Tryptase is the major neutral protease present in mast cells and is secreted upon the coupled activation-degranulation response of this cell type. May play a role in innate immunity (By similarity). Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa, but with more restricted specificity than trypsin. Homotetramer. Released from the secretory granules upon mast cell activation. Mast cells. Glycosylated. Belongs to the peptidase S1 family. Tryptase subfamily.