Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DISACCHARIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68Linked to original sources

Conditioned taste avoidance induced by lactose ingestion in adult rats.

Because adult rats have very low levels of the intestinal enzyme lactase, the ingestion of appreciable quantities of the disaccharide lactose may cause gastrointestinal distress. The present experiment was designed to demonstrate that adult rats will learn to avoid previously neutral stimuli which have been paired with lactose ingestion. Adult rats ingested both a novel solution [either tap water (WA) or 0.1% saccharin (SA)] and a novel food substance (49% powdered lab chow + 50% added disaccharide + 1% saccharin) during a single conditioning session. The added disaccharide was either sucrose (group SU-SA), lactose (groups HL-SA and HL-WA), or equal amounts of these two disaccharides (group LL-SA); a fifth group (LC-SA) consumed a sucrose-containing diet to which lithium chloride was added (5 mg per 1 g of diet). Separate feeding tests and drinking tests, carried out over several weeks, were used to assess the extent of conditioned taste avoidance. In the four feeding tests, rats were allowed to ingest powdered lab chow with added saccharin (but without added disaccharide), while in the four drinking tests, rats chose between tap water and a 0.1% saccharin solution. Group HL-SA demonstrated a substantial conditioned avoidance in both feeding and drinking tests, but group HL-WA showed avoidance only in feeding tests. Conditioned avoidance was weak in group LL-SA; the strongest avoidance was observed in lithium chloride-treated rats (group LC-SA). Results are related to previous research and to the hypothesis that a learned avoidance of milk may facilitate the weaning process in mammals.

Animals↗

Structural composition and differential anticoagulant activities of dermatan sulfates from the skin of four species of rays, Dasyatis americana, Dasyatis gutatta, Aetobatus narinari and Potamotrygon motoro.

We compared the disaccharide composition of dermatan sulfate (DS) purified from the ventral skin of three species of rays from the Brazilian seacoast, Dasyatis americana, Dasyatis gutatta, Aetobatus narinari and of Potamotrygon motoro, a fresh water species that habits the Amazon River. DS obtained from the four species were composed of non-sulfated, mono-sulfated disaccharides bearing esterified sulfate groups at positions C-4 or C-6 of N-acetyl galactosamine (GalNAc), and disulfated disaccharides bearing esterified sulfate groups at positions C-2 of the uronic acid and at position C-4 or C-6 of GalNAc. However, DS from the skin of P. motoro presented a very low content of the disulfated disaccharides. The anticoagulant actions of ray skin DS, measured by both APTT clotting and HCII-mediated inhibition of thrombin assays, were compared to that of mammalian DS. DS from D. americana had both high APTT and HCII activities, whereas DS from D. gutatta showed activity profiles similar to those of mammalian DS. In contrast, DS from both A. narinari and P. motoro had no measurable activity in the APTT assay. Thus, the anticoagulant activity of ray skin DS is not merely a consequence of their charge density. We speculate that the differences among the anticoagulant activities of these three DS may be related to both different composition and arrangements of the disulfated disaccharide units within their polysaccharide chains.

Animals↗

Syntheses of beta-(1-->6)-branched beta-(1-->3)-linked d-galactans that exist in the rhizomes of Atractylodes lancea DC.

