Ultrafast vibrational dynamics and local interactions of hydrated DNA.

Biochemical processes occur mainly in aqueous environments, where interactions with water molecules play a key role for both the structure and function of biomolecules. Deoxyribonucleic acid (DNA), the basic carrier of genetic information, is characterized by an equilibrium double helix structure which is held together by intermolecular hydrogen bonds between base pairs and hydrated by an environment of water molecules with fluctuating hydrogen bonds. Basic vibrational motions of hydrated DNA and the fastest changes in the DNA-water interactions and hydration geometries occur in less than 1 ps. These processes can be accessed by mapping the vibrational dynamics of DNA and water in a time-resolved way by nonlinear ultrafast vibrational spectroscopy. Recent studies provide a detailed understanding of DNA vibrations and their dynamics, and give insight into nonequilibrium properties and structures of hydrated DNA.