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)

The porcine reproductive and respiratory syndrome virus (PRRSV) has a very restricted tropism for well-differentiated cells of the monocyte-macrophage lineage, which is probably determined by specific receptors on these cells. In this study, the importance of heparinlike molecules on porcine alveolar macrophages (PAM) for PRRSV infection was determined. Heparin interacted with the virus and reduced infection of PAM up to 92 or 88% for the American and European types of PRRSV, respectively. Other glycosaminoglycans, similar to heparin, had no significant effect on infection while heparinase treatment of PAM resulted in a significant reduction of the infection. Analysis of infection kinetics showed that PRRSV attachment to heparan sulfate occurs early in infection. A heparin-sensitive binding step was observed which converted completely into a heparin-resistant binding after 120 min at 4 degrees C. Using heparin-affinity chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), it was observed that the structural matrix (M) and nucleocapsid (N) proteins attached to heparin. Nonreducing SDS-PAGE revealed that M bound to heparin mainly as a complex with glycoprotein GP(5) and that the N protein bound to heparin as a homodimer. GP(3), which was identified as a minor structural protein of European types of PRRSV, did not bind to heparin. Since the N protein is not exposed on the virion surface, it was concluded that the structural M protein and the M-GP(5) complex contribute to PRRSV attachment on a heparinlike receptor on PAM. This is the first report that identifies a PRRSV ligand for a cell surface heparinlike receptor on PAM.
...
PMID:Involvement of the matrix protein in attachment of porcine reproductive and respiratory syndrome virus to a heparinlike receptor on porcine alveolar macrophages. 1193 97

The activities of insulin-like growth factor (IGF)-I and -II are regulated by IGF-binding proteins (IGFBPs). Cleavage of IGFBP-4 by the metalloproteinase pregnancy-associated plasma protein-A (PAPP-A) causes release of bound IGF and has been established in several biological systems including the human reproductive system. Using flow cytometry, we first demonstrate that PAPP-A reversibly binds to the cell surface of several cell types analyzed. Heparin and heparan sulfate, but not dermatan or chondroitin sulfate, effectively compete for PAPP-A surface binding, and because incubation of cells with heparinase abrogated PAPP-A adhesion, binding is probably mediated by a cell surface heparan sulfate proteoglycan. Furthermore, the proteolytic activity of PAPP-A is preserved while bound to cells, suggesting that adhesion functions to target its activity to the vicinity of the IGF receptor, decreasing the probability that released IGF is captured by another IGFBP molecule before receptor binding. This mechanism potentially functions in both autocrine and paracrine regulation, as PAPP-A need not be synthesized in a cell to which it adheres. A truncated PAPP-A variant without the five short consensus repeats in the C-terminal third of the 1547-residue PAPP-A subunit, lacked surface binding. We also show that PAPP-A2, a recently discovered IGFBP-5 proteinase with homology to PAPP-A, does not bind cells. This finding allowed further mapping of the PAPP-A adhesion site to short consensus repeat modules 3 and 4 by the expression and analysis of nine PAPP-A/PAPP-A2 chimeras. Interestingly, the proteolytically inactive, disulfide-bound complex of PAPP-A and the proform of eosinophil major basic protein (proMBP), PAPP-A.proMBP, shows only weak surface binding, probably because the adhesion site of PAPP-A is occupied by heparan sulfate, known to be covalently bound to proMBP. This hypothesis was further substantiated by demonstrating that heparinase treatment of PAPP-A.proMBP restores surface binding. We finally propose a model in which IGF bioactivity is regulated by reversible cell surface binding of PAPP-A, which in turn is regulated by proMBP.
...
PMID:Cell surface targeting of pregnancy-associated plasma protein A proteolytic activity. Reversible adhesion is mediated by two neighboring short consensus repeats. 1237 Jan 76

