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 amyloid precursor protein (APP) is a glycoprotein consisting of at least four isoforms derived from a single gene by a process of alternative splicing. The membrane-bound forms of APP have been suggested to have adhesive properties and to mediate neural cell adhesion. Previous studies have demonstrated the ability of Fab' fragments of antibodies to extracellular domains of APP to inhibit neural cell binding to a collagen substrate, suggesting a physiological role for the collagen-binding properties of APP. The binding of APP has been demonstrated to be specific for type IV collagen, and no binding to other extracellular matrix components, including fibronectin and laminin, was detected. The APP-collagen binding appeared to be mediated by a heparin-bridge mechanism, since the binding was abolished by the addition of excess heparan or heparinase. These results were observed by both a homogenate-collagen binding assay and a cell-surface adhesion assay, thus providing further evidence for the adhesion role of APP. They also pose the question of the possible role of the heparin-binding properties of APP in the genesis of the neuritic plaques characteristic of Alzheimer's disease.
Mol Chem Neuropathol
PMID:APP-collagen interaction is mediated by a heparin bridge mechanism. 152 Apr

A protein kinase capable of phosphorylating basic fibroblast growth factor (FGF) can be localized on the outer cell surface of human hepatoma cells (SK-Hep cells). The addition of [gamma-32P]ATP, but not H3(32)PO4, results in a rapid (less than 10 min) incorporation of 32P into exogenously added basic FGF. The reaction is time and concentration dependent (apparent Km, 170 nM) and is stimulated by the addition of cAMP (EC50, 0.5 microM), but not the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate. There is also no tyrosine protein kinase detected on the cell surface. The inhibition of basic FGF binding to its low and/or high affinity sites decreases the phosphorylation of basic FGF by the ecto-protein kinase. Accordingly, pretreatment of cells with heparinase for 30 min or coincubation with heparin (0.1-10 micrograms/ml) decreases phosphorylation in a dose-dependent manner. Furthermore, the addition of a nonphosphorylatable peptide analog of basic FGF ([Val112] basic FGF-(106-146)NH2) that can compete with basic FGF binding to cells prevents the phosphorylation of basic FGF. Together, these observations suggest that 1) exogenous basic FGF must associate with its low and/or high affinity binding sites to be phosphorylated, and 2) the kinase is cAMP dependent and associated with the outer cell surface, and support the hypothesis that phosphorylation may regulate the activity and/or bioavailability of the growth factor.
Mol Endocrinol 1991 Jul
PMID:Phosphorylation of basic fibroblast growth factor by a protein kinase associated with the outer surface of a target cell. 165 31

Organ culture of guinea pig trachea was performed in the presence of [35S]sulfate in order to characterize the sulfated glycoproteins released from the respiratory epithelium and mucosa. The sulfated macromolecules that were synthesized during a 6-h incorporation were separated by CsBr density-gradient centrifugation and gel-filtration chromatography successively. Most of the sulfated secreted macromolecules corresponded to a population of glycoproteins sensitive to reductive beta-elimination but resistant to both chondroitinase ABC and heparinase. These glycoproteins had different buoyant densities (ranging from 1.48 g/ml to 1.16 g/ml) and could be subfractionated according to molecular mass. A major part of the radioactivity was incorporated into high-molecular-mass mucins that were excluded from a Sepharose CL-2B column and did not penetrate into polyacrylamide gel in PAGE. However, a mixture of sulfated O-glycoproteins of much lower molecular mass was also characterized in addition to low amounts of chondroitin sulfate. Epithelial goblet cells are the predominant mucin-containing cells of the respiratory guinea pig trachea. Our results suggest that a wide range of sulfated O-glycoproteins are secreted by the guinea pig tracheal mucosa.
Am J Respir Cell Mol Biol 1991 Feb
PMID:Sulfated O-glycoproteins secreted by guinea pig trachea in organ culture. 189 37

