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)

Yersiniae are equipped with the Yop virulon, an apparatus that allows extracellular bacteria to deliver toxic Yop proteins inside the host cell cytosol in order to sabotage the communication networks of the host cell or even to cause cell death. LcrG is a component of the Yop virulon involved in the regulation of secretion of the Yops. In this paper, we show that LcrG can bind HeLa cells, and we analyse the role of proteoglycans in this phenomenon. Treatment of the HeLa cells with heparinase I, but not chondroitinase ABC, led to inhibition of binding. Competition assays indicated that heparin and dextran sulphate strongly inhibited binding, but that other glycosaminoglycans did not. This demonstrated that binding of HeLa cells to purified LcrG is caused by heparan sulphate proteoglycans. LcrG could bind directly to heparin-agarose beads and, in agreement with these results, analysis of the protein sequence of Yersinia enterocolitica LcrG revealed heparin-binding motifs. In vitro production and secretion by Y. enterocolitica of the Yops was unaffected by the addition of heparin. However, the addition of exogenous heparin decreased the level of YopE-Cya translocation into HeLa cells. A similar decrease was seen with dextran sulphate, whereas the other glycosaminoglycans tested had no significant effect. Translocation was also decreased by treatment of HeLa cells with heparinitase, but not with chondroitinase. Thus, heparan sulphate proteoglycans have an important role to play in translocation. The interaction between LcrG and heparan sulphate anchored at the surface of HeLa cells could be a signal triggering deployment of the Yop translocation machinery. This is the first report of a eukaryotic receptor interacting with the type III secretion and associated translocation machinery of Yersinia or of other bacteria.
Mol Microbiol 1998 Jan
PMID:Heparin interferes with translocation of Yop proteins into HeLa cells and binds to LcrG, a regulatory component of the Yersinia Yop apparatus. 948 97

The use of specific enzymes (heparinase and heparitinases from Flavobacterium heparinum, endoglucuronidase, alphaN-acetylglucosaminidase and beta-glucuronidase from the mollusc Anomalocardia brasiliana) and chemical methods (nitrous acid degradation, hydrazine N-deacetylation and borohydride reduction), led to the proposal of the total sequence of a heparan sulfate derived from bovine pancreas and partial sequences of heparan sulfates from different origins (bovine: lung, liver, brain; hog: liver, brain; rabbit liver; dog liver). It was shown that all the heparan sulfates contain common structural features such as: a N-acetylated and a N-sulfated domain made of glucuronic acid-containing disaccharides and a more sulfated region made of iduronic acid-containing disaccharides. Separating the two domains a peculiar tetrasaccharide made of GlcNAc-(alpha1-4)-IdoUA-(alpha1-4)-GlcNS-(alpha1-4)-IdoUA was identified in all the heparan sulfates analyzed. It was also shown that the non-reducing ends of the heparan sulfates contain the monosaccharides glucosamine N-sulfate and/or glucosamine 2,6 disulfate.
Cell Mol Biol (Noisy-le-grand) 1998 May
PMID:Structure of heparan sulfate: identification of variable and constant oligosaccharide domains in eight heparan sulfates of different origins. 962 Apr 37

Heparan sulphate proteoglycans are increasingly implicated as eukaryotic cell surface receptors for bacterial pathogens. Here, we report that Neisseria gonorrhoeae adheres to proteoglycan receptors on HEp-2 epithelial cells but that internalization of the bacterium by this cell type requires the serum glycoprotein fibronectin. Fibronectin was shown to bind specifically to gonococci producing the OpaA adhesin. Binding assays with fibronectin fragments located the bacterial binding site near the N-terminal end of the molecule. However, none of the tested fibronectin fragments supported gonococcal entry into the eukaryotic cells; a 120 kDa fragment carrying the cell adhesion domain with the amino acid sequence RGD even inhibited the fibronectin-mediated uptake of MS11-OpaA. This inhibition could be mimicked by an RGD-containing hexapeptide and by alpha 5 beta 1 integrin-specific antibodies, suggesting that interaction of the central region of fibronectin with integrin receptors facilitated bacterial uptake. Fibronectin was unable to promote gonococcal entry into HEp-2 cells that had been treated with the enzyme heparinase III, which degrades the glycosaminoglycan side-chains of proteoglycan receptors. On the basis of these results, we propose a novel cellular uptake pathway for bacteria, which involves the binding of the pathogen to glycosaminoglycans that, in turn, act as co-receptors facilitating fibronectin-mediated bacterial uptake through integrin receptors. In this scenario, fibronectin would act as a molecular bridge linking to Opa-proteoglycan complex with host cell integrin receptors.
Mol Microbiol 1998 Jul
PMID:Entry of OpaA+ gonococci into HEp-2 cells requires concerted action of glycosaminoglycans, fibronectin and integrin receptors. 970 28

