Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly transmissible and has caused a pandemic named coronavirus disease 2019 (COVID-19), which has quickly spread worldwide. Although several therapeutic agents have been evaluated or approved for the treatment of COVID-19 patients, efficacious antiviral agents are still lacking. An attractive therapeutic target for SARS-CoV-2 is the main protease (Mpro), as this highly conserved enzyme plays a key role in viral polyprotein processing and genomic RNA replication. Therefore, the identification of efficacious antiviral agents against SARS-CoV-2 Mpro using a rapid, miniaturized and economical high-throughput screening (HTS) assay is of the highest importance at the present. Results In this study, we first combined the fluorescence polarization (FP) technique with biotin-avidin system (BAS) to develop a novel and step-by-step sandwich-like FP screening assay to quickly identify SARS-CoV-2 Mpro inhibitors from a natural product library. Using this screening assay, dieckol, a natural phlorotannin component extracted from a Chinese traditional medicine Ecklonia cava , was identified as a novel competitive inhibitor against SARS-CoV-2 Mpro in vitro with an IC 50 value of 4.5 ± 0.4 µM. Additionally, dieckol exhibited a high affinity with SARS-CoV-2 Mpro using surface plasmon resonance (SPR) analysis and could bind to the catalytic sites of Mpro through hydrogen-bond interactions in the predicted docking model. Conclusions This innovative sandwich-like FP screening assay enables the rapid discovery of antiviral agents targeting viral proteases, and dieckol will be an excellent lead compound for generating more potent and selective antiviral agents targeting SARS-CoV-2 Mpro.
【저자키워드】 SARS-CoV-2, High-throughput screening, Fluorescence polarization, Main protease inhibitor, 3CL protease inhibitor, Dieckol, 【초록키워드】 COVID-19, Treatment, coronavirus disease, coronavirus, pandemic, docking, protease, in vitro, SPR, Replication, MPro, SARS-CoV-2 Mpro, Spread, therapeutic agent, Proteases, antiviral agent, inhibitor, COVID-19 patients, Interaction, Analysis, genomic RNA, therapeutic target, acute respiratory syndrome, enzyme, high affinity, catalytic site, selective, polyprotein, Result, highest, predicted, identify, develop, caused, conserved, evaluated, approved, exhibited, in viral, BAS, Chinese traditional medicine, Ecklonia cava, 【제목키워드】 SARS-CoV-2 main protease, inhibitor, development,