In order to ascertain whether or not the presence of glycosaminoglycans in sputa of patients suffering from chronic bronchial disorders was related to tracheobronchial infection, an electrophoretic procedure was set up. The different acidic macromolecular components of sputum, namely nucleic acids, glycosaminoglycans, and bronchial glycopeptides could be identified in proteolyzed sputum using agarose electrophoresis before and after the action of different enzymes: nucleases, chondroitinases, hyaluronidase and heparinase. This procedure was used to analyze 13 sputum samples from patients suffering from cystic fibrosis (CF) and 12 sputum samples from patients suffering from chronic bronchitis. Chondroitin sulfate was identified in 11 infected sputum samples from patients with CF and also in the noninfected sputum from a patient with chronic bronchitis. These data suggest a relationship between the presence of chondroitin sulfate proteoglycans in sputum and severe tracheobronchial infection in CF.
Am J Respir Cell Mol Biol 1991 Oct
PMID:Chondroitin sulfate in sputum from patients with cystic fibrosis and chronic bronchitis. 191 Aug 15

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.
Am J Respir Cell Mol Biol 1990 Jan
PMID:Endothelial heparan sulfate proteoglycan. I. Inhibitory effects on smooth muscle cell proliferation. 213 6

Monoclonal antibodies, 17B1 and 17Q2, which are specific for large molecular weight mucous glycoproteins of airway epithelium, have been used to develop an ELISA method to quantitate the tracheal mucins of humans and rhesus monkeys. The assay is a double-sandwich system that does not depend on either the binding of mucous antigens to the microtiter plate or the use of a second antibody. The assay protocol includes (1) coating the microtiter well with purified IgG of 17B1 or 17Q2, (2) incubating the wells with mucous samples, (3) binding of alkaline phosphatase-conjugated IgG to the wells, and (4) developing the color with phosphate substrate. This ELISA method is very sensitive for human and rhesus monkey tracheal mucins. Quantitation is not affected by the presence of various proteoglycans (keratan sulfate, hyaluronate, heparin, heparan sulfate, and chondroitin sulfate). However, the quantitation is affected by the treatment of antigen with periodic acid and endo-beta-galactosidase. Other enzymes (e.g., neuraminidase, hyaluronidase, chondroitinase, heparitinase, heparinase, fucosidase, keratanase) have no effect on the antigenicity of substrate. The quantitation is linear, with a concentration from 0.2 to 4 ng protein/sample. The ELISA method developed in this study should be useful for quantitating the mucin content of various biologic fluids, such as sputum, bronchoalveolar lavage, and media from cultures following various pharmacologic and physiologic manipulations.
Am J Respir Cell Mol Biol 1989 Jul
PMID:An ELISA method for the quantitation of tracheal mucins from human and nonhuman primates. 262 58

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.
Mol Biochem Parasitol 1984 Jan
PMID:Characterization of polysaccharides of the eggs and adults of Hymenolepis diminuta. 653 86

The purpose of this study was to determine the biochemical and molecular characteristics of mucin synthesized by cystic fibrosis cells (CFPAC-1), a pancreatic cancer cell line derived from a patient with cystic fibrosis, and pancreatic cancer (SW-1990) cell lines. High molecular weight glycoproteins (HMG) were quantified by [3H]-glucosamine labeling and chromatography on sepharose CL-4B. Mucin gene expression was determined by using cDNA probes for 2 distinct intestinal mucins (MUC2 and MUC3) and one stomach mucin (MUC1). The specific mucin core epitopes were confirmed by immunoblots using antibodies that recognize T, Tn, sialosyl Tn, MUC1, MUC2, and MUC3. The results of these experiments demonstrate that CFPAC-1 cells contained 1.25 fold and 1.4 fold more HMG in the membrane and cytosolic fractions, however, secreted 4-fold more HMG into the medium compared to SW-1990 cells. The HMG of SW-1990 was found to be mucinous in nature and not proteoglycans, as it was not susceptible to hyalurinidase, heparinase and chondroitinase ABC. The HMG of CFPAC-1 was also predominantly (80%) mucinous but with small amounts of proteoglycans. mRNA and immunoblot analysis suggest that these CFPAC-1 and SW-1990 cells predominantly express MUC1 apomucin, small amounts of MUC2 apomucin, and no MUC3. Pulse chase labeling and immunoprecipitation of MUC1 type mucin using the 139H2 monoclonal antibody demonstrated that different sizes of mucin gene product were present in both cell lines, corresponding to the known length polymorphism of this mucin. Both T and Tn antigens were significantly higher in CFPAC-1 and SW-1990 cells as compared to sialosyl Tn antigen. These findings were associated with the increased activities of polypeptidyl N-acetylgalactosaminyl transferase and b1,3-galactosyltransferase. These investigations demonstrate for the first time that cystic fibrosis cells (CFPAC-1) secrete and synthesize high amounts of mucin which is associated with high levels of MUC1 mRNA, low levels of MUC2 mRNA and non detectable MUC3 mRNA.
Biochem Mol Biol Int 1995 Feb
PMID:Cystic fibrosis and pancreatic cancer cells synthesize and secrete MUC1 type mucin gene product. 754 50