Effective syntheses of galactose hepta-, octa-, nona-, and decasaccharides that exist in the rhizomes of Atractylodes lancea DC were achieved with 2,3,4,6-tetra-O-benzoyl-alpha-d-galactopyranosyl trichloroacetimidate (1), 4-methoxyphenyl 2,3,4-tri-O-benzoyl-beta-d-galactopyranoside (2), 6-O-acetyl-2,3,4-tri-O-benzoyl-alpha-d-galactopyranosyl trichloroacetimidate (5), 4-methoxyphenyl 6-O-acetyl-2,4-di-O-benzoyl-beta-d-galactopyranoside (22), and 4-methoxyphenyl 2,4,6-tri-O-benzoyl-beta-d-galactopyranoside (26) as the key synthons. Coupling of 2 with 1, followed by oxidative cleavage of 1-OMP and subsequent trichloroacetimidate formation gave the beta-(1-->6)-linked disaccharide donor 4. Condensation of 2 with 5 and subsequent selective deacetylation by methanolysis produced the beta-(1-->6)-linked disaccharide acceptor 7. Reaction of 7 with 4, oxidative cleavage of 1-OMP, and trichloroacetimidate formation produced the tetrasaccharide donor 9. The penta- (15), the hexa- (17), and the heptasaccharide donor 19 were synthesized similarly. Meanwhile, treatment of 1 with 22 yielded beta-(1-->3)-linked disaccharide 23 and alpha-(1-->3)-linked disaccharide 25. Oxidative cleavage of 1-OMp of 23 followed by trichloroacetimidate formation produced the disaccharide donor 24. Coupling of 26 with 24, again, gave beta-linked 27 and alpha-linked 29. Selective 6-O-deacetylation of 27 afforded the trisaccharide acceptor 28. TMSOTf-promoted condensation 28 of with the tetra- (9), penta- (15), hexa-(17), and heptasaccharide donor 19, followed by deprotection, gave the target compounds.

Adjuvants, Immunologic↗

Isolation and characterization of matrix proteoglycans from human nasal cartilage. Compositional and structural comparison between normal and scoliotic tissues.

The content, types and the fine structures of proteoglycans (PGs) present in human normal nasal cartilage (HNNC) were investigated and compared with those in human scoliotic nasal cartilage (HSNC). Three PG types were identified in both HNNC and HSNC; the large-sized high buoyant density aggrecan, which is the predominant PG population, and the small-sized low buoyant density biglycan and decorin. HSNC contained a significantly higher amount of keratan sulfate (KS)-rich aggrecan (30%) of smaller hydrodynamic size as compared to HNNC. The average molecular sizes (M(r)s) of aggecan-derived chondroitin sulfate (CS) chains in both HNNC and HSNC were identical (18 kDa), but they significantly differ in disaccharide composition, since CS isolated from HSNC contained higher proportions of 6-sulfated disaccharides as compared to those from HNNC. Scoliotic tissue contained also higher amounts (67%) of the small PGs, biglycan and decorin as compared to HNNC. It is worth noticing that both normal and scoliotic human nasal cartilage contain also non-glycanated forms of decorin and biglycan. Dermatan sulfate (DS) was the predominant glycosaminoglycan (GAG) present on biglycan and decorin in both tissues. The small PGs-derived CS chains in both normal and scoliotic cartilage had the same M(r) (20 kDa), whereas DS chains from scoliotic cartilage were of greater M(r) (32 kDa) than those from normal cartilage (24 kDa). Furthermore, scoliotic tissue-derived DS chains contained higher amounts of iduronate (20%) as compared to those of normal cartilage (12%). Disaccharide analysis of small PGs showed that both HNNC and HSNC were rich in 4-sulfated disaccharides and in each case, the small size PGs contained a considerably higher proportion of 4-sulfated disaccharides than the aggrecan of the same tissue. The higher amounts of matrix PGs identified in scoliotic tissue as well as the differences in fine chemical composition of their GAG chains may reflect the modified architecture and functional failure of scoliotic tissue.

Adult↗

Characterization of a small chondroitin sulfate proteoglycan isolated from the mucus surrounding the embryos of Viviparus ater (Mollusca Gastropoda).

