Structural, spatial, and temporal features guiding amelogenins transformation of calcium phosphate into enamel

引导牙釉蛋白将磷酸钙转化为牙釉质的结构、空间和时间特征

• 批准号: 10297021
• 负责人: Wendy J Shaw
• 金额: $ 48.76万
• 依托单位: BATTELLE PACIFIC NORTHWEST LABORATORIES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-19 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10297021
• 关键词: 3-Dimensional; Adsorption; Affect; Amelogenesis Imperfecta; Amino Acid Substitution; Amino Acids; Atomic Force Microscopy; Binding; Coupled; Crystallization; Dental Enamel; Development; Disease; Enamel Formation; Extracellular Matrix; Goals; Growth; Hydroxyapatites; In Situ; In Vitro; Individual; Ions; Knockout Mice; Knowledge; Lead; Maps; Microscopic; Minerals; Modification; Molecular; Morphology; Mus; Mutation; N-terminal; Nanosphere; Natural regeneration; Nature; Needles; Outcome; Phase; Phase Transition; Phenotype; Process; Property; Proteins; Raman Spectrum Analysis; Research; Roentgen Rays; Role; Scanning; Site; Spatial Distribution; Spectrum Analysis; Structural Protein; Structure; System; Techniques; Therapeutic; Time; Tissues; Ursidae Family; Variant; Vertebrates; Work; X ray microscopy; amelogenin; base; biomineralization; calcium phosphate; crystallinity; design; falls; in vivo; insight; mineralization; mouse model; nanoscale; particle; prevent; protein distribution; protein protein interaction; protein structure; repaired; solid state nuclear magnetic resonance; spatial relationship; tomography; tool; transmission process

Project Summary The goal of the proposed work is to develop a molecular level, structural understanding of the role of amelogenin in directing the hierarchical growth of enamel. Enamel is one of the hardest biominerals known, and is hierarchically structured to prevent crack propagation, allowing it to last many people a lifetime. However, naturally occurring diseases or damage do occur to enamel and our current therapies fall far short of nature made enamel. Over the past decade we have come to understand that amelogenin assembles into quaternary structures as oligomers containing 12 proteins, units which further assemble into nanospheres. These assemblies, the molecular level interactions governing them, their interactions with calcium phosphate, and their role in mineral phase transformations, are not well understood for enamel formation. We do know that the protein amelogenin, the predominant protein in the forming enamel milieu, is critical in formation based on amelogenin null mouse models showing severely damaged enamel phenotypes. Protein structure often dictates function, yet we have only begun to reveal the structure of amelogenin. Further, the mineral in the enamel milieu begins as ions, and transitions through an amorphous stage prior to becoming elongated, crystallized HAP needles. Both in vivo and in vitro studies have demonstrated that amelogenin controls this phase transformation process, but the structural, spatial, and temporal aspects of this process are not understood. In our proposed work, we bring a set of advanced characterization techniques to an in vitro system simulating developing enamel to evaluate the structure of amelogenin when interacting with calcium phosphates, to understand the spatial distribution of amelogenin around developing calcium phosphate mineral ribbons, and to develop a molecular level view of the transformation process from calcium phosphate clusters, through the amorphous phase, on to crystalline HAP. This suite of techniques has never been brought to bear on understanding the challenge of enamel growth and will result in an understanding of the development of enamel that is currently lacking. The results of this work are relevant to biomineralization systems in general and may ultimately inform more robust therapeutics for enamel replacements.

项目摘要 拟议工作的目标是发展分子水平的，结构上的理解的作用 釉原蛋白在引导釉质分层生长中的作用。釉质是已知的最坚硬的生物矿物之一， 并且是分级结构的，以防止裂缝扩展，使其能够持续许多人的一生。 然而，自然发生的疾病或损害确实会发生在牙釉质上，而我们目前的治疗方法远远不能 大自然造就了珐琅。在过去的十年里，我们逐渐了解到釉原蛋白组装成 四元结构作为包含12个蛋白质的低聚物，这些单位进一步组装成纳米球。 这些组件，控制它们的分子水平的相互作用，它们与磷酸钙的相互作用， 以及它们在矿物相变中的作用，对于牙釉质的形成还没有很好的了解。我们知道 釉原蛋白是釉质形成环境中的主要蛋白质，在形成过程中起着关键作用。 基于釉原蛋白缺失的小鼠模型显示牙釉质表型严重受损。蛋白质结构 通常决定功能，但我们才刚刚开始揭示釉原蛋白的结构。此外，矿物质中的 釉质环境以离子的形式开始，并在变得细长之前经历无定形阶段， 结晶的HAP针。体内和体外研究都表明釉原蛋白对此有控制作用。 相变过程，但这一过程的结构、空间和时间方面不是 明白了。在我们提出的工作中，我们将一套先进的表征技术引入到体外系统中 模拟牙釉质发育评价釉原蛋白与钙相互作用时的结构 磷酸盐，以了解釉原蛋白在磷酸钙矿物形成过程中的空间分布 条带，并发展从磷酸钙团簇转化过程的分子水平观点， 通过无定形相，进入晶态HAP。这套技术从来没有被运用过。 了解牙釉质生长的挑战，将有助于理解牙釉质发育 目前所缺乏的釉质。这项工作的结果总体上与生物矿化系统有关。 并最终可能为牙釉质替换提供更有力的治疗方法。