Heparin and heparan sulfate fragments, obtained by bacterial heparinase and heparitinases, bearing an unsaturation at C4-C5 of the uronic acid moiety, are able to produce up to 80% reduction of the cytosolic calcium of smooth muscle cell lines. Unsaturated disaccharides from chondroitin sulfate, dermatan sulfate, and hyaluronic acid are inactive, indicating that, besides the unsaturation of the uronic acid, a vicinal 1 --> 4 glycosidic linkage is needed. An inverse correlation between the molecular weight and activity is observed. Thus, the ED(50) of the N-acetylated disaccharide derived from heparan sulfate (430 Da) is 88 microm compared with 250 microm of the trisulfated disaccharide (650 Da) derived from heparin. Except for enoxaparin (which contains an unsaturation at the non-reducing end and 1 --> 4 glycosidic linkage), other low molecular weight heparins and native heparin are practically inactive in reducing the cytosolic calcium levels. Thapsigargin (sarcoplasmic reticulum Ca(2+)-ATPase inhibitor), vanadate (cytoplasmic membrane Ca(2+)-ATPase inhibitor), and nifedipine and verapamil (Ca(2+) channel antagonists) do not interfere with the effect of the trisulfated disaccharide upon the decrease of the intracellular calcium. A significant decrease of the activity of the trisulfated disaccharide is observed by reducing extracellular sodium, suggesting that the fragments might act upon the Na(+)/Ca(2+) exchanger promoting the extrusion of Ca(2+). This was further substantiated by binding experiments and circular dichroism analysis with the exchanger inhibitor peptide.
...
PMID:Heparin and heparan sulfate disaccharides bind to the exchanger inhibitor peptide region of Na+/Ca2+ exchanger and reduce the cytosolic calcium of smooth muscle cell lines. Requirement of C4-C5 unsaturation and 1--> 4 glycosidic linkage for activity. 1237 9

Heparin has a wide range of important biological activities including inhibition of pulmonary artery smooth muscle cell proliferation. To determine the minimum size of the heparin glycosaminoglycan chain essential for antiproliferative activity, porcine intestinal mucosal heparin was partially depolymerized with heparinase and fractionated to give oligosaccharides of different sizes. The structure of these oligosaccharides was fully characterized by 1D and 2D 1H NMR spectroscopy. These oligosaccharides were assayed for antiproliferative effects on cultured bovine pulmonary artery smooth muscle cells (PASMCs). The tetrasaccharide (4-mer) exhibited no heparin-like activity. Decasaccharides (10-mers) and dodecasaccharides (12-mers) displayed a reduced level of activity when compared to full-length heparin. Little effect on activity was observed in deca- and dodecasaccharides with one less 2-O-sulfo group. The 14-, 16-, and 18-mers showed comparable growth-inhibition effects on PAMSC as porcine intestinal mucosal heparin. These data suggest that a 14-mer is the minimum size of oligosaccharide that is essential for full heparin-like antiproliferative activity. Since the 14- to 18-mers have no 3-O-sulfo groups in their glucosamine residues, their full activity confirms that these 3-O-sulfonated glucosamine residues, which are required for heparin's anticoagulant activity, are not an essential requirement for antiproliferative activity.
...
PMID:Heparin oligosaccharide sequence and size essential for inhibition of pulmonary artery smooth muscle cell proliferation. 1243 2

The novel heparinase-producing bacterial strain Corynebacterium sp. was screened and isolated from soil. The optimum medium composition is (g/L): Trypticase 20, NaCl 1, K2HPO4 2.5, MgSO4 0.5, Heparin 2, maltose 20, pH 6.5. The optimum growth temperature was 27 degrees C while, maximum enzyme production was achieved at temperature 31 degrees C. When cultured at a rotating shaker at 30 degrees C for 24 hours, 200 r/min, 40 mL medium in 500 mL flask, the Production of heparinase reached 1700 u/L.
...
PMID:[Strain screening and fermentation conditions of a novel heparinase-producing strain]. 1255 4

