Chapter 24. Formation and Structure of Calciprotein Particles: The Calcium Phosphate-Ahsg/Fetuin-A Interface

  1. Prof. Dr. Edmund Bäuerlein
  1. Alexander Heiss and
  2. Dietmar Schwahn

Published Online: 20 MAR 2008

DOI: 10.1002/9783527619443.ch24

Handbook of Biomineralization: Biological Aspects and Structure Formation

Handbook of Biomineralization: Biological Aspects and Structure Formation

How to Cite

Heiss, A. and Schwahn, D. (2007) Formation and Structure of Calciprotein Particles: The Calcium Phosphate-Ahsg/Fetuin-A Interface, in Handbook of Biomineralization: Biological Aspects and Structure Formation (ed E. Bäuerlein), Wiley-VCH Verlag GmbH, Weinheim, Germany. doi: 10.1002/9783527619443.ch24

Editor Information

  1. Max-Planck-Institute for Biochemistry, Department of Membrane Biochemistry, Am Klopferspitz 18 A, 82152 Planegg, Germany

Publication History

  1. Published Online: 20 MAR 2008
  2. Published Print: 25 MAY 2007

ISBN Information

Print ISBN: 9783527316410

Online ISBN: 9783527619443

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Keywords:

  • fetuin-A;
  • calcification;
  • inhibition;
  • colloid;
  • small-angle neutron scattering;
  • contrast variation;
  • core-shell topology

Summary

Fetuin-A is a plasma protein that acts as a potent systemic inhibitor of ectopic calcification. A lowered fetuin-A serum level in end-stage renal disease patients usually leads to severe vascular and valvular calcifications. Further clinical relevance is provided by fetuin-A-deficient mice developing similar calcifications. The inhibition is based on the formation of nanometer-sized fetuin-calcium phosphate particles, though such inhibition is only transient. This chapter reports on the structural dynamics of these colloidal particles in an in-vitro model system elucidated by small-angle neutron scattering. A two-step particle formation characterized by a rapid increase in particle size was observed. A detailed contrast variation analysis of second-stage particles revealed that they consist of an octacalcium phosphate core shielded by a dense fetuin-A monolayer.