scholarly journals The degradation of cartilage proteoglycans by tissue proteinases. Proteoglycan structure and its susceptibility to proteolysis

1977 ◽  
Vol 167 (3) ◽  
pp. 629-637 ◽  
Author(s):  
P J Roughley ◽  
A J Barrett

1. Proteoglycan was obtained from bovine nasal cartilage by a procedure involving sequential extraction with a low-ionic-strength KCl solution, then a high-ionic-strength CaCl2 solution. Purification was by CsCl-density-gradient centrifugation. 2. The CaCl2- extracted proteoglycan was subjected to proteolytic degradation by papain, trypsin, cathepsin D, cathepsin B, lysosomal elastase or cathepsin G. Degradation was allowed to proceed until no further decrease in viscosity was detectable. 3. The size and chemical composition of the final degradation products varied with the different proteinases. Cathepsin D and cathepsin G produced glycosaminoglycan-peptides of largest average size, and papain produced the smallest product. 4. The KCl-extracted proteoglycan was intermediate in molecular size and composition between the CaCl2-extracted proteoglycan and the largest final degradation products, and may have been formed by limited proteolysis during the extraction procedure. 5. It is postulated that the glycosaminoglycan chains are arranged in groups along the proteoglycan core protein. Proteolytic cleavage between the groups may be common to the majority of proteinases, whereas clevage within the groups is dependent on the specificity of each individual proteinase.

1977 ◽  
Vol 167 (3) ◽  
pp. 639-646 ◽  
Author(s):  
P J Roughley

1. CaCl2-extracted proteoglycan from bovine nasal cartilage was degraded by four tissue proteinases till no further decrease in hydroynamic size was obtained. The proteoglycan and its final degradation products were then fractionated by Sepharose 2B chromatography. 2. The average size of the degradation products was least for cathepsin B and lysosomal elastase, and greatest for cathepsin D and cathepsin G. The latter two proteinases also produced degradation products that showed the widest range of sizes. 3. The structure of the degradation products ranged from peptides containing a single glycosaminoglycan chain to those containing twelve or more chains. Of the four proteinases, only cathepsin B produced peptides that contained a single chondroitin sulphate chain. 4. The proteoglycan was very heterogeneous with respect to size and chemical composition. Its behaviour on electrophoresis suggested that at least two genetically distinct core proteins might exist. 5. Irrespective of their structural variations, all proteoglycan molecules were able to interact with hyaluronic acid. In contrast, none of the degradation products were capable of this type of interaction. 6. A pathway for the proteolytic degradation of proteoglycans is postulated in which the sites of initial cleavage may be common to the majority of proteinases, whereas the production of the final clusters is dependent on the specificity of the proteinase. Only those proteinases of broadest specificity can produce single-chain chondroitin sulphate-peptides.


1984 ◽  
Vol 224 (1) ◽  
pp. 47-58 ◽  
Author(s):  
A Franzén ◽  
D Heinegård

Proteoglycans were extracted in good yields from the mineralized matrix of ground bovine bone, by using a two-step extraction procedure. Proteoglycans (8% of total), not associated with the bone mineral, were extracted at − 20 degrees C with 4M-guanidinium chloride containing proteinase inhibitors. Proteoglycans associated with the mineral, which accounted for 60% of the total, were then solubilized when EDTA was added to the extraction solvent. They were fractionated and purified in the presence of 4M-guanidinium chloride by CsCl-density-gradient centrifugations followed by chromatography on Sepharose CL-4B. Further purification was obtained by chromatography on DEAE-cellulose and hydroxyapatite in the presence of 7 M-urea. Three populations of proteoglycans and additional glycosaminoglycan peptides were obtained. The molecular dimensions of both intact molecules and of their side chains as well as their amino acid composition were different, indicating that they represent separate molecular entities. The main proteoglycan self-aggregated in the absence of 4M-guanidinium chloride or 7 M-urea, a property that was abolished when the proteoglycan core protein was fragmented.


