Hase 2

VeroE6 cells were infected with SARS-CoV-2 (MOI = 0.1) at 37 °C and then treated by ChABC (sigma, Cat^# C2905, 1 U/mL), Hase I-III (Sigma, Cat^# H3917, 100 mU/mL) and Hase II (Sigma, Cat^# H6515, 100 mU/mL) at 14 hpi in the buffer according to the manufacture introduction. After 2 h incubation and washing of cells by PBS, DMEM with or without 4H30 (50 μg/mL) was added to cells for virus culture with the presence of ChABC and Hase. At 20 hpi, viral titers in cell supernatants were measured by RT-qPCR.

VeroE6, A549, and Calu-3 cells were treated by DMEM, 4H30 (12.5 μg/mL), BSA, CS, HS (5 μg/mL), 4H30 + BSA, 4H30 + CS, or 4H30 + HS at 37 °C for 30 min and then washed by PBS. SARS-CoV-2 (MOI = 0.2) was added to cells for attachment at 4 °C for 1 h. After washing the unbound virus, the attached virus was measured by RT-qPCR. For ChABC and Hase assay, A549 cells were treated by ChABC (Sigma, Cat^# C2905, 1 U/mL), Hase I-III (Sigma, Cat^# H3917, 100 mU/mL), and Hase II (Sigma, Cat^# H6515, 100 mU/mL) at 37 °C for 2 h in the buffer according to the manufacture introduction. After washing cells with PBS, DMEM or 4H30 (12.5 μg/mL) was added to cells for 30 min incubation and then cells were washed with PBS. SARS-CoV-2 (MOI = 0.2) was added to cells for attachment at 4 °C for 1 h. The unbound virus was washed by PBS. The attached virus was measured by RT-qPCR.