Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Heparin was administered subcutaneously 2 times a day for 4 days to 5 horses. An additional group of 5 horses was used as time-matched controls. Significant decreases in PCV, erythrocyte count, and hemoglobin concentration were observed during heparin therapy. The mean corpuscular volume (MCV) of the heparin-treated horses increased to a peak value of 66.1 fl on the last day of treatment. Erythrocyte creatine concentration and glucose 6-phosphate dehydrogenase activity increased moderately during the treatment. These data indicated that the rapid, profound increase in MCV during heparin therapy was not primarily a result of release of large immature erythrocytes from the bone marrow. A second experiment was subsequently performed, using 3 horses. These horses were given heparin 2 times a day, as was done in the first experiment. Saline wet mounts of erythrocyte suspensions were examined once a day for the presence of agglutination. Cell suspensions were examined with or without exposure to a dilute trypsin solution, and erythrocyte counts were done on each suspension, using an electronic cell counter. Agglutination of erythrocytes was evident on the first day of treatment and became more pronounced as treatment progressed. Exposure to trypsin solution reversed the agglutination. The apparent erythrocyte count decreased and MCV increased sharply in the samples processed normally, but there was little change in those suspensions exposed to trypsin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Heparin-induced agglutination of erythrocytes in horses. 382 44

The kidney is a key target tissue in animal and human carcinogenesis, yet there are no established short-term tests for studying the genotoxicity of chemicals in the kidney. We have developed an assay for the measurement of chemically induced DNA repair as unscheduled DNA synthesis (UDS) in isolated rat kidney cells following in vivo treatment. Male Fischer-344 rats were injected intraperitoneally with chemicals dissolved in saline or corn oil. After various treatment times, the kidneys were perfused with a collagenase/trypsin solution (CTS), minced into small pieces, and stirred in CTS at 37 degrees C for 1 hr to dissociate cells. Cultures contain a high proportion of epithelial cells from the proximal and distal tubules. Cultures were incubated for 16-18 hr with 3H-thymidine in Williams' Medium E supplemented with 20% fetal bovine serum. UDS was measured by quantitative autoradiography as net grains/nucleus (NG). The percentage of cells in repair (% IR) was defined as the percentage of cells with greater than or equal to 3 NG. Saline- or corn oil-injected controls consistently produced -3 to -5 NG with less than 1% IR. The time course of DNA repair following treatment with the direct-acting mutagen methylmethane sulfonate (MMS) or the renal carcinogen azaserine showed a peak response at 2 hr after treatment. Azaserine showed a rapid decline in UDS at 12 and 24 hr, whereas MMS exhibited a relatively high UDS level at 24 hr. The renal carcinogens methylazoxymethanol acetate, N-methyl-N-nitrosourea, and streptozotocin all yielded strong positive UDS responses. The liver and intestinal carcinogen 1, 1-dimethylhydrazine at doses up to 50 mg/kg was cytotoxic to kidney cells, but induced less than 0 NG. Treatment with 1,2-dimethylhydrazine, which induces kidney tumors in mice but not rats, also induced less than 0 NG. Treatment with o-anisidine, a weak renal carcinogen, did not induce UDS in the kidney, suggesting that it may be acting as a tumor promoter. These results demonstrate the usefulness of this assay for the detection and study of a variety of genotoxic kidney carcinogens.
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PMID:Measurement of unscheduled DNA synthesis in rat kidney cells following in vivo treatment with genotoxic agents. 406 62

Group B Neisseria meningitidis has been subdivided into 11 distinct serotypes by a sensitive bactericidal inhibition technique. The antigens responsible for induction of bactericidal type-specific antibodies were found to be extractable from the group B cells with heating at 100 C either by 0.017 n HCl in saline or by normal saline. These extracted serotype antigens were detected by a capillary precipitin test. The development of methods for extraction and assay of the serotype antigens permitted studies on their immunochemistry. The serotype antigens were distinct from the group-specific substance. Acid extracts contained abundant serotype antigen, but were devoid of group-specific substance. The identity of serotype antigens as proteins was confirmed by their sensitivity to Pronase and trypsin. The molecular weight of these antigens as estimated by G-200 Sephadex chromatography and by electrophoresis in polyacrylamide gels is in excess of 200,000 daltons. Saline extracts containing the serotype antigen could be fractionated into three distinct fractions with acetic acid: pH 4.5 and pH 3.5 precipitated fractions and a pH 3.5 supernatant fraction. The pH 4.5 precipitated fraction contained the serotype antigen.
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PMID:Classification of Neisseria meningitidis group B into distinct serotypes. IV. Preliminary chemical studies on the nature of the serotype antigen. 462 2

