Accelerated Ostwald Ripening by Chemical Activity

Area of Science:

• Biochemistry
• Cell Biology
• Chemical Physics

Background:

• Biomolecular condensates drive membrane-free cellular compartmentalization.
• Condensate dynamics are regulated by energy-dependent processes.
• Phase separation is a key mechanism in cellular organization.

Purpose of the Study:

• To theoretically investigate how active chemical reactions influence the coarsening dynamics of biomolecular condensates.
• To determine the conditions under which chemical reactions can accelerate condensate coarsening.
• To explore the potential applications of controlled condensate coarsening in synthetic biology.

Main Methods:

• Development of a theoretical model for active chemical reactions driving condensate coarsening.
• Analysis of mass conservation effects on droplet volume growth.
• Investigation of reaction localization (inside vs. outside droplets) on coarsening rates.
• Comparison of theoretical predictions with experimental findings on Ostwald ripening.

Main Results:

• Active chemical reactions can significantly increase the rate of condensate coarsening.
• Mass conservation imposes a linear time dependence on droplet volume growth, similar to passive Lifshitz-Slyozov laws.
• Restricting reactions to occur outside droplets can lead to arbitrarily large increases in Ostwald ripening rates.
• Experimental data supports the theory of accelerated coarsening via fueled interconversion reactions.

Conclusions:

• Active chemical reactions provide a mechanism to rapidly coarsen biomolecular condensates.
• The spatial localization of reactions is critical for achieving accelerated coarsening.
• This work offers insights into controlling condensate dynamics for potential synthetic-biological applications, such as metabolic channeling.