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)

Alcohol-induced hypersecretion probably contributes to chronic alcoholic pancreatitis. Feeding of raw soybean flour or soybean trypsin inhibitor also stimulates protein secretion of the pancreas. Therefore, we tested whether or not the pancreatic damage is increased by additional feeding of raw soybean flour in rats fed 20% ethanol. After 11 months, we classified the morphological lesions of the pancreas into seven stages of severity calculated by means of a discriminating procedure. In order to characterize the secretory capacity of the pancreas, we measured the outputs of lipase, phospholipase, A, alpha-amylase, carboxypeptidase A, chymotrypsin, and bicarbonate. Compared with the alcohol-fed animals, the rats fed with alcohol and soya exhibited a lower average degree of morphological damage in the pancreas. Hypertrophy and hyperplasia of the parenchyma and accumulation of secretory products within the acinar cells were main features. On the other hand, some separate regions of the pancreas showed intraductal secretion precipitates as well as plugs, which were sometimes associated with atrophy of acinar cells. Feeding with soybean diet grossly reduced the alcohol-induced enzyme hypersecretion. In the early phase of alcohol-induced pancreatic damage, long-term soybean flour diet thus reduces morphological lesions and hypersecretion of the rat pancreas, whereas protein synthesis in the acinar cells appears increased. However, the precipitation of secretory products on ductal epithelium, the increased formation of plugs, and the more frequent acinar atrophies suggest the development of significant tissue injuries.
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PMID:[Modification of alcohol-induced pancreatic damage in rats by soybean diet]. 816 30

In recent work we have shown that a serine proteinase, stratum corneum chymotryptic enzyme, with properties compatible with a role in desquamation in vitro as well as in vivo, is generally present in human stratum corneum. The enzymologic properties of the stratum corneum chymotryptic enzyme in a KCl extract of dissociated plantar corneocytes were compared with those of other known chymotryptic serine proteinases. Stratum corneum chymotryptic enzyme was found to differ significantly from bovine chymotrypsin, human cathepsin G, and human mast cell chymases in regard to inhibitor profile and substrate specificity. Stratum corneum chymotryptic enzyme was further purified from KCl extracts of dissociated plantar corneocytes by affinity chromatography on gels with covalently linked soybean trypsin inhibitor. The purified preparation contained one major component with apparent molecular weight 25 kD and one minor component with slightly higher apparent molecular weight as revealed by Coomassie staining after electrophoresis in polyacrylamide gels with sodium dodecyl sulphate of samples that had not been reduced. Both these components were associated with chymotrypsin-like activity as revealed by zymography in polyacrylamide gels with co-polymerized casein. On zymography gels, the purified preparation was also found to contain minor amounts of components with trypsin-like activity. The major purified protein had an apparent molecular weight of around 28 kD after reduction and full denaturation and was shown to contain carbohydrate.
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PMID:Purification and preliminary characterization of stratum corneum chymotryptic enzyme: a proteinase that may be involved in desquamation. 839 2

Tryptase and chymase released from activated mast cells degrade the neuropeptides calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP) to peptide fragments. We have examined whether nedocromil sodium can modulate the ability of rat activated peritoneal mast cells to degrade 125I-CGRP and 125I-VIP. Mast cell-dependent degradation of both 125I-CGRP and 125I-VIP was observed with compound 48/80 (0.03-1 microgram/ml) and in the case of 125I-VIP with anti-IgE (1-20 micrograms/ml). Nedocromil sodium (10(-6)-10(-4) M) caused significant inhibition of neuropeptide degradation, with the most effective inhibition observed against anti-IgE-induced degradation of 125I-VIP. Nedocromil sodium had no inhibitory effect on the ability of lysed mast cells, bovine trypsin or chymotrypsin to breakdown 125I-VIP. These results suggest that nedocromil sodium inhibits mast cell-dependent degradation of neuropeptides, such as VIP, as a secondary consequence of inhibiting the release of mast cell proteases.
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PMID:The modulation by nedocromil sodium of proteases released from rat peritoneal mast cells capable of degrading vasoactive intestinal peptide and calcitonin gene-related peptide. 839 43

