Terahertz Dance of Proteins and Sugars with Water

摘要

The influence of water on biomolecular interfaces and functionality has been in the focus of hydration studies. Improved experimental and computational probes gave insight to this question from different perspectives. The aspect of collective water network dynamics has been experimentally accessed by terahertz (THz) spectroscopy, which is sensitive to even small solute-induced rearrangements of the water network in the biomolecular surroundings. THz hydration studies uncovered that the dynamical hydration shell of saccharides consists of several hundred water molecules and up to thousand water molecules for proteins. Mutations at the protein surface and inside the core perturb the dynamical hydration, whereas it is noticeable that native wild-type proteins most significantly affect hydration dynamics. Kinetic THz absorption (KITA) studies of protein folding recently revealed that solvent dynamics are coupled to secondary structure formation of the protein. The solvent water network is dynamically rearranged in milliseconds before the protein folds to its native state within the following seconds. THz spectroscopy gives experimental evidence that collective long-range dynamics are a key factor of biomolecular hydration.