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)

Inhibition of thrombin by heparin cofactor II (HCII) is accelerated by dermatan sulfate, heparan sulfate, and heparin. Purified HCII or defibrinated plasma was incubated with washed confluent cell monolayers, 125I-thrombin was added, and the rate of formation of covalent 125I-thrombin-inhibitor complexes was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Fibroblasts and porcine aortic smooth muscle cells accelerated inhibition of thrombin by HCII 2.3-7.5-fold but had no effect on other thrombin inhibitors in plasma. Human umbilical vein endothelial cells and mouse macrophage-derived cells did not accelerate the thrombin-HCII reaction. IMR-90 normal human fetal lung fibroblasts treated with heparinase or heparitinase accelerated the thrombin-HCII reaction to the same degree as untreated cells. In contrast, treatment with chondroitinase ABC almost totally abolished the ability of these cells to activate HCII while chondroitinase AC had little or no effect, suggesting that dermatan sulfate was responsible for the activity observed. [35S]Sulfate-labeled proteoglycans were isolated from IMR-90 fibroblast monolayers and conditioned medium and fractionated into two peaks on Sepharose CL-2B. The lower Mr proteoglycans contained 74-76% dermatan sulfate and were 11-25 times more active with HCII than the higher Mr proteoglycans which contained 68-97% heparan sulfate. The activity of the lower Mr proteoglycans decreased 70-90% by degradation of the dermatan sulfate component with chondroitinase ABC. These results confirm that dermatan sulfate proteoglycans are primarily responsible for activation of HCII by IMR-90 fibroblasts. We suggest that HCII may inhibit thrombin when plasma is exposed to vascular smooth muscle cells or fibroblasts.
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PMID:Activation of heparin cofactor II by fibroblasts and vascular smooth muscle cells. 379 24

In order to localize and characterize proteoglycans in human lung alveoli, we have used the cationic dye Cuprolinic Blue according to the critical electrolyte concentration method. After staining, five types of Cuprolinic Blue-positive filaments become apparent: two types in the basement membranes of type I and type II epithelial cells respectively and lying in one or two layers; one type, more scattered, localized in the basement membrane of the endothelial cells and another kind associated with collagen fibrils and separated from each other according to the main banding period (+/- 60 nm) of these fibrils. Finally, there was a type of filament which was only locally present at a variety of places. The basement membrane filaments were sensitive to heparinase, heparitinase, pronase (without prefixation) and nitrous acid treatment, but not to Streptomyces hyaluronidase, neuraminidase, chondroitinase ABC, chondroitinase AC, pronase (after prefixation) and 2.0 M MgCl2 treatment. The basement membrane filaments, therefore, represent heparan sulphate-containing proteoglycans. On the other hand, the collagen fibril associated filaments were sensitive to treatment with heparinase, chondroitinase ABC and pronase (without prefixation), but insensitive to Streptomyces hyaluronidase, neuraminidase, nitrous acid, heparitinase, chondroitinase AC, pronase (after prefixation) and 2.0 M MgCl2 (after prefixation) treatment. These filaments thus represent iduronic acid-rich dermatan sulphate-containing proteoglycans. Several physiological functions for these proteoglycans are discussed.
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PMID:Ultrastructural localization and characterization of proteoglycans in human lung alveoli. 397 3

Ultrastructural studies on human lung were performed with special attention to the interstitial acid mucopolysaccharides by Ruthenium Red staining and several enzyme digestion tests with Streptomyces hyaluronidase, chondroitinase ABC, chondroitinase AC, heparinase, trypsin and collagenase. Periodic lateral granules on the major cross bands of collagen fibrils and amorphous coats on them became visible by Ruthenium Red staining. The surface of elastic fibres, associated microfibrils, and some fine fibrils 10-20 nm in diameter were stained. Ruthenium Red also stained the surface of fibroblast and smooth muscle cells, basement membrane and filamentous long segments. In the interstructural space, granular substances 10-80 nm in diameter and fine filaments 3--4 nm thick, which formed a fine reticular network, were clearly observed. They were not visible on the usual thin section. The granular substances were located on the cross points of the fine filaments. They spread continuously and connected with each of the cells and extracellular structures in the pulmonary interstitium. The results of the enzyme digestion tests on the Ruthenium Red-positive material are discussed.
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PMID:Electron microscopic observations on pulmonary connective tissue stained by Ruthenium Red. 617 14

