scholarly journals Hydrazinolysis of heparin and other glycosaminoglycans

1984 ◽  
Vol 217 (1) ◽  
pp. 187-197 ◽  
Author(s):  
P N Shaklee ◽  
H E Conrad
Keyword(s):  
Chemical Modification ◽  
Carboxy Group ◽  
Uronic Acid ◽  
Glucuronic Acid ◽  
Chondroitin Sulphate ◽  
Acid Hydrazide ◽  
Iduronic Acid ◽  
Heparin Treatment ◽  
Hydrazine Sulphate ◽  
Low Rate

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.

scholarly journals Structural studies on heparan sulphate from human lung fibroblasts. Characterization of oligosaccharides obtained by selective periodate oxidation of d-glucuronic acid residues followed by scission in alkali

1980 ◽  
Vol 191 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Ingrid Sjöberg ◽  
Lars-Ȧke Fransson
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Human Lung ◽  
General Structure ◽  
Heparan Sulphate ◽  
Periodate Oxidation ◽  
Exchange Chromatography ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts ◽  
Iduronic Acid

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.

scholarly journals Structure of heparan sulphate oligosaccharides and their degradation by exo-enzymes

1979 ◽  
Vol 183 (3) ◽  
pp. 711-720 ◽  
Author(s):  
A Linker
Keyword(s):  
Structural Analysis ◽  
Nitrous Acid ◽  
Uronic Acid ◽  
Glucuronic Acid ◽  
Heparan Sulphate ◽  
Major Fraction ◽  
Sulphate Content ◽  
Acid Degradation ◽  
Iduronic Acid ◽  
Heparan Sulphate Chain

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.

scholarly journals Physical properties of chondroitin sulphate/dermatan sulphate proteoglycans from bovine aorta

1986 ◽  
Vol 240 (2) ◽  
pp. 575-583 ◽  
Author(s):  
R Kapoor ◽  
C F Phelps ◽  
T N Wight
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Core Protein ◽  
Chondroitin Sulphate ◽  
Polymer Concentration ◽  
Dermatan Sulphate ◽  
Guanidinium Chloride ◽  
Structural Units ◽  
The Core ◽  
Covalently Linked

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.

scholarly journals Synthesis of glycosaminoglycans by human embryonic lung fibroblasts. Different distribution of heparan sulphate, chondroitin sulphate and dermatan sulphate in various fractions of the cell culture

1977 ◽  
Vol 167 (2) ◽  
pp. 383-392 ◽  
Author(s):  
Ingrid Sjöberg ◽  
Lars-Åke Fransson
Keyword(s):  
Glucuronic Acid ◽  
Chondroitin Sulphate ◽  
Heparan Sulphate ◽  
Periodate Oxidation ◽  
Exchange Chromatography ◽  
Lung Fibroblasts ◽  
Relative Distribution ◽  
Dermatan Sulphate ◽  
Human Embryonic Lung ◽  
Iduronic Acid

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.

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
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Core Protein ◽  
Hydrodynamic Size ◽  
Dermatan Sulphate ◽  
Iduronic Acid ◽  
Specific Manner ◽  
Fine Structures ◽  
Chondroitin Ac Lyase ◽  
Two Peaks

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.

scholarly journals Distribution of sulphate and iduronic acid residues in heparin and heparan sulphate

1974 ◽  
Vol 137 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Magnus HÖÖk ◽  
Ulf Lindahl ◽  
Per-Henrik Iverius
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Heparan Sulphate ◽  
Molar Ratio ◽  
Human Aorta ◽  
Hydroxyl Groups ◽  
Free System ◽  
Molar Ratios ◽  
Iduronic Acid ◽  
A Cell

1. A method was developed for determination of the uronic acid composition of heparin-like glycosaminoglycans. Polymers or oligosaccharides are degraded to monosaccharides by a combination of acid hydrolysis and deamination with HNO2. The resulting uronic acid monosaccharides (accounting for about 70% of the uronic acid contents of the starting materials) are isolated and converted into the corresponding aldono-1,4-lactones, which are separated by g.l.c. The calculated ratios of glucuronic acid/iduronic acid are reproducible within 5%. 2. Samples of heparin from pig intestinal mucosa (molar ratio of sulphate/disaccharide unit, 2.40) and heparan sulphate from human aorta (sulphate/disaccharide ratio, 0.46) were subjected to uronic acid analysis. l-Iduronic acid constituted 77% and 19% respectively of the total uronic acid contents. 3. The correlation between the contents of sulphate and iduronic acid indicated by this finding also applied to the fractionated deamination products of the two polymers. The sulphated fragments varied in size from disaccharide to octasaccharide (or larger) and showed sulphate/disaccharide molar ratios in the range of 0.05–2.0. The proportion of iduronic acid increased with increasing ester sulphate contents of the oligosaccharides. 4. Previous studies on the biosynthesis of heparin in a cell-free system have shown that l-iduronic acid residues are formed by C-5 epimerization of d-glucuronic acid units at the polymer level; the process requires concomitant sulphation of the polymer. The results obtained in the present structural study conform to these findings, and suggest further that similar mechanisms may operate in the biosynthesis of heparan sulphate. The epimerization reaction appears to be linked to the sulphation of hydroxyl groups but does not seem to require sulphation of the target uronic acid residues. The significance of sulphamino groups in relation to the formation of iduronic acid is unknown.

scholarly journals The disaccharides formed by deaminative cleavage of N-deacetylated glycosaminoglycans

1986 ◽  
Vol 235 (1) ◽  
pp. 225-236 ◽  
Author(s):  
P N Shaklee ◽  
H E Conrad
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Dermatan Sulphate ◽  
Reaction Sequence ◽  
Keratan Sulphate ◽  
Iduronic Acid ◽  
Intermediate Rate

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.

