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)

1. The electrophoretic mobilities of a mouse lymphoma cell, a Chinese-hamster fibroblast and a somatic-cell hybrid (also fibroblastic), produced by fusion of the hamster cell and a mouse lymphoma cell, were measured at 25 degrees C over a range of pH, concentration of Ca2+ ions and concentration of La3+ ions. 2. All the cells have pI at pH3.5. 3. Ca2+ ions decrease the mobilities and zeta potentials of the cells to zero in the range 1-100mM. 4. La3+ ions lower the mobilities and zeta potentials in the range 10 muM-1 mM, and the cells become positively charged above 1 mM. 5. The data are consistent with specific adsorption of La3+ ions on approx. 2 X 10(14) sites/m2 of cell surface with a free energy of approx. -37kJ/mol. 6. The effects of Ca2+, La3+ and ionic strength on the extent of aggregation of the cells and of neuraminidase-treated cells were studied. 7. Ca2+ ions do not markedly increase aggregation, whereas La3+ ions gave rise to extensive aggregation in the range 10 muM-1 mM, corresponding to the region of La3+ adsorption. 8. Both fibroblastic cell lines are aggregated at high ionic strength. 9. The fibroblastic cells have larger amounts of trypsin-sensitive carbohydrate than does the lymphoma cell; the possible role of this material in cellular aggregation is discussed.
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PMID:The electrophoretic properties and aggregation of mouse lymphoma cells, chinese-hamster fibroblasts and a somatic-cell hybrid. 1 52

Cells from several mouse lymphomas formed rosettes with nonsensitized foreign erythrocytes through C-type virus particles clustered on the cell surface in serum-free medium held at 4 degrees C. This type of rosetting was found most typically in a lymphoma induced by Rauscher leukemia virus in tissue culture (RD-12), but it also occurred in 23 of 61 spontaneous thymic lymphomas in AKR mice. Chemically or X-ray-induced leukemias and spontaneous reticulum cell sarcomas did not form rosettes. The nature of the rosette formation may be interpreted as viral hemadsorption, with a possible relationship to hemagglutination by murine leukemia viruses. The receptor on virus particles was trypsin sensitive and showed high affinity to serum inhibitors (RIF). Serum rosette-inhibiting activity was assessed by a quantitative rosette inhibition test; rosette inhibition proved widely distributed among species. Physicochemical properties of serum RIF and their function both in vivo and in vitro were described. Rosette formation with similar temperature requirements, previously reported in a mouse lymphoma carrying membrane-bound heterophile cold hemagglutinin, was readily distinguished from viral hemadsorption by its insensitivity to mouse serum RIF.
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PMID:Temperature-dependent rosette formation by mouse lymphoma cells as a result of viral hemadsorption. 5 22

Preliminary characterization of two mouse thymus-dependent (T) lymphocyte xenoantigens, T25 and T200, which are selectively labelled by lactoperoxidase-catalysed iodination of T-cells, is described. Both molecules are membrane-bound glycoproteins. Fractionation of membrane vesicles prepared from BW5147 lymphoma cells by sedimentation through sucrose density gradients show that antigens T25 and T200 are in fractions enriched with plasma membrane. Moreover antigen T200 is partially degraded when viable cells are treated briefly with low concentrations of trypsin. Both molecules are efficiently solubilized in buffers containing sodium deoxycholate or Nonidet P-40, as measured by failure to sediment at 100000g for 60min. However, gel filtration on Sepharose 6B showed the presence of aggregated material in Nonidet P-40 extracts which was not found in deoxycholate-solubilized membranes. After solubilization in detergent, antigens T25 and T200 bind to, and may be specifically eluted from, columns of pea lectin--Sepharose or concanavalin A--Sepharose. Both molecules are heterogeneous when examined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. As judged by its binding to columns of pea lectin, at least part of the heterogeneity of mouse thymocyte antigen T25 resides in its carbohydrate moiety.
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PMID:Preliminary characterization of two thymus-dependent xenoantigens from mouse lymphocytes. 6 76

