Skip to main content
PMC home page
Biochemical Journal logoLink to Biochemical Journal
. 2000 Oct 15;351(Pt 2):421–428.

Macromolecular organization of saliva: identification of 'insoluble' MUC5B assemblies and non-mucin proteins in the gel phase.

C Wickström 1, C Christersson 1, J R Davies 1, I Carlstedt 1
PMCID: PMC1221378  PMID: 11023828

Abstract

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.

Full Text

The Full Text of this article is available as a PDF (273.0 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Al-Hashimi I., Levine M. J. Characterization of in vivo salivary-derived enamel pellicle. Arch Oral Biol. 1989;34(4):289–295. doi: 10.1016/0003-9969(89)90070-8. [DOI] [PubMed] [Google Scholar]
  2. Biesbrock A. R., Reddy M. S., Levine M. J. Interaction of a salivary mucin-secretory immunoglobulin A complex with mucosal pathogens. Infect Immun. 1991 Oct;59(10):3492–3497. doi: 10.1128/iai.59.10.3492-3497.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bobek L. A., Tsai H., Biesbrock A. R., Levine M. J. Molecular cloning, sequence, and specificity of expression of the gene encoding the low molecular weight human salivary mucin (MUC7). J Biol Chem. 1993 Sep 25;268(27):20563–20569. [PubMed] [Google Scholar]
  4. Bowes D., Clark A. E., Corrin B. Ultrastructural localisation of lactoferrin and glycoprotein in human bronchial glands. Thorax. 1981 Feb;36(2):108–115. doi: 10.1136/thx.36.2.108. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. CURBY W. A. Device for collection of human parotid saliva. J Lab Clin Med. 1953 Mar;41(3):493–496. [PubMed] [Google Scholar]
  6. Carlstedt I., Herrmann A., Hovenberg H., Lindell G., Nordman H., Wickström C., Davies J. R. 'Soluble' and 'insoluble' mucins--identification of distinct populations. Biochem Soc Trans. 1995 Nov;23(4):845–851. doi: 10.1042/bst0230845. [DOI] [PubMed] [Google Scholar]
  7. Carlstedt I., Herrmann A., Karlsson H., Sheehan J., Fransson L. A., Hansson G. C. Characterization of two different glycosylated domains from the insoluble mucin complex of rat small intestine. J Biol Chem. 1993 Sep 5;268(25):18771–18781. [PubMed] [Google Scholar]
  8. Carlstedt I., Lindgren H., Sheehan J. K., Ulmsten U., Wingerup L. Isolation and characterization of human cervical-mucus glycoproteins. Biochem J. 1983 Apr 1;211(1):13–22. doi: 10.1042/bj2110013. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Creeth J. M., Bridge J. L., Horton J. R. An interaction between lysozyme and mucus glycoproteins. Implications for density-gradient separations. Biochem J. 1979 Sep 1;181(3):717–724. doi: 10.1042/bj1810717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Desseyn J. L., Buisine M. P., Porchet N., Aubert J. P., Laine A. Genomic organization of the human mucin gene MUC5B. cDNA and genomic sequences upstream of the large central exon. J Biol Chem. 1998 Nov 13;273(46):30157–30164. doi: 10.1074/jbc.273.46.30157. [DOI] [PubMed] [Google Scholar]
  11. Ericson T., Rundegren J. Characterization of a salivary agglutinin reacting with a serotype c strain of Streptococcus mutans. Eur J Biochem. 1983 Jun 15;133(2):255–261. doi: 10.1111/j.1432-1033.1983.tb07456.x. [DOI] [PubMed] [Google Scholar]
  12. Glantz P. O., Wirth S. M., Baier R. E., Wirth J. E. Electron microscopic studies of human mixed saliva. Acta Odontol Scand. 1989 Feb;47(1):7–15. doi: 10.3109/00016358909004794. [DOI] [PubMed] [Google Scholar]
