Exploration of the protein conformation and mechanical properties of different spider silks

To analyze the protein conformation and mechanical properties of what types of spider silks, web frame silks from spiders of five different families, Parawixia dehaani ( P. dehaani), Herennia ornatissima ( H. ornatis-sima), Nephilengys malabarensis ( N. malabarensis), Hippasa lycosina ( H. lycosina) and Macrothele bannaensis ( M. bannaensis), were investigated by tensile testing, Raman spectroscopy and X-ray diffraction. The order of the fracture strength or breaking force ( H. ornatissima > N. malabarensis > P. dehaani, H. lycosina > M. bannaensis) is in accordance with the order of the Raman intensity ratios or crystallinity, the order of the extensibility ( H. ornatissima < N. malabarensis < P. dehaani) is inversely proportional to the order of the degree of orientation of the ,B-sheets, which verify the theory that mechanical properties of silk mainly depends on protein conformation. Meanwhile, the Raman spectra of the web frame silks from four Araneidae spiders (Gasteracantha diadesmia, Gasteracantha kuhli, Macracantha arcuata and P . dehaani) and two Tetragnathidae spiders (Leucauge tessellata and H . ornatissima) show that the slight spectral dif-ferences might enable preliminary identification and classification of spiders. We believe that researching either the relationship between or individual performance of the mechanical properties and structures of various types of spider silks would benefit the utilization of silks as biomaterials and the classification of spider silks.(c) 2022 The Authors. Published by Elsevier B.V.

Automated summary

This study analyzed the protein conformation and mechanical properties of web frame silks from spiders of different families. The results showed a correlation between fracture strength and crystallinity as well as protein conformation. Additionally, slight spectral differences in the Raman spectra allowed for preliminary identification and classification of spider silks. The findings of this study are important for the utilization of spider silks as biomaterials and the classification of spider silks.