Binding of lead and copper(II) cations to hemicelluloses of rye bran

1986 ◽  
Vol 51 (10) ◽  
pp. 2250-2258 ◽  
Author(s):  
Rudolf Kohn ◽  
Zdena Hromádková ◽  
Anna Ebringerová
Keyword(s):  
Uronic Acid ◽  
Equilibrium Solution ◽  
Glucuronic Acid ◽  
The Other ◽  
Carboxyl Groups ◽  
Stoichiometric Ratio ◽  
Molar Ratios ◽  
Free Ions ◽  
Uronic Acid Content ◽  
The Relationship

Several fractions of acid hemicelluloses isolated from rye bran were characterized by molar ratios of saccharides (D-Xyl, L-Ara, D-Glc, D-Gal) and 4-O-methyl-D-glucuronic acid and protein content. Binding of Pb2+ and Cu2+ ions to these acid polysaccharides was considered according to function (M)b = f([M2+]f), expressing the relationship between the amount of metal (M)b bound to 1 g of the substance and the concentration of free ions [M2+]f in the equilibrium solution and according to the association degree β of these cations with carboxyl groups of uronic acid at a stoichiometric ratio of both components in the system under investigation. Acid hemicelluloses contained only a very small portion of uronic acid ((COOH) 0.05-0.18 mmol g-1); the model polysaccharide, 4-O-methyl-D-glucurono-D-xylan of beech, was substantially richer in uronic acid content ((COOH) 0.73 mmol g-1). Consequently, the amount of lead and copper bound to acid hemicelluloses is very small ((M)b 0.017-0.025 mmol g-1) at [M2+]f = 0.10 mmol l-1. On the other hand, much greater amount of cations ((M)f 0.09-0.10 mmol g-1) was bound to the glucuronoxylan. The association degree β was like with the majority of samples (β = 0.31-0.38). The amount of lead and copper(II) bound to acid hemicelluloses from rye bran is several times lower than that bound to dietary fiber isolated from vegetables (cabbage, carrot), rich in pectic substances.

scholarly journals Immunochemical analysis of cartilage proteoglycans. Radioimmunoassay of the molecules and the substructures

1980 ◽  
Vol 187 (3) ◽  
pp. 687-694 ◽  
Author(s):  
J Wieslander ◽  
D Heinegárd
Keyword(s):  
Hyaluronic Acid ◽  
Uronic Acid ◽  
Chondroitin Sulphate ◽  
Relative Content ◽  
Binding Region ◽  
Rich Region ◽  
Link Protein ◽  
Specific Radioimmunoassay ◽  
Cartilage Proteoglycans ◽  
Hyaluronic Acid Binding

Antibodies specifically reacting with the link proteins, the hyaluronic acid-binding region and chondroitin sulphate-peptides were used to design specific radioimmunoassay procedures. The sensitivity of the method used for the link protein was about 20 ng/ml, and the other two components could be determined at concentrations of about 2 ng/ml. The radioimmunoassay procedures were tested by using proteoglycan subfractions or fragments thereof. The procedures used to quantify link protein and hyaluronic acid-binding region showed no cross-interference. Fragments of trypsin-digested proteoglycan monomers still reacted in the radioimmunoassay for hyaluronic acid-binding region. Subfractions of proteoglycan monomers separated according to size had a gradually higher relative content of the hyaluronic acid-binding region compared with both chondroitin sulphate-peptides and uronic acid, when the molecules were smaller. The proteoglycans therefore may contain a variably large chondroitin sulphate-rich region, which has a constant substitution with polysaccharide side chains.

Histochemical Differentiation of the Basement Membrane of the Mouse Seminiferous Tubule

1962 ◽  
Vol s3-103 (63) ◽  
pp. 385-391
Author(s):  
A. H. BAILLIE
Keyword(s):  
Basement Membrane ◽  
Protein Metabolism ◽  
Seminiferous Tubule ◽  
Glucuronic Acid ◽  
Chondroitin Sulphate ◽  
Hair Follicles ◽  
Ground Substance ◽  
Seminiferous Tubules ◽  
Active Protein ◽  
Pas Reaction

The ground substance of the testis of the albino mouse is PAS-positive but not metachromatic, and probably highly aggregated. The basement of the seminiferous tubules is intensely PAS-positive, metachromatic, and possibly not so highly aggregated. The reactivity of the ground substance to the PAS reaction and toluidine blue is tentatively ascribed to the presence of chondroitin sulphate C: this compound, previously known to contain N acetyl-galactosamine, glucuronic acid, tyrosine and tryptophane, is associated with arginine. The genesis of the basement membrane of the seminiferous tubule is shown to include the formation of a sheath of atypical elongated fibroblasts, the secretion of a PAS positive, metachromatic substance associated with arginine between this sheath and the seminiferous tubule, the appearance of mitochondria in the cells of the sheath, and lastly, the acquisition of alkaline phosphatase by these fibroblasts and its spread to the intervening ground substance. These changes are thought to be related to the structural and nutritional requirements of the seminiferous tubules. In its intense positive reaction to PAS and in its metachromasy, the basement membrane of the seminiferous tubule agrees with the ground substance adjacent to sites of active protein metabolism, such as growing tumours, embryonic organs, hair follicles, and skin.

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