Human basophils were obtained from three donors with myelogenous leukemia. Proteoglycans were labeled by using [35S]sulfate as precursor and were extracted in 1 M NaCl with protease inhibitors to preserve their native structure. [35S]proteoglycans filtered on Sepharose 4B with an average m.w. similar to that of a rat heparin proteoglycan that has an estimated m.w. of 750,000. The [35S]glycosaminoglycan side chains filtered with an average m.w. slightly smaller than a 60,000-m.w. glycosaminoglycan marker. The [35S]glycosaminoglycans were resistant to heparinase and susceptible to degradation by chondroitin AC lyase and chondroitin ABC lyase. The intact [35S]glycosaminoglycans chromatographed on DEAE Sepharose as a single peak eluting just before an internal heparin marker. These findings indicate that the [35S]glycosaminoglycans were made up only of chondroitin sulfates. No heparin was identified. The chondroitin sulfate disaccharides that resulted from the action of chondroitin ABC lyase on the basophil glycosaminoglycans consisted of 92% delta Di-4S, 6% delta Di-6S, and 2% disulfated disaccharides. The [35S]chondroitin sulfate proteoglycans were susceptible to cleavage with proteases and could be shown to be released intact from basophils during degranulation initiated by the calcium ionophore A23187. The basophil proteoglycans and glycosaminoglycans were capable of binding histamine in water, but not in phosphate-buffered saline, and had no anticoagulant activity.
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PMID:Biochemical and functional characterization of proteoglycans isolated from basophils of patients with chronic myelogenous leukemia. 619 18

Proteoglycans of 300 000 mol.wt. were isolated from dispersed rat basophil tumour cells after labelling of the sulphated mucopolysaccharides with 35S in vitro:90% of the 35S-labelled mucopolysaccharides were extracted at high salt concentration. Alkali degradation of the 35S-labelled proteoglycans yielded glycosaminoglycan chains of 40 000 mol.wt. The composition of the salt-extracted 35S-labelled mucopolysaccharides, as defined by parallel or sequential degradation with chondroitinase AC, chondroitinase ABC and heparinase and resolution of the disaccharide-digestion products obtained with chondroitinase AC, was 48--61% chondroitin 4-sulphate, 20--30% dermatan sulphate, 10--15% heparin and 7--9% chondroitin 6-sulphate. Most of the salt-extracted 35S-labelled mucopolysaccharides were highly charged, with heparin and chondroitin 6-sulphate being relatively uniform in this regard, whereas chondroitin 4-sulphate and dematan sulphate exhibited a range of charge characteristics. The diversity of sulphated mucopolysaccharides present in the rat leukaemic basophil is in contrast with the predominance of heparin in the rat mast cell.
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PMID:Isolation and characterization of sulphated mucopolysaccharides from rat leukaemic (RBL-1) basophils. 644 99

Polysaccharides and other complex carbohydrates were released by proteolysis of the chloroform-methanol insoluble residue of 10 day-old worms and eggs of Hymenolepis diminuta. Gas-liquid chromatographic analysis of alditol acetate derivatives of monosaccharides released from the polysaccharides by hydrolysis revealed that in the 10 day-old worm, glucose was the most abundant sugar, followed by galactose, glucosamine, galactosamine, fucose and possibly rhamnose. Mannose was least abundant and xylose was absent. In the egg, glucose and galactose were equally abundant, followed by the same sugars found in 10 day-old worms, and xylose was present. Uronic acid was detected in both fractions by specific chemical tests. None of the saccharide material from eggs and worms was susceptible to degradation by Streptomyces hyaluronidase, chondroitinase AC, and slightly susceptible to chondroitinase ABC, as shown by electrophoretic analysis on composite 2.2% acrylamide-agarose slab gels and 4.5/12.5% polyacrylamide gels before and after enzymatic treatment. One of the gel-separable bands, however, was degradable by both nitrous acid and Flavobacterium heparinase. Both bands from eggs were degradable by nitrous acid. These results suggest that eggs contain heparin and/or heparan sulfate and perhaps dermatan sulfate and that 10 day-old worms also have these polyglycans but possibly not chondroitin sulfate or hyaluronic acid.
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PMID:Characterization of polysaccharides of the eggs and adults of Hymenolepis diminuta. 653 86

Human gingiva was stained with cupromeronic blue according to Scott's critical electrolyte concentration technique in order to localize glycosaminoglycans (GAG) in the electron microscope. Identification was performed by digestion with chondroitinase AC, ABC and heparinase. The GAG were localized in three compartments of the connective tissue: the supra-alveolar fiber apparatus, the loose connective tissue and the basement membranes. In the supra-alveolar fiber apparatus, consisting mainly of densely packed parallel collagen fibrils, dermatan sulfate GAG are regularly attached to the d-band of the collagen fibrils. The precipitates (6-7 nm in diameter) aggregate to thicker precipitates (up to 16 nm), thus possibly providing stability to the fiber system. In the loose connective tissue with sparse collagen fibrils dermatan and chondroitin sulfate GAG form very large precipitates (up to 30 nm in diameter and 400 nm length) which interconnect the few collagen fibrils. The basement membranes of the epithelium and capillary endothelium contain heparan sulfate GAG as fine precipitates (4-6 nm in diameter) which form a meshwork. These findings are consistent with the Scott model (1) for the interactions among glycans and glycans and collagen fibrils in connective tissues.
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PMID:Ultrastructural localization of glycosaminoglycans in human gingival connective tissue using cupromeronic blue. 777 52