The binding of human acidic fibroblast growth factor (aFGF) to heparin has been analyzed by a variety of different approaches to better elucidate the nature of this protein/sulfated polysaccharide interaction. Static and dynamic light scattering as well as analytical ultracentrifugation analyses indicates that 14-15 molecules of a FGF can bind to a 16-kDa heparin chain, with approximately 10 of these bound relatively uniformly to high-affinity sites. The dissociation constants of these latter sites are estimated to be approximately 50-140 nM on the basis of surface plasmon resonance experiments in which the association and dissociation rates of aFGF interaction with immobilized heparin were measured. The size of the binding site of a FGF on heparin was also determined by heparin lyase digestion of a FGF/heparin complexes followed by isolation and characterization of protected oligosaccharides. The smallest aFGF-protected oligosaccharide comigrated with delta UA2S(1-->4)-alpha-D-GlcNp2S6S(1-->4)-alpha-L-IdoAp-2S( 1-->4)-alpha-D-GlcNp2S6S (where delta UA represents 4-deoxy-alpha-L-threo-hex-4-enopyranosyluronic acid and S is sulfate). Thus, aFGF appears to bind at high density (one molecule every 4-5 polysaccharide units) and with high affinity to heparin. This potentially provides a concentrated, stabilized storage form of the growth factor that can be released for receptor-mediated cellular activation in response to the proper stimuli. It is also possible that close proximity of aFGF molecules on the highly sulfated regions of heparan chains may be involved in the induction of receptor aggregation as suggested by Ornitz et al. [Ornitz, D. M., Yayon, A., Flanagan, J. G., Svahn, C. M., Levi, E., & Leder, P. (1992) Mol. Cell. Biol. 12, 240-247].
 ...
PMID:Nature of the interaction of heparin with acidic fibroblast growth factor. 768 8

This paper describes low-density mucus glycoconjugates released from feline trachea by dirhamnolipid (DRL), a toxin from Pseudomonas aeruginosa. Mucus glycoconjugates in feline tracheas were radiolabeled in vivo with 3H-proline and 14C-glucose. Control mucus and that released by 200 micrograms/ml DRL were dissolved in guanidine hydrochloride buffer (GuHCl) and chromatographed on Sepharose CL-2B. Molecules eluting in the void volume (V0) of the column were isolated by isopycnic density gradient centrifugation in CsCl/GuHCl. All samples gave peaks of radiolabeled and periodic acid/Schiff (PAS)-reactive material at rho = approximately 1.50 and approximately 1.60 g/ml, but DRL-stimulated samples contained low-density material (rho < 1.32 g/ml), also PAS-reactive and radiolabeled. Control secretions incubated with DRL in vitro did not form low-density material. In Triton X-100 (1% vol/vol), a nonionic detergent, low-density material behaved as smaller molecules, running in the partially included volume (Vi) of the column of Sepharose CL-2B, but still in the V0 of Sephacryl S-300. Incubation with chondroitinase ABC, heparinase II and III, and keratanase failed to change its elution profile on S-300, evidence against glycosaminoglycans; but proteolysis with trypsin or proteinase K gave two peaks, peptide fragments near the totally included volume of the column and glycopeptides in V0. The V0 glycopeptides banded between 1.50 and 1.55 g/ml in a CsCl gradient and eluted as a single peak in the Vi of Sephacryl S-400, suggesting a distinct homogeneous glycopeptide, smaller than those from normal mucins. The main 14C-labeled sugars in this glycopeptide were fucose, glucosamine, galactosamine, and galactose, consistent with a mucin. Thus, DRL releases stable but noncovalent complexes containing one or more distinct mucinlike glycoconjugates, probably combined with lipids and peptides. We discuss their possible relevance to airway diseases, including cystic fibrosis.
Am J Respir Cell Mol Biol 1995 Mar
PMID:Mucus glycoconjugate complexes released from feline trachea by a bacterial toxin. 787 96


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