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Free keywords:
Liquid-liquid phase separation, dynamic hybrid protocells, microfluidics, Coacervates, lipid vesicles
Abstract:
In situ, reversible coacervate formation within lipid vesicles represents a key step in the development of responsive synthetic cellular models. Here we exploit the pH responsiveness of a polycation above and below its pKa, to drive liquid-liquid phase separation to form single coacervate droplets within lipid vesicles. The process is completely reversible as coacervate droplets can be disassembled by increasing the pH above the pKa. We further show that pH triggered coacervation in the presence of low concentrations of enzymes activate dormant enzyme reactions by molecular up-concentration into the coacervate droplets. In conclusion, this work establishes a tuneable, pH responsive, enzymatically active multi-compartment synthetic cell. The system is readily transferred into microfluidics, making it a robust model for addressing general questions in biology such as the role of phase separation and its effect on enzymatic reactions using a bottom-up synthetic biology approach.
Abstract:
Die pH‐Responsivität eines Polykations über und unter seinem pKa wurde genutzt, um eine Flüssig‐flüssig‐Phasentrennung unter Bildung von Koazervattröpfchen innerhalb von Lipidvesikeln anzutreiben. Dies erfolgt reversibel, da die Tröpfchen durch Erhöhen des pH über den pKa aufgelöst werden können. pH‐induzierte Koazervierung in Gegenwart niedriger Enzymkonzentrationen aktiviert ruhende Enzymreaktionen, da die lokalen Enzym‐ und Substratkonzentrationen in den Tröpfchen erhöht sind.
