Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interaction of human plasma alpha-1-antichymotrypsin with serine proteinases from different tissues has been investigated. The protein was found to form stable complexes with pancreatic chymotrypsin, leukocyte cathepsin G, and mast cell chymotrypsin. No inhibition of pancreatic trypsin or leukocyte elastase could be demonstrated. With mixtures containing both alpha-1-antichymotrypsin and alpha-1-proteinase inhibitor, it was found that the former preferentially inactivated leukocyte cathepsin G, while the latter showed a strong preference for pancreatic chymotrypsin. However, leukocyte elastase was specifically inactivated by alpha-1-proteinase inhibitor even in 1:1 mixtures with chymotrypsin. All of these results taken together suggest that one of the primary functions of alpha-1-antichymotrypsin is to inactivate leukocyte cathepsin G, while alpha-1-proteinase inhibitor controls the activity of other serine proteinases, particularly leukocyte elastase.
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PMID:Human alpha-1-antichymotrypsin: interaction with chymotrypsin-like proteinases. 72 23

A method is presented whereby light microscopic phenotyping of human basophils and lung mast cells was obtained by simultaneous labeling of surface antigens with specific mouse monoclonal antibodies and an anti-mouse IgG immunogold probe and histochemical staining with alcian blue, a highly specific stain for these cells' granules. The double labeling technique offers a useful immunohistochemical method for the phenotyping of basophils and mast cells in impure cell preparations. The procedure is relatively simple and requires small cell samples while providing accurate information on functional and differentiation markers. Preliminary results of human lung mast cell and peripheral blood basophil phenotyping discloses class I histocompatibility antigens on both cell types and class II antigen HLA DR on 10-20% of mast cells alone. Lung mast cells also unexpectedly exhibit the leukocyte marker HLE-1.
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PMID:Immunogold probe for the light-microscopic phenotyping of human mast cells and basophils. 243 54

The time-dependent inactivation of several serine proteases including human leukocyte elastase, cathepsin G, rat mast cell proteases I and II, and human skin chymase by a number of 3-alkoxy-4-chloroisocoumarins, 3-alkoxy-4-chloro-7-nitroisocoumarins, and 3-alkoxy-7-amino-4-chloroisocoumarins at pH 7.5 and the inactivation of several trypsin-like enzymes including human thrombin and factor XIIa by 7-amino-4-chloro-3-ethoxyisocoumarin and 4-chloro-3-ethoxyisocoumarin are reported. The 3-alkoxy substituent of the isocoumarin is likely interacting with the S1 subsite of the enzyme since the most reactive inhibitor for a particular enzyme had a 3-substituent complementary to the enzyme's primary substrate specificity site (S1). Inactivation of several enzymes including human leukocyte elastase by the 3-alkoxy-7-amino-4-chlorisocoumarins is irreversible, and less than 3% activity is regained upon extensive dialysis of the inactivated enzyme. Addition of hydroxylamine to enzymes inactivated by the 3-alkoxy-7-amino-4-chloroisocoumarins results in a slow (t1/2 greater than 6.7 h) and incomplete (32-57%) regain in enzymatic activity at pH 7.5. Inactivation by the 3-alkoxy-4-chloroisocoumarins and 3-alkoxy-4-chloro-7-nitroisocoumarins on the other hand is transient, and full enzyme activity is regained rapidly either upon standing, after dialysis, or upon the addition of buffered hydroxylamine. The rate of inactivation by the substituted isocoumarins is decreased when substrates or reversible inhibitors are present in the incubation mixture, which indicates active site involvement. The inactivation rates are dependent upon the pH of the reaction mixture, the isocoumarin ring system is opened concurrently with inactivation, and the reaction of 3-alkoxy-7-amino-4-chloroisocoumarins with porcine pancreatic elastase is shown to be stoichiometric. The results are consistent with a scheme where 3-alkoxy-7-amino-4-chloroisocoumarins react with the active site serine of a serine protease to give an acyl enzyme in which a reactive quinone imine methide can be released. Irreversible inactivation could then occur upon alkylation of an active site nucleophile (probably histidine-57) by the acyl quinone imine methide. The finding that hydroxylamine slowly catalyzes partial reactivation indicates that several inactivated enzyme species may exist. The 3-alkoxy-substituted 4-chloroisocoumarins and 4-chloro-7-nitroisocoumarins are simple acylating agents and do not give stable inactivated enzyme structures.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Reaction of serine proteases with substituted 3-alkoxy-4-chloroisocoumarins and 3-alkoxy-7-amino-4-chloroisocoumarins: new reactive mechanism-based inhibitors. 391 97

