We thank Dr. Eugenia Klein for her assistance in conducting the ESEM experiments, Dr. Linda Shimon and Ilit Cohen-Ofri for helping with the X-ray diffraction measurements. S. W. is the incumbent of the Dr. Walter and Dr. Trude Burchardt Professorial Chair of Structural Biology and L. A. is the incumbent of the Dorothy and Patrick Gorman Professorial Chair of Biological Ultrastructure. This research was supported by the Minerva Foundation (L. A., S. W.), the United States–Israel Binational Science Foundation (L. A., S. W.), and grants from the US National Institute of Dental and Cranio-Facial Research (F. W.).
The Transient Phase of Amorphous Calcium Carbonate in Sea Urchin Larval Spicules: The Involvement of Proteins and Magnesium Ions in Its Formation and Stabilization†
Article first published online: 5 JUN 2003
Copyright © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 13, Issue 6, pages 480–486, June, 2003
How to Cite
Raz, S., Hamilton, P.C., Wilt, F.H., Weiner, S. and Addadi, L. (2003), The Transient Phase of Amorphous Calcium Carbonate in Sea Urchin Larval Spicules: The Involvement of Proteins and Magnesium Ions in Its Formation and Stabilization. Adv. Funct. Mater., 13: 480–486. doi: 10.1002/adfm.200304285
- Issue published online: 5 JUN 2003
- Article first published online: 5 JUN 2003
- Manuscript Accepted: 6 FEB 2003
- Manuscript Received: 28 OCT 2002
- Amorphous materials;
- Calcium carbonate, amorphous;
- Sea urchin spicules
Amorphous calcium carbonate (ACC) is a precursor phase of calcite in the formation of the sea urchin larval spicule. The goal of this research is to study the formation and stabilization mode of this transient phase. We first characterized the mineralogy of the spicules from the sea urchin Strongylocentrotus purpuratus. We then examined the role of the macromolecules extracted from the spicules at different growth stages in the formation of transient ACC in vitro.The biogenic amorphous transient phase is shown to be both structurally and compositionally different from the known stable ACC phases. It does not contain bound water, and is thus the first dehydrated ACC phase to be detected. The macromolecules that were extracted at early stages of spicule growth, when the amorphous content of the biogenic mineral is high, induced the formation of transient ACC in vitro in the presence of magnesium ions. In contrast, the macromolecules extracted at a later stage, when the spicules are completely crystalline, induced the formation of single crystals of low magnesian calcite. We therefore deduce that the macromolecules from the sea urchin larval spicules together with magnesium ions, mediate the transient formation of ACC as a precursor to calcite. These observations may well provide novel ideas for improved materials synthesis.