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)

Among the most important events in connective tissue physiology are the nucleation, growth and calcification of collagen fibrils. It has been speculated that all are associated with, or even controlled by collagen-proteoglycan interactions. We therefore developed methods for investigating these associations in tissues, particularly for understanding their significance for type I collagen, the commonest form of collagen in the body, especially predominant in bone. Using an electron-dense dye, Cupromeronic blue, in the 'critical electrolyte concentration' mode, and digestion by hyaluronidase, chondroitinase ABC or keratanase, supported by biochemical analyses, we found that dermatan sulphate proteoglycan of soft connective tissue (skin, tendon, cornea) was regularly and orthogonally arrayed at the fibril surface, at the d or e band. Keratan sulphate proteoglycan in the cornea associates orthogonally at the a and c bands. Bone, demineralized by a non-aqueous technique which retains proteoglycans in the tissue, does not contain orthogonal arrays; the interfibrillar proteoglycan filaments are oriented parallel to the fibril axis. The main proteoglycan in bone is chondroitin sulphate-rich. There are thus four separate specific binding sites on type I collagen fibrils, each one associating with one particular proteoglycan, and apparently no other. This implies that there are two corresponding binding sites in each proteoglycan. Available evidence shows that there are two species of small dermatan sulphate and keratan sulphate proteoglycans. It is suggested that each species is specific for its own band (a, c, d or e). Hyaluronate and chondroitin sulphate are probably mainly interfibrillar, acting in a space-filling capacity.
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PMID:Proteoglycan-collagen interactions. 381 15

Type IX collagen was isolated as a native protein from chicken embryo sternal cartilages and purified to homogeneity. Chondroitin and/or dermatan sulfate were bound covalently to one of the three polypeptide chains present in this protein containing collagenous and noncollagenous domains. Type IX collagen could be metabolically labeled with both radioactive sulfate and glycine. The protein containing either of these labels was sensitive to digestion by bacterial collagenase as well as chondroitinase ABC. Besides the glycosaminoglycans, type IX collagen contains asparagine-linked carbohydrate chains because the protein could be labeled with radioactive mannose and no glycosaminoglycans other than those mentioned above were present. The melting curve indicated that, in contrast to interstitial collagens, this molecule contains at least two disulfide-bonded collagenous domains with distinct thermal stabilities.
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PMID:Type IX collagen from sternal cartilage of chicken embryo contains covalently bound glycosaminoglycans. 385 2

The high-buoyant-density proteoglycans of the nucleus pulposus and annulus fibrosus of the beagle intervertebral disc have been isolated by CsCl density gradient ultracentrifugation. The sulphated proteoglycans were labelled in vivo with 35SO4, 24 h and 60 days prior to killing. The hydrodynamic size and aggregation of the 24 h, 60 day and resident (from hexuronic acid and hexosamine analysis) proteoglycan subunit populations were determined by Sepharose CL-2B chromatography in the presence or absence of excess hyaluronic acid. The hydrodynamic size of the keratan sulphate-proteoglycan core protein complexes were also determined by Sepharose CL-2B chromatography after chondroitinase ABC digestion of proteoglycans. When initially synthesised (24 h) or after 60 days, the percentage aggregation and hydrodynamic size of the proteoglycans derived from the annulus fibrosus were larger than those present in the nucleus pulposus. Hexosamine, hexuronic and protein determination of the high-buoyant-density fractions showed that the proteoglycans of the nucleus pulposus were richer in chondroitin sulphate than those in the annulus. However there was no difference in Mr of the chondroitin sulphate and keratan sulphate attached to the proteoglycans of the two disc regions, nor were differences detected by HPLC between the proportions of chondroitin 4-sulphate and chondroitin 6-sulphate present in these high-density fractions. In contrast, the low-buoyant-density (1.54 greater than p greater than 1.45) proteoglycan fractions and tissue residues remaining after 4 M GuHCl extraction were found to contain dermatan sulphate, suggesting the presence of a third proteoglycan species possibly associated with the collagen of the fibrocartilagenous matrix.
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PMID:The proteoglycans of the canine intervertebral disc. 392 Oct 57

