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)

The chorionic villi of placentas, 10 to 40 weeks of gestation, were examined for A and B blood group antigens with an immunoferritin technique. No specific ferritin attachment was shown on the plasma membrane of the villous trophoblasts. Furthermore, after trophoblast cell-surface mucosubstances (perhaps the barrier of the placental antigenicity, according to some authors) were digested with several enzymes, such as neuraminidase, hyaluronidase, chondroitinase ABC, pepsin, trypsin, and pronase, no ferritin tagging was observed on the plasma membrane of the villous trophoblasts. We have concluded that our failure to detect the A and B blood group antigens was not due to the masking of antigens by mucosubstance coating the trophoblasts, but was due to the intrinsic deficit of those antigens in the plasma membrane of the human trophoblasts.
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PMID:Innumoelectron microscopy of the human chorionic villus in search of blood group A and B antigens. 79 65

Type IX collagen was partially purified from the Swarm rat chondrosarcoma by a series of a conventional salting-out procedures. The preparation was further separated by anion exchange chromatography into an unbound and a bound fraction in an A230 ratio of about 5:1. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the bound fraction appeared as a broad band, whose molecular mass ranged from 250 to 270 kDa. Digestion with chondroitinase ABC reduced the apparent molecular mass of the bound fraction to about 250 kDa, a value comparable to the molecular mass of the unbound fraction. Tryptic peptide maps of the protein moieties of unbound and bound forms showed that their molecular structures were basically identical. A monoclonal antibody specific for LMW, one of the pepsin-resistant fragments of the rat sarcoma type IX, reacted with both the unbound and bound fractions. Together the results indicate that the unbound and bound fractions represent a type IX collagen devoid of the chondroitin sulfate chain and its proteoglycan form with covalently bound chondroitin sulfate, respectively. The extent of glycosaminoglycan attachment to type IX collagen molecules in rat chondrosarcoma (about 16%) is quite different from the extents described in chick embryo cartilage (about 80%), chick vitreous humour (100%) and bovine cartilage (less than 5%). Further studies on the neoplastic tissue will offer additional information regarding the biological basis and biological consequences of the glycosaminoglycan attachment to type IX collagen molecules.
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PMID:Isolation and characterization of type IX collagen-proteoglycan from the Swarm rat chondrosarcoma. 162 94

Calf and mature cow articular cartilage was labeled in vitro with [35S]SO4 and [3H]glycine and kinetics of incorporation of both isotopes by cartilage fragments was determined by scintillation spectroscopy. The cartilage fragments were then extracted in sequence with 4M GuHCl (Guanidium chloride) and pepsin. The pepsin digest was adjusted to 1.3 M NaCl and pepsin-solubilized collagen salted out. The 4M GuHCl extract, collagen and pepsin-resistent residue were then freeze-dried. The 4M GuHCl extract was further fractionated by DEAE (Diethylaminoethyl) 52 ion exchange chromatography to obtain protein and PG (Proteoglycan) fractions. The protein fraction was also characterised by SDS-PAGE and PG fraction by Sepharose C1-2B chromatography under associative conditions in the presence and absence of an exogenous HA (Hyaluronic acid). The GAG (Glycosaminoglycan) side chains of the PG samples were analysed by Sephadex G-200 column chromatography and their composition determined by paper chromatography after chondroitinase ABC digestion. Linear incorporation of both isotopes was observed from 1 to 18 hours of incubation and roughly equal amounts of [35S]SO4 counts were found on per cell bases in both cartilages although less [3H]glycine was incorporated by cow chondrocytes. It was also found that calf chondrocytes synthesize much greater proportion of the collagen whereas the cow cells synthesize PGs of smaller hydrodynamic sizes, bearing shorter GAG side chains that are enriched in KS (Keratan sulfate) and Ch-6S (Chondroitin-6 sulfate isomer). A failure of cow 35S-PGs monomers to interact with an exogenous HA in the presence of other extracted components was also demonstrated. The relevance of these findings for the mechanism of cartilage damage in aging and osteoarthritis is discussed.
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PMID:Age-related changes in the synthesis of matrix macromolecules by bovine articular cartilage. 280 79

