Cell-free Protein Synthesis through Solubilisate Exchange in Water/Oil Emulsion Compartments.

This work is aimed at finding conditions under which syntheticcompartments used as cell models can fuse with each other andallow reagents contained in the different compartments to react.This goal seems to be best achieved by the use of water in oilemulsions (w/o) with dimensions in the range of 30±60 mm. Inparticular, cell-free EGFP (enhanced green fluorescent protein)synthesis takes place in Tween 80/Span 80 w/o emulsions, andthe extent of the reaction can be monitored directly by fluorescence.The medium is mineral oil, containing 0.5% v/v aqueous solution. Different premixing configurations of the components(plasmid, amino acids, E. Coli extract) are used and compared.The in vitro synthesis of EGFP in emulsion droplets proceeds for1 h, and the yield is 7.5 ngmL1 protein. EGFP synthesis in aqueoussolution takes place for at least 5 h. The yield is 10.5 ngmL1protein after 1 h and 15.8 ng/mL protein after 5 h. The resultswith the w/o emulsions show that solubilisate exchange takesplace among the different water droplets, but it is not possible todemonstrate clearly that a true fusion takes place.