Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation
Mast cell tryptase, a tetrameric serine protease stored in mast cell granules in complex with heparin proteoglycan or chondroitin sulphate proteoglycan, is an important effector molecule in inflammatory reactions like allergies and asthma. In this study we have investigated the requirements for acti...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | Inglés sueco |
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SLU/Dept. of Molecular Biosciences
2007
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| Materias: |
| _version_ | 1855571814992838656 |
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| author | Lindahl, Susanne |
| author_browse | Lindahl, Susanne |
| author_facet | Lindahl, Susanne |
| author_sort | Lindahl, Susanne |
| collection | Epsilon Archive for Student Projects |
| description | Mast cell tryptase, a tetrameric serine protease stored in mast cell granules in complex with heparin proteoglycan or chondroitin sulphate proteoglycan, is an important effector molecule in inflammatory reactions like allergies and asthma. In this study we have investigated the requirements for activation of human βI-tryptase and βII-tryptase, the major tryptases of human mast cells. βI-tryptase and βII-tryptase differ in only one amino acid, no. 102, where βI-tryptase has an asparagine (Asn) residue which is also site for glycosylation while βII-tryptase has a lysine (Lys) residue and lacks glycosylation at that site. We found that both βI-tryptase and βII-tryptase were dependent on heparin for activation and that optimal activity for βI-tryptase occurred at acidic pH while activation of βII-tryptase was less pH-dependent. Both βI-tryptase and βII-tryptase had a strong affinity for heparin-Sepharose at acidic pH but this affinity decreased at neutral pH. The β-tryptases both showed a bell shaped dose response curve for heparin induced activity. These results, taken together with results from a parallel study indicate an important role for heparin in the activation of human β-tryptase. |
| format | L3 |
| id | RepoSLU11141 |
| institution | Swedish University of Agricultural Sciences |
| language | Inglés swe |
| publishDate | 2007 |
| publishDateSort | 2007 |
| publisher | SLU/Dept. of Molecular Biosciences |
| publisherStr | SLU/Dept. of Molecular Biosciences |
| record_format | eprints |
| spelling | RepoSLU111412017-09-28T06:44:35Z Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation Lindahl, Susanne mast cell tryptase heparin inflammation Mast cell tryptase, a tetrameric serine protease stored in mast cell granules in complex with heparin proteoglycan or chondroitin sulphate proteoglycan, is an important effector molecule in inflammatory reactions like allergies and asthma. In this study we have investigated the requirements for activation of human βI-tryptase and βII-tryptase, the major tryptases of human mast cells. βI-tryptase and βII-tryptase differ in only one amino acid, no. 102, where βI-tryptase has an asparagine (Asn) residue which is also site for glycosylation while βII-tryptase has a lysine (Lys) residue and lacks glycosylation at that site. We found that both βI-tryptase and βII-tryptase were dependent on heparin for activation and that optimal activity for βI-tryptase occurred at acidic pH while activation of βII-tryptase was less pH-dependent. Both βI-tryptase and βII-tryptase had a strong affinity for heparin-Sepharose at acidic pH but this affinity decreased at neutral pH. The β-tryptases both showed a bell shaped dose response curve for heparin induced activity. These results, taken together with results from a parallel study indicate an important role for heparin in the activation of human β-tryptase. Mastcellstryptas är ett trypsinliknande proteas som lagras i komplex med heparinproteoglykan eller kondroitinsulfatproteoglykan i mastcellens granula. Tryptas är en viktig inflammationsmediator vid bland annat allergiska reaktioner och astma. I denna studie har vi undersökt förutsättningarna för aktivering av humant �I-tryptas och �II-tryptas, vilka är de dominerande typerna av tryptas i humana mastceller. �I-tryptas och �II-tryptas skiljer sig åt strukturellt med endast en aminosyra, nummer 102, där �I-tryptas har asparagin (Asn) som tillika är en glykosyleringsplats och �II-tryptas har lysin (Lys). Detta betyder att �I-tryptas är glykosylerat medan �II-tryptas saknar glykosylering på den positionen. Vi har visat att både �I-tryptas och �II-tryptas är beroende av heparin för aktivering och att optimal aktivitetsnivå uppnåddes vid surt pH för �I-tryptas medan �II-tryptas inte är lika pH-beroende. Både �I-tryptas och �II-tryptas har stark affinitet för heparin-Sepharose vid surt pH, denna affinitet minskar vid neutralt pH. �I-tryptas och �II-tryptas visade båda en klockformad dos-responskurva för heparininducerad aktivering. Resultaten från denna studie visar, sammantaget med resultat från en parallell studie, att heparin har en betydande roll för aktivering av humant �-tryptas. SLU/Dept. of Molecular Biosciences 2007 L3 eng swe https://stud.epsilon.slu.se/11141/ |
| spellingShingle | mast cell tryptase heparin inflammation Lindahl, Susanne Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| title | Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| title_full | Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| title_fullStr | Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| title_full_unstemmed | Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| title_short | Mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| title_sort | mast cell tryptase, a potent inflammatory mediator, requires heparin for enzymatic activation |
| topic | mast cell tryptase heparin inflammation |