Isolation and characterization of human cervical-mucus glycoproteins.
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ABSTRACT:
SUBMITTER: Carlstedt I
PROVIDER: S-EPMC1154324 | biostudies-other | 1983 Apr
REPOSITORIES: biostudies-other
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Project description:Cervical mucins and fragments thereof were studied by sedimentation-velocity, rotatory viscometry and laser light-scattering performed as photon-correlation spectroscopy as well as low-angle total-intensity measurements. The Mr of the whole mucins is 10 X 10(6)-15 X 10(6), whereas fragments obtained after reduction of disulphide bonds ('subunits') have Mr 2.1 X 10(6)-2.9 X 10(6), depending on the method used. Subsequent trypsin digestion of subunits afforded glycopeptides with Mr approx. 0.4 X 10(6). The high frictional ratio for the whole mucins is interpreted as a large degree of expansion. The Stokes radius calculated from the diffusion coefficient is approx. 110nm for the whole mucins, which is in agreement with that estimated from the radius of gyration (130nm) by using the concept of the equivalent hydrodynamic sphere. The ratio of the concentration-dependence parameter for the reciprocal sedimentation coefficient (Ks) to the intrinsic viscosity ( [eta] ) for the whole mucins is 1.42, suggesting that the individual macromolecule occupies a spheroidal domain in solution. The relationship between [eta] and Mr for whole mucins, subunits and T-domains suggests that they are linear flexible macromolecules behaving as somewhat 'stiff' random coils. This conclusion is supported by the relationships between the sedimentation coefficients, the diffusion coefficients and the Mr. The hydrodynamic behaviour of the mucins is thus close to that expected for coiling macromolecules entrapping a lot of solvent, which is consistent with the postulated polymeric structure.
| S-EPMC1153186 | biostudies-other
Project description:Mucus glycoproteins (mucins) were obtained from human cervical and pig gastric mucus as well as from chronic-bronchitic sputum after low-shear extraction. The mucus gel was solubilized in guanidinium chloride supplemented with proteinase inhibitors, and the macromolecules were purified by using isopycnic density-gradient centrifugation. The macromolecules were spread in monolayers of benzyldimethylalkyl-ammonium chloride and studied with electron microscopy after staining with uranyl acetate and/or shadowing with platinum/carbon. The mucins appeared as flexible linear threads with lengths varying from approx. 200 nm to about 400 nm. No regularly branched or star-shaped structures were observed. The macromolecular architecture of cervical, respiratory and gastric mucins is thus similar.
| S-EPMC1147252 | biostudies-other
Project description:The depolymerization of bovine cervical glycoprotein resulting from cleavage of disulphide bonds. Pronase digestion and both procedures sequentially was assessed by using gel filtration. Cleavage of disulphide bonds followed by Pronase digestion produced more extensive depolymerization than did either treatment alone, and gel filtration of the products resulted in two major peaks of glycosylated material on Sepharose CL-2B and Sepharose 4B. The glycopolypeptides in both peaks had similar sugar and sulphate compositions, but they migrated to different extents on gel electrophoresis. Electrophoretic studies indicated that both glycopolypeptides were derived from the same glycoprotein molecule and not from a mixture of two similar glycoproteins. Pronase digestion of glycoproteins in which the disulphide bonds had been labelled with iodo-[1-14C]acetamide revealed that most of the cysteine residues were situated in regions susceptible to Pronase. The results show the presence of two types of structural regions in bovine cervical glycoprotein, namely 'naked' peptide or non-glycosylated regions and glycopolypeptide subunit regions in which glycopolypeptides of two different sizes predominate. Comparison of the cervical glycoproteins isolated from mucus secreted during oestrus and pregnancy, by the methods outlined above, did not reveal any structural differences in the glycoproteins to explain the different physical properties of the mucus secreted under these conditions.