The aim of this study was to establish whether ranitidine treatment influences the trophic effect of caerulein on the pancreas of rats. Ranitidine (20 mg/kg b.w.), caerulein (1 microgram/kg b.w.) were applied for 7 days alone, or combined with caerulein, given intraperitoneally twice a day. Saline treated rats served as control. Caerulein increased pancreatic weight, total pancreatic protein, trypsin, amylase and RNA contents. Ranitidine when given alone did not influence pancreatic growth and composition. When ranitidine, however, was combined with caerulein, it abolished the trophic effect of caerulein on the pancreas. The trophic effect of caerulein on rat pancreas could be abolished by H2-receptor antagonist (ranitidine) treatment. The authors suggest that the drug exerts its inhibitory effect on the acinar cells directly.
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PMID:Ranitidine inhibits the trophic effect of caerulein on the pancreas in rats (preliminary data). 608 12

University of California, Davis line 200 White Leghorn chickens develop an inherited progressive fibrotic disease that includes the appearance of antinuclear antibodies (ANA). To further characterize these ANA, serial aged line 200 birds were studied. Greater than 50% of line 200 birds develop antinuclear and anticytoplasmic antibodies; fluorescent staining patterns included cytoplasmic spider web, most prevalent at 1 mo of age, and fine speckled patterns, characteristic of chickens 6 mo and older. By enzyme-linked immunosorbent assay, 40.4% of line 200 birds were found to have antibodies to single-stranded DNA (ssDNA). In contrast, antibodies to histones, RNA, or poly A . poly U were not detected. Precipitating antibodies to saline extracts from chicken liver were noted in 33.3% of line 200 birds. Saline extracts from turkey, pheasant, and partridge liver but not rat, rabbit, or mouse tissues were also positive in immunodiffusion testing with these line 200 birds. The antigenicity of chicken liver extracts was sensitive to pronase, protease K. and pH variations greater than 10 and less than 5; however, they were resistant to trypsin. DNase. RNase, and incubation at 37 degrees C and 56 degrees C for 1 h. Cell fractionation in conjunction with column chromatographic techniques revealed that several protein antigens with apparent molecular weights in the range of 62,000-290,000 were present in cytoplasm but not in isolated nuclei. Line 200 sera were not reactive against nuclear ribonucleoprotein, Sm, Scl-70, or SS-B/La antigens. Thus, line 200 chickens develop antinuclear and anticytoplasmic antibodies at an early age, which recognize a unique group of protein antigenic determinants found only in avian species. Moreover, and of particular interest, the presence of autoantibodies to saline-extractable antigens correlated with positive ANA, antibodies in ssDNA, and to the clinical expression of disease.
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PMID:Diversity of autoantibodies in avian scleroderma. An inherited fibrotic disease of White Leghorn chickens. 620 15

Salt-extracted microsomal membranes (K-RM) contain an activity that is capable of releasing the signal recognition particle (SRP)-mediated elongation arrest of the synthesis of secretory polypeptides (Walter, P., and G. Blobel, 1981, J. Cell Biol., 91:557-561). This arrest-releasing activity was shown to be a function of an integral microsomal membrane protein, termed the SRP receptor (Gilmore, R., P. Walter, and G. Blobel, 1982, J. Cell Biol., 95:470-477). We attempted to solubilize the arrest-releasing activity of the SRP receptor by mild protease digestion of K-RM using either trypsin or elastase. We found, however, that neither a trypsin, nor an elastase "solubilized" supernatant fraction exhibited the arrest-releasing activity. Only when either the trypsin- or elastase-derived supernatant fraction was combined with the trypsinized membrane fraction, which by itself was also inactive, was the arrest-releasing activity restored. Release of the elongation arrest was followed by the translocation of the secretory protein across the microsomal membrane and the removal of the signal peptide. Thus, although we have been unable to proteolytically sever the arrest-releasing activity from K-RM and thereby to uncouple the release of the elongation arrest from the process of chain translocation, we have been able to proteolytically dissect and reconstitute the arrest-releasing activity. Furthermore, we found that the arrest-releasing activity of the SRP receptor can be inactivated by alkylation of K-RM with N-ethylmaleimide.
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PMID:Protein translocation across the endoplasmic reticulum. I. Detection in the microsomal membrane of a receptor for the signal recognition particle. 629 35

