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:3.1.6.4 (chondroitinase)
2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat 13762NF mammary adenocarcinoma cell surface glycoproteins from s.c. tumor- or lung metastases-derived cell clones of differing spontaneous metastatic potentials were examined for their relationship to metastasis. After treatment with neuraminidase, lectin-binding assays showed that highly metastatic clone MTLn3 cells express approximately twice the quantity of peanut agglutinin (PNA) binding sites (approximately 2.3 X 10(8) sites/cell) than clones of lower metastatic potential. However, the number of wheat germ agglutinin (WGA)-binding sites on the various cell clones decreased slightly as the metastatic potential of the clones increased. The quantities of concanavalin A (conA)-binding sites were similar (approximately 1.7 X 10(8) sites/cell) in all cell clones and growth conditions. Glycoprotein analysis was performed by electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate (SDS-PAGE) and subsequent staining with 125I-labeled lectins. SDS-PAGE gels stained with 125I-labeled conA revealed mainly one glycoprotein (Mr approximately 150 kD), and the amounts of this glycoprotein did not correlate with metastasis. Differences in WGA-binding glycoproteins were detected between s.c. tumor- and lung metastases-derived cell clones. Several desialylated glycoproteins were detected with 125I-labeled PNA after SDS-PAGE, and the labeling intensity of one (Mr approximately 580 kD) correlated with the metastatic potentials of the various cell clones. This high Mr galactoprotein was further analyzed by [3H]glucosamine metabolic labeling, solubilization, sequential gel filtration, and chondroitinase ABC treatment prior to SDS-PAGE. The 580 kD galactoprotein was expressed in increased amounts on the more highly metastatic clones. Chemical labeling of cell surface sialic acid residues using periodate treatment followed by [3H]borohydride reduction showed an additional change in a major sialoglycoprotein (Mr approximately 80 kD), which decreased in labeling intensity on clones of increasing metastatic potential. The results suggest quantitative changes in cell surface glycoproteins rather than major qualitative alterations are associated with differences in the metastatic behavior of 13762NF tumor cell clones.
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PMID:Cell surface glycoproteins of 13762NF mammary adenocarcinoma clones of differing metastatic potentials. 668 89

A transplantable colorectal adenocarcinoma and the normal colonic mucosa derived from rats of ACI/N strain were digested successively with pronase, deoxyribonuclease, chondroitinase ABC, and heparitinase to obtain the corresponding glycopeptide fractions. The amino acid compositions of these two fractions suggested that the polypeptide backbones were quite similar. However, the electrostatic net charges of these fractions were shown to be different by cellulose acetate membrane electrophoresis, ion exchange chromatography, and measurement of sialic acid contents. The glycopeptide fraction derived from adenocarcinoma contained much greater quantities of less acidic glycopeptides than that derived from the normal colonic mucosa. The former exhibited much stronger blood group A and H activities than the latter. Moreover, the former reacted with Ricinus communis lectin I, whereas the latter did not react with this lectin. These results indicate that the carbohydrate structures of tumor sialoglycoproteins are different from those of the corresponding ones in the normal tissue from which the tumor has originated.
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PMID:Sialoglycopeptides obtained from a transplantable rat colorectal adenocarcinoma: a comparison with those from normal colonic mucosa. 688 96

Lectins have specificity for certain carbohydrate structures in macromolecules. Lectins are, therefore, useful histochemical tools for demonstrating the composition and localization of components of connective tissue matrices, such as articular cartilage. In order to assess the significance of observed lectin-binding patterns, experiments were performed in which monoclonal antibodies against chondroitin sulphate- and keratan sulphate-containing proteoglycans and link proteins were applied to sections of bovine articular cartilage after enzymatic digestion with chondroitinase ABC and keratanase. The following conclusions were made: (1) Binding of peanut agglutinin (PNA) in the interterritorial matrix predominantly indicates the presence of keratan sulphate, but may also detect O-linked oligosaccharides of proteoglycans. (2) In normal cartilage wheat germ agglutinin (WGA) binds nearly exclusively to keratan sulphate. In cartilage degraded with chondroitinase ABC and keratanase this lectin may also detect carbohydrates in link protein due to enhanced accessibility. Binding of WGA to O-linked oligosaccharides may eventually occur. (3) In enzymatically digested cartilage matrix, staining with soybean agglutinin (SBA) may be due to link protein, but not to chondroitin sulphate, because specific breakdown of the glycosaminoglycan chain is required for binding of SBA. (4) Ulex europaeus agglutinin I (UEA I) binding sites are only detectable in digested cartilage matrix.
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PMID:Immunohistochemical localization of articular cartilage proteoglycan and link protein in situ using monoclonal antibodies and lectin-binding methods. 768 96