A small chondroitin sulfate proteoglycan was isolated and partially characterized for core protein and glycosaminoglycan structures from the mucus surrounding embryos in the developmental pouch of Viviparus ater (Mollusca Gastropoda). The protein bearing polysaccharide nature was confirmed by gel-permeation chromatography separation of fractions positive to the uronic acid dosage, 7.5% SDS-PAGE under reducing conditions, sequential staining with alcian blue and ammoniacal silver. Its molecular mass was calculated at about 228,800. After degradation of the galactosaminoglycan components by chondroitinase ABC in the presence of proteinase inhibitors, the molecular mass of the core protein was determined at about 72,200. Treatment of the proteoglycan with keratanase did not modify its electrophoretic migration. Isoelectric focusing of the core protein demonstrated a micro-heterogeneity with the presence of two isoforms with different isoelectric point, pI=8.2 and 6.6, in a ratio of about 1:2.2. The glycosaminoglycan component of the proteoglycan was characterized as chondroitin sulfate with a molecular mass of about 30,750 composed of 5% non-sulfated unsaturated disaccharide, 94% monosulfated disaccharides (4-monosulfated to 6-monosulfated disaccharide ratio of 1.36) and 1. 5% disulfated disaccharides (in particular 1.3% 2,6-disulfated disaccharide) with a sulfate to carboxyl ratio of 0.96. Degradation of the chondroitin sulfate with chondroitinase ABC and ACII permitted to determine a percentage of glucuronic acid of about 78.4. The proteoglycan isolated from the mucus surrounding the embryos of Viviparus ater is formed by a small core protein bearing about five chondroitin sulfate chains (80% chondroitin sulfate/20% dermatan sulfate) with potential function in the developmental processes of molluscs embryos.

Animals↗

Oral absorption and bioavailability of ichthyic origin chondroitin sulfate in healthy male volunteers.

OBJECTIVE: Chondroitin sulfate (CS) has proven to be a valuable therapeutic tool as a symptomatic slow-acting drug for the treatment of osteoarthritis after oral administration. The aim of this study was to assess the absorption of CS of ichthyic origin after oral administration to 20 healthy male volunteers. DESIGN: Ichthyic origin CS (from shark cartilage, 4 g) was orally administered to 20 healthy human volunteers, and then extracted and purified from plasma over a 48 h period. The polysaccharide absorbed by oral route was characterized and quantified by agarose-gel electrophoretic technique, and densitometric scanning. In addition, the percentage of constituent disaccharides and charge density were measured. RESULTS: After oral administration, ichthyic CS plasma levels increased (more than 120%) with a peak concentration at 8.7h, with the increase reaching significance from 4 to 16 h. A significant decrease in the relative amount of non-sulfated disaccharide was measured (reaching the minimum relative percentage of 30.86+/-20.79% at 8h). At the same time, 4-sulfated disaccharide increased to a maximum of 51.91+/-25.91% at 6h, and 6-sulfated and disulfated disaccharides appeared in blood, reaching maximum concentrations of 15.24+/-16.60% at 8h and 2.93+/-4.82% at 12h, respectively. Concomitantly, the mean charge density rose from 0.40+/-0.14 at predose to a maximum of 0.72+/-0.22 and 0.72+/-0.21 measured 8 and 12h after ichthyic CS administration. CONCLUSIONS: Ichthyic CS is absorbed slowly, with a t(max)=8.7+/-4.5h and the C(max)averaged 4.87+/-2.05 microg/ml. The differences in the absorption and bioavailability of the various CS formulations is strongly influenced by the structure and characteristics, such as molecular mass, charge density, and cluster of disulfated disaccharides, of the parental molecules.

Absorption↗

Altered content composition and structure of glycosaminoglycans and proteoglycans in gastric carcinoma.

