Purification and Inhibition of SARS-CoV-2 Mpro

Mpro was expressed and purified as reported in [17 (link)]. The pGEX-6P-1 vector to encode the SARS-CoV-2 Mpro (NC_045512) was purchased from GenScript (clone ID_M16788F). For Mpro C-terminal His-tag removal, the Prescission (1 U for 100 µg of protein) cleavage reaction was performed at 4 °C for 4 h, and Prescission protease was then removed by a GSTrap FF column (GE-Healthcare, Chicago, IL, USA). The Mpro solution was further purified by FPLC size-exclusion chromatography on Superdex 75 10/300 GL column. Lopinavir, Ritonavir, Nelfinavir, Carmofur, GC376, and NMV inhibitors were bought from Selleck Chemicals GmbH, Planegg, Germany.