Solid state 13C NMR and FT-IR spectroscopy of the cocoon silk of two common spiders

TitleSolid state 13C NMR and FT-IR spectroscopy of the cocoon silk of two common spiders
Publication TypeJournal Article
Year of Publication2005
AuthorsBramanti, E, Catalano, D, Forte, C, Giovanneschi, M, Masetti, M, Veracini, CA
JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
ISSN13861425 (ISSN)
Keywordsanimal, Animals, Article, carbon, Carbon Isotopes, chemistry, Cocoon silk, Common spiders, comparative study, Complex Compounds, Complex structures, Complexation, crystal structure, Crystalline materials, Fourier Analysis, Fourier Transform Infrared, Fourier transform infrared spectroscopy, FT-IR, Infrared Spectra, Infrared spectroscopy, Magnetic Resonance Spectroscopy, methodology, Mobile domains, NMR, nuclear magnetic resonance, Nuclear magnetic resonance spectroscopy, Protein Conformation, Silk, species difference, Species Specificity, Spectroscopy, spider, Spiders

The structure of the silk from cocoons of two common spiders, Araneus diadematus (family Araneidae) and Achaearanea tepidariorum (family Theridiidae) was investigated by means of 13C solid state NMR and FT-IR spectroscopies. The combined use of these two techniques allowed us to highlight differences in the two samples. The cocoon silk of Achaearanea tepidariorum is essentially constituted by helical and $\beta$-sheet structures, whereas that of Araneus diadematus shows a more complex structure, containing also $\beta$-strands and $\beta$-turns. Moreover, the former silk is essentially crystalline while the latter contains more mobile domains. The structural differences of the two cocoon silks are ascribed to the different habitat of the two species. © 2004 Elsevier B.V. All rights reserved.