Human collagen type IX was isolated from the media of organ cultures of fetal or infant hyaline cartilage. It consisted of three distinct, disulfide-bonded polypeptides of 115, 84, and 72 kDa, respectively. Digestion with chondroitinase ABC reduced the apparent molecular mass of the 115-kDa chain to about 65 kDa demonstrating that also human collagen type IX is a proteoglycan. In the electron microscope, the molecule had a rigid rod-like structure with characteristic kinks and with a globular domain at one end. Digestion of human collagen type IX with pepsin leads to somewhat heterogeneous fragments. Affinity-purified antibodies to the mixture of fragments specifically reacted with the fragment HMW without cross-reaction with chicken HMW. LMW of both species were recognized to the same low extent. Mechanically generated fibril fragments from human fetal cartilage were heterogeneous in diameter. Significantly, they could be immunostained for collagen type IX in a D-periodic pattern and regardless of the fibril diameter. Some fibrils were poorly labeled, again independently of the diameter. Therefore, the role of collagen type IX in cartilage probably is not to control directly the lateral growth during fibrillogenesis but rather to stabilize the fibril network.
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PMID:The structure of human collagen type IX and its organization in fetal and infant cartilage fibrils. 314 13

Microfibrils have been identified within and between corneal collagen lamellae in a number of vertebrate species in a variety of developmental and pathological conditions, but they are relatively rare in normal adult animals. The present study was undertaken to analyze corneal microfibrils in adult rabbits using enzymatic digestion techniques. Transmission electron microscopy (TEM) showed clusters of 10-15 nm microfibrils arranged in quasi-parallel bundles within or between orthogonally arranged stromal collagen lamellae. When corneas were fixed with tannic acid/glutaraldehyde, the entire stroma showed increased electron density and microfibrillar bundles were heterogeneously stained. Peripheral fibrils were more electron-dense than those located more centrally. Following sequential detergent solubilization of unfixed corneas, all cellular elements were removed and collagen lamellae were distorted. Microfibrillar bundles remained intact, however, and resembled untreated controls. Subsequent treatment with pepsin, trypsin or elastase resulted in swollen corneal tissues in which collagen lamellae were no longer distinguishable but individual collagen fibrils maintained their morphological integrity. In these tissues microfibrillar bundles were rarely identifiable and were reduced to randomly oriented fragments or clusters of filamentous material. Testicular hyaluronidase or chondroitinase ABC did not affect the fibrils. These data indicate that rabbit corneal microfibrils are proteinaceous and that the tannic acid-staining component of the bundles is not glycosaminoglycan. The fibrils are indistinguishable from those identified as oxytalan in cornea and other ocular tissues. Moreover, their sensitivity to elastase and preferential staining with tannic acid/glutaraldehyde strongly suggest they may be related to the elastic system of fibrils.
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PMID:Ultrastructural analyses of enzyme-treated microfibrils in rabbit corneal stroma. 328 15

The effects of the enzymes collagenase, pepsin, chondroitinase ABC and keratanase on the polypeptide composition of the mammalian tectorial membrane have been analysed using one dimensional SDS-polyacrylamide gel electrophoresis (SDS-PAGE). After reduction at least ten polypeptides can be consistently and clearly recognized in SDS gels with molecular weights relative to globular protein standards of 245, 235, 190, 165, 155, 145, 100, 93, 60-73 and 35-49 kDa. With the exception of the 60-73 and 35-49 kDa bands all these polypeptides are sensitive to digestion with bacterial collagenase. The 235, 165, 155, 145 and 93 kDa bands also resist degradation by cold, acidic pepsin. Amino acid analysis of whole tectorial membranes demonstrates that glycine accounts for nearly 25% of the total amino acid content, that proline, hydroxyproline and hydroxylysine are present and that amine sugars can be detected in fairly high concentrations. Estimates based on hydroxyproline content suggest that collagens account for 25-50% of the total tectorial membrane protein. Immunoblotting techniques demonstrate the presence of polypeptides cross reacting with antisera to Type II collagen, Type IX collagen and Type V collagen. Results from immunohistochemical studies confirm that these polypeptides are present in the tectorial membrane and are not contaminants of the isolation procedure. Collagenase treatment of tectorial membranes reveals the presence of an additional non-collagenous polypeptide with an apparent molecular weight of 173 kDa on 7.5% polyacrylamide gels, and polydisperse high molecular weight material spreading over a broad range at the top of the gels. This high molecular weight material and the 173, 60-73 and 35-49 kDa non-collagenous polypeptides are pepsin sensitive and all bind wheat germ agglutinin (WGA) suggesting that they contain N-acetyl glucosamine. The 173 kDa band also binds soybean agglutinin (SBA) suggesting the presence of N-acetyl galactosamine. In the absence of reducing agent the 173 and 60-73 kDa bands are no longer observed and high molecular weight material forming a broad band at the top of the separating gel is seen. The electrophoretic behaviour of this non-collagenous, glycosylated, disulphide bonded, high molecular weight material is altered by treatment with keratanase but not by chondroitinase ABC. The results of this study indicate the tectorial membrane contains at least three different collagen types and, in addition to these collagenous proteins, several non-collagenous, glycosylated polypeptides that may account for as much as 50% of the total tectorial membrane protein.
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PMID:Polypeptide composition of the mammalian tectorial membrane. 354 19