Tissue kallikrein (TK) is secreted by serous cells of tracheobronchial submucosal glands and plays a role in allergic airway responses. To better understand the regulation of TK, we used primary cultures of submucosal gland cells that release TK upon stimulation. Media from cultures stimulated with chymase (10(-7) M) showed increased TK activity (0.50 +/- 0.22 mU/ml mean +/- standard error) in comparison with the control group (0.08 +/- 0.02 mU/ml). The increased TK activity was significantly correlated with increases in the levels of the serous cell marker, secretory leukoprotease inhibitor. Anion exchange chromatography of the conditioned culture media showed that TK activity eluted as a broad peak between 1.6 and 1.8 M NaCl, unlike the reported elution (0.3 to 0.6 M NaCl) of kallikreins from other tissues, suggesting that secreted bronchial TK was bound to a negatively charged molecule. Hyaluronidase digestion increased TK activity in both pre- and post-chymase-stimulated culture media, whereas no such change was seen after samples were digested with heparinase or chondroitinase ABC. Further, after hyaluronidase digestion of media, TK eluted from an anion exchange column between 0.3 and 0.6 M NaCl. Enzymatic detection of TK after nondenaturing gel electrophoresis showed that hyaluronidase digestion also reduced the electrophoretic heterogeneity of TK to a single band, whereas adding back hyaluronic acid (HA) to hyaluronidase-digested samples restored the original heterogeneity. Finally, TK activity bound to HA-Sepharose and could be eluted with HA. These studies show that primary cultures of ovine submucosal gland cells secrete TK in a regulated fashion, and that secreted TK binds to HA. This binding reduces TK enzymatic activity; therefore, factors that affect HA turnover could modify the TK activity in the airway lumen. These events could be important in the regulation of kinin-mediated airway inflammation.
Am J Respir Cell Mol Biol 1999 Dec
PMID:Bronchial tissue kallikrein activity is regulated by hyaluronic acid binding. 1057 63

Acharan sulfate is a glycosaminoglycan (GAG), having the structure -->4)-2-acetamido-2-deoxy-alpha-D-glucopyranose(1-->4)-2-sulfo-alpha-L-idopyranosyluronic acid (1-->, isolated from the body of the giant African snail Achatina fulica. This GAG represents 3-5% of the dry weight of this snail's soft body tissues. Frozen sections and polyester wax sections of the snail's body were stained by Alcian blue-periodic acid-Schiff's reagent (PAS) to localize acharan sulfate. Alcian blue staining indicated that GAG was mainly secreted into the outer surface of the body from internal granules. A highly mucous material was collected and treated and the acharan sulfate was recovered by ethanol and cetyl pyridinium chloride precipitation. Crude acharan sulfate was purified by DEAE-Sephacel ion-exchange chromatography. Depolymerization of intact mucus and purified acharan sulfate fractions by heparin lyase II (heparitinase I) from Flavobacterium heparinum produced an unsaturated disaccharide as a major product, establishing the repeating unit of acharan sulfate. These results demonstrate that mucus in the granule and secreted to the outside of the body is composed entirely of acharan sulfate.
Comp Biochem Physiol B Biochem Mol Biol 2001 Dec
PMID:Localization and characterization of acharan sulfate in the body of the giant African snail Achatina fulica. 1169 28

