2.50
Hdl Handle:
http://hdl.handle.net/10541/108785
Title:
Mucins in cat airway secretions.
Authors:
Davies, J R; Gallagher, John T; Richardson, P S; Sheehan, J K; Carlstedt, I
Abstract:
Mucous secretions were obtained from cat tracheas that had received [3H]glucose and [35S]sulphate to radiolabel mucus glycoproteins biosynthetically. Samples were collected under resting ('basal') conditions as well as after pilocarpine stimulation and were separated into gel and sol phases by centrifugation. Macromolecules were partially purified by using gel chromatography on Sepharose CL-4B, and the species that were eluted with the void volume were then separated into two major populations with isopycnic density-gradient centrifugation in CsCl. The major component from the gel phase of pilocarpine-induced secretions had a buoyant density typical of mucins and was observed as linear and apparently flexible chains by electron microscopy. Reduction of disulphide bonds gave subunits that could be further cleaved by trypsin digestion into components of approximately the same size as the high-Mr glycopeptides obtained from other mucins after this treatment. In contrast, the dominant species in the gel phase of the 'basal' secretion had a significantly higher buoyant density than expected for mucins and was largely unaffected by reduction, as studied by gel chromatography. The macromolecules were fragmented by trypsin, suggesting that they contain a polypeptide backbone. This more dense component also predominated in the sol phase both from the 'basal' secretions and from the pilocarpine-released secretions. Digestion with DNAase, chondroitin ABC lyase or heparan sulphate lyase had no effect, which shows that this component is not DNA, a dermatan sulphate/chondroitin sulphate or a heparan sulphate proteoglycan. In contrast, endo-beta-galactosidase and keratanase caused some fragmentation, suggesting that the molecules contain some linkages of the poly-(N-acetyl-lactosamine) type, although the degradation was not as extensive as expected for keratan sulphate. Treatment with alkaline borohydride resulted in extensive fragmentation of the high-Mr glycopeptides from both components, indicating that the glycans were oligosaccharides that were probably O-linked. The monosaccharide compositions of both components were consistent with that expected for mucins. The data are in keeping with the major component from the pilocarpine-stimulated gel secretions being a mucus glycoprotein and the more dense component being a mucin-like molecule, possibly related to the keratanase-sensitive material isolated from canine trachea by Varsano, Basbaum, Forsberg, Borson, Caughey & Nadel [(1987) Exp. Lung Res. 13, 157-184].
Affiliation:
Department of Physiology, St. George's Hospital and Medical School, London, U.K.
Citation:
Mucins in cat airway secretions. 1991, 275 ( Pt 3):663-9 Biochem. J.
Journal:
The Biochemical Journal
Issue Date:
1-May-1991
URI:
http://hdl.handle.net/10541/108785
PubMed ID:
1903925
Type:
Article
Language:
en
ISSN:
0264-6021
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorDavies, J Ren
dc.contributor.authorGallagher, John Ten
dc.contributor.authorRichardson, P Sen
dc.contributor.authorSheehan, J Ken
dc.contributor.authorCarlstedt, Ien
dc.date.accessioned2010-08-02T10:27:35Z-
dc.date.available2010-08-02T10:27:35Z-
dc.date.issued1991-05-01-
dc.identifier.citationMucins in cat airway secretions. 1991, 275 ( Pt 3):663-9 Biochem. J.en
dc.identifier.issn0264-6021-
dc.identifier.pmid1903925-
dc.identifier.urihttp://hdl.handle.net/10541/108785-
dc.description.abstractMucous secretions were obtained from cat tracheas that had received [3H]glucose and [35S]sulphate to radiolabel mucus glycoproteins biosynthetically. Samples were collected under resting ('basal') conditions as well as after pilocarpine stimulation and were separated into gel and sol phases by centrifugation. Macromolecules were partially purified by using gel chromatography on Sepharose CL-4B, and the species that were eluted with the void volume were then separated into two major populations with isopycnic density-gradient centrifugation in CsCl. The major component from the gel phase of pilocarpine-induced secretions had a buoyant density typical of mucins and was observed as linear and apparently flexible chains by electron microscopy. Reduction of disulphide bonds gave subunits that could be further cleaved by trypsin digestion into components of approximately the same size as the high-Mr glycopeptides obtained from other mucins after this treatment. In contrast, the dominant species in the gel phase of the 'basal' secretion had a significantly higher buoyant density than expected for mucins and was largely unaffected by reduction, as studied by gel chromatography. The macromolecules were fragmented by trypsin, suggesting that they contain a polypeptide backbone. This more dense component also predominated in the sol phase both from the 'basal' secretions and from the pilocarpine-released secretions. Digestion with DNAase, chondroitin ABC lyase or heparan sulphate lyase had no effect, which shows that this component is not DNA, a dermatan sulphate/chondroitin sulphate or a heparan sulphate proteoglycan. In contrast, endo-beta-galactosidase and keratanase caused some fragmentation, suggesting that the molecules contain some linkages of the poly-(N-acetyl-lactosamine) type, although the degradation was not as extensive as expected for keratan sulphate. Treatment with alkaline borohydride resulted in extensive fragmentation of the high-Mr glycopeptides from both components, indicating that the glycans were oligosaccharides that were probably O-linked. The monosaccharide compositions of both components were consistent with that expected for mucins. The data are in keeping with the major component from the pilocarpine-stimulated gel secretions being a mucus glycoprotein and the more dense component being a mucin-like molecule, possibly related to the keratanase-sensitive material isolated from canine trachea by Varsano, Basbaum, Forsberg, Borson, Caughey & Nadel [(1987) Exp. Lung Res. 13, 157-184].en
dc.language.isoenen
dc.subject.meshAnimals-
dc.subject.meshBorohydrides-
dc.subject.meshCats-
dc.subject.meshCentrifugation, Isopycnic-
dc.subject.meshChromatography, Gel-
dc.subject.meshGlucose-
dc.subject.meshGlycoside Hydrolases-
dc.subject.meshHydrogen-Ion Concentration-
dc.subject.meshMicroscopy, Electron-
dc.subject.meshMucins-
dc.subject.meshPeptide Fragments-
dc.subject.meshPilocarpine-
dc.subject.meshSulfates-
dc.subject.meshSulfur Radioisotopes-
dc.subject.meshTrachea-
dc.subject.meshTritium-
dc.subject.meshbeta-Galactosidase-
dc.titleMucins in cat airway secretions.en
dc.typeArticleen
dc.contributor.departmentDepartment of Physiology, St. George's Hospital and Medical School, London, U.K.en
dc.identifier.journalThe Biochemical Journalen

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