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Characterization of a heparan sulfate and a peculiar chondroitin 4-sulfate proteoglycan from platelets. Inhibition of the aggregation process by platelet chondroitin sulfate proteoglycan.

A high molecular weight chondroitin sulfate proteoglycan (Mr 240,000) is released from platelet surface during aggregation induced by several pharmacological agents. Some details on the structure of this compound are reported. beta-Elimination with alkali and borohydride produces chondroitin sulfate chains with a molecular weight of 40,000. The combined results indicate a proteoglycan molecule containing 5-6 chondroitin sulfate chains and a protein core rich in serine and glycine residues. Degradation with chondroitinase AC shows that a 4-sulfated disaccharide is the only disaccharide released from this chondroitin sulfate, characterizing it as a chondroitin 4-sulfate homopolymer. It is shown that this proteoglycan inhibits the aggregation of platelets induced by ADP. Analysis of the sulfated glycosaminoglycans not released during aggregation revealed the presence of a heparan sulfate in the platelets. Degradation by heparitinases I and II yielded the four disaccharide units of heparan sulfates: N,O-disulfated disaccharide, N-sulfated disaccharide, N-acetylated 6-sulfated disaccharide, and N-acetylated disaccharide. The possible role of the sulfated glycosaminoglycans on cell-cell interaction is discussed in view of the present findings.

Adenosine Diphosphate↗

Separation of glycosaminoglycan-derived oligosaccharides by capillary electrophoresis using reverse polarity.

A comparative study on compositional analysis of two sets of eight unsaturated disaccharide standards derived from heparin/heparan sulfate and chondroitin/dermatan sulfate was carried out using capillary electrophoresis performed in both normal and reverse polarity modes. While these heparin/heparan sulfate disaccharides (S. A. Ampofo, H. M. Wang, and R. J. Linhardt (1991) Anal. Biochem. 199, 249-255) and chondroitin/dermatan sulfate disaccharides (A. Al-Hakim and R. J. Linhardt (1991) Anal. Biochem. 195, 68-73) have previously been fractionated using normal polarity capillary electrophoresis, multiple buffer systems and conditions were required to separate certain disaccharide isomers and these separations often resulted in poor peak symmetry and significant tailing. This paper demonstrates that reverse polarity capillary electrophoresis completely resolves disaccharide mixtures into all components using a single buffer, 20 mM phosphoric acid-sodium phosphate at pH 3.48. This improved resolution is due primarily to an increase in the sharpness of peaks and improved peak symmetry. Separation of heparin-derived oligosaccharides, ranging from disaccharide to hexasaccharide, had also previously been reported using normal polarity capillary electrophoresis (U.R. Desai, H.M. Wang, S.A. Ampofo, and R.J. Linhardt (1993) Anal. Biochem. 213, 120-127). This paper now demonstrates the separation of 13 heparin-derived oligosaccharides of sizes ranging from disaccharide to tetradecasaccharide using both reverse and normal polarities. An enzymatic digestion of bovine lung heparin containing many of these larger oligosaccharides was also compared in both normal and reverse polarity modes. Mixtures containing oligosaccharides primarily differing in size (number of saccharide units) were better resolved using normal polarity.

Carbohydrate Sequence↗

Altered fine structures of corneal and skeletal keratan sulfate and chondroitin/dermatan sulfate in macular corneal dystrophy.

The content and fine structure of keratan and chondroitin/dermatan sulfate in normal human corneas and corneas affected by macular corneal dystrophies (MCD) types I and II were examined by fluorophore-assisted carbohydrate electrophoresis. Normal tissues (n = 11) contained 15 microg of keratan sulfate and 8 microg of chondroitin/dermatan sulfate per mg dry weight. Keratan sulfates consisted of approximately 4% unsulfated, 42% monosulfated, and 54% disulfated disaccharides with number of average chain lengths of approximately 14 disaccharides. Chondroitin/dermatan sulfates were significantly longer, approximately 40 disaccharides per chain, and consisted of approximately 64% unsulfated, 28% 4-sulfated, and 8% 6-sulfated disaccharides. The fine structural parameters were altered in all diseased tissues. Keratan sulfate chain size was reduced to 3-4 disaccharides; chain sulfation was absent in MCD type I corneas and cartilages, and sulfation of both GlcNAc and Gal was significantly reduced in MCD type II. Chondroitin/dermatan sulfate chain sizes were also decreased in all diseased corneas to approximately 15 disaccharides, and the contents of 4- and 6-sulfated disaccharides were proportionally increased. Tissue concentrations (nanomole of chains per mg dry weight) of all glycosaminoglycan types were affected in the disease types. Keratan sulfate chain concentrations were reduced by approximately 24 and approximately 75% in type I corneas and cartilages, respectively, and by approximately 50% in type II corneas. Conversely, chondroitin/dermatan sulfate chain concentrations were increased by 60-70% in types I and II corneas. Such changes imply a modified tissue content of individual proteoglycans and/or an altered efficiency of chain substitution on the core proteins. Together with the finding that hyaluronan, not normally present in healthy adult corneas, was also detected in both disease subtypes, the data support the conclusion that a wide range of keratocyte-specific proteoglycan and glycosaminoglycan remodeling processes are activated during degeneration of the stromal matrix in the macular corneal dystrophies.

