scholarly journals Immortalized, cloned mouse chondrocytic cells (MC615) produce three different matrix proteoglycans with core-protein-specific chondroitin/dermatan sulphate structures1

1997 ◽  
Vol 327 (3) ◽  
pp. 831-839 ◽  
Author(s):  
Robert KOKENYESI ◽  
E. Jeremiah SILBERT

Cloned immortalized MC615 mouse chondrocytic cells were used to examine their capability to produce multiple types of matrix proteoglycans. Immunofluorescence staining indicated a uniform expression of aggrecan, biglycan and decorin by all cells. After culture with [35S]sulphate, proteo[35S]glycans secreted by the cells were found to elute in two peaks from a Sepharose CL-4B column. The first peak, at the void volume of the column, contained a large proteoglycan with an estimated average hydrodynamic mass of 103 kDa. The glycosaminoglycan chains of this proteoglycan had an average hydrodynamic size of 17 kDa, estimated by Sepharose CL-6B chromatography, indicating the presence of 30-70 glycosaminoglycan chains per core protein, which was consistent with the characteristics of aggrecan. Biglycan and decorin were immunoisolated from the second Sepharose CL-4B peak, and had average glycosaminoglycan hydrodynamic sizes of approx. 25 kDa and 32 kDa respectively. Glycosaminoglycan chains of the aggrecan, biglycan and decorin were treated with chondroitin ABC lyase, chondroitin AC lyase and chondroitin B lyase to determine the positions of sulphation and the degree of uronic acid epimerization. The aggrecan glycosaminoglycan chains were found to contain a 4-sulphate/6-sulphate ratio of 7:3, with no epimerization of glucuronic acid to iduronic acid. The biglycan glycosaminoglycan chains were found to contain a similar ratio of 4-sulphate/6-sulphate, but with approx. 40-45% of the glucuronic acid epimerized to iduronic acid. The decorin glycosaminoglycan chains were found to contain 4-sulphate but no detectable 6-sulphate, and approx. 30-35% epimerization of the glucuronic acid to iduronic acid. The results, using these cloned cells, indicated that a single MC615 cell is able to make all three proteoglycans with distinctive differences between the glycosaminoglycans of aggrecan, biglycan and decorin. These data indicate that a mechanism must exist for a single MC615 cell to regulate the sizes and fine structures of glycosaminoglycans on simultaneously produced, different proteoglycans in a core-protein-specific manner.

1986 ◽  
Vol 240 (2) ◽  
pp. 575-583 ◽  
Author(s):  
R Kapoor ◽  
C F Phelps ◽  
T N Wight

Bovine aortic chondroitin sulphate/dermatan sulphate proteoglycans (PG-25, PG-35 and PG-50) were differentially precipitated with ethanol and analysed by a variety of chemical and physical techniques. The glycosaminoglycan chains of PG-25 and PG-35 contained a mixture of glucuronic acid and iduronic acid, whereas the uronic acid component of PG-50 was primarily glucuronic acid. In addition, various amounts of oligosaccharides containing small amounts of mannose, a galactose/hexosamine ratio of 1:1 and an absence of uronic acid were covalently linked to the core protein of all proteoglycans. The weight-average Mr (Mw) values of the proteoglycans determined by light-scattering in 4 M-guanidinium chloride were 1.3 × 10(6) (PG-25), 0.30 × 10(6) (PG-35) and 0.88 × 10(6) (PG-50). The s0 values of the proteoglycans were distributed between 7 and 8 S, and the reduced viscosities, eta sp./c, of all proteoglycans were dependent on the shear rate and polymer concentration. Electron microscopy of spread molecules revealed that PG-25 contained small structural units that appeared to self-associate into large aggregates, whereas PG-35 and PG-50 appeared mainly as monomers consisting of a core with various numbers of side projections. Hyaluronic acid-proteoglycan complexes occurred only with a small proportion of the molecules present in PG-35, and their formation could be inhibited by oligosaccharides. These results suggest the presence in the aorta of subspecies of chondroitin sulphate and dermatan sulphate proteoglycans, which show large variations in their physicochemical and inter- and intra-molecular association properties.


