Forms of tryptase in mast cells

Release of mature and pro-tryptase from mast cells have distinct mechanisms and effects. Monomeric pro-tryptases are secreted constitutively from mast cells and do not have known activity or function (above line), whereas mature tetrameric tryptases are stored in secretory granules until mast cell activation and degranulation occurs (below line). A number of functional activities relating to the serine proteinase activity of mature beta-tryptases have been identified.