Glycosaminoglycans (GAGs) in proteoglycan (PG) forms or as free GAGs are implicated in the growth and progression of malignant tumors. These macromolecules were investigated in human gastric carcinoma (HGC) and compared with those in human normal gastric mucosa (HNG). We report that HGC contained about 2-fold increased amounts of GAGs in comparison to HNG. Specifically, HGC showed 3- and 2.5-fold net increase in chondroitin sulphate (CS) and hyaluronan (HA) contents, respectively. Dermatan sulphate (DS) was slightly increased, but the amount of heparan sulphate (HS) was decreased. Of particular, interest were the quite different sulphation profiles of CS and DS chains in HGC in which, non-sulphated and 6-sulphated disaccharide units were increased 10 and 4 times, respectively, in comparison to HNG. On PG level, three different populations were identified in both HNG and HGC, being HSPGs, versican (CS/DS chains) and decorin (CS/DS chains). In HGC, the amounts of versican and decorin were significantly increased about 3- and 8-fold, respectively. These PGs were also characterized by marked decrease in hydrodynamic size and GAG content per PG molecule. Analysis of Delta-disaccharide of versican and decorin from HGC showed an increase of 6-sulphated Delta-disaccharides (Delta di-6S) and non-sulphated Delta-disaccharides (Delta di-0S) with a parallel decrease of 4-sulphated Delta-disaccharides (Delta di-4S) as compared to HNG, which closely correlated with the increase of CS content. In addition, the accumulation of core proteins of versican and decorin in HGC was also associated with many post-translational modifications, referring to the number, size, degree and patterns of sulphation and epimerization of CS/DS chains. Studies on the modified metabolism of PGs/GAGs are under progress and will help in deeper understanding of the environment in which tumor cells proliferate and invade.

Adenocarcinoma↗

Compositional analysis and quantification of heparin and heparan sulfate by electrospray ionization ion trap mass spectrometry.

A new method using a combination of electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (MSn) was developed for the identification and quantitative analysis of eight heparan sulfate (HS)- and heparin-derived delta-disaccharides obtained by enzymatic depolymerization. The compositional analysis of nonisomeric disaccharide constituents of heparin/HS was achieved from full-scan MS1 spectra using an internal standard and a calculated response factor for each disaccharide. Diagnostic product ions from MSn spectra of isomeric disaccharides were used for the quantitative analysis of the relative amounts of each of the isomers in mixtures. The protocol was validated using several quality control samples and showed satisfactory accuracy and precision. The analysis is rapid, accurate, and uses no purification or separation steps prior to analysis by MS, thus reducing sample consumption and analysis time of traditional methods. Using this quantitative analysis procedure, percentages of disaccharide compositions for heparins from porcine and bovine intestinal mucosa and heparan sulfate from bovine kidney were determined.

Animals↗

Sucrosemia in untreated celiac disease: a potential screening test.

During studies to develop serum tests of small intestinal permeability, we detected an unidentified disaccharide in HPLC traces of sera from untreated celiacs. This present study aimed to identify the disaccharide and determine whether the presence of the disaccharide in the serum after an oral challenge had potential as a simple screening test for celiac disease. The disaccharide was identified as sucrose by incubation studies of sera with disaccharidases. Twenty untreated celiacs, 15 treated celiacs, and 20 normal or dyspeptic controls were studied for the presence of sucrose in their serum after an oral load (8 g). The results in celiacs were compared with the presence of serum IgA endomysial antibodies. The 10 normal controls were also given a larger sucrose challenge (50 g). Ten of the untreated celiacs and 10 controls had their brush border disaccharidase activities measured. Sucrose eluted in the same position as the unidentified disaccharide in the HPLC trace and the latter could be removed by incubation with sucrase. All untreated celiacs but none of the treated celiacs had sucrose in their serum after the 8-g oral challenge. None of the controls had sucrose in their serum after the 8-g or 50-g challenges. Three untreated celiacs were IgA endomysial antibody negative as were all the treated cases. Brush border sucrase activity was low in untreated celiac disease. The presence of sucrose in the serum after an oral load shows promise as a noninvasive test for celiac disease.

Adult↗

Distribution of iduronate 2-sulphate residues in heparan sulphate. Evidence for an ordered polymeric structure.

