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)

Rat mast cell granules were obtained by homogenization of highly purified rat mast cells and isolated in a Percoll gradient. Diphosphoinositide (DPI) synthesis in rat mast cell granules was assayed by measuring the incorporation of 32P from [gamma 32P]ATP into DPI in the absence of exogenous phosphatidylinositol (PI). Lipids were isolated with methanol/chloroform/HCl and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. DPI areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The addition of phorbol myristate acetate (PMA) to the granules caused an increase of 32P incorporation from [gamma 32P]ATP in the DPI fraction, which can be catalyzed by PI kinase. This effect of PMA in the DPI synthesis was dose dependent and maximal effects were observed at 10 ng/ml.
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PMID:Phorbol myristate acetate stimulates formation of diphosphoinositide in rat mast cell granules. 255 39

Rat mast cell granules were obtained by sonication of highly purified rat mast cells and isolated in a Percoll gradient. Phosphorylation of endogenous phosphatidylinositol in rat mast cell granules, which is catalyzed by phosphatidylinositol kinase in the granules, was assayed by measuring the incorporation of 32P from [gamma 32P]ATP into phosphatidylinositol 4-phosphate. Lipids were isolated with methanol/chloroform/HCl and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. Phosphatidylinositol 4-phosphate areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The phosphorylation reaction was inhibited by 50-500 microM adenosine, ADP and 500 microM AMP in a concentration-dependent manner. Among several anti-allergic drugs investigated. 100-1000 microM theophylline and 10-100 microM azelastine inhibited the phosphorylation reaction, but disodium cromoglycate and ketotifen had little effect.
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PMID:Inhibitory effect of adenine nucleotides and anti-allergic drugs on phosphorylation of phosphatidylinositol in rat mast cell granules. 257 58

Substances released from immunoglobin (Ig) E-stimulated mast cells are likely to be among the chemical mediators responsible for changes in the vagal component of airway reactivity. We have attempted to identify a direct role for mast cell mediators in the control of visceral afferent excitability by examining intracellular electrophysiological changes in vagal neurons after application of extracts prepared from purified and IgE-stimulated human lung mast cells (HLMC). HLMC's, applied by superfusion or by focal pressure ejection from micropipettes, reversibly enhanced the excitability of a subpopulation of rabbit visceral sensory C-fiber neurons by 1) abolishing the slow Ca2+-dependent post-spike after hyperpolarization that uniquely resides in these neurons and controls their spike frequency, 2) depolarizing the cell membrane potential, and 3) increasing membrane input resistance. Control HLMC prepared by subjecting purified human lung mast cells to normal goat serum had no measurable affects on neuronal excitability. The immunologically released constituents responsible for these excitability changes are likely to be lipid mediators, because essentially all biological activity is extractable into an organic phase after methanol-chloroform solvent extraction of the HLMC preparations. These results provide the first unambiguous evidence that products released from immunologically challenged HLMC's directly affect visceral afferent nerve cell function.
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PMID:IgE-challenged human lung mast cells excite vagal sensory neurons in vitro. 339 26

Various fixation and staining procedures have been examined in order to obtain optimal numbers and acceptable morphology of the mucosal mast cells and granular intraepithelial cells in the rat jejunum. For subsequent staining with Alcian Blue, the best fixation of the jejunum was obtained with a methanol-formaldehyde-acetic acid mixture. Specific staining of the granules of these cells has been obtained using Alcian Blue at pH 5.8, at which hydrogen ion concentration more cells stain than in the usual very acid conditions. Specificity is achieved by the use of magnesium chloride concentrations above the critical electrolyte concentrations for staining of protein and nucleic acid by Alcian Blue, and by the use of Safranin O as a competitive counterstain. The critical electrolyte concentration technique has also been applied to a comparative study of the glycosaminoglycan in the two cell types. Evidence is presented that the glycosaminoglycan in the granular intraepithelial cell has either a lower degree of sulphation or a lower molecular weight or both than the material in mucosal mast cells. This finding may support the possibility that the granular intraepithelial lymphocyte is a precursor of the mucosal mast cell.
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PMID:Fixation and staining of granules in mucosal mast cells and intraepithelial lymphocytes in the rat jejunum, with special reference to the relationship between the acid glycosaminoglycans in the two cell types. 616 Jan 26