1976 ◽  
Vol 157 (2) ◽  
pp. 357-367 ◽  
Author(s):  
P J Roughley ◽  
R M Mason

1. Proteoglycans were extracted from bovine nasal cartilage with 2.0M-CaC2 or with 0.15M-KCl followed by 2.0M-CaC2. Proteoglycan fractions were prepared from the extracts by density-gradient centrifugation in CsCl under ‘associative’ and ‘dissociative’ conditions. 2. The heterogeneity of the proteoglycan fractions was investigated by large-pore-gel electrophoresis. It was concluded that extracts made with 2.0M-CaCl2 or sequential 2.0M-CaCl2 contain two major species of proteoglycan ‘subunit’ of different hydrodynamic size, together with proteoglycan aggregates. Both ‘subunits’ have mobilities that are greater than those of proteoglycans obtained from pig articular cartilage McDevitt & Muir (1971) Anal. Biochem. 44, 612-622] and are therefore probably smaller in size than the latter. 3. Proteoglycan fractions isolated from cartilage extracted lith 0.15M-KCl separated into two main components on large-pore-gel electrophoresis with mobilities greater than those of proteoglycans extracted with 2.0M-CaCl2. Proteoglycans extracted at low ionic strength from bovine nasal cartilage are of similar hydrodynamic size to those extracted from pig articular cartilage under the same conditions [McDevitt & Muir (1971) Anal. Biochem. 44, 612-622]. 4. The role of endogenous proteolytic enzymes in producing proteoglycan heterogeneity, particularly in low-ionic-strength cartilage extracts is discussed. 5. Hyaluronic acid and ‘link proteins’ were present in the proteoglycan fraction separated from KCl extracts as well as in the fraction separated from CaCl2 extracts. Hyaluronic acid can only be identified in proteoglycan fractions by large-pore-gel electrophoresis after proteolysis and further purification of the fraction. 6. Collagen was extracted by both salt solutions and was tentatively identified as type II. Small amounts of collagen appear to be associated with the proteoglycan-aggregate fraction from the high-ionic-strength extract but not with the corresponding fraction from the KCl extract.


1988 ◽  
Vol 255 (3) ◽  
pp. 1007-1013 ◽  
Author(s):  
J P Périn ◽  
F Bonnet ◽  
P Maillet ◽  
P Jollès

Human platelet proteoglycan (P.PG) was prepared from a 4 M-guanidinium chloride platelet extract in the presence of proteinase inhibitors. The purification procedure included CsCl-density-gradient centrifugation, DEAE-Sepharose CL-6B ion-exchange chromatography and f.p.l.c. on a Mono Q HR 5/5 column. P.PG was recovered as a polydisperse molecule, but the protein core appeared to be at least 90% homogeneous. This observation could be due to partial proteolysis of the core protein during extraction. The N-terminal sequence of the human P.PG core protein was determined up to residue 66 and was shown to be highly homologous to the propeptide of an embryonic rat yolk-sac tumour proteoglycan (PG19); the significance of this homology is discussed.


1982 ◽  
Vol 207 (3) ◽  
pp. 445-457 ◽  
Author(s):  
R M Mason ◽  
C d'Arville ◽  
J H Kimura ◽  
V C Hascall

1. Primary cultures of chondrocytes from the Swarm rat chondrosarcoma were labelled with either [3H]glucosamine or [14C]glucosamine, and hyaluronate synthesized by the cells was isolated from the cell layer. Parallel cultures were labelled with either [3H]serine or [3H]lysine, and identical fractions were isolated from the cell layer. Some cultures were dual-labelled. 2. In cultures labelled with [3H]serine for between 30 min and 24 h and extracted with 4.0 M-guanidine, a procedure that solubilizes predominantly extracellular macromolecules, small amounts of [3H]serine-labelled molecules were found associated with the hyaluronate fraction purified from the extract by dissociative CsCl-density-gradient centrifugation and dissociative Sepharose CL-2B chromatography. About 75% of the [3H]serine-labelled molecules in the fraction were specifically associated with hyaluronate, since they could be removed by prior treatment with proteinase-free Streptomyces hyaluronidase. The association of the [3H]serine-labelled molecules with hyaluronate was non-covalent, since they could be separated from it by further centrifugation in CsCl density gradients containing 4 M-guanidinium chloride and a zwitterionic detergent. 3. In other experiments the cultures were extracted with a sequential zwitterionic-detergent/guanidinium chloride procedure that completely solubilized the cell layer and enabled fractions containing newly synthesized cell-associated hyaluronate to be isolated. Zwitterionic detergent was present throughout. No [3H]lysine was incorporated into these fractions, irrespective of whether the cultures were pulsed concurrently with [3H]lysine and [14C]glucosamine or sequentially with [3H]lysine to prelabel the protein pool (24 h) followed by [14C]-glucosamine to label hyaluronate (1 h). 4. The results show that newly synthesized hyaluronate is not associated with covalently bound protein, and suggest that chain synthesis is initiated by a mechanism other than on to a core protein. Small amounts of [3H]serine-labelled molecules are, however, non-covalently associated with extracellular hyaluronate. Their identity is at present unknown, but they are probably of low molecular weight.


