Out-of-equilibrium microcompartments for the bottom-up integration of metabolic functions

Abstract

Self-sustained metabolic pathways in microcompartments are the corner-stone for living systems. From a technological viewpoint, such pathways are a mandatory prerequisite for the reliable design of artificial cells functioning out-of-equilibrium. Here we develop a microfluidic platform for the miniaturization and analysis of metabolic pathways in man-made microcompartments formed of water-in-oil droplets. In a modular approach, we integrate in the microcompartments a nicotinamide adenine dinucleotide (NAD)-dependent enzymatic reaction and a NAD-regeneration module as a minimal metabolism. We show that the microcompartments sustain a metabolically active state until the substrate is fully consumed. Reversibly, the external addition of the substrate reboots the metabolic activity of the microcompartments back to an active state. We therefore control the metabolic state of thousands of independent monodisperse microcompartments, a step of relevance for the construction of large populations of metabolically active artificial cells.

Microfluidic Handling and Analysis of Giant Vesicles for Use as Artificial Cells: A Review

“…These include energy conversion, [100] metabolism, [101] polarisation, [19] growth, [14,16,102] division, [103] signaling/communication, [97,104] and motility. In the context of using the bottom-up approach for the construction artificial cells, there are a number of functionalities currently being explored.…”

Survival of self-replicating molecules under transient compartmentalization with natural selection

“…Besides the relevance for the Origins of Life, we hope that our work could trigger new research directions on applications of transient compartmentalization for chemistry or biochemistry. Perhaps, these new research directions could help overcome practical and fundamental hurdles associated with the synthesis of complex molecules, and facilitate the making of new catalysts or artificial cells [31].…”

Toward long-lasting artificial cells that better mimic natural living cells

“…Importantly, this metabolic system was able to convert chemical energy into movement, since the release of oxygen was capable of propelling the compartment. Although the metabolism was not tied to something useful for the cellular mimic, Beneyton et al [119] constructed water-in-oil droplets that contained enzymes that produced NADH and bacterially derived inverted vesicles with embedded, native NADH dehydrogenases. That is, NADH was continuously generated and consumed as long as the feedstock (glucose-6-phosphate) was present.…”