Probing the Molecular Structure and Dynamics of Spider Silk Proteins

探讨蜘蛛丝蛋白的分子结构和动力学

• 批准号: 1264801
• 负责人: Jeffery Yarger
• 金额: $ 44万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1264801&HistoricalAwards=false
• 关键词: Probing; Molecular; Structure; Dynamics; Spider

ID: MPS/DMR/BMAT(7623) 1264801 PI: Yarger, Jeffrey ORG: Arizona State UniversityTitle: Probing the Molecular Structure and Dynamics of Spider Silk Proteins Technical: Spiders produce a variety of proteins, which are pulled into silk fibers possessing mechanical properties that can outperform other natural and synthetic fibers. A full molecular level understanding of the physical properties of these fibers has not yet been achieved. The fibers contain a complex set of secondary protein structures and nanocrystalline domains. The PI will explore the molecular structure and protein-protein dynamics of major and minor ampullate silk proteins (dragline and web-building), cylindrical silk proteins (also named tubuliform, used for egg case) and aciniform silk proteins (prey wrapping). The ultimate goal is to establish relationships between structural features and mechanical function in a variety of natural silk proteins from several different spiders, including orb-weaving (Nephila and Argiope) and cobweaving (Latrodectus hesperus) spiders. Elucidation of molecular structure will primarily be carried out using multidimensional solid-state NMR (ssNMR) techniques. Use of 13C, 15N and 1,2H isotopically enriched silks will allow 2D/3D carbon and nitrogen homo- and heternuclear NMR experiments to determine extensive through-bond and through-space correlations. These techniques, along with ultrafast magic angle spinning (MAS) and advanced 1H homonuclear decoupling, should allow for complete assignment of spider silk spectra and elucidate all secondary structure elements in these biopolymers. Pair distribution functions (PDF) obtained from fiber x-ray and neutron diffraction will further be developed to characterize the nano-structures and short-range amorphous structures in oriented spider silk fibers. The PI will also develop and use 2H/13C 2D NMR techniques to interrogate molecular dynamics of spider silk proteins. Taken together, these studies should produce an unprecedented level of detail regarding the molecular structure and dynamics of natural spider silk fibers.Non-Technical: Spiders produce various protein-based polymers that we call silk. Understanding silk at a molecular level is critical to utilizing this material and reverse engineering its properties. The ability to duplicate spider silk properties in man-made protein-based materials is the key to using these high-performance biopolymers in 'real-world' applications. A first step in this process is giving engineers the molecular level detailed information about the structure and dynamics in the natural material in order to reproduce this in recombinant or synthetic constructs. The proposed project will develop new understandings into the structural design of several natural spider silks. Accomplishment of the objectives outlined above will provide new methodologies to determine protein fiber structures and correlate these structures with mechanical properties as well as provide broad training in molecular structure analysis to students. These research projects will involve a student research team consisting of graduate, undergraduate, and high-school students. The research team will be exposed to scientific research and instrumentation at both Arizona State University and Argonne National Laboratory. The research group will also participate in NSF sponsored K-12 teacher summer research programs and will provide demonstrations of spider silk research to local area K-12 schools. Specific emphasis will be placed on outreach to underrepresented Hispanic and Native American schools and neighborhoods.

ID：MPS/DMR/BMAT（7623）1264801 PI：Yarger，Jeffrey ORG：Arizona State University亚利桑那州立大学蜘蛛丝蛋白的分子结构和动力学研究技术：蜘蛛产生多种蛋白质，这些蛋白质被拉成具有机械性能的丝纤维，这些纤维的机械性能可以超过其他天然和合成纤维。 对这些纤维的物理性质的完整分子水平的理解尚未实现。 纤维包含一组复杂的二级蛋白质结构和纳米晶结构域。 PI将探索主要和次要壶状丝蛋白（拖丝和蛛网），圆柱形丝蛋白（也称为管状，用于卵壳）和腺泡状丝蛋白（猎物包裹）的分子结构和蛋白质-蛋白质动力学。 最终的目标是建立结构特征和机械功能之间的关系，在各种天然丝蛋白从几个不同的蜘蛛，包括圆织（Nephila和Argiope）和cobweaving（Latrodectus hesperus）蜘蛛。 分子结构的解析将主要使用多维固态NMR（ssNMR）技术进行。 使用13 C、15 N和1，2 H同位素富集的丝将允许2D/3D碳和氮同核和异核NMR实验来确定广泛的通过键和通过空间的相关性。 这些技术，沿着与超快魔角自旋（MAS）和先进的1H homopolysaccharide去耦，应该允许蜘蛛丝光谱的完整分配，并阐明这些生物聚合物中的所有二级结构元素。 对分布函数（PDF）从纤维的X射线和中子衍射得到的进一步发展，以表征纳米结构和短程无定形结构的取向蜘蛛丝纤维。 PI还将开发和使用2 H/13 C 2D NMR技术来询问蜘蛛丝蛋白的分子动力学。 总之，这些研究应该产生一个关于天然蜘蛛丝纤维的分子结构和动力学的前所未有的细节水平。非技术：蜘蛛产生各种蛋白质为基础的聚合物，我们称之为丝。 在分子水平上理解蚕丝对于利用这种材料和逆向工程其特性至关重要。 在人造蛋白质材料中复制蜘蛛丝特性的能力是在“现实世界”应用中使用这些高性能生物聚合物的关键。 该过程的第一步是为工程师提供有关天然材料结构和动力学的分子水平详细信息，以便在重组或合成构建体中重现这些信息。 该项目将对几种天然蜘蛛丝的结构设计产生新的认识。 上述目标的实现将提供新的方法来确定蛋白质纤维结构，并将这些结构与机械性能相关联，并为学生提供分子结构分析方面的广泛培训。 这些研究项目将涉及一个由研究生，本科生和高中生组成的学生研究团队。 研究小组将在亚利桑那州立大学和阿贡国家实验室接触科学研究和仪器。 该研究小组还将参加NSF赞助的K-12教师暑期研究计划，并将向当地K-12学校提供蜘蛛丝研究的演示。 具体重点将放在推广到代表性不足的西班牙裔和美洲土著学校和社区。