Synchrotron FTIR Microspectroscopy of Single Natural Silk Fibers

• Published in: Biomacromolecules Vol. 12; no. 9; pp. 3344 - 3349
• Main Authors: Ling, Shengjie, Qi, Zeming, Knight, David P, Shao, Zhengzhong, Chen, Xin
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 12.09.2011
• Subjects: Animals; Antheraea pernyi; Applied sciences; Araneae; Biocompatible Materials - analysis; Biocompatible Materials - chemistry; Bombyx - chemistry; Bombyx mori; Exact sciences and technology; Fibers and threads; Fibroins - analysis; Fibroins - chemistry; Forms of application and semi-finished materials; Magnetic Resonance Spectroscopy; Nephila edulis; Polymer industry, paints, wood; Protein Structure, Secondary; Silk - analysis; Silk - chemistry; Spectroscopy, Fourier Transform Infrared - methods; Spectrum Analysis, Raman; Spiders - chemistry; Synchrotrons; Technology of polymers; Fourier transformation; Saturniidae; Insecta; Bombyx mori; Experimental study; Infrared spectrometry; Solid state; Silk; Arthropoda; Natural fiber; Bombycidae; Lepidoptera; Antheraea pernyi; Invertebrata; Comparative study; Synchrotron radiation; Conformation
• ISSN: 1525-7797; 1526-4602; 1526-4602
• DOI: 10.1021/bm2006032

Synchrotron FTIR (S-FTIR) microspectroscopy was used to monitor the silk protein conformation in a range of single natural silk fibers (domestic and wild silkworm and spider dragline silk). With the selection of suitable aperture size, we obtained high-resolution S-FTIR spectra capable of semiquantitative analysis of protein secondary structures. For the first time, we have determined from S-FTIR the β-sheet content in a range of natural single silk fibers, 28 ± 4, 23 ± 2, and 17 ± 4% in Bombyx mori, Antheraea pernyi, and Nephila edulis silks, respectively. The trend of β-sheet content in different silk fibers from the current study accords quite well with published data determined by XRD, Raman, and 13C NMR. Our results indicate that the S-FTIR microspectroscopy method has considerable potential for the study of single natural silk fibers.