Spatial Positioning and Chemical Coupling in Coacervate‐in‐Proteinosome Protocells

Abstract

The integration of molecularly crowded microenvironments into membrane‐enclosed protocell models represents a step towards more realistic representations of cellular structure and organization. Herein, the membrane diffusion‐mediated nucleation of either negatively or positively charged coacervate microdroplets within the aqueous lumen of individual proteinosomes is used to prepare nested hybrid protocells with spatially organized and chemically coupled enzyme activities. The location and reconfiguration of the entrapped droplets are regulated by tuning the electrostatic interactions between the encapsulated coacervate and surrounding negatively charged proteinosome membrane. As a consequence, alternative modes of a cascade reaction involving membrane‐ and coacervate‐segregated enzymes can be implemented within the coacervate‐in‐proteinosome protocells.

Light-powered CO 2 fixation in a chloroplast mimic with natural and synthetic parts

“…Two recent developments in bio-and nanotechnology promise to afford integrated systems of higher efficiency, approaching or rivaling that of natural biological systems. One is the emergence of microfluidics as technology platform to manipulate and assemble constitutive elements and functions of living systems in miniaturized and confined environments (4,(10)(11)(12)(13)(14)(15)(16). The second is the successful design and realization of complex biomimetic modules and systems from defined biological parts.…”

Membrane-confined liquid-liquid phase separation toward artificial organelles

“…Alternatively, membraneless protocells can be synthesized by spontaneous coacervation leading to liquid-liquid phase separation (LLPS) (18)(19)(20)(21). Notwithstanding versatile protocells currently available, considerable challenges exist in bottom-up synthesis of artificial cells with tiered structures and advanced functions (22)(23)(24)(25)(26)(27).…”

From vesicles to materials: bioinspired strategies for fabricating hierarchically structured soft matter

“…The sub-compartmentalization can be mimicked in vesicles if their core is composed of a reagent mixture that undergoes liquid-liquid phase separations such as oppositely charged reagents that form sub-µm to µm sized coacervates [97,98]. These coacervates can be used to locally up-concentrate enzymes, thereby increasing their efficiency to catalyse biochemical reactions, [97,99] or to control the secondary structures of certain DNA or RNA strands [100]. To enable the in situ formation of sub-compartments within vesicles, phase separations have been triggered through a protein-mediated selective transmembrane transport of DNA, [101] or through external stimuli if some of the reagents respond to them [102].…”