Fig. 4: Probing the binding of SARS-CoV-2 MBP at the S2 subunit level.

a Western blot analysis of S2 subunit treated with TMPRSS2 under reducing conditions. The cleaved S2 subunit (S2’) was detected using an antibody against the His-tag. Lane 1: Ladder, Lane 2: S2 subunit, Lane 3: TMPRSS2, and Lane 4: S2 subunit treated with TMPRSS2. The uncropped scan is provided as Source Data file. Image representative from 3 independent replicates. b Representative FT curves depicting the binding of S2’ subunit to the DOPC/Chol bilayer. Raw data is plotted as a black line, and the binding states are identified using the STaSI algorithm (red line). c Plot of force-dependent lifetime obtained for S2’ subunit (blue dots, n = 9 from at least three independent replicates) and overlaid on the data obtained for the MBP (gray dots, from Fig. 3b). Source data for panels b,c are provided as a Source Data file.