National Facility for Protein Science in Shanghai, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, China.
School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
Methods Mol Biol. 2021;2347:207-219. doi: 10.1007/978-1-0716-1574-4_18.
The secondary structures of silk fibroin (SF) are critical in the determination of the mechanical properties of the animal silks. Different characterization techniques, such as X-ray diffraction, nuclear magnetic resonance, Raman spectroscopy, and Fourier transform infrared (FTIR) technique, have been applied to study the secondary structure of animal silks. Among these techniques, FTIR is most widely used as it is sensitive to all secondary structures of proteins. Especially with the development of FTIR imaging, it is now possible to image the secondary structures of proteins at the micrometer scale, so as to understand the spatial distribution of proteins and the interaction of proteins with other materials at specific locations of interest. In this chapter, we present the methods and protocols of FTIR imaging to silk protein-based materials. We primarily introduce how to set up the instruments and accessories, as well as how to choose the appropriate imaging methods and sample preparation methods according to sample morphologies. The critical protocols for data analysis are also introduced in the last section.
丝素（SF）的二级结构对于动物丝的机械性能的确定至关重要。已经应用了不同的表征技术，例如 X 射线衍射、核磁共振、拉曼光谱和傅里叶变换红外（FTIR）技术，来研究动物丝的二级结构。在这些技术中，FTIR 是应用最广泛的，因为它对蛋白质的所有二级结构都很敏感。特别是随着 FTIR 成像技术的发展，现在可以在微米尺度上对蛋白质的二级结构进行成像，从而了解蛋白质在特定感兴趣位置的空间分布以及蛋白质与其他材料的相互作用。在本章中，我们介绍了基于丝蛋白材料的 FTIR 成像方法和方案。我们主要介绍如何根据样品形态设置仪器和附件，以及如何选择合适的成像方法和样品制备方法。最后一节还介绍了数据分析的关键方案。