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

Proteoglycan Lt (PG-Lt), isolated from 17-day-old chicken embryo sterna, appeared to differ from its counterpart from tibia and femur (Noro, A., Kimata, K., Oike, Y., Shinomura, T., Maeda, N., Yano, S., Takahashi, N., and Suzuki, S. (1983) J. Biol. Chem. 258, 9323-9331). The intact disulfide-bonded molecule of approximately 300 kDa was separable into three chains of 115, 84, and 68 kDa on reduction, the molecular masses being relative to those of collagen standards on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This is in contrast to tibial cartilage PG-Lt, from which there was no observed release of a 68-kDa chain (100 kDa relative to globular protein standards) after reduction. The 115-kDa chain of sternum PG-Lt consists of a core 68-kDa polypeptide to which the chondroitin sulfate chains are attached. The ratio of 4-sulfated to 6-sulfated disaccharides released after either chondroitinase ABC or AC digestion is 3:1. Identity of PG-Lt with type IX collagen was indicated by their similar elution profiles on DEAE-Trisacryl and by the presence in both proteins of co-migrating 84- and 68-kDa bands on SDS-PAGE. This identity was confirmed by immunoblotting PG-Lt after SDS-PAGE, with affinity-purified polyclonal antibodies specific for a triple helical domain (HMW) of type IX collagen. The nonreduced high molecular mass material and all three bands of the reduced PG-Lt were immunoreactive, giving immunostaining patterns similar to autoradiographs from the [14C]glycine-labeled protein.
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PMID:Proteoglycan Lt from chicken embryo sternum identified as type IX collagen. 398 33

Binding of fibronectins (FN) to collagen types I-IV were studied using polyclonal antibodies against human and chicken FNs, proteoglycan monomers, collagen type II and monoclonal antibodies reacting with both soluble and insoluble forms of human FN. Plasma fibronectin and type II collagen were shown to interact specifically in a homologous system. Type II collagen, however, proved to be less effective in inhibition assays compared to other types of collagen. In high density cultures of chicken limb bud cells, fibronectin was first localized within the fibroblast-like cells of 4 hr cultures and an extensive extracellular filamentous network developed by the end of day 1. Fibronectin was present in the newly formed cartilage nodules although it seemed to disappear by day 6, when the proteoglycan accumulation became more intensive. Enzyme treatments (testicular hyaluronidase, chondroitinase ABC) helped to localize FN at this stage of development of chicken cartilage, in microdroplet high density cultures of human fetal chondrocytes and in articular cartilage. Fibronectin was localized only in the pericellular ring of intact human articular cartilage using monoclonal antibodies with the biotin-avidin system.
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PMID:Appearance and persistence of fibronectin in cartilage. Specific interaction of fibronectin with collagen type II. 399 52

Comparative quantitative data are presented concerning the adhesion, proliferation and invasive behaviour of RPMI-3460 melanoma cells on (1) plain collagen gels, (2) monolayer cultures of fibroblasts and endothelial cells growing on the gel surface, and (3) the exposed endothelial and fibroblast extracellular matrices (ECMs). Both types of ECMs enhanced melanoma cell adhesion and proliferation (compared with plain gels) and had marked, but distinctive, effects on melanoma morphology. The thickness and composition of the ECMs was altered by treatment of the matrices with enzymes (trypsin, elastase and chondroitinase ABC) or by using ECMs produced by endothelial cells at various times after confluence. Variations in the thickness and composition of the ECMs had no effect on the behaviour of melanoma cells growing on these matrices; our results suggest that the glycoproteins and glycosaminoglycan ECM constituents removed by digestion with the enzymes do not play an important role in melanoma cell attachment, proliferation and migration. Melanoma cells plated on the surface of a plain collagen gel rapidly migrated down into the collagen matrix, with approximately 30% of the cells found within the gel after 6 days of incubation. Fibroblast and endothelial ECMs significantly and distinctively inhibited melanoma invasion into the underlying collagen gel. The extensive invasion of melanoma cells into the gel was not accompanied by hydrolysis of the collagen fibres. Conversely, fibroblast and endothelial ECMs, which acted as effective barriers, were extensively hydrolysed by the melanoma cells. The possible use of ECMs deposited on collagen in the study of melanoma local invasion (on fibroblast ECMs) and extravasation (on endothelial ECMs) is discussed.
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PMID:The interaction of melanoma cells with fibroblasts and endothelial cells in three-dimensional macromolecular matrices: a model for tumour cell invasion. 401 7

