scholarly journals Model connective-tissue systems. A study of polyion–mobile ion and of excluded-volume interactions of proteoglycans

1974 ◽  
Vol 143 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Wayne D. Comper ◽  
Barry N. Preston
Keyword(s):  
Chondroitin Sulphate ◽  
Intervertebral Discs ◽  
Gelatin Matrix ◽  
Keratan Sulphate ◽  
Sulphate Content ◽  
Gelatin Gels ◽  
Tissue Systems ◽  
The Individual ◽  
Mobile Ions

The osmotic pressure of solutions of sulphated proteoglycans isolated from the intervertebral discs of animals of various ages was determined. The behaviour of the solutions in salt-added systems was investigated in terms of the Donnan distribution of the mobile ions. It is evident that this effect is the dominating factor in explaining the observed nonidealities. Although marked variations in the compositions of the proteoglycan, with regard to their chondroitin sulphate and keratan sulphate content and hence charge content, occur with increasing age of parent tissue, the osmotic activities of the various preparations are very similar. This is explained by the ‘fixation’ of the counterions in such a way as to counteract any change in the charge content of the polyion; an ‘osmotic buffering’ effect. The swelling behaviour of gelatin gels containing the proteoglycan preparations has been measured. In all cases pressures in excess of the sum of the osmotic pressures of the individual components are observed. However, the magnitude of the excess decreases with increasing age of the parent tissue. It is suggested that the age changes, as reflected by a decrease in water content of the gel system, are not the result of changes in the osmotic properties of the individual components but rather reflect changes in the entropic interaction of the proteoglycan with the gelatin matrix. The relevance of this observation to the situation in vivo is discussed.

scholarly journals Biosynthesis and metabolism in vivo of intervertebral-disc proteoglycans in the mouse

1983 ◽  
Vol 215 (2) ◽  
pp. 217-225 ◽  
Author(s):  
G Venn ◽  
R M Mason
Keyword(s):  
Chondroitin Sulphate ◽  
Costal Cartilage ◽  
Intervertebral Discs ◽  
Hydrodynamic Size ◽  
Keratan Sulphate ◽  
Major Species ◽  
Average Size ◽  
A Minor ◽  
Turn Over

The synthesis and turnover in vivo of 35S-labelled proteoglycans in mouse cervical, thoracic and lumbar intervertebral discs, and in costal cartilage, was investigated after intraperitoneal injection of [35S]sulphate. Intervertebral discs and costal cartilage synthesize similar amounts of 35S-labelled proteoglycans per microgram of DNA. Discs and cartilage all synthesize a major proteoglycan species (approx. 85%) of large hydrodynamic size and a minor species (approx. 15%) of small size. Both proteoglycans carry chondroitin sulphate chains. Keratan sulphate was not found associated with either species. The total 35S-labelled proteoglycan pool had a metabolic half-life (t1/2) of 10-12 days in discs, and 17 days in cartilage. The extractable major and minor species turned over at similar rates. Those proteoglycans left in the tissue after 29 days turn over very slowly. Approx. 50% of the major 35S-labelled proteoglycan species formed mixed aggregates with hyaluronic acid and rat chondrosarcoma proteoglycan. The ability to form aggregates did not decrease up to 45 days after synthesis. Of the heterogeneous population of proteoglycans comprising the major species, those remaining in the tissue 9 days after synthesis were of smaller average hydrodynamic size and had shorter chondroitin sulphate side chains than the average size at the time of synthesis. With increasing time after synthesis, proteoglycans were less readily extracted from the tissue by 4.0 M-guanidinium chloride than at the time of synthesis.

scholarly journals The chemical constitution of the proteoglycan of human intervertebral disc

1976 ◽  
Vol 157 (3) ◽  
pp. 753-763 ◽  
Author(s):  
R H Pearce ◽  
B J Grimmer
Keyword(s):  
Chondroitin Sulphate ◽  
Deae Cellulose ◽  
Intervertebral Discs ◽  
Guanidinium Chloride ◽  
Keratan Sulphate ◽  
Qualitative And Quantitative ◽  
Cscl Density Gradient ◽  
Chemical Constitution ◽  
Normal Human ◽  
Quantitative Analyses

