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:4.2.2.7 (heparinase)
1,270 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ascitic form of a chemically-induced pancreatic ductal adenocarcinoma in the Syrian golden hamster was very bloody and indistinguishable from blood macroscopically. Unlike blood, the bloody fluid remained unclotted at room temperature. To explore the possibility of presence of anticoagulants, we mixed 40% cell-free fluid with 60% normal human plasma and tested the clottability of the mixture with standard techniques. Plasma containing the fluid showed markedly prolonged activated partial thromboplastin time (APTT), thrombin time (TT) and recalcification time (RCT), and normal prothrombin time (PT) and reptilase time (RT). Comparing the prolongation of APTT of samples containing the fluid to those containing a commercial heparin, the fluid contained an anticoagulant activity equivalent to 0.436 +/- 0.03 unit heparin per ml (mean +/- SEM, n = 14). In addition to prolonging the APTT, TT and RCT, the fluid also inhibited the clotting and amidolytic activities of thrombin. "Heparsorb" had nearly completely neutralized the anticoagulant activity in fluid samples, while protamine sulfate was only partially effective. Incubation of fluid with pronase or phospholipase did not affect its anticoagulant activity; incubation with heparinase had only a minimal effect. Electrophoresis of an alkali digested fluid on cellulose acetate revealed the presence of heparan sulfate. The native ascitic fluid also contained other hemostatic components including platelets, fibrinogen and antithrombin III, but their concentrations were much lower than in blood. Apparently, heparan sulfate in the neoplastic effusion is largely responsible for the bloody ascites tumor remaining unclotted.
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PMID:Anticoagulant activity in cell-free peritoneal fluid of an experimental pancreatic ascites tumor. 300 55

In a previous study we described a family of monoclonal antibodies directed against tracheal antigens having a variety of cellular and subcellular distributions. In the present study, we have extended our findings on four representative antibodies to determine the periodate sensitivity, glycosidase sensitivity, and apparent molecular weight of the corresponding antigens. Since mild periodate oxidation selectively cleaves carbohydrate moiety leaving amino acids intact, loss of antigenicity following this treatment suggests the involvement of sugar residues in the antigenic determinant. This can be confirmed by testing the sensitivity of the antigens to specific glycosidases. By enzyme-linked immunosorbent assay (ELISA), all four antibodies were found to have highest affinity for void volume components isolated by Bio-Gel A15m chromatography of the total tracheal secretion. Further analysis of this void volume material by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions followed by immunoblot analysis revealed that all antigens were carried by high-molecular-weight species (greater than 200,000) which were periodate-Schiff positive but reacted poorly with Coomassie blue. In parallel experiments using immunofluorescence and ELISA, antibody binding was compared under control conditions and following periodate treatment of antigens under varying intensities (10 mM IO4-, 10 min, 4 degrees C; 50 mM IO4-, 1 h, 4 degrees C; 100 mM IO4-, 12 h, 20 degrees C). Similar results were obtained with the two methods, indicating a partial loss of antigenicity for one of the four antigens following the mildest periodate treatment, and total loss of antigenicity for all four antigens following each of the two prolonged treatments. All four antigens showed marked sensitivity to digestion with mixed exoglycosidases and three antigens were also susceptible to endo-beta-galactosidase digestion. Antigenicity was not decreased during incubation with chondroitinase ABC, heparitinase, or heparinase. Immunofluorescence analysis of tracheal tissue sections showed that the four antibodies recognized determinants in different locations, including gland and goblet cell cytoplasmic granules and the apical epithelial membrane. The characteristic immunofluorescence patterns of all antibodies were abolished by periodate incubation of the tracheal sections. Thus, the four antibodies appear to recognize carbohydrate antigens carried by high-molecular-weight glycoproteins, each with different cellular origins.
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PMID:Tracheal carbohydrate antigens identified by monoclonal antibodies. 301 42

Scatchard analysis of binding of 125I-basic fibroblast growth factor (FGF) to baby hamster kidney (BHK) cells revealed the presence of two binding sites: a high affinity site with KD of 20 pM and 80,000 sites per cell and a low affinity site with KD of about 2 nM and 600,000 sites per cell. The binding to the two sites could be separated by first washing the cells with 2 M NaCl at pH 7.5 which released the low affinity binding and then extracting the cells with 0.5% Triton X-100 to recover the 125I-basic FGF bound to high affinity sites. The binding to the high affinity site was acid sensitive, suggesting that it represented binding to the receptor. Binding to the low affinity site could be competed strongly by heparin and less strongly by heparan sulfate but not by chondroitin sulfate, dermatan sulfate, or keratan sulfate. Treatment of BHK cells with heparinase abolished 62% of the low affinity binding, suggesting that the low affinity binding represented binding to cell-associated, heparin-like molecules. A variety of other cell types, including bovine capillary endothelial (BCE) cells, also demonstrated both low and high affinity binding sites. To test whether the low affinity binding might play a role in the basic FGF stimulation of plasminogen activator (PA) production by BCE cells, heparin was added to BCE cultures at concentrations which totally blocked binding of 125I-basic FGF to the low affinity sites. Addition of the heparin did not diminish the increased PA production induced by basic FGF. This suggests that the low affinity binding has no direct role in the stimulation of PA production in BCE cells.
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PMID:High and low affinity binding sites for basic fibroblast growth factor on cultured cells: absence of a role for low affinity binding in the stimulation of plasminogen activator production by bovine capillary endothelial cells. 303 90

Proteoheparan sulfate biosynthesis was studied in cultured bovine aortic endothelial cells by means of pulse and pulse-chase experiments and subcellular fractionations. Three proteoheparan sulfate species were found in the medium. The major species, which the authors have called HS I, appeared in the medium only after an initial lag period and was also found associated with the plasma membrane. The other two (HS II and HS III) appeared in small amounts in the medium at early time points. At later times these were not readily observed because the large amounts of HS I present in the medium. The major medium species, HS I, appeared to be composed of approximately four heparan sulfate chains of approximately 35,000 daltons and a core protein of approximately 55,000 daltons apparent molecular weight. HS I appeared to be homogeneous by gel filtration on Sepharose CL 2B and 6B and elution from DEAE Sephacel, electrophoresis on Nu-Sieve agarose, and CsCl density centrifugation. After digestion with heparinase the core protein appeared to be homogeneous by S-200 Sephacel chromatography. HS I was also found associated with plasma membrane fractions of the cultured bovine aortic endothelial cells, and antisera raised against it stained epithelial and endothelial cells in patterns consistent with a cell surface localization. Of the other two species found in the medium, one (HS II) also appeared to be a component of the cell layer. This species appeared to contain approximately four heparan sulfate chains of approximately 20,000 daltons apparent molecular weight. Antisera raised against a similar molecule produced by HR 9 cell cultures stained basement membranes intensely, supporting the subcellular matrix localization of this molecule. The third species (HS III) was detected in culture medium only and apparently contained two heparan sulfate chains of approximately 20,000 daltons apparent molecular weight. These results support the concept of multiple endothelial cell proteoheparan sulfate species which exhibit differences in structure and localization and possibly diverse specialized functions.
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PMID:Aortic endothelial cell proteoheparan sulfate. I. Isolation and characterization of plasmamembrane-associated and extracellular species. 303 49

The ability of mouse IL-3-dependent, bone marrow culture-derived mast cells (BMMC) to generate serosal mast cells (SMC) in vivo after adoptive transfer to mast cell-deficient mice has been defined by chemical and immunochemical criteria. BMMC differentiated and grown from WBB6F1-+/+ mouse progenitor cells in medium containing PWM/splenocyte-conditioned medium synthesized a approximately 350,000 Mr protease-resistant proteoglycan bearing approximately 55,000 Mr glycosaminoglycans, as defined by gel filtration of each. Approximately 85% of the glycosaminoglycans bound to the cell-associated BMMC proteoglycans were chondroitin sulfates based upon their susceptibility to chondroitinase ABC digestion; HPLC of the chondroitinase ABC-generated unsaturated disaccharides revealed these glycosaminoglycans to be chondroitin sulfate E. As determined by heparinase and nitrous acid degradations, approximately 10% of the glycosaminoglycans bound to BMMC proteoglycans were heparin. In contrast, mast cells recovered from the peritoneal cavity of congenitally mast cell-deficient WBB6F1-W/Wv mice 15 wk after intraperitoneal injection of BMMC synthesized approximately 650,000 Mr protease-resistant proteoglycans that contained approximately 80% heparin glycosaminoglycans of approximately 105,000 Mr. Thus, after adoptive transfer, the SMC of the previously mast cell-deficient mice were like those recovered from the normal WBB6F1-+/+ mice that were shown to synthesize approximately 600,000 Mr proteoglycans that contained approximately 80% heparin glycosaminoglycans of approximately 115,000 Mr. As assessed by indirect immunofluorescence staining and flow cytometry using the B1.1 rat mAb (an antibody that recognizes an epitope located on the neutral glycosphingolipid globopentaosylceramide), approximately 5% of BMMC bound the antibody detectably, whereas approximately 72% of the SMC that were harvested from mast cell-deficient mice 15 wk after adoptive transfer of BMMC were B1.1-positive; approximately 82% of SMC from WBB6F1-+/+ mice bound the antibody. These biochemical and immunochemical data are consistent with the results of previous adoptive transfer studies that characterized mast cells primarily on the basis of morphologic and histochemical criteria. Thus, IL-3-dependent BMMC developed in vitro, cells that resemble mucosal mast cells, can give rise in vivo to SMC that express phenotypic characteristics of connective tissue mast cells.
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PMID:Phenotypic changes of bone marrow-derived mast cells after intraperitoneal transfer into W/Wv mice that are genetically deficient in mast cells. 310 74

Basophilic leukocytes from two patients with myelogenous leukemia were enriched to a purity of 10 to 45% by density gradient centrifugation. Ultrastructurally, these basophilic leukocytes contained segmented nuclei and granules with reticular patterns resembling those of normal basophils, and other granules with scroll and grating patterns resembling those of normal connective tissue mast cells. The 35S-labeled macromolecules isolated from these cells were approximately 140,000 m.w. Pronase-resistant proteoglycans bearing approximately 15,000 m.w. glycosaminoglycans. On incubation with chondroitinase ABC, nitrous acid, and heparinase, the 35S-labeled proteoglycans were degraded 50 to 84%, 16 to 43%, and 8 to 37%, respectively, indicating the presence of both chondroitin sulfate and heparin. As assessed by high performance liquid chromatography, the 35S-labeled chondroitin sulfate disaccharides liberated by chondroitinase ABC treatment were approximately 95% monosulfated chondroitin sulfate A and approximately 5% disulfated chondroitin sulfate E. The presence of heparin was confirmed by two-dimensional cellulose acetate electrophoresis of the 35S-labeled glycosaminoglycans. Cell preparations, enriched to 75% basophilic leukocytes by sorting for IgE+ cells, also synthesized 35S-labeled proteoglycans containing chondroitin sulfate and heparin. In one experiment, treatment of the cells with 1 microM calcium ionophore A23187 resulted in a 12% net release of both chondroitin sulfate and heparin containing 35S-labeled proteoglycans, a 57% net release of histamine, and the de novo generation of 8, 8, and 0.16 ng of immunoreactive equivalents of prostaglandin D2, leukotriene C4, and leukotriene B4, respectively, per 10(6) cells. Because only mast cells have been found to contain Pronase-resistant heparin proteoglycans, to generate PGD2 on cell activation, and to contain granules with scroll and grating patterns, these findings indicate that in some patients with myelogenous leukemia there are basophilic cells that possess properties of tissue mast cells.
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PMID:Biochemical and morphological characterization of basophilic leukocytes from two patients with myelogenous leukemia. 310 70

Chondroitin sulfate represents approximately 15% of the 35SO4-labeled glycosaminoglycans carried by the proteoglycans of the cell surface and of the basolateral secretions of normal mouse mammary epithelial cells in culture. Evidence is provided that these chondroitin sulfate-carrying proteoglycans are hybrid proteoglycans, carrying both chondroitin sulfate and heparan sulfate chains. Complete N-desulfation but limited O-desulfation, by treatment with dimethyl sulfoxide, of the proteoglycans decreased the anionic charge of the chondroitin sulfate-carrying proteoglycans to a greater extent than it decreased the charge of their constituent chondroitin sulfate chains. Partial depolymerization of the heparan sulfate residues of the proteoglycans with nitrous acid or with heparin lyase also reduced the effective molecular radius of the chondroitin sulfate-carrying proteoglycans. The effect of heparin lyase on the chondroitin sulfate-carrying proteoglycans was prevented by treating the proteoglycan fractions with dimethyl sulfoxide, while the effect of nitrous acid on the dimethyl sulfoxide-treated proteoglycans was prevented by acetylation. This occurrence of heparan sulfate-chondroitin sulfate hybrid proteoglycans suggests that the substitution of core proteins by heparan sulfate or chondroitin sulfate chains may not solely be determined by the specific routing of these proteins through distinct chondroitin sulfate and heparan sulfate synthesizing mechanisms. Moreover, regional and temporal changes in pericellular glycosaminoglycan compositions might be due to variable postsynthetic modification of a single gene product.
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PMID:Heparan sulfate-chondroitin sulfate hybrid proteoglycan of the cell surface and basement membrane of mouse mammary epithelial cells. 316 90

An inhibitory component that diminishes estrogen receptor (ER) binding to nuclei in vitro is present in cytosol prepared from calf uterus. The inhibitor is heat stable and resistant to enzymatic treatment with trypsin, chymotrypsin, proteinase K, deoxyribonuclease I, or ribonucleases A, T1, and U2. Results of chromatography on DEAE-cellulose and Sephadex G-150 indicate that the factor is a negatively charged macromolecule. Inhibitory activity is sensitive to sequential digestion with chondroitinase ABC, hyaluronidase, and heparinase. Approximately 70% of the inhibitory activity is destroyed by treatment with heparinase alone. Heparitinase destroys only 30% of this activity. Furthermore, the addition of pure hyaluronic acid or chondroitin sulfate to the ER-nuclei binding assay results in little inhibition, whereas addition of heparin inhibits 75% of receptor binding. Overall, these results indicate that glycosaminoglycans, present in bovine uterine cytosol, are capable of inhibiting ER-nuclei interactions. The most potent inhibitory glycosaminoglycan displays heparin-like characteristics.
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PMID:Characterization of a cytosolic inhibitor of calf estrogen receptor binding to nuclei. 330 79

Human lung mast cells (HLMC) enriched up to 99% purity by counter current elutriation and density gradient centrifugation were labeled with 35S-sulfate to determine cell-associated proteoglycans. The 35S-labeled proteoglycans were extracted by the addition of detergent and 4 M guanidine-HCl, and separated from unincorporated precursor by Sephadex G-50 chromatography. 35S-Proteoglycans chromatographed over Sepharose 4B with a Kav of 0.48. 35S-Glycosaminoglycans separated from the parent 35S-proteoglycans by beta-elimination and chromatographed over Sepharose 4B with a Kav of 0.63. Characterization of 35S-proteoglycans by chondroitin ABC lyase treatment revealed approximately 36% of the proteoglycan to be composed of chondroitin sulfates. Analysis by HPLC of component disaccharides liberated by chondroitin ABC lyase using an amino-cyano-substituted silica column indicated that the chondroitin sulfates consisted of the monosulfated A disaccharide (GlcUA----GaINAc4SO4) (75%) and the over-sulfated E disaccharide (GlcUA----GaINAc4,6-diSO4) (25%). Nitrous acid/heparinase-susceptible heparin proteoglycans accounted for approximately 62% of the total 35S-proteoglycans present in the HLMC. Proteoglycans remaining after exposure of the original proteoglycan extract to either heparinase or chondroitin ABC lyase were of similar size, suggesting that the majority of heparin and chondroitin sulfate glycosaminoglycans were on separate protein cores. Proteoglycans extracted from HLMC were protease insensitive. Hence, in addition to heparin proteoglycans, HLMC synthesize a hitherto unrecognized quantity of chondroitin sulfate E proteoglycans.
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PMID:Identification of chondroitin sulfate E in human lung mast cells. 335 2

In the preceding two papers, we described two new classes of sulfated N-linked oligosaccharides isolated from total cellular 35SO4-labeled macromolecules of different mammalian cell lines. The first class carries various combinations of sialic acids and 6-O-sulfate esters on typical complex-type chains, while the second carries heparin and heparan-like sequences. In this study, we have characterized a sulfophosphoglycoprotein of 140 kDa from FG-Met-2 pancreatic cancer cells whose oligosaccharides share some properties of both these classes. The molecule was localized to the cell surface by electron microscopy using a monoclonal antibody (S3-53) and by cell surface 125I-labeling. Metabolic labeling of the cells with radioactive glucosamine, methionine, inorganic sulfate, or phosphate all demonstrated a single 140-kDa molecule. Pulse-chase analysis and tunicamycin treatment indicated the glycosylation of a putative primary translation product of 110 kDa via an intermediate (120 kDa) to the mature form (140 kDa). Digestion with peptide:N-glycosidase F (PNGaseF) indicated a minimum of four N-linked glycosylation sites. PNGaseF released more than 90% of the [6-3H]GlcNH2 label and 40-70% of 35SO4 label from the immunoprecipitated 140-kDa molecule. The isolated oligosaccharides were characterized as described in the preceding two papers. The majority of [6-3H]GlcNH2-labeled molecules were susceptible to neuraminidase. More than 50% of the 35SO4 label was associated with only 5-10% of the 3H-labeled chains. Some of the sulfated chains were partly sialylated molecules with four to five negative charges. Treatment with nitrous acid released about 25% of the 35SO4 label as free sulfate, together with 6% of the [6-3H]GlcNH2 label, indicating the presence of N-sulfated glucosamine residues. Some of these oligosaccharides were degraded by heparinase and heparitinase. Therefore, while they are not as highly charged as typical heparin or heparan chains, they must share structural features that permit recognition by the enzymes. Thus, this 140-kDa glycoprotein contains at least four asparagine-linked chains substituted with a heterogeneous mixture of sulfated sequences. The heterogeneity of these molecules is as extensive as that described for whole-cell sulfated N-linked oligosaccharides in the preceding two papers.
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PMID:Sulfated N-linked oligosaccharides in mammalian cells. III. Characterization of a pancreatic carcinoma cell surface glycoprotein with N- and O-sulfate esters on asparagine-linked glycans. 337 52


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