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)

Although the steady-state level of the mouse mast cell protease (mMCP) 7 transcript is below detection in the serosal and mucosal mast cells of the BALB/cJ mouse, the IL-3-dependent, bone marrow-derived mast cells (mBMMC) of this strain and four other strains contain a high steady-state level of the mMCP-7 transcript. To further analyze the expression of this mast cell tryptase, a mMCP-7-specific IgG was obtained by immunizing a rabbit with a 19-residue synthetic peptide that corresponds to its unique amino acid sequence at residues 160 to 178 (anti-mMCP-7(160-178). In a SDS-PAGE/immunoblot analysis of lysates of BALB/cJ mBMMC, anti-mMCP-7(160-178) IgG recognized a diffuse 31- to 36-kDa protein, which shifted to a sharp 27-kDa protein after treatment with N-glycanase. As assessed immunohistochemically, mMCP-7 protein is present not only in the secretory granules of BALB/cJ mBMMC, but also in the ear mast cells of this strain. In contrast, the ear mast cells of the C57BL/6J mouse do not contain detectable levels of mMCP-7 protein, although the ear mast cells of both mouse strains contain mMCP-5 protein. Because mMCP-7 mRNA and protein also were not detected in mBMMC from the C57BL/6J mouse, the failure of the ear mast cells of this strain to express mMCP-7 is most likely a consequence of an intrinsic abnormality in the mast cell-committed progenitor cells themselves, or in the bone marrow microenvironment that induces its mast cell progenitor cells to express this tryptase.
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PMID:Lack of expression of the tryptase mouse mast cell protease 7 in mast cells of the C57BL/6J mouse. 807 72

Human lung mast cell tryptase is a trypsin-like serine proteinase that is stored in mast cell granules and released by activated mast cells. Here we report that mast cell tryptase is a potent activator of single-chain urinary-type plasminogen activator (scu-PA, or prourokinase), the zymogen form of urinary-type plasminogen activator (u-PA). Activation was complete within 75 min using an enzyme:substrate molar ratio of 1:50 and was accompanied by cleavage of scu-PA at Lys158-Ile159, generating active two-chain u-PA. The reaction was dependent on enzyme concentration and obeyed Michaelis-Menten kinetics. Kinetic constants calculated for scu-PA activation by mast cell tryptase are Km = 34 microM, Vmax = 3.6 pmol of u-PA/min, and kcat = 0.08 s-1. These data suggest that tryptase from tumor-associated mast cells may participate in the activation of scu-PA.
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PMID:Human mast cell tryptase activates single-chain urinary-type plasminogen activator (pro-urokinase). 814 24

Expression of a mast cell tryptase mRNA was detected in two human monocytic cell lines, the U-937 and the Mono Mac 6, and in normal human peripheral blood (PB) monocytes. In the U-937 cell line but not in normal PB monocytes, the tryptase expression was upregulated 3-50 fold following phorbol ester (PMA)-induced differentiation, but no such induction was seen after retinoic acid, interferon-gamma or vitamin D3 exposure. The tryptases expressed in PMA-induced and non-induced U-937 and in Mono Mac 6 were characterized by PCR amplification and nucleotide sequence analysis. The U-937 cell line was found to express a tryptase identical to one of the previously cloned mast-cell beta tryptases (Tryptase I), and the tryptase expressed in Mono Mac 6 was found to be nearly identical to the previously cloned alpha tryptase. By northern blot analysis with oligonucleotide probes specific for the alpha and beta tryptases both cell lines were found to express only one type of tryptase. Densitometric quantifications of tryptase mRNA levels, in the two cell lines, showed approximately 80 times higher mRNA levels in Mono Mac 6 compared to non-induced U-937. Immunohistochemical staining for tryptase showed a marked heterogeneity in the Mono Mac 6 cell line. Only one out of 10 cells were positive for the protein but the levels in these cells were very high, equivalent, or even higher than the levels seen in the human mast cell line HMC-1. This shows that the expression of a single tryptase, in this case the alpha tryptase, is sufficient for the production of a stable protein and probably also a stable proteolytically active tetramer. The family of human mast-cell tryptases has been considered to represent a class of proteases specifically expressed in mast cells and basophilic leucocytes. The expression of tryptases in two monocytic cell lines and in normal PB monocytes indicate that in humans, the lineage specificity of these serine proteases is less restricted than earlier expected. The cloning of a full length cDNA for the murine counterpart to the human mast cell tryptases, the MMCP-6, is presented. No expression of the MMCP-6 was detected in a panel of mouse monocyte or macrophage cell lines indicating a species difference in the lineage specificity of the 'mast cell tryptases'.
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PMID:Expression of a mast cell tryptase in the human monocytic cell lines U-937 and Mono Mac 6. 821 Sep 98