Heparin, other sulphated glycosaminoglycans and histamine were extracted from various dissected organs of Anomalocardia brasiliana, a mollusc from the South Atlantic, and quantified. A good correlation between heparin and histamine content was found in the labial palp, intestine, ctenidium, mantle and foot tissues. The tissue location of metachromatic cells, putatively containing heparin, was identified histologically with Alcian Blue, Toluidine Blue, Masson trichrome, Haematoxylin-Eosin and PAS. Except for the foot, cells containing metachromatic granules were found in the epithelium surfaces of all the organs analysed. An in situ identification of heparin using nitrous acid and heparinase degradation has established unequivocally the presence of this compound in the metachromatic cells. The location of 'mast-like' cells at the epithelium surface of mollusc tissues exposed to the environment are very similar to the distribution of mammalian and other vertebrate mast cells and gives support to the suggestion for a role of mast cells in defense mechanisms.
...
PMID:Mast cells are present in epithelial layers of different tissues of the mollusc Anomalocardia brasiliana. In situ characterization of heparin and a correlation of heparin and histamine concentration. 1462 45

Norovirus (NV), a member of the family Caliciviridae, is one of the important causative agents of acute gastroenteritis. In the present study, we found that virus-like particles (VLPs) derived from genogroup II (GII) NV were bound to cell surface heparan sulfate proteoglycan. Interestingly, the VLPs derived from GII were more than ten times likelier to bind to cells than were those derived from genogroup I (GI). Heparin, a sulfated glycosaminoglycan, and suramin, a highly sulfated derivative of urea, efficiently blocked VLP binding to mammalian cell surfaces. The reagents known to bind to cell surface heparan sulfate, as well as the enzymes that specifically digest heparan sulfate, markedly reduced VLP binding to the cells. Treatment of the cells with chlorate revealed that sulfation of heparan sulfate plays an important role in the NV-heparan sulfate interaction. The binding efficiency of NV to undifferentiated Caco-2 (U-Caco-2) cells differed largely between GI NV and GII NV, whereas the efficiency of binding to differentiated Caco-2 (D-Caco-2) cells did not differ significantly between the two genogroups, although slight differences between strains were observed. Digestion with heparinase I resulted in a reduction of up to 90% in U-Caco-2 cells and a reduction of up to only 50% in D-Caco-2 cells, indicating that heparan sulfate is the major binding molecule for U-Caco-2 cells, while it contributed to only half of the binding in the case of D-Caco-2 cells. The other half of those VLPs was likely to be associated with H-type blood antigen, suggesting that GII NV has two separate binding sites. The present study is the first to address the possible role of cell surface glycosaminoglycans in the binding of recombinant VLPs of NV.
...
PMID:Genogroup II noroviruses efficiently bind to heparan sulfate proteoglycan associated with the cellular membrane. 1504 97

Heparin lyases are valuable tools for generating oligosaccharide fragments and in sequence determination of heparan sulfate (HS). Heparin lyase III is known to cleave the linkages between N-acetylglucosamine (GlcNAc) or N-sulfated glucosamine (GlcNS) and glucuronic acid (GlcA) as the primary sites and the linkages between GlcNAc, GlcNAc(6S), or GlcNS and iduronic acid as secondary sites. N-Unsubstituted glucosamine (GlcN) occurs as a minor component in HS, and it has been associated with various bioactivities. Here we investigate the specificity of heparin lyase III toward the GlcN-GlcA linkage using a recombinant enzyme of high purity and as substrates the partially de-N-acetylated polysaccharide of Escherichia coli K5 strain and derived hexasaccharides. The specificity of lyase III toward the GlcN-GlcA linkage is deduced by sequencing of the oligosaccharide products using electrospray mass spectrometry with collision-induced dissociation and MS/MS scanning. The results demonstrate that under controlled conditions for partial digestion, lyase III does not act at the GlcN-GlcA linkage, whereas GlcNAc-GlcA is cleaved. Even under forced conditions for exhaustive digestion, the GlcN-GlcA linkage is only partly cleaved. It is this property of lyase III that has enabled the isolation of a unique, nonsulfated antigenic determinant DeltaUA-GlcN-UA-GlcNAc from HS and from partially de-N-acetylated K5 polysaccharide. It was unexpected that pentasaccharide fragments were also detected among the digestion products of the K5 polysaccharide used. It is possible that these are products of an additional glycosidase activity of lyase III, although other mechanisms cannot be completely ruled out.
...
PMID:Relative susceptibilities of the glucosamine-glucuronic acid and N-acetylglucosamine-glucuronic acid linkages to heparin lyase III. 1522 70

