Dr. Giulio Vistoli and his team at the Department of Pharmaceutical Sciences, University of Milan, Italy, are exploring the therapeutic potential of targeting SARS-CoV-2 non-structural protein 13 (NSP13) helicase. This enzyme plays a crucial role in viral replication and is highly conserved among coronaviruses, making it a promising target for broad-spectrum antiviral drugs.
To address the limited number of known NSP13 inhibitors, the team utilized the services of EU-OPENSCREEN through ISIDORe to conduct large-scale screening campaigns. These screenings aimed to expand the portfolio of NSP13 inhibitors and better characterize the enzyme’s druggable binding sites.
The research involved using a FRET assay to detect NSP13 helicase activity. The assay measured the fluorescence signal changes when the helicase was active or inhibited. Positive and negative controls were employed, with suramin as the positive control and DMSO as the negative control. Computational approaches, including virtual screening and AI-based predictive models, were also used to support the identification of new inhibitors.
The initial screening identified multiple hits, which were then retested to generate a confirmed hit list. The confirmed hits underwent dose-response testing to calculate IC50 values, and their interactions with the protein were analyzed.
The study identified 2-5 compounds with promising inhibitory activities against NSP13 helicase. These findings contribute to the development of broad-spectrum antiviral drugs targeting SARS-CoV-2 and potentially other coronaviruses.