【摘要】 偏振拉曼光谱能有效分析蜘蛛丝的蛋白质结构特征，早期的研究对象多为人工抽取的络新妇属蜘蛛的曳丝，而同为大壶状腺丝的骨架丝及其他科属的蛛丝却很少被研究报道。为探讨自然状态下蛛丝蛋白二级结构与力学性能之间的关系，使用偏振拉曼光谱对艾蛛属的黑腹艾蛛、希蛛属的翘腹希蛛的骨架丝进行研究。结果表明，这两种丝有着相似的氨基酸序列和结构，且β-折叠平行于丝的轴线，但翘腹希蛛丝其余大部分的二级结构却垂直于丝的轴线，这一特殊结构也导致翘腹希蛛丝的断裂伸长率(42.18±11.84%)高于黑腹艾蛛丝(23.85±5.18%)。同时，从不同峰强比、方向不敏感光谱得出，翘腹希蛛丝β-折叠结构的取向度比黑腹艾蛛丝的高，但相近的β-折叠结构、络氨酸氢键含量导致两丝的断裂强度变化差异不显著。蛛丝拉曼光谱的重现性较好，可用于研究更多种类的蛛丝，为开发利用蛛丝提供依据。更多还原

【Abstract】 Polarized Raman spectroscopy is an effective method for analysing features of the protein structure in spider silk, and most of the early study subjects were artificially extracted drag silks of Nephila. To analyse the relationships between the conformations and properties of different spider silks in their natural states, polarized Raman spectroscopy was used to study the web frame silks of Cyclosa nigra(C. nigra, belonging to the genus Cyclosa) and Achaearanea celsabdomina(A. celsabdomina, belonging to the genus Achaearanea), the web frame silk belongs to the same major ampullate silk as the drag silk. The results show that silks that belong in a different family have similar amino acid sequences and structures, and their β-sheets are oriented parallel to the fibre axis. The difference is that the most of the other secondary structures in the A. celsabdomina silk are oriented perpendicular to the fibre axis; as a result, A. celsabdomina silk exhibits a higher ultimate strain(42.18±11.84%) than C. nigra silk(23.85±5.18%). Additionally, the different ratios of peak intensities and orientation-insensitive spectra indicates that the degree of orientation in the β-sheets of A. celsabdomina silk is higher than that of C. nigra silk, but the similar contents of β-sheets(the contents of β-sheets in C. nigra silk and A. celsabdomina silk are 32% and 33%, respectively) and hydrogen-bonded Tyr residues lead to similar breaking strengths for the two silks(the breaking strengths of C. nigra silk and A. celsabdomina silk are 205.00±25.73 MPa and 236.16±19.46 MPa, respectively). The Raman spectra of the silks show good consistency, so Raman spectroscopy can be used to study more varieties of spider silks, which could offer a theoretical basis for the exploitation and utilization of spider silks.更多还原