Exceptional yield recombinant vesicle packaged protein export system for research and industrial biotechnology applications.

Cells use small membrane bound envelopes, called vesicles, to store and export molecules out of the cell. The ability to reprogram a cell to control this process has huge potential for synthetic biology as it would allow us to harness the cell's machinery for the controlled packaging and release of commercially-valuable molecules neatly packaged into vesicles. This project is based on our discovery of a way to hijack the cell to control this process. This simple and cost-effective invention works by adding a small tag onto the protein. This tag results in bacteria producing huge numbers of these membrane packages filled with the tagged molecules of interest. These packages are exported from the cell into the growth broth, and result in more than a 100-fold increase in protein yield. Protein function is preserved within these packages for months in the fridge. This novel technology represents a major breakthrough in recombinant protein production as it facilitates simple, efficient and rapid purification of diverse proteins for use in biotechnology and medical applications. In this project we will develop this technology and apply it to enhance production and purification of a wide range of biotechnologically and medically important proteins. Working with industry (Fujifilm-Diosynth Biotechnologies) we will optimise the system to large scale fermentation cultures, and develop methods to allow simple and cost-effective purification of the vesicle packaged proteins. Finally, we will extend this recombinant vesicle packaging system to more complex types of cell to further extend the range of therapeutic proteins and downstream applications. Development of this technology will benefit both discovery science and commercial applications, as it will allow scientists to produce biomolecules such as diagnostic and therapeutic antibodies, exported by the cells in a stable environment for easier isolation and storage of proteins.

The ability to target the secretion of recombinant proteins into culture media is attractive for improving yield and reducing manufacturing costs. Controlled packaging of user-defined proteins into membrane vesicles supports the development of technologies and products within the applied biotechnology and medical industries. Currently there is a lack of widely applicable methods for secreting recombinant proteins from E. coli. We have developed a simple technology that allows us to do this. We have engineered a novel fusion tag-based system that exports recombinant proteins packaged within extracellular vesicles from E. coli. This first in class technology represents a major breakthrough in E. coli recombinant protein production and typically increases protein yield more than a 100-fold. The vesicles compartmentalise toxic and disulphide-bond containing proteins in a soluble and functional form, and supports simple, efficient and rapid purification of vesicle-packaged, functional proteins for long term storage or direct processing.
Here we will develop the technology to large scale commercial protein production and downstream processing. We will acquire detailed understanding of how different "Vesicle Nucleating peptide" sequences impact upon yield and export, in order to understand and develop the technology. In collaboration with Fujifilm-Diosynth Biotechnologies we will optimise the system to large scale fermenters and develop methods to allow simple, cost-effective purification of the vesicle packaged proteins. Finally, we will extend this technology to a range of expression platforms, including yeast and mammalian cells, to produce more complex proteins, including diagnostic and therapeutic biomolecules such as antibodies. Successful completion of this project will result in translation of the basic discovery for a wide range of applications from discovery science to applied biotechnology and therapeutic applications.