scholarly journals Characterization and N-terminal sequence of human platelet proteoglycan

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.

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.


1978 ◽  
Vol 173 (3) ◽  
pp. 935-939 ◽  
Author(s):  
P Speziale ◽  
M S Speziale ◽  
L Galligani ◽  
C Balduini

Proteoglycans were extracted from bovine cornea with 4M-guanidinium chloride and purified by CsCl-density-gradient centrifugation. Under associative conditions two fractions were found: one capable of forming assemblies of high molecular weight and another lacking this property. The heavier fraction (density 1.59 g/ml) was eluted as a single retarded peak from Sepharose 2B, but on DEAE-Sephadex chromatography, gave two peaks: the first (eluted with 0.75 M-NaCl) contained mainly proteochondroitin sulphate and the second (eluted with 1.25 M-NaCl) mainly proteokeratan sulphate. Each of these proteoglycans was more retarded on Sepharose 2B than was the original sample from density-gradient centrifugation. Re-aggregation was obtained by recombination of the two fractions. The lighter fraction (density 1.44 g/ml), containing predominantly keratan sulphate chains, was eluted from DEAE-Sephadex as a single peak with 1.25 M-NaCl and was retarded on Sepharose 2B: this fraction was not able to form aggregates with proteochondroitin sulphate. Chemical analyses of the carbohydrate and protein moieties of the proteoglycans from DEAE-Sephadex confirmed that, in the cornea, different subunits are present with characteristic aggregation properties and hydrodynamic volumes.


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.


1987 ◽  
Vol 242 (3) ◽  
pp. 779-787 ◽  
Author(s):  
P A Steck ◽  
S M North ◽  
G L Nicolson

The expression of a high-Mr sialogalactoprotein (gp580) on rat 13762NF mammary adenocarcinoma cells was identified and correlated with spontaneous metastatic potential to colonize lung [Steck & Nicolson (1983) Exp. Cell Res. 147, 255-267]. Using a highly metastatic tumour-cell clone, MTLn3, we isolated and characterized gp580 from cells growing in vitro and in vivo in the mammary fat-pads of Fischer 344 rats. The glycoprotein was extracted with 4 M-guanidinium chloride/4% Zwittergent 3-12 solution in the presence of proteinase inhibitors. The extracts were then subjected to dissociative CsCl-density-gradient centrifugation, gel filtration on Sepharose CL-2B columns and ion-exchange chromatography on DEAE-Sephacel. The isolated glycoprotein possessed low electrophoretic mobility in SDS/polyacrylamide gels, and after desialylation bound 125I-labelled peanut agglutinin. Electrophoresis of gp580 in polyacrylamide-gradient gels resulted in a diffuse but homogeneous migrating band of Mr approx. 55,000. After removal of carbohydrate, gp580 was demonstrated to have a protein core of Mr approx. 150,000. The gp580 had a high density (1.430 g/ml) on isopycnic centrifugation in 4 M-guanidinium chloride and was resistant to most proteinases and other degradative enzymes, suggesting a mucin-like structure. Amino acid and carbohydrate analyses revealed that gp580 has high contents of serine, threonine, glutamic acid, aspartic acid, glucosamine and galactosamine; several acidic and neutral oligosaccharides were obtained from alkaline-borohydride digests. Cellular localization studies suggested that gp580 is associated mainly with the cell-surface and extracellular-matrix fractions of MTLn3 cells.


1991 ◽  
Vol 273 (2) ◽  
pp. 415-422 ◽  
Author(s):  
M Lyon ◽  
J T Gallagher

Heparan sulphate proteoglycans were solubilized from whole rat livers by homogenization and dissociative extraction with 4 M-guanidinium chloride containing Triton X-100 and proteinase inhibitors. The extract was subjected to trichloroacetic acid precipitation and the proteoglycan remained soluble. This was then purified to apparent homogeneity by a combination of (a) DEAE-Sephacel chromatography, (b) digestion with chondroitinase ABC followed by f.p.l.c. Mono Q ion-exchange chromatography, and (c) density-gradient centrifugation in CsCl and 4 M-guanidinium chloride. Approx. 1.5 mg of proteoglycan was obtained from 30 livers with an estimated recovery of 25%. The purified proteoglycan was eluted from Sepharose CL6B as an apparently single polydisperse population with a Kav. of 0.19 and displayed a molecular mass of greater than or equal to 200 kDa (relative to protein standards) by SDS/PAGE. Its heparan sulphate chains were eluted with a Kav. of 0.44 and have an estimated molecular mass of 25 kDa. Digestion of the proteoglycan with a combination of heparinases yielded core proteins of 77, 49 and 44 kDa. Deglycosylation using trifluoromethanesulphonic acid, though slightly decreasing the sizes, gave an identical pattern of core proteins. Electrophoretic detergent blotting demonstrated that all of the core proteins were hydrophobic and are probably integral plasma membrane molecules. The peptide maps generated by V8 proteinase digestion of the two major core proteins (77 and 49 kDa) were very similar, suggesting that these two core proteins are structurally related.


