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Antheraea pernyi silk fiber: a potential resource for artificially biospinning spider dragline silk.

Zhang Y, Yang H, Shao H, Hu X - J. Biomed. Biotechnol. (2010)

Bottom Line: It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk.It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk.The tensile properties, the optical orientation and the beta-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China.

ABSTRACT
The outstanding properties of spider dragline silk are likely to be determined by a combination of the primary sequences and the secondary structure of the silk proteins. Antheraea pernyi silk has more similar sequences to spider dragline silk than the silk from its domestic counterpart, Bombyx mori. This makes it much potential as a resource for biospinning spider dragline silk. This paper further verified its possibility as the resource from the mechanical properties and the structures of the A. pernyi silks prepared by forcible reeling. It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk. Under a controlled reeling speed of 95 mm/s, the breaking energy was 1.04 x 10(5) J/kg, the tensile strength was 639 MPa and the initial modulus was 9.9 GPa. It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk. The tensile properties, the optical orientation and the beta-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s.

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SEM images of the surfaces of the A. pernyi silks obtained at different spinning speeds: (a) 25 mm/s, (b) 68 mm/s, and (c) 100 mm/s.
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fig4: SEM images of the surfaces of the A. pernyi silks obtained at different spinning speeds: (a) 25 mm/s, (b) 68 mm/s, and (c) 100 mm/s.

Mentions: Three SEM images of the surfaces of A. pernyi silk fibers obtained at different spinning speeds are given in Figure 4. It can be seen that the surface morphology is obviously affected by the spinning speed. Some longitudinal cracking lines appear and the fiber surface becomes rough when the spinning speed increases. This is probably because the sericin shell or silk fibroin core of the fiber partially ruptures during forcibly silking at higher reeling speeds. Thus the morphological defects also possibly cause the drop of the tensile strength when the reeling speed rises from 95 to 100 mm/s. The rough surface may be further related to sericin coating. As we mentioned previously, insufficient spinning dope could be supplied by the A. pernyi silkworm at 100 mm/s or higher speed. Therefore, the silk fibroin core of the fiber cannot be fully coated with sericin at the spinneret orifice of the silkworm. Comparing to silk fibroin, sericin makes minor contribution to the mechanics of silk fiber. However, it was reported that sericin could induce the transition of silk fibroin from the random coil or α-helix to the β-sheet structure, and further improve the mechanical properties of silk fibroin fibers [49]. The incomplete or ruptured sericin coating is one of the possible reasons for the decrease of the crystallinity index when the reeling speed rises from 95 to 100 mm/s.


Antheraea pernyi silk fiber: a potential resource for artificially biospinning spider dragline silk.

Zhang Y, Yang H, Shao H, Hu X - J. Biomed. Biotechnol. (2010)

SEM images of the surfaces of the A. pernyi silks obtained at different spinning speeds: (a) 25 mm/s, (b) 68 mm/s, and (c) 100 mm/s.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2864894&req=5

fig4: SEM images of the surfaces of the A. pernyi silks obtained at different spinning speeds: (a) 25 mm/s, (b) 68 mm/s, and (c) 100 mm/s.
Mentions: Three SEM images of the surfaces of A. pernyi silk fibers obtained at different spinning speeds are given in Figure 4. It can be seen that the surface morphology is obviously affected by the spinning speed. Some longitudinal cracking lines appear and the fiber surface becomes rough when the spinning speed increases. This is probably because the sericin shell or silk fibroin core of the fiber partially ruptures during forcibly silking at higher reeling speeds. Thus the morphological defects also possibly cause the drop of the tensile strength when the reeling speed rises from 95 to 100 mm/s. The rough surface may be further related to sericin coating. As we mentioned previously, insufficient spinning dope could be supplied by the A. pernyi silkworm at 100 mm/s or higher speed. Therefore, the silk fibroin core of the fiber cannot be fully coated with sericin at the spinneret orifice of the silkworm. Comparing to silk fibroin, sericin makes minor contribution to the mechanics of silk fiber. However, it was reported that sericin could induce the transition of silk fibroin from the random coil or α-helix to the β-sheet structure, and further improve the mechanical properties of silk fibroin fibers [49]. The incomplete or ruptured sericin coating is one of the possible reasons for the decrease of the crystallinity index when the reeling speed rises from 95 to 100 mm/s.

Bottom Line: It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk.It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk.The tensile properties, the optical orientation and the beta-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China.

ABSTRACT
The outstanding properties of spider dragline silk are likely to be determined by a combination of the primary sequences and the secondary structure of the silk proteins. Antheraea pernyi silk has more similar sequences to spider dragline silk than the silk from its domestic counterpart, Bombyx mori. This makes it much potential as a resource for biospinning spider dragline silk. This paper further verified its possibility as the resource from the mechanical properties and the structures of the A. pernyi silks prepared by forcible reeling. It is surprising that the stress-strain curves of the A. pernyi fibers show similar sigmoidal shape to those of spider dragline silk. Under a controlled reeling speed of 95 mm/s, the breaking energy was 1.04 x 10(5) J/kg, the tensile strength was 639 MPa and the initial modulus was 9.9 GPa. It should be noted that this breaking energy of the A. pernyi silk approaches that of spider dragline silk. The tensile properties, the optical orientation and the beta-sheet structure contents of the silk fibers are remarkably increased by raising the spinning speeds up to 95 mm/s.

Show MeSH