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)

13C nmr spectral parameters were measured for intact bovine nasal cartilage tissue, the purified proteoglycan aggregate, and chondroitin 4-sulfate. A comparison of integrated intensities obtained for four different samples of fresh tissue with an ethylene glycol standard indicated that at least 80% of the total glycosaminoglycan carbons in the tissue contributed to the spectrum. This result was confirmed by intensity measurements obtained at 56 degrees on fresh tissue and at 37 degrees after extensive papain digestion of fresh tissue. Spin lattice relaxation times and nuclear Overhauser enhancements were analyzed in terms of the following models of molecular motion: (a) single correlation time; (b) log X2 distribution of correlation times; and (c) anisotropic motion. The analysis indicates that the segmental motions of glycosaminoglycan chains are characterized by a broad distribution of correlation times centered at about 50 ns. Slow motion contributions to glycosaminoglycan line widths were reduced by dipolar decoupling (gammaH2/2pi = 65 kHz). Collagen intensity was observed in dipolar decoupled spectra, but not in scalar decoupled spectra of intact tissue, showing that the type II collagen in cartilage undergoes anisotropic motion like the type I collagen in tendon. Only glycosaminoglycan resonances were observed in spectra of a solution of proteoglycan aggregate before and after chondroitinase digestion. After subsequent digestion with papain, protein resonances were observed. These results suggest that the protein portions of the proteoglycan aggregate structure, in contrast with the glycosaminoglycan chains, have restricted backbone mobility and consequently a defined backbone structure.
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PMID:Investigation of molecular motion of proteoglycans in cartilage by 13C magnetic resonance. 14 Aug 75

Soluble 125I-labeled type I collagen binds to cultured fibroblasts but not to cultured epithelia. The binding of the ligand to fibroblasts is reversible, saturable and highly specific for sequences contained within the helical portions of the alpha1 and alpha2 chains. The amount of ligand bound is dependent upon cell number and ligand concentration. Binding is decreased but measurable at 4 degrees C. The steady state binding is greater at 26 degrees than at 37 degrees C due to a more rapid dissociation of the ligand-acceptor complex at 37 degrees C. The half-life of the complex is 46 min at 37 degrees C and approximately 2.5 hr at 26 degrees C. Scatchard plots of binding data indicate a single class of high affinity binding sites (KD = 1.2 X 10(-11) M) with each fibroblast binding approximately 500,000 molecules at saturation. Pretreatment of fibroblasts with bacterial collagenase, chondroitinase ABC or testicular hyaluronidase does not affect the binding reaction, whereas pretreatment of the cells with phospholipase C increases the amount of ligand bound. Ligand binding is decreased but not abolished after fibroblasts are treated with trypsin concentrations which remove surface fibronectin. Fibroblast monolayers treated with antiserum against fibronectin bind the radiolabeled ligand normally. In contrast to collagen, addition of excess fibronectin does not accelerate the dissociation of bound ligand from fibroblasts. Possible functions for surface-bound collagen are discussed.
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PMID:Binding of soluble type I collagen molecules to the fibroblast plasma membrane. 45 36

The metastatic spread of tumor cells occurs through a complex series of events, one of which involves the adhesion of tumor cells to extracellular matrix (ECM) components. Multiple interactions between cell surface receptors of an adherent tumor cell and the surrounding ECM contribute to cell motility and invasion. The current studies evaluate the role of a cell surface chondroitin sulfate proteoglycan (CSPG) in the adhesion, motility, and invasive behavior of a highly metastatic mouse melanoma cell line (K1735 M4) on type I collagen matrices. By blocking mouse melanoma cell production of CSPG with p-nitrophenyl beta-D-xylopyranoside (beta-D-xyloside), a compound that uncouples chondroitin sulfate from CSPG core protein synthesis, we observed a corresponding decrease in melanoma cell motility on type I collagen and invasive behavior into type I collagen gels. Melanoma cell motility on type I collagen could also be inhibited by removing cell surface chondroitin sulfate with chondroitinase. In contrast, type I collagen-mediated melanoma cell adhesion and spreading were not affected by either beta-D-xyloside or chondroitinase treatments. These results suggest that mouse melanoma CSPG is not a primary cell adhesion receptor, but may play a role in melanoma cell motility and invasion at the level of cellular translocation. Furthermore, purified mouse melanoma cell surface CSPG was shown, by affinity chromatography and in solid phase binding assays, to bind to type I collagen and this interaction was shown to be mediated, at least in part, by chondroitin sulfate. Additionally we have determined that mouse melanoma CSPG is composed of a 110-kD core protein that is recognized by anti-CD44 antibodies on Western blots. Collectively, our data suggests that interactions between a cell surface CD44-related CSPG and type I collagen in the ECM may play an important role in mouse melanoma cell motility and invasion, and that the chondroitin sulfate portion of the proteoglycan seems to be a critical component in mediating this effect.
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PMID:A cell surface chondroitin sulfate proteoglycan, immunologically related to CD44, is involved in type I collagen-mediated melanoma cell motility and invasion. 173 Jul 66

