Intracrystalline Protein Repeat Sequences: Structure and Function

9901356Evans本项目的重点是生物分子为基础的材料的一个新兴领域，称为生物矿化，这是一种生物指导的过程，导致形成复合材料--即与无机材料相关的聚合物。生物矿化的一个有趣的模式系统是海胆和海绵：在它们的胚胎阶段，这两种生物都会产生一种以碳酸钙为基础的矿物结构，称为针状结构。在海胆中，针状物最初是单晶方解石，但形成了包裹钙质相的无定形碳酸钙相。随着显影的进行，无定形相随后转变为方解石。在海绵中，情况略有不同：一些针状体要么完全由无定形碳酸钙组成，要么具有被无定形相包围的钙质核心。在这两种生物中，无机基质都包含一种以蛋白质为基础的、与矿物相平行的自组装基质。组成这种基质的蛋白质含有一种以蛋白质为基础的、与矿物相平行的自组装基质，并被认为可以稳定无定形相和/或表现出抗断裂或弹性性能。为了了解这些蛋白质如何执行其功能，将进行核磁共振和分子模拟研究，以确定海胆针状体基质蛋白质序列的结构，以及这些特定结构域如何相互关联，与矿物环境，或在力伸展下的行为。从这些研究中获得的数据不仅将有助于理解生物自组装、无机相稳定性和抗断裂性能是如何在针状体内发生的，而且还将导致开发一种新型和通用的仿生材料的分子蓝图。该项目的教育目标将包括为研究生和本科生开发多学科培训计划，以及让高中生参与生物、化学和物理领域的研究项目。为了寻找更好的材料，可以用于医学、航空航天和制造，科学家们现在转向自然，在那里，简单的生物，如海胆和海绵，已经开发出保护它们免受环境影响的结构。这些结构包括与碳酸钙等无机材料相关的天然聚合物。我们的计划是在分子水平上研究这些结构。从这些研究中，将出现新的材料加工策略，创造环境友好型材料，并改善材料性能，如抗裂性或材料稳定性。

9901356EvansThe focus of this project is on an emerging area of biomolecular-based materials referred to as biomineralization, an organism-directed process which lead to the formation of composites - i.e., polymers in association with inorganic material. An interesting model system in biomineralization are sea urchins and sponges: in their embryonic stage, both organisms produce a calcium carbonate-based mineral structure known as the spicule. In sea urchins, the spicule begins as single crystal calcite, but develops an amorphous calcium carbonate phase which envelopes the calcitic phase. The amorphous phase then transforms into calcite as development proceeds. In sponges, the story is slightly different: some spicules are either entirely comprised of amorphous calcium carbonate, or, have a calcitic core which is surrounded by the amorphous phase. In both organisms, the inorganic matrix contains a protein-based, self-assembled matrix which runs parallel to the mineral phase. The proteins which comprise this matrix contains a protein-based, self-assembled matrix which runs parallel to the mineral phase, and are believed to stabilize the amorphous phase and/or manifest fracture-resistant or elastic properties. To understand how these proteins perform their functions, NMR and molecular modeling studies will be undertaken to determine the structure of sea urchin spicule matrix protein sequences, and, how these particular domains may either associate with each other, with the mineral environment, or, behave under force extension. The data obtained from these studies will not only help to understanding how biological self-assembly, inorganic phase stability, and fracture resistance occur within spicules, but will also lead to the development of a molecular blueprint for novel and versatile biomimetic-based materials. Educational goals within this project will include the development of multidisciplinary training programs for graduate and undergraduate students, as well as involvement of high school students in research projects which draw from the areas of biology, chemistry, and physics.In a quest for better materials that can be used in medicine, aerospace and manufacturing, scientists are now turning to Nature, where simple organisms, such as sea urchins and sponges, have developed way to generate structures that protect them from their environment. These structures involve naturally-occurring polymers that associate with inorganic-based materials like calcium carbonate. Our plan is to study these structures tat the molecular level. From these studies, new strategies will emerge for material processing, creating environmentally-friendly materials, and improving material properties such as fracture resistance or material stability.