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)

When the murine T-lymphocyte clone L2 is stimulated with concanavalin A, it secretes at least two distinct factors that affect hemopoietic precursor cells, interleukin 3 (IL3) and granulocyte/macrophage colony-stimulating factor (GM-CSF). IL3 accounts for approximately 10% of the colony-stimulating activity in L2-cell-conditioned medium. The IL3 secreted by L2 cells is similar antigenically to the IL3 secreted by WEHI-3 cells. Like the IL3 from WEHI-3 cells, IL3 secreted by L2 cells does not bind to DEAE Sephacel and can be separated from the L2-cell GM-CSF, which does bind to DEAE. By assessment of the functional, morphologic, surface phenotypic, and cytochemical characteristics of bone marrow cells 6 days after stimulation with IL3 in liquid culture, four hemopoietic lineages were found, including macrophage, neutrophilic granulocyte, megakaryocyte, and basophil/mast cell. In addition, when bone marrow cells were stimulated with IL3 in semisolid medium, several types of colonies were found, including mixed colonies containing macrophage, megakaryocyte, and granulocyte lineages.
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PMID:Multiple hemopoietic lineages are found after stimulation of mouse bone marrow precursor cells with interleukin 3. 643 31

Tryptase, the predominant neutral protease in human mast cell secretory granules, was purified to homogeneity from dissociated and concentrated pulmonary mast cells by sequential chromatography on Dowex 1-X2, DEAE-Sephadex, and heparin-agarose. Purified tryptase gave a single stained protein band on polyacrylamide gels after electrophoresis at pH 4.3 in the presence of 4 M urea. The enzyme has an apparent molecular weight of 120,000 to 140,000 by gel filtration chromatography. Electrophoresis of purified tryptase under denaturing conditions revealed subunits with molecular weights of 37,000 and 35,000 in a molar ratio of 1:1, consistent with a tetrameric subunit structure for the holoenzyme of Mr = 144,000. Both subunits bind [3H]diisopropyl fluorophosphate as assessed by the correspondence of radioactivity with the two stained protein bands in a polyacrylamide gel after electrophoresis of purified tryptase under denaturing conditions, indicating that all four subunits of the holoenzyme may have active site capacity. Purified tryptase has a specific activity for tosyl-L-arginine methyl ester of 97 units/mg (1 unit = 1 mumol of substrate cleaved/min at 22 degrees C). Human pulmonary mast cells contain tosyl-L-arginine methyl ester-esterase at levels more than 100-fold higher than those of human neutrophils, eosinophils, and monocytes. One million mast cells contain about 1.1 units, or 6 to 19 micrograms of tryptase, and have the capacity to contribute dominant levels of this enzyme at tissue sites of mast cell degranulation.
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PMID:Tryptase from human pulmonary mast cells. Purification and characterization. 702 44

The intralysosomal localization of the enzymes that catalyse inactivation of rat liver fructose-bisphosphate aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13) to a form with antigenic activity was demonstrated. The inactivating enzymes like all other lysosomal markers tested except acid phosphatase, were readily solubilized by hypotonic shock. The inactivating enzyme activity was inhibited by PMSF, TPCK, TLCK and leupeptin, but not by pepstatin. On partial purification of the inactivating activity from the lysosomal fraction by DEAE-Sephadex (A-50) and Sephadex G-100 column chromatographies, it was copurified with lysosomal carboxypeptidase A and cathepsin B (EC 3.4.22.1). Studies on its substrate specificity and sensitivity to inhibitors indicated that cathepsin B and carboxypeptidase A are responsible for almost all the aldolase-inactivating activity in the lysosomal fraction.
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PMID:Properties of fructose-1,6-bisphosphate aldolase inactivating enzymes in rat liver lysosomes. 726 Jan

