Expression of Trans-Membrane Proteins \textit{in vitro} Using a Cell Free System

Trans-membrane proteins represent a significant portion of the proteins expressed by cells. The expression of proteins \textit{in vitro}, however, remains a challenge. Numerous expression approaches have been developed with cell free expression (CFE) being one of the most promising. CFE is based on a transcription-translation system that has been extracted from \textit{E. coli} bacteria. Adding the desired DNA allows expression of a selected protein, and in the presence of phospholipids the expression of trans-membrane proteins becomes possible. In order to express trans-membrane proteins in a closed native environment, the cell free system (CFS) is encapsulated with a phospholipid bilayer, creating an artificial cell. To verify protein expression, AquaporinZ (AqpZ), a well-known trans-membrane protein tagged with a green fluorescent protein (eGFP), was used so the expressed proteins could be seen under a fluorescent microscope. These artificial cells will serve as an experimental platform for testing the viability of the expressed trans-membrane proteins. Results from the manipulation of these artificial cells by attaching them to the slide surface through streptavidin-biotin bonding will be presented.