Tryptase (EC22.214.171.124, mast cell tryptase, mast cell protease II, skin tryptase, lung tryptase, pituitary tryptase, mast cell neutral proteinase, mast cell neutral proteinase, mast cell serine proteinase II, mast cell proteinase II, mast cell serine proteinase tryptase, rat mast cell protease II, tryptase M) is the most abundant secretory granule-derived serine proteinase contained in mast cells and has been used as a marker for mast cell activation. This enzyme catalyses the following chemical reaction
Preferential cleavage: Arg-, Lys-, but with more restricted specificity than trypsin
Serum levels are normally less than 11.5 ng/mL. Elevated levels of serum tryptase occur in both anaphylactic and anaphylactoid reactions, but a negative test does not exclude anaphylaxis. Tryptase is less likely to be elevated in food allergy reactions as opposed to other causes of anaphylaxis.
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^Kido, H., Fukusen, N. and Katunuma, N. (1985). "Chymotrypsin- and trypsin-type serine proteases in rat mast cells: properties and functions". Arch. Biochem. Biophys239: 436–443. PMID3890754.
^Cromlish, J.A., Seidah, N.G., Marcinkiewitz, M., Hamelin, J., Johnson, D.A. and Chrétien, M. (1987). "Human pituitary tryptase: molecular forms, NH2-terminal sequence, immunocytochemical localization, and specificity with prohormone and fluorogenic substrates". J. Biol. Chem.262: 1363–1373. PMID3543004.
^Harvima, I.T., Schechter, N.M., Harvima, R.J. and Fräki, J.E. (1988). "Human skin tryptase: purification, partial characterization and comparison with human lung tryptase". Biochim. Biophys. Acta957: 71–80. PMID3140898.