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)

AMP deaminase (AMP aminohydrolase, EC 3.5.4.6) has been purified to apparent homogeneity from rat muscle. The preparation exhibits a single polypeptide band with a molecular weight of 60,000 on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The enzyme has a sedimentation coefficient of 11.3 S. Analysis by sedimentation equilibrium techniques showed the nat-ive enzyme to have a molecular weight of 238,000, whereas the enzyme, when analyzed in 6 M guanidine hydrochloride and 10 mM 2-mercaptoethanol, had a molecular weight of only 59,500. The amino acid composition of the enzyme was determined and peptide mapping was performed on a tryptic digest of S-carboxymethylated enzyme. NH2-terminal analysis by both the dansylation and cyanate procedures failed to identify a free NH2 terminus. Treatment of the enzyme with carboxypeptidase A resulted in the release of approximately 0.5 mol each of valine and leucine per 60,000 g of enzyme. The data presented indicate that hte native enzyme has a tetrameric structure consisting of four polypeptide chains each having a molecular weight of 60,000. The COOH-terminal analysis can be interpreted either as an indication of subunit heterogeneity or as a result of incomplete digestion of a -X-Leu-Val sequence at the end of a single type of polypeptide chain. Tryptic peptide maps strongly support the latter interpretation and suggest that the subunits are essentially identical.
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PMID:Rat muscle 5'-adenylic acid aminohydrolase. I. Purification and subunit structure. 115 74

A simple method is described for the preparation of large numbers of mast cells from mouse spleen cells in vitro. Mouse spleen cells were cultured with RPMI 1640 medium supplemented with 10% FCS and 2-ME. Half of the total volume of the medium was changed every 4-5 days. Mast cell numbers increased with the culture time and reached a peak between 16 and 20 days. Using this method, 2 x 10(6) mast cells could be induced from 1 x 10(7) nucleated normal spleen cells. T cells and supernatant derived from ConA-stimulated T cells were unnecessary for mast cell induction. Phenotype analysis by FACS showed that Thy1,2, L3T4, Ly-2, Ig, B220, Asialo GM1, and WGA receptors were all negative but functional IgE receptors were positive. The granules in the cells could be stained by alcian blue but not by safranin. There was 1.632 +/- 0.024 micrograms stored histamine in 1 x 10(6) of the cells. Histamine was released from the cells in an antigen-induced and IgE-mediated process. Compound 48/80 and A23187 induced degranulation of the cells, and the mast cells were able to respond to ConA.
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PMID:Induction and identification of mast cells from long-term culture of mouse spleen cells without conditioned medium. 137 14

Previously we established that in vitro NO2 exposure induced inhibition of histamine release from rat peritoneal mast cells (PMC) stimulated with secretagogues such as compound 48/80 or substance P. To further explore the effects of NO2 exposure on mast cells, we investigated whether the addition of an antioxidant agent, 2-mercaptoethanol (2-ME), can prevent NO2-induced inhibition of mediator release from PMC. Histamine release from 5 ppm NO2-exposed PMC stimulated with 10 and 20 microM substance P was significantly inhibited compared with that from the controls. beta-Hexosaminidase release from 5 ppm NO2-exposed PMC stimulated with 20 microM substance P was also significantly inhibited. However, the inhibition of both histamine and beta-hexosaminidase release from exposed PMC was diminished by the addition of 5 mM 2-ME during NO2 exposure. Although IgE-mediated histamine release from NO2 exposed PMC was markedly inhibited, the addition of 5 mM 2-ME during NO2 exposure induced no inhibition of histamine release. These results suggest a possible relationship between NO2-induced inhibition of mast cell mediator release and production of free radicals by the action of NO2.
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PMID:An antioxidant agent prevents NO2-induced inhibition of mast cell mediator release: evidence that the mechanism involves free radicals. 170 82

Fragments of beta-lactoglobulin were produced by proteolytic cleavage with trypsin, and chemical cleavage with cyanogen bromide, followed by gel filtration on Sephadex G-50. The antigenicity and allergenicity of the products were studied, before and after reductive cleavage by treatment with 2-mercaptoethanol. The former was determined by inhibition ELISA using IgG anti-beta-lactoglobulin raised in rabbits, whilst the latter was determined by inhibition ELISA and mast cell challenge, using respectively the sera and peritoneal cells of rats experimentally sensitised to beta-lactoglobulin. The findings raise interesting points about the structural basis of allergenicity in relation to antigenicity.
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PMID:Investigation of the allergenicity of beta-lactoglobulin and its cleavage fragments. 241 60

