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)

When slices of adult rabbit articular cartilage were incubated in culture medium, the rate of incorporation of [35S]sulphate or [3H]acetate into glycosaminoglycans increased 4-8 fold during the first 5 days of incubation. Similar changes in biosynthetic activity were observed during culture of adult bovine cartilage. The activation of synthesis was not serum-dependent, but appeared to be a result of the depletion of tissue proteoglycan that occurs under these incubation conditions [Sandy, Brown & Lowther (1978) Biochim. Biophys. Acta 543, 536--544]. Thus, although complete activation was observed in serum-free medium, it was not observed if the cartilage was cultured inside dialysis tubing or in medium containing added proteoglycan subunit. The average molecular size of the proteoglycans synthesized by activated tissue was slightly larger than normal, as determined by chromatography on Sepharose CL-2B, and the average molecular size of the glycosaminoglycans synthesized by activated tissue was markedly increased over the normal. The increase in chain size was accompanied by an increase in the proportion of the chains degraded by chondroitinase ABC; these results are consistent with the preferential synthesis by activated chondrocytes of chondroitin sulphate-rich proteoglycans. The increase in glycosaminoglycan chain size was observed whether the chains were formed on endogenous core protein or on exogenous benzyl-beta-D-zyloside. An approximate 4-fold activation in culture of glycosaminoglycan synthesis on protein core was accompanied by a 1.54-fold increase in the rate of incorporation of [3H]serine into the chondroitin sulphate-linkage region of the proteoglycans. A 2.8-fold activation in culture of glycosaminoglycan synthesis on benzyl-beta-D-zyloside was accompanied by a 1.7-fold increase in the rate of incorporation of [3H]benzyl-beta-D-zyloside into glycosaminoglycans. The activation of glycosaminoglycan synthesis was, however, accompanied by no detectable change in the activity of xylosyltransferase (EC 2.4.2.26) in cell-free extracts. These results are discussed in relation to current ideas on the control of proteoglycan synthesis in cartilage.
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PMID:Control of proteoglycan synthesis. Studies on the activation of synthesis observed during culture of articular cartilages. 677 23

Glycosaminoglycans in urine from patients representing the major different mucopolysaccharidoses were separated and measured by use of a procedure that requires only 2 mL of urine. The compounds were resolved by two-dimensional electrophoresis on cellulose acetate plates and made visible by staining with Alcian Blue. They were identified by co-migration with standard glycosaminoglycans, by digestion with specific glycosidases, and by specific degradation with HNO2. They were quantitated by comparing the absorbance of eluates of the stained spots to appropriate standard curves for each glycosaminoglycan. This study revealed additional findings. About half of the patients excreted small amounts of heparin. Further, the keratan sulfate in samples from Morquio's disease patients migrated differently from authentic keratan sulfate unless digested with chondroitinase ABC. Our results for these diseases are in harmony with earlier reports.
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PMID:Direct quantitation of glycosaminoglycans in 2 mL of urine from patients with mucopolysaccharidoses. 677 34

13C NMR was used to study the molecular dynamics of the chick limb bud proteoglycan core protein. Because only about 10% of the proteoglycan is protein, [2-13C]glycine and [3-13C]serine were incorporated into the core protein of the chick limb bud proteoglycan monomer using a chondrocyte culture system. The purified labeled monomer was studied in solution (50 mg/ml, 0.05 M sodium acetate/0.05 M sodium phosphate, pH 7.4) at 37 degrees C. Spin-lattice relaxation times, line widths, and nuclear Overhauser enhancements were measured for the labeled carbons in the protein and for the natural abundance carbons in the glycosaminoglycan chains. Analyses of these data show that correlation times for backbone reorientation of protein and polysaccharide chains in the intact monomer are predominantly in the range of 0.5-5.0 ns. These correlation times are 10(2)-10(3) times smaller than the minimum correlation time calculated for a rigid monomer, indicating that the core protein and polysaccharide backbones are segmentally flexible. Signal intensity data show that at least 80% of the protein backbone is flexible but do not exclude the possibility that 20% of the protein backbone has ordered structure. We observe both broad and narrow signal components in the spectrum of the intact monomer, showing that backbone motion is heterogeneous. The broad signal component is not observed after the monomer is digested with chondroitinase. This result and the strong concentration dependence of the 13C line width observed in solutions of chondroitin 4-sulfate suggest an assignment of the broad signal component to residues near the protein-polysaccharide linkage region. The difference in NMR parameters observed for free and substituted serine carbons confirms that motion of the substituted serine side chain is restricted.
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PMID:13C nuclear magnetic resonance suggests a flexible proteoglycan core protein. 678 60

A differentiated population of cells with metachromatically staining granules and surface IgE receptors was obtained from mouse bone marrow cultured for 2 weeks in the presence of conditioned medium derived from concanavalin A-stimulated splenocytes. The cells were found to incorporate large amounts of [35S]sulfate into an intracellular 35S-labeled proteoglycan of Mr approximately 200,000 containing a maximum of seven glycosaminoglycan side chains (Mr = 25,000). After chondroitinase ABC treatment of density gradient-purified [3H] serine-labeled proteoglycan, the resulting core was Mr approximately 26,000 as assessed by gel filtration. Two-dimensional cellulose acetate electrophoresis of beta-eliminated 35S-labeled glycosaminoglycan revealed a single type of glycosaminoglycan that migrated at the position of oversulfated chondroitin sulfate E from squid cartilage. Chondroitinase ABC degradation of the 35S-labeled glycosaminoglycan yielded two cleavage products in approximately equal molar amounts which co-migrated in both descending paper chromatography and high voltage paper electrophoresis with a monosulfated disaccharide, 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose, and a disulfated disaccharide, 2-acetamido-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-6-di-O-sulfo-D-galactose. The release of some free [35S]sulfate from the oversulfated disaccharide with either chondro-4-sulfatase or chondro-6-sulfatase and the complete desulfation by their combined action established that the oversulfated disaccharide contained N-acetylgalactosamine-4,6-disulfate. The 35S]labeled proteoglycan of these unique IgE receptor-bearing and histamine-containing cells, therefore, is composed of chondroitin sulfate E rather than heparin glycosaminoglycan, and thus is the first identification of such an intracellular localized proteoglycan in a mammalian cell.
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PMID:Culture from mouse bone marrow of a subclass of mast cells possessing a distinct chondroitin sulfate proteoglycan with glycosaminoglycans rich in N-acetylgalactosamine-4,6-disulfate. 680 69

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

The ultrastructural characteristics of alveolar (ABM) and capillary (CBM) basement membranes in the adult rat lung have been defined using tannic acid fixation, ruthenium red staining, or incubation in guanidine HCl. ABM is dense and amorphous, has 3- to 5-nm filaments in the lamina rara externa (facing the alveolus) that run between the lamina densa and the basal cell surface of the epithelium, has an orderly array of ruthenium red-positive anionic sites that appear predominantly (79%) on the lamina rara externa, and has discontinuities beneath alveolar type II cells but not type I cells that allow penetration of type II cytoplasmic processes into the interstitium of the alveolar wall. The CBM is fibrillar and less compact than ABM, has no lamina rara filaments, and has one fifth the number of ruthenium red-positive anionic sites of ABM that appear predominantly (64%) overlying the lamina densa. Incubation of lung tissue with Flavobacterium heparinum enzyme or with chondroitinase has shown that ABM anionic sites represent heparan sulfate proteoglycans, whereas CBM anionic sites contain this and other sulfated proteoglycans. The CBM fuses in a local fashion with ABM, compartmentalizing the alveolar wall into a thick and thin side and establishing a thin, single, basement-membrane gas-exchange surface between alveolar air, and capillary blood. The potential implications of ABM and CBM ultrastructure for permeability, cell differentiation, and repair and morphogenesis of the lung are discussed.
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PMID:Structural features of alveolar wall basement membrane in the adult rat lung. 719 26