Proteins of mast cells purified from human foreskin were separated by 2-D polyacrylamide gel electrophoresis using either nonequilibrium pH gradient electrophoresis or isoelectric focusing in the first dimension and SDS-PAGE in the second dimension. Silver staining showed that a major feature of skin mast cell 2-D protein maps was a variety of relatively abundant proteins in the m.w. range of 29 to 37 kDa and covering a broad pH range from 5.0 to 8.5. Tryptase was identified on Western blots of 2-D-separated proteins by its binding of mAb and of 3H-diisopropylfluorophosphate. The precise distribution of tryptase varied among individuals but this protein generally occupied a continuum of molecular weights between 28 and 37 kDa and ranged in isoelectric point between 5.0 and 6.5. Tryptase was one of a number of mast cell proteins that bound the lectin concanavalin A as well as lectins specific for sialic acid, demonstrating that this enzyme is a sialylated glycoprotein. The diffuse m.w. distribution of skin mast cell tryptase (31 to 36 kDa) observed after SDS-PAGE was reduced to a single band of 30 kDa after treatment with protein-N-glycosidase F to remove asparagine-linked oligosaccharides. This finding suggests that intrinsic m.w. heterogeneity of tryptase in skin mast cells is largely a result of the addition of variable amounts of oligosaccharide to the tryptase polypeptide.
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PMID:Analysis of human skin mast cell proteins by two-dimensional gel electrophoresis. Identification of tryptase as a sialylated glycoprotein. 836 Apr 86

The expression of a tryptic serine protease was detected in the cell line KU812 by Northern blot analysis with an oligonucleotide probe directed against a conserved region present in all of the five presently cloned human mast cell tryptases. PCR primers designed for the amplification of a nearly full-length copy of tryptase mRNAs were used to study the identity of the KU812 tryptase. Ten clones were characterized and all were found to be identical to one of the tryptases previously cloned from a human skin cDNA library. This tryptase has been thought to originate from mast cells of the skin. Two possible explanations may account for the observed identity between the presumed mast cell tryptase and the KU812 tryptase. Firstly, it is possible that the KU812 tryptase is a basophil-specific tryptase which has previously been cloned from a human skin cDNA library containing low levels of cDNA copies derived from basophils in the starting material. Secondly, the KU812 cell line, and possibly normal basophils, express a tryptase which is identical to one of the tryptases expressed in normal skin mast cells. We cannot at present rule out any of the two possibilities, but we favour the second explanation as being the most likely.
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PMID:Characterization of a tryptase mRNA expressed in the human basophil cell line KU812. 843 31

We present the first direct biochemical evidence for the turnover of intact type VI collagen microfibrils. Matrix-degrading enzymes of the serine proteinase class, including rat mast cell chymases I and II, human mast cell tryptase, neutrophil elastase, cathepsin G and trypsin, were able to catabolize intact type VI collagen microfibrils isolated from foetal bovine skin and metabolically labelled intact type VI collagen immunoprecipitated from fibroblast culture medium. By contrast, intact type VI collagen was not degraded by the human matrix metalloproteinases, MMP-1, MMP-2, MMP-3 and MMP-9. These data have important implications for the stability of type VI collagen in connective tissues and highlight the potential role of serine proteinases both in normal type VI collagen turnover and in inflammatory conditions characterized by matrix degradation.
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PMID:Catabolism of intact type VI collagen microfibrils: susceptibility to degradation by serine proteinases. 846

