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)

Cultured mouse blastocysts produce plasminogen activator, a protease that converts the zymogen plasminogen into the trypsin-like enzyme, plasmin. We have fractionated the blastocyst and cultured the constituent cell types. Trophoblast outgrowths free of inner cell mass derivatives secrete plasminogen activator during a time period that closely parallels the invasive phase of trophoblast cells in utero. Isolated inner cell masses also produce plasminogen activator; further fractionation of the inner cell mass as well as studies with primary cultures obtained from midgestation tissues demonstrate that enzyme formation is restricted entirely to parietal endoderm cells. Secretion of the enzyme may facilitate the migration of parietal endoderm cells along the trophoblast layer as the yolk sac cavity enlarges during gestation. F9 embryonal carcinoma cells do not secrete detectable amounts of plasminogen activator. However, when these cells are induced to differentiate, the resulting parietal endoderm-like cells are capable of producing the enzyme. These results are consistent with previous findings suggesting that plasminogen activator production may be a characteristic of invasive and/or migratory cells.
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PMID:Differentiation of early mouse embryonic and teratocarcinoma cells in vitro: plasminogen activator production. 97 58

We have examined the binding and functional activity of monoclonal antibody (MAb) SG-1 that was raised by immunization against embryonal carcinoma cells and screened using KHT fibrosarcoma cells. Quantitative absorption, binding and in situ immunochemical staining assays indicate that the MAb SG-1-defined epitopes are expressed preferentially by the highly metastatic KHT35-L1 cells relative to the weakly metastatic, parental KHTp cells. Furthermore, there was a significant correlation (p less than 0.05) between the expression of MAb SG-1-defined antigen on the cells, following trypsin treatment, and their metastatic ability. Binding of MAb SG-1 to antigen was inhibited by specific sulfated polysaccharides including cerebroside sulfate (brain sulfatide), fucoidan, and dextran sulfate (500 kD) but not by heparan, chondroitin, keratan or dextran (5 kD) sulfates. Initial characterization of antigen from KHT cells indicates that the epitope of MAb SG-1 is defined by sulfated glycoconjugates containing galactose and sulfate but not N-acetylglucosamine. In the total lipid extracts of KHT35-L1 cells the antigen was detected in the delipidated protein fraction as well as in the chloroform/methanol fraction. These results suggest that the sulfated glycoconjugate determinants identified by MAb SG-1 may be relevant to the metastatic process of KHT fibrosarcoma cells.
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PMID:Sulfated glycoconjugate determinants recognized by monoclonal antibody, SG-1, correlate with the experimental metastatic ability of KHT fibrosarcoma cells. 169 55

We have derived and characterized a new cell line from a teratoma with a embryonal carcinoma and seminoma. The medium used for the cell culture was Eagle's MEM synthetic culture medium (Gibco Inc.) supplemented with 10% new calf serum (Tissue plus, Mitsubishi Kasei Co.). Subcultures were performed on 3 to 4 days basis at 1:2 split by the use of 0.25% trypsin solution. The morphology of obtained cells was a epithelial-like shape and the cell grew in a monolayered sheet with about 30-32 hrs of population doubling time. The model chromosome number of this cell line was 73 including one large submetacentric marker chromosome. The temperature sensitivity and the tumorigenicity of this cell were tested in this experiment.
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PMID:[Establishment and characterization of a new human germ cell tumor strain (NOC-Ts) in culture]. 195 31

Fab fragments of rabbit anti-embryonal carcinoma cells IgG dramatically perturb cell-cell interactions between embryonal carcinoma cells and between early mouse embryo blastomeres. These antibodies prevent compaction of preimplantation embryos (or trigger their decompaction) and have similar effects on embryonal carcinoma cells. They probably act through the masking of specific molecules (Fab targets) involved in the mechanisms of recognition between cells during compaction. Fab target molecules have been extracted from embryonal carcinoma cell membranes and purified using their property to inhibit the effects mediated by anti-embryonal carcinoma Fab. The solubilization of the Fab targets could be achieved using both detergent extraction and trypsin treatment of membranes. In the latter case, a glycoprotein of 84,000 daltons could be purified which has all the properties expected from the Fab target and accounts for most of the Fab-inhibiting activity of embryonal carcinoma cell membranes.
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PMID:A cell surface glycoprotein involved in the compaction of embryonal carcinoma cells and cleavage stage embryos. 615 85