Proteoglycan was prepared from three pools of normal human intervertebral discs by extraction with buffered 4M-guanidinium chloride followed by CsCl-density-gradient ultracentrifugation. Chromatography on agarose (Bio-Gel A-150m) and on DEAE-cellulose suggested a single polydisperse proteoglycan species. The intrinsic viscosities of three preparations were 166, 122 and 168 ml/g. After degradation with 0.5M-KOH containing 0.02M-NaBH4, the glycosaminoglycans were recovered quantitatively and their Ca2+ salts separated into a hexuronate-rich fraction (fraction 1), which was precipitated in 0-45% (v/v) ethanol, and a hexose-rich fraction (fraction2), which was precipitated in 45-70% (v/v) ethanol. Qualitative and quantitative analyses of the glycosaminoglycans revealed fraction 1 to be chondroitin sulphate, and fraction 2 to be keratan sulphate; the latter was contaminated with protein and possibly a small amount of another glycosaminoglycan. For both glycosaminoglycans, plots of log(mol.wt.) against weight fell close to a normal distribution. The mode for chondroitin sulphate was close to 20000; that for keratan sulphate, 10000. A threefold range of molecular weight included the central 16-84% [+/- 1 S.D. of log(mol.wt.)] of the weight of both fractions.

scholarly journals Characterization of proteoglycans isolated from associative extracts of human articular cartilage

1993 ◽  
Vol 293 (1) ◽  
pp. 165-172 ◽  
Author(s):  
V Vilím ◽  
A J Fosang
Keyword(s):  
Articular Cartilage ◽  
Molecular Mass ◽  
Core Protein ◽  
Chondroitin Sulphate ◽  
Gel Chromatography ◽  
Human Articular Cartilage ◽  
Keratan Sulphate ◽  
Core Proteins ◽  
Sds Page

Approx. 10% of the total proteoglycan content of normal young human articular cartilage was extracted under associative conditions with Dulbecco's PBS. Proteoglycans isolated from the extract by Q-Sepharose chromatography were separated by gel chromatography and characterized by gradient gel SDS/PAGE and immunoblotting. Three species of small proteoglycans, two main populations of aggrecan and a population of its smaller fragments were identified. The major populations of aggrecan contained chondroitin sulphate chains, all or part of the N-terminal G1 and G2 domains and, therefore, intact keratan sulphate domains. The larger population was estimated by gradient SDS/PAGE to have a molecular mass of approx. 600 kDa or greater. The second population had an apparent molecular mass of approx. 300-600 kDa. Core proteins derived from these populations of proteoglycans separated on SDS/PAGE into several clusters of bands in the range from 120 to approx. 360 kDa. The extract further contained smaller fragments which lacked chondroitin sulphate but reacted with antibodies against keratan sulphate, and against epitopes present in the G2 domain of aggrecan. The presence of the G2 domain in a broad range of populations of decreasing size indicated extensive cleavage of the aggrecan core protein within its chondroitin sulphate domain. These findings suggest that fragmentation of aggrecan probably occurs in vivo in normal articular cartilage of young individuals. Associative extracts also contained decorin, biglycan and fibromodulin. These were resolved from aggrecan by gel chromatography and identified by immunodetection.

scholarly journals The glycosaminoglycans of human tracheobronchial cartilage

1970 ◽  
Vol 120 (4) ◽  
pp. 777-785 ◽  
Author(s):  
R. M. Mason ◽  
F. S. Wusteman
Keyword(s):  
Molecular Weight ◽  
Potassium Hydroxide ◽  
Chondroitin Sulphate ◽  
Cetylpyridinium Chloride ◽  
Exchange Chromatography ◽  
Chemical Heterogeneity ◽  
Keratan Sulphate ◽  
Sulphate Content ◽  
Age Dependent ◽  
Dowex 1

1. The glycosaminoglycans of human tracheobronchial cartilages from subjects of various ages were liberated by proteolysis of the tissue and purified by ion-exchange chromatography. Purified glycosaminoglycans were fractionated on Dowex 1 resin and cetylpyridinium chloride was used to separate chondroitin sulphates and keratan sulphates occurring in the same fraction. 2. The total chondroitin sulphate content of the cartilages decreased linearly with increasing age. Age-dependent changes in the chemical heterogeneity of chondroitin sulphate were observed, a low-sulphated compound making up 25% of the total glycosaminoglycan at birth but rapidly diminishing in content during the first 6 months of life. Of the total chondroitin sulphate the 6-isomer became rather more prominent than the 4-isomer with increasing age. 3. The total keratan sulphate content of the cartilages increased from trace amounts only at birth to a plateau value by the beginning of the fifth decade. Of the total keratan sulphate approx. 70% was due to a high-molecular-weight compound with a sulphate/hexosamine ratio of 1.5–1.8: 1.0. The degree of sulphation varied between compounds isolated from different individuals. The remaining 30% of the keratan sulphate appeared to be intimately associated with chondroitin 6-sulphate and could only be separated from it after treatment with 0.45m-potassium hydroxide. The hybrid glycosaminoglycans were of lower molecular weight and had a lower sulphate/hexosamine ratio than the major keratan sulphate compound.