  13. Herrmann A., Davies J. R., Lindell G., Mårtensson S., Packer N. H., Swallow D. M., Carlstedt I. Studies on the "insoluble" glycoprotein complex from human colon. Identification of reduction-insensitive MUC2 oligomers and C-terminal cleavage. J Biol Chem. 1999 May 28;274(22):15828–15836. doi: 10.1074/jbc.274.22.15828. [DOI] [PubMed] [Google Scholar]
  14. Iontcheva I., Oppenheim F. G., Troxler R. F. Human salivary mucin MG1 selectively forms heterotypic complexes with amylase, proline-rich proteins, statherin, and histatins. J Dent Res. 1997 Mar;76(3):734–743. doi: 10.1177/00220345970760030501. [DOI] [PubMed] [Google Scholar]
  15. Jourdian G. W., Dean L., Roseman S. The sialic acids. XI. A periodate-resorcinol method for the quantitative estimation of free sialic acids and their glycosides. J Biol Chem. 1971 Jan 25;246(2):430–435. [PubMed] [Google Scholar]
  16. Keates A. C., Nunes D. P., Afdhal N. H., Troxler R. F., Offner G. D. Molecular cloning of a major human gall bladder mucin: complete C-terminal sequence and genomic organization of MUC5B. Biochem J. 1997 May 15;324(Pt 1):295–303. doi: 10.1042/bj3240295. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Liu B., Offner G. D., Nunes D. P., Oppenheim F. G., Troxler R. F. MUC4 is a major component of salivary mucin MG1 secreted by the human submandibular gland. Biochem Biophys Res Commun. 1998 Sep 29;250(3):757–761. doi: 10.1006/bbrc.1998.9390. [DOI] [PubMed] [Google Scholar]
  18. Lohmander L. S., De Luca S., Nilsson B., Hascall V. C., Caputo C. B., Kimura J. H., Heinegard D. Oligosaccharides on proteoglycans from the swarm rat chondrosarcoma. J Biol Chem. 1980 Jul 10;255(13):6084–6091. [PubMed] [Google Scholar]
  19. Loomis R. E., Prakobphol A., Levine M. J., Reddy M. S., Jones P. C. Biochemical and biophysical comparison of two mucins from human submandibular-sublingual saliva. Arch Biochem Biophys. 1987 Nov 1;258(2):452–464. doi: 10.1016/0003-9861(87)90366-3. [DOI] [PubMed] [Google Scholar]
  20. Mehrotra R., Thornton D. J., Sheehan J. K. Isolation and physical characterization of the MUC7 (MG2) mucin from saliva: evidence for self-association. Biochem J. 1998 Sep 1;334(Pt 2):415–422. doi: 10.1042/bj3340415. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Nederfors T., Dahlöf C. A modified device for collection and flow-rate measurement of submandibular-sublingual saliva. Scand J Dent Res. 1993 Aug;101(4):210–214. doi: 10.1111/j.1600-0722.1993.tb01106.x. [DOI] [PubMed] [Google Scholar]
  22. Nielsen P. A., Bennett E. P., Wandall H. H., Therkildsen M. H., Hannibal J., Clausen H. Identification of a major human high molecular weight salivary mucin (MG1) as tracheobronchial mucin MUC5B. Glycobiology. 1997 Apr;7(3):413–419. doi: 10.1093/glycob/7.3.413. [DOI] [PubMed] [Google Scholar]
  23. Nielsen P. A., Mandel U., Therkildsen M. H., Clausen H. Differential expression of human high-molecular-weight salivary mucin (MG1) and low-molecular-weight salivary mucin (MG2). J Dent Res. 1996 Nov;75(11):1820–1826. doi: 10.1177/00220345960750110201. [DOI] [PubMed] [Google Scholar]
  24. Pigny P., Guyonnet-Duperat V., Hill A. S., Pratt W. S., Galiegue-Zouitina S., d'Hooge M. C., Laine A., Van-Seuningen I., Degand P., Gum J. R. Human mucin genes assigned to 11p15.5: identification and organization of a cluster of genes. Genomics. 1996 Dec 15;38(3):340–352. doi: 10.1006/geno.1996.0637. [DOI] [PubMed] [Google Scholar]