The authors investigated the presence and distribution of keratin in germ cell tumors using a rabbit-anti-keratin antiserum and a monoclonal antikeratin antibody--which is specific for keratin classes of 40, 50, and 56.5 kdaltons--by various immunohistochemical methods on frozen sections, alcohol-fixed, and formalin-fixed paraffin-embedded tissues. Thirty-four germ cell tumors were studied. These were the following: 18 seminomas, 10 embryonal carcinomas, 2 teratocarcinomas, 3 yolk sac tumors and 1 choriocarcinoma. All seminomas, including four poorly differentiated (so-called anaplastic seminomas), gave negative results, regardless of the method employed. Embryonal carcinoma, the epithelial component of the teratocarcinoma, the yolk sac tumors, and choriocarcinoma were at least focally positive for keratin. The monoclonal antibody provided a cleaner background and stronger staining than the rabbit-anti-total-human-epidermal-keratin antibody. Best results were obtained from fresh-frozen sections or alcohol-fixed, paraffin-embedded materials. Formalin-fixed, nonseminomatous tumors, when predigested with trypsin and incubated overnight with primary antibody, gave no false-negative results but staining was often focal. The authors' results agree with the reported absence of detectable keratin in primordial germ cells of the normal testis, and with prevailing concepts of the histogenesis of germ cell tumors. These results indicate that the presence or absence of keratin by immunocytochemical methods can be helpful in distinguishing seminoma from embryonal carcinoma.
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PMID:Antikeratin antibodies in tumor diagnosis. Distinction between seminoma and embryonal carcinoma. 620 39

Two plasmin inactivators, plasminase A and B, and their inhibitor embrinogen were isolated from embryonal carcinoma F9 cells by preparative two-dimensional electrophoresis. Plasminases A and B have molecular weights of 160,000 and 82,000, respectively. Both are serine proteinases which digest the light chain of plasmin in a time dependent inactivation process. The heavy chain of plasmin is not affected by this action. Plasminases A and B show similar specificity towards synthetic and natural polypeptide inhibitors. The interaction of the two enzymes leads to their inhibition. Embrinogen (m.w. 84,000) inhibits both plasminases A and B as well as urokinase and plasmin. Its activation by trypsin creates embrin, a proteinase directed against plasmin heavy chain.
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PMID:Plasmin regulating system from embryonal carcinoma F9 cells: plasminases A, B and embrinogen. 623 28

The effect of retinoic acid on the synthesis and degradation of basement membrane components by endoderm cells derived from mouse embryonal carcinoma (EC) cells was studied in a serum-free, defined medium. By immunofluorescence these cells accumulate type IV collagen, laminin, and fibronectin after growth in media containing epidermal growth factor (EGF), fibroblast growth factor (FGF), insulin, transferrin, and Pedersen fetuin. Collagen accounted for 2 to 4% of the newly synthesized proteins, of which 90% were found in the culture media. This collagen was identified as Pro-type IV be gel electrophoresis and enzymatic susceptibility. The EC cells preferentially attached to type IV collagen in vitro and such attachment was mediated by laminin. Treatment of EC cells with retinoic acid caused an increased accumulation of collagen (10 to 15% of secreted proteins) and also stimulated the elaboration of latent protease which degraded laminin and type IV collagen. The laminin-degrading activity was plasminogen dependent. The type IV collagen-degrading activity was a metal protease which could be activated by trypsin or plasmin. It is likely that at least part of the laminin degrading activity is plasmin (mediated through plasminogen activator), since highly purified plasmin is shown to degrade native laminin.
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PMID:Stimulation of retinoic acid of synthesis and turnover of basement membrane in mouse embryonal carcinoma-derived endoderm cells. 628 41