Non-infectious, envelope protein-free, retrovirus-like particles (VLP) derived from either Moloney murine leukemia virus (MLV) or human HIV are able to bind efficiently to, but not infect, target cells. Upon subsequent addition to the bound particles of the G protein of vesicular stomatitis virus (VSV-G), an efficient surrogate retrovirus envelope protein, the VLP are efficiently taken up by the cells to produce infection. Cell attachment of the VLP is efficiently inhibited by soluble heparin and dextran sulfate and less efficiently abrogated by several other glycosaminoglycans (GAGs) including chondroitin sulfate A and chondroitin sulfate B (dermatan sulfate), as determined by deconvolution microscopic immunodetection of the viral gag protein and by quantitative binding studies of metabolically labeled (35)S-VLP. Enzymatic digestion of heparan sulfate (HS) from the cell surface with heparinase I also reduces VLP binding. Furthermore, VLP adsorption onto several CHO cell lines variably deficient in cell surface GAG is significantly but incompletely abrogated. De-sulfated heparins are less efficient than native heparin in inhibiting the Polybrene-mediated binding of VLP, whereas growth of human cells in the presence of sodium chlorate leads to significant reduction of Polybrene-mediated VLP binding. In addition, specific inhibition of VLP binding and infectivity of mature infectious VSV-G-pseudotyped virus is observed in the presence of heparin and HS under Polybrene-free conditions. We conclude from these studies that the presence of Polybrene, the degree of sulfation of cell surface GAG, and possibly the presence of charged cell surface macromolecules create an electrostatic environment that promotes optimum binding of VLP to cells. Additionally, our results demonstrate that, in the absence of Polybrene, initial attachments of non-infectious, envelope protein-free VLP and probably mature infectious virus particles are mediated by interactions of the virus particles with cell surface heparan sulfate, and possibly with other GAG molecules.
Mol Ther 2002 May
PMID:Cell surface heparan sulfate is a receptor for attachment of envelope protein-free retrovirus-like particles and VSV-G pseudotyped MLV-derived retrovirus vectors to target cells. 1199 44

PTPsigma is a receptor tyrosine phosphatase that is expressed widely in the developing nervous system and that controls the growth and retinotopic mapping of retinal axons. PTPsigma is also expressed in motor neurons where its function is unclear. Given that invertebrate relatives of PTPsigma can control motor axon guidance, target contact, and synaptogenesis, we have asked if extracellular ligands exist for cPTPsigma, the avian PTPsigma orthologue, in the neuromuscular system. Of the two major isoforms cPTPsigma1 and cPTPsigma2, only the shorter cPTPsigma1 isoform is expressed in developing spinal motor neurons and their axons. We show that ectodomains of cPTPsigma1, but not of cPTPsigma2, bind specifically to developing skeletal myotubes. The putative myotube ligand is not related to the previously described binding of cPTPsigma to heparan sulfates within the proteoglycans agrin and collagen XVIII, since heparinase treatment of myotubes does not alter cPTPsigma1 binding and since most mutations that abolish binding of cPTPsigma1 to heparin do not affect myotube binding. The expression of cPTPsigma1 in motor axons and its direct binding to target myotubes suggest an isoform-specific role for axonally expressed cPTPsigma1 during establishment or maintenance of neuromuscular contacts.
Mol Cell Neurosci 2003 Jan
PMID:Isoform-specific binding of the tyrosine phosphatase PTPsigma to a ligand in developing muscle. 1259 37

