Abstract-Theoretical Insights into sub-Terahertz Acoustic Vibrations of Proteins Measured in Single Molecule Experiments

Adrien Nicolaï, Patrice Delarue, and Patrick Senet

J. Phys. Chem. Lett., Just Accepted Manuscript

DOI: 10.1021/acs.jpclett.6b01812

http://cdn-pubs.acs.org/doi/abs/10.1021/acs.jpclett.6b01812

Proteins are an important class of nanobioparticles with acoustical modes in the sub-THz frequency range. There is a considerable interest to measure and establish the role of these acoustical vibrations for the biological function. So far, the technique providing the most detailed information about the acoustical modes of proteins is the very recent Extraordinary Acoustic Raman (EAR) spectroscopy. In this technique, proteins are trapped in nanoholes and excited by two optical lasers of slightly different wavelengths producing an electric field at low frequency (< 100 GHz). We demonstrate that the acoustical modes of proteins studied by EAR spectroscopy are both infrared and Raman active modes and we provided the interpretation of the spectroscopic fingerprints measured at the single molecule level. Combination of the present calculations with techniques based on excitation of a single nanobioparticle by an electric field, as the EAR spectroscopy, should provide a wealth of information on the role of molecular dynamics for the biological function.