A series of permanent IL-3-dependent cell lines have been established from normal BALB/c or C3H bone marrow using alpha-thioglycerol-supplemented culture medium and PWM-stimulated spleen cell-conditioned medium as a source of IL-3. The cell lines and derivatives cloned in agar resembled "mucosal type" mast cells with respect to phenotypic and functional properties. In this report we demonstrate that in vitro growth of these mast cell lines was not only dependent on IL-3 and synergistically enhanced by IL-4, but in addition regulated by alpha-thioglycerol which could be replaced by 2-ME or cysteamine. We show that these thiol-sensitive mast cell lines respond to a mast cell growth enhancing activity (MEA) present in spleen cell-conditioned medium and acting in concert with IL-3. Partially purified MEA was not able to stimulate the growth of IL-3-dependent 32Dcl.23 cells, IL-2-dependent CTLL-2 cells or the mouse T cell line F4/4K.6 (L3T4+) adapted to grow in purified IL-4. Moreover, 11B11 hybridoma-derived anti-IL-4 mAb specifically neutralizing mouse Il-4 were unable to abolish the bioactivity of MEA. PWM, CSF-1, GM-CSF, IL-1, IL-2, IL-5, IL-6, IL-7, IFN-gamma, TGF-alpha, TNF-alpha, NGF, or EPO did not substitute for MEA in our standard proliferation assay.
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PMID:Thiol-sensitive mast cell lines derived from mouse bone marrow respond to a mast cell growth-enhancing activity different from both IL-3 and IL-4. 278 56

The influence of low oxygen tension on the clonal growth of hemopoietic stem cells in vitro was examined. The numbers of colonies of neutrophil, macrophage, and eosinophil progenitors (CFU-C), derived from human bone marrow, increased at a rate 1.7 times higher in low oxygen tension (7% O2) than in a gas phase that contained air (19% O2). The erythroid (BFU-E) and multipotential (CFU-mix) progenitors increased about 2.4 times in 7% O2, and the increase in the composed cell type of mixed colonies showed no rate difference in either gas phase. Under atmospheric conditions, a mouse mast cell progenitor (CFU-mast) formed colonies, with the addition of 2-mercaptoethanol (2-ME). Under low oxygen tension, the CFU-mast formed colonies without 2-ME, but a further enhancement was observed with the addition of 2-ME. Blood gas analysis of human bone marrow showed a pO2 of 51.8 +/- 14.5 mmHg, which was closed to O2 tension in a gas phase culture media containing 7% O2. This data shows that the physiological O2 tension enhances hemopoietic stem cell proliferation in vitro, and that a part of the enhancing effect by 2-ME is due to a prevention of O2 toxicity at 19% O2.
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PMID:Kinetics of hemopoietic stem cells in a hypoxic culture. 327 28

N alpha-Acetylenkephalin carboxypeptidase was co-purified with N-acetyltyrosine deacetylase from monkey kidney. Almost 90% of the activity from the homogenate was recovered in a high-speed supernatant without the use of detergents. The crucial steps in the purification were Cibacron Blue F3GA--Sepharose chromatography (involving negative and positive binding sequentially) and metal chelate affinity chromatography. The purified enzyme showed three bands on gel electrophoresis under non-denaturing conditions. All the three bands exhibited both N-acetyltyrosine deacetylase and N-acetylenkephalin carboxypeptidase activity, indicating their co-migration, Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis in the presence and absence of 2-mercaptoethanol gave a single protein band of mol.wt. 34 000. The native enzyme was a dimer of mol.wt. 66 000 as observed on Bio-Gel P-300 gel filtration. The carboxypeptidase removed two amino acids from the C-terminal end of either N-acetyl[Met5]- or N-acetyl[Leu5]-enkephalin. Non-acetylated enkephalins were less active as substrates. Peptides with their carboxy end blocked were inactive as substrates. Models suggested for carboxypeptidase A [Hartsuck & Lipscomb (1971) Enzymes 3, 1-56] support the idea that the kidney N-acetylated aromatic amino acid deacetylase or acylase III [Endo (1978) Biochim. Biophys. Acta 523, 207-217] can act as a carboxypeptidase on peptides having hydrophobic amino acids at the C-terminal end.
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PMID:The N alpha-acetylenkephalin carboxypeptidase activity of N-acetyltyrosine deacetylase from monkey kidney. Purification, characterization and substrate specificity. 640 38