Acetylglucosamine↗

Heparinase II from Flavobacterium heparinum. HPLC analysis of the saccharides generated from chemically modified heparins.

Saccharides produced by the action of heparinase II on native pig mucosal heparin (heparin IS), de-N-sulphated heparin (heparin IH), N-acetylheparin (heparin IA), de-N/O-sulphated heparin (heparin IVH), de-O-sulphated heparin (heparin IVS) and de-O-sulphated N-acetylheparin (heparin IVA) were analysed by reversed-phase HPLC using Spherisorb ODS2. Fractions obtained by gel filtration with Bio-Gel P-4 were similarly examined. Heparin IS gave delta UA-2S----GlcNS-6S (IS) as the major unsaturated disaccharide and lesser amounts of delta UA----GlcNS-6S (IIS), delta UA-2S----GlcNS (IIIS), delta UA----GlcNS (IVS), delta UA-2S----GlcNAc-6S (IA), delta UA----GlcNAc-6S (IIA), delta UA-2S----GlcNAc (IIIA) and delta UA----GlcNAc (IVA). Heparins IA, IVA and IVS gave as the predominant unsaturated disaccharide that corresponding to the major repeat structure of the polymer. These were respectively delta UA-2S----GlcNAc-6S (IA), delta UA-GlcNAc (IVA) and delta UA----GlcNS (IVS). Minor disaccharides from the heterogeneous structure in native pig heparin and from residual O-sulphates after the de-O-sulphating process were detected. Heparin IH was degraded more slowly than any of the N-substituted heparins. The predominant unsaturated disaccharide was IH, which was derived from the major repeating unit. In addition, disaccharides IIH, IIIH, IA, IIA and IVA were detected. Heparin IVH showed little degradation, the unsaturated disaccharide IVH not being detected after 24 h. Disaccharide IVA was obtained from the heterogeneous sequence in heparin IVH. Several higher oligosaccharides were identified in the gel-filtration fractions including saccharides from the linkage region (for heparin IS and IVA) and the anti-thrombin binding site (for heparin IS only). A tetrasaccharide and hexasaccharide, with the structures delta UA----GlcNAc----UA----GlcNAc and delta UA----GlcNAc----UA----GlcNAc----UA----GlcNAc, were present in the HPLC profiles of heparins IA and IVA.

Animals↗

Copolymers of chondroitin 4-sulfate and chondroitin 6-sulfate in chick embryo epiphyses and other cartilage.

Tetrasaccharides were prepared from chondroitin sulfate by means of a limited degradation with chondroitinase ABC. Tetrasaccharides containing one sulfate per disaccharide unit were isolated and were found to be of three types: a tetrasaccharide with two 6-sulfated disaccharide units, a tetrasaccharide with two 4-sulfated disaccharide units, and a tetrasaccharide with one 4-sulfated disaccharide unit and one 6-sulfated disaccharide unit. Samples of each of these three types of tetrasaccharides were obtained from chick embryo epiphyseal cartilage and from a mixture of bovine tracheal cartilage and shark cartilage. The presence of both a 4-sulfated disaccharide unit and a 6-sulfated disaccharide unit in the same tetrasaccharide molecule indicates the existence of mixed 4 and 6 sulfation on the same chondroitin sulfate chain.

Animals↗

Gentiobiose: a novel oligosaccharin in ripening tomato fruit.

