Conserved C-Terminal Domain of Spider Tubuliform Spidroin 1 Contributes to Extensibility in Synthetic Fibers

详细信息    查看全文

• 作者：Eric Gnesa ; Yang Hsia ; Jeffery L. Yarger ; Warner Weber ; Joan Lin-Cereghino ; Geoff Lin-Cereghino ; Simon Tang ; Kimiko Agari ; Craig Vierra
• 刊名：Biomacromolecules
• 出版年：2012
• 出版时间：February 13, 2012
• 年：2012
• 卷：13
• 期：2
• 页码：304-312
• 全文大小：466K
• 年卷期：v.13,no.2(February 13, 2012)
• ISSN：1526-4602

文摘

Spider silk is renowned for its extraordinary mechanical properties, having a balance of high tensile strength and extensibility. To date, the majority of studies have focused on the production of dragline silks from synthetic spider silk gene products. Here we report the first mechanical analysis of synthetic egg case silk fibers spun from the Latrodectus hesperus tubuliform silk proteins, TuSp1 and ECP-2. We provide evidence that recombinant ECP-2 proteins can be spun into fibers that display mechanical properties similar to other synthetic spider silks. We also demonstrate that silks spun from recombinant thioredoxin-TuSp1 fusion proteins that contain the conserved C-terminal domain exhibit increased extensibility and toughness when compared to the identical fibers spun from fusion proteins lacking the C-terminus. Mechanical analyses reveal that the properties of synthetic tubuliform silks can be modulated by altering the postspin draw ratios of the fibers. Fibers subject to increased draw ratios showed elevated tensile strength and decreased extensibility but maintained constant toughness. Wide-angle X-ray diffraction studies indicate that postdrawn fibers containing the C-terminal domain of TuSp1 have more amorphous content when compared to fibers lacking the C-terminus. Taken together, these studies demonstrate that recombinant tubuliform spidroins that contain the conserved C-terminal domain with embedded protein tags can be effectively spun into fibers, resulting in similar tensile strength but increased extensibility relative to nontagged recombinant dragline silk proteins spun from equivalently sized proteins.