Tryptase alpha/beta-1（TPSAB1) is a tryptase which is the key neutral protease present in mast cells and is discharged upon the coupled activation-degranulation response of this cell type. TPSAB1 is enzymatically active only as a heparin-stabilized tetramer， and is resistant to all known endogenous proteinase inhibitors. TPSAB1 is implicated as a mediator in the pathogenesis of asthma and other allergic and inflammatory disorders.