Two neutral disaccharides, gentiobiose [beta- D-Glc p-(1-->6)- D-Glc] and nigerose [alpha- D-Glc p-(1-->3)- D-Glc], were detected in tomato ( Lycopersicon esculentum Mill.) pericarp and locule. Gentiobiose was present in the locule of green fruit and ripe fruit at 0.88 and 5.8 micro mol (kg fresh weight)(-1), respectively. When vacuum-infiltrated into green tomato fruit, exogenous gentiobiose (50 or 200 micro g per fruit) hastened the initiation of ripening (as judged by colour change) by 1-3 days relative to fruit that were infiltrated with glucose or isomaltose. Nigerose plus gentiobiose was particularly effective, but nigerose alone had no significant effect. The endogenous disaccharides were found to be present in the apoplastic fluid of the fruit, compatible with a proposed intercellular signalling role. The origin and metabolic fate of the disaccharides were investigated. Phenolic esters of these disaccharides were not detectable in tomato fruit and it is therefore unlikely that the free disaccharides were formed from a pool of such esters. An alternative possible biosynthetic origin, via transglycosylation, is discussed. When [(14)C]gentiobiose was vacuum-infiltrated into unripe or ripe fruit, the disaccharide remained intact for at least 1 h but was largely degraded within 24 h. The results suggest that gentiobiose is a new, naturally occurring oligosaccharin with a rapid turnover rate.

Carbon Radioisotopes↗

Molecular attributes of bovine aortic endothelial cell heparan sulfate.

Heparan sulfate (HS) secreted into the medium of bovine aortic endothelial cell (BAEC) cultures was subjected to chemical and enzymatic degradation followed by analysis using gel-filtration and ion-exchange chromatography. Treatment with HNO2 showed that 41% of the disaccharides were N-sulfated. Degradation by Heparin lyases I (Hep I) showed that 8-9% of the disaccharides contained IdoA(2S) residues. Heparin lyase III (Hep III) degradation produced mainly disaccharides with 67% of the molecules glycosidic linkages susceptible to cleavage. Further degradation of Hep III-resistant fragments with Hep I showed that IdoA(2S) residues were predominantly positioned centrally within the repeating GlcNSO3(+/- 6S)alpha 1-4IdoA containing domains. Digestion with a mixture of Heparin lyases I, II and III degraded the molecule almost entirely to disaccharides, with small amounts of tetrasaccharides containing resistant linkages, suggesting the presence of 3-O sulfated GlcNSO3. Further analysis of the disaccharide products by ion-exchange chromatography and comparison with the data from single enzymatic digestion, allowed an estimate of the disaccharide composition to be made. The results suggest an ordered arrangement of structural domains; however, variations in the structure of these domains results in a heterogeneous population of HS chains. It is suggested that biosynthetic differences in HS structure may act as a regulator of bFGF induced cellular responses.

Animals↗

Characterization of heparins with different relative molecular masses (from 11,600 to 1600) by various analytical techniques.

Heparin was extracted and purified from beef intestinal mucosa, and its structure and physico-chemical properties, e.g. disaccharide pattern (by specific enzymatic cleavage), relative molecular mass and sulfate-to-carboxyl ratio, were evaluated by different techniques. Heparin fractions with different relative molecular mass (from M(r) = 7560 to M(r) = 1600) were prepared by chemical degradation and gel-permeation chromatography. The fractions were characterized with respect to relative molecular mass, disaccharide pattern, sulfate-to-carboxyl ratio and percentage of slow moving and fast moving components by agarose-gel electrophoresis. The percentage of the two heparin species was calculated by densitometric analysis and specific calibration curves. The amount of the slow moving component decreases with relative molecular mass. The disaccharide pattern is different for the two heparin fractions. The percentage of trisulfated disaccharide decreases and the amount of mono- and disulfated disaccharides increases with a decrease of the relative molecular mass. The charge density, evaluated as the sulfate-to-carboxyl ratio, also decreases with the molecular mass of the fractions. This study confirms the heterogeneity of the structure, as evaluated by the constituent disaccharides, of the physico-chemical properties, such as relative molecular mass and charge density, and of the relative amount of the two heparin components also for low molecular mass heparins particularly produced by chemical depolymerization in the presence of free radicals.

Animals↗

Structural and biosynthetic studies on linkage region between poly(galactosylglycerol phosphate) and peptidoglycan in Bacillus coagulans.

