CSIRO Materials Science and Engineering, Pigdons Road, Waurn, Ponds, VIC 3216, Australia.
Biopolymers. 2014 Jun;101(6):630-9. doi: 10.1002/bip.22431.
Raspy crickets produce silk webs that are used to build shelters. These webs have been found to consist of both fiber and film components. Raman spectra obtained from both components were found to be very similar for a given species. The protein structure of the fibers and films produced by both species was predominately β-sheet with lesser amounts of β-turns, unordered and α-helical protein also detected. The orientation of the β-sheet backbone in the fiber was determined to be parallel to the fiber axis. Compared to cocoon and dragline silk the orientation distribution exhibits a significant randomly orientated protein component. Amino acid analysis confirmed the presence of glycine, serine, and alanine in both species, which are known to form antiparallel β-sheet structures. Both species, although at significantly different concentrations, where found to contain proline. This amino acid is uncommon in insect silks, and likely involved in increasing fiber elasticity.
粗嘎作响的蟋蟀会产生用于建造庇护所的丝质蛛网。这些蛛网由纤维和薄膜两种成分构成。研究发现，给定物种的两种成分的拉曼光谱非常相似。两种物种产生的纤维和薄膜的蛋白质结构主要是β-折叠，β-转角、无规卷曲和α-螺旋蛋白质的含量较少。纤维中β-折叠主链的取向被确定为平行于纤维轴。与茧丝和牵引丝相比，取向分布表现出明显的随机取向的蛋白质成分。氨基酸分析证实两种物种都含有甘氨酸、丝氨酸和丙氨酸，它们已知形成反平行β-折叠结构。尽管两种物种的浓度明显不同，但都发现含有脯氨酸。这种氨基酸在昆虫丝中不常见，可能参与增加纤维的弹性。
