Bulletin of the Chemical Society of Japan · 2002 · 29 citations · 50 references
Natural SciencesBiochemistryChemistryMolecular BiophysicsSpectroscopic AnalysisSpectroscopyAbsorption SpectroscopyInfrared SpectroscopyMolecular SpectroscopyOptical SpectroscopySpectroscopy Of BiomoleculesTerahertz SpectroscopyAbsorption Cross SectionsAbsorption SpectraBlack-body RadiationFar-infrared SpectroscopyInfrared SpectraRaman ScatteringResonance Raman SpectroscopySpectral Features
Abstract Pulsed terahertz (THz) radiation and black-body radiation are applied to measure far infrared (FIR) absorption spectra of polypeptides and cytochrome c in the wavenumber region from 7 cm-1 to 160 cm-1. In the region from 7 cm-1 to 55 cm-1, FIR absorption cross sections of polyglycine and poly-L-alanine in powder are greater than those of glycine and L-alanine in powder. On the other hand, FIR absorption spectra of cytochrome c in lyophilized powder show little dependence on protein structures. The structures of biopolymers are investigated by mid-IR absorption (polypeptides and cytochrome c) and by resonance Raman scattering (cytochrome c). FIR spectral features of biopolymers in the THz frequency region are qualitatively discussed in terms of density of states and homogeneous/inhomogeneous broadening.
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