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. 1976 Apr 1;155(1):163–169. doi: 10.1042/bj1550163

The binding of calcium to a salivary phosphoprotein, protein A, common to human parotid and submandibular secretions.

A Bennick
PMCID: PMC1172813  PMID: 180980

Abstract

The binding of Ca2+ to a previously described phosphoprotein from human parotid saliva, protein A [Bennick (1975) Biochem J. 145, 557-567] was studied by means of equilibrium dialysis. In 5 mM-Tris/HC1 buffer, pH7.5, protein A bound 664nmol of Ca/mg of protein. Km was determined to be 181 muM and the binding of Ca2+ to the protein was non-co-operative. The binding of Ca2+ apparently occurs to side-chain carboxyl groups in the protein, but protein phosphate is of minor if any importance in calcium binding. Hydrolysis of protein A by trypsin and collagenase or heating of the protein at 60 degrees or 100 degrees C did not affect Ca2+ binding. The Ca2+ binding decreases with increased concentration of the dialysis buffer and on the addition of SrCl2, or MgCl2 or MnCl2 to the dialysis buffer. Protein A does not aggregate in the presence of Ca2+, since the s20,w was identical when determined in the presence (1.30S) and absence (1.35S) of CaCl2. By use of a specific antiserum to protein A it was found that protein C [Bennick & Connell (1971) Biochem. J. 123, 455-464] and perhaps minor related components cross-reacted with protein A. No other salivary proteins showed immunological similarity. Proteins A and C were also present in submandibular saliva. The possible functions of protein A are discussed.

