1. Protein secondary structure of Green Lynx spider dragline silk investigated by solid-state NMR and X-ray diffraction.
- Author
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Xu D, Shi X, Thompson F, Weber WS, Mou Q, and Yarger JL
- Subjects
- Amino Acid Sequence, Animals, Female, Molecular Sequence Data, Silk ultrastructure, Insect Proteins chemistry, Magnetic Resonance Spectroscopy, Protein Structure, Secondary, Silk chemistry, Spiders chemistry, X-Ray Diffraction
- 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, fc≈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 fa≈0.89. Two-dimensional (13)C-(13)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., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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