Primary cultures of rat hepatocytes maintained as monolayer in a serum-free medium synthesise and secrete sulphated proteoglycans. Nearly 5% of the total 35(S)-sulphated material was obtained in a soluble form from beneath the cell layer. A shift in gel filtration pattern on beta-elimination with alkali suggested that it is a sulphated proteoglycan. On ion exchange chromatography over Dowex AG 1 x 2, the major fraction was eluted with 1.25 M NaCl. Further, nearly 80% of the 35(S)-labeled material was susceptible to nitrous acid degradation and more than 90% of the material was resistant to chondroitinase ABC digestion suggesting that it is predominantly a heparan sulphate proteoglycan (HSPG). Since HSPG is a major component of basement membrane, its binding with collagen was studied by a solid phase binding assay. About 75% of the 35(S) HSPG bound to wells coated with type IV collagen whereas only about 20% bound to type I collagen at physiological pH. Binding to collagen IV was reduced by about 50% when free GAG chains were used indicating that the protein core is also involved in interaction with the collagen. These results indicate the possible role of this basal extracellular heparan sulphate proteoglycan in the basal lamina formation.
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PMID:Isolation of heparan sulfate proteoglycan from beneath the monolayers of rat hepatocytes and its binding to type IV collagen. 187 99

The biosynthesis of interstitial collagens (types I and III) and proteoglycans was studied in fibroblasts isolated from the parietal layer of bovine pericardium. Confluent cultures were labeled with Na2 35SO4 for proteoglycans or 14C-proline for collagens. The proteoglycans synthesized by pericardial fibroblasts were purified by DEAE-Sephacel chromatography and further fractionated into three components by gelfilitration. Two minor high molecular weight proteoglycans were shown by SDS-PAGE to be resistant to chondroitinase ABC and AC, and partially degraded by nitrous acid. The major, low molecular weight proteoglycan had a core protein of 45 kDa and is considered to be a dermatan sulfate/chondroitin sulfate proteoglycan since it was resistant to nitrous acid, but digested partially by chondroitinase AC and completely by ABC. The pericardial fibroblasts synthesized predominantly type I collagen and low amounts (about 10%) of type III collagen which was detected by delayed reduction on SDS-PAGE. The data show that pericardial fibroblasts synthesize the same macromolecules that can be extracted from the intact tissue and suggest that the proteoglycan may play a structural as well as physiological role.
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PMID:The biosynthesis of proteoglycans and interstitial collagens by bovine pericardial fibroblasts. 205 65

Dermatan sulfate proteoglycans (DS-PGs) isolated from bovine articular cartilage have been examined for their effects on the adhesive responses of BALB/c 3T3 cells and bovine dermal fibroblasts on plasma fibronectin (pFN) and/or type I collagen matrices, and compared to the effects of the chondroitin sulfate/keratan sulfate proteoglycan monomers (CS/KS-PGs) from cartilage. DS-PGs inhibited the attachment and spreading of 3T3 cells on pFN-coated tissue culture substrata much more effectively than the cartilage CS/KS-PGs reported previously; in contrast, dermal fibroblasts were much less sensitive to either proteoglycan class unless they were pretreated with cycloheximide. Both cell types failed to adhere to substrata coated only with the proteoglycans; binding of the proteoglycans to various substrata has also been quantitated. While a strong inhibitory effect was obtained with the native intact DS-PGs, little inhibitory effect was obtained with isolated DS chains (liberated by alkaline-borohydride cleavage) or with core protein preparations (liberated by chondroitinase ABC digestion). In marked contrast, DS-PGs did not inhibit attachment or spreading responses of either 3T3 or dermal fibroblasts on type I collagen-coated substrata when the collagen was absorbed with pFN alone, DS-PGs alone, or the two in combination. These results support evidence for (a) collagen-dependent, fibronectin-independent mechanisms of adhesion of fibroblasts, and (b) different sites on the collagen fibrils where DS-PGs bind and where cell surface "receptors" for collagen bind. Experiments were developed to determine the mechanism(s) of inhibition. All evidence indicated that the mechanism using the intact pFN molecule involved the binding of the DS-PGs to the glycosaminoglycan (GAG)-binding sites of substratum-bound pFN, thereby inhibiting the interaction of the fibronectin with receptors on the cell surface. This was supported by affinity chromatography studies demonstrating that DS-PGs bind completely and effectively to pFN-Sepharose columns whereas only a subset of the cartilage CS/KS-PG binds weakly to these columns. In contrast, when a 120-kD chymotrypsin-generated cell-binding fragment of pFN (CBF which has no detectable GAG-binding activity as a soluble ligand) was tested in adhesion assays, DS-PGs inhibited 3T3 adherence on CBF more effectively than on intact pFN. A variety of experiments indicated that the mechanism of this inhibition also involved the binding of DS-PGs to only substratum-bound CBF due to the presence of a cryptic GAG-binding domain not observed in the soluble CBF.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Fibronectin-mediated adhesion of fibroblasts: inhibition by dermatan sulfate proteoglycan and evidence for a cryptic glycosaminoglycan-binding domain. 295 85

