Tryptase (EC 3.4.21.59, 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.[1][2][3][4][5] This enzyme catalyses the following chemical reaction
- Preferential cleavage: Arg-, Lys-, but with more restricted specificity than trypsin
Clinical use
Serum levels are normally less than 11.5 ng/mL.[6] 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.
Physiology
Tryptase is involved with allergenic response and is suspected to act as a mitogen for fibroblast lines. Tryptase may use the morpheein model of allosteric regulation.[7]
Genes
Human genes that encode proteins with tryptase activity include:
References
- ↑ Tanaka T, McRae BJ, Cho K, Cook R, Fraki JE, Johnson DA, Powers JC (November 1983). "Mammalian tissue trypsin-like enzymes. Comparative reactivities of human skin tryptase, human lung tryptase, and bovine trypsin with peptide 4-nitroanilide and thioester substrates". J. Biol. Chem. 258 (22): 13552–7. PMID 6358206.
- ↑ Vanderslice P, Ballinger SM, Tam EK, Goldstein SM, Craik CS, Caughey GH (May 1990). "Human mast cell tryptase: multiple cDNAs and genes reveal a multigene serine protease family". Proc. Natl. Acad. Sci. U.S.A. 87 (10): 3811–5. doi:10.1073/pnas.87.10.3811. PMC 53993. PMID 2187193.
- ↑ Kido, H., Fukusen, N. and Katunuma, N. (1985). "Chymotrypsin- and trypsin-type serine proteases in rat mast cells: properties and functions". Arch. Biochem. Biophys 239: 436–443. PMID 3890754.
- ↑ 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. PMID 3543004.
- ↑ 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. Acta 957: 71–80. PMID 3140898.
- ↑ Mayo Clinic > Test ID: FFTRS91815, Tryptase. Retrieved October, 2012
- ↑ T. Selwood and E. K. Jaffe. (2011). "Dynamic dissociating homo-oligomers and the control of protein function.". Arch. Biochem. Biophys. 519 (2): 131–43. doi:10.1016/j.abb.2011.11.020. PMC 3298769. PMID 22182754.
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