Antibody Research

Infectivity of SARS-CoV-2 is regulated by three sites on the spike protein: a receptor binding motif (RBM), a subunit (S)1/S2 cleavage site acted upon by the host protease furin, and an S2’ cleavage site acted upon by host protease TMPRSS2. The RBM of the spike protein binds to angiotensin converting enzyme 2 (ACE2) that is highly expressed in cells of the lower respiratory tract. Cleavage of the S1/S2 site by furin liberates a RRAR sequence that is C-terminal in the S1 domain that subsequently binds to neuropilin-1 receptors expressed in respiratory and olfactory epithelial cells. Additionally, cleavage at the S1/S2 site enables a structural change that allows further proteolytic processing by TMPRSS2 that is essential for membrane fusion.

Infectivity of SARS-CoV-2 is regulated by three sites on the spike protein: a receptor binding motif (RBM), a subunit (S)1/S2 cleavage site acted upon by the host protease furin, and an S2’ cleavage site acted upon by host protease TMPRSS2. The RBM of the spike protein binds to angiotensin converting enzyme 2 (ACE2) that is highly expressed in cells of the lower respiratory tract. Cleavage of the S1/S2 site by furin liberates a RRAR sequence that is C-terminal in the S1 domain that subsequently binds to neuropilin-1 receptors expressed in respiratory and olfactory epithelial cells. Additionally, cleavage at the S1/S2 site enables a structural change that allows further proteolytic processing by TMPRSS2 that is essential for membrane fusion.