Chick-embryo cartilage contains a unique set of proteoglycans. Type H proteoglycan (PG-H) is the most abundant, constituting over 90% of the total cartilage hexuronate. We previously showed that treatment of PG-H with chondroitinase ACII and keratanase yields a protein-enriched core molecule [PG(-CS,KS)] with enzymically modified linkage oligosaccharides of the chondroitin sulphate and keratan sulphate chains. We report here that further treatment of PG(-CS,KS) with pepsin and N-oligosaccharide glycopeptidase (almond glycopeptidase) released four distinct types of mannose-containing oligosaccharide. Two of them were shown to be: (Formula: see text). Of the mannose-containing glycopeptides formed by pepsin digestion, about 40% (as mannose) were resistant to N-oligosaccharide glycopeptidase. Since the resistant fraction was enriched in keratan sulphate remnants, it is suggest that the mannose-containing oligosaccharides in this fraction represent those located in a keratan sulphate-enriched region of PG-H.
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PMID:The core molecule from type H proteoglycan. Release of mannose-containing oligosaccharides by digestion with N-oligosaccharide glycopeptidase. 405 10

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

This report describes the biochemical characterization of a novel extracellular matrix component, " myotendinous antigen," which appears early in chick limb morphogenesis at sites connecting developing muscle fibers, tendons, and bone ( Chiquet , M., and D. Fambrough , 1984; J. Cell Biol., 98:1926-1936). This extracellular matrix antigen is a major component of the secretory proteins released into the medium by fibroblast and muscle cultures; the soluble form is characterized here. This form of myotendinous antigen is a large glycoprotein complex consisting of several disulfide linked subunits (Mr approximately 150,000-240,000). The differently sized antigen subunits are related, since they yielded very similar proteolytic cleavage patterns. M1 antibody can bind to the denatured subunits. The antigen subunits, as well as a Mr approximately 80,000 pepsin-resistant antigenic domain derived from them, are resistant to bacterial collagenase. Despite possessing subunits similar in size to fibronectin, myotendinous antigen appears to be both structurally and antigenically unrelated to fibronectin or to other known extracellular matrix components. About seven times more M1 antigen per cell nucleus was released into the medium in fibroblast as compared to muscle cultures. In muscle conditioned medium, myotendinous antigen is noncovalently complexed to very high molecular weight material that could be heavily labeled by [3H]glucosamine and [35S]sulfate. This material is sensitive to chondroitinase ABC and hence appears to contain sulfated glycosaminoglycans. We speculate that myotendinous antigen might interact with proteoglycans on the surface of muscle fibers, thereby acting as a link to tendons.
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PMID:Chick myotendinous antigen. II. A novel extracellular glycoprotein complex consisting of large disulfide-linked subunits. 620 99

The small dermatan sulphate proteoglycan of bovine tendon demonstrated a unique ability to inhibit fibrillogenesis of both type I and type II collagen from bovine tendon and cartilage respectively in an assay performed in vitro. None of the other proteoglycan populations from cartilage, tendon or aorta, even those similar in size and chemical structure, had this effect. Alkali treatment of the small proteoglycan of tendon eliminated its ability to inhibit fibrillogenesis, whereas chondroitinase digestion did not. This indicates that its interaction with collagen depends on the core protein. Fibrillogenesis of pepsin-digested collagens was affected similarly, indicating that interaction with the collagen telopeptides is not involved. The results suggest that interactions between collagen and proteoglycans may be quite specific both for the type of proteoglycan and its tissue of origin.
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PMID:Specific inhibition of type I and type II collagen fibrillogenesis by the small proteoglycan of tendon. 643 84


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