scholarly journals Absence of keratan sulphate from skeletal tissues of mouse and rat

1985 ◽  
Vol 228 (2) ◽  
pp. 443-450 ◽  
Author(s):  
G Venn ◽  
R M Mason
Keyword(s):  
Monoclonal Antibody ◽  
Degradation Products ◽  
Chondroitin Sulphate ◽  
Lumbar Disc ◽  
Heparan Sulphate ◽  
Costal Cartilage ◽  
Animal Experiments ◽  
Keratan Sulphate

The absence of keratan sulphate synthesis from skeletal tissues of young and mature mice and rats has been confirmed by (1) analysis of specific enzyme degradation products of newly synthesized glycosaminoglycans, and (2) immunohistochemistry and radioimmunoassay using a monoclonal antibody directed against keratan sulphate. Approx. 98% of the [35S]glycosaminoglycans synthesized in vivo by mouse and rat costal cartilage, and all of those of lumbar disc, are chondroitin sulphate. The remainder in costal cartilage were identified as heparan sulphate in mature rats. In contrast, [35S]glycosaminoglycans synthesized by cornea of both species comprised both chondroitin sulphate and keratan sulphate. In mice keratan sulphate accounted for 12-25% and in rats 40-50% of the total [35S]glycosaminoglycans, depending on the age of the animal. Experiments in vitro with organ culture of cartilage and cornea confirm these results. Absence of keratan sulphate from mouse costal cartilage and lumbar disc D1-proteoglycans was corroborated by inhibition radioimmunoassay with the monoclonal antibody MZ15 and by lack of staining for keratan sulphate in indirect immunofluorescence studies using the same antibody.

scholarly journals Proteoglycans isolated from dissociative extracts of differently aged human articular cartilage: characterization of naturally occurring hyaluronan-binding fragments of aggrecan

1994 ◽  
Vol 304 (3) ◽  
pp. 887-894 ◽  
Author(s):  
V Vilim ◽  
A J Fosang
Keyword(s):  
Articular Cartilage ◽  
Density Gradient ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Proteolytic Processing ◽  
Human Articular Cartilage ◽  
Globular Domain ◽  
Keratan Sulphate ◽  
Core Proteins

Proteoglycans extracted with 4 M guanidinium chloride from young (mean 20 years) or old (mean 79 years) macroscopically normal human articular cartilage were separated by density gradient centrifugation and Q-Sepharose chromatography and characterized by gradient gel SDS/PAGE and immunodetection before and after removal of glycosaminoglycan chains. The extracts contained two large populations of aggrecan, a population of small N-terminal aggrecan fragments, as well as decorin, biglycan and fibromodulin. The distribution of all these species in density gradient fractions has been determined. The large aggrecan populations comprised four different chondroitin sulphate-bearing core proteins while the population of smaller fragments comprised eight different components. The two smallest fragments (35 and 42 kDa), identified as the first globular domain of aggrecan (N-terminal) (G1) and containing no glycosaminoglycan, were detected only in extracts of old cartilage. A 55 and a 70 kDa fragment of G1 were present in both keratan sulphate-containing and non-keratan sulphate-containing forms. Four other fragments, each containing keratan sulphate epitopes, were identified and these contained either G1 epitopes (one 95 kDa species), or G1 and G2 epitopes (three species). These results have suggested that proteolytic processing at the N-terminus is more extensive than has previously been recognized and raises the possibility that more than one proteinase may be involved in aggrecan degradation in vivo. With the exception of the two smallest G1 fragments, the repertoire of proteoglycan fragments found in young and old human articular cartilage is essentially the same, although the relative abudnance of various species differed. The older tissue contains a larger proportion of C-terminally truncated aggrecan fragments and a significantly decreased content of decorin and biglycan.

