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

Pancreas of the cat was fractionated into its subcellular components by centrifugation through an exponential ficoll-sucrose density gradient in a zonal rotor. This enables a preparation of four fractions enriched in plasma membranes, endoplasmic reticulum, mitochondria and zymogen granules, respectively. The first fraction, enriched by 9- to 15-fold in the plasma membrane marker enzymes, hormone-stimulated adenylate cyclase, (Na+K+)-ATPase, and 5'-nucleotidase, is contaminated by membranes derived from endoplasmic reticulum but is virtually free from mitochondrial and zymogen-granule contamination. The second fraction from the zonal gradient shows only moderate enrichment of the above marker enzymes but contains a considerable quantity of plasma membrane marker enzymes and represents mostly rough endoplasmic reticulum. The third fraction contains the bulk of mitochondria and the fourth mainly zymogen granules as assessed by electron microscopy and marker enzymes for both mitochondria and zymogen granules, namely succinic dehydrogenase, trypsin and amylase. Further purification of the plasma membrane fractions by differential and sucrose step-gradient centrifugation yields plasma membranes enriched 40-fold in basal and hormone-stimulated adenylate cyclase and (Na+K+)-ATPase.
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PMID:Studies on isolated subcellular components of cat pancreas. I. Isolation and enzymatic characterization. 14 36

1. Starved cells of a strain of Escherichia coli and its mutant uncA, treated with colicin K, E2 or E3, remained fully rescuable upon trypsin treatment (stage I in colicin action). The transition to stage II in colicin action (cells no longer rescuable by trypsin) was promoted by the addition of either glucose or D-lactate. 2. Aerobically glucose-grown cells of the normal strain were irreversibly killed by colicin K, E2 or E3 under anerobic conditions, while similarly treated cells ot its mutant uncA remained fully rescuable. The stage I-stage II transition in colicin action was blocked in normal cells under anaerobic conditions when succinate was the sole carbon source. 3. Arsenate alone had little effect on the progression of the stage I-stage II transition in normal cells, treated with colicin K. However, this transition was abolished in the presence of both arsenate and anaerobic conditions. 4. The initiation of colicin action could be coupled to the anaerobic electron transfer systems formate dehydrogenase-nitrate reductase and alpha-glycerophosphate dehydrogenase-fumarate reductase. 5. These results indicate that an energized state of the cytoplasmic membrane is required for the initiation of colicin action and that no high-energy phosphorylated compounds are necessary.
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PMID:Energy requirement for the initiation of colicin action in Escherichia coli. 109 62

Significant increase of liver succinic dehydrogenase (SHD) activity was produced by carrageenin-induced edema in rats. Pretreatment with human placental extract "Placentrex" inhibited the increased liver SHD activity in a dose-dependent manner. "Placentrex" was found to have no effect on the liver SHD activity in normal rats. Furthermore, heat-induced erythrocyte lysis was inhibited to a substantial extent by "Placentrex" and was found to be almost dose-responsive. However, adenosine diphosphate (ADP)-induced platelet aggregation and trypsin activity were not changed in vitro by the "Placentrex". No alkaline phosphatase activity was found in this preparation. All these studies indicate that the membrane stabilization and depletion of adenosine triphosphate (ATP) synthesis may be the basis of anti-inflammatory effect of this drug.
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PMID:Anti-inflammatory effect of human placental extract: a biochemical mechanistic approach. 130 3

Significant increase of liver succinic dehydrogenase (SDH, EC 1.3.99.1) activity was produced by carrageenin-induced edema in rats. Pretreatment with human placental extract inhibited the increased liver SDH activity in a dose-dependent manner. Placental extract was found to have little or no effect on the liver SDH activity in normal rats. Furthermore, heat-induced erythrocyte lysis was inhibited to a substantial extent by the extract and was found to be dose-responsive. However, adenosine diphosphate (ADP)-induced platelet aggregation and trypsin activity were not changed by the placental extract in vitro. The study indicates that the membrane stabilization and depletion of adenosine triphosphate (ATP) synthesis may contribute to antiinflammatory effect of the extract.
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PMID:Role of human placental extract on succinic dehydrogenase activity in carrageenin-induced edema in rats in vivo and its effect on erythrocyte lysis, platelet aggregation and trypsin activity in vitro. 806 56

A method for primary cell culture of fetal rat gastric fundic epithelial cells was developed. The tissue was incubated with 0.125% trypsin at 4 degrees C for 8-10 hours. The epithelial cells isolated were then cultured in DMEM/F12 medium supplemented with 20% fetal calf serum. Within 24 hours the cells attached to the culture plate and became confluent in 3 days. On phase contrast microscopy, over 90% of cell possessed epithelial characteristics. Immunocytochemical studies showed: (a) 90% of cells were positive in anti-cytokeratin antibody staining; (b) 90% of the epithelial cells contained PAS positive granules; (c) 20% of epithelial cells gave a strong reaction for succinic dehydrogenase activity. Electron microscopy (EM) showed microvilli on the surface of cells, junctional complexes (tight juntion and desmosome), glycogen and mitochondria. Autoradiographic studies showed that these cells possessed the capability to synthesize DNA and this ability was maximum on day 2. This in vitro system may provide a valuable model for studies of cellular functions of gastric mucosa.
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PMID:[Primary culture of fetal rat gastric mucosal epithelium]. 1007 56

