Protein dynamics in the THz-range

The mechanism by which the protein dynamics give rise to the particular function is still not understood. We have characterised different amino acids and different proteins in the THz-regime with FTIR absorption spectroscopy over a large frequency range (0.5 THz to 9 THz). We compare these results with molecular dynamics simulations and the spectra of their constituents - water and amino acids. In contrast to amino acids, proteins do not show sharp absorption peaks in the THz-range. Their dynamical behaviour is, as that of water, dominated by relaxation processes.