The primary subsite specificities of human leukocyte elastase, cathepsin G, porcine pancreatic elastase, rat mast cell proteases I and II, bovine chymotrypsin A alpha, and the protease from strain V-8 of Staphylococcus aureus have been mapped with a series of tripeptide thiobenzyl ester substrates of the general formula Boc-Ala-Ala-AA-SBzl, where AA represents one of 13 amino acids. In addition, the effects of a P2 Pro and P4 methoxysuccinyl and succinyl groups were investigated. In an attempt to introduce specificity and/or reactivity into the substrate Boc-Ala-Ala-Leu-SBzl(X), the 4-chloro-, 4-nitro-, and 4-methoxythiobenzyl ester derivatives were studied. Enzymatic hydrolyses of the substrates were measured in the presence of 4,4'-dithiobis(pyridine) or 5,5'-dithiobis(2-nitrobenzoic acid), which provided a highly sensitive assay method for free thiol. The thio esters were excellent substrates for the enzymes tested, and in many cases, the best substrates reported here have kcat/KM values higher than those reported previously. The best substrate for human leukocyte elastase was Boc-Ala-Pro-Nva-SBzl(Cl), which has a kcat/KM of 130 X 10(6) M-1 s-1. A very reactive rat mast cell protease substrate, Boc-Ala-Ala-Leu-SBzl(NO2), was also found. The S. aureus V-8 protease was the most specific enzyme tested since it hydrolyzed only Boc-Ala-Ala-Glu-SBzl. Substituents on the thiobenzyl ester moiety of Boc-Ala-Ala-Leu-SBzl resulted in decreased KM values with human leukocyte elastase and rat mast cell protease I when compared to the unsubstituted derivative.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Active site mapping of the serine proteases human leukocyte elastase, cathepsin G, porcine pancreatic elastase, rat mast cell proteases I and II. Bovine chymotrypsin A alpha, and Staphylococcus aureus protease V-8 using tripeptide thiobenzyl ester substrates. 638 May 80

The hematopoietic neutral serine proteases leukocyte elastase and cathepsin G are synthesized as inactive precursors, but become activated by removal of an amino-terminal dipeptide and are stored in granules. Moreover, the pro forms of elastase and cathepsin G show carboxyl-terminal prodomains of 20 and 11 amino acids, respectively, which are not present in the mature enzymes. To investigate mechanisms of processing, activation, and granular targeting, we have utilized transgenic expression of myeloid serine proteases in the rat basophilic/mast cell line RBL-1 (Gullberg, U., Lindmark, A., Nilsson, E., Persson, A.-M., and Olsson, I. (1994) J. Biol. Chem. 269, 25219-25225). Leukocyte elastase was stably expressed in RBL-1 cells, and the translation products were characterized by biosynthetic labeling followed by immunoprecipitation, SDS-polyacrylamide gel electrophoresis, and fluorography. Processing of a main pro form of 34 kDa into mature 31- and 29-kDa forms was demonstrated. Translocation of mature forms to granule-containing fractions was shown by subcellular fractionation experiments. The processed forms were enzymatically active, judging by the occurrence of amino-terminal processing demonstrated by radiosequence analysis, the acquisition of affinity for the protease inhibitor aprotinin, and the appearance of elastase activity in transfected RBL cells. To investigate the function of the carboxyl-terminal prodomains, deletion mutants of leukocyte elastase and cathepsin G lacking the carboxyl-terminal extension were constructed and transfected into RBL cells. Our results show that as full-length proteins, the deletion mutants were converted to active enzymes and transferred to granules with kinetics similar to that of wild-type enzymes. We conclude that human leukocyte elastase and cathepsin G are converted into enzymatically active forms when expressed in RBL cells and targeted for storage in granules; the carboxyl-terminal prodomains are necessary neither for enzymatic activation nor for targeting to granules in RBL cells.
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PMID:Carboxyl-terminal prodomain-deleted human leukocyte elastase and cathepsin G are efficiently targeted to granules and enzymatically activated in the rat basophilic/mast cell line RBL. 753 7

