Solid State NMR Structure/Function Studies of Amelogenin

釉原蛋白的固态核磁共振结构/功能研究

• 批准号: 7060029
• 负责人: Wendy J Shaw
• 金额: $ 40.49万
• 依托单位: BATTELLE PACIFIC NORTHWEST LABORATORIES
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7060029
• 关键词: amelogenin; calcium phosphate; chemical kinetics; crystallization; dental development; molecular assembly /self assembly; nuclear magnetic resonance spectroscopy; protein binding; protein structure function; site directed mutagenesis; structural biology

DESCRIPTION: The overall goal of this research is to elucidate the structure-function relationships of the biomineralization proteins driving the formation of enamel. Enamel is the most highly ordered biomineralization crystal and is uniquely designed to handle abrasions and mechanical stress. As with many biomineralization processes, though, very little is understood about the mechanisms controlling enamel nucleation and growth, although the presence of proteins has been deemed critical. Enamelins, tuftelins, ameloblastins and amelogenins are all present during enamel formation and all have been suggested as candidates for crystal nucleation. Amelogenin consists of 90% of the protein present during enamel growth, is necessary for proper enamel formation and is likely a major contributor in the development of the calcium phosphate crystal. In addition to a possible nucleation role, amelogenin forms unique self assembled nanospheres which are thought to be tied to the elongated growth of enamel crystals during development. Structure-function relationships will be elucidated primarily using solid state NMR (SSNMR), Quartz Crystal Microbalance (QCM) and constant composition kinetics (CCK) to study the immobilized protein under the wide variety of conditions found in developing enamel. SSNMR will be used to accurately determine the secondary structure, dynamics and amino acids important in binding the protein or protein self assembly to calcium phosphates. QCM will be used to investigate nucleation rates and protein binding kinetics. The surface specific interactions will be probed with CCK to determine crystal growth inhibition and change in crystal growth mechanism. Site directed mutations, shown to cause defects in enamel will also be studied, to further aid in understanding of the developing enamel interface. Correlating the SSNMR results with kinetic measurements will provide a great deal of insight into the importance of the secondary and quaternary structure of amelogenin in formation of the enamel matrix. These studies will yield an in depth understanding of the molecular level processes involved in the formation of teeth, and more generally will provide basic insight into protein/crystal interactions.

描述：这项研究的总体目标是阐明驱动搪瓷形成的生物矿化蛋白的结构 - 功能关系。搪瓷是最有序的生物矿化晶体，其独特而设计用于处理擦伤和机械应力。但是，与许多生物矿化过程一样，尽管蛋白质的存在被认为是至关重要的，但对控制牙釉质成核和生长的机制几乎没有理解。搪瓷蛋白，塔夫蛋白，蛋白蛋白酶和氨基蛋白蛋白在搪瓷形成期间都存在，并且都建议将其作为晶体成核的候选物。氨基蛋白蛋白在牙釉质生长过程中由90％的蛋白质组成，对于适当的搪瓷形成是必要的，可能是磷酸钙晶体发展的主要贡献者。除了可能的成核作用外，阿米尔根蛋白还形成独特的自组装纳米球，被认为与发育过程中搪瓷晶体的延长生长有关。结构 - 功能关系将主要使用固态NMR（SSNMR），石英晶体微量平衡（QCM）和恒定组成动力学（CCK）阐明，以研究在发育搪瓷发育中发现的各种条件下固定的蛋白质。 SSNMR将用于准确确定在将蛋白质或蛋白质自组装与磷酸钙结合至关重要的二级结构，动力学和氨基酸。 QCM将用于研究成核速率和蛋白质结合动力学。表面特定相互作用将与CCK探测，以确定晶体生长抑制和晶体生长机制的变化。还将研究牙釉质中显示缺陷的位置突变，以进一步帮助理解发育中的搪瓷界面。将SSNMR结果与动力学测量结果相关联，将为amelogenin在搪瓷基质形成中的二次和第四纪结构的重要性提供大量见解。这些研究将对牙齿形成所涉及的分子水平过程产生深入的了解，并且更普遍将提供对蛋白质/晶体相互作用的基本见解。