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 sulfated proteoglycans synthesized by definitive chondroblasts in cultured 10-day chick vertebral or epiphyseal cartilages were characterized by their sedimentation profile in a sucrose gradient and their susceptibility to chondroitinase ABC (EC 4.2.2.4; chondroitin ABC lyase). These sulfated proteoglycans were indistinguishable from those synthesized by definitive chondroblasts that emerge from older cultures of somites plus notochord or in older cultures of limb buds. The sulfated proteoglycans of these definitive chondroblasts are readily distinguished from those synthesized by their mother cells, the presumptive chondroblasts, or those synthesized by dedifferentiated or bromodeoxyuridine-suppressed chondroblasts. However, the sulfated proteoglycans synthesized by presumptive chondroblasts or by dedifferentiated or bromodeoxyuridine-suppressed chondroblasts cannot be dintinguished by these techniques from those synthesized by (i) blastodisc cells, (ii) fibroblasts, (iii) spinal cord cells, or (iv) skeletal, cardiac, or smooth muscle cells. Addition of glycosaminoglycans or collagen to the medium did not induce somite or limb presumptive chondroblasts to synthesize the chondroblast-unique sulfated proteoglycans. Cells moving from the presumptive chondroblast compartment into the chondroblast compartment acquire not only the option to initiate the synthesis of chondroblast-unique collagen chains, but also the capacity to synthesize chondroblast-unique sulfated proteoglycans.
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PMID:Differences among sulfated proteoglycans synthesized in nonchondrogenic cells, presumptive chondroblasts, and chondroblasts. 13 59

Histological aspects of cervical ripening were studied on the human uterine cervix during pregnancy. Cervical specimens were taken from 25 cases of cervical laceration of primiparous women immediately after delivery, 8 primiparous women whose cervixes opened 2-3 cm, and 5 cesarean-sectioned women with unripeness of cervix. The following histochemical techniques were used: alcian blue, azure A, hyaluronidase digestion, and chondroitinase ABC digestion. The collagen bundles disintegrated into fine fibers and also underwent quantitative changes during the ripening process of the cervix. The number of connective tissue cells was increased during pregnancy, but that of mast cells was decreased. In late pregnancy, acid mucopolysaccharides in the cervical ground substance were found to increase.
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PMID:Histological aspects of cervical ripening. 13 67

After chondroitinase digestion of bovine nasal and tracheal cartilage proteoglycans, subsequent treatment with trypsin or trypsin followed by chymotrypsin yielded two major types of polypeptide-glycosaminoglycan fragments which could be separated by Sepharose 6B chromatography. One fragment, located close to the hyaluronic acid-binding region of the protein core, had a high relative keratan sulfate content. This fragment contained about 60% of the total keratan sulfate, but less than 10% of the total chondroitin sulfate present in the original proteoglycan preparation. The weight average molecular weight of the keratan sulfate-enriched fragment was 122,000, as determined by sedimentation equilibrium centrifugation. The chemical and physical data indicate that this fragment contains an average of 10 to 15 keratan sulfate chains, if the average molecular weight of individual chains is assumed to be about 8,000, and about 5 chondroitin sulfate chains attached to a peptide of about 20,000 daltons. The other population of fragments was derived from the other end of the proteoglycan molecule, the chondroitin sulfate-enriched region, and contained mainly chondroitin sulfate chains. About 90% of the total chondroitin sulfate, but only 20 to 30% of the total keratan sulfate was recovered in these fragments. On the average, approximately 5 chondroitin sulfate chains and 1 keratan sulfate chain could be linked to the same peptide. Another 10 to 20% of the total keratan sulfate, originally found in or near the hyaluronic acid-binding region, was not separated from the chondroitin sulfate-enriched fragments. Hydroxylamine could be used to liberate a large molecular size, chondroitin sulfate-enriched fragment (Kav 0.54 on Sepharose 2B) from the proteoglycan aggregates. The remainder of the protein core, containing the keratan sulfate-enriched region, was bound to hyaluronic acid with the link proteins and recovered in the void volume on the Sepharose 2B column.
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PMID:Distribution of keratan sulfate in cartilage proteoglycans. 13 6

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

Rat liver cells grown in primary cultures in the presence of [(35)S]sulphate synthesize a labelled heparan sulphate-like glycosaminoglycan. The characterization of the polysaccharide as heparan sulphate is based on its resistance to digestion with chondroitinase ABC or hyaluronidase and its susceptibility to HNO(2) treatment. The sulphate groups (including sulphamino and ester sulphate groups) are distributed along the polymer in the characteristic block fashion. In (3)H-labelled heparan sulphate, isolated after incubation of the cells with [(3)H]galactose, 40% of the radioactive uronic acid units are l-iduronic acid, the remainder being d-glucuronic acid. The location of heparan sulphate at the rat liver cell surface is demonstrated; part of the labelled polysaccharide can be removed from the cells by mild treatment with trypsin or heparitinase. Further, a purified plasma-membrane fraction isolated from rats previously injected with [(35)S]sulphate contains radioactively labelled heparan sulphate. A proteoglycan macromolecule composed of heparan sulphate chains attached to a protein core can be solubilized from the membrane fraction by extraction with 6m-guanidinium chloride. The proteoglycan structure is degraded by treatment with papain, Pronase or alkali. The production of heparan [(35)S]sulphate by rat liver cells incubated in the presence of [(35)S]sulphate was followed. Initially the amount of labelled polysaccharide increased with increasing incubation time. However, after 10h of incubation a steady state was reached where biosynthetic and degradative processes were in balance.
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PMID:Structure and metabolism of rat liver heparan sulphate. 14 28