The HF treatment of teichoic acid-glycopeptide complexes isolated from lysozyme digests of Bacillus coagulans AHU 1366 cell walls gave a disaccharide, glucosyl beta (1 leads to 4)N-acetylglucosamine, along with dephosphorylated repeating units of the teichoic acid chain, galactosyl alpha (1 leads to 2) glycerol. Mild alkali treatment of the complexes yielded the disaccharide linked to glycopeptide, whereas direct heating of the cell walls at pH 2.5 yielded the same disaccharide linked to teichoic acid. The Smith degradation of the complexes revealed that the galactose residue is a component of backbone chain. Thus it is concluded that this disaccharide is involved in the linkage region between poly(galactosylglycerol phosphate) and peptidoglycan in cell walls. Membrane-catalyzed synthesis of this disaccharide on a lipid followed by transfer of glycerol phosphate from CDP-glycerol to the disaccharide-linked lipid in the absence or in the presence of UDP-galactose also supports this conclusion.

Bacillus↗

Study of Staphylococcus aureus teichoic acid immunodominant site by help of synthetic haptens.

The beta ribitol teichoic acid was extracted and purified from Staphylococcus aureus strain Wood 46 and chemically and immunologically characterised. Rabbit antiserum was prepared against formalin killed Staphylococcus aureus cells. Liquid phase immunoprecipitation of the beta ribitol teichoic acid-anti-Staphylococcus aureus serum system was studied by laser nephelometry. Various mono- and disaccharides (N-acetyl-glucosamine-ribitol with alpha- or beta-linkage and N-acetyl-glucosamine-ribitol-phosphate with beta-linkage) were prepared by organic synthesis, reproducing part of the ribitol teichoic acid molecule. Inhibition by those mono- or disaccharides of the precipitation of the beta-ribitol teichoic acid-Staphylococcus aureus antibodies system was studied quantitatively by determining inhibitory ratio of each inhibitor. Glucose, ribitol and glucosamine were weak inhibitors whereas N-acetyl-glucosamine was a better one, stronger than disaccharide with an alpha-linkage. The beta linked disaccharide and beta-methyl-N-acetyl-glucosamine gave comparable inhibition and both compounds were effective inhibitors. The most potent inhibitor was phosphorylated beta-linked disaccharide which inhibited 25% more than the same disaccharide without phosphorus. Thus, the function of phosphorus in Staphylococcus aureus beta ribitol teichoic acid recognition by antibodies was demonstrated.

Chromatography, Gas↗

Dermatan sulfates of normal and scarred fascia.

We evaluated the composition of dermatan sulfates (DS) derived from 23 samples of normal and 23 samples of scarred fascia lata. We analyzed the molecular weight of intact DS chains and the length of chain regions comprising: (1) clusters of L-iduronate-containing disaccharides ("iduronic sections"); (2) clusters of D-glucuronate-containing disaccharides ("glucuronic sections"); and (3) copolymeric sections with both types of disaccharides. A portion of scarred fascia DS chains demonstrated higher molecular weight compared with those from normal tissue. Most disaccharides of DS chains derived from both fascia types form copolymeric segments - heterogeneous in size - with alternatively distributed single disaccharides with glucuronic residues and mainly single ones with iduronate. Only a small number of disaccharides form "glucuronic sections" of heterogeneous size or short "iduronic sections". However, the scarred fascia DS chains demonstrate an increased content of shorter "glucuronic sections" and shorter, often oversulfated, copolymeric segments. It seems that in normal fascia, the DS chain type with a single, long copolymeric region and a single, shorter "glucuronic section" is predominant, while in scarred tissue an increase in multidomain DS chain content may occur.

Adult↗

Specificity of the hyaluronate lyase of group-B streptococcus toward unsulphated regions of chondroitin sulphate.

