Protein Conformational Dynamics Measured With Terahertz Time Domain Spectroscopy

Tertiary structural vibrational modes of proteins are at far infrared or terahertz frequencies. These modes involve collective motion of many atoms and are indicative of the protein structure, hydration and binding with ligands and other proteins. The measurements of conformational change have focused on the hydration, denaturing effects, and photoactive proteins bacteriorhodopsin. In addition, a strong sensitivity of the terahertz response to heme protein oxidation state is shown. The impact of the results on biomolecular switching mechanisms as well as applications to biomolecular sensing is discussed.