Because the dermis of myxedematous humans is known to accumulate increased amounts of glycosaminoglycan (GAG), we were prompted to study the effects of thyroid hormone depletion in vitro. Human skin fibroblasts were grown to confluence in medium containing 10% fetal calf serum (FCS). Some cultures were shifted to a medium containing FCS depleted of thyroid hormone (D-FCS) or to a D-FCS medium to which 10(-7) M triiodothyronine (T3) was added (D-FCS + T3). Cultures were then labeled for 16 h with [3H]-acetate, harvested and combined with the media. After pronase digestion, the non-trichloroacetic acid precipitable, non-dialysable material was digested with streptomyces hyaluronidase followed by chondroitinase ABC. Digestable material was separated by G-50 Sephadex column chromatography. The cultures incubated in media containing D-FCS accumulated 2.8-fold more hyaluronic acid and 2.1-fold more chondroitin sulfate than did sister cultures incubated in the presence of D-FCS + T3. The addition of T3 to the D-FCS reduced the amounts of GAG accumulated nearly to the levels observed in cultures grown in FCS. The data indicate that thyroid hormone exerts an inhibitory effect on GAG accumulation in human skin fibroblasts. This model offers the opportunity to study thyroid hormone action in vitro using an easily accessible human tissue.
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PMID:The effect of thyroid hormone on glycosaminoglycan accumulation in human skin fibroblasts. 722 12

Retinal microvessels were isolated from bovine eyes and the basement membranes were purified either directly or after incubation with [35S]sulfate and [14C]glucosamine. The basement membranes, which were purified by osmotic lysis and sequential treatment with detergents, had the general compositional features associated with basement membrane collagens, including high levels of hydroxyproline and hydroxylysine and the presence of 3-hydroxyproline and cystine. After pronase digestion, cellulose acetate electrophoresis of glycosaminoglycans from retinal microvessel basement membrane revealed material comigrating with heparan sulfate that was insensitive to digestion with Streptomyces hyaluronidase ad chondroitinase ABC. Retinal microvessels also incorporated [35S]- and [14C]glucosamine into glycosaminoglycans that were isolated following pronase digestion of the retinal microvessel basement membrane purified from these incubations. The findings provide the first demonstration that glycosaminoglycans are integral components of the retinal microvascular basement membrane and suggest that heparan sulfate is the major glycosaminoglycan species in this basement membrane.
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PMID:Presence of glycosaminoglycans in retinal capillary basement membrane. 723 37

Ruthenium-103 red has been used previously to detect nanogram quantities of glycosaminoglycans after they have been separated by electrophoresis on cellulose diacetate. We have applied the critical electrolyte principle to the binding of this dye to polyanions. This eliminates interaction with nucleic acids and hyaluronan. After samples are digested with chondroitinase ABC the method allows the measurement of chondroitin sulfates and heparan sulfates at the 2-ng level in dot blots of tissue extracts.
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PMID:A ruthenium-103 red dot blot assay specific for nanogram quantities of sulfated glycosaminoglycans. 751 34

Kidney epithelia have separate origins; collecting ducts develop by ureteric bud growth and arborisation, nephrons by induced mesenchyme-epithelium transition. Both express sulphated glycosaminoglycans (GAGs) which are strikingly upregulated during nephron differentiation. However, sodium chlorate, an inhibitor of GAG sulphation, and the GAG-degrading enzymes heparitinase plus chondroitinase, did not prevent nephron development. In contrast, ureteric bud growth and branching were reversibly inhibited by the above reagents, the inhibition correlating quantitatively with sulphated GAG deprivation caused by a range of chlorate concentrations. Growth and branching could be independently restored during GAG deprivation by hepatocyte growth factor and phorbol-12-myristate acetate (PMA) respectively. Together these signalling effectors stimulated both branch initiation and growth. Thus growth and morphogenesis of ureteric bud involve distinct signalling pathways both regulated by GAGs.
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PMID:Sulphated proteoglycan is required for collecting duct growth and branching but not nephron formation during kidney development. 778 80


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