Although epidemiological studies have suggested that carbon disulfide produces cardiovascular effects in occupationally exposed workers, little is known about its cellular mechanism. The purpose of the present study was to evaluate the functional and histological effects on cardiac myocytes cultured under a condition of carbon disulfide exposure. Cardiac myocytes were isolated from neonatal rat ventricles by trypsin, dispersed and cultured for 3 days in a full Dulbecco's Modified Eagle Medium containing 2% calf serum. Then the myocytes (10(6) myocytes/mL) were incubated with carbon disulfide at concentrations of 0, 20, 40, and 80 micromol/mL for 24 h. The beating arrest rate of myocytes for each group was examined, succinodehydrogenase (SDH) activity in the myocardial cells was assessed using a cytochemical method, and a morphological examination was performed. We found that the beating arrest rate of cardiac myocytes increased with increasing exposure levels. Vacuolization and pseudopodia could be seen in the cytoplasm of the exposed group. SDH activity decreased with increasing exposure levels. The results suggest that CS2 has a direct and dose-dependent cytotoxic effect. The biochemical mechanism may be a reduction of the availability of energy (adenosine triphosphate) to cardiac myocytes, resulting in a decrease of contractility by lack of energy.
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PMID:Carbon disulfide cytotoxicity on cultured cardiac myocytes of rats. 1220 52

Although mostly epidemiological studies suggested that carbon disulfide produces cardiovascular effects in occupationally exposed workers, little is known about its cellular mechanism. The purpose of the present study was to evaluate the functional and histological effects on cardiac myocytes cultured under the condition of carbon disulfide exposure. Cardiac myocytes were isolated from neonatal rat ventricles by trypsin dispersion and cultured for 3 days in a full (Dulbecco's modified eagle medium) medium containing 2% calf serum. Thereafter the myocytes (10(6) myocytes/culture flask) were incubated with carbon disulfide at (CS(2)) the concentrations of 0, 20, 40, and 80 micromol/mL) for 24h. The beating arrest rate of myocytes for each group was examined and succinodehydrogenase (SDH) activity in the myocardial cells was also assessed by cytochemical method, and morphological examination was also performed. We found that the beating arrest rate of cardiac myocytes increased with increasing exposure levels. Vacuolization and pseudopodia may be seen in the cytoplasm of exposure group. SDH activity decreased with increasing exposure levels. The results suggested that CS(2) has a direct cytotoxic effect which is dose dependent. The biochemical mechanism may be a reduction of the availability of energy of the cardiac cytocyte in the form of ATP, resulting in a decrease of contractility by lacking of energy.
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PMID:Carbon disulfide cytotoxicity on cultured cardiac myocyte cell of rats. 1274 64

In order to survive in the host and initiate infection, Salmonella enterica needs to undergo a transition between aerobic and anaerobic growth by modulating its central metabolic pathways. In this study, a comparative analysis of the proteome of S. enterica serovar Typhimurium grown in the presence or absence of oxygen was performed. The most prominent changes in expression were measured in a semiquantitative manner using difference in-gel electrophoresis (DIGE) to reveal the main protein factors involved in the adaptive response to anaerobiosis. A total of 38 proteins were found to be induced anaerobically, while 42 were repressed. The proteins of interest were in-gel digested with trypsin and identified by MALDI TOF mass spectrometry using peptide mass fingerprinting. In the absence of oxygen, many fermentative enzymes catalysing reactions in the mixed-acid or arginine fermentations were overexpressed. In addition, the enzyme fumarate reductase, which is known to provide an alternative electron acceptor for the respiratory chains in the absence of oxygen, was shown to be induced. Increases in expression of several glycolytic and pentose phosphate pathway enzymes, as well as two malic enzymes, were detected, suggesting important roles for these in anaerobic metabolism. Substantial decreases in expression were observed for a large number of periplasmic transport proteins. The majority of these are involved in the uptake of amino acids and peptides, but permeases transporting iron, thiosulphate, glucose/galactose, glycerol 3-phosphate and dicarboxylic acids were also repressed. Decreases in expression were also observed for a superoxide dismutase, ATP synthase, inositol monophosphatase, and several chaperone and hypothetical proteins. The changes were monitored in two different isolates, and despite their very similar expression patterns, some variability in the adaptive response to anaerobiosis was also observed.
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PMID:Proteomic analysis of the adaptive response of Salmonella enterica serovar Typhimurium to growth under anaerobic conditions. 1938 76