Bioengineered amyloid peptide for rapid screening of inhibitors against main protease of SARS-CoV-2

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has evoked a worldwide pandemic. As the emergence of variants has hampered the neutralization capacity of currently available vaccines, developing effective antiviral therapeutics against SARS-CoV-2 and its variants becomes a significant challenge. The main protease (M^pro) of SARS-CoV-2 has received increased attention as an attractive pharmaceutical target because of its pivotal role in viral replication and proliferation. Here, we generated a de novo M^pro-inhibitor screening platform to evaluate the efficacies of M^pro inhibitors based on M^pro cleavage site-embedded amyloid peptide (MCAP)-coated gold nanoparticles (MCAP-AuNPs). We fabricated MCAPs comprising an amyloid-forming sequence and M^pro-cleavage sequence, mimicking in vivo viral replication process mediated by M^pro. By measuring the proteolytic activity of M^pro and the inhibitory efficacies of various drugs, we confirmed that the MCAP-AuNP-based platform was suitable for rapid screening potential of M^pro inhibitors. These results demonstrated that our MCAP-AuNP-based platform has great potential for discovering M^pro inhibitors and may accelerate the development of therapeutics against COVID-19.