scholarly journals Studies on protein–polysaccharides from pig laryngeal cartilage. Heterogeneity, fractionation and characterization

1969 ◽  
Vol 113 (5) ◽  
pp. 885-894 ◽  
Author(s):  
C. P. Tsiganos ◽  
Helen Muir
Keyword(s):  
Amino Acid ◽  
Chain Length ◽  
Chondroitin Sulphate ◽  
Guanidine Hydrochloride ◽  
Gel Filtration ◽  
Preceding Paper ◽  
Average Chain Length ◽  
Keratan Sulphate ◽  
Sulphate Content ◽  
Laryngeal Cartilage

1. Protein–polysaccharides from pig laryngeal cartilage extracted by two procedures described in the preceding paper (Tsiganos & Muir, 1969) were shown to consist of macromolecules of various sizes as assessed by gel filtration in 4% and 6% agarose. 2. A larger proportion of the smaller molecules was present in the preparation obtained by brief extraction in iso-osmotic sodium acetate (procedure I) than in that obtained by more prolonged extraction in 10% (w/v) calcium chloride (procedure II). 3. Two fractions were separated by gel filtration in 6% agarose and by electrophoresis in compressed glass fibre. These fractions differed in chemical composition and in antigenic determinants. The gel-retarded fraction R and that of higher electrophoretic mobility possessed the same single antigen, whereas the gel-excluded fraction E and the slower electrophoretic fraction contained all the antigens of the starting material including that of fraction R. 4. Five N-terminal amino acid residues were identified in preparation I and fraction E, only two of which were present in fraction R. 5. The relative proportions of gel-excluded and gel-retarded fractions did not change when solutions of high ionic strength, urea or guanidine hydrochloride were used for elution. 6. The differences in chemical and amino acid composition between fractions R and E showed that the latter was not a simple aggregate of the former. Fraction E contained more basic and aromatic amino acids, and some methionine and cystine; the last two were absent from fraction R. Hydroxyproline was not detected in either fraction. 7. The number of glycosidic linkages in both fractions was estimated by alkaline β-elimination. Appreciable amounts of threonine as well as serine were destroyed in both fractions. An average chain length for chondroitin sulphate was calculated from the galactosamine content of both fractions and the amounts of hydroxy amino acid destroyed. Average chain lengths were also calculated from the xylose and galactosamine content of each fraction. Each independent method gave a value of approximately 28 disaccharide units for the chain length in both fractions and hence their difference in size could not be explained by differences in the length of carbohydrate chains. 8. All fractions contained glucosamine, which was attributed to keratan sulphate. Content of both protein and keratan sulphate increased with the size of the macromolecules. 9. It is suggested, from these results, that chondroitin sulphate–protein complexes normally exist as a heterogeneous population of macromolecules in cartilage, and that keratan sulphate is involved in the formation of larger molecules.

scholarly journals Fractionation of proteoglycans from bovine corneal stroma

1975 ◽  
Vol 145 (3) ◽  
pp. 491-500 ◽  
Author(s):  
I Axelsson ◽  
D Heinegård
Keyword(s):  
Chondroitin Sulphate ◽  
Corneal Stroma ◽  
Molecular Size ◽  
Equal Weight ◽  
Keratan Sulphate ◽  
Before And After ◽  
Weight One ◽  
Tenfold Excess ◽  
Covalently Linked ◽  
The Individual

Proteoglycans were extracted from bovine corneal stroma with 4M-guanidinum chloride, purified by DEAE-dellulose chromatography (Antonopoulos et al., 1974) and fractionated by precipitation with ethanol into three fractions of approximately equal weight. One of these fractions consisted of a proteoglycan that contained keratan sulphate as the only glycosaminoglycan. In the othertwo fractions proteoglycans that contained chondroitin sulphate, dermatan sulphate and keratan sulphate were present. Proteoglycans which had a more than tenfold excess of galactosaminoglycans over keratan sulphate could be obtianed by further subfractionation. The gel-chromatographic patterns of the glucosaminoglycans before and after digestion with chondroitinase AC differed for the fractions. The individual chondroitin sulphate chains seemed to be larger in cornea than in cartilage. Oligosaccharides, possibly covalently linked to the protein core of the proteoglycans, could be isolated from all fractions. The corneal proteoglycans were shown to have higher protein contents and to be of smaller molecular size than cartilage proteoglycans.