1986 ◽  
Vol 235 (1) ◽  
pp. 225-236 ◽  
Author(s):  
P N Shaklee ◽  
H E Conrad

Chondroitin 4-sulphate, chondroitin 6-sulphate, dermatan sulphate and keratan sulphate were N-deacetylated by treatment with hydrazine and then cleaved with HNO2 at pH 4.0, and the resulting products were reduced with NaB3H4. This reaction sequence cleaved the glycosaminoglycans at their N-acetyl-D-glucosamine or N-acetyl-D-galactosamine residues, which were converted into 3H-labelled 2,5-anhydro-D-mannitol (AManR) or 2,5-anhydro-D-talitol (ATalR) residues respectively. The end-labelled disaccharides, composed of D-glucuronic acid (GlcA), L-iduronic acid (IdoA) or D-galactose (Gal) and one of the anhydrohexitols, were identified as follows: both chondroitin 4-sulphate and chondroitin 6-sulphate gave GlcA→ATalR(4-SO4), GlcA→ATalR(6-SO4), IdoA→ATalR (4-SO4) and GlcA(2-SO4)→ATalR(6-SO4); dermatan sulphate gave IdoA→ATalR(4-SO4), GlcA→ATalR(4-SO4), GlcA→ATalR(6-SO4)→IdoA(2-SO4)ATalR(4-SO4) and IdoA→ATalR (4,6-diSO4); keratan sulphate gave Gal(6-SO4)→AManR(6-SO4), Gal→AManR(6-SO4), Gal(6-SO4)→AManR and Gal→AManR. Several additional disaccharides were generated by treatment of the uronic acid-containing disaccharides with hydrazine to epimerize their uronic acid residues at C-5. A number of these disaccharides were found to be substrates for lysosomal sulphatases and glycuronidases. Methods were developed for the separation of all of the disaccharide products by h.p.l.c. The rate of N-deacetylation of chondroitin 4-sulphate by hydrazinolysis was significantly lower than the rate of N-deacetylation of chondroitin 6-sulphate or chondroitin. Dermatan sulphate was N-deacetylated at an intermediate rate. The relative amounts of disaccharides obtained from chondroitin 4-sulphate, chondroitin 6-sulphate and dermatan sulphate under optimum hydrazinolysis/deamination conditions were comparable with the amounts of the corresponding products released from the polymers by chondroitinase treatment.


1980 ◽  
Vol 191 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Ingrid Sjöberg ◽  
Lars-Ȧke Fransson

1. 3H- and 35S-labelled heparan sulphate was isolated from monolayers of human lung fibroblasts and subjected to degradations by (a) deaminative cleavage and (b) periodate oxidation/alkaline elimination. Fragments were resolved by gel- and ion-exchange-chromatography. 2. Deaminative cleavage of the radioactive glycan afforded mainly disaccharides with a low content of ester-sulphate and free sulphate, indicating that a large part (approx. 80%) of the repeating units consisted of uronosyl-glucosamine-N-sulphate. Blocks of non-sulphated [glucuronosyl-N-acetyl glucosamine] repeats (3–4 consecutive units) accounted for the remainder of the chains. 3. By selective oxidation of glucuronic acid residues associated with N-acetylglucosamine, followed by scission in alkali, the radioactive glycan was degraded into a series of fragments. The glucuronosyl-N-acetylglucosamine-containing block regions yielded a compound N-acetylglucosamine–R, where R is the remnant of an oxidized and degraded glucuronic acid. Periodate-insensitive uronic acid residues were recovered in saccharides of the general structure glucosamine–(uronic acid–glucosamine)n–R. 4. Further degradations of these saccharides via deaminative cleavage and re-oxidations with periodate revealed that iduronic acid may be located in sequences such as glucosamine-N-sulphate→iduronic acid→N-acetylglucosamine. Occasionally the iduronic acid was sulphated. Blocks of iduronic acid-containing repeats may contain up to five consecutive units. Alternating arrangements of iduronic acid- and glucuronic acid-containing repeats were also observed. 5. 3H- and 35S-labelled heparan sulphates from sequential extracts of fibroblasts (medium, EDTA, trypsin digest, dithiothreitol extract, cell-soluble and cell-insoluble material) afforded similar profiles after both periodate oxidation/alkaline elimination and deaminative cleavage.


1984 ◽  
Vol 217 (1) ◽  
pp. 187-197 ◽  
Author(s):  
P N Shaklee ◽  
H E Conrad

Heparin, carboxy-group-reduced heparin, several sulphated monosaccharides and disaccharides formed from heparin, and a tetrasaccharide prepared from chondroitin sulphate were treated at 100 degrees C with hydrazine containing 1% hydrazine sulphate for periods sufficient to cause complete N-deacetylation of the N-acetylhexosamine residues. Under these hydrazinolysis conditions both the N-sulphate and the O-sulphate substituents on these compounds were completely stable. However, the uronic acid residues were converted into their hydrazide derivatives at rates that depended on the uronic acid structures. Unsubstituted L-iduronic acid residues reacted much more slowly than did unsubstituted D-glucuronic acid or 2-O-sulphated L-iduronic acid residues. The chemical modification of the carboxy groups resulted in a low rate of C-5 epimerization of the uronic acid residues. The hydrazinolysis reaction also caused a partial depolymerization of heparin but not of carboxy-group-reduced heparin. Treatment of the hydrazinolysis products with HNO2 at either pH 4 or pH 1.5 or with HIO3 converted the uronic acid hydrazides back into uronic acid residues. The use of the hydrazinolysis reaction in studies of the structures of uronic acid-containing polymers and the implications of the uronic acid hydrazide formation are discussed.


