Non-monotonous Concentration Dependent Solvation of ATP Could Help to Rationalize Its Anomalous Impact on Various...

Area of Science:

• Biophysics
• Molecular Biology
• Chemical Physics

Background:

• Adenosine triphosphate (ATP) is crucial for biological processes.
• ATP exhibits hydrotropic properties, aiding protein and RNA solubility.
• High ATP concentrations (>10 mM) paradoxically promote biomolecular aggregation.

Purpose of the Study:

• Investigate the concentration-dependent solvation dynamics of ATP.
• Elucidate the molecular mechanisms behind ATP's anomalous behavior at high concentrations.
• Understand ATP's role in protein and RNA folding and phase separation.

Main Methods:

• Terahertz (THz) spectroscopy (time-domain and frequency-domain).
• Spectroscopic analysis of adenosine (Adn), sodium triphosphate (TPP), and ATP solutions.
• Molecular dynamics (MD) simulations.

Main Results:

• At low ATP concentrations (2-10 mM), both adenosine and triphosphate moieties contribute equally to solvation.
• At high ATP concentrations (>10 mM), the adenosine moiety's influence on solvation structure increases.
• Higher ATP concentrations lead to slower relaxation dynamics and altered solvation shells, indicating ATP aggregation.

Conclusions:

• ATP's solvation shell and dynamics change significantly with concentration.
• The adenosine moiety plays a dominant role in ATP's aggregation behavior at supra-physiological concentrations.
• Understanding these dynamics is key to comprehending ATP's complex biological roles.