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Selected References

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

  1. Ahrens G., Lücke H. The effects of stimulation and time of day on the calcium concentrations in human parotid and submandibular saliva. Caries Res. 1972;6(2):148–155. doi: 10.1159/000259786. [DOI] [PubMed] [Google Scholar]
  2. Arneberg P. Partial characterization of five glycoprotein fractions secreted by the human parotid glands. Arch Oral Biol. 1974 Oct;19(10):921–928. doi: 10.1016/0003-9969(74)90055-7. [DOI] [PubMed] [Google Scholar]
  3. Azen E. A., Oppenheim F. G. Genetic polymorphism of proline-rich human salivary proteins. Science. 1973 Jun 8;180(4090):1067–1069. doi: 10.1126/science.180.4090.1067. [DOI] [PubMed] [Google Scholar]
  4. Bennick A. Chemical and physical characteristics of a phosphoprotein from human parotid saliva. Biochem J. 1975 Mar;145(3):557–567. doi: 10.1042/bj1450557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bennick A., Connell G. E. Purification and partial characterization of four proteins from human parotid saliva. Biochem J. 1971 Jul;123(3):455–464. doi: 10.1042/bj1230455. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Benzonana G., Capony J. P., Pechere J. F. The binding of calcium to muscular parvalbumins. Biochim Biophys Acta. 1972 Aug 31;278(1):110–116. doi: 10.1016/0005-2795(72)90111-0. [DOI] [PubMed] [Google Scholar]
  7. Boat T. F., Wiesman U. N., Pallavicini J. C. Purification and properties of the calcium-precipitable protein in submaxillary saliva of normal and cystic fibrosis subjects. Pediatr Res. 1974 May;8(5):531–539. doi: 10.1203/00006450-197405000-00001. [DOI] [PubMed] [Google Scholar]
  8. Calissano P., Moore B. W., Friesen A. Effect of calcium ion on S-100, a protein of the nervous system. Biochemistry. 1969 Nov;8(11):4318–4326. doi: 10.1021/bi00839a015. [DOI] [PubMed] [Google Scholar]
  9. Dawes C., Ong B. Y. Circadian rhythms in the concentrations of protein and the main electrolytes in human unstimulated parotid saliva. Arch Oral Biol. 1973 Oct;18(10):1233–1242. doi: 10.1016/0003-9969(73)90035-6. [DOI] [PubMed] [Google Scholar]
  10. Dawes C. The effects of flow rate and duration of stimulation on the condentrations of protein and the main electrolytes in human parotid saliva. Arch Oral Biol. 1969 Mar;14(3):277–294. doi: 10.1016/0003-9969(69)90231-3. [DOI] [PubMed] [Google Scholar]
  11. FOLSCH G., OSTERBERG R. The apparent acid ionization constants of some O-phosphorylated peptides and related compounds. J Biol Chem. 1959 Sep;234:2298–2303. [PubMed] [Google Scholar]
  12. Ferguson D. B., Fort A., Elliott A. L., Potts A. J. Circadian rhythms in human parotid saliva flow rate and composition. Arch Oral Biol. 1973 Sep;18(9):1155–1173. doi: 10.1016/0003-9969(73)90089-7. [DOI] [PubMed] [Google Scholar]
  13. Gron P. Saturation of human saliva with calcium phosphates. Arch Oral Biol. 1973 Nov;18(11):1385–1392. doi: 10.1016/0003-9969(73)90112-x. [DOI] [PubMed] [Google Scholar]
  14. Gron P. The state of calcium and inorganic orthophosphate in human saliva. Arch Oral Biol. 1973 Nov;18(11):1365–1378. doi: 10.1016/0003-9969(73)90110-6. [DOI] [PubMed] [Google Scholar]
  15. Hay D. I., Oppenheim F. G. The isolation from human parotid saliva of a further group of proline-rich proteins. Arch Oral Biol. 1974 Aug;19(8):627–632. doi: 10.1016/0003-9969(74)90130-7. [DOI] [PubMed] [Google Scholar]
  16. Hay D. I. The interaction of human parotid salivary proteins with hydroxyapatite. Arch Oral Biol. 1973 Dec;18(12):1517–1529. doi: 10.1016/0003-9969(73)90127-1. [DOI] [PubMed] [Google Scholar]
  17. Henkin R. I., Lippoldt R. E., Bilstad J., Edelhoch H. A zinc protein isolated from human parotid saliva. Proc Natl Acad Sci U S A. 1975 Feb;72(2):488–492. doi: 10.1073/pnas.72.2.488. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Hermsdorf C. L., Bronner F. Vitamin D-dependent calcium-binding protein from rat kidney. Biochim Biophys Acta. 1975 Feb 27;379(2):553–561. doi: 10.1016/0005-2795(75)90161-0. [DOI] [PubMed] [Google Scholar]
  19. Hitchman A. J., Harrison J. E. Calcium binding proteins in the duodenal mucosa of the chick, rat, pig, and human. Can J Biochem. 1972 Jul;50(7):758–765. doi: 10.1139/o72-106. [DOI] [PubMed] [Google Scholar]
  20. Keller P. J., Robinovitch M., Iversen J., Kauffman D. L. The protein composition of rat parotid saliva and secretory granules. Biochim Biophys Acta. 1975 Feb 27;379(2):562–570. doi: 10.1016/0005-2795(75)90162-2. [DOI] [PubMed] [Google Scholar]
  21. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  22. MacLennan D. H., Wong P. T. Isolation of a calcium-sequestering protein from sarcoplasmic reticulum. Proc Natl Acad Sci U S A. 1971 Jun;68(6):1231–1235. doi: 10.1073/pnas.68.6.1231. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Mutzbauer H., Schulz G. V. Die Bestimmung der molekularen Konstanten von alpha-Amylase aus Humanspeichel. Biochim Biophys Acta. 1965 Jul 22;102(2):526–532. [PubMed] [Google Scholar]
  24. Nordwig A. Collagenolytic enzymes. Adv Enzymol Relat Areas Mol Biol. 1971;34:155–205. doi: 10.1002/9780470122792.ch4. [DOI] [PubMed] [Google Scholar]
  25. Oldham S. B., Fischer J. A., Shen L. H., Arnaud C. D. Isolation and properties of a calcium-binding protein from porcine parathyroid glands. Biochemistry. 1974 Nov 5;13(23):4790–4796. doi: 10.1021/bi00720a017. [DOI] [PubMed] [Google Scholar]
  26. Oppenheim F. G., Hay D. I., Franzblau C. Proline-rich proteins from human parotid saliva. I. Isolation and partial characterization. Biochemistry. 1971 Nov;10(23):4233–4238. doi: 10.1021/bi00799a013. [DOI] [PubMed] [Google Scholar]
  27. Ostwald T. J., MacLennan D. H. Isolation of a high affinity calcium-binding protein from sarcoplasmic reticulum. J Biol Chem. 1974 Feb 10;249(3):974–979. [PubMed] [Google Scholar]
  28. Percy M. E., Buchwald B. M. A manual method of sequential Edman degradation followed by dansylation for the determination of protein sequences. Anal Biochem. 1972 Jan;45(1):60–67. doi: 10.1016/0003-2697(72)90007-3. [DOI] [PubMed] [Google Scholar]
  29. Robinovitch M. R., Keller P. J., Iversen J., Kauffman D. L. Demonstration of a class of proteins loosely associated with secretory granule membranes. Biochim Biophys Acta. 1975 Mar 13;382(2):260–24b. doi: 10.1016/0005-2736(75)90184-4. [DOI] [PubMed] [Google Scholar]
  30. Rölla G., Jonsen J. The calcium-binding effect of a human salivary glycoprotein. Caries Res. 1967;1(4):343–348. doi: 10.1159/000259534. [DOI] [PubMed] [Google Scholar]
  31. SCHNEYER L. H. Amylase content of separate salivary gland secretions of man. J Appl Physiol. 1956 Nov;9(3):453–455. doi: 10.1152/jappl.1956.9.3.453. [DOI] [PubMed] [Google Scholar]
  32. Truelove E. L., Bixler D., Merritt A. D. Simplified method for collection of pure submandibular saliva in large volumes. J Dent Res. 1967 Nov-Dec;46(6):1400–1403. doi: 10.1177/00220345670460064301. [DOI] [PubMed] [Google Scholar]
  33. VALLEE B. L., STEIN E. A., SUMERWELL W. N., FISCHER E. H. Metal content of alpha-amylases of various origins. J Biol Chem. 1959 Nov;234:2901–2905. [PubMed] [Google Scholar]
  34. Wallach D., Schramm M. Calcium and the exportable protein in rat parotid gland. Parallel subcellular distribution and concomitant secretion. Eur J Biochem. 1971 Aug 16;21(3):433–437. doi: 10.1111/j.1432-1033.1971.tb01489.x. [DOI] [PubMed] [Google Scholar]
  35. Wasserman R. H., Corradino R. A., Taylor A. N. Vitamin D-dependent calcium-binding protein. Purification and some properties. J Biol Chem. 1968 Jul 25;243(14):3978–3986. [PubMed] [Google Scholar]
  36. Windeler A. S., Jr, Shannon I. L. The effect of flow rate on parotid fluid calcium and protein levels. Arch Oral Biol. 1966 Oct;11(10):1043–1045. doi: 10.1016/0003-9969(66)90205-6. [DOI] [PubMed] [Google Scholar]
  37. Wolff D. J., Siegel F. L. Purification of a calcium-binding phosphoprotein from pig brain. J Biol Chem. 1972 Jul 10;247(13):4180–4185. [PubMed] [Google Scholar]

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