The emerging role of ATP as a cosolute for biomolecular processes.

ATP is an important small molecule that appears at outstandingly high concentration within the cellular medium. Apart from its use as a source of energy and a metabolite, there is increasing evidence for important functions as a cosolute for biomolecular processes. Owned to its solubilizing kosmotropic triphosphate and hydrophobic adenine moieties, ATP is a versatile cosolute that can interact with biomolecules in various ways. We here use three models to categorize these interactions and apply them to review recent studies. We focus on the impact of ATP on biomolecular solubility, folding stability and phase transitions. This leads us to possible implications and therapeutic interventions in neurodegenerative diseases.