1979 ◽  
Vol 183 (3) ◽  
pp. 711-720 ◽  
Author(s):  
A Linker

Oligosaccharides obtained from heparan sulphate by nitrous acid degradation were shown to be degraded sequentially by beta-D-glucuronidase or alpha-L-iduronidase followed by alpha D-N-acetylglucosaminidase. Structural analysis of the tetrasaccharide fraction showed the following. (1) N-Acetylglucosamine is preceded by a non-sulphated uronic acid residue that can be either D-glucuronic of L-iduronic acid, but followed by a glucuronic acid residue. (2) The N-acetylglucosamine in the major fraction is sulphated. (3) Very few if any of the uronic acid residues are sulphated (4). The results indicate that the area of the heparan sulphate chain where disaccharides containing N-acetylglucosamine and N-sulphated glucosamine residues alternate is higher in sulphate content than expected and that the sulphate groups are mainly located on the hexosamine units.


1979 ◽  
Author(s):  
B. Casu

The structure of heparin is largely accounted for by disaccharide sequences of α1,4-linked 2-0-sulphated L-iduroic acid and N,6-0-disulphated D-glucosamine. However, the insertion of other residues (especially D-glucuronic acid, nor-sulphated L-iduronic acid and N-acetylated D-glucosamine) leads to hybrid structures. Also the other iduromc acid-containing glycosaminoglycans are structurally heterogeneous. Heparan sulphates contain variable amounts of heparin-like blocks, ana dermatan sulphate contains also chondroitin -like segments.Available evidence on the structure and conformation of the above glycosaminoglycans will be discussed in terms of the availability ot individual functional groups for interaction with plasma proteins.


1977 ◽  
Vol 167 (2) ◽  
pp. 383-392 ◽  
Author(s):  
Ingrid Sjöberg ◽  
Lars-Åke Fransson

Foetal human lung fibroblasts, grown in monolayer, were allowed to incorporate 35SO42− for various periods of time. 35S-labelled macromolecular anionic products were isolated from the medium, a trypsin digest of the cells in monolayer and the cell residue. The various radioactive polysaccharides were identified as heparan sulphate and a galactosaminoglycan population (chondroitin sulphate and dermatan sulphate) by ion-exchange chromatography and by differential degradations with HNO2 and chondroitinase ABC. Most of the heparan sulphate was found in the trypsin digest, whereas the galactosaminoglycan components were largely confined to the medium. Electrophoretic studies on the various 35S-labelled galactosaminoglycans suggested the presence of a separate chondroitin sulphate component (i.e. a glucuronic acid-rich galactosaminoglycan). The 35S-labelled galactosaminoglycans were subjected to periodate oxidation of l-iduronic acid residues followed by scission in alkali. A periodate-resistant polymer fraction was obtained, which could be degraded to disaccharides by chondroitinase AC. However, most of the 35S-labelled galactosaminoglycans were extensively degraded by periodate oxidation–alkaline elimination. The oligosaccharides obtained were essentially resistant to chondroitinase AC, indicating that the iduronic acid-rich galactosaminoglycans (i.e. dermatan sulphate) were composed largely of repeating units containing sulphated or non-sulphated l-iduronic acid residues. The l-iduronic acid residues present in dermatan sulphate derived from the medium and the trypsin digest contained twice as much ester sulphate as did material associated with the cells. The content of d-glucuronic acid was low and similar in all three fractions. The relative distribution of glycosaminoglycans among the various fractions obtained from cultured lung fibroblasts was distinctly different from that of skin fibroblasts [Malmström, Carlstedt, Åberg & Fransson (1975) Biochem. J.151, 477–489]. Moreover, subtle differences in co-polymeric structure of dermatan sulphate isolated from the two cell types could be detected.


