The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, Florida, United States
Abstract: Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has killed nearly 7 million people worldwide since its outbreak in late 2019. Even with the rapid development and production of vaccines and intensive research, there is still a huge need for specific anti-viral drugs that address the rapidly arising new variants. To address this concern, the National Institute of Allergy and Infectious Diseases (NIAID) established multiple Antiviral Drug Discovery (AViDD) Centers for pathogens of pandemic potential. As part of the Herbert Wertheim UF Scripps Institute we are the HTS Center for the Midwest AViDD and are charged with the responsibility to address multiple targets spanning many different viruses including Lassa, Machupo, Zika, and SARS-CoV-2. The focus of this study is the SARS-CoV2 non-structural protein 13 (nsP13) which is a viral helicase that is essential for viral replication. Following assay development and transfer from Dr. Chung’s lab at the University of Louisville, we successfully adapted an assay that detects SARS-CoV2 nsP13 helicase activity in 1,536 well-plates. This enabled us to screen approximately 650,000 compounds from the UF Scripps Drug Discover library. The primary screen identified 7,009 compounds as hits. The assay is robust with an average Z’ is 0.86 ± 0.05. Of hits from the primary screen, 1763 compounds were confirmed with inhibitory activity. Following in-silico analysis we identified 890 compounds for further testing in titration assays. This involved an additional orthogonal assay, resulting in 674 compounds with IC50s < 10 micromolar. We then confirmed activity as powders while also incorporating multiple counterscreen assays. We are now in the hits to leads transition for anti-helicase SARS CoV2 drugs.