Heparin with high anticoagulant activity (activated partial thromboplastin time of 347 +/- 56.4 and anti-Xa activity of 317 +/- 48.3) was isolated from the marine clam species Tapes phylippinarum in an amount of approximately 2.1 mg/g dry animals. Agarose-gel electrophoresis showed a high content of the slow-moving heparin component (22 +/- 6.8%) and 78 +/- 5.4% of the fast-moving species. An average molecular mass of 13,600 was calculated by PAGE analysis, whereas a number average molecular weight Mn value of 10,700, a weight average molecular weight Mw of 14,900, and a dispersity index Mn/Mw of 1.386 were obtained by high-performance size-exclusion chromatography. Structural analysis of clam heparin, performed by depolymerizing heparin samples with heparinase (EC 4.2.2.7) and then separating the resulting unsaturated oligosaccharides by strong anion exchange-HPLC revealed the presence of large amounts (more than 130% than standard pharmaceutical heparin obtained from bovine intestine) of the oligosaccharide sequence bearing part of the ATIII-binding region, DeltaUA2S (1-->4)-alpha-D-GlcN2S6S (1-->4)-alpha-L-IdoA (1-->4)-alpha-D-GlcNAc6S (1-->4)-beta-D-GlcA (1-->4)-alpha-D-GlcN2S3S6S in the T. phylippinarum heparin, in comparison with bovine mucosal heparin and a sample of porcine mucosal heparin previously published. Furthermore, as expected from the oligosaccharide compositional analysis, due to the presence of a great mol % (80.6%) of the trisulfated disaccharide DeltaUA2S(1-->4)-alpha-D-GlcN2S6S, mollusc heparin is a more sulfated polysaccharide than bovine mucosal heparin (73.5%) and a sample of porcine mucosal (72.8%) heparin previously reported. To our knowledge, this is the first article describing a clam heparin having the ATIII binding site mainly identical to that of human and porcine intestinal mucosal heparins and bovine intestinal mucosal heparin but different from that found in beef lung heparin.
...
PMID:Isolation and characterization of a heparin with high anticoagulant activity from the clam Tapes phylippinarum: evidence for the presence of a high content of antithrombin III binding site. 1525 29

Heparin has been widely reported to inhibit the growth of several cell types including neonatal rat cardiac myocyte (NRCM) but its effect on adult rat ventricular myocyte (ARVM) is unknown. To determine whether heparin is able to modulate ARVM protein synthesis capacity and if so which pathway is involved in this response, ARVM were cultured in presence or absence of 5% human serum and exposed to heparin (2-2,000 microg/ml) or its analogue xylan (0.5 and 50 microg/ml), and either the Ca(2+) chelator BAPTA/AM (10 microg/ml), or the calcineurin inhibitor FK506 (10 microg/ml), and heparinase I (0.1-10 U/ml) for 2 days. The protein synthesis (PS) was measured after 24 h incorporation of [14C]-Phenylalanine in ARVM. Independently of the serum presence, heparin and xylan altered PS in a bimodal dose-dependent manner. At high doses, heparin and xylan (2,000 and 50 microg/ml, respectively) either had no effect (without serum) or inhibited PS (with serum). In absence of serum, low doses of heparin or xylan (20 and 0.5 microg/ml, respectively) amplified the PS process in ARVM (2-fold, P < 0.05). FK506 inhibited the trophic response to 20 microg/ml heparin alone (-39%, P < 0.05). In presence of serum, the heparin induced-trophic effect, that was not significantly altered by FK506, was inhibited by BAPTA/AM (-32%, P < 0.05). Finally, heparinase I that increased PS in NRCM had no effect on ARVM growth. This study strongly suggests that heparin dose-dependently modulated PS in ARVM, this result being not observed in neonatal cells. Different mechanisms involving intracellular Ca(2+) play a role in the PS response of ARVM to low concentrations of heparin, the intracellular pathways depending on the presence of serum.
...
PMID:Dual effect of heparin on cultured adult rat cardiomyocytes. 1525 4


<< Previous 1 2 3 4 5 6 7 8 9 10

---