Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Combinatorial chemistry approach was applied to design chromogenic substrates of human beta-tryptase. The most active substrate, Ala-Ala-Pro-Ile-Arg-Asn-Lys-ANB-NH(2), was selected from among over 9 million heptapeptides. The amide of 5-amino-2-nitrobenzoic acid (ANB-NH(2)) attached at the C-terminus served as a chromophore. In order to determine the optimal length of the tryptase substrate, a series of N-terminally truncated fragments of this substrate was synthesized. Pro-Ile-Arg-Asn-Lys-ANB-NH(2), with the determined value of the specificity constant (k(cat)/K(M)) above 9 x 10(6) M(-1) s(-1), appeared to be the most specific substrate of tryptase. This substrate was twice as active as the parent heptapeptide substrate. We postulate that the optimal size of the pentapeptide substrate for the interaction with human beta-tryptase is associated with the unique structure of this proteinase, comprising four almost identical monomer subunits arranged in a square flat ring with its substrate pockets faced inside, forming a tetramer with a central pore that can be penetrated by this short peptide.
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PMID:The influence of substrate peptide length on human beta-tryptase specificity. 1832 May 60

Although mast cells (MCs) often are abundant in the synovial tissues of patients with rheumatoid arthritis, the contribution of MCs to joint inflammation and cartilage loss remains poorly understood. MC-restricted tryptase/heparin complexes have proinflammatory activity, and significant amounts of human tryptase beta (hTryptase-beta) are present in rheumatoid arthritis synovial fluid. Mouse MC protease-6 (mMCP-6) is the ortholog of hTryptase-beta, and this serine protease is abundant in the synovium of arthritic mice. We now report that C57BL/6 (B6) mice lacking their tryptase/heparin complexes have attenuated arthritic responses, with mMCP-6 as the dominant tryptase responsible for augmenting neutrophil infiltration in the K/BxN mouse serum-transfer arthritis model. While inflammation in this experimental arthritis model was not dependent on protease-activated receptor-2, it was dependent on the chemokine receptor CXCR2. In support of the latter data, exposure of synovial fibroblasts to hTryptase-beta/heparin or mMCP-6/heparin complexes resulted in expression of the neutrophil chemotactic factors CXCL1/KC, CXCL5/LIX, and CXCL8/IL-8. Our proteomics, histochemistry, and immunohistochemistry data also revealed substantial loss of cartilage-derived aggrecan proteoglycans in the arthritic joints of wild-type B6 mice but not mMCP-6-null B6 mice. These observations demonstrate the functional contribution of MC-restricted tryptase/heparin complexes in the K/BxN mouse arthritis model and connect our mouse findings with rheumatoid arthritis pathophysiology.
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PMID:Mast cells contribute to autoimmune inflammatory arthritis via their tryptase/heparin complexes. 1910 98

Here we report the design, chemical and recombinant synthesis, and functional properties of a series of novel inhibitors of human mast cell tryptase beta, a protease of considerable interest as a therapeutic target for the treatment of allergic asthma and inflammatory disorders. These inhibitors are derived from a linear variant of the cyclic cystine knot miniprotein MCoTI-II, originally isolated from the seeds of Momordica cochinchinensis. A synthetic cyclic miniprotein that bears additional positive charge in the loop connecting the N- and C-termini inhibits all monomers of the tryptase beta tetramer with an overall equilibrium dissociation constant K(i) of 1 nM and thus is one of the most potent proteinaceous inhibitors of tryptase beta described to date. These cystine knot miniproteins may therefore become valuable scaffolds for the design of a new generation of tryptase inhibitors.
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PMID:Engineered cystine knot miniproteins as potent inhibitors of human mast cell tryptase beta. 1985 71

The aim of this study was to evaluate splenic eosinophil and mast cell accumulation using pagoda red stain in a series of anaphylaxis-related deaths that underwent medico-legal investigations. Our goal was to assess whether fatal reactions to insect stings, intramuscularly administered antibiotics and intravenously injected contrast media are responsible for specific patterns of eosinophil and mast cell accumulation. Two study groups were prospectively formed, an anaphylaxis-related death group and a control group. Autopsy, histology (haematoxylin-eosin stain, pagoda red stain and immunohistochemistry using anti-tryptase antibodies), toxicology and postmortem biochemistry (beta-tryptase, total IgE and specific IgE) were performed in all cases. All tested parameters (spleen weight, beta-tryptase and total IgE levels as well as eosinophil, mast cell and degranulated mast cell numbers in the spleen) were significantly higher in the anaphylaxis-related death group. No statistically significant differences were observed among the various groups (intramuscular antibiotic injection, intravenous contrast medium administration and stinging insects) in any combination, suggesting that mast cell and eosinophil accumulation in the spleen during anaphylaxis does not have any specific pattern related to the triggering allergen. Despite a lower sensitivity than immunohistochemical staining in discriminating eosinophil and mast cells, pagoda red stain allowed these cells to be identified and could therefore be proposed as a low-cost, first-line diagnostic procedure in those situations where immunohistochemistry is not systematically performed or cannot be carried out.
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PMID:Splenic hypereosinophilia in anaphylaxis-related death: different assessments depending on different types of allergens? 2478 64


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