1983 ◽  
Vol 213 (2) ◽  
pp. 289-296 ◽  
Author(s):  
T Nakamura ◽  
E Matsunaga ◽  
H Shinkai

A proteodermatan sulphate was isolated from 0.15 M-NaCl and 0.45 M-NaCl extracts of newborn-calf skin. The proteoglycan was separated from collagen and hyaluronic acid by precipitation with cetylpyridinium chloride and CsCl-density-gradient centrifugation. Further purification was performed by ion-exchange, affinity and molecular-sieve chromatography. The proteoglycan bound to concanavalin A-Sepharose in 1 M-NaCl. It gave a positive reaction with periodic acid/Schiff reagent and contained 8.3% of uronic acid. The dermatan sulphate, the only glycosaminoglycan component, was composed of 74% iduronosylhexosamine units and 26% glucuronosylhexosamine units. The Mr was assessed to be 15000-20000 by gel chromatography. The core protein was found to be a sialoglycoprotein that had O-glycosidic oligosaccharides with N-acetylgalactosamine at the reducing termini. The molar ratio of oligosaccharide chains to dermatan sulphate was approx. 3:1. From these results the proposed structure of proteodermatan sulphate is: one dermatan sulphate chain (average Mr 17500), three O-glycosidic oligosaccharide chains and probably N-glycosidic oligosaccharide chain(s) bound to one core-protein molecule (Mr 55000).


1986 ◽  
Vol 235 (1) ◽  
pp. 117-123 ◽  
Author(s):  
C P Tsiganos ◽  
D H Vynios ◽  
D L Kalpaxis

Hyaluronate from rooster comb was isolated by ion-exchange chromatography on DEAE-cellulose from tissue extracts and papain digests. The preparations were labelled with [14C]acetic anhydride and subjected to CsCl-density-gradient centrifugation in 4 M-guanidinium chloride in the presence and absence of 4% ZwittergentTM 3-12. A radioactive protein fraction was separated from the hyaluronate when the zwitterionic detergent was also present. The protein could also be separated from the glycosaminoglycan by chromatography on Sepharose CL-6B eluted with the same solvent mixture. The protein fraction contained three protein bands of Mr 15,000-17,000 as assessed by polyacrylamide-gel electrophoresis in 0.1% SDS, and seemed to lack lysozyme activity. No evidence of other protein or amino acid(s) covalently linked with the hyaluronate was obtained. The hyaluronate-protein complex may be re-formed upon mixing the components, the extent of its formation depending on the conditions used. The results show that, as in chondrosarcoma [Mason, d'Arville, Kimura & Hascall (1982) Biochem. J. 207, 445-457] and teratocarcinoma cells [Prehm (1983) Biochem. J. 211, 191-198] the rooster comb hyaluronate also is not linked covalently to a core protein.


1972 ◽  
Vol 127 (4) ◽  
pp. 705-713 ◽  
Author(s):  
Janet N. Ryan ◽  
J. Frederick Woessner

1. The earlier observation (Woessner, 1969) of oestradiol inhibition of collagen breakdown is confirmed and extended. Administration of 100μg of oestradiol-17β/day to parturient rats strongly inhibits the loss of collagen from the involuting uterus. Three experiments show that this effect is due to an inhibition of collagen degradation rather than to a stimulation of collagen synthesis. 2. Uterine collagen was labelled with hydroxy[14C]-proline by the administration of [14C]proline near the end of pregnancy. By 3 days post partum, control uteri lost 83% of their collagen and 90% of their hydroxy[14C]proline. Uteri from oestradiol-treated rats lost only 50% of both total and labelled hydroxyproline, with no decrease in the specific radioactivity of the hydroxyproline. 3. Incorporation of [14C]proline into uterine collagen hydroxyproline in vivo was not affected by oestradiol treatment. 4. Urinary excretion of hydroxyproline was increased in post-partum control rats and decreased in oestradiol-treated rats. 5. An enzyme capable of cleaving 4-phenylazobenzyloxycarbonyl-l-prolyl-l-leucylglycyl- l-prolyl-d-arginine (a substrate for clostridial collagenase) increased in activity in the post-partum uterus and was unaffected by oestradiol treatment. 6. Uterine homogenates digested uterine collagen extensively at pH3.2. This digestion was unaffected by the oestradiol treatment. 7. Lysosomal fractions prepared by density-gradient centrifugation of uterine homogenates contained coincident peaks of cathepsin D activity and peptide-bound hydroxyproline. The cathepsin D and hydroxyproline contents of this peak were unaffected by oestradiol treatment.


1985 ◽  
Vol 232 (1) ◽  
pp. 111-117 ◽  
Author(s):  
M T Bayliss ◽  
P J Roughley

Proteoglycan was extracted from adult human articular cartilage from both the knee and the hip, and A1 preparations were prepared by CsCl-density-gradient centrifugation at starting densities of 1.69 and 1.5 g/ml. Irrespective of whether the cartilage was diced to 1 mm cubes or sectioned to 20 micron slices there was always a lower proportion of both protein and proteoglycan aggregate in the A1 preparation prepared at 1.69 g/ml. Furthermore, the addition of exogenous hyaluronic acid to the extracts before centrifugation did not improve the yield of aggregate at 1.69 g/ml. These results were not affected by the presence of proteinase inhibitors in the extraction medium. It appears that adult human articular cartilage contains a high proportion of low-density proteoglycan subunits and hyaluronic acid-binding proteins that make most of the re-formed proteoglycan aggregates of a lower density than is usually encountered with younger human and mammalian hyaline cartilages.


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