Comparison of vibrational spectra of proteins with similar secondary and different tertiary structures

Methods of vibrational (Raman and FTIR) spectroscopy are used in a search for spectral features sensitive to changes of the tertiary structure of protein molecules. Spectra of several proteins with similar secondary and substantially different tertiary structures are measured in the fingerprint and low-frequency spectral intervals. Spectral changes related to natural degradation caused by long-term storage of coiled-coil protein (fibrinogen) are revealed and discussed in terms of changes of the secondary and tertiary structures. Selection of spectral bands sensitive to changes of the tertiary structure is based on the comparative analysis of the vibrational spectra of proteins with different tertiary structures.