Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The properties of rat liver cytoplasmic alpha-tocopherol binding protein have been studied. 2. The binding protein sedimented in the 3 S region of sucrose density gradients, and gel filtration indicated an approximate molecular weight of 30 500. 3. Of the tissues examined by the present assay, binding was detectable only in the liver. 4. Optimal binding was achieved by incubation at 26 degrees C for 4 h and was independent of pH between 7.4 and 9.0. 5. Pronase completely abolished binding. The binding protein was, however, almost completely resistant to trypsin, and unaffected by RNAase, DNAase, triacylglycerol lipase, and phospholipase C. 6. A variety of tocopherol analogues and other lipid-soluble compounds were tested for their ability to compete for binding. Only alpha-tocopherol and to a lesser extent alpha-tocotrienol and gamma-tocopherol exhibited competition. alpha-Tocopherol acetate, alpha-tocopherol quinone and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid had no effect on binding. 7. Tocopherol binding was reversible, and the tocopherol was not metabolized during incubation.
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PMID:Rat liver alpha-tocopherol binding protein. 87 71

Exposure of rabbit pulmonary arterial smooth muscle cells to hydrogen peroxide cause dose-dependent stimulation of [14C] arachidonic acid (AA) release and enhancement of the cell membrane-associated phospholipase A2 activity as well as of the cell membrane-bound serine esterase activity tested against synthetic substrate p-tosyl-L-arginine methyl ester. While pretreatment of cells with serine protease inhibitors, viz. phenyl methyl sulphonyl fluoride, diisopropyl fluorophosphate and alpha-1-proteinase inhibitor, and antioxidant vitamin E prevents H2O2 stimulation of AA release and the cell membrane-bound serine esterase and PLA2 activities, that with actinomycin D and cycloheximide is devoid of any effect on H2O2 caused stimulation of AA release and the smooth muscle cell membrane associated serine esterase and PLA2 activities. Treatment of the smooth muscle cell membrane suspension with the serine protease trypsin markedly stimulates PLA2 activity. These results suggest that on exposure to H2O2 the smooth muscle cell membrane-bound serine esterase plays an important role in stimulating the cell membrane associated PLA2 activity thereby resulting in an increase in AA release.
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PMID:Role of serine esterase in hydrogen peroxide-mediated activation of phospholipase A2 in rabbit pulmonary arterial smooth muscle cells. 129 64

Microsomes from rat liver were used to investigate the mechanisms by which thiol compounds protect cellular membranes against damage from oxidants. Glutathione (GSH), dihydrolipoate and dithioerythritol, but not cysteine, ameliorated the loss of thiol groups of microsomal proteins attacked by Fe/ADP/NADPH or Fe/ADP/ascorbate prooxidant systems. The protection by GSH, but not dihydrolipoate or dithioerythritol, appeared to be enzymic since it was lost after microsomes were heated or treated with trypsin. The blocking of microsomal protein thiols with N-ethylmaleimide also diminished the protective effect of GSH. Lipid peroxidation, as assessed by chemiluminescence and vitamin-E loss, was inhibited in parallel with the protection of protein thiols. In microsomes lacking vitamin E, the protection of protein thiols by exogenous thiols was diminished. However, the GSH-dependent protection of vitamin E showed no preference for alpha-tocopherol over other tocopherol homologs. It is suggested that a GSH-dependent enzyme maintains protein thiols in the face of oxidative damage during microsomal peroxidation. A maintenance of protein thiols might not only protect important metabolic functions, but may also afford an antioxidant capacity to membranes, and account for one facet of the GSH-dependent inhibition of lipid peroxidation.
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PMID:Protection by glutathione and other thiol compounds against the loss of protein thiols and tocopherol homologs during microsomal lipid peroxidation. 144 67

Two brothers of Arab origin, aged 15 and 10 years, with isolated congenital lipase and colipase deficiency are described. Both were normally developed with a history of passing greasy stools since early infancy. Both have remarkable steatorrhoea and low serum carotene and vitamin E concentrations. After exocrine pancreatic stimulation, lipase and colipase activities in the duodenal fluid were almost completely absent, while amylase trypsin, bile salt, and pH values were normal. No other aetiology for exocrine pancreatic insufficiency was found. This is the first report of congenital combined lipase and colipase deficiency in two brothers.
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PMID:Isolated lipase and colipase deficiency in two brothers. 226 86

