Effects of bovine amelogenins on the crystal morphology of octacalcium phosphate in a model system of tooth enamel formation
Effects of bovine amelogenins on the crystal morphology of octacalcium phosphate in a model system of tooth enamel formation
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DOI：
10.1016/s0022-0248(00)00984-2
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发表时间：
2001-01-01
影响因子：
1.8
通讯作者：
Moradian-Oldak, J
中科院分区：
文献类型：
--
作者：
Iijima, M;Moriwaki, Y;Moradian-Oldak, J
釉原蛋白是发育中的牙釉质的细胞外基质的主要蛋白质组分，并且被认为通过提供微晶起始和生长的适当结构框架而在控制釉质微晶的生长中起关键作用。在牙釉质形成的模型系统中评价了牛釉原蛋白对磷酸八钙（OCP）晶体生长的影响，其中离子扩散由阳离子选择膜和透析膜控制。反应在37 ℃下进行，在膜之间的小空间中有和没有10%的釉原蛋白，使用10 mM Ca和PO4溶液调节至pH 6.5作为离子源。在5%白蛋白和10%明胶中进行一些平行反应以进行比较。白蛋白和明胶使OCP晶体尺寸减小，而釉原蛋白对OCP晶体生长的影响是显著的。在10%的釉原蛋白中，棒状和棱柱状的OCP晶体占主导地位，而特征性的带状OCP在没有蛋白质的情况下生长，并且具有明胶和白蛋白。此外，在釉原蛋白中生长的晶体的侧面上观察到蛋白质吸附。在釉原蛋白中生长的OCP晶体的宽度与厚度（WIT）之比显著小于对照OCP和在明胶和白蛋白中生长的OCP晶体。釉原蛋白抑制OCP生长的顺序为b轴方向> c棱方向> a轴方向。这些数据表明，釉原蛋白与OCP晶体的相互作用在（0 1 0）面上比在（1 0 0）面上强。从釉原蛋白的晶体结构和疏水性两个方面讨论了釉原蛋白与OCP晶体的相互作用。本实验表明，疏水性釉原蛋白参与控制生物矿化过程，如晶体形态的调制。(C)2001 Elsevier Science B.V.保留所有权利。
Amelogenins are the major protein component of the extracellular matrix of developing dental enamel and are believed to play critical roles in controlling the growth of enamel crystallites by providing the appropriate structural framework within which the crystallites initiate and grow. Effects of bovine amelogenins on the growth of octacalcium phosphate (OCP) crystals were evaluated in a model system of tooth enamel formation, where ionic diffusion was controlled by a cation selective membrane and a dialysis membrane. Reactions were carried out at 37 degreesC with and without 10% amelogenins in a small space between the membranes, using 10 mM Ca and PO4 solutions adjusted at pH 6.5 as ionic sources. Some parallel reactions were carried out in 5% albumin and 10% gelatin for a comparison. While albumin and gelatin decreased the crystal size of OCP, the effect of amelogenins on the growth of OCP crystals was remarkable. Rod-like and prism-like OCP crystals were predominant in 10% amelogenins, while characteristic ribbonlike OCP grew without protein, and with gelatin and albumin. Moreover, protein adsorption was observed on the side faces of the crystals grown in amelogenins. The width to thickness (WIT) ratio of OCP crystals grown in amelogenins was significantly smaller than those of control OCP and OCP crystals grown in gelatin and albumin. Amelogenin suppressed the growth of OCP in the order, b-axis > c-arris > a-axis direction. These data suggest that interactions of amelogenins with OCP crystals are stronger on the (0 1 0) faces than those on the (1 0 0) faces. The interaction between amelogenins and OCP crystal is discussed from the view point of the crystal structure and hydrophobic nature of amelogenins. The present experiment suggests that the hydrophobic amelogenin proteins are involved in controlling biomineralization processes such as modulation of crystal morphology. (C) 2001 Elsevier Science B.V. All rights reserved.