1991 ◽  
Vol 276 (3) ◽  
pp. 667-675 ◽  
Author(s):  
D J Thornton ◽  
J K Sheehan ◽  
H Lindgren ◽  
I Carlstedt

Mucus glycoproteins (mucins) were isolated from sputum of patients with cystic fibrosis (CF) after separation into sol and gel phases. The mucus gel was solubilized with gentle stirring in 6 M-guanidinium chloride supplemented with proteinase inhibitors, and purification of mucins was subsequently achieved by isopycnic density-gradient centrifugation in CsCl/guanidinium chloride. Density-gradient centrifugation also revealed a heterogeneity of the macromolecules, the pattern of which varied between individuals, and mucins from the gel phase was pooled as ‘heavy’ and ‘light’ fractions. Gel chromatography on Sepharose CL-2B showed that the heavy fraction contained a larger proportion of smaller species than the ‘light’ fraction and that the gel phase mucins were much larger than those from the sol. An apparently homogeneous high-Mr mucin population from one individual contained approx. 70% (w/w) carbohydrate, the major sugars being N-acetylglucosamine (17.8%), N-acetylgalactosamine (6.7%), galactose (20.7%), fucose (13.2%) and sialic acid (11.4%). These mucins had an S020.w of 47 S, and an Mr of 15 x 10(6) -20 x 10(6), and rate-zonal centrifugation revealed a polydisperse size distribution [range (5-30) x 10(6)] with a weight-average Mr of 17 x 10(6). The whole mucins were visualized with electron microscopy as linear and apparently flexible threads, disperse in size. Reduction produced subunits which were included on Sepharose CL-2B, and subsequent trypsin digestion yielded high-Mr glycopeptides which were further retarded. The size distributions and fragmentation patterns of mucin from two other CF patients were the same, as studied by gel chromatography, rate-zonal centrifugation and electron microscopy. We conclude that CF mucins are heterogeneous in both size and buoyant density and that the various populations, though differing in buoyant density, share the same architecture and macromolecular properties and are, in this respect, similar to mucins from normal respiratory secretions [Thornton, Davies, Kraayenbrink, Richardson, Sheehan & Carlstedt (1990) Biochem. J. 265, 179-186] and human cervical mucus [Carlstedt & Sheehan (1989) SEB Symp. XLIII 289-316].


1983 ◽  
Vol 211 (1) ◽  
pp. 13-22 ◽  
Author(s):  
I Carlstedt ◽  
H Lindgren ◽  
J K Sheehan ◽  
U Ulmsten ◽  
L Wingerup

Mucus glycoproteins (mucins) were extracted from human cervical pregnancy mucus by 6 M-guanidinium chloride in the presence of proteinase inhibitors. Purification was subsequently achieved by isopycnic density-gradient centrifugation in CsCl/ guanidinium chloride gradients. The purified macromolecules represented approx. 85% of the total and were devoid of nucleic acids and proteins, as judged by analytical density-gradient centrifugation, disc electrophoresis and u.v. spectroscopy. Sedimentation-velocity centrifugation revealed a single unimodal peak with S20,W 50.1S in 0.2M-NaCl and 37.0S in 6 M-guanidinium chloride. Molecular weights obtained by light-scattering were 9.7 × 10(6) and 5.9 × 10(6) in 0.2M-NaCl and 6 M-guanidinium chloride respectively. The chemical analyses were typical of those of epithelial mucins. The macromolecules contained approx. 20% (w/w) of protein, and 65% (w/w) was accounted for as carbohydrate. Serine and threonine constituted 32 mol/100 mol and proline 10 mol/100 mol of the amino acids. The major sugars found were N-acetylglucosamine (12.8%), N-acetylgalactosamine (9.7%), galactose (18.7%), sialic acid (15.0%) and fucose (7.5%).


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.


1992 ◽  
Vol 283 (3) ◽  
pp. 807-811 ◽  
Author(s):  
E C I Veerman ◽  
P A M van den Keybus ◽  
M Valentijn-Benz ◽  
A V Nieuw Amerongen

By using CsCl-density-gradient ultracentrifugation, two high-Mr mucin species were isolated from human whole saliva, having buoyant densities in 0.2 M-guanidinium chloride of approx. 1.56 g/ml (pool IA) and 1.48 g/ml (pool IIA). Analytical density-gradient centrifugation of submandibular, sublingual, labial and palatal saliva, followed by immunochemical analysis with anti-mucin monoclonal antibodies, indicated immunochemical and physicochemical similarities between the high-density mucins of pool IA and mucins from palatal salivary glands. Chemical analysis indicated that the putative palatal mucin was rich in sulphate, but poor in sialic acid. The lower-density mucins of pool IIA equated with the high-Mr mucins of submandibular-sublingual saliva, both immunochemically and physicochemically (buoyant density).


1996 ◽  
Vol 316 (3) ◽  
pp. 937-942 ◽  
Author(s):  
Fiona J. J. FOGG ◽  
David A. HUTTON ◽  
Kornelia JUMEL ◽  
Jeffrey P. PEARSON ◽  
Stephen E. HARDING ◽  
...  

Pig colonic mucins isolated from the adherent mucus gel in the presence of proteinase inhibitors were solubilized by homogenization and the component mucins fractionated by CsCl density-gradient centrifugation. Polymeric and reduced pig colonic mucin were both largely excluded on Sepharose CL-2B, papain-digested colonic mucin was included. The Mr values of polymeric, reduced and digested mucins were 5.5×106, 2.1×106 and 0.6×106 respectively. This suggests that pig colonic mucin is comprised of 2–3 subunits, each subunit containing 3–4 glycosylated regions. The intrinsic viscosities of polymeric, reduced and digested mucin were 240 ml·g-1, 100 ml·g-1 and 20 ml·g-1 respectively. Polymeric pig colonic mucin comprised 16% protein per mg of glycoprotein and was rich in serine, threonine and proline (43% of total amino acids). There were approx. 150 disulphide bridges and 53 free thiol groups per mucin polymer. A seventh of the protein content was lost on reduction. This protein was particularly rich in proline and the hydrophobic amino acids. Papain-digested pig colonic mucin contained 11% protein per mg of glycoprotein and was rich in serine, threonine, glutamate and aspartate. All types of amino acids with the exception of aspartate were lost on digestion. The amino acid analysis of the proteolytically digested regions of pig colonic mucin are markedly different to the tandem repeat regions of the human mucin genes shown to be expressed in the colon.


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