Interaction between cartilage proteoglycan and the collagen(s) composed of 1 alpha, 2 alpha, and 3 alpha chains was studied in vitro. Most of the collagen was insoluble under the conditions of assay (0.15 M NaCl, 0.008 M phosphate buffer, pH 7.4; 4 degrees C) and was in the form of fibrils 20 nm in diameter or thinner. The larger fibrils had 60-70 nm periodicity, characteristic of native collagens. Proteoglycan monomers which had been labeled by incubating cartilage slices in vitro with Na2 35SO4 were used to assay the interaction. The insoluble collagen fraction bound proteoglycan from solution. At proteoglycan:collagen ratios lower than 1:2, binding was rapid and linear, and the dissociation constant was 1.7 X 10(-9) M. At higher proteoglycan:collagen ratios, more proteoglycan was bound, but at a slower rate. Binding of proteoglycan to collagen did not require fibrils, since soluble 1 alpha, 2 alpha, and 3 alpha containing collagen also bound to proteoglycan and formed an insoluble complex. Denatured collagens did not bind proteoglycan or compete for binding with normal collagen. Optimum binding occurred with intact proteoglycan, but proteoglycan which had been treated with protease was also bound at low levels. Both protease-treated proteoglycan and free chondroitin sulfate competed with intact proteoglycan in the binding assays, but neither chondroitinase ABC-treated proteoglycan nor the oligosaccharides produced by digestion of chondroitin sulfate with testicular hyaluronidase altered the binding of proteoglycan to collagen. Hyaluronic acid did not compete with radioactive proteoglycan, but heparin and dextran sulfate were extremely effective inhibitors of binding. These data suggest a relatively nonspecific interaction between sulfated polyanions and 1 alpha, 2 alpha, and 3 alpha containing collagens. However, given the location of these collagens near the chondrocyte surface, the interaction of fibrillar 1 alpha, 2 alpha, 3 alpha collagen with proteoglycan is likely to occur and to be of biological importance.
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PMID:Interaction of proteoglycans with the pericellular (1 alpha, 2 alpha, 3 alpha) collagens of cartilage. 403 Jul 69

The distribution of anionic sites was studied in the trophoblastic and fetal capillary basal laminas of developing human placental villi with the cationic stain ruthenium red. At 7-12 weeks of gestation the trophoblastic basal lamina (TBL) contained ruthenium red-positive granules in a quasi-regular array throughout the lamina densa or sometimes concentrated at the interstitial surface of the lamina densa. The capillary basal lamina (CBL) (and anionic sites) were not present at this age. Anionic sites were also associated with collagen or reticular fibrils. At term, the TBL was largely devoid of anionic sites except for some distributed along its interstitial surface. The CBL was present in later gestation and sometimes had arrays of anionic sites. In order to characterize the anionic sites, minced pieces of villi were incubated in the presence or absence of either chondroitinase ABC, heparitinase, neuraminidase, or Streptomyces hyaluronidase in appropriate buffer systems. Incubation of early villi with heparitinase resulted in the disappearance of the TBL-associated sites. Chondroitinase ABC appeared to reduce staining of collagen-associated sites. In term villi, heparitinase removed those few sites still associated with the TBL but did not affect sites associated with the CBL or collagen. Chondroitinase ABC resulted in the disappearance of all anionic sites. In later gestation, a number of developmentally important macromolecules are transported across the trophoblast and enter the fetal capillaries. We conclude that the absence of an array of polyanionic sites from the term placenta TBL and the reduction in the amount of extracellular matrix intervening between the trophoblast and capillaries are adaptations to enhance the exchange of macromolecules across the placenta.
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PMID:Distribution and characterization of anionic sites in trophoblast and capillary basal laminas of human placental villi. 407 43

The dye, triethyl-carbocyanin DBTC, was tested for differential staining of cartilage structures. Femoral head articular cartilage from neonatal rats was processed for histology to demonstrate the interlacunar network. Sections of glycol methacrylate (GMA) embedded cartilage were stained at pH 2.8, 5.4, 6.1 and 8.0 to determine the optimal staining conditions. Only at pH 6.1 were all cartilage structures stained and the best contrast achieved. Streptomyces hyaluronidase, chondroitinase ABC, pepsin, trypsin, and pronase digestions were carried out prior to staining at pH 6.1 to evaluate the selectivity of the stain. Undigested chondrocyte nuclear chromatin stained dark purple; staining intensity was reduced slightly by pepsin or trypsin digestion. Undigested chondrocyte cytoplasm stained light blue but stained purple after hyaluronidase digestion. Undigested extracellular matrix stained light violet; staining was almost entirely eliminated by chondroitinase ABC digestion, was unaffected by hyaluronidase, and was either unaffected or increased after proteinase digestion. Staining of a narrow zone of matrix adjacent to the network was prevented by proteinase digestion while the network element appeared as a thin dark line. The network appears to be a trilaminar structure; a core element of hyaluronic acid and protein surrounded by a protein sheath. Triethyl-carbocyanin DBTC staining of cartilage offers slightly more selectivity and contrast than methylene blue, toluidine blue or safranin O. At pH 6.1, DNA, perhaps RNA, and hyaluronic acid stained deep purple; chondroitin sulfate, light violet; protein (collagen), stained very light violet if at all.
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PMID:Staining glycol methacrylate embedded cartilage with triethyl-carbocyanin DBTC ("ethyl-stains all") with special reference to the interlacunar network. 608 77


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