The Role of TMPRSS2 and TMPRSS2- Inhibitors in Cell Entry Mechanism of COVID-19

Abstract

The enzymes trypsin, furine and other proprotein convertases, cathepsin, transmembrane proteases (TMPRSS) and elastases play a role in the cell entry of coronaviruses (Coronaviridae). The proteases TMPRSS2 and TMPRSS11a, which are abundant in the respiratory tract and expressed on cell surfaces, promote the entry of SARS-CoV-1 viruses. For the TMPRSS protease TMPRSS11d - also known as human airway trypsin-like protease (HAT) - a proteolytic activation of the S- protein of SARS-CoV-1 was demonstrated. TMPRSS2, in turn, complexes with the ACE2 receptor, which allows efficient penetration of the virus directly at the cell surface. TMPRSS2 and TMPRSS11D activate the S protein by cleaving it into the S1 and S2 subunits, thus allowing endosome-independent cell entry at the cell membrane. Virus-based therapies include monoclonal antibodies, antiviral peptides that dock to the S protein of viruses, viral nucleic acid synthesis inhibitors and inhibitors for docking to other viral structures and accessory proteins.