The structure of human skin fibroblast heparan sulphate has been examined by depolymerization with heparinase, which specifically cleaves highly sulphated disaccharides of structure GlcNSO3 (+/-6S)-alpha 1,4IdoA(2S) [N-sulphated glucosamine (6-sulphate)-alpha 1,4-iduronic acid 2-sulphate]. Heparan sulphate contained only a small proportion (approximately 10%) of linkages susceptible to this enzyme. The major products of depolymerization with heparinase were large oligosaccharides with an average molecular mass of 10 kDa (dp approximately 40, where dp is degree of polymerization; for disaccharides, dp = 2 etc.) as assessed by gel filtration on Sepharose CL-6B, compared with a molecular mass of 45 kDa (dp approximately 200) for the intact chains. The large heparinase-resistant oligosaccharides were highly susceptible to depolymerization with the enzyme heparitinase, which cleaves heparan sulphate in areas of low sulphation, where N-acetylated disaccharides [GlcNAc-alpha 1,4GlcA (N-acetylglucosaminyl-alpha 1,4-glucuronic acid)] are the predominant structural unit. Further analysis of the location of the heparinase cleavage sites indicated that they were predominantly found in a central position in GlcNSO3-alpha 1,4IdoA repeat sequences of average length four to seven disaccharides (dp 8-14). These results indicate that heparinase cleaves heparan sulphate in approximately four or five N-sulphated domains, each domain containing a cluster of two or three susceptible disaccharides; the domains are separated by long N-acetyl-rich sequences that are markedly deficient in sulphate groups. On the basis of these findings a model is proposed which depicts heparan sulphate as an ordered polymeric structure composed of an alternate arrangement of sulphate-rich and sulphate-poor regions. The sulphate-rich regions are likely to be flexible areas of the chain because of their high content of the conformationally versatile IdoA and IdoA(2S) residues. The model has important implications for the biosynthesis and functions of heparan sulphate.

Adult↗

Comparative biochemistry of human skin: glycosaminoglycans from different body sites in normal subjects and in patients with localized scleroderma.

OBJECTIVES: The aim of this investigation is to compare the relative proportions of disaccharides of chondroitinase-digestible glycosaminoglycans (GAGs) among the different body sites in control human skin and in the skin lesions of patients with localized scleroderma. METHODS: The disaccharide relative proportions were determined using high-performance liquid chromatography (HPLC). RESULTS: DeltaDi-4S, the main disaccharide unit of dermatan sulphate (DS), was the major skin GAG disaccharide (approximately 70% of the total) in control skin among all different body sites studied here. In scleroderma there was an increase in the relative proportion of both deltaDi-HA, the main disaccharide unit of hyaluronic acid (HA), and deltaDi-diS(B) (alpha-deltaUA(2SO4)-1-->3-GalNAc(4SO4)), derived from DS, and a decrease in deltaDi-4S, as compared with the uninvolved skin or the site-matched control skin. CONCLUSION: DS is the major GAG species in normal skin from different body sites. In addition, our results suggest a decrease and also a structural change in DS and an increase in the proportion of HA in scleroderma skin.

Adult↗

Chemical and immunological assay of the nonreducing terminal residues of chondroitin sulfate from human aggrecan.

Samples of aggrecan chondroitin sulfate, isolated from normal human knee cartilages of individuals from fetal to 72 years of age, were digested with chondroitin lyases. The products were analyzed by fluorescence-based anion exchange high performance liquid chromatography to separate and quantitate nonreducing terminal structures, in addition to internal unsaturated disaccharide products. The predominant terminal structures were the monosaccharides, GalNAc4S and GalNAc4,6S as they were present on 85-90% of all chains. The remaining chains terminated with the disaccharides GlcAbeta1,3GalNAc4S and GlcAbeta1,3GalNAc6S. Marked changes in the relative abundance of these terminals were identified in the transition from growth cartilage to adult articular cartilage. First, terminal GalNAc residues were almost exclusively 4-sulfated in aggrecan from fetal through 15 years of age, but were approximately 50% 4,6-disulfated in aggrecans from adults (22-72 years of age). Second, the terminal disaccharide GlcAbeta1,3GalNAc4S was on approximately 7% of chains on aggrecan from fetal through 15 years of age, but on only approximately 3% of chains on adult aggrecan. In contrast, the proportion of chains terminating in GlcAbeta1,3GalNAc6S, approximately 9%, was unchanged from fetal to 72 years of age. This terminal disaccharide is proposed to be recognized by the widely used monoclonal antibody 3B3. However, chemical quantitation of the structure together with solid phase 3B3(-) immunoassay of fetal and adult aggrecans showed that the content of the terminal disaccharide does not necessarily correlate with immunoreactivity of the proteoglycan, as chain density and presentation on the solid phase are critical factors for recognition of chain terminals by 3B3. The quantitative results obtained from chemical analyses of all nonreducing termini of aggrecan chondroitin sulfate chains revealed important changes in chain termination that occur when cellular activities are altered as adult articular cartilage is formed after removal of growth cartilage. These findings are discussed in relation to specific enzymatic steps that generate the nonreducing termini of chains in the biosynthesis pathway of chondroitin sulfate proteoglycans and their modulation in tissue development and pathology.