The vitamin E deficiency was studied for its effect on the activity of enzymes participating in metabolism of xenobiotics. Experiments with 54 rats have demonstrated that the maintenance of animals on the vitamin-E-deficient diet within 13-14 weeks decreases the activity of microsomal monooxygenases (demethylase and hydroxylase), NADH- and NADPH-reductases, aryl- and aliesterases in the liver and lungs, which is a result of disturbance of hydrophobic and polar interactions in microsomal membranes. Vitamin E deficiency makes the extent of solubilization of these enzymes higher under the influence of deoxycholate and trypsin and intensifies inactivation of these enzymes under the effect of urea. In the lungs and in the liver of the vitamin E deficient rats the content of reduced glutathione decreases as well as the activity of glutathione reductase, glutathione-S-transferase, aldehyde dehydrogenase, while the activity of gamma-glutamyltransferase increases; glutathione disulphide is accumulated.
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PMID:[The effect of vitamin E deficiency on enzyme activity and the status of the membrane fraction of rat liver microsomes]. 258 40

The effect of vitamin E deficiency on levels of proteinase inhibitors in sex glands of male rats was studied. Inhibitor levels against cysteine proteinases, such as ficin and cathepsin H, and against serine proteinase such as trypsin were examined. Vitamin E deficiency for 4 mo after weaning induced a fivefold increase in cysteine proteinase inhibitor level in testis, a two- to fourfold increase in prostate and epididymis and no change in seminal vesicle. No appreciable change was observed in trypsin inhibitor level in testis, epididymis or seminal vesicle. Therefore, vitamin E deficiency was reflected most sensitively by the cysteine proteinase inhibitor level in testis. These observations agree with our previous findings that alpha-cysteine proteinase inhibitors in serum increased greatly whereas trypsin inhibitor in serum did not change in vitamin E-deficient rats. Major histological changes were observed in the testes of rats fed a vitamin E-deficient diet for 4 mo, although testis weight was not significantly affected by vitamin E deficiency.
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PMID:Enhancement of testicular cysteine proteinase inhibitor level in vitamin E-deficient rats. 349 20

The effect of Se deficiency on pancreatic digestive enzyme activity and nutrient digestibility was studied by using pigs weaned at 3 wk of age from sows fed a diet deficient in Se and low in vitamin E. Pigs were fed a Torula yeast diet supplemented with 100 IU dl-alpha-tocopheryl acetate/kg of diet. Treatments were levels of supplemental Se of 0, .025, .050, .075 or .100 ppm. Apparent digestibility was determined at the end of the second and fourth week. Digestive enzyme activity, glutathione peroxidase (GSH-Px) activity and Se concentration were determined in pancreatic tissue at the end of the 4-wk experiment. Selenium concentration in the pancreas increased linearly (P less than .01) and quadratically (P less than .05) in response to increasing level of Se supplementation. The correlation between pancreas Se level and GSH-Px activity was .36 (P less than .05). Supplementation of Se had no effect on pancreas weight, protein content or the activity of pancreatic trypsin, chymotrypsin, alpha-amylase or lipase. Apparent digestibility increased linearly for dry matter (P less than .01) and N (P less than .05) as Se supplementation increased. There was however, no significant effect on ether extract digestibility. Apparent digestibilities were higher (P less than .01) at 4 wk than those measured at 2 wk.
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PMID:Effect of supplemental selenium on pancreatic function and nutrient digestibility in the pig. 660 13

Dehulled seeds from Cucumeropsis Mannii Naudin mainly consist of lipids (40.3%) and proteins (34.5%). Carbohydrates, minerals, and water amount to 16.5, 3.7, and 5.9%, resp. From this composition a caloric value of 2 190 kJ/100 g is calculated. The major component of the oil linoleic acid (57.9%). Short-chain fatty acids are absent. All important macro and micro nutrient elements are present in sufficient amounts for human nutrition. The seeds are rich in vitamin E and in niacin (30.8 mg/100 g and 14.3 mg/100 g. resp.). Consumption of 100 g dehulled seeds covers the daily requirement of essential fatty acids, vitamin E and essential amino acids--methionine excepted. Besides starch (14.3 g/100 g) sucrose (1.14 g/100 g), raffinose (0.42 g/100 g) and stachyose (0.41 g/100 g) as well as traces of glucose and fructose are present. The proteins extracted with various solvents (H2O, 0.1 M KCl-, 0.1 mM K3PO4-, and 0.5% SDS-solution) are studied by amino acid analysis. SDS-electrophoresis and isoelectric focusing. Molecular weights of these proteins are between 5,000 and 80,000 daltons with the fraction between 20,000 and 35,000 predominating. The seeds exhibit weak inhibition of trypsin and do not inhibit alpha-chymotrypsin.
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PMID:[Chemical composition of seeds from Cucumeropsis mannii Naudin and their suitability as food]. 662 67

