Huang W, Lin Z, Sin Y M, Li D, Gong Z, Yang D
Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543 Singapore, Singapore.
Biochimie. 2006 Jul;88(7):849-58. doi: 10.1016/j.biochi.2006.02.010. Epub 2006 Mar 29.
Spider silks are renowned for their excellent mechanical properties. Although several spider fibroin genes, mainly from dragline and capture silks, have been identified, there are still many members in the spider fibroin gene family remain uncharacterized. In this study, a novel silk cDNA clone from the golden web spider Nephila antipodiana was isolated. It is serine rich and contains two almost identical fragments with one varied gap region and one conserved spider fibroin-like C-terminal domain. Both in situ hybridization and immunoblot analyses have shown that it is specifically expressed in the tubuliform gland. Thus, it likely encodes the silk fibroin from the tubuliform gland, which supplies the main component of the inner egg case. Unlike other silk proteins, the protein encoded by the novel cDNA in water solution exhibits the characteristic of an alpha-helical protein, which implies the distinct property of the egg case silk, though the fiber of tubuliform silk is mainly composed of beta-sheet structure. Its sequence information facilitates elucidation of the evolutionary history of the araneoid fibroin genes.
蜘蛛丝以其出色的力学性能而闻名。尽管已经鉴定出几个主要来自拖牵丝和捕丝的蜘蛛丝蛋白基因，但蜘蛛丝蛋白基因家族中仍有许多成员尚未得到表征。在本研究中，从黄金圆蛛中分离出一个新的丝 cDNA 克隆。它富含丝氨酸，包含两个几乎相同的片段，有一个可变的间隔区域和一个保守的类蜘蛛丝蛋白 C 末端结构域。原位杂交和免疫印迹分析均表明它在管状腺中特异性表达。因此，它可能编码来自管状腺的丝蛋白，管状腺为内卵袋提供主要成分。与其他丝蛋白不同，新 cDNA 在水溶液中编码的蛋白质表现出α-螺旋蛋白的特征，这意味着卵袋丝具有独特的性质，尽管管状丝纤维主要由β-折叠结构组成。其序列信息有助于阐明园蛛科丝蛋白基因的进化史。