Cocultures of rabbit fibroblasts and mouse B-16 melanoma cells produce increased levels of collagenase against type I collagen. This stimulatory effect was also found when fibroblasts were cultured in conditioned media from tumor cells. However, the level of the stimulatory factor in conditioned media was influenced by matrix deposited by fibroblasts. Thus, conditioned media collected from monolayers of B-16 plated on fibroblast matrix consistently showed high levels of the factor activity. The influence of the matrix on the level of the factor was not removed by treating the fibroblast matrix with collagenase or chondroitinase ABC and was not reproduced by collagen-coated dishes.
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PMID:Matrix influence on the tumor cell stimulation of fibroblast collagenase production. 299 20

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

Types I, III and V collagens and proteoglycan were localized in the aorta by indirect immunofluorescence techniques. Type I collagen was more prominent in media and adventitia than in intima while type III collagen predominated in intima and media but appeared less significant in adventitia. Type V collagen was observed in intima and media only and was seen surrounding smooth muscle cells. Type I collagen was located between elastic fibres but type III collagen appeared to envelop the fibres, suggesting an interaction between elastic fibres and type III collagen. Pretreatment of sections with testicular hyaluronidase caused no changes in staining for type I collagen, but adventitial areas showed increased staining for type III collagen. After digestion with chondroitinase ABC, intimal and medial areas showed increased staining for type III collagen. Therefore, type III collagen forms stronger interactions with proteoglycans and hyaluronic acid than does type I collagen and type III collagen in adventitia is largely masked by hyaluronic acid, while type III collagen in intima and media is associated with proteoglycan. Thus, type III collagen is a more significant component of adventitia than previously recognized. Proteoglycan was also partly localized along elastic fibres. It is, therefore, suggested that elastic fibres are coated with type III collagen, which itself is coated with proteoglycan.
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PMID:Investigation of relationships between collagens, elastin and proteoglycans in bovine thoracic aorta by immunofluorescence techniques. 635 43

We report further characterization of a cementum-derived protein that promotes the adhesion and spreading of periodontal cells. The cementum attachment protein (CAP) was extracted from bovine cementum, separated by diethylamino ethyl (DEAE)-cellulose chromatography, and purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and C18 reverse phase high performance liquid chromatography. The purified preparation contained a single protein band migrating with M(r) 56,000. It did not cross-react with polyclonal antibodies to osteopontin, vitronectin, or other attachment proteins. The attachment activity was resistant to chondroitinase ABC digestion. An internal amino acid sequence of six peptides was determined by microsequencing, and the peptide sequences were not present in other attachment proteins described in cementum. Four sequences contained Gly-X-Y repeats typical of collagen helix. One 17 amino acid peptide had 82% homology with a type XII collagen domain. However, bovine type XII collagen did not promote fibroblast attachment. Although another 19-amino-acid-long peptide had 95% homology to bovine alpha 1 [I], two other peptides were only 74% and 68% homologous, and the CAP was not recognized by anti-type I collagen antibody. The attachment activity of CAP was susceptible to bacterial collagenase. The CAP did not cross-react with antibodies to type V, XII, and XIV collagens. These data and our previous immunostaining data indicate that the CAP is not related to other collagens or attachment proteins and that it is a collagenous attachment protein localized in cementum.
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PMID:Characterization of a collagenous cementum-derived attachment protein. 915 84


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