Virus Protease

Viral proteases are enzymes encoded by the genetic material (DNA or RNA) of viral pathogens. Viral proteases catalyze the cleavage of specific peptide bonds in viral polyprotein precursors or in cellular proteins. Viral proteases may use different catalytic mechanisms involving either serine, cysteine or aspartic acid residues to attack the scissile peptide bond. Selective recognition of these sequence patterns by a complementary substrate binding site of the enzyme ensures a high degree of specific recognition and cleavage.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the cause of the respiratory illness coronavirus disease 2019 (COVID-19). Initial spike protein priming by transmembrane protease, serine 2 (TMPRSS2) is essential for entry of SARS-CoV-2. After a SARS-CoV-2 virion attaches to a target cell, the cell's protease TMPRSS2 cuts open the spike protein of the virus, exposing a fusion peptide.