Abstract-Determination of silk fibroin secondary structure by Terahertz time domain spectroscopy

Chao Yan,   Bin Yang and   Cheng Zhi Yu  

http://pubs.rsc.org/en/content/articlelanding/2013/ay/c3ay41358f#!divAbstract

Silk fibroin membranes with different secondary structure were fabricated, and subsequently employed as an ideal system model for the investigation on conformational transition of native protein by Terahertz time domain spectroscopy (THz-TDS). In comparison to conventional Fourier Transform Infrared (FTIR) Spectroscopy, THz spectroscopy present distinct feature for each kind of secondary stucture with narrower bandwidth. Based on the theoretical calculation, absorption features observed in the range of 2.0-2.6THz may be attributed to intramolecular modes of peptide chain. Three bands centered at 1.84 THz, 1.68 THz, and 1.55 THz are attributed to random coil, α-helix, and antiparallel β-pleated sheet, respectively. The results indicate that THz-TDS present great poential as complementary method to FTIR in determining secondary structure of silk fibrion.