Abstract: Spider silk is a promising natural proteinaceous fiber that draws many researchers’ attention because of its remarkable properties and features. Relying on the rich spider resources of Yunnan province, the web frame silks of Psechrus ghecuanus (P. ghecuanus) and Araneus gratiolus (A. gratiolus) were the study subjects; single fiber strength system, Raman spectroscopy and X-ray diffraction were used to study these two spider silks. The results reflected that the Raman spectroscopy of these two silks showed consistent peaks and β-sheets were mostly parallel to the fiber axis. But there were also some differences in the content of structures which were reflected by the peak intensity ratios. For the silk of P. ghecuanus, hydrogen-bonded Tyr was stronger and the content of β-sheets was higher, resulting in a higher strength; for the silk of A. gratiolus, the degree of orientation of the β-sheets was lower, resulting in a higher toughness. At the same time, the measurement of the X-ray diffraction pattern showed that the crystallinity of P. ghecuanus silk and A. gratiolus silk were 33% and 20%, respectively.

Key words: spider silk; protein structure; Raman spectroscopy; X-ray diffraction; mechanical property