Among the variety of signals stimulating pancreatic secretion, cholecystokinin (CCK) and related hormones are assumed to be responsible for modulating proteinase output. In some species, intraduodenal tryptic activity has to be abolished to demonstrate feedback-induced CCK release. The aim of this study was to investigate in vivo effects of modest inhibition of intraduodenal proteolytic enzymes on the secretion patterns of pancreatic enzymes and plasma CCK concentrations. Two inhibitors (Kunitz trypsin inhibitor and Bowman-Birk inhibitor) were applied. Intermittent sampling of plasma nd duodenal juice was performed during intraduodenal saline and inhibitor instillations in six healthy volunteers. Enzyme activities and concentrations were determined in the duodenal samples and expressed as percentage of basal values. Instillation of Kunitz trypsin inhibitor caused an increase in trypsin and the pancreatic secretory trypsin inhibitor (PSTI), without changes in plasma CCK. This result demonstrates, for the first time, that pancreatic exocrine secretion of trypsin and chymotrypsin is regulated by different mechanisms. Bowman-Birk inhibitor additionally stimulated the secretion of chymotrypsin and carboxypeptidase A and B and increased plasma CCK. Elastase 1 and amylase secretions were not increased by either instillations. Although the inhibitors have similar in vitro inhibition patterns, their in vivo effects are different. The nonparallel secretion of proteinases (trypsin, chymotrypsin and elastase 1) supports the view of a complex system involved in feedback regulation of human pancreatic exocrine secretion, including signals other than CCK.
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PMID:Proteinase inhibitors induce selective stimulation of human trypsin and chymotrypsin secretion. 859 48

The objective of this research was to formulate a mixture of commercial proteases that would mimic the rate and extent of protein degradation obtained using strained ruminal fluid. The proteolytic activity of strained ruminal fluid and several commercial proteases was characterized using 13 L-amino acid p-nitroanilides as artificial substrates. A mixture of Streptomyces griseus protease, chymotrypsin, and proteinase K at .042, 2.5, and .5 enzyme units/mL, respectively, was similar to the activity of strained ruminal fluid against the same artificial substrates. However, degradative activities were different in incubations with feed proteins as substrates. The rates of degradation of expeller soybean meal, solvent soybean meal, and casein were .08, .05, and .08/h, respectively, using the enzyme mixture and .03, .15, and .24/h using strained ruminal fluid. A second experiment compared degradative activity of S. griseus protease at .066 enzyme units/mL, ficin at .5 enzyme units/mL, and a mixture of trypsin, carboxypeptidase B, chymotrypsin, and carboxypeptidase A at 116.6, .5, 2.5, and .5 enzyme units/mL, respectively. Protein degradation rates obtained with strained ruminal fluid were two to six times faster than those obtained with the enzyme mixtures. A third experiment compared the degradability of 15 feed proteins with the mixture of trypsin, carboxypeptidase B, chymotrypsin and carboxypeptidase A to that with strained ruminal fluid. Degradation rates obtained using strained ruminal fluid ranged from .007 to .217/h; degradation rates using the enzyme mixture ranged from .010 to .079/h and were lower (P = .004) than with strained ruminal fluid. Overall, the experiments indicated that the commercial enzymes tested did not mimic the protein degradative activity of strained ruminal fluid.
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PMID:Characterization of the proteolytic activity of commercial proteases and strained ruminal fluid. 870 28

We have examined the effect of alpha-chymotrypsin on isolated mast cells from different sources. The enzyme induced a dose-dependent secretion of histamine from purified and non-purified populations of rat peritoneal mast cells. The release was non-cytotoxic and was inhibited by metabolic blockers and extremes of temperature. The process was relatively slow, being essentially complete within 20 min, and was unaffected by phosphatidylserine. A substantial component of the secretion persisted in the absence of extracellular Ca2+. The release was suppressed by extremes of pH and a variety of anti-allergic compounds and serine esterase inhibitors. In addition to the secretion of preformed mediators, alpha-chymotrypsin also induced the metabolism of arachidonic acid, resulting in the release of prostaglandin D2 in a dose-related manner from purified rat peritoneal mast cells. alpha-Chymotrypsin exhibited a marked tissue and species selectivity in its action and tissue mast cells of the rat, guinea pig and human were generally resistant to the enzyme except at cytotoxic concentrations. On the basis of these results, the possible role of endogenous serine esterases in mast cell activation is discussed.
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PMID:Some studies on the effects of alpha-chymotrypsin on mast cells from the rat and other species. 872 May 91

The effect of nickel (Ni) on the enzymatic activities in the pancreas of mice was studied. Administration of Ni at the dose of 5 mg Ni/kg increased the trypsin activity and decreased carboxypeptidase A activity, but did not affect the activities of chymotrypsin, carboxypeptidase B, amylase, and lipase. Increases in Ca concentrations in the pancreas after Ni administration were observed. In the pancreatic slice experiments, Ni treatment showed a slight decrease in trypsin activity and remarkable decreases in chymotrypsin and carboxypeptidase A activities, and Ca treatment induced increases in the activities of trypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Ni administration results from the activation of trypsinogen by the Ca ion and that the decrease in carboxypeptidase A activity is based on the inhibitory effect of Ni on carboxypeptidase A activity.
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PMID:Effect of nickel on enzymatic activities in the mouse pancreas. 877 77

Dietary proteins are degraded by both endogenous enzymes and the caecal microflora. In conventional rats the enzyme content of the pancreas depends on the amount of dietary protein. The influence of the caecal microflora on this process is unknown. We report here the effect of the caecal microflora on pancreatic enzymes (proteases, amylase (EC 3.2.1.1), lipase (EC 3.1.1.3)) and on colonic metabolites (NH3, urea, short-chain fatty acids). Germ-free and conventional male Fischer rats were fed for 3 weeks with a diet containing 220 or 450 g protein/kg provided as a mixture of fish concentrate and soyabean isolate. The excretion of NH3 and the pH were specifically increased by the high-protein diet in the germ-free rats. The higher production of isobutyrate, valerate and isovalerate in conventional rats fed on the high-protein diet reflected a high bacterial proteolytic activity since these short-chain fatty acids are specific indicators of this activity. The microflora hydrolysed urea to NH3 and maintained the pH at neutrality whatever the amount of protein in the diet since there were changes in germ-free rats but not in conventional ones. In germ-free rats, amylase, trypsin (EC 3.4.21.4), elastase (EC 3.4.21.36) and carboxypeptidase A (EC 3.4.17.1) specific activities were significantly lower than in conventional rats. The adaptation of the pancreas to the 450 g protein/kg diet was not impaired by the bacterial status except for the specific activity of chymotrypsin (EC 3.4.21.1) which was more increased by this diet in germ-free than in conventional rats. Moreover, the specific activity of lipase increased only in conventional rats fed on the 450 g protein/kg diet. In conclusion, we observed a relationship between the enzyme content of the pancreas and the presence or absence of the caecal microflora suggesting that bacterial fermentation influences pancreatic function.
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PMID:Influence of caecal microflora and of two dietary protein levels on the adaptation of the exocrine pancreas: comparative study in germ-free and conventional rats. 878 16

