– Tryptases are Trypsin-like Serine Proteases. β-Tryptases are the main isoenzymes in mast cells. Βtryptases form active tetramers with heparin proteoglycan. In the tetramer, the unique arrangement of the active sites facing a narrow central pore, β-Tryptases are resistant to macromolecule protease inhibitors . When mast cells are activated, β-Tryptases are released and participate in provoking inflammatory conditions . β-Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic disorders.