A high-performance liquid chromatography method for analyzing disaccharides derived from chondroitin sulfate glycosaminoglycans has been developed which employs a Whatman Partisil-10 PAC amino-cyano column and an acetonitrile/methanol/ammonium acetate solvent to resolve disulfated, monosulfated, and unsulfated disaccharides in a chromatographic run of less than 20 min. The single known trisulfated chrondroitin disaccharide can be eluted in an alternate solvent system containing the same mobile phase components in different proportions. Disaccharides were prepared for chromatography from glycosaminoglycans and proteoglycans of known compositions by digestion with chondroitinase ABC, with the exception of king crab cartilage glycosaminoglycan which was incubated sequentially with hyaluronidase and chondroitinase ABC. Disaccharides were extracted from the digestion mixtures in 80% ethanol, dried over nitrogen, resuspended in the HPLC solvent, and chromatographed at a flow rate of 1 ml/min. Unsaturated disaccharides in the column eluate were detected by continuous ultraviolet absorbance monitoring at 232 nm; alternatively, fractions were collected and assayed for uronic acid content or radioactivity. By utilizing the HPLC technique in conjunction with chondroitinase ABC and AC digestion and sulfatase hydrolysis, the epimeric structures of chondroitin sulfates E and H were confirmed. With this technique, rapid and reproducible analyses of chondroitin sulfate disaccharides generated from mouse mast cell proteoglycan and from glycosaminoglycans of squid cranial cartilage, shark skin, hagfish skin, and hagfish notocord were in close agreement with compositions obtained by other techniques.
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PMID:Analysis of polysulfated chondroitin disaccharides by high-performance liquid chromatography. 643 72

The synthesis of the mast cell-degranulating peptide by liquid-phase fragment condensation is described. After the carboxyterminal of the peptide is condensated with polyethylene-glycol (Mr 10000) the following fragments are coupled stepwise on the polymer, a soluble carrier in dichloromethane by the dicyclohexylcarbodiimide/hydroxybenzotriazole-method. Pos. 17-21 Boc-Lys(Z)-Ile-Cys(SiPr)-Gly-Lys(Z) (I) Pos. 12-16 Boc-Pro-His(Trt)-Ile-Cys(Trt)-Arg(Tos) (II) Pos. 8-11 Boc-His(Trt)-Val-Ile-Lys(Z) (III) Pos. 5-7 Boc-Cys(SiPr)-Lys(Z)-Arg(Tos) (IV) Pos. 1-4 Boc-Ile-Lys(Z)-Cys(Trt)-Asn(Mbh) (V) It is practical to crystallize the polyethyleneglycol peptide-coupling products from ethanol after each step. Most of the protecting groups can be removed by treatment of the complete polyethylene-glycol-peptide in trifluoroacetic acid/HBr. In methanol, saturated with ammonia, the peptide is removed in the amid-form from the carrier. The guanidyl-blocking group disappears by solving the peptide in liquid HF. The crude peptide is converted into the tetra-S-sulfonate derivate by oxidative sulfitolysis and purified by ion-exchange and gel chromatography. After reduction by mercaptoethanol a cautious air-reoxidation of the SH- to the SS-peptide followed. Rechromatography on ion-exchange and dextran gels yields a peptide with good biological activity in rat cell histamin-liberation and inflammation inhibition compared with the natural recombinated product.
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PMID:[Basic peptides from bee venom, IV. Synthesis of the mast cell-degranulating peptide by liquid-phase fragment condensation (author's transl)]. 738 Mar 91

A bifidogenic growth stimulator was present in the cell-free filtrate of Propionibacterium freudenreichii 7025 culture and in the methanol extract fraction of the cells. Several intestinal bacteria, such as Bacteroides, Enterobacter, and Enterococcus, which also released a growth stimulator for bifidobacteria, may play an important role in regulation of a bifidobacterial population in colonic microflora. The water-soluble stimulator from the methanol extract of the cells was partially purified. The molecular weight of the stimulator appeared to be < 3000. The stimulatory activity was unaffected by treatments with pronase, carboxypeptidase A, ribonuclease, or nuclease P1 and was heat stable over a wide pH range. This stimulator differed from cyanocobalamin and from organic acids, such as acetate and propionate. Because it was stable to heat and proteolytic enzymes, the stimulator is a useful bifidogenic factor that can reach the large intestine while retaining its activity. Short-chain fatty acids were highly inhibitory to the growth of many intestinal bacteria, particularly Gram-negative facultative and obligatory anaerobes. The short-chain fatty acids (especially propionate) stimulated the growth of bifidobacteria. The growth of Bifidobacterium adolescentis 6003 was further enhanced in the presence of short-chain fatty acids and the stimulator produced by P. freudenreichii 7025. Viable counts of strain 6003 grown with Bacteroides vulgatus JCM 5826T increased more than 10(4) over those of the single culture of strain 6003. However, the growth of strain 6003 was inhibited in the mixed culture with Clostridium perfringens 7028. In continuous culture, the growth of bifidobacterial strain 6003 could be greatly enhanced, even in the presence of clostridial strain 7028, in media with short-chain fatty acids and stimulator produced by P. freudenreichii 7025.
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PMID:Growth stimulator for bifidobacteria produced by Propionibacterium freudenreichii and several intestinal bacteria. 818 63

