蜘蛛牵引丝不同溶剂伸缩特性及丝蛋白构象变化的研究

Study on the Shrinkage in Solvents and the Change of Secondary Structure of Spider Silk

动物丝纤维的特殊性能与丝蛋白的构象密切相关,本文对蜘蛛牵引丝的不同溶剂下的收缩率和水处理的构象变化进行了研究。水中蜘蛛丝收缩最大,达到50%;通过红外光谱分析,对水处理的丝蛋白的构象进行了研究,结果表明丝蛋白β折叠结构增加,而β转角变化很小。氢键受到水分子的影响高频组份与低频组份比例发生变化,进而对酰胺I谱带的C=O的振动的频率产生影响,使C=O的电子云密度降低,酰胺I频率向低频方向发生移动,这说明酰胺I的振动频率与氢键是紧密相关的。

The properties of animal silk are closely related with the secondary structure of silk protein, the shrinkage in different solvents and the change of secondary structure of spider silk by different condition water are studied in the paper. The results demonstrate that the spider silk shrinks strongly to 50 percent of its length treated by water; the IR absorbing spectra demonstrates thatβ-sheet of the secondary structure of spider silk treated by water increases, at the sametime , β-turn changes little. The high frequency parts and low frequency parts of hydrogen bonds changes due to water affecting , then make the amide I C =O electron cloud density decrease, which means the vibration frequency of amideI decrease too. The result proofs that the frequency of amide I is closely related with hydrogen bonds.