A carboxypeptidase A-like enzyme known as cathepsin A was purified from rat brain by extraction with Triton X-100, followed by chromatography on DEAE-Sephadex A-50 and gel-filtration. Purified enzyme was devoid of contamination of tryptic-like enzymes, by dipeptidyl carboxypeptidase (angiotensin converting enzyme) and of enkephalinnases cleaving the Tyr-Gly and Gly-Phe bonds of Met-enkephalin. Incubation of purified enzyme with Met-enkephalin-Arg6-Phe7, a naturally occurring enkephalin surrogate, was accompanied by the release of three products as detected by reverse phase HPLC. Subsequent amino acid analysis identified these as Phe, Met-enkephalin-Arg6, and Met-enkephalin, indicating cleavage at the Arg6-Phe7 and Met5-Phe6 bonds. Breakdown followed a precursor-product-relationship with the hexapeptide appearing as an intermediate and the pentapeptide as the final product. The Km for cleavage of the Arg-Phe site was 0.09 mM. Rates of cleavage of hexa- and heptapeptide accord with those found for synthetic N-protected dipeptide substrates. Cathepsin A does not act as an enkephalinase in the accepted sense, since no breakdown of Met-enkephalin was observed.
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PMID:Conversion of Met-enkephalin-Arg6-Phe7 by a purified brain carboxypeptidase (cathepsin A). 729 Oct 41

An inhibitor of the metallo-ectoenzyme, pyroglutamyl aminopeptidase II (PPII), a thyrotropin releasing hormone-specific peptidase, was identified by screening extracts from marine species of the Cuban coast-line belonging to the phylla Chordata, Echinodermata, Annelida, Mollusca, Cnidaria, Porifera, Chlorophyta and Magnoliophyta. Isolation of the inhibitor (HcPI), from the marine annelide Hermodice carunculata, was achieved by trichloroacetic acid treatment of the aqueous extract, followed by ion-exchange chromatography on DEAE Sephacel, gel filtration on Sephadex G-25 and reverse phase-HPLC. HcPI had a small apparent molecular weight (below 1000 Da) and was not a peptide. It inhibited rat PPII (a membrane preparation with 8.5mg protein/ml) with an apparent K(i) of 51 nM. HcPI did not inhibit serine (trypsin, chymotrypsin, elastase and dipeptidyl aminopeptidase IV), cysteine (papain, bromelain and pyroglutamyl aminopeptidase I), aspartic (pepsin and recombinant human immunodeficiency virus 1 protease (HIV1-PR)) nor other metallo proteinases (collagenase, gelatinase, angiotensin converting enzyme, aminopeptidase N and carboxypeptidase A). HcPI was non-toxic and active in vivo. Intraperitoneal injection of HcPI reduced mouse pituitary and brain PPII activity. Potency of the effect was higher in hypophysis and hypothalamus than in other brain regions. Intrathecal administration to male rats reduced PPII activity in the spinal cord. In conclusion we have identified a specific inhibitor of PPII that is the first M1 family zinc metallo-peptidase inhibitor isolated from marine invertebrates. It may be useful for elucidating the in vivo role of PPII in the pituitary and central nervous system.
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PMID:Purification of a specific inhibitor of pyroglutamyl aminopeptidase II from the marine annelide Hermodice carunculata. in vivo effects in rodent brain. 1459 39

1. A proteolytic enzyme with some features of a carboxypeptidase has been purified some 1180-fold from the sap of French beans (Phaseolus vulgaris var. Prince). A bright blue protein, plastocyanin, was separated from the enzyme by DEAE-cellulose chromatography. 2. Unlike carboxypeptidase A or B of animal origin, there is no evidence that the enzyme is a metalloprotein. There was no stimulation of activity by a number of metal ions, reducing agents or 2-mercapto-ethanol. Neither EDTA nor 1,10-o-phenanthroline inhibited the enzyme. 3. The proteolytic enzyme from beans, readily soluble at neutral or slightly acidic pH values, has a pH optimum of pH5.6 for the hydrolysis of leucine from benzyloxy-carbonylglycyl-l-leucine. Solutions of the enzyme in 0.1m-sodium acetate, pH5.5, lose about 2% of their activity/week at 4 degrees . Virtually no loss of activity results after prolonged storage at -15 degrees . 4. Incubation of the bean enzyme with peptides indicates that the enzyme will release acidic, neutral and basic amino acid residues as well as proline, although adjacent acidic residues in a peptide appear to inhibit the enzyme. The possibility of endopeptidase activity in the purified preparation requires further examination.
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PMID:Purification and properties of a proteolytic enzyme from French beans. 1674 7


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