Self-assembly und structure formation of spider silk proteins in (ultra-)thin films

（超）薄蜘蛛丝膜（d = 2 - 100 nm）的制备与各种（新）重组蜘蛛丝蛋白的设计相结合提供了独特的可能性，以研究丝蛋白在薄膜中在限定界面处的结构形成和自组装行为，并允许将这些过程与本体溶液中的那些进行比较。通过从水溶液中沉积来实现基底的涂覆和膜的制备。通过自组装和表面相互作用，形成了具有纳米级畴的相分离结构。该建议旨在阐明蜘蛛丝蛋白内的结构形成依赖于它们的氨基酸序列（氨基酸组成以及定义的氨基酸模块的序列）。该提案的一般问题解决了蜘蛛丝相关膜的沉积和取向的模式，以及一级结构（即序列）、氨基酸电荷和（超）薄膜中蜘蛛丝蛋白分子量的影响，以及所用支撑材料的表面化学和形貌的影响。所获得的结构纳米尺寸域的尺寸将通过模块的顺序来控制。以下目标得到了详细解决：· 蜘蛛丝蛋白膜表面结构元素的折叠（二级结构）和取向的时程（动力学、动力学）· 电荷的影响（氨基酸E与K的交换，从C-到Kappa-模块）及其与盐度和pH的关系· 通常主要部分的无规卷曲/α-螺旋富集的亲水性无定形相关于在蜘蛛丝材料内形成次要部分的β-折叠富集的疏水性结晶相的作用（包埋）· 水性（缓冲液、pH、盐度）和有机溶剂的作用· 机械纹理的作用，通过偏振FTIR光谱对二级结构单元取向的表征和高分辨率原子力显微镜技术对蜘蛛丝肽段的分离，可以得出关于结构形成机制的结论，并建立蜘蛛丝肽段的一般组装模型。丝基薄膜

The preparation of (ultra) thin spider silk films (d = 2 – 100 nm) in combination with the design of various (new) recombinant spider silk proteins offers the unique possibility to investigate the structure formation and self-assembly behavior of silk proteins in thin films at defined interfaces and allows to compare these processes to those in bulk solution. The coating of the substrates and preparation of the films is achieved by deposition from aqueous solution. By self-assembly as well as surface interaction phase separated structures with domains in the nanoscale are formed. This proposal aims at the elucidation of structure formation within spider silk proteins in dependence of their amino acid sequence (amino acid composition as well as sequence of defined amino acid modules). The general question of this proposal addresses the modalities of deposition and orientation of spider silk-related films as well as the influence of primary structure (i.e. sequence), of amino acid charge, and of the molecular weight of spider silk proteins in (ultra-)thin films, as well as the influence of surface chemistry and topography of the used support materials. The size of the gained structural nano-sized domains will be controlled via the sequence of the modules. The following aims are tackled in detail:• Time course (kinetics, dynamics) of the folding (secondary structure) and orientation of the structural elements in spider silk protein films at surfaces• Influence of charge (exchange of amino acid E by K, from C- to Kappa-module) and its relation to salinity and pH• Role of the typically major fraction of the random coil/alpha-helix rich hydrophilic amorphous phase concerning the formation of the minor fraction of beta-sheet rich hydrophobic crystalline phases within spider silk materials (embedding) • Role of the aqueous (buffer, pH, salinity) respectively organic solvent• Role of mechanical textures, orientation and surface properties of substrates concerning structure formation and orientation of the domainsThe characterization of the orientation of secondary structural elements by polarised FTIR spectroscopy and of the separation of spider silk peptide blocks by high resolution atomic force microscopy techniques allows to draw conclusions with respect to the mechanism of structure formation and to create a general assembly model of spider silk based thin films.