Institute of Biological Sciences and Biotechnology, Donghua University, 2999 North Renmin Road 201620, Shanghai 201620, China.
Institute of Biological Sciences and Biotechnology, Donghua University, 2999 North Renmin Road 201620, Shanghai 201620, China.
Acta Biomater. 2020 Oct 1;115:210-219. doi: 10.1016/j.actbio.2020.08.009. Epub 2020 Aug 13.
Spiders spin a range of silks from different glands for distinct functions, and each silk type exhibits distinct material properties. Silk extruded by the aciniform gland is used for prey wrapping and egg case construction and displays high toughness and extensibility. So far, only the aciniform spidroin 1 (AcSp1) gene which was firstly identified as a silk gene in aciniform gland has been obtained. Here we present the gene sequence for the second type of full-length aciniform silk protein, AcSp2. Analysis of the AcSp2 primary sequence reveals relatively conserved terminal regions and a distinct repetitive sequence relative to AcSp1. A fraction of the gene can be expressed in recombinant systems. Secondary structure analysis of the recombinant AcSp2 protein in solution reveals that the protein adopts mainly an α-helical conformation. Artificial spinning of recombinant AcSp2 demonstrates that the spidroins can be spun into fine fibers which display up to 142% extensibility. The silk fibers are dominated by β-sheet and β-turn secondary structures. Moreover, the mechanical data collected from these synthetic fibers revealed that the mechanical properties are partly correlated with the molecular weights. Overall, our studies enrich our knowledge of spidroin gene family members and provide a new insight into creation of high-performance silk fibers for next generation biomaterials. STATEMENT OF SIGNIFICANCE: In this study, we presented the second type of aciniform silk protein (AcSp2) gene sequence of orb-weaving spider Araneus ventricosus, expanding the spider silk gene family members. The primary structure revealed the central repetitive sequence of the new spidroin gene is distinctly different from other AcSp1 genes. Characterization of the recombinant minispidroin fibers of AcSp2 revealed the mechanical properties are partly correlate with the molecular weights, and the spidroins can be spun into fine fibers which display up to 142% extensibility. Overall, our studies enrich our knowledge of spidroin gene family members and provide a new insight into creation of high-performance silk fibers for next generation biomaterials.
蜘蛛从不同的腺体中纺出多种不同用途的丝，每种丝类型都表现出独特的材料性能。由栉状腺分泌的丝用于包裹猎物和建造卵囊，具有高韧性和高延展性。到目前为止，只有最初在栉状腺中被鉴定为丝基因的栉状丝蛋白 1（AcSp1）基因被获得。在这里，我们展示了第二种全长栉状丝蛋白 AcSp2 的基因序列。对 AcSp2 一级序列的分析表明，与 AcSp1 相比，它具有相对保守的末端区域和独特的重复序列。该基因的一部分可以在重组系统中表达。对溶液中重组 AcSp2 蛋白的二级结构分析表明，该蛋白主要采用α-螺旋构象。重组 AcSp2 的人工纺丝表明，丝蛋白可以纺成具有高达 142%延展性的细纤维。这些丝纤维主要由β-折叠和β-转角二级结构组成。此外，从这些合成纤维中收集的力学数据表明，力学性能与分子量部分相关。总的来说，我们的研究丰富了对丝蛋白基因家族成员的认识，并为下一代生物材料的高性能丝纤维的创造提供了新的见解。
