Discovering Severe Acute Respiratory Syndrome Coronavirus 3CL Protease Inhibitors: Virtual Screening,Surface Plasmon Resonance,and Fluorescence Resonance Energy Transfer Assays

Abstract

An integrated system has been developed for discovering potent inhibitors of severe acute respiratory syndrome coronavirus 3C-like protease (SARS-CoV 3CL^pro) by virtual screening correlating with surface plasmon resonance (SPR) and fluorescence resonance energy transfer (FRET) technologies-based assays. The authors screened 81,287 small molecular compounds against SPECS database by virtual screening; 256 compounds were subsequently selected for biological evaluation. Through SPR technology-based assay, 52 from these 256 compounds were discovered to show binding to SARS-CoV 3CL^pro. The enzymatic inhibition activities of these 52 SARS-CoV 3CL^pro binders were further applied to FRET-based assay, and IC₅₀ values were determined. Based on this integrated assay platform, 8 new SARS-CoV 3CL^pro inhibitors were discovered. The fact that the obtained IC₅₀ values for the inhibitors are in good accordance with the discovered dissociation equilibrium constants (K_Ds) assayed by SPR implied the reliability of this platform. Our current work is hoped to supply a powerful approach in the discovery of potent SARS-CoV 3CL^pro inhibitors, and the determined inhibitors could be used as possible lead compounds for further research.

Keywords

SARS SARS-CoV 3CLpro inhibitor virtual screening SPR FRET

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