| S-EPMC1185863 | biostudies-other
Project description:Mucous secretions were collected from tracheas of patients undergoing minor surgery under general anaesthesia with tracheal intubation, and mucus glycoproteins were isolated by using isopycnic density-gradient centrifugation in CsCl/guanidinium chloride. 'Whole' mucins were excluded from a Sepharose CL-2B gel, whereas subunits obtained after reduction were included. Trypsin digestion of subunits afforded high-Mr glycopeptides (T-domains), which were further included in the gel. The latter fragments are heterogeneous and comprise two or three populations, as indicated by gel chromatography and ion-exchange h.p.l.c. Rate-zonal centrifugation showed that the 'whole' mucins are polydisperse in size, with a weight-average Mr of (14-16) x 10(6). The macromolecules were observed by electron microscopy, as linear and apparently flexible thread-like structures. Subunits and T-domains had weight-average contour lengths of 490 nm and 160 nm respectively. It is concluded that mucus glycoproteins are present in secretions from the healthy lower respiratory tract. The 'whole' tracheal mucins are assembled from subunits, which in turn can be fragmented into high-Mr glycopeptides corresponding to the oligosaccharide domains typically found in mucus glycoproteins. The size and macromolecular architecture of the tracheal mucins is thus similar to that observed for mucins from human cervical mucus, chronic bronchitic sputum and pig stomach, providing yet another example of this general design of these macromolecules, i.e. subunits assembled end-to-end into very large linear and flexible macromolecules.
| S-EPMC1136628 | biostudies-other
Project description:Mucus glycoproteins (mucins) from cervical pregnancy mucus were fractionated by using rate-zonal centrifugation in a gradient of guanidinium chloride. The distribution of the macromolecules, as assessed by using sialic acid determination, suggested the presence of three populations of different size. Individual fractions were subjected to laser light-scattering performed as total-intensity measurements as well as photon correlation spectroscopy. The results showed that points of inflexion were present in the distribution of both Mr and DT (translational diffusion coefficient) and that the three populations have Mr values of approx. 24 X 10(6), 16 X 10(6) and 6 X 10(6) respectively. The weight-average Mr for the whole distribution, as calculated from the values obtained for the individual fractions, was 13.6 X 10(6), which is in good agreement with that found for the unfractionated material (11.1 X 10(6]. Plots of log RG (radius of gyration) and log (1/DT) versus log Mr are in keeping with the macromolecules being linear flexible chains.
| S-EPMC1148195 | biostudies-other
Project description:Preterm birth is a leading cause of neonatal mortality and lacks an effective therapy. Ascending microbial infections from the lower genital tract lead to infection of the placenta, amniotic fluid and fetus causing preterm birth or stillbirth. Directly in the path of an ascending infection is the cervical mucus plug (CMP), a dense mucoid structure in the cervical canal with potential antimicrobial properties. In this study, we aimed to define the components of CMP responsible for antimicrobial activity against a common lower genital tract organism associated with preterm birth and stillbirths, namely Group B Streptococcus (GBS). Using a quantitative proteomic approach, we identified antimicrobial factors in CMPs that were collected from healthy human pregnancies. This study aims to provide new insight into how the human CMP may limit ascending bacterial infection.
2018-02-09 | PXD008600 | Pride
Project description:BACKGROUND:Endometriosis is a chronic gynecological inflammatory disease characterized by the presence of functional endometrial glands and stroma outside of the uterine cavity. It affects 7-10% of women of reproductive age and up to 50% of women with infertility. The current gold standard for the diagnosis combines laparoscopic evaluation and biopsy of the visualized lesions. However, laparoscopy requires general anesthesia and developed surgical skills and it has a high procedural cost. In addition, it is associated with the risk, although rare, of potential intraoperative or postoperative complications. To date, several noninvasive biomarkers have been proposed; however, no definite diagnostic biomarker is yet available. The aim of this study was to characterize the CM proteome in patients with endometriosis using high resolution mass spectrometry-based proteomics, implemented by bioinformatic tools for quantitative analysis, in order to investigate the pathophysiological mechanisms of endometriosis. METHODS:Cervical mucus samples were collected from patients affected by endometriosis and fertile controls. An aliquot of the soluble acidic fraction of each cervical mucus sample, corresponding to 0.5 mg of total protein, was left to digest with sequencing grade modified porcine trypsin. The peptides were analyzed by LC-MS/MS on a high resolution Orbitrap Elite mass spectrometer and data were evaluated using bioinformatic tools. RESULTS:We aimed at the first total profiling of the cervical mucus proteome in endometriosis. From the list of identified proteins, we detected a number of differentially expressed proteins, including some functionally significant proteins. Six proteins were quantitatively increased in endometriosis, almost all being involved in the inflammatory pattern. Nine proteins were quantitatively reduced in endometriosis, including some proteins related with local innate immunity (CRISP-3 and Pglyrp1) and protection against oxidative stress (HSPB1). Fifteen proteins were not detected in endometriosis samples including certain proteins involved in antimicrobial activity (SLURP1 and KLK13) and related to seminal plasma liquefaction and male fertility (KLK13). CONCLUSIONS:This is the first application of high resolution mass spectrometry-based proteomics aimed in detecting an array of proteins in CM to be proposed for the noninvasive diagnosis of endometriosis. This chronic disease presents in CM an inflammatory protein pattern.
