoma, Kaposi / virology
  • Structure-Activity Relationship

Substances

  • Antigens, Viral
  • Antiviral Agents
  • Imidazoles
  • Nuclear Proteins
  • latency-associated nuclear antigen
  • imidazole