Table 2.
Proteolytic processing of the SARS-CoV spike protein important for cell-cell fusion and/or virus entry. The table summarizes the different proteases involved in the cleavage of SARS-CoV spike protein and their roles in activating cell-cell fusion and/or virus entry.
| Protease | Cleavage site | Cell-cell fusion | Virus Entry |
|---|---|---|---|
| Cathepsin L [72,79] | S1/S2 HTVSLLRSTSQKSIVAYTMSL | - | + |
| Elastase [74,85] | S2’ LPDPLKPTKRSFIEDLLFNKV | + | + |
| HAT (TMPRSS11d) [84] | S1/S2 HTVSLLRSTSQKSIVAYTMSL | + | - |
| Plasmin [82] |
S1/S2 HTVSLLRSTSQKSIVAYTMSL S2’ LPDPLKPTKRSFIEDLLFNKV |
n.d. | + |
| TMPRSS11a [82] |
S1/S2 HTVSLLRSTSQKSIVAYTMSL S2’ LPDPLKPTKRSFIEDLLFNKV |
n.d. | + |
| TMPRSS2 [81,83,84] | Multiple sites | + | + |
| Trypsin [7373,75] |
S1/S2 HTVSLLRSTSQKSIVAYTMSL S2’ LPDPLKPTKRSFIEDLLFNKV |
+ | + |