| S-EPMC5290661 | biostudies-literature
Project description:The major structural components of protective mucus hydrogels on mucosal surfaces are the secreted polymeric gel-forming mucins. The very high molecular weight and extensive O-glycosylation of gel-forming mucins, which are key to their viscoelastic properties, create problems when studying mucins using conventional biochemical/structural techniques. Thus, key structural information, such as the secondary structure of the various mucin subdomains, and glycosylation patterns along individual molecules, remains to be elucidated. Here, we utilized Raman spectroscopy, Raman optical activity (ROA), circular dichroism (CD), and tip-enhanced Raman spectroscopy (TERS) to study the structure of the secreted polymeric gel-forming mucin MUC5B. ROA indicated that the protein backbone of MUC5B is dominated by unordered conformation, which was found to originate from the heavily glycosylated central mucin domain by isolation of MUC5B O-glycan-rich regions. In sharp contrast, recombinant proteins of the N-terminal region of MUC5B (D1-D2-D'-D3 domains, NT5B), C-terminal region of MUC5B (D4-B-C-CK domains, CT5B) and the Cys-domain (within the central mucin domain of MUC5B) were found to be dominated by the β-sheet. Using these findings, we employed TERS, which combines the chemical specificity of Raman spectroscopy with the spatial resolution of atomic force microscopy to study the secondary structure along 90 nm of an individual MUC5B molecule. Interestingly, the molecule was found to contain a large amount of α-helix/unordered structures and many signatures of glycosylation, pointing to a highly O-glycosylated region on the mucin.
| S-EPMC5218386 | biostudies-literature
Project description:Human cervical-mucus glycoproteins (mucins) were extracted with 6 M-guanidinium chloride in the presence of proteinase inhibitors and purified by isopycnic density-gradient centrifugation. The whole mucins (Mr approx. 10 X 10(6] were degraded into 'subunits' (Mr approx. 2 X 10(6] by reduction of disulphide bonds. Trypsin digestion of the 'subunits' produced glycopeptides with Mr approx. 380000, which appear to be rod-like with a length of approx. 105 nm. The relationship between the radius of gyration and the Mr value obtained by light-scattering for whole mucins, 'subunits' and 'domains' suggest that cervical-mucus glycoproteins are linear flexible macromolecules composed of, on the average, four or five 'domains'/subunit and four subunits/whole mucin macromolecule. The shape-dependent particle scattering function for the whole mucins and the 'subunits' are in accordance with that of a linear flexible chain. No evidence for a branched or a star-like structure was found. A tentative model for cervical mucins is proposed.
| S-EPMC1152144 | biostudies-other
Project description:BackgroundCervical cancer is the most common gynecological cancer, encompassing cervical squamous cell carcinoma, adenocarcinoma, and other epithelial tumors. There are many diagnostic methods to detect cervical cancers but no precision screening tool for cervical adenocarcinoma at present.Material and methodsThe cervical mucus from three normal cervices (Ctrl), three endocervical adenocarcinoma (EA), and three cervical adenocarcinoma in situ (AIS) was collected for proteomic analysis. The proteins were screened using liquid chromatography-mass spectrometry analysis (LC-MS). The biological function of the differently expressed proteins were predicted by Gene Ontology (GO).ResultsA total of 711 proteins were identified, including 237 differently expressed proteins identified in EA/Ctrl comparison, 256 differently expressed proteins identified in AIS/Ctrl comparison, and 242 differently expressed proteins identified in AIS/EA comparison (up-regulate ≥ 1.5 or down-regulate ≤ 0.67). Functional annotation was performed using GO analysis on 1,056 differently expressed proteins to identify those that may impact cervical cancer, such as heme protein myeloperoxidase, which is involved in the immune process, and APOA1, which is associated with lipid metabolism.ConclusionWe used proteomic analysis to screen out differently expressed proteins from normal cervical mucus and cervical adenocarcinoma mucus samples. These differently expressed proteins may be potential biomarkers for the diagnosis and treatment of cervical adenocarcinoma but require additional study.
| S-EPMC7394065 | biostudies-literature