Adolescent↗

Characterization of a neutrophil cell surface glycosaminoglycan that mediates binding of platelet factor 4.

Platelet factor 4 (PF-4) is a platelet-derived alpha-chemokine that binds to and activates human neutrophils to undergo specific functions like exocytosis or adhesion. PF-4 binding has been shown to be independent of interleukin-8 receptors and could be inhibited by soluble chondroitin sulfate type glycosaminoglycans or by pretreatment of cells with chondroitinase ABC. Here we present evidence that surface-expressed neutrophil glycosaminoglycans are of chondroitin sulfate type and that this species binds to the tetrameric form of PF-4. The glycosaminoglycans consist of a single type of chain with an average molecular mass of approximately 23 kDa and are composed of approximately 85-90% chondroitin 4-sulfate disaccharide units type CSA (-->4GlcAbeta1-->3GalNAc(4-O-sulfate)beta1-->) and of approximately 10-15% di-O-sulfated disaccharide units. A major part of these di-O-sulfated disaccharide units are CSE units (-->4GlcAbeta1-->3GalNAc(4,6-O-sulfate)beta1-->). Binding studies revealed that the interaction of chondroitin sulfate with PF-4 required at least 20 monosaccharide units for significant binding. The di-O-sulfated disaccharide units in neutrophil glycosaminoglycans clearly promoted the affinity to PF-4, which showed a Kd approximately 0.8 microM, as the affinities of bovine cartilage chondroitin sulfate A, porcine skin dermatan sulfate, or bovine cartilage chondroitin sulfate C, all consisting exclusively of monosulfated disaccharide units, were found to be 3-5-fold lower. Taken together, our data indicate that chondroitin sulfate chains function as physiologically relevant binding sites for PF-4 on neutrophils and that the affinity of these chains for PF-4 is controlled by their degree of sulfation.

Animals↗

Structural studies on the D-arabinose-containing lipid A from Rhodospirillum tenue 2761.

Structural studies carried out on the isolated free lipid A of Rhodospirillum tenue 2761 revealed a new type of structure for this lipid. The lipid A backbone of 1',6-linked glucosamine disaccharide (central disaccharide) is substituted by three different sugar residues: the non-reducing end of the disaccharide by 4-amino-4-deoxy-L-arabinose 1-phosphate and its reducing end glycosidically by D-arabinofuranose 1-phosphate; further, the reducing glucosamine of the disaccharide is branched to a third glucosamine residue by a 1'',4-glycosidic linkage. The amino and the hydroxyl groups of the central disaccharide are acylated by 3-hydroxydecanoic acid (amide-linked) and palmitic and myristic acids (ester-linked). Neither amino nor hydroxyl groups of the three external sugar residues are acylated. The results suggest the following chemical structure for the lipid A of R. tenue 2761: (formula: see text).

Arabinose↗

Isolation, characterization and properties of the oversulphated chondroitin sulphate proteoglycan from squid skin with peculiar glycosaminoglycan sulphation pattern.

