Conserved C-terminal domain of spider tubuliform spidroin 1 contributes to extensibility in synthetic fibers
Document Type
Article
Publication Title
Biomacromolecules
Department
Biological Sciences
ISSN
1525-7797
Volume
13
Issue
2
DOI
10.1021/bm201262n
First Page
304
Last Page
312
Publication Date
2-13-2012
Abstract
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.
Recommended Citation
Gnesa, E.,
Hsia, Y.,
Yarger, J.,
Weber, W.,
Lin-Cereghino, J.,
Lin-Cereghino, G. P.,
Tang, S.,
Agari, K.,
&
Vierra, C.
(2012).
Conserved C-terminal domain of spider tubuliform spidroin 1 contributes to extensibility in synthetic fibers.
Biomacromolecules, 13(2), 304–312.
DOI: 10.1021/bm201262n
https://scholarlycommons.pacific.edu/cop-facarticles/721
Comments
This work was supported by NSF RUI Grants MCB-0950372 and DMR-1105310 entitled Molecular Characterization of Black Widow Spider Silks and Mechanical Behavior of Spider Glue Silks, respectively. The X-ray analysis was supported by the National Science Foundation, Division of Materials Research, under Award No. DMR-0805197 (J.L.Y.) and the Department of Defense Air Force Office of Scientific Research (AFOSR) Award No. FA9550-10-1-0275 (J.L.Y.). We would also like to acknowledge Robert Henning for the assistance with the BioCARS beamline and his work is supported by the U.S. DOE, Argonne National Laboratories. under Contract No. DE-AC02-06CH11357. Lastly, we thank Dr. Kristin Kohler for her critical reading of the manuscript.