scholarly journals Macromolecular organization of saliva: identification of ‘insoluble’ MUC5B assemblies and non-mucin proteins in the gel phase

2000 ◽  
Vol 351 (2) ◽  
pp. 421-428 ◽  
Author(s):  
Claes WICKSTRÖM ◽  
Cecilia CHRISTERSSON ◽  
Julia R. DAVIES ◽  
Ingemar CARLSTEDT

Stimulated human submandibular/sublingual (HSMSL) and whole saliva were separated into sol and gel phases and mucins were isolated by density-gradient centrifugation in CsCl/4M guanidinium chloride. MUC5B and MUC7 were identified using anti-peptide antisera raised against sequences within the MUC5B and MUC7 apoproteins respectively. MUC7 was found mainly in the sol phase of both HSMSL and whole saliva, but some MUC7 was consistently present in the gel phase, suggesting that this mucin may interact with the salivary gel matrix. In HSMSL saliva, MUC5B was found in the gel phase; however, most of the material was ‘insoluble’in guanidinium chloride and was only brought into solution by reduction. In whole saliva, the MUC5B mucin was present both in the sol and gel phases although some material was again ‘insoluble’. Rate-zonal centrifugation of whole saliva showed that MUC5B mucins in the sol phase were smaller than those in the gel phase, suggesting differences in oligomerization and/or degradation. Antibodies against IgA, secretory component, lysozyme and lactoferrin were used to study the distribution of non-gel-forming proteins in the different phases of saliva. The majority of these proteins was found in the sol phase of both HSMSL and whole saliva. However, a significant fraction was present in the gel phase of whole saliva, suggesting a post-secretory interaction with the salivary gel matrix. A monoclonal antibody against a parotid salivary agglutinin was used to show that this protein is present mainly in the gel phase of both whole saliva and parotid secretion.

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].


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).


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.


1991 ◽  
Vol 130 (3) ◽  
pp. 357-365 ◽  
Author(s):  
G. Dirami ◽  
L. W. Poulter ◽  
B. A. Cooke

ABSTRACT A method involving centrifugal elutriation followed by density gradient centrifugation and incubation with a macrophage monoclonal antibody has been investigated to separate and characterize Leydig cells and macrophages from adult rat testes. After dispersion of the testes with collagenase, the isolated interstitial cells were found to contain 18% Leydig cells and 12% macrophages. These cells were then separated by centrifugal elutriation into eight fractions (F1–F8) (9 to 74 ml/min at 386 g). Each of these fractions was then further purified by density gradient centrifugation on 0–90% Percoll gradients. After centrifugal elutriation, the macrophages were mainly eluted in the first three fractions (F1–F3), whereas the Leydig cell percentage increased in each fraction with increasing flow rate. After further purification of each fraction on Percoll gradients, high percentages of macrophages (11–20%) were found in fractions F1–F3 (average density 1·045 g/ml), containing 11–37% Leydig cells. Less than 3% of the cells in fraction F4–F8 (average density 1 ·075 g/ml) were macrophages and more than 95% were Leydig cells. Heterogeneity of Leydig cells with respect to sedimentation velocities and function was found. Leydig cells from elutriated-and Percoll-purified fractions F4–F8 were heterogeneous with respect to testosterone and cyclic AMP (cAMP) production but showed a similar binding capacity for 125I-labelled human chorionic gonadotrophin. Leydig cells with the highest sedimentation velocity (35·7 mm/h-g) from fractions F7 and F8 were approximately twofold more responsive to LH (3·3 nmol/l) with respect to testosterone and cAMP production compared with Leydig cells with the lowest sedimentation velocity (20·7 mm/h-g). The elutriated and Percoll-purified cells (corresponding to fractions F4–F8) were further purified by incubation with magnetic beads coated with a macrophage monoclonal antibody; this yielded very pure Leydig cells containing <0·3% macrophages. The incubation temperature (room temperature or 4 °C) during the purification with magnetic beads did not affect the degree of purity or the responsiveness of the Leydig cells to LH. The removal of the remaining macrophages with magnetic beads did not have any significant effect on the Leydig cell responsiveness to LH. It was concluded that Leydig cells purified by elutriation and density gradient centrifugation are heterogeneous with respect to their sedimentation velocities and responses to LH; the higher the sedimentation velocity, the higher is their capacity to respond to LH. Leydig cells free from macrophages can be prepared by further purification using magnetic beads coated with a macrophage monoclonal antibody. Journal of Endocrinology (1991) 130, 357–365


1999 ◽  
Vol 344 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Julia R. DAVIES ◽  
Naila SVITACHEVA ◽  
Louise LANNEFORS ◽  
Ragnhild KORNFÄLT ◽  
Ingemar CARLSTEDT

