Fig. 3: Typical cases of enzymatic regulation in coacervate systems.
From: Recent advances in coacervate protocells from passive catalysts to chemically programmable systems
a (I) Schematic comparing a homogeneous solution with a phase-separated system: co-localizing enzyme and substrate in the dense phase increases local and overall rates. (II) A representative kinetic trace shows faster product accumulation with coacervates than in bulk. Reproduced with permission49. Copyright 2025, Springer Nature. b Cascade in a coacervate-in-proteinosome hybrid (uricase → H₂O₂ → HRP (horseradish peroxidase) /Amplex Red → resorufin). The coacervate interface and the proteinosome membrane form two transport barriers in series; product must exit the droplet and cross the membrane, so overall flux is capped even if the first step is faster. Reproduced with permission50. Copyright 2021, Royal Society of Chemistry. c (I) Schematic of pH-triggered in situ coacervation inside a GUV (giant unilamellar vesicle) that co-localizes enzyme (E) and substrate (S) to switch a dormant reaction ON. (II) Corresponding confocal images of the same system (scale bar: 5 μm): pH 11 (OFF, no coacervates) and pH 9 (ON, coacervates); returning to high pH turns the reaction OFF again. Reproduced with permission53. Copyright 2020, Wiley-VCH GmbH.
