Analysis of self-assembly and apatite binding properties of amelogenin proteins lacking the hydrophilic C-terminal
Analysis of self-assembly and apatite binding properties of amelogenin proteins lacking the hydrophilic C-terminal
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DOI：
10.1016/s0945-053x(01)00190-1
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发表时间：
2002-03-01
期刊：
影响因子：
6.9
通讯作者：
Gharakhanian, N
中科院分区：
文献类型：
--
作者：
Moradian-Oldak, J;Bouropoulos, N;Gharakhanian, N
釉原蛋白是矿化牙釉质细胞外基质的主要蛋白质成分，对于正常牙釉质形成至关重要，正如一组遗传性疾病的连锁研究中所记录的那样。牙釉质形成有缺陷，称为釉质生成不全。最近的牙釉质生成不全病例包括导致牙釉原蛋白截短、缺乏亲水性 C 末端氨基酸的突变。当前关于牙釉蛋白结构、纳米球组装及其对晶体生长的影响的知识进展支持了这样的假设：牙釉蛋白纳米球为牙釉质磷灰石晶体的引发和调节生长提供有组织的微观结构。为了评估保守的亲水性C末端端肽在牙釉质生物矿化过程中的功能。本研究旨在分析缺乏亲水性 C 末端的牙釉蛋白及其异构体的自组装和磷灰石结合行为。我们应用动态光散射来研究由一系列天然和重组蛋白形成的牙釉蛋白纳米球的尺寸分布。此外，使用市售羟基磷灰石晶体检查了这些牙釉蛋白的磷灰石结合特性。缺乏羧基末端的牙釉蛋白（天然 P161 和重组 rM166）形成的纳米球比其全长前体（天然 P173 和重组 rM179）形成的纳米球更大。这些数据表明，在去除亲水性羧基末端片段后，纳米球通过疏水性相互作用进一步缔合。缺乏羧基末端区域的牙釉蛋白与磷灰石晶体的亲和力显着低于其母体牙釉蛋白。这些结构功能分析表明，亲水性羧基末端在牙釉质矿化中起着关键的功能作用，并且缺乏该片段会导致矿化异常。 (C) 2002 年 Elsevier Science B.V. 和国际基质生物学学会。版权所有。
Amelogenins, the major protein component of the mineralizing enamel extracellular matrix are critical for normal enamel formation as documented in the linkage studies of a group of inherited disorders. with defective enamel formation, called Amelogenesis imperfecta. Recent cases of Amelogenesis imperfecta include mutations that resulted in truncated amelogenin protein lacking the hydrophilic C-terminal amino acids. Current advances in knowledge on amelogenin structure, nanospheres assembly and their effects on crystal growth have supported the hypothesis that amelogenin nanospheres provide the organized microstructure for the initiation and modulated growth of enamel apatite crystals. In order to evaluate the function of the conserved hydrophilic C-terminal telopeptide during enamel biomineralization. the present study was designed to analyze the self-assembly and apatite binding behavior of amelogenin proteins and their isoforms lacking the hydrophilic C-terminal. We applied dynamic light scattering to investigate the size distribution of amelogenin nanospheres formed by a series of native and recombinant proteins. In addition, the apatite binding properties of these amelogenins were examined using commercially available hydroxyapatite crystals. Amelogenins lacking the carboxy-terminal (native P161 and recombinant rM166) formed larger nanospheres than those formed by their full-length precursors: native P173 and recombinant rM179. These data suggest that after removal of the hydrophilic carboxy-terminal segment further association of the nanospheres takes place through hydrophobic interactions. The affinity of amelogenins lacking the carboxy-terminal regions to apatite crystals was significantly lower than their parent amelogenins. These structure-functional analyses suggest that the hydrophilic carboxy-terminal plays critical functional roles in mineralization of enamel and that the lack of this segment causes abnormal mineralization. (C) 2002 Elsevier Science B.V. and International Society of Matrix Biology. All rights reserved.