Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-26T12:40:11.789Z Has data issue: false hasContentIssue false
  • English
  • Français

Composition and structure of micellar calcium phosphate

Published online by Cambridge University Press:  01 June 2009

Carl Holt ,
Mathea J. J. M. van Kemenade ,
Lowell S. Nelson Jr ,
Lindsay Sawyer ,
John E. Harries ,
Raymond T. Bailey  and
David W. L. Hukins
Carl Holt
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK.
Mathea J. J. M. van Kemenade
Affiliation:
Van't Hoff Laboratory, University of Utrecht, 3584 CH, Utrecht, The Netherlands.
Lowell S. Nelson Jr
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK. Department of Medical Biophysics, University of Manchester, Manchester M13 9PT, UK.
Lindsay Sawyer
Affiliation:
Department of Biochemistry, University of Edinburgh, Edinburgh EH8 9XD, UK.
John E. Harries
Affiliation:
SERC Daresbury Laboratory, Warrington WA4 4AD, UK.
Raymond T. Bailey
Affiliation:
Department of Chemistry, University of Strathclyde, Glasgow Gl 1XL, UK
David W. L. Hukins
Affiliation:
Department of Medical Biophysics, University of Manchester, Manchester M13 9PT, UK.
Get access Rights & Permissions [Opens in a new window]

Summary

Micellar calcium phosphate has the chemical composition and physicochemical properties that are consistent with it being a complex of the phosphate centres of casein with an acidic amorphous calcium phosphate. Similar acidic amorphous calcium phosphates have been prepared in the laboratory and for these, as well as for micellar calcium phosphate, the most appropriate crystalline model compound from which the short-range structure may be derived is brushite, CaHPO4.2H2O. The predicted secondary structures around sites of phosphorylation in the Ca2+-sensitive caseins often comprise an α-hclix-loop-α-helix motif with the sites of phosphorylation in the loop region. This motif may be important in linking the colloidal calcium phosphate with casein in native casein micelles.

Type
Original Articles
Information
Journal of Dairy Research , Volume 56 , Issue 3: Special Issue: Proceedings of the Hannah Research Institute Casein Conference , May 1989 , pp. 411 - 416
Copyright
Copyright © Proprietors of Journal of Dairy Research 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Betts, F. & Posner, A. S. 1974 An X-ray radial distribution study of amorphous calcium phosphate. Materials Research Bulletin 9, 353–360CrossRefGoogle Scholar
Blumenthal, N. C., Posner, A. S. & Holmes, J. M. 1972 Effect of preparation conditions on the properties and transformation of amorphous calcium phosphate. Materials Research Bulletin 7 1181–1190Google Scholar
Brown, W. E., Smith, J. P., Lehr, J. R. & Frazier, A. W. 1958 Crystallography of hydrated monocalcium phosphates Containing potassium or ammonium. Journal of Physical Chemistry 62 625–627CrossRefGoogle Scholar
Harries, J. E., Irlam, J. C., Holt, G., Hasnain, S. S. & Hukins, D. W. L. 1987 Analysis of EXAFS spectra from the brushite and monetite forms of calcium phosphate. Materials Research Bulletin 22 1151–1157CrossRefGoogle Scholar
Holt, C. 1982 Inorganic constituents of milk. III. The colloidal calcium phosphate of cow's milk. Journal of Dairy Research 49 29–38CrossRefGoogle ScholarPubMed
Holt, C. 1985 In Developments in Dairy Chemistry. vol. 3 pp. 143–181 (Ed. Fox, P. F.). Barking: Elsevier Applied ScienceCrossRefGoogle Scholar
Holt, C., Davies, D. T. & Law, A. J. R. 1986 Effects of colloidal calcium phosphate content and free calcium ion concentration in the milk serum on the dissociation of bovine casein micelles. Journal of Dairy Research 53 557–572CrossRefGoogle Scholar
Holt, C., Hasnain, S. S. & Hukins, D. W. L. 1982 Structure of bovine milk calcium phosphate detennined by X-ray absorption spectroscopy. Biochimica et Biophysica Acta 719 299–303CrossRefGoogle Scholar
Holt, C., Kemenade, M. J. J. M. Van, Harries, J. E., Nelson, L. S. Jr, Bailey, R. T., Hukins, D. W. L., Hasnain, S. S. & De Bruyn, P. L. 1988 a Preparation of amorphous calcium magnesium phosphates at pH 7 and characterization by X-ray absorption and Fourier transform infrared spectroscopy. Journal of Crystal Growth 92 239–252CrossRefGoogle Scholar
Holt, C., Kemenade, M. J. J. M. Van, Nelson, L. S. Jr, Hukins, D. W. L., Bailey, R. T., Harries, J. E., Hasnain, S. S. & De Bruyn, P. L. 1988 b Amorphous calcium phosphates prepared at pH 6·5 and 6·0. Materials Research Bulletin (In the Press)CrossRefGoogle Scholar
Holt, C. & Sawyer, L. 1988 Primary and predicted secondary structures of the caseins in relation to their biological functions. Protein Engineering 2 251–259CrossRefGoogle ScholarPubMed
McGann, T. C. A., Buchheim, W., Kearney, R. D. & Rlchardson, T. 1983 Composition and ultrastrue of calcium phosphate-citrate complexes in bovine milk Systems. Biochimica et Biophysica Acta 760 415–420CrossRefGoogle ScholarPubMed
McGann, T. C. A. & Pyne, G. T. 1960 The colloidal phosphate of milk. III. Nature of its association with casein. Journal of Dairy Research 27 403–417CrossRefGoogle Scholar
Pyne, G. T. 1934 The colloidal phosphate of milk. Biochemicat Journal 28 940–948Google Scholar
Pyne, G. T. & McGann, T. C. A. 1960 The colloidal phosphate of milk. II. Influence of citrate. Journal of Dairy Research 27 9–17Google Scholar
Pyne, G. T. & Ryan, J. J. 1932 Colloidal calcium phosphate of milk. Scientific Proceedings of the Royal Dublin Society 20 471–470Google Scholar
Schmidt, D. G. 1982 In Developments in Dairy Chemistry vol. 1. pp. 61–80 (Ed. Fox, P. F.). Barking: Elsevier Applied ScienceGoogle Scholar
Termine, J. D. & Eanes, E. D. 1972 Comparative changes in amorphous and apatitic calcium phosphate. Calcified Tissue Research 10 171–197Google Scholar