Neurons in the human visual cortex were demonstrated to possess an intensely negatively charged surface coat which was stained with cationic iron colloid and aldehyde fuchsin. Digestion with hyaluronidase eliminated both the iron colloid and fuchsin stainings of the coats. Treatment with chondroitinase ABC, heparitinase and keratanase eliminated the iron colloid staining of the coats, but did not interfere with the fuchsin staining. Electron microscopy of ultrathin sections revealed that the cationic iron particles were preferentially deposited in the perineuronal tissue spaces. These findings indicate that the surface coats consist of sulfated proteoglycans, which, as an extracellular matrix, occupy the perineuronal tissue spaces. This study further demonstrates that neurons with such surface coats are identical with neurons labeled with lectin Vicia villosa agglutinin. The cell surface glycoproteins reactive to this lectin may not be the structural elements of the sulfated coats since the lectin labeling was not interrupted by the hyaluronidase digestion.
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PMID:Neurons with intensely negatively charged extracellular matrix in the human visual cortex. 773 78

Previous studies have suggested that mucin gene expression is tissue-specific; however, the relationship between unique mucin gene products and the biochemical properties of mucins is unknown. The purpose of this study was to determine the biochemical and molecular characteristics of mucin synthesized by adenocarcinoma cell lines derived from breast (ZR-75-1), stomach (MGC-803), pancreas (Capan-2), and lung (Chago K-1). Mucin was quantitated by [3H]glucosamine labeling and Sepharose CL-4B chromatography. The mucinous nature of the labeled high molecular weight glycoproteins (HMG) was verified by alkaline borohydride treatment, cesium chloride density gradient ultracentrifugation, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Specific mucin gene expression was determined using cDNA probes for 2 distinct intestinal mucins (MUC-2 and MUC-3) and one breast cancer mucin (MUC-1). Specific core mucin proteins were confirmed by immunoblots using antibodies that recognize MUC-1, MUC-2, and MUC-3 core peptides. These experiments demonstrate that all cell lines contained HMG in the medium, cytosol, and membrane fractions. The HMG was mucinous in breast, pancreatic, and lung cell lines. In contrast, most of the HMG secreted by the gastric cell line was proteoglycan-like, due to its susceptibility to hyaluronidase, heparinase, and chondroitinase avidin-biotin complex. Ion-exchange (DEAE-Sephacel) chromatography of [3H]glucosamine-labeled HMG demonstrated that the acidic or basic nature of the mucin was different in all cancer cell lines tested. Despite these differences, mRNA and immunoblot analysis suggest that all cell lines predominantly express MUC-1 apomucin, small amounts of MUC-2 apomucin, and no MUC-3. Immunoprecipitation of MUC-1-type mucin using the 139H2 monoclonal antibody demonstrated that different sizes of mucin peptides were present in all cell lines, corresponding to the known length polymorphism of this mucin. The amount and nature of carbohydrate epitopes were analyzed by immunoblots using anti-T (peanut lectin), anti-Tn (91S8 monoclonal antibody), and anti-sialosyl Tn (JT10e monoclonal antibody). T and Tn antigens were significantly higher in breast and pancreatic cells as compared with lung and gastric cell lines. These findings correlated with increased activities of polypeptidyl N-acetylgalactosaminyl transferase and beta-1,3-galactosyltransferase.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Mucin synthesis and secretion in various human epithelial cancer cell lines that express the MUC-1 mucin gene. 844 22

The human visual cortex, especially its ganglionic lamina, was found to contain many neurons with perineuronal sulfated proteoglycans which were stained with cationic iron colloid and aldehyde fuchsin. It also contained many neurons with surface glycoproteins labeled with lectin Vicia villosa agglutinin (VVA) or Glycine max agglutinin (SBA). Double staining frequently showed that the neurons stained with cationic iron colloid were not labeled with lectin VVA or SBA. Hyaluronidase and chondroitinase ABC/heparitinase/keratanase digestions eliminated the perineuronal cationic iron colloid reaction, but never interfered with the cell surface lectin labeling. These findings indicate that the cell surface glycoproteins reactive to lectin VVA or SBA are neither structural elements nor adhesive molecules of the proteoglycans. Double staining further demonstrated that in some neurons with perineuronal sulfated proteoglycans, the cytoplasm was labeled with lectin Arachis hypogaea agglutinin (PNA). It was further noticed that the lectin VVA-labeled neurons were not always identical with the neurons labeled with lectin SBA or with lectin PNA.
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PMID:Neurons with perineuronal sulfated proteoglycans in the human visual cortex, with special reference to their reactions to lectins. 852 42

The deduced amino acid sequence of an estrogen-dependent sheep oviductal glycoprotein (M(r) 90,000-116,000) revealed the presence of several potential sites for glycan substitution on a protein backbone of M(r) approximately 66,500, and identity with chitinases. In order to further define the nature of the secreted glycoprotein, the objectives of the present study were 1) to devise a method to significantly enrich for the glycoprotein from oviductal secretions, 2) to biochemically characterize the glycoprotein by use of lectin blotting and enzymatic and chemical digestion, and 3) to determine whether unfractionated and enriched fractions containing the glycoprotein have chitinase activity. Oviducts were obtained from ovariectomized ewes treated with estradiol for 6 days and explant-cultured for 24 h. The oviductal glycoprotein was enriched approximately 80-85% from explant culture media by Maackia amurensis agglutinin (MAA) lectin affinity chromatography. Enriched fractions containing the oviductal protein were separated on SDS gels, transferred to polyvinyl difluoride, and probed with digoxigenin-labeled lectins. Lectin blotting revealed that the glycoprotein contained the carbohydrate moieties N-acetylgalactosamine, N-acetylglucosamine, galactose, fucose, and sialic acid both in alpha(2,3) and alpha(2,6) linkages, typical of sialomucins. Enzymatic digestion with neuraminidase and N-glycanase indicated that approximately 20% and approximately 6% of the molecular weight of the oviductal glycoprotein can be accounted for by sialic acid and N-linked glycans, respectively. The oviductal glycoprotein was resistant to digestion with O-glycanase alone and chondroitinase ABC, with the latter indicating that it was not a proteoglycan. Treatment with trifluoromethanesulfonic acid resulted in a deglycosylated product of M(r) approximately 66,000 immunoreactive with antibodies to the oviductal glycoprotein. No chitinase activity could be detected for unfractionated culture medium proteins or enriched fractions containing the M(r) 90,000-116,000 oviductal glycoprotein when the substrate methylumbelliferyl chitotriose was used. These data show that 1) MAA lectin chromatography can significantly enrich for the M(r) 90,000-116,000 glycoprotein from oviductal secretions, 2) the secreted glycoprotein contains saccharide residues typical of sialomucins, and 3) despite primary amino acid sequence identity, the oviductal glycoprotein does not share an enzymatic relationship with chitinases.
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PMID:An estrogen-dependent sheep oviductal glycoprotein has glycan linkages typical of sialomucins and does not contain chitinase activity. 856 10

Subsets of neurons ensheathed by perineuronal nets containing chondroitin unsulfated proteoglycan have been immunohistochemically mapped throughout the rat central nervous system from the olfactory bulb to the spinal cord. A variable proportion of neurons were outlined by immunoreactivity for the monoclonal antibody (Mab 1B5), but only after chondroitinase ABC digestion. In forebrain cortical structures the only immunoreactive nets were around interneurons; in contrast, throughout the brainstem and spinal cord a large proportion of projection neurons were surrounded by intense immunoreactivity. Immunoreactivity was ordinarily found in the neuropil between neurons surrounded by an immunopositive net. By contrast, within the pyriform cortex the neuropil of the plexiform layer was intensely immunoreactive even though no perineuronal net could be found. The presence of perineuronal nets could not be correlated with any single class of neurons; however a few functionally related groups (e.g., motor and motor-related structures: motor neurons both in the spinal cord and in the efferent somatic nuclei of the brainstem, deep cerebellar nuclei, vestibular nuclei; red nucleus, reticular formation; central auditory pathway: ventral cochlear nucleus, trapezoid body, superior olive, nucleus of the lateral lemniscus, inferior colliculus, medial geniculate body) were the main components of the neuronal subpopulation displaying chondroitin unsulfated proteoglycans in the surrounding extracellular matrix. The immunodecorated neurons found in the present study and those shown by different monoclonal antibodies or by lectin cytochemistry, revealed consistent overlapping of their distribution patterns.
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PMID:Immunohistochemical mapping of perineuronal nets containing chondroitin unsulfated proteoglycan in the rat central nervous system. 859 57