Monolayer cultures of human epithelial and endothelial cells were used to study the association of latent transforming growth factor-beta 1 (TGF-beta 1) to extracellular matrices and its release and activation during matrix degradation. Human umbilical vein endothelial cells and embryonic lung fibroblasts produced relatively high levels of TGF-beta 1, its propeptide (beta 1-latency-associated protein), and latent TGF-beta-binding protein and incorporated latent TGF-beta 1 into their matrices as shown by immunoblotting. Amnion epithelial cells produced lower levels of these proteins. Confluent cultures of epithelial cells were exposed to matrix-degrading proteases and glycosidases. Mast cell chymase, leukocyte elastase, and plasmin efficiently released matrix-bound latent TGF-beta 1 complexes, while chondroitinase ABC and heparitinases were ineffective. The ability of the proteases to activate recombinant latent TGF-beta 1 was tested using growth inhibition assays and a novel sodium deoxycholate-polyacrylamide gel electrophoresis followed by immunoblotting. Sodium deoxycholate solubilized M(r) 25,000 TGF-beta 1 but did not dissociate high M(r) latent TGF-beta 1 complexes, allowing separation of these forms by polyacrylamide gel electrophoresis. Mast cell chymase and leukocyte elastase did not activate latent TGF-beta 1, suggesting that its release from matrix and activation are controlled by different mechanisms. The release of TGF-beta from the matrix by leukocyte and mast cell enzymes may contribute to the accumulation of connective tissue in inflammation.
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PMID:Human mast cell chymase and leukocyte elastase release latent transforming growth factor-beta 1 from the extracellular matrix of cultured human epithelial and endothelial cells. 787 40

The azurophil granules of neutrophil granulocytes contain neutral proteases such as leukocyte elastase and cathepsin G. These are synthesized as inactive precursors, but following proteolytic processing, they are stored in granules as active enzymes. We describe the establishment of a transgenic cellular model for expression of the human myeloid serine protease cathepsin G. The cDNA for preprocathepsin G was stably expressed in the rat basophilic/mast cell line RBL-1 and the translation product was characterized by use of biosynthetic labeling followed by immunoprecipitation, SDS-polyacrylamide gel electrophoresis, and fluorography. Conversion into complex form of an asparagine-linked carbohydrate unit of approximately 3.5 kDa was shown, as judged by the products obtained upon treatment with endoglycosidase H and N-glycanase. Proteolytic processing of 32.5-kDa procathepsin G into a 31-kDa form, within 1-2 h after synthesis, was demonstrated by pulse-chase experiments. Further processing into a 30-kDa form also occurred to a minor extent. The processed forms were enzymatically active, as judged by affinity for the serine protease inhibitors diisopropylfluorophosphate and aprotinin. Translocation of processed forms of cathepsin G to high density fractions, indicating targeting of the protease to granules, was demonstrated by subcellular fractionation. The weak base NH4Cl was shown to delay the processing and enzymatic activation of cathepsin G, whereas the monovalent ionophore monensin completely inhibited both events. Our data demonstrate that human cathepsin G transfected to rat RBL-1 cells, is proteolytically processed into enzymatically active forms and that subcellular transfer to granular organelles occurs. As the processing of transgenic human cathepsin G corresponds to that of endogenous protease of myeloid cells, the model should provide new unique possibilities to further characterize the activation and granular targeting of myeloid serine proteases.
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PMID:Processing of human cathepsin G after transfection to the rat basophilic/mast cell tumor line RBL. 792 11

There is evidence that beta-amyloid (A beta) peptide infusion in vivo produces a degranulation of vascular mast cells. It would be useful to investigate the interaction between A beta and mast cells in a simple in vitro model system in order to determine the cellular mechanism by which exposure to A beta peptides results in mast cell degranulation. In the present study, the effect of A beta(1-42) upon the release of granular hexosaminidase and serotonin has been investigated using the cognate rat mast cell line, RBL-2H3. Sensitization of these cells for 1 h with anti-DNP IgE (monoclonal anti-dinitrophenyl) results in a large release of hexosaminidase and serotonin due to degranulation when the cells are exposed to DNP-HSA (albumin, human dinitrophenyl). Pretreatment overnight with A beta(1-42) (10 and 30 microM) did not affect either the basal or antigen-stimulated release of hexosaminidase or serotonin. A similar lack of effect of A beta(25-35) and the lipid peroxidation product HNE upon antigen-stimulated release of hexosaminidase or serotonin was also found. It is concluded that RBL-2H3 cells are not a useful model for mechanistic studies into the effects of beta-amyloid peptides upon vascular mast cells.
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PMID:Investigation into the effects of amyloid (1-42) beta-peptide upon basal and antigen-stimulated hexosaminidase and serotonin release from rat RBL-2H3 basophilic leukemia cells. 1129 5