1974 ◽  
Vol 143 (2) ◽  
pp. 369-378 ◽  
Author(s):  
Lars-Åke Fransson ◽  
Lars Cöster ◽  
Anders Malmström ◽  
Ingrid Sjöberg

Selective periodate oxidation of unsubstituted l-iduronic acid residues in copolymeric dermatan sulphate chains was followed by reduction-hydrolysis or alkaline elimination. By this procedure the glucuronic acid-containing periods were isolated in oligosaccharide form; general formula: [Formula: see text] Further degradation of these oligosaccharides with chondroitinase-AC yielded three types of products: (a) sulphated trisaccharide containing an unsaturated uronosyl moiety in the non-reducing terminal and a C4 fragment in the reducing terminal, ΔUA-GalNAc-(-SO4)-R; (b) monosulphated, unsaturated disaccharide, ΔUA-GalNAc-SO4 when n is greater than or equal to 2; and (c) N-acetylgalactosamine with or without sulphate. Oligosaccharides containing a single glucuronic acid residue (n=1) comprised more than half of the glucuronic acid-containing oligosaccharides. The terminal N-acetylgalactosamine moiety of the shortest oligosaccharide was largely 4-sulphated, whereas higher oligosaccharides primarily contained 6-sulphated or unsulphated hexosamine moieties in the same position. Moreover, IdUA-SO4-containing oligosaccharides were encountered. These oligosaccharides were resistant to the action of chondroitinase-ABC.


1981 ◽  
Vol 198 (3) ◽  
pp. 669-675 ◽  
Author(s):  
A Malmström

The formation of L-iduronic acid during biosynthesis of dermatan sulphate has been studied in culture human fibroblasts and in microsomes from the same cells. The cells were incubated with D-[14C]glucose and D-[5-3H]glucose for 72 h. The [14C,3H]dermatan sulphate was hydrolysed and the disaccharides obtained were acetylated and separated by ion-exchange chromatography. The ratio of 3H/14C was 0.36 for N-acetyldermosine and 1.36 N-acetylchondrosine. A microsomal preparation from the fibroblasts was incubated with UDP-D-[5-3H]glucuronic acid, UDP-D-[14C]glucuronic acid, UDP-N-acetyl-D-galactosamine and 3′-phospho-5′-adenylyl sulphate. The polymeric products were separated into nonsulphated and sulphated components which had 3H/14C ratios of 0.51 and 0.20 and contained 9% and 70% of their uronosyl residues in the L-ido-configuration, respectively. Chondroitinase-AC digestion of these polymers liberated all of the remaining 3H activity. Hydrolysis and N-acetylation followed by paper chromatography showed that the L-iduronic acid-containing products were devoid of 3H. The data obtained indicate that the epimerization of D-glucuronosyl to L-iduronosyl residues during biosynthesis of dermatan sulphate involves an abstraction of the C-5 hydrogen of the uronosyl residue.


2004 ◽  
Vol 384 (3) ◽  
pp. 567-575 ◽  
Author(s):  
Takayoshi YAMADA ◽  
Shiori OHTAKE ◽  
Makoto SATO ◽  
Osami HABUCHI

C4ST-1 (chondroitin 4-sulphotransferase-1) and C6ST-1 (chondroitin 6-sulphotransferase-1) transfer sulphate from PAPS (adenosine 3′-phosphate 5′-phosphosulphate) to positions 4 and 6 respectively of the GalNAc residues of chondroitin. We showed previously that C4ST-1 purified from rat chondrosarcoma and recombinant C4ST-1 both transfer sulphate efficiently to position 4 of the GalNAc residues of DSDS (desulphated dermatan sulphate). We report here the specificity of C4ST-1 and C6ST-1 in terms of uronic acid residue recognition around the GalNAc residue to which sulphate is transferred. When [35S]glycosaminoglycans formed from DSDS after incubation with [35S]PAPS and C4ST-1 were digested with chondroitinase ACII, a major part of the radioactivity was recovered in disaccharide fractions and the remainder distributed to tetrasaccharides and larger fractions, indicating that C4ST-1 mainly transferred sulphate to position 4 of the GalNAc residue located at the GlcA-GalNAc-GlcA sequence. Structural analysis of tetrasaccharide and larger oligosaccharide fractions indicated that C4ST-1 mainly transferred sulphate to the GalNAc residue adjacent to the reducing side of the GlcA residue. On the other hand, when [35S]glycosaminoglycans formed from DSDS after incubation with [35S]PAPS and C6ST-1 were digested with chondroitinase ACII, a major part of the radioactivity was recovered in fractions larger than hexasaccharides, indicating that C6ST-1 transferred sulphate to the GalNAc residues located in the L-iduronic acid-rich region. Structural analysis of the tetrasaccharide and larger oligosaccharide fractions indicated that C6ST-1 showed very little preference for the GalNAc residue neighbouring the GlcA residue. These results indicate that C4ST-1 and C6ST-1 differ from each other in the recognition of uronic acid residues adjacent to the targeted GalNAc residue.


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