title: Low-frequency spectroscopic analysis of monomeric and fibrillar lysozyme.
abstract: Terahertz time-domain spectroscopy (THz-TDS) and Fourier transform infrared (FT-IR) spectroscopy were used to generate far-infrared and low-frequency spectral measurements of monomeric lysozyme and lysozyme fibrils. The formation of lysozyme fibrils was verified by the Thioflavin T assay and transmission electron microscopy (TEM). It was evident in the FT-IR spectra that between 150 and 350 cm(-1) the two spectra diverge, with the lysozyme fibrils showing higher absorbance intensity than the monomeric form. The broad absorption phenomenon is likely due to light scattered from the fibrillar architecture of lysozyme fibrils as supported by simulation of Rayleigh light scattering. The lack of discrete phonon-like peaks suggest that far-infrared spectroscopy cannot detect vibrational modes between the highly ordered hydrogen-bonded beta-pleated sheets of the lysozyme subunit.
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Hidayatul A
authors.initials: HA
authors.lastname: Zakaria
authors.forename: Bernd M
authors.initials: BM
authors.lastname: Fischer
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Bradley
authors.forename: Inke
authors.initials: I
authors.lastname: Jones
authors.forename: Derek
authors.initials: D
authors.lastname: Abbott
authors.forename: Anton P J
authors.initials: AP
authors.lastname: Middelberg
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Falconer
mesh_terms: D000682:Amyloid / Q000737:chemistry* / Q000648:ultrastructure; D000818:Animals; D002645:Chickens; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D055068:Terahertz Spectroscopy / Q000379:methods*
chemical_list: D000682:Amyloid; D009113:Muramidase