Primitive Molecular Buffering by Low-Multivalency Coacervates

Area of Science:

• Biochemistry
• Origin of Life Studies
• Biophysics

Background:

• Coacervate droplets, formed via liquid-liquid phase separation (LLPS), model intracellular condensates and protocells.
• Protocells and cells require homeostasis to maintain internal functions against environmental fluctuations (salinity, pH).

Purpose of the Study:

• To investigate how coacervate molecular composition and RNA compartmentalization are affected by varying salinity and pH.
• To evaluate the potential of coacervates to provide molecular buffering and resist environmental changes.

Main Methods:

• Formation and analysis of oligoarginine (R10)/ATP coacervates under diverse salinity and pH conditions.
• Assessment of coacervate molecular composition and RNA accumulation within droplets.

Main Results:

• R10/ATP coacervates demonstrated molecular buffering, resisting changes in oligoarginine concentration across different salt conditions.
• RNA accumulation was observed within coacervates across a range of pH, salinity, and R10/ATP stoichiometry.
• Salinity influenced molecular buffering and RNA compartmentalization by altering intermolecular binding modes.

Conclusions:

• LLPS in coacervates provides mechanisms for resisting environmental changes and maintaining molecular availability, mimicking primitive homeostasis.
• These findings support the role of coacervates in the emergence of life and suggest potential biotechnological applications.