Instant messaging developed for artificial cells

A step forward has been made in the development of artificial systems that mimic the function of complex biological systems. Chemists at the Universities of Sheffield and Cambridge have found a new way to send signals across synthetic versions of biological membranes thus allowing chemical communications to be made between the inside and the outside of artificial cells.

Prof. Nick Williams research into vesiclesRecent years have seen great progress in the development of synthetic biological systems. Such research aims to learn from the complex functions that nature performs, and to use or copy these functions. Among other important technology breakthroughs, it has the potential to lead to new controlled drug delivery mechanisms and new biological sensing applications for medicine.

Professor Nick Williams from the University of Sheffield’s Department of Chemistry said, “It has previously been quite easy to create artificial versions of cell compartments by using cell membranes that are robust enough maintain separate chemical environments inside and outside the compartment. It has been much more difficult to control from the outside what happens on the inside, although this is a vital function in biology.

“As part of a long standing collaboration with Professor Chris Hunter (now at Cambridge University), we have taken inspiration from the way cells use proteins that span the cell membrane and pass information to the inside by changing shape, to design chemical systems that can function the same way.

Until now the only way to do this artificially was to actually transfer the molecule or ion across the membrane, which left the compartment permeable and means that the chemistry on the inside depends on the structure of the chemical signal. The research reported this week in Nature Chemistry describes the development of a completely new way of signalling using a tool that doesn’t compromise the integrity of the membrane, and converts the change in chemical environment outside into a different response inside.

Professor Williams explained, “We have created a molecule that is only long enough to reach half way through the membrane so it cannot reach the inside of the synthetic compartment to send its chemical signals. However, if the outside environment, in this case, becomes more alkaline, then the charge on the compound changes and it moves across the membrane to the internal compartment.

“Once the membrane has been crossed, the other end of the protein acts as a catalyst inside the cell and triggers a chemical reaction, in this case, the production of a fluorescent product that we could see by microscopy to confirm success in both converting and amplifying the signal.”

This new research is exciting because the signalling process can be reversed, which provides a new degree of control in these synthetic biology systems. Ultimately, the use of this kind of technology could provide the capacity to develop sensors or drug delivery systems that respond to their environment.

The full research paper is available via Nature Chemistry.

For further information, please contact: Professor Nick Williams, Department of Chemistry, University of Sheffield, n.h.williams@sheffield.ac.uk, phone 0114 222 9304.

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