The action pattern of polysaccharide lyases on glycosaminoglycan substrates was examined using viscosimetric measurements and gradient polyacrylamide gel electrophoresis (PAGE). Heparin lyase I (heparinase, EC 4.2.2.7) and heparin lyase II (no EC number) both acted on heparin in a random endolytic fashion. Heparin lyase II showed an ideal endolytic action pattern on heparan sulphate, while heparin lyase I decreased the molecular weight of heparan sulphate more slowly. Heparin lyase III (heparitinase, EC 4.2.2.8) acted endolytically only on heparan sulphate and did not cleave heparin. Chondroitin ABC lyase (chondroitinase ABC, EC 4.2.2.4) from Proteus vulgaris acted endolytically on chondroitin-6-sulphate (chondroitin sulphate C) and dermatan sulphate at nearly identical initial rates, but acted on chondroitin-4-sulphate (chondroitin sulphate A) at a reduced rate, decreasing its molecular weight much more slowly. Two chondroitin AC lyases (chondroitinase AC, both EC 4.2.2.5) were examined towards chondroitin-4- and -6-sulphates. The exolytic action of chondroitin AC lyase A from Arthrobacter aurescens on both chondroitin-4- and -6-sulphates was demonstrated viscosimetrically and confirmed using both gradient PAGE and gel permeation chromatography. Chondroitin AC lyase F from Flavobacterium heparinum (Cytophagia heparinia) acted endolytically on the same substrates. Chondroitin B lyase (chondroitinase B, no EC number) from F.heparinum acted endolytically on dermatan sulphate giving a nearly identical action pattern as observed for chondroitin ABC lyase acting on dermatan sulphate.
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PMID:Action pattern of polysaccharide lyases on glycosaminoglycans. 794 54

Borrelia burgdorferi adhere to mammalian cells in vitro but neither the ligand(s) nor the receptor(s) has (have) been clearly established. Using an in vitro attachment-inhibition assay, a B. burgdorferi attachment mechanism has been identified. Heparin, heparan sulfate, and dermatan sulfate reduced the attachment of virulent B. burgdorferi strain 297 to HeLa cells by approximately 60%. In addition, virulent, but not avirulent, B. burgdorferi strains B31, N40, and HB19 demonstrated heparin attachment-inhibition. Attachment to Chinese hamster ovary cells deficient in heparan sulfate proteoglycans was reduced by 68% compared to attachment to wild-type cells and was identical to attachment at maximum heparin inhibition to the wild-type cells. Pretreatment of HeLa cell monolayers with heparitinase, heparinase, and chondroitinase ABC, but not with chondroitinase AC, reduced borrelial attachment by approximately 50%. A moderately high affinity, low copy number, promiscuous B. burgdorferi glycosaminoglycan receptor was demonstrated by equilibrium binding studies. A 39-kD polypeptide, purified by heparin affinity chromatography from Triton X-100 extracts derived from virulent borrelia, was a candidate for this receptor. These studies indicate that one mode of B. burgdorferi attachment to eukaryotic cells is mediated by a borrelial glycosaminoglycan receptor attaching to surface-exposed proteoglycans on mammalian cells.
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PMID:Borrelia burgdorferi bind to epithelial cell proteoglycans. 811 83

Binding of urinary protein C inhibitor (PCI) to cultured human epithelial kidney tumor cells (TCL-598) was studied. Binding was dose-dependent, time-dependent, and saturable. Heparin interfered in a dose-dependent way with PCI binding to TCL-598 as did heparan sulfate and to a lesser degree also dermatan sulfate. Pretreatment of TCL-598 with protamine sulfate inhibited subsequent binding of PCI in a dose-dependent manner and > 100 micrograms/ml protamine sulfate reduced binding of PCI to < 10% of the control. Binding of 125I-PCI was specific, and bound 125I-PCI was recovered from the cells by heparin treatment or detached together with intact cells by EDTA treatment, migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with the same mobility (M(r) = 57,000) as unbound 125I-PCI. Furthermore, cell-bound PCI was functionally active as judged from its ability to inhibit the amidolytic activity of urokinase, and its inhibitory activity was stimulated approximately 3-4-fold as compared to fluid-phase PCI. Immunogold electron microscopy revealed that PCI-antigen presented to the cells from the luminal side bound exclusively to that surface in native as well as in prefixed cells. This binding of PCI was abolished in the presence of heparin (50 micrograms/ml) and after pretreatment of the cells either with protamine sulfate (400 micrograms/ml) or with heparinase III (0.5 unit/ml). A slight decrease in PCI binding was seen after pretreatment of the cells with chondroitinase ABC and chondroitinase AC. In contrast, binding of PCI to extracellular matrices of TCL-598 was decreased to approximately 70% after chondroitinase ABC treatment of the extracellular matrices, whereas both heparinase III or chondroitinase AC treatment only reduced matrix-bound PCI to approximately 95%. These data suggest that heparan sulfate-containing proteoglycans are predominantly involved in binding of PCI to the luminal side of TCL-598, while dermatan sulfate-containing proteoglycans, the overall predominant PCI-binding proteoglycans in TCL extracts, are responsible for PCI binding to the extracellular matrix. Heparan sulfate, however, exposed to an environment containing PCI under physiological conditions, might localize PCI and modulate its target enzyme specificity in vivo.
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PMID:Binding of urinary protein C inhibitor to cultured human epithelial kidney tumor cells (TCL-598). The role of glycosaminoglycans present on the luminal cell surface. 818 78


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