Interaction of Osmolytes and Ions with Biopolymers

Different solutes can have tremendously different effects on the stability of proteins. For instance, simple inorganic cations follow an important rule of thumb: the higher the surface charge density of the cation the stronger the ion destabilizes proteins in solution. Interestingly, the opposite trend is observed for anions. Similarly, the small molecules tert-butanol and trimethylamine-N-oxide are structurally very similar, however they destabilize and stabilize proteins, respectively. Despite such effects on biomolecules are well established, the molecular level details are not fully understood.

We currently study the effect of osmolytes and ions on the mobility of water and protein model building blocks. Thus, we aim at unravelling the underlying molecular-level interaction between these solutes and proteins. In our present work we use the rotation of molecules, which sensitively reports on interaction of the molecules with their respective environment.