Calcified Tissue International

, Volume 27, Issue 1, pp 75–82 | Cite as

Effect of proteoglycans on in vitro hydroxyapatite formation

  • N. C. Blumenthal
  • A. S. Posner
  • L. D. Silverman
  • L. C. Rosenberg
Laboratory Investigations

Summary

Well-characterized bovine nasal proteoglycan A1 fraction (aggregate) and proteoglycan D1 fraction (subunit) have been shown to be effective inhibitors of hydroxyapatite (HA) formation in two in vitro test systems: (a) the transformation of amorphous calcium phosphate (ACP) to crystalline HA, and, (b) the direct precipitation of HA from low-concentration calcium phosphate solutions. A1 or D1 in solution slowed the transformation kinetics in system (a) without affecting the time to the onset of conversion. In system (b), A1 or D1 in solution increased the time to the onset of HA formation without affecting the HA formation kinetics. In both test systems A1 was a more effective inhibitor than D1, although the difference was not great. In both systems the inhibitory effect was proportional to the A1 or D1 solution concentration. The action of solutions of low and high molecular weight neutral dextrans on both test systems showed that high molecular weight and/or extended spatial molecular conformation has a much stronger correlation with inhibitory ability than solution viscosity. Proteoglycans have been implicated as playing a role in regulating biological mineralization particularly in the epiphyseal growth plate. Our study suggests that just enzymatic cleavage of aggregate into subunit is not sufficient to allow mineralization to occur, since we find that D1 itself is a potent inhibitor of HA formation. Further degradation and/or removal of D1 appears to be necessary for calcification to take place.

Key words

Proteoglycans Hydroxyapatite Amorphous calcium phosphate Nucleation Calcification 

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References

  1. 1.
    Howell, D.S., Pita, J.C.: Calcification of growth plate cartilage with special reference to studies on micropuncture fluid, Clin. Orthop.118:208–229, 1976PubMedGoogle Scholar
  2. 2.
    Matukas, V.J., Krikos, G.A.: Evidence for changes in protein polysaccharide associated with the onset of calcification in cartilage. J. Cell. Biol.39:43–46, 1968PubMedCrossRefGoogle Scholar
  3. 3.
    Howell, D.S., Carlson, L.: Alterations in the composition of growth cartilage septa during calcification studied by microscopic x-ray elemental analysis, Exp. Cell Res.51:185–195, 1968PubMedCrossRefGoogle Scholar
  4. 4.
    Howell, D.S., Pita, J.C., Marquez, J.F., Madruga, J.E.: Partition of calcium phosphate and protein in the fluid phase aspirated at calcifying sites in epiphyseal cartilage, J. Clin. Invest.47:1121–1132, 1968PubMedGoogle Scholar
  5. 5.
    Howell, D.S., Pita, J.C., Marquez, J.F., Gatter, R.A.: Demonstration of macromolecular inhibitors of calcification and nucleational factors in fluid from calcifying sites in cartilage, J. Clin. Invest.48:630–641, 1969CrossRefPubMedGoogle Scholar
  6. 6.
    Cuervo, L.A., Pita, J. C., Howell, D.S.: Inhibition of calcium phosphate mineral growth by proteoglycan aggregate fractions in a synthetic lymph, Calcif. Tissue Res.13:1–10, 1973PubMedCrossRefGoogle Scholar
  7. 7.
    Rosenberg, L., Wolfenstein-Todel, C., Margolis, R., Pal, S., Strider, W.: Proteoglycans from bovine proximal humeral articular cartilage, J. Biol. Chem.251:6439–6444, 1976PubMedGoogle Scholar
  8. 8.
    Blumenthal, N.C., Posner, A.S., Holmes, J.M.: Effect of preparation conditions on the properties and transformations of amorphous calcium phosphate, Mat. Res. Bull.7:1181–1190, 1972CrossRefGoogle Scholar
  9. 9.
    Boskey, A.L., Posner, A.S.: Conversion of amorphous calcium phosphate to microcrystalline hydroxyapatite: a pH-dependent, solution mediated, solid-solid conversion, J. Phys. Chem.77:2313–2317, 1973CrossRefGoogle Scholar
  10. 10.
    Boskey, A.L., Posner, A.S.: Formation of hydroxyapatite at low supersaturation, J. Phys. Chem.80:40–45, 1976CrossRefGoogle Scholar
  11. 11.
    Blumenthal, N.C., Betts, F., Posner, A.S.: Stabilization of amorphous calcium phosphate by Mg and ATP, Calcif. Tissue Res.23:245–250, 1977PubMedCrossRefGoogle Scholar
  12. 12.
    Rosenberg, L., Hellmann, W., Kleinschmidt, A.K.: Electron microscopic studies of proteoglycan aggregates from bovine articular cartilage, J. Biol. Chem.250:1877–1883, 1975PubMedGoogle Scholar
  13. 13.
    Physicochemical state of ions and water in living tissues and model systems, N.Y. Acad. Sci.204: 1973Google Scholar
  14. 14.
    Balazs, E.A., Bothner-By, A.A., Gergely, J.: Proton magnetic resonance studies on water in the presence of various macromolecular substances, J Mol. Biol.1:147–154, 1959CrossRefGoogle Scholar
  15. 15.
    Blumenthal, N.C., Betts, F., Posner, A.S.: Effect of carbonate and biological macromolecules on formation and properties of hydroxyapatite, Calcif. Tissue Res.18:81–90, 1975PubMedGoogle Scholar
  16. 16.
    Maroudas, A.: Biophysical chemistry of cartilaginous tissues with special reference to solute and fluid transport, Biorheology12:233–248, 1975PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • N. C. Blumenthal
    • 1
  • A. S. Posner
    • 1
  • L. D. Silverman
    • 1
  • L. C. Rosenberg
    • 2
  1. 1.Hospital For Special SurgeryCornell University Medical CollegeNew York
  2. 2.Montefiore HospitalAlbert Einstein College of MedicineBronx

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