STUDIES OF MUSSEL BYSSAL THREADS AND PROTEIN FILMS FROM ARTIFICIAL SPIDER SILK

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 生物材料的性能往往超过人造材料。具有优异力学性能的两种材料分别是贻贝独特的锚固系统、贻贝和蜘蛛牵引丝。虽然贻贝丝线的机械性能一端是软橡胶，另一端是坚硬的尼龙，但蜘蛛拉线丝在整个长度上都非常坚韧。我们的目标是在分子水平上了解这些材料，并获得它们在生物材料应用方面的高潜力。为此，我们在BioCAT光束线18ID上使用了使用显微衍射仪的纤维X射线衍射，检测到沿线蛋白质组分的取向和二级结构存在显著差异。虽然丝线的弹性部分由取向较少的蛋白质组成，但硬质部分的成分沿线轴线定向良好。在硬线上可以观察到代表胶原三螺旋结构的信号。此外，分线状反射表明胶原纤维呈周期性排列，类似于脊椎动物I型胶原的D-周期。我们还设计并重组生产了人造蜘蛛拖丝蛋白。这些蛋白质可以加工成不同的形态，如薄膜、凝胶、泡沫和胶囊。我们能够从不同溶液中浇铸的薄膜获得衍射图。我们目前正在改进样品制备方法，以获得更好的分辨率衍射图。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The properties of biological materials often exceed those of man-made ones. Two materials with outstanding mechanical properties are the unique anchorage system of the mussel Mytilus galloprovincialis, the mussel byssus, and spider dragline silk. While the mechanical properties of mussel byssal threads resemble those of soft rubber at one end and rigid nylon at the other, spider dragline silk is very tough throughout its length. Our goal is to understand these materials on a molecular level and to access their high potential for biomaterial applications. To this end, we used Fiber X-Ray Diffraction using the micro-diffraction instrument on the BioCAT beamline 18ID and detected significant differences in the orientation and the secondary structure of proteinaceous components along the thread. While the elastic part of the thread consists of less-oriented proteins, the components of the stiff portion are well-oriented along the thread axis. In the stiff thread signals representative for the triple helical structure of collagen were observed. Additionally meridonal reflections indicate a periodic arrangement of the collagen fibrils similar to the D-Period in vertebrate collagen type I. We have also designed and recombinantly produced artificial spider dragline silk proteins. These proteins can be processed into different morphologies, such as films, gels, foams and capsules. We were able to obtain diffraction patterns from films cast from different solutions. We are now working on improved sample preparation methods in order to obtain better resolved diffraction patterns.