Silk fibers are known for their superior mechanical properties, with the strongest possessing over seven times the toughness of kevlar. Recently, low molecular weight non-spidroin protein, spider-silk constituting element (SpiCE), has been reported to enhance the mechanical properties of silk; however, its specific action mechanism has not yet been elucidated. Here, we explored the mechanism by which SpiCE strengthened the mechanical properties of major ampullate spidroin 2 (MaSp2) silk through hydrogen bonds and salt bridges of the silk structure via all-atom molecular dynamics simulations. Tensile pulling simulation on silk fiber with SpiCE protein revealed that the SpiCE protein enhanced the Young's modulus by up to 40% more than that of the wild type. Bond characteristic analysis revealed that SpiCE and MaSp2 formed more hydrogen bonds and salt bridges than the MaSp2 wild-type model. Sequence analysis of MaSp2 silk fiber and SpiCE protein revealed that SpiCE protein contained more amino acids that could act as hydrogen bond acceptors/donors and salt bridge partners. Our results provide insights into the mechanism by which non-spidroin proteins strengthen the properties of silk fibers and lay the groundwork for the development of material selection criteria for the design of de novo artificial silk fibers.
|Journal of the Mechanical Behavior of Biomedical Materials
|Published - 2023 Jul
Bibliographical noteFunding Information:
Funding: This work was supported by the NRF ( National Research Foundation of Korea ) funded by the Korean Government (NRF-2018-Fostering Core Leaders of the Future Basic Science Program/Global PhD Fellowship Program) [grant number 2018H1A2A1062291 ] and the Ministry of Science, ICT & Future Planning [grant number NRF-2022R1A2B5B01001928 ].
- Fiber design
- Mechanical properties
- Molecular dynamics
- Spider silk
- Spider-silk constituting element (SpiCE)
ASJC Scopus subject areas
- Biomedical Engineering
- Mechanics of Materials