Coacervate-based bioreactors for enzyme cascades

Complex coacervates are phase-separated compartments formed by oppositely charged polyelectrolytes that provide biomimetic environments for enzymatic transformations. While numerous biochemical reactions have been carried out within coacervates, how these environments influence enzyme activity still remains poorly understood. Here, we develop a polyelectrolyte complex coacervate system stabilized by a comb polymer to host a two-step enzymatic cascade involving alcohol dehydrogenation followed by reductive amination in separate micro-compartments. Using high-throughput experimentation, we map a wide compositional phase space to reveal how coacervate structure directs enzyme localization and catalytic performance. Using electron microscopy and confocal imaging, we further investigate how internal condensate organization governs enzymatic reactivity. Finally, we demonstrate the generality of this platform by extending it to multiple enzymatic systems, establishing coacervates as versatile biomimetic reactors for coupled transformations.