Human mast cell tryptase beta (EC 3.4.21.59) is a trypsin-like serine protease that is stored in and released from mast cell granules. This enzyme has been expressed in Pichia pastoris via homologous recombination of the cDNA coding for the mature active tryptase with the addition of a KEX 2 processing site into the Pichia genome. Cells producing recombinant human tryptase (rHT) were selected by screening with antibodies. Induction with methanol resulted in the secretion of rHT into the Pichia growth medium; tryptase activity was stabilized by the addition of heparin to the culture medium. Increasing levels of enzyme were detected in the medium for up to 3 days. Fully active enzyme was purified from the culture medium with a 100% yield of activity via a simple two-step procedure, with hydrophobic interaction chromatography followed by affinity chromatography on immobilized heparin. Bands of 33 (faint), 34.2, 35.9 and 50 kDa (diffuse) were observed on SDS/PAGE. These multiple forms were due to differences in post-translational glycosylation of asparagine residues, because enzymic deglycosylation resulted in only one band at 33 kDa. A single symmetrical peak with an estimated size of 197 kDa was obtained on gel filtration. Kinetic analyses in comparison with native human lung mast cell tryptase (HLT) yielded similar Km values, but the kcat of rHT was more than twice that of HLT.
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PMID:Recombinant human mast cell tryptase beta: stable expression in Pichia pastoris and purification of fully active enzyme. 975 42

The carboxypeptidase A-catalyzed syntheses of dipeptides from L-amino acids (Phe, Tyr, Trp, Leu and Ile) were studied in various water-miscible (acetone, acetonitrile, ethanol, methanol and 1,4-dioxane) organic solvents. The highest yield (43%) was achieved in acetonitrile with L-Phe as substrate, after a 24-h incubation. The optimal conditions of Phe-Phe synthesis in acetonitrile were determined. For maximal conversion 1.2 mM L-Phe, 1.4 mg ml-1 enzyme and about 10% water are needed in buffered aqueous acetonitrile (pH 5.5) at 30 degrees C.
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PMID:Carboxypeptidase A-catalyzed dipeptide synthesis in organic media. 986 61

Oligomers of beta-amino acids (beta-peptides), which are readily available by standard meth ods either in solution or on solid support, adopt a large variety of different secondary structures in solution and in the solid state. beta-Peptides 4, 5 and 10 fold into a helix with 3 residues per turn and 14-membered H-bonded rings (314 helix) that is left-handed for 5 and 10 and right-handed for 2 (due to the reversal of the chirality of the building blocks), as was clearly demonstrated by two-dimensional NMR-spectroscopy. This helix thermally is very stable in methanol solution upon heating. As shown by NMR- and CD-spectroscopy, it is partially populated even at 100 C (Figure 3). Another helix was dis covered for mixed beta-peptide 8 in methanol solution: it is characterized by 12- and 10- membered turns (Figure 4, left) and its central 10-membered turn has been found in the solid state of a geminally disubtituted beta-peptide (Figure 4, right). This central 10-membered turn was used as a scaffold to attach beta-amino acid residues that prefer a linear (non-helical) conformation (beta-peptide 21): a hairpin (pleated sheet-turn-pleated sheet) structure was determined in solution by NMR-spectroscopy (Figure 5). In contrast to this antiparallel pleated-sheet, a parallel pleated sheet was found for a beta-tripeptide in the solid state. For the first time it was possible to observe reversible peptide folding in MD simulations by studying beta-peptides (Figure 6) and to determine folding pathways and intermediates. beta-Peptides are a new class of promising peptidomimetics. They are resistant against the degradation by proteolytic enzymes such as pepsin, elastase, carboxypeptidase A, pro nase or proteasom 20S. A variety of beta-amino acids (27-34) was shown to be non- mutagenic by Ames tests and beta-peptides 47 and 48 reveal large elimination half-lives of 3 h (for 47) and 10 h (for 48) in the serum of rodents (Figure 7). Conjugates of alpha- and beta- peptides are efficient ligands for the HLA*B27 MHC Class I protein, a five fold increase of binding (2.0 microM for 55) compared to a natural peptidic ligand 51 was observed. Furthermore, beta-peptides are able to mimic natural a-peptidic hormones such as somatostatin. The cyclo-beta-tetrapeptide 57 binds to the five human somatostatin receptors in the micromolar range. In addition, several other non-natural oligomers such as beta-peptide nucleic acids (built from 58 and 59), beta-peptoids (60), oligomers of anthranilic acids and beta-sulfonamido peptides are discussed.
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PMID:Beta-peptides: twisting and turning. 1051 5


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