Nucleation of apatite crystals in vitro by self-assembled dentin matrix protein, 1
Nucleation of apatite crystals in vitro by self-assembled dentin matrix protein, 1
复制标题
DOI：
10.1038/nmat945
复制
发表时间：
2003-08-01
期刊：
影响因子：
41.2
通讯作者：
George, A
中科院分区：
文献类型：
--
作者：
He, G;Dahl, T;George, A
骨骼和牙齿是生物复合材料，在其自组装过程中需要控制矿物沉积以形成具有独特机械性能的组织。酸性细胞外基质蛋白在生物矿物质形成过程中起着关键作用。然而，蛋白质介导的矿物起始机制尚不清楚。在这里，我们报道了牙本质基质蛋白1 (DMP1)，一种酸性蛋白，可以在体外形成羟基磷灰石的多步骤过程中形成核，该过程始于DMP1结合钙离子并启动矿物沉积。成核的无定形磷酸钙沉淀成熟，形成纳米晶。随后，这些晶体膨胀并合并成沿c轴方向拉长的微尺度晶体。DMP1中功能域的表征表明，酸性团簇在分子间组装成p片模板是观察到的矿物成核所必需的。本文所讨论的蛋白质介导的纳米晶体起始可能为构建纳米级复合材料提供一种新的方法；通过定制肽序列的多肽自组装。
Bones and teeth are biocomposites that require controlled mineral deposition during their self-assembly to form tissues with unique mechanical properties. Acidic extracellular matrix proteins play a pivotal role during biomineral formation. However, the mechanisms of protein-mediated mineral initiation are far from understood. Here we report that dentin matrix protein 1 (DMP1), an acidic protein, can nucleate the formation of hydroxyapatite in vitro in a multistep process that begins by DMP1 binding calcium ions and initiating mineral deposition. The nucleated amorphous calcium phosphate precipitates ripen and nanocrystals form. Subsequently, these expand and coalesce into microscale crystals elongated in the c-axis direction. Characterization of the functional domains in DMP1 demonstrated that intermolecular assembly of acidic clusters into a P-sheet template was essential for the observed mineral nucleation. Protein-mediated initiation of nanocrystals, as discussed here, might provide a new methodology for constructing nanoscale composites; by self-assembly of polypeptides with tailor-made peptide sequences.