Leukocyte adhesion may play a central role in the pathogenesis of preservation-reperfusion injury to liver grafts. We previously showed that lymphocyte adhesion to sinusoids is dependent on the length of cold ischemia. In the present study we examined the mechanisms of lymphocyte adherence after harvesting combined with a short and a long preservation time. The effects of lymphocyte adherence on liver function were also examined. Rat livers were stored at 1 degrees C in University of Wisconsin solution for 45 min or 30 hr and then reperfused at 37 degrees C in the isolated perfused rat liver with isogeneic lymphocytes in an asanguineous perfusate. The role of reactive oxygen intermediates was investigated with allopurinol, a vitamin E analog and ascorbate or superoxide dismutase and catalase. For us to determine the role of Kupffer cells, Kupffer cell blockade was produced by gadolinium chloride. Leukotriene B4 effects were examined with the lipooxygenase inhibitor, nordihydroguaiaretic acid. We evaluated the possible presence of mechanical obstruction by studying flow rates and the circulation of red blood cells. We examined the role of adhesion molecules by pretreating lymphocytes with trypsin or neuraminidase and by exposing livers to arabinogalactan. We investigated the effects of lymphocyte adhesion on liver function by comparing perfusate liver enzymes in livers reperfused with and without lymphocytes, with trypsinized lymphocytes and with an increased number of lymphocytes. Allopurinol significantly reduced hypoxanthine degradation, and nordihydroguaiaretic acid inhibited leukotriene B4 release into the perfusate. The ability of gadolinium chloride to inhibit Kupffer cells was shown by colloid carbon uptake. In livers harvested and preserved for 45 min, lymphocytes decreased about 40% during reperfusion. In livers preserved for 30 hr, the reduction was significantly greater (about 80%). Lymphocyte adherence was lessened in livers preserved for 45 min by all three of the reactive oxygen intermediate protectants and by gadolinium chloride. In contrast, neither reactive oxygen intermediate protectants nor gadolinium chloride reduced adherence in livers preserved for 30 hr. Nordihydroguaiaretic acid had no effect in livers preserved for either 45 min or 30 hr. Portal flow in livers preserved for 45 min and 30 hr was similar, suggesting an absence of mechanical obstruction, and this finding was supported by a complete absence of red cell trapping. Trypsinization of lymphocytes and exposure of livers to arabinogalactan significantly lessened lymphocyte adherence in livers preserved for 30 hr but not in those preserved for 45 min.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Lymphocyte adherence in the reperfused rat liver: mechanisms and effects. 838 Jul 89

Exposure of bovine pulmonary-arterial endothelial cells to the oxidant lipid t-butyl hydroperoxide (t-Bu-OOH) increases cell-membrane-associated phospholipase A2 (PLA2) activity and stimulates arachidonic acid (AA) release. To test the hypothesis that a membrane-associated serine esterase plays an important role in activating PLA2, the present study was undertaken. In addition to increasing PLA2 activity and AA release, t-Bu-OOH also enhances the activity of a membrane-associated serine esterase that cleaves the synthetic substrate N alpha-p-tosyl-L-arginine methyl ester (TAME). Changes in the activity of this membrane-bound serine esterase correlate directly with changes in the activity of PLA2. Serine esterase inhibitors such as phenylmethanesulphonyl fluoride, di-isopropyl fluorophosphate and alpha 1-proteinase inhibitor, and TAME, a synthetic substrate for serine esterase, prevent the increase in serine esterase activity, PLA2 activity and AA release caused by t-Bu-OOH. Pretreatment of the endothelial cells with the antioxidant vitamin E prevents t-Bu-OOH-induced stimulation of AA release and the cell-membrane-associated serine esterase and PLA2 activities. Adding t-Bu-OOH or the serine esterase trypsin to the endothelial-cell membrane fraction also significantly augments PLA2 activity, implying that these treatments activate latent PLA2. These results suggest that t-Bu-OOH stimulates a membrane-associated serine esterase that plays a crucial role in activating PLA2 and releasing AA.
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PMID:Role of a membrane-associated serine esterase in the oxidant activation of phospholipase A2 by t-butyl hydroperoxide. 850 92


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