The maltose-regulated mlr-2 gene from the hyperthermophilic archaeon Pyrococcus furiosus having homology to bacterial and eukaryal prolyl endopeptidase (PEPase) was cloned and overexpressed in Escherichia coli. Extracts from recombinant cells were capable of hydrolyzing the PEPase substrate benzyloxycarbonyl-Gly-Pro-p-nitroanilide (ZGPpNA) with a temperature optimum between 85 and 90 degrees C. Denaturing gel electrophoresis of purified PEPase showed that enzyme activity was associated with a 70-kDa protein, which is consistent with that predicted from the mlr-2 sequence. However, an apparent molecular mass of 59 kDa was obtained from gel permeation studies. In addition to ZGPpNA (K(Mapp) of 53 microM), PEPase was capable of hydrolyzing azocasein, although at a low rate. No activity was detected when ZGPpNA was replaced by substrates for carboxypeptidase A and B, chymotrypsin, subtilisin, and neutral endopeptidase. N-[N-(L-3-trans-Carboxirane-2-carbonyl)-L-Leu]-agmatine (E-64) and tosyl-L-Lys chloromethyl ketone did not inhibit PEPase activity. Both phenylmethylsulfonyl fluoride and diprotin A inhibited ZGPpNA cleavage, the latter doing so competitively (K(lapp) of 343 microM). At 100 degrees C, the enzyme displayed some tolerance to sodium dodecyl sulfate treatment. Stability of PEPase over time was dependent on protein concentration; at temperatures above 65 degrees C, dilute samples retained most of their activity after 24 h while the activity of concentrated preparations diminished significantly. This decrease was found to be due, in part, to autoproteolysis. Partially purified PEPase from P. furiosus exhibited the same temperature optimum, molecular weight, and kinetic characteristics as the enzyme overexpressed in E. coli. Extracts from P. furiosus cultures grown in the presence of maltose were approximately sevenfold greater in PEPase activity than those grown without maltose. Activity could not be detected in clarified medium obtained from maltose-grown cultures. We conclude that mlr-2, now called prpA, encodes PEPase; the physiological role of this protease is presently unknown.
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PMID:Overexpression and characterization of a prolyl endopeptidase from the hyperthermophilic archaeon Pyrococcus furiosus. 917 7

Leukosialin (CD43), the major sialoprotein on circulating leukocytes, has been previously described to be down-regulated on neutrophils following activation with phorbol myristate acetate (PMA). The other single cells previously examined, blood lymphocytes, do not down-regulate CD43 when stimulated by PMA. Recently, we have characterized leukosialin on the human mast cell line HMC-1 and observed that leukosialin is down-regulated after stimulation with PMA. In the present study, we have investigated the mechanism of PMA-mediated down-regulation of CD43 on HMC-1 cells (subclone 5C6). PMA caused the release of soluble leukosialin (123 kD) during HMC-1 cell activation. The molecular weight of soluble leukosialin was nearly identical to that of the cell-membrane bound molecule, suggesting a cleavage proximal from the cell membrane. Inhibitors of serine proteases, like phenylmethylsulphonyl fluoride (PMSF), benzamidine and 3, 4-dichloroisocoumarin, blocked the PMA-mediated cleavage of CD43. In all experiments, the inhibition of CD43-down-regulation was dependent on the concentration of protease inhibitors. Treatment of HMC-1 cells with various proteases (trypsin, alpha-chymotrypsin, elastase, papain, nagarse) substantially decreased anti-CD43 binding capacity and caused the release of soluble leukosialin (116 kD) or its fragments into the supernatant. Pretreatment of HMC-1 cells with neuraminidases from Vibrio cholerae or Arthrobacter ureafaciens resulted in an increased sensitivity of CD43 against proteases, whereas the effects of PMA were not influenced. In conclusion, proteolytic cleavage of CD43 is described for the first time in a cell other than neutrophils, namely HMC-1 cells. Our results suggest that serine proteases are involved in the PMA-mediated down-regulation of leukosialin on HMC-1 cells.
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PMID:Leukosialin (CD43) is proteolytically cleaved from stimulated HMC-1 cells. 924 33


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