pH-Driven Compartmentalization in Coacervate Protocells Enables Programmable Microreactors

Area of Science:

• Synthetic Biology
• Biochemistry
• Materials Science

Background:

• Bottom-up construction of artificial cells is crucial for understanding protocell evolution.
• Developing functional protocell models requires efficient methods for creating responsive microcompartments.

Purpose of the Study:

• To develop a streamlined method for constructing pH-adaptive protocells.
• To engineer protocells capable of functioning as microreactors for cascade biochemical reactions.

Main Methods:

• Utilized liquid-liquid phase separation (LLPS) of poly(diallyldimethylammonium chloride) (PDDA) and adenosine triphosphate (ATP) to form coacervate microdroplets.
• Self-assembled phospholipid semipermeable membranes around coacervates.
• Manipulated pH to alter ATP hydrolysis, modulating coacervate surface charge, surface potential, and interfacial tension, inducing secondary phase separation and dynamic microcompartments.

Main Results:

• Successfully constructed pH-adaptive protocells via LLPS of PDDA and ATP.
• Demonstrated that pH changes induce secondary phase separation, creating reconfigurable internal microcompartments.
• Showcased coupling of biocatalysis with structural dynamics, where enzymatic reactions drive pH-mediated micro-compartmentalization.

Conclusions:

• The engineered protocell model exhibits programmable dynamic micro-compartmentalization.
• This model serves as an efficient microreactor for cascade biochemical reactions.
• Offers potential applications in cellular mimicry, synthetic protobiology, and artificial biomolecular microreactors.