We described a case of anaphylaxis diagnosed by the evaluation of plasma mast cell tryptase and a case of anaphylactoid reaction. In a patient undergoing pulmonary lobectomy, anaphylaxis, showing the elevation of plasma tryptase, was provoked by physiological glue for hemostasis during the operation. During the operation, cardiovascular collapse occurred suddenly, at which time the cause was not diagnosed. After completion of the operation and removal of drapes, diffuse urticaria with wide erythema on the torso and the upper extremity was noticed. Suspecting allergic adverse reaction, plasma tryptase was measured 2h and 5h after the start of the episode, showing 34.6 ng.ml-1 at 2h and 15.3 at 5h. Because these elevations of plasma tryptase indicated degranulation of mast cells, evaluation of the causative drugs was performed 7 weeks after the episode. Physiological glue was confirmed to be causative drug. In another patient for total hysterectomy and bilateral oophorectomy, adverse reaction occurred after completion of the operation and extubation. Increase in plasma histamine concentration to 4.94 ng.ml-1 that could induce systemic reaction was noticed; however, concentrations of plasma tryptase 25 min, 3h and 7h after the episode were not elevated. This finding indicated that the adverse reaction was not based on degranulation of mast cell, and was anaphylactoid reaction provoked by nonspecific histamine-release. In conclusion, measurement of plasma tryptase is a useful method for differential diagnosis of anaphylaxis and anaphylactoid reaction.
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PMID:[Usefulness of measurement of mast cell tryptase for differential diagnosis of anaphylaxis and anaphylactoid reaction]. 852 64

LAMA-84, a human leucocytic cell line, which upon establishment was described as having megakaryocytic, erythroid and granulocytic characteristics, was analysed for expression of various differentiation markers. In addition to some of the previously described phenotypic characteristics, this cell line was found to express mRNA for several proteins characteristic for basophilic leucocytes and mast cells. The authors show that LAMA-84 cells express mRNA for the mast cell tryptase, the proteoglycan core protein, carboxypeptidase A and the alpha and beta chains of the high affinity IgE receptor (Fc epsilon RI). The authors examined the potential of LAMA-84 to differentiate in serum-free medium or after DMSO or PMA treatment. Depending on the inducing factor, surface expression of the Fc epsilon RI alpha-chain was increased from 20% to 35-50% of the cells and mRNA levels for tryptase were increased in serum-free medium and after DMSO treatment. LAMA-84 was found to express CD13, CDw17, CD29, CD33, CD40, CD45 and CD117. Furthermore, mRNA for the eosinophil/basophil markers Charcot-Leyden crystal (CLC) protein and the major basic protein (MBP), as well as the erythrocyte differentiation marker alpha-globin, was detected. However, the authors observed only trace amounts of mRNA for another erythroid differentiation marker (glycophorin), trace amounts of the megakaryocytic marker GPIIIa, and no detectable level of GPIb alpha. By comparing the expression pattern of a panel of differentiation markers in LAMA-84, and a second human cell line (KU812) expressing a basophil phenotype, it is evident that these cell lines, which presently are the only two cell lines identified with basophilic characteristics, share a large number of phenotypic characteristics.
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PMID:Characterization of a human basophil-like cell line (LAMA-84). 869 92

We tested the hypothesis of anaphylaxis as a pathogenic factor in acute myocardial infarction. Mast cells were counted in the myocardium, coronary arteries and airways. Total serum IgE, mast cell tryptase, complements C3, C4, and factor B, were measured in 29 cases of sudden death from coronary artery thrombosis and in 27 controls. We found increased numbers of mast cells in the coronary arteries following coronary death: 46 +/- 21 (SD) compared with 22 +/- 10 (SD) in the control group (P < 0.002). In the myocardium and airways there were no differences between the groups. The concentrations of tryptase and IgE in serum did not differ between the groups although 20% of the coronary deaths had elevated values (> 200 kU/l) compared with 8% in the control group. Of the complement factors, C3 was higher in the coronary deaths (P < 0.05) than in the controls. The results give no evidence of anaphylactic reaction in the pathogenesis of acute myocardial infarction.
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PMID:Immunoglobulin E, mast cell-specific tryptase and the complement system in sudden death from coronary artery thrombosis. 870 40

Sera from 29 patients who had reacted to a platelet (27) or packed red cell (2) transfusion and from 5 patients who had received platelets without reacting were collected over a 13-month period. The sera were assayed for total IgE, and IgE specific for ethylene oxide, phthalic anhydride, hexamethylene diisocyanate, methylene diphenyl diisocyanate, toluene diisocyanate, and mast cell tryptase. Three patients with reactions had elevated total IgE levels, and specific IgE was positive for hexamethylene diisocyanate in 2 of 28 (7.1%), methylene diphenyl diisocyanate in 1 of 29 (3.4%), and toluene diisocyanate in 14 of 27 (51.9%). No positives were found in patients without reactions and no patients had an elevated tryptase level. It is unlikely that anti-plasticizer hypersensitivity was responsible for the transfusion reactions, but the prevalence and significance of such antibodies in both the hospital population and the general population would merit further investigation.
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PMID:Anti-plasticizer specific IgE is present in the serum of transfused patients. 871 85


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