The purification and properties of a hyaluronate lyase secreted by Streptococcus agalactiae, which is believed to facilitate the invasion of host tissues by the organism, have been described previously [Pritchard, Lin, Willingham and Baker (1994) Arch. Biochem. Biophys. 315, 431-436]. The specificity of the limited cleavage of chondroitin sulphate by the enzyme is the subject of this report. To simplify the task, a chondroitin sulphate from the Swarm rat chondrosarcoma, which contains only 4-sulphated and unsulphated disaccharide repeats, was used in this study. Tetrasaccharides from an ovine testicular hyaluronidase digest of the chondroitin sulphate were isolated, identified and tested as substrates of the streptococcal hyaluronate lyase. Only tetrasaccharides with an unsulphated disaccharide at the reducing end were cleaved (by elimination at the N-acetylgalactosaminidic bond). Thus chondroitin sulphate chains are cleaved by the action of this lyase at every unsulphated disaccharide repeat, but release of unsaturated unsulphated disaccharides only occurs from sites where two or more sequential unsulphated disaccharide repeats are present. Analysis of the chondrosarcoma chondroitin sulphate showed that of approximately five unsulphated disaccharide repeats per chain, two are clustered. The ability of group-B streptococcal hyaluronate lyase to cleave chondroitin sulphate may allow the organisms to invade tissues more efficiently. The demonstrated specific and highly limited cleavage of chondroitin sulphate by this bacterial lyase promises to be a useful tool in the determination of chondroitin sulphate structure and variability.

Animals↗

Distribution of chondroitin sulfate in cartilage proteoglycans under associative conditions.

Proteoglycan aggregates and proteoglycan subunits were extracted from bovine articular cartilage with guanidine-HC1 folowed by fractionation by equilibrium centrifugation in cesium chloride density gradients. The distribution of chondroitin sulfates (CS) in the cartilage proteoglycans was studied at the disaccharide level by digestion with chondroitinases. In the proteoglycan aggregate fraction, it was observed that the proportion of 4-sulfated disaccharide units to total CS increased from the bottom to the top fractions, whereas that of 6-sulfated disaccharide units was in the reverse order. Thus, the ratio of 4-sulfated disaccharide units to 6-sulfated disaccharide units increased significantly with decreasing density. The proportion of non-sulfated disaccharide units to total CS tended to increase with increasing density. These data indicate a polydisperse distribution of CS chains, under the conditions used here, in proteoglycan aggregates from bovine articular cartilage.

Animals↗

Anomalous structure of urinary chondroitin sulfate from cancer patients. A potential new marker for diagnosis of neoplasias.

BACKGROUND: Chondroitin sulfate is significantly increased in tumors (10 to 100 times) when compared to the amounts present in normal adjacent tissues. To investigate if the changes in concentration of chondroitin sulfate could be reflected in the urine of cancer patients we have analyzed the chondroitin sulfate excreted by 44 patients with different types of tumors, 50 normal individuals and 15 patients with unrelated diseases. EXPERIMENTAL DESIGN: The identification and structural analyses of the sulfated glycosaminoglycans were made by electrophoresis and degradation with specific enzymes (chondroitinases AC and ABC), identification/quantitation of their disaccharide products by chromatography (paper and HPLC) and chemical determinations. RESULTS: The disaccharide products formed from chondroitin sulfate of the 44 cancer patients by action of chondroitinase ABC show a substantial relative increase of non sulfated disaccharide (32.1% +/- 15.2) with a relative decrease of 6-sulfated disaccharide (28.9% +/- 11.5) and 4-sulfated disaccharide (39.0% +/- 13.5) when compared to the chondroitin sulfate of normal subjects (9.1% +/- 2.2, 40.6% +/- 4.5 and 50.2% +/- 4.5, respectively) or from patients with unrelated diseases. There is a direct correlation between the non sulfated disaccharide content and the stage of malignancy of the cancer patients. A significant change of the ratio of chondroitin sulfate and heparan sulfate and a decrease in the electrophoretic migration of chondroitin sulfate were also observed in cancer patients. CONCLUSIONS: All the cancer patients analyzed so far have shown the structural anomaly of the urinary chondroitin sulfate and this may be useful in the diagnosis and follow up of cancer therapy.

Adolescent↗

Glycosaminoglycan composition of electric organ basement membranes.

The basement membranes of the innervated surface of the electric organ of Discopyge tschudii present a high concentration of mucopolysaccharides as revealed by intense ruthenium red-positive reaction. Glycosaminoglycans (GAGs) were isolated and characterized from these pure basement membranes by using a combination of agarose gel electrophoresis and enzymatic degradation with specific enzymes. The isolated basement membrane showed a high concentration of GAGs (130 mg/g of dry tissue); of this amount 49% was hyaluronic acid, 24% was chondroitin-6-sulfate, 12% was heparan sulfate, and 14% was dermatan sulfate. Controlled digestion with heparinase and heparitinases I and II was used to study the structural features of the heparan sulfate. Four unsaturated disaccharide units were found in the heparan sulfate: disulfated, N-sulfated, N-acetylated, and N-acetylated O-sulfated disaccharides. The disaccharide units of the cholinergic heparan sulfate present a high amount of disulfated disaccharides and a low amount of N-acetylated O-sulfated disaccharides. The N-sulfated disaccharides, in contrast to the N-acetylated ones, were found through all the structure of the cholinergic heparan sulfate. Finally our work shows for the first time the presence of dermatan sulfate in the basal lamina of the electric organ.