Oversulphated chondroitin sulphate proteoglycan from squid skin was isolated from 4 M guanidine hydrochloride extract by ion-exchange chromatography, gel chromatography and density gradient centrifugation. The proteoglycan had Mr 3.5 x 10(5), contained on average six oversulphated chondroitin sulphate chains (Mr 4 x 10(4)) bound on a polypeptide of Mr 2.8 x 10(4), and oligosaccharides consisting of both hexosamines, glucuronic acid, sulphates and fucose as the only neutral monosaccharide. The major amino acids of the proteoglycan protein core are glycine (corresponding to about one third of the total amino acids), aspartic acid/asparagine and serine, together amounting to 50% of the total. The proteoglycan was resistant to the proteolytic enzymes V8 protease, trypsin (treated with diphenylcarbamoyl chloride), alpha-chymotrypsin and pronase, while it was completely degraded by papain and to a large extent by collagenase. Pretreated proteoglycan with chondroitinase AC was degraded by pronase to a large extent and slightly by V8 protease and trypsin. The proteoglycan did not interact with hyaluronic acid and did not form self-aggregates. Oversulphated chondroitin sulphate chains were composed of unusual sulphated disaccharide units which were isolated and characterized by HPLC. In particular, it contained 2-acetamido-2-deoxy-3-O-(alpha-L-threo-4-enopyranosyluronic acid)-D-galactose 4-sulphate (delta di-4S) and disulphated disaccharides (delta di-diS) [90% 2-acetamido-2-deoxy-3-O-(alpha-L-threo-4-enopyranosyluronic acid 2/3-sulphate)-D-galactose 6-sulphate (delta di-diSD) and 10% 2-acetamido-2-deoxy-3-O-(alpha-L-threo-4-enopyranosyluronic acid 2/3-sulphate)-D-galactose 4-sulphate (delta di-diSK)] as the major disaccharides, significant amounts of trisulphated disaccharides (delta di-triS) and small amounts of 2-acetamido-2-deoxy-3-O-(alpha-L-threo-4-enopyranosyluronic acid)-D-galactose 6-sulphate (delta di-6S) and 2-acetamido-2-deoxy-3-O-(alpha-L-threo-4-enopyranosyluronic acid)-D-galactose (delta di-OS). Trisulphated disaccharides contained sulphate groups at C-4 and C-6 of the galactosamine and at C-2 or C-3 of the glucuronic acid. By HPLC analysis of a pure preparation of oversulphated chondroitin sulphate, it was found that it contains glucose, galactose, mannose and fucose most likely as branches.

Amino Acids↗

Two squid skin proteoglycans each containing chondroitin sulfates with different sulfation patterns.

Two chondroitin sulfate containing proteoglycans, amounting to approximately 6% of the tissue proteoglycans, were isolated from the skin of the squid. They were almost completely extracted by 4 M guanidine hydrochloride in the presence of proteinase inhibitors, and then they were separated by DEAE-Sephacel chromatography and isolated by further chromatography on Sepharose CL-4B. Each proteoglycan contained two types of chondroitin sulfates that differed in their sulfation patterns. One proteoglycan (molecular mass (M(r)) 5.6 x 10(5)) contained, on the average, four chondroitins (M(r) 8.4 x 10(4)) and five chondroitin sulfates (M(r) 3.4 x 10(4)), whereas the other proteoglycan (M(r) 5.2 x 10(5)) contained three chondroitin sulfates (M(r) 1.1 x 10(5)) and five oversulfated chondroitin sulfates (M(r) 4.3 x 10(4)). The glycosaminoglycans were released from the proteoglycans by treatment with alkaline borohydride, separated from the oligosaccharides by chromatography on Bio-Gel P-30, and isolated by chromatography on DEAE-Sephacel and Sepharose CL-6B. Chondroitin sulfates were degraded by chondroitinase AC to an extent of 70% and consisted of significant amounts of disaccharides sulfated at C-4 of the galactosamine, disulfated disaccharides, and small amounts of nonsulfated disaccharides, as well as disaccharides that bore sulfates at C-6. Oversulfated chondroitin sulfate was degraded by chondroitinase AC to only 40% and contained appreciable amounts of disulfated and trisulfated disaccharides. The glycosaminoglycans also contained neutral monosaccharides; glucose was the predominant neutral sugar. A part of the oligosaccharides of both proteoglycans was of identical structure to that of chondroitin sulfate.

