Mesoscale Confinement in Bagworm Silk: A Hidden Structural Organization
Mesoscale Confinement in Bagworm Silk: A Hidden Structural Organization
复制标题
成虫丝中的中尺度限制：隐藏的结构组织
DOI：
10.1021/acs.nanolett.2c03734
复制
发表时间：
2023
期刊：
影响因子：
10.8
通讯作者：
Riekel Christian
中科院分区：
文献类型：
--
作者：
Yoshioka Taiyo;Kameda Tsunenori;Burghammer Manfred;Riekel Christian
虽然由蚕和蜘蛛产生的丝纤维经常被描述为由结晶β-折叠纳米结构域增强的无定形蛋白质链的网络，但高阶自组装结构的重要性已经被认识到用于机械性能的高级建模。然而，普遍接受的层次结构模型，目前缺乏实验结果的限制。事实上，蜘蛛拖丝型纤维的X射线散射研究特别受到低堆积的限制。在这里，我们报告探测异常结晶的桑蚕丝纤维的局部结构的X射线纳米束散射。用X-射线纳米束探测横截面的可比厚度允许从外部丝胶层去除强散射背景，并且由于丝心蛋白相中的中尺度纳米纤丝束的直径的径向梯度而揭示隐藏的结构组织。我们的研究结果提供了直接支持的纳米纤维之间的横向相互作用。
While silk fibers produced by silkworms and spiders are frequently described as a network of amorphous protein chains reinforced by crystalline β-sheet nanodomains, the importance of higher-order, self-assembled structures has been recognized for advanced modeling of mechanical properties. General acceptance of hierarchical structural models is, however, currently limited by lack of experimental results. Indeed, X-ray scattering studies of spider’s dragline-type fibers have been particularly limited by low crystallinities. Here we are reporting on probing the local structure of exceptionally crystalline bagworm silk fibers by X-ray nanobeam scattering. Probing the comparable thickness of cross sections with an X-ray nanobeam allows removing the strong scattering background from the outer sericin layer and reveals a hidden structural organization due to a radial gradient in diameters of mesoscale nanofibrillar bundles in the fibroin phase. Our results provide direct support for lateral interactions between nanofibrils.