To investigate the genetic identities of the mucins secreted in cystic fibrosis (CF) airways, sputum was collected from five individuals. Samples were separated into gel and sol phases by high-speed centrifugation and the gel phase was extracted in 6 M guanidinium chloride. The ‘insoluble’ residue remaining after extraction of the gel phase was brought into solution by reduction/alkylation. Density-gradient centrifugation in CsCl revealed polydisperse distributions of sialic acid-containing mucins in the gel phase, insoluble residue and sol phase fractions and the degree of variation between the different individuals was low. Antibodies recognizing MUC5AC and MUC5B identified these mucins in each of the fractions. MUC2, however, was present only as a component of the insoluble residue from the gel which accounted for less than 4% by mass of the total mucins. MUC5B and MUC5AC from the gel phase were large oligomeric species composed of disulphide-bond linked subunits and MUC5B was present as two populations with different charge densities which are likely to correspond to MUC5B ‘glycoforms’. The sol phase contained, in addition to MUC5AC and MUC5B, mainly smaller mucins which did not react with the antisera and which were probably degraded. MUC5AC appeared to be enriched in the sol, suggesting that this mucin may be more susceptible to proteolytic degradation than MUC5B. The mucins present in sputum remained broadly similar during acute exacerbation and following antibiotic treatment, although the relative amount of an acidic MUC5B glycoform was decreased during infection.


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%).


1983 ◽  
Vol 215 (3) ◽  
pp. 705-708 ◽  
Author(s):  
M T Bayliss ◽  
G D Ridgway ◽  
S Y Ali

Pieces of adult human articular cartilage and chondrosarcoma were incubated in the presence of [35S]sulphate. After continuous or pulse-change incorporation of radioactivity, proteoglycans were extracted with 4.0 M-guanidinium chloride, purified by equilibrium density-gradient centrifugation and fractionated by gel chromatography. A comparison of the results suggests that the formation of stable aggregates occurs at a lower rate in articular cartilage than in chondrosarcoma.


Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 819-822 ◽  
Author(s):  
J Szer ◽  
HJ Deeg ◽  
FR Appelbaum ◽  
R Storb

Abstract Hematopoietic stem cell toxicity of the murine monoclonal antibody 7.2, recognizing Ia-like antigens on canine cells, was tested in an autologous bone marrow transplantation model. Dogs were given 9.2 Gy of total body irradiation followed by the infusion of autologous marrow treated by one of two methods to remove Ia+ cells. In six dogs, the marrow cells were pelleted, treated with antibody 7.2 (1:1,000) and rabbit complement (1:4), resuspended in culture medium, and infused. All six dogs had prompt and sustained engraftment surviving greater than 26 days. Indirect immunofluorescence showed, however, that the depletion of Ia+ cells was incomplete. Four dogs received marrow cells first separated by density gradient centrifugation and then treated with an excess of antibody 7.2 and two cycles of undiluted rabbit complement. None of these dogs, surviving 17 to 22 days, had sustained engraftment. With antibody 7.2 used as the marker, only one dog had detectable residual Ia+ cells (0.9%) after treatment. Dogs receiving marrow cells obtained by density gradient centrifugation without additional manipulation, or with subsequent treatment with complement only or with complement and an antibody (DT-2) directed at a subpopulation of T cells, engrafted promptly and completely. We conclude that Ia+ bone marrow cells are essential for the successful engraftment of transplanted marrow in dogs.


Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 819-822
Author(s):  
J Szer ◽  
HJ Deeg ◽  
FR Appelbaum ◽  
R Storb

Hematopoietic stem cell toxicity of the murine monoclonal antibody 7.2, recognizing Ia-like antigens on canine cells, was tested in an autologous bone marrow transplantation model. Dogs were given 9.2 Gy of total body irradiation followed by the infusion of autologous marrow treated by one of two methods to remove Ia+ cells. In six dogs, the marrow cells were pelleted, treated with antibody 7.2 (1:1,000) and rabbit complement (1:4), resuspended in culture medium, and infused. All six dogs had prompt and sustained engraftment surviving greater than 26 days. Indirect immunofluorescence showed, however, that the depletion of Ia+ cells was incomplete. Four dogs received marrow cells first separated by density gradient centrifugation and then treated with an excess of antibody 7.2 and two cycles of undiluted rabbit complement. None of these dogs, surviving 17 to 22 days, had sustained engraftment. With antibody 7.2 used as the marker, only one dog had detectable residual Ia+ cells (0.9%) after treatment. Dogs receiving marrow cells obtained by density gradient centrifugation without additional manipulation, or with subsequent treatment with complement only or with complement and an antibody (DT-2) directed at a subpopulation of T cells, engrafted promptly and completely. We conclude that Ia+ bone marrow cells are essential for the successful engraftment of transplanted marrow in dogs.


Author(s):  
Lee F. Ellis ◽  
Richard M. Van Frank ◽  
Walter J. Kleinschmidt

The extract from Penicillum stoliniferum, known as statolon, has been purified by density gradient centrifugation. These centrifuge fractions contained virus particles that are an interferon inducer in mice or in tissue culture. Highly purified preparations of these particles are difficult to enumerate by electron microscopy because of aggregation. Therefore a study of staining methods was undertaken.


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