Transmembrane protease serine 11D (TMPRSS11D)

May play some biological function in the host defense mechanisms on the mucous membrane independently of or in cooperation with other compounds in airway bronchial or mucous secretions. Plays a role in the proteolytic processing of ACE2.

Proteolytically cleaves and activates the human coronavirus 229E (HCoV-229E) spike glycoprotein which facilitate virus-cell membrane fusions; spike proteins are synthesized and maintained in precursor intermediate folding states and proteolysis allows the refolding and energy discharge required to create steady virus-cell linkages and membrane coalescence. Preferentially cleaves the C-terminal side of arginine residues at the P1 position of certain peptides, cleaving Boc-Phe-Ser-Arg-4-methylcoumaryl-7-amide most efficiently and with an optimum pH of 8.