Journal: Phytochemistry

Article Title: Natural biflavones are potent inhibitors against SARS-CoV-2 papain-like protease

doi: 10.1016/j.phytochem.2021.112984

Figure Lengend Snippet: Functions of SARS-CoV-2 PL pro and benefits by targeting PL pro . (A) PL pro proteolyzes viral polyprotein at the LXGG site to generate mature nsp1, nsp2 and nsp3. (B) PL pro removes ISG15 and ubiquitin modifiers from host proteins to evade innate antiviral immunity.

Article Snippet: Recombinant SARS-CoV-2 papain-like protease (Glu1564-Val1880, Cat. 40593-V07E) and recombinant human pro-ISG15 protein (Met1-Ser165, Cat. 12729-HNAE) were purchased from Sino-Biological Inc (Beijing, China).

Techniques:

Journal: bioRxiv

Article Title: Drug repurposing screening identified tropifexor as a SARS-CoV-2 papain-like protease inhibitor

doi: 10.1101/2021.12.02.471030

Figure Lengend Snippet: Characterization of SARS-CoV-2 PL pro inhibitors identified from the high-throughput screening. (A) Chemical structures of the positive control GRL0617 and the three hits EACC, KY-226, and tropifexor. (B) IC 50 curves of the hits in inhibiting SARS CoV-2 PL pro with the FRET peptide substrate 1. (C) IC 50 curves of the hits in inhibiting SARS CoV PL pro with the FRET peptide substrate 1. (D) IC 50 curves of the hits in inhibiting MERS-CoV PL pro with the FRET peptide substrate 1. (E) IC 50 curves of the hits in inhibiting SARS CoV-2 M pro with the FRET peptide substrate 2. (F) IC 50 curves of the hits in inhibiting SARS CoV-2 PL pro with the Ub-AMC substrate. (G) IC 50 curves of the hits in inhibiting SARS CoV-2 PL pro with the ISG15-AMC substrate. Please refer to the methods and materials section for assay conditions. Values represent the average ± standard deviation of three replicates.

Article Snippet: Using the previously optimized FRET assay condition, we performed a high-throughput screening of SARS-CoV-2 PL pro against the MedChemExpress bioactive compound library which consists of 9,791 compounds including FDA-approved drugs, clinical candidates, and natural products.

Techniques: High Throughput Screening Assay, Positive Control, Standard Deviation

Journal: bioRxiv

Article Title: Drug repurposing screening identified tropifexor as a SARS-CoV-2 papain-like protease inhibitor

doi: 10.1101/2021.12.02.471030

Figure Lengend Snippet: Thermal shift binding assay of SARS-CoV-2 PL pro protease against identified inhibitors. All inhibitors display dose-dependent melting temperature (T m ) shift. Values represent the average ± standard deviation of three replicates.

Article Snippet: Using the previously optimized FRET assay condition, we performed a high-throughput screening of SARS-CoV-2 PL pro against the MedChemExpress bioactive compound library which consists of 9,791 compounds including FDA-approved drugs, clinical candidates, and natural products.

Techniques: Binding Assay, Standard Deviation

Journal: bioRxiv

Article Title: Drug repurposing screening identified tropifexor as a SARS-CoV-2 papain-like protease inhibitor

doi: 10.1101/2021.12.02.471030

Figure Lengend Snippet: FlipGFP SARS CoV-2 PL pro assay to determine cellular protease inhibitory activity of identified inhibitors. (A) Representative images of FlipGFP-PL pro assay with increasing concentrations of GRL0617 (positive control), GC376 (negative control), EACC, KY-226, and tropifexor. GRL0617 showed does-dependent decrease of GFP signal with the increasing drug concentration, while almost no GFP signal change was observed with the increasing concentration of negative control compound GC376. (B) Dose-response curves of the GFP/mCherry ratio with increasing drug concentrations. mCherry signal alone was used to calculate transfection efficiency and compound cytotoxicity. All three hits displayed significant cytotoxicity at high drug concentrations. Values represent the average ± standard deviation of three replicates.

Article Snippet: Using the previously optimized FRET assay condition, we performed a high-throughput screening of SARS-CoV-2 PL pro against the MedChemExpress bioactive compound library which consists of 9,791 compounds including FDA-approved drugs, clinical candidates, and natural products.

Techniques: Activity Assay, Positive Control, Negative Control, Concentration Assay, Transfection, Standard Deviation

Journal: bioRxiv

Article Title: Drug repurposing screening identified tropifexor as a SARS-CoV-2 papain-like protease inhibitor

doi: 10.1101/2021.12.02.471030

Figure Lengend Snippet: Antiviral activity of SARS-CoV-2 PL pro inhibitors GRL0617 (A), EACC(B), KY-226 (C), and tropifexor (D) against SARS-CoV-2 in Calu-3 cells. The results were quantified by immunofluorescence assay. Values represent the average ± standard deviation of three replicates.

Article Snippet: Using the previously optimized FRET assay condition, we performed a high-throughput screening of SARS-CoV-2 PL pro against the MedChemExpress bioactive compound library which consists of 9,791 compounds including FDA-approved drugs, clinical candidates, and natural products.

Techniques: Activity Assay, Immunofluorescence, Standard Deviation

Journal: bioRxiv

Article Title: Drug repurposing screening identified tropifexor as a SARS-CoV-2 papain-like protease inhibitor

doi: 10.1101/2021.12.02.471030

Figure Lengend Snippet: Molecular docking of SARS-CoV-2 PL pro inhibitors GRL0617 (A), EACC(B), KY-226 (C), and tropifexor (D) in PL pro (PDB: 7JRN).

Article Snippet: Using the previously optimized FRET assay condition, we performed a high-throughput screening of SARS-CoV-2 PL pro against the MedChemExpress bioactive compound library which consists of 9,791 compounds including FDA-approved drugs, clinical candidates, and natural products.

Techniques: