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

---

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

Proteoglycans have been isolated from a high speed supernatant fraction of a mouse mastocytoma by procedures which should minimize alteration of the native protein-polysaccharide molecule. The methods used include in vivo labeling proteoglycans with 35S-sulfate, 3H-leucine and 3H-lysine, centrifugation of the tumor homogenate at 105,000 g, cetylpyridinium fractionation of the supernatant, and further purification of some of the fractions obtained by DEAE-cellulose column chromatography, gel filtration on Sepharose 4B and cellulose acetate electrophoresis. Two major sulfated proteoglycans were obtained, one containing keratan sulfate-like material (KSP-S), the other a heparin-like polymer (HP-S). The presence in HP-S of a compound similar to heparin was confirmed by its digestibility with flavobacterium heparinase. HP-S contained about 4 per cent protein. Glycine was the predominant amino acid, and serine did not appear to be involved in the peptide-carbohydrate linkage. The proteoglycan present in HP-S appeared to be homogeneous when examined using cellulose acetate electrophoresis. KSP-S was found to contain sialic acid and its protein content was significantly higher than that of HP-S. Glutamic and aspartic acids were the most abundant amino acids in KSP-S.
...
PMID:Proteoglycans of soluble fraction of mouse mastocytoma. 12 69

Two mAbs that are specific for heparan sulfate-related epitopes have been raised and used to analyze the cellular and tissular distribution of this glycosaminoglycan during development. mAb 10E4 reacts with an epitope that occurs in native heparan sulfate chains and that is destroyed by N-desulfation of the glycosaminoglycan. The antibody does not react with hyaluronate, chondroitin sulfate, or DNA, and reacts only poorly with heparin. The reactivity of proteoglycan extracts or tissue sections with the 10E4 antibody is completely abolished by heparitinase, but is only partially affected by heparinase. mAb 3G10, in contrast, reacts only with heparitinase-treated heparan sulfate chains, proteoglycans, or tissue sections. The 3G10 epitope is destroyed by treatment with mercuric acetate, which indicates that the desaturated uronate generated by the lyase is essential for the reactivity of the antibody. The 3G10 epitope is not generated by treating heparan sulfate proteoglycans with heparinase or chondroitin sulfate proteoglycans with chondroitin sulfate lyases, which indicates that the 3G10 antibody recognizes desaturated uronates that occur in specific structural contexts. The antibody 10E4 and, after heparitinase treatment, the antibody 3G10 decorate the surfaces of many cell types and the extracellular matrix in proximity of the cells, in particular, the basement membranes. The analysis of embryonic and adult tissues reveals important temporal and regional differences in the abundance of the 10E4 and 3G10 epitopes at these sites. Moreover, the staining pattern of the two antibodies is not always superimposable, which is indicative of regional differences in the exposure or structure of the tissular heparan sulfates. As a whole the results suggest that heparan sulfate abounds at sites of active morphogenesis and that the expression of this glycosaminoglycan is developmentally regulated.
...
PMID:Developmental changes in heparan sulfate expression: in situ detection with mAbs. 138 49

Basic fibroblast growth factor (bFGF) binds to cell surface receptors and to heparin sulfate proteoglycans. Heparan sulfate binding may limit bFGF degradation and be an obligatory step for bFGF cell interaction. Transforming growth factor-beta 1 (TGF-beta 1) is a potent regulator of proteoglycan production and composition. The possibility that TGF-beta 1 synergistically regulates bFGF activity by altering bFGF-proteoglycan interactions was investigated. TGF-beta 1 increased 125I-bFGF binding to the extracellular matrix (ECM) of Balb/c3T3 cells 2-4-fold by increasing the number of bFGF binding sites. Increased bFGF binding correlated with a 2-5-fold increase in the production of sulfated proteoglycans, including heparan sulfate proteoglycans. TGF-beta 1 selectively stimulated production of high molecular mass proteoglycans (190-300 kDa) in conditioned medium and stimulated all proteoglycans in ECM. 125I-bFGF bound to TGF-beta 1 induced proteoglycans immobilized onto cationic nylon filters. Furthermore, ECM isolated from TGF-beta 1-treated cells incorporated more mitogenically active bFGF than native ECM. The mitogenic potential of the ECM was significantly reduced by treatment with heparinase. These results suggest that the ability of TGF-beta 1 to stimulate binding of bFGF to ECM, increase ECM heparan sulfate proteoglycan, and potentiate the mitogenic activity of bFGF are linked. Thus one aspect of TGF-beta 1/bFGF synergy may involve modulation of the ECM.
...
PMID:Transforming growth factor beta 1 stimulates the production of basic fibroblast growth factor binding proteoglycans in Balb/c3T3 cells. 140 Apr 36

A very high molecular weight mucin-like glycoprotein was isolated by gel filtration of interphotoreceptor matrix (IPM) from fresh bovine eyes and purified to apparent homogeneity by cesium chloride/guanidine hydrochloride (GuHCl) equilibrium density gradient centrifugation. Although a molecular weight in excess of 10(7) Da is suggested by gel filtration, the presence of SDS or GuHCl did not alter its elution position, indicating that the large size was not simply due to aggregation. Treatment of this material with disulfide reagents, however, led to a decrease in molecular size. On a relative basis, substantially more of this glycoprotein is present in IPM prepared from retina than from retinal pigment epithelium. While the carbohydrate and amino acid composition are not those of a true 'mucin', the large size and many other properties are quite 'mucin-like'. The carbohydrate composition suggests the presence of both N- and O-glycosidically linked sugar chains. The presence of a mucin-type O-glycosidic linkage is indicated by its susceptibility to alkaline cleavage, with concomitant loss of serine and threonine and increase in 240 nm absorbance; production of a fluorescent product upon reaction with cyanoacetamide; lectin binding properties; and production of N-acetylgalactosaminitol upon alkaline borohydride elimination. This glycoprotein was digested by pronase and trypsin, confirming its protein nature, but was resistant to digestion with chondroitin ABC lyase, hyaluronidase and heparinase, as well as RNAase, indicating that these components were not present to any appreciable extent. ELISA for cartilage keratan sulfate was also negative. Centrifugation in CsCl/GuHCl gradients indicated a density much lower than that of a proteoglycan or nucleic acid as well. In vitro biosynthetic studies suggest that both retina and retinal pigment epithelium may be major sources of material in the IPM. The elution patterns of radioactivity were strikingly similar to the UV elution patterns of IPM. The medium from retinal incubations contained very high molecular weight material which was resistant to enzymes which hydrolyse glycosaminoglycans, suggesting that retina may be the source of this high molecular weight, mucin-like glycoprotein.
...
PMID:High molecular weight mucin-like glycoproteins of the bovine interphotoreceptor matrix. 154 29

The sulfated proteoglycans in the normal human lamina cribrosa were studied by electron microscopy after cuprolinic blue dye binding. Within the cores of the laminar plates, three types of cuprolinic blue-positive proteoglycan filaments with different sizes were associated with collagen fibers. These filaments, which were partially sensitive to chondroitinase AC and chondroitinase B, were completely removed by chondroitinase ABC and were identified as chondroitin/dermatan sulfate proteoglycans. In addition, small punctate and filamentous structures that stained with cuprolinic blue were associated with the basal laminae of astrocytes and blood vessels. Enzyme chondroitinase ABC had no effect, but heparinase digested all of these basement membrane-associated structures, indicating that they represented heparan sulfate proteoglycan molecules. Keratanase did not affect any of the cuprolinic blue-positive materials. This investigation illustrates the ultrastructural distribution and morphology of proteoglycans in the human lamina cribrosa and provides baseline information for future studies regarding the roles of proteoglycan molecules in diseases such as glaucoma.
...
PMID:Sulfated proteoglycans in the human lamina cribrosa. 163 36

The effect of nerve growth factor (NGF) on proliferation/differentiation of mast cells was investigated in vitro. Although NGF alone neither supported colony formation of bone marrow-derived cultured mast cells (BMCMC) nor induced development of mast cell colonies from nonadherent bone marrow cells (NBMC), addition of NGF to the suboptimal dose of interleukin 3 (IL-3) significantly increased the numbers of mast cell colonies produced by BMCMC or NBMC in methylcellulose. When stimulated by IL-3 alone, cells in mast cell colonies were not stained by berberine sulfate, a fluorescent dye. In contrast, mast cells developing in methylcellulose cultures obtaining both IL-3 and NGF were stained by berberine sulfate. The fluorescence was abolished by the treatment of heparinase but not of chondroitinase ABC, suggesting that mast cells stimulated by IL-3 and NGF produced and stored heparin proteoglycan. The histamine content of BMCMC maintained by IL-3 was also increased by addition of NGF. Since BMCMC showed mucosal mast cell-like phenotype, NGF appeared to induce the phenotypic change to connective tissue-type mast cells (CTMC). In the culture containing BMCMC, 3T3 fibroblasts, and IL-3, the phenotypic change of BMCMC to CTMC was observed as well. Since NGF was detected in this coculture and since addition of anti-NGF monoclonal antibody suppressed the phenotypic change, NGF produced by fibroblasts appeared to induce the phenotypic change. Neither BMCMC alone nor IL-3 alone increased the concentration of NGF. Therefore, there is a possibility that BMCMC stimulated by IL-3 may induce the production and/or release of NGF by fibroblasts.
...
PMID:Nerve growth factor induces development of connective tissue-type mast cells in vitro from murine bone marrow cells. 171 69

A human cell strain (designated HBM-M) that was derived from the bone marrow of a child with diffuse cutaneous mastocytosis was previously found to possess features that suggested it belonged in the mast cell/monocyte lineage. HBM-M cells synthesized approximately 150-Kd Pronase-resistant proteoglycans that were recognized by an antihuman secretory granule proteoglycan peptide core antibody. These cells also contained in relatively high abundance the same sized mRNA transcript that encodes the peptide core of proteoglycans that are normally localized to secretory granules of hematopoietic cells. However, unlike most other hematopoietic cells, HBM-M cells continuously released their newly synthesized 35S-labeled proteoglycans rather than retaining them in an intracellular storage compartment. Chondroitinase ABC, nitrous acid, and heparinase degraded approximately 76%, 17%, and 7%, respectively, of the HBM-M cell-derived 35S-labeled proteoglycans. As assessed by high performance liquid chromatography, 91% of the unsaturated 35S-labeled disaccharides generated by treatment with chondroitinase ABC were delta Di-4S. The remaining chondroitin sulfate 35S-labeled disaccharides appeared to be primarily a complex mixture of disulfated disaccharides. The 35S-labeled glycosaminoglycans that were not degraded by chondroitinase ABC migrated in two-dimensional cellulose acetate electrophoresis as if they were heparan sulfate or under-sulfated heparin. Thus, although the HBM-M cell-derived proteoglycans had some of the features of proteoglycans produced by normal human mast cells, the heparin-like and chondroitin sulfate glycosaminoglycans bound to the HBM-M cell proteoglycans were considerably less sulfated. Because the only human cell types that have so far been shown to synthesize proteoglycans that have heparin-like glycosaminoglycans bound to a protease-resistant peptide core are mast cells and basophilic leukocytes from patients with myelogenous leukemia, it is possible that the HBM-M cell is a mast cell progenitor cell.
...
PMID:Continuous release of secretory granule proteoglycans from a cell strain derived from the bone marrow of a patient with diffuse cutaneous mastocytosis. 172 5

The domain structure of heparan sulphate chains from an endothelial low-density proteoglycan was examined using specific degradations of the chains while attached to the intact proteoglycan. 'Inner' chain fragments, remaining on the protein core, were separated from 'outer' fragments by gel chromatography, and were subsequently released from the protein core by alkaline cleavage. The structure of 'inner' and 'outer' chain fragments was then examined and compared. Using deaminative cleavage we obtained evidence that the first N-sulphated glucosamine residue is variably positioned some 10-17 disaccharides from the xylose-serine linkage of the proteoglycan. Digestion with heparinase yielded 'inner' and 'outer' fragments covering a broad range of different sizes, indicating a scarce and variable distribution of sulphated iduronic acid in the native chains. N-sulphated glucosamine occurred more frequently in the 'outer' fragments. We also studied the affinity of the endothelial heparan sulphate chains towards two presumptive biological ligands, namely antithrombin III and lipoprotein lipase. A major part of the endothelial heparan sulphate chains showed a weak affinity for antithrombin III and the affinity was essentially lost on heparinase digestion. On lipoprotein lipase-agarose the endothelial heparan sulphate chains were eluted at the same salt concentration as heparin, and the binding persisted, although with decreased strength, after digestion with heparinase.
...
PMID:Domain structure of endothelial heparan sulphate. 195 77

Bovine cardiac sarcolemmal (SL) vesicles contain basic fibroblast growth factor (bFGF)-binding proteins. Binding to native SL vesicles was specific and saturable with a Kd of 6.9 nM and a Bmax of 15.2 pmoles bFGF/mg vesicle protein. Using radioiodinated bFGF as a probe, autoradiography of SL proteins subjected to SDS-PAGE and electroblotting onto nitrocellulose revealed a set of 3-4 bands, of an apparent molecular weight of 100-150 kDa. bFGF binding to these bands was reduced by pretreatment of SL vesicles with heparinase. Binding was abolished by treatment of blot strips with heparinase or high salt concentrations (greater than 0.6 NaCl) but not endoglycosidase F. bFGF-binding activity remained associated with the membrane fraction following an alkaline wash, which removed peripheral membrane proteins. These data suggest that the cardiac SL contains an integral proteoglycan(s) which may be a low affinity binding/storage site of endogenous bFGF.
...
PMID:Detection of the basic fibroblast growth factor low affinity binding site in cardiac sarcolemmal vesicles. 211 2

Proliferation of smooth muscle cells is an important component of pulmonary arterial morphogenesis, both during normal development and pathologic remodeling. However, little is known of the factors that regulate smooth muscle proliferation in these vessels. To investigate the hypothesis that factors produced by endothelial cells may regulate smooth muscle cell growth, we studied the effects of culture medium conditioned by fetal bovine pulmonary arterial endothelium on proliferation of smooth muscle cells in culture. This conditioned medium contains an inhibitor of smooth muscle proliferation that is degraded by nitrous acid, heparinase, and heparitinase, but resists degradation by protease, boiling, and chondroitin ABC lyase, indicating that the inhibitor is structurally similar to heparin. Inhibitor release occurs in both growing and confluent endothelial cell cultures and in the presence and absence of serum. A growth-inhibiting proteoglycan purified to homogeneity from endothelial cell-conditioned medium has physicochemical characteristics similar to those of the prototypic basement membrane heparan sulfate proteoglycan of the Englebreth-Holm-Swarm tumor: an overall size of approximately 10(6) D, heparan sulfate chains of 60,000 D, and a buoyant density of 1.33 g/ml. Antibody raised against the tumor basement proteoglycan recognizes this endothelial heparan sulfate proteoglycan, and Western blotting after SDS-PAGE demonstrates that the core proteins of both proteoglycans migrate as a doublet at apparent molecular weights of 450,000 and 360,000 D. Heparan sulfate glycosaminoglycan prepared from purified medium proteoglycan is a potent inhibitor of smooth muscle cell growth, exhibiting activity approximately 1,000 times greater than that of heparin. These results indicate that endothelial cells cultured from fetal bovine pulmonary arteries produce a basement membrane heparan sulfate proteoglycan that is a potent inhibitor of smooth muscle proliferation. This proteoglycan may mediate endothelial regulation of smooth muscle growth during development or pathologic pulmonary arterial remodeling.
...
PMID:Endothelial heparan sulfate proteoglycan. I. Inhibitory effects on smooth muscle cell proliferation. 213 6


1 2 3 4 5 6 7 8 9 10 Next >>

---