  25. Prakobphol A., Levine M. J., Tabak L. A., Reddy M. S. Purification of a low-molecular-weight, mucin-type glycoprotein from human submandibular-sublingual saliva. Carbohydr Res. 1982 Oct 1;108(1):111–122. doi: 10.1016/s0008-6215(00)81896-0. [DOI] [PubMed] [Google Scholar]
  26. Prakobphol A., Tangemann K., Rosen S. D., Hoover C. I., Leffler H., Fisher S. J. Separate oligosaccharide determinants mediate interactions of the low-molecular-weight salivary mucin with neutrophils and bacteria. Biochemistry. 1999 May 25;38(21):6817–6825. doi: 10.1021/bi990145m. [DOI] [PubMed] [Google Scholar]
  27. Prakobphol A., Thomsson K. A., Hansson G. C., Rosen S. D., Singer M. S., Phillips N. J., Medzihradszky K. F., Burlingame A. L., Leffler H., Fisher S. J. Human low-molecular-weight salivary mucin expresses the sialyl lewisx determinant and has L-selectin ligand activity. Biochemistry. 1998 Apr 7;37(14):4916–4927. doi: 10.1021/bi972612a. [DOI] [PubMed] [Google Scholar]
  28. Ramasubbu N., Reddy M. S., Bergey E. J., Haraszthy G. G., Soni S. D., Levine M. J. Large-scale purification and characterization of the major phosphoproteins and mucins of human submandibular-sublingual saliva. Biochem J. 1991 Dec 1;280(Pt 2):341–352. doi: 10.1042/bj2800341. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Reddy M. S., Bobek L. A., Haraszthy G. G., Biesbrock A. R., Levine M. J. Structural features of the low-molecular-mass human salivary mucin. Biochem J. 1992 Oct 15;287(Pt 2):639–643. doi: 10.1042/bj2870639. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Sheehan J. K., Carlstedt I. Size heterogeneity of human cervical mucus glycoproteins. Studies performed with rate-zonal centrifugation and laser light-scattering. Biochem J. 1987 Aug 1;245(3):757–762. doi: 10.1042/bj2450757. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Thornton D. J., Holmes D. F., Sheehan J. K., Carlstedt I. Quantitation of mucus glycoproteins blotted onto nitrocellulose membranes. Anal Biochem. 1989 Oct;182(1):160–164. doi: 10.1016/0003-2697(89)90735-5. [DOI] [PubMed] [Google Scholar]
  32. Thornton D. J., Howard M., Khan N., Sheehan J. K. Identification of two glycoforms of the MUC5B mucin in human respiratory mucus. Evidence for a cysteine-rich sequence repeated within the molecule. J Biol Chem. 1997 Apr 4;272(14):9561–9566. doi: 10.1074/jbc.272.14.9561. [DOI] [PubMed] [Google Scholar]
  33. Thornton D. J., Khan N., Mehrotra R., Howard M., Veerman E., Packer N. H., Sheehan J. K. Salivary mucin MG1 is comprised almost entirely of different glycosylated forms of the MUC5B gene product. Glycobiology. 1999 Mar;9(3):293–302. doi: 10.1093/glycob/9.3.293. [DOI] [PubMed] [Google Scholar]
  34. Van-Seuningen I., Houdret N., Hayem A., Davril M. Strong ionic interactions between mucins and two basic proteins, mucus proteinase inhibitor and lysozyme, in human bronchial secretions. Int J Biochem. 1992 Feb;24(2):303–311. doi: 10.1016/0020-711x(92)90262-y. [DOI] [PubMed] [Google Scholar]
  35. Wickström C., Davies J. R., Eriksen G. V., Veerman E. C., Carlstedt I. MUC5B is a major gel-forming, oligomeric mucin from human salivary gland, respiratory tract and endocervix: identification of glycoforms and C-terminal cleavage. Biochem J. 1998 Sep 15;334(Pt 3):685–693. doi: 10.1042/bj3340685. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES