Protein-mineral interactions at the organic-inorganic interface in biominerals

生物矿物质中有机-无机界面的蛋白质-矿物质相互作用

• 批准号: RGPIN-2016-05031
• 负责人: McKee, Marc
• 金额: $ 2.4万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=659323
• 关键词: Protein; mineral; interactions; organic; inorganic

Bones, teeth, otoconia, eggshells, snail and sea shells, corals and many other biomineralized structures in the plant and animal kingdoms arise from synergistic interactions between co-existing organic (usually proteins) and inorganic mineral phases. These composites have specialized properties, and hierarchically organized supramolecular assemblies that provide a framework for biomineralization. Negatively charged proteins may attain regulatory chemical complementarity by binding to mineral calcium at the organic-inorganic interface − a mechanism to influence crystal growth processes. It is hypothesized that the molecular precision of such organic-inorganic interfacial interactions regulates crystal growth. My biomineralization research program focuses on specific proteins/peptides (notably osteopontin) that regulate mineral growth.***Intriguingly, amino acids, peptides and full-length proteins can be occluded within mineral crystals. Related to this, biomineralization can proceed initially through assembly of amorphous precursor nanoparticles forming within a confined, protein/peptide-rich reaction nanoenvironment. Within these nanoparticle domains, transformation towards a crystalline phase may occur over different length scales such that single crystals (by diffraction) can actually consist of aligned mineral nanoparticles, the fusion of which builds mesocrystals having occluded organics. This notion is in stark contrast to classical crystallization theory which postulates ion-by-ion attachment. My biomineralization research program compares these scenarios by exploring fundamental principles of how organics (amino acids, and relevant peptides and proteins) influence biomineralization.***We will compare two polymorphs of calcium carbonate crystals (calcite and vaterite) grown in the presence of osteopontin protein/peptides/amino acids to two biomineralized structures − avian eggshell and mouse inner ear otoconia. To study the growth of calcium carbonate crystals in the presence of these organics, a variety of morphological, biochemical, immunochemical, cell biological/molecular, and characterization techniques will be used including: electron microscopy, atomic force microscopy, confocal microscopy, X-ray and electron diffraction, Canadian Light Source synchrotron analyses, Raman spectroscopy, immunocytochemistry on mouse otoconia, in vitro cell culture and crystal growth systems, mass spectroscopy, and RosettaSurface energy-minimization computational simulations.***With this mechanistic biomineralization information on how proteins and peptides bind to crystals to regulate their growth, we will be well-positioned to create tunable mineralization events that advance biomaterials and tissue engineering applications to the benefit of Canadians and citizens worldwide.**

骨骼、牙齿、耳石、蛋壳、蜗牛和贝壳、珊瑚以及植物和动物界中的许多其他生物矿化结构都是由共存的有机（通常是蛋白质）和无机矿物相之间的协同相互作用产生的。这些复合材料具有特殊的性能和分层组织的超分子组装体，为生物矿化提供了框架。带负电的蛋白质可以通过在有机-无机界面处与矿物钙结合来实现调节化学互补性——这是一种影响晶体生长过程的机制。据推测，这种有机-无机界面相互作用的分子精度调节晶体生长。我的生物矿化研究项目重点关注调节矿物质生长的特定蛋白质/肽（尤其是骨桥蛋白）。***有趣的是，氨基酸、肽和全长蛋白质可以被封闭在矿物晶体内。与此相关的是，生物矿化最初可以通过在有限的、富含蛋白质/肽的反应纳米环境中形成的无定形前体纳米颗粒的组装来进行。在这些纳米颗粒域内，可能会在不同的长度尺度上发生向晶相的转变，使得单晶（通过衍射）实际上可以由排列整齐的矿物纳米颗粒组成，其融合形成具有吸留有机物的介晶。这一概念与假设离子间附着的经典结晶理论形成鲜明对比。我的生物矿化研究计划通过探索有机物（氨基酸以及相关肽和蛋白质）如何影响生物矿化的基本原理来比较这些情况。***我们将比较在骨桥蛋白/肽/氨基酸存在下生长的碳酸钙晶体（方解石和球霰石）的两种多晶型物与两种生物矿化结构 - 禽蛋壳和 小鼠内耳耳石。为了研究碳酸钙晶体在这些有机物存在下的生长，将使用各种形态学、生化、免疫化学、细胞生物学/分子和表征技术，包括：电子显微镜、原子力显微镜、共焦显微镜、X射线和电子衍射、加拿大光源同步加速器分析、拉曼光谱、免疫细胞化学 小鼠耳石、体外细胞培养和晶体生长系统、质谱和 RosettaSurface 能量最小化计算模拟。***有了有关蛋白质和肽如何与晶体结合以调节其生长的机械生物矿化信息，我们将处于有利位置，可以创建可调节的矿化事件，推动生物材料和组织工程应用，造福加拿大人和全世界公民。**