scholarly journals ETIOLOGY AND PATHOGENESIS OF IDIOPATHIC SCOLIOSIS

2006 ◽  
pp. 084-093
Author(s):  
Alla Mikhailovna Zaidman ◽  
Anastasia Viktorovna Korel ◽  
Valentina Ivanovna Rykova ◽  
Elvira Vitalyevna Grigoryeva ◽  
Tatyana Yuryevna Eschenko ◽  
...  
Keyword(s):  
Gene Expression ◽  
Idiopathic Scoliosis ◽  
Chondroitin Sulphate ◽  
Molecular Genetic ◽  
Sharp Decrease ◽  
Intervertebral Discs ◽  
Cartilage Tissue ◽  
Quantitative Composition ◽  
Spine Deformity ◽  
Keratan Sulphate

Objective. To study etiologic factors and pathogenetic mechanisms of scoliosis development. Material and Methods. We investigated vertebral body growth plates (GP) from convex and concave sides of the curve, intervertebral discs (IVD), and vertebral bone tissue – surgical material obtained from 100 patients at the age from 10 to 14 years with III–IV grade idiopathic scoliosis (IS). Structural components of the spine of 12–14 years old children obtained from the forensic medicine department were used as controls. The methods of morphohistochemistry, biochemistry, and ultrastructural analysis were used to study glycosaminoglycans (GAGs), oxidation-reduction enzymes, alkali and acid phosphatases, RNA, DNA, qualitative and quantitative composition of GAGs. The expression of proteoglycan genes of cartilage tissue and their protein products was investigated with molecular genetic assays. Results. Pathogenetic mechanism of spine deformity formation in idiopathic scoliosis was formulated. It was shown that idiopathic scoliosis development is predetermined by a disorder in regulation and synthesis of proteoglycans in vertebral GP. The decrease of chondroitin sulphate and increase of keratan sulphate components in proteoglycans indicate the change of proteoglycan spectrum in IS. The revealed keratan sulphate fraction is a result of increased expression of lumikan gene in condition of sharp decrease of aggrecan gene expression and its protein product quantity in chondroblasts of patients with III–IV grade IS. Conclusion. Alteration in aggrecan gene expression at the level of transcription and translation testifies for its involvement in scoliosis development.

scholarly journals Mature bovine articular cartilage contains abundant aggrecan that is C-terminally truncated at Ala719-Ala720, a site which is readily cleaved by m-calpain

2004 ◽  
Vol 382 (1) ◽  
pp. 253-259 ◽  
Author(s):  
Hidefumi OSHITA ◽  
John D. SANDY ◽  
Kiichi SUZUKI ◽  
Atsushi AKAIKE ◽  
Yun BAI ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Articular Cartilage ◽  
Chondroitin Sulphate ◽  
Globular Domain ◽  
Cleavage Sites ◽  
Keratan Sulphate ◽  
Bovine Articular Cartilage ◽  
The Matrix ◽  
A Site

Extracts of normal mature articular cartilage contain aggrecan molecules which bear the G1 domain (the N-terminal globular domain of aggrecan) and are C-terminally truncated by proteolysis at a number of sites. A proportion of these molecules are generated by an aggrecanase and/or matrix-metalloproteinase-mediated cleavage in the IGD (interglobular domain between the G1 and G2 domains of aggrecan). However, the proteinase(s) responsible for formation of the majority of the larger G1-G2 and glycosaminoglycan-bearing truncated species is (are) unknown. N-terminal sequencing of aggrecan core fragments generated by m-calpain digestion of bovine aggrecan has identified four novel cleavage sites: one within the CS (chondroitin sulphate)-1 domain (at one or more of the bonds Ser1229–Val1230, Ser1249–Val1250, Ser1287–Val1288, Gly1307–Val1308 and Ser1346–Val1347), two within the IGD (at bonds Ala474–Ala475 and Gly365–Gly366) and one within the KS (keratan sulphate) domain (at Ala719–Ala720). A new monoclonal antibody (SK-28) to the C-terminal neoepitope at M710VTQVGPGVA719 showed that aggrecan products generated by this cleavage are present in high abundance in mature bovine articular cartilage extracts. We conclude that m-calpain, or an unidentified proteinase with the capacity to cleave at the same site, is active during aggrecan biosynthesis/secretion by mature chondrocytes or in the matrix of mature bovine articular cartilage in vivo.

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