Protein secondary structure of Green Lynx spider dragline silk investigated by solid-state NMR and X-ray diffraction

Dian Xu, Xiangyan Shi, Forrest Thompson, Warner S. Weber, Qiushi Mou, Jeffery Yarger

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

In this study, the secondary structure of the major ampullate silk from Peucetia viridans (Green Lynx) spiders is characterized by X-ray diffraction and solid-state NMR spectroscopy. From X-ray diffraction measurement, β-sheet nanocrystallites were observed and found to be highly oriented along the fiber axis, with an orientational order, f<inf>c</inf>≈0.98. The size of the nanocrystallites was determined to be on average 2.5nm×3.3nm×3.8nm. Besides a prominent nanocrystalline region, a partially oriented amorphous region was also observed with an f<inf>a</inf>≈0.89. Two-dimensional <sup>13</sup>C-<sup>13</sup>C through-space and through-bond solid-state NMR experiments were employed to elucidate structure details of P. viridans silk proteins. It reveals that β-sheet nanocrystallites constitutes 40.0±1.2% of the protein and are dominated by alanine-rich repetitive motifs. Furthermore, based upon the NMR data, 18±1% of alanine, 60±2% glycine and 54±2% serine are incorporated into helical conformations.

Original languageEnglish (US)
Pages (from-to)171-179
Number of pages9
JournalInternational Journal of Biological Macromolecules
Volume81
DOIs
StatePublished - Nov 1 2015

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Keywords

  • Green Lynx
  • Peucetia viridans
  • Solid-state NMR
  • Spider silk
  • Wide-angle X-ray diffraction

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Structural Biology

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