van der Waals Forces in Biomolecular Systems: from Solvation to Long-range Interaction Mechanisms

One decisive characteristic of the biomolecular machinery is the access to a rich set of well-defined, coordinated processes. Most of these processes involve collective conformational changes and occur in an aqueous environment. Conformational changes of (bio)molecules as well as their interaction with water are thereby largely governed by non-covalent van der Waals (vdW) dispersion interactions. By virtue of their intrinsically collective nature, vdW forces also represent a key factor for collective nuclear behavior. Our understanding of intra- and intermolecular response and vdW interaction in complex (bio)molecular systems, however, is still rather limited. Here, we investigate the electronic response properties and vdW interaction in biomolecular systems within a quantum-mechanical many-body treatment. In particular, we analyze the non-local reponse of solvated proteins and highlight the role of beyond-pairwise vdW forces for protein stability and the protein-water interaction. We further examine the electronic behaviors in an enzyme-DNA complex from which the catalytically-active regions emerge as electronically-correlated domains. This phenomenon is proposed to form the basis of an efficient long-range interaction mechanism assisting biomolecular regulation and allostery.