The mechanical properties of chimeric silk are improved by expressing the full-length Trichonephila clavipes major ampullate spidroin gene in the silkworm Bombyx mori via recombinant AcMNPV

Xinyu Tong; Min Zhu; Jijie Li; Qunnan Qiu; Yongjie Feng; Xiaolong Hu; Chengliang Gong

doi:10.1016/j.jmbbm.2024.106742

The mechanical properties of chimeric silk are improved by expressing the full-length Trichonephila clavipes major ampullate spidroin gene in the silkworm Bombyx mori via recombinant AcMNPV

J Mech Behav Biomed Mater. 2024 Sep 12:160:106742. doi: 10.1016/j.jmbbm.2024.106742. Online ahead of print.

Authors

Xinyu Tong¹, Min Zhu¹, Jijie Li¹, Qunnan Qiu¹, Yongjie Feng¹, Xiaolong Hu², Chengliang Gong³

Affiliations

¹ School of Life Sciences, Suzhou Medical College of Soochow University, Soochow University, Suzhou, 215123, China.
² School of Life Sciences, Suzhou Medical College of Soochow University, Soochow University, Suzhou, 215123, China; Agricultural Biotechnology Research Institute, Agricultural Biotechnology and Ecological Research Institute, Soochow University, Suzhou, 215123, China.
³ School of Life Sciences, Suzhou Medical College of Soochow University, Soochow University, Suzhou, 215123, China; Agricultural Biotechnology Research Institute, Agricultural Biotechnology and Ecological Research Institute, Soochow University, Suzhou, 215123, China. Electronic address: gongcl@suda.edu.cn.

PMID: 39284273
DOI: 10.1016/j.jmbbm.2024.106742

Abstract

Spider silk is a type of natural protein fiber with excellent toughness and tensile strength. The mechanical properties of chimeric silk have been improved by integrating the spider silk protein gene into the silkworm (Bombyx mori) genome, but this strategy requires a long time to produce genetically modified silkworms. In this study, to rapidly produce chimeric silkworms/spider silk with improved toughness and tensile strength, recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV), AcMNPV-FHP-MaSp-G, harboring a full-length Trichonephila clavipes major ampullate spidroin G (MaSp-G) gene driven by the silkworm fibroin heavy chain (Fib-H) promoter, was constructed, in which the signal peptide sequence of the MaSp-G gene was replaced by the signal peptide sequence of the Fib-H gene. Western blot and LC-MS/MS results showed that MaSp-G was successfully expressed in the posterior silk gland of silkworm larvae infected with AcMNPV-FHP-MaSp-G and secreted into the cocoon. Mechanical property tests revealed that the average maximum breaking stress and the average maximum elastic strain of chimeric silkworms/spider silk were 497.867 MPa and 14.824%, respectively, which were 36.53% and 23.55% greater than those of silk produced by normal silkworms. Fourier transform infrared (FTIR) spectroscopy revealed that the proportions of β-sheets, α-helices, and β-turns in the chimeric silk increased by 18.22%, 16.92%, and 18.72%, respectively. These results indicate that the mechanical properties of the chimeric silk produced by silkworms infected with AcMNPV-FHP-MaSp-G were significantly improved, which provides a new method for rapid production of chimeric silk in a genetically modified/genome-edited silkworm-independent manner.

Keywords: Bombyx mori; Chimeric silk; Major ampullate spidroin; Mechanical properties; Recombinant baculovirus; Trichonephila clavipes.