Dynamical and Structural Studies of Spider Silk Fibers

蜘蛛丝纤维的动力学和结构研究

• 批准号: 0805197
• 负责人: Jeffery Yarger
• 金额: $ 37.5万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0805197&HistoricalAwards=false
• 关键词: Dynamical; Structural; Studies; Spider; Silk

ID: MPS/DMR/BMAT(7623) 0805197 PI: Yarger, Jeffrey ORG: Arizona StateTitle: Dynamical and Structural Studies of Spider Silk FibersINTELLECTUAL MERIT: Spider silk is among the most interesting of all the naturally occurring fibers. A spider may produce up to six different silks which display a wide range of strength and extensibility. In some cases the strength and extensibility significantly exceed what has been observed in man made fibers. Some dragline silks exhibit the phenomenon of supercontraction wherein they contract by as much 55% in length upon exposure to water, leading to an increase in extensibility and reduction in strength. The origin of different behaviors in different silks is thought to relate to the primary amino acid sequence and to the secondary structure of the peptide chain, which has yet to be fully understood. The proposal outlines a schedule of research, based largely on solid state nuclear magnetic resonance spectroscopy (NMR) and neutron and X-ray scattering, designed to provide a major extension of our knowledge of the molecular structure and dynamics in the disordered region in spider silk fibers. The objectives are as follows: (1) Develop NMR spectroscopic techniques to better elucidate the short-range order, intermediate range order and/or secondary structure in amorphous or semi-crystalline biopolymers, such as spider silk fibers. (2) Better elucidate the role water plays in the (i) solvation, (ii) plastizing, and (iii) as an intercalant molecule in spider silk fibers and to determine both dynamic and structural changes brought about by hydration. (3) Provide a complete secondary structural analysis of the amorphous region in spider silk fibers using multidimensional, multinuclear NMR spectroscopy. (4) Use X-ray and neutron diffraction in collaboration with scientists at the Argonne National Laboratory to further elucidate the short and intermediate range order in spider silk fibers. (5) Correlate information regarding secondary structure with known primary amino acid sequences in order to devise a fundamental understanding of how these repetitive motifs relate to spider silk?s impressive mechanical properties. (6) Use the group's expertise in multi-instrument characterization of amorphous materials to further elucidate thermal and physical properties of spider silk materials. BROADER IMPACTS: These studies offer a new window into the relationship of structure and mechanical properties of a fascinating class of natural biological fibers. Understanding of these substances can lead to design of better synthetic polymers for a variety of important applications. Students involved in the project will be trained for scientific careers in biomaterials science, physical chemistry, and chemical physics and will have an opportunity to become familiar with the capabilities of a major national laboratory. The PI participates in several educational and outreach activities. He has teamed with the Center for Research on Education in Science, Mathematics, Engineering and Technology (CRESMET) to become a research lab partner for the inaugural 2007 Math and Science Teaching Fellows program at Arizona State University. This program brings high school and junior high teachers into the research labs for the summer for immersion in active research and the development of activities for articulating research into their K-12 classrooms. This program is funded jointly by the National Science Foundation and Science Foundation Arizona, and continues throughout the school year with in-school activities, including regular communication with the PI and research group members at the university and at the school site. An emphasis has been placed on involving underrepresented minorities in both research and educational outreach projects. Specifically, several school districts with large populations of Hispanic and Native American students have been targeted for the K-12 outreach activities described above.

ID：MPS/DMR/BMAT（7623）0805197 PI：Yarger，Jeffrey ORG：亚利桑那州州名：蜘蛛丝纤维的动力学和结构研究智力优势：蜘蛛丝是所有天然纤维中最有趣的一种。 一只蜘蛛可以产生多达六种不同的丝，它们显示出各种各样的强度和延展性。 在某些情况下，强度和延伸性显著超过在人造纤维中观察到的。一些拖丝表现出超收缩现象，其中它们在暴露于水时长度收缩多达55%，导致延展性增加和强度降低。 不同丝的不同行为的起源被认为与一级氨基酸序列和肽链的二级结构有关，这还没有完全理解。 该提案概述了一个研究时间表，主要基于固态核磁共振光谱（NMR）和中子和X射线散射，旨在提供我们对蜘蛛丝纤维中无序区域的分子结构和动力学知识的主要扩展。其目标如下：（1）开发NMR光谱技术，以更好地阐明无定形或半结晶生物聚合物（如蜘蛛丝纤维）中的短程有序、中程有序和/或二级结构。 (2)更好地阐明水在（i）溶剂化，（ii）塑化，和（iii）作为蜘蛛丝纤维中的嵌入分子中发挥的作用，并确定水合作用所带来的动态和结构变化。(3)使用多维多核核磁共振光谱法对蜘蛛丝纤维中的无定形区域进行完整的二级结构分析。(4)与阿贡国家实验室的科学家合作，使用X射线和中子衍射进一步阐明蜘蛛丝纤维中的短程和中程有序。 (5)将有关二级结构的信息与已知的一级氨基酸序列关联起来，以便对这些重复基序与蜘蛛丝的关系有一个基本的了解？令人印象深刻的机械性能。(6)利用该团队在非晶材料多仪器表征方面的专业知识，进一步阐明蜘蛛丝材料的热性能和物理性能。更广泛的影响：这些研究为了解一类迷人的天然生物纤维的结构和机械性能之间的关系提供了一个新的窗口。 对这些物质的了解可以为各种重要应用设计更好的合成聚合物。 参与该项目的学生将接受生物材料科学，物理化学和化学物理方面的科学职业培训，并将有机会熟悉主要国家实验室的能力。 PI参加了一些教育和外联活动。 他与科学、数学、工程和技术教育研究中心（CRESMET）合作，成为亚利桑那州立大学2007年首届数学和科学教学研究员项目的研究实验室合作伙伴。该计划将高中和初中教师带入夏季的研究实验室，沉浸在积极的研究中，并开发活动，将研究融入他们的K-12教室。 该计划由美国国家科学基金会和亚利桑那科学基金会共同资助，并在整个学年继续开展校内活动，包括与PI和研究小组成员在大学和学校进行定期交流。 重点是让代表性不足的少数群体参与研究和教育推广项目。 具体而言，上述K-12外联活动的目标是拥有大量西班牙裔和美洲土著学生的几个学区。