Animals↗

Dermatan sulfate proteoglycans from the mineralized matrix of the avian eggshell.

The eggshell of the chicken is a useful model to study matrix components which affect biomineralization. As an extension of our previous immunohistochemical work which suggested the presence of dermatan sulfate proteoglycans in the mineralized region of the eggshell, a study was undertaken to characterize these molecules biochemically. After demineralization with HCl and extraction with 4 M guanidinium chloride containing protease inhibitors, the extract was partitioned by anion exchange chromatography. Step elution with 0.25 M and 1.0 M sodium chloride resulted in the generation of two fractions, both of which contain chondroitinase-sensitive proteoglycans with molecular weights estimated at 200,000 by gel electrophoresis. The proteoglycans in each fraction have core proteins with molecular weights of approximately 120,000 and glycosaminoglycans with average molecular weights of 22,000. Based on differential sensitivity to chondroitinase ABC and AC II, these glycosaminoglycans contain a small proportion of dermatan sulfate. The disaccharide compositions of these glycosaminoglycans differ for the proteoglycans eluted with 0.25 M and 1.0 M sodium chloride. Those eluted with lower sodium chloride are enriched in unsulfated chondroitin and have much more 4-sulfated than 6-sulfated disaccharides; those eluted with 1.0 M sodium chloride contain primarily 4-sulfated disaccharides, a small amount of 6-sulfated disaccharides, and less unsulfated disaccharides than the proteoglycans eluted with 0.25 M sodium chloride. The large difference in the proportions of unsulfated chondroitin may be the reason for the elution at different sodium chloride concentrations. Both of the anion exchange column fractions contain other proteins in addition to the proteoglycans. These proteins are not separated from the proteoglycans by a second anion exchange column or by molecular sieve chromatography under dissociative conditions. Of particular interest is the observation that the eggshell proteoglycans and their core proteins are recognized by a monoclonal antibody which recognizes an epitope on the core protein of avian versican. This suggests that, in spite of the large differences in the sizes of the core proteins of versican and the eggshell proteoglycans, these core proteins share some homology. Because anionic molecules are thought to be important regulators of biomineralization, and because preparations like those analyzed in this study have been shown to influence in vitro calcium carbonate crystallization, the eggshell proteoglycans may play a role in eggshell mineralization.

Amino Acid Sequence↗

Structural requirements for arthritogenicity of peptidoglycans from Staphylococcus aureus and Lactobacillus plant arum and analogous synthetic compounds.

The comparative studies on the arthritogenicity of chemically well defined peptidoglycans (PG)2 from the cell walls of Staphylococcus aureus (FDA 209P) and Lactobacillus plantarum (ATCC 8014) showed that 1) a polymer of disaccharide-peptide with or without the presence of N-acetylglucosaminyl-ribitol-teichoic acid produced severe arthritis; 2) oligosaccharide-peptides with or without the special structure (N-acetylglucosaminyl-ribitol-teichoic acid in S. aureus, a polymer of rhamnose and glucose in L. plantarum) produced severe disease; 3) disaccharide-heptapeptide-disaccharide with or without the presence of either glucose-ribitol-teichoic acid or a polymer of rhamnose and glucose appeared to be arthritogenic but much less effective for disease production; 4) N-acetylmuramyl-heptapeptide-N-acetylmuramic acid and disaccharide-hexapeptide were non-arthritogenic; 5) none of the synthetic N-acetylmuramyl-peptides, including tetrapeptide, produced the disease. Thus it is concluded that arthritis-inducing activity is related to the peptidoglycan moiety but not to the special structure, and the most important moiety responsible for disease production may be located in a chain length of two or more disaccharide units on PG subunits. However, it is discussed that non-arthritogenicity of peptidoglycans, including synthetic compounds, may be due to a lack of adjuvanticity in rats rather than a lack of antigenic determinant(s) responsible for production of arthritis.

Animals↗