Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, People's Republic of China.
Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, People's Republic of China.
Int J Biol Macromol. 2020 Feb 15;145:437-444. doi: 10.1016/j.ijbiomac.2019.12.027. Epub 2019 Dec 13.
Orb-weaving spiders produce a diversity of silk fibers throughout their entire lifecycle, and each silk type is given a specific purpose. As a dry fiber material with wet glue, pyriform silks are different from other silk fibers and make the attachment discs which are used for bonding fibers together and attaching dragline silk to other substrates. To date, only two full-length pyriform spidroin 1 (PySp1) gene sequences were identified. Here we present a novel full-length pyriform spidroin 2 (PySp2) from orb-weaving spider, Araneus ventricosus. Although the A. ventricosus PySp2 lack the long linker regions, the central repetitive region of PySp2 is more complex than PySp1 and can be classified into four types of repetitive regions including three novel repetitive sequences and one type of repetitive region that is similar to PySp1 repeats. Prediction of hydrophobicity of A. ventricosus PySp2 reveals the two new repetitive regions display strong hydrophilicity. Analysis of CD spectrum and secondary structure prediction for A. ventricosus PySp2 repeat unit reveal α-helix conformation dominates the repetitive region. Furthermore, recombinant protein-based artificial fibers show the single repeat unit is sufficient for self-assembling into silk fiber.
结网蜘蛛在其整个生命周期中产生多种类型的丝纤维，每种丝类型都有特定的用途。作为一种具有湿胶的干性纤维材料，梨形丝不同于其他丝纤维，它形成用于将纤维粘在一起的附盘，并将牵引丝固定在其他基质上。迄今为止，仅鉴定出两种全长梨形丝蛋白 1 (PySp1) 基因序列。在这里，我们展示了来自结网蜘蛛 Araneus ventricosus 的一种新型全长梨形丝蛋白 2 (PySp2)。尽管 A. ventricosus PySp2 缺乏长连接区，但 PySp2 的中心重复区比 PySp1 更复杂，可分为四种重复区，包括三种新型重复序列和一种与 PySp1 重复相似的重复区。对 A. ventricosus PySp2 疏水性的预测表明，两个新的重复区具有很强的亲水性。对 A. ventricosus PySp2 重复单元的 CD 光谱和二级结构预测分析表明，α-螺旋构象主导重复区。此外，基于重组蛋白的人工纤维表明，单个重复单元足以自行组装成丝纤维。