The present study deals with the biochemical properties of high-molecular-weight glycopeptides isolated from the surface of human teratocarcinoma cells. This cell surface material released by mild trypsin digestion from galactose-labeled human teratocarcinoma cells, Tera I and PA1, was digested extensively with pronase. Most of the resulting glycopeptides were large and were excluded from a Sephadex G-50 column. The properties of these large cell surface glycopeptides isolated from Tera I cells have been examined in detail. It is clear from these experiments that they are neither acidic mucopolysaccharides nor mucin-type glycopeptides with short oligosaccharide chains. Although the glycopeptides are hardly hydrolyzed by beta-galactosidase even after prior digestion with neuraminidase, around 30% of the glycopeptides are depolymerized by treatment with endo-beta-galactosidase from Escherichia freundii. The large cell surface glycopeptides from Tera I cells therefore appear to be very similar to the large glycopeptides seen on mouse embryonal carcinoma cells, which have core structures composed of galactose and N-acetylglucosamine. Like the mouse cell glycopeptides, a fraction of the large glycopeptides from these human cells bind to agarose-conjugated fucose-binding proteins and peanut agglutinin.
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PMID:Biochemical properties of the high-molecular-weight glycopeptides released from the cell surface of human teratocarcinoma cells. 680 82

Compaction, a process of cell-cell adhesion between mouse blastomeres or between embryonal carcinoma (EC) cells requires calcium ions. A decompaction effect similar to that observed in the absence of Ca2+ is triggered by Fab fragments of rabbit anti-EC IgG. This effect occurs through the recognition of a specific cell-surface glycoprotein named uvomorulin. An 84,000 dalton fragment of uvomorulin (UMt) has been previously extracted by trypsin from EC cell membranes and purified. WE present evidence that effects of Ca2+ on compaction are transmitted through conformational changes in uvomorulin. First, Ca2+ protects UMt from further proteolysis by trypsin. Mn2+ and Sr2+ have similar effects, whereas this protection is reversed by La3+. Second, UMt can bind the monoclonal antibody De1 only in the presence of Ca2+ (half-binding at 10(-5) M Ca2+). This antigenic exposure also takes place in the presence of Mn2+ or Sr2+ and is reversed by La3+. Third, metal ions (Ca2+, Mn2+, Sr2+) that promote trypsin resistance and recognition by DE1 are found to trigger the compaction of morulae and EC cells. Metal ions (La3+) that reduce trypsin resistance and affinity for DE1 result in decompaction.
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PMID:Cell-cell interactions in early embryogenesis: a molecular approach to the role of calcium. 697 38

Previous studies have demonstrated the presence of amyloid beta (Abeta) in neurons (NT2N) derived from a human embryonal carcinoma cell line (NT2) by steady state metabolic radiolabeling and immunoprecipitation. We show here that Abeta is present intracellularly since trypsin digestion of intact NT2N cells at 4 degrees C did not eliminate the Abeta recovered in cell lysates. To determine whether both Abeta40 and Abeta42 are produced intracellularly, quantitative sandwich enzyme-linked immunosorbent assay (ELISA) was performed using COOH-terminal end-specific anti-Abeta monoclonal antibodies. Sandwich ELISA detected intracellular Abeta40 and A++beta42 in NT2N cell lysates at a ratio of 3:1, whereas secreted Abeta40 and Abeta42 were recovered in medium conditioned by NT2N cells at a ratio of approximately 20:1. Metabolic steady state and pulse-chase labeling studies demonstrated a 2-h delay in the detection of cell-associated Abeta40/Abeta42 in the medium, suggesting that Abeta is generated at a slow rate intracellularly prior to its secretion. Finally, as NT2N cells mature over time in culture, the secretion of Abeta40 and Abeta42 increases more than 5-fold over 7 weeks. This increase in the secretion of Abeta40/Abeta42 in NT2N cells as a function of time may recapitulate a similar phenomenon in the aging brain.
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PMID:Amyloids beta40 and beta42 are generated intracellularly in cultured human neurons and their secretion increases with maturation. 862 41


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