Stabilization of amorphous calcium carbonate by phosphate rich organic matrix proteins and by single phosphoamino acids
Stabilization of amorphous calcium carbonate by phosphate rich organic matrix proteins and by single phosphoamino acids
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DOI：
10.1016/j.jsb.2010.04.007
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发表时间：
2010-08-01
影响因子：
3
通讯作者：
Berman, Amir
中科院分区：
文献类型：
--
作者：
Bentov, Shmuel;Weil, Simy;Berman, Amir
稳定的无定形碳酸钙（ACC）是一种独特的材料，仅作为生物矿物天然产生。证明了从生物来源的稳定ACC提取的蛋白质在体外诱导和稳定合成ACC。聚磷酸盐分子类似地显示在体外诱导无定形碳酸钙形成。因此，我们测试的假设，生物ACC的诱导和稳定是由磷酸化残基的磷蛋白介导的。我们发现，从红螯螯虾Cherax quadricarinatus胃石中提取的细胞外有机基质在体外诱导稳定的ACC形成。这种有机基质的蛋白质部分高度磷酸化，并在沉淀过程中掺入ACC矿物相。我们已经确定了有机基质的主要磷蛋白，并表明它们具有高的钙结合能力。在此基础上，在体外沉淀实验与单一的磷酸氨基酸进行，表明磷酸丝氨酸或磷酸苏氨酸单独可以诱导形成高度稳定的ACC。结果表明，磷蛋白可能在ACC的形成和稳定的控制中发挥重要作用，其磷酸氨基酸部分是在这个过程中的关键组成部分。(C)2010年爱思唯尔公司All rights reserved.
Stable amorphous calcium carbonate (ACC) is a unique material produced naturally exclusively as a biomineral. It was demonstrated that proteins extracted from biogenic stable ACC induce and stabilize synthetic ACC in vitro. Polyphosphate molecules were similarly shown to induce amorphous calcium carbonate formation in vitro. Accordingly, we tested the hypothesis that biogenic ACC induction and stabilization is mediated by the phosphorylated residues of phosphoproteins. We show that extracellular organic matrix extracted from gastroliths of the red claw crayfish Cherax quadricarinatus induce stable ACC formation in vitro. The proteinaceous fraction of this organic matrix is highly phosphorylated and is incorporated into the ACC mineral phase during precipitation. We have identified the major phosphoproteins of the organic matrix and showed that they have high calcium binding capacity. Based on the above, in vitro precipitation experiments with single phosphoamino acids were performed, indicating that phosphoserine or phosphothreonine alone can induce the formation of highly stable ACC. The results indicate that phosphoproteins may play a major role in the control of ACC formation and stabilization and that their phosphoamino acid moieties are key components in this process. (C) 2010 Elsevier Inc. All rights reserved.