Cascade Reactions in Multicompartmentalized Polymersomes

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Abstract

Enzyme-filled polystyrene-b-poly(3-(isocyano-L-alanyl-aminoethyl)thiophene) (PS-b-PIAT) nanoreactors are encapsulated together with free enzymes and substrates in a larger polybutadiene-b-poly(ethylene oxide) (PB-b-PEO) polymersome, forming a multicompartmentalized structure, which shows structural resemblance to the cell and its organelles. An original cofactor-dependent three-enzyme cascade reaction is performed, using either compatible or incompatible enzymes, which takes place across multiple compartments.

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A vesicle bioreactor as a step toward an artificial cell assembly.

Vincent Noireaux, Albert Libchaber (2004)

An Escherichia coli cell-free expression system is encapsulated in a phospholipid vesicle to build a cell-like bioreactor. Large unilamellar vesicles containing extracts are produced in an oil-extract emulsion. To form a bilayer the vesicles are transferred into a feeding solution that contains ribonucleotides and amino acids. Transcription-translation of plasmid genes is isolated in the vesicles. Whereas in bulk solution expression of enhanced GFP stops after 2 h, inside the vesicle permeability of the membrane to the feeding solution prolongs the expression for up to 5 h. To solve the energy and material limitations and increase the capacity of the reactor, the alpha-hemolysin pore protein from Staphylococcus aureus is expressed inside the vesicle to create a selective permeability for nutrients. The reactor can then sustain expression for up to 4 days with a protein production of 30 muM after 4 days. Oxygen diffusion and osmotic pressure are critical parameters to maintain expression and avoid vesicle burst.

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Synthetic protein scaffolds provide modular control over metabolic flux.

John Dueber, Gabriel C Wu, G Malmirchegini … (2009)

Engineered metabolic pathways constructed from enzymes heterologous to the production host often suffer from flux imbalances, as they typically lack the regulatory mechanisms characteristic of natural metabolism. In an attempt to increase the effective concentration of each component of a pathway of interest, we built synthetic protein scaffolds that spatially recruit metabolic enzymes in a designable manner. Scaffolds bearing interaction domains from metazoan signaling proteins specifically accrue pathway enzymes tagged with their cognate peptide ligands. The natural modularity of these domains enabled us to optimize the stoichiometry of three mevalonate biosynthetic enzymes recruited to a synthetic complex and thereby achieve 77-fold improvement in product titer with low enzyme expression and reduced metabolic load. One of the same scaffolds was used to triple the yield of glucaric acid, despite high titers (0.5 g/l) without the synthetic complex. These strategies should prove generalizeable to other metabolic pathways and programmable for fine-tuning pathway flux.

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Respiratory metabolism: glycolysis, the TCA cycle and mitochondrial electron transport.

Fernando Carrari, Alisdair R. Fernie, Lee Sweetlove (2004)

The respiratory pathways of glycolysis, the tricarboxylic acid (TCA) cycle and the mitochondrial electron transport chain are ubiquitous throughout nature. They are essential for both energy provision in heterotrophic cells and a wide range of other physiological functions. Although the series of enzymes and proteins that participate in these pathways have long been known, their regulation and control are much less well understood. Further complexity arises due to the extensive interaction among these pathways in particular, and also between cytosolic and mitochondrial metabolism in general. These interactions include those between mitochondrial function in the photosynthetic and photorespiratory processes, amino-acid biosynthesis and the regulation of cellular redox. Recently, a wide range of molecular and biochemical strategies have been adopted to elucidate the functional significance of these interactions.