The tapeworm Hymenolepis diminuta releases proteins that inhibit trypsin activity. These proteins may be either antienzymes or nonspecific macromolecules that interfere with trypsin. Saline solutions with initial pH values ranging from 5.5 to 10.0 were all acidified to pH 5.0 by tapeworms. If the initial pH was lower than 5.0, it was raised. Because trypsin activity is inhibited at pH 5.0, this intestinal parasite can protect itself from digestion by regulating its environmental pH or releasing trypsin inhibitors, or both.
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PMID:Trypsin inhibition by tapeworms: antienzyme secretion or pH adjustment? 682 82

The cytotoxic test system for Shigella shigae toxin was improved and used to study the stability of the toxin to various pH values, temperature, and chemicals. Inhibition of protein synthesis is the first demonstrable effect in cells treated with Shigella toxin. This inhibition appears to be at the level of peptide chain elongation. An inhibition effect on cell-free protein synthesis is exhibited by toxin pretreated first with trypsin and then with dithiothreitol and 8 M urea or 1% sodium dodecyl sulfate. Ribosomes treated with toxin or its A1 fragment had lost most of their ability to polymerize [14C]phenylalanine in a poly(U)-dependent cell-free system. Salt-washed ribosomes in simple buffered solutions were inactivated at a rate of at least 40 ribosomes/(min) (A1 fragment). Addition of antitoxin immediately stopped further inactivation, but it did not reactivate the inactivated ribosomes. 60 S ribosomal subunits from toxin-treated ribosomes had a marked reduction in ability to support polyphenylanine synthesis, whereas 40 S subunits from toxin-treated ribosomes retained their activity. Toxin-treated ribosomes retained their ability to incorporate [3H]puromycin into growing peptide chains, indicating that the peptide bond formation is not the function inhibited.
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PMID:The cytotoxic activity of Shigella toxin. Evidence for catalytic inactivation of the 60 S ribosomal subunit. 689 22

Previous reports have shown that rough microsomes treated with high salt (Warren and Dobberstein, 1978, Nature, 273:569-571) or proteases (Walter et al., 1979, Proc. Natl. Acad. Sci, U. S. A., 76:1,795) are unable to vectorially translocate nascent proteins. Readdition of the high salt or protease extracts restored activity to such inactive rough microsomes. A detailed study was carried out to determine how this factor interacts with the rough microsomal membrane. Proteolytic cleavage was found to be necessary but not sufficient to remove this factor from the membrane. A subsequent treatment with high salt had to be carried out. Endogenous (pancreatic) protease could effect the required cleavage, but low levels of trypsin, clostripain, or elastase were far more efficient. Several proteases were not effective. The minimum level of salt (after proteolysis) required to solubilize the active factor was approximately 200 mM KCl. Salt extracts prepared by treatment with one of the effective proteases were capable of restoring activity to inactive microsomes produced by treatment with one of the others.
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PMID:A membrane component essential for vectorial translocation of nascent proteins across the endoplasmic reticulum: requirements for its extraction and reassociation with the membrane. 700 Jul 96

Saline extracts prepared from the electric lobe, the electromotor nerves, and the electric organ (the electromotor system) of Torpedo californica increase the number of ACh receptors on uninnervated chick myotubes in culture, while extracts from T. californica liver or skeletal muscle do not. The extracts also increase the ACh sensitivity of treated myotubes, indicating that newly synthesized receptors are functional. The active substance(s) is heat sensitive but not trypsin sensitive. Gel filtration on Bio-Gel P-150 shows that the activity is associated with a peak of low (less than 5,000-dalton) molecular weight activity. Labeling studies with rhodamine-conjugated alpha-bungarotoxin show that, in addition to their effect on receptor number, these extracts also cause aggregation of prelabeled ACh receptors on the myotube surface.
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PMID:Extracts of electric lobe and electric organ from Torpedo californica increase the total number as well as the number of aggregates of chick myotube acetylcholine receptors. 711 73


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