In order to obtain structural information and to facilitate studies of the covalent structure of T-cell immunoglobulin, we have performed investigations of the peptide fragments of the heavy chain of this molecule, on a comparative basis, with heavy chains of serum immunoglobulins. T-cell immunoglobulin was isolated from 125I-labelled culture medium of monoclonal continuously cultured T-lymphoma cells by means of immunoadsorbents. Peptides were prepared from the purified 125I-labelled heavy chain by means of cleavage with cyanogen bromide or digestion with trypsin. We then resolved these peptides and compared them with those peptides derived from 131I-labelled murine mu, gamma and alpha chains separately and in mixed label experiments by means of polyacrylamide gel electrophoresis in sodium dodecyl sulfate containing buffers, 2 dimensional peptide mapping and ion exchange chromatography. The profiles of the radiolabelled peptides obtained from the T-lymphoma heavy chains were quite distinct from those of murine gamma chains but indicated a structural similarity to both mu and alpha chains, which share some common peptides. These results are consistent with the antigenic and physicochemical data available and suggest that T-cell immunoglobulin is a new isotype that shows similarities to IgA and IgM, but of which the precise nature of the constant region has yet to be delineated.
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PMID:Molecular properties of T-lymphoma immunoglobulin. II. Peptide composition of the heavy chain. 10 42

Structural studies of T-cell immunoglobulin light chains have been carried out in order to ascertain whether they possess a unique structure or if they resemble standard kappa or lambda isotypes. T-cell immunoglobulin was isolated from 125I-labelled culture medium of monoclonal, continuously cultured T-lymphoma cells, and the purified 125I-labelled light chains were subjected to either cleavage by cyanogen bromide or digestion with trypsin. These peptides were then resolved and compared with those derived from 125I- and 131I-labelled murine kappa and lambda chains in mixed label experiments, by means of polyacrylamide gel electrophoresis in sodium dodecyl sulfate-containing buffers and ion exchange chromatography. The profiles obtained suggested that T-lymphoma immunoglobulin light chains are immunoglobulin polypeptides and most closely resemble kappa chains. These results support available antigenic and mRNA hybridization data, which also suggest that T cells bear kappa-like light chains.
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PMID:Molecular properties of T-lymphoma immunoglobulin. III. Peptide composition of the light chain. 10 43

A Herpesvirus saimiri-infected marmoset lymphoid cell line (MLC-1) was examined for the presence of soluble factors which might affect lymphocyte functions and, therefore, relate to the pathogenesis of lymphoma in vivo. MLC-1 cells, cell extracts, and culture fluids were shown to reduce the spontaneous deoxyribonucleic acid (DNA) synthesis of normal peripheral blood lymphocytes and to completely inhibit their response to phytohemagglutinin (PHA). Suppression of PHA response was demonstrated against a variety of human and nonhuman primate species, with 90 to 95% inhibition occurring at dilutions of extract as great as 1:5,120. Inhibition of this type was also demonstrated using extracts of two of five other lymphoblastoid cell lines tested. Physical-chemical characteristics of the active factor(s) revealed a non-sedimentable, non-dialyzable, trypsin-resistant molecule, which was stable at 56 C for 30 min but inactivated at 80 C for 30 min. The factor(s) also exerted an effect on some but not all established lymphoblastoid cell lines, where DNA, ribonucleic acid, and protein synthesis were all inhibited, with DNA synthesis being the most affected (95% suppression). Cellular respiration was not affected by the presence of the factor(s), and the inhibition of DNA synthesis was reversible after 24 h. Purified human interferon did not reduce the PHA response of normal owl monkey peripheral blood lymphocytes and was less effective against an established lymphoblastoid cell line than the MLC-1 extract. Antiviral activity was also demonstrated in the preparations and may represent interferon, which these cells are known to produce at low levels.
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PMID:Inhibition of the mitogenic response of normal peripheral lymphocytes by extracts or supernatant fluids of a Herpesvirus saimiri lymphoid tumor cell line. 17 49

A specific marker for an immature population of thymus cells in the rat was shown by the rosette formation between thymus cells and guinea pig erythrocytes. This method was used to classify murine leukemia virus-induced rat lymphomas. Eight of nine Gross virus-induced rat lymphoma lines, which originated in the thymus, formed rosettes; whereas Friend, Rauscher, or Moloney virus-induced rat lymphoma lines, which originated in either the thymus, spleen, or mesenteric lymph nodes, did not form rosettes. The percentage of the total cells which formed rosettes in the Gross lymphoma lines decreased with in vivo passages. If the tumor cells were exposed to trypsin treatment, then the tumor cells would form rosettes. Lymphoma lines which lacked rosette-forming cells did not show rosette formation after trypsin treatment. An immunofluorescence test showed that none of the lymphoma lines induced by Gross, Friend, Rauscher, or Moloney viruses carried the surface immunoglobulin characteristic of B-cells. These results suggest that Gross lymphomas may be derived from the thymic cortex and that Friend, Rauscher, or Moloney lymphomas may be derived from either mature thymus cells (non-rosette-forming cells) or from a subpopulation of the B-cell series which does not have the surface immunoglobulin G receptor.
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PMID:A thymus cell marker in murine leukemia virus-induced lymphomas of rats. 22 24

A cell surface glycoprotein (designated T100) of apparent m.w. 100,000 by SDS-PAGE under reducing and nonreducing conditions was precipitated from NP-40 extracts of surface radiolabeled thymocytes from a variety of inbred strains of mice by the standard noncongenic Lyt-2.1-typing serum. The inbred stain distribution, trypsin sensitivity on intact cells, and apparent m.w. of T100 suggest that it is different from Lyt-2.1. Inheritance and expression of T100 suggest that it is determined by an allele at a single locus, and testing of CXB recombinant inbred strains and B6.C minor histocompatibility congenic strains suggest that this locus is linked to H-25. Antiserum absorption experiments, two-stage cytotoxicity assays, and results of immunoprecipitations performed after prebinding antibody to radiolabeled thymocytes suggest that some T100 is accessible to antibody on the intact cell surface. However, for unknown reasons the number of cells required to absorb anti-T100 precipitating activity from antiserum was much higher than for removal of anti-Lyt-2.1 activity. A molecule with properties of T100 was also detected on lymph node cells and on the AKTB-1 lymphoma.
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PMID:T100: a new murine cell surface glycoprotein detected by anti-Lyt-2.1 serum. 31 40

Chemotactic factors for malignant neoplastic cells can be generated from either the fifth component of complement or from leukotactic fractions obtained from zymosanactivated serum. Digestion of the fifth component of complement by trypsin initially produced leukotactic activity, but as digestion continues, leukotactic activity is lost and tumor cell chemotactic activity is generated. Separation of the leukotactic activity is lost and tumor cell chemotactic activity is generated. Separation of the leukotactic activity and tumor cell chemotactic activity can be accomplished by gel filtration or isoelectric focusing. Gel filtration indicates that the tumor cell chemotactic factor has a molecular weight of approximately 8000 daltons. Tumor cell chemotactic activity can be generated by trypsinizing the leukotactic fractions isolated by isoelectric focusing. The responses of cultured Walker tumor cells or of Walker ascites tumor cells are dose-dependent and truly chemotactic. Cells from a murine malignant lymphoma do not respond to the complement-derived chemotactic factor for tumor cells, indicating that not all malignant cells share this functional property.
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PMID:Characteristics of the chemotactic response of neoplastic cells to a factor derived from the fifth component of complement. 56 88

The bovine pancreatic inhibitor of trypsin (trasylol, Bayer) (T) and the soy bean trypsin inhibitor (SBI) were coupled with peroxidase (P). With each one of these coupling products (T and P and SBI and P) the cell distribution of proteolytic enzymes (PE) of ascitic cells of L5178Y murine lymphoma, was localized. The reactions were developed by means of Karnowsky's reaction with diaminobenzidine and H2O2. The preparations were observed under light and electronic microscopy. It was found that L5178Y cells contain intracellular PE in granules measuring 0.1 to 0.8 min diameter, and superficial PE that form a continuous layer of 80 to 120 nm over the cell surface. Superficial PE were not identified in 20 per cent of L5178Y cells, while in every case intracellular granules were found. Both the macrophages and the polimorphonuclear cells present in the ascitic fluid contained intracellular PE granules measuring 0.05 to 0.4 micron in diameter, and did not contain superficial PE.
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PMID:Proteolytic enzymes marking of malignant lymphoblasts, study of the L5178Y murine lymphoma. 63 54


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