The endothelial glycocalyx is believed to play a major role in microvascular permeability. We tested the hypothesis that specific components of the glycocalyx, via cytoskeletal-mediated signaling, actively participate in barrier regulation. With the use of polymers of arginine and lysine as a model of neutrophil-derived inflammatory cationic proteins, we determined size- and dose-dependent responses of cultured bovine lung microvascular endothelial cell permeability as assessed by transendothelial electrical resistance (TER). Polymers of arginine and lysine >11 kDa produced maximal barrier dysfunction as demonstrated by a 70% decrease in TER. Monomers of l-arginine and l-lysine did not alter barrier function, suggesting a cross-linking requirement of cell surface "receptors". To test the hypothesis that glycosaminoglycans (GAGs) are candidate receptors for this response, we used highly selective enzymes to remove specific GAGs before polyarginine (PA) treatment and examined the effect on TER. Heparinase III attenuated PA-induced barrier dysfunction by 50%, whereas heparinase I had no effect. To link changes in barrier function with structural alterations, we examined actin organization and syndecan localization after PA. PA induced actin stress fiber formation and clustering of syndecan-1 and syndecan-4, which were significantly attenuated by heparinase III. PA-induced cytoskeletal rearrangement and barrier function did not involve myosin light chain kinase (MLCK) or p38 MAPK, as ML-7, a specific MLCK inhibitor, or SB-20358, a p38 MAPK inhibitor, did not alter PA-induced barrier dysfunction. In summary, lung endothelial cell heparan sulfate proteoglycans are key participants in inflammatory cationic peptide-induced signaling that links cytoskeletal reorganization with subsequent barrier dysfunction.
Am J Physiol Lung Cell Mol Physiol 2003 Nov
PMID:Lung endothelial heparan sulfates mediate cationic peptide-induced barrier dysfunction: a new role for the glycocalyx. 1455 Oct 39

Heparin lyase I was purified to homogeneity from Bacteroides stercoris HJ-15 isolated from human intestine, by a combination of DEAE-Sepharose, gel-filtration, hydroxyapatite, and CM-Sephadex C-50 column chromatography. This enzyme preferred heparin to heparan sulfate, but was inactive at cleaving acharan sulfate. The apparent molecular mass of heparin lyase I was estimated as 48,000 daltons by SDS-PAGE and its isoelectric point was determined as 9.0 by IEF. The purified enzyme required 500 mM NaCl in the reaction mixture for maximal activity and the optimal activity was obtained at pH 7.0 and 50 degrees C. It was rather stable within the range of 25 to 50 degrees C but lost activity rapidly above 50 degrees C. The enzyme was activated by Co(2+) or EDTA and stabilized by dithiothreitol. The kinetic constants, K(m) and V(max) for heparin were 1.3 10(-5) M and 8.8 micromol/min.mg. The purified heparin lyase I was an eliminase that acted best on porcine intestinal heparin, and to a lesser extent on porcine intestinal mucosa heparan sulfate. It was inactive in the cleavage of N-desulfated heparin and acharan sulfate. In conclusion, heparin lyase I from Bacteroides stercoris was specific to heparin rather than heparan sulfate and its biochemical properties showed a substrate specificity similar to that of Flavobacterial heparin lyase I.
J Biochem Mol Biol 2004 Nov 30
PMID:Purification and characterization of heparin lyase I from Bacteroides stercoris HJ-15. 1560 27

Endothelial monocyte-activating polypeptide-II (EMAP II) is an antiangiogenic factor for rapidly growing endothelial cells that is released from tumor cells under physiological stress such as hypoxia. We have previously shown that the interaction between EMAP II and the alpha-subunit of ATP synthase, alpha-ATP synthase, can play a regulatory function in the growth of endothelial cells. In the current study, we found that EMAP II-alpha-ATP synthase interaction could be inhibited by excess heparin, whereas the interaction could be enhanced by a low concentration of heparin. Both EMAP II and alpha-ATP synthase could specifically interact with heparin, and this interaction was increased under acidic conditions. In addition, EMAP II and alpha-ATP synthase were found to contain the heparin binding motifs determined by analysis using site-directed mutant forms. In endothelial cells, binding of EMAP II to cells was dramatically enhanced, and alpha-ATP synthase could associate with heparan sulfate at acidic pH. The inhibitory effect of EMAP II on the growth of cultured endothelial cells was also significantly enhanced at acidic pH. Analysis using mutant EMAP II proteins demonstrated that heparan sulfate was essential for the enhanced binding and EMAP II function to endothelial cells at acidic pH. Furthermore, the enhanced inhibitory effects of EMAP II could be abrogated by excess heparin or heparinase treatment. In the endothelial cell, heparan sulfate may regulate the function of EMAP II released from the tumor cell in hypoxic condition.
Mol Pharmacol 2005 May
PMID:Heparan sulfate regulates the antiangiogenic activity of endothelial monocyte-activating polypeptide-II at acidic pH. 1571 Jul 45


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