Biophysical Screens Identify Fragments That Bind to the Viral DNA-Binding Proteins EBNA1 and LANA

• Published in: Molecules (Basel, Switzerland) Switzerland), 2020-04, Vol.25 (7), p.1760
• Main Authors: Messick, Troy E, Tolvinski, Lois, Zartler, Edward R, Moberg, Anna, Frostell, Åsa, Smith, Garry R, Reitz, Allen B, Lieberman, Paul M
• Format: Article
• Language: English
• Subjects: Antigens; Antigens, Viral - chemistry; Antigens, Viral - metabolism; BASIC BIOLOGICAL SCIENCES; Binding; Crystal structure; Crystallography; Deoxyribonucleic acid; Disease; DNA; DNA, Viral - chemistry; DNA, Viral - metabolism; DNA-binding protein; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - metabolism; Drug Discovery - methods; Epstein-Barr virus; Epstein-Barr Virus Nuclear Antigens - chemistry; Epstein-Barr Virus Nuclear Antigens - metabolism; Epstein–Barr nuclear antigen 1; fragment-based lead discovery; Gammapapillomavirus; Gene expression; Genomes; Herpesvirus 4, Human; Herpesvirus 8, Human - metabolism; Humans; Inhibitors; Kaposis sarcoma; Kaposi’s sarcoma associated herpesvirus (KSHV); Latency; Latency-associated nuclear antigen; Ligands; Lymphoma; Magnetic Resonance Spectroscopy; Models, Molecular; NMR; NMR spectroscopy; Nuclear magnetic resonance; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Proteins; protein–DNA interaction; Sarcoma; saturation transfer difference-nuclear magnetic resonance; Small Molecule Libraries; Spectrum analysis; Structure-Activity Relationship; Surface plasmon resonance; Viruses
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules25071760

The human gamma-herpesviruses Epstein-Barr virus (EBV) (HHV-4) and Kaposi's sarcoma-associated herpesvirus (KSHV) (HHV-8) are responsible for a number of diseases, including various types of cancer. Epstein-Barr nuclear antigen 1 (EBNA1) from EBV and latency-associated nuclear antigen (LANA) from KSHV are viral-encoded DNA-binding proteins that are essential for the replication and maintenance of their respective viral genomes during latent, oncogenic infection. As such, EBNA1 and LANA are attractive targets for the development of small-molecule inhibitors. To this end, we performed a biophysical screen of EBNA1 and LANA using a fragment library by saturation transfer difference (STD)-NMR spectroscopy and surface plasmon resonance (SPR). We identified and validated a number of unique fragment hits that bind to EBNA1 or LANA. We also determined the high-resolution crystal structure of one fragment bound to EBNA1. Results from this screening cascade provide new chemical starting points for the further development of potent inhibitors for this class of viral proteins.