The administration of mercuric chloride (HgCl2), gold compounds, or D-penicillamine to Brown Norway (BN) rats causes a T helper (Th)2 cell-associated autoimmune syndrome characterized by the production of a number of autoantibodies, marked elevation of serum IgE concentration, and tissue injury in the form of a vasculitis and arthritis. We have recently shown that the same compounds in vitro sensitize BN rat peritoneal mast cells for IgE-triggered mediator release and interleukin-4 mRNA production. We wished to test the hypothesis that these agents influence mast cell function via an effect on intracellular reactive oxygen species (ROS) production/redox balance. Mast cells were obtained from BN rats by peritoneal washout. Incubation with HgCl2, gold compounds or D-penicillamine (the latter only in the presence of copper ions) led to the intracellular production of ROS as shown by the oxidative production of the fluorescent compound 2',7'-dichlorofluorescein. Mast cells were more sensitive than splenocytes to this effect. Direct oxidative stress (exposure to H2O2) produced a similar sensitization for mediator release to that caused by HgCl2. Inhibition of ROS formation by desferrioxamine or catalase diminished the enhancement of IgE-mediated serotonin release caused by HgCl2, as did replenishment of intracellular glutathione. 2-Mercaptoethanol exacerbated the toxicity of HgCl2, perhaps due to the formation of a lipophilic complex that enhanced HgCl2 uptake. Blocking of glutathione synthesis increased the toxicity of HgCl2, but also abolished any sensitizing effect on mediator release. These results support three main predictions of our hypothesis: (1) the compounds known to influence mast cell function all lead to the generation of ROS within the mast cell; (2) direct oxidative stress causes sensitization for mediator release by the mast cell; and (3) modulation of ROS production/redox balance within the mast cell modulates the effects of these compounds on mast cell function. The balance of oxidative/antioxidative influences may play an important role in the modulation of mast cell function, particularly in the context of chemically induced autoimmunity.
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PMID:Alterations in intracellular reactive oxygen species generation and redox potential modulate mast cell function. 902 32

The azaspiracids are a group of marine toxins recently described that currently includes 20 analogues. Not much is known about their mechanism of action, although effects on some cellular functions have been found in vitro. We used the reported effects on cell viability, actin cytoskeleton, and caspase activation to study the structure-activity relationship of AZA-1 and AZA-2 and the role of the carboxylic acid moiety in toxicity. AZA-1, AZA-2, and the synthetic AZA-2-methyl ester (AZA-2-ME), where the C1 carboxylic acid moiety of AZA-2 was esterified to the corresponding methyl ester moiety, induced a reduction of cell viability in neuroblastoma and hepatocyte cell lines with similar potency and kinetics. Interestingly, the mast cell line HMC-1 was resistant to AZA-induced cytotoxicity. Actin cytoskeleton alterations and caspase activation appeared after treatment with AZA-1, AZA-2, AZA-2-ME, and biotin-AZA-2 (AZA-2 labeled with biotin at C1) in neuroblastoma cells with similar qualitative, quantitative, and kinetics characteristics. Irreversibility of AZA effects on the actin cytoskeleton and cell morphology after short incubations with the toxin were common to AZA-1, AZA-2, and AZA-2-ME; however, 10-fold higher concentrations of biotin-AZA-2 were needed for irreversible effects. AZA-2-ME was rapidly metabolized in the cell to AZA-2, while transformation of biotin-AZA-2 into AZA-2 was less efficient, which explains the different potency in short exposure times. The moiety present at C1 is related to AZA toxicity in vitro. However, the presence of a methyl moiety at C8 is irrelevant to AZA toxicity since AZA-1 and AZA-2 were equipotent regardless of the readout effect.
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PMID:Azaspiracid substituent at C1 is relevant to in vitro toxicity. 1870 38