Animals↗

The Engelbreth-Holm-Swarm mouse tumor produces undersulfated heparan sulfate and oversulfated galactosaminoglycans.

Glycosaminoglycans were prepared from the Engelbreth-Holm-Swarm mouse tumor. Enzymatic analysis demonstrated heparan sulfate (95.8%) and chondroitinase ABC-sensitive galactosaminoglycans (4.2%). HPLC analysis of the disaccharide units showed that heparan sulfate chains were undersulfated on average, comprising approximately 30% nonsulfated and 60% N-sulfated disaccharide units with small proportions of other monosulfated and disulfated disaccharide units. In contrast, galactosaminoglycan chains were oversulfated, containing an appreciable proportion (15%) of a 4,6-disulfated (so-called E-type) disaccharide unit in addition to 51% of a 4-sulfated, 22% of a 6-sulfated, and 11% of a nonsulfated disaccharide unit. The significance of the oversulfated disaccharide structure is discussed in relation to the possible regulation of functions of hybrid proteoglycans from which the galactosaminoglycan chains are derived.

Animals↗

Effects of chondroitin sulfates with different structures on leukemia cells: U-937 cell proliferation and differentiation.

Chondroitin sulfates extracted and purified by different manufacturers were tested to evaluate their effects on proliferation and differentiation processes of U-937 cells. The different chondroitin sulfates were evaluated for purity, structure and physicochemical properties. The three chondroitin sulfates utilized did not present other contaminant glycosaminoglycans and proteins and had about the same relative molecular mass but different disaccharide patterns and charge density. Chondroitin sulfates with small amounts of disulfated disaccharides and low charge density, at 5 micrograms/ml concentration, doubled (about + 133%) cell proliferation in comparison to controls. In contrast, chondroitin sulfates with large amounts of disulfated disaccharides and high sulfate to carboxyl ratio were less effective (about + 15%) in stimulating cell proliferation at low concentration. A decrease of U-937 cell proliferation was observed in proportion to the increased amounts of chondroitin sulfate with low sulfate to carboxyl ratio. On the contrary, chondroitin sulfate with large amounts of disulfated disaccharides produced increased cell proliferation depending on concentration. Small amounts (5-10 micrograms/ml) of chondroitin sulfates with low charge density reduced the differentiative process of U-937 cells. Chondroitin sulfate with large amounts of disulfated disaccharides and high charge density seemed to be able to produce a significant decrease of differentiative processes only at very high concentrations (1000 micrograms/ml). These contrasting effects of chondroitin sulfates with different disaccharide patterns (and structure) and charge density on a leukemia cell line could help to explain the regulation of proliferative and/or differentiative processes of hemopoietic cells. This is underlined by the changes of types, physicochemical properties and structure of glycosaminoglycans induced by different extracellular factors and agents.

Antigens, CD↗

Structure of chondroitin sulfates. Analyses of the products formed from chondroitin sulfates A and C by the action of the chondroitinases C and AC from Flavobacterium heparinum.

The structures of chondroitin sulfate A from whale cartilage and chondroitin sulfate C from shark cartilage have been examined with the aid of the chondroitinases AC and C from Flavobacterium heparinum. The analyses of the products formed from the chondroitin sulfates by the action of the chondroitinases have shown that three types of oligosaccharides compose the structure of chondroitin sulfate A, namely, a dodeca-, hexa- and a tetra-saccharide, containing five, two and one 4-sulfated disaccharides per 6-sulfated disaccharide residue, respectively. The polymer contains an average of 3 mol of each oligosaccharide per mol of chondroitin sulfate A. Each mol of chondroitin sulfate C contains an average of 5 mol of 4-sulfated disaccharide units. A tetra-saccharide containing one 4-sulfated disaccharide and one 6-sulfated disaccharide C indicating that the 4-sulfated disaccharides are not linked together in one specific region but spaced in the molecule.

Chondroitin↗