Distribution of complex carbohydrates in the peripheral and central nervous systems was investigated cytochemically with a lectin that binds specifically to terminal alpha GalNAc and with monoclonal antibodies against carbohydrate epitopes, including glucuronic acid 3-SO4 and chondroitins 6-SO4 and 4-SO4. Comparative staining with these methods differentiated and partially characterized several glycoconjugates in various sites and allowed a comparison of chemical heterogeneity to neural specialization. Distal terminals of sensory neurons concerned with hearing, balance, taste, touch, and sight expressed glucuronyl 3-SO4, which apparently was present in an undefined glycoprotein. Some neurons in sensory nuclei of the brainstem exhibited a similar constituent on their surfaces. Retinal rod outer segments and the cerebellar granular layer possessed masked glucuronyl 3-SO4 that became immunopositive after digestion with chondroitinase ABC and that occurred in chondroitin 6-SO4 and chondroitin 4-SO4, respectively. The surface of neurons in the eighth nerve root and in neighboring nodes of Ranvier stained for unmasked glucuronic acid 3-SO4 and chondroitin 6-SO4. Some neurons of the cerebral cortex expressed unmasked glucuronyl 3-SO4, chondroitin 6-SO4, and terminal alpha GalNAc on their surfaces. Certain cortical neurons and nerve tracts with chondroitin 6-SO4 and terminal alpha GalNAc lacked glucuronyl 3-SO4, and other neurons possessing chondroitin 6-SO4 failed to express either glucuronyl 3-SO4 or terminal alpha GalNAc. Lability of lectin affinity to hyaluronidase suggested the presence of terminal alpha GalNAc in the chondroitin 6-SO4 on cortical neurons. The findings document further the heterogeneity of neural glycoconjugates, expand knowledge about the diversity of neurons with respect to their content of partially characterized glycoconjugates, and link glucuronyl 3-SO4 with or without chondroitin 6-SO4 spatially to sites of active Na+ transport in sensory nerves.
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PMID:Differentiation of glycoconjugates localized to sensory terminals and selected sites in brain. 882 66

We have previously suggested that sulfated polysaccharides could be used in a vaginal formulation to inhibit infection by human immunodeficiency virus (HIV-1). This supposition was based on studies in which we developed and employed an in vitro model to simulate the mechanism of HIV-1 transmission during coitus. We found that adhesion of mononuclear cells to epithelia was the initial step in infection and speculated that blocking adhesion would prevent HIV-1 transmission. We observed that certain sulfated polysaccharides prevented adhesion of lymphoma cell lines to epithelial cell lines, which were derived from the genital tract, in concentrations of a few milligrams per milliliter; and we theorized that sulfated polysaccharides could thus be used as active ingredients in a topical "microbicide." In the present in vitro study, evidence is presented that a number of sulfated polysaccharides, including carrageenan, dextran sulfate, heparin, fucoidan, and pentosan polysulfate, are capable of blocking infection by mechanisms other than adhesion at concentrations of a thousand times lower than the dosages that are needed to block cell adhesion. One of these compounds, iota carrageenan, is capable not only of blocking infection of epithelia at concentrations of 1-2 micrograms, but of blocking adhesion to a far greater extent than the other sulfated polysaccharides tested. For this reason, as well as for considerations of safety, stability, and gelling properties, we suggest that iota carrageenan may be the best choice of the sulfated polysaccharides tested for use as a vaginal microbicide. The same in vitro model was employed to decipher the cell surface molecules involved in lymphocyte-to-epithelial adhesion. To accomplish this, we screened for the presence of cell adhesion molecules (CAMs), carbohydrates, proteoglycans, and carbohydrate-binding sites. HIV-1-infected lymphocytic cells expressed a CAM profile typical of activated, infected cells (e.g., HLA-DR+, CD4-, LFA-1+, ICAM-1+, LFA-3+, CD2+) whereas epithelia expressed few CAMs (LFA-3, ICAM-1, VLA-5, CD44, CD26, sLEX). Both cell types expressed heparan sulfate and chondroitin sulfate proteoglycans. A variety of sugars (mannose, fucose, galactose, Nac-galactosamine, Nac-glucosamine) were also present, but these cells expressed few carbohydrate-binding sites; lymphocytes bound beta-galactose. We were unable to block the adhesion with anti-CAM antibodies or with exogenous sugars. When enzymes were used against sulfated cell surface molecules, chondroitinase was found to block the adhesion. Our evidence suggests that this CAM-independent adhesion may be a lectin-glycosaminoglycan interaction.
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PMID:Sulfated polysaccharides inhibit lymphocyte-to-epithelial transmission of human immunodeficiency virus-1. 883 15


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