Proteoglycans were extracted from bovine articular cartilage with guanidine-HCl and fractionated in cesium chloride density gradients by equilibrium ultracentrifugation. The acidic glycosaminoglycan (AGAG) components were then determined enzymatically with chondroitinase-ABC and streptomyces hyaluronidase. Under associative and dissociative conditions, the distribution of the AGAG components was as follows: the ratio of 4-sulfated disaccharide units to total AGAG increased with decreasing density gradients whereas that of 6-sulfated disaccharide units to total AGAG increased with increasing density gradients. The ratio of disulfated disaccharide units to total AGAG increased somewhat with decreasing density gradients whereas that of non-sulfated disaccharide units tended to decrease. Although the cartilage proteoglycan macromolecules were heterogeneous, a certain regularity was observed with respect to the distribution of sulfate and the degree of sulfation in the chondroitin sulfate chains of the proteoglycans.
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PMID:Constitutional heterogeneity of the glycosaminoglycans in articular cartilage proteoglycans. 14 4

Medullary tissue of the normal rat kidney was perfused with 3 percent glutaraldehyde (GA), incubated in 0.5 percent cetyl pyridinium chloride and postfixed in 1 percent OsO4. In comparison with the ordinary fixation with GA and OSO4, the medullary interstitium represented abundant matrical substance that is rich in acid mucopolysaccharides (AMPS) and morphologically represents a diffuse reticular structure consisting of 30 to 150 a thick microfibrils and granular structures of 300 to 500 A in diameter. When chondroitinase was applied before OsO4 treatment, the dense granes disappeared and the microfibrils were replaced by loosely textured 30 A thick microfilaments. After hyaluronidase treatment the microfibrils disappeared and most granules changed into a ring-shaped structure with an electronlucent central portion. These results suggest that the reticular structure consists of microfilaments of hyaluronates and amorphous masking substance of chondroitin sulfates. In the dense granule, hyaluronates become concentrated in the central portion and chondroitin sulfate in the peripheral zone. When perfused with a CPC-containing GA, the medullary interstitium was diffusely filled with a large amount of fine granular substances suggesting the presence of water soluble free AMPS filling the reticular space.
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PMID:Ultrastructure and histochemistry of the medullary interstitial matrix of rat kidney. 14 5

The basic subunit of cartilage proteoglycan consists of multiple glycosaminoglycan chains covalently attached to a core protein. It is unclear as to whether there is a single core protein or multiple different core proteins, since previous studies using either chondroitinase or testicular hyaluronidase to enzymatically remove chondroitin sulfate side chains from the proteoglycan subunit have yielded conflicting results. In the present study, a chondroitinase-produced core protein preparation isolated as a single peak on Sepharose gel chromatography was found to contain at least two immunologically distinct components. Hyaluronidase-produced core protein from the same proteoglycan subunit fraction was found to contain multiple components nearly all of which were smaller than the components in the chondroitinase digest. A possible explanation of these findings is that they resulted from proteolytic degradation of the core protein in the course of the enzymatic removal of its chondroitin sulfate. The presence of small amounts of protease contaminants in several commercial chondroitinase and hyaluronidase preparations was detected by an extremely sensitive radioassay. Until proteases can be rigorously excluded from enzyme preparations used to degrade the proteoglycan subunit, it will not be possible to determine whether it consists of a single or several different core proteins.
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PMID:A comparison of bovine nasal cartilage proteoglycan core protein produced by chondroitinase and hyaluronidase: the possible role of protease contaminants. 14 80

A study of human articular cartilage indicated that componenet proteoglycans can be phosphorylated. Phosphorylation, also found in a specimen of human epiphysial cartilage, occurred when [gamma-32P]-ATP or 32Pi was included in the in vitro incubation medium. Treatment of the phosphorylated proteoglycans with chondroitinase and chondrosulfatases effectively removed the chondroitin sulfate without dephosphorylating the remaining molecule. Since phosphorylation could be effected in a totally chemically defined medium, it appears that the necessary enzyme systems for this reaction are contained entirely within chondrocytes.
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PMID:Phosphorylation of proteoglycans in human articular cartilage. 15 Sep 63

The incorporation of [35S]sulfate into glycosaminoglycans was studied in cultures of normal and diabetic skin fibroblasts. Heparan sulfate was determined by column chromatography after enzymatic degradation of chondroitin sulfates and dermatan sulfate by chondroitinase ABE. Cultured skin fibroblasts from both insulin-dependent and noninsulin-dependent diabetics were found to have increased proportions of heparan sulfate in the media relative to the other sulfated glycosaminoglycans.
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PMID:Studies of cultured human fibroblasts in diabetes mellitus: changes in heparan sulfate. 15 51


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